Super-precision bearings - SKF

1 Super-precision bearings SKF, BeyondZero, KMT and KMTA are registered trademarks of the SKF Group. NitroMax is a trademark of the SKF is a trademark of Apple Inc., registered in the US and other Play is a trademark of Google Inc. SKF Group 2016 The contents of this publication are the copyright of the publisher and may not be reproduced (even extracts) unless prior written permission is granted. Every care has been taken to ensure 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 information contained BU/P1 13383/2 EN March 2016 This publication supersedes publication image(s) used under license from mobile appsSKF mobile apps are available from both Apple App Store and Google Play.

2 These apps provide useful information and allow you to make critical calculations, providing SKF Knowledge Engineering at your AppStoreGoogle Play312456789 Principles of bearing selection and applicationAngular contact ball bearingsCylindrical roller bearingsDouble direction angular contact thrust ball bearingsAxial-radial cylindrical roller bearingsAngular contact thrust ball bearings for screw drivesPrecision lock nutsGaugesIndexes1 This is SKF .. 6 SKF the knowledge engineering company .. 8 Unit conversions .. 10 Foreword .. 111 Principles of bearing selection and application .. 19 Selecting Super-precision bearings .. 20 Bearing types and designs .. 21 Basic selection criteria .. 23 Bearing life and load ratings .. 33 Dynamic bearing loads and life.

3 33 Permissible static loads .. 36 Friction .. 37 Effects of clearance and preload on friction .. 37 Effects of grease fill on friction .. 37 Frictional behaviour of hybrid bearings .. 37 Speeds .. 38 Permissible speeds .. 39 Attainable speeds .. 44 Attainable speeds for typical spindle bearing systems .. 44 Bearing specifics .. 46 Boundary dimensions .. 46 Tolerances .. 47 Preload and internal clearance .. 50 Materials .. 51 Design considerations .. 57 Bearing arrangements .. 57 System rigidity .. 66 Radial location of bearings .. 70 Axial location of bearings .. 78 Provisions for mounting and dismounting .. 88 Bearing preload .. 90 Sealing solutions .. 95 Lubrication .. 99 Grease lubrication .. 99 Oil lubrication .. 113 Lubricant storage.

4 122 Content2 Mounting and dismounting .. 123 Where to mount .. 123 Methods and tools .. 123 Mounting recommendations .. 123Te s t r unning .. 124 Dismounting .. 124 Reusing bearings .. 124 SKF spindle service .. 125 Bearing storage .. 1252 Angular contact ball bearings .. 127 Assortment .. 128 Designs and variants .. 128 Bearing arrangement design .. 141 Markings on bearings and bearing sets .. 145 Bearing data .. 146 Preload .. 151 Axial stiffness .. 173 Fitting and clamping bearing rings .. 183 Load carrying capacity of bearing sets .. 189 Equivalent bearing loads .. 190 Attainable speeds .. 192 Mounting .. 194 Designation system .. 196 Product Angular contact ball bearings .. 1983 Cylindrical roller bearings .. 263 Designs and variants .. 264 Bearing data.

5 269 Radial internal clearance or preload in mounted bearings .. 275 Radial stiffness .. 275 Equivalent bearing loads .. 277 Attainable speeds .. 277 Design considerations .. 278 Mounting .. 280 Designation system .. 286 Product Single row cylindrical roller bearings .. Double row cylindrical roller bearings .. 2944 Double direction angular contact thrust ball bearings .. 301 Designs and variants .. 302 Markings on bearings .. 305 Bearing data .. 306 Preload .. 308 Axial stiffness .. 309 Equivalent bearing loads .. 310 Attainable speeds .. 310 Mounting .. 310 Designation system .. 311 Product Double direction angular contact thrust ball bearings .. 3123 Content5 Axial-radial cylindrical roller bearings .. 319 Designs and variants.

6 320 Bearing data .. 321 Preload and stiffness .. 322 Friction .. 322 Lubrication .. 324 Design considerations .. 324 Load carrying capacity .. 327 Equivalent bearing loads .. 327 Permissible moment load .. 328 Mounting .. 330 Designation system .. 333 Product Axial-radial cylindrical roller bearings .. 3346 Angular contact thrust ball bearings for screw drives .. 337 Designs and variants .. 338 Bearing arrangement design .. 346 Markings on bearings .. 352 Bearing data .. 353 Preload .. 355 Axial stiffness .. 358 Frictional moment .. 360 Lifting force .. 360 Load carrying capacity of bearing sets .. 361 Equivalent bearing loads .. 361 Axial load carrying capacity .. 362 Mounting .. 362 Attainable speeds .. 363 Designation system .. 364 Product Single direction angular contact thrust ball bearings .

7 Double direction angular contact thrust ball bearings .. Double direction angular contact thrust ball bearings for bolt mounting .. Cartridge units with a flanged housing .. 3727 precision lock nuts .. 375 Designs .. 376 Product data .. 378 Installation and removal .. 379 Designation system .. 382 Product KMT precision lock nuts with locking pins .. KMTA precision lock nuts with locking pins .. KMD precision lock nuts with axial locking screws .. 38848 Gauges .. 391 GRA 30 ring gauges .. 393 Product GRA 30 ring gauges .. 394 DMB taper gauges .. 396 Product DMB taper gauges .. 398GB 30 and GB 10 internal clearance gauges .. 400 Product GB 30 and GB 10 internal clearance gauges for cylindrical roller bearings .. 402GB 49 internal clearance gauges.

8 404 Product GB 49 internal clearance gauges for cylindrical roller bearings .. 4069 Indexes .. 408 Text index .. 409 Product index .. 4205 This is SKFFrom one simple but inspired solution to a mis-alignment problem in a textile mill in Sweden, and fifteen employees 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, mecha tronics, services and lubrication systems. Our know-ledge network includes 46 000 employees, 15 000 distributor partners, offices in more than 130 countries, and a growing number of SKF Solution Factory sites around the world. Research and development We have hands-on experience in over forty industries based on our employees knowledge of real life conditions.

9 In addition, our world-leading experts and university partners pioneer advanced theoretical research and development in areas including tribology, condition monitor-ing, asset management and bearing life theory. Our ongoing commitment to research and devel opment helps us keep our customers at the forefront of their industries. SKF Solution Factory makes SKF knowledge and manu facturing expertise available locally to provide unique solu-tions and services to our 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 re spon sibly grow their for a sustainable future Since 2005, SKF has worked to reduce the negative environmental impact from our oper-ations and those of our suppliers.

10 Our continu-ing technology development resulted in the introduction of the SKF BeyondZero portfolio of prod ucts and services which improve efficiency and reduce energy losses, as well as enable new technol ogies har nessing wind, solar and ocean power. This combined approach helps reduce the en vir on mental impact both in our oper-ations and our customers oper with SKF IT and logistics systems and application experts, SKF Authorized Distributors deliver a valuable mix of product and application knowledge to customers Our knowledge your successSKF Life Cycle Management is how we combine our technology plat-forms and advanced ser vices, and apply them at each stage of the asset life cycle, to help our cus-tomers to be more success ful, sustainable and closely with you Our objective is to help our customers improve productivity, minimize main ten ance, achieve higher energy and resource efficiency, and opti-mize designs for long service life and reliability.