Timken Cylindrical Roller Bearing Product Overview Part A

1. Narrated by David Beach Motion Industries Retired Timken Cylindrical Roller Bearing Product OverviewPart A

2. Agenda • Features of CRB’s • Basic designs • Roller-raceway profiles • Cage design • Precision • Application considerations • Part numbers CRB Product Overview

3. Features and Advantages

4. CRB Features Assembly • Separable races for easier installation • Line contact for high radial loads • Single or multi-row designs • Cylindrical or tapered bore • Preset radial clearance • Size range - 10-1600mm bore Line Contact CRB Product Overview

5. Advantages of CRBs P (radial load) • Maximum radial load capability • Low friction, high speed capability (under pure radial load) • Extensive float capability • Separable design - flexibility at installation Inner Race Installation Feature CRB Product Overview

6. Disadvantages of CRBs • Very limited (up to 10% of radial) or no thrust capability • Limited ability to handle misalignment conditions (<0.0005”/ in) T (thrust load) CRB Product Overview

7. Basic Designs

8. Single Row CRB - Basic Designs NU • Outer ring has two integral ribs • Inner ring has a cylindrical OD without ribs • Supports heavy radial load • Accommodates axial expansion or contraction • Axial displacement between rings with minimum friction while rotating N • Inner ring has two integral ribs • Outer ring has a cylindrical bore without ribs CRB Product Overview

9. Single Row CRB - Basic Designs NJ • Outer ring has two integral ribs • Inner ring has a single rib • Supports heavy radial load • Supports light unidirectional thrust load up to 10% of radial load • The thrust load is transmitted between diagonally opposed rib faces NF • Inner ring has two integral ribs • Outer ring has a single rib CRB Product Overview

10. Single Row CRB - Basic Designs NP • Outer ring has two integral ribs • Inner ring has a single rib • An abutting loose rib • Carries light thrust loads in both directions • Provides axial location • May be used with RN or RU bearing to accommodate axial expansion/contraction • Shaft end play (float) is determined by the bearing axial clearance NUP • Inner ring has two integral ribs • Outer ring has a single rib • An abutting loose rib CRB Product Overview

11. Double Row CRBs • Sold as complete assembly, ring roller cage assembly, or separable ring • Not currently a standard Catalog offering. Available in same size range as single row product. • Current designs use NN, NNU nomenclature • Standard cage design is a drilled pocket, finger style bronze retainer NN NNU CRB Product Overview

12. Thrust Cylindrical Roller • Good thrust capacity • TP – multi-row roller pocket configuration • TPS - self adjusting for initial static misalignment CRB Product Overview

13. Roller-raceway Stress Distribution and Roller Profiles

14. Stress Distribution • Causes of non-uniform stress distribution • Angular misalignment between shaft and housing • Shaft bores not machined or aligned correctly • Housing bores not machined or aligned correctly • Bearings not installed correctly • Extreme loads • Overturning moments • Lead to edge loading, edge stress, reduced life • Roller profiling is a method for achieving more uniform stress distribution CRB Product Overview

15. Roller Profile Considerations • Optimize on load and misalignment • Flat rollers • End tapered • Multi-radius dub (MRD) • Timken analysis tools can predict the optimum bearing profile. CRB Product Overview

16. Roller Profile - MRD • Balanced stress distribution • Standard design • Or applicationspecific Timken MRD profiles CRB Product Overview

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