SKF-BEARINGS-905535-Intech

January 18, 2018 | Penulis: Đình Hà Trần | Kategori: N/A
Share Embed


Deskripsi

Rolling bearings

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

SKF mobile apps

Apple AppStore

SKF mobile apps are available from both Apple App Store and Google Play. These apps provide useful information and allow you to make critical calculations, providing SKF Knowledge ­Engineering at your fingertips.

Google Play

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

® SKF, CARB, ICOS, INSOCOAT, KMT, KMTA, NoWear, SensorMount and Wave are registered trademarks of the SKF Group. ™ SKF Explorer is a trademark of the SKF Group. AMP Superseal 1.6 Series is a trademark of the TE connec­ tivity family of companies Apple is a trademark of Apple Inc., registered in the US and other countries. Google Play is a trademark of Google Inc. © SKF Group 2012 The contents of this publication are the copyright of the pub­ lisher and may not be reproduced (even extracts) unless prior written permission is granted. Every care has been taken to en­ sure the accuracy of the information contained in this publication but no liability can be accepted for any loss or damage whether direct, indirect or consequential arising out of the use of the in­ formation contained herein. PUB BU/P1 10000 EN ·  October 2012 This publication supersedes publications 6000 EN and 6000/I EN and PUB PSD/P1 06003 EN. Certain image(s) used under license from Shutterstock.com

Rolling bearings

Rolling bearings

Unit conversions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Foreword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . This is SKF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SKF – the knowledge engineering company. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



8 9 14 16

Principles of bearing selection and application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

18

A Bearing basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selecting rolling bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terminology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing types and designs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Boundary dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basic bearing designation system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basic selection criteria. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



21 22 23 26 40 42 46

B Selecting bearing size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A systems approach to bearing selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing life and load ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selecting bearing size using the life equations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic bearing loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selecting bearing size using the static load carrying capacity. . . . . . . . . . . . . . . . . . . . . . Calculation examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SKF calculation tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SKF Engineering Consultancy Services. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SKF life testing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



61 62 63 64 84 87 90 92 94 95

C Friction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Estimating the frictional moment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The SKF model for calculating the frictional moment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Starting torque. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Power loss and bearing temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

97 98 99 114 114

D Speeds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basics of bearing speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reference speed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limiting speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Special cases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vibration generation at high speeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



2

117 118 118 126 127 128

E Bearing specifics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tolerances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing internal clearance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Materials for rolling bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



131 132 132 149 150

F Design considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Radial location of bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Axial location of bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Design of associated components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selecting internal clearance or preload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sealing solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



159 160 165 204 210 212 226

G Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basics of lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Grease lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricating greases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SKF greases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relubrication procedures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



239 240 242 244 249 252 258 262

H Mounting, dismounting and bearing care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dismounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inspection and cleaning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .



271 272 275 285 291 291

Product data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 1 Deep groove ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 1.1 Single row deep groove ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Capped single row deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.3 ICOS oil sealed bearing units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Single row deep groove ball bearings with a snap ring groove. . . . . . . . . . . . . . . . 1.5 Single row deep groove ball bearings with a snap ring and shields. . . . . . . . . . . . 1.6 Stainless steel deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.7 Capped stainless steel deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 Single row deep groove ball bearings with filling slots. . . . . . . . . . . . . . . . . . . . . . 1.9 Single row deep groove ball bearings with filling slots and a snap ring. . . . . . . . . 1.10 Double row deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Y-bearings (insert bearings) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 2.1 Y-bearings with grub screws, metric shafts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 Y-bearings with grub screws, inch shafts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3 Y-bearings with an eccentric locking collar, metric shafts. . . . . . . . . . . . . . . . . . . 2.4 Y-bearings with an eccentric locking collar, inch shafts. . . . . . . . . . . . . . . . . . . . . 2.5 SKF ConCentra Y-bearings, metric shafts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 SKF ConCentra Y-bearings, inch shafts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

295

322 346 374 376 382 386 394 410 414 416

421

458 460 464 466 468 469 3

2.7. 2.8. 2.9.

Y-bearings with a tapered bore on an adapter sleeve, metric shafts. . . . . . . . . . . 470 Y-bearings with a tapered bore on an adapter sleeve, inch shafts. . . . . . . . . . . . . 471 Y-bearings with a standard inner ring, metric shafts. . . . . . . . . . . . . . . . . . . . . . . 472

3 Angular contact ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 3.1. Single row angular contact ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2. Double row angular contact ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.3. Capped double row angular contact ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . 3.4. Four-point contact ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

475

506 522 526 530

4 Self-aligning ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 4.1. Self-aligning ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2. Sealed self-aligning ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3. Self-aligning ball bearings with an extended inner ring. . . . . . . . . . . . . . . . . . . . . 4.4. Self-aligning ball bearings on an adapter sleeve. . . . . . . . . . . . . . . . . . . . . . . . . . .

537

5 Cylindrical roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 5.1. Single row cylindrical roller bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2. High-capacity cylindrical roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3. Single row full complement cylindrical roller bearings. . . . . . . . . . . . . . . . . . . . . . 5.4. Double row full complement cylindrical roller bearings. . . . . . . . . . . . . . . . . . . . . 5.5. Sealed double row full complement cylindrical roller bearings. . . . . . . . . . . . . . .

567

6 Needle roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 6.1. Needle roller and cage assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2. Drawn cup needle roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.3. Needle roller bearings with machined rings with flanges, without an inner ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4. Needle roller bearings with machined rings with flanges, with an inner ring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5. Needle roller bearings with machined rings without flanges, without an inner ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.6. Needle roller bearings with machined rings without flanges, with an inner ring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.7. Alignment needle roller bearings, without an inner ring . . . . . . . . . . . . . . . . . . . . 6.8. Alignment needle roller bearings with an inner ring. . . . . . . . . . . . . . . . . . . . . . . . 6.9. Needle roller / angular contact ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.10. Needle roller / thrust ball bearings, full complement thrust bearing. . . . . . . . . . . 6.11. Needle roller / thrust ball bearings, thrust bearing with a cage. . . . . . . . . . . . . . . 6.12. Needle roller / cylindrical roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . 6.13. Needle roller bearing inner rings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.14. Needle rollers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Tapered roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 7.1. Metric single row tapered roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2. Inch single row tapered roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3. Single row tapered roller bearings with a flanged outer ring. . . . . . . . . . . . . . . . . 7.4. Matched bearings arranged face-to-face. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4





552 560 562 564

604 640 644 656 668

673 722 730 744 758 770

774 776 778 780 784 786 788 790 794

797

824 842 864 866

7.5. 7.6.

Matched bearings arranged back-to-back . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 872 Matched bearings arranged in tandem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 876

8 Spherical roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 8.1. Spherical roller bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2. Sealed spherical roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3. Spherical roller bearings for vibratory applications. . . . . . . . . . . . . . . . . . . . . . . . 8.4. Spherical roller bearings on an adapter sleeve. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5. Spherical roller bearings on a withdrawal sleeve. . . . . . . . . . . . . . . . . . . . . . . . . . 8.6. Sealed spherical roller bearings on an adapter sleeve. . . . . . . . . . . . . . . . . . . . . . 9 CARB toroidal roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 9.1. CARB toroidal roller bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.2. Sealed CARB toroidal roller bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9.3. CARB toroidal roller bearings on an adapter sleeve. . . . . . . . . . . . . . . . . . . . . . . . 9.4. CARB toroidal roller bearings on a withdrawal sleeve . . . . . . . . . . . . . . . . . . . . . . 10 Thrust ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 10.1. Single direction thrust ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.2. Single direction thrust ball bearings with a sphered housing washer. . . . . . . . . . 10.3. Double direction thrust ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10.4. Double direction thrust ball bearings with sphered housing washers. . . . . . . . . .

879

904 928 936 940 946 954

957 980 996 1000 1004 1009 1016 1026 1030 1034

11 Cylindrical roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1037 Product table 11.1. Cylindrical roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1048 12 Needle roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1057 Product tables 12.1. Needle roller and cage thrust assemblies and appropriate washers. . . . . . . . . . . 1070 12.2. Needle roller thrust bearings with a centring flange and appropriate washers . . 1074 13 Spherical roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1077 Product table 13.1. Spherical roller thrust bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1090 14 Track runner bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 14.1. Single row cam rollers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.2. Double row cam rollers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14.3. Support rollers without flange rings, without an inner ring. . . . . . . . . . . . . . . . . . 14.4. Support rollers without flange rings, with an inner ring. . . . . . . . . . . . . . . . . . . . 14.5. Support rollers with flange rings, with an inner ring . . . . . . . . . . . . . . . . . . . . . . . 14.6. Cam followers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

1099 1126 1128 1130 1132 1134 1140

15 Engineered products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1149 15A Sensor bearing units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1151 Product table 15A.1 Motor encoder units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1166 5

15B Bearings for extreme temperatures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 15B.1 Single row deep groove ball bearings for extreme temperatures . . . . . . . . . . . . . 15B.2 Y-bearings for extreme temperatures, metric shafts. . . . . . . . . . . . . . . . . . . . . . . 15B.3 Y-bearings for extreme temperatures, inch shafts. . . . . . . . . . . . . . . . . . . . . . . . . 15C Bearings with Solid Oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15D SKF DryLube bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15E INSOCOAT bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 15E.1 INSOCOAT deep groove ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15E.2 INSOCOAT cylindrical roller bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15F Hybrid bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 15F.1 Hybrid deep groove ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15F.2 Sealed hybrid deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15F.3 XL hybrid deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15F.4 Hybrid cylindrical roller bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15G NoWear coated bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15H Polymer ball bearings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 15H.1 Polymer single row deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . 15H.2 Polymer thrust ball bearings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Bearing accessories. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Product tables 16.1. Adapter sleeves for metric shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.2. Adapter sleeves for inch shafts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.3. Adapter sleeves with inch dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.4. Withdrawal sleeves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.5. KM(L) and HM .. T lock nuts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.6. MB(L) lock washers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.7. HM(E) lock nuts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.8. MS locking clips. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.9. N and AN inch lock nuts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.10. W inch lock washers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.11. PL inch locking plates. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.12. KMK lock nuts with an integral locking device. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.13. KMFE lock nuts with a locking screw. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.14. KMT precision lock nuts with locking pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.15. KMTA precision lock nuts with locking pins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16.16. KMD precision lock nuts with axial locking screws. . . . . . . . . . . . . . . . . . . . . . . . .

1169 1178 1182 1183 1185 1191 1205 1212 1214 1219 1230 1232 1236 1238 1241 1247 1262 1266 1269 1290 1298 1304 1310 1316 1318 1320 1324 1326 1330 1332 1333 1334 1336 1338 1340

Indexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1342 Text index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1343 Product index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1364

6

7

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Unit conversions

Unit conversions

8

Quantity

Unit

Conversion

Length

inch foot yard mile

1 mm 1m 1m 1 km

0.03937 in. 3.281 ft. 1.094 yd. 0.6214 mi.

1 in. 1 ft. 1 yd. 1 mi.

25,40 mm 0,3048 m 0,9144 m 1,609 km

Area

square inch square foot

1 mm2 1 m2

0.00155 sq-in 10.76 sq-ft

1 sq-in 1 sq-ft

645,16 mm2 0,0929 m2

Volume

cubic inch cubic foot imperial gallon US gallon

1 cm 3 1 m3 1l 1l

0.061 cu-in 35 cu-ft 0.22 gallon 0.2642 US gallon

1 cu-in 1 cu-ft 1 gallon 1 US gallon

16,387 cm 3 0,02832 m 3 4,5461 l 3,7854 l

Speed, velocity

foot per second mile per hour

1 m/s 1 km/h

3.28 ft/s 0.6214 mph

1 ft/s 1 mph

0,30480 m/s 1,609 km/h

Mass

ounce pound short ton long ton

1g 1 kg 1 tonne 1 tonne

0.03527 oz. 2.205 lb. 1.1023 short ton 0.9842 long ton

1 oz. 1 lb. 1 short ton 1 long ton

28,350 g 0,45359 kg 0,90719 tonne 1,0161 tonne

Density

pound per cubic inch

1 g/cm 3

0.0361 lb/cu-in

1 lb/cu-in

27,680 g/cm 3

Force

pound-force

1N

0.225 lbf.

1 lbf.

4,4482 N

Pressure, stress

pounds per square inch

1 MPa 1 N/mm2 1 bar

145 psi 145 psi 14.5 psi

1 psi

6,8948 ¥ 10 3 Pa

1 psi

0,068948 bar

Moment

pound-force inch

1 Nm

8.85 lbf-in

1 lbf-in

0,113 Nm

Power

foot-pound per second horsepower

1W 1 kW

0.7376 ft-lbf/s 1.36 hp

1 ft-lbf/s 1 hp

1,3558 W 0,736 kW

Temperature

degree

Celsius

t C = 0.555 (t F – 32)

Fahrenheit

t F = 1,8 t C + 32

Foreword

This catalogue contains the standard assort­ ment of SKF rolling bearings typically used in industrial applications. To provide the highest levels of quality and customer service, these products are available worldwide through SKF sales channels. For information about lead times and deliveries, contact your local SKF representative or SKF Authorized Distributor. The data in this catalogue reflect SKF’s state-of-the-art technology and production capabilities as of 2012. The data contained within may differ from that shown in earlier catalogues because of redesign, technological developments, or revised calculation methods. SKF reserves the right to continually improve its products with respect to materials, design and manufacturing methods, some of which are driven by technological developments.

Getting started This catalogue contains detailed information about standard SKF rolling bearings, several special engineered products and bearing ac­ cessories. Engineered products include motor encoder units, which can measure the speed and direction of rotation, polymer bearings and rolling bearings designed to fulfil add­ itional requirements, such as: • extreme temperatures • electrical insulation • dry lubrication • insufficient lubrication • rapid speed changes • high vibration levels • oscillating movements

a particular application. In this section, bear­ ing service life, speed capabilities, friction, general design considerations and lubrication are discussed in detail. Installation and main­ tenance information is also included. More practical information about mounting and maintenance is provided in the SKF bearing maintenance handbook (ISBN 978-91978966-4-1).

The latest developments The main content updates compared to the previous catalogue include the addition of Ybearings and needle roller bearings as well as the following featured products: SKF Energy Efficient bearings

To meet the ever-increasing demand to reduce energy consumption, SKF has developed the SKF Energy Efficient (E2) performance class of rolling bearings. SKF E2 bearings are charac­ terized by a frictional moment in the bearing

SKF Energy Efficient bearings are identified by an E in the designation prefix.

The first section, which contains general tech­ nical information, is designed to help the read­ er select the best, most effective products for 9

that is at least 30% lower when compared to a same-sized SKF standard bearing. High-capacity cylindrical roller bearings

SKF high-capacity cylindrical roller bearings combine the high load carrying capacity of full complement bearings and the high speed capability of bearings with a cage. They are designed for applications such as industrial gearboxes, gearboxes in wind turbines and mining equipment.

SKF high-capacity cylindrical roller bearing

SKF DryLube bearings

SKF DryLube bearings are a new option for extreme temperature applications. They are filled with a dry lubricant, based on graphite and molybdenum disulfide. The dry lubricant can protect the rolling elements and raceways from damage caused by solid contaminants. SKF DryLube bearings provide effective lubri­ cation for high temperature applications, low start-up torque at any temperature and low frictional moment during operation.

SKF DryLube bearing

Polymer ball bearings

Polymer ball bearings are an excellent solution from both a technical and economic perspec­ tive, in applications where resistance to mois­ ture or chemicals is essential. Polymer ball bearings use bearing rings or washers made of various polymer materials and balls made of glass, stainless steel or polymers. They are lightweight, self lubricating, quiet running, and resistant to corrosion, chemicals and wear and fatigue. SKF ConCentra Y-bearings (insert bearings)

Polymer ball bearing

The SKF ConCentra locking technology pro­ vides a true concentric fit of the bearing on a shaft, to virtually eliminate fretting corrosion. These bearings are as easy to mount as bear­ ings with grub screw locking.

SKF ConCentra Y-bearing

10

end ed ner r ca t as • light ring rotati relia bl of which 9 0 L10 , i.e. the pped bear- in on y ti • oper load (P ≤ 0, relu br lu br ic ated. % of the bear me period 05 C) at ic T atin vals, pa ation interv he method ings are still tempe g tempera to al ge ra s es († 2 tu tim 52 and sh re zone ture within († ta ould no ) represen Relubricatio ate th of the bl e 4, pa • st at ts the t be us grea se e green T he gr ge L01 gr n interio ea se lif • low nary machi 305) on the ea se life fo ed. vibr at ne e oper at r capp io factor ed in n g le be tem vels . ar For st Diagr It can be ob perature an ings depend ai tained am 1 is d the sp s grea se nless steel ball be fr be ar ings valid for st an om the diag eed and m , use the sc al ar ings fille (GPF) . is liste T he grea se dard deep rams. ultiply d with e corr groove d in ta gr am Diagr perfor by 0,2 the value ob esponding to V T 378 am bl . tained deep gr 2 is valid e 4 († pagemance factor for from th GPF = 1 oo 3 e diaT he gr ve ball bear SK F Energy 05). Ef ficien follow ea se life fo ings. t ing op er atin r each is va lid g cond itions: under the

Text in dex Grease life calculation for capped deep groove ball bearings

Capped deep groove ball bearings and Y-bear­ ings (insert bearings) are typically greased for A life. SKF did extensive research to enable a A theoretical approach to estimateanthe grease gular cont nu ts an ac t ball be life depending on bearing speed,mlootckoperating or enco d lock ing dear ings 47 9, 5 0 4 der un tr ac vice A BM A k runner be it s 1 161 s 1 28 0, 1 2 temperature, load and other factors. ar ings 89 st anda

Gr ea se wher e life for ca pped P = 0, de ep 05 C gr oo Gr ea se

100 00

life L

0

10

ve ball

bear in

gs

[h]

n dm =

Diagra

100 00

m1

0

200 00 ca 0 lc ul at n dm = ion 20 00 30m co 0 00 0 pa0re d ex amples 10 00 adju 0 40st in0g be to limit ing sp1 25 0 00 ar ings abut m an ee d 1 rd s 41 1 10 3, gu la en 50 26 1 107, 0 000 r cont abut m t collars fo ac 1 r 1 t in 2 ba ents 206 5 ll bear 600 00tern al cl fo dimen in ea r pr el 0 oad 2 rance 27 gs 49 8 pr tolera sions 2 0 70oc 18 –2 7 0 00 ed A C 5 nces 169,8 –2 0 9 tapere0ur es 2 2 1– 2 0 1 000 0 2 0 0 –2 2 25 d rolle A A C curr 4 FB 02 r bear M A st ent in an gs ag da ricultur pr ot ec rd s 41 8 16 –8 17 and Y- al applic at pr ot tion w it h A C motec tion w it h hy br id bear sp ec bear ings ions A H 45 if ic at ion lif 435, 4 4 6 –4 acce ss or s 1 152 IN S O C O AT ings 1 2 2 0, e be 7 1 or 47 8 2 ar 100 3 2 ings alcoho acet on ie s 1 269 1209 6 ls 1 2 GPF = –1 3 41 1 40al ig nm 51 ac id s e 1 251 GPF = ent ne 45 50 2 55 ca re sist le lle GPF = 55 ed ge s 69 60 ro an 4 70 60 65 r bear 3 65 –6 de 70 re sist ce of poly 9 70 75 in gs 75 si80 gns an 75 580, 714 8 ac ry lo ance of se mer ball be 85 d90 dimen varian 85 90 80 6 85 3, 7 76 –7 al ni tr ile 95 ts 79 100610 -but ad m at er ials ar ings 1 2 fi ts an sion st anda 8 35 95 100 1090 95 10 hy dr 0 105 rd d to 5 110 11 n = ro in A D A ogenat ed ac iene ru bb er 15 6 –157 51 110 11 115 tel rnal lerance cl s 70 3 0 115 120 12 5 8 0, 6 dm = be tationa ry (N sp as lo cl B 5 130 120 125 13 5 ni tr ile ad ap te R se s 7 ar ing 0 lo meas eed [r/meain]rance 0 135 14 -but ad ) 155 for va 16 = 0,5 (d ad r slee ve2 n dia 7 7 1 rious 0 145 m1et er 02 –70 + D) iene ru mis gr ea se Op er at ing te ax ial lo s 1 27 [mm] al 3 ig pe m 3 bb pe rform er (HN 0 6 mount nment 52 ance fa rature [°C bear in ad carr ying 0 –1 274, 1 B R) 1 ] ct or s 2 (GPF ) 56 pr oduc ing 718 , 702 –70 3 co at in g seat tolera capaci ty 8 9 0 –1 3 0 9 94 nces tempe t ta bles 7 de sign gs 1 270 2 0 0 –2 76 01 tolera rature limit –7 79 de sign at ion sy st em alipha nces 702 s 714 dimen s and varian 1 28 8 –1 tic –7 28 sion st ts 1 2 re sist hy dr oc ar bo 0 3 anda 70 –1 9 an Tfodiarsm pC AeouRrntein re sist ce of fluorons g bear rd s 1 274 27 3 d in B gs r al oalllro kalis ance of poly ru bb er 1 28 8 –2 for inch toroid e r m 56 t 8 er ball h sh ller ber u s 9 af ts 1 re sist for met bear in ar in t b an 2 gs 1 2 re sist ce of po for oil ric shaf ts 9 8 –1 3 0 3 gs 9e7a 1) 5,r1in 51 0 0g0s A llen w ance of po ly mer ball be –10 0 3 for se inje ct ion 1 1 2 9 0 –1 2 97 ly re , ar 1 27 3 lf2 ings alumin nc he s † ur et hane for sp aligning ba 70 –1 272 1 251 iu 1 he heri ll in poly m ox ide (A l xagonal ke57 1 27 3 cal roller bebear ings 5 ys 4 6 –5 ar ings on IN mer ball be 2 O3 ) for Y-be 89 8 –8 47, 5 6 4 –5 ambien S O C O AT be ar ings 1 mount ar ings 42 9 9, 94 6 2 0 –945 5, 1 27 3 amines t tempera ar ings (coa 51 , 1 26 0 on a st ing bear ings 2 –42 3, 42 , 95 4 –9 ture ting) 1 7, ep 5 47 24 6 am 2 pe 1206 55, 78 0 –471 0 d shaf mon pr oduc t A MP S ia 152 , 1 sp acer t ta bles 1 2 07, 1 270 5 2 angle up er seal ™ 4 tapers rings 2 07, 9 0 –1 3 0 9 co ri ng nn s 57 1 1 270 ec tors angle thread 1 274 ,6 se angula ries 4 0 0 4 –6 39 1 15 4, 1 155 tolera s 1 274 , 1 161 r co nces adju st nt ac t ball w it h 1 274 bear in ment ad ap te inch dimen as du gs 47 so ring m rt men 5 –535 ou A DB rs 1 10 8 , 1 sions 1 3 0 4 t ax nt 47 ing ial lo 6, 5 1 10 –1 3 0 9 addi ti 8 0, 6 02 bear in ad carr ying 5 0 0 –5 02 2 2 1– 2 25, 2 ve s 77 cage s g ar rangem capaci ty 47 in gr ea combi 4 8 0 –4 8 1 , ents 16 0 –1 6, 49 8 in oil se 24 4, 24 ne 49 2 63 8 6 d 7 , 25 4 5 –26 6 w it h a adju st cont ac ed ne t ed le rolle adju st bear ing de sign angle 47 sy st ed r 6 de sign pr ov isions , 4 8 6 –4 87, bear ing 6 8 adju st re ference sp ems 16 3 ment de sign at ion sy st em49 8 –49 9 49 8 , 5 0 4 4 –6 85, 78 fact or ee d 1 2 0 0 –78 3 s and s 1 2 1– 5 0 4 –5 di va m ri 1 24 en 05 an Not e: dimen sion st anda ts 28 , 476 Desig rd nation dou bl sional st abili s 4 8 6 –4 –4 8 4 pr ef ix e row 87 ty es and 49 be for un 7 ar in su ff ix iv es ar e four-p er sal m atchgs 478 –47 show n 9, oint co nt ac t ing 47 7, 5 0 52 2 –52 9 in bol d. ball be ar ings 0, 5 0 6 –52 1 4 8 0, 5 3 0 –535

Extended assortment for value-added bearings

The assortment of capped bearings, SKF Explorer bearings, electrically insulated bear­ ings and hybrid bearings has been extended.

Deep

How to use this catalogue

ner b e

Grease life estimation for capped bearings

Bear in

groov

g t y pe

e ball

an d de bearin This catalogue is divided into two main sec­ signs gs 1 Y -bear tions: a technical section and a product sec­ i n g s (inse tion. The technical section describes in detail r t bea how to select and apply rolling bearings and rings) 2 ngula covers eight main topicssinmarked printed gle dir withA ec tion r A c o with o section is div­ n tabs from A to H. The product t ac t ba r sc rew without (70 ll bear ided into chapters by product dow n Each chapter ) a cov dou ble type. 71 ings b e e r a r in dirabout gs ec tion the bear­ 3 contains specific information (71) Selfalignin ing type and its optional variants and product g ball tables. Each product chapter is clearly marked bearin gs 4navigation by cut tabs with an easily identifiable icon. Printed and cut tabs simplify

Cylind r

arin

ical ro ller be ar

gs Find information quickly r b e ar in h a thic gs († paThe ge 10catalogue is designed so that specific in­ k 99 unt un walled ouformation ter r in ) arecan be found quickly. At the front it s are Neofedl g . T he ac k s a u e in acatalogue n d c on s e d the ll t y pe se there is the full table of con­ v e y or s of s y s t em tents. Ats. the back, there is a product index and

a full text index.

C am r

Taper ed

oller s

single r dou ble ow (72) row (7 3)

s

Spher ical r

roller

roller

ings

5

bearin gs 6

bearin gs 7

oller b ear

ings

1 343

8 Index al roll r bear Aecomprehensive index helps to locate ing text specific information 9 quickly. Thrus S uppo t ball b r t r oll er s earing withou t f la C s 10 with o nyglein r d s ic r with ingr a l r o o u l ler thr t c on t withou ac u s t be with a t an inner r in t seals n inne arings g r r ing (7 11 Needl 4) e rolle r thInc., Distributed by: Intech Bearing 4955 Gulf Freeway, Houston, TX 77023 ru st b earing ph.: 713.926.1136,Stoll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com s 12 pheric with f lange a l r o r bear in ings, b ller th gs a sed o ru st b n ne e d with o earing le rolle r with 11 r ou t co s 13 with a n t ac c seals with a age-guided tT ra k r full co mplem roller sc u ent ro et (75) nner b ller se earin t 73

C ARB

toroid

Foreword Find product details quickly

A quick way to access detailed product data is via a product table number. Product table numbers are listed in the table of contents at the front of the catalogue, in the table of con­ tents at the start of each product chapter and in the product index at the back of the catalogue. Identify products

Product designations for SKF rolling bearings typically contain information about the bear­ ing and additional features. To specify an SKF bearing or to find more information about it, there are three options:

• Product index The product index at the end of the cata­ logue lists series designations, relates them to the bearing type and guides the reader to the relevant product chapter and product table. • Designation charts Product designations in each product chap­ ter are located on the pages preceding the product tables. These charts identify com­ monly used designation prefixes and suffixes. • Text index The text index at the end of the catalogue contains designation suffixes in alphabetical order. They are printed bold for quick browsing.

Produ ct inde Tex t in

de x

J

A bu tm

1, 2

da min .

in .

171 171 172 172 174 17 7

18 1 81 82 82 7

16 5 16 2 16 8 16 3 174 171 18 1

17 7 17 3 18 0 176 185 193 18 8 18 4 19 0 185 19 8

19 9 194 2 02 19 8 208 2 15 2 10 220

223 2 27 22 1 2 32 230

d fillet

da m ax .

mm 161 161 16 2 16 2 16 4 16 4 167

en t an

229 229 25 8 25 8 276 32 3 249 249 26 8 26 8 293

30 6 30 6 32 3 299 3 26 3 26 343 343

2 2 2 2 3

2 ,5 2 ,5 3

C alcu

ra m ax .

e

lation

fact or

Y1

2 2 2 2 2 ,5 2 ,5 3

0,2 0,28 0,28 0,37 0,24 0,33 0,33 0,2 0,28 0,28 0,37 0,25 0,33

3,4 2 ,4 2 ,4 1 ,8 2 ,8 2 2

3,4 2 ,4 2 ,4 1 ,8 2 ,7 2

0,2 2 0,3

5 3,6 3,6 2 ,7 4,2 3 3

5 3,6 3,6 2 ,7 4 3

3

s

Y2



2 2 2 2 2 ,5 3

2 2 2 ,5 2 ,5 3

2 2 ,5 2 ,5 3 3

sions

Da m ax .

2 14 2 14 238 238 256 256 303

269 269 28 6 28 6 303

dimen

x

J

Desig

Y0

3,2 2 ,5 2 ,5 1 ,8 2 ,5 2

4,6 2 ,3 0,28 Numbered product make it easier to ­access 2 ,8 3,4 tables 2 ,4 0,37 2 ,2 3,6 1 ,8 product 0,25 data. 2 ,5 2 ,7 2 ,7

0,2 2 0,3 1 0,28 0,37 0,24

4,6 3,3 3,6 2 ,7 4,2

2 ,8 2 ,2 2 ,5 1 ,8 1 Deep 0,3 groove 2 ball be ,8 2 ,3 0,4 ar ings 3,4 1 ,7 0,24 2 ,2 2 ,5 2 ,8D esign 4,2 ation s21,8,6 0,2 2 ystem 3 0,3 4,6 2 ,3 0,4 2 ,8 1 ,7Prefixes 3,4 0,24 2 ,2 2 ,5 2 ,8E2. 0,35 1 ,6 SK F En 1 ,9D/ICOWS- 4,2 Oil erg Eff seale d2y,8 icient W 2 ,9 Stainl bearing be es ste aring unit Stainl s1 el, inc es s ste,8 h dim Ba sic

Lis ted Su ffi xe Gr oup E

de sig

in dia

el, me

nation

gr am

2 (†

s

1: Int

er nal

de sig

page

The product index makes finding information based on a bearing’s designation easy.

1 ,8 2 ,5

4

3 2 ,2 2 ,4 1 ,8 2 ,8

L

Gr oup

en tric dim sions ensions

1 Gr oup

2 Gr oup

43)

n

Reinforc ed ball se t Gr oup 2: Ex ter nal de sign (se N als , sn NR ap rin Snap g gr oo N1 ring gro ve etc Snap .) ov R e in rin One loc g groove the ou ter -R S1 , in ring Flang ating slot (no the ou ter -R S2 , -2RS 1 ed ring, wi Conta ou ter rin tch) in on -R SH -2RS 2 g e ou ter th appropri ct , Conta seal, NBR, ate ring sid -R SL , -2RS H ct seal, on e face snap ring on -2 Conta e or bo FK M, -R Z, -2 RS L ct Lo w-fri seal, NBR, on one or bo th sides -Z , -2 RZ Z Non-conction seal, on one or bo th sides -Z NR Shield tac t seal, NBR, on on th sides e Shield on one or bo NBR, on on or both sid -2 ZNR e es on th or both one sid sides the op sides -2 ZS e, Shield po sit e side snap ring gro X of Shield on both sid the shield ove in the es ou ter Boundaon both sid , snap rin ring, sn g gro es , ry dim ap rin ensionsheld in place ove in the g on Gr oup ou by not in 3: Cage accord a ret ainingter ring, wi de sig th snap ance wi rin n – ring th ISO g dimen M sion ser Stamp ies ed ste Machine el cage MA (S) identi d bra ss ca , ball centre MB (S) fie ge, ba Machine d by a numb ll centred TN 9 d er d; bra fol Machine ss low ing dif fer en TNH t de sig d bra cage, ou the Gla ss ns or ma VG15 fibre rei ss cage, innter ring cen M, e.g . M2 61 ter ial Gla ss grade fibre rei nforce d PA er ring cen tre d. The S s are Gla ss fibre rei nforce d PE 66 cage, ba tre d. The S indicates a ll centre indicates lubric ati EK nforce d PA 46 cage, ball a lubric on groov centre d cage, e in ation d

0 2 8 .. 0 3.. . . . . . . . . . ..... . 0 7. . . . . . . . . . . . Inch . . 0 9. . . . . . . . . . . . . . . . Inch single ro w ..... ..... tape sing . . . .K . . . . . . Inch sing le ro w tape re d roller be . . In 1 0.. ch sing le ro w tape re d roller be ar ings . . . . .. 1 1 .. . . . . . . . . . C A R B to re ar le . ..... roid al row tapere d roller bear ings . . . . . . . . . . . . . . . 1 1 2 .. . . . . . . . . . cy . ... li d ro ... ings el f-alig ro ller b . . . . . n driSca 1 1 5.. . . . . . . . . . cy rollenirng ba earing ller bear ings . . . . . . . . .. . . . . . . . . . .. . . . . . . l. lin. Inchl si . s . b . ll . e . be 9 a ng . 6 ri . 1 2 .. . . . . . . . . . p. .o. . . driSca ar l rollele row ngs in5gs ..... ......... ...... 0 , 978 el f..... . . . . ly . r ta . m . 7 al th . . pe e 3 . ig . . ru st red ro , 6 0.2. . . . . ..... ........ 1 3.. . . . . . sp . Inr ch b all b ening ba ..... . . earinlle . singleari ng ll bebar .... 1 3 0.. . . . . . . . . . . . .h. e. rica ar ings . . . . . . . . . sr be ings g l ro w ta s S ro 1 el 1 . 0 Yll f. w . . 2 e 3 . . . . al it r eari pere6d 0 . 9, 0.4. . . . . ..... .b.e. ari n h 1 4 .. S elg s ignibng .K 2 , 0.4. . . . .. . . . . . . . . . . .. ba n bes 8 roller be an ex te1nd . . . . .v 1 5.. . . . . . . . . . 3. 0. . . . S el f-al4ig5ni7ng ba ll g ar in8gs 7 .... 2 , 9 ar ings . ed in1ne . . . . . . . r ring . . . . . . . . . . .lo.ck . .B In f-aligning ll bear ings . .0. 2 ..... 1 55.. . . . . . . . . . .C.A. R . . ... . . to ba ... chid ... ... ..... ro . ll bear siang 1 6 0.. . . . . . . . . . sp . Inch le ro l ro ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .d.e llewr ta . . . . h. erica l rosing b epe 1 6 0.. . . . . . . . . .ke to rendgro . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .de . ari erlebro ..... /H ..... . . n e In5ch sillng ..... s lle9r6be eawrita pe . n . 1 61 .. R . . . . .ke y. .sl. . . s S1in re ar 6 le . 0 . . g ..... ..... . . .d.im s 8d ro2ller , 9in ro w 78gs . . . . . .o ts . . . , 9 0be 1 61 .. . . . . . . . . ke 1 2gl7e8ro . w de ep tapere d 8 2 ar ings . . . . . . . . . . . . . . . . . . . . . . . . fo rolle . . r. . . .ys /H . . . † Pol ym er, 1si2ng 8le 17 26 2 . . . . . . ke 0 –1gr2oo ve ball r bear ings . . . . . . . . . . . . . . . . . . . . . . . . . fo . . r. .s . . .y.w. a . hSeinxa g 8 .. . gl . o ro . be . . 1 n e . . . w . , a . ro ..... ..... ..... . .ys P1 ..... 17 26 3 keepys deep1gr w lde 289 ar ings . . . . 2 ol ki . . . . 7 .. . ym . in . ln oo . . 8 . . gr . . . .... st .... s. . . .... , 1si28 0 ve ba er ... oo ve 1 8 6.. ....a le–ro 1w . . . . . . . . . .a.n.d. . Y-bear ings ng 28de1epball bear in ll bear ings . . . . . . . . . . .. . . . . . . . . . . . lo o . 19.. b eaY-be . . . .se ..... .....a ngarsin w it h a st anda gr oove ballgs . . . . . . . .. . . . . . . . . . . . . . . . . . . .. . m . . . . . . . .n.d. .S Inri .. . . . .a.ti n r ewxt ..... bear in it hrea st rd inne ch singfogs .. . . . KF D ki.n. e. m . . . . . . . . . . . . . . pre ry gs m 2 .. . an r le ri e L da ro ng . u In te ci . . .. ch ng b e bwe tape . a . . s mrdp einra netu arinre 2 .. NR . . . . . . . . .ki n em tic repsi r ring . . . . . . . . . . . . . . . . . . . . . . . . . . . . .pro. . . . lenislehrow ta gsd ro . . .d. u. c . ..... s . 1. 1 ..... 1 1lle9r3bearre . ment/pere . . 2 ..-2 Z . . . . . . . . . . . . .aticS in vi . 7 . . . d sc . . ..... . to st arvroaller be ings . . . 6 . . . . . . . o si ty . . le . . . ra ... . . n. ..... . 2 ..-2 Z . . . . . . . . . . . . . S in gle row de† . . it. h ep vi sc si ty tion ar ..... ......... ...w . 10in0gs . . . . . . a , . . . 2 ..-Z NR . . . . . . . . . . S hi gle row de ep gr ooove . 10 2 . . . . . . .. lo .. .. ba . .h . . . . . . . . . . . . . . .w . .a. . . 2 ..-Z N . . . . . . . . . . . . . . S hi elde d single gr oo ve ba ll bear ings w ..... n . . . it . .h . . . . . .w ..... 2 1 3.. R . . . . . . . . . . . . S hi elde d single ro w de ep grll bear ings w it h filling sl . . . . it ch . . . . in lo ck w .... 2 2 .. . . . . . . . . . . . . . . S hi elde d single ro w de ep gr oo ve ball be it h filling sl ot s . . . . . a sh . ..... . ot el . e . ro r 2 2 ..-2 . . . . .L . . . . Sph de d single w de ep gr oo ve ball be ar ings w it s and a sn . . . . . . . .de sig h filling . . . . .n 1 ..... ap ring ro w oo ve er ic ar in 2 2 2 .. R S 1 . . . . cy .. . slot . .in. st el f-aligal roller bearde ep gr oo ve ball bear in gs w it h filli . . . .li. n driSca . . a. ll. .ati.o. ng sl s . . . . . gs 2 2 2 .. . . . . . . . . . lo . in ba ... . .ro -2 ll nir ng . . . nu S eallero . .d.u. ct ll bear gs . . . . . . ll bear ings w it h filling ot s and a sn. . p baleba 2 2 3.. C S 5 . . . . . ck . . Stsphan d seelfa . ta sl . in . w ri lo .. ot ap .. it ngs gs . . . ck inng .p .m erdic lo ck inigning g cl. ip 2 2 3.. . . . . . . . . . . .o. ly 02 . . . . . .. . . . . . . . . . .h filling slot ss . . . . . . . . . ri . eSrea . .s. . rolle g d ball6be b a al /V . ..... . in ehe ..... 2 2 3.. A 4 0 5 . . .sl. e. e. ve ari grsbeearviincegss .1ar . sSph lelld bsp . . . . . . . . . . . . . . and a snapde.si. g. n 1 2. 28 gs . . . . /V . ri . . er7ic3al, rinca l ro1lle 2r6be 2 2 3.. A 4 0 6 . .L 4.B. . .5. 75Sph1 2 . . . .7 all a. ti 1ro2lle 0 ar in. . . .9. . . . . . .. . . . . . . . . . .. . . . . . . . . . .. . . . . . . .in. .st.ng 8 -2 C S 5 .5.B. . . , r 9 o 6 er be L n . 0 . . . gs ic ar ings ..... ..... . . . . . pro du. . . . . a 3 al rolle 2 3.. .. .... 6. S . . . . . ct ta . . . . . 0 3 pher ic al ro r bear ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . lo . . . . . b le 2 3..-2 . . . . . . . . .L 5.D. A . . ck S ea ller ... ... ... . . in . for . . g p te 2 3 0.. R S 1 . . . .L7.B. . . . 1 2S4el2 ,le1d2sp . s herica bear ings fo vibr at or y ap. . . . . . . . . . . . . . . . . . . . . . . . . . . .d.e si.g. . .la Gr . . . . .6 0 3 f-alig4 4 . . . .n. 1. . . ..... ..... , 1 24l 5roller be r vibr ator plic at io 2 3 0.. .4.1. ou. p. 4. . . . L . . .2.78 – . . . . in . ns . . .7.D. .A .1 S eale d ning ba y ar -2 C S 4.2 . . a. ll. a . . 2S4 2 , self-al ll bear ings ings . . . applic at ions . . . . . . . . . . . . . . . . . . st 4.3 2 3 0.. . . ti . . o . . 4.4 la n . . . an . . b. yr pher1ic24 4 igning p. .ro . -2 . . .d.u. ct . 4.5 . in . 4.6 al ro, lle 2 3 1 .. C S 5 . . la ....b 1 2r 45 ball bear. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . .. . . . . . lo . . le . . . . e. . thSse eaalelsd 2 . . . . . ta bear in ..... ..... . . . . . .g. a. ri ings .b.e aS sphe 2 3 1 .. . . . . . . . . . rg 28ri, ca .ic. .p. riea 2 3l ro . . . . thm -2 npgle4.6 . 2 ller gs . . . . . . . . . . . . . . . . .. . . . . . . . . . .. . . . . . . . . . . . in ro ou sd: Otsp 2he7he 2 32 .. C S 5 . . . .e.ff. e. ct . oSGrph . . . . .cy.li.n. d. ri . . . file bear in ..... ..... ..... ,ria2ca r5 vari .H. . . . n . 8 er l ca . . re L 5 ro nt . . . . gs . ic s . . in . . . lu lle al . . . 2 32 .. . . . . . T 2 3. SGrea ..... ..... . . . . . tap e.re . . l ro l8 briro r bear ..... calle -2 . . . . . . .d. ro tirobe 0ou4ple d: 0 n in arte Lu spbrhe –4.53 2 32 .. C S . . . . .li fe. . . . . 3 ings ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . lo . . . . ller8 icatio . . o. se SGJph rica n l -2 . . .fi. ts ..... ..... . . N er ic 5 , 3 2 roller rv al. . 2 . .5. 4. . 4 . . . .1.70 2 3 6.. C S 5 . . . ca . SHTea . . . . . . . . . . . . . . . . . . . lo r al ro ller1 . .w be . -f . . lc ar . ri . . . . . . . u . ct le in LH be . . . . . . . la oT2n3 ds sphe .. .. . . . io . gs . . ..... 4 2 3 8 .. . .w LTea e xa . . . de . . Sti rica ar ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . lo . . .ct . . .n. b. e ari ng. LT 10 le ds spm p le l ro lle . ..... ..... . . . L. .-f. ri 8 . .io. 2 39. . . . . . . . . . . . . . fi. n . it io In f Greahericasl 9 0 –r be ar in . . . . . . . . MTn . als .1 6ng ch .e 33 si 3 . .0.2. . .n. se . . . . . . . . . . . . . . . . . . . . . . . .S. . 6 gs . . su ffi xe ro lle 9 2 8 .2 3 2 39. .- . . . . . . . . . . .q.u. a. tioSMT s lesero . r s 47 . († be n . . . . . L . . s . . ph w ta table paar ings ..... ..... T . .... ..... . s4al 8 .2 –8 . ge 30 . . . . 3. 0 24 0.. 2 C S . . . . . .te. .st. in . VT9378er6ic 4 – 3. .0.5. ro3ller pere d4,ro . ller5)be . . . . . . . . . . . . . . . . . . . . . . . . . . . . .L. T . . .n. . gSWTph c , 32 8.1 . . . . .1 0. . .3.0. 4 24 0.. . . . . . . . . . u .co S ea 5er ic al rolle bear ings ar ings ..... ..... -2 C S 2 . . . . . . .–.3. 0 1 . . . it r bear . le sp . . SnGrve ouprsdio ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . lu he . . b. ri . . . . .w it. h . . 5, 382.21 nt. fi. .lm taribca : Stn . .ca ..... ..... . . abiliz riph l . le . . ro . . a ber4.4 . ic li fe .a.d. . vaSS0 . . 8 . ati lle al s . 7 . . .1 1) e .... oprora lleonr be 0 r bear ings . . . . . . . . . . . . . . . . . . . . . . . . . . . . .ff. e. ct ju stS1mealele Start in Bearie . . .o.f.inle ... .. .. sp ng rin ti n gar in gs e d Be he g page li fe m o gs heat co n . t 8 .2 ri ari . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .e.ff. e. ct ngo ct dd it io sta dif ic atint fa rin . . .o.f.ki n. sh8e.2ari n gs he rca 6l ro at liofftth for op n s . .8. . . 5stallebilbilrizeizebe . e . .ff. e. ct inegpr oduc Gr oup o n fa eratin ..... ......... ......... ...e d forar g tem1 4.3: Be . . .o.n. fr. m a7.ti2c st a ct opin ..... ..... . . . . fo erags . pe ar ing o r 6 bl let ta ting tem .pe.rat. ur. es limit in tack . 1 36 4 e. . se ts, . . 4 2 . ≤ . . . DB 7 –7 15 rm . .≤ . .0.°C (30 ..... ..... . . . . ic tion rat ur es 8 .1 g spDFe e Tw4o ,be9 0 3 matched bear0, 7 3 al mo ... o. . . . . . . a. ti 20 0 °C. . .0.°F ) lu ings d 1Tw2o be6 arings match (39 0 °F. . . com DT . . . . . n. . 241 8 ca . . . . . . . . . . . . . . bri ) , 2.165 ... Tw o be arings match ed for mo ..... . . . . . n ts linear p are d to re un arings . . . . . dry 8 .2 . .. match ed for moun ting back-tolu fe b e re ed for . . . . . b.ri. ca tin .n nce sp moun g face-to- back lo ad ra aGrriounpg4.2s: Ac4cu e 8 . ts tin ff . .1 fac . g e e e . in 1 ct .. 1 gs 6 3 5racy, clearance, e d 1 18tandem lo ad ra tinP6P5 funct on p oly am8.292 , 1 quiet –6 Dim

K

8.2

3,2 2 ,5 2 ,5 1 ,8 2 ,8 2 2

nat ion

angula cy lind r contact b a ri spheri cal roller b ll bearings tap ere cal roller b e earings 5 8 4 8 0, 5 0 4 a 2 d rolle JA r b eari rings 9 02 , 6 02 ngs 8 cy lind 22 ri spheri cal roller b JB 5 8 cal roller earings 60 2 , 6P0 ro2duct b e ari ng s 9 02 2

933

Designation chart to decode designation suffixes

12

t

3

/

Designation suffixes listed in the text index reduce search time.

en4 tio running Dimen sional and ru for an P6P522 P5 + C2sional and ru nning acc ur guP6la ac nning acc ur y to P5 tol 3 r coP6 + C2 for f CN ac y to eran Pn

ide 6 6 io c grea se n 24 0 s 24 4 oil s –2

Units of measurement

This catalogue is for global use. Therefore, the predominant units of measurement are in accordance with ISO 80000-1. Exceptionally, imperial units are used when it is required by the product. Unit conversions can be made us­ ing the conversion table († page 8). For easier use, temperature values are pro­ vided in both, °C and °F. Temperature values are typically rounded. Therefore, the two ­values do not always exactly match when ­u sing the conversion formula.

More SKF rolling bearings Other rolling bearings, not presented in this catalogue, include: • super-precision bearings • ball and roller bearing units • fixed section ball bearings • large deep groove ball bearings with filling slots • large angular contact thrust ball bearings • tapered roller thrust bearings • multi-row ball or roller bearings • split roller bearings • crossed tapered roller bearings • slewing bearings • linear ball bearings • bearings for inline skates and skateboards • backing bearings for cluster mills • indexing roller units for continuous furnaces of sintering plants • application specific bearings for railway rolling stock • application specific bearings for cars and trucks • triple ring bearings for the pulp and paper industry • bearings for printing press rollers • bearings for critical aerospace applications For information about these products, contact SKF or visit skf.com.

13

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

This is SKF

From one simple but inspired solution to a friction problem in a mill in Sweden, and a handful of engineers in 1907, SKF has grown to become a global industrial knowledge leader. Over the years we have built on our expertise in bearings, extending it to seals, mechatronics, services and lubrication systems. Our knowledge network includes 46 000 employees, 15 000 distributor partners, offices in more than 130 countries, and a growing number of SKF Solution Factories around the world. Research and development We have hands-on experience in over forty industries, based on our employees’ knowledge of real life conditions. In addition our worldleading experts and university partners who pioneer advanced theoretical research and development in areas including tribology, condition monitoring, asset management and bearing life theory. Our ongoing commitment to research and development helps us keep our customers at the forefront of their industries.

SKF Solution Factories make SKF knowledge and manufacturing expertise available locally, to provide unique solutions and services to our customers

14

Meeting the toughest challenges Our network of knowledge and experience along with our understanding of how our core technologies can be combined helps us create innovative solutions that meet the toughest of challenges. We work closely with our customers throughout the asset life cycle, helping them to profitably and responsibly grow their businesses. Working for a sustainable future Since 2005, SKF has worked to reduce the negative environmental impact from our own operations and those of our suppliers. Our continuing technology development introduced the SKF BeyondZero portfolio of products and services which improve efficiency and reduce energy losses, as well as enable new technologies harnessing wind, solar and ocean power. This combined approach helps reduce the environmental impact both in our own operations and in our customers’.

Working with SKF IT and logistics systems and application experts, SKF Authorized Distributors deliver a valuable mix of product and application knowledge to customers worldwide.

15

SKF – the knowledge engineering company Design and develo p

Spe c

if

n

Man ufa ctu

dc om m

ta in

an dr ep air Opera te and monitor

Working closely with you Our objective is to help our customers improve productivity, minimize maintenance, achieve higher energy and resource efficiency, and optimize designs for long service life and reliability. Innovative solutions Whether the application is linear or rotary or a combination of the two, SKF engineers can work with you at each stage of the asset life cycle to improve machine performance by looking at the

16

re an d

st te

SKF Life Cycle Management in Ma

SKF Life Cycle Management is how we combine our technology platforms and advanced ser vices, and apply them at each stage of the asset life cycle, to help our customers to be more successful, sustainable and profitable.

tio ica

ission

Our knowledge – your success

n la tal Ins

entire application. This approach doesn’t just focus on individual components like bearings or seals. It looks at the whole application to see how each component interacts with the next. Design optimization and verification SKF can work with you to optimize current or new designs with proprietary 3-D modeling software that can also be used as a virtual test rig to confirm the integrity of the design.

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Bearings SKF is the world leader in the design, development and manufacture of high performance rolling bearings, plain bearings, bearing units and housings.

Machinery maintenance Condition monitoring technologies and maintenance services from SKF can help minimize unplanned downtime, improve operational efficiency and reduce maintenance costs.

Sealing solutions SKF offers standard seals and custom engineered sealing solutions to increase uptime, improve machine reliability, reduce friction and power losses, and extend lubricant life.

Mechatronics SKF fly-by-wire systems for aircraft and drive-by-wire systems for off-road, agricultural and forklift applications replace heavy, grease or oil consuming mechanical and hydraulic systems.

Lubrication solutions From specialized lubricants to state-of-the-art lubrication systems and lubrication management services, lubrication solutions from SKF can help to reduce lubrication related downtime and lubricant consumption.

Actuation and motion control With a wide assortment of products – from actuators and ball screws to profile rail guides – SKF can work with you to solve your most pressing linear system challenges.

17

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Principles of bearing selection and application

21

A

Selecting bearing size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

B

Friction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

C

117

D

Bearing specifics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

E

Design considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159

F

Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239

G

Mounting, dismounting and bearing care . . . . . . . . . . . . 271

H

Bearing basics

Speeds

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

19

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Bearing basics

Selecting rolling bearings. . . . . . . . . . . . . 22 Terminology. . . . . . . . . . . . . . . . . . . . . . . . . Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bearing systems. . . . . . . . . . . . . . . . . . . . . . Radial bearings. . . . . . . . . . . . . . . . . . . . . . . Thrust bearings . . . . . . . . . . . . . . . . . . . . . .



23 23 24 24 25

Bearing types and designs . . . . . . . . . . . . Radial bearings. . . . . . . . . . . . . . . . . . . . . . . Thrust bearings . . . . . . . . . . . . . . . . . . . . . . Track runner bearings. . . . . . . . . . . . . . . . . Cages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stamped metal cages. . . . . . . . . . . . . . . . Machined metal cages . . . . . . . . . . . . . . . Polymer cages . . . . . . . . . . . . . . . . . . . . . Cage guidance. . . . . . . . . . . . . . . . . . . . . . Materials. . . . . . . . . . . . . . . . . . . . . . . . . .



26 26 33 35 37 37 38 38 39 39

A

Basic selection criteria . . . . . . . . . . . . . . . Available space. . . . . . . . . . . . . . . . . . . . . . . Loads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnitude of load. . . . . . . . . . . . . . . . . . . Direction of load. . . . . . . . . . . . . . . . . . . . Misalignment . . . . . . . . . . . . . . . . . . . . . . . . Precision. . . . . . . . . . . . . . . . . . . . . . . . . . . . Speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Friction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Quiet running. . . . . . . . . . . . . . . . . . . . . . . . Stiffness. . . . . . . . . . . . . . . . . . . . . . . . . . . . Axial displacement. . . . . . . . . . . . . . . . . . . . Mounting and dismounting . . . . . . . . . . . . . Cylindrical bore. . . . . . . . . . . . . . . . . . . . . Tapered bore. . . . . . . . . . . . . . . . . . . . . . . Sealing solutions . . . . . . . . . . . . . . . . . . . . .



46 47 48 48 48 52 53 53 54 54 54 55 56 56 56 58

Boundary dimensions . . . . . . . . . . . . . . . . 40 ISO general plans. . . . . . . . . . . . . . . . . . . . . 40 General plans for inch bearings. . . . . . . . . . 41 Basic bearing designation system. . . . . . Basic designations. . . . . . . . . . . . . . . . . . . . Prefixes and suffixes. . . . . . . . . . . . . . . . . . Bearing designations not covered by the basic bearing designation system. . . . .

42 42 45 45

21

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Bearing basics

Selecting rolling bearings A bearing system consists of more than just bearings. Associated components like the shaft and housings are integral parts of the overall system. The lubricant and sealing elem­ents also play a critical role. To maximize bearing performance, the correct amount of an appropriate lubricant must be present to reduce friction in the bearing and protect it from corrosion. Sealing elements are impor­ tant, because they keep the lubricant in, and contaminants out, of the bearing cavity. This is particularly important because cleanliness has a profound effect on bearing service life – which is why SKF manufactures and sells a wide range of industrial seals and lubrication systems. There are a number of factors that go into the bearing selection process. Understanding the dynamic behaviour of the application is probably one of the most important. Dynamic behaviour, in this case, means: • available space • loads (magnitude and direction) • misalignment • precision and stiffness • speeds • operating temperature • vibration levels • contamination levels • lubrication type and method Once the dynamic behaviour has been estab­ lished, a suitable bearing type and size can be selected. However, during the bearing selec­ tion process there are several other factors that need to be considered: • a suitable form and design of other com­ ponents of the arrangement • appropriate fits and bearing internal clear­ ance or preload • holding devices • adequate seals • the type and quantity of lubricant • installation and removal methods When designing an application, every decision affects the performance, reliability and econ­ omy of the bearing system. 22

As the leading bearing supplier, SKF manu­ factures a large number of bearing types, series, designs, variants and sizes. The most common of them are introduced under Bearing types and designs († page 26). There are also bearings that are not included in this cata­ logue. Information about most of these bear­ ings is provided in special catalogues or online at skf.com/bearings. In this section and in sections B through H, the designer of a bearing system can find the necessary basic information presented in the order in which it is generally required. Obvi­ ously, it is impossible to include all the infor­ mation needed to cover every conceivable application. For this reason, in many places, reference is made to the SKF application engin­eer­ing ser­vice. This technical service can perform complex calculations, diagnose and solve bearing performance issues, and help with the bearing selection process. SKF also recommends this service to anyone working to improve the performance of their application. The information contained in this section and in sections B through H is general and applies to most rolling bearings. Information specific to one bearing type is provided in the relevant product chapter. Additional cata­ logues and brochures covering specific appli­ cation areas are available on request. Detailed information about almost all SKF rolling bear­ ings, bearing units, housings, plain bearings and seals is available online at skf.com/bearings. It should be noted that the values listed in the product tables for load and speed ratings as well as for the fatigue load limit are heavily rounded.

Terminology Fig. 1

A

B r d a

r H

D d D

Terminology Some frequently used bearing terms are explained here. For a detailed collection of bearing-specific terms and definitions, refer to ISO 5593 Rolling bearings – Vocabulary.

Symbols Symbols used in this catalogue are mainly in accordance with ISO standards. Most common symbols for bearing boundary dimensions are shown in fig. 1. Other symbols are listed below. All symbols can be used with a sub­ script to identify specifications. A = speed factor = n dm [mm/min] C = bearing load rating [kN] dm = bearing mean diameter [mm] = 0,5 (d + D) F = actual bearing load [kN] L = life, typically in million revolutions or operating hours n = rotational speed [r/min] P = equivalent bearing load [kN] Pu = fatigue load limit [kN] h c = factor for contamination level k = viscosity ratio: actual versus required n = oil viscosity [mm2 /s]

23

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Bearing basics

Bearing systems († fig. 2) 1 Cylindrical roller bearing 2 Four-point contact ball bearing 3 Housing 4 Shaft 5 Shaft abutment shoulder 6 Shaft diameter 7 Shaft seat 8 End plate 9 Radial shaft seal 10 Distance ring 11 Housing bore diameter 12 Housing seat 13 Housing cover 14 Snap ring

Fig. 2

14

12

1

3

5 13 2 7 4

11

6 8

10 9

Radial bearings († figs. 3 and 4) 1 Inner ring 2 Outer ring 3 Rolling element: ball, cylin­ dric­al roller, needle roller, taper­ed roller, spherical roller, toroidal roller 4 Cage 5 Capping device Seal – made of elastomer Shield – made of sheet steel 6 Outer ring outside surface 7 Inner ring bore 8 Inner ring shoulder surface 9 Outer ring shoulder surface 10 Snap ring groove 11 Snap ring 12 Outer ring side face 13 Recess for capping device

24

Fig. 3

9

6

2

14

10

11

18 12 13

4

3

5

16 17 8 7

1

15

19

18

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Terminology

A 14 Outer ring raceway 15 Inner ring raceway 16 Recess for capping device 17 Inner ring side face 18 Chamfer 19 Bearing pitch circle diameter 20 Total bearing width 21 Guide flange 22 Retaining flange 23 Contact angle

Fig. 4

20

6 2

a

12 14

3

21

4

17

22 15

1 7

a 23

Thrust bearings († fig. 5) 24 Shaft washer 25 Rolling element and cage assembly 26 Housing washer 27 Housing washer with a sphered seat surface 28 Seat washer

Fig. 5

24 25 26

27 24 28 24 25 26

25

Bearing basics

Bearing types and designs

Radial bearings Radial bearings accommodate loads that are predominantly vertical to the shaft. The bear­ ings are typically classified by the type of roll­ ing element and shape of the raceways.

Deep groove ball bearings († page 295)

1

2

single row open basic design (1) with shields with contact seals (2) single row, stainless steel open basic design (1) with shields with seals (2) single row, with filling slots open basic design (3) with shields with a snap ring groove, with or without a snap ring

3

double row (4)

4

thin section bearings1) open basic design (5) with contact seals

5 1) Contact the SKF application engineering service.

26

Bearing types and designs

A Y-bearings (insert bearings) († page 421)

with grub screws inner ring extended on one side (6) inner ring extended on both sides (7)

6

7

with an eccentric locking collar inner ring extended on one side (8) inner ring extended on both sides (9)

8

9

with a tapered bore inner ring extended on both sides, for adapter sleeve mounting (10)

10

with a standard inner ring for locating by interference fit on the shaft (11)

11

27

Bearing basics

Angular contact ball bearings († page 475)

single row basic design for single mounting design for universal matching (12)

12

super-precision single row 1) basic design open or with contact seals high-speed design open or with contact seals (13) high-capacity design open or with contact seals

13

double row with a one-piece inner ring (14) open basic design with shields with contact seals with a two-piece inner ring 14

four-point contact ball bearings (15)

15

Self-aligning ball bearings († page 537)

with a cylindrical or tapered bore open basic design (16) with contact seals (17)

16

17

1) Refer to product information available online at

skf.com/super-precision or separate catalogue.

28

Bearing types and designs

A with an extended inner ring (18)

18

Cylindrical roller bearings († page 567)

single row NU design (19) with one or two angle rings N design (20) 19

20

single row NJ design (21) with an angle ring NUP design (22)

21

22

single row high-capacity NCF design (23) NJF design NUH design 23

double row 1) with a cylindrical or tapered bore NNU design (24) NN design (25) NNUP design 24

25

1) Refer to product information available online at

skf.com/bearings or separate catalogue.

29

Bearing basics

Cylindrical roller bearings (cont.)

four-row 1) with a cylindrical or tapered bore open design (26) with contact seals 26

full complement cylindrical roller bearings single row NCF design (27) NJG design (28)

27

28

double row with integral flanges on the inner ring (29) with integral flanges on the inner and outer rings with contact seals (30) 29

30

Needle roller bearings († page 673)

needle roller and cage assemblies single row (31) double row (32)

31

32

drawn cup needle roller bearings, open ends single and double row open basic design (33) with contact seals (34)

33

34

1) Refer to product information available online at

skf.com/bearings or separate catalogue.

30

Bearing types and designs

A drawn cup needle roller bearings, closed end single and double row open basic design (35) with a contact seal (36)

35

36

needle roller bearings with flanges single and double row without an inner ring (37) with an inner ring open basic design with contact seals (38) 37

38

needle roller bearings without flanges single and double row with an inner ring (39) without an inner ring (40)

39

40

alignment needle roller bearings without an inner ring with an inner ring (41)

41

combined needle roller bearings needle roller / angular contact ball bearings single direction (42) double direction (43)

42

43

31

Bearing basics

Needle roller bearings (cont.)

needle roller / thrust ball bearings with a full complement ball set (44) with a cage-guided ball set with or without (45) a cover 44

45

needle roller / cylindrical roller thrust bearings without a cover (46) with a cover (47)

46

47

Tapered roller bearings († page 797)

48

49

single row single bearings (48) matched bearings face-to-face (49) back-to-back tandem

double row 1) TDO configuration (back-to-back) (50) TDI configuration (face-to-face) (51)

50

51

four-row 1) TQO configuration open design (52) with contact seals TQI configuration 52

1) Refer to product information available online at

skf.com/bearings or separate catalogue.

32

Bearing types and designs

A Spherical roller bearings († page 879)

with a cylindrical or tapered bore open basic designs (53) with contact seals (54) for vibratory applications 53

54

CARB toroidal roller bearings († page 957)

with a cylindrical or tapered bore with a cage-guided roller set (55) with a full complement roller set with contact seals (56) 55

56

Thrust bearings Thrust bearings accommodate loads that are predominantly in the direction of the shaft. The bearings are typically classified by the type of rolling elem­ent and shape of the raceways. Thrust ball bearings († page 1009)

single direction with a flat housing washer (57) with a sphered housing washer with (58) or without a sphered seat washer 57

58

double direction with flat housing washers (59) with sphered housing washers with (60) or without seat washers

59

60

33

Bearing basics

Angular contact thrust ball bearings 1)

super-precision bearings single direction basic design for single mounting (61) design for universal matching matched bearings (62) 61

62

double direction basic design (63) high-speed design (64)

63

64

Cylindrical roller thrust bearings († page 1037)

65

66

single direction single row (65) double row (66) double direction components cylindrical roller and cage thrust assemblies shaft and housing washers Needle roller thrust bearings († page 1057)

67

68

single direction needle roller and cage thrust assemblies (67) needle roller thrust bearings with a centring flange (68) raceway washers thrust washers double direction Spherical roller thrust bearings († page 1077)

single direction (69)

69 1) Refer to product information available online at

skf.com/super-precision or separate catalogue.

34

Bearing types and designs

A Tapered roller thrust

bearings 1)

single direction with or without (70) a cover screw down bearings double direction (71) 70

71

Track runner bearings Track runner bearings († page 1099) are bearings with a thick walled outer ring. These ready-to-mount units are used in all types of cam drives, tracks and conveyor systems. Cam rollers

single row (72) double row (73)

72

73

Support rollers

without flange rings with or without contact seals without an inner ring with an inner ring (74) 74

with flange rings, based on needle roller bearings with or without contact seals with a cage-guided roller set (75) with a full complement roller set 75

1) Refer to product information available online at

skf.com/bearings or separate catalogue.

35

Bearing basics

Support rollers (cont.)

with flange rings, based on cylindrical roller bearings with labyrinth seals (76) with contact seals (77) with lamellar seals 76

77

Cam followers

78

based on needle roller bearings with or without contact seals with a concentric seat (78) with an eccentric seat collar with a cage-guided roller set (78) with a full complement roller set

based on cylindrical roller bearings with labyrinth seals (79) with contact seals with a concentric seat (79) with an eccentric seat collar 79

36

Bearing types and designs

Cages

Fig. 6

With the exception of full complement bear­ ings, all rolling bearings contain a cage. The number of cages depends on the number of ball or roller sets within the bearing and on the cage design. The primary purposes of a cage are: • Keeping the rolling elements at a proper distance from each other to reduce the fric­ tional moment and frictional heat in the bearing. • Keeping the rolling elements evenly spaced to optimize load distribution and enable quiet and uniform operation. • Guiding the rolling elements in the unloaded zone, to improve the rolling conditions and to prevent damaging sliding movements. • Retaining the rolling elements of separable bearings when one bearing ring is removed during mounting or dismounting. Cages are mechanically stressed by frictional, strain and inertial forces. They can also be chemically stressed by certain lubricants, lubricant additives or by-products of their ageing, organic solvents or coolants. There­ fore, the design and material of a cage have a significant influence on the suitability of a roll­ ing bearing for a particular application. There­ fore, SKF has developed a variety of cages, made of different materials, for the different bearing types. In each product chapter, information about standard cages and possible alternatives is provided. If a bearing with a non-standard cage is required, check availability prior to ordering. Cages can be classified according to the manufacturing process and material group into:

A



a

b

c

d

Stamped metal cages Stamped metal cages for SKF bearings († fig. 6) are generally made of sheet steel and with some exceptions, of sheet brass. Depending on the bearing type, the following stamped metal cages are available: • a ribbon-type cage (a) • a riveted cage (b) • a snap-type cage (c) • a window-type cage (d) Stamped metal cages are lightweight. They provide ample space inside the bearing to maximize the effects of the lubricant.

• stamped metal cages • machined metal cages • polymer cages

37

Bearing basics Fig. 7



a

b

c

c

d

Machined metal cages Machined metal cages for SKF bearings († fig. 7) are made of brass, steel or light alloy. Depending on the bearing type, design and size, the following machined metal cages are available:

Fig. 8

• a two-piece machined riveted metal cage (a) • a two-piece machined metal cage with inte­ gral rivets (b) • a one-piece machined window-type metal cage (c) • a double prong-type machined metal cage (d) Machined metal cages, which generally permit higher speeds, are typically used when forces, other than pure rotational forces, are super­ imposed on the cage. Polymer cages Polymer cages for SKF bearings († fig. 8) are injection moulded. SKF also manufactures a fabric reinforced phenolic resin cage, but only for super-precision bearings, which are not included in this catalogue. Depending on the bearing type, design and size, the following polymer cages are available: • a polymer window-type cage (a) • a polymer snap-type cage (b) Polymer cages are characterized by a favour­ able combination of strength and elasticity. The good sliding properties of the polymer on 38



a

b

Bearing types and designs lubricated steel surfaces and the smoothness of the cage surfaces in contact with the rolling elements produce little friction so that fric­ tional heat and wear in the bearing are min­im­ ized. The low density of the material means that the inertial forces generated by the cage are minor. The excellent running properties of polymer cages under poor lubrication condi­ tions permit continued operation of the bear­ ing for some time without the risk of seizure and secondary damage. Cage guidance Stamped metal cages are typically guided by the rolling elements. Depending on the bearing type and design, machined metal and polymer cages are radi­ ally centred († fig. 9) either on: • the rolling elements (a) • the inner ring (shoulder(s)) (b) • the outer ring (shoulder(s)) (c) Cages guided by the rolling elements permit the lubricant to enter the bearing easily. Ring guided cages, which provide more pre­ cise guidance, are typically used when bearing arrangements must accommodate high speeds, frequent, rapid accelerations or high vibration levels. Suitable steps must be taken to provide a sufficient supply of lubricant to the guiding surfaces of the cage. For higher speeds, SKF recommends oil lubrication († Lubrication, page 239 and/or relevant product chapter).

Fig. 9

A

a

b

c

Materials For information about materials used for cages, refer to Cage materials († page 152).

39

Bearing basics

Boundary dimensions Boundary dimensions are the main dimen­ sions of a bearing († fig. 10). They comprise: • the bore diameter (d) • the outside diameter (D) • the width or height (B, C, T or H) • the chamfer dimensions (r) The boundary dimensions for standard metric bearings are contained in the general plans as specified in ISO (International Organization for Standardization) standards: • ISO 15 for radial rolling bearings, except Y-bearings, some types of needle roller bearings and tapered roller bearings • ISO 10 4 for thrust bearings • ISO 355 for tapered roller bearings

ISO general plans The ISO general plans for boundary dimen­ sions of radial bearings contain a progressive series of standardized outside diameters for every standard bore diameter arranged in diameter series 7, 8, 9, 0, 1, 2, 3 and 4 (in order of increasing outside diameter). Within each diameter series different width series have also been established (width series 8, 0, 1, 2, 3, 4, 5 and 6 in order of increasing width). The height series for thrust bearings (height series 7, 9, 1 and 2 in order of increasing height) corresponds to the width series for radial bearings. Dimension series are formed by combining the number for the width or height series with the number for the diameter series. († fig. 11). In the ISO general plan for single row metric tapered roller bearings (ISO 355), the bound­ ary dimensions are grouped for certain ranges of the contact angle a, known as the angle series (angle series 2, 3, 4, 5, 6 and 7 in order of increasing angle). Based on the relationship between the bore and outside diameter, and between the total bearing width and the cross-sectional height, diameter and width series have also been established. Here, a dimension series is obtained by combining an angle series with a diameter and a width series († fig. 12). The dimension series consists of a number for the angle series and two letters. The first letter identifies the diameter series; the second identifies the width series. Fig. 10

B

r d1

r

D

r

d

H1)

d r D1 D

1) ISO uses symbol T

40

Boundary dimensions With very few exceptions, the bearings in this catalogue comply with the ISO general plans or with other ISO standards for the dimensions of some bearing types for which an ISO dimension series is not available. Experi­ ence has shown that the requirements of the vast majority of bearing applications can be met using bearings with these standardized dimensions. Following ISO standards for the boundary dimensions is a prerequisite for interchangeability of bearings. Specific infor­ mation about compliance to dimension stand­ ards is provided in each product chapter.

General plans for inch bearings A large group of bearings with inch dimensions are inch tapered roller bearings. The dimen­ sions of these bearings are in accordance with AFBMA Standard 19 (ANSI B3.19). ANSI/ ABMA Standard 19.2 has replaced this stand­ ard, but does not include dimensions. In addition to the inch tapered roller bear­ ings, some inch ball bearings and cylindrical roller bearings are also available, but not listed in this catalogue.

Fig. 11

3 Diameter series

03

2 0

13

23

10

00

33

22

12

02

32

20

30

d

Dimension series Width series

0

1

2

3

Fig. 12

G F E D C B

B D C E

B D C E

B D C E

BC D E

BCD E

B C D E

41

A

Bearing basics

Basic bearing designation system

Diagram 1 Designations for SKF rolling bearings

The designations of most SKF rolling bearings follow a designation system. The complete bearing designation may consist of a basic designation with or without one or more sup­ plementary designations († diagram 1). The complete designation is always marked on the bearing package, whereas the marking on the bearing may be incomplete or deviate from the designation. The basic designation identifies:

Examples

• the bearing type • the basic design • the boundary dimensions

Suffix

Prefixes and suffixes identify bearing com­ ponents or variants having a design and/or feature(s) that differ in some respect from the basic design.

Basic designations A basic designation typically contains three to five digits. Some products, like cylindrical roller bearings, can have a combination of alphanumeric characters. The basic designa­ tion system is shown in diagram 2. The number and letter combin­ations have the fol­ lowing meaning: • The first digit or letter or combination of let­ ters identifies the bearing type and eventu­ ally a basic variant. • The following two digits identify the ISO dimension series. The first digit indicates the width or height series (dimensions B, T or H). The second digit identifies the diam­ eter series (dimension D). • The last two digits of the basic designation identify the size code of the bearing bore. The size code multiplied by 5 gives the bore diameter (d) in mm. The most important exceptions in the basic bearing designation system are: 1 In a few cases the digit for the bearing type or the first digit of the dimension series identification is omitted. These digits are shown in brackets in diagram 2. 42

R

NU 2212

W

6008

/

ECML C3

23022

-

2CS

Prefix Space or non-separated Basic designation Space, oblique stroke or hyphen

2 Bearings with a bore diameter of 10, 12, 15 or 17 mm have the following size code identifications: 00 = 10 mm 01 = 12 mm 02 = 15 mm 03 = 17 mm 3 For bearings with a bore diameter < 10 mm, or ≥ 500 mm, the bore diameter is generally given in millimetres (uncoded). The size identification is separated from the rest of the bearing designation by an oblique stroke, e.g. 618/8 (d = 8 mm) or 511/530 (d = 530 mm). This is also true of standard bearings in accordance with ISO 15 that have a bore diameter of 22, 28 or 32 mm, e.g. 62/22 (d = 22 mm). 4 For some bearings with a bore diameter < 10 mm, such as deep groove, self-aligning and angular contact ball bearings, the bore diameter is also given in millimetres (uncoded) but is not separated from the series designation by an oblique stroke, e.g. 629 or 129 (d = 9 mm). 5 Bore diameters that deviate from the standard bore diameter of a bearing are uncoded and given in millimetres up to three decimal places. This bore diameter identifi­ cation is part of the basic designation and is separated from the basic designation by an oblique stroke, e.g. 6202/15.875 (d = 15,875 mm = 5 /8 in).

Basic bearing designation system Diagram 2 Basic designation system for SKF standard metric ball and roller bearings Bearing series

(0)33 (0)32

544 524 543 523 542 522

223 213 232 222 241 231 240 230 249 239 248 238

139 130 (1)23 1(0)3 (1)22 1(0)2 1(1)0

323 313 303 332 322 302 331 330 320 329

294 293 292

4(2)3 4(2)2

534 514 533 513 532 512 511 510 591 590

6(0)4 623 6(0)3 622 6(0)2 630 6(1)0 16(0)0 639 619 609 638 628 618 608 637 627 617

A 23 32 22 41 31 60 50 40 30 69 59 49 39 29

814 894 874 813 893 812 811

7(0)4 7(0)3 7(0)2 7(1)0 719 718 708

(0)4 33 23 (0)3 22 12 (0)2 31 30 20 10 39 29 19 38 28 18

41 31 60 50 40 30 69 49 39 48

23 (0)3 12 (0)2 10 19

Bearing type NC, NCF NF, NFP NJ, NJF, NJP NP, NPF NU, NUH NUP, NUPJ

(0)

1

2

3

4

6

5

8

7

Radial bearings Width (B, T)

8 0 H T B

1

2

3

4

NNF NNC NNCF NNCL NNU

N

C

NN

QJ

Thrust bearings Height (H)

5

9

7

6

1

2

Diameter series

D 7

8

9

Dimen­sion series

0

1

2

3

4

XXXXX Bearing series

Size d/5

Code Bearing type

Code Bearing type

0

7

1 2 3 4 5 6

Double row angular contact ball bearing Self-aligning ball bearing Spherical roller bearing, spherical roller thrust bearing Tapered roller bearing Double row deep groove ball bearing Thrust ball bearing Single row deep groove ball bearing

8 C N

Code Bearing type

Single row angular contact ball QJ bearing T Cylindrical roller thrust bearing CARB toroidal roller bearing Cylindrical roller bearing. Two or more letters are used to identify the number of the rows or the configuration of the flanges, e.g. NJ, NU, NUP, NN, NNU, NNCF etc.

Four-point contact ball bearing Tapered roller bearing in accordance with ISO 355

43

Bearing basics Diagram 3 Designation system for suffixes Designation example Group 1

Group 2

Group 3 / 4.1

6205-RS1NRTN9/P63LT20CVB123 23064 CCK/HA3C084S2W33

6205 23064

-RS1NR TN9 CC

Basic designation Space Suffixes Group 1: Internal design Group 2: External design (seals, snap ring groove, etc.) Group 3: Cage design Oblique stroke Group 4: Variants Group 4.1: Materials, heat treatment Group 4.2: Accuracy, clearance, quiet running Group 4.3: Bearing sets, matched bearings Group 4.4: Stabilization Group 4.5: Lubrication Group 4.6: Other variants

44

K

/ /

4.2

Group 4 4.3 4.4

P63 HA3

C084

4.5

4.6

LT20C VB123 S2

W33

Basic bearing designation system Series designations

Each standard bearing belongs to a given bearing series, which is identified by the basic designation without the size identification. Series designations often include a suffix A, B, C, D or E or a combination of these letters. These letters are used to identify differences in internal design. The most common series designations are shown in diagram 2 († page 43) above the illustrations. The digits in brackets are omitted in the series designation.

Bearing designations not covered by the basic bearing designation system Y-bearings (insert bearings)

The designations for Y-bearings differ some­ what from the system described above and are covered in the relevant product chapter. Needle roller bearings

The designations for needle roller bearings do not fully follow the system described above and are covered in the relevant product chapter.

Prefixes and suffixes

Tapered roller bearings

Prefixes and suffixes provide additional infor­ mation about the bearing. Prefixes and suf­ fixes and their significance are explained in the relevant product chapter. Prefixes are mainly used to identify com­ ponents of a bearing. They can also identify bearing variants.

The designations for metric tapered roller bearings follow either the system described above or a designation system established by ISO in 1977 († ISO 355). Inch tapered roller bearings are designated in accordance with the relevant ANSI/ABMA standard. The designation system for tapered roller bearings is explained in the relevant product chapter.

Suffixes

Customized bearings

Suffixes identify designs or variants, which differ in some way from the original design or from the current basic design. The suffixes are divided into groups. When more than one spe­ cial feature is to be identified, suffixes are pro­ vided in the order shown in diagram 3.

Bearings designed to meet a specific customer requirement are typically designated by a drawing number. The drawing number does not provide any information about the bearing.

Prefixes

Other rolling bearings

Rolling bearings not covered in this catalogue, such as super-precision bearings, thin section bearings, slewing bearings or linear bearings follow designation systems, which can differ significantly from the system described above. Information about these designation systems is provided in the relevant catalogues.

45

A

Bearing basics

Basic selection criteria Each bearing type displays characteristic properties, based on its design, which makes it more, or less, appropriate for a given applica­ tion. For example, deep groove ball bearings can accommodate normal radial loads as well as axial loads. These low-friction bearings, which are also available in the SKF Energy Efficient performance class, can be manufac­ tured with a high degree of running accuracy and are available in quiet running variants. Therefore, they are preferred for small and medium-size electric motors. Spherical and toroidal roller bearings can accommodate very heavy loads and are selfaligning. These properties make them popular for applications, where there are heavy loads, shaft deflections and misalignment. In many cases, however, several factors have to be considered and weighed against each other when selecting a bearing, so that no general rules can be given. The information provided here should serve to indicate the most important factors to be considered when selecting a standard bearing: • available space • loads • misalignment • precision • speed • friction • quiet running • stiffness • axial displacement • mounting and dismounting • sealing solutions The total cost of a bearing system and inven­ tory considerations can also influence bearing selection. Some of the most important criteria to con­ sider, when designing a bearing arrangement, are covered in depth in separate sections of this catalogue. These include load carrying capacity and life, friction, permissible speeds, bearing internal clearance or preload, lubrica­ tion and sealing solutions. Detailed information on the individual bear­ ing types, including their characteristics and the available designs, is provided in each prod­ uct chapter. 46

Fig. 13

Fig. 14

Fig. 15

Basic selection criteria This catalogue does not cover the complete SKF rolling bearings assortment. Specific cata­ logues and brochures are available for bear­ ings not covered here. For additional informa­ tion, contact SKF.

Fig. 16

A

Available space In many cases, the principal dimensions of a bearing are predetermined by the machine’s design. For example, the shaft diameter deter­ mines the bearing bore diameter. For small-diameter shafts all types of ball bearings can be used, the most popular being deep groove ball bearings; needle roller bear­ ings are also suitable († fig. 13). For largediam­eter shafts, cylindrical, tapered, spherical and toroidal roller bearings and deep groove ball bearings are available († fig. 14). When radial space is limited, bearings with a low cross-sectional height, should be chosen, i.e. bearings in the 8 or 9 diameter series. Needle roller and cage assemblies, drawn cup needle roller bearings and needle roller bear­ ings with or without an inner ring († fig. 15) are very appropriate, as well as bearings in the small diameter series of deep groove and angular contact ball bearings, cylindrical, tapered, spherical and toroidal roller bearings. When axial space is limited, narrow series cylindrical roller bearings and deep groove ball bearings can be used to accommodate radial or combined loads († fig. 16). Combined nee­ dle roller bearings († fig. 17) can also be used. For purely axial loads, needle roller and cage thrust assemblies (with or without wash­ ers) as well as thrust ball bearings and cylin­ drical roller thrust bearings can be used († fig. 18).

Fig. 17

Fig. 18

47

Bearing basics

Loads

Fig. 19

Magnitude of load The magnitude of the load is one of the factors that usually determines the size of the bear­ ing. Generally, roller bearings are able to sup­ port heavier loads than similar-sized ball bearings († fig. 19). Bearings with a full complement of rolling elements can accom­ modate heavier loads than corresponding bearings with a cage. Ball bearings are typic­ ally used in applications where loads are light to normal (P ≤ 0,1 C). Roller bearings are used in applications where loads are heavier (P > 0,1 C), or where shaft diameters are large. Direction of load Radial loads

Fig. 20

NU and N design cylindrical roller bearings, needle roller bearings and toroidal roller bear­ ings can only support pure radial loads († fig. 20). All other radial bearings can accommodate some axial loads in addition to radial loads († Combined loads, page 50). Axial loads

Thrust ball bearings and four-point contact ball bearings († fig. 21) are suitable for light or normal loads that are purely axial. Single direction thrust ball bearings can only accom­ modate axial loads in one direction. For axial loads acting in both directions, double direc­ tion thrust ball bearings are needed. Fig. 21

48

Basic selection criteria Angular contact thrust ball bearings can support normal axial loads at high speeds. Here, the single direction bearings can also accommodate simultaneously acting radial loads, while double direction bearings are nor­ mally used only for purely axial loads († fig. 22). For normal to heavy loads that are purely axial and act in one direction only, needle roller thrust bearings, cylindrical and tapered roller thrust bearings are suitable. Spherical roller thrust bearings († fig. 23) can accommodate axial loads in one direction only as well as radial loads. For heavy alternating axial loads, two cylindrical roller thrust bearings or two spherical roller thrust bearings can be mounted in pairs.

A

Fig. 23

Fig. 22

49

Bearing basics Combined loads

A combined load consists of a radial and axial load acting simultaneously. The ability of a bearing to accommodate an axial load is determined by the contact angle a. The greater the angle, the higher the axial load carrying capacity of the bearing. An indication of this is given by the calculation factor Y, which becomes smaller as the contact angle a increases. The values of the angle a or the fac­ tor Y are listed in the relevant product chapter. The axial load carrying capacity of a deep groove ball bearing depends on its internal design and the operational internal clearance († Deep groove ball bearings, page 295). For combined loads, single and double row angular contact ball bearings and single row tapered roller bearings are most commonly used, although deep groove ball bearings and spherical roller bearings are suitable († fig. 24). In addition, self-aligning ball bearings and NJ and NUP design cylindrical roller bearings as well as NJ and NU design cylindrical roller bearings with HJ angle rings can be used for combined loads when the axial component is relatively small († fig. 25). Single row angular contact ball bearings, single row tapered roller bearings, NJ design cylindrical roller bearings, NU design cylin­ dric­al roller bearings with an HJ angle ring and spherical roller thrust bearings can accommo­ date axial loads in one direction only. For axial loads that alternate direction, these bearings must be combined with a second bearing. For this reason, universally matchable angular contact ball bearings and matched sets of tapered roller bearings are available († Bearings for universal matching, page 477, or Matched bearings, page 802).

50

Fig. 24

a

a

a

a

a

Fig. 25

Basic selection criteria When the axial component of the combined load is significantly large, a second bearing, free of radial load may be necessary. In add­ ition to thrust bearings, some radial bearings, e.g. deep groove ball bearings or four-point contact ball bearings († fig. 26) are suitable. To make sure that the bearing is subjected to a purely axial load, the bearing outer ring must be mounted with radial clearance.

Fig. 26

A

Moment loads

When a load acts eccentrically on a bearing, a tilting moment occurs. Double row bearings, e.g. deep groove and angular contact ball bearings, can accommodate tilting moments, but paired single row angular contact ball bearings and tapered roller bearings arranged back-to-back, are more suitable († fig. 27).

Fig. 27

51

Bearing basics

Misalignment Angular misalignment between the shaft and housing occurs when the shaft deflects (bends) under the operating load. Misalign­ ment can also occur when the bearings are too far apart. Rigid bearings, i.e. deep groove ball bear­ ings and cylindrical roller bearings can accom­ modate only a few minutes of misalignment without damaging the bearing. Self-aligning bearings, e.g. self-aligning ball bearings, spherical roller bearings, toroidal roller bear­ ings and spherical roller thrust bearings († fig. 28), can accommodate shaft deflec­ tions as well as initial misalignment resulting from machining or mounting errors. Values for the permissible misalignment are listed in the

relevant product chapter. If the expected mis­ alignment exceeds the permissible values, contact the SKF application engin­eer­ing service. Thrust ball bearings with sphered housing and seat washers, Y-bearing units and align­ ment needle roller bearings († fig. 29) can compensate for initial misalignment arising from machining or mounting errors.

Fig. 28

Fig. 29

52

Basic selection criteria

Precision

Fig. 30

When dealing with rolling bearings, precision is described by tolerance classes for running accuracy and dimensional accuracy. Each product chapter provides information about the tolerance classes to which the bear­ ings are manufactured. SKF manufactures a comprehensive assortment of super-precision bearings, including single row angular contact ball bearings, single and double row cylindrical roller bearings and single and double direction angular contact thrust ball bearings. For information about super-precision bearings, refer to the product information available online at skf.com/super-precision.

A

Speed The permissible operating temperature puts limits on the speed at which rolling bearings can be operated. Bearing types that operate with low friction and generate low frictional heat are therefore the most suitable for highspeed operation. The highest speeds can be achieved with deep groove ball bearings and self-aligning ball bearings († fig. 30) when loads are purely radial. Angular contact ball bearings († fig. 31) are typically used when there are combined loads. This is particularly true for super-precision angular contact ball bearings and deep groove ball bearings with ceramic rolling elements, also referred to as hybrid bearings. Because of their design, thrust bearings cannot accommodate speeds as high as radial bearings.

Fig. 31

53

Bearing basics

Friction

Stiffness

Rolling bearings are also known as “anti-fric­ tion bearings”, but of course, some frictional losses occur in the bearing. One contributing factor to rolling friction in a bearing is the result of elastic deformation of the rolling elem­ents and raceways under load. Other sources include, but are not limited to, the sliding friction that occurs between the rolling elements and cage, flanges and guide rings, and between seals and their counterface. Fric­ tion in the lubricant also contributes to the total frictional moment. The frictional moment of SKF rolling bearings can be calculated († Friction, page 97). In general, ball bearings have a lower fric­ tional moment than roller bearings. If very low friction is an essential requirement, SKF Energy Efficient (E2) bearings should be con­ sidered. The frictional moment in SKF E2 bearings is at least 30% lower than a similarsized SKF standard bearing. SKF E2 bearings are available for several bearing types:

The stiffness of a rolling bearing is character­ ized by the magnitude of the elastic deforma­ tion (resilience) in the bearing under load. Generally, this deformation is very small and can be neglected. However, in applications like machine tool spindles and transmission differ­ entials, stiffness is a key operational parameter. Because of the contact conditions between the rolling elements and raceways, roller bearings, e.g. cylindrical or tapered roller bearings († fig. 32), have a higher degree of stiffness than ball bearings. Bearing stiffness can be further enhanced by applying a preload († Bearing preload, page 214).

• single row deep groove ball bearings • Y-bearings (insert bearings) • double row angular contact ball bearings • single row tapered roller bearings • spherical roller bearings • cylindrical roller bearings

Quiet running In certain applications, e.g. small electric motors for household appliances or office machinery, the noise level in operation is an important factor and can influence the choice of bearing type. SKF manufactures a deep groove ball bearing variant specifically for these types of applications.

54

Fig. 32

Basic selection criteria

Axial displacement Shafts, or other rotating machine com­pon­ ents, are generally supported by a locating and a non-locating bearing († Bearing systems, page 160). The bearing in the locating position must be able to locate the shaft axially in both direc­ tions. The most suitable bearings for the locating position are those bearings that can accommodate combined loads, or can provide axial guidance in combination with a second bearing. Non-locating bearings must accommodate axial movement of the shaft, to avoid induced axial loads when, for example, thermal elong­a­ tion of the shaft occurs. Bearings suitable for the non-locating position include needle roller bearings and NU and N design cylindrical roller bearings († fig. 33). NJ design cylindrical roller bearings and some full complement design cylindrical roller bearings can also be used. In applications where the required axial dis­ placement is relatively large and misalignment may also occur, a CARB toroidal roller bearing is an excellent choice as the non-locating bearing († fig. 34). All of these bearings accommodate axial displacement between the shaft and the hous­ ing, within the bearing. Values for the permis­ sible axial displacement within the bearing are listed in the relevant product tables. If non-separable bearings, e.g. deep groove ball bearings or spherical roller bearings († fig. 35) are used as non-locating bearings, one of the bearing rings must have a loose fit († Radial location of bearings, page 165).

Fig. 33

A

Fig. 34

Fig. 35

55

Bearing basics

Mounting and dismounting Cylindrical bore Bearings with a cylindrical bore are easier to mount and dismount if they are separable, particularly if interference fits are required for both rings. Separable bearings are also pref­ erable if frequent mounting and dismounting are required, because the ring with the rolling element and cage assembly of these separable bearings can be fitted independently of the other ring, e.g. four-point contact ball bear­ ings, cylindrical, needle and tapered roller bearings († fig. 36), as well as ball and roller thrust bearings. Tapered bore Bearings with a tapered bore († fig. 37) can be mounted easily on a tapered shaft seat or on a cylindrical shaft seat using an adapter or withdrawal sleeve († fig. 38).

Fig. 36

56

Basic selection criteria Fig. 37

Fig. 38

A

57

Bearing basics

Sealing solutions

Fig. 39

To keep lubricant in and contaminants out of the bearing, SKF supplies bearings capped with integral seals or shields: • shields († fig. 39) • non-contact seals († fig. 40) • low-friction seals († fig. 41) • contact seals († fig. 42) These bearings can provide cost-effective and space-saving solutions for many applications. Capped bearings are available for different bearing types: • deep groove ball bearings • angular contact ball bearings • self-aligning ball bearings • cylindrical roller bearings • needle roller bearings • spherical roller bearings • CARB toroidal roller bearings • track runner bearings • Y-bearings (insert bearings)

Fig. 40

Bearings capped on both sides are typically lubricated for the life of the bearing and should not be washed or relubricated. They are filled with the appropriate amount of high-quality grease under clean conditions.

Fig. 41

58

Basic selection criteria Fig. 42

A

59

Selecting bearing size B A systems approach to bearing selection. . . . . . . . . . . . . . . . . . . . . . . . . . Bearing system life. . . . . . . . . . . . . . . . . .

62 62

Bearing life and load ratings. . . . . . . . . Bearing life definition. . . . . . . . . . . . . . . . Load ratings. . . . . . . . . . . . . . . . . . . . . . . Dynamic load ratings . . . . . . . . . . . . . . . . Static load ratings. . . . . . . . . . . . . . . . . . .

63 63 63 63 64



Selecting bearing size using the life equations. . . . . . . . . . . . . . . . . . . . . . . . . Basic rating life. . . . . . . . . . . . . . . . . . . . . SKF rating life. . . . . . . . . . . . . . . . . . . . . . SKF life modification factor a SKF . . . . . . . Lubrication conditions – the viscosity ratio k . . . . . . . . . . . . . . . . . . . . . . . . . . . . Considering EP additives. . . . . . . . . . . . . Factor hc for contamination level. . . . . . . Calculating life with variable operating conditions. . . . . . . . . . . . . . . . . . . . . . . . . Influence of the operating temperature . Requisite rating life . . . . . . . . . . . . . . . . . Dynamic bearing loads. . . . . . . . . . . . . . Calculating dynamic bearing loads . . . . . Equivalent dynamic bearing load. . . . . . . Requisite minimum load. . . . . . . . . . . . . .



Selecting bearing size using static load carrying capacity . . . . . . . . . . . . . . . . . . Equivalent static bearing load. . . . . . . . . Required basic static load rating. . . . . . . Checking the static load carrying capacity. . . . . . . . . . . . . . . . . . . . . . . . . . . Calculation examples. . . . . . . . . . . . . . .

64 64 64 65

SKF calculation tools. . . . . . . . . . . . . . . Calculation tools available online at skf.com/bearingcalculator. . . . . . . . . . . . SKF bearing beacon. . . . . . . . . . . . . . . . . Orpheus . . . . . . . . . . . . . . . . . . . . . . . . . . Beast. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other programs . . . . . . . . . . . . . . . . . . . .



92



92 93 93 93 93

SKF Engineering Consultancy Services. . . . . . . . . . . . . . . . . . . . . . . . . . Advanced computer programs. . . . . . . . .

94 94

SKF life testing. . . . . . . . . . . . . . . . . . . .

95

71 73 74 81 82 82 84 84 85 86 87 88 88 89 90

61

Selecting bearing size

A systems approach to bearing selection In the SKF life rating equation, the stresses resulting from external loads are considered together with the tribological stresses in the rolling contact area. Understanding the influ­ ence of these combined stress systems on bearing life enables a more accurate predic­ tion of how a bearing will perform in its application. Due to its complexity, a detailed description of the theory is beyond the scope of this cata­ logue. Therefore, a simplified approach is pres­ ented under SKF rating life († page 64). This enables users to fully exploit bearing life potential, to undertake controlled downsizing, and to recognize the influence of lubrication and contamination on bearing service life.

ant to remember that the complete bearing can be viewed as a system in which the life of each component, i.e. rolling elements, race­ ways, cage, lubricant and seals, when present, contributes equally and in some cases dictates the effective endurance of the bearing († fig. 1). In the different sections of this catalogue, references are made to relevant aspects of the strength and suitability of other components of the bearing viewed as a system that need to be checked to ensure the best performance.

Bearing system life Metal fatigue of the rolling contact surfaces is generally the dominant failure mode for most rolling bearings. Metal fatigue can be the result of a variety of factors including but not limited to excessive frictional heat, poor or contaminated lubrication conditions, and heavy external and/or indeterminate loads. Therefore, a criterion based on raceway fatigue is generally sufficient for the selection and sizing of a rolling bearing for a given appli­ cation. International standards such as ISO 281 are based on metal fatigue of the roll­ ing contact surfaces. Nevertheless, it is import­ Fig. 1 Bearing system life

L bearing = f (L raceways, L rolling elements, L cage, L lubricant , L seals)

62

Bearing life and load ratings

Bearing life and load ratings Bearing life definition Under controlled laboratory conditions, seem­ ingly identical bearings operating under iden­ tical conditions have different individual endurance lives. A clearer definition of the term “bearing life” is therefore essential to calculate bearing size. All information pres­ ented by SKF with regard to load ratings is based on the life that 90% of a sufficiently large group of apparently identical bearings can be expected to attain or exceed. The life of a rolling bearing is expressed as the number of revolutions or the number of operating hours at a given speed that the bearing is capable of enduring before the first sign of metal fatigue (spalling) occurs on a raceway of the inner or outer ring or a rolling element. Table 2 († page 70) provides commonly used conversion factors for bearing life in units other than million revolutions. The rated life based on the above definition has to satisfy the requisite life expectations of the bearing application. In the absence of pre­ vious experience, guidelines regarding specifi­ cation life of different bearing applications are provided in tables 9 and 10 († page 83). Due to the statistical nature of bearing life, it must be pointed out that the observed time to failure of an individual bearing installed in an application can be related to its rated life only if the failure probability, of that particular bearing, can be determined in relation to the general population of bearings running under similar conditions. For instance, if a bearing failure is observed in a bearing fan application counting a total of two hundred installed bear­ ings working under similar conditions, this represent a failure probability of just 0,5%, (an observed life L0,5), thus a reliability for the installed application of 99,5%. Several investigations performed through­ out the years regarding the failures of bear­ ings used in a variety of applications have shown that in a very large population (several million bearings), the observed failures are a relatively rare event and not directly related to typical raceway spalling. This shows that the design guidelines based on 90% reliability and the use of static and dynamic safety factors can lead to robust bearing solutions in which

typical fatigue failures are in general avoided. Indeed, observed field failures are mostly related to abrasive wear, moisture, corrosion, improper installation, improper shaft/housing fits, skidding of rolling elements, unforeseen contamination or related to failure of the cage, of the sealing or of the lubrication system.

Load ratings

B

A bearing is typically selected on the basis of its load rating relative to the applied loads and the requirements regarding bearing life and reliability. Values for the basic dynamic load rating C and the basic static load rating C0 are listed in the product tables. Both dynamic and static bearing load condi­ tions should be independently verified and should include any heavy, short duration shock loads that may occur on rare occasions.

Dynamic load ratings The basic dynamic load rating C is used for life calculations involving dynamically stressed bearings, i.e. bearings that rotate under load. It expresses the bearing load that will result in an ISO 281 basic rating life of 1 000 000 revo­ lutions. It is assumed that the load is constant in magnitude and direction and is radial for radial bearings and axial, centrically acting, for thrust bearings. The basic dynamic load ratings for SKF bearings are determined in accordance with the procedures outlined in ISO 281. The load ratings provided in this catalogue apply to chromium steel bearings, heat-treated to a minimum hardness of 58 HRC, and operating under normal conditions. An exception to this are polymer bearings († page 1247). SKF Explorer performance class bearings have undergone, among other things, material and manufacturing improvements that require adjusted factors to calculate the dynamic load ratings in accordance with ISO 281.

63

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Selecting bearing size

Static load ratings The basic static load rating as defined in ISO 76 corresponds to a calculated contact stress at the centre of the most heavily loaded rolling element / raceway contact. The contact stress values are: • 4 600 MPa for self-aligning ball bearings • 4 200 MPa for all other ball bearings • 4 000 MPa for all roller bearings This stress produces a total permanent defor­ mation of the rolling element and raceway, which is approximately 0,0001 of the rolling element diameter. The loads are purely radial for radial bearings and centrically acting axial loads for thrust bearings. The basic static load rating C0 is used under the following conditions: • very slow rotational speeds (n < 10 r/min) • very slow oscillating movements • stationary bearings under load for extended periods Verification of static bearing loads is per­ formed by checking the static safety factor of the application, which is defined as C s0 = —0 P0 where s0 = static safety factor C0 = basic static load rating [kN] P 0 = equivalent static bearing load [kN] The maximum load that can occur on a bearing should be used when calculating the equivalent static bearing load. For additional information about the recommended values for the safety factor and its calculation, refer to Selecting bearing size using static load carrying capacity († page 87).

64

Selecting bearing size using the life equations Basic rating life The basic rating life of a bearing in accordance with ISO 281 is q C w p L 10 = — < P z If the speed is constant, it is often preferable to calculate the life expressed in operating hours using 106 L 10h = —— L 10 60 n where L 10 = basic rating life (at 90% reliability) [million revolutions] L 10h = basic rating life (at 90% reliability) [operating hours] C = basic dynamic load rating [kN] P = equivalent dynamic bearing load [kN] († page 85) n = rotational speed [r/min] p = exponent of the life equation –– for ball bearings, p = 3 –– for roller bearings, p = 10/3

SKF rating life For modern high quality bearings, the basic rating life can deviate significantly from the actual service life in a given application. Ser­ vice life in a particular application depends on a variety of influencing factors including lubri­ cation, the degree of contamination, proper installation and other environmental conditions. Therefore, ISO 281 uses a modified life ­factor to supplement the basic rating life. The SKF life modification factor a SKF applies the same concept of a fatigue load limit Pu as used in ISO 281. Values of Pu are listed in the product tables. Like ISO 281, the SKF life modification factor a SKF takes the lubrication conditions (viscosity ratio k, † page 71) and a factor hc († page 74) for the contamination level into

Selecting bearing size using the life equations consideration to reflect the operating condi­ tions using q C w p L nm = a1 a SKF L 10 = a1 a SKF — < P z If the speed is constant, the life can be expressed in operating hours using 106 L nmh = —–– L nm 60 n where L nm = SKF rating life (at 100 – n1) % reliability) [million revolutions] Lnmh = SKF rating life (at 100 – n1) % reliability) [operating hours] L 10 = basic rating life (at 90% reliability) [million revolutions] a1 = life adjustment factor for reliability († table 1, values in accordance with ISO 281) a SKF = SKF life modification factor († diagrams 1 to 4) C = basic dynamic load rating [kN] P = equivalent dynamic bearing load [kN] n = rotational speed [r/min] p = exponent of the life equation –– for ball bearings, p = 3 –– for roller bearings, p = 10/3

SKF life modification factor a SKF This factor represents the relationship between the fatigue load limit ratio (Pu /P), the lubrication condition (viscosity ratio k) and the contamination level in the bearing (hc). Values for the factor a SKF can be obtained from four diagrams, depending on the bearing type, as a function of hc (Pu /P) for SKF standard and SKF Explorer bearings and for different values of the viscosity ratio k. The diagrams are ­referenced in the following. • for radial ball bearings († diagram 1, page 66) • for radial roller bearings († diagram 2, page 67) • for thrust ball bearings († diagram 3, page 68) • for thrust roller bearings († diagram 4, page 69) The diagrams are drawn for values and safety factors typically associated with fatigue load limits for other mechanical components. Con­ sidering the simplifications inherent in the SKF rating life equation, even if the operating con­ ditions are accurately identified, it is not meaningful to use values of aSKF in excess of 50.

Table 1 Values for life adjustment factor a 1 Reliability Failure probability n

SKF rating life

Factor

L nm

a1

%

%

million revolutions



90 95 96

10 5 4

L 10m L 5m L4m

1 0,64 0,55

97 98 99

3 2 1

L 3m L 2m L 1m

0,47 0,37 0,25

1) The factor n represents the failure probability, which is the

difference between the requisite reliability and 100%.

65

B

Selecting bearing size Diagram 1 Factor a SKF for radial ball bearings

aSKF 50,0

20,0

0,5

0,6

1 0,8

5,0

2

k=

4

10,0

0,4

2,0

0,

3

1,0

0,5

0,2 0,2

0,15 0,1

0,1

0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

Other SKF standard 5,0 bearings

2,0

P hc ––u P 0,005

0,01

0,02

0,05

0,1

0,2

If k > 4, use curve for k = 4. As the value of hc (P u /P) tends to zero, a SKF tends to 0,1 for all values of k.

66

0,5

1,0

2,0

P hc ––u P

SKF Explorer bearings

Selecting bearing size using the life equations Diagram 2 Factor a SKF for radial roller bearings

aSKF 50,0

B

20,0

10,0

2

k=

4

5,0

0,6

0,8

1

2,0

0,

5

1,0

4

0,

0,5

0,3

0,2

0,2

0,15 0,1

0,1

0,05 0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

Other SKF standard 5,0 bearings

2,0 Pu ––– P

hc 0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

2,0

SKF Explorer bearings

Pu hc ––– P

If k > 4, use curve for k = 4. As the value of hc (P u /P) tends to zero, a SKF tends to 0,1 for all values of k.

67

Selecting bearing size Diagram 3 Factor a SKF for thrust ball bearings

aSKF 50,0

20,0

10,0

1

k=

2

4

5,0

0,

5

0,6

0,8

2,0

1,0

4

0,

3

0,5

0,

0,2

0,2

0,15

0,1

0,1

0,05 0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

2,0

5,0 u hc P –– P

If k > 4, use curve for k = 4. As the value of hc (P u /P) tends to zero, a SKF tends to 0,1 for all values of k.

68

SKF standard bearings

Selecting bearing size using the life equations Diagram 4 Factor a SKF for thrust roller bearings

aSKF 50,0

B

20,0

10,0

5,0

k=

4

2,0

1 0, 8

2

1,0

6

0,

0,5

5

0,

0,4

0,3 0,2

0,2 0,15 0,1

0,05 0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

0,1

Other SKF standard 5,0 bearings

2,0

P hc ––u P 0,005

0,01

0,02

0,05

0,1

0,2

0,5

1,0

2,0

SKF Explorer bearings

P hc ––u P

If k > 4, use curve for k = 4. As the value of hc (P u /P) tends to zero, a SKF tends to 0,1 for all values of k.

69

Selecting bearing size Calculating the life modification factor a SKF

SKF engineering programs like SKF Bearing Select, available online at skf.com/bearingselect can be used to calculate the factor a SKF. Fur­ thermore, SKF has also developed sophisti­ cated computer programs incorp­orating the SKF rating life equation directly at the rolling contact stress level, permitting other factors influencing bearing life, such as misalignment, shaft deflection and housing deformation, to be taken into account († SKF calculation tools, page 92).

Table 2 Units conversion factors for bearing life

g 3

1

0 2

The complete oscillation = 4 g (= from point 0 to point 4)

4 Basic units

Conversion factor Million revolutions

1 million revolutions

Operating hours

Million kilometres travelled

Million oscillation cycles1)

1

10 6 —— 60 n

p D —– 10 3

80 1 —— 2 g

1 operating hour

6 0 n —— 10 6

1

0n p D 6 ———— 10 9

180 ¥ 60 n ————— 2 g 10 6

1 million kilometres

10 3 —– p D

10 9 ———– 60 n p D

1

180 ¥ 10 3 ————– 2gpD

1 million oscillation cycles 1)

2 g —— 180

2 g 10 6 ———––– 180 ¥ 60 n

2g p D ————– 180 ¥ 10 3

1

D = vehicle wheel diameter [m] n = rotational speed [r/min] g = oscillation amplitude (angle of max. deviation from centre position) [°] 1) Not valid for small amplitudes (g < 10°).

70

Selecting bearing size using the life equations

Lubrication conditions – the viscosity ratio k The effectiveness of a lubricant is primarily determined by the degree of surface separ­ ation between the rolling contact surfaces. If an adequate lubricant film is to be formed, the lubricant must have a given minimum viscosity when the application has reached its operating temperature. The condition of the lubricant is described by the viscosity ratio k as the ratio of the actual viscosity n to the rated viscosity n1 for adequate lubrication, when the lubricant is at normal operating temperature († Selecting lubricating oils, page 266). It follows from using

B

n k=— n1 where k = viscosity ratio n = actual operating viscosity of the lubricant [mm2 /s] n1 = rated viscosity of the lubricant depending on the bearing mean diameter and rotational speed [mm2 /s] The rated viscosity n1, required for adequate lubrication († Viscosity ratio k, page 241), can be determined from diagram 5 († page 72), using the bearing mean ­diameter dm = 0,5 (d + D) [mm] and the rota­ tional speed of the bearing n [r/min]. This ­diagram takes the latest findings of tribology in rolling bearings into account. When the operating temperature is known from experience or can otherwise be deter­ mined, the corresponding viscosity at the internationally standardized reference tem­ perature of 40 °C (105 °F) can be obtained from diagram 6 († page 73), or can be ­c alculated. The diagram is compiled for a ­viscosity index of 95. Table 3 lists the viscosity grades in accordance with ISO 3448 showing the viscosity range for each grade at 40 °C (105 °F). Certain bearing types like spherical roller bearings, tapered roller bearings and spherical roller thrust bearings, normally have a higher operating temperature than other bearing types, such as deep groove ball bear­ ings and cylindrical roller bearings, under comparable operating conditions.

Table 3 Viscosity classification in accordance with ISO 3448 Viscosity grade

Kinematic viscosity limits at 40 °C (105 °F) mean min. max.



mm2 /s

ISO VG 2 ISO VG 3 ISO VG 5

2,2 3,2 4,6

1,98 2,88 4,14

2,42 3,52 5,06

ISO VG 7 ISO VG 10 ISO VG 15

6,8 10 15

6,12 9,00 13,5

7,48 11,0 16,5

ISO VG 22 ISO VG 32 ISO VG 46

22 32 46

19,8 28,8 41,4

24,2 35,2 50,6

ISO VG 68 ISO VG 100 ISO VG 150

68 100 150

61,2 90,0 135

74,8 110 165

ISO VG 220 ISO VG 320 ISO VG 460

220 320 460

198 288 414

242 352 506

ISO VG 680 ISO VG 1 000 ISO VG 1 500

680 1 000 1 500

612 900 1 350

748 1 100 1 650

71

Selecting bearing size Calculation example

viscosity class, with an actual viscosity n of at least 32 mm2 /s at the reference temperature of 40 °C (105 °F), is required.

A bearing with a bore diameter d = 340 mm and an outside diameter D = 420 mm is required to operate at a speed n = 500 r/min. Since dm = 0,5 (d + D) = 380 mm, from diagram 5, the minimum rated viscosity n1 required to provide adequate lubrication at the operating temperature is approximately 11 mm2 /s. From diagram 6, assuming that the operating temperature of the bearing is 70 °C (160 °F), a lubricant in the ISO VG 32

Diagram 5 Estimation of the minimum kinematic viscosity n1 at operating temperature Required viscosity n1 at operating temperature [mm2 /s]

1 000

2

5

500 10

20

200

50

100

n[

r/m

10

0

in]

20

0

50

50

0

10 1 5 00 2 0 00 3 0 00 0 50 0 00

20

10

10 20

50 00 5 10 0 00 0 0 10

00

0

00

20

0

50

100

200

500

1 000

2 000

dm = 0,5 (d + D) [mm]

72

Selecting bearing size using the life equations

Considering EP additives

For the remaining range, the life modifica­ tion factor a SKF can be determined using the actual k of the application. In case of severe contamination, i.e. contamination factor hc < 0,2, the possible benefit of an EP additive should be proven by testing. Refer to the infor­ mation about EP additives under Lubrication († page 239).

EP additives in the lubricant can extend bear­ ing service life when, in accordance with ISO 281, k < 1 and the factor for the contami­ nation level hc ≥ 0,2. Under these conditions, a value of k = 1 can be applied in the calcula­ tion of a SKF, if a proven lubricant with effective EP additives is used. In this case, the life modi­ fication factor has to be limited to a SKF ≤ 3, but should never be lower than a SKF for normal lubricants.

Diagram 6 Conversion to kinematic viscosity n at reference temperature (ISO VG classification) Required viscosity n1 at operating temperature [mm2 /s]

1 000

500

200

IS

O

1 100

0

46

0

1

50

0

0

32

0

22

0

15

50

68

VG

00

10

0

0

46

68

32

20

22 10

15

10

5 20 (70)

30 (85)

40 (105)

50 (120)

60 (140)

70 (160)

80 (175)

90 (195)

100 (210)

110 (230)

120 (250)

Operating temperature [°C (°F)]

73

B

Selecting bearing size

Factor hc for contamination level

ISO contamination classification and filter rating

This factor was introduced to consider the contamination level of the lubricant in the bearing life calculation. The influence of con­ tamination on bearing fatigue depends on a number of parameters including bearing size, relative lubricant film thickness, size and dis­ tribution of solid contaminant particles and types of contaminants (soft, hard etc.). The influence of these parameters on bearing life is complex and many of the parameters are difficult to quantify. It is therefore not possible to allocate precise values to hc that would have general validity. However, some guideline ­values in accordance with ISO 281 are listed in table 4.

The standard method for classifying the con­ tamination level in a lubrication system is described in ISO 4406. In this classification system, the result of the solid particle count is converted into a code using a scale number († table 5 and diagram 7, pages 75 and 78). One method to check the contamination ­level of bearing oil is the microscope counting method. This method uses two particle size ranges: ≥ 5 mm and ≥ 15 mm. Another more modern method is to use an optical automatic particle counter in accordance with ISO 11171. The calibration scale of the automatic counting method differs from that of the microscopic counting method. It uses three particle size ranges indicated by the symbol (c) e.g. ≥ 4 mm(c), Table 4

Guideline values for factor hc for different levels of contamination Conditions

Factor hc 1) for bearings with mean diameter dm < 100 mm dm ≥ 100 mm

Extreme cleanliness • particle size approximately the same as the lubricant film thickness • l aboratory conditions

1

1

High cleanliness • oil filtered through an extremely fine filter • typical conditions: sealed bearings that are greased for life

0,8 … 0,6

0,9 … 0,8

Normal cleanliness • oil filtered through a fine filter • typical conditions: shielded bearings that are greased for life

0,6 … 0,5

0,8 … 0,6

Slight contamination • typical conditions: bearings without integral seals, coarse filtering, wear particles and slight ingress of contaminants

0,5 … 0,3

0,6 … 0,4

Typical contamination • conditions typical of bearings without integral seals, coarse filtering, wear particles and ingress from surroundings

0,3 … 0,1

0,4 … 0,2

Severe contamination • typical conditions: high levels of contamination due to excessive wear and/or ineffective seals • bearing arrangement with ineffective or damaged seals

0,1 … 0

0,1 … 0

contamination • typical conditions: contamination levels so severe that values of hc are outside the scale, which significantly reduces the bearing life

0

0

1) The scale for h

c refers only to typical solid contaminants. Contaminants like water or other fluids detrimental to bearing life is not included. Due to strong abrasive wear in highly contaminated environments (hc = 0) the useful life of a bearing can be signifi­ cantly shorter than the rated life.

74

Selecting bearing size using the life equations ≥ 6 mm(c) and ≥ 14 mm(c). Typically, only the two larger particle size ranges are used, as the larger particles have a more significant impact on bearing fatigue. Typical examples of contamination level classifications for lubricating oils are –/15/12 (A) or 22/18/13 (B), as shown in diagram 7 († page 78). Example A indicates that the oil contains between 160 and 320 particles ≥ 5 mm and between 20 and 40 particles ≥ 15 mm per ­millilitre of oil. Though it would be optimal if lubricating oils were continuously filtered, the viability of a filtration system would depend on the equipment costs versus maintenance and downtime costs. Table 5 ISO classification – allocation of scale number Number of particles per millilitre oil over incl.

Scale number

2 500 000 1 300 000 640 000 320 000 160 000

2 500 000 1 300 000 640 000 320 000

> 28 28 27 26 25

80 000 40 000 20 000 10 000 5 000

160 000 80 000 40 000 20 000 10 000

24 23 22 21 20

2 500 1 300 640 320 160

5 000 2 500 1 300 640 320

19 18 17 16 15

80 40 20 10 5

160 80 40 20 10

14 13 12 11 10

2,5 1,3 0,64 0,32 0,16

5 2,5 1,3 0,64 0,32

9 8 7 6 5

0,08 0,04 0,02 0,01 0,00

0,16 0,08 0,04 0,02 0,01

4 3 2 1 0

A filter rating is an indication of filter effi­ ciency and is expressed as a reduction factor (b). The higher the b value, the more efficient the filter is for the specified particle size. The filter rating b is expressed as a ratio between the number of specified particles before and after filtering. This can be calculated using n b = —1 x(c) n2 where bx(c) = filter rating related to a specified particle size x x = particle size (c) [μm] based on the automatic particle counting method, calibrated in accordance with ISO 11171 n1 = number of particles per volume unit larger than x, upstream the filter n2 = number of particles per volume unit larger than x, downstream the filter Note: The filter rating b only relates to one ­particle size in μm, which is shown in the index such as b3(c), b6(c), b12(c), etc. For example, a complete rating “b6(c) = 75” means that only 1 in 75 particles, 6 μm or larger passes through the filter.

75

B

Selecting bearing size Determining hc when the contamination level is known

Once the oil contamination level is known, either from the microscope counting method or the automatic particle counting method, both in accordance with ISO 4406, or indir­ ectly as a result of the filtration ratio that is applied in an oil circulation system, this infor­ mation can be used to determine the factor hc . Note that the factor hc cannot be derived solely from a particle count. It depends largely on the lubrication conditions, such as k, and the size of the bearing. A simplified method in accord­ ance with ISO 281 is presented here to obtain the hc ­factor for a given application. From the oil ­contamination code (or filtration ratio of the application), the contamination factor hc is obtained, using the bearing mean diameter dm = 0,5 (d + D) [mm] and the viscosity ratio k for that bearing († diagrams 8 and 9, page 79).

Diagrams 8 and 9 provide typical values for the factor hc for circulating oil lubrication sys­ tems with different degrees of oil filtration and oil contamination codes. Similar contamin­ ation factors can be applied in applications where an oil bath shows virtually no increase in the contamination particles present in the system. On the other hand, if the number of particles in an oil bath continues to increase over time, due to excessive wear or the ingress of contaminants, this must be reflected in the choice of the factor hc used for the oil bath sys­ tem as indicated in ISO 281. For grease lubrication, hc can be determined in a similar way using ISO values for five levels of contamination as shown in table 6. Diagrams 10 and 11 († page 80), provide typical values for the factor hc for grease lubri­ cation for high and normal cleanliness († table 6).

Table 6 Factors to determine contamination levels for a grease lubricated application in accordance with ISO 281 Contamination level

Operating conditions

c1

c2

High cleanliness

• v ery clean assembly; very good sealing system relative to the operating conditions; relubrication is continuous or at short intervals • sealed bearings that are greased for life, with appropriate sealing capacity for the operating conditions

0,0864

0,6796

Normal cleanliness

• c lean assembly; good sealing system relative to the operating conditions; relubrication according to manufacturer’s specifications • shielded bearings that are greased for life with appropriate sealing capacity for the operating conditions

0,0432

1,141

Slight to typical contamination

• c lean assembly; moderate sealing capacity relative to the operating conditions; relubrication according to manufacturer’s specifications

0,0177

1,8871)

Severe contamination • a ssembly in workshop; bearing and application not adequately washed prior to mounting; ineffective seal relative to the operating conditions; relubrication intervals longer than recommended by manufacturer

0,0115

2,662

Very severe contamination

0,00617

4,06

1) When d

76

• a ssembly in contaminated environment; inadequate sealing system; too long relubrication intervals

m ≥ 500 mm, use 1,677

Selecting bearing size using the life equations For other degrees of contamination or in the most general case of circulating oil, oil bath and grease lubrication, the contamination fac­ tor for a bearing arrangement can be deter­ mined using the simplified equation t q c 2 w y hc = min (c 1 k 0,68 dm0,55, 1) 1 – ——— v < 3PJL dm z b

B

min (#1, #2) = use the smallest of the two values where c 1 and c 2 are constants characterizing the cleanliness of the oil in accordance with ISO 4406, or of the grease according to the classifications in table 6. Note that in case of oil filtration, the corresponding level of filtra­ tion efficiency (in accordance with ISO 4372) († table 7) can also be applied in place of the metrological characterization of the status of cleanliness of the oil.

Table 7 Factors to determine contamination levels for an oil lubricated application in accordance with ISO 281 Filtration ratio

ISO 4406

bx(c)

Basic code

Circulating oil lubrication with in-line filters c1 c2

Oil lubrication without filtration or with off-line filters c1 c2

b 6(c) = 200 b12(c) = 200 b 25(c) = 75 b 40(c) = 75 –

–/13/10 –/15/12 –/17/14 –/19/16 –/21/18

0,0864 0,0432 0,0288 0,0216 –

0,0864 0,0288 0,0133 0,00864 0,00411

0,5663 0,9987 1,6329 2,3362 –

0,5796 1,141 1,67 2,5164 3,8974

77

Selecting bearing size Diagram 7 ISO classification of contamination level and examples for particle counting

Number of particles per millilitre of oil larger than indicated size

>28 Scale number

2,5 10 6 1,3

28 27

6,4

26

3,2

25

10 5 1,6 8

24 23

4 10 4

22

2

21 20

5

B

2,5 10 3 1,3

19 18 17

6,4

16

3,2 10 2

15

1,6

14

8

A

4 10

13 12

2

11 10

5

9

2,5 1

8

1,3

7

6,4

6

3,2 10 –1

5

1,6

4

8

3

4 10 –2

A = microscope particle count (–/15/12) B = automatic particle count (22/18/13)

78

2

2

1 –

5

15

A

Particle size [µm]

4

6

14

B

Particle size (c) [µm]

Selecting bearing size using the life equations Diagram 8 Contamination factor hc for – circulating oil lubrication – solid contamination level –/15/12 in accordance with ISO 4406 – filter rating b12 = 200

hc 1,0

dm [mm]

0,9

2 000

B

1 000

0,8

500

0,7

200

0,6

100

0,5

50

0,4

25

0,3 0,2 0,1 0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5 2,7 2,9 3,1 3,3 3,5 3,7 3,9 4,1 k

Diagram 9 Contamination factor hc for – circulating oil lubrication – solid contamination level –/17/14 in accordance with ISO 4406 – filter rating b 25 = 75

hc 1,0

dm [mm]

0,9

2 000

0,8

1 000

0,7

500

0,6

200 100

0,5

50

0,4

25

0,3 0,2 0,1 0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5 2,7 2,9 3,1 3,3 3,5 3,7 3,9 4,1 k

79

Selecting bearing size Diagram 10 Contamination factor hc for grease lubrication, extreme cleanliness

hc 1,0

dm [mm]

0,9

2 000 1 000

0,8

500

0,7

200

0,6

100

0,5

50

0,4

25

0,3 0,2 0,1 0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5 2,7 2,9 3,1 3,3 3,5 3,7 3,9 4,1 k

Diagram 11 Contamination factor hc for grease lubrication, normal cleanliness

hc dm [mm]

1,0 0,9

2 000

0,8

1 000

0,7

500

0,6

200

0,5

100

0,4

50

0,3

25

0,2 0,1 0,1 0,3 0,5 0,7 0,9 1,1 1,3 1,5 1,7 1,9 2,1 2,3 2,5 2,7 2,9 3,1 3,3 3,5 3,7 3,9 4,1 k

80

Selecting bearing size using the life equations

Calculating life with variable operating conditions In some applications, like industrial gearboxes, the operating conditions, such as the magnitude and direction of loads, speeds, temperatures and lubrication conditions are continually changing. In these types of applications, ­bearing life cannot be calculated without first reducing the load spectrum or duty cycle of the application to a limited number of simpler load cases († diagram 12). In case of continuously changing load, each different load level can be accumulated and the load spectrum reduced to a histogram of constant load blocks. Each block should characterize a given percentage or time-fraction during operation. Note that heavy and normal loads consume bearing life at a faster rate than light loads. Therefore, it is important to have shock and peak loads well represented in the load diagram, even if the occurrence of these loads is relatively rare and limited to a few revolutions. Within each duty interval, the bearing load and operating conditions can be averaged to some constant value. The number of operat­ ing hours or revolutions expected from each duty interval showing the life fraction required by that particular load condition should also be included. Therefore, if N1 equals the number of revolutions required under the load condition P 1, and N is the expected number of revolutions for the completion of all variable loading cycles, then the cycle fraction U 1 = N1 /N is used by the load condition P 1, which has a calculated life of L 10m1. Under variable operating condi­ tions, bearing life can be rated using 1 L 10m = ———————————– U2 U3 U 1   +  … ——–  +  ——–  +  ——– L 10m1 L 10m2 L 10m3

where L 10m L 10m1, L 10m2, …

U 1, U2, ...

= SKF rating life (at 90% reliability) [million revolutions] = SKF rating lives (at 90% reliability) under constant conditions 1, 2, … [million revolutions] = life cycle fraction under the conditions 1, 2, … Note: U 1 + U2 + … Un = 1

The use of this calculation method depends very much on the availability of representative load diagrams for the application. Note that this type of load history can also be derived from a similar type of application.

Diagram 12

P P1

Duty interval

P2 P3 P4

V V3

V2

V4

V1 U1

U2

U3

U4

100%

81

B

Selecting bearing size

Influence of the operating temperature In operation, the dimensions of a bearing change as a result of structural transformations within the material. These transformations are influenced by temperature, time and stress. To avoid inadmissible dimensional changes as a result of structural transformation, bear­ ing components undergo a special heat treat­ ment († table 8). Depending on the bearing type, standard bearings made of steels for through-hardening or induction-hardening have a recommended maximum operating temperature between 120 and 200 °C (250 and 390 °F). These max­ imum operating temperatures are directly related to the heat treatment that was applied. For additional information, refer to the intro­ ductory text of the relevant product chapter. If the normal operating temperatures of the application are higher than the recommended temperature limit, a bearing with a higher ­stabilization class should be considered. For applications where bearings operate continu­ ously at elevated temperatures, the dynamic load carrying capacity of the bearing may need to be adjusted in the life calculations. For add­ itional information, contact the SKF application engineering service. The satisfactory operation of bearings at elevated temperatures also depends on whether the lubricant retains its lubricating properties and whether the materials used for the seals, cages etc. are suitable († Lubrication, page 239, and Materials for rolling bearings, page 150). Table 8 Dimensional stability Stabilization class

Stabilized up to



°C

°F

SN

120

250

S0

150

300

S1

200

390

S2

250

480

S3

300

570

S4

350

660

82

For bearings operating at high tempera­ tures requiring a higher stabilization class than S1, contact the SKF application engineer­ ing service.

Requisite rating life When determining bearing size, verify the cal­ culated SKF rating life with the specification life of the application, if it is available. This usually depends on the type of machine and the requirements regarding duration of ser­ vice and operational reliability. In the absence of previous experience, the guideline values listed in tables 9 and 10 can be used.

Table 9 Guideline values of specification life for different machine types Machine type

Specification life Operating hours

Household machines, agricultural machines, instruments, technical equipment for medical use

300 … 3 000

Machines used for short periods or intermittently: electric hand tools, lifting tackle in workshops, construction equipment and machines

3 000 … 8 000

Machines used for short periods or intermittently where high operational reliability is required: lifts (elevators), cranes for packaged goods or slings of drums etc.

8 000 … 12 000

Machines for use 8 hours a day, but not always fully utilized: gear drives for general purposes, electric motors for industrial use, rotary crushers

10 000 … 25 000

Machines for use 8 hours a day and fully utilized: machine tools, woodworking machines, machines for the engineering industry, cranes for bulk materials, ventilator fans, conveyor belts, printing equipment, separators and centrifuges

20 000 … 30 000

Machines for continuous 24 hour use: rolling mill gear units, medium-size electrical machinery, compressors, mine hoists, pumps, textile machinery

40 000 … 50 000

Wind energy machinery, this includes main shaft, yaw, pitching gearbox, generator bearings

30 000 … 100 000

Water works machinery, rotary furnaces, cable stranding machines, propulsion machinery for ocean-going vessels

60 000 … 100 000

Large electric machines, power generation plant, mine pumps, mine ventilator fans, tunnel shaft bearings for ocean-going vessels

> 100 000

B

Table 10 Guideline values of specification life for axlebox bearings and units for railway vehicles Type of vehicle

Specification life Million kilometres

Freight wagons to UIC specification based on continuously acting maximum axle load

0,8

Mass transit vehicles: suburban trains, underground carriages, light rail and tramway vehicles

1,5

Main line passenger coaches

3

Main line diesel and electric multiple units

3…4

Main line diesel and electric locomotives

3…5

83

Selecting bearing size

Dynamic bearing loads Calculating dynamic bearing loads The loads acting on a bearing can be calcu­ lated according to the laws of mechanics if the external forces, such as forces from power transmission, work forces or inertial forces, are known or can be calculated. When calcu­ lating the load components for a single bear­ ing, the shaft is considered as a beam resting on rigid, moment-free supports for the sake of simplification. Elastic deformations in the bearing, the housing or the machine frame are not considered, nor are the moments ­produced in the bearing as a result of shaft deflection. These simplifications are necessary if a bearing arrangement is to be calculated with­ out a computer program. The standardized methods for calculating basic load ratings and equivalent bearing loads are based on similar assumptions. It is possible to calculate bearing loads based on the theory of elasticity, without mak­ ing the above assumptions, but this requires the use of complex computer programs. In these programs, the bearings, shaft and hous­ ing are considered as resilient components of a system. If external forces and loads like inertial forces or loads resulting from the weight of a shaft and its components are not known, they can be calculated. However, when determining work forces and loads, e.g. rolling forces, moment loads, unbalanced loads and shock loads, it may be necessary to rely on estimates based on experience with similar machines or bearing arrangements. Geared transmissions

With geared transmissions, the theoretical tooth forces can be calculated from the power transmitted and the design characteristics of the gear teeth. However, there are additional dynamic forces, produced either by the gear, or by the input or output shaft. Additional dynamic forces from gears can be the result of form errors of the teeth and from unbalanced rotating components. Because of the require­ ments for quiet running, gears are made to such a high level of accuracy that these forces are generally negligible, and not considered when making bearing calculations. 84

Additional forces arising from the type and mode of operation of the machines coupled to the transmission can only be determined when the operating conditions are known. Their influence on the rating lives of the bearings is considered using an “operation” factor that takes shock loads and the efficiency of the gears into account. Values of this factor for different operating conditions can usually be found in information published by the gear manufacturer. Belt drives

When calculating bearing loads for belt driven applications, “belt pull” must be taken into consideration. Belt pull, which is a circumfer­ ential load, depends on the amount of torque being transmitted. The belt pull must be multi­ plied by a factor, which depends on the type of belt, belt tension and any additional dynamic forces. Belt manufacturers usually publish values. However, should information not be available, the following values can be used: • toothed belts = 1,1 to 1,3 • V-belts = 1,2 to 2,5 • plain belts = 1,5 to 4,5 The larger values apply when the distance between shafts is short, for heavy or shocktype duty, or where belt tension is high.

Dynamic bearing loads

Equivalent dynamic bearing load The above information can be used to calcu­ late the bearing load F. When the bearing load fulfills the requirements for the basic dynamic load rating C, i.e. the load is constant in mag­ nitude and direction and acts radially on a radial bearing or axially and centrically on a thrust bearing, then P = F and the load may be inserted directly into the life equations. In all other cases, the equivalent dynamic bearing load must be calculated first. The equivalent dynamic bearing load is defined as that hypothetical load, constant in magnitude and direction, acting radially on a radial bear­ ing or axially and centrically on a thrust bear­ ing which, if applied, would have the same influence on bearing life as the actual loads to which the bearing is subjected († fig. 2). Radial bearings are often subjected to simul­ taneously acting radial and axial loads. If the resultant load is constant in magnitude and direction, the equivalent dynamic bearing load P can be obtained from the general equation P = X Fr + Y Fa

radial bearing if the ratio Fa /Fr exceeds a cer­ tain limiting factor e. With double row bear­ ings, even light axial loads are generally significant. The same general equation also applies to spherical roller thrust bearings, which can accommodate both axial and radial loads. Other thrust bearings like thrust ball bearings and cylindrical and needle roller thrust bear­ ings, can accommodate pure axial loads only. For these bearings, provided the load acts centrically, the equation can be simplified to P = Fa Information and data required for calculating the equivalent dynamic bearing load is pro­ vided in the relevant product chapter. Fluctuating bearing load

In many cases, the magnitude of the load fluc­ tuates. The formula to calculate fluctuating loads can be found under Calculating life with variable operating conditions († page 81). Mean load within a duty interval

where P = equivalent dynamic bearing load [kN] Fr = actual radial bearing load [kN] Fa = actual axial bearing load [kN] X = radial load factor for the bearing Y = axial load factor for the bearing An additional axial load only influences the equivalent dynamic load P for a single row Fig. 2

Within each loading interval the operating conditions can vary slightly from the nominal value. Assuming that the operating conditions like speed and load direction are fairly constant and the magnitude of the load constantly ­varies between a minimum value Fmin and a maximum value Fmax († diagram 13, page 86), the mean load can be obtained from Fmin + 2 Fmax Fm = —————– 3

Fa Fr

P

85

B

Selecting bearing size Diagram 13

F Fm

Fmax Fmin

U

Diagram 14 Rotating load

F1

F2

Diagram 15 Rotating load

fm 1,00 0,95 0,90 0,85 0,80 0,75 0,70

86

0

0,2

0,4

Rotating load

If, as illustrated in diagram 14, the load on a bearing consists of a load F1, which is constant in magnitude and direction, such as the weight of a rotor, and a rotating constant load F2, such as an unbalance load, the mean load can be obtained from

Load averaging

0,6

0,8

1,0 F1 F1 + F2

Fm = f m (F1 + F2) Values for the factor f m are provided in diagram 15.

Requisite minimum load The correlation between load and service life is less important for applications where there are very light loads. Failure mechanisms other than fatigue often prevail. To provide satisfactory operation, ball and roller bearings must always be subjected to a given minimum load. A general “rule of thumb” indicates that minimum loads corresponding to 0,02 C should be imposed on roller bearings and minimum loads cor­res­pond­ing to 0,01 C on ball bearings. The importance of applying a minimum load increases in applications where there are rapid accelerations or rapid starts and stops, and where speeds exceed 50% of the limiting speeds listed in the product tables († Speeds, page 117). If minimum load requirements cannot be met, NoWear coated bearings should be considered († page 1241). Recommendations for calculating the requis­ ite minimum load for different bearing types are provided in the relevant product chapter.

Selecting bearing size using static load carrying capacity

Selecting bearing size using static load carrying capacity Bearing size should be selected on the basis of static load ratings C0 instead of on bearing life when one of the following conditions exist: • The bearing is stationary and is subjected to continuous or intermittent (shock) loads. • The bearing makes slow oscillating or align­ ment movements under load. • The bearing rotates under load at very slow speed (n < 10 r/min) and is only required to have a short life. In other words, the life equation in this case, for a given equivalent load P, would give such a low requisite basic dynamic load rating C, that the bearing selected on a life basis would be seriously overloaded in service. • The bearing rotates and, in addition to the normal operating loads, has to sustain heavy shock loads.

The extent to which these changes are det­ rimental to bearing performance depends on the demands placed on the bearing in a par­ ticular application. It is therefore necessary to make sure that permanent deformations do not occur, or only occur to a very limited extent by selecting a bearing with sufficiently high static load carrying capacity, if one of the fol­ lowing demands has to be satisfied:

B

• high reliability • quiet running, such as for electric motors • vibration-free operation, such as for machine tools • constant bearing frictional moment , such as for measuring apparatus and test equipment • low starting friction under load, such as for cranes

In all these cases, the permissible load for the bearing is the maximum load the bearing can accommodate without permanent deformation to the rolling elements or raceways. Perman­ ent deformation is typically caused by: • heavy loads acting on the bearing while it is stationary or oscillating slowly • heavy shock loads acting on the bearing while it is rotating Depending on the operating conditions and load, the resulting damage can be flattened areas on the rolling elements or indentations on the raceways. The indentations can be irregularly spaced around the raceway, or may be evenly spaced at positions corresponding to the spacing of the rolling elements. Permanent deformations usually lead to higher vibration and/or noise levels and increased friction. It is also possible that the internal clearance will increase or the character of the fits may be changed.

87

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Selecting bearing size

Equivalent static bearing load

Required basic static load rating

Static loads comprising radial and axial com­ ponents must be converted into an equivalent static bearing load. This is defined as that hypothetical load (radial for a radial bearing and axial for a thrust bearing) which, if applied, would cause the same maximum rolling elem­ ent load in the bearing as the actual loads to which the bearing is subjected. It is obtained from the general equation

When determining bearing size based on the static load carrying capacity, a given safety factor s0, which represents the relationship between the basic static load rating C0 and the equivalent static bearing load P 0, is used to calculate the requisite basic static load rating. The required basic static load rating C0 can be determined from

P 0 = X0 Fr + Y 0 Fa where P 0 = equivalent static bearing load [kN] Fr = actual radial bearing load (see below) [kN] Fa = actual axial bearing load (see below) [kN] X0 = radial load factor for the bearing Y 0 = axial load factor for the bearing Information and data required for calculating the equivalent static bearing load is provided in the relevant product chapter.

C0 = s0 P 0 where C0 = basic static load rating [kN] P 0 = equivalent static bearing load [kN] s0 = static safety factor Guideline values for the static safety factor s0 based on experience are listed in table 11. At elevated temperatures, the static load carry­ ing capacity is reduced. For additional infor­ mation, contact the SKF application engineer­ ing service.

When calculating P 0, the maximum load that can occur should be used and its radial and axial components († fig. 3) inserted in the equation above. If a static load acts in different directions on a bearing, the magnitude of these components changes. In these cases, the components of the load with the highest value of the equivalent static bearing load P 0 should be used.

Fig. 3

Fa Fr

P0

88

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Selecting bearing size using static load carrying capacity

Checking the static load carrying capacity For dynamically loaded bearings, where the equivalent static bearing load P 0 is known, it is advisable to check that the static load carrying capacity is adequate using

B

C s = —0 0 P0 If the s0 value obtained is less than the recom­ mended guideline value († table 11), a bear­ ing with a higher basic static load rating should be selected.

Table 11 Guideline values for the static safety factor s 0 Type of operation

Rotating bearing Performance requirements unimportant normal

high

Ball bearings

Ball bearings

Roller bearings

Non-rotating bearing

Ball Roller bearings bearings

Roller bearings

Ball bearings

Roller bearings

Smooth, vibration-free

0,5

1

1

1,5

2

3

0,4

0,8

Normal

0,5

1

1

1,5

2

3,5

0,5

1

Pronounced shock loads 1)

≥ 1,5

≥ 2,5

≥ 1,5

≥3

≥2

≥4

≥1

≥2

For spherical roller thrust bearings, it is advisable to use s 0 ≥ 4. 1) Where the magnitude of the shock load is not known, values of s

0 at least as large as those quoted above should be used. If the magnitude of the shock loads is known, smaller values of s 0 can be applied.

89

Selecting bearing size

Calculation examples Example 1: Basic rating life and SKF rating life

An SKF Explorer 6309 deep groove ball bearing is to operate at 3 000 r/min under a constant radial load Fr = 10 kN. Oil lubrication is to be used, the oil has an actual kinematic viscosity n = 20 mm2 /s at normal operating tempera­ ture. The desired reliability is 90% and it is assumed that the operating conditions are very clean. What are the basic and SKF rating lives? a) The basic rating life for 90% reliability is q C w 3 L 10 = — < P z From the product table for bearing 6309, C = 55,3 kN. Since the load is purely radial, P = Fr = 10 kN († Equivalent dynamic bearing load, page 85). q 55,3 w 3 L = –—– 10 < 10 z

= 169 million revolutions

or in operating hours, using 106 L 10h = —–– L 10 60 n 1 000 000 L 10h = ————– ¥ 169 60 ¥ 3 000

= 940 operating hours

b) The SKF rating life for 90% reliability is L 10m = a1 a SKF L 10 • As a reliability of 90% is required, the L 10m life is to be calculated and a1 = 1 († table 1, page 65). • From the product table for bearing 6309, dm = 0,5 (d + D) = 0,5 (45 + 100) = 72,5 mm

90

• From diagram 5 († page 72), the rated oil viscosity at operating temperature for a speed of 3 000 r/min, n1 = 8,15 mm2 /s. Therefore, k = n/n1 = 20/8,15 = 2,45 • From the product table Pu = 1,34 kN and Pu /P = 1,34/10 = 0,134. As the conditions are very clean, hc = 0,8 and hc (Pu /P) = 0,107. With k = 2,45 and using the SKF Explorer scale in diagram 1 († page 66), the value of a SKF = 8 is obtained. Then, according to the SKF rating life equation L 10m = 1 ¥ 8 ¥ 169

= 1 352 million revolutions

or in operating hours using 106 L 10mh = —–– L 10m 60 n 1 000 000 ———– ¥ 1 352 L 10mh = — 60 ¥ 3 000

= 7 512 operating hours

Example 2: Check contamination conditions

An existing application has to be reviewed. An SKF Explorer 6309-2RS1 deep groove ball bearing with integral seals and standard grease fill is working under the same condi­ tions as described in example 1 (k = 2,45). The con­t am­in­ation conditions of this application have to be checked to determine if it is possible to use a more cost-effective bearing for a ­min­imum requisite life of 3 000 hours of operation. • Considering grease lubrication and integral seals, the level of contamination can be characterized as high cleanliness and from table 4 († page 74), hc = 0,8. With Pu /P = 0,134, hc (Pu /P) = 0,107, using the SKF Explorer scale in diagram 1 († page 66) and k = 2,45, a SKF = 8. L 10mh = 8 ¥ 940 = 7 520 operating hours

Calculation examples • A more cost-effective bearing arrangement would use a shielded SKF Explorer 6309-2Z bearing. The contamination level can be characterized as normal cleanliness, then from table 4 († page 74) hc = 0,5. With Pu /P = 0,134, hc (Pu /P) = 0,067, using the SKF Explorer scale in diagram 1 († page 66) and k = 2,45, a SKF ≈ 3,5. L 10mh = 3,5 ¥ 940 = 3 290 operating hours Conclusion: This application would be able to take advantage of a more cost-effective solu­ tion by replacing the sealed bearing with a shielded bearing. Example 3: Verify dynamic and static load conditions

The duty cycle of a sealed SKF Explorer spher­ ical roller bearing 24026-2CS2/VT143 used in heavy transportation equipment of a steel plant has the operating conditions listed in the table below. The static load of this application is deter­ mined with reasonable accuracy by taking into account the inertial loads that occur during loading and the shock loads that can occur if something is accidently dropped. It is required to verify the dynamic and static load conditions of this application, assuming a required L 10mh operating life of 60 000 hours and a minimum static safety factor of 1,5.

• From the product table and introductory text: Load ratings: C = 540 kN; C0 = 815 kN; Pu = 81,5 kN Dimensions: d = 130 mm; D = 200 mm, thus, dm = 0,5 (130 + 200) = 165 mm

B

Grease fill Extreme pressure grease with a lithium thickener and mineral base oil, of NLGI con­ sistency class 2, for a temperature range of –20 to +110 °C (–5 to +230 °F) and a base oil viscosity at 40 and 100 °C (105 and 210 °F) of 200 and 16 mm2 /s, respectively. • The following calculations are made or ­values determined: 1 n1 = rated viscosity, mm2 /s († diagram 5, page 72) – input: dm and speed 2 n = actual operating viscosity, mm2 /s († diagram 6, page 73) – input: lubri­ cant viscosity at 40 °C (105 °F) and oper­ ating temperature 3 k = viscosity ratio – calculated (n/n1) 4 hc = factor for contamination level († table 4, page 74) – “High cleanliness”, sealed bearing: hc = 0,8 Example 3/1

Operating conditions Duty interval

Equivalent dynamic load P

Time fraction U

Speed

Temperature

Equivalent static load

n

T

P0



kN



r/min

°C

°F

kN

1

200

0,05

50

50

120

500

2

125

0,40

300

65

150

500

3

75

0,45

400

65

150

500

4

50

0,10

200

60

140

500

91

Selecting bearing size

SKF calculation tools

5 L 10h = basic rating life according to the equation († page 64) – input: C, P and n

SKF possesses one of the most comprehensive and powerful sets of modelling and simulation packages in the bearing industry. They range from easy-to-use tools based on SKF cata­ logue Rolling bearings formulae to the most sophisticated calculation and simulation sys­ tems, running on parallel computers. SKF has developed a range of programs to satisfy a number of customer requirements; from fairly simple design checks, through moderately complex investigations, to the most advanced simulations for bearing and machine design. Wherever possible, these programs are available for customers to use on their computers. Moreover, particular care is taken to provide integration and interoper­ ability of the different systems with each other.

6 a SKF = from diagram 2 († page 67) – input: SKF Explorer bearing, hc , Pu, P and k 7 L 10mh1,2, … = SKF rating life according to the equation († page 65) – input: a SKF and L 10h1,2, … 8 L 10mh = SKF rating life according to the equation († page 81) – input: L 10mh1, L 10mh2, … and U 1, U2, … The SKF rating life of 84 300 hours exceeds the required operating life, therefore, the dynamic load conditions of the bearing are verified. Finally, the static safety factor of this appli­ cation is verified using

Calculation tools available online at skf.com/bearingcalculator

C 815 s0 = —0– = —— = 1,63 P 0 500

Easy-to-use tools for bearing selection and calculation are available online at skf.com/bearingcalculator. Bearing searches are a­ vailable based on designation or dimen­ sions, and simple bearing arrangements can be ­evaluated as well. The equations used are consistent with those used in this catalogue. SKF’s interactive engineering tools make it possible to generate drawings of bearings and housings that can be used in most com­ mercially available CAD programs.

s0 = 1,63 > s0 req The above shows that the static safety of this application is verified. As the static load is determined accurately, the relatively small margin between the calculated and recom­ mended static safety is of no concern.

Example 3/2 Calculation values Duty Equivalent interval dynamic load P

Rated viscosity

Operating viscosity

n1

n



mm2 /s

mm2 /s

kN

k1)

hc

Basic rating life





h

a SKF

L 10h –

SKF rating life

Time fraction

Resulting SKF rating life

L 10mh

U

L 10mh

h



h

1

200

120

120

1

0,8

9 136

1,2

11 050

0,05

2

125

25

60

2,3

0,8

7 295

7,8

57 260

0,40

3

75

20

60

3

0,8

30 030

43

1 318 000

0,45

4

50

36

75

2

0,8

232 040

50

11 600 000

0,10

1) Grease with EP additives

92

r s s f s s c

84 300

SKF calculation tools

SKF bearing beacon

Other programs

SKF bearing beacon is the mainstream bearing application program used by SKF engineers to find the best solution for customers’ bearing systems. Working in a virtual environment, SKF engineers combine mechanical systems containing shafts, gears and housings with a precise bearing model for an in-depth analysis of the system’s behaviour. The program can also analyze rolling fatigue in a bearing using the SKF rating life method. SKF bearing beacon is the result of years of research and develop­ ment within SKF.

In addition to the above-mentioned programs, SKF has developed dedicated computer pro­ grams that enable SKF scientists to provide customers with bearings having an optimized bearing surface finish to extend bearing ser­ vice life under severe operating conditions. These programs can calculate the lubricant film thickness in elasto-hydrodynamically lubricated contacts. In addition, the local film thickness resulting from the deformation of the three dimensional surface topography inside such contacts is calculated in detail and the consequent reduction of bearing fatigue life. SKF engineers also use commercial pack­ ages to perform, for example, finite element or generic system dynamics analyses. These tools are integrated with the SKF proprietary systems enabling a faster and more robust connection with customer data and models.

Orpheus The numerical tool Orpheus is used to study and optimize the dynamic behaviour of noise and vibration-critical bearing applications, such as electric motors, gearboxes. The pro­ gram is also used to solve complete non-linear equations of motion for a bearing arrangement and the surrounding components, such as gears, shafts and housings. Orpheus can provide a profound under­ standing of the dynamic behaviour of an appli­ cation, including the bearings, accounting for form deviations (waviness) and misalignment. This enables SKF en­gin­eers to determine the most suitable bearing type and size as well as the corresponding mounting and preload con­ ditions for a given application.

Beast Beast is a simulation program that enables SKF engineers to simulate the detailed dynamics inside a bearing. It can be seen as a virtual test rig performing detailed studies of forces, moments etc. inside a bearing under virtually any load condition. This enables the “testing” of new concepts and designs in a shorter time and with more information gained compared with traditional physical testing.

93

B

Selecting bearing size

SKF Engineering Consultancy Services The basic information required to calculate and design a bearing arrangement can be found in this catalogue. But there are applica­ tions where it is desirable to predict the expected bearing life as accurately as possible, either because sufficient experience with similar bearing arrangements is lacking, or because economy and/or operational reliability are of extreme importance. In these cases, for example, it is advisable to consult SKF Engin­ eering Consultancy Services. They provide calculations and simulations utilizing hightech computer programs, in combination with one hundred years of accumulated experience in the field of rotating machine components. They can provide support with the complete SKF application know-how. The SKF applica­ tion engineering specialists can support with the following services: • analyse technical problems • suggest appropriate system solutions • select the appropriate lubricant and lubrica­ tion method and an optimized maintenance programme SKF Engineering Consultancy Services pro­ vides a new approach to services concerning machines and installations for OEMs and endusers. Some of these service benefits are: • faster development processes and reduced time to market • reduced implementation costs by virtual testing before production starts • improved bearing arrangement by reducing noise and vibration levels • higher power density by upgrading • extended service life by improving the lubri­ cation or sealing system

94

Advanced computer programs Within the SKF Engineering Consultancy Services, there are highly advanced computer programs which can be used for the following: • analytical modelling of complete bearing arrangements, consisting of shaft, housing, gears, couplings, etc. • static analysis to determine the elastic deformations and stresses in components of mechanical systems • dynamic analysis to determine the vibration behaviour of systems under working condi­ tions (“virtual testing”) • visual and animated presentation of struc­ tural and component deflection • optimizing system costs, service life, vibra­ tion and noise levels The standard computer programs used within the SKF Engineering Consultancy Services for calculations and simulations are described briefly under SKF calculation tools († page 92). For additional information about the SKF Engineering Consultancy Services, contact your local SKF representative.

SKF life testing

SKF life testing SKF endurance testing activities are concen­ trated at the SKF Engineering Research Cen­ tre in the Netherlands. The test facilities are unique in the bearing industry with regard to sophistication and the number of test rigs and are ISO 17025 accredited. The centre also supports work carried out at the research facilities of the major SKF manufacturing facilities. SKF undertakes life testing, mainly to be able to continuously improve the design, the materials and the manufacturing processes of bearing products. Furthermore it is also essential to develop and continuously improve the engineering models required for the design of bearing applications. Typical endurance testing activities include tests on bearing population samples under:

B

• full-film lubrication conditions • reduced lubricant film conditions • predefined contamination conditions of the lubricant SKF also undertakes life tests to: • verify the performance commitments made in product catalogues • audit the quality of the SKF standard bear­ ing production • research the influences of lubricants and lubricating conditions on bearing life • support the development of theories for rolling contact fatigue • compare with competitive products The powerful and firmly controlled life tests combined with post-test investigations with state-of-the-art equipment make it possible to investigate the factors that affect the life of the bearings in a systematic way. High performance SKF Explorer and SKF Energy Efficient (E2) bearings are examples of the implementation of the optimized influencing factors on the basis of analytical simulation models and experimental verification at the component and complete bearing level.

95

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Friction

Estimating the frictional moment. . . . . 98 The SKF model for calculating the frictional moment . . . . . . . . . . . . . . . Rolling frictional moment. . . . . . . . . . . . . . Inlet shear heating reduction factor . . . Kinematic replenishment/starvation reduction factor . . . . . . . . . . . . . . . . . . . Sliding frictional moment. . . . . . . . . . . . . . Effect of lubrication on sliding friction. . . . . . . . . . . . . . . . . . . . . Frictional moment of seals. . . . . . . . . . . . . Drag losses. . . . . . . . . . . . . . . . . . . . . . . . . Drag losses in oil bath lubrication . . . . . Drag losses for oil jet lubrication. . . . . . Additional effects on the frictional moment. . . . . . . . . . . . . . . . . . . . . . . . . . . . Effects of clearance and misalignment on friction . . . . . . . . . . . . Effects of grease fill on friction. . . . . . . Additional information for specific bearing types and performance classes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hybrid bearings . . . . . . . . . . . . . . . . . . . SKF Energy Efficient bearings. . . . . . . . Y-bearings (insert bearings). . . . . . . . . . Needle roller bearings . . . . . . . . . . . . . .

C

99 100 101 102 103 103 109 110 110 112 113 113 113 113 113 113 113 113

Starting torque. . . . . . . . . . . . . . . . . . . . . 114 Power loss and bearing temperature . . 114

97

Friction Table 1

The friction in a rolling bearing determines the amount of heat generated by the bearing. The amount of friction depends on the loads and several other factors, including:

Constant coefficient of friction µ for open bearings (bearings without contact seals) Bearing type

Coefficient of friction µ

• bearing type and size • operating speed • properties and quantity of the lubricant

Deep groove ball bearings

0,0015

Angular contact ball bearings – single row – double row – four-point contact

0,0020 0,0024 0,0024

Self-aligning ball bearings

0,0010

Cylindrical roller bearings – with a cage, when Fa ≈ 0 – full complement, when Fa ≈ 0

0,0011 0,0020

Needle roller bearings with a cage

0,0020

Tapered roller bearings

0,0018

Spherical roller bearings

0,0018

CARB toroidal roller bearings with a cage

0,0016

Thrust ball bearings

0,0013

Cylindrical roller thrust bearings

0,0050

Needle roller thrust bearings

0,0050

Spherical roller thrust bearings

0,0018

The total resistance to rotation in a bearing is the result of rolling and sliding friction in the contact areas, between the rolling elements and raceways, between the rolling elements and cage, and between the rolling elements and other guiding surfaces. Friction is also generated by lubricant drag and contact seals, if applicable.

Estimating the frictional moment Under certain conditions, the frictional moment can be estimated with sufficient accuracy using a constant coefficient of friction μ. The conditions are: • bearing load P ≈ 0,1 C • good lubrication • normal operating conditions The frictional moment under these conditions can be estimated using M = 0,5 μ P d For radial needle roller bearings, use F or Fw instead of d. where M = frictional moment [Nmm] μ = constant coefficient of friction for the bearing († table 1) P = equivalent dynamic bearing load [N] d = bearing bore diameter [mm] F = inner ring raceway diameter [mm] Fw = diameter under the rollers [mm]

98

The SKF model for calculating the frictional moment

The SKF model for calculating the frictional moment A sketch of the frictional moment in a typical bearing, as a function of rotational speed or viscosity, is presented in diagram 1. During the start-up period (zone 1), as speed or ­viscosity increases, the frictional moment decreases as a hydrodynamic (lubricant) film is being formed. As speeds or viscosity continue to increase and the bearing enters into the full elasto-hydrodynamic lubrication (EHL) zone, the thickness of the hydrodynamic film increases (increasing k value, page 241), which also increases friction (zone 2). Eventually, speed or viscosity increase to the point where kinematic starvation and inlet shear cause friction to reach a plateau or even decrease (zone 3). For additional information, refer to Inlet shear heating reduction factor († page 101) and Kinematic replenishment/starvation reduction factor († page 102). To accurately calculate the total frictional moment in a rolling bearing, the following sources and their tribological effects must be taken into account:

• the rolling frictional moment and eventual effects of high-speed starvation and inlet shear heating • the sliding frictional moment and its effect on the quality of the lubrication • the frictional moment from seal(s) • the frictional moment from drag losses, churning, splashing etc. The SKF model for calculating the frictional moment closely follows the real behaviour of the bearing as it considers all contact areas, design changes and improvements made to SKF bearings as well as internal and external influences.

Diagram 1 Bearing frictional moment as a function of speed or viscosity

M

1

2

3 n, n

Zone 1: Mixed lubrication Zone 2: Elasto-hydrodynamic lubrication (EHL) Zone 3: EHL + thermal and starvation effects

99

C

Friction The SKF model for calculating the frictional moment uses M = Mrr + Msl + Mseal + Mdrag where M = total frictional moment Mrr = rolling frictional moment Msl = sliding frictional moment († page 103) Mseal = frictional moment of seals († page 109) Mdrag = frictional moment of drag losses, churning, splashing etc. († page 110) The SKF model is derived from more advanced computational models developed by SKF. It is designed to provide approximate reference values under the following application conditions: • grease lubrication: –– only steady state conditions (after several hours of operation) –– lithium soap grease with mineral oil –– bearing free volume filled approximately 30% –– ambient temperature 20 °C (70 °F) or higher • oil lubrication: –– oil bath, oil-air or oil jet –– viscosity range from 2 to 500 mm2 /s • loads equal to or larger than the recommended minimum load and at least: –– 0,01 C for ball bearings –– 0,02 C for roller bearings • constant loads in magnitude and direction • normal operating clearance • constant speed but not higher than the permissible speed For paired bearings, the frictional moment can be calculated separately for each bearing and added together. The radial load is divided equally over the two bearings; the axial load is shared according to the bearing arrangement.

100

Rolling frictional moment The rolling frictional moment can be calculated using Mrr = fish frs Grr (n n)0,6 where Mrr = rolling frictional moment [Nmm] fish = inlet shear heating reduction factor frs = kinematic replenishment/starvation reduction factor († page 102) Grr = variable († table 2, page 104), depending on: • the bearing type • the bearing mean diameter dm [mm ] = 0,5 (d + D) • the radial load Fr [N] • the axial load Fa [N] n = rotational speed [r/min] n = kinematic viscosity at operating temperature of the oil or the base oil viscosity of the grease [mm2 /s] Note: The formulae provided in this section lead to rather complex calculations. Therefore, SKF strongly recommends calculating the frictional moment using the tools available online at skf.com/bearingcalculator.

The SKF model for calculating the frictional moment Inlet shear heating reduction factor Compared with the quantity of lubricant available in the bearing, not all of it can go through the contact area. Only a tiny amount of lubricant is used to form a hydrodynamic film. Therefore, some of the oil close to the contact area inlet is rejected and produces a reverse flow († fig. 1). This reverse flow shears the lubricant, generating heat, which lowers the oil viscosity and reduces the film thickness and rolling friction. For the effect described above, the inlet shear heating reduction factor can be estimated using

Fig. 1

Reverse flow

C

1 fish = JJJJJJJJJJJJKLL 1 + 1,84 ¥ 10–9 (n dm)1,28 n0,64 where fish = inlet shear heating reduction factor († diagram 2) n = rotational speed [r/min] dm = bearing mean diameter [mm] = 0,5 (d + D) n = kinematic viscosity at operating temperature of the oil or the base oil viscosity of the grease [mm2/s] Diagram 2 Inlet shear heating reduction factor f ish

fish 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0

0

0,4

0,8

1,2

1,6 1,28

(n dm)

2,0 ¥ 10

9

0,64

n

101

Friction Kinematic replenishment/starvation reduction factor For oil-air, oil jet, low level oil bath lubrication (i.e. oil level H lower than the centre of the lowest rolling element) and grease lubrication methods, continuous over-rolling displaces excess lubricant from the raceways. In applications where viscosity or speeds are high, the lubricant may not have sufficient time to replenish the raceways, causing a “kinematic starvation” effect. Kinematic starvation reduces the thickness of the hydrodynamic film (decreasing k value, page 241) and rolling friction. For the type of lubrication methods described above, the kinematic replenishment/starvation reduction factor can be estimated using 1

frs = e

Krs n n (d + D)

Kz 2 (D – d)

where frs = kinematic replenishment/starvation reduction factor e = base of natural logarithm ≈ 2,718 Krs = replenishment/starvation constant: • for low level oil bath and oil jet lubrication † 3 ¥ 10–8 • for grease and oil-air lubrication † 6 ¥ 10–8 KZ = bearing type related geometric constant († table 5, page 112) n = kinematic viscosity at operating temperature [mm2/s] n = rotational speed [r/min] d = bearing bore diameter [mm] D = bearing outside diameter [mm]

102

The SKF model for calculating the frictional moment

Sliding frictional moment The sliding frictional moment can be calculated using Msl = Gsl μsl where Msl = sliding frictional moment [Nmm] Gsl = variable († table 2, page 104), depending on: • the bearing type • the bearing mean diameter dm [mm] = 0,5 (d + D) • the radial load Fr [N] • the axial load Fa [N] μ sl = sliding friction coefficient Effect of lubrication on sliding friction The sliding friction coefficient for full-film and mixed lubrication conditions can be estimated using μsl = fbl μbl + (1 – fbl) μEHL where μsl = sliding friction coefficient fbl = weighting factor for the sliding friction coefficient

μEHL = sliding friction coefficient in full-film conditions Values for μEHL are: • 0,02 for cylindrical roller bearings • 0,002 for tapered roller bearings Other bearings • 0,05 for lubrication with mineral oils • 0,04 for lubrication with synthetic oils • 0,1 for lubrication with transmission fluids Diagram 3 shows the influence of lubrication conditions on the weighting factor for the sliding friction coefficient: • For full-film lubrication (corresponding to large values of k, page 241), the value of the weighting factor for the sliding friction coefficient fbl tends to zero. • For mixed lubrication, which can occur when lubricant viscosity or the bearing speed is low, the value of the weighting factor for the sliding friction coefficient fbl tends to 1, as occasional metal-to-metal contact may occur and friction increases.

1 = JJJJJJJLL –8 (n n)1,4 d 2,6 ¥ 10 m e († diagram 3) e = base of natural logarithm ≈ 2,718 n = rotational speed [r/min] n = kinematic viscosity at operating temperature of the oil or the base oil viscosity of the grease [mm2/s] dm = bearing mean diameter [mm] = 0,5 (d + D) μbl = coefficient depending on the additive package in the lubricant, generally ≈ 0,15

Diagram 3 Weighting factor f bl for the sliding friction coefficient

fbl 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0

5

10

6

10

7

10

8

10

1,4

(n n)

dm

103

C

Friction Table 2a Geometric and load dependent variables for rolling and sliding frictional moments – radial bearings Bearing type

Rolling frictional variable Grr

Deep groove ball bearings

when Fa = 0

when Fa = 0

Grr = R1 dm1,96 Fr0,54

Gsl = S1 dm–0,26 Fr5/3

when Fa > 0 R2 w0,54 q Grr = R1 dm1,96 Fr + JJK Fa < sin aF z

Sliding frictional variable G sl

when Fa > 0

1/3

S2 dm1,5 4 w q Gsl = S1 dm–0,145 Fr5 + JJJK Fa < sin aF z

aF = 24,6 1Fa/C020,24 [°] Angular contact ball bearings 1)

Four-point contact ball bearings

Grr = R1 dm1,97 3Fr + Fg + R2 Fa40,54

Gsl = S1 dm0,26 31Fr + Fg24/3 + S2 Fa4/34

Fg = R3 dm4 n2

Fg = S3 dm4 n2

Grr = R1 dm1,97 3Fr + Fg + R2 Fa40,54

Gsl = S1 dm0,26 31Fr + Fg24/3 + S2 Fa4/34

Fg = R3 dm4 n2

Fg = S3 dm4 n2

Grr = R1 dm2 3Fr + Fg + R2 Fa40,54

Gsl = S1 dm–0,12 31Fr + Fg24/3 + S2 Fa4/34

Fg = R3 dm3,5 n2

Fg = S3 dm3,5 n2

Cylindrical roller bearings

Grr = R1 dm2,41 Fr0,31

Gsl = S1 dm0,9 Fa + S2 dm Fr

Tapered roller bearings 1)

Grr = R1 dm2,38 1Fr + R2 Y Fa20,31

Gsl = S1 dm0,82 1Fr + S2 Y Fa2

Grr.e = R1 dm1,85 1Fr + R2 Fa20,54

Gsl.e = S1 dm0,25 1Fr4 + S2 Fa421/3

Grr.l = R3 dm2,3 1Fr + R4 Fa20,31

Gsl.l = S3 dm0,94 1Fr3 + S4 Fa321/3

when Grr.e < Grr.l

when Gsl.e < Gsl.l

Grr = Grr.e

Gsl = Gsl.e

Self-aligning ball bearings

For the axial load factor Y for single row bearings † product tables Spherical roller bearings

CARB toroidal roller bearings

otherwise

otherwise

Grr = Grr.l

Gsl = Gsl.l

when Fr < 1R21,85 dm0,78/R11,8522,35

when Fr < 1S2 dm1,24/S121,5

Grr = R1 dm1,97 Fr0,54

Gsl = S1 dm–0,19 Fr5/3

otherwise

otherwise

Grr = R2 dm2,37 Fr0,31

Gsl = S2 dm1,05 Fr

The geometry constants R and S are listed in table 3, starting on page 105. Both loads, Fr and Fa are always considered as positive. 1) The value to be used for F is the external axial load. a

104

The SKF model for calculating the frictional moment Table 2b Geometric and load dependent variables for rolling and sliding frictional moments – thrust bearings Bearing type

Rolling frictional variable Grr

Sliding frictional variable G sl

Thrust ball bearings

Grr = R1 dm1,83 Fa0,54

Gsl = S1 dm0,05 Fa4/3

Cylindrical roller thrust bearings

Grr = R1 dm2,38 Fa0,31

Gsl = S1 dm0,62 Fa

Spherical roller thrust bearings

Grr.e = R1 dm1,96 (Fr + R2 Fa)0,54

Gsl.e = S1 dm–0,35 (Fr5/3 + S2 Fa5/3)

Grr.l = R3 dm2,39 (Fr + R4 Fa)0,31

Gsl.l = S3 dm0,89 (Fr + Fa)

when Grr.e < Grr.l

when Gsl.e < Gsl.l

Grr = Grr.e

Gsr = Gsl.e

otherwise

otherwise

Grr = Grr.l

Gsr = Gsl.l

C

Gf = S4 dm0,76 (Fr + S5 Fa) Gf Gsl = Gsr + JJJJJKKK –6 10 (n n)1,4 dm e

Table 3 Geometric constants for rolling and sliding frictional moments Bearing type

Geometric constants for rolling frictional moments R1 R2 R3

sliding frictional moments S1 S2 S

Deep groove ball bearings

(† table 3a)

(† table 3a)

Angular contact ball bearings – single row – double row – four-point contact

5,03 ¥ 10–7 6,34 ¥ 10–7 4,78 ¥ 10–7

Self-aligning ball bearings

(† table 3b)

(† table 3b)

Cylindrical roller bearings

(† table 3c)

(† table 3c)

Tapered roller bearings

(† table 3d)

(† table 3d)

Spherical roller bearings

(† table 3e)

(† table 3e)

CARB toroidal roller bearings

(† table 3f)

(† table 3f)

Thrust ball bearings

1,03 ¥ 10–6

1,6 ¥ 10–2

Cylindrical roller thrust bearings

2,25 ¥ 10–6

0,154

Spherical roller thrust bearings

(† table 3g)

(† table 3g)

1,97 1,41 2,42

1,90 ¥ 10–12 7,83 ¥ 10–13 1,40 ¥ 10–12

1,30 ¥ 10–2 7,56 ¥ 10–3 1,20 ¥ 10–2

0,68 1,21 0,9

1,91 ¥ 10–12 7,83 ¥ 10–13 1,40 ¥ 10–12

105

Friction Table 3a Geometric constants for rolling and sliding frictional moments of deep groove ball bearings Bearing series

Geometric constants for rolling frictional moments R1 R2

sliding frictional moments S1 S2

2, 3

4,4 ¥ 10–7

1,7

2,00 ¥ 10–3

100

42, 43

5,4 ¥ 10–7

0,96

3,00 ¥ 10–3

40

60, 630 62, 622 63, 623

4,1 ¥ 10–7 3,9 ¥ 10–7 3,7 ¥ 10–7

1,7 1,7 1,7

3,73 ¥ 10–3 3,23 ¥ 10–3 2,84 ¥ 10–3

14,6 36,5 92,8

64 160, 161 617, 618, 628, 637, 638

3,6 ¥ 10–7 4,3 ¥ 10–7 4,7 ¥ 10–7

1,7 1,7 1,7

2,43 ¥ 10–3 4,63 ¥ 10–3 6,50 ¥ 10–3

198 4,25 0,78

619, 639

4,3 ¥ 10–7

1,7

4,75 ¥ 10–3

3,6

Table 3b Geometric constants for rolling and sliding frictional moments of self-aligning ball bearings Bearing series

Geometric constants for rolling frictional moments R1 R2 R3

sliding frictional moments S1 S2 S3

12 13 22 23

3,25 ¥ 10–7 3,11 ¥ 10–7 3,13 ¥ 10–7 3,11 ¥ 10–7

6,51 5,76 5,54 3,87

2,43 ¥ 10–12 3,52 ¥ 10–12 3,12 ¥ 10–12 5,41 ¥ 10–12

4,36 ¥ 10–3 5,76 ¥ 10–3 5,84 ¥ 10–3 0,01

9,33 8,03 6,60 4,35

2,43 ¥ 10–12 3,52 ¥ 10–12 3,12 ¥ 10–12 5,41 ¥ 10–12

112 130 139

3,25 ¥ 10–7 2,39 ¥ 10–7 2,44 ¥ 10–7

6,16 5,81 7,96

2,48 ¥ 10–12 1,10 ¥ 10–12 5,63 ¥ 10–13

4,33 ¥ 10–3 7,25 ¥ 10–3 4,51 ¥ 10–3

8,44 7,98 12,11

2,48 ¥ 10–12 1,10 ¥ 10–12 5,63 ¥ 10–13

106

The SKF model for calculating the frictional moment Table 3c Geometric constants for rolling and sliding frictional moments of cylindrical roller bearings Bearing series

Geometric constants for rolling frictional moments R1

sliding frictional moments S1 S2

Bearing with cage of the N, NU, NJ or NUP design 2, 3 4 10

1,09 ¥ 10–6 1,00 ¥ 10–6 1,12 ¥ 10–6

0,16 0,16 0,17

0,0015 0,0015 0,0015

12, 20 22 23

1,23 ¥ 10–6 1,40 ¥ 10–6 1,48 ¥ 10–6

0,16 0,16 0,16

0,0015 0,0015 0,0015

0,16 0,16

0,0015 0,0015

0,16

0,0015

C

High capacity bearings with cage of the NCF .. ECJB, RN .. ECJB, NJF .. ECJA, RNU .. ECJA or NUH .. ECMH design 22 23

1,54 ¥ 10–6 1,63 ¥ 10–6

Full complement bearings of the NCF, NJG, NNCL, NNCF, NNC or NNF design All series

2,13 ¥ 10–6

Table 3d Geometric constants for rolling and sliding frictional moments of tapered roller bearings Bearing series

Geometric constants for rolling frictional moments R1 R2

sliding frictional moments S1 S2

302 303 313 (X)

1,76 ¥ 10–6 1,69 ¥ 10–6 1,84 ¥ 10–6

10,9 10,9 10,9

0,017 0,017 0,048

2 2 2

320 X 322 322 B

2,38 ¥ 10–6 2,27 ¥ 10–6 2,38 ¥ 10–6

10,9 10,9 10,9

0,014 0,018 0,026

2 2 2

323 323 B 329

2,38 ¥ 10–6 2,79 ¥ 10–6 2,31 ¥ 10–6

10,9 10,9 10,9

0,019 0,030 0,009

2 2 2

330 331 332

2,71 ¥ 10–6 2,71 ¥ 10–6 2,71 ¥ 10–6

11,3 10,9 10,9

0,010 0,015 0,018

2 2 2

LL L LM

1,72 ¥ 10–6 2,19 ¥ 10–6 2,25 ¥ 10–6

10,9 10,9 10,9

0,0057 0,0093 0,011

2 2 2

M HM H

2,48 ¥ 10–6 2,60 ¥ 10–6 2,66 ¥ 10–6

10,9 10,9 10,9

0,015 0,020 0,025

2 2 2

HH

2,51 ¥ 10–6

10,9

0,027

2

All other

2,31 ¥ 10–6

10,9

0,019

2

107

Friction Table 3e Geometric constants for rolling and sliding frictional moments of spherical roller bearings Bearing series

Geometric constants for rolling frictional moments R1 R2 R3

R4

sliding frictional moments S1 S2 S3

S4

213 E, 222 E 222 223

1,6 ¥ 10–6 2,0 ¥ 10–6 1,7 ¥ 10–6

5,84 5,54 4,1

2,81 ¥ 10–6 2,92 ¥ 10–6 3,13 ¥ 10–6

5,8 5,5 4,05

3,62 ¥ 10–3 5,10 ¥ 10–3 6,92 ¥ 10–3

508 414 124

8,8 ¥ 10–3 9,7 ¥ 10–3 1,7 ¥ 10–2

117 100 41

223 E 230 231

1,6 ¥ 10–6 2,4 ¥ 10–6 2,4 ¥ 10–6

4,1 6,44 4,7

3,14 ¥ 10–6 3,76 ¥ 10–6 4,04 ¥ 10–6

4,05 6,4 4,72

6,23 ¥ 10–3 4,13 ¥ 10–3 6,70 ¥ 10–3

124 755 231

1,7 ¥ 10–2 1,1 ¥ 10–2 1,7 ¥ 10–2

41 160 65

232 238 239

2,3 ¥ 10–6 3,1 ¥ 10–6 2,7 ¥ 10–6

4,1 12,1 8,53

4,00 ¥ 10–6 3,82 ¥ 10–6 3,87 ¥ 10–6

4,05 12 8,47

8,66 ¥ 10–3 1,74 ¥ 10–3 2,77 ¥ 10–3

126 9 495 2 330

2,1 ¥ 10–2 5,9 ¥ 10–3 8,5 ¥ 10–3

41 1 057 371

240 241 248

2,9 ¥ 10–6 2,6 ¥ 10–6 3,8 ¥ 10–6

4,87 3,8 9,4

4,78 ¥ 10–6 4,79 ¥ 10–6 5,09 ¥ 10–6

4,84 3,7 9,3

6,95 ¥ 10–3 1,00 ¥ 10–2 2,80 ¥ 10–3

240 86,7 3 415

2,1 ¥ 10–2 2,9 ¥ 10–2 1,2 ¥ 10–2

68 31 486

249

3,0 ¥ 10–6

6,67

5,09 ¥ 10–6

6,62

3,90 ¥ 10–3

887

1,7 ¥ 10–2

180

Table 3f Geometric constants for rolling and sliding frictional moments of CARB toroidal roller bearings with a cage Bearing series

Geometric constants for rolling frictional moments R1 R2

sliding frictional moments S1 S2

C 22 C 23 C 30 C 31

1,17 ¥ 10–6 1,20 ¥ 10–6 1,40 ¥ 10–6 1,37 ¥ 10–6

2,08 ¥ 10–6 2,28 ¥ 10–6 2,59 ¥ 10–6 2,77 ¥ 10–6

1,32 ¥ 10–3 1,24 ¥ 10–3 1,58 ¥ 10–3 1,30 ¥ 10–3

0,8 ¥ 10–2 0,9 ¥ 10–2 1,0 ¥ 10–2 1,1 ¥ 10–2

C 32 C 39 C 40 C 41

1,33 ¥ 10–6 1,45 ¥ 10–6 1,53 ¥ 10–6 1,49 ¥ 10–6

2,63 ¥ 10–6 2,55 ¥ 10–6 3,15 ¥ 10–6 3,11 ¥ 10–6

1,31 ¥ 10–3 1,84 ¥ 10–3 1,50 ¥ 10–3 1,32 ¥ 10–3

1,1 ¥ 10–2 1,0 ¥ 10–2 1,3 ¥ 10–2 1,3 ¥ 10–2

C 49 C 59 C 60 C 69

1,49 ¥ 10–6 1,77 ¥ 10–6 1,83 ¥ 10–6 1,85 ¥ 10–6

3,24 ¥ 10–6 3,81 ¥ 10–6 5,22 ¥ 10–6 4,53 ¥ 10–6

1,39 ¥ 10–3 1,80 ¥ 10–3 1,17 ¥ 10–3 1,61 ¥ 10–3

1,5 ¥ 10–2 1,8 ¥ 10–2 2,8 ¥ 10–2 2,3 ¥ 10–2

Table 3g Geometric constants for rolling and sliding frictional moments of spherical roller thrust bearings Bearing series

Geometric constants for rolling frictional moments R1 R2 R3

R4

sliding frictional moments S1 S2 S3

S4

S5

292 292 E

1,32 ¥ 10–6 1,32 ¥ 10–6

1,57 1,65

1,97 ¥ 10–6 2,09 ¥ 10–6

3,21 2,92

4,53 ¥ 10–3 5,98 ¥ 10–3

0,26 0,23

0,02 0,03

0,1 0,17

0,6 0,56

293 293 E 294 E

1,39 ¥ 10–6 1,16 ¥ 10–6 1,25 ¥ 10–6

1,66 1,64 1,67

1,96 ¥ 10–6 2,00 ¥ 10–6 2,15 ¥ 10–6

3,23 3,04 2,86

5,52 ¥ 10–3 4,26 ¥ 10–3 6,42 ¥ 10–3

0,25 0,23 0,21

0,02 0,025 0,04

0,1 0,15 0,2

0,6 0,58 0,54

108

The SKF model for calculating the frictional moment

Frictional moment of seals Where bearings are fitted with contact seals, the frictional losses from the seals may exceed those generated by the bearing. The frictional moment of seals for bearings that are sealed on both sides can be estimated using Mseal = KS1 dsb + KS2 where Mseal = frictional moment of seals [Nmm] KS1 = constant († table 4), depending on: • the seal type • the bearing type and size ds = seal counterface diameter [mm] († table 4)

= exponent († table 4), depending on: • the seal type • the bearing type KS2 = constant († table 4), depending on: • the seal type • the bearing type and size b

In cases where there is only one seal, the friction generated is 0,5 Mseal. For deep groove ball bearings with RSL seals and D > 25 mm, use the calculated value of Mseal, irrespective whether there is one or two seals.

Table 4 Seal frictional moment: Exponent and constants Seal type Bearing type

Bearing outside diameter [mm] D over incl.

Exponent and constants b

K S1

K S2

Seal counter­face diameter d s1)

– 25

25 52

0 2,25

0 0,0018

0 0

d2 d2

RZ seals Deep groove ball bearings



175

0

0

0

d1

RSH seals Deep groove ball bearings



52

2,25

0,028

2

d2

– 62 80 100

62 80 100

2,25 2,25 2,25 2,25

0,023 0,018 0,018 0,018

2 20 15 0

d1, d2 d1, d2 d1, d2 d1, d2

Angular contact ball bearings

30

120

2

0,014

10

d1

Self-aligning ball bearings

30

125

2

0,014

10

d2

LS seals Cylindrical roller bearings

42

360

2

0,032

50

E

CS, CS2 and CS5 seals Spherical roller bearings

62

300

2

0,057

50

d2

CARB toroidal roller bearings

42

340

2

0,057

50

d2

RSL seals Deep groove ball bearings

RS1 seals Deep groove ball bearings

1) Designation of the dimension listed in the product tables

109

C

Friction

Drag losses Bearings lubricated by the oil bath method are partially submerged or, in special situations, completely submerged. The drag losses that occur when the bearing is rotating in an oil bath contribute to the total frictional moment and should not be neglected. Drag losses are not only influenced by bearing speed, oil viscosity and oil level, but also by the size and geometry of the oil reservoir. External oil agitation, which can originate from mechanical elements, like gears or cams, in close proximity to the bearing should also be taken into consideration. Drag losses in oil bath lubrication The SKF model for calculating the drag losses in oil bath lubrication considers resistance of the rolling elements when moving through the oil and includes the effects of the viscosity of the oil. It provides results with sufficient ­accuracy under the following conditions:

• The oil reservoir is large. Effects from reservoir size and geometry or external oil agitation are negligible. • The shaft is horizontal. • The inner ring rotates at a constant speed. The speed is not higher than the permissible speed. • The oil viscosity is within the limits: –– ≤ 500 mm2 /s when the bearing is submerged up to half or less (oil level H ≤ D/2) –– ≤ 250 mm2 /s when the bearing is submerged more than half (oil level H > D/2) The oil level H is measured from the lowest contact point between the outer ring raceway and the rolling element († fig. 2, page 112). It can be estimated with sufficient accuracy using: • for tapered roller bearings: outside diameter D [mm] • for all other radial rolling bearings: outer ring mean diameter [mm] = 0,5 (D + D1)

The frictional moment of drag losses for ball bearings can be estimated using q n dm2 ft w –1,379 Mdrag = 0,4 VM Kball dm5 n2 + 1,093 ¥ 10–7 n2 dm3 JJKK Rs < n z The frictional moment of drag losses for roller bearings can be estimated using q n dm2 ft w –1,379 Mdrag = 4 VM Kroll Cw B dm4 n2 + 1,093 ¥ 10–7 n2 dm3 JJKK Rs < n z The rolling element related constants are: irw Kz (d + D) Kball = JJJJJK 10–12 D–d KL KZ (d + D) Kroll = JJJJJK 10–12 D–d 110

The SKF model for calculating the frictional moment The variables and functions used in the equations for the frictional moment of drag losses are: Cw = 2,789 ¥ 10–10 lD3 – 2,786 ¥ 10–4 lD2 + 0,0195 lD + 0,6439 KL B lD = 5 JJ dm e sin (0,5 t), when 0 ≤ t ≤ p ft = d x 1, when p < t < 2 p

C

Rs = 0,36 dm2 (t – sin t) fA q 0,6 dm – H w t = 2 cos–1 JJKLJJ When H ≥ dm, use H = dm < 0,6 dm z

Kz (D + d) fA = 0,05 JJKLJL D–d where Mdrag = frictional moment of drag losses [Nmm] VM = drag loss factor († diagram 4, page 112) B = bearing width [mm] • for tapered roller bearings † width T • for thrust bearings † height H dm = bearing mean diameter [mm] = 0,5 (d + D) d = bearing bore diameter [mm] D = bearing outside diameter [mm] H = oil level († fig. 2, page 112) [mm] irw = number of ball rows KZ = bearing type related geometric constant († table 5, page 112) KL = rolling bearing type related geometric constant († table 5, page 112) n = rotational speed [r/min] n = kinematic viscosity at operating temperature [mm2/s]

111

Friction Drag losses for vertical shaft arrangements

Fig. 2

To calculate drag losses for vertical shaft arrangements, the model for fully submerged bearings can be used to get an approximate value. The obtained value for Mdrag should be multiplied by a factor equal to the width (height) that is submerged relative to the total bearing width (height). Drag losses for oil jet lubrication To calculate drag losses for the oil jet lubrication method, use the oil bath model, with the oil level H at half the diameter of the lowest rolling element. The obtained value for Mdrag should be multiplied by a factor of two. Certainly, this approximation can vary depending on the rate and direction of oil. However, if the oil level H is known when oil is flowing and the bearing is at a stand-still, this value can be used directly in the drag loss calculation to obtain a more accurate estimate.

d

D

Oil level H

Diagram 4 Drag loss factor V M

VM 0,0016

Table 5

Bearing type

Geometric constants KZ KL

3,1



Angular contact ball bearings – single row – double row – four-point contact

4,4 3,1 3,1

– – –

Self-aligning ball bearings

4,8



Cylindrical roller bearings – with a cage – full complement

5,1 6,2

0,65 0,7

Tapered roller bearings

6

0,7

Spherical roller bearings

5,5

0,8

CARB toroidal roller bearings – with a cage – full complement

5,3 6

0,8 0,75

0,0008

Ball bearings

0,0006 0,0002 0

0

0,5

1,0

1,5 H/dm

VM 0,00030 0,00025

Roller bearings

0,00020 0,00015

Thrust ball bearings

3,8



Cylindrical roller thrust bearings

4,4

0,43

Spherical roller thrust bearings

5,6

0,581)

112

Roller bearings

0,0010

0,0004

Deep groove ball bearings – single and double row

1) Only for single mounted bearings

0,0014 0,0012

Geometric constants K Z and K L

Ball bearings

0,00010 0,00005 0

0

0,05

0,1

0,15

0,2 H/dm

The SKF model for calculating the frictional moment

Additional effects on the frictional moment

Additional information for specific bearing types and performance classes

Effects of clearance and misalignment on friction Changes in clearance or misalignment in ­bearings influence the frictional moment. The model above considers normal internal operating clearance and an aligned bearing. However, high bearing operating temperatures or speeds might reduce internal bearing clearance, which can increase friction. Misalignment generally increases friction. However, for self-aligning ball bearings, spherical roller bearings, CARB toroidal roller bearings and spherical roller thrust bearings, the corres­ ponding increase of friction is negligible. For applications that are sensitive to changes in clearance or misalignment, contact the SKF application engineering service.

Hybrid bearings The higher values for the modulus of elasticity of rolling elements made of silicon nitride decreases the contact area in the raceways to significantly reduce rolling and sliding friction. Additionally, the lower density of ceramic ­rolling elements, when compared with steel, reduces the centrifugal forces, which also may reduce friction at high speeds.

Effects of grease fill on friction When a bearing has just been lubricated or relubricated with the recommended amount of grease, the bearing can realize considerably higher frictional values than had been calculated originally. It can be seen as an increase in operating temperature. The time it takes for friction to decrease depends on the speed of the application and how long it takes for the grease to distribute itself within the free space in the bearing. This effect can be estimated by multiplying the rolling frictional moment by a factor of 2 to 4, where 2 applies for light series bearings (narrow width series) and 4 for heavy series bearings. However, after the running-in period, the values for the frictional moment in the bearing is similar to, or even lower than the values for oil lubricated bearings. Bearings filled with an excessive amount of grease may show higher values of friction. For additional information, refer to Relubrication († page 252), or contact the SKF application engineering service.

Standard hybrid ball bearings

Using the above equations, the frictional moment for hybrid angular contact ball bearings can be calculated by multiplying the geometric constants R3 and S3 of the all-steel bearings by a factor 0,41, that is 0,41 R 3 and 0,41 S3, respectively. Hybrid deep groove ball bearings in highspeed applications are usually preloaded axially. Under these conditions, hybrid deep groove ball bearings behave like angular contact ball bearings with a similar reduced frictional moment. SKF recommends contacting the SKF application en­gin­eer­ing service when calculating the frictional moment for hybrid deep groove ball bearings. Hybrid super-precision bearings

For information about the frictional moment for SKF super-precision bearings, contact the SKF application engineering service. SKF Energy Efficient bearings To obtain values for the frictional moment for SKF Energy Efficient (E2) bearings, SKF recommends using the tools available online at skf.com/bearingcalculator. Y-bearings (insert bearings) To obtain values for the frictional moment for Y-bearings, SKF recommends using the tools available online at skf.com/bearingcalculator. Needle roller bearings To obtain values for the frictional moment for needle roller bearings, SKF recommends using the tools available online at skf.com/bearingcalculator.

113

C

Friction

Starting torque The starting torque of a rolling bearing is defined as the frictional moment that must be overcome by the bearing to start rotating. Therefore, only the sliding frictional moment and the frictional moment of seals, if applied, must be taken into consideration. At an ambient temperature of 20 to 30 °C (70 to 85 °F), the starting torque can be calculated using Mstart = Msl + Mseal where Mstart = starting frictional moment [Nmm] Msl = sliding frictional moment [Nmm] Mseal = frictional moment of the seals [Nmm] However, the starting torque can be considerably higher for roller bearings with a large contact angle. It can be up to four times higher for tapered roller bearings in the 313, 322 B, 323 B and T7FC series, and up to eight times higher for spherical roller thrust bearings.

114

Power loss and bearing temperature The power loss in a bearing as a result of bearing friction can be estimated using NR = 1,05 ¥ 10–4 M n where NR = power loss [W] M = total frictional moment of the bearing [Nmm] n = rotational speed [r/min] The cooling factor Ws is defined as the heat being removed from the bearing per degree of temperature difference between the bearing and ambient. If the value of Ws is known, a rough estimate of the temperature increase in the bearing can be obtained using DT = NR /Ws where DT = temperature increase [°C] NR = power loss [W] Ws = cooling factor [W/°C]

Power loss and bearing temperature

C

115

Speeds

Basics of bearing speed . . . . . . . . . . . . . 118 Reference speed. . . . . . . . . . . . . . . . . . . . Influence of load and oil viscosity on reference speed. . . . . . . . . . . . . . . . . . . . . Oil lubrication. . . . . . . . . . . . . . . . . . . . . Grease lubrication . . . . . . . . . . . . . . . . . Speeds above the reference speed. . . . . .

118 120 120 120 125

D

Limiting speed. . . . . . . . . . . . . . . . . . . . . . 126 Special cases. . . . . . . . . . . . . . . . . . . . . . . 127 Slow speeds . . . . . . . . . . . . . . . . . . . . . . . . 127 Oscillating movements. . . . . . . . . . . . . . . . 127 Vibration generation at high speeds. . . Excitation due to a varying number of loaded rolling elements. . . . . . . . . . . . . Accuracy of associated components. . . . . Influence of the bearing on the vibration behaviour of the application. . . . . . . . . . . .

128 128 128 128

117

Speeds

Basics of bearing speed There is a limit to the speed at which rolling bearings can be operated. Generally, the temperature limit of the lubricant or the mater­ial of the bearing components sets the speed limit. The speed at which a bearing reaches its operating temperature limit depends on the heat generated in the bearing, any externally applied heat, and the amount of heat that can be transferred away from the bearing. The amount of heat generated in the bearing depends on the bearing type and size, internal design, load, lubrication and alignment. Other factors include cage design, accuracy and ­internal clearance. In the product tables, two speeds are generally listed: reference speed (thermal) and limit­ing speed (mechanical). In general, the limiting speed is higher than the reference speed for a bearing. For some bearing series, however, due to favourable frictional characteristics compared to the ­mechanical ability of the bearing to sustain high speeds, the reference speed can be higher than the limiting speed. In every case, however, the limiting speed of the bearing must always be observed, even under the most favourable operating conditions.

Reference speed The main purpose of the reference speed (thermal) is to provide a quick assessment of the speed capabilities of a bearing based on standardized reference values for the heat flow density as established in ISO 15312 († diagram 1). This ISO standard provides reference operating conditions and standard values for the heat flow under those reference conditions. The standard reference heat flow densities shown in diagram 1 are within the values found in bearing applications, shown as the shaded area. To assess the actual temperature rise and heat flow in a particular application, a detailed analysis of the cooling conditions surrounding the bearing would be required. This is outside the scope of the present ISO speed rating standard. For detailed temperature rise calcu118

lations, contact the SKF application engineering service. The values of the reference speeds are based on ISO 15312. The ISO standard, ­established for oil lubrication, is also valid for grease lubrication. Outer ring rotation is not covered by the ISO standard. Therefore, it may be ne­cessary to reduce the reference speed ­r atings in applications where the outer ring rotates. For additional information, contact the SKF application engineering service. For bearings with contact seals, speed ­c ap­a bil­ity of the bearing is not determined by the frictional heat generated in the rolling element / raceway contacts. Therefore, these bearings are not included in the ISO reference speed standard and only the limiting speeds are listed in the product tables. The ISO reference speed is based on open bearings under the following operating conditions: • light load s: –– r adial load P = 0,05 C0 for radial bearings –– a xial load P = 0,02 C0 for thrust bearings • nominal temperature increase of 50 °C (90 °F ) above an ambient reference temperature of 20 °C (70 °F) • good lubrication and clean conditions • sufficient operating clearance († Bearing internal clearance, page 149) Grease lubricated bearings may undergo a temperature peak during initial start-up, ­requiring a running-in period before they reach normal operating temperature.

Reference speed Diagram 1 Heat flow density

Reference heat flow density q [W/mm2]

0,060 0,050 0,040 0,030

Reference heat flow density for thrust bearings in accordance with ISO 15312

0,020 0,015

Reference heat flow density for radial bearings in accordance with ISO 15312

0,010

D 0,005

10

20

50 100

1 000

10 000

100 000

1 000 000

Heat emitting reference surface Ar [mm2]

119

Speeds

Influence of load and oil viscosity on reference speed When load or viscosity values higher than the reference values are applied, the frictional ­resistance increases and the reference speed should be adjusted. Conversely, lower viscosity or load values can enable higher speeds. The influence of load and kinematic viscosity on the reference speed can be estimated from the diagrams referenced in the following: • for radial ball bearings († diagram 2) • for radial roller bearings († diagram 3, page 122) • for thrust ball bearings († diagram 4, page 123) • for thrust roller bearings († diagram 5, page 124)

Oil lubrication Values for the adjustment factors for oil lubrication can be obtained from diagrams 2 to 5 as a function of P/C0 and the bearing mean ­diameter dm: • f P for the influence of the equivalent ­dynamic bearing load P • fn for the influence of the viscosity where P = equivalent dynamic bearing load [kN] C0 = basic static load rating [kN] († product tables) dm = bearing mean diameter [mm] = 0,5 (d + D) The viscosity values in the diagrams are expressed with ISO designations, for example ISO VG 32, where 32 is the oil viscosity at 40 °C (105 °F). The adjusted reference speed for oil lubrication can be estimated using nar = nr fP fn where: nar = adjusted reference speed [r/min] nr = nominal reference speed [r/min] († product tables) fP = adjustment factor for bearing load P fn = adjustment factor for oil viscosity Grease lubrication The values for the adjustment factor for the bearing load (f P) provided in diagrams 2 to 5 are valid for grease lubrication. When greases with a base oil viscosity between 100 and 200 mm2 /s at 40 °C (105 °F) are used, the reference speed does not need to be adjusted (fn = 1). For other base oil viscosities, the value for fn needs to be compared with the value for ISO VG 150 oil. The adjusted reference speed for grease lubrication can be estimated using fn actual base oil viscosity nar = nr fP ———————— fn ISO VG150

120

Reference speed Diagram 2 Adjustment factors f p and fn for radial ball bearings

Self-aligning ball bearings

fP

dm ≤ 20 mm

0,9

dm = 70 mm dm ≥ 120 mm

0,7

0,5 All other radial ball bearings

0,3

dm ≤ 20 mm

D

dm = 70 mm dm = 120 mm

0,1 0

0,1

0,3

0,5

0,7

0,9

P/C0

dm ≥ 600 mm

1,4 ISO VG 15 1,2

ISO VG 32

1,0

0,8

ISO VG 68 ISO VG 150

0,6

ISO VG 220 ISO VG 460

0,4 fn

121

Speeds Diagram 3 Adjustment factors f p and fn for radial roller bearings

fP 0,9

dm ≤ 35 mm

0,7

dm = 150 mm dm = 400 mm

0,5

dm ≥ 600 mm

0,3

0,1 0

0,1

0,3

0,5

1,0

0,9 ISO VG 32 ISO VG 68 0,8 ISO VG 150

0,7

ISO VG 220 ISO VG 460

0,6

fn

122

0,7

P/C0

Reference speed Diagram 4 Adjustment factors f p and fn for thrust ball bearings

fP 0,9

0,7

0,5 dm ≤ 17 mm dm ≥ 500 mm

0,3

D

0,1 0 0,1

0,3

0,5

0,7

P/C0

ISO VG 15 1,1 ISO VG 32

1,0

0,9 ISO VG 68 ISO VG 150–220 0,8

fn

ISO VG 460

123

Speeds Diagram 5 Adjustment factors f p and fn for thrust roller bearings

fP 0,9

0,7

dm ≤ 95 mm 0,5 dm ≥ 300 mm

0,3

0,1 0 0,05

0,15

1,0

0,9

ISO VG 68 0,8 ISO VG 150 ISO VG 220 0,7 fn

124

ISO VG 460

0,25

0,35

P/C0

Reference speed Example 1

An SKF Explorer 6210 deep groove ball bearing is lubricated via an oil bath. The oil viscosity is 68 mm2 /s at 40 °C (105 °F), load P = 0,24 C0. What is the adjusted reference speed? For bearing 6210: dm = 0,5 (50 + 90) = 70 mm and nr = 15 000 r/min. From diagram 2, page 121, with dm = 70 mm and P/C0 = 0,24, f P = 0,63 and with P/C0 = 0,24 and ISO VG 68, fn = 0,85. nar = 15 000 ¥ 0,63 ¥ 0,85 = 8 030 r/min Note that the limiting speed for this bearing is 10 000 r/min, which is higher than its adjusted reference speed. In cases like this, the lower of the two rated speeds is the most significant for the service life of the bearing. In general, speeds up to the adjusted reference speed provide conditions favourable for extended bearing service life. Higher speeds up to the bearing limiting speed can, in principle, be adopted after further assessment of the specific temperature conditions surrounding the bearing arrangement. Example 2

A grease lubricated SKF Explorer 22222 E spherical roller bearing is subjected to a load P = 0,15 C0. The grease has a base oil viscosity of 220 mm2 /s at 40 °C (105 °F). What is the adjusted reference speed? For bearing 22222 E: dm = 0,5 (110 + 200) = 155 mm and nr = 3 000 r/min. From diagram 3, page 122, with dm = 155 mm and P/C0 = 0,15, f P = 0,53 and with P/C0 = 0,15 and ISO VG 220, f n actual = 0,83; with P/C0 = 0,15 and ISO VG 150, fn ISO VG150 = 0,87. nar = 3 000 ¥ 0,53 ¥ 0,83/0,87 = 1 520 r/min Up to this speed, the bearing thermal conditions are generally considered normal. Higher speeds, up to the limiting speed of 4 000 r/min, can also be considered under certain circumstances. This would require an assessment of the temperature rise of the a­ pplication based on the actual frictional and cooling conditions within the application. In cases like this, the lubricant, heat dissipation, bearing internal clearance and accuracy of the bearing seats must be verified and adapted to accommodate higher speeds. For these types of evaluations,

contact the SKF application ­engineering service.

Speeds above the reference speed As mentioned in the previous example, it is possible to operate bearings at speeds above the reference speed provided the increase in operating temperature can be controlled and does not have a negative impact on the bearing or the application. Prior to operating a bearing above its reference speed, make sure that all bearing com­ ponents, including the cage(s) and seal(s), can accommodate the increased temperatures. Also, check that clearance or preload values and the lubricant can accommodate higher temperatures. The operating temperature can be kept under control if friction within the bearing can be reduced or if heat can be removed from the bearing arrangement. Friction can be reduced to some extent with an optimized lubrication system that applies accurately metered, small quantities of grease or oil to the bearing. Heat can be removed from a bearing arrangement in a number of ways. Typical solutions to cool the oil in oil lubricated applications include fans, auxiliary coolers and circulating oil systems († Oil lubrication methods, page 262). When applying any of these solutions to a non-locating bearing, it is important to check that reduced temperatures do not affect the bearing's ability to move axially. In some cases, it may also be ne­ces­s ary to improve other speed-limiting factors such as bearing running accuracy, the cage design and bearing mater­ ials. Any increase in bearing temperature ­lowers the viscosity and effectiveness of the lubricant, making it more difficult for the lubricant to maintain an effective hydrodynamic film. In most cases, this further increases friction and frictional heat. When temperatures increase to the point that the inner ring becomes significantly hotter than the outer ring, the operating clearance in the bearing can be reduced to the point that the bearing seizes. Any increase in speed above the reference speed generally means that the temperature difference between the inner and outer rings is greater than normal. Therefore, a bearing 125

D

Speeds with a larger internal clearance than initially selected might be required († Bearing internal clearance, page 149). It may also be ne­ cessary to look more closely at the tem­pera­ ture distribution in the bearing, as well as the temperature limits of the cage and lubricant as steady-state temperatures higher than 70 °C (160 °F) may reduce their service life († Polymer cages, page 153 and Lubricating greases, page 244). For specific assessments of applications ­operating above the reference speed (thermal), contact the SKF application engineering service. As a general rule, the limiting speed of the bearing must be observed even under the most favourable frictional and cooling conditions.

Limiting speed The limiting speed (mechanical) is determined by criteria that include the form stability or strength of the cage, lubrication of the cage guiding surfaces, centrifugal and gyratory forces ­acting on the rolling elements, bearinghousing precision and other speed-limiting factors, such as seals and the lubricant for sealed bearings. Experience shows that even under the most favourable loading and frictional conditions, there are maximum speeds that should not be exceeded for technical reasons or because of the very high costs involved in keeping the running conditions stable for any length of time. The limiting speeds listed in the product ­tables are valid for the basic bearing design. In cases where the limiting speed is higher than the reference speed, temperatures ­significantly higher than the reference value can be expected. Under these conditions, ­appropriate measures might be necessary († Speeds above the ­reference speed, page 125). If these measures are not adequate, the bearing internal clearance and accuracy of the housing and shaft seats should be verified and adapted to the more ­demanding operating conditions († Tolerances for total radial ­run-out, page 200). The compatibility of the materials in the bearing system must also be considered relative to the bearing temperature and required service life († Materials for rolling bearings, 126

page 150 and Lubricating greases, page 244). When the steady state operating temperature is higher than the maximum recommended by the bearing material stabilization class, i.e. 120 °C (250 °F) for the SN class († Influence of the operating temperature, page 82), a bearing with a higher stabilization class might be necessary to maintain the mounting stress and bearing internal clearance. For grease lubrication, additional factors such as lubrication of the cage guiding sur­ faces and grease consistency at the operating temperature should be taken into con­sid­er­ ation († Grease lubrication, page 242). Some open ball bearings have very low friction, and the reference speeds listed might be higher than the limiting speeds. Therefore, the adjusted reference speed needs to be calculated and compared to the limiting speed. The lower of the two values should be used. To function satisfactorily, particularly at high speeds, bearings must be subjected to a given minimum load. For detailed information about the required minimum load, refer to Loads in the relevant product chapter. In some special cases, such as for some cylin­dric­al roller bearings, the choice of an ­alternative cage can make it possible to operate bearings at speeds higher than the limiting speed for the standard execution listed in the tables († Permissible speed, table 9, page 600). In general, if the limiting speed is not able to meet the requirements of the application, modifications to the bearing, lubrication system or application may be required. Modifications could include improving bearing running accuracy, changing cage ­materials, changing the lubricant or lubrication method, or improving heat dissipation. In that case, SKF recommends contacting the SKF application engineering service for assistance.

Special cases

Special cases In certain applications, the speed limits are ­superseded in importance by other considerations.

Slow speeds At very slow speeds, it is very difficult for an elasto-hydrodynamic lubricant film to be built up in the contact areas between the rolling elem­ents and raceways. In these applications, lubricants containing EP additives should be considered († Grease lubrication, page 242). Alternatively, consider the use of Solid Oil († page 1185) or SKF DryLube bearings († page 1191).

Oscillating movements

D

With this type of movement, the direction of rotation changes before the bearing has completed a single revolution. As the rotational speed is zero at the point where the direction of rotation is reversed, a full hydrodynamic lubricant film is difficult to maintain. As a result, SKF recommends using a lubricant containing an effective EP additive to maintain a boundary lubricant film capable of supporting the applied loads. Hybrid bearings († page 1219) perform well under insufficient lubrication conditions and can therefore provide favourable results in applications where rapid acceler­ ations, decelerations and load reversals (­directional changes) occur. In general, it is not possible to give a limit or a rating for the speed of oscillating movements, as the upper limit is not dictated by a heat balance but by the inertial forces that come into play. With each reversal, there is a danger that inertia causes the rolling elements to slide for a short distance and smear the raceways. The accelerations and decelerations depend on the mass of the rolling elements and cage, the type and quantity of lubricant, the operating clearance and the loads on the bearing.

127

Speeds

Vibration generation at high speeds When bearings operate at high speeds, high over-rolling frequencies are generated in the bearing and a high-pitched noise can be expected from the application. What is perceived as “bearing noise” is the audible effect of the vibration generated by the bearing and transmitted through the surrounding structure. The surrounding structure also contributes to the attenuation or amplification of the noise characteristics of the application. In addressing noise issues in high-speed bearing applications, it is useful to consider the following add­itional aspects.

Excitation due to a varying number of loaded rolling elements When a radial load is applied to a bearing, the number of rolling elements carrying the load varies slightly during operation, this means alternating between 2–3–2–3. This generates a displacement in the direction of the load. The resulting vibration cannot be avoided, but can be reduced by applying an axial preload to load all the rolling elements. This, however, is not possible for cylindrical roller, needle roller and CARB toroidal roller bearings.

Accuracy of associated components In cases where there is a tight fit between the bearing ring and the housing or shaft, the bearing ring may take the shape of the ­adjacent component. If form deviations are present, these may cause vibrations during operation. Therefore, it is important to m ­ achine the shaft and housing seats to the required tolerances († Tolerances for total radial runout, page 200). Presence of local raceway damage or indentations caused by solid contaminants also reduce the accuracy of the raceway microgeom­etry and increase vibrations in the bearing. High cleanliness of the lubricant and protection from solid contaminants can help to reduce bearing noise issues in an application.

128

Influence of the bearing on the vibration behaviour of the application In many applications, bearing stiffness is of the same order as the stiffness of the surrounding structure. This opens the possibility of reducing vibrations in an application by either replacing the bearing or adjusting the preload or clearance in the bearing arrangement. There are three ways to reduce vibration: • Remove the critical excitation vibration from the application. • Dampen the critical excitation vibration ­between excitant component and resonant components. • Change the stiffness of the structure to change the critical frequency.

Vibration generation at high speeds

D

129

Bearing specifics

Dimensions . . . . . . . . . . . . . . . . . . . . . . . 132 Chamfer dimensions. . . . . . . . . . . . . . . . . 132 Tolerances. . . . . . . . . . . . . . . . . . . . . . . . Tolerance symbols. . . . . . . . . . . . . . . . . . Diameter series identification. . . . . . . . . Tolerance tables. . . . . . . . . . . . . . . . . . . . Chamfer dimension limits . . . . . . . . . . . .



132 132 132 133 133

Bearing internal clearance. . . . . . . . . . 149 Materials for rolling bearings. . . . . . . . Materials for bearing rings and rolling elements. . . . . . . . . . . . . . . . . . . . . . . . . . Bearing steels for throughhardening. . . . . . . . . . . . . . . . . . . . . . . Bearing steels for inductionhardening. . . . . . . . . . . . . . . . . . . . . . . Bearing steels for case-hardening . . . Stainless steels. . . . . . . . . . . . . . . . . . . High-temperature bearing steels. . . . Ceramics. . . . . . . . . . . . . . . . . . . . . . . . Cage materials. . . . . . . . . . . . . . . . . . . . . Stamped metal cages. . . . . . . . . . . . . . Machined metal cages. . . . . . . . . . . . . Polymer cages . . . . . . . . . . . . . . . . . . . Cages made of other materials . . . . . . Seal materials. . . . . . . . . . . . . . . . . . . . . . Acrylonitrile-butadiene rubber . . . . . Hydrogenated acrylonitrilebutadiene rubber. . . . . . . . . . . . . . . . . Fluoro rubber . . . . . . . . . . . . . . . . . . . . Polyurethane. . . . . . . . . . . . . . . . . . . . Lubricants. . . . . . . . . . . . . . . . . . . . . . . . . Coatings . . . . . . . . . . . . . . . . . . . . . . . . . .

150 151

E

151

151 151 151 151 152 152 152 152 153 155 155 155



156 156 157 157 157

131

Bearing specifics

Dimensions

Tolerances

For information about main dimensions of a bearing, refer to Boundary dimensions († page 40).

The dimensional and running accuracy of rolling bearings has been standardized internationally. In addition to the Normal tolerances, the ISO standards also cover closer tolerances, such as:

Chamfer dimensions

• tolerance class 6, which corresponds to SKF P6 tolerance class • tolerance class 5, which corresponds to SKF P5 tolerance class

Minimum values for the chamfer dimensions († fig. 1) in the radial direction (r 1, r3) and the axial direction (r2, r4) are listed in the product tables. These values are in accordance with the general plans listed in the following standards: • ISO 15, ISO 12043 and ISO 12044 for radial rolling bearings • ISO 355 for radial tapered roller bearings • ISO 104 for thrust rolling bearings The appropriate maximum chamfer limits that are important when dimensioning fillet radii are in accordance with ISO 582 († Tolerances).

For special applications like machine tool ­spindles, SKF also manufactures bearings with higher accuracy. These include the P4, P4A, PA9A, SP and UP tolerance classes. For add­itional information, refer to Super-­ precision bearings († skf.com/super-precision). For tolerance information about each bearing type, refer to Tolerances in the relevant product chapter. Bearings with higher accuracy than Normal are typically identified by a designation suffix for the tolerance class.

Tolerance symbols The tolerance symbols and their definitions are provided in table 1 († page 134).

Diameter series identification

Fig. 1

r1, r3

r2 , r4

132

The bore and outside diameter variation tolerances Vdp and V Dp for metric rolling bearings († tables 3 to 5, pages 137 to 139 – except tapered roller bearings) are not universally valid for all diameter series. To determine the diameter series of a radial bearing, refer to table 2 († page 136).

Tolerances

Tolerance tables The actual tolerances are listed in the tables referenced in the following: • Normal tolerances for radial bearings, ­except tapered roller bearings († table 3, page 137) • P6 class tolerances for radial bearings, ­except tapered roller bearings († table 4, page 138) • P5 class tolerances for radial bearings, ­except tapered roller bearings († table 5, page 139) • Normal and CL7C class tolerances for metric tapered roller bearings († table 6, page 140) • CLN class tolerances for metric tapered roller bearings († table 7, page 141) • P5 class tolerances for metric tapered roller bearings († table 8, page 142) • Tolerances for inch tapered roller bearings († table 9, page 143) • Tolerances for thrust bearings († table 10, page 144) • Normal, P6 and P5 class tolerances for ­t apered bore, taper 1:12 († table 11, page 145) • Normal tolerances for tapered bore, taper 1:30 († table 12, page 146)

The limits for metric bearings are in accordance with ISO 582. The limits for inch tapered roller bearings, which differ considerably from those for metric bearings, are described in ANSI/ABMA 19.2, but are not standardized. Example What is the largest radial value (r 1 max) for the chamfer of a 6211 deep groove ball bearing? From the product table († page 328), r 1 min = 1,5 mm and d = 55 mm. From table 13 († page 147) with r s min = 1,5 mm and d < 120 mm, the largest radial value r 1 max = 2,3 mm.

E

Where standardized, the values are in accordance with ISO 492, ISO 199 and ANSI/ABMA Std 19.2.

Chamfer dimension limits Fig. 2

• chamfer dimension limits for metric radial and thrust bearings, except tapered roller bearings († table 13, page 147) • chamfer dimension limits for metric radial tapered roller bearings († table 14, page 147) • chamfer dimension limits for inch tapered roller bearings († table 15, page 148)

r1 min r3 min r1 max r3 max

To prevent the improper dimensioning of fillets on associated components for rolling bearings and facilitate calculations to locate retaining rings, the maximum chamfer limits († fig. 2) for the relevant minimum chamfer dimensions († product tables) are listed in the following tables:

r2 max r4 max

r2 min r4 min

133

Bearing specifics Table 1 Tolerance symbols Tolerance symbol

Definition Bore diameter

d

Nominal bore diameter

ds

Single bore diameter

dmp

1 Mean bore diameter; arithmetical mean of the largest and smallest single bore diameters in one plane 2 Mean diameter at the small end of a tapered bore; arithmetical mean of the largest and smallest single diameters

D ds

Deviation of a single bore diameter from the nominal (D ds = d s – d)

D dmp

Deviation of the mean bore diameter from the nominal (D dmp = dmp – d)

Vdp

Bore diameter variation; difference between the largest and smallest single bore diameters in one plane

Vdmp

Mean bore diameter variation; difference between the largest and smallest mean bore diameters

d1

Nominal diameter at the theoretical large end of a tapered bore

d 1mp

Mean diameter at the theoretical large end of a tapered bore; arithmetical mean of the largest and smallest single bore diameters

D d1mp

Deviation of the mean bore diameter at the theoretical large end of a tapered bore from the nominal (D d1mp = d 1mp – d 1)

Outside diameter D

Nominal outside diameter

Ds

Single outside diameter

D mp

Mean outside diameter; arithmetical mean of the largest and smallest single outside diameters in one plane

D Ds

Deviation of a single outside diameter from the nominal (D Ds = D s – D)

D Dmp

Deviation of the mean outside diameter from the nominal (D Dmp = D mp – D)

V Dp

Outside diameter variation; difference between the largest and smallest single outside diameters in one plane

V Dmp

Mean outside diameter variation; difference between the largest and smallest mean outside diameters

Chamfer limits rs

Single chamfer dimension

r s min

Smallest single chamfer dimension of r s, r 1, r2, r3, r4 …

r 1 , r3

Radial direction chamfer dimensions

r2 , r 4

Axial direction chamfer dimensions

134

Tolerances cont. table 1 Tolerance symbols Tolerance symbol

Definition Width or height

B, C

Nominal width of an inner ring and outer ring, respectively

B s, C s

Single width of an inner ring and outer ring, respectively

B 1s, C 1s

Single width of an inner ring and outer ring, respectively, of a bearing specifically manufactured for paired mounting 1)

D Bs, D Cs

Deviation of a single inner ring width or single outer ring width from the nominal (D Bs = Bs – B; D Cs = C s – C; D B1s = B 1s – B 1; D C1s = C 1s – C 1)

V Bs, V Cs

Ring width variation; difference between the largest and smallest single widths of an inner ring and outer ring, respectively

T

1 Nominal width (abutment width) of a tapered roller bearing; distance between an inner ring (cone) back face and outer ring (cup) back face 2 Nominal height H of a single direction thrust bearing (except spherical roller thrust bearing † T4)

T1

1 Nominal width of a tapered roller bearing, cone assembled with a master cup 2 Nominal height H 1 of a single direction thrust ball bearing with a seat washer

T2

1 Nominal width of a tapered roller bearing, cup assembled with a master cone 2 Nominal height H of a double direction thrust bearing

T3

Nominal height H 1 of a double direction thrust ball bearing with seat washers

T4

Nominal height H of a spherical roller thrust bearing

DTs

1 Deviation of the effective single width of a tapered roller bearing from the nominal 2 Deviation of the height of a single direction thrust bearing from the nominal (except spherical roller thrust bearing † DT4s)

DT1s

1 Deviation of an effective single width of a cone from the nominal 2 Deviation of the height of a single direction thrust ball bearing with a seat washer from the nominal

DT2s

1 Deviation of the effective single width of a cup from the nominal 2 Deviation of the height of a double direction thrust bearing from the nominal

DT3s

Deviation of the height of a double direction thrust ball bearing with seat washers from the nominal

DT4s

Deviation of the height of a spherical roller thrust bearing from the nominal

E

Running accuracy K ia , K ea

Radial run-out of an inner ring and outer ring, respectively, of an assembled bearing

Sd

Side face run-out with reference to the bore (of an inner ring)

SD

Outside inclination variation; variation in inclination of the outside cylindrical surface to the outer ring side face

S ia , S ea

Axial run-out of the inner ring and outer ring, respectively, of an assembled bearing

S i, S e

Thickness variation, measured from the middle of the raceway to the back (seat) face of a shaft washer and of a housing washer, respectively (axial run-out)

1) Does not apply to universally matchable angular contact ball bearings.

135

Bearing specifics Table 2 Diameter series (radial bearings) Bearing type

Diameter series 7, 8, 9

0, 1

2, 3, 4

Deep groove ball bearings 1)

617, 618, 619 627, 628 637, 638, 639

60 160, 161 630

2, 3 42, 43 62, 63, 64, 622, 623

70

32, 33 72, 73 QJ 2, QJ 3

10, 130

12, 13, 112 22, 23

NU 10, 20 NJ 10

NU 2, 3, 4, 12, 22, 23 NJ 2, 3, 4, 22, 23 NUP 2, 3, 22, 23 N 2, 3

Angular contact ball bearings

Self-aligning ball bearings 2)

139

Cylindrical roller bearings

Needle roller bearings

NA 48, 49, 69

Full complement cylindrical roller bearings

NCF 18, 19, 28, 29 NNC 48, 49 NNCF 48, 49 NNCL 48, 49

NCF 30 NNF 50 NNCF 50

NCF 22 NJG 23

Spherical roller bearings

238, 239 248, 249

230, 231 240, 241

222, 232 213, 223

CARB toroidal roller bearings

C 39, 49, 59, 69

C 30, 31 C 40, 41

C 22, 23 C 32

1) Bearings 604, 607, 608, 609 belong to diameter series 0,

bearings 623, 624, 625, 626, 627, 628 and 629 to diameter series 2, bearings 634, 635 and 638 to diameter series 3

2) Bearing 108 belongs to diameter series 0,

bearings 126, 127 and 129 to diameter series 2, bearing 135 to diameter series 3

136

Tolerances Table 3 Normal tolerances for radial bearings, except tapered roller bearings Inner ring D dmp1)

d over

incl.

mm

high

low

µm

Vdp Diameter series 7, 8, 9 0, 1 2, 3, 4 max. max. max.

Vdmp

D Bs

max.

high

µm

µm

µm

D B1s low

high

low

µm

V Bs

K ia

max.

max.

µm

µm

– 2,5 10

2,5 10 18

0 0 0

–8 –8 –8

10 10 10

8 8 8

6 6 6

6 6 6

0 0 0

–40 –120 –120

– 0 0

– –250 –250

12 15 20

10 10 10

18 30 50

30 50 80

0 0 0

–10 –12 –15

13 15 19

10 12 19

8 9 11

8 9 11

0 0 0

–120 –120 –150

0 0 0

–250 –250 –380

20 20 25

13 15 20

80 120 180

120 180 250

0 0 0

–20 –25 –30

25 31 38

25 31 38

15 19 23

15 19 23

0 0 0

–200 –250 –300

0 0 0

–380 –500 –500

25 30 30

25 30 40

250 315 400

315 400 500

0 0 0

–35 –40 –45

44 50 56

44 50 56

26 30 34

26 30 34

0 0 0

–350 –400 –450

0 0 0

–500 –630 –630

35 40 50

50 60 65

500 630 800

630 800 1 000

0 0 0

–50 –75 –100

63 – –

63 – –

38 – –

38 – –

0 0 0

–500 –750 –1 000

0 – –

–800 – –

60 70 80

70 80 90

1 000 1 250 1 600

1 250 1 600 2 000

0 0 0

–125 –160 –200

– – –

– – –

– – –

– – –

0 0 0

–1 250 –1 600 –2 000

– – –

– – –

100 120 140

100 120 140

E

Outer ring D over

D Dmp incl.

mm

high

low

µm

V Dp2) Diameter series 7, 8, 9 0, 1 2, 3, 4 max. max. max.

Capped bearings 3) max.

V Dmp2) max.

max.

µm

µm

µm

µm

D Cs, D C1s, V Cs

K ea

2,5 18 30

18 30 50

0 0 0

–8 –9 –11

10 12 14

8 9 11

6 7 8

10 12 16

6 7 8

50 80 120

80 120 150

0 0 0

–13 –15 –18

16 19 23

13 19 23

10 11 14

20 26 30

10 11 14

25 35 40

150 180 250

180 250 315

0 0 0

–25 –30 –35

31 38 44

31 38 44

19 23 26

38 – –

19 23 26

45 50 60

315 400 500

400 500 630

0 0 0

–40 –45 –50

50 56 63

50 56 63

30 34 38

– – –

30 34 38

70 80 100

630 800 1 000

800 1 000 1 250

0 0 0

–75 –100 –125

94 125 –

94 125 –

55 75 –

– – –

55 75 –

120 140 160

1 250 1 600 2 000

1 600 2 000 2 500

0 0 0

–160 –200 –250

– – –

– – –

– – –

– – –

– – –

190 220 250

1) Tolerances for tapered bores († table 11, page 145 and table 12, page 2) Applies to bearings prior to mounting with any snap rings removed. 3) Applies only to bearings of diameter series 2 and 3.

Values are identical to those for the inner ring of the same bearing.

15 15 20

146).

137

Bearing specifics Table 4 P6 class tolerances for radial bearings, except tapered roller bearings Inner ring D dmp1)

d over

incl.

mm

high

low

µm

Vdp Diameter series 7, 8, 9 0, 1 2, 3, 4 max. max. max.

Vdmp

D Bs

max.

high

µm

µm

µm

D B1s low

high

low

µm

V Bs

K ia

max.

max.

µm

µm

– 2,5 10

2,5 10 18

0 0 0

–7 –7 –7

9 9 9

7 7 7

5 5 5

5 5 5

0 0 0

–40 –120 –120

– 0 0

– –250 –250

12 15 20

5 6 7

18 30 50

30 50 80

0 0 0

–8 –10 –12

10 13 15

8 10 15

6 8 9

6 8 9

0 0 0

–120 –120 –150

0 0 0

–250 –250 –380

20 20 25

8 10 10

80 120 180

120 180 250

0 0 0

–15 –18 –22

19 23 28

19 23 28

11 14 17

11 14 17

0 0 0

–200 –250 –300

0 0 0

–380 –500 –500

25 30 30

13 18 20

250 315 400

315 400 500

0 0 0

–25 –30 –35

31 38 44

31 38 44

19 23 26

19 23 26

0 0 0

–350 –400 –450

0 0 0

–500 –630 –630

35 40 45

25 30 35

500 630 800

630 800 1 000

0 0 0

–40 –50 –60

50 – –

50 – –

30 – –

30 – –

0 0 0

–500 –750 –1 000

0 – –

–800 – –

50 55 60

40 45 50

1 000 1 250 1 600

1 250 1 600 2 000

0 0 0

–75 –90 –115

– – –

– – –

– – –

– – –

0 0 0

–1 250 –1 600 –2 000

– – –

– – –

70 70 80

60 70 80

low

V Dp Diameter series 7, 8, 9 0, 1 2, 3, 4 max. max. max.

Capped bearings 3) max.

max.

max.

µm

µm

µm

µm

Outer ring D over

D Dmp incl.

mm

high µm

V Dmp2)

D Cs, D C1s, V Cs

K ea

2,5 18 30

18 30 50

0 0 0

–7 –8 –9

9 10 11

7 8 9

5 6 7

9 10 13

5 6 7

50 80 120

80 120 150

0 0 0

–11 –13 –15

14 16 19

11 16 19

8 10 11

16 20 25

8 10 11

13 18 20

150 180 250

180 250 315

0 0 0

–18 –20 –25

23 25 31

23 25 31

14 15 19

30 – –

14 15 19

23 25 30

315 400 500

400 500 630

0 0 0

–28 –33 –38

35 41 48

35 41 48

21 25 29

– – –

21 25 29

35 40 50

630 800 1 000

800 1 000 1 250

0 0 0

–45 –60 –75

56 75 –

56 75 –

34 45 –

– – –

34 45 –

60 75 85

1 250 1 600 2 000

1 600 2 000 2 500

0 0 0

–90 –115 –135

– – –

– – –

– – –

– – –

– – –

100 100 120

1) Tolerances for tapered bores († table 11, page 145). 2) Applies to bearings prior to mounting with any snap rings removed. 3) Applies only to bearings of diameter series 0, 1, 2 and 3.

138

Values are identical to those for the inner ring of the same bearing.

8 9 10

Tolerances Table 5 P5 class tolerances for radial bearings, except tapered roller bearings Inner ring d over

D dmp incl.

mm

high

low

µm

K ia

Sd

S ia1)

Vdp Diameter series 7, 8, 9 0, 1, 2, 3, 4 max. max.

Vdmp

D Bs

D B1s

V Bs

max.

high low

high low

max. max. max. max.

µm

µm

µm

µm

µm

µm

µm

µm

– 2,5 10

2,5 10 18

0 0 0

–5 –5 –5

5 5 5

4 4 4

3 3 3

0 0 0

–40 –40 –80

0 0 0

–250 –250 –250

5 5 5

4 4 4

7 7 7

7 7 7

18 30 50

30 50 80

0 0 0

–6 –8 –9

6 8 9

5 6 7

3 4 5

0 0 0

–120 –120 –150

0 0 0

–250 –250 –250

5 5 6

4 5 5

8 8 8

8 8 8

80 120 180

120 180 250

0 0 0

–10 –13 –15

10 13 15

8 10 12

5 7 8

0 0 0

–200 –250 –300

0 0 0

–380 –380 –500

7 8 10

6 8 10

9 10 11

9 10 13

250 315 400

315 400 500

0 0 0

–18 –23 –28

18 23 28

14 18 21

9 1 1

0 0 0

–350 –400 –450

0 0 0

–500 –630 –630

13 15 18

13 15 17

13 15 18

15 20 23

500 630 800

630 800 1 000

0 0 0

–35 –45 –60

35 – –

26 – –

1 – –

0 0 0

–500 –750 –1 000

0 – –

–800 – –

20 26 32

19 22 26

20 26 32

25 30 30

1 000 1 250 1 600

1 250 1 600 2 000

0 0 0

–75 –90 –115

– – –

– – –

– – –

0 0 0

–1 250 –1 600 –2 000

– – –

– – –

38 45 55

30 35 40

38 45 55

30 30 30

E

Outer ring D over

DDmp incl.

mm

high

low

µm

V Dmp2)

D Cs, D C1s

V Cs

K ea

SD

S ea1)

V Dp Diameter series 7, 8, 9 0, 1, 2, 3, 4 max. max.

max.

max. max. max.

max.

µm

µm

µm

µm

µm

µm

5 5 5

5 6 7

8 8 8

8 8 8

2,5 18 30

18 30 50

0 0 0

–5 –6 –7

5 6 7

4 5 5

3 3 4

50 80 120

80 120 150

0 0 0

–9 –10 –11

9 10 11

7 8 8

5 5 6

6 8 8

8 10 11

8 9 10

10 11 13

150 180 250

180 250 315

0 0 0

–13 –15 –18

13 15 18

10 11 14

7 8 9

8 10 11

13 15 18

10 11 13

14 15 18

315 400 500

400 500 630

0 0 0

–20 –23 –28

20 23 28

15 17 21

10 12 14

13 15 18

20 23 25

13 15 18

20 23 25

630 800 1 000

800 1 000 1 250

0 0 0

–35 –50 –63

35 50 –

26 29 –

18 25 –

20 25 30

30 35 40

20 25 30

30 35 45

1 250 1 600 2 000

1 600 2 000 2 500

0 0 0

–80 –100 –125

– – –

– – –

– – –

35 38 45

45 55 65

35 40 50

55 55 55

Values are identical to those for the inner ring of the same bearing.

1) Applies only to deep groove and angular contact ball bearings. 2) Does not apply to capped bearings.

139

Bearing specifics Table 6 Normal and CL7C class tolerances for metric tapered roller bearings Inner ring, bearing width and ring widths d over

incl.

mm

D dmp

Vdp

Vdmp

D Bs

high low

max.

max.

high low

K ia DTs Tolerance classes Normal CL7C max. max. high

µm

µm

µm

µm

µm

DT1s low

high

DT2s low

high

µm

µm

µm

low

10 18 30

18 30 50

0 0 0

–12 –12 –12

12 12 12

9 9 9

0 0 0

–120 –120 –120

15 18 20

7 8 10

+200 0 +200 0 +200 0

+100 0 +100 0 +100 0

+100 0 +100 0 +100 0

50 80 120

80 120 180

0 0 0

–15 –20 –25

15 20 25

11 15 19

0 0 0

–150 –200 –250

25 30 35

10 13 –

+200 0 +200 –200 +350 –250

+100 0 +100 –100 +150 –150

+100 0 +100 –100 +200 –100

180 250 315

250 315 400

0 0 0

–30 –35 –40

30 35 40

23 26 30

0 0 0

–300 –350 –400

50 60 70

– – –

+350 –250 +350 –250 +400 –400

+150 –150 +150 –150 +200 –200

+200 –100 +200 –100 +200 –200

D Dmp

V Dp

V Dmp

D Cs

high low

max.

max.

K ea Tolerance classes Normal CL7C max. max.

µm

µm

µm

µm

Outer ring D over

incl.

mm 18 30 50

30 50 80

0 0 0

–12 –14 –16

12 14 16

9 11 12

80 120 150

120 150 180

0 0 0

–18 –20 –25

18 20 25

14 15 19

180 250 315

250 315 400

0 0 0

–30 –35 –40

30 35 40

400 500 630

500 630 800

0 0 0

–45 –50 –75

45 60 80

140

Values are identical to those for the inner ring of the same bearing.

18 20 25

9 10 13

35 40 45

18 20 23

23 26 30

50 60 70

– – –

34 38 55

80 100 120

– – –

Tolerances Table 7 CLN class tolerances for metric tapered roller bearings Inner ring, bearing width and ring widths d over

incl.

mm

D dmp

Vdp

Vdmp

D Bs

D Cs

K ia

DTs

high low

max.

max.

high low

high low

max.

high

µm

µm

µm

µm

µm

µm

µm

µm

DT1s low

high

DT2s low

high

low

µm

10 18 30

18 30 50

0 0 0

–12 –12 –12

12 12 12

9 9 9

0 0 0

–50 –50 –50

0 0 0

–100 –100 –100

15 18 20

+100 0 +100 0 +100 0

+50 +50 +50

0 0 0

+50 +50 +50

50 80 120

80 120 180

0 0 0

–15 –20 –25

15 20 25

11 15 19

0 0 0

–50 –50 –50

0 0 0

–100 –100 –100

25 30 35

+100 0 +100 0 +150 0

+50 +50 +50

0 0 0

+50 0 +50 0 +100 0

180 250 315

250 315 400

0 0 0

–30 –35 –40

30 35 40

23 26 30

0 0 0

–50 –50 –50

0 0 0

–100 –100 –100

50 60 70

+150 0 +200 0 +200 0

+50 0 +100 0 +100 0

+100 0 +100 0 +100 0

0 0 0

Outer ring D over

incl.

mm

D Dmp

V Dp

V Dmp

K ea

high low

max.

max.

max.

µm

µm

µm

µm

18 30 50

30 50 80

0 0 0

–12 –14 –16

12 14 16

9 11 12

18 20 25

80 120 150

120 150 180

0 0 0

–18 –20 –25

18 20 25

14 15 19

35 40 45

180 250 315

250 315 400

0 0 0

–30 –35 –40

30 35 40

23 26 30

50 60 70

400 500

500 630

0 0

–45 –50

45 50

34 38

80 100

E

141

Bearing specifics Table 8 P5 class tolerances for metric tapered roller bearings Inner ring and bearing width d over

D dmp incl.

mm

high

low

µm

Vdp

Vdmp

D Bs

max.

max.

high

µm

µm

µm

low

K ia

Vdp

DTs

max.

max.

high

µm

µm

µm

low

10 18 30

18 30 50

0 0 0

–7 –8 –10

5 6 8

5 5 5

0 0 0

–200 –200 –240

5 5 6

7 8 8

+200 +200 +200

–200 –200 –200

50 80 120

80 120 180

0 0 0

–12 –15 –18

9 11 14

6 8 9

0 0 0

–300 –400 –500

7 8 11

8 9 10

+200 +200 +350

–200 –200 –250

180 250 315

250 315 400

0 0 0

–22 –25 –30

17 19 23

11 13 15

0 0 0

–600 –700 –800

13 16 19

11 13 15

+350 +350 +400

–250 –250 –400

V Dp

V Dmp

D Cs

K ea

SD

low

max.

max.

max.

max.

µm

µm

µm

µm

Outer ring D over

D Dmp incl.

mm

high µm

18 30 50

30 50 80

0 0 0

–8 –9 –11

6 7 8

5 5 6

80 120 150

120 150 180

0 0 0

–13 –15 –18

10 11 14

7 8 9

180 250 315

250 315 400

0 0 0

–20 –25 –28

15 19 22

400 500

500 630

0 0

–33 –38

25 29

142

Values are identical 6 to those for the 7 inner ring of the 8 same bearing. 10 11 13

9 10 10

10 13 14

15 18 20

11 13 13

17 19

23 25

15 18

8 8 8

Tolerances Table 9 Tolerances for inch tapered roller bearings Inner ring d over

incl.

mm

D ds Tolerance classes Normal, CL2 CL3, CL0 high low high low µm

µm

– 76,2 101,6

76,2 101,6 266,7

+13 +25 +25

0 0 0

+13 +13 +13

0 0 0

266,7 304,8 609,6

304,8 609,6 914,4

+25 +51 +76

0 0 0

+13 +25 +38

0 0 0

Outer ring D over

incl.

mm

D ds Tolerance classes Normal, CL2 CL3, CL0 high low high low

K ia , K ea, S ia , S ea Tolerance classes Normal CL2 CL3 max. max. max.

µm

µm

µm

CL0 max.

– 304,8 609,6

304,8 609,6 914,4

+25 +51 +76

0 0 0

+13 +25 +38

0 0 0

51 51 76

38 38 51

8 18 51

4 9 26

914,4 1 219,2

1 219,2 –

+102 +127

0 0

+51 +76

0 0

76 76

– –

76 76

38 –

E

Abutment width of single row bearing d over

D incl.

mm

over

incl.

mm

DTs Tolerance classes Normal CL2 high low high µm

low

µm

CL3, CL0 high low µm

– 101,6 266,7

101,6 266,7 304,8

– – –

– – –

+203 +356 +356

0 –254 –254

+203 +203 +203

0 0 0

+203 +203 +203

–203 –203 –203

304,8 304,8 609,6

609,6 609,6 –

– 508 –

508 – –

+381 +381 +381

–381 –381 –381

+381 +381 –

–381 –381 –

+203 +381 +381

–203 –381 –381

143

Bearing specifics Table 10 Tolerances for thrust bearings Nominal diameter d, D over

incl.

mm

Shaft washer Tolerance classes Normal, P6, P5 Vdp D dmp high low max.

Tolerance classes Normal P6 S i1) S i1) max. max.

P5 S i1) max.

Housing washer Tolerance classes Normal, P6, P5 D Dmp high low

V Dp max.

µm

µm

µm

µm

µm

µm

µm

– 18 30

18 30 50

0 0 0

–8 –10 –12

6 8 9

10 10 10

5 5 6

3 3 3

0 0 0

–11 –13 –16

8 10 12

50 80 120

80 120 180

0 0 0

–15 –20 –25

11 15 19

10 15 15

7 8 9

4 4 5

0 0 0

–19 –22 –25

14 17 19

180 250 315

250 315 400

0 0 0

–30 –35 –40

23 26 30

20 25 30

10 13 15

5 7 7

0 0 0

–30 –35 –40

23 26 30

400 500 630

500 630 800

0 0 0

–45 –50 –75

34 38 55

30 35 40

18 21 25

9 11 13

0 0 0

–45 –50 –75

34 38 55

800 1 000 1 250

1 000 1 250 1 600

0 0 0

–100 –125 –160

75 95 120

45 50 60

30 35 40

15 18 25

0 0 0

–100 –125 –160

75 95 120

1 600 2 000

2 000 2 500

0 0

–200 –250

150 190

75 90

– –

– –

0 0

–200 –250

150 190

Se max.

Values are identical to those for shaft washer of same bearing.

Bearing height D over

DT1s

DTs incl.

mm

high

low

µm

high

DT2s low

high

DT3s low

high

µm

µm

µm

DT4s ISO low

high

SKF

SKF Explorer

low

high low

high low

µm

– 30 50

30 50 80

+20 +20 +20

–250 –250 –300

+100 –250 +100 –250 +100 –300

+150 –400 +150 –400 +150 –500

+300 +300 +300

–400 –400 –500

– – +20

– – –300

– – 0

– – –125

– – 0

– – –100

80 120 180

120 180 250

+25 +25 +30

–300 –400 –400

+150 –300 +150 –400 +150 –400

+200 –500 +200 –600 +250 –600

+400 –500 +400 –600 +500 –600

+25 +25 +30

–300 –400 –400

0 0 0

–150 –175 –200

0 0 0

–100 –125 –125

250 315 400

315 400 500

+40 +40 +50

–400 –500 –500

– – –

– – –

– – –

– – –

– – –

– – –

+40 +40 +50

–400 –500 –500

0 0 0

–225 –300 –420

0 0 –

–150 –200 –

500 630 800

630 800 1 000

+60 +70 +80

–600 –750 –1 000

– – –

– – –

– – –

– – –

– – –

– – –

+60 +70 +80

–600 –750 –1 000

0 0 0

–500 –630 –800

– – –

– – –

+100 –1 400 +120 –1 600

– –

– –

– –

– –

– –

– –

+100 –1 400 +120 –1 600

0 0

–1 000 –1 200

– –

– –

1 000 1 250 1 250 1 600

1) Does not apply to spherical roller thrust bearings.

144

Tolerances Table 11 Normal, P6 and P5 class tolerances for tapered bores, taper 1:12

B B

d + Ddmp

d1 + Dd1mp

d

d1 a

a

Dd1mp – Ddmp 2 Half angle of taper 1:12

Largest theoretical diameter d1 1 d1 = d + — B 12

a = 2° 23© 9,4"

Bore diameter d over

incl.

mm

Tolerance classes Normal, P6 D dmp

Vdp1)

D d1mp – D dmp

P5 D dmp

high

max.

high

high

µm

µm

low

µm

low

low

µm

Vdp1)

D d1mp – D dmp

max.

high

µm

µm

E

low

18 30 50

30 50 80

+21 +25 +30

0 0 0

13 15 19

+21 +25 +30

0 0 0

+13 +16 +19

0 0 0

13 15 19

+13 +16 +19

0 0 0

80 120 180

120 180 250

+35 +40 +46

0 0 0

25 31 38

+35 +40 +46

0 0 0

+22 +25 +29

0 0 0

22 25 29

+22 +25 +29

0 0 0

250 315 400

315 400 500

+52 +57 +63

0 0 0

44 50 56

+52 +57 +63

0 0 0

+32 +36 +40

0 0 0

32 36 –

+32 +36 +40

0 0 0

500 630 800

630 800 1 000

+70 +80 +90

0 0 0

70 – –

+70 +80 +90

0 0 0

+44 +50 +56

0 0 0

– – –

+44 +50 +56

0 0 0

1 000 1 250 1 600

1 250 1 600 2 000

+105 +125 +150

0 0 0

– – –

+105 +125 +150

0 0 0

+66 +78 +92

0 0 0

– – –

+66 +78 +92

0 0 0

1) Applies to any single radial plane of the bore.

145

Bearing specifics Table 12 Normal tolerances for tapered bores, taper 1:30

B B

d + Ddmp

d1 + Dd1mp

d

d1 a

a

Dd1mp – Ddmp 2 Half angle of taper 1:30

Largest theoretical diameter d 1 1 d1 = d + — B 30

a = 0° 57© 17,4"

Bore diameter d over

incl.

mm

Tolerance class Normal D dmp

Vdp1)

D d1mp – D dmp

high

max.

high

µm

µm

low

µm

low

– 80 120

80 120 180

+15 +20 +25

0 0 0

19 22 40

+30 +35 +40

0 0 0

180 250 315

250 315 400

+30 +35 +40

0 0 0

46 52 57

+46 +52 +57

0 0 0

400 500 630

500 630 800

+45 +50 +75

0 0 0

63 70 –

+63 +70 +100

0 0 0

800 1 000 1 250

1 000 1 250 1 600

+100 +125 +160

0 0 0

– – –

+100 +115 +125

0 0 0

1 600

2 000

+200

0



+150

0

1) Applies to any single plane of the bore.

146

Tolerances Table 13

Table 14

Chamfer dimension limits for metric radial and thrust bearings, except tapered roller bearings

Chamfer dimension limits for metric radial tapered roller bearings

Minimum Nominal bearing single bore diameter chamfer dimension

Maximum chamfer dimensions Radial Thrust bearings bearings

Minimum Nominal bearing single bore/outside chamfer diameter dimension

r 1, 3 max.

r s min

d, D over

mm

mm

0,3

– 40

40 –

0,7 0,9

1,4 1,6

0,5

– 40

40 –

1,1 1,2

1,7 1,9

0,6

– 40

40 –

1,1 1,3

1,7 2

r s min

d over

mm

mm

0,05 0,08 0,1

– – –

– – –

0,1 0,16 0,2

0,2 0,3 0,4

0,1 0,16 0,2

0,15 0,2 0,3

– – – 40

– – 40 –

0,3 0,5 0,6 0,8

0,6 0,8 1 1

0,3 0,5 0,8 0,8

0,6

– 40 – 50 – 120

40 – 50 – 120 –

1 1,3 1,5 1,9 2 2,5

2 2 3 3 3,5 4

1,5 1,5 2,2 2,2 2,7 2,7

1

– 50

50 –

1,6 1,9

2,5 3

1,5

– 120 250

120 250 –

2,3 2,8 3,5

3 3,5 4

– 120 – 80 220 – 280

120 – 80 220 – 280 –

2,3 3 3 3,5 3,8 4 4,5

4 5 4,5 5 6 6,5 7

3,5 3,5 4 4 4 4,5 4,5

2

– 120 250

120 250 –

2,8 3,5 4

4 4,5 5

2,5

– 120 250

120 250 –

3,5 4 4,5

5 5,5 6

– 100 280 – 280

100 280 – 280 –

3,8 4,5 5 5 5,5

6 6 7 8 8

– – – 5,5 5,5

3

– 120 250 400

120 250 400 –

4 4,5 5 5,5

5,5 6,5 7 7,5

4 5 6

– – –

– – –

6,5 8 10

9 10 13

6,5 8 10

4

– 120 250 400

120 250 400 –

5 5,5 6 6,5

7 7,5 8 8,5

7,5 9,5 12

– – –

– – –

12,5 15 18

17 19 24

12,5 15 18

5

– 180

180 –

6,5 7,5

8 9

6

– 180

180 –

7,5 9

10 11

1 1,1 1,5 2 2,1 2,5 3

incl.

r2, 4 max.

r 1, 2, 3, 4 max.

Maximum chamfer dimensions

mm

incl.

r 1, 3 max.

r2, 4 max.

mm

E

147

Bearing specifics Table 15 Chamfer dimension limits for inch tapered roller bearings Inner ring

Outer ring

Minimum single chamfer dimension

Nominal bearing bore diameter

Maximum chamfer dimensions

Nominal bearing out­side diameter

Maximum chamfer dimensions

r s min over

d over

r1 max.

D over

r3 max.

incl.

mm

incl.

mm

r2 max.

mm

incl.

mm

r4 max.

mm

0,6

1,4

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 0,9

r2 min + 1,3 r2 min + 1,8 r2 min + 2

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 0,9

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 2

1,4

2,5

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 2

r2 min + 1,3 r2 min + 1,8 r2 min + 3

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 2

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 3

2,5

4,0

– 101,6 254 400

101,6 254 400 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 2 r 1 min + 2,5

r2 min + 1,3 r2 min + 1,8 r2 min + 4 r2 min + 4,5

– 168,3 266,7 355,6 400

168,3 266,7 355,6 400 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 2 r3 min + 2,5

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 4 r4 min + 4,5

4,0

5,0

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 2,5

r2 min + 1,3 r2 min + 1,8 r2 min + 4

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 2,5

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 4

5,0

6,0

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 3

r2 min + 1,3 r2 min + 1,8 r2 min + 5

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 3

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 5

6,0

7,5

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 4,5

r2 min + 1,3 r2 min + 1,8 r2 min + 6,5

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 4,5

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 6,5

7,5

9,5

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 6,5

r2 min + 1,3 r2 min + 1,8 r2 min + 9,5

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 6,5

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 9,5

9,5

12

– 101,6 254

101,6 254 –

r 1 min + 0,5 r 1 min + 0,6 r 1 min + 8

r2 min + 1,3 r2 min + 1,8 r2 min + 11

– 168,3 266,7 355,6

168,3 266,7 355,6 –

r3 min + 0,6 r3 min + 0,8 r3 min + 1,7 r3 min + 8

r4 min + 1,2 r4 min + 1,4 r4 min + 1,7 r4 min + 11

148

Bearing internal clearance

Bearing internal clearance Bearing internal clearance († fig. 3) is defined as the total distance through which one bearing ring can be moved relative to the other in the radial direction (radial internal clearance) or in the axial direction (axial internal clearance). It is necessary to distinguish between initial internal clearance in the bearing prior to mounting and operating internal clearance, which applies to a bearing in operation that has reached a stable temperature. In almost all applications, the initial clearance in a bearing is greater than its operating clearance. The difference can be attributed to the need for an interference fit on the shaft and/or in the housing, combined with thermal expansion of the bearing rings and associated components. Sufficient internal clearance in a bearing during operation is extremely important if the bearing is to operate satisfactorily. As a general rule, ball bearings should have an oper­ ating clearance (or preload) that is virtually zero. Cylindrical, needle, spherical and CARB toroidal roller bearings, on the other hand, should always have some residual (radial) clearance – however small – in operation. The same is true for tapered roller and angular contact ball bearings. However, in applications where a high degree of stiffness is required, tapered roller and angular contact ball bearings can be mounted with a certain amount of preload († Bearing preload, page 214).

E

Fig. 3 Radial internal clearance

Axial internal clearance

149

Bearing specifics The initial internal clearance referred to as Normal implies that a suitable operating clearance can be obtained if the recommended shaft and housing fits are realized during mounting and operating conditions are normal. Where operating and mounting ­conditions differ from normal, for example, when interference fits are used for both bearing rings or considerable temperature differences prevail, bearings with greater or smaller internal clearance than Normal are required. In these cases, SKF recommends checking residual (radial) clearance in the bearing after it has been mounted. Bearings with an internal clearance other than Normal are identified by the suffixes C1 to C5 († table 16). The clearance values for the various bearing types are listed in the relevant product chapters and are valid for unmounted bearings. For paired (universally matchable) single row angular contact ball bearings and tapered roller bearings, double row angular contact ball bearings and four-point contact ball bearings, values for the axial internal clearance are listed instead of radial clearance, as the axial clearance is of greater importance for these bearing types. For additional information about clearance or preload, refer to Selecting internal clearance or preload († page 212).

Table 16 Supplementary designation for internal clearance Suffix

Internal clearance

C1

Smaller than C2

C2

Smaller than Normal

CN

Normal, only used together with an additional letter that identifies a reduced or displaced clearance range.

C3

Greater than Normal

C4

Greater than C3

C5

Greater than C4

150

Materials for rolling bearings The materials from which bearing components are made, determine, to a large extent, the performance and reliability of the bearing. For the bearing rings and rolling elements, typical considerations include hardness for load carrying capacity, fatigue resistance in the rolling contact area, under clean or contaminated ­lubrication conditions, and the dimensional stability of the bearing components. For the cage, considerations include friction, strain, inertial forces, and in some cases, the chemical action of certain lubricant additives, solvents, coolants and refrigerants. The relative import­ ance of these considerations can be affected by other operational parameters including moisture, elevated temperatures, shock loads or a combination of these and other conditions. Rolling bearings with integral contact seals can also have a considerable impact on the performance and reliability of the bearings. Their materials must be able to resist heat, chemicals and oxidation. Bearings that are capped on both sides normally are lubricated for life. For detailed information about lubrication and lubricants, refer to Lubrication († page 239). SKF has the competence and facilities to provide a variety of materials, processes and coatings. Therefore, SKF application engineers can assist in selecting materials that can provide superior performance for a particular application.

Materials for rolling bearings

Materials for bearing rings and rolling elements Bearing steels for through-hardening The most common steel for through-hardening is a carbon chromium steel, containing approxi­ mately 1% carbon and 1,5% chromium, in accordance with ISO 683-17. Today, carbonchromium steel is one of the oldest and most intensively investigated steels due to the continuously increasing demands for extended bearing service life. The composition of this bearing steel provides an optimum balance between manufacturing and application performance. This steel normally undergoes a martensitic or bainitic heat treatment to obtain a hardness between 58 and 65 HRC. Within the last few years, process developments have enabled more stringent cleanliness specifications to be realized, which has had a significant impact on the consistency and quality of SKF’s bearing steel. The reduction of oxygen and harmful non-metallic inclusions has led to significantly improved prop­ erties of rolling bearing steels – the steels from which SKF Explorer bearings are made. Bearing steels for induction-hardening Surface induction-hardening offers the possibility to selectively harden a component’s raceway, while leaving the remainder of the component unaffected by the hardening pro­ cess. The steel grade and the manufacturing processes used prior to surface inductionhardening dictate the properties in the un­ affected areas, which means that a combi­ nation of properties can be achieved in one component. An example of this is the flanged wheel hub bearing unit (HBU), where the properties of the unhardened flange must resist structural fatigue, while the raceways are hardened to resist rolling contact fatigue.

Bearing steels for case-hardening Chromium-nickel and manganese-chromium alloyed steels in accordance with ISO 683-17 with a carbon content of approximately 0,15% are the steels most commonly used for casehardened SKF rolling bearing components. In applications where there are high tensile interference fits and heavy shock loads, SKF recommends bearings with case-hardened rings and/or rolling elements. Stainless steels The most common stainless steels used for SKF bearing rings and rolling elements are high chromium content steels like X65Cr14 in accordance with ISO 683-17 and X105CrMo17 in accordance with EN 10088-1. It should be noted that for some applications, corrosion resistant coatings might be an excellent alternative to stainless steel. For add­ itional information about alternative coatings, contact the SKF application engineering service. High-temperature bearing steels Depending on the bearing type, standard bearings made of steels for through-hardening and surface-hardening have a recommended maximum operating temperature, which ranges between 120 and 200 °C (250 to 390 °F). The maximum operating temperature is directly related to the heat treat process. For operating temperatures up to 250 °C (480 °F), a special heat treat (stabilization) process can be applied. In this case, however, the process reduces the load carrying capacity of the bearing, which must be taken into consideration. For bearings operating at elevated tempera­ tures above 250 °C (480 °F) for extended ­periods, highly alloyed steels like 80MoCrV42-16, manufactured in accordance with ISO 683-17, should be used. This steel, which retains its hardness, enables the bearing to maintain its performance characteristics even under extreme temperature conditions. For additional information about high-temperature bearing steels, contact the SKF application engineering service.

151

E

Bearing specifics Ceramics The common ceramic used for SKF bearing rings and rolling elements is a bearing grade silicon nitride material in accordance with ISO 26602. It consists of fine elongated grains of beta-silicon nitride in a glassy phase matrix. It provides a combination of favourable prop­ erties for rolling bearings, such as high hardness, low density, low coefficient of thermal expansion, high electric resistivity, low dielectric constant and no response to magnetic fields († table 17).

Cage materials Stamped metal cages Sheet steel cages

The majority of stamped sheet steel cages are made of continuously hot-rolled low carbon steel in accordance with EN 10111. These lightweight cages have relatively high strength and can be surface treated to further reduce friction and wear. Stamped cages normally used in stainless steel bearings are made of X5CrNi18-10 stainless steel, in accordance with EN 10088-1. Sheet brass cages

Stamped sheet brass cages are used for some small and medium-size bearings. The brass used for these cages is in accordance with EN 1652. In applications like refriger­ation compressors that use ammonia, season cracking in sheet brass might occur, therefore machined brass or steel cages should be used instead.

Table 17 Comparison of the material properties of bearing steel and bearing grade silicon nitride Material properties

Bearing steel

Bearing grade silicon nitride

Mechanical properties Density [g/cm 3] Hardness Modulus of elasticity [kN/mm2] Thermal expansion [10 –6 /K]

7,9 700 HV10 210 12

3,2 1 600 HV10 310 3

0,4 ¥ 10 –6 (Conductor) – –

10 12 (Insulator) 15 8

Electrical properties (at 1 MHz) Electrical resistivity [Wm] Dielectric strength [kV/mm] Relative dielectric constant

152

Materials for rolling bearings Machined metal cages

Polymer cages

Machined steel cages

Polyamide 66

Machined steel cages are normally made of non-alloyed structural S355GT (St 52) type steel in accordance with EN 10 025:1990 + A:1993. To improve sliding and wear-resistance properties, some machined steel cages are surface treated. Machined steel cages are used for large bearings or in applications where there is a danger that season cracking, caused by a chemical reaction, may occur if a brass cage is used. Steel cages can be used at operating temperatures up to 300 °C (570 °F). They are not affected by the mineral or synthetic oilbased lubricants normally used for rolling bearings, or by the organic solvents used to clean bearings.

For the majority of injection moulded cages, polyamide 66 (PA66) is used. This material, with or without glass fibres, is characterized by a favourable combination of strength and elasticity. The mechanical properties like strength and elasticity of polymer materials are temperature dependent and subject to ageing. The most important factors that play a role in the ageing process are temperature, time and the medium (lubricant) to which the polymer is exposed. Diagram 1 shows the relationship between these factors for glass fibre reinforced PA66. It shows that cage life decreases with increasing temperature and the aggressiveness of the lubricant.

Machined brass cages

Most brass cages are machined from a CW612N cast or wrought brass in accordance with EN 1652. They are unaffected by most common bearing lubricants, including synthetic oils and greases, and can be cleaned ­u sing normal organic solvents. Brass cages should not be used at temperatures above 250 °C (480 °F).

E Diagram 1

Cage ageing life for glass fibre reinforced polyamide 66 Mild lubricants Aggressive lubricants

Cage ageing life [h]

100 000

10 000

1 000

100

50 (120)

100 (210)

150 (300)

200 (390) Bearing temperature [°C (°F)]

153

Bearing specifics Therefore, whether polyamide cages are suitable for a specific application depends on the operating conditions and life requirements. The classification of lubricants into “aggressive” and “mild” is reflected by the “permissible operating temperature” for cages made of glass fibre reinforced PA66 with various lubricants († table 18). The permissible operating temperature in table 18 is defined as the temperature that provides a cage ageing life of at least 10 000 operating hours. Some media are even more “aggressive” than those provided in table 18. A typical example is ammonia, used as a refrigerant in compressors. In those cases, cages made of glass fibre reinforced PA66 should not be used at operating temperatures above 70 °C (160 °F). Polyamide also has a low temperature limit because it loses its elasticity, which can result in cage failures under extremely cold conditions. As a result, cages made of glass fibre ­reinforced PA66 should not be used in applica-

tions where the continuous operating temperature is below –40 °C (–40 °F). In applications where a high degree of toughness is a critical operational parameter, such as in railway axleboxes, a super-tough modified PA66 can be used. For additional information, contact the SKF application engin­ eer­ing service.

Table 18 Permissible operating temperatures for PA66 cages with various bearing lubricants

Lubricant

Permissible operating temperature 1)



°C

°F

Mineral oils Oils without EP additives, e.g. machine or hydraulic oils

120

250

Oils with EP additives, e.g. industrial and automotive gearbox oils

110

230

Oils with EP additives, e.g. automotive rear axle and differential gear oils (automotive), hypoid gear oils

100

210

Synthetic oils Polyglycols, poly-alpha-olefins Diesters, silicones Phosphate esters

120 110 80

250 230 175

Greases Lithium greases Polyurea, bentonite, calcium complex greases

120 120

250 250

For sodium and calcium greases and other greases with a maximum operating temperature ≤ 120 °C (250 °F), the maximum temperature for a polyamide cage is the same as the maximum operating temperature for the grease.

1) Measured on the outside surface of the outer ring; defined as the temperature that provides a cage ageing life of at least

10 000 operating hours.

154

Materials for rolling bearings Polyamide 46

Seal materials

Glass fibre reinforced polyamide 46 (PA46) is the standard cage material for some small and medium-size CARB toroidal roller bearings. The permissible operating temperature is 15 °C (25 °F) higher than for glass fibre reinforced PA66.

Seals integrated in SKF bearings are typically made of elastomers. The type of material can depend on the series and size of the bearing as well as the application requirements. SKF seals are generally made of the materials listed below.

Polyetheretherketone

Acrylonitrile-butadiene rubber Acrylonitrile-butadiene rubber (NBR) is the “universal” seal material. This copolymer, produced from acrylonitrile and butadiene, has good resistance to the following media:

The use of the glass fibre reinforced polyetheretherketone (PEEK) has become more popular for demanding conditions regarding high speeds, chemical resistance or high temperatures. The exceptional properties of PEEK provide a superior combination of strength and flexibility, high operating temperature range, high chemical and wear-resistance and good processability. Due to these outstanding features, PEEK cages are available as standard for some ball and cylindrical roller bearings, such as hybrid and/or super-precision bearings. The material does not show signs of ageing by temperature or oil additives up to 200 °C (390 °F). However, the maximum temperature for high-speed use is limited to 150 °C (300 °F) as this is the softening temperature of the polymer.

• most mineral oils and greases with a mineral oil base • normal fuels, such as petrol, diesel and light heating oils • animal and vegetable oils and fats • hot water It also can tolerate dry running of the lip for short periods. The permissible operating tem­ pera­ture range is –40 to +100 °C (–40 to +210 °F). Temperatures up to 120 °C (250 °F) can be tolerated for brief periods. At higher temperatures, the material hardens.

Phenolic resin

Lightweight, fabric reinforced phenolic resin cages can withstand heavy inertial forces, but are not able to accommodate high operating temperatures. In most cases, these cages are used as standard in super-precision angular contact ball bearings. Cages made of other materials In addition to the materials described above, SKF bearings for special applications may be fitted with cages made of other engineered polymers, light alloys or special cast iron. For additional information about alternative cage materials, contact the SKF application engin­ eer­ing service.

155

E

Bearing specifics Hydrogenated acrylonitrile-butadiene rubber Hydrogenated acrylonitrile-butadiene rubber (HNBR) has appreciably better wear-characteristics than NBR so that seals made of this material have a longer service life. HNBR is also more resistant to heat, ageing and hardening in hot oil or ozone exposure. The upper operating temperature limit is 150 °C (300 °F), which is appreciably higher than that of NBR. Fluoro rubber Fluoro rubbers (FKM) are characterized by their high thermal and chemical resistance. Their resistance to ageing and ozone is very good and their gas permeability is very slight. They have exceptionally good wear-characteristics even under harsh environmental conditions and can withstand operating temperatures up to 200 °C (390 °F). Seals made of this material can tolerate dry running of the lip for short periods. FKM is also resistant to oils and hydraulic fluids, fuels and lubricants, mineral acids and aliphatic as well as aromatic hydrocarbons which would cause seals made of other mater­ ials to fail. In the presence of esters, ethers, ketones, certain amines and hot anhydrous hydrofluorides, FKM should not be used. Seals made of FKM exposed to an open flame or temperatures above 300 °C (570 °F) are a health and environmental hazard! They remain dangerous even after they have cooled. Read and follow the safety precautions († WARNING).

156

W arning Safety precautions for fluoro rubber and Polytetrafluoroethylene Fluoro rubber (FKM) and Polytetrafluoro­ ethylene (PTFE) are very stable and harmless under normal operating conditions up to 200 °C (390 °F). However, if exposed to extreme temperatures above 300 °C (570 °F), such as fire or the open flame of a cutting torch, FKM and PTFE give off hazardous fumes. These fumes can be harmful if inhaled, as well as if they contact the eyes. In addition, once the seals have been heated to such temperatures, they are dangerous to handle even after they have cooled. Therefore, they should never come in contact with the skin. If it is necessary to handle bearings with seals that have been subjected to high temperatures, such as when dismounting the bearing, the following safety precautions should be observed: • Always wear protective goggles, gloves and an appropriate breathing apparatus. • Place the remains of the seals in an airtight plastic container marked with a symbol for “material will etch”. • Follow the safety precautions in the ­appropriate material safety data sheet (MSDS). If there is unintentional contact with the seals, wash hands with soap and plenty of water and flush eyes with plenty of water and consult a doctor immediately. If the fumes have been inhaled, consult a doctor immediately. The user is responsible for the correct use of the product during its service life and its proper disposal. SKF takes no responsibility for the improper handling of FKM or PTFE, or for any injury resulting from their use.

Materials for rolling bearings Polyurethane Polyurethane (PUR) is a wear-resistant organic material which has good elastic properties. It withstands operating temperatures from –20 up to +80 °C (–5 to 175 °F). It has good resistance to mineral oil-based greases, mineral oils with no or a low proportion of EP additives, ­water and water-oil mixtures. It is not ­resistant to acids, alkalis or polar solvents.

Lubricants Capped bearings normally have a factory grease fill. The lubricant is an integral part of the bearing. For additional information, refer to the relevant product chapter.

Coatings Coating is a well-established method to upgrade materials and to provide bearings with additional benefits for specific application conditions. Two different coating methods de­ veloped by SKF are available and have been proven successful in many applications. NoWear is a wear-resistant surface coating that applies a low-friction carbon coating on the bearing inner ring raceway(s) and/or the rolling elements. It can withstand long periods of operation under marginal lubrication conditions. For additional information, refer to NoWear coated bearings († page 1241). INSOCOAT bearings are standard bearings that have the external surfaces of their inner or outer ring plasma-sprayed with an alu­min­ ium oxide to form a coating. It offers resistance to the damage that can be caused by the passage of stray electric current through the bearing. For additional information, refer to INSOCOAT bearings († page 1205). Other coatings like zinc chromate, for ex­ ample, can offer an alternative to stainless steel bearings in a corrosive environment, ­especially for ready-to-mount bearing units.

E

157

Design considerations

Bearing systems . . . . . . . . . . . . . . . . . . Locating/non-locating bearing system. . Adjusted bearing system. . . . . . . . . . . . . “Floating” bearing system. . . . . . . . . . . .



160 160 163 164

Radial location of bearings. . . . . . . . . . Selecting fits for bearings with a cylindrical bore . . . . . . . . . . . . . . . . . . . Bearings with a tapered bore. . . . . . . . . . Recommended fits. . . . . . . . . . . . . . . . . . Shaft and housing tolerances and fits. . . Fits for hollow shafts . . . . . . . . . . . . . . . . Dimensional and geometrical tolerances of bearing seats and abutments . . . . . . . Dimensional tolerances. . . . . . . . . . . . Tolerances for total radial run-out . . . Tolerances for total axial run-out. . . . Tolerances for tapered shaft seats . . . Surface roughness of bearing seats . . . .

165

200 200 200 200 202 204

Axial location of bearings . . . . . . . . . . . Methods of location . . . . . . . . . . . . . . . . . Bearings with a cylindrical bore. . . . . . Bearings with a tapered bore. . . . . . . . Abutment and fillet dimensions. . . . . . . . CARB toroidal roller bearings . . . . . . .

204 205 205 207 208 209

165 169 169 171 176

Design of associated components . . . . 210 Raceways on shafts and in housings. . . . 210 Provisions for mounting and dismounting. . . . . . . . . . . . . . . . . . . . . . . 210

Selecting internal clearance or preload. . . . . . . . . . . . . . . . . . . . . . . . . . . Clearance versus preload. . . . . . . . . . . . . Bearing clearance. . . . . . . . . . . . . . . . . . . Selecting a clearance class . . . . . . . . . Bearing preload . . . . . . . . . . . . . . . . . . . . Considerations for preload. . . . . . . . . . Effects of bearing preload. . . . . . . . . . Preload in bearing systems with angular contact ball or tapered roller bearings . . . . . . . . . . . . . . . . . . . Adjustment procedures. . . . . . . . . . . . . . Individual adjustment. . . . . . . . . . . . . . Collective adjustment. . . . . . . . . . . . . . Preloading with springs. . . . . . . . . . . . Selecting the correct preload. . . . . . . . . . Bearings for preloaded bearing systems. . . . . . . . . . . . . . . . . . . . Sealing solutions . . . . . . . . . . . . . . . . . . Seal types. . . . . . . . . . . . . . . . . . . . . . . . . Selecting seal type. . . . . . . . . . . . . . . . . . Non-contact seals . . . . . . . . . . . . . . . . Contact seals . . . . . . . . . . . . . . . . . . . . Integral bearing seals. . . . . . . . . . . . . . . . Bearings with shields. . . . . . . . . . . . . . Bearings with contact seals. . . . . . . . . External seals. . . . . . . . . . . . . . . . . . . . . . Non-contact seals . . . . . . . . . . . . . . . . Contact seals . . . . . . . . . . . . . . . . . . . .



212 213 213 213 214 215 217 218 221 221 224 224 225 225 226 226 227 228 228 229 229 229 231 231 234

159

F

Design considerations

Bearing systems A bearing system, which is typically used to support a rotating shaft, generally requires two bearing arrangements – one at each end of the shaft. Depending on the requirements, such as stiffness or load directions, a bearing arrangement consists of one or more (matched) bearings. Typically, the purpose of a bearing system is to support and locate the shaft radially and axially, relative to stationary components, like housings. Depending on the application, loads, requisite running accuracy and cost considerations, various bearing systems can be designed: • a locating/non-locating bearing system • an adjusted bearing system • a “floating” bearing system

Alternatively, the bearing arrangement in the locating position can consist of a com­bin­ ation of two bearings: • A radial bearing that only accommodates radial load, such as a cylindrical roller bearing that has one ring without flanges. • A bearing that provides axial location, such as a deep groove ball bearing, a four-point contact ball bearing, or a double direction thrust bearing. The bearing that locates the shaft axially must not be located radially and is typically mounted with a small radial gap in the housing. There are two ways to accommodate thermal displacements of the shaft at the nonFig. 1

Bearing systems consisting of a single bearing that can support radial, axial and moment loads, e.g. for an articulated joint, are not ­covered in this catalogue. For information about these bearing systems, contact the SKF application engineering service.

Locating/non-locating bearing system A locating/non-locating bearing system in a typical industrial application is designed to accommodate thermal expansion and contraction of a shaft. In this system, the bearing arrangement at one end of the shaft must be able to locate the shaft axially. This is accomplished by securing one bearing axially on the shaft and in the housing. The bearing arrangement on the opposite end of the shaft is non-locating and is designed to accommodate thermal displacements of the shaft relative to the housing to avoid induced internal loads. For the locating bearing position, radial bearings that can accommodate combined (­r adial and axial) loads are used. These include deep groove ball bearings, double row or matched single row angular contact ball bearings, self-aligning ball bearings, spherical roller bearings, matched tapered roller bearings, NUP design cylindrical roller bearings, or NJ design cylindrical roller bearings mounted with an HJ angle ring.

160

Fig. 2

Bearing systems locating bearing position. The first is to use a bearing that only accommodates radial loads and enables axial displacement within the bearing. These include CARB toroidal roller bearings, needle roller bearings and cylindrical roller bearings that have one ring without flanges. The other method is to use a radial bearing mounted with a small radial gap in the housing so that the outer ring is free to move axially. From the large number of locating/non-­ locating bearing combinations, the popular ones are listed in the following. For stiff bearing arrangements requiring “frictionless” axial displacement within a bearing, the following combinations should be considered:

Fig. 3

• deep groove ball bearing / cylindrical roller bearing († fig. 1) • double row angular contact ball bearing / NU or N design cylindrical roller bearing († fig. 2) • matched single row tapered roller bearings / NU or N design cylindrical roller bearing († fig. 3) • NUP design cylindrical roller bearing / NU design cylindrical roller bearing († fig. 4) • NU design cylindrical roller bearing and a four-point contact ball bearing / NU design cylindrical roller bearing († fig. 5)

Fig. 4

F Fig. 5

161

Design considerations For the bearing systems listed above, angular misalignment of the shaft relative to the housing must be kept to a minimum. If this is not possible, SKF recommends a self-aligning bearing system comprised of either:

Fig. 7

• spherical roller bearing / CARB toroidal ­roller bearing († fig. 6) • self-aligning ball bearing / CARB toroidal roller bearing The ability of this bearing system to accom­mo­ date angular misalignment of the shaft relative to the housing, as well as axial displacement of the shaft within the CARB bearing, avoids induced internal axial loads in the bearing system. For bearing systems with a rotating inner ring load, where changes in the shaft length are to be accommodated between the bearing and its seat, axial displacement should take place between the bearing outer ring and its housing. The most common combinations are:

Fig. 8

• deep groove ball bearing / deep groove ball bearing († fig. 7) • self-aligning ball or spherical roller bearing / self-aligning ball or spherical roller bearing († fig. 8) • matched single row angular contact ball bearings / deep groove ball bearing († fig. 9)

Fig. 6

162

Fig. 9

Bearing systems

Adjusted bearing system

Fig. 10

In an adjusted bearing system, the shaft is axially located in one direction by one bearing arrangement and in the opposite direction by the other. This system is referred to as crosslocated and is generally used for short shafts. The most suitable bearings are: • angular contact ball bearings († fig. 10) • tapered roller bearings († fig. 11) In a number of cases where single row angular contact ball bearings or tapered roller bearings are used for a cross-located bearing system preload may be necessary († Bearing preload, page 214). Fig. 11

F

163

Design considerations

“Floating” bearing system Like an adjusted bearing system, a “floating” bearing system is also cross-located. How­ ever, a “floating” bearing system is more suitable for applications where axial stability of the shaft is less demanding or where other components on the shaft locate it axially. Suitable bearings for this system are: • deep groove ball bearings († fig. 12) • self-aligning ball bearings • spherical roller bearings In this system, it is important that one ring of each bearing, preferably the outer ring, is able to move axially on its seat. A “floating” bearing system can also be obtained with two NJ design cylindrical roller bearings used in mirrored ­arrangements with offset rings († fig. 13). In this case, axial displacement can occur within the bearings.

Fig. 12

164

Fig. 13

Radial location of bearings

Radial location of bearings If the load carrying ability of a bearing is to be fully exploited, its rings or washers should be fully supported around their complete circumference and across the entire width of the raceway. The support, which should be firm and even, can be provided by a cylindrical or tapered seat or, for thrust bearing washers, by a flat (plane) support surface. This means that bearing seats should be manufactured to adequate tolerance classes and uninterrupted by grooves, holes or other features. In addition, the bearing rings should be reliably secured to prevent them from turning on or turning in their seats under load. In general, satisfactory radial location and adequate support can only be obtained when the rings are mounted with an appropriate degree of interference († Bearing clearance, page 213 and Bearing preload, page 214). ­Inadequately or incorrectly secured bearing rings generally can cause damage to the bearing system. However, when axial displacement (as with a non-locating bearing) or easy mounting and dismounting are required, an interference fit cannot always be used. In ­c ases where a loose fit is required, special precautions are necessary to limit the inevit­ able wear from creep (turning). This can be done, for example, by surface hardening the bearing seat and abutments, lubricating ­mating surfaces via special lubrication grooves, or providing locating slots in the bearing ring side faces to accommodate keys or other holding devices († fig 12).

Selecting fits for bearings with a cylindrical bore

• rotating load • stationary load • direction of load indeterminate Rotating loads pertain if either the ring or the direction of the applied load is stationary while the other rotates. Heavy loads that do not rotate but oscillate, such as loads acting on connecting rod bearings, are generally considered to be rotating loads. A bearing ring subjected to a rotating load creeps on its seat if mounted with a too loose fit, and leads to wear and/or fretting corrosion of the contact surfaces. To prevent this, an adequate interference fit between the rotating ring and its seat must be used. The degree of interference is dictated by the operating conditions († points 2 and 4 below). Stationary loads pertain if either both the bearing ring and the direction of the applied load are stationary or both are rotating at the same speed. Under these conditions, a bearing ring normally does not turn on its seat. Therefore, the ring does not need to have an interfer­ ence fit, unless it is required for other reasons. Direction of load indeterminate refers to variable external loads, shock loads, vibrations and unbalanced loads in high-speed applications. These give rise to changes in the direction of load, which cannot be accurately described. When the direction of load is indeterminate and particularly where heavy loads are involved, SKF recommends an interference fit for both rings. For the inner ring, the recommended fit for a rotating load is normally used. However, when the outer ring must be free to move axially in the housing, and the load is not heavy, a somewhat looser fit than that recommended for a rotating load can be used.

When selecting fits for bearings with a ­c ylindrical bore, the information provided in this section should be considered, together with the general guidelines in the section thereafter. 1. Conditions of rotation

Conditions of rotation take the relationship between the direction of an applied load and the rotating bearing ring into consideration († table 1, page 166). Essentially, there are three different conditions: 165

F

Design considerations 2. Magnitude of the load

The degree of interference between the inner ring and the shaft seat must be selected based on the magnitude of the load on the bearing. Typically, the inner ring of a bearing deforms proportionately to the load. This deformation can loosen the interference fit between the ­inner ring and shaft, causing the ring to creep (turn) on its shaft seat. The heavier the load, the tighter the interference fit required († fig. 14). An interference fit has an influ-

ence on the bearing clearance or preload († Bearing clearance, page 213 and Bearing preload, page 214). Shock loads and vibration also need to be considered, as a tighter fit might be necessary under these conditions. Magnitude of bearing load is defined as: • light load: • normal load: • heavy load: • very heavy load:

P ≤ 0,05 C 0,05 C < P ≤ 0,1 C 0,1 C < P ≤ 0,15 C P > 0,15 C Table 1

Conditions of rotation and loading Operating conditions

Schematic illustration

Load condition

Example

Recommended fits

Rotating inner ring

Rotating load on the inner ring

Belt driven shafts

Interference fit for the inner ring

Stationary outer ring

Stationary load on the outer ring

Loose fit for the outer ring possible

Constant load direction

Stationary inner ring

Stationary load on the inner ring

Conveyor idlers

Loose fit for the inner ring possible

Rotating outer ring

Rotating load on the outer ring

Car wheel hub bearings

Interference fit for the outer ring

Rotating inner ring

Stationary load on the inner ring

Vibratory applications

Interference fit for the outer ring

Stationary outer ring

Rotating load on the outer ring

Vibrating screens or motors

Loose fit for the inner ring possible

Stationary inner ring

Rotating load on the inner ring

Gyratory crusher

Interference fit for the inner ring

Rotating outer ring

Stationary load on the outer ring

(Merry-go-round drivers)

Loose fit for the outer ring possible

Constant load direction

Load rotates with the inner ring

Load rotates with the outer ring

166

Radial location of bearings 3. Bearing internal clearance

Fig. 14

Bearings with an interference fit on a shaft or in a housing elastically deform (expand or compress) the ring to reduce the bearing internal clearance. However, a certain minimum clearance should remain († Bearing clearance, page 213). The interference fit can be so tight that bearings with an initial clearance that is greater than Normal have to be used to prevent unwanted preload († fig. 15). 4. Temperature differences

In many applications, the inner ring temperature is higher than the outer ring temperature. This can reduce internal clearance († fig. 16 and Bearing clearance, page 213) or increase preload († Bearing preload, page 214). In operation, bearing rings normally reach a temperature that is higher than that of the components to which they are fitted. This can loosen the fit of the inner ring on its seat, while outer ring expansion can prevent the desired axial displacement of the ring in its housing. Fast start-ups can also loosen the inner ring fit when frictional heat generated by the bearing is not dissipated quickly enough. In some cases, friction from bearing seals can generate enough heat to loosen the inner ring fit. Temperature differences and the direction of heat flow in the bearing arrangement must be taken into consideration.

Fig. 15

Clearance before mounting

Clearance after mounting

Fit

F

5. Running accuracy

For applications requiring a high degree of running accuracy, interference fits are recommended. Loose fits can reduce stiffness and contribute to vibration. Bearing seats should conform at least to IT5 tolerance grade for the shaft and IT6 tolerance grade for the housing. Tight total run-out tolerances should also be applied († table 11, page 202).

Fig. 16 Cold

Compression

Reduced clearance Expansion

Warm

167

Design considerations 6. Design and material of the shaft and housing

The fit of a bearing ring on its seat must not distort the ring (out-of-round). This can be caused, for example, by discontinuities in the seat surface. Therefore, SKF generally does not recommend split housings where outer rings require a tight, M7 or even tighter, interference fit. The selected tolerance class for a split housing should not result in a fit tighter than that obtained with tolerance group H (or at most, tolerance group K). To provide adequate support for bearing rings mounted in thin-walled housings, light alloy housings or on hollow shafts, tighter ­interference fits than those normally recommended for thick-walled steel or cast iron housings or for solid shafts should be used († Fits for hollow shafts, page 176). Also, sometimes interference fits that are not so tight may be required if the shaft material has a higher coefficient of thermal expansion than standard steel. 7. Ease of mounting and dismounting

Bearings with a loose fit are usually easier to mount and dismount than those with interference fits. In applications that require interference fits and relatively easy mounting and dismounting, separable bearings or bearings with a tapered bore should be considered († Bearings with a tapered bore). Bearings with a ­t apered bore can be mounted on adapter or withdrawal sleeves on plain or stepped shafts, or mounted directly on a tapered shaft seat († figs. 25 to 27, page 207). 8. Displacement of the bearing in the non-locating position

If bearings in the non-locating position cannot accommodate axial displacement internally (within the bearing), the outer ring must be free to move axially on its seat at all times. To do this, the ring that carries a stationary load can have a loose fit († fig. 20, page 205). For some particular applications, where the outer ring is under stationary load and the bearing must move axially in the housing seat to accommodate displacement, a hardened intermediate bushing or sleeve can be fitted in the housing bore to prevent the bearing from damaging its seat. Any damage to the housing seat can restrict axial movement or prohibit it 168

entirely over time. This is particularly import­ ant if the housing is made of a light alloy. If needle roller bearings, CARB toroidal roller bearings or cylindrical roller bearings without flanges on one ring are used, both bearing rings can be mounted with an interference fit, because axial displacement can take place internally, within the bearing.

Radial location of bearings

Bearings with a tapered bore Bearings with a tapered bore can be mounted directly on tapered shaft seats, or on adapter or withdrawal sleeves († figs. 25 to 28, page 207). Sleeves that are fitted to cylindrical shaft seats have an external taper. Whether the bearing is mounted on a sleeve or directly on the shaft, the fit of the bearing inner ring is not pre-determined by the bearing seat, as is the case for bearings with a cylindrical bore. Instead, the fit for bearings with a tapered bore is determined by the distance through which the ring is driven up on its tapered seat or on the sleeve. Special precautions relative to the internal clearance reduction must be considered as mentioned under Bearing clearance († page 213) and under Self-aligning ball bearings († page 537), Spherical roller bearings († page 879), and CARB toroidal roller bearings († page 957). If the bearings are to be mounted on an adapter or withdrawal sleeve, larger diameter tolerances are permitted for the sleeve seat, but the tolerances for total radial run-out must be tighter († Dimensional and geo­met­ ric­al tolerances of bearing seats and abutments, page 200).

Recommended fits The tolerances for the bore and outside diameter of rolling bearings are standardized internationally († Tolerances, page 132). To achieve an interference or loose fit for metric bearings with a cylindrical bore and outside surface, suitable tolerance classes for the bearing seat on the shaft and in the housing bore are selected from the ISO tolerance system. Only a limited number of ISO tolerance classes need be considered for the shaft and housing seats for rolling bearings. The location of the most commonly used tolerance classes relative to the bearing bore and outside diameter surface are shown in fig. 17, page 170 (valid for bearings with Normal tolerances). Each ISO tolerance class is identified by a letter and a number. The letter, lower case for shaft diameters and upper case for housing bores, locates the tolerance zone relative to the nominal dimension. The number indicates the range of the tolerance zone. The higher the number, the larger the tolerance zone.

Recommendations for bearing fits for solid steel shafts are provided in the tables referenced in the following: • radial bearings with a cylindrical bore († table 2, page 172) • thrust bearings († table 3, page 174) Recommendations for bearing fits for cast iron and steel housings are provided in the tables referenced in the following: • radial bearings – non-split housings († table 4, page 174) • radial bearings – split or non-split housings († table 5, page 175) • thrust bearings (†table 6, page 175) These recommendations are based on the general selection guidelines described above, which take developments in bearing and housing materials, design and manufacturing into account. Modern bearings and housings can accommodate substantially heavier loads than was previously possible. The recommendations in this catalogue reflect these improvements. NOTE: All ISO tolerance classes are valid with the envelope requirement (such as H7V E ) in accordance with ISO 14405-1. For practical reasons, this is not indicated in the following tables. ISO 14405-1 offers more possibilities to specify fits. For additional information, contact the SKF application engineering service.

169

F

Design considerations Stainless steel bearings or shafts

The recommended fits in tables 2 to 6 († pages 172 to 175) can be used for stainless steel bearings. However, footnote 3 in table 2 († page 172) does not apply, because stainless steel has a much higher coefficient of thermal expansion than standard steel. If tighter fits than those recommended in table 2 († page 172) are needed, contact the SKF application engineering service. It may also be necessary to consider the initial bearing clearance, such as when using stainless steel shafts at elevated temperatures († Bearing internal clearance, page 149).

Fig. 17

+ 0 – F7 G7 G6 H10 H9 H8 H7 H6 J7 J6 JS7 JS6

K7 K6

M7

Loose fit Transition fit Interference fit

M6 N7

N6 P7

p7

j6 + f6 g6 g5 h8 h6 h5 0 –

1) s7 min ± IT7/2 2) s6 min ± IT6/2

170

k6 j5 js6 js5

m6 k5

n6 m5

r7 p6

P6 s71) s62) r6

n5

Interference fit Transition fit Loose fit

Radial location of bearings

Shaft and housing tolerances and fits The values listed for the shaft († tables 7, page 178) and housing († tables 8, page 190) tolerances enable the character of the fit to be established: • the upper and lower limits of Normal tolerances for the bearing bore or outside diameter deviations • the upper and lower limits of the shaft or housing bore diameter deviations in accordance with ISO 286-2 • the smallest and largest values of the the­ oretical interference (–) or clearance (+) in the fit • the smallest and largest values of the probable interference (–) or clearance (+) in the fit

When bearings with higher dimensional accuracy than Normal are used, the bore and outside diameter tolerances are tighter. Therefore, values for an interference or loose fit need to be adjusted correspondingly. For information about calculating these limits more accurately, contact the SKF application engineering service. Note: The signs for clearance and interference in this catalogue are in accordance with ISO 286-1. Clearance is now indicated with a “+” sign and interference with a “–” sign.

The appropriate values for rolling bearing shaft seats are listed for the following tolerances: • f5, f6, g5, g6, h5 († table 7a, page 178) • h6, h8, h9, j5, j6 († table 7b, page 180) • js4, js5, js6, js7, k4 († table 7c, page 182) • k5, k6, m5, m6, n5 († table 7d, page 184) • n6, p6, p7, r6, r7 († table 7e, page 186) • s6min ± IT6/2, s7min ± IT7/2 († table 7f, page 188) The appropriate values for rolling bearing housing seats are listed for the following tolerances:

F

• F7, G6, G7, H5, H6 († table 8a, page 190) • H7, H8, H9, H10, J6 († table 8b, page 192) • J7, JS5, JS6, JS7, K5 († table 8c, page 194) • K6, K7, M5, M6, M7 († table 8d, page 196) • N6, N7, P6, P7 († table 8e, page 198) Normal tolerances for the bore and outside diameter, for which the limiting values have been calculated, are valid for all metric rolling bearings except for metric tapered roller bearings when d ≤ 30 mm or D ≤ 150 mm and thrust bearings when D ≤ 150 mm. The diameter tolerances for these bearings deviate from the Normal tolerances for other rolling bearings († tables 3 to 10, pages 137 to 144). The values for the probable interference or loose fit cover 99% of all the combinations. 171

Design considerations

Fits for solid steel shafts Radial bearings with a cylindrical bore 1) Conditions

Examples

Rotating inner ring load or direction of load indeterminate Light and variable loads (P ≤ 0,05 C)

Conveyors, lightly loaded gearbox bearings

Normal to heavy loads (P > 0,05 C)

General bearing applications, electric motors, turbines, pumps, gearing, wood-working machines

Heavy to very heavy loads and shock loads under difficult operating conditions (P > 0,1 C)

Axleboxes for heavy railway vehicles, traction motors, rolling mills, wind turbines

High demands on running accuracy with light loads (P ≤ 0,05 C) 11)

Machine tools (precision class bearings)

Stationary inner ring load Easy axial displacement of inner ring on shaft desirable

Wheels on non-rotating axles

Easy axial displacement of inner ring on shaft unnecessary

Tension pulleys, rope sheaves

Axial loads only Bearing applications of all kinds

1) For needle roller bearings † Needle roller bearings, page 673. For Y-bearings † Y -bearings, page 421. 2) All ISO tolerance classes are valid with the envelope requirement (such as H7 E ) in accordance with ISO 14405-1. 3) Ball bearings under normal to heavy loads (P > 0,05 C) often require radial internal clearance greater than Normal when the

V

shaft tolerance classes listed above are used. If radial clearance is greater than Normal, but the operating conditions require tighter fits to prevent the inner ring from creeping, use the following tolerance classes: E   for shaft diameters 10 to 17 mm • n6V E   for shaft diameters > 140 to 300 mm • k4V E   for shaft diameters > 17 to 25 mm • p6V E   for shaft diameters > 300 to 500 mm • k5V E   for shaft diameters > 25 to 140 mm • m5V For additional information, contact the SKF application engineering service. The recommendations provided under this footnote are not valid for stainless steel bearings. 4) The tolerance in brackets applies to stainless steel bearings. 5) For stainless steel bearings within the diameter range 17 to 30 mm, tolerance class j5 E applies. V

172

Radial location of bearings Table 2

Shaft diameter [mm] Ball bearings 3)

Tolerance class 2)

Cylindrical roller bearings

Tapered roller bearings

CARB and spherical roller bearings

≤ 17 > 17 to 100 > 100 to 140 –

– ≤ 25 > 25 to 60 > 60 to 140

– ≤ 25 > 25 to 60 > 60 to 140

– – – –

js5 (h5) 4) j6 (j5) 4) k6 m6

≤ 10 > 10 to 17 > 17 to 100 – > 100 to 140 > 140 to 200 – > 200 to 500 – > 500 – –

– – – ≤ 30 > 30 to 50 – > 50 to 65 > 65 to 100 > 100 to 280 – > 280 to 500 > 500

– – – ≤ 40 – > 40 to 65 – > 65 to 200 > 200 to 360 – > 360 to 500 > 500

– – < 25 – 25 to 40 – > 40 to 60 > 60 to 100 > 100 to 200 – > 200 to 500 > 500

js5 j5 (js5) 4) k55) k6 m5 m6 n5 6) n6 6) p6 8) p76) r6 6) r76)

– – – – – –

> 50 to 65 > 65 to 85 > 85 to 140 > 140 to 300 > 300 to 500 > 500

– > 50 to 110 > 110 to 200 > 200 to 500 – > 500

> 50 to 70 – > 70 to 140 > 140 to 280 > 280 to 400 > 400

n5 6) n6 6) p6 8) r69) s6min ± IT6/28) s7min ± IT7/28)

8 to 240 – – – –

– 25 to 40 > 40 to 140 > 140 to 200 > 200 to 500

– 25 to 40 > 40 to 140 > 140 to 200 > 200 to 500

– – – – –

js4 js4 (j5) 10) k4 (k5) 10) m5 n5

F g612) h6

≤ 250 > 250

– –

≤ 250 > 250

≤ 250 > 250

j6 js6

6) 7)

Bearings with radial internal clearance greater than Normal may be necessary. Bearings with radial internal clearance greater than Normal are recommended for d ≤ 150 mm. When d > 150 mm, bearings with radial internal clearance greater than Normal may be necessary. 8) Bearings with radial internal clearance greater than Normal are recommended. 9) Bearings with radial internal clearance greater than Normal may be necessary. For cylindrical roller bearings, radial internal clearance greater than Normal is recommended. 10) The tolerance class in brackets applies to tapered roller bearings. For lightly loaded tapered roller bearings adjusted via the E   or js6V E   should be used. inner ring, tolerance class js5V 11) For a high degree of running accuracy, bearings with higher precision than Normal are required. The tolerances for the bore and outside diameter are tighter, which has an influence on the probable fits. To obtain relevant values, contact the SKF application engineering service. 12) Tolerance class f6 E   can be selected for large bearings to facilitate axial displacement on the shaft. V

173

Design considerations Table 3 Fits for solid steel shafts (for thrust bearings) 1) Conditions

Shaft diameter [mm]

Tolerance class 2)



h6

≤ 250 > 250 ≤ 200 > 200 to 400 > 400

j6 js6 k6 m6 n6

Axial loads only Thrust ball bearings Combined radial and axial loads on spherical roller thrust bearings Stationary load on shaft washer Rotating load on shaft washer, or direction of load indeterminate

1) 2)

For cylindrical roller thrust bearings † Cylindrical roller thrust bearings, page 1037. For needle roller thrust bearings † Needle roller thrust bearings, page 1057. All ISO tolerance classes are valid with the envelope requirement (such as h7V E ) in accordance with ISO 14405-1. Table 4

Fits for non-split cast iron and steel housings (for radial bearings) 1) Conditions

Examples

Tolerance class 2) 3)

Displacement of outer ring

Heavy loads on bearings in thin-walled housings, heavy shock loads (P > 0,1 C)

Roller bearing wheel hubs, big-end bearings

P7

Cannot be displaced

Normal to heavy loads (P > 0,05 C)

Ball bearing wheel hubs, big-end bearings, crane travelling wheels

N7

Cannot be displaced

Light and variable loads (P ≤ 0,05 C)

Conveyor rollers, rope sheaves, belt tensioner pulleys

M7

Cannot be displaced

Rotating outer ring load

Direction of load indeterminate Heavy shock loads

Electric traction motors

M7

Cannot be displaced

Normal to heavy loads (P > 0,05 C), axial displacement of outer ring unnecessary

Electric motors, pumps, crankshaft bearings

K7

In most cases, cannot be displaced

Small electric motors

J65)

Cannot be displaced

Accurate or quiet running 4) Ball bearings Tapered roller bearings 6)

1) For needle roller bearings † Needle roller bearings, page 673. 2) All ISO tolerance classes are valid with the envelope requirement (such as H7 E ) in accordance with ISO 14405-1. 3) For ball bearings, when D ≤ 100 mm, IT6 tolerance grade is often preferable and is recommended for bearings with thin-walled

V

rings, such as in the 7, 8 or 9 diameter series. For these series, total radial run-out tolerances IT4 are also recommended. 4) For super-precision bearings to tolerance class P5 or better, other recommendations apply. For additional information, refer to the information available online at skf.com/super-precision. 5) Tolerance class H6 E   can be selected instead of J6 E   to facilitate axial displacement in the housing bore. V V 6) Contact the SKF application engineering service.

174

Radial location of bearings Table 5 Fits for split or non-split cast iron and steel housings (for radial bearings) 1) Conditions

Examples

Tolerance class 2) 3)

Displacement of outer ring

Medium-size electric motors and generators, pumps, crankshaft bearings

J7

In most cases, can be displaced, but some (induced) axial force might occur

Loads of all kinds

General engineering, railway axleboxes

H74)

Can be displaced

Light to normal loads (P ≤ 0,1 C) with simple working conditions

General engineering

H8

Can be displaced

Thermal expansion of the shaft

Drying cylinders, large electrical machines with spherical roller bearings

G75)

Can be displaced

Direction of load indeterminate Light to normal loads (P ≤ 0,1 C), axial displacement of outer ring desirable Stationary outer ring load

1) For needle roller bearings † Needle roller bearings, page 673. 2) All ISO tolerance classes are valid with the envelope requirement (such as H7 E ) in accordance with ISO 14405-1. 3) For ball bearings, when D ≤ 100 mm, IT6 tolerance grade is often preferable and is recommended for bearings with thin-walled

V

rings, such as in the 7, 8 or 9 diameter series. For these series, cylindricity tolerances IT4 are also recommended. 4) For large bearings (D > 250 mm) or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class E   should be used instead of tolerance class H7V E. G7V 5) For large bearings (D > 500 mm) or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class E   should be used instead of tolerance class G7V E. F7V Table 6 Fits for cast iron and steel housings (for thrust bearings) 1) Conditions

F

Tolerance class 2)

Remarks

Thrust ball bearings

H8

For less accurate bearing arrangements, there can be a radial clearance of up to 0,001 D.

Spherical roller thrust bearings where separate bearings provide radial location



Housing washer must be fitted with an adequate radial gap so that no radial load can act on the thrust bearings.

Stationary load on housing washer

H7

For additional information, refer to Design of bearing arrangements († page 1085).

Rotating load on housing washer

M7

Axial loads only

Combined radial and axial loads on spherical roller thrust bearings

1) For cylindrical roller thrust bearings † Cylindrical roller thrust bearings, page

† Needle roller thrust bearings, page 1057.

1) All ISO tolerance classes are valid with the envelope requirement (such as H7

1037. For needle roller thrust bearings

E ) in accordance with ISO 14405-1. V

175

Design considerations

Fits for hollow shafts If bearings are to be mounted with an interference fit on a hollow shaft, to achieve the same surface pressure between the inner ring and shaft seat, it is generally necessary to use a tighter interference fit than would be used for a solid shaft. The following diameter ratios are important when deciding on the fit to be used: di d and ce = J ci = J d de The fit is not appreciably affected until the diameter ratio of the hollow shaft ci ≥ 0,5. If the average outside diameter of the inner ring, i.e. the average diameter between the shoulder and raceway († diagram 1), is not known, the diameter ratio ce can be estimated with sufficient accuracy using d ce = JJJJJ k (D – d) + d where ci = diameter ratio of the hollow shaft ce = diameter ratio of the inner ring d = outside diameter of the hollow shaft, bearing bore diameter [mm] D = bearing outside diameter [mm] di = inside diameter of the hollow shaft [mm] de = average outside diameter of the inner ring [mm] († diagram 1) k = a factor for the bearing type –– for self-aligning ball bearings in the 22 and 23 series, k = 0,25 –– for cylindrical roller bearings, k = 0,25 –– for all other bearings, k = 0,3 The requisite interference fit for a bearing mounted on a hollow shaft can be determined based on the mean probable interference for the same bearing on a solid shaft, neglecting plastic deformation (smoothing) of the mating surfaces produced during mounting. The mean probable interference for the bearing on a solid shaft, D S, is the mean value of the smallest and largest values of the probable interference listed in table 7 († page 178). Diagram 1 provides values for the ratio between the mean probable interference of the bearing inner ring on a hollow shaft, D H, and 176

on a solid shaft, D S, depending on the diameter ratios ci and ce. Example

A 6208 deep groove ball bearing with d = 40 mm and D = 80 mm is to be mounted on a hollow shaft with a diameter ratio ci = 0,8. What is the requisite interference and what are the appropriate shaft limits? If the bearing is to be mounted on a solid steel shaft and subjected to normal loads, a tolerance class k5V E   is recommended. From table 7d († page 184), for a 40 mm shaft diam­eter, the mean probable interference DV = (22 + 5) / 2 = 13,5 μm. For ci = 0,8 and 40 ce = JJJJJJJJ = 0,77 0,3 (80 – 40) + 40 so that from diagram 1 the ratio D H / D S = 1,7. Therefore, the requisite interference for the hollow shaft D H = 1,7 ¥ 13,5 = 23 μm. Consequently, tolerance class m6V E   is selected for the hollow shaft as this gives a similar fit as k5V E   for a solid shaft.

Radial location of bearings

Diagram 1 Relationship of interference ∆ H, needed for a hollow steel shaft, to the known interference ∆ S for a solid steel shaft

F

DH / DS 2,0 1,8 di d de

ce = 0,7 1,6 1,4

0,8

1,2 1,0 raceway diameter

de

shoulder diameter d 1

0,9 0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9 ci

177

Design considerations Table 7a Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

incl.

mm

Bearing Bore diameter tolerance D dmp

f5V E

low

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+)

high

mm

Shaft diameter deviations, resultant fits Tolerance classes f6V E

g5V E

g6V E

h5V E

mm



3

–8

0

–6 –2 –1

–10 +10 +9

–6 –2 0

–12 +12 +10

–2 –6 –5

–6 +6 +5

–2 –6 –4

–8 +8 +6

0 –8 –7

–4 +4 +3

3

6

–8

0

–10 +2 +3

–15 +15 +14

–10 +2 +4

–18 +18 +16

–4 –4 –3

–9 +9 +8

–4 –4 –2

–12 +12 +10

0 –8 –7

–5 +5 +4

6

10

–8

0

–13 +5 +7

–19 +19 +17

–13 +5 +7

–22 +22 +20

–5 –3 –1

–11 +11 +9

–5 –3 –1

–14 +14 +12

0 –8 –6

–6 +6 +4

10

18

–8

0

–16 +8 +10

–24 +24 +22

–16 +8 +10

–27 +27 +25

–6 –2 0

–14 +14 +12

–6 –2 0

–17 +17 +15

0 –8 –6

–8 +8 +6

18

30

–10

0

–20 +10 +12

–29 +29 +27

–20 +10 +13

–33 +33 +30

–7 –3 –1

–16 +16 +14

–7 –3 0

–20 +20 +17

0 –10 –8

–9 +9 +7

30

50

–12

0

–25 +13 +16

–36 +36 +33

–25 +13 +17

–41 +41 +37

–9 –3 0

–20 +20 +17

–9 –3 +1

–25 +25 +21

0 –12 –9

–11 +11 +8

50

80

–15

0

–30 +15 +19

–43 +43 +39

–30 +15 +19

–49 +49 +45

–10 –5 –1

–23 +23 +19

–10 –5 –1

–29 +29 +25

0 –15 –11

–13 +13 +9

80

120

–20

0

–36 +16 +21

–51 +51 +46

–36 +16 +22

–58 +58 +52

–12 –8 –3

–27 +27 +22

–12 –8 –2

–34 +34 +28

0 –20 –15

–15 +15 +10

120

180

–25

0

–43 +18 +24

–61 +61 +55

–43 +18 +25

–68 +68 +61

–14 –11 –5

–32 +32 +26

–14 –11 –4

–39 +39 +32

0 –25 –19

–18 +18 +12

180

250

–30

0

–50 +20 +26

–70 +70 +64

–50 +20 +28

–79 +79 +71

–15 –15 –9

–35 +35 +29

–15 –15 –7

–44 +44 +36

0 –30 –24

–20 +20 +14

250

315

–35

0

–56 +21 +29

–79 +79 +71

–56 +21 +30

–88 +88 +79

–17 –18 –10

–40 +40 +32

–17 –18 –9

–49 +49 +40

0 –35 –27

–23 +23 +15

315

400

–40

0

–62 +22 +30

–87 +87 +79

–62 +22 +33

–98 +98 +87

–18 –22 –14

–43 +43 +35

–18 –22 –11

–54 +54 +43

0 –40 –32

–25 +25 +17

400

500

–45

0

–68 +23 +32

–95 +95 +86

–68 +23 +35

–108 +108 +96

–20 –25 –16

–47 +47 +38

–20 –25 –13

–60 +60 +48

0 –45 –36

–27 +27 +18

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

178

Radial location of bearings Table 7a Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

incl.

mm

Bearing Bore diameter tolerance D dmp

f5V E

low

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+)

high

mm

Shaft diameter deviations, resultant fits Tolerance classes f6V E

g5V E

g6V E

h5V E

mm

500

630

–50

0

–76 +26 +36

–104 +104 +94

–76 +26 +39

–120 +120 +107

–22 –28 –18

–50 +50 +40

–22 –28 –15

–66 +66 +53

0 –50 –40

–28 +28 +18

630

800

–75

0

–80 +5 +17

–112 +112 +100

–80 +5 +22

–130 +130 +113

–24 –51 –39

–56 +56 +44

–24 –51 –34

–74 +74 +57

0 –75 –63

–32 +32 +20

800

1 000

–100

0

–86 –14 0

–122 +122 +108

–86 –14 +6

–142 +142 +122

–26 –74 –60

–62 +62 +48

–26 –74 –54

–82 +82 +62

0 –100 –86

–36 +36 +22

1 000

1 250

–125

0

–98 –27 –10

–140 +140 +123

–98 –27 –3

–164 +164 +140

–28 –97 –80

–70 +70 +53

–28 –97 –73

–94 +94 +70

0 –125 –108

–42 +42 +25

1 250

1 600

–160

0

–110 –50 –29

–160 +160 +139

–110 –50 –20

–188 +188 +158

–30 –130 –109

–80 +80 +59

–30 –130 –100

–108 +108 +78

0 –160 –139

–50 +50 +29

1 600

2 000

–200

0

–120 –80 –55

–180 +180 +155

–120 –80 –45

–212 +212 +177

–32 –168 –143

–92 +92 +67

–32 –168 –133

–124 +124 +89

0 –200 –175

–60 +60 +35

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

179

Design considerations Table 7b Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes h6V E

h8 V E

h9 V E

j5V E

j6V E

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm



3

–8

0

0 –8 –6

–6 +6 +4

0 –8 –6

–14 +14 +12

0 –8 –5

–25 +25 +22

+2 –10 –9

–2 +2 +1

+4 –12 –10

–2 +2 0

3

6

–8

0

0 –8 –6

–8 +8 +6

0 –8 –5

–18 +18 +15

0 –8 –5

–30 +30 +27

+3 –11 –10

–2 +2 +1

+6 –14 –12

–2 +2 0

6

10

–8

0

0 –8 –6

–9 +9 +7

0 –8 –5

–22 +22 +19

0 –8 –5

–36 +36 +33

+4 –12 –10

–2 +2 0

+7 –15 –13

–2 +2 0

10

18

–8

0

0 –8 –6

–11 +11 +9

0 –8 –5

–27 +27 +24

0 –8 –5

–43 +43 +40

+5 –13 –11

–3 +3 +1

+8 –16 –14

–3 +3 +1

18

30

–10

0

0 –10 –7

–13 +13 +10

0 –10 –6

–33 +33 +29

0 –10 –6

–52 +52 +48

+5 –15 –13

–4 +4 +2

+9 –19 –16

–4 +4 +1

30

50

–12

0

0 –12 –8

–16 +16 +12

0 –12 –7

–39 +39 +34

0 –12 –7

–62 +62 +57

+6 –18 –15

–5 +5 +2

+11 –23 –19

–5 +5 +1

50

80

–15

0

0 –15 –11

–19 +19 +15

0 –15 –9

–46 +46 +40

0 –15 –9

–74 +74 +68

+6 –21 –17

–7 +7 +3

+12 –27 –23

–7 +7 +3

80

120

–20

0

0 –20 –14

–22 +22 +16

0 –20 –12

–54 +54 +46

0 –20 –12

–87 +87 +79

+6 –26 –21

–9 +9 +4

+13 –33 –27

–9 +9 +3

120

180

–25

0

0 –25 –18

–25 +25 +18

0 –25 –15

–63 +63 +53

0 –25 –15

–100 +100 +90

+7 –32 –26

–11 +11 +5

+14 –39 –32

–11 +11 +4

180

250

–30

0

0 –30 –22

–29 +29 +21

0 –30 –18

–72 +72 +60

0 –30 –17

–115 +115 +102

+7 –37 –31

–13 +13 +7

+16 –46 –38

–13 +13 +5

250

315

–35

0

0 –35 –26

–32 +32 +23

0 –35 –22

–81 +81 +68

0 –35 –20

–130 +130 +115

+7 –42 –34

–16 +16 +8

+16 –51 –42

–16 +16 +7

315

400

–40

0

0 –40 –29

–36 +36 +25

0 –40 –25

–89 +89 +74

0 –40 –23

–140 +140 +123

+7 –47 –39

–18 +18 +10

+18 –58 –47

–18 +18 +7

400

500

–45

0

0 –45 –33

–40 +40 +28

0 –45 –28

–97 +97 +80

0 –45 –26

–155 +155 +136

+7 –52 –43

–20 +20 +11

+20 –65 –53

–20 +20 +8

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

180

Radial location of bearings Table 7b Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes h6V E

h8 V E

h9 V E

j5V E

j6V E

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

500

630

–50

0

0 –50 –37

–44 +44 +31

0 –50 –31

–110 +110 +91

0 –50 –29

–175 +175 +154

– – –

– – –

+22 –72 –59

–22 +22 +9

630

800

–75

0

0 –75 –58

–50 +50 +33

0 –75 –48

–125 +125 +98

0 –75 –45

–200 +200 +170

– – –

– – –

+25 –100 –83

–25 +25 +8

800

1 000

–100

0

0 –100 –80

–56 +56 +36

0 –100 –67

–140 +140 +107

0 –100 –61

–230 +230 +191

– – –

– – –

+28 –128 –108

–28 +28 +8

1 000

1 250

–125

0

0 –125 –101

–66 +66 +42

0 –125 –84

–165 +165 +124

0 –125 –77

–260 +260 +212

– – –

– – –

+33 –158 –134

–33 +33 +9

1 250

1 600

–160

0

0 –160 –130

–78 +78 +48

0 –160 –109

–195 +195 +144

0 –160 –100

–310 +310 +250

– – –

– – –

+39 –199 –169

–39 +39 +9

1 600

2 000

–200

0

0 –200 –165

–92 +92 +57

0 –200 –138

–230 +230 +168

0 –200 –126

–370 +370 +296

– – –

– – –

+46 –246 –211

–46 +46 +11

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

181

Design considerations Table 7c Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes js4V E

js5V E

js6V E

js7V E

k4V E

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm



3

–8

0

+1,5 –9,5 –8,5

–1,5 +1,5 +0,5

+2 –10 –9

–2 +2 +1

+3 –11 –9

–3 +3 +1

+5 –13 –11

–5 +5 +3

+3 –11 –10

0 0 –1

3

6

–8

0

+2 –10 –9

–2 +2 +1

+2,5 –10,5 –9

–2,5 +2,5 +1

+4 –12 –10

–4 +4 +2

+6 –14 –12

–6 +6 +4

+5 –13 –12

+1 –1 –2

6

10

–8

0

+2 –10 –9

–2 +2 +1

+3 –11 –9

–3 +3 +1

+4,5 –12,5 –11

–4,5 +4,5 +3

+7,5 –15,5 –13

–7,5 +7,5 +5

+5 –13 –12

+1 –1 –2

10

18

–8

0

+2,5 –10,5 –9,5

–2,5 +2,5 +1,5

+4 –12 –10

–4 +4 +2

+5,5 –13,5 –11

–5,5 +5,5 +3

+9 –17 –14

–9 +9 +6

+6 –14 –13

+1 –1 –2

18

30

–10

0

+3 –13 –10,5

–3 +3 +1,5

+4,5 –14,5 –12

–4,5 +4,5 +2

+6,5 –16,5 –14

–6,5 +6,5 +4

+10,5 –20,5 –17

–10,5 +10,5 +7

+8 –18 –16

+2 –2 –4

30

50

–12

0

+3,5 –15,5 –13,5

–3,5 +3,5 +1,5

+5,5 –17,5 –15

–5,5 +5,5 +3

+8 –20 –16

–8 +8 +4

+12,5 –24,5 –20

–12,5 +12,5 +8

+9 –21 –19

+2 –2 –4

50

80

–15

0

+4 –19 –15,5

–4 +4 +1,5

+6,5 –21,5 –18

–6,5 +6,5 +3

+9,5 –24,5 –20

–9,5 +9,5 +5

+15 –30 –25

–15 +15 +10

+10 –25 –22

+2 –2 –5

80

120

–20

0

+5 –25 –22

–5 +5 +2

+7,5 –27,5 –23

–7,5 +7,5 +3

+11 –31 –25

–11 +11 +5

+17,5 –37,5 –31

–17,5 +17,5 +11

+13 –33 –30

+3 –3 –6

120

180

–25

0

+6 –31 –27

–6 +6 +2

+9 –34 –28

–9 +9 +3

+12,5 –37,5 –31

–12,5 +12,5 +6

+20 –45 –37

–20 +20 +12

+15 –40 –36

+3 –3 –7

180

250

–30

0

+7 –37 –32

–7 +7 +2

+10 –40 –34

–10 +10 +4

+14,5 –44,5 –36

–14,5 +14,5 +6

+23 –53 –43

–23 +23 +13

+18 –48 –43

+4 –4 –9

250

315

–35

0

+8 –4 –37

–8 +8 +2

+11,5 –46,5 –39

–11,5 +11,5 +4

+16 –51 –42

–16 +16 +7

+26 –61 –49

–26 +26 +14

+20 –55 –49

+4 –4 –10

315

400

–40

0

+9 –49 –42

–9 +9 +2

+12,5 –52,5 –44

–12,5 +12,5 +4

+18 –58 –47

–18 +18 +7

+28,5 –68,5 –55

–28,5 +28,5 +15

+22 –62 –55

+4 –4 –11

400

500

–45

0

+10 –55 –48

–10 +10 +3

+13,5 –58,5 –49

–13,5 +13,5 +4

+20 –65 –53

–20 +20 +8

+31,5 –76,5 –62

–31,5 +31,5 +17

+25 –70 –63

+5 –5 –12

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

182

Radial location of bearings Table 7c Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes js4V E

js5V E

js6V E

js7V E

k4V E

Deviations (shaft diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

500

630

–50

0

– – –

– – –

+14 –64 –54

–14 +14 +4

+22 –72 –59

–22 +22 +9

+35 –85 –69

–35 +35 +19

– – –

– – –

630

800

–75

0

– – –

– – –

+16 –91 –79

–16 +16 +4

+25 –100 –83

–25 +25 +8

+40 –115 –93

–40 +40 +18

– – –

– – –

800

1 000

–100

0

– – –

– – –

+18 –118 –104

–18 +18 +4

+28 –128 –108

–28 +28 +8

+45 –145 –118

–45 +45 +18

– – –

– – –

1 000

1 250

–125

0

– – –

– – –

+21 –146 –129

–21 +21 +4

+33 –158 –134

–33 +33 +9

+52 –177 –145

–52 +52 +20

– – –

– – –

1 250

1 600

–160

0

– – –

– – –

+25 –185 –164

–25 +25 +4

+39 –199 –169

–39 +39 +9

+62 –222 –182

–62 +62 +22

– – –

– – –

1 600

2 000

–200

0

– – –

– – –

+30 –230 –205

–30 +30 +5

+46 –246 –211

–46 +46 +11

+75 –275 –225

–75 +75 +25

– – –

– – –

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

183

Design considerations Table 7d Shaft tolerances and resultant fits

+ 0 – Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes k5V E

k6V E

m5V E

m6V E

n5V E

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm



3

–8

0

+4 –12 –11

0 0 –1

+6 –14 –12

0 0 –2

+6 –14 –13

+2 –2 –3

+8 –16 –14

+2 –2 –4

+8 –16 –15

+4 –4 –5

3

6

–8

0

+6 –14 –13

+1 –1 –2

+9 –17 –15

+1 –1 –3

+9 –17 –16

+4 –4 –5

+12 –20 –18

+4 –4 –6

+13 –21 –20

+8 –8 –9

6

10

–8

0

+7 –15 –13

+1 –1 –3

+10 –18 –16

+1 –1 –3

+12 –20 –18

+6 –6 –8

+15 –23 –21

+6 –6 –8

+16 –24 –22

+10 –10 –12

10

18

–8

0

+9 –17 –15

+1 –1 –3

+12 –20 –18

+1 –1 –3

+15 –23 –21

+7 –7 –9

+18 –26 –24

+7 –7 –9

+20 –28 –26

+12 –12 –14

18

30

–10

0

+11 –21 –19

+2 –2 –4

+15 –25 –22

+2 –2 –5

+17 –27 –25

+8 –8 –10

+21 –31 –28

+8 –8 –11

+24 –34 –32

+15 –15 –17

30

50

–12

0

+13 –25 –22

+2 –2 –5

+18 –30 –26

+2 –2 –6

+20 –32 –29

+9 –9 –12

+25 –37 –33

+9 –9 –13

+28 –40 –37

+17 –17 –20

50

80

–15

0

+15 –30 –26

+2 –2 –6

+21 –36 –32

+2 –2 –6

+24 –39 –35

+11 –11 –15

+30 –45 –41

+11 –11 –15

+33 –48 –44

+20 –20 –24

80

120

–20

0

+18 –38 –33

+3 –3 –8

+25 –45 –39

+3 –3 –9

+28 –48 –43

+13 –13 –18

+35 –55 –49

+13 –13 –19

+38 –58 –53

+23 –23 –28

120

180

–25

0

+21 –46 –40

+3 –3 –9

+28 –53 –46

+3 –3 –10

+33 –58 –52

+15 –15 –21

+40 –65 –58

+15 –15 –22

+45 –70 –64

+27 –27 –33

180

250

–30

0

+24 –54 –48

+4 –4 –10

+33 –63 –55

+4 –4 –12

+37 –67 –61

+17 –17 –23

+46 –76 –68

+17 –17 –25

+51 –81 –75

+31 –31 –37

250

315

–35

0

+27 –62 –54

+4 –4 –12

+36 –71 –62

+4 –4 –13

+43 –78 –70

+20 –20 –28

+52 –87 –78

+20 –20 –29

+57 –92 –84

+34 –34 –42

315

400

–40

0

+29 –69 –61

+4 –4 –12

+40 –80 –69

+4 –4 –15

+46 –86 –78

+21 –21 –29

+57 –97 –86

+21 –21 –32

+62 –102 –94

+37 –37 –45

400

500

–45

0

+32 –77 –68

+5 –5 –14

+45 –90 –78

+5 –5 –17

+50 –95 –86

+23 –23 –32

+63 –108 –96

+23 –23 –35

+67 –112 –103

+40 –40 –49

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

184

Radial location of bearings Table 7d Shaft tolerances and resultant fits

+ 0 – Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes k5V E

k6V E

m5V E

m6V E

n5V E

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm

500

630

–50

0

+29 –78 –68

0 0 –10

+44 –94 –81

0 0 –13

+55 –105 –94

+26 –26 –36

+70 –120 –107

+26 –26 –39

+73 –122 –112

+44 –44 –54

630

800

–75

0

+32 –107 –95

0 0 –12

+50 –125 –108

0 0 –17

+62 –137 –125

+30 –30 –42

+80 –155 –138

+30 –30 –47

+82 –157 –145

+50 –50 –62

800

1 000

–100

0

+36 –136 –122

0 0 –14

+56 –156 –136

0 0 –20

+70 –170 –156

+34 –34 –48

+90 –190 –170

+34 –34 –54

+92 –192 –178

+56 –56 –70

1 000

1 250

–125

0

+42 –167 –150

0 0 –17

+66 –191 –167

0 0 –24

+82 –207 –190

+40 –40 –57

+106 –231 –207

+40 –40 –64

+108 –233 –216

+66 –66 –83

1 250

1 600

–160

0

+50 –210 –189

0 0 –21

+78 –238 –208

0 0 –30

+98 –258 –237

+48 –48 –69

+126 –286 –256

+48 –48 –78

+128 –288 –267

+78 –78 –99

1 600

2 000

–200

0

+60 –260 –235

0 0 –25

+92 –292 –257

0 0 –35

+118 –318 –293

+58 –58 –83

+150 –350 –315

+58 –58 –93

+152 –352 –327

+92 –92 –117

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

185

Design considerations Table 7e Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes n6V E

p6V E

p7V E

r6V E

r7V E

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm

50

80

–15

0

+39 –54 –50

+20 –20 –24

+51 –66 –62

+32 –32 –36

+62 –77 –72

+32 –32 –38

– – –

– – –

– – –

– – –

80

100

–20

0

+45 –65 –59

+23 –23 –29

+59 –79 –73

+37 –37 –43

+72 –92 –85

+37 –37 –44

+73 –93 –87

+51 –51 –57

+86 –106 –99

+51 –51 –58

100

120

–20

0

+45 –65 –59

+23 –23 –29

+59 –79 –73

+37 –37 –43

+72 –92 –85

+37 –37 –44

+76 –96 –90

+54 –54 –60

+89 –109 –102

+54 –54 –61

120

140

–25

0

+52 –77 –70

+27 –27 –34

+68 –93 –86

+43 –43 –50

+83 –108 –100

+43 –43 –51

+88 –113 –106

+63 –63 –70

+103 –128 –120

+63 –63 –71

140

160

–25

0

+52 –77 –70

+27 –27 –34

+68 –93 –86

+43 –43 –50

+83 –108 –100

+43 –43 –51

+90 –115 –108

+65 –65 –72

+105 –130 –122

+65 –65 –73

160

180

–25

0

+52 –77 –70

+27 –27 –34

+68 –93 –86

+43 –43 –50

+83 –108 –100

+43 –43 –51

+93 –118 –111

+68 –68 –75

+108 –133 –125

+68 –68 –76

180

200

–30

0

+60 –90 –82

+31 –31 –39

+79 –109 –101

+50 –50 –58

+96 –126 –116

+50 –50 –60

+106 –136 –128

+77 –77 –85

+123 –153 –143

+77 –77 –87

200

225

–30

0

+60 –90 –82

+31 –31 –39

+79 –109 –101

+50 –50 –58

+96 –126 –116

+50 –50 –60

+109 –139 –131

+80 –80 –88

+126 –156 –146

+80 –80 –90

225

250

–30

0

+60 –90 –82

+31 –31 –39

+79 –109 –101

+50 –50 –58

+96 –126 –116

+50 –50 –60

+113 –143 –135

+84 –84 –92

+130 –160 –150

+84 –84 –94

250

280

–35

0

+66 –101 –92

+34 –34 –43

+88 –123 –114

+56 –56 –65

+108 –143 –131

+56 –56 –68

+126 –161 –152

+94 –94 –103

+146 –181 –169

+94 –94 –106

280

315

–35

0

+66 –101 –92

+34 –34 –43

+88 –123 –114

+56 –56 –65

+108 –143 –131

+56 –56 –68

+130 –165 –156

+98 –98 –107

+150 –185 –173

+98 –98 –110

315

355

–40

0

+73 –113 –102

+37 –37 –48

+98 –138 –127

+62 –62 –73

+119 –159 –146

+62 –62 –75

+144 –184 –173

+108 –108 –119

+165 –205 –192

+108 –108 –121

355

400

–40

0

+73 –113 –102

+37 –37 –48

+98 –138 –127

+62 –62 –73

+119 –159 –146

+62 –62 –75

+150 –190 –179

+114 –114 –125

+171 –211 –198

+114 –114 –127

400

450

–45

0

+80 –125 –113

+40 –40 –52

+108 –153 –141

+68 –68 –80

+131 –176 –161

+68 –68 –83

+166 –211 –199

+126 –126 –138

+189 –234 –219

+126 –126 –141

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

186

Radial location of bearings Table 7e Shaft tolerances and resultant fits

+ 0 –

Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes n6V E

p6V E

p7V E

r6V E

r7V E

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm

450

500

–45

0

+80 –125 –113

+40 –40 –52

+108 –153 –141

+68 –68 –80

+131 –176 –161

+68 –68 –83

+172 –217 –205

+132 –132 –144

+195 –240 –225

+132 –132 –147

500

560

–50

0

+88 –138 –125

+44 –44 –57

+122 –172 –159

+78 –78 –91

+148 –198 –182

+78 –78 –94

+194 –244 –231

+150 –150 –163

+220 –270 –254

+150 –150 –166

560

630

–50

0

+88 –138 –125

+44 –44 –57

+122 –172 –159

+78 –78 –91

+148 –198 –182

+78 –78 –94

+199 –249 –236

+155 –155 –168

+225 –275 –259

+155 –155 –171

630

710

–75

0

+100 –175 –158

+50 –50 –67

+138 –213 –196

+88 –88 –105

+168 –243 –221

+88 –88 –110

+225 –300 –283

+175 –175 –192

+255 –330 –308

+175 –175 –197

710

800

–75

0

+100 –175 –158

+50 –50 –67

+138 –213 –196

+88 –88 –105

+168 –243 –221

+88 –88 –110

+235 –310 –293

+185 –185 –202

+265 –340 –318

+185 –185 –207

800

900

–100

0

+112 –212 –192

+56 –56 –76

+156 –256 –236

+100 –100 –120

+190 –290 –263

+100 –100 –127

+266 –366 –346

+210 –210 –230

+300 –400 –373

+210 –210 –237

900

1 000

–100

0

+112 –212 –192

+56 –56 –76

+156 –256 –236

+100 –100 –120

+190 –290 –263

+100 –100 –127

+276 –376 –356

+220 –220 –240

+310 –410 –383

+220 –220 –247

1 000

1 120

–125

0

+132 –257 –233

+66 –66 –90

+186 –311 –287

+120 –120 –144

+225 –350 –317

+120 –120 –153

+316 –441 –417

+250 –250 –274

+355 –480 –447

+250 –250 –283

1 120

1 250

–125

0

+132 –257 –233

+66 –66 –90

+186 –311 –287

+120 –120 –144

+225 –350 –317

+120 –120 –153

+326 –451 –427

+260 –260 –284

+365 –490 –457

+260 –260 –293

1 250

1 400

–160

0

+156 –316 –286

+78 –78 –108

+218 –378 –348

+140 –140 –170

+265 –425 –385

+140 –140 –180

+378 –538 –508

+300 –300 –330

+425 –585 –545

+300 –300 –340

1 400

1 600

–160

0

+156 –316 –286

+78 –78 –108

+218 –378 –348

+140 –140 –170

+265 –425 –385

+140 –140 –180

+408 –568 –538

+330 –330 –360

+455 –615 –575

+330 –330 –370

1 600

1 800

–200

0

+184 –384 –349

+92 –92 –127

+262 –462 –427

+170 –170 –205

+320 –520 –470

+170 –170 –220

+462 –662 –627

+370 –370 –405

+520 –720 –670

+370 –370 –420

1 800

2 000

–200

0

+184 –384 –349

+92 –92 –127

+262 –462 –427

+170 –170 –205

+320 –520 –470

+170 –170 –220

+492 –692 –657

+400 –400 –435

+550 –750 –700

+400 –400 –450

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

187

F

Design considerations Table 7f Shaft tolerances and resultant fits

+ 0 – Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes s6V E min ± IT6/2

s7V E min ± IT7/2

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm

200

225

–30

0

+144 –174 –166

+115 –115 –123

+153 –183 –173

+107 –107 –117

225

250

–30

0

+154 –184 –176

+125 –125 –133

+163 –193 –183

+117 –117 –127

250

280

–35

0

+174 –209 –200

+142 –142 –151

+184 –219 –207

+132 –132 –144

280

315

–35

0

+186 –221 –212

+154 –154 –163

+196 –231 –219

+144 –144 –156

315

355

–40

0

+208 –248 –237

+172 –172 –183

+218 –258 –245

+161 –161 –174

355

400

–40

0

+226 –266 –255

+190 –190 –201

+236 –276 –263

+179 –179 –192

400

450

–45

0

+252 –297 –285

+212 –212 –224

+263 –308 –293

+200 –200 –215

450

500

–45

0

+272 –317 –305

+232 –232 –244

+283 –328 –313

+220 –220 –235

500

560

–50

0

+302 –352 –339

+258 –258 –271

+315 –365 –349

+245 –245 –261

560

630

–50

0

+332 –382 –369

+288 –288 –301

+345 –395 –379

+275 –275 –291

630

710

–75

0

+365 –440 –423

+315 –315 –332

+380 –455 –433

+300 –300 –322

710

800

–75

0

+405 –480 –463

+355 –355 –372

+420 –495 –473

+340 –340 –362

800

900

–100

0

+458 –558 –538

+402 –402 –422

+475 –575 –548

+385 –385 –412

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

188

Radial location of bearings Table 7f Shaft tolerances and resultant fits

+ 0 – Shaft Nominal diameter d

over

Bearing Bore diameter tolerance D dmp

incl.

mm

low

high

mm

Shaft diameter deviations, resultant fits Tolerance classes s6V E min ± IT6/2

s7V E min ± IT7/2

Deviations (shaft diameter) Theoretical interference (–) Probable interference (–) mm

900

1 000

–100

0

+498 –598 –578

+442 –442 –462

+515 –615 –588

+425 –425 –452

1 000

1 120

–125

0

+553 –678 –654

+487 –487 –511

+572 –697 –664

+467 –467 –500

1 120

1 250

–125

0

+613 –738 –714

+547 –547 –571

+632 –757 –724

+527 –527 –560

1 250

1 400

–160

0

+679 –839 –809

+601 –601 –631

+702 –862 –822

+577 –577 –617

1 400

1 600

–160

0

+759 –919 –889

+681 –681 –711

+782 –942 –902

+657 –657 –697

1 600

1 800

–200

0

+866 +774 –1 066 –774 –1 031 –809

+895 +745 –1 095 –745 –1 045 –795

1 800

2 000

–200

0

+966 +874 –1 166 –874 –1 131 –909

+995 –1 195 –1 145

+845 –845 –895

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

189

Design considerations Table 8a Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp F7V E G6V E G7V E

high low mm

H5V E

H6V E

Deviations (housing bore diameter) Theoretical clearance (+) Probable clearance (+) mm

6

10

0

–8

+13 +13 +16

+28 +36 +33

+5 +5 +7

+14 +22 +20

+5 +5 +8

+20 +28 +25

0 0 +2

+6 +14 +12

0 0 +2

+9 +17 +15

10

18

0

–8

+16 +16 +19

+34 +42 +39

+6 +6 +8

+17 +25 +23

+6 +6 +9

+24 +32 +29

0 0 +2

+8 +16 +14

0 0 +2

+11 +19 +17

18

30

0

–9

+20 +20 +23

+41 +50 +47

+7 +7 +10

+20 +29 +26

+7 +7 +10

+28 +37 +34

0 0 +2

+9 +18 +16

+0 0 +3

+13 +22 +19

30

50

0

–11

+25 +25 +29

+50 +61 +57

+9 +9 +12

+25 +36 +33

+9 +9 +13

+34 +45 +41

0 0 +3

+11 +22 +19

0 0 +3

+16 +27 +24

50

80

0

–13

+30 +30 +35

+60 +73 +68

+10 +10 +14

+29 +42 +38

+10 +10 +15

+40 +53 +48

0 0 +3

+13 +26 +23

0 0 +4

+19 +32 +28

80

120

0

–15

+36 +36 +41

+71 +86 +81

+12 +12 +17

+34 +49 +44

+12 +12 +17

+47 +62 +57

0 0 +4

+15 +30 +26

0 0 +5

+22 +37 +32

120

150

0

–18

+43 +43 +50

+83 +101 +94

+14 +14 +20

+39 +57 +51

+14 +14 +21

+54 +72 +65

0 0 +5

+18 +36 +31

0 0 +6

+25 +43 +37

150

180

0

–25

+43 +43 +51

+83 +108 +100

+14 +14 +21

+39 +64 +57

+14 +14 +22

+54 +79 +71

0 0 +6

+18 +43 +37

0 0 +7

+25 +50 +43

180

250

0

–30

+50 +50 +60

+96 +126 +116

+15 +15 +23

+44 +74 +66

+15 +15 +25

+61 +91 +81

0 0 +6

+20 +50 +44

0 0 +8

+29 +59 +51

250

315

0

–35

+56 +56 +68

+108 +143 +131

+17 +17 +26

+49 +84 +75

+17 +17 +29

+69 +104 +92

0 0 +8

+23 +58 +50

0 0 +9

+32 +67 +58

315

400

0

–40

+62 +62 +75

+119 +159 +146

+18 +18 +29

+54 +94 +83

+18 +18 +31

+75 +115 +102

0 0 +8

+25 +65 +57

0 0 +11

+36 +76 +65

400

500

0

–45

+68 +68 +83

+131 +176 +161

+20 +20 +32

+60 +105 +93

+20 +20 +35

+83 +128 +113

0 0 +9

+27 +72 +63

0 0 +12

+40 +85 +73

500

630

0

–50

+76 +76 +92

+146 +196 +180

+22 +22 +35

+66 +116 +103

+22 +22 +38

+92 +142 +126

0 0 +10

+28 +78 +68

0 0 +13

+44 +94 +81

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

190

Radial location of bearings Table 8a Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp F7V E G6V E G7V E

high low mm

H5V E

H6V E

Deviations (housing bore diameter) Theoretical clearance (+) Probable clearance (+) mm

630

800

0

–75

+80 +80 +102

+160 +235 +213

+24 +24 +41

+74 +149 +132

+24 +24 +46

+104 +179 +157

0 0 +12

+32 +107 +95

0 0 +17

+50 +125 +108

800

1 000

0

–100

+86 +86 +113

+176 +276 +249

+26 +26 +46

+82 +182 +162

+26 +26 +53

+116 +216 +189

0 0 +14

+36 +136 +122

0 0 +20

+56 +156 +136

1 000 1 250

0

–125

+98 +98 +131

+203 +328 +295

+28 +28 +52

+94 +219 +195

+28 +28 +61

+133 +258 +225

0 0 +17

+42 +167 +150

0 0 +24

+66 +191 +167

1 250 1 600

0

–160

+110 +110 +150

+235 +395 +355

+30 +30 +60

+108 +268 +238

+30 +30 +70

+155 +315 +275

0 0 +21

+50 +210 +189

0 0 +30

+78 +238 +208

1 600 2 000

0

–200

+120 +120 +170

+270 +470 +420

+32 +32 +67

+124 +324 +289

+32 +32 +82

+182 +382 +332

0 0 +25

+60 +260 +235

0 0 +35

+92 +292 +257

2 000 2 500

0

–250

+130 +130 +189

+305 +555 +496

+34 +34 +77

+144 +394 +351

+34 +34 +93

+209 +459 +400

0 0 +30

+70 +320 +290

0 0 +43

+110 +360 +317

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

191

Design considerations Table 8b Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp H7V E H8 V E H9 V E

high low mm

H10 V E

J6V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

6

10

0

–8

0 0 +3

+15 +23 +20

0 0 +3

+22 +30 +27

0 0 +3

+36 +44 +41

0 0 +3

+58 +66 +63

–4 –4 –2

+5 +13 +11

10

18

0

–8

0 0 +3

+18 +26 +23

0 0 +3

+27 +35 +32

0 0 +3

+43 +51 +48

0 0 +3

+70 +78 +75

–5 –5 –3

+6 +14 +12

18

30

0

–9

0 0 +3

+21 +30 +27

0 0 +3

+33 +42 +39

0 0 +4

+52 +61 +57

0 0 +4

+84 +93 +89

–5 –5 –2

+8 +17 +14

30

50

0

–11

0 0 +4

+25 +36 +32

0 0 +4

+39 +50 +46

0 0 +5

+62 +73 +68

0 0 +5

+100 +111 +106

–6 –6 –3

+10 +21 +18

50

80

0

–13

0 0 +5

+30 +43 +38

0 0 +5

+46 +59 +54

0 0 +5

+74 +87 +82

0 0 +6

+120 +133 +127

–6 –6 –2

+13 +26 +22

80

120

0

–15

0 0 +5

+35 +50 +45

0 0 +6

+54 +69 +63

0 0 +6

+87 +102 +96

0 0 +7

+140 +155 +148

–6 –6 –1

+16 +31 +26

120

150

0

–18

0 0 +7

+40 +58 +51

0 0 +7

+63 +81 +74

0 0 +8

+100 +118 +110

0 0 +8

+160 +178 +170

–7 –7 –1

+18 +36 +30

150

180

0

–25

0 0 +8

+40 +65 +57

0 0 +10

+63 +88 +78

0 0 +10

+100 +125 +115

0 0 +11

+160 +185 +174

–7 –7 0

+18 +43 +36

180

250

0

–30

0 0 +10

+46 +76 +66

0 0 +12

+72 +102 +90

0 0 +13

+115 +145 +132

0 0 +13

+185 +215 +202

–7 –7 +1

+22 +52 +44

250

315

0

–35

0 0 +12

+52 +87 +75

0 0 +13

+81 +116 +103

0 0 +15

+130 +165 +150

0 0 +16

+210 +245 +229

–7 –7 +2

+25 +60 +51

315

400

0

–40

0 0 +13

+57 +97 +84

0 0 +15

+89 +129 +114

0 0 +17

+140 +180 +163

0 0 +18

+230 +270 +252

–7 –7 +4

+29 +69 +58

400

500

0

–45

0 0 +15

+63 +108 +93

0 0 +17

+97 +142 +125

0 0 +19

+155 +200 +181

0 0 +20

+250 +295 +275

–7 –7 +5

+33 +78 +66

500

630

0

–50

0 0 +16

+70 +120 +104

0 0 +19

+110 +160 +141

0 0 +21

+175 +225 +204

0 0 +22

+280 +330 +308

– – –

– – –

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

192

Radial location of bearings Table 8b Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp H7V E H8 V E H9 V E

high low mm

H10 V E

J6V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

630

800

0

–75

0 0 +22

+80 +155 +133

0 0 +27

+125 +200 +173

0 0 +30

+200 +275 +245

0 0 +33

+320 +395 +362

– – –

– – –

800

1 000

0

–100

0 0 +27

+90 +190 +163

0 0 +33

+140 +240 +207

0 0 +39

+230 +330 +291

0 0 +43

+360 +460 +417

– – –

– – –

1 000

1 250

0

–125

0 0 +33

+105 +230 +197

0 0 +41

+165 +290 +249

0 0 +48

+260 +385 +337

0 0 +53

+420 +545 +492

– – –

– – –

1 250

1 600

0

–160

0 0 +40

+125 +285 +245

0 0 +51

+195 +355 +304

0 0 +60

+310 +470 +410

0 0 +67

+500 +660 +593

– – –

– – –

1 600

2 000

0

–200

0 0 +50

+150 +350 +300

0 0 +62

+230 +430 +368

0 0 +74

+370 +570 +496

0 0 +83

+600 +800 +717

– – –

– – –

2 000

2 500

0

–250

0 0 +59

+175 +425 +366

0 0 +77

+280 +530 +453

0 0 +91

+440 +690 +599

0 0 +103

+700 +950 +847

– – –

– – –

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

193

Design considerations Table 8c Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp J7V E JS5V E JS6V E

high low mm

JS7V E

K5V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

6

10

0

–8

–7 –7 –4

+8 +16 +13

–3 –3 –1

+3 +11 +9

–4,5 –4,5 –3

+4,5 +12,5 +11

–7,5 –7,5 –5

+7,5 +15,5 +13

–5 –5 –3

+1 +9 +7

10

18

0

–8

–8 –8 –5

+10 +18 +15

–4 –4 –2

+4 +12 +10

–5,5 –5,5 –3

+5,5 +13,5 +11

–9 –9 –6

+9 +17 +14

–6 –6 –4

+2 +10 +8

18

30

0

–9

–9 –9 –6

+12 +21 +18

–4,5 –4,5 –2

+4,5 +13,5 +11

–6,5 –6,5 –4

+6,5 +15,5 +13

–10,5 –10,5 –7

+10,5 +19,5 +16

–8 –8 –6

+1 +10 +8

30

50

0

–11

–11 –11 –7

+14 +25 +21

–5,5 –5,5 –3

+5,5 +16,5 +14

–8 –8 –5

+8 +19 +16

–12,5 –12,5 –9

+12,5 +23,5 +20

–9 –9 –6

+2 +13 +10

50

80

0

–13

–12 –12 –7

+18 +31 +26

–6,5 –6,5 –3

+6,5 +19,5 +16

–9,5 –9,5 –6

+9,5 +22,5 +19

–15 –15 –10

+15 +28 +23

–10 –10 –7

+3 +16 +13

80

120

0

–15

–13 –13 –8

+22 +37 +32

–7,5 –7,5 –4

+7,5 +22,5 +19

–11 –11 –6

+11 +26 +21

–17,5 –17,5 –12

+17,5 +32,5 +27

–13 –13 –9

+2 +17 +13

120

150

0

–18

–14 –14 –7

+26 +44 +37

–9 –9 –4

+9 +27 +22

–12,5 –12,5 –7

+12,5 +30,5 +25

–20 –20 –13

+20 +38 +31

–15 –15 –10

+3 +21 +16

150

180

0

–25

–14 –14 –6

+26 +51 +43

–9 –9 –3

+9 +34 +28

–12,5 –12,5 –6

+12,5 +37,5 +31

–20 –20 –12

+20 +45 +37

–15 –15 –9

+3 +28 +22

180

250

0

–30

–16 –16 –6

+30 +60 +50

–10 –10 –4

+10 +40 +34

–14,5 –14,5 –6

+14,5 +44,5 +36

–23 –23 –13

+23 +53 +43

–18 –18 –12

+2 +32 +26

250

315

0

–35

–16 –16 –4

+36 +71 +59

–11,5 –11,5 –4

+11,5 +46,5 +39

–16 –16 –7

+16 –51 +42

–26 –26 –14

+26 +61 +49

–20 –20 –12

+3 +38 +30

315

400

0

–40

–18 –18 –5

+39 +79 +66

–12,5 –12,5 –4

+12,5 +52,5 +44

–18 –18 –7

+18 +58 +47

–28,5 –28,5 –15

+28,5 +68,5 +55

–22 –22 –14

+3 +43 +35

400

500

0

–45

–20 –20 –5

+43 +88 +73

–13,5 –13,5 –4

+13,5 +58,5 +49

–20 –20 –8

+20 +65 +53

–31,5 –31,5 –17

+31,5 +76,5 +62

–25 –25 –16

+2 +47 +38

500

630

0

–50

– – –

– – –

–14 –14 –4

+14 +64 +54

–22 –22 –9

+22 +72 +59

–35 –35 –19

+35 +85 +69

– – –

– – –

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

194

Radial location of bearings Table 8c Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp J7V E JS5V E JS6V E

high low mm

JS7V E

K5V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

630

800

0

–75

– – –

– – –

–16 –16 –4

+16 +91 +79

–25 –25 –8

+25 +100 +83

–40 –40 –18

+40 +115 +93

– – –

– – –

800

1 000

0

–100

– – –

– – –

–18 –18 –4

+18 +118 +104

–28 –28 –8

+28 +128 +108

–45 –45 –18

+45 +145 +118

– – –

– – –

1 000

1 250

0

–125

– – –

– – –

–21 –21 –4

+21 +146 +129

–33 –33 –9

+33 +158 +134

–52 –52 –20

+52 +177 +145

– – –

– – –

1 250

1 600

0

–160

– – –

– – –

–25 –25 –4

+25 +185 +164

–39 –39 –9

+39 +199 +169

–62 –62 –22

+62 +222 +182

– – –

– – –

1 600

2 000

0

–200

– – –

– – –

–30 –30 –5

+30 +230 +205

–46 –46 –11

+46 +246 +211

–75 –75 –25

+75 +275 +225

– – –

– – –

2 000

2 500

0

–250

– – –

– – –

–35 –35 –5

+35 +285 +255

–55 –55 –12

+55 +305 +262

–87 –87 –28

+87 +337 +278

– – –

– – –

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

195

Design considerations Table 8d Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp K6V E K7V E M5V E

high low mm

M6V E

M7V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

6

10

0

–8

–7 –7 –5

+2 +10 +8

–10 –10 –7

+5 +13 +10

–10 –10 –8

–4 +4 +2

–12 –12 –10

–3 +5 +3

–15 –15 –12

0 +8 +5

10

18

0

–8

–9 –9 –7

+2 +10 +8

–12 –12 –9

+6 +14 +11

–12 –12 –10

–4 +4 +2

–15 –15 –13

–4 +4 +2

–18 –18 –15

0 +8 +5

18

30

0

–9

–11 –11 –8

+2 +11 +8

–15 –15 –12

+6 +15 +12

–14 –14 –12

–4 +4 +2

–17 –17 –14

–4 +5 +2

–21 –21 –18

0 +9 +6

30

50

0

–11

–13 –13 –10

+3 +14 +11

–18 –18 –14

+7 +18 +14

–16 –16 –13

–5 +6 +3

–20 –20 –17

–4 +7 +4

–25 –25 –21

0 +11 +7

50

80

0

–13

–15 –15 –11

+4 +17 +13

–21 –21 –16

+9 +22 +17

–19 –19 –16

–6 +7 +4

–24 –24 –20

–5 +8 +4

–30 –30 –25

0 +13 +8

80

120

0

–15

–18 –18 –13

+4 +19 +14

–25 –25 –20

+10 +25 +20

–23 –23 –19

–8 +7 +3

–28 –28 –23

–6 +9 +4

–35 –35 –30

0 +15 +10

120

150

0

–18

–21 –21 –15

+4 +22 +16

–28 –28 –21

+12 +30 +23

–27 –27 –22

–9 +9 +4

–33 –33 –27

–8 +10 +4

–40 –40 –33

0 +18 +11

150

180

0

–25

–21 –21 –14

+4 +29 +22

–28 –28 –20

+12 +37 +29

–27 –27 –21

–9 +16 +10

–33 –33 –26

–8 +17 +10

–40 –40 –32

0 +25 +17

180

250

0

–30

–24 –24 –16

+5 +35 +27

–33 –33 –23

+13 +43 +33

–31 –31 –25

–11 +19 +13

–37 –37 –29

–8 +22 +14

–46 –46 –36

0 +30 +20

250

315

0

–35

–27 –27 –18

+5 +40 +31

–36 –36 –24

+16 +51 +39

–36 –36 –28

–13 +22 +14

–41 –41 –32

–9 +26 +17

–52 –52 –40

0 +35 +23

315

400

0

–40

–29 –29 –18

+7 +47 +36

–40 –40 –27

+17 +57 +44

–39 –39 –31

–14 +26 +18

–46 –46 –35

–10 +30 +19

–57 –57 –44

0 +40 +27

400

500

0

–45

–32 –32 –20

+8 +53 +41

–45 –45 –30

+18 +63 +48

–43 –43 –34

–16 +29 +20

–50 –50 –38

–10 +35 +23

–63 –63 –48

0 +45 +30

500

630

0

–50

–44 –44 –31

0 +50 +37

–70 –70 –54

0 +50 +34

– – –

– – –

–70 –70 –57

–26 +24 +11

–96 –96 –80

–26 +24 +8

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

196

Radial location of bearings Table 8d Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp K6V E K7V E M5V E

high low mm

M6V E

M7V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

630

800

0

–75

–50 –50 –33

0 +75 +58

–80 –80 –58

0 +75 +53

– – –

– – –

–80 –80 –63

–30 +45 +28

–110 –110 –88

–30 +45 +23

800

1 000

0

–100

–56 –56 –36

0 +100 +80

–90 –90 –63

0 +100 +73

– – –

– – –

–90 –90 –70

–34 +66 +46

–124 –124 –97

–34 +66 +39

1 000

1 250

0

–125

–66 –66 –42

0 +125 +101

–105 –105 –72

0 +125 +92

– – –

– – –

–106 –106 –82

–40 +85 +61

–145 –145 –112

–40 +85 +52

1 250

1 600

0

–160

–78 –78 –48

0 +160 +130

–125 –125 –85

0 +160 +120

– – –

– – –

–126 –126 –96

–48 +112 +82

–173 –173 –133

–48 +112 +72

1 600

2 000

0

–200

–92 –92 –57

0 +200 +165

–150 –150 –100

0 +200 +150

– – –

– – –

–158 –150 –115

–58 +142 +107

–208 –208 –158

–58 +142 +92

2 000

2 500

0

–250

–110 –110 –67

0 +250 +207

–175 –175 –116

0 +250 +191

– – –

– – –

–178 –178 –135

–68 +182 +139

–243 –243 –184

–68 +182 +123

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

197

Design considerations Table 8e Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp N6V E N7V E P6V E

high low mm

P7V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

6

10

0

–8

–16 –16 –14

–7 +1 –1

–19 –19 –16

–4 +4 +1

–21 –21 –19

–12 –4 –6

–24 –24 –21

–9 –1 –4

10

18

0

–8

–20 –20 –18

–9 –1 –3

–23 –23 –20

–5 +3 0

–26 –26 –24

–15 –7 –9

–29 –29 –26

–11 –3 –6

18

30

0

–9

–24 –24 –21

–11 –2 –5

–28 –28 –25

–7 +2 –1

–31 –31 –28

–18 –9 –12

–35 –35 –32

–14 –5 –8

30

50

0

–11

–28 –28 –25

–12 –1 –4

–33 –33 –29

–8 +3 –1

–37 –37 –34

–21 –10 –13

–42 –42 –38

–17 –6 –10

50

80

0

–13

–33 –33 –29

–14 –1 –5

–39 –39 –34

–9 +4 –1

–45 –45 –41

–26 –13 –17

–51 –51 –46

–21 –8 –13

80

120

0

–15

–38 –38 –33

–16 –1 –6

–45 –45 –40

–10 +5 0

–52 –52 –47

–30 –15 –20

–59 –59 –54

–24 –9 –14

120

150

0

–18

–45 –45 –39

–20 –2 –8

–52 –52 –45

–12 +6 –1

–61 –61 –55

–36 –18 –24

–68 –68 –61

–28 –10 –17

150

180

0

–25

–45 –45 –38

–20 +5 –2

–52 –52 –44

–12 +13 +5

–61 –61 –54

–36 –11 –18

–68 –68 –60

–28 –3 –11

180

250

0

–30

–51 –51 –43

–22 +8 0

–60 –60 –50

–14 +16 +6

–70 –70 –62

–41 –11 –19

–79 –79 –69

–33 –3 –13

250

315

0

–35

–57 –57 –48

–25 +10 +1

–66 –66 –54

–14 +21 +9

–79 –79 –70

–47 –12 –21

–88 –88 –76

–36 –1 –13

315

400

0

–40

–62 –62 –51

–26 +14 +3

–73 –73 –60

–16 +24 +11

–87 –87 –76

–51 –11 –22

–98 –98 –85

–41 –1 –14

400

500

0

–45

–67 –67 –55

–27 +18 +6

–80 –80 –65

–17 +28 +13

–95 –95 –83

–55 –10 –22

–108 –108 –93

–45 0 –15

500

630

0

–50

–88 –88 –75

–44 +6 –7

–114 –114 –98

–44 +6 –10

–122 –122 –109

–78 –28 –41

–148 –148 –132

–78 –28 –44

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

198

Radial location of bearings Table 8e Housing tolerances and resultant fits

+ 0 – Housing Nominal bore diameter D

over

incl.

mm

Bearing Housing bore diameter deviations, resultant fits Outside diameter Tolerance classes tolerance D Dmp N6V E N7V E P6V E

high low mm

P7V E

Deviations (housing bore diameter) Theoretical interference (–)/clearance (+) Probable interference (–)/clearance (+) mm

630

800

0

–75

–100 –100 –83

–50 +25 +8

–130 –130 –108

–50 +25 +3

–138 –138 –121

–88 –13 –30

–168 –168 –146

–88 –13 –35

800

1 000

0

–100

–112 –112 –92

–56 +44 +24

–146 –146 –119

–56 +44 +17

–156 –156 –136

–100 0 –20

–190 –190 –163

–100 0 –27

1 000

1 250

0

–125

–132 –132 –108

–66 +59 +35

–171 –171 –138

–66 +59 +26

–186 –186 –162

–120 +5 –19

–225 –225 –192

–120 +5 –28

1 250

1 600

0

–160

–156 –156 –126

–78 +82 +52

–203 –203 –163

–78 +82 +42

–218 –218 –188

–140 +20 –10

–265 –265 –225

–140 +20 –20

1 600

2 000

0

–200

–184 –184 –149

–92 +108 +73

–242 –242 –192

–92 +108 +58

–262 –262 –227

–170 +30 –5

–320 –320 –270

–170 +30 –20

2 000

2 500

0

–250

–220 –220 –177

–110 +140 +97

–285 –285 –226

–110 +140 +81

–305 –305 –262

–195 +55 +12

–370 –370 –311

–195 +55 –4

F

Values are valid for most bearings with Normal tolerances. For exceptions, refer to Shaft and housing tolerances and fits († page 171).

199

Design considerations

Dimensional and geometrical tolerances of bearing seats and abutments The tolerances for cylindrical bearing seats on shafts and in housings and the seats for thrust bearing washers and for their support surfaces (abutments for bearings provided by shaft and housing shoulders etc.) should correspond to the tolerance class of the bearings. Guideline values for the dimensional and geometrical tolerances are provided hereafter. Dimensional tolerances For bearings made to Normal tolerances, the dimensional tolerances for cylindrical seats should be, at the very minimum, IT6 grade for the shaft and IT7 for the housing. Where adapter or withdrawal sleeves are used, wider diameter tolerances (IT9 grade) can be permitted for shaft seats († table 9). The numerical values of standard IT tolerance grades in accordance with ISO 286-1 are listed in table 10. For bearings with higher dimensional accuracy, correspondingly tighter grades should be used. Tolerances for total radial run-out Depending on the application requirements, the total radial run-out tolerances as defined in ISO 1101 should be one to two IT grades tighter than the prescribed dimensional tolerance. For example, if the specifications require a shaft seat in accordance with a tolerance class m6V E  , the total radial run-out should be IT5 or IT4. The tolerance value t 3 for total radial run-out is obtained for an assumed shaft diameter of 150 mm from t 3 = IT5/2 = 18/2 = 9 μm. Guideline values for the tolerances for total radial run-out are listed in table 11 († page 202). When bearings are to be mounted on adapter or withdrawal sleeves, the total radial run-out of the sleeve seat should be IT5/2 for tolerance class h9V E   († table 9).

200

Tolerances for total axial run-out Abutments for bearing rings should have a total axial run-out tolerance as defined in ISO 1101, which is better by at least one IT grade than the diameter tolerance of the associated cylindrical seat. For thrust bearing washer seats, the tolerance for total axial runout should not exceed IT5. Guideline values for the tolerances for total axial run-out are listed in table 11 († page 202).

Radial location of bearings Table 9 Shaft diameter and geometrical tolerances for sleeve mounting Shaft diameter d Nominal over

Diameter and geometrical tolerances Tolerance class Total radial run-out h9 V E IT5/2 Deviations high low max.

incl.

mm

mm

10 18 30

18 30 50

0 0 0

–43 –52 –62

4 5 6

50 80 120

80 120 180

0 0 0

–74 –87 –100

7 8 9

180 250 315

250 315 400

0 0 0

–115 –130 –140

10 12 13

400 500 630

500 630 800

0 0 0

–155 –175 –200

14 16 18

800 1 000

1 000 1 250

0 0

–230 –260

20 24

Table 10 Values of ISO standard tolerance grades Nominal dimension over incl.

Tolerance grades IT1 IT2 IT3 max.

mm

mm

IT4

IT5

IT6

IT7

IT8

IT9

IT10

IT11

IT12

1 3 6

3 6 10

0,8 1 1

1,2 1,5 1,5

2 2,5 2,5

3 4 4

4 5 6

6 8 9

10 12 15

14 18 22

25 30 36

40 48 58

60 75 90

100 120 150

10 18 30

18 30 50

1,2 1,5 1,5

2 2,5 2,5

3 4 4

5 6 7

8 9 11

11 13 16

18 21 25

27 33 39

43 52 62

70 84 100

110 130 160

180 210 250

50 80 120

80 120 180

2 2,5 3,5

3 4 5

5 6 8

8 10 12

13 15 18

19 22 25

30 35 40

46 54 63

74 87 100

120 140 160

190 220 250

300 350 400

180 250 315

250 315 400

4,5 6 7

7 8 9

10 12 13

14 16 18

20 23 25

29 32 36

46 52 57

72 81 89

115 130 140

185 210 230

290 320 360

460 520 570

400 500 630

500 630 800

8 – –

10 – –

15 – –

20 – –

27 32 36

40 44 50

63 70 80

97 110 125

155 175 200

250 280 320

400 440 500

630 700 800

800 1 000 1 250

1 000 1 250 1 600

– – –

– – –

– – –

– – –

40 47 55

56 66 78

90 105 125

140 165 195

230 260 310

360 420 500

560 660 780

900 1050 1250

1 600 2 000

2 000 2 500

– –

– –

– –

– –

65 78

92 110

150 175

230 280

370 440

600 700

920 1 100

1 500 1 750

F

201

Design considerations Tolerances for tapered shaft seats When a bearing is mounted directly onto a ­t apered shaft seat, the tolerance grade of the diam­eter of the shaft seat can be wider than the tolerance grade for a cylindrical seat. Fig. 18 shows an IT9 grade diameter tolerance, while the stipulated geometrical tolerance is the same as for a cylindrical shaft seat. For rolling bearings mounted on tapered shaft seats, SKF recommends:

• The permissible deviation for the slope of the taper should be a ± tolerance in accordance with IT7/2, and is based on the bearing width B († fig. 18). For design purposes, the tolerance value has to be expressed in degrees. The value can be determined using IT7/2 Dk = ——– B Table 11

Geometrical tolerances for bearing seats on shafts and in housings

A

B

t4 A-B

t3 A-B A

B

dA

dB

DB

DA

t4 A-B

Surface Characteristic

Symbol for geometrical characteristic

t3 A-B

Permissible deviations Bearings of tolerance class 1) Normal, CLN P6

P5

t3

IT5/2

IT4/2

IT3/2

IT2/2

t4

IT5

IT4

IT3

IT2

tolerance zone

Cylindrical seat Total radial run-out Flat abutment Total axial run-out

Explanation

For normal demands

For special demands with respect to running accuracy or even support

1) For bearings with a tolerance class higher than Normal (tolerance class P4 etc.), refer to Super-precision bearings

(† skf.com/super-precision).

202

Radial location of bearings The permissible deviation for the slope of the taper can be determined using IT7/2 Vk = 1/k ± ——– B where Dk = the permissible deviation of the slope of the taper [°] Vk = the permissible range of dispersion of the slope of the taper [°] B = bearing width [mm] IT7 = the value of the tolerance grade, based on the bearing width [mm] k = factor for the taper – for taper 1:12, k = 12 – for taper 1:30, k = 30 • The straightness tolerance grade IT5/2, based on the diameter d, is defined as: “In each axial plane through the tapered surface of the shaft, the tolerance zone is limited by two parallel lines a distance “t” apart.”

• The circularity tolerance grade IT5/2, based on the diameter d, is defined as distance “t” in each radial plane between two concentric circles along the tapered surface of the shaft. In applications where a high degree of running accuracy is required, IT4/2 should be used instead. Only dimensional and geometrical tolerances of the taper are indicated in fig. 18. To locate the taper axially, individual specifications have to be provided. To check whether a shaft taper is within its recommended tolerances, SKF recommends measuring it with a special taper gauge, based on two saddles. More practical, but less accur­ ate measurement methods include ring gauges, taper gauges and sine bars. For information about SKF measuring devices such as RKM, 9205, GRA 30 series ring gauges and DMB ­t aper gauges, contact the SKF application ­engineering service.

Fig. 18

1/k ± (IT7/2) / B

F

t

t IT5/2 Ra 1,6

t IT5/2

d js9 E

t

B

203

Design considerations Table 12 Surface roughness of bearing seats Seat diameter d (D) 1)

over

incl.

mm –

Recommended R a value for ground seats Diameter tolerance grade IT7 IT6 IT5 mm

80

1,6

0,8

0,4

80

500

1,6

1,6

0,8

500

1 250

3,2 2)

1,6

1,6

1) For diameters > 1 250 mm, contact the SKF application

engineering service.

2) When using the oil injection method for mounting, R

should not exceed 1,6 mm.

a

Surface roughness of bearing seats The surface roughness of a bearing seat does not have the same degree of influence on bearing performance as the dimensional and geometrical tolerances of the seat. However, obtaining a desired interference fit depends on the roughness of the mating surfaces, which is directly proportional to fit accuracy. For less critical bearing arrangements a relatively rough surface finish is permitted. Guideline values for the mean surface roughness Ra are listed in table 12 for ­different bearing seat tolerance grades. These recommendations apply to ground seats, which are normally assumed for shaft seats.

204

Axial location of bearings In general, an interference fit alone is inad­ equate to locate a bearing ring on a cylindrical seat. Under load and deflection, a bearing ring can wander on its seat. Some suitable means to secure the bearing axially are needed. For a locating bearing, both rings should be secured axially on both sides. For a non-separable bearing in the non-­ locating position, the ring with an interference fit, typically the inner ring, should be secured axially on both sides. The other ring must be free to move axially on its seat to accommodate axial displacement. For non-locating bearings, CARB, cylindrical and needle roller bearings are exceptions. The inner and outer rings of these bearings must be secured axially in both directions. For a cross-located bearing system, each bearing ring needs to be secured axially on one side only.

Axial location of bearings

Methods of location

Fig. 20

Bearings with a cylindrical bore Bearing rings that are mounted with an interference fit typically have one ring that abuts a shoulder on the shaft († fig. 19) or in the housing. On the opposite side, the inner ring is normally secured by a KM lock nut with an MB lock washer attached to the shaft end († fig. 19) or an end plate († fig. 20). Outer rings are typically located by a housing cover († fig. 21) or a threaded ring († fig. 22).

Fig. 21

F Fig. 19

Fig. 22

205

Design considerations Instead of integral shaft or housing shoulders, spacer sleeves or collars can be used between the bearing rings or between a bearing ring and an adjacent component, such as a gear († fig. 23). The use of snap rings to locate rolling bearings axially, saves space, enables fast mounting and dismounting, and simplifies the machining of shafts and housing bores. If normal or heavy axial loads have to be supported, an abutment collar should be inserted between the bearing ring and snap ring, so that the snap ring is not subjected to excessive bending moments († fig. 24). The usual axial play between the snap ring and snap ring groove can be reduced, if necessary, by choosing suitable tolerances for the abutment collar or by using shims. Another way to locate a bearing axially, which is typically found in super-precision bearing applications, is to use a stepped sleeve with a tight interference fit on the shaft. For detailed information, refer to Super-precision bearings († skf.com/super-precision).

Fig. 23

206

Fig. 24

Axial location of bearings Bearings with a tapered bore Bearings with a tapered bore, mounted ­directly on a tapered shaft seat, are typically located axially on the shaft by a lock nut († fig. 25). When using an adapter sleeve on a stepped shaft, an L-shaped spacer ring, not supplied by SKF, is fitted between the shaft shoulder and inner ring on one side. A lock nut locates the bearing relative to the sleeve on the opposite side († fig. 26). Where plain shafts without integral abutments are used († fig. 27), the friction between the shaft and sleeve governs the axial load carrying capacity of the bearing († Self-aligning ball bearings, page 537 and Spherical roller bearings, page 879). When bearings are mounted on withdrawal sleeves, an abutment, such as a spacer ring, which is frequently designed as a labyrinth ring, must support the inner ring. The withdrawal sleeve is axially located by an end plate or lock nut († fig. 28).

Fig. 26

Fig. 27

F Fig. 25

Fig. 28

207

Design considerations

Abutment and fillet dimensions The dimensions of components adjacent to a bearing (such as shaft and housing shoulders, spacer sleeves) must be able to provide sufficient support for the bearing rings. However, there must not be any contact between the rotating parts of the bearing and a stationary adjacent component. Appropriate abutment and fillet dimensions are listed in the product tables. The transition between the bearing seat and shaft or housing shoulder can be a fillet in accordance with the dimensions r a and rb in the product tables, or an undercut († table 13). As the fillet radius increases, the stress distribution in the fillet area improves. Therefore, heavily loaded shafts, which typically require a larger radius, use a spacing collar between the inner ring and shaft shoulder to provide a sufficiently large support surface for the bearing ring. The side of the collar that abuts the shaft shoulder should be designed so that it does not contact the fillet († fig. 29).

Table 13 Undercut dimensions

ba rs ha

rc

ha

rc

rs

rs rs ba

Bearing chamfer dimension rs

Undercut dimensions

mm

mm

1 1,1 1,5

ba

ha

rc

2 2,4 3,2

0,2 0,3 0,4

1,3 1,5 2

2 2,1 3

4 4 4,7

0,5 0,5 0,5

2,5 2,5 3

4 5 6

5,9 7,4 8,6

0,5 0,6 0,6

4 5 6

7,5 9,5

10 12

0,6 0,6

7 9

Fig. 29

208

Axial location of bearings CARB toroidal roller bearings CARB toroidal roller bearings can accommodate axial displacement of the shaft within the bearing. To be sure that displacement of the shaft relative to the housing can occur, sufficient space C a must be provided on both sides of the bearing († fig. 30). For additional information, refer to CARB toroidal roller bearings († page 957).

Fig. 30

Ca

Ca

F

209

Design considerations

Design of associated components

For additional information, contact the SKF application engineering service.

Raceways on shafts and in housings

Provisions for mounting and dismounting

If the load carrying capacity of a bearing or assembly is to be fully exploited, the raceways machined in associated components for cylindrical and needle roller bearings with only one ring, must have a hardness between 58 and 64 HRC. The surface roughness should be Ra ≤ 0,2 μm or R z ≤ 1 μm. For less demanding applications, lower hardness and rougher surfaces may be used. Roundness should be within 25% and the total radial run-out tolerance should be within 50% of the actual diameter tolerance range of the raceway. The permissible axial run-out of the raceways for thrust assemblies are the same as for the shaft and housing washers of thrust bearings († table 10, page 144). Suitable materials for the raceways include steels for through-hardening, such as 100Cr6 in accordance with ISO 683-17, steels for case-hardening, such as 20Cr3 or 17MnCr5 in accordance with ISO 683-17, as well as steels for induction-hardening that can be partially hardened. The recommended case depth for raceways machined in associated components depends on various factors, including the dynamic and static load ratios (P/C and P 0 /C0 respectively) as well as the core hardness, which makes it difficult to generalize. For example, when core hardness is 350 HV, the recommended case depth is generally 0,1 times the rolling element diameter for purely static loads less than or equal to the basic static load rating. Shallower case depths are permitted for dynamic loads. Fig. 31

210

Particularly when large bearings are involved, SKF recommends making provisions during the design stage to facilitate mounting and dismounting. If, for example, slots or recesses are machined in the shaft and/or housing shoulders, it is possible to apply withdrawal tools († fig. 31). Threaded holes in the housing shoulders also enable the use of bolts to push or pull the bearing from its seat († fig. 32). If the oil injection method is to be used to mount or dismount bearings on a tapered seat, or to dismount bearings from a cylindrical seat, ducts and grooves should be provided in the shaft († fig. 33). Recommended dimensions for the appropriate grooves, ducts and threaded holes to connect the oil supply are listed in tables 14 and 15.

Fig. 32

Designing associated components Fig. 33

Table 14 Recommended dimensions for oil supply ducts and distribution grooves

L

Table 15 Design and recommended dimensions for threaded holes for connecting oil supply

L 3

60° Na

ba ra

Ga

ha

Ga

Na

Gc

Gb

Gc Gb

Design A

Design B

N

F Seat diameter over

incl.

mm

Dimensions ba

ha

Thread ra

N

mm

Design

Ga

Dimensions Gb





mm

G c 1)

Na max.

– 100 150

100 150 200

3 4 4

0,5 0,8 0,8

2,5 3 3

2,5 3 3

M6

A

10

8

3

G 1/8

A

12

10

3

200 250 300

250 300 400

5 5 6

1 1 1,25

4 4 4,5

4 4 5

G 1/4

A

15

12

5

G 3/8

B

15

12

8

400 500 650

500 650 800

7 8 10

1,5 1,5 2

5 6 7

5 6 7

G 1/2

B

18

14

8

G 3/4

B

20

16

8

800

1 000

12

2,5

8

8

L = width of bearing seat

1) Effective threaded length

211

Design considerations

Selecting internal clearance or preload The operating clearance or preload in a bearing is determined by: • the initial internal clearance prior to mounting • the actual fits • the effects of form errors • the internal clearance or preload built into the bearing after mounting • the dimensional changes resulting from the operating temperature

Shaft deflection and axial displacement, such as in CARB toroidal roller bearings, might also need to be considered. The operating clearance or preload in a bearing influences friction, size of the load zone and fatigue life. Diagram 2 shows the relationship between clearance and preload, and the primary parameters. The diagram is based on rolling bearings under radial load.

Diagram 2 Clearance and preload versus performance of primary parameters

Performance

2,0 1,8 1,6 1,4 1,2 1,0 Rolling frictional moment

0,8 0,6

Bearing service life

0,4

Load zone

0,2 0

-2

Preload

212

-1

0

1

2

3

Clearance

Selecting internal clearance or preload

Clearance versus preload For most applications, bearings operate with some residual clearance. Normally, a positive operating clearance near zero is the optimum († diagram 2). A somewhat greater clearance may be more suitable for: • high-speed applications to reduce frictional heat • form errors on the shaft or housing seat such as ovality The initial internal clearance prior to mounting and permissible reduction after mounting, depend on the type and size of the bearing. The reduction in clearance due to an interference fit may require greater initial internal clearance than Normal to avoid preloading the bearing († fig. 15, page 167). Preload (negative operating clearance) has advantages, but can also be risky. If a high degree of stiffness is required, light preload can be suitable († Bearing preload, page 214). A light preload may also be required when there is a very light or no external load on the bearing in operation. In this case, however, there is a risk that too much preload causes the bearing to overheat, which further increases preload, friction and heat. This cycle can continue until the bearing seizes. It could be argued that preload is acceptable, provided the bearing operates in a zone that does not exceed light preload († diagram 2, zone between 0 and –1). In this case, however, there is an increase in friction and frictional heat. Although all bearing types can run with some preload, SKF recommends a positive operating clearance. This is particularly important for roller bearings such as cylindrical roller, needle roller, spherical roller and CARB toroidal roller bearings.

Bearing clearance Selecting a clearance class The clearance values listed in the relevant product chapters are valid for unmounted bearings. To select the best clearance value for an application, the required operating clearance in the bearing (in operation) must be determined first. Because there are many factors that can ­influence operating clearance in a bearing, these calculations are best done with the aid of sophisticated computer programs. As a result, SKF recommends using one of the computer programs available through the SKF application engineering service. These programs consider tolerances, fits and component temperatures, to calculate the required initial internal clearance. The required initial internal clearance of an unmounted bearing can be estimated using r = rop + Drfit + Drtemp where r = required initial internal clearance for the unmounted bearing [mm] rop = desired operating clearance [mm] Drfit = clearance reduction caused by the fit [mm] Drtemp = clearance reduction caused by temperature difference [mm] Clearance reduction caused by an interference fit

The reduction equals the effective interference fit multiplied by a reduction factor using Drfit = D1 f1 + D2 f2 where Drfit = clearance reduction caused by the fit [mm] f1 = reduction factor for the inner ring f2 = reduction factor for the outer ring D1 = effective interference between the inner ring and shaft [mm] D2 = effective interference between the outer ring and housing [mm]

213

F

Design considerations The reduction factors can be obtained from diagram 3 as a function of the ratio of the bearing bore diameter d to the outside diameter D. It is valid for a solid steel shaft and a cast iron or steel housing. For the effective interference fit, the mean value of the smallest and largest values of the probable interference listed in table 7 († page 178) and table 8 († page 190) can be used. Clearance reduction caused by a temperature difference between the bearing rings

When the inner ring temperature is higher than the outer ring temperature, the internal clearance within the bearing is reduced. The internal clearance reduction can be estimated using

Diagram 3 Factors f 1 and f 2 for clearance reduction caused by interference fits

f1, f2 1,0 Outer ring

0,9 0,8

Inner ring

0,7 0,4

0,5

0,6

0,7

0,8

Diagram 4

Dr temp = a D DT where Drtemp = clearance reduction caused by temperature difference [mm] D = bearing outside diameter [mm] a = thermal coefficient of expansion [°C–1] for steel, a = 12 ¥ 10–6 DT = temperature difference between the shaft and housing [°C] The temperature difference between compon­ ents during start-up can be much higher than under steady state conditions († diagram 4) and unwanted preload may result. It is import­ ant to avoid unwanted preload during startup, because even short periods of preload can have a negative impact on bearing service life. One way to avoid excessive heat and the resulting preload is to start the application at a slow speed and increase the speed incrementally.

Bearing preload Depending on the applications, there might be a need to preload the bearing arrangement i.e. apply a negative operating clearance. In applications like machine tool spindles, automotive differentials and electric motors, where preload enhances stiffness or running accuracy, SKF recommends applying preload with springs if an adjustment nut is not available. Springs should also be used under very light or no-load conditions to provide a min­ 214

0,9

d/D

Temperature differences during start-up Temperature Shaft

DTmax

Housing

Ambient temperature

Time

Selecting internal clearance or preload imum load on the bearing († Requisite min­ imum load, page 86). Preload can be expressed as a force or as a distance (path), but is typically expressed as a force. Depending on the adjustment method, preload is also indirectly related to the frictional moment in the bearing. Empirical preload values can be obtained from proven designs and can be applied to similar designs. For new designs, SKF recommends calculating the preload force and checking its accuracy by testing the application. In general, all influencing factors in operation cannot be fully identified in the design stage and adjustments may be necessary. The ­accuracy of the calculation depends on how closely the estimated operating temperature and elastic behaviour of the associated components – most importantly the housing – ­coincide with the actual conditions in operation. Considerations for preload Depending on the bearing type, preload may be either radial or axial. Cylindrical roller bearings, for example, can only be preloaded radially because of their design, while thrust ball and cylindrical roller thrust bearings can only be preloaded axially. Single row angular contact ball bearings and tapered roller bearings († fig. 34), which are normally subjected to axial preload, are generally mounted together with a second bearing of the same type and size in a back-to-back (load lines diverge) or face-to-face (load lines converge) arrangement. Deep groove ball bearings can also be preloaded axially. If so, the bearings should have a greater radial internal clearance than Normal (such as C3) so that, as with angular contact ball bearings, a contact angle that is greater than zero is obtained.

Fig. 34

Back-to-back arrangement

F

Face-to-face arrangement

215

Design considerations For both tapered roller and angular contact ball bearings, the distance L between the pressure centres is longer when the bearings are arranged back-to-back († fig. 35) compared to bearings that are arranged face-toface († fig. 36). This means that bearings ­arranged back-to-back can accommodate ­relatively large tilting moments even if the distance between the bearing centres is relatively short. The radial loads and bearing deformation resulting from a moment load is smaller for bearings arranged back-to-back than for bearings arranged face-to-face. If in operation the shaft temperature is higher than the housing temperature, the preload, which was adjusted at ambient temperature during mounting, increases. The in-

crease is greater for bearings arranged faceto-face than for bearings arranged back-to-back. In both cases, however, thermal expansion of the inner ring in the radial direction serves to reduce clearance or increase preload. This tendency is increased by thermal expansion of the rings in the axial direction when the bearings are face-to-face, but is reduced for back-to-back arrangements. For back-to-back arrangements only: ­Depending on the distance between the bearings, when the coefficient of thermal expansion is the same for the bearings and associated components, thermal expansion in both the radial and axial directions can cancel each other out so that preload remains unchanged.

Fig. 35 Back-to-back arrangements

Face-to-face arrangements

L

L

L

216

Fig. 36

L

Selecting internal clearance or preload Effects of bearing preload The primary benefits resulting from preload include but are not limited to: • enhanced stiffness • reduced noise levels • improved shaft guidance • compensation for wear and settling • extended bearing service life Enhanced stiffness

Bearing stiffness [kN/mm] is defined as the ratio of the force acting on the bearing to the elastic deformation in the bearing. The elastic deformation caused by a load in preloaded bearings is smaller for a given load range than for bearings that are not preloaded. Reduced noise levels

As operating clearance in a bearing decreases, guidance of the rolling elements in the un­ loaded zone improves, which reduces noise levels in operation. Improved shaft guidance

Preloaded bearings provide more accurate shaft guidance because preload provides a higher degree of stiffness, which limits the ability of the shaft to deflect under load. For example, preloading the ring and pinion bearings in a differential results in increased stiffness, which keeps gear mesh accurate and constant. This minimizes dynamic forces and reduces noise levels, which can extend the ser­vice life of the gears.

F

Compensation for wear and settling

Wear and settling in a bearing arrangement in operation increases the clearance. This clearance can be compensated for with preload. Extended bearing service life

In certain applications, an optimum preloaded bearing system († Selecting the correct preload, page 225) can enhance operational reliability, provide more favourable load distribution in the bearings and extend bearing service life.

217

Design considerations Preload in bearing systems with angular contact ball or tapered roller bearings When determining preload, the preload force required to provide an optimum combination of stiffness, bearing service life and oper­ ational reliability should be calculated first. Then calculate the preload force to be used when adjusting the bearings during mounting. When mounting, the bearings should be at ambient temperature and should not be subjected to any other load. The appropriate preload at normal operating temperature depends on the bearing load. An angular contact ball bearing or a tapered roller bearing can accommodate radial and ­a xial loads simultaneously. Under radial load, these bearings produce a resultant axial load which must be accommodated by a second bearing facing the opposite direction. Purely radial displacement of one bearing ring relative to the other means that half of the rolling elements are under load. The resultant axial load produced in the bearing can be determined by: • for single row angular contact ball bearings Fa = R Fr • for single row tapered roller bearings Fa = 0,5 Fr / Y

where Fa = axial bearing load († fig. 37) Fr = radial bearing load († fig. 37) R = variable for inside contact conditions († Calculating the axial load for bearings mounted singly or paired in tandem, page 495) Y = calculation factor († product tables) When a single bearing is subjected to a radial load Fr, an axial load Fa (external) of the same magnitude as the resultant load must be applied to the bearing if the basic load rating is to be fully exploited. If the applied external load is lighter, there are fewer rolling elements supporting the load and the load carrying capacity of the bearing is correspondingly reduced. In a bearing system consisting of two single row angular contact ball bearings or two ­t apered roller bearings arranged back-to-back or face-to-face, each bearing arrangement must accommodate the axial load in one direction. When these bearing systems are ad­ justed to near-zero clearance, the radial load is shared equally between the two bearings and half the rolling elements in each bearing are loaded. In other cases, where there is an external axial load, it may be necessary to preload the bearings to compensate for the clearance that can occur when the axially loaded bearing deforms elastically. Preload also distributes the loads more favourably in an axially unloaded bearing. Fig. 37

Fa

Fa

Fr

218

Selecting internal clearance or preload Preload also increases the stiffness of a bearing system. However, keep in mind that stiffness is also influenced by the elasticity of the shaft and housing, the shaft and housing fits, as well as the elastic deformation of all other components adjacent to the bearings, including the abutments. Each of these has a considerable impact on the resilience of the total bearing system. The axial and radial resiliences of a bearing depend on its internal design, contact conditions (point or line contact), the number and diameter of rolling ­elements and the contact angle. The greater the contact angle, the higher the degree of stiffness in the axial direction. If, as a first approximation, a linear dependence of the resilience on the load is assumed, such as a constant spring ratio, a comparison shows that the axial displacement in a bearing system under preload is smaller than for a bearing system without preload for the same external axial force K a († diagram 5). A pinion arrangement design († figs. 39 and 40, page 222) typically consists of two different size tapered roller bearings, A and B, with different spring constants c A and cB. Both are subjected to a pre­load force F0. If an axial force K a acts on bearing A, bearing B becomes unloaded, and the additional load acting on bear-

ing A results in an axial displace­ment da that is smaller than it would be if the bearings had not been preloaded. However, B is relieved of the axial preload force and the axial displacement under additional load is the same as it is for a bearing system without preload, that means determined solely by the spring constant c A , if the external axial force exceeds the value q cA w K = F 1 + J a 0 < cB z To prevent bearing B from becoming unloaded when bearing A is subjected to an axial force K a, the following preload force is required q cB w F0 = Ka JJJ < cA + cB z

Diagram 5 Axial displacement in bearing systems with and without preload External axial force K a

F

With preload F 0 Without preload K da = c a A

c Ka = F0 (1 + c A ) B

Axial displacement d a

219

Design considerations From diagram 6, it is also possible to explain the relationship between components, for example in a pinion arrangement design († fig. 39, page 222), where bearing A is located adjacent to a gear and is adjusted against bearing B to provide preload. The external axial force K a (axial component of tooth forces) is superimposed on the preload force F01 (curve 1) in such a way that bearing A is subjected to add­itional load while bearing B is unloaded. The load on bearing A is designated FaA and on bearing B it is designated FaB. ­Under the influence of the axial force K a, the pinion shaft is axially displaced by the amount da1. The smaller preload force F02 (curve 2) has been chosen so that bearing B is just unloaded by the axial force K a, that means FaB = 0 and FaA = K a. The pinion shaft is displaced in this case by the amount da2 > da1. When the arrangement is not preloaded (curve 3), the axial displacement of the pinion shaft is greatest (da3 > da2).

Loads and elastic displacements in a pre­ loaded bearing system, as well as the effects of a change in preload, are easily understood from a preload force / axial displacement diagram († diagram 6). This consists of the spring curves of the components that are adjusted against each other to apply preload and enables the following: • the relationship of the preload force and ­a xial displacement within the preloaded bearing system • the relationship between an externally ­applied axial force K a and the bearing load for a preloaded bearing system, as well as the elastic deformation produced by an external load In diagram 6, all the components subjected to external loads in operation are represented by the curves that increase from left to right, and all the unloaded components by the curves that increase from right to left. Curves 1, 2 and 3 are for different preload forces (F01, F02 < F01 and F03 = 0). The broken lines represent individual bearings, while the solid lines represent the total bearing system (bearing(s) and associated components) for different preload forces.

Diagram 6 Influence of preload and axial load on axial displacement in bearing systems Axial load Fa , preload force F 0

Bearing A Bearing B

Bearing position A (total)

Bearing position B (total)

1 F01

Ka

2

FaA

F02

Ka FaB

3 F03 da2 da3

220

da1

Axial displacement d a

Selecting internal clearance or preload

Adjustment procedures Adjustment means setting the bearing internal clearance († Mounting, page 275) or preload in a bearing system. The radial preload typically used for cylindrical roller bearings, double row angular contact ball bearings and sometimes for deep groove ball bearings, for example, is achieved by an interference fit on one or both bearing rings. The degree of interference should reduce residual clearance to zero, which is further reduced to a negative clearance (preload) when the bearing is in operation. Bearings with a tapered bore are particularly suitable for radial preloading since, by driving the bearing up onto its tapered seat, the preload can be applied to within narrow limits. Axial preload in a bearing system with single row angular contact ball bearings, tapered roller bearings and deep groove ball bearings is produced by displacing one bearing ring ­a xially, relative to the other, by an amount ­corresponding to the desired preload force. There are basically two principal methods to adjust preload: individual adjustment and ­collective adjustment. Individual adjustment With individual adjustment, each bearing system is adjusted separately using nuts, shims, spacer sleeves, crush sleeves etc. Measuring and inspection procedures provide that the established nominal preload is obtained with the least possible deviation. There are different methods to obtain the required preload:

F

• axial displacement method • frictional moment method • direct force method The method used depends on, among other things, the application design and the number of bearings to be mounted. Individual adjustment can accommodate enough tolerance stack-up so that if individual components are produced to Normal tolerances, the desired preload can be achieved with a relatively high degree of accuracy.

221

Design considerations Fig. 38

Fig. 39

Fig. 40

222

Selecting internal clearance or preload Axial displacement method

The axial displacement method is based on the relationship between the preload force and the elastic deformations within the bearing system. The requisite preload can be determined from a preload force / axial displacement diagram († diagram 7). This method of adjustment is frequently used when the components of a bearing system are pre-assembled. The required preload, which is expressed as a linear value, requires measuring total axial displacement (end play) of the shaft relative to a fixed surface. This is typically done with a dial indicator. Shims, intermediate rings or spacers can then be used to adjust axial displacement to the correct value. The preload is achieved, for example, for pinion arrangement designs by: • fitting intermediate rings between the inner and outer rings of the two bearings († fig. 38) • inserting shims between the housing shoulder and the bearing outer ring or between the cartridge and the housing († fig. 39), where the cartridge in this case is the ­f langed angled insert

• fitting a spacer between a shaft shoulder and one of the bearing inner rings († fig. 40) or between the inner rings of both bearings The width of the shims, intermediate rings or spacers is determined by: • the distance between the shaft and housing shoulders • the total width of both bearings • the axial displacement corresponding to the desired preload force • a correction factor for the axial displacement to account for thermal expansion in operation • the manufacturing tolerances of all related components, established by measuring the actual dimensions before mounting • a correction factor to account for a certain loss of preload as a result of settling and wear

Diagram 7 Relationship between the preload force and the axial displacements within a bearing system, for example in a pinion arrangement design Preload force F 0

F

F 0 © Preload force on the pinion shaft (bearing system) d 01 Axial displacement for the pinion head bearing and surrounding components F0©

d 02 Axial displacement for the bearing at the flange side and surrounding components d 0 Total axial displacement for pinion bearing system

d02

d01

Axial displacement d

d0

223

Design considerations Frictional moment method

This method is common in series production because it is fast and can be automated. Since there is a relationship between bearing preload and the frictional moment in the bearings, it is possible to stop adjustment when a frictional moment corresponding to the desired preload has been reached. This can be done if the frictional moment is continuously monitored while setting preload. However, the frictional moment can vary from bearing to bearing, and it also depends on the preservative, the lubricant and the sealing method. Direct force method

As the purpose of bearing adjustment is to obtain a specific preload, it would seem sensible to use a method either to produce or to measure the force directly. However, in practice, the indirect methods of adjustment by axial displacement or frictional moment are preferred as they are simple and can be achieved easily and more cost-effectively. Collective adjustment This method can also be referred to as “random statistical adjustment”. Using this method, the bearings, shaft, housing, and any other components are manufactured to Normal ­tolerances. The components, which are considered fully interchangeable, are assembled randomly. Where tapered roller bearings are concerned, this interchangeability also extends to the inner ring assemblies and outer rings. To avoid high machining costs and the use of

precision bearings, it is assumed that given the limiting values of the tolerances, it is stat­ istically improbable that tolerance stack-up occurs. If, however, accurate preload is to be obtained with as little scatter as possible, manufacturing tolerances must be narrowed. The advantage of collective adjustment is that no inspection is required and no extra equipment is needed when mounting the bearings. Preloading with springs By preloading bearings in small electric motors (up to frame size of 132) or similar applications, it is possible to reduce bearing noise levels. The bearing system in this case comprises a single row deep groove ball bearing at each end of the shaft. The simplest method of applying preload is to use a spring or spring package († fig. 41). The spring acts on the outer ring of one of the two bearings. This ­outer ring must be able to be axially displaced. The preload force remains practically constant, even when there is axial displacement of the bearing as a result of thermal elongation. The requisite preload force can be estimated using F=kd where F = preload force [kN] d = bearing bore diameter [mm] k = a factor, † following Depending on the design of the electric motor, values of between 0,005 and 0,01 are used for Fig. 41

224

Selecting internal clearance or preload the factor k. If preload is used primarily to protect the bearing from the damage caused by external vibrations when stationary, then greater preload is required and k = 0,02 should be used. Spring loading is also a common method of applying preload to angular contact ball bearings in high-speed grinding spindles. The method is not suitable, however, for bearing applications where a high degree of stiffness is required, where the direction of load changes, or where undefined shock loads can occur.

Selecting the correct preload When selecting the preload for a bearing system, the degree of stiffness increases marginally once preload exceeds a given optimum value. When exceeding the optimum value, friction and the resulting increase in heat can substantially reduce bearing service life and negate any benefits († diagram 2, page 212). Excessive preload involves a risk that the ­operational reliability of a bearing system is compromised. Because of the complexity normally required to calculate an appropriate preload, SKF recommends contacting the SKF application engineering service. When adjusting preload in a bearing system, it is also important that the established preload value, determined either by calculation or by experience, is attained with the least possible scatter. To reduce scatter when mounting ­t apered roller bearings, for example, the shaft should be turned several times, if possible, so that the rollers are not skewed and the roller ends are in contact with the guide flange of the inner ring. Turning the shaft also enables the rollers to make full contact with the outer ring and avoids damage to the raceways. When the rollers are not fully settled into position, a much smaller preload than the requisite value results.

Bearings for preloaded bearing systems For certain applications, SKF supplies single bearings or matched bearings, which are ­specifically made to enable simple and reliable adjustment, or which are matched during manufacture so that after mounting, a predetermined preload is obtained. These include: • tapered roller bearings to CL7C specifications for higher running accuracy, such as automotive differentials († Tapered roller bearings, page 797) • universally matchable single row angular contact ball bearings († Angular contact ball bearings, page 475) • matched single row tapered roller bearings († Tapered roller bearings, page 797) • matched single row deep groove ball bearings († Deep groove ball bearings, page 295)

F

225

Design considerations

Sealing solutions

Fig. 42

All bearing systems include a shaft, bearings, housing(s), lubricant, associated components, and seals. Seals are vital to the cleanliness of the lubricant and the service life of the bearings. Where seals for rolling bearings are concerned, a distinction is made between seals that are integrated in the bearing and those that are positioned outside the bearing. Bearings that are capped with seals or shields are generally used in bearing systems where an effective external sealing arrangement is not practical due to space or cost reasons, or where these seals or shields are adequate for the operating conditions.

Seal types The purpose of a seal is to retain lubricant and prevent any contaminants from entering into a controlled environment. To be effective, a seal should exhibit the following main characteris­ tics: • flexible enough to compensate for any ­surface irregularities • strong enough to withstand operating pressures • able to accommodate a wide range of ­operating temperatures • resistant to common chemicals • operate with lowest possible friction, frictional heat and wear There are several basic seal types: • static seals • dynamic seals • non-contact seals • bellows and membranes Seals that make contact with stationary surfaces are called static seals. Their effectiveness depends on the radial or axial deformation of their cross section when installed. Gaskets († fig. 42) and O-rings († fig. 43) are typical examples of static seals. Seals in contact with sliding surfaces are called dynamic seals and are used to seal passages between machine components that move relative to each other either linearly or 226

circumferentially. Dynamic seals are designed to retain lubricant, exclude contaminants, separate different media and withstand differential pressures. There are various types of dynamic seals, including packing or piston rings, which are used for linear or oscillating movements. However, the most common seal is the radial shaft seal († fig. 44), which makes contact with both a stationary and ­rotating component. Non-contact radial shaft seals form a narrow gap between the stationary seal lip and rotating component. The gap can be arranged axially, radially or in combination. Non-contact seals, which range from simple gap-type seals to multi-stage labyrinths († fig. 45), generate almost no friction and, therefore, do not wear. Bellows and membranes are used to seal components that have limited movement relative to each other. Because of their importance for bearing ­applications, the following information deals almost exclusively with contact and non-contact radial shaft seals, their various designs and executions.

Sealing solutions Fig. 43

Selecting seal type Seals for bearing arrangements should provide maximum protection with a minimum amount of friction and wear, even under the most arduous operating conditions. Because bearing performance and service life are so closely tied to the effectiveness and cleanliness of the lubricant, the seal is a key compon­ ent in a bearing system. For more information on the influence of contaminants on bearing performance, refer to Selecting bearing size († page 61). Many factors have to be considered when selecting the most suitable seal for a particular bearing system. They include:

Fig. 44

• the lubricant type: oil, grease or other • the circumferential speed of the seal counterface • the shaft arrangement: horizontal or vertical • possible shaft misalignment or deflection • run-out and concentricity • available space • seal friction and the resulting temperature increase • environmental influences • cost Where full application details are available, ­refer to: • Power transmission seals († skf.com/seals) • the product information available online at skf.com/seals

Fig. 45

SKF is one of the largest seal manufacturers in the world and can assist in the selection pro­ cess if little or no experience is available for a given application. For additional information, contact the SKF application engin­eer­ing service.

227

F

Design considerations Non-contact seals The effectiveness of a non-contact seal depends, in principle, on the sealing action of the narrow gap between the shaft and housing. The gap may be arranged radially, axially or in combination († fig. 46). These seals can be as simple as a gap-type radial shaft seal or more complex, like a labyrinth seal. In either case, because there is no contact, these seals generate almost no friction and do not wear. They are not easily damaged by solid con­t am­ in­ants and are particularly well suited for high speeds and high temperatures. Contact seals The effectiveness of a contact seal is determined by the amount of pressure available to keep the seal lip in contact with the seal counterface on the shaft. This pressure († fig. 47) can be produced either by:

Contact seals are generally very reliable. Their effectiveness, however, depends on the surface finish of the counterface, the condition of the seal lip and the presence of lubricant between the seal lip and counterface. Friction between the seal lip and counterface can generate a significant amount of heat. As a result, these seals have circumferential speed limits. They are also susceptible to mechanical damage as a result of improper mounting, or by solid contaminants. To protect the seal from the damage caused by solid contaminants, a non-contact seal is typically placed in front of a contact seal.

• the resilience of the seal, resulting from the elastic properties of the seal material (a) • the designed interference between the seal and its counterface (b) • a tangential force exerted by a garter spring incorporated in the seal (c)

Fig. 46

Fig. 47



228

a

b

c

Sealing solutions

Integral bearing seals SKF supplies several bearing types capped with a seal or shield on one or both sides. These provide an economic and space-saving solution to many sealing problems. Bearings capped on both sides are supplied already greased and are generally considered main­ ten­ance-free. Actual seal designs are described in detail in the relevant product chapter.

Fig. 48

Bearings with shields Bearings fitted with shields († fig. 48) are used in applications where the operating conditions are dry and relatively clean. Shields are also used in applications where reduced friction is important due to speed or operating temperature considerations. Shields form either a narrow gap towards the inner ring shoulder (a) or an effective labyrinth with a recess in the inner ring shoulder (b). Bearings with contact seals Bearings with contact seals, referred to simply as seals, are preferred for arrangements where contamination is moderate and the presence of water or moisture cannot be ruled out, or where maximum bearing service life and minimum maintenance are required. SKF has developed a variety of seal designs († fig. 49). Depending on the bearing type or size, the seal makes contact with: • the inner ring or inner ring shoulder (a) • the recess in the inner ring shoulder (b, c) • the lead-in chamfer on the sides of the inner ring raceway (d, e) • the outer ring (f)



a

F

b

Fig. 49



a

b

c

d

e

f

229

Design considerations For deep groove ball bearings, SKF has de­ veloped additional seal types († fig. 50): • The SKF non-contact seal (a) forms an extremely narrow gap with the land of the ­inner ring shoulder. • The SKF low-friction seal (b, c) makes almost no contact with the inner ring, but provides very good low-friction operation. • The SKF WAVE seal (d), a spring-loaded radial shaft seal designed for oil lubricated applications, is incorporated on one side of the bearing († ICOS oil sealed bearing units, page 304) SKF bearing seals are generally made of an elastomeric compound that is vulcanized to a sheet steel reinforcement ring. Depending on the series, size and the application requirements, typical seal materials are: • acrylonitrile-butadiene rubber (NBR) • hydrogenated acrylonitrile-butadiene ­r ubber (HNBR) • fluoro rubber (FKM) • polyurethane (PUR) The selection of the appropriate seal material depends on the expected operating temperature and the lubricant that is applied. For permissible operating temperatures, refer to Seal materials († page 155).

Fig. 50



230

a

b

c

d

Sealing solutions

External seals

Fig. 51

For bearing arrangements where the effect­ iveness of the seal under specific operating conditions is more important than space con­ sid­er­ations or cost, there are several possible seal types to choose from. For seals that are not supplied by SKF, the information provided in the following section is to be used as a guideline only. SKF does not accept liability for the performance of any products not supplied by SKF. Make sure to understand the seal’s performance criteria before incorporating that seal into an application. Non-contact seals The simplest seal used outside a bearing is the gap-type seal, which creates a small gap between the shaft and housing († fig. 51). This type of seal is adequate for grease lubricated applications that operate in dry, dust-free environments. To enhance the effectiveness of this seal, one or more concentric grooves can be machined in the housing bore at the shaft end († fig. 52). The grease emerging through the gap fills the grooves and helps to prevent the entry of contaminants. With oil lubrication and horizontal shafts, helical grooves – right-hand or left-hand depending on the direction of shaft rotation – can be machined into the shaft or housing bore († fig. 53). These grooves are designed to return emerging oil to the bearing position. Therefore, it is essential that the shaft rotates in one direction only.

Fig. 52

F Fig. 53

231

Design considerations Single or multi-stage labyrinth seals, typic­ ally used with grease lubrication, are considerably more effective than simple gap-type seals, but are also more expensive. Their effectiveness can be further improved by periodically applying a water-insoluble grease, such as a grease with a lithium-calcium thickener, via a duct to the labyrinth passages. The passages of the labyrinth seal can be arranged axially († fig. 54) or radially († fig. 55), depending on the housing type (split or nonsplit), mounting procedures, available space etc. The width of the axial passages of the laby­ rinth († fig. 54) remain unchanged when axial displacement of the shaft occurs in operation and can therefore be very narrow. If angular misalignment of the shaft relative to the housing can occur, labyrinths with inclined passages can be used († fig. 56). Effective and inexpensive labyrinth seals can be made using commercially available products, such as SKF sealing washers († fig. 57). Sealing effectiveness increases with the number of washer sets and can be further improved by incorporating flocked washers. For additional information on these sealing washers, refer to Power transmission seals († skf.com/seals). Rotating discs († fig. 58) are often fitted to the shaft to improve the sealing action of shields. Flingers, grooves or discs are used for the same purpose with oil lubrication. The oil from the flinger is collected in a channel in the housing and returned to the housing sump through suitable ducts († fig. 59).

Fig. 54

Fig. 55

Fig. 56

232

Sealing solutions Fig. 57

Fig. 58

F Fig. 59

233

Design considerations Contact seals There are four common types of contact seals:

Fig. 60

• radial shaft seals († figs. 60 and 61) • V-ring seals († fig. 62) • axial clamp seals († fig. 63) • mechanical seals († fig. 64, page 236) The seal type selected for a particular application typically depends on its primary purpose (retain lubricant or exclude contaminants), type of lubricant (oil, grease or other) and operating conditions (speed, temperature, level of contamination). Radial shaft seals

Radial shaft seals († figs. 60 and 61) are contact seals that are used mainly in oil lubricated applications. These ready-to-mount components typically consist of a metal reinforcement or casing, a synthetic rubber body, a seal lip and a garter spring. The seal lip is pressed against the shaft by the garter spring. Depending on the seal material and medium to be retained and/or excluded, radial shaft seals can be used at temperatures between –60 and +190 °C (–75 to 375 °F). The seal counterface, that part of the shaft where the seal lip makes contact, is of vital importance to sealing effectiveness. The surface hardness of the counterface should be at least 55 HRC at a depth of at least 0,3 mm. The surface roughness should be in accordance with ISO 4288 and within the guidelines of Ra = 0,2 to 0,8 μm. In applications where speeds are slow, lubrication is good, and contamination levels are minimal, a lower hardness can be acceptable. To avoid the pumping effect induced by helical grinding marks, SKF recommends plunge grinding the counterface. If the primary purpose of the radial shaft seal is lubricant retention, the seal should be mounted with the lip facing inward († fig. 60). If the primary purpose is to exclude contaminants, the lip should face outward, away from the bearing († fig. 61).

234

Fig. 61

Sealing solutions V-ring seals

V-ring seals († fig. 62) can be used with either oil or grease lubrication. The elastic rubber body of the seal grips the shaft and rotates with it, while the seal lip exerts a light axial pressure on a stationary component, such as a housing. Depending on the material, V-rings can be used at operating temperatures between –40 and +150 °C (–40 to 300 °F). They are simple to install and permit relatively large angular misalignments of the shaft at slow speeds. A surface roughness of Ra = 2 to 3 μm is sufficient for the counterface. At circumferential speeds above 8 m/s, the body of the seal must be located axially on the shaft. At speeds above 12 m/s, the body must be prevented from lifting from the shaft. A sheet metal support ring can be used to do this. When circumferential speeds exceed 15 m/s, the seal lip lifts away from the counterface and the V-ring becomes a gap-type seal. The good sealing ability of a V-ring seal can be attributed to the body of the seal, which acts as a flinger, repelling dirt and fluids. As a result, these seals are generally arranged outside the housing in grease lubricated applications and inside the housing, with the lip pointing away from the bearing, in oil lubricated applications. Used as a secondary seal, V-rings protect the primary seal from excessive contaminants and moisture.

Fig. 62

Fig. 63

F

Axial clamp seals

Axial clamp seals († fig. 63) are used as ­secondary seals for large diameter shafts in applications where protection is required for the primary seal. They are clamped in position on a non-rotating component and seal axially against a rotating counterface. For this type of seal, it is sufficient if the counterface is fine turned and has a surface roughness Ra = 2,5 μm.

235

Design considerations Mechanical seals

Fig. 64

Mechanical seals († fig. 64) are used to seal grease or oil lubricated applications where speeds are relatively slow and operating conditions difficult and arduous. They consist of two sliding steel rings with finely finished sealing surfaces and two plastic cup springs (Belleville washers), which position the sliding rings in the housing bore and provide the neces­s ary preload force to the sealing sur­ faces. There are no special demands on the mating surfaces in the housing bore. Other seals

Felt seals († fig. 65) are generally used with grease lubrication. They are simple, costeffective and can be used at circumferential speeds of up to 4 m/s and at operating temperatures up to 100 °C (205 °F). The counterface should be ground to a surface roughness Ra ≤ 3,2 μm. The effectiveness of a felt seal can be improved substantially by mounting a simple labyrinth seal as a secondary seal. Before being inserted in the housing groove, felt seals should be soaked in oil at about 80 °C (175 °F) prior to mounting. Metal seals († fig. 66) are simple, cost-­ effective and space-saving seals for grease ­lubricated bearings, particularly deep groove ball bearings. The seals are clamped against either the inner or outer ring and exert a resili­ ent axial pressure against the other ring. After a certain running-in period, these seals become non-contact seals by forming a very narrow gap with the rotating ring. For additional information about seals supplied by SKF, refer to Power transmission seals († skf.com/seals).

236

Fig. 65

Fig. 66

Sealing solutions

F

237

Lubrication

Grease lubrication . . . . . . . . . . . . . . . . . . . 242

Relubrication procedures . . . . . . . . . . . . . Replenishment. . . . . . . . . . . . . . . . . . . . . . . Renewing the grease fill. . . . . . . . . . . . . . . . Continuous relubrication. . . . . . . . . . . . . . .

258 258 260 261

Lubricating greases. . . . . . . . . . . . . . . . . . Temperature range – the SKF traffic light concept. . . . . . . . . . . . . . . . . . . . . . . . . Temperature zones . . . . . . . . . . . . . . . . . Consistency. . . . . . . . . . . . . . . . . . . . . . . . . . Base oil viscosity. . . . . . . . . . . . . . . . . . . . . . Protection against corrosion . . . . . . . . . . . . Load carrying ability. . . . . . . . . . . . . . . . . . . Extreme pressure additives. . . . . . . . . . . Anti-wear additives. . . . . . . . . . . . . . . . . Miscibility . . . . . . . . . . . . . . . . . . . . . . . . . . .

Oil lubrication. . . . . . . . . . . . . . . . . . . . . . . Oil lubrication methods . . . . . . . . . . . . . . . . Oil bath. . . . . . . . . . . . . . . . . . . . . . . . . . . Oil pick-up ring. . . . . . . . . . . . . . . . . . . . . Circulating oil. . . . . . . . . . . . . . . . . . . . . . Oil jet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil-air. . . . . . . . . . . . . . . . . . . . . . . . . . . . Oil mist . . . . . . . . . . . . . . . . . . . . . . . . . . . Lubricating oils. . . . . . . . . . . . . . . . . . . . . . . Selecting lubricating oils. . . . . . . . . . . . . . . Oil change. . . . . . . . . . . . . . . . . . . . . . . . . . .

262 262 262 263 263 264 264 264 265 266 267

Basics of lubrication . . . . . . . . . . . . . . . . . 240 Viscosity ratio k . . . . . . . . . . . . . . . . . . . . 241

244 244 246 246 246 248 248 248 248 248

SKF greases. . . . . . . . . . . . . . . . . . . . . . . . . 249 Relubrication. . . . . . . . . . . . . . . . . . . . . . . . 252 Relubrication intervals. . . . . . . . . . . . . . . . . 252 Adjustments of relubrication intervals due to operating conditions and bearing types. 252 Operating temperature. . . . . . . . . . . . . . 252 Vertical shafts. . . . . . . . . . . . . . . . . . . . . 253 Vibration. . . . . . . . . . . . . . . . . . . . . . . . . . 253 Outer ring rotation. . . . . . . . . . . . . . . . . . 253 Contamination. . . . . . . . . . . . . . . . . . . . . 253 Very slow speeds . . . . . . . . . . . . . . . . . . . 254 High speeds . . . . . . . . . . . . . . . . . . . . . . . 254 Heavy and very heavy bearing loads. . . . 254 Very light bearing loads. . . . . . . . . . . . . . 254 Misalignment. . . . . . . . . . . . . . . . . . . . . . 254 Large bearings. . . . . . . . . . . . . . . . . . . . . 254 Cylindrical roller bearings . . . . . . . . . . . . 254 Observations . . . . . . . . . . . . . . . . . . . . . . 255

G

239

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Lubrication

Basics of lubrication Rolling bearings need to be adequately lubricated to operate reliably and to prevent direct metal-to-metal contact between the rolling elements, raceways, cages and other compon­ ents. The lubricant also inhibits wear and protects the bearing surfaces against corrosion. The choice of a suitable lubricant and lubrication method is important, as is proper maintenance. A wide assortment of greases, oils and ­alternative lubricants like graphite-based compounds are available to lubricate rolling bearings. Selecting a lubricant depends primarily on the operating conditions such as the temperature range and speeds. However, other factors like vibration and loads can also influence lubricant selection. Generally, the most favourable operating temperatures can be obtained when the min­ imum amount of lubricant needed to reliably lubricate a bearing is provided. However, when the lubricant has additional functions, such as sealing or removing heat, additional amounts of lubricant may be required. The lubricant in a bearing arrangement gradually loses its lubricating properties as a result of mechanical working, ageing and the build-up of contaminants. It is therefore necessary for grease to be replenished or renewed and for oil to be filtered and changed at regular intervals. The information and recommendations in this section relate to bearings without integral seals or shields. SKF bearings and bearing units with an integral seal and/or shield on both sides are factory-greased. Information about the standard greases used by SKF is provided in the relevant product chapters, ­together with a brief description of the performance data. Under normal operating conditions, the service life of the grease in sealed bearings ­exceeds the service life of the bearing so that, with some exceptions, no provision is made for the relubrication of these bearings. For purposes of this discussion, normal ­operating conditions can be defined as:

240

• constant loads in magnitude and direction • loads equal to or larger than the recommended minimum load and at least: –– 0,01 C for ball bearings –– 0,02 C for roller bearings • constant speed, but not higher than the ­permissible speed • appropriate operating clearance • for grease lubrication: –– only steady state conditions (after several hours of operation) –– lithium soap grease with mineral oil –– bearing free volume filled approximately 30% –– minimum ambient temperature 20 °C (70 °F) • for oil lubrication: –– oil bath, oil-air or oil jet –– viscosity range from 2 to 500 mm2 /s

Ring centred cages Bearings with ring centred cages are primarily designed for oil lubrication. Grease lubrication can be used for moderate speeds. Information about the cage designs and the limits are provided in the relevant product chapters, if applicable.

Lubricant specifications Differences in the lubricating properties of seemingly identical lubricants – particularly grease – produced at different locations, or even different production batches from the same location, can exist. Therefore, SKF cannot accept liability for any lubricant or its performance. The user is therefore ­advised to specify lubricant properties in detail to obtain the most suitable ­lubricant for the application.

Basics of lubrication Viscosity ratio k The importance of the oil viscosity to form a hydrodynamic oil film that separates the bearing contact surfaces is already mentioned ­under Lubrication conditions – the viscosity ­ratio k († page 71). That information ­applies equally to the base oil viscosity of ­lubricating greases and oils. The condition of the lubricant is described by the viscosity ratio k as the ratio of the actual viscosity n to the rated viscosity n 1 for adequate lubrication, when the lubricant is at normal operating temperature. n k = KK n 1 where k = viscosity ratio n = actual operating viscosity of the lubricant [mm2/s] n1 = rated viscosity of the lubricant depending on the bearing mean diameter and rotational speed [mm2/s] To separate the bearing contact surfaces, a minimum viscosity ratio k = 1 is required. Fullfilm conditions exist when k ≥ 2, i.e. a sufficient hydrodynamic film is formed for ad­ equate lubrication. However, SKF recommends limiting k to 4, otherwise the frictional heat decreases the operating viscosity. In applications where k < 1, a sufficient hydro­ dynamic film cannot be formed and metal-tometal contact may occur. The use of lubricants containing extreme pressure or anti-wear ­additives († Load carrying ability, page 248) might extend bearing service life. For oil lubricated applications where k < 0,4, an oil with EP additives must be used. In applications where k < 1, hybrid bearings († Hybrid bearings, page 1219) can be con­ sidered. Even under inadequate lubrication conditions, there is reduced risk of smearing ­between silicon nitride and steel surfaces.

G

241

Lubrication

Grease lubrication The majority of rolling bearings are grease ­lubricated. Compared to oil, the advantage is that grease is more easily retained in the bearing arrangement, particularly where shafts are inclined or vertical. Grease also contributes to sealing the arrangement against solid and liquid contaminants as well as moisture. The terms used to categorize speed ranges, temperatures and loads for grease lubrication can differ from those used for bearings. Terms typically used for grease lubricated bearings are defined in the following tables: • table 1 : speed ranges for grease lubricated radial bearings • table 2: grease temperature • table 3: load ranges for greases The quantity of grease applied to a bearing depends on the application. Too little grease leads to metal-to-metal contact and premature bearing failure. Excessive amounts of grease cause the operating temperature within the bearing to rise rapidly, particularly when running at high speeds. Bearings with seals or shields (capped bearings) are filled by SKF with a sufficient amount of grease to provide long bearing service life. Depending on the speed range († table 1), SKF recommends the following grease fill ­percentages for bearings: • 100% for slow speeds • 30–50% for medium to high speeds The free volume in the housing should be partly filled with grease. Before operating at full speed, the excess grease in the bearing must be given time to settle or escape during a running-in period. At the end of the runningin period, the operating temperature drops considerably, indicating that the grease has been distributed in the bearing arrangement. In applications where bearings operate at very slow speeds and good protection against contaminants and corrosion is required, SKF recommends filling the housing up to 90% with grease.

242

Grease lubrication Table 1 Speed ranges for grease lubricated radial bearings Speed range

Speed factor Ball bearings



mm/min

A = n dm

VL L M H VH EH

Very slow Slow Medium High Very high Extremely high

– < 100 000 < 300 000 < 500 000 < 700 000 ≥ 700 000

Needle roller, spherical roller, tapered roller, CARB toroidal roller bearings

Cylindrical roller bearings

< 30 000 < 75 000 < 210 000 ≥ 210 000 – –

< 30 000 < 75 000 < 270 000 ≥ 270 000 – –

n = rotational speed [r/min] dm = bearing mean diameter [mm] = 0,5 (d + D)

Note: Reliable grease life calculations can only be made considering the speed intervals listed in this table. Table 2 Grease temperature Temperature range

Range



°C

°F

< 50 50 to 100 100 to 150 > 150

< 120 120 to 210 210 to 300 > 300

L M H VH

Low Medium High Very high

Table 3 Load ranges for greases Load range

Load ratio C/P

L M H VH

> 15 >8 1 († Viscosity ­ratio k, page 241), SKF does not ­generally ­recommend using EP or AW additives. However, there are circumstances where EP/AW additives may be beneficial such as if excessive sliding between the rollers and raceways is expected. Extreme pressure additives EP (extreme pressure) additives are an option to overcome metal-to-metal contact of the asperities on the contact surfaces. Elevated temperatures, induced by local asperity contact, activate these additives, which promote mild chemical wear at the points of contact. The result is a smoother surface, lower contact stresses and extended bearing service life. Some modern EP additives contain sulphurphosphorus, which may become chemically active even without asperity contact. In these cases, high operating temperatures and/or contact stresses become the catalyst. The resulting chemical activity may not be restricted to the asperity contacts and can have a detrimental effect on the strength of the bearing steel matrix. This can promote corrosion/diffusion mechanisms in the contacts and may lead to accelerated bearing damage, usually initiated by micro spalls. 248

Therefore, SKF recommends using EP a­ dditives that are less reactive in applications with operating temperatures > 80 °C (175 °F) and < 100 °C (210 °F). For very slow speeds, solid lubricant additives such as graphite and molyb­denum disulfide (MoS2) can be used to enhance the EP effect. These additives should have a high purity level and a very small particle size. Otherwise, dents due to overrolling of the particles might reduce bearing service life. For additional information about EP additives, contact the SKF application engineering service. Anti-wear additives AW (anti-wear) additives, like EP additives, prevent direct metal-to-metal contact. However, the way they work is very different. The main difference is that AW additives build a protective layer that adheres to the surface of the metal. The asperities can then slide over each other, avoiding direct contact. The surface finish is therefore not affected by mild wear as is the case with EP additives. Note that AW additives, like EP additives, may contain elements that can weaken the steel structure close to the surface. Certain thickeners (e.g. calcium sulphonate complex) also provide an EP/AW effect without chemical activity and the resulting effect on bearing fatigue life. These thickeners do not have a temperature limit. For additional information about AW additives, contact the SKF application engineering service.

Miscibility If it becomes necessary to change from one grease to another, the miscibility or the ability to mix greases without adverse effects should be considered. If incompatible greases are mixed, the resulting consistency can change so dramatically that bearing damage due to severe leakage could result. Greases with the same thickener and similar base oils can generally be mixed without any detrimental consequences. For example, a lithium thickener / mineral oil grease can ­generally be mixed with another lithium ­thickener / mineral oil grease. Also, some greases with different thickeners, such as

SKF greases c­ alcium complex and lithium complex, are miscible. In cases where changing from one grease to another could result in low grease consistency and grease escaping from the bearing arrangement, all the old grease should be ­removed from the arrangement and the lubrication ducts († Relubrication, page 252). The preservative with which SKF bearings are treated is compatible with the majority of lubricating greases with the possible exception of polyurea greases. Note that synthetic fluorinated oil based greases using a PTFE thickener, e.g. SKF LGET 2 grease, are not compatible with standard ­preservatives and the preservatives must be removed before ­applying grease. For additional information, contact the SKF application engineering service.

W ar n i n g PTFE exposed to an open flame or temperatures above 300 °C (570 °F) are a health and environmental hazard! They remain dangerous even after they have cooled. Read and follow the safety precautions under Seal materials († page 155).

SKF greases The assortment of SKF greases for rolling bearings covers virtually all application ­requirements. These greases have been ­developed based on the latest information about rolling bearing lubrication. SKF continuously monitors the quality of its greases prior to use or sale. The most important technical specifications for SKF greases, together with a quick selection guide, are provided in table 4 († page 250). The temperature ranges where the SKF greases can be used are schematically illustrated according to the SKF traffic light concept in diagram 3 († page 247). For additional information about SKF ­greases, refer to the catalogue SKF Mainten­ ance and Lubrication Products or visit skf.com/mapro. For a more detailed selection of the appropriate grease for a specific bearing type and application, use the internet based SKF grease selection program, SKF LubeSelect, available ­online at skf.com/lubeselect.

G

249

Lubrication

SKF greases – technical specifications and characteristics Desig­ nation

Description

Tempera­ Speed ture

Load

NLGI class

Temperature range 1) LTL HTPL

Base oil ­v iscosity at 40 °C 100 °C (105 °F) (210 °F)













°C/°F

mm 2 /s

LGMT 2

General purpose, industrial and automotive

M

M

L to M

2

–30 –20

120 250

110

11

LGMT 3

General purpose, industrial and automotive

M

M

L to M

3

–30 –20

120 250

120

12

LGEP 2

Extreme pressure, heavy load

M

L to M

H

2

–20 –5

110 230

200

16

LGWA 2

Wide temperature 3) , extreme pressure

M to H

L to M

L to H

2

–30 –20

140 285

185

15

LGFP 2

Food compatible

M

M

L to M

2

–20 –5

110 230

130

7,3

LGGB 2

Green biodegradable, low toxicity

L to M

L to M

M to H

2

–40 –40

90 2) 195

110

13

LGBB 2

Wind turbine blade and yaw bearing grease

L to M

VL

M to H

2

–40 –40

120 250

68

10

LGLT 2

Low temperature, extremely high speeds

L to M

M to EH

L

2

–50 –60

110 230

18

4,5

LGWM 1

Extreme pressure, low temperature

L to M

L to M

H

1

–30 –20

110 230

200

16

LGWM 2

Heavy load, wide temperature

L to M

L to M

M to H

2

–40 –40

110 230

80

8,6

LGEM 2

High viscosity, solid lubricants

M

VL

H to VH

2

–20 –5

120 250

500

32

LGEV 2

Extremely high viscosity, solid lubricants

M

VL

H to VH

2

–10 –15

120 250

1 020

58

LGHB 2

EP high viscosity, high temperature 4) ,

M to H

VL to M

L to VH

2

–20 –5

150 300

400

26,5

LGHP 2

High performance polyurea grease

M to H

M to H

L to M

2

–40 –40

150 300

96

10,5

LGET 2

Extreme temperature

VH

L to M

H to VH

2

–40 –40

260 500

400

38

1) LTL: Low temperature limit HTPL: High temperature performance limit 2) LGGB 2 can withstand temperature peaks of 120 °C (250 °F) 3) LGWA 2 can withstand temperature peaks of 220 °C (430 °F) 4) LGHB 2 can withstand temperature peaks of 200 °C (390 °F)

250

SKF greases Table 4

Desig­ nation

Vertical shaft

Fast outer ring rotation

Oscillation movements

Severe vibrations

Shock load or frequent start-up

Low noise

Low friction

Rust inhibiting properties

LGMT 2

L





+





L

+

LGMT 3

+

L



+





L

L

LGEP 2

L



L

+

+



L

+

LGWA 2

L

L

L

L

+



L

+

LGFP 2

L











L

+

LGGB 2

L



+

+

+





+

LGBB 2





+

+

+





+

LGLT 2

L







L

+

+

+

LGWM 1





+



+





+

LGWM 2

L

L

+

+

+





+

LGEM 2

L



+

+

+





+

LGEV 2

L



+

+

+





+

LGHB 2

L

+

+

+

+





+

LGHP 2

+





+

L

+

L

+

LGET 2

L

+

+

L

L





L



G

Symbols: + Recommended L Suitable – Not suitable

251

Lubrication

Relubrication Rolling bearings have to be relubricated if the service life of the grease is shorter than the expected service life of the bearing. Relubrication should always occur while the existing ­lubricant is still satisfactory. The time at which the bearing should be relubricated depends on many related factors. These include: • bearing type and size • speed • operating temperature • grease type • space around the bearing • bearing environment It is only possible to base recommendations on statistical rules. The SKF relubrication intervals are defined as the time period, at the end of which 99% of the bearings are still reliably lubricated. This represents the L 1 grease life. SKF recommends using experience based data from actual applications and tests, ­together with the estimated relubrication ­intervals provided. For many applications, there is a temperature limit for standard greases when the bearing ring with the highest temperature exceeds an operating temperature of 100 °C (210 °F). Above this temperature, special greases should be used. In addition, the temperature limits of the bearing and adjacent machine components, such as external seals, should be taken into consideration. For additional information about high temperature applications, contact the SKF application engineering service.

Relubrication intervals The relubrication intervals t f for bearings with a rotating inner ring on horizontal shafts under normal and clean operating conditions can be obtained from diagram 4 († page 256) as a function of:

252

• the speed factor A multiplied by the relevant bearing factor bf where A = n dm [mm/min] bf = bearing factor dependent on bearing type and load conditions († table 5, page 257) dm = bearing mean diameter [mm] = 0,5 (d + D) n = rotational speed [r/min] • the load ratio C/P The relubrication interval t f is the estimated number of operating hours that a good quality grease, consisting of mineral oil and a lithium base thickener, can perform adequately when the operating temperature is 70 °C (160 °F). When bearing operating conditions differ, the relubrication intervals († diagram 4, page 256) need to be adjusted († Adjust­ ments of relubrication intervals due to operat­ ing conditions and bearing types). If the speed factor A exceeds 70% of the ­recommended limits († table 5, page 257), verify the influence of the selected lubricant on the speed limits that are provided under Speeds († page 117) and check whether the rotational speed is within these limits. When using high performance greases, an extended relubrication interval and grease ­ser­vice life may be possible. For grease life of capped bearings, refer to the relevant product chapters. For additional information, contact the SKF application engineering service.

Adjustments of relubrication intervals due to operating conditions and bearing types Operating temperature To account for the accelerated ageing of grease with increasing temperature, SKF ­recommends halving the obtained intervals († diagram 4, page 256) for every 15 °C (27 °F) increase in operating temperature above 70 °C (160 °F). The high temperature performance limit HTPL for the grease († diagram 1, page 245) should not be exceeded.

Relubrication The relubrication interval t f may be extended at temperatures below 70 °C (160 °F) if the temperature is not close to the lower temperature performance limit LTPL († diagram 1, page 245). SKF does not recommend extending the relubrication interval t f by more than a factor of two. Do not extend the obtained t f values († diagram 4, page 256) for full complement bearings or thrust roller bearings. Moreover, it is not advisable to use relubrication intervals in excess of 30 000 hours.

particles. Liquid contaminants such as water and/or process fluids also require a reduced relubrication ­interval. In case of severe contamination, continuous relubrication should be considered.

Vertical shafts For bearings on vertical shafts, the intervals obtained from diagram 4 († page 256) should be halved. The use of an effective seal, shield or baffle plate is a prerequisite to prevent grease leaking from the bearing arrangement. Vibration Moderate vibration does not have a negative effect on grease life. However, high vibration and shock levels, such as those in vibrating screen applications, cause the grease to churn. In these cases, the relubrication interval should be reduced. If, during operation, the grease becomes too soft, use a more ­mechanically stable grease, e.g. SKF LGHB 2 or grease with higher stiffness up to NLGI 3. Outer ring rotation In applications where the outer ring rotates, the speed factor A is calculated differently. In this case, use the bearing outside diameter D instead of dm. The use of an effective seal is a prerequisite to avoid grease leakage. In applications where there are high outer ring speeds (i.e. > 40% of the reference speed listed in the product tables), greases with good oil bleeding properties should be applied. For spherical roller thrust bearings with a rotating housing washer, oil lubrication is recommended.

G

Contamination In applications where the ingress of solid contaminants is an issue, more frequent relubrication than indicated by the relubrication interval is necessary. Relubrication reduces the level of contamination while reducing the damaging effects caused by overrolling the 253

Lubrication Very slow speeds Selecting the proper grease and grease fill is very important for slow speed applications. Bearings that operate at very slow speeds ­under light loads require a low consistency grease. Bearings that operate at slow speeds under heavy loads should be lubricated with a grease that has a high viscosity base oil containing EP additives. Solid additives such as graphite and molybdenum disulfide (MoS2) can be considered for a speed factor A < 20 000 mm/min. High speeds Relubrication intervals for bearings used at speeds above the recommended speed factor A († table 5, page 257) should only be applied when using special greases or modified bearing executions such as hybrid bearings. In these cases, continuous relubrication techniques such as circulating oil or the oil-air method are more effective than grease. Heavy and very heavy bearing loads For bearings operating at a speed factor A > 20 000 mm/min and subjected to a load ratio C/P < 4, the relubrication interval is ­reduced to the point that SKF recommends ­continuous grease relubrication or the oil bath lubrication method. In applications where the speed factor A < 20 000 mm/min and the load ratio C/P = 1–2, refer to Very slow speeds. For heavy loads and high speeds, SKF generally recommends a circulating oil system with auxiliary cooling. Very light bearing loads In many cases, the relubrication interval can be extended if the loads are light, i.e. C/P = 30 to 50. To obtain satisfactory operation, the bearings should be subjected to the minimum load as stated in the relevant product chapters. Misalignment Static misalignment, within the permissible limits, does not adversely affect grease service life in spherical roller bearings, self-aligning ball bearings or CARB toroidal roller bearings.

254

Large bearings Large roller bearings, d > 300 mm, used in process machinery, require a proactive approach. For these critical applications, SKF recommends strict adherence to the relubrication quantities but with shorter initial relubrication intervals. Prior to relubrication, check the used grease for both solid and liquid contaminants. Also, check the sealing system completely, looking for wear, damage and leaks. If, over time, the condition of the grease and associated compon­ents is found to be satisfactory, the ­relubrication interval can be increased gradually. SKF recommends a similar procedure for spherical roller thrust bearings, prototype machines and upgrades of high-density power equipment or wherever application experience is limited. Cylindrical roller bearings The relubrication intervals († diagram 4, page 256) are valid for cylindrical roller bearings fitted with: • a glass fibre reinforced PA66 cage, roller centred, designation suffix P • a machined brass cage, roller centred, ­designation suffix M The obtained relubrication intervals († diagram 4, page 256) should be halved and a grease with good oil bleeding properties should be applied to cylindrical roller bearings with: • a stamped steel cage, roller centred, no designation suffix or suffix J • a machined brass cage, inner or outer ring centred, designation suffixes MA, MB, MH, ML or MP • a sheet steel cage, inner or outer ring ­centred, designation suffixes JA or JB

Relubrication Observations If, during testing, the determined value for the relubrication interval t f is too short for a particular application, SKF recommends the following: • Check the bearing operating temperature. • Check whether the grease contains solid or liquid contaminants. • Check the operating conditions, e.g. load or misalignment. • Check whether a more suitable grease is necessary.

G

255

Lubrication Diagram 4 Relubrication intervals at operating temperatures of 70 °C (160 °F)

t f [operating hours]

50 000

10 000

5 000

1 000

500 C/P ≥ 15

C/P ª 8

C/P ª 4 100 0

256

200 000

400 000

600 000

800 000

A b f [mm/min]

Relubrication Table 5 Bearing factors and recommended limits for speed factor A Bearing type 1)

Bearing factor bf

Recommended limits for speed factor A for load ratio C/P ≥ 15 C/P ≈ 8 C/P ≈ 4





mm/min

Deep groove ball bearings

1

500 000

400 000

300 000

Y-bearings

1

500 000

400 000

300 000

Angular contact ball bearings

1

500 000

400 000

300 000

Self-aligning ball bearings

1

500 000

400 000

300 000

Cylindrical roller bearings –– non-locating bearing –– locating bearing, without external axial loads or with light but alternating axial loads –– locating bearing, with constantly acting light axial load –– without a cage, full complement 2)

1,5

450 000

300 000

150 000

2 4 4

300 000 200 000 NA 3)

200 000 120 000 NA 3)

100 000 60 000 20 000

Needle roller bearings –– with a cage –– without a cage, full complement

3 350 000 200 000 100 000 Contact the SKF application engineering service.

Tapered roller bearings

2

350 000

300 000

200 000

2 2 2

350 000 250 000 150 000

200 000 150 000 80 000 4)

100 000 80 000 50 000 4)

2 2 2

230 000 170 000 100 000

130 000 100 000 50 000 4)

65 000 50 000 30 000 4)

6

150 000

50 000 4)

30 000 4)

2 4

350 000 NA 3)

200 000 NA 3)

100 000 20 000

Spherical roller bearings –– when the load ratio Fa /Fr ≤ e and dm ≤ 800 mm series 213, 222, 238, 239 series 223, 230, 231, 232, 240, 248, 249 series 241 –– when the load ratio Fa /Fr ≤ e and dm > 800 mm series 238, 239 series 230, 231, 240, 248, 249 series 241 –– when the load ratio Fa /Fr > e all series CARB toroidal roller bearings –– with a cage –– without a cage, full complement 2) Thrust ball bearings

2

200 000

150 000

100 000

Cylindrical roller thrust bearings

10

100 000

60 000

30 000

Needle roller thrust bearings

10

100 000

60 000

30 000

Spherical roller thrust bearings –– rotating shaft washer

4

200 000

120 000

60 000

Track runner bearings

Contact the SKF application engineering service.

G

1) The bearing factors and recommended speed factor A limits apply to bearings with standard internal geometry

and standard cage execution. For alternative internal bearing design and special cage execution, contact the SKF application ­engineering service.

2) The t value obtained from diagram 4 needs to be divided by a factor of 10. f 3) Not applicable, as a bearing with a cage is recommended for these C/P values. 4) For higher speeds, oil lubrication is recommended.

257

Lubrication

Relubrication procedures The relubrication procedure generally depends on the application and on the relubrication interval t f. SKF recommends one of the following procedures: • Replenishment is a convenient and preferred procedure if the relubrication interval is shorter than six months. It enables uninterrupted operation and provides, when compared with continuous relubrication, a lower steady state temperature. • Renewing the grease fill is generally recommended when the relubrication interval is longer than six months. This procedure is often applied as part of a bearing mainten­ ance schedule. • Continuous relubrication is used when the estimated relubrication intervals are short due to the adverse effects of contamination, or when other relubrication methods are inconvenient because access to the bearing is difficult. SKF does not recommend continuous relubrication for applications with high rotational speeds since the intensive churning of the grease can lead to very high operating temperatures and destruction of the grease thickener structure. When using different bearings in a bearing arrangement, it is common practice to apply the lowest estimated relubrication interval for all bearings in the arrangement. The guidelines and grease quantities for the three alternative procedures are provided below.

Replenishment As mentioned in the introduction of Lubrica­ tion, the free volume in the bearing should be completely filled during installation, while the free volume in the housing generally should be partly filled. Depending on the intended method of replenishment, SKF recommends the following grease fill percentages for this free volume in the housing: • 40% when replenishing from the side of the bearing († fig. 1). • 20% when replenishing through the lubrication holes in the bearing inner or outer ring († fig. 2). 258

Suitable quantities for replenishment from the side of a bearing can be obtained from Gp = 0,005 D B and for replenishment through the bearing outer or inner ring from Gp = 0,002 D B where Gp = grease quantity to be added when replenishing [g] B = total bearing width [mm] (for tapered roller bearings use T, for thrust bearings use height H) D = bearing outside diameter [mm] Fig. 1

Fig. 2

Relubrication procedures To apply grease with a grease gun, a grease fitting is needed on the housing. If contact seals are used, an escape hole in the housing should also be provided so that excess grease does not build up in the space surrounding the bearing († figs. 1 and 2). Otherwise, this can cause a permanent increase in bearing temperature. The escape hole should be plugged when high-pressure water is used for cleaning. Excess grease collecting in the space surrounding the bearing can cause temperature peaks, which can have a detrimental effect on the grease as well as the bearing. It is more pronounced when bearings operate at high speeds. In these cases, SKF recommends ­u sing a grease flinger in combination with an escape hole. This prevents over-lubrication and enables relubrication to be performed while the machine is in operation. A grease flinger is basically a disc that rotates with the shaft and forms a narrow gap together with the housing end cover († fig. 3). Excess and used grease is flung into an annular cavity and leaves the housing through an opening on the underside of the end cover. For additional information about the design and dimensioning of grease flingers, contact the SKF application engineering service. To be sure that fresh grease actually reaches the bearing and replaces the old grease, the lubrication duct in the housing should either feed the grease adjacent to the outer ring side face († figs. 1 and 4) or, preferably, into the bearing. To facilitate efficient lubrication, some bearing types, e.g. spherical roller bearings, are provided with an annular groove and/or one or more lubrication holes in the inner or outer ring († figs. 2 and 5).

Fig. 3

Fig. 4

Fig. 5

G

259

Lubrication To effectively replace used grease, it is im­ portant to relubricate the bearing while the ­machine is in operation. In cases where the machine is not in operation, the bearing should be rotated during replenishment. When lubricating the bearing directly through the inner or outer ring, the fresh grease is applied ­directly to the free volume in the bearing. Therefore, the amount of grease needed is ­reduced, when compared with relubricating from the side. It is assumed that the lubrication ducts were filled with grease during the mounting process. If not, a larger quantity of grease is needed to compensate for the empty ducts during the first replenishment. Where long lubrication ducts are used, check whether the grease can be adequately pumped at the prevailing ambient temperature. The grease in the housing should be replaced when the free volume in the housing is approximately 75% full. When relubricating from the side and starting with 40% initial fill of the housing, the complete grease fill should be replaced after approximately five replenishments. Due to the lower initial fill of the housing and the reduced topping-up quantity during replenishment when relubricating the bearing directly through the inner or outer ring, renewal is only ­required in exceptional cases.

260

Renewing the grease fill When renewing the grease fill at the estimated relubrication interval or after a certain number of replenishments, the used grease in the bearing and housing should be completely removed and replaced. The used grease should be disposed of in an environmentally safe and responsible way. Filling the bearing and housing with grease should be done in accordance with the guidelines provided under Replenishment († page 258). To renew the grease fill, the housing should be accessible and easily opened. The cap of split housings and the covers of non-split housings can usually be removed to expose the bearing. After removing the used grease, fresh grease should first be packed between the rolling elements. Precautions should be taken to prevent contaminants from being introduced into the bearing, housing or grease container. SKF recommends using grease ­resistant gloves to prevent any allergic skin reactions. When housings are less accessible, but are provided with grease fittings and escape holes, it is possible to completely renew the grease fill by relubricating several times in close succession until fresh grease is purged from the housing. This procedure requires much more grease than is needed for manual renewal. In addition, this method of renewal has speed limitations. At high speeds, temperatures can increase as a result of grease churning.

Relubrication procedures

Continuous relubrication This procedure is used when the calculated ­relubrication interval is very short, e.g. due to the adverse effects of contamination, or when other procedures of relubrication are inconvenient, e.g. access to the bearing is difficult. Due to the excessive churning of the grease, which can lead to increased temperature, continuous lubrication is only recommended when rotational speeds are relatively slow such as the following speed factors: • A < 150 000 mm/min for ball bearings • A < 75 000 mm/min for roller bearings In these cases, the initial grease fill for the housing can be up to 90% and the quantity for relubrication per time unit is derived from the equations for Gp († Replenishment, page 258) by spreading the required quantity over the relubrication interval. When using continuous relubrication, check whether the grease can be adequately pumped through the ducts at the prevailing ambient temperature. Continuous lubrication can be achieved via single-point or multi-point automatic lubricators, e.g. SYSTEM 24 or SYSTEM MultiPoint. For additional information, contact the SKF application engineering service. Centralized lubrication systems, such as SYSTEM MonoFlex, SYSTEM ProFlex, SYSTEM DuoFlex and SYSTEM MultiFlex, can reliably deliver grease in a wide range of quantities. For additional ­information about SKF lubrication systems, visit skf.com/lubrication.

G

261

Lubrication

Oil lubrication Oil is generally used to lubricate rolling bearings when: • high speeds or operating temperatures ­preclude the use of grease • excessive heat has to be removed from the bearing position • adjacent components (gears etc.) are lubricated with oil To extend bearing service life, all methods of bearing lubrication that use clean oil are ­acceptable. These include: • the circulating oil lubrication method • the oil jet method • the oil-air method When using the circulating oil or oil-air ­ ethod, adequately dimensioned ducts should m be provided so that oil flowing from the bearing can leave the arrangement.

Oil lubrication methods Oil bath The simplest method of oil lubrication is the oil bath († fig. 6). The oil, which is picked up by the rotating components of the bearing, is distributed within the bearing and then flows back to the sump in the housing. The oil level should almost reach the centre of the lowest rolling element when the bearing is stationary. SKF recommends the use of oil levellers such as the SKF LAHD 500 to maintain the correct oil level. When operating at high speed, the oil level can drop significantly and the housing can become overfilled by the oil leveller. If this occurs, contact the SKF application engin­eering service.

262

Fig. 6

Oil lubrication Oil pick-up ring For bearing applications where speeds and ­operating temperatures require oil to be de­ livered reliably, SKF recommends using an oil pick-up ring († fig. 7). The pick-up ring hangs loosely on a sleeve on the shaft on one side of the bearing and dips into the oil sump in the lower half of the housing. As the shaft rotates, the ring follows and transports oil from the sump to a collecting trough. The oil then flows through the bearing back into the sump. SKF SONL plummer block housings are designed for the oil pick-up ring lubrication method. For additional information, contact the SKF application engineering service. Circulating oil High-speed operation increases the operating temperature and accelerates ageing of the oil. To avoid frequent oil changes and to achieve a fully flooded lubrication condition, the circulating oil lubrication method is generally preferred († fig. 8). Circulation is usually controlled by a pump. After the oil has passed through the bearing, it generally settles in a tank where it is filtered and, if required, cooled before being returned to the bearing. Proper filtering decreases the contamination level and extends bearing service life († SKF ­rating life, page 64). Cooling the oil can also significantly reduce the operating temperature of the bearing.

Fig. 7

Fig. 8

G

263

Lubrication Oil jet For very high-speed operation, a sufficient but not excessive amount of oil must be supplied to the bearing to provide adequate lubrication, without increasing the operating temperature more than necessary. One particularly ef­ fective method of achieving this is the oil jet method († fig. 9). A jet of oil under high pressure is directed at the side of the bearing. The velocity of the oil jet must be sufficiently high (≥ 15 m/s) to penetrate the turbulence surrounding the rotating bearing. Oil-air With the oil-air method († fig. 10) – also called the oil-spot method – compressed air is mixed with very small, accurately metered quantities of oil and directed at each bearing. This minimum quantity lubrication method enables bearings to operate at lower temperatures or at higher speeds than any other lubrication method. The compressed air serves to cool the bearing and also produces an excess pressure in the bearing housing to prevent contaminants from entering. For additional information about the design of oil-air lubrication arrangements, visit skf.com/lubrication. Oil mist Oil mist lubrication is not recommended for general applications due to possible negative environmental effects. Today, oil mist lubrication is used in very specific applications such as the petroleum industry.

264

Fig. 9

Fig. 10

Oil lubrication

Lubricating oils Straight mineral oils are generally the favoured lubricant for lubricating rolling bearings. Oils containing extreme pressure (EP) or anti-wear (AW) additives to improve lubricant properties are generally used only in special cases. The information covering EP and AW additives in grease († Load carrying ability, page 248) also apply to these additives in oils. Synthetic versions of many of the popular lubricant classes are available. Synthetic oils are generally only considered for bearing lubrication in extreme cases, e.g. at very low or very high operating temperatures. The term, synthetic oil, covers a wide assortment of different base stocks. The main ones are poly­ alphaolefins (PAO), esters and polyalkylene glycols (PAG). These synthetic oils have different properties than mineral oils († table 6). The thickness of the hydrodynamic film, which prevents metal-to-metal contact in a bearing, plays a major role in bearing fatigue life. The thickness of the hydrodynamic film is determined, in part, by the viscosity index (VI) and the pressure-viscosity coefficient. For most mineral oil based lubricants, the pressure-viscosity coefficient is similar, and gen­ eric values obtained from literature can be used. However, for synthetic oils, the effect on viscosity to increasing pressure is determined by the chemical structure of its base stock. As a result, there is considerable variation in pressure-viscosity coefficients for different types of synthetic base stocks. Due to the differences in the viscosity index and pressure-

viscosity coefficient, it should be remembered that the formation of a hydrodynamic lubricant film, when using a synthetic oil, may differ from that of a mineral oil with the same viscosity. For additional information about synthetic oils, contact the lubricant supplier. In addition, additives play a role in the formation of a hydrodynamic film. Due to differences in solubility, different types of additives are used in synthetic oils that are not included in mineral oil based lubricants.

Table 6 Properties of lubricating oil types

G

Properties

Base oil type Mineral

PAO

Ester

PAG

Pour point [°C] [°F]

–30 .. 0 –20 .. 30

–50 .. –40 –60 .. –40

–60 .. –40 –75 .. –40

appr. –30 appr. –20

Viscosity index

low

moderate

high

high

Pressure-viscosity coefficient

high

moderate

low to moderate

moderate

265

Lubrication

Selecting lubricating oils Selecting oil is primarily based on the viscosity required to form a sufficiently thick hydro­ dynamic film at normal operating temperature. The viscosity of oil is temperature depend­ ent, becoming lower as the temperature rises. The viscosity-temperature relationship of an oil is characterized by the viscosity index (VI). For rolling bearings, oils with a viscosity index of at least 95 (little change with temperature) are recommended. To form a sufficiently thick oil film in the contact area between the rolling elements and raceways, the oil must retain a minimum viscosity at normal operating temperature. The rated viscosity n 1 required at normal ­operating temperature to provide adequate lubrication can be determined from diagram 5 († page 268), provided a mineral oil is used. When the operating temperature is known from experience or can otherwise be determined, the corresponding viscosity at the internationally standardized reference temperature of 40 °C (105 °F), i.e. the oil ISO VG viscosity class, can be obtained from diagram 6 († page 269), which is compiled for a viscosity index of 95. Certain bearing types, such as spherical roller bearings, toroidal roller bearings, ­t apered roller bearings, and spherical roller thrust bearings, typically have a higher operating temperature than other bearing types such as ball bearings and cylindrical roller bearings, under comparable operating conditions. When selecting an oil, consider the following: • Bearing life may be extended by selecting an oil where the viscosity n at normal operating temperature is higher than the obtained ­viscosity n 1 († diagram 5, page 268). The condition n > n 1 can be obtained by choosing a mineral oil with a higher ISO VG viscosity class or by selecting an oil with a higher viscosity index, provided the oil has the same pressure-­viscosity coefficient. Since higher viscosity increases operating temperature, there is frequently a practical limit to the lubrication improvement that can be obtained using this method.

266

• If the viscosity ratio k < 1 († Viscosity ­ratio k, page 241), SKF recommends using an oil containing EP additives. If k < 0,4 an oil with EP additives must be used. Oils with EP additives may also enhance operational reliability in cases where k > 1 and mediumand large-size roller bearings are used. It should be remembered that some EP additives may cause adverse effects. • For exceptionally slow or high speeds, for critical loading conditions, or for unusual ­lubricating conditions, contact the SKF ­application engineering service. Example

A bearing with a bore diameter d = 340 mm and an outside diameter D = 420 mm is required to rotate at a speed n = 500 r/min. What is the required viscosity n at the reference temperature of 40 °C (105 °F)? From diagram 5 († page 268) with dm = 0,5 (340 + 420) = 380 mm and n = 500 r/min, the rated viscosity n 1 required for adequate lubrication at normal operating temperature is approximately 11 mm2 /s. From diagram 6 († page 269), assuming that the normal operating temperature is 70 °C (160 °F), a lubricating oil in the ISO VG 32 viscosity class, with an actual viscosity n ≥ 32 mm2 /s at the reference temperature of 40 °C (105 °F), is required.

Oil lubrication

Oil change How frequently oil changes are needed depends mainly on the operating conditions and the quantity of oil. With the oil bath lubrication method, it is generally sufficient to change the oil once a year, provided the operating temperature does not exceed 50 °C (120 °F) and there is little risk of contamination. Higher temperatures require more frequent oil changes, e.g. for operating temperatures around 100 °C (210 °F), the oil should be changed every three months. Frequent oil changes are also necessary if ­other operating conditions are arduous. With circulating oil lubrication systems, the period between oil changes is also determined by how frequently the total oil quantity is circulated and whether or not the oil is cooled. It is only possible to determine a suitable interval through testing and regular inspection to see that the oil is not contamin­ated or excessively oxidized. The same applies for the oil jet lubrication method. With the oil-air lubrication method, the oil only passes through the bearing once and is not recirculated.

G

267

Lubrication Diagram 5 Estimation of the rated viscosity n 1 at operating temperature

Rated viscosity n 1 at operating temperature [mm 2 /s]

1 000

2

5

500 10

20

200

50

100

n[

r/m

10

0

in]

20

0

50

50

0

10 1 5 00 2 0 00 3 0 00 0 50 0 00

20

10

10 20

50 00 5 10 0 00 0 0 10

00

0

00

20

0

50

100

200

500

1 000

2 000

dm = 0,5 (d + D) [mm]

268

Oil lubrication Diagram 6 Conversion to viscosity n at reference temperature (ISO VG classification)

Viscosity n at operating temperature [mm 2 /s]

1 000

500

200

IS

O

1 100

0

46

0

1

50

0

0

32

0

22

0

15

50

68

VG

00

10

0

0

46

68

32

20

22 10

15

10

G 5 20 (70)

30 (85)

40 (105)

50 (120)

60 (140)

70 (160)

80 (175)

90 (195)

100 (210)

110 (230)

120 (250)

Operating temperature [°C (°F)]

269

Mounting, dismounting and bearing care General. . . . . . . . . . . . . . . . . . . . . . . . . . . Where to mount. . . . . . . . . . . . . . . . . . . . Preparations prior to mounting or dismounting. . . . . . . . . . . . . . . . . . . . . . . Bearing handling . . . . . . . . . . . . . . . . . . .

272 272 272 274

Mounting. . . . . . . . . . . . . . . . . . . . . . . . . Mounting bearings with a cylindrical bore. . . . . . . . . . . . . . . . . . . . . Cold mounting. . . . . . . . . . . . . . . . . . . . Hot mounting. . . . . . . . . . . . . . . . . . . . Bearing adjustment. . . . . . . . . . . . . . . . . Mounting bearings with a tapered bore . Small and medium-size bearings . . . . Medium- and large-size bearings. . . . Obtaining an interference fit. . . . . . . . Test running. . . . . . . . . . . . . . . . . . . . . . .

275 275 275 276 277 278 278 278 280 284

Dismounting . . . . . . . . . . . . . . . . . . . . . . Dismounting bearings fitted on a cylindrical shaft seat. . . . . . . . . . . . . . . Cold dismounting. . . . . . . . . . . . . . . . . Hot dismounting. . . . . . . . . . . . . . . . . . Dismounting bearings fitted on a tapered shaft seat. . . . . . . . . . . . . . . Dismounting bearings fitted on an adapter sleeve. . . . . . . . . . . . . . . . . Dismounting bearings fitted on a withdrawal sleeve. . . . . . . . . . . . . . .

285

Bearing storage . . . . . . . . . . . . . . . . . . . Storage conditions. . . . . . . . . . . . . . . . Shelf life of open bearings . . . . . . . . . . Shelf life of capped bearings . . . . . . . .



285 285 286 287 288 290 291 291 291 291

H

Inspection and cleaning. . . . . . . . . . . . . 291

271

Mounting, dismounting and bearing care

General Rolling bearings are reliable machine elements that can provide long service life, provided they are mounted and maintained properly. Proper mounting requires experience, accuracy, a clean work environment and the appropriate tools. To promote proper installation techniques, speed, accuracy and safety, SKF offers a comprehensive assortment of high quality installation and maintenance products. The assortment includes everything from mechanical and hydraulic tools to bearing heaters and grease. For information about SKF mainten­ ance products, refer to the product information available online at skf.com/mapro. Mounting bearings correctly is often more difficult than it appears, especially where large bearings are concerned. To be sure that bearings are mounted and maintained properly, SKF offers seminars and hands-on training courses as part of the SKF Reliability Systems concept. Installation and maintenance assistance may also be available from your local SKF company or SKF Authorized Distributor. The information provided in the following section is quite general and is intended pri­ marily to indicate what must be considered by machine and equipment designers in order to facilitate bearing mounting and dismounting. For additional information about mounting and dismounting procedures, refer to the SKF bearing maintenance handbook.

More information Mounting, dismounting and bearing care . . . . †  SKF bearing maintenance handbook (ISBN 978-91-978966-4-1) Mounting instructions for individual bearings. . . . . . . . . . . . . †  skf.com/mount Mounting bearings on a tapered seat . . . . . . . . . . . . . . . . . . . †  skf.com/drive-up

272

Where to mount Bearings should be mounted in a dry, dustfree area away from machines producing swarf and dust. When bearings have to be mounted in an unprotected area, which is often the case with large bearings, steps should be taken to protect the bearing and mounting position from contaminants like dust, dirt and moisture. This can be done by covering or wrapping bearings, machine components etc. with plastic or foil.

Preparations prior to mounting or dismounting Prior to mounting, be sure all the necessary parts, tools, equipment and data are readily available. It is also advisable to review any drawings or instructions to determine the correct order and direction that components are to be assembled. Leave the bearings in their original packages until immediately prior to mounting so that they are not exposed to any contaminants. If there is a risk that the bearings have become contaminated due to improper handling or damaged packaging, they should be washed and dried prior to mounting.

General Fig. 1

a

b

1

2 a

b

3

1

2 3 4

4

Checking associated components

Removing the preservative

Housings, shafts, seals and other components of the bearing system should be checked to make sure that they are clean. This is particularly important for threaded holes, lead-ins or grooves where remnants of previous machining operations might have collected. Also, be sure that all unpainted surfaces of cast housings are free of core sand and that any burrs are removed. When all components have been cleaned and dried, check the dimensional and form tolerances of each piece. The bearings only perform satisfactorily if the associated compon­ ents comply with the prescribed tolerances. The diameters of cylindrical shaft and housing seats are usually checked with a micrometer or internal gauge at two cross-sections and in four directions († fig. 1). Tapered shaft seats can be checked using a ring gauge (GRA 30 series), a taper gauge (DMB series) or a sine bar (9205 series). It is advisable to keep a record of all measurements. When measuring, it is important that the components and the measuring instruments are approximately the same ­temperature. This is particularly important for large bearings and their associated ­com­ponents.

Normally, the preservative applied to new bearings does not need to be removed. It is only necessary to wipe off the outside and bore surfaces. However, if bearings are to be grease lubricated and used at very high or very low temperatures or if the lubricant to be used is not compatible with the preservative, the bearing should be washed and dried carefully. Bearings capped with seals or shields are filled with grease and should not be washed prior to mounting. When taken from its original packaging, some large bearings with an outside diameter D > 420 mm may be covered with a relatively thick, greasy layer of preservative. These bearings should be washed thoroughly with white mineral spirits or other safe cleaning fluid, and dried.

H

273

Mounting, dismounting and bearing care

Bearing handling SKF recommends using gloves as well as carry­ing and lifting tools († fig. 2) that have been specially designed for handling bearings. Using the proper tools enhances safety while saving time and effort. When handling hot or oily bearings, SKF recommends wearing the appropriate heat or oil resistant gloves. For large, heavy bearings, lifting tackle that supports the bearing from the bottom should be used († fig. 3). A spring between the hook and tackle can facilitate positioning the bearing onto the shaft. To ease lifting, large bearings can be provided, on request, with threaded holes in the ring side faces to accommodate eye bolts. These holes are designed to accommodate only the weight of the bearing, because the size and depth of the hole is limited by the ring thickness. Make sure that the eye bolts are only subjected to load in the direction of the shank axis († fig. 4). When mounting a non-split large housing over a bearing that is already in position on a shaft, it is advisable to provide three-point suspension for the housing, and for the length of one sling to be adjustable. This facilitates the process of aligning the housing bore with the bearing outer ring.

Fig. 2

Fig. 3

Fig. 4

274

Mounting

Mounting Depending on the bearing type and size, mechanical, thermal or hydraulic methods are used for mounting. In the following, the bearing size is categorized: • small † d ≤ 80 mm • medium-size † 80 mm < d < 200 mm • large † d ≥ 200 mm In all cases, it is important that the bearing rings, cages and rolling elements or seals are never struck directly with any hard object and that the mounting force is never applied through the rolling elements. For an interference fit, the mating surfaces should be coated with a thin layer of light oil. For a loose fit, the mating surfaces should be coated with SKF anti-fretting agent.

(† fig. 6) instead of a sleeve enables the mounting force to be applied centrally. Large numbers of bearings are generally mounted with a press. If a bearing has to be pressed onto the shaft and into the housing bore at the same time, the mounting force must be applied equally to both rings and the abutment surfaces of the mounting tool must lie in the same plane. Whenever possible, mounting should be done with an SKF bearing fitting tool († fig. 5).

Mounting bearings with a cylindrical bore With non-separable bearings, the ring that is to have the tighter fit is usually mounted first. Cold mounting If the fit is not too tight, small bearings can be driven into position by applying light hammer blows to a sleeve placed against the bearing ring side face. The blows should be evenly distributed around the ring to prevent the bearing from tilting or skewing. The use of a bearing fitting tool († fig. 5) or a mounting dolly Fig. 5

Fig. 6

H

275

Mounting, dismounting and bearing care With self-aligning bearings, the use of an intermediate mounting ring prevents the outer ring from tilting and swiveling when the bearing and shaft assembly is introduced into the housing bore († fig. 7). The balls of larger self-aligning ball bearings in the 12 and 13 series protrude from the sides of the bearing. This design feature needs to be considered when mounting these bearings. With separable bearings, the inner ring can be mounted independently of the outer ring, which simplifies mounting, particularly where both rings have an interference fit. When installing the shaft and inner ring assembly into the housing containing the outer ring, careful alignment is required to avoid scoring the raceways and rolling elements. When mounting cylindrical or needle roller bearings with an inner ring without flanges or a flange on one side, a guiding sleeve should be used († fig. 8). The outside diameter of the sleeve should be the same as the raceway diameter of the inner ring and should be machined to tolerance class d10 V E for cylindrical roller bearings, and to tolerance 0/–0,025 mm for needle roller bearings. Hot mounting It is generally not possible to mount larger bearings without heating either the bearing or the housing, as the force required to mount a bearing increases considerably with increasing bearing size. The requisite difference in temperature between the bearing ring and shaft or housing depends on the degree of interference and the diameter of the bearing seat. Open bearings must not be heated to more than 120 °C (250 °F). SKF does not recommend heating bearings capped with seals or shields above 80 °C (175 °F). However, if higher temperatures are necessary, make sure that the temperature does not exceed the permissible temperature of either the seal or grease, whichever is lowest. When heating bearings, local overheating must be avoided. To heat bearings evenly, SKF electric induction heaters († fig. 9) are recommended. If hotplates are used, the bearing must be turned over a number of times. The seals on sealed bearings should never contact the heating plate directly. Place a ring between the plate and bearing. 276

Fig. 7

Fig. 8

Fig. 9

Mounting

Bearing adjustment

Fig. 10

The internal clearance of single row angular contact ball bearings and single row tapered roller bearings is only established when the bearing is adjusted against a second bearing. Usually, these bearings are arranged in pairs, either back-to-back or face-to-face, and one bearing ring is axially displaced until a given clearance or preload is obtained. For information about bearing preload, refer to Bearing preload († page 214). The following recommendations refer only to the adjustment of the internal clearance for bearing arrangements with angular contact ball bearings or tapered roller bearings. The appropriate value for the clearance to be obtained when mounting, depends on the bearing size and arrangement and operating conditions such as load and temperature. Since there is a definite relationship between the radial and axial internal clearance of angular contact ball bearings and tapered roller bearings, it is sufficient to specify one value, generally the axial internal clearance. This specified value is then obtained, from a condition of zero clearance by loosening or tightening a nut on the shaft or a threaded ring in the housing bore or by inserting calibrated washers or shims between one of the bearing rings and its abutment. The actual method used to adjust and measure the clearance depends largely on the number of bearings to be mounted. One way to check the axial clearance in a bearing arrangement is to use a dial indicator attached to the hub († fig. 10). When adjusting tapered roller bearings and measuring clearance, the shaft or housing should be turned through several revolutions in both directions to be sure that there is proper contact of the roller ends with the guide flange on the inner ring. Without proper contact, the measured result will not be correct.

H

277

Mounting, dismounting and bearing care

Mounting bearings with a tapered bore

Fig. 11

For bearings with a tapered bore, inner rings are always mounted with an interference fit. The degree of interference is determined by how far the bearing is driven up onto a tapered shaft seat or an adapter or withdrawal sleeve. As the bearing is driven up the tapered seat, its radial internal clearance is reduced. This reduction in clearance or the axial drive-up distance can be measured to determine the degree of interference and the proper fit. Recommended values of clearance reduction and axial drive-up are listed in the relevant product chapter. Small and medium-size bearings Small and medium-size bearings (d ≤ 120 mm) can be driven up onto a tapered seat using either a bearing fitting tool or, preferably, a lock nut. For adapter sleeves, use the sleeve nut that can be tightened with a hook or impact spanner. Withdrawal sleeves can be driven into the bearing bore using a bearing fitting tool or an end plate. Starting from a 50 mm thread, SKF hydraulic nuts can also be used. Medium- and large-size bearings Because larger bearings (d > 120 mm) require considerably more force to mount, SKF hydraulic nuts should be used. Where applic­ able, SKF also recommends preparing the shaft for the oil injection method prior to mounting. When combining the two methods, bearing installation and removal becomes much faster, easier and safer. For additional information about the oil injection equipment required for both the hydraulic nut and the oil injection method, refer to the information available online at skf.com/mapro. Mounting with SKF hydraulic nuts

Bearings with a tapered bore can be mounted with the aid of an SKF hydraulic nut: • on a tapered shaft seat († fig. 11) • on an adapter sleeve († fig. 12) • on a withdrawal sleeve († fig. 13) The hydraulic nut can be positioned onto a threaded section of the shaft († fig. 11), onto the thread of a sleeve († fig. 12) or held in place on the shaft by a nut († fig. 13) or plate 278

Fig. 12

Fig. 13

Mounting Fig. 14

attached to the end of the shaft. The annular piston abuts the inner ring of the bearing († figs. 11 and 12) or the stop on the shaft († fig. 13). Pumping oil into the hydraulic nut displaces the piston axially with the force needed for accurate and safe mounting.

Fig. 15

Oil injection method

With the oil injection method, oil under high pressure is injected via ducts and distribution grooves between the bearing and bearing seat to form an oil film. This oil film separates the mating surfaces and considerably reduces the friction between them. This method is typical­ly used when mounting bearings directly on tapered shaft seats († fig. 14). The necessary ducts and grooves should be an integral part of the shaft design. This method can also be used to mount bearings on adapter or withdrawal sleeves if they have been properly prepared. A spherical roller bearing mounted on a withdrawal sleeve with oil ducts is shown in fig. 15. Oil is injected between all mating surfaces so that the withdrawal sleeve can be pressed into the bearing bore as the bolts are tightened.

H

279

Mounting, dismounting and bearing care Obtaining an interference fit During mounting, the degree of interference is normally determined by one of the following methods:

Fig. 16

• measuring the clearance reduction • measuring the lock nut tightening angle • measuring the axial drive-up • measuring the inner ring expansion For self-aligning ball bearings, feeling the clearance reduction by swivelling the outer ring is an additional method († page 548). Measuring the clearance reduction

A feeler gauge is most often used to measure the radial internal clearance in medium- and large-size spherical and CARB toroidal roller bearings. Recommended values for the reduction of radial internal clearance to obtain the correct interference fit are listed in the relevant product chapter. Before mounting, the clearance should be measured between the outer ring and uppermost roller († fig. 16). After mounting, the clearance should be measured between the inner or outer ring and lowest roller, depending on the bearing internal design († fig. 17). Before measuring, the inner or outer ring should be rotated a few times. Both bearing rings and the roller complement must be centrically arranged relative to each other. For larger bearings, especially those with a thin-walled outer ring, the measurements are affected by the elastic deformation of the rings, caused by the weight of the bearing or the force to draw the feeler gauge blade through the gap between the raceway and an unloaded roller. To establish the “true” clearance before and after mounting, use the following procedure († fig. 18):

280

Fig. 17

Mounting Fig. 18

a

b c

c b

Fig. 19

a

a

1 Measure the clearance “c” at the 12 o’clock position for a standing bearing or at the 6 o’clock position for an unmounted bearing hanging from the shaft. 2 Measure the clearance “a” at the 9 o’clock position and “b” at the 3 o’clock position without moving the bearing. 3 Obtain the “true” radial internal clearance with relatively good accuracy from 0,5 (a + b + c). Measuring the lock nut tightening angle

This method can be used for mounting small to medium-size bearings with a tapered bore (d ≤ 120 mm). Recommended values for the tightening angle a are listed in the relevant product chapter. Before starting the final tightening pro­ cedure, the bearing should be pushed up on the tapered seat until it is firmly in position. By tightening the nut through the recommended angle a († fig. 19), the bearing is driven up over the proper distance on the tapered seat. The bearing inner ring then has the requisite interference fit. The residual clearance should be checked whenever possible.

281

H

Mounting, dismounting and bearing care Fig.20

Fig. 21

“Zero” position

2

Start position

ss

Final position

1

4

3

Measuring the axial drive-up

Mounting bearings with a tapered bore can be done by measuring the axial drive-up of the inner ring on its seat. Recommended values for the required axial drive-up are listed in the relevant product chapter. However, the SKF Drive-up Method is recommended for medium- and large-size bearings. This method provides a reliable and easy way to determine the degree of interference. The correct fit is achieved by controlling the axial displacement of the bearing from a predetermined position. This method incorp­or­ates the use of an SKF hydraulic nut (1) fitted with a dial indicator (2), and a hydraulic pump (3) fitted with a pressure gauge (4), appropriate to the mounting conditions († fig. 20). The SKF Drive-up Method is based on a two stage mounting procedure († fig. 21):

282

• Stage one By applying a predetermined pressure in the hydraulic nut, the bearing is pushed from the “zero” position to a reliable start position. • Stage two By increasing the pressure in the hydraulic nut, the bearing inner ring is pushed further on its tapered seat to the final position. The displacement ss is measured by the dial indicator. Recommended values for the requisite oil pressure to reach the start position and the axial displacement to reach the final position for individual bearings are available online at skf.com/mount or skf.com/drive-up.

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Mounting Fig. 22

0.450

ON 0FF

CLR

MAX

TMEM 1500

Measuring the inner ring expansion

Measuring the inner ring expansion is a quick and accurate method to determine the correct position of large spherical and CARB toroidal roller bearings on their seats (d ≥ 340 mm, depending on the series). To take this ­measurement, use common hydraulic mounting tools and SensorMount, which comprises a bearing with a sensor imbedded in the inner ring and a dedicated hand-held indicator († fig. 22). Aspects like bearing size, shaft material and design (solid or hollow), and surface finish do not need any special con­sid­er­ ation. For additional information about SensorMount, contact the SKF application engineering service.

H

283

Mounting, dismounting and bearing care

Test running Once assembly is complete, an application should undergo a test run to determine that all components are operating properly. During a test run, the application should run under partial load and – where there is a wide speed range – at slow or moderate speeds. A rolling bearing should never be started up unloaded and then accelerated to high speed, as there is a risk that the rolling elements slide and damage the raceways, or that the cage is subjected to impermissible stresses. A minimum bearing load needs to be applied (refer to Minimum load in the relevant product chapter). Any noise or vibration can be checked using an SKF electronic stethoscope. Normally, bearings produce an even “purring” noise. Whistling or screeching indicates inadequate lubrication. An uneven rumbling or hammering is in most cases due to the presence of contaminants in the bearing or to bearing damage caused during mounting. An increase in bearing temperature immediately after start-up is normal. In the case of grease lubrication, the temperature does not drop until the grease has been evenly distributed in the bearing arrangement, after which an equilibrium temperature is reached. Un­u sually high temperatures or constant peaking indicate that there is too much lubricant in the arrangement or that the bearing is radially or axially distorted. Other causes could be that associated components have not been made or mounted correctly, or that the seals are generating too much heat. During the test run, or immediately afterwards, check the seals, any lubrication systems and all fluid levels. If noise and vibration levels are severe, it is advisable to check the lubricant for signs of contamination.

284

Dismounting Fig. 23

Dismounting If bearings are to be used again after removal, the force used to dismount them must never be applied through the rolling elements. With separable bearings, the ring with the rolling element and cage assembly can be removed independently of the other ring. With non-separable bearings, the ring having the looser fit should be withdrawn from its seat first. To dismount a bearing with an interference fit, the tools described in the following section can be used. The choice of tools depends on the bearing type, size and fit. In the following, the bearing size is categorized:

Fig. 24

• small † d ≤ 80 mm • medium-size † 80 mm < d < 200 mm • large † d ≥ 200 mm

Dismounting bearings fitted on a cylindrical shaft seat

Fig. 25

Cold dismounting Small bearings can be removed from a shaft by applying light hammer blows via a suitable drift to the ring side face, or preferably by using a mechanical puller. The claws must be applied to the inner ring or an adjacent component († fig. 23). Dismounting is made easier if slots for the claws of a puller are provided in the shaft and/or housing shoulders. Alternatively, tapped holes in the housing shoulder can be provided to accommodate withdrawal screws († fig. 24). Medium- and large-size bearings generally require greater force than a mechanical tool can provide. Therefore, SKF recommends using either hydraulically assisted tools or the oil injection method, or both. This presupposes that the necessary oil supply ducts and distribution grooves have been designed into the shaft arrangement († fig. 25).

285

H

Mounting, dismounting and bearing care Hot dismounting Dismounting with heat is a suitable method when removing inner rings of needle roller bearings or NU, NJ and NUP design cylindrical roller bearings. Two different tools for this purpose are common: heating rings and adjustable induction heaters. Heating rings are typically used to mount and dismount the inner ring of small to me­dium-size bearings that are all the same size. Heating rings are made of light alloy. They are radially slotted and equipped with insulated handles († fig. 26). If inner rings with different diameters are dismounted frequently, SKF recommends using an adjustable induction heater. These heaters († fig. 27) heat the inner ring rapidly without heating the shaft. Special fixed induction heaters have been developed to dismount the inner rings of large cylindrical roller bearings († fig. 28). Induction heaters and heating rings are available from SKF. For additional information, visit skf.com/mapro.

Fig. 26

Fig. 27

Fig. 28

286

Dismounting

Dismounting bearings fitted on a tapered shaft seat Small bearings can be dismounted using a mechanical or hydraulically assisted puller that engages the inner ring. Self-centring pullers equipped with spring-operated arms should be used to simplify the procedure and avoid damage to the bearing seat. If it is not possible to apply the claws of the puller to the inner ring, withdraw the bearing via the outer ring or use a puller in combination with a pulling plate († fig. 29). Dismounting medium- and large-size bearings is easier and much safer when the oil injection method is used. This method injects oil, under high pressure, between the two tapered mating surfaces, via a supply duct and a distribution groove. This significantly reduces the friction between the two surfaces and produces an axial force that separates the bearing from its seat († fig. 30).

Fig. 29

Fig. 30

Wa rning To avoid the risk of serious injury, attach a provision such as a lock nut to the shaft end to limit bearing travel when the bearing suddenly comes loose.

H

287

Mounting, dismounting and bearing care

Dismounting bearings fitted on an adapter sleeve Small bearings fitted on an adapter sleeve and a plain shaft can be dismounted by tapping a small steel block with an appropriate hammer evenly around the bearing inner ring side face († fig. 31). Before doing so, the sleeve lock nut has to be loosened a few turns. Small bearings fitted on an adapter sleeve and a stepped shaft can be dismounted by a couple of sharp hammer blows applied to a dolly abutting the sleeve lock nut († fig. 32). Before doing so, the sleeve lock nut has to be loosened a few turns. Using a hydraulic nut for dismounting bearings fitted on an adapter sleeve and a stepped shaft makes bearing removal easy. To use this method however, it must be possible to mount a suitable stop that abuts to the piston of the hydraulic nut († fig. 33). If the sleeves are provided with oil supply ducts and distribution grooves, dismounting becomes easier because the oil injection method can be used.

288

Fig. 31

Dismounting Fig. 32

Fig. 33

H

289

Mounting, dismounting and bearing care

Dismounting bearings fitted on a withdrawal sleeve When dismounting a bearing fitted on a withdrawal sleeve, the locking device (e.g. lock nut, end plate etc.) has to be removed. Small and medium-size bearings can be dismounted with a lock nut and a hook or impact spanner († fig. 34). Medium- and large-size bearings fitted on a withdrawal sleeve can be easily dismounted with a hydraulic nut. SKF strongly recommends providing a stop behind the hydraulic nut at the shaft end († fig. 35). The stop prevents the withdrawal sleeve and hydraulic nut from shooting off the shaft if the sleeve separ­ ates suddenly from its seat. Withdrawal sleeves with a bore diameter ≥ 200 mm are provided, as standard, with two oil supply ducts and distribution grooves in both the bore and outside surface. When using the oil injection method, two hydraulic pumps and appropriate extension pipes are needed († fig. 36).

Fig. 34

Fig. 35

Fig. 36

290

Inspection and cleaning

Bearing storage

Inspection and cleaning

The conditions under which bearings, seals and lubricants are stored can have an adverse effect on their performance. Inventory control can also play an important role in performance, particularly if seals and lubricants are involved. Therefore, SKF recommends a “first in, first out” inventory policy.

As with all other important machine compon­ ents, rolling bearings must be cleaned and inspected frequently. The intervals between these inspections depend entirely on the operating conditions. If it is possible to ascertain the condition of a bearing during service, by using condition monitoring equipment, listening to the bearing with a stethoscope, monitoring temperature or lubricant analysis, then it is usually sufficient to clean and inspect all components annually. Where loads are heavy, the frequency of inspection should be increased. After the bearing components have been cleaned with a suitable solvent such as white mineral spirits, they should be oiled or greased immediately to prevent corrosion. This is particularly important for bearings in machines that are left to stand for extended periods.

Storage conditions To maximize the service life of bearings, SKF recommends the following basic housekeeping practices: • Store bearings flat, in a vibration-free, dry area with a cool, steady temperature. • Control and limit the relative humidity of the storage area as follows: –– 75% at 20 °C (68 °F) –– 60% at 22 °C (72 °F) –– 50% at 25 °C (77 °F) • Keep bearings in their original unopened packages until immediately prior to mounting to prevent the ingress of contaminants and corrosion. • Bearings that are not stored in their original packaging should be well protected against corrosion and contaminants. Note: Machines on standby should be rotated or run as frequently as possible to redistribute the grease within the bearings and change the position of the rolling elements relative to the raceways. Shelf life of open bearings SKF bearings are coated with a rust-inhibiting compound and suitably packaged before distribution. For open bearings, the preservative provides protection against corrosion for approximately five years, provided the storage conditions are appropriate.

H

Shelf life of capped bearings The maximum storage interval for capped SKF bearings is dictated by the lubricant inside the bearings. Lubricant deteriorates over time as a result of ageing, condensation, and separ­ ation of the oil and thickener. Therefore, capped bearings should not be stored for more than three years. 291

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

Product data

Deep groove ball bearings 1 Y-bearings (insert bearings) 2 Angular contact ball bearings 3 Self-aligning ball bearings 4 Cylindrical roller bearings 5 Needle roller bearings 6 Tapered roller bearings 7 Spherical roller bearings 8 CARB toroidal roller bearing 9 Thrust ball bearings 10 Cylindrical roller thrust bearings 11 Needle roller thrust bearings 12 Spherical roller thrust bearings 13 Track runner bearings 14 Engineered products 15 Bearing accessories 16

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

1 Deep groove ball bearings

Designs and variants. . . . . . . . . . . . . . . Single row deep groove ball bearings . . . Stainless steel deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . . . Single row deep groove ball bearings with filling slots. . . . . . . . . . Double row deep groove ball bearings. . Cages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sealing solutions . . . . . . . . . . . . . . . . . . . Shields. . . . . . . . . . . . . . . . . . . . . . . . . . Non-contact seals . . . . . . . . . . . . . . . . Low-friction seals. . . . . . . . . . . . . . . . . Contact seals. . . . . . . . . . . . . . . . . . . . ICOS oil sealed bearing units. . . . . . . . Greases for capped bearings . . . . . . . . Grease life for capped bearings. . . . . . Bearings with a snap ring groove . . . . . . Quiet running bearings. . . . . . . . . . . . . . . Matched bearing pairs. . . . . . . . . . . . . . .

296 296 296 297 298 298 300 301 301 302 303 304 304 306 308 309 309

Performance classes. . . . . . . . . . . . . . . 310 SKF Explorer bearings. . . . . . . . . . . . . . . 310 SKF Energy Efficient (E2) bearings. . . . . 310 Bearing data. . . . . . . . . . . . . . . . . . . . . . 312 (Dimension standards, tolerances, internal clearance, misalignment, friction, starting torque, power loss, defect frequencies) Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 (Minimum load, axial load carrying capacity, equivalent loads)

Product tables 1.1 Single row deep groove ball bearings. . . . . . . . . . . . . . . . . . 322 1.2 Capped single row deep groove ball bearings. . . . . . . . . . . . . . . . . . . . . 346 1.3 ICOS oil sealed bearing units . . . . . 374 1.4 Single row deep groove ball bearings with a snap ring groove. . 376 1.5 Single row deep groove ball bearings with a snap ring and shields. . . . . . 382 1.6 Stainless steel deep groove ball bearings. . . . . . . . . . . . . . . . . . 386 1.7 Capped stainless steel deep groove ball bearings. . . . . . . . 394 1.8 Single row deep groove ball bearings with filling slots. . . . . 410 1.9 Single row deep groove ball bearings with filling slots and a snap ring. . . 414 1.10 Double row deep groove ball bearings. . . . . . . . . . . . . . . . . . 416 Other deep groove ball bearings Sensor bearing units . . . . . . . . . . . . . . . . 1151 Bearings for extreme temperatures . . . . 1169 Bearings with Solid Oil . . . . . . . . . . . . . . . 1185 SKF DryLube bearings . . . . . . . . . . . . . . 1191 INSOCOAT bearings . . . . . . . . . . . . . . . . . 1205 Hybrid bearings . . . . . . . . . . . . . . . . . . . . 1219 NoWear coated bearings . . . . . . . . . . . . . 1241 Polymer ball bearings . . . . . . . . . . . . . . . 1247

Temperature limits. . . . . . . . . . . . . . . . . 318 Permissible speed. . . . . . . . . . . . . . . . . . 318 Designation system . . . . . . . . . . . . . . . . 320

295

1 Deep groove ball bearings

Designs and variants

Fig. 1

Deep groove ball bearings are particularly versatile. They are simple in design, non-­ separable, suitable for high and very high speeds and are robust in operation, requiring little maintenance. Because deep groove ball bearings are the most widely used bearing type, they are available from SKF in many designs, variants and sizes. In addition to the bearings presented in this chapter, deep groove ball bearings for special applications are shown under Engineered products. Deep groove ball bearings for special applications include: • sensor bearing units († page 1151) • bearings for extreme temperatures († page 1169) • bearings with Solid Oil († page 1185) • SKF DryLube bearings († page 1191) • INSOCOAT bearings († page 1205) • hybrid bearings († page 1219) • NoWear coated bearings († page 1241) • polymer ball bearings († page 1247)

More information Bearing life and load ratings. . . . . . Design considerations. . . . . . . . . . . Bearing systems. . . . . . . . . . . . . . . . . Recommended fits. . . . . . . . . . . . . . . Abutment and fillet dimensions. . . . .



63 159 160 169 208

Lubrication . . . . . . . . . . . . . . . . . . . . 239 Mounting, dismounting and bearing care . . . . . . . . . . . . . . . . . . . 271 Mounting instructions for individual bearings . . . . . . . . . . . . . . † skf.com/mount

296

Single row deep groove ball bearings SKF single row deep groove ball bearings († fig. 1) have deep, uninterrupted raceway grooves. These raceway grooves have a close osculation with the balls, enabling the bearings to accommodate radial loads and axial loads in both directions. Single row deep groove ball bearings are available open or capped (with seals or shields). Open bearings that are also available capped, may have recesses in the outer ring († fig. 2). Inch single row deep groove ball bearings and bearings with a tapered bore are not pres­ ented in this catalogue. For information about inch single row deep groove ball bearings, refer to the product information available online at skf.com/bearings. For add­itional information about deep groove ball bearings with a tapered bore, contact the SKF application engineering service.

Stainless steel deep groove ball bearings SKF stainless steel deep groove ball bearings († fig. 1) are corrosion resistant when exposed to moisture and several other media. They can accommodate radial loads and axial loads in both directions. These bearings have a lower load carrying capacity than same-sized bearings made of high chromium steel. The bearings are available open or capped (with seals or shields). Open bearings that are also available capped, may have recesses in

1 Designs and variants both the inner and outer rings or only in the outer ring († fig. 2). Flanged stainless steel deep groove ball bearings and inch bearings are not presented in this catalogue. For information about these bearings, refer to the product information available online at skf.com/bearings.

Fig. 3

Single row deep groove ball bearings with filling slots Single row deep groove ball bearings with filling slots have a filling slot in both the inner and outer rings († fig. 3) to accommodate more balls than standard deep groove ball bearings. Filling slot bearings have a higher radial load carrying capacity than bearings without filling slots, but their axial load carrying capacity is limited. They are also unable to operate at the same high speeds as bearings without filling slots. Deep groove ball bearings with filling slots are available open or with shields. They are also available with or without a snap ring groove. Open bearings that are also available with shields, may have recesses in the outer ring († fig. 4).

Fig. 2

Fig. 4

297

1 Deep groove ball bearings

Double row deep groove ball bearings

Cages

SKF double row deep groove ball bearings († fig. 5) correspond in design to single row deep groove ball bearings. Their deep, uninter­ rupted raceway grooves have a close oscul­ ation with the balls, enabling the bearings to accommodate radial loads and axial loads in both directions. Double row deep groove ball bearings are very suitable for bearing arrangements where the load carrying capacity of a single row bearing is inadequate. For the same bore and outside diameter, double row bearings are slightly wider than single row bearings in the 62 and 63 series, but have a considerably higher load carrying capacity. Double row deep groove ball bearings are only available as open bearings (without seals or shields).

Depending on their design, series and size, SKF deep groove ball bearings are fitted with one of the cages shown in table 1. Double row bearings are equipped with two cages. The standard stamped steel cage is not identified in the bearing designation. If non-standard cages are required, check availability prior to ordering. The lubricants generally used for rolling bearings do not have a detrimental effect on cage properties. However, some synthetic oils and greases with a synthetic oil base and lubricants containing a high proportion of EP additives, when used at high temperatures, can have a detrimental effect on polyamide cages. For additional information about the suitability of cages, refer to Cages († page 37) and Cage materials († page 152).

Fig. 5

298

1 Designs and variants Table 1 Cages for deep groove ball bearings Steel cages

a

Polymer cages

Brass cages

Snap-type, ball centred

Riveted, ball, outer ring or inner ring centred

PA66, glass PA46, glass PEEK, glass fibre reinforced fibre reinforced fibre reinforced

Machined brass

M, MA or MB

b

Cage type

Ribbontype, ball centred

Material

Stamped steel

Suffix







TN9

VG1561

Single row bearings

Standard

Standard (a)



Check availability

Standard for Check SKF E2 availability bearings, check availability for other bearings

Standard

Stainless steel bearings

Standard, stainless steel

Standard (a), stainless steel

Standard, stainless steel

Check availability







Single row bearings with filling slots



Standard (b)











Double row bearings







Standard







Riveted, ball centred

Snap-type, ball centred

TNH

299

1 Deep groove ball bearings

Sealing solutions

Bearings capped on both sides are lubricated for the life of the bearing and should not be washed or relubricated. They are filled with the appropriate amount of a high-quality grease under clean conditions. The bearings are considered maintenance-free. If they are to be hot mounted, an induction heater should be used. SKF does not recommend heating capped bearings above 80 °C (175 °F). However, if higher temperatures are necessary, make sure that the temperature does not exceed the permissible temperature of either the seal or grease, whichever is lowest. The seals, which are fitted in a recess on the outer ring, make good, positive contact with the recess, without deforming the outer ring († figs. 7 to 9, pages 301 to 303).

SKF supplies the most popular sizes of deep groove ball bearings capped with a seal or shield on one or both sides. Selection guidelines for different sealing solutions under various operating conditions are listed in table 2. However, these guidelines cannot substitute for testing a seal in its application. For add­ itional information, refer to Sealing solutions († page 226). ICOS oil sealed bearing units, which are standard deep groove ball bearings with an integrated radial shaft seal, are also available. When capped bearings must operate under certain extreme conditions, such as very high speeds or high temperatures, grease may leak at the inner ring. For bearing arrangements where this would be detrimental, special design steps must be undertaken. For add­ itional information, contact the SKF application engineering service.

Table 2 Selection guidelines for SKF sealing solutions Requirement

Shields

Non-contact seals

Low-friction seals

Contact seals

Z, ZS

RZ

RSL

RSH

RS1

Low friction

+++

+++

++

L

L

High speed

+++

+++

+++

L

L

Grease retention

L

+

+++

+++

++

Dust exclusion

L

+

++

+++

+++

Water exclusion static dynamic high pressure

– – –

– – –

L L L

+++ + +++

++ +

Symbols:

300

+++ = best

++ = very good

+ = good

L = fair

– = not recommended

L

1 Designs and variants Shields Bearings with shields are primarily intended for applications where the inner ring rotates. Shields are fitted in the outer ring and do not make contact with the inner ring, but form a narrow gap with it. Shields are made of sheet steel. For stainless steel bearings, stainless steel is used. Depending on the bearing design, series and size, SKF supplies shields in different designs. Shields identified by the designation suffix Z typically have an extension in the shield bore to form a long, narrow gap with the land of the inner ring shoulder († fig. 6a). Some shields do not have the extension († fig. 6b). The bore of a Z shield on some stainless steel deep groove ball bearings can extend into a recess on the inner ring († fig. 6c). Shields identified by the designation suffix ZS are available for stainless steel bearings only. These shields are fixed in the outer ring by a retaining ring († fig. 6d) and may extend into a recess on the inner ring.

by the designation suffix RZ or 2RZ. Noncontact seals are available for single row deep groove ball bearings only. Some stainless steel bearings are available with non-contact seals on request. The exact seal design may differ from the illustration († fig. 7).

Fig. 7

Non-contact seals Bearings with non-contact seals can be operated at the same speeds as bearings with shields, but with improved sealing effectiveness. The seals form an extremely narrow gap with the land of the inner ring shoulder († fig. 7). Non-contact seals are made of oil and wear-resistant NBR that is reinforced by a sheet steel insert. SKF deep groove ball bearings with a noncontact seal on one or both sides are identified

RZ

Fig. 6

a



b

Z

c

Z

d

Z

ZS

301

1 Deep groove ball bearings Low-friction seals Bearings with low-friction seals can accommodate the same speeds as bearings with shields, but with improved sealing effectiveness. The seals are practically non-contacting with a recess in the inner ring shoulder. Single row deep groove ball bearings with a low-friction seal on one or both sides are identified by the designation suffix RSL or 2RSL. The seals are made of oil and wear-resistant NBR that is reinforced with a sheet steel insert. Low-friction seals are available for bearings in the 60, 62 and 63 series. They are manufactured in two designs depending on bearing size († fig. 8).

Fig. 8

a



302

b

RSL D ≤ 25 mm

RSL 25 < D ≤ 52 mm

1 Designs and variants Contact seals Contact seals († fig. 9) are made of oil and wear-resistant NBR or FKM and are reinforced with a sheet steel insert. SKF deep groove ball bearings with a contact seal made of NBR on one or both sides are manufactured in five designs depending on the bearing:

W a rn i ng Seals made of FKM (fluoro rubber) exposed to an open flame or temperatures above 300 °C (570 °F) are a health and environmental hazard! They remain dangerous even after they have cooled. Read and follow the safety precautions under Seal materials († page 155).

• Bearings in the 60, 62, and 63 series are equipped with RSH seals to design (a) when D ≤ 25 mm. • Bearings in the 60, 62 and 63 series are equipped with RSH seals to design (b) when 25 mm < D ≤ 52 mm. • Other bearings have RS1 seals, which seal against the land of the inner ring shoulder (c) or against a recess in the inner ring side face (d). The difference is indicated by dimension d1 or d2 in the product tables. • Stainless steel bearings are equipped with RS1 seals to design (c) or (e). The exact seal design may differ from the illustrations. Bearings with seals made of FKM are available on request. They are identified by the designation suffix RS2 or 2RS2.

Fig. 9

a



b

RSH

c

RSH

d

RS1

e

RS1

RS1

303

1 Deep groove ball bearings ICOS oil sealed bearing units ICOS oil sealed bearing units are designed for applications where sealing requirements exceed the capabilities of bearings with contact seals. An ICOS unit consists of a 62 series deep groove ball bearing and one integral SKF WAVE seal († fig. 10). The SKF WAVE seal is a single lip, spring loaded radial shaft seal made of NBR. ICOS units need less axial space than an arrangement using a bearing and an external seal. They simplify mounting and avoid expensive machining of the shaft because the inner ring shoulder is the seal counterface. The limiting speeds quoted in the product table are based on the permissible circumferential speed for the seal, which is 14 m/s. Greases for capped bearings Depending on the design, series and size, bearings capped on both sides are filled with one of the following standard greases: • basic design deep groove ball bearings † table 3 • SKF Energy Efficient deep groove ball bearings † low-friction grease GE2 • stainless steel deep groove ball bearings † LHT23 • deep groove ball bearings with filling slots † GJN.

Fig. 10

On request, bearings can be supplied with the following special greases: • high temperature grease GJN when D ≤ 62 mm • wide temperature range grease HT or WT • wide temperature range and silent running grease LHT23 (for bearings where it is not standard) • low temperature grease LT • non-toxic grease (designation suffix VT378) for stainless steel deep groove ball bearings This grease fulfils the requirements of the “Guidelines of section 21 CFR 178.3570” of the FDA (US Food and Drug Administration) regulations and is approved by the USDA (United States Department of Agriculture) for category H1 use (lubricants with incidental food contact).

Table 3 SKF standard greases for capped single row deep groove ball bearings made of carbon chromium steel Bearings in diameter series

SKF standard greases in bearings with outside diameter D ≤ 30 mm d < 10 mm

d ≥ 10 mm

30 < D ≤ 62 mm

D > 62 mm

8, 9

LHT23

LT10

MT47

MT33

0, 1, 2, 3

MT47

MT47

MT47

MT33

304

1 Designs and variants The technical specifications of the various greases are listed in table 4. The standard grease is not identified in the bearing designation (no designation suffix). Special greases are indicated by the corresponding grease suffix. Check availability of bearings with special grease prior to ordering.

Table 4 Technical specifications of SKF standard and special greases for capped deep groove ball bearings Grease

Temperature range 1)

Thickener

Base oil type

NLGI consist­ency class

Base oil viscosity [mm2 /s] at 40 °C at 100 °C (105 °F) (210 °F)

Grease performance factor (GPF)

–50

0

50 100 150 200 250 °C

–50

0

50 100 150 200 250 °C Lithium soap

Mineral

3

100

10

1

MT47

Lithium soap

Mineral

2

70

7,3

1

LT10

Lithium soap

Diester

2

12

3,3

2

LHT23

Lithium soap

Ester

2–3

27

5,1

2

LT

Lithium soap

Diester

2

15

3,7

1

WT

Polyurea soap

Ester

2–3

70

9,4

4

GJN

Polyurea soap

Mineral

2

115

12,2

2

HT

Polyurea soap

Mineral

2–3

98

10,5

2

VT378

Aluminium complex soap

PAO

2

150

15,5



Lithium soap

Synthetic

2

25

4,9



MT33

GE2

–60 30 120 210 300 390 480 °F –60 30 120 210 300 390 480 °F

1) Refer to the SKF traffic light concept †

page 244

305

1 Deep groove ball bearings Grease life for capped bearings Grease life for capped bearings should be estimated according to the procedure described in this section. The grease life for capped bearings is presented as L 10, i.e. the time period at the end of which 90% of the bearings are still reliably lubricated. The method to estimate relubrication intervals († Relubrication intervals, page 252) represents the L01 grease life and should not be used. The grease life for capped bearings depends on the operating temperature and the speed factor. It can be obtained from the diagrams. Diagram 1 is valid for standard deep groove ball bearings. The grease performance factor (GPF) is listed in table 4 († page 305). Diagram 2 is valid for SKF Energy Efficient deep groove ball bearings. The grease life for each is valid under the following operating conditions:

• horizontal shaft • inner ring rotation • light load (P ≤ 0,05 C) • operating temperature within the green temperature zone of the grease († table 4, page 305) • stationary machine • low vibration levels For stainless steel bearings filled with VT378 grease, use the scale corresponding to GPF = 1 and multiply the value obtained from the diagram by 0,2.

Diagram 1 Grease life for capped deep groove ball bearings where P = 0,05 C Grease life L 10 [h]

100 000

n dm = 20 000

n dm = 100 000 200 000 300 000 400 000

10 000

500 000 600 000 700 000

1 000

100 GPF = 1 GPF = 2 GPF = 4

40 55 70

45 60 75

50 65 80

55 70 85

60 75 90

65 70 75 80 85 90 95 100 105 110 115 80 85 90 95 100 105 110 115 120 125 130 95 100 105 110 115 120 125 130 135 140 145 Operating temperature [°C] for various grease performance factors (GPF)

n = rotational speed [r/min] dm = bearing mean diameter [mm] = 0,5 (d + D)

306

1 Designs and variants Table 5

If the operating conditions differ, the grease life obtained from the diagrams has to be adjusted:

Reduction factor for the grease life, depending on the load

• For vertical shafts, use 50% of the value from the diagram. • For heavier loads (P > 0,05 C), use the reduction factor listed in table 5.

Load P

Reduction factor

≤ 0,05 C 0,1 C

1 0,7

0,125 C 0,25 C

0,5 0,2

Diagram 2 Grease life for SKF Energy Efficient deep groove ball bearings where P = 0,05 C Grease life L 10 [h]

n dm = 100 000

100 000

n dm = 40 000

200 000 300 000 400 000 500 000

10 000

600 000 650 000

1 000

100 50

60

70

80

90

100

110

120

130

140

150

Operating temperature [°C]

n = rotational speed [r/min] dm = bearing mean diameter [mm] = 0,5 (d + D)

307

1 Deep groove ball bearings

Bearings with a snap ring groove Deep groove ball bearings with a snap ring groove can simplify the design of an arrangement because the bearings can be axially located in the housing by a snap ring († fig. 11). This saves space and can significantly reduce installation time. Appropriate snap rings are shown in the product tables with their designation and dimensions. They can be supplied separately or fitted to the bearing. The following variants († fig. 12) are available for basic design deep groove ball bearings and for bearings with filling slots: • open bearings with a snap ring groove only (designation suffix N) • open bearings with a snap ring (designation suffix NR) • bearings with a snap ring and a shield on the opposite side (designation suffix ZNR) • bearings with a snap ring and a shield on both sides (designation suffix 2ZNR)

Fig. 11

For bearings with filling slots, the snap ring groove is on the same side as the filling slots.

Fig. 12



308

N

NR

ZNR

2ZNR

1 Designs and variants

Quiet running bearings SKF Quiet Running deep groove ball bearings are designed to comply with stringent noise requirements in applications such as wind turbine generators and to provide consistent performance over a variety of operating conditions. These bearings are identified by the designation suffix VQ658. The range covers bearing sizes typically used in wind turbine generators. For additional information, contact the SKF application engin­eering service.

Matched bearing pairs For bearing arrangements where the load carrying capacity of a single bearing is inadequate, or where the shaft has to be axially located in both directions with a specific axial clearance, SKF can supply matched pairs of single row deep groove ball bearings on request. Depending on the requirements, the matched pairs can be supplied in tandem, back-to-back, or face-to-face arrangements († fig. 13). The bearings are matched in production so that, when mounted immediately adjacent to each other, the load is evenly distributed between the bearings without having to use shims or similar devices. For additional information about matched bearing pairs, refer to the product information available online at skf.com/bearings.

Fig. 13

Tandem arrangement

Back-to-back arrangement

Face-to-face arrangement

309

1 Deep groove ball bearings

Performance classes SKF Explorer bearings In response to the ever-demanding performance requirements of modern machinery, SKF developed the SKF Explorer performance class of rolling bearings. SKF Explorer deep groove ball bearings realized this substantial improvement in performance by optimizing the internal geometry and surface finish of all contact surfaces, redesigning the cage, combining the extremely clean and homogenous steel with a unique heat treatment and improving the quality and consistency of the balls. Deep groove ball bearings within this performance class provide superior performance especially in applications like electric motors, two-wheelers and transmissions. These improvements provide the following benefits: • higher dynamic load carrying capacity • reduced noise and vibration levels • less frictional heat • significantly longer bearing service life These bearings reduce environmental impact by enabling downsizing and reducing both lubricant and energy consumption. Just as importantly, SKF Explorer bearings can reduce the need for maintenance and contribute to increased productivity. SKF Explorer bearings are shown with an asterisk in the product tables. The bearings retain the designation of earlier standard bearings. However, each bearing and its box are marked with the name “SKF EXPLORER”.

310

SKF Energy Efficient (E2) bearings To meet the ever-increasing demand to reduce friction and energy consumption, SKF has developed the SKF Energy Efficient (E2) performance class of rolling bearings. Deep groove ball bearings within this performance class are characterized by a frictional moment in the bearing that is at least 30% lower when compared to a same-sized SKF Explorer bearing. The bearings realized the substantial reduction of the frictional moment by optimizing the internal geometry of the bearing, redesigning the cage and applying a new, lowfriction grease. SKF E2 deep groove ball bearings have been shown to last longer and consume less lubricant than comparable SKF Explorer deep groove ball bearings. The enhanced performance characteristics require the following conditions: • speed n > 1 000 r/min • load P ≤ 0,125 C If conditions vary, contact the SKF application engineering service. Typical applications include electric motors, pumps, conveyors and fans. SKF E2 deep groove ball bearings are available in the 60, 62 and 63 dimension series. They are supplied with a shield on both sides and have C3 radial internal clearance as standard.

1 Performance classes

311

1 Deep groove ball bearings

Bearing data Single row deep groove ball bearings Dimension standards

Boundary dimensions: ISO 15 Snap rings and grooves: ISO 464

Tolerances

Normal P6 or P5 on request

For additional information († page 132) Internal clearance

SKF Explorer and SKF E2 bearings Dimensional accuracy to P6 and reduced width tolerance: D ≤ 110 mm † 0/ –60 μm D > 110 mm † 0/ –100 μm

Running accuracy D ≤ 52 mm † P5 52 mm < D ≤ 110 mm † P6 D > 110 mm † Normal tolerances

Values: ISO 492, († tables 3 to 5, pages 137 to 139) Normal Check availability of C2, C3, C4, C5, reduced ranges of standard clearance classes or partitions of adjacent classes SKF E2 bearings C3 Check availability of other clearance classes

For additional information († page 149)

Values: ISO 5753-1, († table 6, page 314), except for stainless steel …

Misalignment

≈ 2 to 10 minutes of arc The permissible angular misalignment between the inner and outer rings depends on the size and internal design of the bearing, the radial internal clearance in operation and the forces and moments acting on the …

Friction, start- Frictional moment, starting torque, and power loss can be calculated as specified under Friction († page 97), or using the tools … ing torque, power loss Defect frequencies

312

Defect frequencies can be calculated using the tools …

1 Bearing data

Stainless steel deep groove ball bearings

Single row deep groove ball bearings with filling slots

Double row deep groove ball bearings

Boundary dimensions: ISO 15, except for bearings with suffix X

Boundary dimensions : ISO 15 Snap rings and grooves: ISO 464

Boundary dimensions: ISO 15

Normal Other classes on request

Normal

Normal

Normal Check availability of other clearance classes d < 10 mm († table 7, page 315)

Normal

Normal Check availability of C3 clearance class

… bearings with d < 10 mm. Values are valid for unmounted bearings under zero measuring load. ≈ 2 to 10 minutes of arc

≈ 2 to 5 minutes of arc

≤ 2 minutes of arc

… bearing. As a result, only approximate values are listed here. Any misalignment increases bearing noise and reduces bearing service life. … available online at skf.com/bearingcalculator.

… available online at skf.com/bearingcalculator.

313

1 Deep groove ball bearings Table 6 Radial internal clearance of deep groove ball bearings

Bore diameter d over incl.

Radial internal clearance C2 Normal min. max. min. max.

mm

μm

C3 min.

max.

C4 min.

max.

C5 min.

max.

2,5 6 10

6 10 18

0 0 0

7 7 9

2 2 3

13 13 18

8 8 11

23 23 25

– 14 18

– 29 33

– 20 25

– 37 45

18 24 30

24 30 40

0 1 1

10 11 11

5 5 6

20 20 20

13 13 15

28 28 33

20 23 28

36 41 46

28 30 40

48 53 64

40 50 65

50 65 80

1 1 1

11 15 15

6 8 10

23 28 30

18 23 25

36 43 51

30 38 46

51 61 71

45 55 65

73 90 105

80 100 120

100 120 140

1 2 2

18 20 23

12 15 18

36 41 48

30 36 41

58 66 81

53 61 71

84 97 114

75 90 105

120 140 160

140 160 180

160 180 200

2 2 2

23 25 30

18 20 25

53 61 71

46 53 63

91 102 117

81 91 107

130 147 163

120 135 150

180 200 230

200 225 250

225 250 280

2 2 2

35 40 45

25 30 35

85 95 105

75 85 90

140 160 170

125 145 155

195 225 245

175 205 225

265 300 340

280 315 355

315 355 400

2 3 3

55 60 70

40 45 55

115 125 145

100 110 130

190 210 240

175 195 225

270 300 340

245 275 315

370 410 460

400 450 500

450 500 560

3 3 10

80 90 100

60 70 80

170 190 210

150 170 190

270 300 330

250 280 310

380 420 470

350 390 440

520 570 630

560 630 710

630 710 800

10 20 20

110 130 140

90 110 120

230 260 290

210 240 270

360 400 450

340 380 430

520 570 630

490 540 600

700 780 860

800 900 1 000

900 1 000 1 120

20 20 20

160 170 180

140 150 160

320 350 380

300 330 360

500 550 600

480 530 580

700 770 850

670 740 820

960 1 040 1 150

1 120 1 250 1 400

1 250 1 400 1 600

20 30 30

190 200 210

170 190 210

410 440 470

390 420 450

650 700 750

630 680 730

920 1 000 1 060

890 – –

1 260 – –

314

1 Bearing data Table 7 Radial internal clearance of stainless steel deep groove ball bearings with a bore diameter < 10 mm

Bore diameter d over incl.

Radial internal clearance C1 C2 min. max. min. max.

mm

μm



9,525

0

5

3

8

Normal min. max.

C3 min.

max.

C4 min.

max.

C5 min.

max.

5

8

13

13

20

20

28

10

Table 8 Calculation factors for deep groove ball bearings Single row and double row bearings Normal clearance

Single row bearings C3 clearance

C4 clearance

f 0 Fa /C 0

e

X

Y

e

X

Y

e

X

Y

0,172 0,345 0,689

0,19 0,22 0,26

0,56 0,56 0,56

2,3 1,99 1,71

0,29 0,32 0,36

0,46 0,46 0,46

1,88 1,71 1,52

0,38 0,4 0,43

0,44 0,44 0,44

1,47 1,4 1,3

1,03 1,38 2,07

0,28 0,3 0,34

0,56 0,56 0,56

1,55 1,45 1,31

0,38 0,4 0,44

0,46 0,46 0,46

1,41 1,34 1,23

0,46 0,47 0,5

0,44 0,44 0,44

1,23 1,19 1,12

3,45 5,17 6,89

0,38 0,42 0,44

0,56 0,56 0,56

1,15 1,04 1

0,49 0,54 0,54

0,46 0,46 0,46

1,1 1,01 1

0,55 0,56 0,56

0,44 0,44 0,44

1,02 1 1

Calculation factors must be selected according to the operating clearance in the bearing, which may differ from the internal clearance before mounting. For additional information or for calculation factors for other clearance classes, contact the SKF application engineering service. Intermediate values can be obtained by linear interpolation.

315

1 Deep groove ball bearings

Loads Single row deep groove ball bearings Minimum load

For additional information († page 86) Axial load ­c arrying capacity

Stainless steel deep groove ball bearings

q n n w 2/3 q dm w 2 F = k JJJ JJL rm r < 1 000 z < 100 z The weight of the components supported by the bearing, together with external forces, generally exceed the requisite minimum load. If this is not the case, the bearing must be subjected to an additional radial load. For applications where single row or stainless steel deep groove ball bearings are used, … Pure axial load

† Fa ≤ 0,5 C0

Pure axial load † Fa ≤ 0,25 C0

Small bearings1) and light series bearings2) † Fa ≤ 0,25 C0 Excessive axial load can lead to a considerable reduction in bearing service life.

Equivalent dynamic ­bearing load

Fa /Fr ≤ e † P = Fr Fa /Fr > e † P = X Fr + Y Fa

For additional information († page 85) Equivalent static bearing load

P 0 = 0,6 Fr + 0,5 Fa P 0 < Fr † P 0 = Fr

For additional information († page 88)

1) d ≤ 12 mm 2) Diameter series 8, 9, 0, and 1

316

1 Loads

Single row deep groove ball bearings with filling slots

Double row deep groove ball bearings

… an axial preload can be applied by adjusting the inner and outer rings against each other, or by using springs.

Fa ≤ 0,6 Fr

Pure axial load † Fa ≤ 0,5 C0

Fa /Fr ≤ 0,6 and P ≤ 0,5 C0 † P = Fr + Fa

Fa /Fr ≤ e † P = Fr Fa /Fr > e † P = X Fr + Y Fa

Fa /Fr ≤ 0,6 † P 0 = Fr + 0,5 Fa

P 0 = 0,6 Fr + 0,5 Fa P 0 < Fr † P 0 = Fr

Symbols C0 = basic static load rating [kN] († product tables) dm = bearing mean diameter [mm] = 0,5 (d + D) e = limit for the load ratio depending on the ­relationship f 0 Fa /C0 († table 8, page 315) f 0 = calculation factor († product tables) Fa = axial load [kN] Fr = radial load [kN] Frm = minimum radial load [kN] k r = minimum load factor († product tables) n = rotational speed [r/min] P = equivalent dynamic bearing load [kN] P 0 = equivalent static bearing load [kN] X = calculation factor for the radial load († table 8, page 315) Y = calculation factor for the axial load depending on the relationship f 0 Fa /C0 († table 8, page 315) n = oil viscosity at operating temperature [mm2 /s]

317

1 Deep groove ball bearings

Temperature limits The permissible operating temperature for deep groove ball bearings can be limited by: • the dimensional stability of the bearing rings and balls • the cage • the seals • the lubricant When temperatures outside the permissible range are expected, contact the SKF application engineering service. Bearing rings and balls

SKF deep groove ball bearings undergo a special heat treatment. The bearings are heat stabilized up to at least 120 °C (250 °F). Cages

Steel or brass cages can be used at the same operating temperatures as the bearing rings and balls. For temperature limits of polymer cages, refer to Cage materials († page 152). Seals

The permissible operating temperature for seals depends on the material: • NBR seals: –40 to +100 °C (–40 to +210 °F) ­Temperatures up to 120 °C (250 °F) can be tolerated for brief periods. • FKM seals: –30 to +230 °C (–20 to +445 °F)

318

Lubricants

Temperature limits for greases used in SKF deep groove ball bearings capped on both sides are provided in table 4 († page 305). Temperature limits for other SKF greases are provided under Lubrication († page 239). When using lubricants not supplied by SKF, the temperature limits should be evaluated according to the SKF traffic light concept († page 244).

Permissible speed The permissible speed can be estimated using the speed ratings listed in the product tables and applying the information provided under Speeds († page 117). If no reference speed is listed in the product tables, the limiting speed is the permissible speed. SKF recommends oil lubrication for bearings with a ring centred cage (designation suffix MA or MB). When these bearings are grease lubricated († Lubrication, page 239) the speed factor is limited to A ≤ 450 000 mm/min. where A = n dm [mm/min] dm = bearing mean diameter [mm] = 0,5 (d + D) n = rotational speed [r/min] For applications exceeding these values, contact the SKF application engineering service. Matched bearing pairs

For matched bearing pairs, the permissible speed calculated for a single bearing should be reduced to approximately 80% of the quoted value.

1 Permissible speed

319

1 Deep groove ball bearings

Designation system Group 1 Group 2 Group 3

Prefixes E2. ICOSD/W W

SKF Energy Efficient bearing Oil sealed bearing unit Stainless steel, inch dimensions Stainless steel, metric dimensions

Basic designation Listed in diagram 2 († page 43) Suffixes Group 1: Internal design E

Reinforced ball set

Group 2: External design (seals, snap ring groove etc.) N NR N1 R -RS1, -2RS1 -RS2, -2RS2 -RSH, -2RSH -RSL, -2RSL -RZ, -2RZ -Z, -2Z -ZNR -2ZNR -2ZS X

Snap ring groove in the outer ring Snap ring groove in the outer ring, with appropriate snap ring One locating slot (notch) in one outer ring side face Flanged outer ring Contact seal, NBR, on one or both sides Contact seal, FKM, on one or both sides Contact seal, NBR, on one or both sides Low-friction seal, NBR, on one or both sides Non-contact seal, NBR, on one or both sides Shield on one or both sides Shield on one side, snap ring groove in the outer ring, snap ring on the opposite side of the shield Shield on both sides, snap ring groove in the outer ring, with snap ring Shield on both sides, held in place by a retaining ring Boundary dimensions not in accordance with ISO dimension series

Group 3: Cage design – M MA(S) MB(S) TN9 TNH VG1561

320

Stamped steel cage, ball centred Machined brass cage, ball centred; different designs or material grades are identified by a number following the M, e.g. M2 Machined brass cage, outer ring centred. The S indicates a lubrication groove in the guiding surface. Machined brass cage, inner ring centred. The S indicates a lubrication groove in the guiding surface. Glass fibre reinforced PA66 cage, ball centred Glass fibre reinforced PEEK cage, ball centred Glass fibre reinforced PA46 cage, ball centred

/

1 Designation system

Group 4 4.1

4.2

4.3

4.4

4.5

4.6 Group 4.6: Other variants Group 4.5: Lubrication GJN HT LHT23 LT LT10 MT33 MT47 VT378 WT

r s s f Grease suffixes († table 4, page 305) s s c

Group 4.4: Stabilization S0 S1

Bearing rings heat stabilized for operating temperatures ≤ 150 °C (300 °F) Bearing rings heat stabilized for operating temperatures ≤ 200 °C (390 °F)

Group 4.3: Bearing sets, matched bearings DB DF DT

Two bearings matched for mounting back-to-back Two bearings matched for mounting face-to-face Two bearings matched for mounting in tandem

Group 4.2: Accuracy, clearance, quiet running P5 P6 P52 P62 P63 CN

C1 C2 C3 C4 C5 VQ658

Dimensional and running accuracy to P5 tolerance class Dimensional and running accuracy to P6 tolerance class P5 + C2 P6 + C2 P6 + C3 Normal radial internal clearance; only used together with an additional letter that identifies a reduced or displaced clearance range H Reduced clearance range corresponding to the upper half of the actual clearance range L Reduced clearance range corresponding to the lower half of the actual clearance range P Displaced clearance range comprising the upper half of the actual clearance range plus the lower half of the next larger clearance range The above letters are also used together with the clearance classes C2, C3, C4 and C5, e.g. C2H Radial internal clearance smaller than C2 Radial internal clearance smaller than Normal Radial internal clearance greater than Normal Radial internal clearance greater than C3 Radial internal clearance greater than C4 Quiet running properties

Group 4.1: Materials, heat treatment

321

1.1 Single row deep groove ball bearings d 3 – 10 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



3

10

4

0,54

0,18

0,007

130 000

80 000

0,0015

623

4

9 11 12 13 16

2,5 4 4 5 5

0,423 0,624 0,806 0,936 1,11

0,116 0,18 0,28 0,29 0,38

0,005 0,008 0,012 0,012 0,016

140 000 130 000 120 000 110 000 95 000

85 000 80 000 75 000 67 000 60 000

0,0007 0,0017 0,0021 0,0031 0,0054

618/4 619/4 604 624 634

5

11 13 16 19

3 4 5 6

0,468 0,884 1,14 2,34

0,143 0,335 0,38 0,95

0,006 0,014 0,016 0,04

120 000 110 000 95 000 80 000

75 000 70 000 60 000 50 000

0,0012 0,0025 0,005 0,0085

618/5 619/5 * 625 * 635

6

13 15 19

3,5 5 6

0,715 0,884 2,34

0,224 0,27 0,95

0,01 0,011 0,04

110 000 100 000 80 000

67 000 63 000 50 000

0,002 0,0039 0,0081

618/6 619/6 * 626

7

14 17 19 22

3,5 5 6 7

0,78 1,06 2,34 3,45

0,26 0,375 0,95 1,37

0,011 0,016 0,04 0,057

100 000 90 000 85 000 70 000

63 000 56 000 53 000 45 000

0,0022 0,0049 0,0076 0,012

618/7 619/7 * 607 * 627

8

16 19 22 24

4 6 7 8

0,819 1,46 3,45 3,9

0,3 0,465 1,37 1,66

0,012 0,02 0,057 0,071

90 000 85 000 75 000 63 000

56 000 53 000 48 000 40 000

0,003 0,0071 0,012 0,018

618/8 619/8 * 608 * 628

9

17 20 24 26

4 6 7 8

0,871 2,34 3,9 4,75

0,34 0,98 1,66 1,96

0,014 0,043 0,071 0,083

85 000 80 000 70 000 60 000

53 000 50 000 43 000 38 000

0,0034 0,0076 0,014 0,02

618/9 619/9 * 609 * 629

10

19 22 26 28 30 35

5 6 8 8 9 11

1,72 2,7 4,75 5,07 5,4 8,52

0,83 1,27 1,96 2,36 2,36 3,4

0,036 0,054 0,083 0,1 0,1 0,143

80 000 70 000 67 000 60 000 56 000 50 000

48 000 45 000 40 000 38 000 36 000 32 000

0,0053 0,01 0,019 0,024 0,031 0,053

61800 61900 * 6000 16100 * 6200 * 6300

** SKF Explorer bearing

322

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



3

5,2

7,5

8,2

0,15

4,2

8,8

0,1

0,025

7,5

4

5,2 6,1 6,1 6,7 8,4

7,5 9 9,9 10,3 12

– 9,9 – 11,2 13,3

0,1 0,15 0,2 0,2 0,3

4,6 4,8 5,4 5,8 6,4

8,4 10,2 10,6 11,2 13,6

0,1 0,1 0,2 0,2 0,3

0,015 0,02 0,025 0,025 0,03

6,5 6,4 10 10 8,4

5

6,8 7,5 8,4 11,1

9,2 10,5 12 15,2

– 11,2 13,3 16,5

0,15 0,2 0,3 0,3

5,8 6,4 7,4 7,4

10,2 11,6 13,6 16,6

0,1 0,2 0,3 0,3

0,015 0,02 0,025 0,03

7,1 11 8,4 13

6

8 8,2 11,1

11 11,7 15,2

– 13 16,5

0,15 0,2 0,3

6,8 7,4 8,4

12,2 13,6 16,6

0,1 0,2 0,3

0,015 0,02 0,025

7 6,8 13

7

9 10,4 11,1 12,1

12 13,6 15,2 17,6

– 14,3 16,5 19,2

0,15 0,3 0,3 0,3

7,8 9 9 9,4

13,2 15 17 19,6

0,1 0,3 0,3 0,3

0,015 0,02 0,025 0,025

7,2 7,3 13 12

8

10,5 10,5 12,1 14,4

13,5 15,5 17,6 19,8

– 16,7 19,2 21,2

0,2 0,3 0,3 0,3

9,4 10 10 10,4

14,6 17 20 21,6

0,2 0,3 0,3 0,3

0,015 0,02 0,025 0,025

7,5 6,6 12 13

9

11,5 11,6 14,4 14,8

14,5 16,2 19,8 21,2

– 17,5 21,2 22,6

0,2 0,3 0,3 0,3

10,4 11 11 11,4

15,6 18 22 23,6

0,2 0,3 0,3 0,3

0,015 0,02 0,025 0,025

7,7 12 13 12

10

12,7 13,9 14,8 17 17 17,5

16,3 18,2 21,2 23,2 23,2 26,9

– – 22,6 24,8 24,8 28,7

0,3 0,3 0,3 0,3 0,6 0,6

12 12 12 14,2 14,2 14,2

17 20 24 23,8 25,8 30,8

0,3 0,3 0,3 0,3 0,6 0,6

0,015 0,02 0,025 0,025 0,025 0,03

15 14 12 13 13 11

323

1.1 Single row deep groove ball bearings d 12 – 22 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



12

21 24 28 30 32 37

5 6 8 8 10 12

1,74 2,91 5,4 5,07 7,28 10,1

0,915 1,46 2,36 2,36 3,1 4,15

0,039 0,062 0,1 0,1 0,132 0,176

70 000 67 000 60 000 60 000 50 000 45 000

43 000 40 000 38 000 38 000 32 000 28 000

0,0063 0,011 0,021 0,026 0,037 0,06

61801 61901 * 6001 16101 * 6201 * 6301

15

24 28 32 32 35 42

5 7 8 9 11 13

1,9 4,36 5,85 5,85 8,06 11,9

1,1 2,24 2,85 2,85 3,75 5,4

0,048 0,095 0,12 0,12 0,16 0,228

60 000 56 000 50 000 50 000 43 000 38 000

38 000 34 000 32 000 32 000 28 000 24 000

0,0065 0,016 0,03 0,03 0,045 0,082

* * * *

26 30 35 35

5 7 8 10

2,03 4,62 6,37 6,37

1,27 2,55 3,25 3,25

0,054 0,108 0,137 0,137

56 000 50 000 45 000 45 000

34 000 32 000 28 000 28 000

0,0075 0,016 0,038 0,038

61803 61903 * 16003 * 6003

40 40 47 62

12 12 14 17

9,95 11,4 14,3 22,9

4,75 5,4 6,55 10,8

0,2 0,228 0,275 0,455

38 000 38 000 34 000 28 000

24 000 24 000 22 000 18 000

0,065 0,064 0,11 0,27

* 6203 6203 ETN9 * 6303 6403

32 37 42 42

7 9 8 12

4,03 6,37 7,28 9,95

2,32 3,65 4,05 5

0,104 0,156 0,173 0,212

45 000 43 000 38 000 38 000

28 000 26 000 24 000 24 000

0,018 0,037 0,05 0,067

61804 61904 * 16004 * 6004

47 47 52 52 72

14 14 15 15 19

13,5 15,6 16,8 18,2 30,7

6,55 7,65 7,8 9 15

0,28 0,325 0,335 0,38 0,64

32 000 32 000 30 000 30 000 24 000

20 000 20 000 19 000 19 000 15 000

0,11 0,098 0,14 0,14 0,41

* 6204 6204 ETN9 * 6304 6304 ETN9 6404

50 56

14 16

14 18,6

7,65 9,3

0,325 0,39

30 000 28 000

19 000 18 000

0,13 0,18

17

20

22

** SKF Explorer bearing

324

61802 61902 16002 6002 6202 6302

62/22 63/22

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



12

14,8 16 17 17 18,4 19,5

18,3 20,3 23,2 23,4 25,7 29,5

– – 24,8 24,8 27,4 31,5

0,3 0,3 0,3 0,3 0,6 1

14 14 14 14,4 16,2 17,6

19 22 26 27,6 27,8 31,4

0,3 0,3 0,3 0,3 0,6 1

0,015 0,02 0,025 0,025 0,025 0,03

13 15 13 13 12 11

15

17,8 18,8 20,5 20,5 21,7 23,7

21,3 24,2 26,7 26,7 29 33,7

– 25,3 28,2 28,2 30,4 36,3

0,3 0,3 0,3 0,3 0,6 1

17 17 17 17 19,2 20,6

22 26 30 30 30,8 36,4

0,3 0,3 0,3 0,3 0,6 1

0,015 0,02 0,02 0,025 0,025 0,03

14 14 14 14 13 12

17

19,8 20,4 23 23

23,3 26,6 29,2 29,2

– 27,7 31,2 31,2

0,3 0,3 0,3 0,3

19 19 19 19

24 28 33 33

0,3 0,3 0,3 0,3

0,015 0,02 0,02 0,025

14 15 14 14

24,5 24,5 26,5 32,4

32,7 32,7 37,4 46,6

35 – 39,6 48,7

0,6 0,6 1 1,1

21,2 21,2 22,6 23,5

35,8 35,8 41,4 55,5

0,6 0,6 1 1

0,025 0,03 0,03 0,035

13 12 12 11

23,8 25,5 27,3 27,2

28,3 31,4 34,6 34,8

– 32,7 – 37,2

0,3 0,3 0,3 0,6

22 22 22 23,2

30 35 40 38,8

0,3 0,3 0,3 0,6

0,015 0,02 0,02 0,025

15 15 15 14

28,8 28,2 30,3 30,3 37,1

38,5 39,6 41,6 42,6 54,8

40,6 – 44,8 – –

1 1 1,1 1,1 1,1

25,6 25,6 27 27 29

41,4 41,4 45 45 63

1 1 1 1 1

0,025 0,025 0,03 0,03 0,035

13 12 12 12 11

32,2 32,9

41,8 45,3

44 –

1 1,1

27,6 29

44,4 47

1 1

0,025 0,03

14 12

20

22

325

1.1 Single row deep groove ball bearings d 25 – 35 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 25

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



37 42 47 47

7 9 8 12

4,36 7,02 8,06 11,9

2,6 4,3 4,75 6,55

0,125 0,193 0,212 0,275

38 000 36 000 32 000 32 000

24 000 22 000 20 000 20 000

0,022 0,045 0,06 0,078

61805 61905 * 16005 * 6005

52 52 62 62 80

15 15 17 17 21

14,8 17,8 23,4 26 35,8

7,8 9,8 11,6 13,4 19,3

0,335 0,4 0,49 0,57 0,815

28 000 28 000 24 000 24 000 20 000

18 000 18 000 16 000 16 000 13 000

0,13 0,12 0,23 0,22 0,54

* 6205 6205 ETN9 * 6305 6305 ETN9 6405

28

58 68

16 18

16,8 25,1

9,5 13,7

0,405 0,585

26 000 22 000

16 000 14 000

0,17 0,3

30

42 47 55 55

7 9 9 13

4,49 7,28 11,9 13,8

2,9 4,55 7,35 8,3

0,146 0,212 0,31 0,355

32 000 30 000 28 000 28 000

20 000 19 000 17 000 17 000

0,025 0,049 0,089 0,12

61806 61906 * 16006 * 6006

62 62 72 72 90

16 16 19 19 23

20,3 23,4 29,6 32,5 43,6

11,2 12,9 16 17,3 23,6

0,475 0,54 0,67 0,735 1

24 000 24 000 20 000 22 000 18 000

15 000 15 000 13 000 14 000 11 000

0,2 0,18 0,35 0,33 0,75

* 6206 6206 ETN9 * 6306 6306 ETN9 6406

47 55 62 62

7 10 9 14

4,36 10,8 13 16,8

3,35 7,8 8,15 10,2

0,14 0,325 0,375 0,44

30 000 26 000 24 000 24 000

18 000 16 000 15 000 15 000

0,029 0,08 0,11 0,15

61807 61907 * 16007 * 6007

72 72 80 100

17 17 21 25

27 31,2 35,1 55,3

15,3 17,6 19 31

0,655 0,75 0,815 1,29

20 000 20 000 19 000 16 000

13 000 13 000 12 000 10 000

0,29 0,26 0,46 0,97

* 6207 6207 ETN9 * 6307 6407

35

** SKF Explorer bearing

326

62/28 63/28

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm 25

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



28,5 30,2 33,3 32

33,2 36,8 40,7 40

– 37,7 – 42,2

0,3 0,3 0,3 0,6

27 27 27 28,2

35 40 45 43,8

0,3 0,3 0,3 0,6

0,015 0,02 0,02 0,025

14 15 15 14

34,3 33,1 36,6 36,3 45,4

44 44,5 50,4 51,7 62,9

46,3 – 52,7 – –

1 1 1,1 1,1 1,5

30,6 30,6 32 32 34

46,4 46,4 55 55 71

1 1 1 1 1,5

0,025 0,025 0,03 0,03 0,035

14 13 12 12 12

28

37 41,7

49 55,5

51,5 57,8

1 1,1

33,6 35

52,4 61

1 1

0,025 0,03

14 13

30

33,7 35,2 37,7 38,2

38,4 41,7 47,3 46,8

– 42,7 – 49

0,3 0,3 0,3 1

32 32 32 34,6

40 45 53 50,4

0,3 0,3 0,3 1

0,015 0,02 0,02 0,025

14 14 15 15

40,3 39,5 44,6 42,3 50,3

51,6 52,9 59,1 59,6 69,7

54,1 – 61,9 – –

1 1 1,1 1,1 1,5

35,6 35,6 37 37 41

56,4 56,4 65 65 79

1 1 1 1 1,5

0,025 0,025 0,03 0,03 0,035

14 13 13 12 12

38,2 42,2 44 43,7

42,8 50,1 53 53,3

– 52,2 – 55,7

0,3 0,6 0,3 1

37 38,2 37 39,6

45 51,8 60 57,4

0,3 0,6 0,3 1

0,015 0,02 0,02 0,025

14 16 14 15

46,9 46,1 49,5 57,4

60 61,7 65,4 79,6

62,7 – 69,2 –

1,1 1,1 1,5 1,5

42 42 44 46

65 65 71 89

1 1 1,5 1,5

0,025 0,025 0,03 0,035

14 13 13 12

35

327

1.1 Single row deep groove ball bearings d 40 – 55 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 40

45

50

55

kN

Mass

Designation

kN

r/min

kg



52 62 68 68

7 12 9 15

4,49 13,8 13,8 17,8

3,75 10 10,2 11

0,16 0,425 0,44 0,49

26 000 24 000 22 000 22 000

16 000 14 000 14 000 14 000

0,032 0,12 0,13 0,19

61808 61908 * 16008 * 6008

80 80 90 110

18 18 23 27

32,5 35,8 42,3 63,7

19 20,8 24 36,5

0,8 0,88 1,02 1,53

18 000 18 000 17 000 14 000

11 000 11 000 11 000 9 000

0,37 0,34 0,63 1,25

* 6208 6208 ETN9 * 6308 6408

58 68 75 75

7 12 10 16

6,63 14 16,5 22,1

6,1 10,8 10,8 14,6

0,26 0,465 0,52 0,64

22 000 20 000 20 000 20 000

14 000 13 000 12 000 12 000

0,04 0,14 0,17 0,24

61809 61909 * 16009 * 6009

85 100 120

19 25 29

35,1 55,3 76,1

21,6 31,5 45

0,915 1,34 1,9

17 000 15 000 13 000

11 000 9 500 8 500

0,42 0,84 1,55

* 6209 * 6309 6409

65 72 80 80

7 12 10 16

6,76 14,6 16,8 22,9

6,8 11,8 11,4 16

0,285 0,5 0,56 0,71

20 000 19 000 18 000 18 000

13 000 12 000 11 000 11 000

0,052 0,14 0,18 0,26

61810 61910 * 16010 * 6010

90 110 130

20 27 31

37,1 65 87,1

23,2 38 52

0,98 1,6 2,2

15 000 13 000 12 000

10 000 8 500 7 500

0,45 1,1 1,95

* 6210 * 6310 6410

72 80 90 90

9 13 11 18

9,04 16,5 20,3 29,6

8,8 14 14 21,2

0,375 0,6 0,695 0,9

19 000 17 000 16 000 16 000

12 000 11 000 10 000 10 000

0,083 0,19 0,27 0,39

61811 61911 * 16011 * 6011

100 120 140

21 29 33

46,2 74,1 99,5

29 45 62

1,25 1,9 2,6

14 000 12 000 11 000

9 000 8 000 7 000

0,61 1,35 2,35

* 6211 * 6311 6411

** SKF Explorer bearing

328

C0

Speed ratings Reference Limiting speed speed

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm 40

45

50

55

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



43,2 46,9 49,4 49,2

48,1 55,1 58,6 58,8

– – – 61,1

0,3 0,6 0,3 1

42 43,2 42 44,6

50 58,8 66 63,4

0,3 0,6 0,3 1

0,015 0,02 0,02 0,025

15 16 16 15

52,6 52 56,1 62,8

67,4 68,8 73,8 87

69,8 – 77,7 –

1,1 1,1 1,5 2

47 47 49 53

73 73 81 97

1 1 1,5 2

0,025 0,025 0,03 0,035

14 13 13 12

49,1 52,4 55 54,7

53,9 60,6 65 65,3

– – – 67,8

0,3 0,6 0,6 1

47 48,2 48,2 50,8

56 64,8 71,8 69,2

0,3 0,6 0,6 1

0,015 0,02 0,02 0,025

17 16 14 15

57,6 62,1 68,9

72,4 82,7 95,9

75,2 86,7 –

1,1 1,5 2

52 54 58

78 91 107

1 1,5 2

0,025 0,03 0,035

14 13 12

55,1 56,9 60 59,7

59,9 65,1 70 70,3

– – – 72,8

0,3 0,6 0,6 1

52 53,2 53,2 54,6

63 68,8 76,8 75,4

0,3 0,6 0,6 1

0,015 0,02 0,02 0,025

17 16 14 15

62,5 68,7 75,4

77,4 91,1 105

81,7 95,2 –

1,1 2 2,1

57 61 64

83 99 116

1 2 2

0,025 0,03 0,035

14 13 12

60,6 63,2 67 66,3

66,4 71,8 78,1 78,7

– – – 81,5

0,3 1 0,6 1,1

57 59,6 58,2 61

70 75,4 86,8 84

0,3 1 0,6 1

0,015 0,02 0,02 0,025

17 16 14 15

69 75,3 81,5

85,8 99,5 114

89,4 104 –

1,5 2 2,1

64 66 69

91 109 126

1,5 2 2

0,025 0,03 0,035

14 13 12

329

1.1 Single row deep groove ball bearings d 60 – 75 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 60

65

70

75

kN

Mass

Designation

kN

r/min

kg



78 85 95 95

10 13 11 18

11,9 16,5 20,8 30,7

11,4 14,3 15 23,2

0,49 0,6 0,735 0,98

17 000 16 000 15 000 15 000

11 000 10 000 9 500 9 500

0,11 0,2 0,29 0,41

61812 61912 * 16012 * 6012

110 130 150

22 31 35

55,3 85,2 108

36 52 69,5

1,53 2,2 2,9

13 000 11 000 10 000

8 000 7 000 6 300

0,78 1,7 2,85

* 6212 * 6312 6412

85 90 100 100

10 13 11 18

12,4 17,4 22,5 31,9

12,7 16 19,6 25

0,54 0,68 0,83 1,06

16 000 15 000 14 000 14 000

10 000 9 500 9 000 9 000

0,13 0,22 0,3 0,44

61813 61913 * 16013 * 6013

120 140 160

23 33 37

58,5 97,5 119

40,5 60 78

1,73 2,5 3,15

12 000 10 000 9 500

7 500 6 700 6 000

1 2,1 3,35

* 6213 * 6313 6413

90 100 110 110

10 16 13 20

12,4 23,8 29,1 39,7

13,2 21,2 25 31

0,56 0,9 1,06 1,32

15 000 14 000 13 000 13 000

9 000 8 500 8 000 8 000

0,14 0,35 0,44 0,61

61814 61914 * 16014 * 6014

125 150 180

24 35 42

63,7 111 143

45 68 104

1,9 2,75 3,9

11 000 9 500 8 500

7 000 6 300 5 300

1,1 2,55 4,95

* 6214 * 6314 6414

95 105 115 115

10 16 13 20

12,7 24,2 30,2 41,6

14,3 22,4 27 33,5

0,61 0,965 1,14 1,43

14 000 13 000 12 000 12 000

8 500 8 000 7 500 7 500

0,15 0,37 0,46 0,65

61815 61915 * 16015 * 6015

130 160 190

25 37 45

68,9 119 153

49 76,5 114

2,04 3 4,15

10 000 9 000 8 000

6 700 5 600 5 000

1,2 3,05 5,8

* 6215 * 6315 6415

** SKF Explorer bearing

330

C0

Speed ratings Reference Limiting speed speed

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm 60

65

70

75

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



65,6 68,2 72 71,3

72,4 76,8 83 83,7

– – – 86,5

0,3 1 0,6 1,1

62 64,6 63,2 66

76 80,4 91,8 89

0,3 1 0,6 1

0,015 0,02 0,02 0,025

17 16 14 16

75,5 81,8 88,1

94,6 108 122

98 113 –

1,5 2,1 2,1

69 72 74

101 118 136

1,5 2 2

0,025 0,03 0,035

14 13 12

71,6 73,2 76,5 76,3

78,4 81,8 88,4 88,7

– – – 91,5

0,6 1 0,6 1,1

68,2 69,6 68,2 71

81,8 85,4 96,8 94

0,6 1 0,6 1

0,015 0,02 0,02 0,025

17 17 16 16

83,3 88,3 94

103 117 131

106 122 –

1,5 2,1 2,1

74 77 79

111 128 146

1,5 2 2

0,025 0,03 0,035

15 13 12

76,6 79,7 83,3 82,8

83,4 90,3 96,8 97,2

– – – 99,9

0,6 1 0,6 1,1

73,2 74,6 73,2 76

86,8 95,4 106 104

0,6 1 0,6 1

0,015 0,02 0,02 0,025

17 16 16 16

87 94,9 103

108 125 146

111 130 –

1,5 2,1 3

79 82 86

116 138 164

1,5 2 2,5

0,025 0,03 0,035

15 13 12

81,6 84,7 88,3 87,8

88,4 95,3 102 103

– – – 105

0,6 1 0,6 1,1

78,2 79,6 78,2 81

91,8 100 111 109

0,6 1 0,6 1

0,015 0,02 0,02 0,025

17 17 16 16

92 101 110

113 134 155

117 139 –

1,5 2,1 3

84 87 91

121 148 174

1,5 2 2,5

0,025 0,03 0,035

15 13 12

331

1.1 Single row deep groove ball bearings d 80 – 100 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 80

85

90

95

100

kN

Mass

Designation

kN

r/min

kg



100 110 125 125

10 16 14 22

13 25,1 35,1 49,4

15 20,4 31,5 40

0,64 1,02 1,32 1,66

13 000 12 000 11 000 11 000

8 000 7 500 7 000 7 000

0,15 0,38 0,61 0,87

61816 61916 * 16016 * 6016

140 170 200

26 39 48

72,8 130 163

55 86,5 125

2,2 3,25 4,5

9 500 8 500 7 500

6 000 5 300 4 800

1,45 3,65 6,85

* 6216 * 6316 6416

110 120 130 130

13 18 14 22

19,5 31,9 35,8 52

20,8 30 33,5 43

0,88 1,25 1,37 1,76

12 000 11 000 11 000 11 000

7 500 7 000 6 700 6 700

0,27 0,55 0,64 0,92

61817 61917 * 16017 * 6017

150 180 210

28 41 52

87,1 140 174

64 96,5 137

2,5 3,55 4,75

9 000 8 000 7 000

5 600 5 000 4 500

1,8 4,25 8,05

* 6217 * 6317 6417

115 125 140 140

13 18 16 24

19,5 33,2 43,6 60,5

22 31,5 39 50

0,915 1,29 1,56 1,96

11 000 11 000 10 000 10 000

7 000 6 700 6 300 6 300

0,28 0,59 0,85 1,15

61818 61918 * 16018 * 6018

160 190 225

30 43 54

101 151 186

73,5 108 150

2,8 3,8 5

8 500 7 500 6 700

5 300 4 800 4 300

2,2 4,95 9,8

* 6218 * 6318 6418

120 130 145 145 170 200

13 18 16 24 32 45

19,9 33,8 44,9 63,7 114 159

22,8 33,5 41,5 54 81,5 118

0,93 1,34 1,63 2,08 3 4,15

11 000 10 000 9 500 9 500 8 000 7 000

6 700 6 300 6 000 6 000 5 000 4 500

0,3 0,61 0,89 1,1 2,65 5,75

* * * *

125 140 150 150 180 215

13 20 16 24 34 47

17,8 42,3 46,2 63,7 127 174

18,3 41,5 44 54 93 140

0,95 1,63 1,7 2,04 3,35 4,75

10 000 9 500 9 500 9 500 7 500 6 700

6 300 6 000 5 600 5 600 4 800 4 300

0,31 0,83 0,94 1,25 3,15 7,1

61820 61920 * 16020 * 6020 * 6220 6320

** SKF Explorer bearing

332

C0

Speed ratings Reference Limiting speed speed

61819 61919 16019 6019 6219 6319

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm 80

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



86,6 89,8 95,3 94,4

93,4 101 110 111

– 103 – 115

0,6 1 0,6 1,1

83,2 84,6 83,2 86

96,8 105 121 119

0,6 1 0,6 1

0,015 0,02 0,02 0,025

17 14 16 16

101 108 116

123 142 163

127 147 –

2 2,1 3

91 92 96

129 158 184

2 2 2,5

0,025 0,03 0,035

15 13 12

93,2 96,4 100 99,4

102 109 115 116

– – – 120

1 1,1 0,6 1,1

89,6 91 88,2 92

105 114 126 123

1 1 0,6 1

0,015 0,02 0,02 0,025

17 16 17 16

106 114 123

130 151 172

135 156 –

2 3 4

96 99 105

139 166 190

2 2,5 3

0,025 0,03 0,035

15 13 12

98,2 101 106 105

107 114 124 125

– – – 129

1 1,1 1 1,5

94,6 96 94,6 97

110 119 135 133

1 1 1 1,5

0,015 0,02 0,02 0,025

17 17 16 16

112 121 132

138 159 181

143 164 –

2 3 4

101 104 110

149 176 205

2 2,5 3

0,025 0,03 0,035

15 13 13

95

103 106 111 111 118 127

112 119 129 130 147 168

– – – 134 152 172

1 1,1 1 1,5 2,1 3

99,6 101 99,6 102 107 109

115 124 140 138 158 186

1 1 1 1,5 2 2,5

0,015 0,02 0,02 0,025 0,025 0,03

17 17 16 16 14 13

100

108 112 116 115 124 135

117 128 134 135 155 180

– – – 139 160 184

1 1,1 1 1,5 2,1 3

105 106 105 107 112 114

120 134 145 143 168 201

1 1 1 1,5 2 2,5

0,015 0,02 0,02 0,025 0,025 0,03

13 16 17 16 14 13

85

90

333

1.1 Single row deep groove ball bearings d 105 – 140 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



105

130 145 160 160 190 225

13 20 18 26 36 49

20,8 44,2 54 76,1 140 182

19,6 44 51 65,5 104 153

1 1,7 1,86 2,4 3,65 5,1

10 000 9 500 8 500 8 500 7 000 6 300

6 300 5 600 5 300 5 300 4 500 4 000

0,32 0,87 1,2 1,6 3,8 8,15

61821 61921 * 16021 * 6021 * 6221 6321

110

140 150 170 170 200 240

16 20 19 28 38 50

28,1 43,6 60,5 85,2 151 203

26 45 57 73,5 118 180

1,25 1,66 2,04 2,6 4 5,7

9 500 9 000 8 000 8 000 6 700 6 000

5 600 5 600 5 000 5 000 4 300 3 800

0,49 0,9 1,45 1,95 4,45 9,65

61822 61922 * 16022 * 6022 * 6222 6322

120

150 165 180 180 215 260

16 22 19 28 40 55

29,1 55,3 63,7 88,4 146 208

28 57 64 80 118 186

1,29 2,04 2,2 2,75 3,9 5,7

8 500 8 000 7 500 7 500 6 300 5 600

5 300 5 000 4 800 4 800 4 000 3 400

0,54 1,2 1,55 2,1 5,25 12,5

61824 61924 * 16024 * 6024 6224 6324

130

165 180 200 200

18 24 22 33

37,7 65 83,2 112

43 67 81,5 100

1,6 2,28 2,7 3,35

8 000 7 500 7 000 7 000

4 800 4 500 4 300 4 300

0,77 1,6 2,35 3,25

61826 61926 * 16026 * 6026

230 280 280

40 58 58

156 229 229

132 216 216

4,15 6,3 6,3

5 600 5 000 5 000

3 600 3 200 4 500

5,85 15 17,5

6226 6326 6326 M

175 190 190 210 210

18 24 24 22 33

39 66,3 66,3 80,6 111

46,5 72 72 86,5 108

1,66 2,36 2,36 2,8 3,45

7 500 7 000 7 000 6 700 6 700

4 500 4 300 5 600 4 000 4 000

0,85 1,7 2 2,55 3,45

61828 61928 61928 MA 16028 6028

250 300 300

42 62 62

165 251 251

150 245 245

4,55 7,1 7,1

5 300 4 800 4 800

3 400 3 000 4 300

7,75 18,5 21,5

6228 6328 6328 M

140

** SKF Explorer bearing

334

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



105

112 117 123 122 131 141

123 133 142 143 164 188

– – – 147 167 –

1 1,1 1 2 2,1 3

110 111 110 116 117 119

125 139 155 149 178 211

1 1 1 2 2 2,5

0,015 0,02 0,02 0,025 0,025 0,03

13 17 16 16 14 13

110

118 122 130 129 138 149

132 138 150 151 172 200

– – – 156 177 –

1 1,1 1 2 2,1 3

115 116 115 119 122 124

135 144 165 161 188 226

1 1 1 2 2 2,5

0,015 0,02 0,02 0,025 0,025 0,03

14 17 16 16 14 13

120

128 134 139 139 150 164

142 151 161 161 185 215

– – – 166 190 –

1 1,1 1 2 2,1 3

125 126 125 129 132 134

145 159 175 171 203 246

1 1 1 2 2 2,5

0,015 0,02 0,02 0,025 0,025 0,03

14 17 17 16 14 14

130

140 145 153 152

155 164 176 177

– – – 182

1,1 1,5 1,1 2

136 137 136 139

159 173 192 191

1 1,5 1 2

0,015 0,02 0,02 0,025

16 16 16 16

160 177 177

198 232 232

– – –

3 4 4

144 147 147

216 263 263

2,5 3 3

0,025 0,03 0,03

15 14 14

150 156 156 163 162

164 174 175 186 188

– – – – 192

1,1 1,5 1,5 1,1 2

146 147 147 146 149

169 183 183 204 201

1 1,5 1,5 1 2

0,015 0,02 0,02 0,02 0,025

16 15 17 17 16

175 190 190

213 249 249

– – –

3 4 4

154 157 157

236 283 283

2,5 3 3

0,025 0,03 0,03

15 14 14

140

335

1.1 Single row deep groove ball bearings d 150 – 180 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



150

190 210 225 225 270 320 320

20 28 24 35 45 65 65

48,8 88,4 92,3 125 174 276 276

61 93 98 125 166 285 285

1,96 2,9 3,05 3,9 4,9 7,8 7,8

6 700 6 300 6 000 6 000 5 000 4 300 4 300

4 300 5 300 3 800 3 800 3 200 2 800 4 000

1,2 3,05 3,15 4,3 10 23 26

61830 61930 MA 16030 6030 6230 6330 6330 M

160

200 220 220 240 240

20 28 28 25 38

49,4 92,3 92,3 99,5 143

64 98 98 108 143

2 3,05 3,05 3,25 4,3

6 300 6 000 6 000 5 600 5 600

4 000 3 800 5 000 3 600 3 600

1,25 2,7 3,2 3,65 5,2

61832 61932 61932 MA 16032 6032

290 340 340

48 68 68

186 276 276

186 285 285

5,3 7,65 7,65

4 500 4 000 4 000

3 000 2 600 3 800

13 26 30,5

6232 6332 6332 M

215 230 260 260 260

22 28 28 42 42

61,8 93,6 119 168 168

78 106 129 173 173

2,4 3,15 3,75 5 5

6 000 5 600 5 300 5 300 5 300

3 600 4 800 3 200 3 200 4 300

1,65 3,4 5 7 8,15

61834 61934 MA 16034 6034 6034 M

310 310 360 360

52 52 72 72

212 212 312 312

224 224 340 340

6,1 6,1 8,8 8,8

4 300 4 300 3 800 3 800

2 800 3 800 2 400 3 400

16 18 31 36

6234 6234 M 6334 6334 M

225 250 250 280 280 280

22 33 33 31 46 46

62,4 119 119 138 190 190

81,5 134 134 146 200 200

2,45 3,9 3,9 4,15 5,6 5,6

5 600 5 300 5 300 4 800 4 800 4 800

3 400 3 200 4 300 3 000 3 000 4 000

1,75 5 5 6,5 9,1 10,5

61836 61936 61936 MA 16036 6036 6036 M

320 320 380 380

52 52 75 75

229 229 351 351

240 240 405 405

6,4 6,4 10,4 10,4

4 000 4 000 3 600 3 600

2 600 3 800 2 200 3 200

42 18,5 36,5 42

6236 6236 M 6336 6336 M

170

180

336

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



150

162 169 174 174 190 205 205

178 191 200 200 228 264 264

– – – 206 – – –

1,1 2 1,1 2,1 3 4 4

156 159 156 160 164 167 167

184 201 219 215 256 303 303

1 2 1 2 2,5 3 3

0,015 0,02 0,02 0,025 0,025 0,03 0,03

17 16 17 16 15 14 14

160

172 179 179 185 185

188 201 202 214 215

– – – – 219

1,1 2 2 1,5 2,1

166 169 169 167 169

194 211 211 233 231

1 2 2 1,5 2

0,015 0,02 0,02 0,02 0,025

17 17 17 17 16

205 218 218

243 281 281

– – –

3 4 4

174 177 177

276 323 323

2,5 3 3

0,025 0,03 0,03

15 14 14

184 189 200 198 198

202 212 229 232 232

– – – – –

1,1 2 1,5 2,1 2,1

176 179 177 180 180

209 221 253 250 250

1 2 1,5 2 2

0,015 0,02 0,02 0,025 0,025

17 17 16 16 16

218 218 230 230

259 259 299 299

– – – –

4 4 4 4

187 187 187 187

293 293 343 343

3 3 3 3

0,025 0,025 0,03 0,03

15 15 14 14

194 202 202 213 212 212

211 228 229 246 248 248

– – – – – –

1,1 2 2 2 2,1 2,1

186 189 189 189 190 190

219 241 241 271 270 270

1 2 2 2 2 2

0,015 0,02 0,02 0,02 0,025 0,025

17 17 17 16 16 16

226 226 244 244

274 274 315 315

– – – –

4 4 4 4

197 197 197 197

303 303 363 363

3 3 3 3

0,025 0,025 0,03 0,03

15 15 14 14

170

180

337

1.1 Single row deep groove ball bearings d 190 – 240 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 190

200

220

240

338

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



240 260 260 290 290 290

24 33 33 31 46 46

76,1 117 117 148 195 195

98 134 134 166 216 216

2,8 3,8 3,8 4,55 5,85 5,85

5 300 5 000 5 000 4 800 4 800 4 800

3 200 3 200 4 300 3 000 3 000 3 800

2,25 4,5 5,2 6,9 9,55 11

61838 61938 61938 MA 16038 6038 6038 M

340 340 400 400

55 55 78 78

255 255 371 371

280 280 430 430

7,35 7,35 10,8 10,8

3 800 3 800 3 400 3 400

2 400 3 400 2 200 3 000

19,5 22 42 48,5

6238 6238 M 6338 6338 M

250 280 280

24 38 38

76,1 148 148

102 166 166

2,9 4,55 4,55

5 000 4 800 4 800

3 200 3 000 3 800

2,35 6,3 7,3

61840 61940 61940 MA

310 310 310 360 360

34 51 51 58 58

168 216 216 270 270

190 245 245 310 310

5,1 6,4 6,4 7,8 7,8

4 300 4 300 4 300 3 600 3 600

2 800 2 800 3 600 2 200 3 200

8,8 12,5 14,5 23,5 26,5

16040 6040 6040 M 6240 6240 M

270 300 300

24 38 38

78 151 151

110 180 180

3 4,75 4,75

4 500 4 300 4 300

2 800 2 600 3 600

2,55 6,8 7,95

61844 61944 61944 MA

340 340 340 400 400

37 56 56 65 65

174 247 247 296 296

204 290 290 365 365

5,2 7,35 7,35 8,8 8,8

4 000 4 000 4 000 3 200 3 200

2 400 2 400 3 200 2 000 3 000

11,5 16 19 33,5 37

16044 6044 6044 M 6244 6244 M

300 320 320

28 38 38

108 159 159

150 200 200

3,8 5,1 5,1

4 000 4 000 4 000

2 600 2 400 3 200

3,9 7,3 8,55

61848 61948 61948 MA

360 360 360 360 500

37 37 56 56 95

203 203 255 255 442

255 255 315 315 585

6,3 6,3 7,8 7,8 12,9

3 600 3 600 3 600 3 600 2 600

2 200 3 000 2 200 3 000 2 400

12,5 14 17 20,5 92,5

16048 16048 MA 6048 6048 M 6348 M

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm 190

200

220

240

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



206 212 212 223 222 222

224 238 239 256 258 258

1,5 2 2 2 2,1 2,1

197 199 199 199 200 200

233 251 251 281 280 280

1,5 2 2 2 2 2

0,015 0,02 0,02 0,02 0,025 0,025

17 17 17 16 16 16

239 239 259 259

249 290 331 331

4 4 5 5

207 207 210 210

323 323 380 380

3 3 4 4

0,025 0,025 0,03 0,03

15 15 14 14

216 225 225

234 255 256

1,5 2,1 2,1

207 210 210

243 270 270

1,5 2 2

0,015 0,02 0,02

17 16 16

237 235 235 254 254

273 275 275 303 303

2 2,1 2,1 4 4

209 210 210 217 217

301 300 300 343 343

2 2 2 3 3

0,02 0,025 0,025 0,025 0,025

16 16 16 15 15

236 245 245

254 275 276

1,5 2,1 2,1

227 230 230

263 290 290

1,5 2 2

0,015 0,02 0,02

17 17 17

261 258 258 282 282

298 302 302 335 335

2,1 3 3 4 4

230 233 233 237 237

330 327 327 383 383

2 2,5 2,5 3 3

0,02 0,025 0,025 0,025 0,025

17 16 16 15 15

259 265 265

281 295 296

2 2,1 2,1

249 250 250

291 310 310

2 2 2

0,015 0,02 0,02

17 17 17

279 279 277 277 330

318 321 322 322 411

2,1 2,1 3 3 5

250 250 253 253 260

350 350 347 347 480

2 2 2,5 2,5 4

0,02 0,02 0,025 0,025 0,03

17 17 16 16 15

339

1.1 Single row deep groove ball bearings d 260 – 360 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 260

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



320 360 360

28 46 46

111 212 212

163 270 270

4 6,55 6,55

3 800 3 600 3 600

2 400 2 200 3 000

4,15 12 14,5

61852 61952 61952 MA

400 400 400 400

44 44 65 65

238 238 291 291

310 310 375 375

7,2 7,2 8,8 8,8

3 200 3 200 3 200 3 200

2 000 2 800 2 000 2 800

18 22,5 25 30

16052 16052 MA 6052 6052 M

350 380 380

33 46 46

138 216 216

200 285 285

4,75 6,7 6,7

3 400 3 200 3 200

2 200 2 000 2 800

6,25 12 15,5

61856 61956 61956 MA

420 420 420 420

44 44 65 65

242 242 302 302

335 335 405 405

7,5 7,5 9,3 9,3

3 000 3 000 3 000 3 000

1 900 2 600 1 900 2 600

19 24 26 31,5

16056 16056 MA 6056 6056 M

300

380 380 420 420 540

38 38 56 56 85

172 172 270 270 462

245 245 375 375 670

5,6 5,6 8,3 8,3 13,7

3 200 3 200 3 000 3 000 2 400

2 000 2 600 1 900 2 400 2 000

8,9 10,5 19 24,5 88,5

61860 61860 MA 61960 61960 MA 6260 M

320

400 400 480 480

38 38 50 74

172 172 281 371

255 255 405 540

5,7 5,7 8,65 11,4

3 000 3 000 2 600 2 600

1 900 2 400 2 200 2 200

9,5 11 34 46

61864 61864 MA 16064 MA 6064 M

340

420 420 520 520

38 38 57 82

178 178 345 423

275 275 520 640

6 6 10,6 13,2

2 800 2 800 2 400 2 400

1 800 2 400 2 000 2 000

10 11,5 45 62

61868 61868 MA 16068 MA 6068 M

360

440 480 540 540

38 56 57 82

182 291 351 442

285 450 550 695

6,1 9,15 11 14

2 600 2 600 1 800 2 400

2 200 2 000 1 400 1 900

12 28 49 64,5

61872 MA 61972 MA 16072 MA 6072 M

280

340

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm 260

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



279 291 291

301 329 330

2 2,1 2,1

269 270 270

311 350 350

2 2 2

0,015 0,02 0,02

17 17 17

307 307 304 304

351 353 356 356

3 3 4 4

273 273 277 277

387 387 383 383

2,5 2,5 3 3

0,02 0,02 0,025 0,025

16 16 16 16

302 311 311

327 349 350

2 2,1 2,1

289 291 291

341 369 369

2 2 2

0,015 0,02 0,02

17 17 17

327 327 324 324

371 374 376 376

3 3 4 4

293 293 296 296

407 407 404 404

2,5 2,5 3 3

0,02 0,02 0,025 0,025

17 17 16 16

300

325 325 338 338 383

355 356 382 384 457

2,1 2,1 3 3 5

309 309 313 313 320

371 371 407 407 520

2 2 2,5 2,5 4

0,015 0,015 0,02 0,02 0,025

17 17 16 16 15

320

345 345 372 370

375 376 428 431

2,1 2,1 4 4

332 332 335 335

388 388 465 465

2 2 3 3

0,015 0,015 0,02 0,025

17 17 17 16

340

365 365 398 397

395 396 462 463

2,1 2,1 4 5

352 352 355 360

408 408 505 500

2 2 3 4

0,015 0,015 0,02 0,025

17 17 16 16

360

385 398 418 416

415 443 482 485

2,1 3 4 5

372 373 375 378

428 467 525 522

2 2,5 3 4

0,015 0,02 0,02 0,025

17 17 16 16

280

341

1.1 Single row deep groove ball bearings d 380 – 600 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



380

480 520 560 560

46 65 57 82

242 338 377 436

390 540 620 695

8 10,8 12,2 13,7

2 400 2 400 1 700 2 200

2 000 1 900 1 400 1 800

20 40 51 70,5

61876 MA 61976 MA 16076 MA 6076 M

400

500 540 600

46 65 90

247 345 520

405 570 865

8,15 11,2 16,3

2 400 2 200 2 000

1 900 1 800 1 700

20,5 41,5 87,5

61880 MA 61980 MA 6080 M

420

520 560 620

46 65 90

251 351 507

425 600 880

8,3 11,4 16,3

2 200 2 200 2 000

1 800 1 800 1 600

21,5 43 91,5

61884 MA 61984 MA 6084 M

440

540 600 650

46 74 94

255 410 553

440 720 965

8,5 13,2 17,6

2 200 2 000 1 900

1 800 1 600 1 500

22,5 60,5 105

61888 MA 61988 MA 6088 M

460

580 620 680

56 74 100

319 423 582

570 750 1 060

10,6 13,7 19

2 000 1 900 1 800

1 600 1 600 1 500

35 62,5 120

61892 MA 61992 MA 6092 MB

480

600 650 700

56 78 100

325 449 618

600 815 1 140

10,8 14,6 20

1 900 1 800 1 700

1 600 1 500 1 400

36,5 74 125

61896 MA 61996 MA 6096 MB

500

620 670 720

56 78 100

332 462 605

620 865 1 140

11,2 15 19,6

1 800 1 700 1 600

1 500 1 400 1 300

40,5 77 135

618/500 MA 619/500 MA 60/500 N1MAS

530

650 710 780

56 82 112

332 488 650

655 930 1 270

11,2 15,6 20,8

1 700 1 600 1 500

1 400 1 300 1 200

39,5 90,5 185

618/530 MA 619/530 MA 60/530 N1MAS

560

680 750 820

56 85 115

345 494 663

695 980 1 370

11,8 16,3 22

1 600 1 500 1 400

1 300 1 200 1 200

42 105 210

618/560 MA 619/560 MA 60/560 N1MAS

600

730 800

60 90

364 585

765 1 220

12,5 19,6

1 500 1 400

1 200 1 100

52 125

618/600 MA 619/600 MA

342

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



380

412 425 443 437

449 476 497 503

2,1 4 4 5

392 395 395 400

468 505 545 540

2 3 3 4

0,015 0,02 0,02 0,025

17 17 17 16

400

432 445 463

471 496 537

2,1 4 5

412 415 418

488 525 582

2 3 4

0,015 0,02 0,025

17 17 16

420

452 465 482

491 516 557

2,1 4 5

432 435 438

508 545 602

2 3 4

0,015 0,02 0,025

17 17 16

440

472 492 506

510 549 584

2,1 4 6

452 455 463

528 585 627

2 3 5

0,015 0,02 0,025

17 17 16

460

498 511 528

542 569 614

3 4 6

473 476 483

567 604 657

2,5 3 5

0,015 0,02 0,025

17 17 16

480

518 535 550

564 595 630

3 5 6

493 498 503

587 632 677

2,5 4 5

0,015 0,02 0,025

17 17 16

500

538 555 568

582 617 650

3 5 6

513 518 523

607 652 697

2,5 4 5

0,015 0,02 0,025

17 17 16

530

568 587 612

613 653 700

3 5 6

543 548 553

637 692 757

2,5 4 5

0,015 0,02 0,025

17 17 16

560

598 622 648

644 689 732

3 5 6

573 578 583

667 732 797

2,5 4 5

0,015 0,02 0,025

17 17 16

600

642 663

688 736

3 5

613 618

717 782

2,5 4

0,015 0,02

18 17

343

1.1 Single row deep groove ball bearings d 630 – 1 180 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



630

780 850 920

69 100 128

442 624 819

965 1 340 1 760

15,3 21,2 27

1 400 1 300 1 200

1 100 1 100 1 000

73 160 285

618/630 MA 619/630 N1MA 60/630 N1MBS

670

820 900 980

69 103 136

442 676 904

1 000 1 500 2 040

15,6 22,4 30

1 300 1 200 1 100

1 100 1 000 900

83,5 185 345

618/670 MA 619/670 MA 60/670 N1MAS

710

870 950 1 030

74 106 140

475 663 956

1 100 1 500 2 200

16,6 22 31,5

1 200 1 100 1 000

1 000 900 850

93,5 220 375

618/710 MA 619/710 MA 60/710 MA

750

920 1 000

78 112

527 761

1 250 1 800

18,3 25,5

1 100 1 000

900 850

110 255

618/750 MA 619/750 MA

800

980 1 060 1 150

82 115 155

559 832 1 010

1 370 2 040 2 550

19,3 28,5 34,5

1 000 950 900

850 800 750

130 275 535

618/800 MA 619/800 MA 60/800 N1MAS

850

1 030 1 120

82 118

559 832

1 430 2 160

19,6 29

950 850

750 750

140 310

618/850 MA 619/850 MA

1 000

1 220

100

637

1 800

22,8

750

600

245

618/1000 MA

1 060

1 280

100

728

2 120

26,5

670

560

260

618/1060 MA

1 120

1 360

106

741

2 200

26,5

630

530

315

618/1120 MA

1 180

1 420

106

761

2 360

27,5

560

480

330

618/1180 MB

344

1.1

ra ra

Da

da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



630

678 702 725

732 778 825

4 6 7,5

645 653 658

765 827 892

3 5 6

0,015 0,02 0,025

17 17 16

670

718 745 772

772 825 878

4 6 7,5

685 693 698

805 877 952

3 5 6

0,015 0,02 0,025

17 17 16

710

761 790 813

818 870 927

4 6 7,5

725 733 738

855 927 1 002

3 5 6

0,015 0,02 0,025

17 17 16

750

804 835

866 915

5 6

768 773

902 977

4 5

0,015 0,02

17 17

800

857 884 918

922 976 1 032

5 6 7,5

818 823 828

962 1 037 1 122

4 5 6

0,015 0,02 0,025

17 17 16

850

907 939

972 1 031

5 6

868 873

1 012 1 097

4 5

0,015 0,02

18 17

1 000

1 076

1 145

6

1 023

1 197

5

0,015

18

1 060

1 132

1 209

6

1 083

1 257

5

0,015

18

1 120

1 201

1 278

6

1 143

1 337

5

0,015

18

1 180

1 262

1 339

6

1 203

1 397

5

0,015

18

345

1.2 Capped single row deep groove ball bearings d 3 – 7 mm

B

r1

r2

r1

r2 d2

d d1

D D2

2Z Principal dimensions d

D

B

mm

2RSL

2RZ

2RS1

2RSH

2RS1

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

Designations Bearing capped on both sides

kN

r/min

kg



one side

3

10 10

4 4

0,54 0,54

0,18 0,18

0,007 0,007

130 000 –

60 000 40 000

0,0015 0,0015

623-2Z 623-2RS1

623-Z 623-RS1

4

9 9 11 12 13

3,5 4 4 4 5

0,54 0,54 0,624 0,806 0,936

0,18 0,18 0,18 0,28 0,29

0,07 0,07 0,008 0,012 0,012

140 000 140 000 130 000 120 000 110 000

70 000 70 000 63 000 60 000 53 000

0,001 0,0013 0,0017 0,0021 0,0031

628/4-2Z 638/4-2Z 619/4-2Z 604-2Z 624-2Z

– – – 604-Z 624-Z

16 16 16

5 5 5

1,11 1,11 1,11

0,38 0,38 0,38

0,016 0,016 0,016

95 000 95 000 –

48 000 48 000 28 000

0,0054 0,0054 0,0054

634-2Z 634-2RZ 634-2RS1

634-Z 634-RZ 634-RS1

11 11 13 16 16

4 5 4 5 5

0,64 0,64 0,884 1,14 1,14

0,26 0,26 0,335 0,38 0,38

0,011 0,011 0,014 0,016 0,016

120 000 120 000 110 000 104 000 95 000

60 000 60 000 56 000 55 000 48 000

0,0014 0,0016 0,0025 0,005 0,005

628/5-2Z 638/5-2Z 619/5-2Z E2.625-2Z * 625-2Z

– – – – * 625-Z

19 19 19 19

6 6 6 6

2,21 2,34 2,34 2,34

0,95 0,95 0,95 0,95

0,04 0,04 0,04 0,04

90 000 80 000 80 000 –

47 000 40 000 40 000 24 000

0,009 0,0093 0,009 0,009

E2.635-2Z * 635-2Z * 635-2RZ * 635-2RS1

– * 635-Z * 635-RZ * 635-RS1

6

13 15 19 19 19 19

5 5 6 6 6 6

0,88 0,884 2,21 2,34 2,34 2,34

0,35 0,27 0,95 0,95 0,95 0,95

0,015 0,011 0,04 0,04 0,04 0,04

110 000 100 000 90 000 80 000 80 000 –

53 000 50 000 47 000 40 000 40 000 24 000

0,0026 0,0039 0,0084 0,0084 0,0084 0,0084

628/6-2Z 619/6-2Z E2.626-2Z * 626-2Z * 626-2RSL * 626-2RSH

– – – * 626-Z * 626-RSL * 626-RSH

7

14 17

5 5

0,956 1,06

0,4 0,375

0,017 0,016

100 000 90 000

50 000 45 000

0,0031 0,0049

628/7-2Z 619/7-2Z

19 19 19 19

6 6 6 6

2,21 2,34 2,34 2,34

0,95 0,95 0,95 0,95

0,04 0,04 0,04 0,04

90 000 85 000 85 000 –

47 000 43 000 43 000 24 000

0,008 0,0084 0,0078 0,0078

E2.607-2Z * 607-2Z * 607-2RSL * 607-2RSH

5

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

346

– – – * 607-Z * 607-RSL * 607-RSH

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



3

5,2 5,2

– –

8,2 8,2

0,15 0,15

4,2 4,2

5,1 5,1

8,8 8,8

0,1 0,1

0,025 0,025

7,5 7,5

4

5,2 5,2 6,1 6,1 6,7

– – – – –

8,1 8,1 9,9 9,8 11,2

0,1 0,1 0,15 0,2 0,2

4,6 4,6 4,8 5,4 5,8

5,1 5,1 5,8 6 6,6

8,4 8,4 10,2 10,6 11,2

0,1 0,1 0,1 0,2 0,2

0,015 0,015 0,02 0,025 0,025

10 10 6,4 10 7,3

8,4 8,4 8,4

– – –

13,3 13,3 13,3

0,3 0,3 0,3

6,4 6,4 6,4

8,3 8,3 8,3

13,6 13,6 13,6

0,3 0,3 0,3

0,03 0,03 0,03

8,4 8,4 8,4

6,8 – 7,5 8,4 8,4

– 6,2 – – –

9,9 9,9 11,2 13,3 13,3

0,15 0,15 0,2 0,3 0,3

5,8 5,8 6,4 7,4 7,4

6,7 6 7,5 8,3 8,3

10,2 10,2 11,6 13,6 13,6

0,1 0,1 0,2 0,3 0,3

0,015 0,015 0,02 0,025 0,025

11 11 11 8,4 8,4

11,1 11,1 11,1 11,1

– – – –

16,5 16,5 16,5 16,5

0,3 0,3 0,3 0,3

7,4 7,4 7,4 7,4

10,6 10,6 10,6 10,6

16,6 16,6 16,6 16,6

0,3 0,3 0,3 0,3

0,03 0,03 0,03 0,03

13 13 13 13

6

– 8,2 11,1 11,1 – –

7,4 – – – 9,5 9,5

11,7 13 16,5 16,5 16,5 16,5

0,15 0,2 0,3 0,3 0,3 0,3

6,8 7,4 8,4 8,4 8,4 8,4

7,2 8 11 11 9,4 9,4

12,2 13,6 16,6 16,6 16,6 16,6

0,1 0,2 0,3 0,3 0,3 0,3

0,015 0,02 0,025 0,025 0,025 0,025

11 6,8 13 13 13 13

7

– 10,4

8,5 –

12,7 14,3

0,15 0,3

7,8 9

8 9,7

13,2 15

0,1 0,3

0,015 0,02

11 7,3

11,1 11,1 – –

– – 9,5 9,5

16,5 16,5 16,5 16,5

0,3 0,3 0,3 0,3

9 9 9 9

11 11 9,4 9,4

17 17 17 17

0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025

13 13 13 13

5

347

1.2 Capped single row deep groove ball bearings d 7 – 9 mm

B

r1

r2

r1

r2 d2

d d1

D D2

2Z Principal dimensions d

D

B

mm

2RSL

2RZ

2RS1

2RSH

2RS1

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side

– E2.627-2Z * 627-2Z * 627-2RSL * 627-2RSH

– * 627-Z * 627-RSL * 627-RSH

22 7 cont. 22 22 22

7 7 7 7

3,32 3,45 3,45 3,45

1,37 1,37 1,37 1,37

0,06 0,057 0,057 0,057

80 000 70 000 70 000 –

42 000 36 000 36 000 22 000

0,013 0,013 0,013 0,013

8

16 16 16 19 19 19

5 5 6 6 6 6

1,33 1,33 1,33 1,46 1,46 2,34

0,57 0,57 0,57 0,465 0,465 0,95

0,024 0,024 0,024 0,02 0,02 0,04

90 000 – 90 000 85 000 – 85 000

45 000 26 000 45 000 43 000 24 000 43 000

0,0036 0,0036 0,0043 0,0071 0,0071 0,0072

22 22 22 22 22

7 7 7 7 11

3,32 3,45 3,45 3,45 3,45

1,37 1,37 1,37 1,37 1,37

0,06 0,057 0,057 0,057 0,057

80 000 75 000 75 000 – –

42 000 38 000 38 000 22 000 22 000

0,012 0,013 0,012 0,012 0,016

E2.608-2Z * 608-2Z * 608-2RSL * 608-2RSH 630/8-2RS1

– * 608-Z * 608-RSL * 608-RSH –

24 24 24 24 28

8 8 8 8 6

3,71 3,9 3,9 3,9 1,33

1,66 1,66 1,66 1,66 0,57

0,072 0,071 0,071 0,071 0,024

75 000 63 000 63 000 – 60 000

37 000 32 000 32 000 19 000 30 000

0,017 0,018 0,017 0,017 0,03

E2.628-2Z * 628-2Z * 628-2RZ * 628-2RS1 638-2RZ

– * 628-Z * 628-RZ * 628-RS1 638-RZ

17 17 20

5 5 6

1,43 1,43 2,34

0,64 0,64 0,98

0,027 0,027 0,043

85 000 – 80 000

43 000 24 000 40 000

0,0043 0,0043 0,0076

24 24 24 24

7 7 7 7

3,71 3,9 3,9 3,9

1,66 1,66 1,66 1,66

0,072 0,071 0,071 0,071

75 000 70 000 70 000 –

37 000 34 000 34 000 19 000

0,014 0,015 0,014 0,014

E2.609-2Z * 609-2Z * 609-2RSL * 609-2RSH

– * 609-Z * 609-RSL * 609-RSH

26 26 26 26

8 8 8 8

4,62 4,75 4,75 4,75

1,93 1,96 1,96 1,96

0,08 0,083 0,083 0,083

70 000 60 000 60 000 –

36 000 30 000 30 000 19 000

0,02 0,021 0,02 0,02

E2.629-2Z * 629-2Z * 629-2RSL * 629-2RSH

– * 629-Z * 629-RSL * 629-RSH

9

628/8-2Z 628/8-2RS1 638/8-2Z 619/8-2Z 619/8-2RS1 607/8-2Z

628/9-2Z 628/9-2RS1 619/9-2Z

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

348

– – – – – 607/8-Z

628/9-Z – –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



7 cont.

12,1 12,1 – –

– – 10,5 10,5

19,2 19,2 19,2 19,2

0,3 0,3 0,3 0,3

9,4 9,4 9,4 9,4

12,1 12,1 10,5 10,5

19,6 19,6 19,6 19,6

0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025

12 12 12 12

8

10,1 10,1 – – – 11,1

– – 9,6 9,8 9,8 –

14,2 14,2 14,2 16,7 16,7 16,5

0,2 0,2 0,2 0,3 0,3 0,3

9,4 9,4 9,4 9,5 9,5 10

10 9,4 9,5 9,8 9,8 11

14,6 14,6 14,6 17 17 17

0,2 0,2 0,2 0,3 0,3 0,3

0,015 0,015 0,015 0,02 0,02 0,025

11 11 11 6,6 6,6 13

12,1 12,1 – – 11,8

– – 10,5 10,5 –

19,2 19,2 19,2 19,2 19

0,3 0,3 0,3 0,3 0,3

10 10 10 10 10

12 12 10,5 10,5 11,7

20 20 20 20 20

0,3 0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025 0,025

12 12 12 12 12

14,4 14,4 14,4 14,4 14,8

– – – – –

21,2 21,2 21,2 21,2 22,6

0,3 0,3 0,3 0,3 0,3

10,4 10,4 10,4 10,4 10,4

14,4 14,4 14,4 14,4 14,7

21,6 21,6 21,6 21,6 25,6

0,3 0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025 0,03

13 13 13 13 12

– – 11,6

10,7 10,7 –

15,2 15,2 17,5

0,2 0,2 0,3

10,4 10,4 11

10,5 10,5 11,5

15,6 15,6 18

0,2 0,2 0,3

0,015 0,015 0,02

11 11 12

14,4 14,4 – –

– – 12,8 12,8

21,2 21,2 21,2 21,2

0,3 0,3 0,3 0,3

11 11 11 11

14,3 14,3 12,5 12,5

22 22 22 22

0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025

13 13 13 13

14,8 14,8 – –

– – 13 13

22,6 22,6 22,6 22,6

0,3 0,3 0,3 0,3

11,4 11,4 11,4 11,4

14,7 14,7 12,5 12,5

23,6 23,6 23,6 23,6

0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025

12 12 12 12

9

349

1.2 Capped single row deep groove ball bearings d 10 – 12 mm

B

r1

r2

r1

r2 2RSL

d2

d d1

D D2

2RS1

2RS1

2RSH

2Z Principal dimensions d

D

B

mm 10

12

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

Designations Bearing capped on both sides

kN

r/min

kg

– 61800-2Z 61800-2RS1 61900-2Z 61900-2RS1

– – – –

19 19 22 22

5 5 6 6

1,72 1,72 2,7 2,7

0,83 0,83 1,27 1,27

0,036 0,036 0,054 0,054

80 000 – 70 000 –

38 000 22 000 36 000 20 000

0,0055 0,0055 0,01 0,01

26 26 26 26 26 28

8 8 8 8 12 8

4,62 4,75 4,75 4,75 4,62 5,07

1,93 1,96 1,96 1,96 1,96 2,36

0,08 0,083 0,083 0,083 0,083 0,1

70 000 67 000 67 000 – – 60 000

36 000 34 000 34 000 19 000 19 000 30 000

0,019 0,02 0,019 0,019 0,025 0,026

E2.6000-2Z * 6000-2Z * 6000-2RSL * 6000-2RSH 63000-2RS1 16100-2Z

– * 6000-Z * 6000-RSL * 6000-RSH – –

30 30 30 30 30

9 9 9 9 14

5,07 5,4 5,4 5,4 5,07

2,32 2,36 2,36 2,36 2,36

0,098 0,1 0,1 0,1 0,1

61 000 56 000 56 000 – –

32 000 28 000 28 000 17 000 17 000

0,032 0,034 0,032 0,032 0,04

E2.6200-2Z * 6200-2Z * 6200-2RSL * 6200-2RSH 62200-2RS1

– * 6200-Z * 6200-RSL * 6200-RSH –

35 35 35 35 35

11 11 11 11 17

8,32 8,52 8,52 8,52 8,06

3,4 3,4 3,4 3,4 3,4

0,143 0,143 0,143 0,143 0,143

55 000 50 000 50 000 – –

29 000 26 000 26 000 15 000 15 000

0,053 0,055 0,053 0,053 0,06

E2.6300-2Z * 6300-2Z * 6300-2RSL * 6300-2RSH 62300-2RS1

– * 6300-Z * 6300-RSL * 6300-RSH –

21 21 24 24

5 5 6 6

1,74 1,74 2,91 2,91

0,915 0,915 1,46 1,46

0,039 0,039 0,062 0,062

70 000 – 67 000 –

36 000 20 000 32 000 19 000

0,0063 0,0063 0,011 0,011

28 28 28 28 28

8 8 8 8 12

5,07 5,4 5,4 5,4 5,07

2,32 2,36 2,36 2,36 2,36

0,098 0,1 0,1 0,1 0,1

66 000 60 000 60 000 – –

33 000 30 000 30 000 17 000 17 000

0,022 0,022 0,021 0,021 0,029

E2.6001-2Z * 6001-2Z * 6001-2RSL * 6001-2RSH 63001-2RS1

30 30

8 8

5,07 5,07

2,36 2,36

0,1 0,1

60 000 –

30 000 16 000

0,028 0,028

16101-2Z 16101-2RS1

61801-2Z 61801-2RS1 61901-2Z 61901-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

350

one side

– – – – – * 6001-Z * 6001-RSL * 6001-RSH – – –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 10

12

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



12,7 – 13,9 –

– 11,8 – 13,2

17,2 17,2 19,4 19,4

0,3 0,3 0,3 0,3

12 11,8 12 12

12,5 11,8 12,9 12

17 17 20 20

0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02

15 15 14 14

14,8 14,8 – – 14,8 17

– – 13 13 – –

22,6 22,6 22,6 22,6 22,6 24,8

0,3 0,3 0,3 0,3 0,3 0,3

12 12 12 12 12 14,2

14,7 14,7 12,5 12,5 14,7 16,6

24 24 24 24 24 23,8

0,3 0,3 0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025 0,025 0,025

12 12 12 12 12 13

17 17 – – 17

– – 15,2 15,2 –

24,8 24,8 24,8 24,8 24,8

0,6 0,6 0,6 0,6 0,6

14,2 14,2 14,2 14,2 14,2

16,9 16,9 15 15 16,9

25,8 25,8 25,8 25,8 25,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

13 13 13 13 13

17,5 17,5 – – 17,5

– – 15,7 15,7 –

28,7 28,7 28,7 28,7 28,7

0,6 0,6 0,6 0,6 0,6

14,2 14,2 14,2 14,2 14,2

17,4 17,4 15,5 15,5 17,4

30,8 30,8 30,8 30,8 30,8

0,6 0,6 0,6 0,6 0,6

0,03 0,03 0,03 0,03 0,03

11 11 11 11 11

14,8 – 16 –

– 13,8 – 15,3

19,2 19,2 21,4 21,4

0,3 0,3 0,3 0,3

14 13,6 14 14

14,7 13,8 15,8 15,2

19 19 22 22

0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02

13 13 15 15

17 17 – – 17

– – 15,2 15,2 –

24,8 24,8 24,8 24,8 24,8

0,3 0,3 0,3 0,3 0,3

14 14 14 14 14

16,9 16,9 15 15 16,9

26 26 26 26 26

0,3 0,3 0,3 0,3 0,3

0,025 0,025 0,025 0,025 0,025

13 13 13 13 13

17 16,7

– –

24,8 24,8

0,3 0,3

14,4 14,4

16,6 16,6

27,6 27,6

0,3 0,3

0,025 0,025

13 13

351

1.2 Capped single row deep groove ball bearings d 12 – 15 mm

B

r1

r2

r1

r2 d2

d d1

D D2

2Z Principal dimensions d

D

B

mm

2RSL

2RZ

2RS1

2RSH

2RS1

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side



32 12 cont. 32 32 32 32

10 10 10 10 14

7,02 7,28 7,28 7,28 6,89

3,1 3,1 3,1 3,1 3,1

0,132 0,132 0,132 0,132 0,132

55 000 50 000 50 000 – –

29 000 26 000 26 000 15 000 15 000

0,037 0,039 0,038 0,038 0,045

E2.6201-2Z * 6201-2Z * 6201-2RSL * 6201-2RSH 62201-2RS1

– * 6201-Z * 6201-RSL * 6201-RSH –

37 37 37 37

12 12 12 12

9,95 10,1 10,1 10,1

4,15 4,15 4,15 4,15

0,176 0,176 0,176 0,176

49 000 45 000 45 000 –

25 000 22 000 22 000 14 000

0,06 0,063 0,06 0,06

E2.6301-2Z * 6301-2Z * 6301-2RSL * 6301-2RSH

– * 6301-Z * 6301-RSL * 6301-RSH

24 24 28 28 28

5 5 7 7 7

1,9 1,9 4,36 4,36 4,36

1,1 1,1 2,24 2,24 2,24

0,048 0,048 0,095 0,095 0,095

60 000 – 56 000 56 000 –

30 000 17 000 28 000 28 000 16 000

0,0074 0,0074 0,016 0,016 0,016

32 32 32 32 32 32

8 9 9 9 9 13

5,85 5,53 5,85 5,85 5,85 5,59

2,85 2,75 2,85 2,85 2,85 2,85

0,12 0,118 0,12 0,12 0,12 0,12

50 000 55 000 50 000 50 000 – –

26 000 28 000 26 000 26 000 14 000 14 000

0,025 0,03 0,032 0,03 0,03 0,039

* 16002-2Z E2.6002-2Z * 6002-2Z * 6002-2RSL * 6002-2RSH 63002-2RS1

* 16002-Z – * 6002-Z * 6002-RSL * 6002-RSH –

35 35 35 35 35

11 11 11 11 14

7,8 8,06 8,06 8,06 7,8

3,75 3,75 3,75 3,75 3,75

0,16 0,16 0,16 0,16 0,16

47 000 43 000 43 000 – –

25 000 22 000 22 000 13 000 13 000

0,045 0,048 0,046 0,046 0,054

E2.6202-2Z * 6202-2Z * 6202-2RSL * 6202-2RSH 62202-2RS1

– * 6202-Z * 6202-RSL * 6202-RSH –

42 42 42 42 42

13 13 13 13 17

11,4 11,9 11,9 11,9 11,4

5,3 5,4 5,4 5,4 5,4

0,224 0,228 0,228 0,228 0,228

41 000 38 000 38 000 – –

21 000 19 000 19 000 12 000 12 000

0,083 0,086 0,085 0,085 0,11

E2.6302-2Z * 6302-2Z * 6302-2RSL * 6302-2RSH 62302-2RS1

– * 6302-Z * 6302-RSL * 6302-RSH –

15

61802-2Z 61802-2RS1 61902-2Z 61902-2RZ 61902-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

352

– – – – –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 12 cont.

15

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



18,4 18,4 – – 18,5

– – 16,6 16,6 –

27,4 27,4 27,4 27,4 27,4

0,6 0,6 0,6 0,6 0,6

16,2 16,2 16,2 16,2 16,2

18,4 18,4 16,5 16,5 18,4

27,8 27,8 27,8 27,8 27,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

12 12 12 12 12

19,5 19,5 – –

– – 17,7 17,7

31,5 31,5 31,5 31,5

1 1 1 1

17,6 17,6 17,6 17,6

19,4 19,4 17,6 17,6

31,4 31,4 31,4 31,4

1 1 1 1

0,03 0,03 0,03 0,03

11 11 11 11

17,8 17,8 18,8 18,8 18,8

– – – – –

22,2 22,2 25,3 25,3 25,3

0,3 0,3 0,3 0,3 0,3

17 17 17 17 17

17,8 17,8 18,3 18,3 18,3

22 22 26 26 26

0,3 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02

14 14 14 14 14

20,5 20,5 20,5 – – 20,5

– – – 18,7 18,7 –

28,2 28,2 28,2 28,2 28,2 28,2

0,3 0,3 0,3 0,3 0,3 0,3

17 17 17 17 17 17

20,1 20,4 20,4 18,5 18,5 20,4

30 30 30 30 30 30

0,3 0,3 0,3 0,3 0,3 0,3

0,02 0,025 0,025 0,025 0,025 0,025

14 14 14 14 14 14

21,7 21,7 – – 21,7

– – 19,4 19,4 –

30,4 30,4 30,4 30,4 30,4

0,6 0,6 0,6 0,6 0,6

19,2 19,2 19,2 19,2 19,2

21,6 21,6 19,4 19,4 21,6

30,8 30,8 30,8 30,8 30,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

13 13 13 13 13

23,7 23,7 – – 23,7

– – 21,1 21,1 –

36,3 36,3 36,3 36,3 36,3

1 1 1 1 1

20,6 20,6 20,6 20,6 20,6

23,6 23,6 21 21 23,6

36,4 36,4 36,4 36,4 36,4

1 1 1 1 1

0,03 0,03 0,03 0,03 0,03

12 12 12 12 12

353

1.2 Capped single row deep groove ball bearings d 17 – 20 mm

B

r1

r2

r1

r2 d2

d d1

D D2

2Z Principal dimensions d

D

B

mm 17

20

2RSL

2RZ

2RS1

2RSH

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

Designations Bearing capped on both sides

kN

r/min

kg

– 61803-2Z 61803-2RZ 61803-2RS1 61903-2Z 61903-2RZ 61903-2RS1

one side

– – – – – –

26 26 26 30 30 30

5 5 5 7 7 7

2,03 2,03 2,03 4,62 4,62 4,62

1,27 1,27 1,27 2,55 2,55 2,55

0,054 0,054 0,054 0,108 0,108 0,108

56 000 56 000 – 50 000 50 000 –

28 000 28 000 16 000 26 000 26 000 14 000

0,0082 0,0082 0,0082 0,017 0,018 0,017

35 35 35 35 35 35

8 10 10 10 10 14

6,37 5,85 6,37 6,37 6,37 6,05

3,25 3 3,25 3,25 3,25 3,25

0,137 0,127 0,137 0,137 0,137 0,137

45 000 49 000 45 000 45 000 – –

22 000 25 000 22 000 22 000 13 000 13 000

0,032 0,039 0,041 0,039 0,039 0,052

* 16003-2Z E2.6003-2Z * 6003-2Z * 6003-2RSL * 6003-2RSH 63003-2RS1

– – * 6003-Z * 6003-RSL * 6003-RSH –

40 40 40 40 40

12 12 12 12 16

9,56 9,95 9,95 9,95 9,56

4,75 4,75 4,75 4,75 4,75

0,2 0,2 0,2 0,2 0,2

41 000 38 000 38 000 – –

21 000 19 000 19 000 12 000 12 000

0,065 0,068 0,067 0,067 0,089

E2.6203-2Z * 6203-2Z * 6203-2RSL * 6203-2RSH 62203-2RS1

– * 6203-Z * 6203-RSL * 6203-RSH –

47 47 47 47 47

14 14 14 14 19

13,8 14,3 14,3 14,3 13,5

6,55 6,55 6,55 6,55 6,55

0,275 0,275 0,275 0,275 0,275

37 000 34 000 34 000 – –

19 000 17 000 17 000 11 000 11 000

0,12 0,12 0,12 0,12 0,16

E2.6303-2Z * 6303-2Z * 6303-2RSL * 6303-2RSH 62303-2RS1

– * 6303-Z * 6303-RSL * 6303-RSH –

32 32 37 37

7 7 9 9

4,03 4,03 6,37 6,37

2,32 2,32 3,65 3,65

0,104 0,104 0,156 0,156

45 000 – 43 000 –

22 000 13 000 20 000 12 000

0,018 0,018 0,038 0,038

61804-2RZ 61804-2RS1 61904-2RZ 61904-2RS1

42 42 42 42 42

12 12 12 12 16

9,36 9,95 9,95 9,95 9,36

5 5 5 5 5

0,212 0,212 0,212 0,212 0,212

41 000 38 000 38 000 – –

21 000 19 000 19 000 11 000 11 000

0,069 0,071 0,067 0,067 0,086

E2.6004-2Z * 6004-2Z * 6004-2RSL * 6004-2RSH 63004-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

354

2RS1

– – – – – * 6004-Z * 6004-RSL * 6004-RSH –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 17

20

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



19,8 19,8 – 20,4 20,4 –

– – 18,8 – – 19,4

24,2 24,2 24,2 27,7 27,7 27,7

0,3 0,3 0,3 0,3 0,3 0,3

19 19 18 19 19 19

19,6 19,6 18,6 20,3 20,3 19,3

24 24 24 28 28 28

0,3 0,3 0,3 0,3 0,3 0,3

0,015 0,015 0,015 0,02 0,02 0,02

14 14 14 15 15 15

23 23 23 – – 23

– – – 20,7 20,7 –

31,2 31,2 31,2 31,2 31,2 31,2

0,3 0,3 0,3 0,3 0,3 0,3

19 19 19 19 19 19

22,6 22,9 22,9 20,5 20,5 22,9

33 33 33 33 33 33

0,3 0,3 0,3 0,3 0,3 0,3

0,02 0,025 0,025 0,025 0,025 0,025

14 14 14 14 14 14

24,5 24,5 – – 24,5

– – 22,2 22,2 –

35 35 35 35 35

0,6 0,6 0,6 0,6 0,6

21,2 21,2 21,2 21,2 21,2

24,4 24,4 22 22 24,4

35,8 35,8 35,8 35,8 35,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

13 13 13 13 13

26,5 26,5 – – 26,5

– – 24 24 –

39,6 39,6 39,6 39,6 39,6

1 1 1 1 1

22,6 22,6 22,6 22,6 22,6

26,4 26,4 23,5 23,5 26,4

41,4 41,4 41,4 41,4 41,4

1 1 1 1 1

0,03 0,03 0,03 0,03 0,03

12 12 12 12 12

23,8 23,8 25,5 –

– – – 23,1

29,4 29,4 32,7 32,7

0,3 0,3 0,3 0,3

22 22 22 22

23,6 23,6 25,5 23

30 30 35 35

0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02

15 15 15 15

27,2 27,2 – – 27,2

– – 24,9 24,9 –

37,2 37,2 37,2 37,2 37,2

0,6 0,6 0,6 0,6 0,6

23,2 23,2 23,2 23,2 23,2

27,1 27,1 24,5 24,5 27,1

38,8 38,8 38,8 38,8 38,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

14 14 14 14 14

355

1.2 Capped single row deep groove ball bearings d 20 – 25 mm

B

r1

r2

r1

r2 d2

d d1

D D2

2Z Principal dimensions d

D

B

mm

2RSL

2RZ

2RS1

2RSH

2RS1

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side



47 20 cont. 47 47 47 47

14 14 14 14 18

12,7 13,5 13,5 13,5 12,7

6,55 6,55 6,55 6,55 6,55

0,28 0,28 0,28 0,28 0,28

35 000 32 000 32 000 – –

19 000 17 000 17 000 10 000 10 000

0,11 0,11 0,11 0,11 0,13

E2.6204-2Z * 6204-2Z * 6204-2RSL * 6204-2RSH 62204-2RS1

– * 6204-Z * 6204-RSL * 6204-RSH –

52 52 52 52 52

15 15 15 15 21

16,3 16,8 16,8 16,8 15,9

7,8 7,8 7,8 7,8 7,8

0,34 0,335 0,335 0,335 0,335

34 000 30 000 30 000 – –

18 000 15 000 15 000 9 500 9 500

0,15 0,15 0,15 0,15 0,21

E2.6304-2Z * 6304-2Z * 6304-2RSL * 6304-2RSH 62304-2RS1

– * 6304-Z * 6304-RSL * 6304-RSH –

22

50

14

14

7,65

0,325



9 000

0,12

62/22-2RS1



25

37 37 42 42

7 7 9 9

4,36 4,36 7,02 7,02

2,6 2,6 4,3 4,3

0,125 0,125 0,193 0,193

38 000 – 36 000 –

19 000 11 000 18 000 10 000

0,022 0,022 0,045 0,045

61805-2RZ 61805-2RS1 61905-2RZ 61905-2RS1

– – – –

47 47 47 47 47

12 12 12 12 16

11,1 11,9 11,9 11,9 11,2

6,1 6,55 6,55 6,55 6,55

0,26 0,275 0,275 0,275 0,275

35 000 32 000 32 000 – –

18 000 16 000 16 000 9 500 9 500

0,08 0,083 0,08 0,08 0,11

E2.6005-2Z * 6005-2Z * 6005-2RSL * 6005-2RSH 63005-2RS1

– * 6005-Z * 6005-RSL * 6005-RSH –

52 52 52 52 52

15 15 15 15 18

13,8 14,8 14,8 14,8 14

7,65 7,8 7,8 7,8 7,8

0,325 0,335 0,335 0,335 0,335

30 000 28 000 28 000 – –

16 000 14 000 14 000 8 500 8 500

0,13 0,13 0,13 0,13 0,15

E2.6205-2Z * 6205-2Z * 6205-2RSL * 6205-2RSH 62205-2RS1

– * 6205-Z * 6205-RSL * 6205-RSH –

62 62 62 62 62

17 17 17 17 24

22,9 23,4 23,4 23,4 22,5

11,6 11,6 11,6 11,6 11,6

0,49 0,49 0,49 0,49 0,49

28 000 24 000 24 000 – –

15 000 13 000 13 000 7 500 7 500

0,23 0,23 0,23 0,23 0,32

E2.6305-2Z * 6305-2Z * 6305-2RZ * 6305-2RS1 62305-2RS1

– * 6305-Z * 6305-RZ * 6305-RS1 –

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

356

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 20 cont.

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



28,8 28,8 – – 28,8

– – 26,3 26,3 –

40,6 40,6 40,6 40,6 40,6

1 1 1 1 1

25,6 25,6 25,6 25,6 25,6

28,7 28,7 26 26 28,7

41,4 41,4 41,4 41,4 41,4

1 1 1 1 1

0,025 0,025 0,025 0,025 0,025

13 13 13 13 13

30,3 30,3 – – 30,3

– – 27,2 27,2 –

44,8 44,8 44,8 44,8 44,8

1,1 1,1 1,1 1,1 1,1

27 27 27 27 27

30,3 30,3 27 27 30,3

45 45 45 45 45

1 1 1 1 1

0,03 0,03 0,03 0,03 0,03

12 12 12 12 12

22

32,2



44

1

27,6

32

44,4

1

0,025

14

25

28,5 – 30,2 30,2

– 27,4 – –

34,2 34,2 37,7 37,7

0,3 0,3 0,3 0,3

27 27 27 27

28,4 27,3 30,1 30,1

35 35 40 40

0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02

14 14 15 15

32 32 – – 32

– – 29,7 29,7 –

42,2 42,2 42,2 42,2 42,2

0,6 0,6 0,6 0,6 0,6

28,2 28,2 28,2 28,2 29,2

31,9 31,9 29,5 29,5 31,9

43,8 43,8 43,8 43,8 43,8

0,6 0,6 0,6 0,6 0,6

0,025 0,025 0,025 0,025 0,025

14 14 14 14 14

34,3 34,3 – – 34,4

– – 31,8 31,8 –

46,3 46,3 46,3 46,3 46,3

1 1 1 1 1

30,6 30,6 30,6 30,6 30,6

34,3 34,3 31,5 31,5 34,3

46,4 46,4 46,4 46,4 46,4

1 1 1 1 1

0,025 0,025 0,025 0,025 0,025

14 14 14 14 14

36,6 36,6 36,6 36,6 36,6

– – – – –

52,7 52,7 52,7 52,7 52,7

1,1 1,1 1,1 1,1 1,1

32 32 32 32 32

36,5 36,5 36,5 36,5 36,5

55 55 55 55 55

1 1 1 1 1

0,03 0,03 0,03 0,03 0,03

12 12 12 12 12

357

1.2 Capped single row deep groove ball bearings d 30 – 35 mm

B

r1

r2

r1

r2

2Z Principal dimensions d

D

B

mm 30

35

2RS1

2RZ

d2

d d1

D D2

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

Designations Bearing capped on both sides

kN

r/min

kg

– 61806-2RZ 61806-2RS1 61906-2RZ 61906-2RS1

one side

– – – –

42 42 47 47

7 7 9 9

4,49 4,49 7,28 7,28

2,9 2,9 4,55 4,55

0,146 0,146 0,212 0,212

32 000 – 30 000 –

16 000 9 500 15 000 8 500

0,025 0,025 0,05 0,05

55 55 55 55 55

13 13 13 13 19

12,7 13,8 13,8 13,8 13,3

7,35 8,3 8,3 8,3 8,3

0,31 0,355 0,355 0,355 0,355

30 000 28 000 28 000 – –

15 000 14 000 14 000 8 000 8 000

0,12 0,12 0,12 0,12 0,17

E2.6006-2Z * 6006-2Z * 6006-2RZ * 6006-2RS1 63006-2RS1

– * 6006-Z * 6006-RZ * 6006-RS1 –

62 62 62 62 62

16 16 16 16 20

19,5 20,3 20,3 20,3 19,5

11,2 11,2 11,2 11,2 11,2

0,475 0,475 0,475 0,475 0,475

26 000 24 000 24 000 – –

14 000 12 000 12 000 7 500 7 500

0,2 0,2 0,2 0,2 0,25

E2.6206-2Z * 6206-2Z * 6206-2RZ * 6206-2RS1 62206-2RS1

– * 6206-Z * 6206-RZ * 6206-RS1 –

72 72 72 72 72

19 19 19 19 27

28,6 29,6 29,6 29,6 28,1

16 16 16 16 16

0,67 0,67 0,67 0,67 0,67

22 000 20 000 20 000 – –

12 000 11 000 11 000 6 300 6 300

0,36 0,36 0,36 0,36 0,5

E2.6306-2Z * 6306-2Z * 6306-2RZ * 6306-2RS1 62306-2RS1

– * 6306-Z * 6306-RZ * 6306-RS1 –

47 47 55 55

7 7 10 10

4,36 4,36 10,8 10,8

3,35 3,35 7,8 7,8

0,14 0,14 0,325 0,325

30 000 – 26 000 –

15 000 8 500 13 000 7 500

0,03 0,022 0,08 0,08

62 62 62 62

14 14 14 20

16,8 16,8 16,8 15,9

10,2 10,2 10,2 10,2

0,44 0,44 0,44 0,44

24 000 24 000 – –

12 000 12 000 7 000 7 000

0,16 0,16 0,16 0,23

* 6007-2Z * 6007-2RZ * 6007-2RS1 63007-2RS1

* 6007-Z * 6007-RZ * 6007-RS1 –

72 72 72 72

17 17 17 23

25,5 27 27 25,5

15,3 15,3 15,3 15,3

0,64 0,655 0,655 0,655

22 000 20 000 – –

12 000 10 000 6 300 6 300

0,3 0,3 0,3 0,4

E2.6207-2Z * 6207-2Z * 6207-2RS1 62207-2RS1

– * 6207-Z * 6207-RS1 –

61807-2RZ 61807-2RS1 61907-2RZ 61907-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

358

2RS1

– – – –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 30

35

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



33,7 – 35,2 –

– 32,6 – 34,2

39,4 39,4 42,7 42,7

0,3 0,3 0,3 0,3

32 32 32 32

33,6 32,5 35,1 34

40 40 45 45

0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02

14 14 14 14

38,2 38,2 38,2 38,2 38,2

– – – – –

49 49 49 49 49

1 1 1 1 1

34,6 34,6 34,6 34,6 34,6

38,1 38,1 38,1 38,1 38,1

50,4 50,4 50,4 50,4 50,4

1 1 1 1 1

0,025 0,025 0,025 0,025 0,025

15 15 15 15 15

40,3 40,3 40,3 40,3 40,3

– – – – –

54,1 54,1 54,1 54,1 54,1

1 1 1 1 1

35,6 35,6 35,6 35,6 35,6

40,3 40,3 40,3 40,3 40,3

56,4 56,4 56,4 56,4 56,4

1 1 1 1 1

0,025 0,025 0,025 0,025 0,025

14 14 14 14 14

44,6 44,6 44,6 44,6 44,6

– – – – –

61,9 61,9 61,9 61,9 61,9

1,1 1,1 1,1 1,1 1,1

37 37 37 37 37

44,5 44,5 44,5 44,5 44,5

65 65 65 65 65

1 1 1 1 1

0,03 0,03 0,03 0,03 0,03

13 13 13 13 13

38,2 38,2 42,2 42,2

– – – –

44,4 44,4 52,2 52,2

0,3 0,3 0,6 0,6

37 37 38,2 38,2

38 38 41,5 41,5

45 45 51,8 51,8

0,3 0,3 0,6 0,6

0,015 0,015 0,02 0,02

14 14 16 16

43,7 43,7 43,7 43,7

– – – –

55,7 55,7 55,7 55,7

1 1 1 1

39,6 39,6 39,6 39,6

43,7 43,7 43,7 43,7

57,4 57,4 57,4 57,4

1 1 1 1

0,025 0,025 0,025 0,025

15 15 15 15

46,9 46,9 46,9 46,9

– – – –

62,7 62,7 62,7 62,7

1,1 1,1 1,1 1,1

42 42 42 42

46,8 46,8 46,8 46,8

65 65 65 65

1 1 1 1

0,025 0,025 0,025 0,025

14 14 14 14

359

1.2 Capped single row deep groove ball bearings d 35 – 45 mm

B

r1

r2

r1

r2

2Z Principal dimensions d

D

B

mm

2RS1

2RZ

d2

d d1

D D2

2RS1

2Z Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side

– E2.6307-2Z * 6307-2Z * 6307-2RS1 62307-2RS1

– * 6307-Z * 6307-RS1 –

80 35 cont. 80 80 80

21 21 21 31

33,8 35,1 35,1 33,2

19 19 19 19

0,815 0,815 0,815 0,815

20 000 19 000 – –

11 000 9 500 6 000 6 000

0,48 0,48 0,47 0,68

40

52 52 62 62

7 7 12 12

4,49 4,49 13,8 13,8

3,75 3,75 10 10

0,16 0,16 0,425 0,425

26 000 – 24 000 –

13 000 7 500 12 000 6 700

0,034 0,034 0,12 0,12

68 68 68 68

15 15 15 21

17,8 17,8 17,8 16,8

11 11 11 11

0,49 0,49 0,49 0,49

22 000 22 000 – –

11 000 11 000 6 300 6 300

0,2 0,2 0,2 0,27

* 6008-2Z * 6008-2RZ * 6008-2RS1 63008-2RS1

* 6008-Z * 6008-RZ * 6008-RS1 –

80 80 80 80 80

18 18 18 18 23

30,7 32,5 32,5 32,5 30,7

18,6 19 19 19 19

0,78 0,8 0,8 0,8 0,8

20 000 18 000 18 000 – –

11 000 9 000 9 000 5 600 5 600

0,38 0,38 0,38 0,38 0,47

E2.6208-2Z * 6208-2Z * 6208-2RZ * 6208-2RS1 62208-2RS1

– * 6208-Z * 6208-RZ * 6208-RS1 –

90 90 90 90 90

23 23 23 23 33

41 42,3 42,3 42,3 41

24 24 24 24 24

1,02 1,02 1,02 1,02 1,02

18 000 17 000 17 000 – –

10 000 8 500 8 500 5 000 5 000

0,65 0,65 0,65 0,65 0,92

E2.6308-2Z * 6308-2Z * 6308-2RZ * 6308-2RS1 62308-2RS1

– * 6308-Z * 6308-RZ * 6308-RS1 –

58 58 68 68

7 7 12 12

6,63 6,63 14 14

6,1 6,1 10,8 10,8

0,26 0,26 0,465 0,465

22 000 – 20 000 –

11 000 6 700 10 000 6 000

0,04 0,04 0,14 0,14

61809-2RZ 61809-2RS1 61909-2RZ 61909-2RS1

75 75 75

16 16 23

22,1 22,1 20,8

14,6 14,6 14,6

0,64 0,64 0,64

20 000 – –

10 000 5 600 5 600

0,25 0,25 0,36

* 6009-2Z * 6009-2RS1 63009-2RS1

45

61808-2RZ 61808-2RS1 61908-2RZ 61908-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

360

– – – –

– – – – * 6009-Z * 6009-RS1 –

1.2

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



35 cont.

49,5 49,5 49,5 49,5

– – – –

69,2 69,2 69,2 69,2

1,5 1,5 1,5 1,5

44 44 44 44

49,5 49,5 49,5 49,5

71 71 71 71

1,5 1,5 1,5 1,5

0,03 0,03 0,03 0,03

13 13 13 13

40

43,2 – 46,9 46,9

– 42,1 – –

49,3 49,3 57,3 57,3

0,3 0,3 0,6 0,6

42 42 43,2 43,2

43 42 46,8 46,8

50 50 58,8 58,8

0,3 0,3 0,6 0,6

0,015 0,015 0,02 0,02

15 15 16 16

49,2 49,2 49,2 49,2

– – – –

61,1 61,1 61,1 61,1

1 1 1 1

44,6 44,6 44,6 44,6

49,2 49,2 49,2 49,2

63,4 63,4 63,4 63,4

1 1 1 1

0,025 0,025 0,025 0,025

15 15 15 15

52,6 52,6 52,6 52,6 52,6

– – – – –

69,8 69,8 69,8 69,8 69,8

1,1 1,1 1,1 1,1 1,1

47 47 47 47 47

52,5 52,5 52,5 52,5 52,5

73 73 73 73 73

1 1 1 1 1

0,025 0,025 0,025 0,025 0,025

14 14 14 14 14

56,1 56,1 56,1 56,1 56,1

– – – – –

77,7 77,7 77,7 77,7 77,7

1,5 1,5 1,5 1,5 1,5

49 49 49 49 49

56 56 56 56 56

81 81 81 81 81

1,5 1,5 1,5 1,5 1,5

0,03 0,03 0,03 0,03 0,03

13 13 13 13 13

49,1 49,1 52,4 52,4

– – – –

55,4 55,4 62,8 62,8

0,3 0,3 0,6 0,6

47 47 48,2 48,2

49 49 52,3 52,3

56 56 64,8 64,8

0,3 0,3 0,6 0,6

0,015 0,015 0,02 0,02

17 17 16 16

54,7 54,7 54,7

– – –

67,8 67,8 67,8

1 1 1

50,8 50,8 50,8

54,7 54,7 54,7

69,2 69,2 69,2

1 1 1

0,025 0,025 0,025

15 15 15

45

361

1.2 Capped single row deep groove ball bearings d 45 – 55 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm

55

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides



32,5 35,1 35,1 33,2

20,4 21,6 21,6 21,6

0,865 0,915 0,915 0,915

18 000 17 000 – –

10 000 8 500 5 000 5 000

0,43 0,43 0,43 0,51

E2.6209-2Z * 6209-2Z * 6209-2RS1 62209-2RS1

– * 6209-Z * 6209-RS1 –

100 100 100 100

25 25 25 36

52,7 55,3 55,3 52,7

31,5 31,5 31,5 31,5

1,34 1,34 1,34 1,34

16 000 15 000 – –

9 000 7 500 4 500 4 500

0,87 0,87 0,87 1,2

E2.6309-2Z * 6309-2Z * 6309-2RS1 62309-2RS1

– * 6309-Z * 6309-RS1 –

65 65 72 72

7 7 12 12

6,76 6,76 14,6 14,6

6,8 6,8 11,8 11,8

0,285 0,285 0,5 0,5

20 000 – 19 000 –

10 000 6 000 9 500 5 600

0,052 0,052 0,14 0,14

80 80 80 80

16 16 16 23

22,9 22,9 22,9 21,6

15,6 15,6 15,6 15,6

0,71 0,71 0,71 0,71

18 000 18 000 – –

9 000 9 000 5 000 5 000

0,27 0,27 0,27 0,38

* 6010-2Z * 6010-2RZ * 6010-2RS1 63010-2RS1

* 6010-Z * 6010-RZ * 6010-RS1 –

90 90 90 90

20 20 20 23

37,1 37,1 37,1 35,1

23,2 23,2 23,2 23,2

0,98 0,98 0,98 0,98

15 000 15 000 – –

8 000 8 000 4 800 4 800

0,47 0,47 0,47 0,54

* 6210-2Z * 6210-2RZ * 6210-2RS1 62210-2RS1

* 6210-Z * 6210-RZ * 6210-RS1 –

110 110 110 110

27 27 27 40

62,4 65 65 61,8

38 38 38 38

1,6 1,6 1,6 1,6

15 000 13 000 – –

8 000 6 700 4 300 4 300

1,1 1,1 1,1 1,6

E2.6310-2Z * 6310-2Z * 6310-2RS1 62310-2RS1

– * 6310-Z * 6310-RS1 –

72 72 80 80 90 90

9 9 13 13 18 18

9,04 9,04 16,5 16,5 29,6 29,6

8,8 8,8 14 14 21,2 21,2

0,375 0,375 0,6 0,6 0,9 0,9

19 000 – 17 000 – 16 000 –

9 500 5 300 8 500 5 000 8 000 4 500

0,083 0,083 0,19 0,19 0,4 0,4

61811-2RZ 61811-2RS1 61911-2RZ 61911-2RS1 * 6011-2Z * 6011-2RS1

– – – – * 6011-Z * 6011-RS1

61810-2RZ 61810-2RS1 61910-2RZ 61910-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

362

one side

19 19 19 23

85 45 cont. 85 85 85

50

Basic load ratings dynamic static

– – – –

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm 45 cont.

50

55

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



57,6 57,6 57,6 57,6

75,2 75,2 75,2 75,2

1,1 1,1 1,1 1,1

52 52 52 52

57,5 57,5 57,5 57,5

78 78 78 78

1 1 1 1

0,025 0,025 0,025 0,025

14 14 14 14

62,1 62,1 62,1 62,1

86,7 86,7 86,7 86,7

1,5 1,5 1,5 1,5

54 54 54 54

62,1 62,1 62,1 62,1

91 91 91 91

1,5 1,5 1,5 1,5

0,03 0,03 0,03 0,03

13 13 13 13

55,1 55,1 56,9 56,9

61,8 61,8 67,3 67,3

0,3 0,3 0,6 0,6

52 52 53,2 53,2

55 55 56,8 56,8

63 63 68,8 68,8

0,3 0,3 0,6 0,6

0,015 0,015 0,02 0,02

17 17 16 16

59,7 59,7 59,7 59,7

72,8 72,8 72,8 72,8

1 1 1 1

54,6 54,6 54,6 54,6

59,7 59,7 59,7 59,7

75,4 75,4 75,4 75,4

1 1 1 1

0,025 0,025 0,025 0,025

15 15 15 15

62,5 62,5 62,5 62,5

81,7 81,7 81,7 81,7

1,1 1,1 1,1 1,1

57 57 57 57

62,4 62,4 62,4 62,4

83 83 83 83

1 1 1 1

0,025 0,025 0,025 0,025

14 14 14 14

68,7 68,7 68,7 68,7

95,2 95,2 95,2 95,2

2 2 2 2

61 61 61 61

68,7 68,7 68,7 68,7

99 99 99 99

2 2 2 2

0,03 0,03 0,03 0,03

13 13 13 13

60,6 60,6 63,2 63,2 66,3 66,3

68,6 68,6 74,2 74,2 81,5 81,5

0,3 0,3 1 1 1,1 1,1

57 57 59,6 59,6 61 61

60,5 60,5 63,1 63,1 66,2 66,2

70 70 75,4 75,4 84 84

0,3 0,3 1 1 1 1

0,015 0,015 0,02 0,02 0,025 0,025

17 17 16 16 15 15

363

1.2 Capped single row deep groove ball bearings d 55 – 65 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side



100 55 cont. 100 100

21 21 25

46,2 46,2 43,6

29 29 29

1,25 1,25 1,25

14 000 – –

7 000 4 300 4 300

0,64 0,64 0,75

* 6211-2Z * 6211-2RS1 62211-2RS1

* 6211-Z * 6211-RS1 –

120 120 120 120

29 29 29 43

71,5 74,1 74,1 71,5

45 45 45 45

1,9 1,9 1,9 1,9

13 000 12 000 – –

7 000 6 300 3 800 3 800

1,4 1,4 1,4 2,05

E2.6311-2Z * 6311-2Z * 6311-2RS1 62311-2RS1

– * 6311-Z * 6311-RS1 –

78 78 85 85

10 10 13 13

11,9 11,9 16,5 16,5

11,4 11,4 14,3 14,3

0,49 0,49 0,6 0,6

17 000 – 16 000 –

8 500 4 800 8 000 4 500

0,11 0,11 0,2 0,2

61812-2RZ 61812-2RS1 61912-2RZ 61912-2RS1

95 95 95 110 110 110

18 18 18 22 22 28

30,7 30,7 30,7 55,3 55,3 52,7

23,2 23,2 23,2 36 36 36

0,98 0,98 0,98 1,53 1,53 1,53

15 000 15 000 – 13 000 – –

7 500 7 500 4 300 6 300 4 000 4 000

0,43 0,43 0,43 0,81 0,81 1

* * * * *

130 130 130 130

31 31 31 46

81,9 85,2 85,2 81,9

52 52 52 52

2,2 2,2 2,2 2,2

12 000 11 000 – –

6 700 5 600 3 400 3 400

1,8 1,8 1,8 2,55

E2.6312-2Z * 6312-2Z * 6312-2RS1 62312-2RS1

85 85 90 90

10 10 13 13

12,4 12,4 17,4 17,4

12,7 12,7 16 16

0,54 0,54 0,68 0,68

16 000 – 15 000 –

8 000 4 500 7 500 4 300

0,13 0,13 0,22 0,22

61813-2RZ 61813-2RS1 61913-2RZ 61913-2RS1

100 100 120 120 120

18 18 23 23 31

31,9 31,9 58,5 58,5 55,9

25 25 40,5 40,5 40,5

1,06 1,06 1,73 1,73 1,73

14 000 – 12 000 – –

7 000 4 000 6 000 3 600 3 600

0,46 0,46 1,05 1,05 1,4

60

65

* * * *

6012-2Z 6012-2RZ 6012-2RS1 6212-2Z 6212-2RS1 62212-2RS1

6013-2Z 6013-2RS1 6213-2Z 6213-2RS1 62213-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

364

– – – – * * * * *

6012-Z 6012-RZ 6012-RS1 6212-Z 6212-RS1 –

– * 6312-Z * 6312-RS1 – – – – – * * * *

6013-Z 6013-RS1 6213-Z 6213-RS1 –

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm 55 cont.

60

65

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



69 69 69

89,4 89,4 89,4

1,5 1,5 1,5

64 64 64

69 69 69

91 91 91

1,5 1,5 1,5

0,025 0,025 0,025

14 14 14

75,3 75,3 75,3 75,3

104 104 104 104

2 2 2 2

66 66 66 66

75,2 75,2 75,2 75,2

109 109 109 109

2 2 2 2

0,03 0,03 0,03 0,03

13 13 13 13

65,6 65,6 68,2 68,2

74,5 74,5 79,2 79,2

0,3 0,3 1 1

62 62 64,6 64,6

65,5 65,5 68,1 68,1

76 76 80,4 80,4

0,3 0,3 1 1

0,015 0,015 0,02 0,02

17 17 16 16

71,3 71,3 71,3 75,5 75,5 75,5

86,5 86,5 86,5 98 98 98

1,1 1,1 1,1 1,5 1,5 1,5

66 66 66 69 69 69

71,2 71,2 71,2 75,4 75,4 75,4

89 89 89 101 101 101

1 1 1 1,5 1,5 1,5

0,025 0,025 0,025 0,025 0,025 0,025

16 16 16 14 14 14

81,8 81,8 81,8 81,8

113 113 113 113

2,1 2,1 2,1 2,1

72 72 72 72

81,8 81,8 81,8 81,8

118 118 118 118

2 2 2 2

0,03 0,03 0,03 0,03

13 13 13 13

71,6 71,6 73,2 73,2

80,5 80,5 84,2 84,2

0,6 0,6 1 1

68,2 68,2 69,6 69,6

71,5 71,5 73,1 73

81,8 81,8 85,4 85,4

0,6 0,6 1 1

0,015 0,015 0,02 0,02

17 17 17 17

76,3 76,3 83,3 83,3 83,3

91,5 91,5 106 106 106

1,1 1,1 1,5 1,5 1,5

71 71 74 74 74

76,2 76,2 83,2 83,2 83,2

94 94 111 111 111

1 1 1,5 1,5 1,5

0,025 0,025 0,025 0,025 0,025

16 16 15 15 15

365

1.2 Capped single row deep groove ball bearings d 65 – 75 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side



140 65 cont. 140 140 140

33 33 33 48

93,6 97,5 97,5 92,3

60 60 60 60

2,5 2,5 2,5 2,5

11 000 10 000 – –

5 300 5 300 3 200 3 200

2,15 2,15 2,15 3

E2.6313-2Z * 6313-2Z * 6313-2RS1 62313-2RS1

– * 6313-Z * 6313-RS1 –

70

90 90 100 100 110 110

10 10 16 16 20 20

12,4 12,4 23,8 23,8 39,7 39,7

13,2 13,2 21,2 21,2 31 31

0,56 0,56 0,9 0,9 1,32 1,32

15 000 – 14 000 – 13 000 –

7 500 4 300 7 000 4 000 6 300 3 600

0,14 0,14 0,35 0,35 0,64 0,63

61814-2RZ 61814-2RS1 61914-2RZ 61914-2RS1 * 6014-2Z * 6014-2RS1

– – – – * 6014-Z * 6014-RS1

125 125 125

24 24 31

63,7 63,7 60,5

45 45 45

1,9 1,9 1,9

11 000 – –

5 600 3 400 3 400

1,15 1,1 1,4

* 6214-2Z * 6214-2RS1 62214-2RS1

* 6214-Z * 6214-RS1 –

150 150 150 150

35 35 35 51

104 111 111 104

68 68 68 68

2,75 2,75 2,75 2,75

11 000 9 500 – –

5 000 5 000 3 000 3 000

2,65 2,65 2,6 3,75

E2.6314-2Z * 6314-2Z * 6314-2RS1 62314-2RS1

– * 6314-Z * 6314-RS1 –

95 95 105 105

10 10 16 16

12,7 12,7 24,2 24,2

14,3 14,3 22,4 22,4

0,61 0,61 0,965 0,965

14 000 – 13 000 –

7 000 4 000 6 300 3 600

0,15 0,15 0,37 0,37

61815-2RZ 61815-2RS1 61915-2RZ 61915-2RS1

115 115 115 130 130

20 20 20 25 25

41,6 41,6 41,6 68,9 68,9

33,5 33,5 33,5 49 49

1,43 1,43 1,43 2,04 2,04

12 000 12 000 – 10 000 –

6 000 6 000 3 400 5 300 3 200

0,67 0,7 0,67 1,25 1,2

* * * * *

160 160 160

37 37 37

114 119 119

76,5 76,5 76,5

3,05 3 3

10 000 9 000 –

4 500 4 500 2 800

3,15 3,15 3,15

E2.6315-2Z * 6315-2Z * 6315-2RS1

75

6015-2Z 6015-2RZ 6015-2RS1 6215-2Z 6215-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

366

– – – – * * * * *

6015-Z 6015-RZ 6015-RS1 6215-Z 6215-RS1

– * 6315-Z * 6315-RS1

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



65 cont.

88,3 88,3 88,3 88,3

122 122 122 122

2,1 2,1 2,1 2,1

77 77 77 77

88,3 88,3 88,3 88,3

128 128 128 128

2 2 2 2

0,03 0,03 0,03 0,03

13 13 13 13

70

76,6 76,6 79,7 79,7 82,8 82,8

85,5 85,5 93,3 93,3 99,9 99,9

0,6 0,6 1 1 1,1 1,1

73,2 73,2 74,6 74,6 76 76

76,5 76,5 79,6 79,6 82,8 82,8

86,8 86,8 95,4 95,4 104 104

0,6 0,6 1 1 1 1

0,015 0,015 0,02 0,02 0,025 0,025

17 17 16 16 16 16

87 87 87

111 111 111

1,5 1,5 1,5

79 79 79

87 87 87

116 116 116

1,5 1,5 1,5

0,025 0,025 0,025

15 15 15

94,9 94,9 94,9 94,9

130 130 130 130

2,1 2,1 2,1 2,1

82 82 82 82

94,9 94,9 94,9 94,9

138 138 138 138

2 2 2 2

0,03 0,03 0,03 0,03

13 13 13 13

81,6 81,6 84,7 84,7

90,5 90,5 98,3 98,3

0,6 0,6 1 1

78,2 78,2 79,6 79,6

81,5 81,5 84,6 84,6

91,8 91,8 100 100

0,6 0,6 1 1

0,015 0,015 0,02 0,02

17 17 17 17

87,8 87,8 87,8 92 92

105 105 105 117 117

1,1 1,1 1,1 1,5 1,5

81 81 81 84 84

87,8 87,8 87,8 92 92

109 109 109 121 121

1 1 1 1,5 1,5

0,025 0,025 0,025 0,025 0,025

16 16 16 15 15

101 101 101

139 139 139

2,1 2,1 2,1

87 87 87

100 100 100

148 148 148

2 2 2

0,03 0,03 0,03

13 13 13

75

367

1.2 Capped single row deep groove ball bearings d 80 – 90 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm 80

85

90

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides



100 100 110 110 125 125

10 10 16 16 22 22

13 13 25,1 25,1 49,4 49,4

15 15 20,4 20,4 40 40

0,64 0,64 1,02 1,02 1,66 1,66

13 000 – 12 000 – 11 000 –

6 300 3 600 6 000 3 400 5 600 3 200

0,15 0,15 0,4 0,4 0,91 0,89

61816-2RZ 61816-2RS1 61916-2RZ 61916-2RS1 * 6016-2Z * 6016-2RS1

– – – – * 6016-Z * 6016-RS1

140 140 170 170 170

26 26 39 39 39

72,8 72,8 124 130 130

55 55 86,5 86,5 86,5

2,2 2,2 3,25 3,25 3,25

9 500 – 9 500 8 500 –

4 800 3 000 4 300 4 300 2 600

1,55 1,5 3,75 3,75 3,7

* 6216-2Z * 6216-2RS1 E2.6316-2Z * 6316-2Z * 6316-2RS1

* 6216-Z * 6216-RS1 – * 6316-Z * 6316-RS1

110 110 130 130

13 13 22 22

19,5 19,5 52 52

20,8 20,8 43 43

0,88 0,88 1,76 1,76

12 000 – 11 000 –

6 000 3 400 5 300 3 000

0,27 0,27 0,96 0,94

61817-2RZ 61817-2RS1 * 6017-2Z * 6017-2RS1

– – * 6017-Z * 6017-RS1

150 150 180 180

28 28 41 41

87,1 87,1 140 140

64 64 96,5 96,5

2,5 2,5 3,55 3,55

9 000 – 8 000 –

4 500 2 800 4 000 2 400

1,9 1,9 4,4 4,35

* * * *

* * * *

115 115 140 140

13 13 24 24

19,5 19,5 60,5 60,5

22 22 50 50

0,915 0,915 1,96 1,96

11 000 – 10 000 –

5 600 3 200 5 000 2 800

0,28 0,28 1,2 1,2

61818-2RZ 61818-2RS1 * 6018-2Z * 6018-2RS1

– – * 6018-Z * 6018-RS1

160 160 190 190

30 30 43 43

101 101 151 151

73,5 73,5 108 108

2,8 2,8 3,8 3,8

8 500 – 7 500 –

4 300 2 600 3 800 2 400

2,3 2,3 5,1 5,1

* * * *

* * * *

6217-2Z 6217-2RS1 6317-2Z 6317-2RS1

6218-2Z 6218-2RS1 6318-2Z 6318-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing E2 † SKF Energy Efficient bearing

368

one side

6217-Z 6217-RS1 6317-Z 6317-RS1

6218-Z 6218-RS1 6318-Z 6318-RS1

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm 80

85

90

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



86,6 86,6 89,8 89,8 94,4 94,4

95,5 95,5 103 103 115 115

0,6 0,6 1 1 1,1 1,1

83,2 83,2 84,6 84,6 86 86

86,5 86,5 89,7 89,7 94,3 94,3

96,8 96,8 105 105 119 119

0,6 0,6 1 1 1 1

0,015 0,015 0,02 0,02 0,025 0,025

17 17 14 14 16 16

101 101 108 108 108

127 127 147 147 147

2 2 2,1 2,1 2,1

91 91 92 92 92

100 100 107 107 107

129 129 158 158 158

2 2 2 2 2

0,025 0,025 0,03 0,03 0,03

15 15 13 13 13

93,2 93,2 99,4 99,4

105 105 120 120

1 1 1,1 1,1

89,6 89,6 92 92

93,1 93,1 99,3 99,3

105 105 123 123

1 1 1 1

0,015 0,015 0,025 0,025

17 17 16 16

106 106 114 114

135 135 156 156

2 2 3 3

96 96 99 99

105 105 114 114

139 139 166 166

2 2 2,5 2,5

0,025 0,025 0,03 0,03

15 15 13 13

98,2 98,2 105 105

110 110 129 129

1 1 1,5 1,5

94,6 94,6 97 97

98,1 98,1 105 105

110 110 133 133

1 1 1,5 1,5

0,015 0,015 0,025 0,025

17 17 16 16

112 112 121 121

143 143 164 164

2 2 3 3

101 101 104 104

112 112 120 120

149 149 176 176

2 2 2,5 2,5

0,025 0,025 0,03 0,03

15 15 13 13

369

1.2 Capped single row deep groove ball bearings d 95 – 110 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm 95

100

105

110

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides



120 120 130 145 145

13 13 18 24 24

19,9 19,9 33,8 63,7 63,7

22,8 22,8 33,5 54 54

0,93 0,93 1,34 2,08 2,08

11 000 – – 9 500 –

5 300 3 000 3 000 4 800 2 800

0,3 0,3 0,65 1,25 1,25

61819-2RZ 61819-2RS1 61919-2RS1 * 6019-2Z * 6019-2RS1

– – – * 6019-Z * 6019-RS1

170 170 200 200

32 32 45 45

114 114 159 159

81,5 81,5 118 118

3 3 4,15 4,15

8 000 – 7 000 –

4 000 2 400 3 600 2 200

2,75 2,75 5,85 5,85

* * * *

* * * *

125 125 150 150

13 13 24 24

17,8 17,8 63,7 63,7

18,3 18,3 54 54

0,95 0,95 2,04 2,04

10 000 – 9 500 –

5 300 3 000 4 500 2 600

0,31 0,31 1,35 1,3

61820-2RZ 61820-2RS1 * 6020-2Z * 6020-2RS1

– – * 6020-Z * 6020-RS1

180 180 215 215

34 34 47 47

127 127 174 174

93 93 140 140

3,35 3,35 4,75 4,75

7 500 – 6 700 –

3 800 2 400 3 400 2 000

3,3 3,3 7,3 7,1

* 6220-2Z * 6220-2RS1 6320-2Z 6320-2RS1

* 6220-Z * 6220-RS1 6320-Z 6320-RS1

130 130 160 160

13 13 26 26

20,8 20,8 76,1 76,1

19,6 19,6 65,5 65,5

1 1 2,4 2,4

10 000 – 8 500 –

5 000 2 800 4 300 2 400

0,32 0,32 1,65 1,65

61821-2RZ 61821-2RS1 * 6021-2Z * 6021-2RS1

– – * 6021-Z * 6021-RS1

190 190 225

36 36 49

140 140 182

104 104 153

3,65 3,65 5,1

7 000 – 6 300

3 600 2 200 3 200

3,9 3,95 8,25

* 6221-2Z * 6221-2RS1 6321-2Z

* 6221-Z * 6221-RS1 6321-Z

140 140 170 170

16 16 28 28

28,1 28,1 85,2 85,2

26 26 73,5 73,5

1,25 1,25 2,4 2,4

9 500 – 8 000 –

4 500 2 600 4 000 2 400

0,6 0,6 2,05 2,05

61822-2RZ 61822-2RS1 * 6022-2Z * 6022-2RS1

– – * 6022-Z * 6022-RS1

200 200 240 240

38 38 50 50

151 151 203 203

118 118 180 180

4 4 5,7 5,7

6 700 – 6 000 –

3 400 2 000 3 000 1 800

4,5 4,5 9,7 9,7

* 6222-2Z * 6222-2RS1 6322-2Z 6322-2RS1

* 6222-Z * 6222-RS1 6322-Z 6322-RS1

6219-2Z 6219-2RS1 6319-2Z 6319-2RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing

370

one side

6219-Z 6219-RS1 6319-Z 6319-RS1

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm 95

100

105

110

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



103 103 106 111 111

115 115 122 134 134

1 1 1,1 1,5 1,5

99,6 99,6 101 102 102

102 102 105 111 111

115 115 124 138 138

1 1 1 1,5 1,5

0,015 0,015 0,02 0,025 0,025

17 17 17 16 16

118 118 127 127

152 152 172 172

2,1 2,1 3 3

107 107 109 109

118 118 127 127

158 158 186 186

2 2 2,5 2,5

0,025 0,025 0,03 0,03

14 14 13 13

108 108 115 115

120 120 139 139

1 1 1,5 1,5

105 105 107 107

107 107 115 115

120 120 143 143

1 1 1,5 1,5

0,015 0,015 0,025 0,025

13 13 16 16

124 124 135 135

160 160 184 184

2,1 2,1 3 3

112 112 114 114

124 124 135 135

168 168 201 201

2 2 2,5 2,5

0,025 0,025 0,03 0,03

14 14 13 13

112 112 122 122

125 125 147 147

1 1 2 2

110 110 116 116

112 112 122 122

125 125 149 149

1 1 2 2

0,015 0,015 0,025 0,025

13 13 16 16

131 131 141

167 167 194

2,1 2,1 3

117 117 119

131 131 140

178 178 211

2 2 2,5

0,025 0,025 0,03

14 14 13

118 118 129 129

135 135 156 156

1 1 2 2

115 115 119 119

118 118 128 128

135 135 161 161

1 1 2 2

0,015 0,015 0,025 0,025

14 14 16 16

138 138 149 149

177 177 209 209

2,1 2,1 3 3

122 122 124 124

137 137 149 149

188 188 226 226

2 2 2,5 2,5

0,025 0,025 0,03 0,03

14 14 13 13

371

1.2 Capped single row deep groove ball bearings d 120 – 160 mm

B

r1

r2

r1

r2 2RZ

d d1

D D2

2RS1

2Z Principal dimensions d

D

B

mm 120

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Speed ratings Reference Limiting speed speed 1)

Mass

kN

r/min

kg

Designations Bearing capped on both sides

one side



150 150 180 180

16 16 28 28

29,1 29,1 88,4 88,4

28 28 80 80

1,29 1,29 2,75 2,75

8 500 – 7 500 –

4 300 2 400 3 800 2 200

0,65 0,65 2,2 2,15

61824-2RZ 61824-2RS1 * 6024-2Z * 6024-2RS1

215 215 260 260

40 40 55 55

146 146 208 208

118 118 186 186

3,9 3,9 5,7 5,7

6 300 – 5 600 –

3 200 1 900 2 800 1 700

5,35 5,3 12,7 12,6

6224-2Z 6224-2RS1 6324-2Z 6324-2RS1

130

165 165 200 200 230 230

18 18 33 33 40 40

37,7 37,7 112 112 156 156

43 43 100 100 132 132

1,6 1,6 3,35 3,35 4,15 4,15

8 000 – 7 000 – 5 600 –

3 800 2 200 3 400 2 000 3 000 1 800

0,93 0,93 3,35 3,35 6 5,9

61826-2RZ 61826-2RS1 * 6026-2Z * 6026-2RS1 6226-2Z 6226-2RS1

– – * 6026-Z * 6026-RS1 6226-Z 6226-RS1

140

175 175 210 210

18 18 33 33

39 39 111 111

46,5 46,5 108 108

1,66 1,66 3,45 3,45

7 500 – 6 700 –

3 600 2 000 3 200 1 800

0,99 0,99 3,6 3,55

61828-2RZ 61828-2RS1 6028-2Z 6028-2RS1

– – 6028-Z 6028-RS1

150

225 225

35 35

125 125

125 125

3,9 3,9

6 000 –

3 000 1 700

4,35 4,35

6030-2Z 6030-2RS1

6030-Z 6030-RS1

160

240 240

38 38

143 143

143 143

4,3 4,3

5 600 –

2 800 1 600

5,35 5,3

6032-2Z 6032-2RS1

6032-Z 6032-RS1

1) For bearings with only one shield or one non-contact seal (Z, RZ), the limiting speeds for open bearings are valid. ** SKF Explorer bearing

372

– – * 6024-Z * 6024-RS1 6224-Z 6224-RS1 6324-Z 6324-RS1

1.2

ra ra

Da

da

Dimensions d

d1 ~

D2 ~

r 1,2 min.

mm 120

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



128 128 139 139

145 145 166 166

1 1 2 2

125 125 129 129

128 128 139 139

145 145 171 171

1 1 2 2

0,015 0,015 0,025 0,025

14 14 16 16

150 150 165 165

190 190 220 220

2,1 2,1 3 3

132 132 134 134

150 150 164 164

203 203 246 246

2 2 2,5 2,5

0,025 0,025 0,03 0,03

14 14 14 14

130

140 140 152 152 160 160

158 158 182 182 203 203

1,1 1,1 2 2 3 3

136 136 139 139 144 144

139 139 152 152 160 160

159 159 191 191 216 216

1 1 2 2 2,5 2,5

0,015 0,015 0,025 0,025 0,025 0,025

16 16 16 16 15 15

140

150 150 162 162

167 167 192 192

1,1 1,1 2 2

146 146 149 149

150 150 162 162

169 169 201 201

1 1 2 2

0,015 0,015 0,025 0,025

16 16 16 16

150

174 174

206 206

2,1 2,1

160 160

173 173

215 215

2 2

0,025 0,025

16 16

160

185 185

219 219

2,1 2,1

169 169

185 185

231 231

2 2

0,025 0,025

16 16

373

1.3 ICOS oil sealed bearing units d 12 – 30 mm C B

r1

r2

r1

r2 d D2 D

D1 d 1

Principal dimensions d

D

B

C

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

Limiting speed

Mass

Designation

kN

r/min

kg



12

32

10

12,6

7,28

3,1

0,132

14 000

0,041

* ICOS-D1B01 TN9

15

35

11

13,2

8,06

3,75

0,16

12 000

0,048

* ICOS-D1B02 TN9

17

40

12

14,2

9,95

4,75

0,2

11 000

0,071

* ICOS-D1B03 TN9

20

47

14

16,2

13,5

6,55

0,28

9 300

0,11

* ICOS-D1B04 TN9

25

52

15

17,2

14,8

7,8

0,335

7 700

0,14

* ICOS-D1B05 TN9

30

62

16

19,4

20,3

11,2

0,475

6 500

0,22

* ICOS-D1B06 TN9

** SKF Explorer bearing

374

1.3

ra

ra db

Da da

Dimensions d

d1 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

d a, d b min.

kr

da max.

db max.

Da max.

ra max.

mm

f0



12

18,4

–1)

27,34 0,6

16,2

18,4

18

27,8

0,6

0,025

12

15

21,7

30,8

30,35 0,6

19,2

21,7

21,5

30,8

0,6

0,025

13

17

24,5

35,6

34,98 0,6

21,2

24,5

24

35,8

0,6

0,025

13

20

28,8

42

40,59 1

25,6

28,8

28,5

41,4

1

0,025

13

25

34,3

47

46,21 1

30,6

34,3

34

46,4

1

0,025

14

30

40,3

55,6

54,06 1

35,6

40,3

40

56,4

1

0,025

14

1) Full rubber cross section

375

1.4 Single row deep groove ball bearings with a snap ring groove d 10 – 45 mm

f B

r1

C b

min. 0,5

r1

r2

D4

d d1

D D2

r0

r2

D3

N Principal dimensions d

D

B

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

NR

Speed ratings Reference Limiting speed speed

Mass

Designations Bearing with snap ring snap ring groove groove and snap ring

kN

r/min

kg



Snap ring

10

30

9

5,4

2,36

0,1

56 000

36 000

0,032

* 6200 N

* 6200 NR

SP 30

12

32

10

7,28

3,1

0,132

50 000

32 000

0,037

* 6201 N

* 6201 NR

SP 32

15

35

11

8,06

3,75

0,16

43 000

28 000

0,045

* 6202 N

* 6202 NR

SP 35

17

40 47

12 14

9,95 14,3

4,75 6,55

0,2 0,275

38 000 34 000

24 000 22 000

0,065 0,12

* 6203 N * 6303 N

* 6203 NR * 6303 NR

SP 40 SP 47

20

42 47 52

12 14 15

9,95 13,5 16,8

5 6,55 7,8

0,212 0,28 0,335

38 000 32 000 30 000

24 000 20 000 19 000

0,069 0,11 0,14

* 6004 N * 6204 N * 6304 N

* 6004 NR * 6204 NR * 6304 NR

SP 42 SP 47 SP 52

25

47 52 62

12 15 17

11,9 14,8 23,4

6,55 7,8 11,6

0,275 0,335 0,49

32 000 28 000 24 000

20 000 18 000 16 000

0,08 0,13 0,22

* 6005 N * 6205 N * 6305 N

* 6005 NR * 6205 NR * 6305 NR

SP 47 SP 52 SP 62

30

55 62 72

13 16 19

13,8 20,3 29,6

8,3 11,2 16

0,355 0,475 0,67

28 000 24 000 20 000

17 000 15 000 13 000

0,12 0,2 0,35

* 6006 N * 6206 N * 6306 N

* 6006 NR * 6206 NR * 6306 NR

SP 55 SP 62 SP 72

35

62 72 80 100

14 17 21 25

16,8 27 35,1 55,3

10,2 15,3 19 31

0,44 0,655 0,82 1,29

24 000 20 000 19 000 16 000

15 000 13 000 12 000 10 000

0,15 0,3 0,45 0,96

* 6007 N * 6207 N * 6307 N 6407 N

* 6007 NR * 6207 NR * 6307 NR 6407 NR

SP 62 SP 72 SP 80 SP 100

40

68 80 90 110

15 18 23 27

17,8 32,5 42,3 63,7

11 19 24 36,5

0,49 0,8 1,02 1,53

22 000 18 000 17 000 14 000

14 000 11 000 11 000 9 000

0,19 0,36 0,62 1,25

* 6008 N * 6208 N * 6308 N 6408 N

* 6008 NR * 6208 NR * 6308 NR 6408 NR

SP 68 SP 80 SP 90 SP 110

45

75 85 100 120

16 19 25 29

22,1 35,1 55,3 76,1

14,6 21,6 31,5 45

0,64 0,915 1,34 1,9

20 000 17 000 15 000 13 000

12 000 11 000 9 500 8 500

0,24 0,41 0,83 1,55

* 6009 N * 6209 N * 6309 N 6409 N

* 6009 NR * 6209 NR * 6309 NR 6409 NR

SP 75 SP 85 SP 100 SP 120

** SKF Explorer bearing

376

1.4 ba max. 0,5

ra

da

Db Da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r 1,2 r 0 min. max.

mm

da min.

Da Db max. min.

ba min.

Calculation factors

Ca ra kr max. max.

mm

f0



10

17

24,8

28,17

34,7

1,35

1,12

2,06

0,6

0,4

14,2

25,8 36

1,5

3,18 0,6

0,025

13

12

18,4 27,4

30,15

36,7

1,35

1,12

2,06

0,6

0,4

16,2

27,8

38

1,5

3,18 0,6

0,025

12

15

21,7

30,4 33,17

39,7

1,35

1,12

2,06

0,6

0,4

19,2

30,8 41

1,5

3,18 0,6

0,025

13

17

24,5 26,5

35 39,6

44,6 52,7

1,35 1,35

1,12 1,12

2,06 2,46

0,6 1

0,4 0,4

21,2 35,8 22,6 41,4

46 54

1,5 1,5

3,18 0,6 3,58 1

0,025 0,03

13 12

20

27,2 37,2 39,75 28,8 40,6 44,6 30,3 44,8 49,73

46,3 52,7 57,9

1,35 1,35 1,35

1,12 1,12 1,12

2,06 2,46 2,46

0,6 1 1,1

0,4 0,4 0,4

23,2 38,8 48 25,6 41,4 54 27 45 59

1,5 1,5 1,5

3,18 0,6 3,58 1 3,58 1

0,025 0,025 0,03

14 13 12

25

32 42,2 44,6 34,3 46,3 49,73 36,6 52,7 59,61

52,7 57,9 67,7

1,35 1,35 1,9

1,12 1,12 1,7

2,06 2,46 3,28

0,6 1 1,1

0,4 0,4 0,6

28,2 43,8 54 30,6 46,4 59 32 55 69

1,5 1,5 2,2

3,18 0,6 3,58 1 4,98 1

0,025 0,025 0,03

14 14 12

30

38,2 49 52,6 40,3 54,1 59,61 44,6 61,9 68,81

60,7 67,7 78,6

1,35 1,9 1,9

1,12 1,7 1,7

2,06 3,28 3,28

1 1 1,1

0,4 0,6 0,6

34,6 35,6 37

50,4 62 56,4 69 65 80

1,5 2,2 2,2

3,18 1 4,98 1 4,98 1

0,025 0,025 0,03

15 14 13

35

43,7 46,9 49,5 57,4

55,7 62,7 69,2 79,6

59,61 68,81 76,81 96,8

67,7 78,6 86,6 106,5

1,9 1,9 1,9 2,7

1,7 1,7 1,7 2,46

2,06 3,28 3,28 3,28

1 1,1 1,5 1,5

0,6 0,6 0,6 0,6

39,6 42 44 46

57,4 65 71 89

69 80 88 108

2,2 2,2 2,2 3

3,76 4,98 4,98 5,74

1 1 1,5 1,5

0,025 0,025 0,03 0,035

15 14 13 12

40

49,2 52,6 56,1 62,8

61,1 69,8 77,7 87

64,82 76,81 86,79 106,81

74,6 86,6 96,5 116,6

1,9 1,9 2,7 2,7

1,7 1,7 2,46 2,46

2,49 3,28 3,28 3,28

1 1,1 1,5 2

0,6 0,6 0,6 0,6

44,6 47 49 53

63,4 73 81 97

76 88 98 118

2,2 2,2 3 3

4,19 4,98 5,74 5,74

1 1 1,5 2

0,025 0,025 0,03 0,035

15 14 13 12

45

54,7 57,6 62,1 68,9

67,8 75,2 86,7 95,9

71,83 81,81 96,8 115,21

81,6 91,6 106,5 129,7

1,9 1,9 2,7 3,1

1,7 1,7 2,46 2,82

2,49 3,28 3,28 4,06

1 1,1 1,5 2

0,6 0,6 0,6 0,6

50,8 52 54 58

69,2 78 91 107

83 93 108 131

2,2 2,2 3 3,5

4,19 4,98 5,74 6,88

1 1 1,5 2

0,025 0,025 0,03 0,035

15 14 13 12

38,1 44,6

377

1.4 Single row deep groove ball bearings with a snap ring groove d 50 – 90 mm

f B

r1

C b

min. 0,5

r1

r2

D4

d d1

D D2

r0

r2

D3

N Principal dimensions d

D

B

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

NR

Speed ratings Reference Limiting speed speed

Mass

Designations Bearing with snap ring snap ring groove groove and snap ring

kN

r/min

kg



Snap ring

50

80 90 110 130

16 20 27 31

22,9 37,1 65 87,1

16 23,2 38 52

0,71 0,98 1,6 2,2

18 000 15 000 13 000 12 000

11 000 10 000 8 500 7 500

0,26 0,47 1,05 1,9

* 6010 N * 6210 N * 6310 N 6410 N

* 6010 NR * 6210 NR * 6310 NR 6410 NR

SP 80 SP 90 SP 110 SP 130

55

90 100 120 140

18 21 29 33

29,6 46,2 74,1 99,5

21,2 29 45 62

0,9 1,25 1,9 2,6

16 000 14 000 12 000 11 000

10 000 9 000 8 000 7 000

0,38 0,6 1,35 2,35

* 6011 N * 6211 N * 6311 N 6411 N

* 6011 NR * 6211 NR * 6311 NR 6411 NR

SP 90 SP 100 SP 120 SP 140

60

95 110 130 150

18 22 31 35

30,7 55,3 85,2 108

23,2 36 52 69,5

0,98 1,53 2,2 2,9

15 000 13 000 11 000 10 000

9 500 8 000 7 000 6 300

0,4 0,77 1,7 2,8

* 6012 N * 6212 N * 6312 N 6412 N

* 6012 NR * 6212 NR * 6312 NR 6412 NR

SP 95 SP 110 SP 130 SP 150

65

100 120 140 160

18 23 33 37

31,9 58,5 97,5 119

25 40,5 60 78

1,06 1,73 2,5 3,15

14 000 12 000 10 000 9 500

9 000 7 500 6 700 6 000

0,43 1 2,1 3,35

* 6013 N * 6213 N * 6313 N 6413 N

* 6013 NR * 6213 NR * 6313 NR 6413 NR

SP 100 SP 120 SP 140 SP 160

70

110 125 150

20 24 35

39,7 63,7 111

31 45 68

1,32 1,9 2,75

13 000 11 000 9 500

8 000 7 000 6 300

0,6 1,05 2,55

* 6014 N * 6214 N * 6314 N

* 6014 NR * 6214 NR * 6314 NR

SP 110 SP 125 SP 150

75

115 130 160

20 25 37

41,6 68,9 119

33,5 49 76,5

1,43 2,04 3

12 000 10 000 9 000

7 500 6 700 5 600

0,64 1,15 3

* 6015 N * 6215 N * 6315 N

* 6015 NR * 6215 NR * 6315 NR

SP 115 SP 130 SP 160

80

125 140

22 26

49,4 72,8

40 55

1,66 2,2

11 000 9 500

7 000 6 000

0,85 1,45

* 6016 N * 6216 N

* 6016 NR * 6216 NR

SP 125 SP 140

85

130 150

22 28

52 87,1

43 64

1,76 2,5

11 000 9 000

6 700 5 600

0,9 1,8

* 6017 N * 6217 N

* 6017 NR * 6217 NR

SP 130 SP 150

90

140 160

24 30

60,5 101

50 73,5

1,96 2,8

10 000 8 500

6 300 5 300

1,1 2,2

* 6018 N * 6218 N

* 6018 NR * 6218 NR

SP 140 SP 160

** SKF Explorer bearing

378

1.4 ba max. 0,5

ra

da

Db Da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r 1,2 r 0 min. max.

mm

da min.

Da Db max. min.

ba min.

Calculation factors

Ca ra kr max. max.

mm

f0



50

59,7 62,5 68,7 75,4

72,8 81,7 95,2 105

76,81 86,79 106,81 125,22

86,6 96,5 116,6 139,7

1,9 2,7 2,7 3,1

1,7 2,46 2,46 2,82

2,49 3,28 3,28 4,06

1 1,1 2 2,1

0,6 0,6 0,6 0,6

54,6 57 61 64

75,4 83 99 116

88 98 118 141

2,2 3 3 3,5

4,19 5,74 5,74 6,88

1 1 2 2

0,025 0,025 0,03 0,035

15 14 13 12

55

66,3 69 75,3 81,5

81,5 89,4 104 114

86,79 96,8 115,21 135,23

96,5 106,5 129,7 149,7

2,7 2,7 3,1 3,1

2,46 2,46 2,82 2,82

2,87 3,28 4,06 4,9

1,1 1,5 2 2,1

0,6 0,6 0,6 0,6

61 64 66 69

84 91 109 126

98 108 131 151

3 3 3,5 3,5

5,33 5,74 6,88 7,72

1 1,5 2 2

0,025 0,025 0,03 0,035

15 14 13 12

60

71,3 75,5 81,8 88,1

86,5 98 113 122

91,82 106,81 125,22 145,24

101,6 116,6 139,7 159,7

2,7 2,7 3,1 3,1

2,46 2,46 2,82 2,82

2,87 3,28 4,06 4,9

1,1 1,5 2,1 2,1

0,6 0,6 0,6 0,6

66 69 72 74

89 101 118 136

103 118 141 162

3 3 3,5 3,5

5,33 5,74 6,88 7,72

1 1,5 2 2

0,025 0,025 0,03 0,035

16 14 13 12

65

76,3 83,3 88,3 94

91,5 106 122 131

96,8 115,21 135,23 155,22

106,5 129,7 149,7 169,7

2,7 3,1 3,1 3,1

2,46 2,82 2,82 2,82

2,87 4,06 4,9 4,9

1,1 1,5 2,1 2,1

0,6 0,6 0,6 0,6

71 74 77 79

94 111 128 146

108 131 151 172

3 3,5 3,5 3,5

5,33 6,88 7,72 7,72

1 1,5 2 2

0,025 0,025 0,03 0,035

16 15 13 12

70

82,8 99,9 87 111 94,9 130

106,81 116,6 2,7 120,22 134,7 3,1 145,25 159,7 3,1

2,46 2,82 2,82

2,87 4,06 4,9

1,1 1,5 2,1

0,6 0,6 0,6

76 79 82

104 116 138

118 136 162

3 3,5 3,5

5,33 1 6,88 1,5 7,72 2

0,025 0,025 0,03

16 15 13

75

87,8 92 101

105 117 139

111,81 121,6 2,7 125,22 139,7 3,1 155,22 169,7 3,1

2,46 2,82 2,82

2,87 4,06 4,9

1,1 1,5 2,1

0,6 0,6 0,6

81 84 87

109 121 148

123 141 172

3 3,5 3,5

5,33 1 6,88 1,5 7,72 2

0,025 0,025 0,03

16 15 13

80

94,4 101

115 127

120,22 134,7 3,1 135,23 149,7 3,1

2,82 2,82

2,87 4,9

1,1 2

0,6 0,6

86 91

119 129

136 151

3,5 3,5

5,69 7,72

1 2

0,025 0,025

16 15

85

99,4 106

120 135

125,22 139,7 3,1 145,24 159,7 3,1

2,82 2,82

2,87 4,9

1,1 2

0,6 0,6

92 96

123 139

141 162

3,5 3,5

5,69 7,72

1 2

0,025 0,025

16 15

90

105 112

129 143

135,23 149,7 155,22 169,7

2,82 2,82

3,71 4,9

1,5 2

0,6 0,6

97 101

133 149

151 172

3,5 3,5

6,53 1,5 7,72 2

0,025 0,025

16 15

3,1 3,1

379

1.4 Single row deep groove ball bearings with a snap ring groove d 95 – 120 mm

f B

r1

C b

min. 0,5

r1

r2

D4

d d1

D D2

r0

r2

D3

N Principal dimensions d

D

B

mm

Basic load ratings dynamic static

Fatigue load limit

C

Pu

C0

kN

NR

Speed ratings Reference Limiting speed speed

Mass

Designations Bearing with snap ring snap ring groove groove and snap ring

kN

r/min

kg



Snap ring

95

170

32

114

81,5

3

8 000

5 000

2,6

* 6219 N

* 6219 NR

SP 170

100

150 180

24 34

63,7 127

54 93

2,04 3,35

9 500 7 500

5 600 4 800

1,25 3,15

* 6020 N * 6220 N

* 6020 NR * 6220 NR

SP 150 SP 180

105

160

26

76,1

65,5

2,4

8 500

5 300

1,6

* 6021 N

* 6021 NR

SP 160

110

170

28

85,2

73,5

2,6

8 000

5 000

1,95

* 6022 N

* 6022 NR

SP 170

120

180

28

88,4

80

2,75

7 500

4 800

2,05

* 6024 N

* 6024 NR

SP 180

** SKF Explorer bearing

380

1.4 ba max. 0,5

ra

da

Db Da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r 1,2 r 0 min. max.

mm

da min.

Da Db max. min.

ba min.

Calculation factors

Ca ra kr max. max.

mm



95

118

152

163,65 182,9 3,5

3,1

5,69

2,1

0,6

107

158

185

4

8,79

100

115 124

139 160

145,24 159,7 173,66 192,9

3,1 3,5

2,82 3,1

3,71 5,69

1,5 2,1

0,6 0,6

107 112

143 168

162 195

3,5 4

105

122

147

155,22 169,7

3,1

2,82

3,71

2

0,6

116

149

172

110

129

156

163,65 182,9 3,5

3,1

3,71

2

0,6

119

161

185

120

139

166

173,66 192,9

3,1

3,71

2

0,6

129

171

195

3,5

f0

2

0,025

14

6,53 1,5 8,79 2

0,025 0,025

16 14

3,5

6,53 2

0,025

16

4

6,81 2

0,025

16

4

6,81 2

0,025

16

381

1.5 Single row deep groove ball bearings with a snap ring and shields d 10 – 60 mm

f

B r2 r1

C

r1

r2

b

min. 0,5

D4

d d1

D D2

r0 D3

ZNR Principal dimensions d

D

B

mm

2ZNR

Basic load ratings Fatigue Speed ratings dynamic static load limit Reference Limiting speed speed 1) Pu C C0

Mass

Designations Bearing with a snap ring and a shield on one a shield on side both sides

kN

kg



kN

r/min

Snap ring

10

30

9

5,4

2,36

0,1

56 000

36 000

0,032

* 6200-ZNR

* 6200-2ZNR

SP 30

12

32

10

7,28

3,1

0,132

50 000

32 000

0,037

* 6201-ZNR

* 6201-2ZNR

SP 32

15

35

11

8,06

3,75

0,16

43 000

28 000

0,045

* 6202-ZNR

* 6202-2ZNR

SP 35

17

40 47

12 14

9,95 14,3

4,75 6,55

0,2 0,275

38 000 34 000

24 000 22 000

0,065 0,12

* 6203-ZNR * 6303-ZNR

* 6203-2ZNR * 6303-2ZNR

SP 40 SP 47

20

42 47 52

12 14 15

9,95 13,5 16,8

5 6,55 7,8

0,212 0,28 0,335

38 000 32 000 30 000

24 000 20 000 19 000

0,069 0,11 0,15

* 6004-ZNR * 6204-ZNR * 6304-ZNR

* 6004-2ZNR * 6204-2ZNR * 6304-2ZNR

SP 42 SP 47 SP 52

25

47 52 62

12 15 17

11,9 14,8 23,4

6,55 7,8 11,6

0,275 0,335 0,49

32 000 28 000 24 000

20 000 18 000 16 000

0,08 0,13 0,24

* 6005-ZNR * 6205-ZNR * 6305-ZNR

* 6005-2ZNR * 6205-2ZNR * 6305-2ZNR

SP 47 SP 52 SP 62

30

62 72

16 19

20,3 29,6

11,2 16

0,475 0,67

24 000 20 000

15 000 13 000

0,21 0,37

* 6206-ZNR * 6306-ZNR

* 6206-2ZNR * 6306-2ZNR

SP 62 SP 72

35

72 80

17 21

27 35,1

15,3 19

0,655 0,82

20 000 19 000

13 000 12 000

0,3 0,47

* 6207-ZNR * 6307-ZNR

* 6207-2ZNR * 6307-2ZNR

SP 72 SP 80

40

80 90

18 23

32,5 42,3

19 24

0,8 1,02

18 000 17 000

11 000 11 000

0,39 0,65

* 6208-ZNR * 6308-ZNR

* 6208-2ZNR * 6308-2ZNR

SP 80 SP 90

45

85 100

19 25

35,1 55,3

21,6 31,5

0,915 1,34

17 000 15 000

11 000 9 500

0,43 0,87

* 6209-ZNR * 6309-ZNR

* 6209-2ZNR * 6309-2ZNR

SP 85 SP 100

50

90 110

20 27

37,1 65

23,2 38

0,98 1,6

15 000 13 000

10 000 8 500

0,48 1,1

* 6210-ZNR * 6310-ZNR

* 6210-2ZNR * 6310-2ZNR

SP 90 SP 110

55

100 120

21 29

46,2 74,1

29 45

1,25 1,9

14 000 12 000

9 000 8 000

0,64 1,45

* 6211-ZNR * 6311-ZNR

* 6211-2ZNR * 6311-2ZNR

SP 100 SP 120

60

110 130

22 31

55,3 85,2

36 52

1,53 2,2

13 000 11 000

8 000 7 000

0,81 1,8

* 6212-ZNR * 6312-ZNR

* 6212-2ZNR * 6312-2ZNR

SP 110 SP 130

1) For bearings with a shield on both sides (2Z), limiting speeds are about 80% of the quoted value. ** SKF Explorer bearing

382

1.5 ba max. 0,5

ra

da

Db Da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r 1,2 r 0 da min. max. min.

mm

da Da Db max. max. min.

ba min.

Calculation factors Ca ra kr max. max.

mm

f0



10

17

24,8

28,17

34,7

1,35 1,12 2,06

0,6

0,4

14,2

16,9

12

18,4 27,4

30,15

36,7

1,35 1,12 2,06

0,6

0,4

16,2

18,4 27,8

15

21,7

30,4 33,17

39,7

1,35 1,12 2,06

0,6

0,4

19,2

17

24,5 26,5

35 39,6

44,6 52,7

1,35 1,12 2,06 1,35 1,12 2,46

0,6 1

0,4 0,4

21,2 24,4 22,6 26,4

20

27,2 37,2 39,75 28,8 40,6 44,6 30,3 44,8 49,73

46,3 52,7 57,9

1,35 1,12 2,06 1,35 1,12 2,46 1,35 1,12 2,46

0,6 1 1,1

25

32 42,2 44,6 34,3 46,3 49,73 36,6 52,7 59,61

52,7 57,9 67,7

1,35 1,12 2,06 1,35 1,12 2,46 1,9 1,7 3,28

30

40,3 54,1 59,61 44,6 61,9 68,81

67,7 78,6

1,9 1,9

1,7 1,7

35

46,9 49,5

62,7 69,2

68,81 76,81

78,6 86,6

1,9 1,9

1,7 1,7

40

52,6 69,8 56,1 77,7

76,81 86,79

86,6 96,5

45

57,6 75,2 62,1 86,7

81,81 96,8

1,5

3,18 0,6

0,025 13

38

1,5

3,18 0,6

0,025 12

21,6 30,8 41

1,5

3,18 0,6

0,025 13

46 54

1,5 1,5

3,18 0,6 3,58 1

0,025 13 0,03 12

0,4 0,4 0,4

23,2 27,1 38,8 48 25,6 28,7 41,4 54 27 30,3 45 59

1,5 1,5 1,5

3,18 0,6 3,58 1 3,58 1

0,025 14 0,025 13 0,03 12

0,6 1 1,1

0,4 0,4 0,6

28,2 31,9 43,8 54 30,6 34,3 46,4 59 32 36,5 55 69

1,5 1,5 2,2

3,18 0,6 3,58 1 4,98 1

0,025 14 0,025 14 0,03 12

3,28 3,28

1 1,1

0,6 0,6

35,6 37

40,3 56,4 69 44,5 65 80

2,2 2,2

4,98 4,98

1 1

0,025 14 0,03 13

3,28 3,28

1,1 1,5

0,6 0,6

42 44

46,8 65 49,5 71

80 88

2,2 2,2

4,98 4,98

1 1,5

0,025 14 0,03 13

1,9 2,7

1,7 3,28 2,46 3,28

1,1 1,5

0,6 0,6

47 49

52,5 73 56 81

88 98

2,2 3

4,98 5,74

1 1,5

0,025 14 0,03 13

91,6 1,9 106,5 2,7

1,7 3,28 2,46 3,28

1,1 1,5

0,6 0,6

52 54

57,5 78 62,1 91

93 108

2,2 3

4,98 5,74

1 1,5

0,025 14 0,03 13

50

62,5 81,7 86,79 96,5 2,7 68,7 95,2 106,81 116,6 2,7

2,46 3,28 2,46 3,28

1,1 2

0,6 0,6

57 61

62,4 83 68,7 99

98 118

3 3

5,74 5,74

1 2

0,025 14 0,03 13

55

69 89,4 75,3 104

96,8 106,5 2,7 115,21 129,7 3,1

2,46 3,28 2,82 4,06

1,5 2

0,6 0,6

64 66

69 75,2

91 109

108 131

3 3,5

5,74 1,5 6,88 2

0,025 14 0,03 13

60

75,5 98 81,8 113

106,81 116,6 2,7 125,22 139,7 3,1

2,46 3,28 2,82 4,06

1,5 2,1

0,6 0,6

69 72

75,4 101 81,8 118

118 141

3 3,5

5,74 1,5 6,88 2

0,025 14 0,03 13

38,1 44,6

25,8 36

35,8 41,4

383

1.5 Single row deep groove ball bearings with a snap ring and shields d 65 – 70 mm

f

B r2 r1

C

r1

r2

b

min. 0,5

D4

d d1

D D2

r0 D3

ZNR Principal dimensions d

D

B

mm

2ZNR

Basic load ratings Fatigue Speed ratings dynamic static load limit Reference Limiting speed speed 1) Pu C C0

Mass

Designations Bearing with a snap ring and a shield on one a shield on side both sides

kN

kg



kN

r/min

Snap ring

65

120 140

23 33

58,5 97,5

40,5 60

1,73 2,5

12 000 10 000

7 500 6 700

1,05 2,2

* 6213-ZNR * 6313-ZNR

* 6213-2ZNR * 6313-2ZNR

SP 120 SP 140

70

125 150

24 35

63,7 111

45 68

1,9 2,75

11 000 9 500

7 000 6 300

1,15 2,65

* 6214-ZNR * 6314-ZNR

* 6214-2ZNR * 6314-2ZNR

SP 125 SP 150

1) For bearings with a shield on both sides (2Z), limiting speeds are about 80% of the quoted value. ** SKF Explorer bearing

384

1.5 ba max. 0,5

ra

da

Db Da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r 1,2 r 0 da min. max. min.

mm

da Da Db max. max. min.

ba min.

Calculation factors Ca ra kr max. max.

mm

f0



65

83,3 106 88,3 122

115,21 129,7 3,1 135,23 149,7 3,1

2,82 4,06 2,82 4,9

1,5 2,1

0,6 0,6

74 77

83,2 111 88,3 128

131 151

3,5 3,5

6,88 1,5 7,72 2

0,025 15 0,03 13

70

87 94,9

120,22 134,7 3,1 145,25 159,7 3,1

2,82 4,06 2,82 4,9

1,5 2,1

0,6 0,6

79 82

87 94,9

136 162

3,5 3,5

6,88 1,5 7,72 2

0,025 15 0,03 13

111 130

116 138

385

1.6 Stainless steel deep groove ball bearings d 0,6 – 5 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

d2

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



0,6

2,5

1

0,034

0,007

0

260 000

160 000

0,02

W 618/0.6

1

3 3 4

1 1,5 1,6

0,052 0,052 0,092

0,012 0,012 0,018

0,001 0,001 0,001

240 000 240 000 220 000

150 000 150 000 140 000

0,03 0,1 0,1

W 618/1 W 638/1 W 619/1

1,5

4 5 6

1,2 2 2,5

0,062 0,135 0,19

0,016 0,036 0,051

0,001 0,002 0,002

220 000 200 000 180 000

140 000 120 000 110 000

0,1 0,2 0,38

W 618/1.5 W 619/1.5 W 60/1.5

2

4 5 5 6 6 7

1,2 1,5 2 2,3 2,5 2,8

0,068 0,094 0,094 0,19 0,19 0,221

0,019 0,025 0,025 0,051 0,051 0,067

0,001 0,001 0,001 0,002 0,002 0,003

200 000 200 000 200 000 180 000 180 000 160 000

130 000 120 000 120 000 110 000 110 000 100 000

0,1 0,15 0,16 0,28 0,3 0,5

W 617/2 W 618/2 W 618/2 X W 619/2 W 619/2 X W 602

2,5

6 7 8

1,8 2,5 2,8

0,117 0,221 0,312

0,036 0,067 0,088

0,002 0,003 0,004

170 000 160 000 160 000

110 000 100 000 95 000

0,2 0,4 0,6

W 618/2.5 W 619/2.5 W 60/2.5

3

6 7 8 9 10 13

2 2 3 3 4 5

0,117 0,178 0,319 0,325 0,358 0,741

0,036 0,057 0,09 0,095 0,11 0,25

0,002 0,002 0,004 0,004 0,005 0,011

170 000 160 000 150 000 140 000 140 000 110 000

110 000 100 000 95 000 90 000 90 000 70 000

0,2 0,34 0,7 0,8 1,6 3,1

W 617/3 W 618/3 W 619/3 W 603 W 623 W 633

4

7 8 9 10

2 2 2,5 3

0,178 0,225 0,364 0,553

0,057 0,072 0,114 0,245

0,003 0,003 0,005 0,011

150 000 150 000 140 000 130 000

95 000 90 000 85 000 80 000

0,2 0,4 0,6 1

W 617/4 W 617/4 X W 618/4 W 637/4 X

11 12 13 16

4 4 5 5

0,54 0,54 0,741 0,761

0,176 0,176 0,25 0,265

0,008 0,008 0,011 0,011

130 000 130 000 110 000 100 000

80 000 80 000 70 000 63 000

2 2 2,8 5

W 619/4 W 604 W 624 W 634

8 9 11 13

2 2,5 3 4

0,174 0,247 0,403 0,761

0,061 0,085 0,143 0,335

0,003 0,004 0,006 0,014

140 000 130 000 120 000 110 000

85 000 85 000 75 000 70 000

0,3 0,5 1,2 2,4

W 617/5 W 627/5 X W 618/5 W 619/5

5

386

1.6

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



0,6

1,1



2



0,05

1

2,1

0,05

0,02

1

1,5 1,5 2

– – –

2,5 2,5 3,2

– – –

0,05 0,05 0,1

1,4 1,4 1,8

2,6 2,6 3,3

0,05 0,05 0,1

0,02 5,6 0,02 5,6 0,025 5,8

1,5

2,1 2,5 3

– – –

3,1 4 4,8

– – –

0,05 0,15 0,15

1,9 2,4 2,7

3,6 4,1 4,9

0,05 0,15 0,15

0,02 6,4 0,025 5,9 0,03 6

2

2,5 2,7 2,7 3 3 3,8

– – – – – –

3,5 3,9 3,9 4,8 4,8 5,7

– – – – – –

0,05 0,08 0,1 0,15 0,15 0,15

2,4 2,5 2,6 2,9 2,9 3,2

3,6 4,4 4,2 4,9 4,9 5,8

0,05 0,08 0,1 0,15 0,15 0,15

0,015 0,02 0,02 0,025 0,025 0,03

2,5

3,7 3,8 4,1

– – –

4,9 5,7 6,4

– – –

0,08 0,15 0,15

3,1 3,7 3,7

5,4 5,8 6,8

0,08 0,15 0,15

0,02 7,1 0,025 6,6 0,03 5,9

3

3,7 4,2 4,3 4,8 – –

– – – – 4,3 6

4,9 5,8 6,7 7,2 7,1 10,5

– – – – 8 11,4

0,1 0,1 0,15 0,15 0,15 0,2

3,6 3,8 4,2 4,2 4,2 4,6

5,2 6,2 6,8 7,8 8,8 11,5

0,1 0,1 0,15 0,15 0,15 0,2

0,015 0,02 0,025 0,03 0,03 0,035

7,1 7,1 6,1 6,4 6,3 6,4

4

4,7 5 5,2 5,9

– – – –

6,3 6,8 7,5 8,2

– – – –

0,1 0,15 0,1 0,2

4,6 4,9 4,8 5,6

6,4 6,9 8,2 8,4

0,1 0,15 0,1 0,2

0,015 0,015 0,02 0,02

7,3 7,2 6,5 12

– – – –

5,6 5,6 6 6,7

9 9 10,5 11,7

9,9 9,9 11,4 13

0,15 0,2 0,2 0,3

5,2 5,3 5,6 6

10 10,4 11,5 14

0,15 0,2 0,2 0,3

0,025 0,03 0,03 0,035

6,4 6,4 6,4 6,8

5,7 6 6,8 –

– – – 6,6

7,3 7,8 9,2 10,5

– – – 11,2

0,1 0,15 0,15 0,2

5,6 5,9 6,2 6,3

7,4 7,9 9,8 11,4

0,1 0,15 0,15 0,2

0,015 0,015 0,02 0,025

7,7 7,6 7,1 11

5

5,7

6,7 6,5 6,5 6 6 6,6

387

1.6 Stainless steel deep groove ball bearings d 5 – 10 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

d2

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



5 cont.

14 16 19

5 5 6

0,761 1,43 2,34

0,26 0,63 0,88

0,011 0,027 0,038

110 000 100 000 85 000

67 000 63 000 56 000

3,1 4,6 7,5

W 605 W 625 W 635

6

10 12 13 15

2,5 3 3,5 5

0,286 0,403 0,618 0,761

0,112 0,146 0,224 0,265

0,005 0,006 0,01 0,011

120 000 110 000 110 000 100 000

75 000 70 000 67 000 63 000

0,6 1,3 1,9 3,6

W 617/6 W 627/6 X W 618/6 W 619/6

17 19 22

6 6 7

1,95 1,53 2,34

0,83 0,585 0,8

0,036 0,025 0,034

95 000 85 000 75 000

60 000 56 000 48 000

5,5 7,2 12

W 606 W 626 W 636

11 13 14 17

2,5 3 3,5 5

0,26 0,312 0,663 0,923

0,104 0,143 0,26 0,365

0,004 0,006 0,011 0,016

110 000 100 000 100 000 90 000

70 000 63 000 63 000 56 000

0,6 1,6 2,1 4,9

W 617/7 W 627 X W 618/7 W 619/7

19 22 26

6 7 9

1,53 1,99 3,97

0,585 0,78 1,96

0,025 0,034 0,083

85 000 75 000 67 000

56 000 48 000 40 000

6,8 11,5 22,5

W 607 W 627 W 637

12 14 16 19

2,5 3,5 4 6

0,312 0,462 0,715 1,25

0,14 0,193 0,3 0,455

0,006 0,008 0,012 0,02

100 000 95 000 90 000 85 000

63 000 60 000 56 000 53 000

0,7 1,9 3,2 6,3

W 617/8 W 637/8 X W 618/8 W 619/8

22 24 28

7 8 9

1,99 2,47 3,97

0,78 1,12 1,96

0,034 0,048 0,083

75 000 70 000 67 000

48 000 45 000 40 000

11 16,5 27,5

W 608 W 628 W 638

9

14 17 20 24 26 30

3 4 6 7 8 10

0,52 0,761 2,12 2,03 3,97 4,94

0,236 0,335 1,06 0,815 1,96 2,32

0,01 0,014 0,045 0,036 0,083 0,1

95 000 85 000 80 000 70 000 67 000 60 000

60 000 53 000 50 000 43 000 40 000 36 000

1,2 3,5 7,2 13,5 18 33,5

W 617/9 W 618/9 W 619/9 W 609 W 629 W 639

10

15 19 19 22

3 5 7 6

0,488 1,48 1,48 2,7

0,22 0,83 0,83 1,27

0,009 0,036 0,036 0,054

85 000 80 000 80 000 70 000

56 000 48 000 48 000 45 000

1,4 4,8 6,8 8,9

W 61700 W 61800 W 63800 W 61900

7

8

388

1.6

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



5 cont.

– – –

6,9 7,5 8,5

11,3 12,5 15,1

12,2 13,4 16,5

0,2 0,3 0,3

6,6 7 7

12,4 14 17

0,2 0,3 0,3

0,03 6,6 0,03 12 0,035 12

6

7 7,7 8 –

– – – 7,5

8,9 10,2 11 11,7

– – – 13

0,15 0,2 0,15 0,2

6,9 7,6 7,2 7,3

9 10,4 11,8 13,4

0,15 0,2 0,15 0,2

0,015 0,015 0,02 0,025

– – –

8,2 8,5 10,5

13,8 15,1 18,1

14,8 16,5 19,1

0,3 0,3 0,3

8 8 8

15 17 20

0,3 0,3 0,3

0,03 11 0,03 7,9 0,035 7,2

8 9,3 9 –

– – – 9,2

10 11,2 12 13,6

– – – 14,3

0,15 0,2 0,15 0,3

7,9 8,6 8,2 9

10,1 11,4 12,8 15

0,15 0,2 0,15 0,3

0,015 0,03 0,02 0,025

– – –

9 10,5 13,9

15,1 18 21,3

16,5 19,1 22,4

0,3 0,3 0,3

8,7 9 9

17 20 24

0,3 0,3 0,3

0,03 7,9 0,03 7,2 0,035 12

9 9,8 10,5 –

– – – 9,8

10,9 12,2 13,5 15,5

– – – 16,7

0,15 0,2 0,2 0,3

8,9 9,6 9,6 9,7

11 12,4 14,4 17

0,15 0,2 0,2 0,3

0,015 0,02 0,02 0,025

– – –

10,5 11,9 13,9

18 18,7 21,3

19,1 19,9 22,4

0,3 0,3 0,3

10 10 10

20 22 26

0,3 0,3 0,3

0,03 7,2 0,03 10 0,035 12

9

10,3 11,5 11,6 – – –

– – – 12,1 13,9 15,3

12,7 14,5 16,2 19,5 21,3 23,8

13,2 – 17,5 20,5 22,4 25,3

0,1 0,2 0,3 0,3 0,6 0,6

9,8 10,6 11 11 13 13

13,3 15,4 18 22 22,6 26

0,1 0,2 0,3 0,3 0,6 0,6

0,015 0,02 0,025 0,03 0,03 0,035

7,8 7,7 13 7,5 12 13

10

11,2 – – –

– 11,8 11,8 13,2

13,6 16,3 16,3 18,2

– 17,2 17,2 19,4

0,15 0,3 0,3 0,3

11 11,5 11,5 12

14,5 17,5 17,5 20

0,15 0,3 0,3 0,3

0,015 0,02 0,02 0,025

8 15 15 14

7

8

7,9 7,4 7 6,8

8,1 8,3 7,2 7,3

8,2 7,8 7,5 6,6

389

1.6 Stainless steel deep groove ball bearings d 10 – 20 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

d2

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



10 cont.

26 30 35

8 9 11

3,97 4,36 7,02

1,96 2,32 3,4

0,083 0,1 0,146

67 000 60 000 53 000

40 000 36 000 34 000

17,5 29 50,5

W 6000 W 6200 W 6300

12

18 21 21 24

4 5 7 6

0,527 1,51 1,51 2,51

0,265 0,9 0,9 1,46

0,011 0,039 0,039 0,062

75 000 70 000 70 000 67 000

48 000 43 000 43 000 40 000

2,7 5,4 7,6 10,5

W 61701 W 61801 W 63801 W 61901

28 32 37

8 10 12

4,42 5,72 9,75

2,36 3 4,15

0,102 0,127 0,176

60 000 53 000 48 000

36 000 34 000 30 000

18,5 34,5 56,5

W 6001 W 6201 W 6301

21 24 24 28

4 5 7 7

0,527 1,65 1,65 3,71

0,29 1,08 1,08 2,24

0,012 0,048 0,048 0,095

67 000 60 000 60 000 56 000

40 000 38 000 38 000 34 000

3,3 6,4 9,1 15

W 61702 W 61802 W 63802 W 61902

32 35 42

9 11 13

4,88 6,37 9,95

2,8 3,6 5,4

0,12 0,156 0,232

50 000 48 000 40 000

32 000 30 000 26 000

27,5 42 78,5

W 6002 W 6202 W 6302

23 26 26 30

4 5 7 7

0,559 1,78 1,78 3,97

0,34 1,27 1,27 2,55

0,015 0,054 0,054 0,108

60 000 56 000 56 000 50 000

38 000 34 000 34 000 32 000

3,6 7,3 10 16

W 61703 W 61803 W 63803 W 61903

35 40 47

10 12 14

4,94 8,06 11,7

3,15 4,75 6,55

0,137 0,2 0,28

45 000 40 000 36 000

28 000 26 000 22 000

36,5 62 109

W 6003 W 6203 W 6303

27 32 32 37

4 7 10 9

0,676 3,12 3,12 5,53

0,39 2,08 2,08 3,65

0,017 0,09 0,09 0,156

50 000 48 000 48 000 43 000

32 000 30 000 30 000 26 000

5,4 16 23 33

W 61704 W 61804 W 63804 W 61904

42 47 52

12 14 15

9,36 12,5 13,8

5,1 6,55 7,8

0,212 0,28 0,335

38 000 34 000 34 000

24 000 22 000 20 000

62 102 140

W 6004 W 6204 W 6304

15

17

20

390

1.6

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D1 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



10 cont.

– – 17,7

13,9 15,3 –

21,3 23,8 27,4

22,4 25,3 29,3

0,3 0,6 0,6

12 14 14

24 26 31

0,3 0,6 0,6

0,03 12 0,03 13 0,035 11

12

13,8 – – –

– 13,8 13,8 15,3

16,1 18,3 18,3 20,3

16,7 19,2 19,2 21,4

0,2 0,3 0,3 0,3

13,5 13,5 13,5 14

17 19,5 19,5 22

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

– 18,5 19,3

16 – –

23,6 26,2 29,9

25,2 28 32

0,3 0,6 1

14 16 17

26 28,5 32,5

0,3 0,6 1

0,03 13 0,03 12 0,035 11

16,8 – – 18,8

– 16,8 16,8 –

19,1 21,3 21,3 24,2

19,7 22,2 22,2 25,3

0,2 0,3 0,3 0,3

16,5 16,5 16,5 17

20 22,5 22,5 26

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

– 21,7 24,5

18,6 – –

27 29,5 34,9

29,1 31,4 36,8

0,3 0,6 1

17 19 20

30 32 37,5

0,3 0,6 1

0,03 14 0,03 13 0,035 12

18,8 – – 21

– 18,8 18,8 –

21,1 23,3 23,3 26,8

21,7 24,2 24,2 27,8

0,2 0,3 0,3 0,3

18,5 18,5 18,5 19

22 24,5 24,5 28,5

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

23,5 24,9 27,5

– – –

30,1 33,6 38,9

31,9 35,8 41,1

0,3 0,6 1

19 21 22

33 37,5 42

0,3 0,6 1

0,03 14 0,03 13 0,035 12

22,3 – – –

– 22,6 22,6 23,6

24,6 28,2 28,2 32

25,5 29,6 29,6 33,5

0,2 0,3 0,3 0,3

21,5 22 22 22

26 30,5 30,5 35

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

27,6 29,5 30

– – –

35,7 39,5 41,7

38,8 41 45,4

0,6 1 1,1

24 25 26,5

39,5 42 46

0,6 1 1

0,03 14 0,03 13 0,035 12

15

17

20

8,2 13 13 15

8,4 14 14 14

8,5 14 14 15

8,7 13 13 15

391

1.6 Stainless steel deep groove ball bearings d 25 – 50 mm

B

r1

r2

r1

r2 D2

d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 25

C0

kN

d2

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



32 37 37 42

4 7 10 9

0,715 3,9 3,9 6,05

0,465 2,55 2,55 4,5

0,02 0,108 0,108 0,193

43 000 38 000 38 000 34 000

26 000 24 000 24 000 22 000

6,5 20 28,5 39,5

W 61705 W 61805 W 63805 W 61905

47 52 62

12 15 17

10,1 13,8 20,8

5,85 7,8 11,2

0,25 0,335 0,48

32 000 30 000 26 000

20 000 19 000 17 000

73 125 228

W 6005 W 6205 W 6305

37 42 42 47

4 7 10 9

0,65 3,58 3,58 6,24

0,53 2,9 2,9 5

0,022 0,125 0,125 0,212

36 000 34 000 34 000 30 000

22 000 20 000 20 000 19 000

7,6 23 35 44,5

W 61706 W 61806 W 63806 W 61906

55 62 72

13 16 19

13,3 19 22,9

8,3 11,4 15

0,355 0,48 0,64

28 000 26 000 22 000

17 000 16 000 14 000

108 188 340

W 6006 W 6206 W 6306

35

44 47 55 62 72 80

5 7 10 14 17 21

1,06 3,71 9,36 13,8 22,1 28,6

0,915 3,35 7,65 10,2 15,3 19

0,039 0,14 0,325 0,44 0,655 0,815

30 000 30 000 26 000 24 000 22 000 20 000

19 000 18 000 16 000 15 000 14 000 13 000

14 27 70 141 268 447

W 61707 W 61807 W 61907 W 6007 W 6207 W 6307

40

50 52 62 68 80

6 7 12 15 18

1,43 4,49 11,9 14,6 25,1

1,27 3,75 9,8 11,4 17,6

0,054 0,16 0,425 0,49 0,75

26 000 26 000 24 000 22 000 20 000

16 000 16 000 14 000 14 000 12 000

21,5 29,5 105 177 345

W 61708 W 61808 W 61908 W 6008 W 6208

45

55 58 68 75 85

6 7 12 16 19

1,46 5,72 14 18,2 28,1

1,37 5 10,8 15 20,4

0,06 0,212 0,465 0,64 0,865

24 000 24 000 20 000 20 000 18 000

15 000 14 000 13 000 12 000 11 000

23,5 34,5 118 229 377

W 61709 W 61809 W 61909 W 6009 W 6209

50

62 65 72 80 90

6 7 12 16 20

1,53 5,07 12,5 19 30,2

1,53 5,5 11,6 16,6 23,2

0,067 0,236 0,5 0,71 0,98

22 000 20 000 19 000 18 000 17 000

13 000 13 000 12 000 11 000 10 000

35 48 132 246 428

W 61710 W 61810 W 61910 W 6010 W 6210

30

392

1.6

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D1 ~

D2 ~

r 1,2 min.

mm 25

Abutment and fillet dimensions

Calculation factors

da min.

kr

Da max.

ra max.

mm

f0



27,3 28,2 28,2 30,9

– – – –

29,7 33,2 33,2 37,5

30,3 34,2 34,2 39,5

0,2 0,3 0,3 0,3

26,5 27 27 27

31 35 35 40,5

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

31,7 34 38,1

– – –

40,3 44,2 51

42,8 45,8 53,3

0,6 1 1,1

29 30 31,5

44,5 47 55,5

0,6 1 1

0,03 15 0,03 14 0,035 13

32,4 33,1 33,1 35,1

– – – –

34,7 38,2 38,2 42

35,7 39,2 39,2 44,1

0,2 0,3 0,3 0,3

31,5 32 32 32

36 40 40 45

0,2 0,3 0,3 0,3

0,015 0,02 0,02 0,025

38 40,7 44,9

– – –

47,3 52,9 59,3

50 55,2 62,4

1 1 1,1

35 35 36,5

50,5 57 65,5

1 1 1

0,03 15 0,03 14 0,035 13

35

38 38,2 42,2 44 47,6 –

– – – – – 46,7

41,1 42,8 50,1 54,3 61,6 66,7

42,2 43,7 52,2 57,1 64,9 71,6

0,3 0,3 0,6 1 1,1 1,5

37 37 39 40 41,5 43

42,5 45 52,5 57,5 65,5 73,5

0,3 0,3 0,6 1 1 1,5

0,015 0,02 0,025 0,03 0,03 0,035

8,9 14 16 15 14 13

40

43,3 43,2 46,9 49,2 –

– – – – 50,1

46,8 48,1 55,6 59,6 67,2

47,9 49 57,6 62,5 70,8

0,3 0,3 0,6 1 1,1

42 42 44 45 46,5

48,5 50 59,5 63,5 73,5

0,3 0,3 0,6 1 1

0,015 0,02 0,025 0,03 0,03

9 15 16 15 14

45

48,3 48,2 52,4 54,5 –

– – – – 53,5

51,8 54 61,2 65,8 72,9

53,2 54,9 63,2 69 76,4

0,3 0,3 0,6 1 1,1

47 47 49 50 51,5

53,5 56 64 70 78,5

0,3 0,3 0,6 1 1

0,015 0,02 0,025 0,03 0,03

9,1 15 16 15 14

50

54,3 54,6 56,8 60 –

– – – – 60

57,8 60,3 65,6 71 78,1

59,2 61,6 67,9 74,6 82,2

0,3 0,3 0,6 1 1,1

52 52 54 55 56,5

60 63 68,5 75,5 83,5

0,3 0,3 0,6 1 1

0,015 0,02 0,025 0,03 0,03

9,2 15 16 16 14

30

8,8 14 14 15

8,9 14 14 16

393

1.7 Capped stainless steel deep groove ball bearings d 1,5 – 4 mm

B

r1

r2

r1

r2 2ZS

d2

d d1

D D2

2ZS

2RS1

2RS1

2Z

2Z

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



1,5

4 5 6

2 2,6 3

0,062 0,135 0,19

0,016 0,036 0,051

0,001 0,002 0,002

220 000 200 000 180 000

110 000 100 000 90 000

0,14 0,25 0,42

W 638/1.5-2Z W 639/1.5-2Z W 630/1.5-2Z

2

4 5 5

2 2,3 2,5

0,068 0,094 0,094

0,019 0,025 0,025

0,001 0,001 0,001

200 000 200 000 200 000

100 000 100 000 100 000

0,09 0,2 0,2

W 637/2-2Z W 638/2-2Z W 638/2 X-2Z

6 6 6 7 7

2,3 2,5 3 3 3,5

0,094 0,19 0,19 0,221 0,221

0,025 0,051 0,051 0,067 0,067

0,001 0,002 0,002 0,003 0,003

200 000 180 000 180 000 160 000 160 000

100 000 90 000 90 000 80 000 80 000

0,35 0,31 0,35 0,5 0,6

W 619/2-2Z W 619/2 X-2Z W 639/2-2Z W 602 X-2ZS W 630/2-2ZS

2,5

6 7 8 8

2,6 3,5 2,8 4

0,117 0,221 0,178 0,312

0,036 0,067 0,057 0,088

0,002 0,003 0,002 0,004

170 000 160 000 160 000 160 000

85 000 80 000 80 000 80 000

0,35 0,55 0,73 0,85

W 638/2.5-2Z W 639/2.5-2ZS W 60/2.5-2Z W 630/2.5-2Z

3

6 7 7 8 8 8

2,5 3 3 3 4 4

0,117 0,178 0,178 0,26 0,319 0,319

0,036 0,057 0,057 0,072 0,09 0,09

0,002 0,002 0,002 0,003 0,004 0,004

170 000 160 000 – 150 000 150 000 –

85 000 80 000 45 000 75 000 75 000 43 000

0,25 0,5 0,5 0,6 0,83 0,83

W 627/3-2Z W 638/3-2Z W 638/3-2RS1 W 619/3-2Z W 639/3-2Z W 639/3-2RS1

9 9 10 10 13 13

4 5 4 4 5 5

0,377 0,325 0,358 0,358 0,741 0,741

0,095 0,095 0,11 0,11 0,25 0,25

0,004 0,004 0,005 0,005 0,011 0,011

140 000 140 000 – 140 000 – 110 000

70 000 70 000 40 000 70 000 32 000 56 000

1 1 1,7 1,7 3,3 3,2

W 603 X-2Z W 630/3-2Z W 623-2RS1 W 623-2Z W 633-2RS1 W 633-2Z

7 7 8 9 9

2,5 2,5 3 4 4

0,143 0,143 0,225 0,364 0,364

0,053 0,053 0,072 0,114 0,114

0,002 0,002 0,003 0,005 0,005

150 000 150 000 150 000 140 000 –

75 000 75 000 75 000 70 000 40 000

0,3 0,3 0,5 0,9 1

W 627/4-2Z W 627/4-2ZS W 637/4 X-2Z W 638/4-2Z W 638/4-2RS1

4

394

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



1,5

2,1 2,5 3

– – –

3,5 4,5 5,4

0,05 0,15 0,15

1,9 2,4 2,7

2,1 2,5 2,9

3,6 4,5 5,4

0,05 0,15 0,15

0,02 0,025 0,03

6,4 5,9 6

2

2,5 2,7 2,7

– – –

3,7 4,4 4,4

0,05 0,08 0,1

2,4 2,5 2,6

2,5 2,6 2,6

3,8 4,5 4,5

0,05 0,08 0,1

0,02 0,02 0,02

6,7 6,5 6,5

2,7 3 3 – –

– – – 3,1 3,1

4,4 5,4 5,4 6,2 6,2

0,15 0,15 0,15 0,15 0,15

2,6 2,9 2,9 3 3

2,6 2,9 2,9 3,1 3,1

4,8 5,4 5,4 6,2 6,2

0,15 0,15 0,15 0,15 0,15

0,025 0,025 0,025 0,03 0,03

6,5 6 6 6,6 6,6

2,5

3,7 3,8 – 4,1

– – 3,8 –

5,4 6,2 6,4 7,1

0,08 0,15 0,15 0,15

3,1 3,7 3,7 3,7

3,6 3,8 3,8 4

5,5 6,2 6,8 7,2

0,08 0,15 0,15 0,15

0,02 0,025 0,03 0,03

7,1 6,6 7,1 5,9

3

3,7 – – 5 4,3 4,3

– 3,8 3,8 – – –

5,4 6,4 6,4 7,4 7,3 7,3

0,1 0,1 0,1 0,1 0,15 0,15

3,6 3,7 3,7 3,8 4,2 4,2

3,6 3,8 3,8 4,9 4,3 4,3

5,5 6,5 6,5 7,5 7,3 7,3

0,1 0,1 0,1 0,1 0,15 0,15

0,015 0,02 0,02 0,025 0,025 0,025

7,1 7,1 7,1 7,2 6,1 6,1

– – – – – –

4,3 4,3 4,3 4,3 6 6

7,9 7,9 8 8 11,4 11,4

0,15 0,15 0,15 0,15 0,2 0,2

4,2 4,2 4,2 4,2 4,6 4,6

4,3 4,3 4,3 4,3 5,9 5,9

8 8 8,8 8,8 11,5 11,5

0,15 0,15 0,15 0,15 0,2 0,2

0,03 0,03 0,03 0,03 0,035 0,035

6,4 6,4 6,3 6,3 6,4 6,4

4,8 4,8 5 5,2 5,2

– – – – –

6,5 6,3 7,4 8,1 8,1

0,1 0,1 0,1 0,1 0,1

4,6 4,6 4,8 4,8 4,8

4,7 4,7 4,9 5,1 5,1

6,5 6,4 7,5 8,2 8,2

0,1 0,1 0,1 0,1 0,1

0,015 0,015 0,02 0,02 0,02

7,6 7,6 7,2 6,5 6,5

4

395

1.7 Capped stainless steel deep groove ball bearings d 4 – 6 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm 4 cont.

5

6

396

2RS1

2RS1

2Z

Principal dimensions D

2ZS

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



10 10 11 11 12 12

4 4 4 4 4 4

0,637 0,637 0,54 0,54 0,54 0,54

0,25 0,25 0,176 0,176 0,176 0,176

0,011 0,011 0,008 0,008 0,008 0,008

– 130 000 130 000 – – 130 000

36 000 63 000 63 000 36 000 36 000 63 000

1,4 1,3 2,2 2,2 2,1 2,2

W 638/4 X-2RS1 W 638/4 X-2Z W 619/4-2Z W 619/4-2RS1 W 604-2RS1 W 604-2Z

13 13 16 16

5 5 5 5

0,741 0,741 0,761 0,761

0,25 0,25 0,265 0,265

0,011 0,011 0,011 0,011

– 110 000 – 100 000

32 000 56 000 30 000 50 000

3 3 5,2 5,3

W 624-2RS1 W 624-2Z W 634-2RS1 W 634-2Z

8 8 9 9

2,5 2,5 3 3

0,14 0,14 0,247 0,247

0,045 0,045 0,085 0,085

0,002 0,002 0,004 0,004

140 000 140 000 130 000 130 000

70 000 70 000 67 000 67 000

0,4 0,4 0,5 0,6

W 627/5-2Z W 627/5-2ZS W 637/5 X-2Z W 637/5 X-2ZS

11 11 11 11

4 4 5 5

0,403 0,403 0,403 0,403

0,143 0,143 0,143 0,143

0,006 0,006 0,006 0,006

– 120 000 120 000 –

34 000 60 000 60 000 34 000

1,8 1,5 1,8 1,8

W 628/5-2RS1 W 628/5-2Z W 638/5-2Z W 638/5-2RS1

13 13 13 14 14

4 4 5 5 5

0,761 0,761 0,761 0,761 0,761

0,335 0,335 0,335 0,26 0,26

0,014 0,014 0,014 0,011 0,011

110 000 – 110 000 – 110 000

56 000 32 000 56 000 30 000 53 000

2,3 2,3 2,9 3,4 3,4

W 619/5-2Z W 619/5-2RS1 W 619/5 X-2Z W 605-2RS1 W 605-2Z

16 16 19 19

5 5 6 6

1,43 1,43 2,34 2,34

0,63 0,63 0,88 0,88

0,027 0,027 0,038 0,038

– 100 000 85 000 –

28 000 50 000 43 000 24 000

4,9 4,8 8 8

W 625-2RS1 W 625-2Z W 635-2Z W 635-2RS1

10 13 13 15 15

3 5 5 5 5

0,286 0,618 0,618 0,761 0,761

0,112 0,224 0,224 0,265 0,265

0,005 0,01 0,01 0,011 0,011

120 000 – 110 000 – 100 000

60 000 30 000 53 000 30 000 50 000

0,7 2,5 2,5 3,8 3,9

W 627/6-2Z W 628/6-2RS1 W 628/6-2Z W 619/6-2RS1 W 619/6-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 4 cont.

5

6

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



5,9 5,9 – – – –

– – 5,6 5,6 5,6 5,6

8,8 8,8 9,9 9,9 9,9 9,9

0,2 0,2 0,15 0,15 0,2 0,2

5,6 5,6 5,2 5,2 5,3 5,3

5,8 5,8 5,5 5,5 5,5 5,5

8,8 8,8 10 10 10,4 10,4

0,2 0,2 0,15 0,15 0,2 0,2

0,02 0,02 0,025 0,025 0,03 0,03

12 12 6,4 6,4 6,4 6,4

– – – –

6 6 6,7 6,7

11,4 11,4 13 13

0,2 0,2 0,3 0,3

5,6 5,6 6 6

5,9 5,9 6,6 6,6

11,5 11,5 14 14

0,2 0,2 0,3 0,3

0,03 0,03 0,035 0,035

6,4 6,4 6,8 6,8

5,8 5,8 6 6

– – – –

7,5 7,4 8,4 8,2

0,1 0,1 0,15 0,15

5,6 5,6 5,9 5,9

5,7 5,7 5,9 5,9

7,5 7,5 8,4 8,2

0,1 0,1 0,15 0,15

0,015 0,015 0,02 0,02

7,8 7,8 7,6 7,6

6,8 6,8 – –

– – 6,2 6,2

9,9 9,9 9,9 9,9

0,15 0,15 0,15 0,15

6,2 6,2 5,9 5,9

6,7 6,7 6,1 6,1

10 10 10 10

0,15 0,15 0,15 0,15

0,02 0,02 0,02 0,02

7,1 7,1 7,1 7,1

– – – – –

6,6 6,6 6,6 6,9 6,9

11,2 11,2 11,2 12,2 12,2

0,2 0,2 0,2 0,2 0,2

6,3 6,3 6,3 6,6 6,6

6,5 6,5 6,5 6,8 6,8

11,4 11,4 11,4 12,4 12,4

0,2 0,2 0,2 0,2 0,2

0,025 0,025 0,025 0,03 0,03

11 11 11 6,6 6,6

– – – –

7,5 7,5 8,5 8,5

13,4 13,4 16,5 16,5

0,3 0,3 0,3 0,3

7 7 7 7

7,4 7,4 8,4 8,4

14 14 17 17

0,3 0,3 0,3 0,3

0,03 0,03 0,035 0,035

12 12 12 12

7 – – – –

– 7,4 7,4 7,5 7,5

9,4 11,7 11,7 13 13

0,1 0,15 0,15 0,2 0,2

6,8 7,2 7,2 7,3 7,3

6,9 7,3 7,3 7,4 7,4

9,5 11,8 11,8 13,4 13,4

0,1 0,15 0,15 0,2 0,2

0,015 0,02 0,02 0,025 0,025

7,8 7 7 6,8 6,8

397

1.7 Capped stainless steel deep groove ball bearings d 6 – 8 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm 6 cont.

7

8

398

2RS1

2Z

Principal dimensions D

2ZS

2ZS

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



16 16 17 17

5 5 6 6

0,761 0,761 1,95 1,95

0,265 0,265 0,83 0,83

0,011 0,011 0,036 0,036

– 100 000 – 95 000

30 000 50 000 26 000 48 000

4,7 4,8 5,8 6

W 619/6 X-2RS1 W 619/6 X-2Z W 606-2RS1 W 606-2Z

19 19 22 22

6 6 7 7

1,53 1,53 2,34 2,34

0,585 0,585 0,8 0,8

0,025 0,025 0,034 0,034

– 85 000 – 75 000

24 000 43 000 22 000 38 000

7,7 7,8 13 13

W 626-2RS1 W 626-2Z W 636-2RS1 W 636-2Z

11 14 14 17 17

3 5 5 5 5

0,302 0,663 0,663 0,923 0,923

0,104 0,26 0,26 0,365 0,365

0,004 0,011 0,011 0,016 0,016

110 000 100 000 – 90 000 –

56 000 50 000 28 000 45 000 26 000

0,8 2,8 2,8 5,1 5,2

W 627/7-2ZS W 628/7-2Z W 628/7-2RS1 W 619/7-2Z W 619/7-2RS1

19 19 22 22 26 26

6 6 7 7 9 9

1,53 1,53 1,99 1,99 3,97 3,97

0,585 0,585 0,78 0,78 1,96 1,96

0,025 0,025 0,034 0,034 0,083 0,083

– 85 000 – 75 000 – 67 000

24 000 43 000 22 000 38 000 19 000 32 000

7,3 7,4 12,5 12,5 23,5 24

W 607-2RS1 W 607-2Z W 627-2RS1 W 627-2Z W 637-2RS1 W 637-2Z

12 12 16 16 16 16

3,5 3,5 4 5 5 6

0,312 0,312 0,715 0,715 0,715 0,715

0,14 0,14 0,3 0,3 0,3 0,3

0,006 0,006 0,012 0,012 0,012 0,012

100 000 100 000 90 000 – 90 000 90 000

53 000 50 000 45 000 26 000 45 000 45 000

1,1 1 3,1 3,8 3,8 4,1

W 637/8-2Z W 637/8-2ZS W 618/8-2Z W 628/8-2RS1 W 628/8-2Z W 638/8-2Z

19 19 22 22

6 6 7 7

1,25 1,25 1,99 1,99

0,455 0,455 0,78 0,78

0,02 0,02 0,034 0,034

– 85 000 – 75 000

24 000 43 000 22 000 38 000

6,5 6,8 11,5 11,5

W 619/8-2RS1 W 619/8-2Z W 608-2RS1 W 608-2Z

24 24 28 28

8 8 9 9

2,47 2,47 3,97 3,97

1,12 1,12 1,96 1,96

0,048 0,048 0,083 0,083

70 000 – – 67 000

36 000 20 000 19 000 32 000

17 17 28 28,5

W 628-2Z W 628-2RS1 W 638-2RS1 W 638-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 6 cont.

7

8

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



– – – –

7,5 7,5 8,2 8,2

13 13 14,8 14,8

0,2 0,2 0,3 0,3

7,3 7,3 8 8

7,4 7,4 8,1 8,1

14,4 14,4 15 15

0,2 0,2 0,3 0,3

0,025 0,025 0,03 0,03

6,8 6,8 11 11

– – – –

8,5 8,5 10,5 10,5

16,5 16,5 19,1 19,1

0,3 0,3 0,3 0,3

8 8 8 8

8,4 8,4 10,4 10,4

17 17 20 20

0,3 0,3 0,3 0,3

0,03 0,03 0,035 0,035

7,9 7,9 7,2 7,2

8 – – – –

– 8,5 8,5 9,2 9,2

10,3 12,7 12,7 14,3 14,3

0,15 0,15 0,15 0,3 0,3

7,9 8,2 8,2 9 9

8 8,4 8,4 9,1 9,1

10,3 12,8 12,8 15 15

0,15 0,15 0,15 0,3 0,3

0,015 0,02 0,02 0,025 0,025

8,1 7,2 7,2 7,3 7,3

– – – – – –

9 9 10,5 10,5 13,9 13,9

16,5 16,5 19,1 19,1 22,4 22,4

0,3 0,3 0,3 0,3 0,3 0,3

8,7 8,7 9 9 9 9

8,9 8,9 10,4 10,4 13,8 13,8

17 17 20 20 24 24

0,3 0,3 0,3 0,3 0,3 0,3

0,03 0,03 0,03 0,03 0,035 0,035

7,9 7,9 7,2 7,2 12 12

9 9 – – – –

– – 9,6 9,6 9,6 9,6

11,4 11,4 14,2 14,2 14,2 14,2

0,1 0,1 0,2 0,2 0,2 0,2

8,8 8,8 9,5 9,5 9,5 9,5

8,9 9 9,6 9,6 9,6 9,6

11,5 11,5 14,4 14,4 14,4 14,4

0,1 0,1 0,2 0,2 0,2 0,2

0,02 0,02 0,02 0,02 0,02 0,02

8,2 8,2 7,5 7,5 7,5 7,5

– – – –

9,8 9,8 10,5 10,5

16,7 16,7 19,1 19,1

0,3 0,3 0,3 0,3

9,7 9,7 10 10

9,7 9,7 10,4 10,4

17 17 20 20

0,3 0,3 0,3 0,3

0,025 0,025 0,03 0,03

6,6 6,6 7,2 7,2

– – – –

11,9 11,9 13,9 13,9

19,9 19,9 22,4 22,4

0,3 0,3 0,3 0,3

10 10 10 10

11,8 11,8 13,8 13,8

22 22 26 26

0,3 0,3 0,3 0,3

0,03 0,03 0,035 0,035

10 10 12 12

399

1.7 Capped stainless steel deep groove ball bearings d 9 – 12 mm

B

r1

r2

r1

r2 2ZS

d2

d d1

D D2

2ZS

2RS1

2RS1

2Z

2Z

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm 9

10

12

400

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



14 17 17 17 20 20

4,5 5 5 6 6 6

0,52 0,761 0,761 0,761 2,12 2,12

0,236 0,335 0,335 0,335 1,06 1,06

0,01 0,014 0,014 0,014 0,045 0,045

95 000 – 85 000 85 000 80 000 –

45 000 24 000 43 000 43 000 40 000 22 000

1,8 4,2 4,1 4,9 7,7 7,6

W 637/9-2ZS W 628/9-2RS1 W 628/9-2Z W 638/9-2Z W 619/9-2Z W 619/9-2RS1

24 24 26 26 30 30

7 7 8 8 10 10

2,03 2,03 3,97 3,97 4,94 4,94

0,815 0,815 1,96 1,96 2,32 2,32

0,036 0,036 0,083 0,083 0,1 0,1

– 70 000 – 67 000 – 60 000

20 000 36 000 19 000 32 000 16 000 30 000

14,5 14,5 19 19,5 35 33,5

W 609-2RS1 W 609-2Z W 629-2RS1 W 629-2Z W 639-2RS1 W 639-2Z

15 15 19 19 19 19

4 4 5 5 7 7

0,488 0,488 1,48 1,48 1,48 1,48

0,22 0,22 0,83 0,83 0,83 0,83

0,009 0,009 0,036 0,036 0,036 0,036

– 85 000 – 80 000 80 000 –

24 000 43 000 22 000 38 000 38 000 22 000

1,8 1,8 5,2 5,1 7,1 7,1

W 61700 X-2RS1 W 61700 X-2Z W 61800-2RS1 W 61800-2Z W 63800-2Z W 63800-2RS1

22 22 26 26

6 6 8 8

2,7 2,7 3,97 3,97

1,27 1,27 1,96 1,96

0,054 0,054 0,083 0,083

– 70 000 – 67 000

20 000 36 000 19 000 32 000

9,4 9,5 18,5 18,5

W 61900-2RS1 W 61900-2Z W 6000-2RS1 W 6000-2Z

30 30 35 35

9 9 11 11

4,36 4,36 7,02 7,02

2,32 2,32 3,4 3,4

0,1 0,1 0,146 0,146

– 60 000 – 53 000

16 000 30 000 15 000 26 000

30,5 30,5 51 53

W 6200-2RS1 W 6200-2Z W 6300-2RS1 W 6300-2Z

18 18 21 21 21 21

4 4 5 5 7 7

0,527 0,527 1,51 1,51 1,51 1,51

0,265 0,265 0,9 0,9 0,9 0,9

0,011 0,011 0,039 0,039 0,039 0,039

– 75 000 – 70 000 – 70 000

22 000 38 000 20 000 36 000 20 000 36 000

3 2,9 6 5,8 8,2 7,8

W 61701-2RS1 W 61701-2Z W 61801-2RS1 W 61801-2Z W 63801-2RS1 W 63801-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 9

10

12

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



– – – – 11,6 11,6

10,2 10,7 10,7 10,7 – –

13,2 15,2 15,2 15,2 17,5 17,5

0,1 0,2 0,2 0,2 0,3 0,3

9,8 10,3 10,3 10,3 11 11

10,2 10,6 10,6 10,6 11,5 11,5

13,3 15,4 15,4 15,4 18 18

0,1 0,2 0,2 0,2 0,3 0,3

0,02 0,02 0,02 0,02 0,025 0,025

7,8 7,7 7,7 7,7 13 13

– – – – – –

12,1 12,1 13,9 13,9 15,3 15,3

20,5 20,5 22,4 22,4 25,3 25,3

0,3 0,3 0,6 0,6 0,6 0,6

11 11 13 13 13 13

12 12 13,8 13,8 15,2 15,2

22 22 22,6 22,6 26 26

0,3 0,3 0,6 0,6 0,6 0,6

0,03 0,03 0,03 0,03 0,035 0,035

7,5 7,5 12 12 13 13

11,2 11,2 – – – –

– – 11,8 11,8 11,8 11,8

14,2 14,1 17,2 17,2 17,2 17,2

0,15 0,15 0,3 0,3 0,3 0,3

11 11 11,5 11,5 11,5 11,5

11 11 11,5 11,5 11,5 11,5

14,5 14,5 17,5 17,5 17,5 17,5

0,15 0,15 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02 0,02

8 8 15 15 15 15

– – – –

13,2 13,2 13,9 13,9

19,4 19,4 22,4 22,4

0,3 0,3 0,3 0,3

12 12 12 12

13 13 13,5 13,5

20 20 24 24

0,3 0,3 0,3 0,3

0,025 0,025 0,03 0,03

14 14 12 12

– – 17,7 17,7

15,3 15,3 – –

25,3 25,3 29,3 29,3

0,6 0,6 0,6 0,6

14 14 14 14

15 15 17,5 17,5

26 26 31 31

0,6 0,6 0,6 0,6

0,03 0,03 0,035 0,035

13 13 11 11

13,8 13,8 – – – –

– – 13,8 13,8 13,8 13,8

16,7 16,7 19,2 19,2 19,2 19,2

0,2 0,2 0,3 0,3 0,3 0,3

13,5 13,5 13,5 13,5 13,5 13,5

13,5 13,5 13,5 13,5 13,5 13,5

17 17 19,5 19,5 19,5 19,5

0,2 0,2 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02 0,02

8,2 8,2 13 13 13 13

401

1.7 Capped stainless steel deep groove ball bearings d 12 – 17 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm 12 cont.

15

17

402

2RS1

2RS1

2Z

Principal dimensions D

2ZS

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



24 24 28 28

6 6 8 8

2,51 2,51 4,42 4,42

1,46 1,46 2,36 2,36

0,062 0,062 0,102 0,102

– 67 000 – 60 000

19 000 32 000 16 000 30 000

11 11,5 20 20

W 61901-2RS1 W 61901-2Z W 6001-2RS1 W 6001-2Z

32 32 37 37

10 10 12 12

5,72 5,72 9,75 9,75

3 3 4,15 4,15

0,127 0,127 0,176 0,176

– 53 000 – 48 000

15 000 28 000 14 000 24 000

36 36 57 60

W 6201-2RS1 W 6201-2Z W 6301-2RS1 W 6301-2Z

21 21 24 24 24 24

4 4 5 5 7 7

0,618 0,618 1,65 1,65 1,65 1,65

0,3 0,3 1,08 1,08 1,08 1,08

0,012 0,012 0,048 0,048 0,048 0,048

– 67 000 – 60 000 – 60 000

19 000 32 000 17 000 30 000 17 000 30 000

3,6 3,6 7,1 6,8 9,9 9,6

W 61702-2RS1 W 61702-2Z W 61802-2RS1 W 61802-2Z W 63802-2RS1 W 63802-2Z

28 28 32 32

7 7 9 9

3,71 3,71 4,88 4,88

2,24 2,24 2,8 2,8

0,095 0,095 0,12 0,12

– 56 000 – 50 000

16 000 28 000 14 000 26 000

16 16 29 29

W 61902-2RS1 W 61902-2Z W 6002-2RS1 W 6002-2Z

35 35 42 42

11 11 13 13

6,37 6,37 9,95 9,95

3,6 3,6 5,4 5,4

0,156 0,156 0,232 0,232

– 48 000 – 40 000

13 000 24 000 11 000 20 000

44 44 79,5 82,5

W 6202-2RS1 W 6202-2Z W 6302-2RS1 W 6302-2Z

23 23 26 26 26 26

4 4 5 5 7 7

0,559 0,559 1,78 1,78 1,78 1,78

0,34 0,34 1,27 1,27 1,27 1,27

0,015 0,015 0,054 0,054 0,054 0,054

– 60 000 – 56 000 – 56 000

17 000 30 000 16 000 28 000 16 000 28 000

3,9 3,9 8 7,6 11 10,5

W 61703-2RS1 W 61703-2Z W 61803-2RS1 W 61803-2Z W 63803-2RS1 W 63803-2Z

30 30 35 35

7 7 10 10

3,97 3,97 4,94 4,94

2,55 2,55 3,15 3,15

0,108 0,108 0,137 0,137

– 50 000 – 45 000

14 000 24 000 13 000 22 000

17,5 17 38,5 39

W 61903-2RS1 W 61903-2Z W 6003-2RS1 W 6003-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 12 cont.

15

17

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



– – – –

15,3 15,3 16 16

21,4 21,4 25,2 25,2

0,3 0,3 0,3 0,3

14 14 14 14

15 15 15,5 15,5

22 22 26 26

0,3 0,3 0,3 0,3

0,025 0,025 0,03 0,03

15 15 13 13

18,5 18,5 19,3 19,3

– – – –

28 28 32 32

0,6 0,6 1 1

16 16 17 17

18 18 19 19

28,5 28,5 32,5 32,5

0,6 0,6 1 1

0,03 0,03 0,035 0,035

12 12 11 11

16,8 16,8 – – – –

– – 16,8 16,8 16,8 16,8

19,7 19,7 22,2 22,2 22,2 22,2

0,2 0,2 0,3 0,3 0,3 0,3

16,5 16,5 16,5 16,5 16,5 16,5

16,5 16,5 16,5 16,5 16,5 16,5

20 20 22,5 22,5 22,5 22,5

0,2 0,2 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02 0,02

8,4 8,4 14 14 14 14

18,8 18,8 – –

– – 18,6 18,6

25,3 25,3 29,1 29,1

0,3 0,3 0,3 0,3

17 17 17 17

18,5 18,5 18,5 18,5

26 26 30 30

0,3 0,3 0,3 0,3

0,025 0,025 0,03 0,03

14 14 14 14

21,7 21,7 24,5 24,5

– – – –

31,4 31,4 36,8 36,8

0,6 0,6 1 1

19 19 20 20

21,5 21,5 24 24

32 32 37,5 37,5

0,6 0,6 1 1

0,03 0,03 0,035 0,035

13 13 12 12

18,8 18,8 – – – –

– – 18,8 18,8 18,8 18,8

21,7 21,7 24,2 24,2 24,2 24,2

0,2 0,2 0,3 0,3 0,3 0,3

18,5 18,5 18,5 18,5 18,5 18,5

18,5 18,5 18,5 18,5 18,5 18,5

22 22 24,5 24,5 24,5 24,5

0,2 0,2 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02 0,02

8,5 8,5 14 14 14 14

21 21 23,5 23,5

– – – –

27,8 27,8 31,9 31,9

0,3 0,3 0,3 0,3

19 19 19 19

20,5 20,5 23 23

28,5 28,5 33 33

0,3 0,3 0,3 0,3

0,025 0,025 0,03 0,03

15 15 14 14

403

1.7 Capped stainless steel deep groove ball bearings d 17 – 25 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm

2RS1

2RS1

2Z

Principal dimensions D

2ZS

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



17 cont.

40 40 47 47

12 12 14 14

8,06 8,06 11,7 11,7

4,75 4,75 6,55 6,55

0,2 0,2 0,28 0,28

– 40 000 – 36 000

12 000 20 000 10 000 18 000

64,5 65,5 113 113

W 6203-2RS1 W 6203-2Z W 6303-2RS1 W 6303-2Z

20

27 27 32 32 32 32

4 4 7 7 10 10

0,585 0,585 3,12 3,12 3,12 3,12

0,39 0,39 2,08 2,08 2,08 2,08

0,017 0,017 0,09 0,09 0,09 0,09

50 000 – – 48 000 – 48 000

26 000 14 000 13 000 24 000 13 000 24 000

5,7 5,9 18 17,5 24,5 24,5

W 61704-2ZS W 61704-2RS1 W 61804-2RS1 W 61804-2Z W 63804-2RS1 W 63804-2Z

37 37 42 42

9 9 12 12

5,53 5,53 9,36 9,36

3,65 3,65 5,1 5,1

0,156 0,156 0,212 0,212

– 43 000 – 38 000

12 000 20 000 11 000 19 000

35,5 35,5 65,5 65

W 61904-2RS1 W 61904-2Z W 6004-2RS1 W 6004-2Z

47 47 52 52

14 14 15 15

12,5 12,5 13,8 13,8

6,55 6,55 7,8 7,8

0,28 0,28 0,335 0,335

– 34 000 – 34 000

10 000 17 000 9 500 17 000

105 106 146 146

W 6204-2RS1 W 6204-2Z W 6304-2RS1 W 6304-2Z

32 37 37 37 37

4 7 7 10 10

0,618 3,9 3,9 3,9 3,9

0,465 2,55 2,55 2,55 2,55

0,02 0,108 0,108 0,108 0,108

– – 38 000 – 38 000

12 000 11 000 19 000 11 000 19 000

7,3 21,5 21 29,5 29,5

W 61705-2RS1 W 61805-2RS1 W 61805-2Z W 63805-2RS1 W 63805-2Z

42 42 47 47

9 9 12 12

6,05 6,05 10,1 10,1

4,5 4,5 5,85 5,85

0,193 0,193 0,25 0,25

– 34 000 – 32 000

10 000 17 000 9 500 16 000

42 42,5 77 78

W 61905-2RS1 W 61905-2Z W 6005-2RS1 W 6005-2Z

52 52 62 62

15 15 17 17

11,7 11,7 20,8 20,8

7,65 7,65 11,2 11,2

0,335 0,335 0,48 0,48

– 30 000 – 26 000

8 500 15 000 7 500 13 000

130 130 235 236

W 6205-2RS1 W 6205-2Z W 6305-2RS1 W 6305-2Z

25

404

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



17 cont.

24,9 24,9 27,5 27,5

– – – –

35,8 35,8 41,1 41,1

0,6 0,6 1 1

21 21 22 22

24,5 24,5 27 27

37,5 37,5 42 42

0,6 0,6 1 1

0,03 0,03 0,035 0,035

13 13 12 12

20

22,3 22,3 – – – –

– – 22,6 22,6 22,6 22,6

25,3 25,5 29,6 29,6 29,6 29,6

0,2 0,2 0,3 0,3 0,3 0,3

21,5 21,5 22 22 22 22

22 22 22,5 22,5 22,5 22,5

26 26 30,5 30,5 30,5 30,5

0,2 0,2 0,3 0,3 0,3 0,3

0,015 0,015 0,02 0,02 0,02 0,02

8,7 8,7 13 13 13 13

– – 27,6 27,6

23,6 23,6 – –

33,5 33,5 38,8 38,8

0,3 0,3 0,6 0,6

22 22 24 24

23,5 23,5 27,5 27,5

35 35 39,5 39,5

0,3 0,3 0,6 0,6

0,025 0,025 0,03 0,03

15 15 14 14

29,5 29,5 30 30

– – – –

41 41 45,4 45,4

1 1 1,1 1,1

25 25 26,5 26,5

29 29 29,5 29,5

42 42 46 46

1 1 1 1

0,03 0,03 0,035 0,035

13 13 12 12

27,3 28,2 28,2 28,2 28,2

– – – – –

30,3 34,2 34,2 34,2 34,2

0,2 0,3 0,3 0,3 0,3

26,5 27 27 27 27

27 28 28 28 28

31 35 35 35 35

0,2 0,3 0,3 0,3 0,3

0,015 0,02 0,02 0,02 0,02

8,8 14 14 14 14

30,9 30,9 31,7 31,7

– – – –

39,5 39,5 42,8 42,8

0,3 0,3 0,6 0,6

27 27 29 29

30,5 30,5 31,5 31,5

40,5 40,5 44,5 44,5

0,3 0,3 0,6 0,6

0,025 0,025 0,03 0,03

15 15 15 15

34 34 38,1 38,1

– – – –

45,8 45,8 53,3 53,3

1 1 1,1 1,1

30 30 31,5 31,5

33,5 33,5 38 38

47 47 55,5 55,5

1 1 1 1

0,03 0,03 0,035 0,035

14 14 13 13

25

405

1.7 Capped stainless steel deep groove ball bearings d 30 – 40 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm 30

35

40

406

2RS1

2Z

Principal dimensions D

2RS1

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



42 42 42 42 47 47

7 7 10 10 9 9

3,58 3,58 3,58 3,58 6,24 6,24

2,9 2,9 2,9 2,9 5 5

0,125 0,125 0,125 0,125 0,212 0,212

– 34 000 – 34 000 – 30 000

9 500 17 000 9 500 17 000 8 500 15 000

24,5 24 36 36 47,5 48,5

W 61806-2RS1 W 61806-2Z W 63806-2RS1 W 63806-2Z W 61906-2RS1 W 61906-2Z

55 55 62 62 72 72

13 13 16 16 19 19

13,3 13,3 19 19 22,9 22,9

8,3 8,3 11,4 11,4 15 15

0,355 0,355 0,48 0,48 0,64 0,64

– 28 000 – 26 000 – 22 000

8 000 14 000 7 000 13 000 6 300 11 000

113 115 196 196 352 350

W 6006-2RS1 W 6006-2Z W 6206-2RS1 W 6206-2Z W 6306-2RS1 W 6306-2Z

44 47 47 55 55

5 7 7 10 10

1,06 3,71 3,71 9,36 9,36

0,915 3,35 3,35 7,65 7,65

0,039 0,14 0,14 0,325 0,325

– – 30 000 – 26 000

8 500 8 500 15 000 7 500 13 000

15,5 29 28 74,5 74

W 61707-2RS1 W 61807-2RS1 W 61807-2Z W 61907-2RS1 W 61907-2Z

62 62 72 72 80 80

14 14 17 17 21 21

13,8 13,8 22,1 22,1 28,6 28,6

10,2 10,2 15,3 15,3 19 19

0,44 0,44 0,655 0,655 0,815 0,815

– 24 000 – 22 000 – 20 000

6 700 12 000 6 000 11 000 5 600 10 000

148 149 280 279 459 457

W 6007-2RS1 W 6007-2Z W 6207-2RS1 W 6207-2Z W 6307-2RS1 W 6307-2Z

50 52 52 62 62

6 7 7 12 12

1,43 4,49 4,49 11,9 11,9

1,27 3,75 3,75 9,8 9,8

0,054 0,16 0,16 0,425 0,425

– – 26 000 – 24 000

7 500 7 500 13 000 6 700 12 000

23,5 32 31 111 112

W 61708-2RS1 W 61808-2RS1 W 61808-2Z W 61908-2RS1 W 61908-2Z

68 68 80 80

15 15 18 18

14,6 14,6 25,1 25,1

11,4 11,4 17,6 17,6

0,49 0,49 0,75 0,75

– 22 000 – 20 000

6 300 11 000 5 600 10 000

186 186 358 357

W 6008-2RS1 W 6008-2Z W 6208-2RS1 W 6208-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 30

35

40

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



33,1 33,1 33,1 33,1 35,1 35,1

– – – – – –

39,2 39,2 39,2 39,2 44,1 44,1

0,3 0,3 0,3 0,3 0,3 0,3

32 32 32 32 32 32

33 33 33 33 35 35

40 40 40 40 45 45

0,3 0,3 0,3 0,3 0,3 0,3

0,02 0,02 0,02 0,02 0,025 0,025

14 14 14 14 16 16

38 38 40,7 40,7 44,9 44,9

– – – – – –

50 50 55,2 55,2 62,4 62,4

1 1 1 1 1,1 1,1

35 35 35 35 36,5 36,5

37,5 37,5 40,5 40,5 44,5 44,5

50,5 50,5 57 57 65,5 65,5

1 1 1 1 1 1

0,03 0,03 0,03 0,03 0,035 0,035

15 15 14 14 13 13

38 38,2 38,2 42,2 42,2

– – – – –

42,2 43,7 43,7 52,2 52,2

0,3 0,3 0,3 0,6 0,6

37 37 37 39 39

37,5 38 38 42 42

42,5 45 45 52,5 52,5

0,3 0,3 0,3 0,6 0,6

0,015 0,02 0,02 0,025 0,025

8,9 14 14 16 16

44 44 47,6 47,6 – –

– – – – 46,7 46,7

57,1 57,1 64,9 64,9 71,6 71,6

1 1 1,1 1,1 1,5 1,5

40 40 41,5 41,5 43 43

43,5 43,5 47,5 47,5 46,5 46,5

57,5 57,5 65,5 65,5 73,5 73,5

1 1 1 1 1,5 1,5

0,03 0,03 0,03 0,03 0,035 0,035

15 15 14 14 13 13

43,3 43,2 43,2 46,9 46,9

– – – – –

47,9 49 49 57,6 57,6

0,3 0,3 0,3 0,6 0,6

42 42 42 44 44

43 43 43 46,5 46,5

48,5 50 50 59,5 59,5

0,3 0,3 0,3 0,6 0,6

0,015 0,02 0,02 0,025 0,025

9 15 15 16 16

49,2 49,2 – –

– – 50,1 50,1

62,5 62,5 70,8 70,8

1 1 1,1 1,1

45 45 46,5 46,5

49 49 50 50

63,5 63,5 73,5 73,5

1 1 1 1

0,03 0,03 0,03 0,03

15 15 14 14

407

1.7 Capped stainless steel deep groove ball bearings d 45 – 50 mm

B

r1

r2

r1

r2

2Z Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

B

mm 45

50

408

2RS1

2Z

Principal dimensions D

2RS1

d2

d d1

D D2

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

g



55 58 58 68 68

6 7 7 12 12

1,46 5,72 5,72 14 14

1,37 5 5 10,8 10,8

0,06 0,212 0,212 0,465 0,465

– – 24 000 – 20 000

6 700 6 700 12 000 6 000 10 000

26 37,5 36,5 125 125

W 61709-2RS1 W 61809-2RS1 W 61809-2Z W 61909-2RS1 W 61909-2Z

75 75 85 85

16 16 19 19

18,2 18,2 28,1 28,1

15 15 20,4 20,4

0,64 0,64 0,865 0,865

– 20 000 – 18 000

5 600 10 000 5 000 9 000

239 238 394 392

W 6009-2RS1 W 6009-2Z W 6209-2RS1 W 6209-2Z

62 65 65 72 72

6 7 7 12 12

1,53 5,07 5,07 12,5 12,5

1,53 5,5 5,5 11,6 11,6

0,067 0,236 0,236 0,5 0,5

– – 20 000 – 19 000

6 000 6 000 10 000 5 600 9 500

37,5 50,5 50 139 140

W 61710-2RS1 W 61810-2RS1 W 61810-2Z W 61910-2RS1 W 61910-2Z

80 80 90 90

16 16 20 20

19 19 30,2 30,2

16,6 16,6 23,2 23,2

0,71 0,71 0,98 0,98

– 18 000 – 17 000

5 000 9 000 4 800 8 500

258 258 444 448

W 6010-2RS1 W 6010-2Z W 6210-2RS1 W 6210-2Z

1.7

ra ra

Da

da

Dimensions d

d1 ~

d2 ~

D2 ~

r 1,2 min.

mm 45

50

Abutment and fillet dimensions

Calculation factors

da min.

kr

da max.

Da max.

ra max.

mm

f0



48,3 48,2 48,2 52,4 52,4

– – – – –

53,2 54,9 54,9 63,2 63,2

0,3 0,3 0,3 0,6 0,6

47 47 47 49 49

48 48 48 52 52

53,5 56 56 64 64

0,3 0,3 0,3 0,6 0,6

0,015 0,02 0,02 0,025 0,025

9,1 15 15 16 16

54,5 54,5 – –

– – 53,5 53,5

69 69 76,4 76,4

1 1 1,1 1,1

50 50 51,5 51,5

54 54 53,5 53,5

70 70 78,5 78,5

1 1 1 1

0,03 0,03 0,03 0,03

15 15 14 14

54,3 54,6 54,6 56,8 56,8

– – – – –

59,2 61,6 61,6 67,9 67,9

0,3 0,3 0,3 0,6 0,6

52 52 52 54 54

54 54,5 54,5 56,5 56,5

60 63 63 68,5 68,5

0,3 0,3 0,3 0,6 0,6

0,015 0,02 0,02 0,025 0,025

9,2 15 15 16 16

60 60 – –

– – 60 60

74,6 74,6 82,2 82,2

1 1 1,1 1,1

55 55 56,5 56,5

59,5 59,5 60 60

75,5 75,5 83,5 83,5

1 1 1 1

0,03 0,03 0,03 0,03

16 16 14 14

409

1.8 Single row deep groove ball bearings with filling slots d 25 – 85 mm

B

r1

r2

r1

r2

D D2

d d1

Z Principal dimensions

Basic load ratings dynamic static

d

C

D

B

mm

C0

kN

2Z Fatigue Speed ratings load limit Reference Limiting speed speed 1) Pu

Mass

Designations Bearing open with a shield on one side both sides

kN

r/min

kg



25

62

17

22,9

15,6

0,67

20 000

13 000

0,24

305

305-Z

305-2Z

30

62 72

16 19

20,9 29,7

16,3 21,6

0,695 0,93

20 000 18 000

12 000 11 000

0,21 0,37

206 306

206-Z 306-Z

206-2Z 306-2Z

35

72 80

17 21

27,5 34,7

22 26,5

0,93 1,12

17 000 16 000

10 000 9 500

0,31 0,48

207 307

207-Z 307-Z

207-2Z 307-2Z

40

80 90

18 23

33,6 45,7

27 36

1,16 1,53

15 000 14 000

9 500 8 500

0,39 0,64

208 308

208-Z 308-Z

208-2Z 308-2Z

45

85 100

19 25

35,2 55

30 44

1,27 1,86

14 000 13 000

8 500 7 500

0,44 0,88

209 309

209-Z 309-Z

209-2Z 309-2Z

50

90 110

20 27

39,1 64,4

34,5 52

1,46 2,2

13 000 11 000

8 000 7 000

0,5 1,15

210 310

210-Z 310-Z

210-2Z 310-2Z

55

100 120

21 29

48,4 79,2

44 67

1,86 2,85

12 000 10 000

7 000 6 300

0,66 1,5

211 311

211-Z 311-Z

211-2Z 311-2Z

60

110 130

22 31

56,1 91,3

50 78

2,12 3,35

11 000 9 500

6 700 6 000

0,85 1,85

212 312

212-Z 312-Z

212-2Z 312-2Z

65

120 140

23 33

60,5 102

58,5 90

2,5 3,75

10 000 9 000

6 000 5 300

1,05 2,3

213 313

213-Z 313-Z

213-2Z 313-2Z

70

125 150

24 35

66 114

65,5 102

2,75 4,15

9 500 8 000

5 600 5 000

1,15 2,75

214 314

214-Z 314-Z

214-2Z 314-2Z

75

130 160

25 37

72,1 125

72 116

3 4,55

9 000 7 500

5 300 4 800

1,25 3,25

215 315

215-Z 315-Z

215-2Z 315-2Z

80

140 170

26 39

88 138

85 129

3,45 4,9

8 500 7 000

5 000 4 300

1,55 3,95

216 316

216-Z 316-Z

216-2Z 316-2Z

85

150 180

28 41

96,8 147

100 146

3,9 5,3

7 500 6 700

4 800 4 000

1,95 4,6

217 317

217-Z 317-Z

217-2Z 317-2Z

1) For bearings with a shield on both sides (2Z), limiting speeds are about 80% of the quoted value.

410

1.8

ra ra da

Da

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

r 1,2 min.

mm

da min.

d a 1) max.

Da max.

ra max.

mm

Minimum load factor kr –

25

36,6

52,7

1,1

32

32,7

55

1

0,05

30

40,3 44,6

54,1 61,9

1 1,1

35,6 37

40,2 44,5

56,4 65

1 1

0,04 0,05

35

46,9 49,5

62,7 69,2

1,1 1,5

42 44

46,8 49,4

65 71

1 1,5

0,04 0,05

40

52,6 56,1

69,8 77,7

1,1 1,5

47 49

52,5 56

73 81

1 1,5

0,04 0,05

45

57,6 62,1

75,2 86,7

1,1 1,5

52 54

57,5 62

78 91

1 1,5

0,04 0,05

50

62,5 68,7

81,7 95,2

1,1 2

57 61

62,4 68,6

83 99

1 2

0,04 0,05

55

69 75,3

89,4 104

1,5 2

64 66

68,9 75,2

91 109

1,5 2

0,04 0,05

60

75,5 81,8

98 113

1,5 2,1

69 72

75,4 81,7

101 118

1,5 2

0,04 0,05

65

83,3 88,3

106 122

1,5 2,1

74 77

83,2 88,2

111 128

1,5 2

0,04 0,05

70

87 93,7

111 130

1,5 2,1

79 82

87 93,7

116 138

1,5 2

0,04 0,05

75

92 99,7

117 139

1,5 2,1

84 87

92 99,6

121 148

1,5 2

0,04 0,05

80

95,8 106

127 147

2 2,1

88,8 92

88,8 105

129 158

2 2

0,04 0,05

85

104 112

135 156

2 3

96 98

96,9 112

139 167

2 2,5

0,04 0,05

1) Only applicable for shielded bearings.

411

1.8 Single row deep groove ball bearings with filling slots d 90 – 100 mm

B

r1

r2

r1

r2

D D2

d d1

Z Principal dimensions

Basic load ratings dynamic static

d

C

D

B

mm

C0

kN

2Z Fatigue Speed ratings load limit Reference Limiting speed speed 1) Pu

Mass

Designations Bearing open with a shield on one side both sides

kN

r/min

kg



90

160 190

30 43

112 157

114 160

4,3 5,7

7 000 6 300

4 300 4 000

2,35 5,4

218 318

218-Z 318-Z

218-2Z 318-2Z

95

170

32

121

122

4,5

6 700

4 000

2,7

219

219-Z

219-2Z

100

180

34

134

140

5

6 300

4 000

3,45

220

220-Z

220-2Z

1) For bearings with a shield on both sides (2Z), limiting speeds are about 80% of the quoted value.

412

1.8

ra ra da

Da

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

r 1,2 min.

mm

da min.

d a 1) max.

Da max.

ra max.

mm

Minimum load factor kr –

90

110 119

143 164

2 3

100 103

110 118

150 177

2 2,5

0,04 0,05

95

116

152

2,1

107

116

158

2

0,04

100

123

160

2,1

112

122

168

2

0,04

1) Only applicable for shielded bearings.

413

1.9 Single row deep groove ball bearings with filling slots and a snap ring d 25 – 95 mm

r1 r1

C b

r2

f

B

r2

min. 0,5

r0

d d1

D D2

D4

D3

NR Principal dimensions d

D

B

mm

ZNR

2ZNR

Basic load ratings Fatigue dynamic static load limit Pu C C0

Speed ratings Mass ReferLimiting ence speed 1) speed

Designations Bearing open with a shield on one side both sides

kN

kN

r/min

kg



Snap ring

25

62

17

22,9

15,6

0,67

20 000

13 000

0,24

305 NR

305-ZNR

305-2ZNR

SP 62

30

62 72

16 19

20,9 29,7

16,3 21,6

0,695 0,93

20 000 18 000

12 000 11 000

0,21 0,37

206 NR 306 NR

206-ZNR 306-ZNR

206-2ZNR 306-2ZNR

SP 62 SP 72

35

72 80

17 21

27,5 34,7

22 26,5

0,93 1,12

17 000 16 000

10 000 9 500

0,31 0,48

207 NR 307 NR

207-ZNR 307-ZNR

207-2ZNR 307-2ZNR

SP 72 SP 80

40

80 90

18 23

33,6 45,7

27 36

1,16 1,53

15 000 14 000

9 500 8 500

0,39 0,64

208 NR 308 NR

208-ZNR 308-ZNR

208-2ZNR 308-2ZNR

SP 80 SP 90

45

85 100

19 25

35,2 55

30 44

1,27 1,86

14 000 13 000

8 500 7 500

0,44 0,88

209 NR 309 NR

209-ZNR 309-ZNR

209-2ZNR 309-2ZNR

SP 85 SP 100

50

90 110

20 27

39,1 64,4

34,5 52

1,46 2,2

13 000 11 000

8 000 7 000

0,5 1,15

210 NR 310 NR

210-ZNR 310-ZNR

210-2ZNR 310-2ZNR

SP 90 SP 110

55

100 120

21 29

48,4 79,2

44 67

1,86 2,85

12 000 10 000

7 000 6 300

0,66 1,5

211 NR 311 NR

211-ZNR 311-ZNR

211-2ZNR 311-2ZNR

SP 100 SP 120

60

110 130

22 31

56,1 91,3

50 78

2,12 3,35

11 000 9 500

6 700 6 000

0,85 1,85

212 NR 312 NR

212-ZNR 312-ZNR

212-2ZNR 312-2ZNR

SP 110 SP 130

65

120 140

23 33

60,5 102

58,5 90

2,5 3,75

10 000 9 000

6 000 5 300

1,05 2,3

213 NR 313 NR

213-ZNR 313-ZNR

213-2ZNR 313-2ZNR

SP 120 SP 140

70

125 150

24 35

66 114

65,5 102

2,75 4,15

9 500 8 000

5 600 5 000

1,15 2,75

214 NR 314 NR

214-ZNR 314-ZNR

214-2ZNR 314-2ZNR

SP 125 SP 150

75

130

25

72,1

72

3

9 000

5 300

1,25

215 NR

215-ZNR

215-2ZNR

SP 130

80

140

26

88

85

3,45

8 500

5 000

1,55

216 NR

216-ZNR

216-2ZNR

SP 140

85

150

28

96,8

100

3,9

7 500

4 800

1,95

217 NR





SP 150

90

160

30

112

114

4,3

7 000

4 300

2,35

218 NR





SP 160

95

170

32

121

122

4,5

6 700

4 000

2,7

219 NR





SP 170

1) For bearings with a shield on both sides (2Z), limiting speeds are about 80% of the quoted value.

414

1.9 ba max. 0,5

ra

Da Db

da

Ca

Dimensions d

d1 ~

Abutment and fillet dimensions D2 ~

D3

D4

b

f

C

r0 r 1,2 max. min.

mm

da min.

d a 1) max.

Da Db max. min.

ba min.

Ca ra max. max.

mm

Minimum load factor kr –

25

36,6

59,61

67,7

1,9

1,7

3,28

0,6

1,1

32

32,7

55

69

2,2

4,98

1

0,05

30

40,3 54,1 59,61 44,6 61,9 68,81

67,7 78,6

1,9 1,9

1,7 1,7

3,28 3,28

0,6 0,6

1 1,1

35,6 37

40,2 44,5

56,4 69 65 80

2,2 2,2

4,98 4,98

1 1

0,04 0,05

35

46,9 49,5

62,7 69,2

68,81 76,81

78,6 86,6

1,9 1,9

1,7 1,7

3,28 3,28

0,6 0,6

1,1 1,5

42 44

46,8 49,4

65 71

80 88

2,2 2,2

4,98 4,98

1 1,5

0,04 0,05

40

52,6 69,8 56,1 77,7

76,81 86,79

86,6 96,5

1,9 2,7

1,7 3,28 2,46 3,28

0,6 0,6

1,1 1,5

47 49

52,5 56

73 81

88 98

2,2 3

4,98 5,74

1 1,5

0,04 0,05

45

57,6 75,2 62,1 86,7

81,81 96,8

91,6 1,9 106,5 2,7

1,7 3,28 2,46 3,28

0,6 0,6

1,1 1,5

52 54

57,5 62

78 91

93 108

2,2 3

4,98 5,74

1 1,5

0,04 0,05

50

62,5 81,7 86,79 96,5 2,7 68,7 95,2 106,81 116,6 2,7

2,46 3,28 2,46 3,28

0,6 0,6

1,1 2

57 61

62,4 68,6

83 99

98 118

3 3

5,74 5,74

1 2

0,04 0,05

55

69 89,4 75,3 104

96,8 106,5 2,7 115,21 129,7 3,1

2,46 3,28 2,82 4,06

0,6 0,6

1,5 2

64 66

68,9 75,2

91 109

108 131

3 3,5

5,74 1,5 6,88 2

0,04 0,05

60

75,5 98 81,8 113

106,81 116,6 2,7 125,22 139,7 3,1

2,46 3,28 2,82 4,06

0,6 0,6

1,5 2,1

69 72

75,4 81,7

101 118

118 141

3 3,5

5,74 1,5 6,88 2

0,04 0,05

65

83,3 106 88,3 122

115,21 129,7 3,1 135,23 149,7 3,1

2,82 4,06 2,82 4,9

0,6 0,6

1,5 2,1

74 77

83,2 88,2

111 128

131 151

3,5 3,5

6,88 1,5 7,72 2

0,04 0,05

70

87 93,7

111 130

120,22 134,7 3,1 145,24 159,7 3,1

2,82 4,06 2,82 4,9

0,6 0,6

1,5 2,1

79 82

87 93,7

116 138

136 162

3,5 3,5

6,88 1,5 7,72 2

0,04 0,05

75

92

117

125,22 139,7 3,1

2,82 4,06

0,6

1,5

84

92

121

141

3,5

6,88 1,5

0,04

80

95,8

127

135,23 149,7

3,1

2,82 4,9

0,6

2

88,8 88,8

129

151

3,5

7,72

2

0,04

85

104

135

145,24 159,7

3,1

2,82 4,9

0,6

2

96



139

162

3,5

7,72

2

0,04

90

110

143

155,22 169,7

3,1

2,82 4,9

0,6

2

100



150

172

3,5

7,72

2

0,04

95

116

152

163,65 182,9 3,5

3,1

0,6

2,1

107



158

185

4

8,79

2

0,04

52,7

5,69

1) Only applicable for shielded bearings.

415

1.10 Double row deep groove ball bearings d 10 – 65 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



10

30

14

9,23

5,2

0,224

40 000

22 000

0,049

4200 ATN9

12

32 37

14 17

10,6 13

6,2 7,8

0,26 0,325

36 000 34 000

20 000 18 000

0,052 0,092

4201 ATN9 4301 ATN9

15

35 42

14 17

11,9 14,8

7,5 9,5

0,32 0,405

32 000 28 000

17 000 15 000

0,059 0,12

4202 ATN9 4302 ATN9

17

40 47

16 19

14,8 19,5

9,5 13,2

0,405 0,56

28 000 24 000

15 000 13 000

0,09 0,16

4203 ATN9 4303 ATN9

20

47 52

18 21

17,8 23,4

12,5 16

0,53 0,68

24 000 22 000

13 000 12 000

0,14 0,21

4204 ATN9 4304 ATN9

25

52 62

18 24

19 31,9

14,6 22,4

0,62 0,95

20 000 18 000

11 000 10 000

0,17 0,34

4205 ATN9 4305 ATN9

30

62 72

20 27

26 41

20,8 30

0,88 1,27

17 000 16 000

9 500 8 500

0,29 0,5

4206 ATN9 4306 ATN9

35

72 80

23 31

35,1 50,7

28,5 38

1,2 1,63

15 000 14 000

8 000 7 500

0,4 0,68

4207 ATN9 4307 ATN9

40

80 90

23 33

37,1 55,9

32,5 45

1,37 1,9

13 000 12 000

7 000 6 700

0,5 0,95

4208 ATN9 4308 ATN9

45

85 100

23 36

39 68,9

36 56

1,53 2,4

12 000 11 000

6 700 6 000

0,54 1,25

4209 ATN9 4309 ATN9

50

90 110

23 40

41 81,9

40 69,5

1,7 2,9

11 000 10 000

6 000 5 300

0,58 1,7

4210 ATN9 4310 ATN9

55

100 120

25 43

44,9 97,5

44 83

1,9 3,45

10 000 9 000

5 600 5 000

0,8 2,15

4211 ATN9 4311 ATN9

60

110 130

28 46

57,2 112

55 98

2,36 4,15

9 500 8 500

5 300 4 500

1,1 2,65

4212 ATN9 4312 ATN9

65

120 140

31 48

67,6 121

67 106

2,8 4,5

8 500 8 000

4 800 4 300

1,45 3,25

4213 ATN9 4313 ATN9

416

1.10

ra

ra da

Da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factor

da min.

kr

Da max.

ra max.

mm

f0



10

16,7

23,3

0,6

14,2

25,8

0,6

0,05

12

12

18,3 20,5

25,7 28,5

0,6 1

16,2 17,6

27,8 31,4

0,6 1

0,05 0,06

12 12

15

21,5 24,5

29 32,5

0,6 1

19,2 20,6

30,8 36,4

0,6 1

0,05 0,06

13 13

17

24,3 28,7

32,7 38,3

0,6 1

21,2 22,6

35,8 41,4

0,6 1

0,05 0,06

13 13

20

29,7 31,8

38,3 42,2

1 1,1

25,6 27

41,4 45

1 1

0,05 0,06

14 13

25

34,2 37,3

42,8 49,7

1 1,1

30,6 32

46,4 55

1 1

0,05 0,06

14 13

30

40,9 43,9

51,1 58,1

1 1,1

35,6 37

56,4 65

1 1

0,05 0,06

14 13

35

47,5 49,5

59,5 65,4

1,1 1,5

42 44

65 71

1 1,5

0,05 0,06

14 13

40

54 56,9

66 73,1

1,1 1,5

47 49

73 81

1 1,5

0,05 0,06

15 14

45

59,5 63,5

71,5 81,5

1,1 1,5

52 54

78 91

1 1,5

0,05 0,06

15 14

50

65,5 70

77,5 90

1,1 2

57 61

83 99

1 2

0,05 0,06

15 14

55

71,2 76,5

83,8 98,5

1,5 2

64 66

91 109

1,5 2

0,05 0,06

16 14

60

75,6 83,1

90,4 107

1,5 2,1

69 72

101 118

1,5 2

0,05 0,06

15 14

65

82,9 89,6

99,1 115

1,5 2,1

74 77

111 128

1,5 2

0,05 0,06

15 14

417

1.10 Double row deep groove ball bearings d 70 – 90 mm

B

r1

r2

r1

r2 d d1

D D1

Principal dimensions

Basic load ratings dynamic static

Fatigue load limit

d

C

Pu

D

B

mm

C0

kN

Speed ratings Reference Limiting speed speed

Mass

Designation

kN

r/min

kg



70

125 150

31 51

70,2 138

73,5 125

3,1 5

8 000 7 000

4 300 3 800

1,5 3,95

4214 ATN9 4314 ATN9

75

130 160

31 55

72,8 156

80 143

3,35 5,5

7 500 6 700

4 000 3 600

1,6 4,8

4215 ATN9 4315 ATN9

80

140

33

80,6

90

3,6

7 000

3 800

2

4216 ATN9

85

150

36

93,6

102

4

7 000

3 600

2,55

4217 ATN9

90

160

40

112

122

4,65

6 300

3 400

3,2

4218 ATN9

418

1.10

ra

ra da

Da

Dimensions d

d1 ~

D1 ~

r 1,2 min.

mm

Abutment and fillet dimensions

Calculation factor

da min.

kr

Da max.

ra max.

mm

f0



70

89,4 96,7

106 124

1,5 2,1

79 82

116 138

1,5 2

0,05 0,06

15 14

75

96,9 103

114 132

1,5 2,1

84 87

121 148

1,5 2

0,05 0,06

16 14

80

102

120

2

91

129

2

0,05

16

85

105

125

2

96

139

2

0,05

15

90

114

136

2

101

149

2

0,05

15

419

Distributed by: Intech Bearing Inc., 4955 Gulf Freeway, Houston, TX 77023 ph.: 713.926.1136, toll-free: 800.327.7424, fax: 713.926.3110, www.intechbearing.com

2 Y-bearings (insert bearings)

Designs and variants. . . . . . . . . . . . . . . Y-bearings with grub screws. . . . . . . . . . Basic design bearings. . . . . . . . . . . . . . Bearings with zinc-coated rings. . . . . . Stainless steel bearings. . . . . . . . . . . . Y-bearings with an eccentric locking collar. . . . . . . . . . . . . . . . . . . . . . . SKF ConCentra Y-bearings. . . . . . . . . . . Y-bearings with a tapered bore. . . . . . . . Y-bearings with a standard inner ring. . . Cages. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sealing solutions . . . . . . . . . . . . . . . . . . . Standard seals. . . . . . . . . . . . . . . . . . . Standard seals with additional flingers. . . . . . . . . . . . . . . . . . . . . . . . . Multiple seals . . . . . . . . . . . . . . . . . . . . 5-lip seals. . . . . . . . . . . . . . . . . . . . . . . Seals for SKF Energy Efficient Y-bearings. . . . . . . . . . . . . . . . . . . . . . . RS1 seals . . . . . . . . . . . . . . . . . . . . . . . Shields. . . . . . . . . . . . . . . . . . . . . . . . . . Greases for capped bearings. . . . . . . . Grease life for Y-bearings. . . . . . . . . . . Relubrication . . . . . . . . . . . . . . . . . . . . Y-bearings for agricultural applications. Rubber seating rings . . . . . . . . . . . . . . . .

422 424 424 424 424 425 426 427 428 428 429 429 429 429 430 430 430 431 431 432 434 435 436

Performance classes. . . . . . . . . . . . . . . 438 SKF Energy Efficient (E2) bearings. . . . . 438 Bearing data. . . . . . . . . . . . . . . . . . . . . . 440 (Dimension standards, tolerances, radial internal clearance, misalignment, friction, starting torque, power loss, defect frequencies) Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444 (Minimum load, axial load carrying capacity, equivalent loads)

Temperature limits . . . . . . . . . . . . . . . . 446 Permissible speed. . . . . . . . . . . . . . . . . . 446 Design of bearing arrangements. . . . . 447 Axial displacement. . . . . . . . . . . . . . . . . . 447 Shaft tolerances. . . . . . . . . . . . . . . . . . . . 450 Mounting and dismounting. . . . . . . . . . 451 Assembling Y-bearings into housings with fitting slots. . . . . . . . . . . . 454 SKF ConCentra Y-bearings. . . . . . . . . . . 455 Designation system . . . . . . . . . . . . . . . . 456 Product tables 2.1 Y-bearings with grub screws, metric shafts. . . . . . . . . . . . . . . . . . . 2.2 Y-bearings with grub screws, inch shafts. . . . . . . . . . . . . . . . . . . . . 2.3 Y-bearings with an eccentric locking collar, metric shafts. . . . . . . 2.4 Y-bearings with an eccentric locking collar, inch shafts. . . . . . . . . 2.5 SKF ConCentra Y-bearings, metric shafts. . . . . . . . . . . . . . . . . . . 2.6 SKF ConCentra Y-bearings, inch shafts. . . . . . . . . . . . . . . . . . . . . 2.7 Y-bearings with a tapered bore on an adapter sleeve, metric shafts. . . 2.8 Y-bearings with a tapered bore on an adapter sleeve, inch shafts. . . . . 2.9 Y-bearings with a standard inner ring, metric shafts. . . . . . . . . .

458 460 464 466 468 469 470 471 472

Other Y-bearings Bearings for extreme temperatures. . . . 1169 Bearings with Solid Oil. . . . . . . . . . . . . . . 1185 SKF DryLube bearings. . . . . . . . . . . . . . . 1191 Y-bearing units . . . . . . . . . . . † SKF catalogue Y-bearings and Y-bearing units 421

2  Y-bearings

Designs and variants Y-bearings (insert bearings) are based on sealed deep groove ball bearings in the 62 and 63 series. Y-bearings typically have a sphered (convex) outside surface and an extended inner ring († fig. 1) with different locking devices to enable quick and easy mounting onto the shaft. The various Y-bearing series differ in the way the bearing is locked onto the shaft: • with grub (set) screws († fig. 2) • with an eccentric locking collar († fig. 3) • with SKF ConCentra locking technology († fig. 4) • with an adapter sleeve († fig. 5) • with an interference fit († fig. 6) The standard SKF Y-bearing assortment includes application specific variants:

Other variants are available on request. These include Y-bearings with: • a cylindrical outer ring • a customized design or dimensions • a hexagonal or square bore • a special cage • special grease and special grease quantity • a special coating For additional information about these variants, contact the SKF application engineering service. Y-bearing units

SKF also supplies a wide variety of Y-bearing units, but are not listed in this rolling bearing catalogue. For information about Y-bearing units, refer to the SKF catalogue Y-bearings and Y-bearing units or the product information available online at skf.com/bearings.

• bearings made of stainless steel or with zinc-coated rings for the food industry († page 424) • bearings for agricultural applications († page 435) • bearings for extreme temperatures († page 1169) • bearings with Solid Oil († page 1185) • SKF DryLube bearings († page 1191)

More information Bearing life and load ratings. . . . . . Design considerations. . . . . . . . . . . Bearing systems. . . . . . . . . . . . . . . . . Recommended fits. . . . . . . . . . . . . . . Abutment and fillet dimensions. . . . .



63 159 160 169 208

Lubrication . . . . . . . . . . . . . . . . . . . . 239 Mounting, dismounting and bearing care . . . . . . . . . . . . . . . . . . . 271 SKF bearing maintenance handbook . . . . . . . . . . . . (ISBN 978-91-978966-4-1)

422

Fig. 1

Design and variants Fig. 4

Fig. 2

Fig. 5

Fig. 3

Fig. 6

423

2

2  Y-bearings

Y-bearings with grub screws Y-bearings with grub (set) screws in the inner ring are locked onto the shaft by tightening the two cup point hexagonal grub screws, pos­ itioned 120° apart. These bearings are suitable for applications for both constant and alternating direction of rotation. Basic design bearings Two different basic design Y-bearings with grub screws are available. Y-bearings in the YAT 2 series († fig. 7) have an inner ring extended on one side. Y-bearings in the YAR 2 series († fig. 8) have an inner ring extended on both sides. This reduces the extent to which the inner ring can tilt on the shaft, which enables the bearing to run more smoothly. Bearings in both the YAT 2 and YAR 2 series are fitted with a rugged standard seal († Standard seals, page 429) and a flinger on both sides. Flinger options are: • a plain sheet steel flinger, designation suffix 2F • a rubberized sheet steel flinger (multiple seal), designation suffix 2RF Y-bearings in the YAT 2 and YAR 2 series have two lubrication holes in the outer ring as standard, one on each side, positioned 120° apart. Bearings without lubrication holes can be supplied on request (designation suffix W).

SKF YAT 2 and YAR 2 series bearings are available for metric shafts from 12 to 100 mm and for inch shafts from 1 /2 to 3 inches. Bearings with zinc-coated rings Y-bearings with an inner ring extended on both sides are also available with zinc-coated rings for use in corrosive environments. Bearings in the YAR 2..-2RF/VE495 series are fitted with a highly effective multiple seal († Multiple seals, page 429) made of food-compatible rubber with a stainless steel insert and a stainless steel flinger on both sides. The grub screws are made of stainless steel. The bearings are filled with a food-grade grease and can be relubricated through one of the two lubrication holes in the outer ring. The lubrication holes are positioned 120° apart, one on each side. SKF Y-bearings with zinc-coated rings are available for metric shafts from 20 to 50 mm and for inch shafts from 3 /4 to 1 15 /16 inches. Stainless steel bearings All steel components of these bearings are made of stainless steel, including rings, balls, sheet metal parts of both seals and flingers, and grub screws. The inner ring is extended on both sides. Bearings in the YAR 2..-2RF/HV series are fitted with a highly effect­ive multiple seal († Multiple seals, page 429) made of foodcompatible rubber with a stainless steel insert and a stainless steel flinger on both sides. They are filled with a food-grade grease and can be relubricated through the lubrication

Fig. 7

YAT 2

424

Fig. 8

YAR 2

Design and variants

2

hole in the outer ring groove. This lubrication groove is located on the side oppos­ite the locking device. The dynamic load carrying capacity of a stainless steel bearing is less than that of a same-sized bearing made of high grade carbon chromium steel. SKF stainless steel Y-bearings are available for metric shafts from 20 to 50 mm and for inch shafts from 3 /4 to 1 15 /16 inches.

Y-bearings with an eccentric locking collar Y-bearings with an eccentric locking collar are intended primarily for use in applications where the direction of rotation is constant. On one side, the extended inner ring of the bearing has an eccentric step. The step accommodates the locking collar. Turning the locking collar in the direction of rotation locks the collar and bearing onto the shaft. A single grub screw further secures the collar to the shaft. The eccentric collar is zinc-coated for bearings with a metric bore and black oxidized for bearings with an inch bore. There are two standard series available from SKF. Y-bearings in the YET 2 series have an inner ring extended on one side († fig. 9). Y-bearings in the YEL 2 series have an inner ring extended on both sides († fig. 10). This reduces the extent to which the inner ring can tilt on the shaft, which enables the bearing to run more smoothly. Bearings in both the YET2 and YEL 2 series are fitted with a rugged standard seal († Standard seals, page 429) and a flinger on both sides. Flinger options are:

Fig. 9

YET 2

Fig. 10

• a plain sheet steel flinger, designation suffix 2F • a rubberized sheet steel flinger (multiple seal), designation suffix 2RF/VL065 Y-bearings in the YET 2 and YEL 2 series have two lubrication holes in the outer ring as standard, one on each side, positioned 120° apart. Bearings without lubrication holes can be supplied on request (designation suffix W). SKF Y-bearings with an eccentric locking collar are available for metric shafts from 15 to 60 mm and for inch shafts from 1 /2 to 2 7/16 inches.

YEL 2

425

2  Y-bearings

SKF ConCentra Y-bearings SKF ConCentra Y-bearings have an inner ring symmetrically extended on both sides († fig. 11). The patented SKF ConCentra locking technology is based on the expansion and contraction of two mating surfaces: the bearing bore and the external surface of the stepped sleeve. Both surfaces have precisionengineered serrations. When the grub screws in the mounting collar are tightened, the inner ring is displaced axially, relative to the stepped sleeve († fig. 12). This forces the bearing inner ring to expand and the stepped sleeve to contract evenly, providing a true concentric fit on the shaft. SKF ConCentra Y-bearings provide an easy, quick and reliable way to lock a bearing onto a shaft. The true concentric fit on the shaft provides low noise and vibration levels and virtually eliminates fretting corrosion. Even more important is that the fit on the shaft does not loosen, even in applications where there are heavy loads and/or high speeds. The shaft tolerance does not limit the permissible bearing speed and the full limiting speed can be achieved, even when using commercial grade shafts. The bearings can be used in applications for both constant and alternating direction of rotation. SKF ConCentra Y-bearings, series designation YSP 2, are equipped with a rugged standard seal on both sides, fitted with additional plain sheet steel flingers († Standard seals with additional flingers, page 429). The outer ring has two lubrication holes as standard, one

Fig. 11

on each side, positioned 120° apart. Bearings without lubrication holes can be supplied on request (designation suffix W). SKF Y-bearings in the YSP 2 series are available for metric shafts from 25 to 60 mm and for inch shafts from 1 to 2 11 /16 inches.

Fig. 12

Prior to installation

426

After installation

Design and variants

Y-bearings with a tapered bore

Fig. 13

Y-bearings with a tapered bore († fig. 13) have an inner ring symmetrically extended on both sides and a tapered bore (taper 1:12) enabling them to be mounted on a standard H 23 series adapter sleeve. Mounting onto an adapter sleeve enables the bearings to run smoothly and the full limiting speed can be achieved, even when using commercial grade shafts. The bearings can be used in applications for both constant and alternating direction of rotation. The appropriate adapter sleeve is not part of the bearing and must be ordered separately. Y-bearings with a tapered bore, series designation YSA 2, are equipped with a rugged standard seal, fitted with an additional plain sheet steel flinger on both sides († Standard seals with additional flingers, page 429). The outer ring has two lubrication holes as standard, one on each side, positioned 120° apart. Bearings without lubrication holes can be supplied on request (designation suffix W). SKF Y-bearings in the YSA 2 series are available with bore diameters ranging from 25 to 65 mm, which fit adapter sleeves in the H 23 series for metric shafts ranging from 20 to 60 mm. These bearings can also be used on adapter sleeves in the HA 23, HE 23 and HS 23 series for inch shafts ranging from 3 /4 to 2 3 /8 inches.

427

2

2  Y-bearings

Y-bearings with a standard inner ring Y-bearings with a standard inner ring († fig. 14) have normal tolerances for the bearing bore diameter and are locked onto the shaft using an appropriate interference fit. These bearings in the 17262 and 17263 series have the same dimensions and features as deep groove ball bearings in the 62 and 63 series, but have a sphered (convex) outside surface. The bearings are suitable for applications where the direction of the load alternates and where smooth running is a key operational parameter. They can accommodate heavier axial loads than any other Y-bearings and can operate at the same speeds as a corresponding sealed deep groove ball bearing. They do not have any lubrication holes in the outer ring. SKF Y-bearings with a standard inner ring are available for metric shafts from 17 to 60 mm.

Cages Y-bearings are fitted as standard with a ­snap-type, glass fibre reinforced PA66 cage († fig. 15), no designation suffix. The lubricants generally used for rolling bearings do not have a detrimental effect on cage properties. However, some synthetic greases with a synthetic oil base and lubricants containing a high proportion of EP additives, when used at high temperatures, can have a detrimental effect on polyamide cages. For additional information about the suitability of cages, refer to Cages († page 37) and Cage materials († page 152).

428

Fig. 14

Fig. 15

Design and variants

Sealing solutions

Fig. 16

SKF supplies all Y-bearings capped with a seal or shield on both sides. In typical Y-bearing applications, no additional external protection is necessary. Therefore, Y-bearings are available with several sealing arrangement designs to meet the demands of a wide range of operating conditions. Standard seals The standard seals for Y-bearings (no designation suffix) consist of a pressed sheet steel washer with a seal lip made of NBR, vulcanized to its inner surface († fig. 16). The non-contact sheet steel washer forms a narrow gap with the cylindrical surface of the inner ring shoulder and protects the land-­r iding seal against coarse contaminants.

Fig. 17

Standard seals with additional flingers For more contaminated environments, SKF recommends Y-bearings equipped with a standard seal and an additional plain flinger on both sides († fig. 17, designation suffix 2F). The flinger, made of sheet steel or stainless sheet steel, has an interference fit on the inner ring to considerably improve the effect­iveness of the seal without increasing friction. These seals are only available for bearings with an inner ring extended on both sides. Multiple seals For very contaminated environments, SKF recommends Y-bearings equipped with the highly effective multiple seal on both sides († fig. 18, designation suffix 2RF). This sealing arrangement consists of a standard seal and a flinger with a vulcanized NBR lip. The flinger lip seals axially against the standard seal. The space between the flinger lip and the shaft is filled with grease to provide additional protection. These seals are only available for bearings with an inner ring extended on both sides.

Fig. 18

429

2

2  Y-bearings 5-lip seals For extremely contaminated environments, such as agricultural applications, SKF recommends Y-bearings equipped with the patented 5-lip seal on both sides († fig. 19). The seal consists of a sheet steel insert with a vulcanized 5-lip contact seal made of a low-friction NBR compound. The steel insert, which protects the bearing from solid contaminants, is held in place by a groove in the bearing outer ring. Each seal lip has a different design to provide superior sealing performance in response to different operating conditions, including dynamic misalignment. The outermost and innermost lips act as a labyrinth to prevent contaminant ingress and grease leakage respectively. The three inner lips make constant contact with the inner ring shoulder.

Fig. 19

Fig. 20

Seals for SKF Energy Efficient Y-bearings These seals minimize the frictional moment in SKF Energy Efficient Y-bearings while providing effective protection in less contamin­ ated environments. The seals are made of NBR and are sheet steel reinforced. The lip has an innovative thin and flexible design († fig. 20). They are fitted in a recess on the outer ring and seal against the inner ring shoulder. The sheet steel insert protects against solid contaminants. Depending on the bearing series, the sealing effect can be enhanced by adding plain sheet steel flingers (designation suffix 2F). The flingers have an interference fit on the inner ring and do not increase friction. RS1 seals Y-bearings with a standard inner ring are equipped with an RS1 seal on both sides. These NBR contact seals, developed for standard SKF deep groove ball bearings, are reinforced with a sheet steel insert († fig. 21, designation suffix 2RS1). They are fitted in a recess on the outer ring and ride against the inner ring shoulder.

430

Fig. 21

Design and variants Shields On request, Y-bearings can be supplied with a shield on both sides. The sheet steel shields are fitted in a recess on the outer ring and do not make contact with the inner ring, but form a narrow gap († fig. 22, designation suffix VP076). They are designed for applications where the contamination level is low and add­ itional friction should be avoided. Bearings with shields should not be used if water, steam or moisture can enter the bearing.

Fig. 22

Greases for capped bearings Y-bearings are filled with one of the following greases: • SKF Energy Efficient Y-bearings † low-friction grease GE2 • zinc-coated and stainless steel Y-bearings † food-grade grease GFJ This grease fulfils the requirements listed in the Guidelines of section 21 CFR 178.3570 of the FDA (US Food and Drug Administration) regulations. It is approved by the USDA (United States Department of Agriculture) for Category H1 use (occasional contact with food stuffs). –50Y-bearings 0 50 100 150 200 250 °C • all other † standard grease VT307 The technical specifications for the various greases are listed in table 1.

Table 1 Technical specifications of SKF greases for Y-bearings Thickener

Base oil type

NLGI consistency class

Base oil viscosity [mm2 /s] at 40°C at 100 °C (105 °F) (210 °F)

VT307

Lithiumcalcium soap

Mineral

2

190

15

GFJ

Aluminiumcomplex soap

Synthetic hydrocarbon

2

100

14

GE2

Lithium soap

Synthetic

2

25

4,9

Grease

Temperature range 1) –50

0

50 100 150 200 250 °C

–60 30 120 210 300 390 480 °F

1) Refer to the SKF traffic light concept †

page 244 XX

431

2

2  Y-bearings Grease life for Y-bearings Grease life for Y-bearings should be estimated according to the procedure described in this section. The grease life for Y-bearings is pres­ ented as L 10, i.e. the time period at the end of which 90% of the bearings are still reliably lubricated. The method to estimate relubrication intervals († Relubrication intervals, page 252) represents the L01 grease life and should not be used. The grease life for Y-bearings depends on the operating temperature and the speed factor. It can be obtained from the diagrams. Diagram 1 is valid for Y-bearings filled with VT307 grease or GFJ food-grade grease. Diagram 2 is valid for SKF Energy Efficient Y-bearings. The grease life for each is valid under the following operating conditions: • horizontal shaft • very light to moderate loads (P ≤ 0,05 C) • stationary machine • low vibration levels If operating conditions differ, the grease life obtained from the diagrams has to be adjusted: • For vertical shafts, use 50% of the value from the diagram. • For heavier loads (P > 0,05 C), use the reduction factor listed in table 3. The values for adjusting the grease life are estimates. Vibration can have a negative influence on grease life. The extent cannot be quantified, and the influence increases with increasing operating temperature. For add­ itional information, refer to Lubrication († page 239) or contact the SKF application engineering service.

Table 2 Bearing mean diameter dm

dm

Bearing size 1)

Bearing mean diameter dm



mm

03 04 05

28,5 33,5 39

06 07 08

46 53,5 60

09 10 11

65 70 77,5

12 13 14

85 92,5 97,5

15 16 17

102,5 110 117,5

18 20

126 141

1) For example: bearing size 06 includes all bearings

based on a Y 206 bearing, such as YAR 206-101-2F, YAR 206-102-2F, YAR 206-2F, YAR 206-103-2F, YAR 206-104-2F Table 3

Reduction factor for the grease life, depending on the load

432

Load P

Reduction factor

≤ 0,05 C 0,1 C

1 0,7

0,125 C 0,25 C

0,5 0,2

Design and variants Diagram 1 Grease life for Y-bearings with VT307 or GFJ grease where load P = 0,05 C

Grease life L 10 [h]

100 000

n dm = 100 000 150 000 200 000 250 000 300 000 350 000

70 000 50 000 30 000 20 000

n dm = 20 000 50 000

10 000 7 000 5 000 3 000 2 000 1 000

40 (105)

50 (120)

60 (140)

70 (160)

80 (175)

90 (195)

100 (210)

110 (230)

120 (250)

Operating temperature [°C (°F)] n = rotational speed [r/min] dm = mean diameter [mm] † table 2 Diagram 2 Grease life for SKF Energy Efficient Y-bearings where load P = 0,05 C Grease life L 10 [h]

100 000 70 000 50 000 30 000 20 000

n dm = 100 000 150 000 200 000 250 000 300 000 350 000

n dm = 20 000 50 000

10 000 7 000 5 000 3 000 2 000 1 000 50 (120)

60 (140)

70 (160)

80 (175)

90 (195)

100 (210)

110 (230)

120 (250)

Operating temperature [°C (°F)] n = rotational speed [r/min] dm = mean diameter [mm] † table 2

433

2

2  Y-bearings Relubrication Y-bearings do not need relubrication when the grease life († Grease life for Y-bearings, page 432) exceeds the SKF rating life of the bearing († Selecting bearing size, page 61). Relubrication can extend bearing service life under any of the following conditions: • The bearings are exposed to high humidity or severe contamination. • The bearings accommodate normal or heavy loads. • The bearings operate for extended periods at high speeds or at temperatures above 55 °C (130 °F), above 75 °C (170 °F) for SKF Energy Efficient Y-bearings. • The bearings are subjected to high vibration levels. To relubricate Y-bearings, the following greases can be used: • SKF Energy Efficient Y-bearings † exclusively low-friction grease SKF LEGE 2 • zinc-coated and stainless steel Y-bearings † food-grade grease SKF LGFP 2 • all other Y-bearings † SKF LGWA 2, LGMT 2 or LGMT 3 grease If relubrication is needed, the relubrication intervals can be estimated following the method explained under Lubrication († page 239) When relubricating, the shaft should be turned and grease should be pumped slowly until fresh grease starts to escape from the seal(s). Excessive pressure from pumping too quickly can damage the seals. When machines and equipment are used for a limited period of time, SKF recommends relubricating each bearing at the end of the operational period, i.e. immediately before being laid up. Relubrication features

SKF Y-bearings are designed to facilitate relubrication. They have two lubrication holes in the outer ring as standard, one on each side, positioned 120° apart. Bearings without lubrication holes can be supplied on request (designation suffix W). The following bearings do not have the standard relubrication features:

434

• Stainless steel Y-bearings with grub screws have a lubrication groove in the outer ring located on the side opposite the locking device and one lubrication hole within this groove. • Y-bearings with a standard inner ring and Y-bearings for agricultural applications are lubricated for life and cannot be relubricated. They do not have any lubrication holes.

Design and variants

Y-bearings for agricultural applications Y-bearings for agricultural applications are designed to withstand the demanding operating conditions that occur in machinery like combines and balers, harvesters and disk ­harrows. Extensive laboratory tests and field experience confirm that these bearings outlast conventional bearings, which typically have a one to three year life span. Y-bearings for agricultural applications are equipped with a patented 5-lip seal on both sides († page 430). The bearings are lubricated for life with VT307 grease († table 1, page 431). The grease has a high resistance to water washout, enabling long bearing ser­vice life in wet environments. The bearings cannot be relubricated. Y-bearings for agricultural applications are dimensionally interchangeable with standard Y-bearings, enabling easy upgrades of existing applications to reduce machine downtime and environmental impact. SKF Y-bearings for agricultural applications are available for ­metric shafts from 20 to 50 mm and for inch shafts from 1 to 1 15 /16 inches. The bearings are available with three different locking methods († fig. 23):

• Y-bearings in the YARAG 2 series, which are interchangeable with bearings in the YAR 2 series, are locked onto the shaft with two grub screws. They are typically used for moderate loads. • Y-bearings in the YELAG 2 series, which are interchangeable with bearings in the YEL 2 series, are locked onto the shaft by an eccentric locking collar. The eccentric collar is black oxidized. The bearings are typically used for moderate loads. • Y-bearings in the YSPAG 2 series, which are interchangeable with bearings in the YSP 2 series, are locked onto the shaft by the patented SKF ConCentra locking technology. This locking technology enables the bearing to accommodate heavier loads than other locking methods. Other Y-bearings for agricultural applications are available on request: • bearings with zinc-coated rings • bearings with a cylindrical outer ring • bearings with other locking methods

Fig. 23

YARAG 2

YELAG 2

YSPAG 2

435

2

2  Y-bearings

Rubber seating rings Rubber seating rings in the RIS 2 series († fig. 24) are primarily intended to “cushion” Y-bearings in stamped steel plummer block housings. Located on the bearing outer ring and in housing bore († fig. 25), they are intended to dampen vibration and noise and enable the bearings to be displaced slightly in their housings to accommodate minor shaft elongation or misalignment. The seating rings in the RIS 2 series are made of NBR and have a sphered (convex) outside surface. The rings can withstand temperatures ranging from –30 to +100 °C (–20 to +210 °F). The designations and dimensions for rubber seating rings are listed in table 4. Rubber seating rings are available as an accessory and must be ordered separately. They can be fitted on all SKF Y-bearings, except for Y-bearings with a standard inner ring (17262 and 17263 series). However, Y-bearings in the YET 2 series can be supplied with the seating ring already fitted († fig. 26). These products are identified by the series prefix CYS, followed by the bearing bore diameter and the bearing identification suffix FM. E.g. CYS 20 FM is a YET 204 bearing with a 20 mm bore, fitted with an RIS 204 rubber seating ring.

Fig. 24

Fig. 25

Fig. 26

436

Design and variants

2

Table 4 Rubber seating rings

C B

D1

Y-bearing Outside diameter D mm

Size



d1 d2

Rubber seating ring Designation Dimensions d1 D1 mm –

d2

B

C

mm

Mass

g

40

03

RIS 203

47,3

35,5

39,8

12

18

12

47

04

RIS 204

52,3

41,2

46,8

14

19

11,5

52

05

RIS 205

62,3

46,4

51,8

15

20,5

26,5

62

06

RIS 206 A

72,3

54,6

61,8

18

21,5

31

72

07

RIS 207 A

80,3

63,7

71,8

19

23

32

80

08

RIS 208 A

85,3

70,7

79,7

21

24

26

437

2  Y-bearings

Performance classes SKF Energy Efficient (E2) bearings To meet the ever-increasing demand to reduce friction and energy consumption, SKF has developed the SKF Energy Efficient (E2) performance class of rolling bearings. Y-bearings within this performance class are characterized by a frictional moment in the bearing that is at least 50% lower when compared to a same-sized standard Y-bearing. This substantial reduction of the frictional moment was achieved by a new contact seal and applying a new, low-friction grease. Due to the reduction of the frictional moment, SKF E2 Y-bearings run up to 30 °C (55 °F) cooler than standard bearings. This extends grease life and potentially bearing service life. SKF E2 Y-bearings are dimensionally interchangeable with standard bearings enabling both, easy upgrades of existing applications as well as improving the energy efficiency of new applications. Typical applications include conveyors, industrial fans and textile machinery. SKF E2 Y-bearings are available in the YAR 2, YET 2 and SKF ConCentra YSP 2 series. Bearings in the YET 2 series are supplied with a contact seal on both sides († page 430). Bearings in the YAR 2 and YSP 2 series are equipped with a contact seal and a plain sheet steel flinger on both sides, improving the sealing effect without increasing friction. The good performance of the seal combined with the cooler running and the extended grease life enable SKF E2 Y-bearings to operate without relubrication under normal operating conditions. When necessary, they can be relubricated through the outer ring († Relubrication, page 434).

438

Performance classes

2

439

2  Y-bearings

Bearing data Y-bearings with grub screws (series YAT 2, YAR 2, YARAG 2)

with an eccentric locking collar (series YET 2, YEL 2, YELAG 2)

Dimension standards

Boundary dimensions: Boundary dimensions: ISO 9628 ISO 9628 Bearings in the YAT 2 series are not standardized. However, the bore and outside diameter and the outer ring width are in accordance with ISO 9628.

Tolerances

Values for the bore and outside diameter: († table 5, page 442) The values for bore and outside diameter tolerances are slightly tighter than those listed in ISO 9628.

For additional information († page 132) Radial internal clearance For additional information († page 149)

ISO 9628 – Group N Values: († table 6, page 442)

Misalignment

Static misalignment Y-bearings can accommodate initial misalignment by tilting in the housing († fig. 27, page 443), because of their sphered outside surface. The permissible values depend on the housing type:

Values are valid for unmounted bearings under zero measuring load.

• SKF cast iron and composite housings –– relubrication is not required † 5° –– relubrication is required † 2° Friction, starting torque, power loss

Frictional moment, starting torque and power loss can be calculated ...

Defect frequencies Defect frequencies can be calculated using the tools available online ...

440

Bearing data

2 with SKF ConCentra locking technology (series YSP 2, YSPAG 2)

with a tapered bore (series YSA 2)

with a standard inner ring (series 17262, 17263)

Boundary dimensions: not standardized However, the outside diameter and the outer ring width are in accordance with ISO 9628.

Boundary dimensions: JIS B 1558 Adapter sleeves in the H 23 series: ISO 2982-1

Boundary dimensions: ISO 15, except for the sphered outside surface

Values for the outside diameter: († table 5, page 442) Before mounting, the sleeve bore is larger than the nominal value to ease sliding on the shaft.

Values for the outside diameter:(† table 5, page 442) The tapered bore fits H23 series adapter sleeves, for metric and inch shafts.

Normal Values: ISO 492 († table 3, page 137), except for the sphered outside surface († table 5, page 442)

ISO 9628 – Group 3 Values: († table 6, page 442)

Normal Values: ISO 5753-1 († table 6, page 314)

• SKF stamped steel housings Misalignment cannot be accommodated once the attachment bolts have been fully tightened, unless a rubber seating ring is used († page 436). Dynamic misalignment Y-bearings can accommodate a few minutes of arc (misalignment) between the inner and outer rings. ... using the tools available online at skf.com/bearingcalculator.

... at skf.com/bearingcalculator.

441

2  Y-bearings Table 5 Tolerances for SKF Y-bearings Nominal diameter d, D over

incl.

mm

Inner ring Bearing series YAT 2, YAR 2, YARAG 2, YET 2, YEL 2, YELAG 2 D dmp high low

Outer ring All bearings D Dmp high

µm

µm

low

10 18

18 31,75

+15 +18

+5 +5

– –

– –

31,75 50,8

50,8 80,962

+19 +21

+5 +5

0 0

–10 –10

80,962 120 150

120 150 180

+25 – –

+5 – –

0 0 0

–15 –15 –20

d = nominal bore diameter Δ dmp = deviation of the mean bore diameter from the nominal D = nominal outside diameter Δ Dmp = deviation of the mean outside diameter from the nominal Table 6 Radial internal clearance for Y-bearings Bearing size 1)

Radial internal clearance of Y-bearings in the series

from

YET 2, YEL 2, YELAG 2 min. max.

to



YAT 2, YAR 2, YARAG 2,

YSP 2, YSPAG 2, YSA 2

min.

max.

µm

03 04 05

03 04 06

10 12 12

25 28 28

– – 23

– – 41

07 09 11

08 10 13

13 14 18

33 36 43

28 30 38

46 51 61

14 17

16 20

20 24

51 58

– –

– –

1) For example: bearing size 06 includes all bearings based on a Y 206 bearing, such as YAR 206-101-2F, YAR 206-102-2F,

YAR 206-2F, YAR 206-103-2F, YAR 206-104-2F

442

Bearing data Fig. 27



443

2

2  Y-bearings

Loads Symbols Minimum load

For additional information († page 86) Axial load ­c arrying capacity

Equivalent dynamic bearing load

= basic dynamic load rating († product tables) The importance of imposing a min­imum C0 = basic static load rating († product tables) load increases where accelerations in the bearing are high, and where speeds e = limiting value († table 7) are in the region of 75% or more of the f 0 = calculation factor limit­ing speed quoted in the product tables. The weight of the components († table 8) supported by the Y-bearing, together Fa = axial load [kN] with external forces, generally exceed Fr = radial load [kN] the requisite minimum load. Frm = minimum radial load [kN] P = equivalent dynamic Fa ≤ 0,25 C0 bearing load [kN] P 0 = equivalent static bearing load [kN] The maximal permissible axial load of X = radial load factor any locking mechnism is always († table 7) > 0,25 C0. Y = axial load factor († table 7) Fa /Fr ≤ e † P = Fr Fa /Fr > e † P = X Fr + Y Fa Frm = 0,01 C

For additional information († page 85) Equivalent static bearing load For additional information († page 88)

444

P 0 = 0,6 Fr + 0,5 Fa

C

Loads Table 7 Calculation factors Relative thrust load f 0 Fa /C 0

Bearing series YAT 2, YAR 2, YARAG 2, YET 2, YEL 2, YELAG 2, YSP 2, YSPAG 2, YSA 2 e X Y

0,172 0,345 0,689

0,29 0,32 0,36

0,46 0,46 0,46

1,03 1,38 2,07

0,38 0,4 0,44

3,45 5,17 6,89

0,49 0,54 0,54

17262, 17263 e

X

Y

1,88 1,71 1,52

0,19 0,22 0,26

0,56 0,56 0,56

2,3 1,99 1,71

0,46 0,46 0,46

1,41 1,34 1,23

0,28 0,3 0,34

0,56 0,56 0,56

1,55 1,45 1,31

0,46 0,46 0,46

1,1 1,01 1

0,38 0,42 0,44

0,56 0,56 0,56

1,15 1,04 1

Table 8 Calculation factor f 0 Bearing series sizes

Factor f 0

YAT 2, YAR 2, YARAG 2, YET 2, YEL 2, YELAG 2, YSP 2, YSPAG 2, YSA 2 03-04 05-12 13-18 20

13 14 15 14

17262 03-04 05-12

13 14

17263 05 06-10

12 13

445

2

2  Y-bearings

Temperature limits

Permissible speed

The permissible operating temperature for Y-bearings can be limited by:

Y-bearings should not operate at speeds above the limiting speed listed in the product tables. This speed limit is set by the seals. For Y-bearings with grub screws or an eccentric locking collar, the permissible speed is also influenced by the shaft tolerance. When using these bearings on shafts with wider tolerances than h6, compare the speed values listed in the product tables with those in table 9. The lower value is the permissible speed. The permissible speed of Y-bearings for agricultural applications is valid under the following conditions:

• the dimensional stability of the bearing rings and balls • the cage • the seals • the lubricant When temperatures outside the permissible range are expected, contact the SKF application engineering service. Bearing rings and balls

Y-bearings undergo a special heat treatment. The bearing rings and balls are heat stabilized up to at least 150 °C (300 °F). Cages

Table 9 Permissible speeds for Y-bearings with grub screws or an eccentric locking collar

For temperature limits of PA66 cages, refer to Cage materials († page 152).

Bearing size 1)

Permissible speed for shafts machined to tolerance class E h8 V E h9 V E h11V E h7V

Seals



r/min

The permissible operating temperature for NBR seals is –40 to +100 °C (–40 to +210 °F). Temperatures up to 120 °C (250 °F) can be tolerated for brief periods.

03 04 05

6 000 5 300 4 500

4 300 3 800 3 200

1 500 1 300 1 000

950 850 700

06 07 08

4 000 3 400 3 000

2 800 2 200 1 900

900 750 670

630 530 480

09 10 11

2 600 2 400 2 000

1 700 1 600 1 400

600 560 500

430 400 360

12 13 14

1 900 1 700 1 600

1 300 1 100 1 000

480 430 400

340 300 280

15 16 17

1 500 1 400 1 300

950 900 850

380 360 340

260 240 220

18 20

1 200 1 100

800 750

320 300

200 190

Lubricants

Temperature limits for the greases used in Y-bearings are provided in table 1 († page 431). Temperature limits for other SKF greases are provided under Lubrication († page 239). When using lubricants not supplied by SKF, the temperature limits should be evaluated according to the SKF traffic light concept († page 244).

1) For example: bearing size 06 includes all bearings based

on a Y 206 bearing, such as YAR 206-2F, YAR 206-101-2F, YAR 206-102-2F, YAR 206-103-2F, YAR 206-104-2F

446

Design of bearing arrangements • outer ring temperature ≤ 60 °C (140 °F) • environment temperature ≤ 25 °C (80 °F) • very light to moderate loads (P ≤ 0,05 C) • cast iron housing For other conditions, contact the SKF application engineering service. For applications operating at elevated speeds or when low vibration levels or quiet running are required, use SKF ConCentra Y-bearings, Y-bearings on an adapter sleeve or Y-bearings with a standard inner ring.

2

Design of bearing arrangements Axial displacement Y-bearings are not intended to accommodate axial displacement of the shaft relative to the housing. The distance between bearing pos­ itions should therefore be short to avoid exces­ sive induced axial loads as a result of thermal elongation of the shaft. Design for small axial displacement

To accommodate small axial displacement, the bearings should be supported by resilient sheet metal support surfaces or walls († fig. 28). Fig. 28

447

2  Y-bearings Design for larger axial displacement

In applications where there are slow speeds and light loads, a Y-bearing with grub screws can be used to accommodate axial displacement. The shaft at the non-locating bearing position should be provided with one or two grooves 120° apart, to engage a modified grub screw: • Hexagon socket grub (set) screws with a dog point, in accordance with ISO 4028, but with a fine thread according to table 10. The grub screw should be secured by a nut and spring washer or star lock washer († fig. 29). • Slotted pan head screws in accordance with ISO 1580, but with fine thread according to table 10, locked with a spring or star lock washer († fig. 30). The screws and groove(s) accommodate changes in shaft length and prevent the shaft from turning independently of the bearing. The ends of the grub screws should be ground and the sliding surfaces in the shaft grooves coated with a lubricant paste.

Fig. 29

448

Fig. 30

Design of bearing arrangements Table 10 Threaded holes in the inner ring of bearings in the YAT 2, YAR 2 and YARAG 2 series

G2

d1

Bearing size 1)

Outside diameter of inner ring d1

Threaded holes YAR bearing with metric bore G2



mm



03 04 05

24,2 28,2 33,7

06 07 08

YAR bearing with inch bore G2

YAT bearing with metric bore G2

YAT bearing with inch bore G2

M 6x0,75 M 6x0,75 M 6x0,75

#10-32 UNF 1/4-28 UNF 1/4-28 UNF

M 6x0,75 M 6x0,75 M 6x0,75

#10-32 UNF 1/4-28 UNF 1/4-28 UNF

39,7 46,1 51,8

M 6x0,75 M 6x0,75 M 8x1

1/4-28 UNF 5/16-24 UNF 5/16-24 UNF

M 6x0,75 M 6x0,75 M 6x0,75

5/16-24 UNF 5/16-24 UNF 5/16-24 UNF

09 10 11

56,8 62,5 69,1

M 8x1 M 10x1 M 10x1

5/16-24 UNF 3/8-24 UNF 3/8-24 UNF

M 6x0,75 M 8x1 –

5/16-24 UNF 3/8-24 UNF 3/8-24 UNF

12 13 14

75,6 82,5 87

M 10x1 M 10x1 M 10x1

3/8-24 UNF 3/8-24 UNF 7/16-20 UNF

– – –

3/8-24 UNF – –

15 16 17

92 97,4 105

M 10x1 M 10x1 M 12x1,5

7/16-20 UNF 7/16-20 UNF –

– – –

3/8-24 UNF 3/8-24 UNF –

18 20

112,5 124,8

M 12x1,5 M 12x1,5

– –

– –

– –

1) For example: bearing size 06 includes all bearings based on a Y 206 bearing, such as YAR 206-101-2F, YAR 206-102-2F,

YAR 206-2F, YAR 206-103-2F, YAR 206-104-2F

449

2

2  Y-bearings

Shaft tolerances Recommended fits for Y-bearings are listed in table 11. Fig. 31 illustrates the relative pos­ ition of the upper and lower limits of the most commonly used ISO shaft tolerance classes for Y-bearings with grub (set) screws or an eccentric locking collar. The values for these tolerance classes are listed in table 12. For Y-bearings on an adapter sleeve or SKF ConCentra Y-bearings the total radial run-out of the shaft seat should be IT5/2 for tolerance class h9V E . The values for the ISO tolerance class h9 are listed in table 12. For Y-bearings with a standard inner ring, the same recommendations apply as for standard deep groove ball bearings († table 11). The values for these ISO tolerance classes are listed in table 7 († page 178).

Table 11 Recommended fits Tolerance class 1)

Y-bearings with grub screws or an eccentric locking collar P > 0,05 C and/or high speeds

h6

0,035 C < P ≤ 0,05 C

h7

0,02 C < P ≤ 0,035 C and/or slow speeds

h8

Simple bearing arrangements or P ≤ 0,02 C

h9 – h11

1) All ISO tolerance classes are valid with the envelope

E ) in accordance with requirement (such as h7V ISO 14405-1.

450

h10 E

j6

h11 E

P ≤ 0,035 C Shaft diameter ≥ 20 mm

h8 E

j5 k5

h9 E

h9/IT5

Y-bearings with a standard inner ring P > 0,035 C Shaft diameter ≤ 17 mm Shaft diameter ≥ 20 mm

h6 E

Fig. 31

Y-bearings with a tapered bore on an adapter sleeve or SKF ConCentra Y-bearings All loads and speeds

h7 E

Operating conditions

Mounting and dismounting

Mounting and dismounting

Fig. 32

When mounting Y-bearings on a shaft, ­suitable tools should be used and the locking components should be tightened to the torque values / tightening angles listed in tables 13 to 15 († pages 452 to 454). For SKF ConCentra Y-bearings, mounting kits are available from SKF (designation 626830), which include mounting instructions, hexagonal keys and torque indicators. The correct tightening torque is achieved when the long end of the hexagonal key comes in contact with the torque indicator († fig. 32). For additional information about mounting and dismounting Y-bearings and assembling Y-bearing units, refer to the SKF bearing maintenance handbook.

Table 12 ISO shaft deviations for Y-bearings, except for Y-bearings with a standard inner ring

Shaft

diameter d over

incl.



Shaft diameter deviations Tolerance class E h7V E h6V Deviation high low high low

h8 V E

h9 V E

h10 V E

h11V E

high

low

high

low

high

low

high

low

µm

10 18 30

18 30 50

0 0 0

–11 –13 –16

0 0 0

–18 –21 –25

0 0 0

–27 –33 –39

0 0 0

–43 –52 –62

0 0 0

–70 –84 –100

0 0 0

–110 –130 –160

50 80

80 120

0 0

–19 –22

0 0

–30 –35

0 0

–46 –54

0 0

–74 –87

0 0

–120 –140

0 0

–190 –220

451

2

2  Y-bearings Table 13 Grub screws in inner rings and eccentric locking collars – key sizes and recommended tightening torques

N

N

Bearing size 1)

Bearing with metric bore Hexagonal Tightening key size torque N

Bearing with inch bore Hexagonal Tightening key size torque N

Bearing size 1)

Bearing with metric bore Hexagonal Tightening key size torque N

Bearing with inch bore Hexagonal Tightening key size torque N



mm

in.

Nm



mm

in.

Nm

4 4 4

03 04 05

3 3 3

4 4 4

3 / 32

4 4 4

4 6,5 6,5

06 07 08

3 3 3

4 4 4

5 / 32

6,5 16,5 16,5

09 10 11

3 4 –

4 6,5 –

5 / 32

16,5 16,5 28,5

12 15 16

– – –

– – –

3 / 16

Nm

Bearings in the YAR 2 or YARAG 2 series

Bearings in the YAT 2 series

03 04 05

3 3 3

4 4 4

3 / 32

06 07 08

3 3 4

4 4 6,5

1 /8

09 10 11

4 5 5

6,5 16,5 16,5

5 / 32

12 13 14

5 5 5

16,5 16,5 16,5

3 / 16

15 16 17

5 5 6

16,5 16,5 28,5

7/ 32

7/ 32 –

28,5 28,5 –

18 20

6 6

28,5 28,5

– –

– –

1 /8 1 /8

5 / 32 5 / 32

3 / 16 3 / 16

3 / 16 7/ 32

Nm

1 /8 1 /8

5 / 32 5 / 32

5 / 32 3 / 16

3 / 16 3 / 16

6,5 6,5 6,5 6,5 6,5 16,5 16,5 16,5 16,5

Bearings in the YET 2, YEL 2 or YELAG 2 series 03 04 05

3 3 3

4 4 4

1 /8

06 07 08

4 5 5

6,5 16,5 16,5

5 / 32

09 10 11 12

5 5 5 5

16,5 16,5 16,5 16,5

3 / 16

1 /8 1 /8

3 / 16 3 / 16

3 / 16 7/ 32 7/ 32

4 4 4 6,5 16,5 16,5 16,5 16,5 28,5 28,5

1) For example: bearing size 06 includes all bearings based on a Y 206 bearing, such as YAR 206-101-2F, YAR 206-102-2F,

YAR 206-2F, YAR 206-103-2F, YAR 206-104-2F

452

Mounting and dismounting Table 14 Hook spanners for Y-bearings on an adapter sleeve – sizes and recommended tightening angles

a

Designation Y-bearing + adapter sleeve

Shaft diameter d

Hook spanner

Lock nut tightening angle 1) a



mm

in.



°

YSA 205-2FK + HE 2305 YSA 205-2FK + H 2305

– 20

3 /4 –

HN 5 HN 5

90 90

YSA 206-2FK + HA 2306 YSA 206-2FK + H 2306 YSA 206-2FK + HE 2306

– 25 –

– 1

15 / 16

HN 6 HN 6 HN 6

95 95 95

YSA 207-2FK + H 2307 YSA 207-2FK + HA 2307

30 –

– 1 3 / 16

HN 7 HN 7

100 100

YSA 208-2FK + HE 2308 YSA 208-2FK + H 2308

– 35

1 1 /4 –

HN 8 HN 8

105 105

YSA 209-2FK + HA 2309 YSA 209-2FK + HE 2309 YSA 209-2FK + H 2309

– – 40

1 7/ 16 1 1 /2 –

HN 9 HN 9 HN 9

110 110 110

YSA 210-2FK + HS 2310 YSA 210-2FK + HA 2310 YSA 210-2FK + HE 2310 YSA 210-2FK + H 2310

– – – 45

1 5 /8 1 11 / 16 1 3 /4 –

HN 10 HN 10 HN 10 HN 10

115 115 115 115

YSA 211-2FK + HA 2311 B YSA 211-2FK + H 2311 YSA 211-2FK + HE 2311

– 50 –

1 15 / 16 – 2

HN 11 HN 11 HN 11

90 90 90

YSA 212-2FK + HS 2312 YSA 212-2FK + H 2312

– 55

2 1 /8 –

HN 12 HN 12

95 95

YSA 213-2FK + HA 2313 YSA 213-2FK + HE 2313 YSA 213-2FK + H 2313 YSA 213-2FK + HS 2313

– – 60 –

2 3 / 16 2 1 /4 – 2 3 /8

HN 13 HN 13 HN 13 HN 13

100 100 100 100

1) The listed values are to be used as guideline values only, as it is difficult to establish an exact starting position.

453

2

2  Y-bearings Table 15 Grub screws in SKF ConCentra Y-bearings – key sizes and recommended tightening torques

N

Bearing size 1) from

to

– 05 07

06 13

Screw size

Hexagonal key size N

Tightening torque



mm

Nm

M5 M6

2,5 3

4,2 7,4

Assembling Y-bearings into housings with fitting slots When installing a Y-bearing into a housing with fitting slots, the bearing should be inserted into the fitting slot in the housing bore († fig. 33) and then swivelled into position. When installing Y-bearings with two lubrication holes in the outer ring and the bearing has to be relubricated, make sure that one of the relubrication holes in the bearing coincides with the relubrication facility in the housing († fig 34, right). Be sure that the other relubrication hole is not aligned with either of the fitting slots, otherwise grease leakage may result († fig. 34, left). Fig. 33

1) For example: bearing size 07 includes all bearings

based on a Y 207 bearings such as YSP 207 SB-2F, YSP 207-104 SB-2F, YSP 207-106 SB-2F, YSP 207-107 SB-2F

Fig. 34

454

Mounting and dismounting

2

Eccentric locking collars should be removed from the bearing prior to installation and reinstalled when the bearing is in position in the housing. SKF recommends installing SKF Y-bearings only into SKF Y-housings to avoid a mismatch of components and to enable proper bearing relubrication.

SKF ConCentra Y-bearings When mounting SKF ConCentra Y-bearings, position the collar so that one grub screw is directly opposite the slit in the sleeve. C AUTION: Do not tighten the grub (set) screws until the bearing is positioned on the shaft. If the screws are tightened prematurely, the stepped sleeve may deform. No attempt should be made to disassemble the sleeve and the mounting collar from the bearing prior to installation. To dismount SKF ConCentra Y-bearings loosen the grub screws first. Then gently tap the edge of the sleeve on the collar side, or the inner ring side face on the opposite side to loosen the lock († fig. 35).

Fig. 35

Sleeve edge

Inner ring side face

455

2  Y-bearings

Designation system Group 1

Prefixes E2.

SKF Energy Efficient bearing

Basic designation Bearing design YAR YARAG YAT YEL YELAG YET YSA YSP YSPAG 172

Bearing with grub screws, inner ring extended on both sides Bearing with grub screws, inner ring extended on both sides, for agricultural applications Bearing with grub screws, inner ring extended on one side Bearing with an eccentric locking collar, inner ring extended on both sides Bearing with an eccentric locking collar, inner ring extended on both sides, for agricultural applications Bearing with an eccentric locking collar, inner ring extended on one side Bearing with a tapered bore, inner ring symmetrically extended on both sides Bearing with SKF ConCentra locking technology, inner ring symmetrically extended on both sides Bearing with SKF ConCentra locking technology, inner ring symmetrically extended on both sides, for agricultural applications Bearing with a standard inner ring

Dimension series 2 62 63

Outside diameter to ISO 15, diameter series 2 Bearing in accordance with ISO 15, dimension series 02, sphered outside surface Bearing in accordance with ISO 15, dimension series 03, sphered outside surface

Bore diameter d 03/12 03/15 03 04 to 20

Bearings for metric shafts d = 12 mm d = 15 mm d = 17 mm d = 20 mm to d = 100 mm

-008 to -300

Bearings for inch shafts Three-digits combination that follows the designation of the basic metric bearing and is separated from this by a hyphen; the first digit is the number of whole inches and the second and third digits are the number of sixteenths of an inch, e.g. 204-012 d = 1 /2 in. (12,7 mm) to d = 3 in. (76,2 mm)

Suffixes Group 1: Internal design SB

456

SKF ConCentra ball bearing with shortened inner ring

Designation system

2 Group 2 Group 3

/

Group 4 4.1

4.2

4.3

4.4

4.5

4.6 Group 4.6: Other variants AH

Bearing for air-handling applications

Group 4.5: Lubrication G GR W

Lubrication groove in the outside surface, located at the side opposite the locking device Lubrication groove in the outside surface, located at the side of the locking device Bearing without lubrication hole(s)

Group 4.4: Stabilization Group 4.3: Bearing sets, paired bearings Group 4.2: Accuracy, clearance, preload, quiet running Group 4.1: Materials, heat treatment HV VE495 VL065

Bearing components of stainless steel; seals and flingers with food-compatible rubber; food-grade grease Zinc-coated inner and outer rings; seals and flingers with stainless steel inserts and food-compatible rubber; food-grade grease Zinc-coated inner ring bore and side faces

Group 3: Cage design Group 2: External design (seals, snap ring groove etc.) -2F -2RF -2RS1 VP076 C K U

Contact seal, NBR, additional plain flinger, on both sides Contact seal, NBR, additional rubberized flinger, on both sides Contact seal, NBR, on both sides Shield on both sides Cylindrical outside surface Tapered bore, taper 1:12 Bearing without locking device

457

2.1 Y-bearings with grub screws, metric shafts d 12 – 100 mm

C

B

r2

r1

D

YAR-2F

E2.YAR-2F

YAR-2RF

YARAG

d d1 s1

YAT Dimensions d

D

B

C

d1 ~

s1

r 1,2 min.

mm

Basic load ratings dynamic static C C0

Fatigue load limit Pu

Limiting speed with shaft tolerance h6

Mass

Designation

kN

kN

r/min

kg



12

40

27,4

12

24,2

15,9

0,3

9,56

4,75

0,2

9 500

0,11

YAR 203/12-2F

15

40

27,4

12

24,2

15,9

0,3

9,56

4,75

0,2

9 500

0,1

YAR 203/15-2F

17

40 40

22,1 27,4

12 12

24,2 24,2

15,9 15,9

0,3 0,3

9,56 9,56

4,75 4,75

0,2 0,2

9 500 9 500

0,07 0,09

YAT 203 YAR 203-2F

20

47 47 47

25,5 31 31

14 14 14

28,2 28,2 28,2

18,3 18,3 18,3

0,6 0,6 0,6

12,7 12,7 12,7

6,55 6,55 6,55

0,28 0,28 0,28

8 500 8 500 8 500

0,11 0,14 0,14

YAT 204 E2.YAR 204-2F YAR 204-2F

47 47 47 47

31 31 31 31

14 14 14 14

28,2 28,2 28,2 28,2

18,3 18,3 18,3 18,3

0,6 0,6 0,6 0,6

12,7 10,8 12,7 12,7

6,55 6,55 6,55 6,55

0,28 0,28 0,28 0,28

5 000 5 000 5 000 1 800

0,14 0,14 0,14 0,15

YAR 204-2RF YAR 204-2RF/HV YAR 204-2RF/VE495 YARAG 204

52 52 52

27,2 34,1 34,1

15 15 15

33,7 33,7 33,7

19,5 19,8 19,8

0,6 0,6 0,6

14 14 14

7,8 7,8 7,8

0,335 0,335 0,335

7 000 7 000 7 000

0,14 0,19 0,17

YAT 205 E2.YAR 205-2F YAR 205-2F

52 52 52 52

34,1 34,1 34,1 34,1

15 15 15 15

33,7 33,7 33,7 33,7

19,8 19,8 19,8 19,8

0,6 0,6 0,6 0,6

14 11,9 14 14

7,8 7,8 7,8 7,8

0,335 0,335 0,335 0,335

4 300 4 300 4 300 1 500

0,17 0,18 0,18 0,19

YAR 205-2RF YAR 205-2RF/HV YAR 205-2RF/VE495 YARAG 205

62 62 62

30,2 38,1 38,1

18 18 18

39,7 39,7 39,7

21 22,2 22,2

0,6 0,6 0,6

19,5 19,5 19,5

11,2 11,2 11,2

0,475 0,475 0,475

6 300 6 300 6 300

0,23 0,3 0,28

YAT 206 E2.YAR 206-2F YAR 206-2F

62 62 62 62

38,1 38,1 38,1 38,1

18 18 18 18

39,7 39,7 39,7 39,7

22,2 22,2 22,2 22,2

0,6 0,6 0,6 0,6

19,5 16,3 19,5 19,5

11,2 11,2 11,2 11,2

0,475 0,475 0,475 0,475

3 800 3 800 3 800 1 200

0,28 0,29 0,29 0,3

YAR 206-2RF YAR 206-2RF/HV YAR 206-2RF/VE495 YARAG 206

25

30

E2 † SKF Energy Efficient bearing

458

Dimensions d

D

B

C

d1 ~

s1

r 1,2 min.

mm 35

Basic load ratings dynamic static C C0

Fatigue load limit Pu

Limiting speed with shaft tolerance h6

Mass

Designation

kN

kN

r/min

kg



2.1

72 72 72

33 42,9 42,9

19 19 19

46,1 46,1 46,1

23,3 25,4 25,4

1 1 1

25,5 25,5 25,5

15,3 15,3 15,3

0,655 0,655 0,655

5 300 5 300 5 300

0,31 0,44 0,41

YAT 207 E2.YAR 207-2F YAR 207-2F

72 72 72 72

42,9 42,9 42,9 42,9

19 19 19 19

46,1 46,1 46,1 46,1

25,4 25,4 25,4 25,4

1 1 1 1

25,5 21,6 25,5 25,5

15,3 15,3 15,3 15,3

0,655 0,655 0,655 0,655

3 200 3 200 3 200 1 100

0,41 0,42 0,42 0,44

YAR 207-2RF YAR 207-2RF/HV YAR 207-2RF/VE495 YARAG 207

80 80 80

36 49,2 49,2

21 21 21

51,8 51,8 51,8

25,3 30,2 30,2

1 1 1

30,7 30,7 30,7

19 19 19

0,8 0,8 0,8

4 800 4 800 4 800

0,43 0,59 0,55

YAT 208 E2.YAR 208-2F YAR 208-2F

80 80 80 80

49,2 49,2 49,2 49,2

21 21 21 21

51,8 51,8 51,8 51,8

30,2 30,2 30,2 30,2

1 1 1 1

30,7 26 30,7 30,7

19 19 19 19

0,8 0,8 0,8 0,8

2 800 2 800 2 800 950

0,55 0,56 0,56 0,59

YAR 208-2RF YAR 208-2RF/HV YAR 208-2RF/VE495 YARAG 208

45

85 85 85 85 85

37 49,2 49,2 49,2 49,2

22 22 22 22 22

56,8 56,8 56,8 56,8 56,8

25,8 30,2 30,2 30,2 30,2

1 1 1 1 1

33,2 33,2 33,2 33,2 33,2

21,6 21,6 21,6 21,6 21,6

0,915 0,915 0,915 0,915 0,915

4 300 4 300 4 300 2 400 850

0,48 0,65 0,6 0,6 0,66

YAT 209 E2.YAR 209-2F YAR 209-2F YAR 209-2RF YARAG 209

50

90 90 90 90 90 90

38,8 51,6 51,6 51,6 51,6 51,6

22 22 22 22 22 22

62,5 62,5 62,5 62,5 62,5 62,5

27,6 32,6 32,6 32,6 32,6 32,6

1 1 1 1 1 1

35,1 35,1 35,1 29,6 35,1 35,1

23,2 23,2 23,2 23,2 23,2 23,2

0,98 0,98 0,98 0,98 0,98 0,98

4 000 4 000 2 200 2 200 2 200 800

0,54 0,69 0,69 0,69 0,69 0,74

YAT 210 YAR 210-2F YAR 210-2RF YAR 210-2RF/HV YAR 210-2RF/VE495 YARAG 210

55

100 100

55,6 55,6

25 25

69 69

33,4 33,4

1 1

43,6 43,6

29 29

1,25 1,25

3 600 1 900

0,94 0,94

YAR 211-2F YAR 211-2RF

60

110 110

65,1 65,1

26 26

75,6 75,6

39,7 39,7

1,5 1,5

52,7 52,7

36 36

1,53 1,53

3 400 1 800

1,35 1,35

YAR 212-2F YAR 212-2RF

65

120 120

68,3 68,3

27 27

82,5 82,5

42,9 42,9

1,5 1,5

57,2 57,2

40 40

1,7 1,7

3 000 1 600

1,7 1,7

YAR 213-2F YAR 213-2RF

70

125

69,9

28

87

39,7

1,5

62,4

45

1,86

2 800

1,9

YAR 214-2F

75

130

73,3

29

92

46,3

1,5

66,3

49

2,04

2 600

2,1

YAR 215-2F

80

140

77,8

30

97,4

47,6

2

72,8

53

2,16

2 400

2,7

YAR 216-2F

85

150

81

34

105

50,8

2

83,2

62

2,4

2 200

3,35

YAR 217-2F

90

160

89

36

112

54

2

95,6

72

2,7

2 000

4,1

YAR 218-2F

100

180

98,4

40

124

63,4

2

124

93

3,35

1 900

5,35

YAR 220-2F

40

E2 † SKF Energy Efficient bearing

459

2.2 Y-bearings with grub screws, inch shafts d 1 /2 – 1 11 /16 in. 12,7 – 42,863 mm C

B

r2

r1

D

YAR-2F

E2.YAR-2F

YAR-2RF

YARAG

d d1 s1

YAT Principal dimensions d

D

B

C

d1 ~

s1

r 1,2 min.

in./mm mm 1 /2

Basic load ratings dynamic static C C0

Fatigue load limit Pu

Limiting Mass speed with shaft tolerance h6

Designation

kN

kN

r/min

kg



40

27,4

12

24,2

15,9

0,3

9,56

4,75

0,2

9 500

0,12

YAR 203-008-2F

40 15,875 40

22,5 27,4

12 12

24,2 24,2

16 15,9

0,3 0,3

9,56 9,56

4,75 4,75

0,2 0,2

9 500 9 500

0,1 0,11

YAT 203-010 YAR 203-010-2F

3 /4

47

25,5

14

28,2

18,3

0,6

12,7

6,55

0,28

8 500

0,14

YAT 204-012

47 47 47 47 47 47

31 31 31 31 31 31

14 14 14 14 14 14

28,2 28,2 28,2 28,2 28,2 28,2

18,3 18,3 18,3 18,3 18,3 18,3

0,6 0,6 0,6 0,6 0,6 0,6

12,7 12,7 12,7 12,7 10,8 12,7

6,55 6,55 6,55 6,55 6,55 6,55

0,28 0,28 0,28 0,28 0,28 0,28

8 500 8 500 8 500 5 000 5 000 5 000

0,14 0,17 0,16 0,16 0,16 0,16

E2.YAR 204-012-2F YAR 204-012-2F YAR 204-012-2F/AH YAR 204-012-2RF YAR 204-012-2RF/HV YAR 204-012-2RF/VE495

7/ 8

52 22,225 52

27,2 34,1

15 15

33,7 33,7

19,5 19,8

0,6 0,6

14 14

7,8 7,8

0,335 0,335

7 000 7 000

0,17 0,21

YAT 205-014 E2.YAR 205-014-2F

15 / 16

52 23,813 52 52 52

27,2 34,1 34,1 34,1

15 15 15 15

33,7 33,7 33,7 33,7

19,5 19,8 19,8 19,8

0,6 0,6 0,6 0,6

14 14 14 14

7,8 7,8 7,8 7,8

0,335 0,335 0,335 0,335

7 000 7 000 7 000 4 300

0,18 0,2 0,21 0,21

YAT 205-015 E2.YAR 205-015-2F YAR 205-015-2F YAR 205-015-2RF/VE495

1 25,4

52 52 52 52

27,2 34,1 34,1 34,1

15 15 15 15

33,7 33,7 33,7 33,7

19,5 19,8 19,8 19,8

0,6 0,6 0,6 0,6

14 14 14 14

7,8 7,8 7,8 7,8

0,335 0,335 0,335 0,335

7 000 7 000 7 000 7 000

0,16 0,18 0,19 0,19

YAT 205-100 E2.YAR 205-100-2F YAR 205-100-2F YAR 205-100-2F/AH

52 52 52 52

34,1 34,1 34,1 34,1

15 15 15 15

33,7 33,7 33,7 33,7

19,8 19,8 19,8 19,8

0,6 0,6 0,6 0,6

14 11,9 14 14

7,8 7,8 7,8 7,8

0,335 0,335 0,335 0,335

4 300 4 300 4 300 1 500

0,19 0,19 0,19 0,18

YAR 205-100-2RF YAR 205-100-2RF/HV YAR 205-100-2RF/VE495 YARAG 205-100

1 1 / 16 62 26,988 62

38,1 38,1

18 18

39,7 39,7

22,2 22,2

0,6 0,6