Bearing and method of forming a bearing

Patent metadata

Field	Value
Publication number	US-10060479-B2
Application number	US-201515305383-A
Country	US
Kind code	B2
Filing date	May 13, 2015
Priority date	May 15, 2014
Publication date	Aug 28, 2018
Grant date	Aug 28, 2018

Abstract

A bearing assembly having an inner race ring ( 14 ) that defines an inner raceway and an outer race ring that defines an outer raceway on which the plurality of rolling elements ( 22 ) roll. The bearing raceways are machined using surface finishing operations to create preferred surface profiles and textures for improving lubrication performance. The profile of the raceway is initially created using a first grinding process to form a rough surface profile including a rough central band ( 34 ) and rough recessed side bands ( 38 ). A second grinding process is used to smooth the central band. This raceway surface profile increases lubrication performance.

First claim

What is claimed is:

1. A bearing assembly comprising:
an inner race ring defining an inner raceway;
an outer race ring defining an outer raceway;
a plurality of rolling elements in rolling contact with the inner raceway and the outer raceway;
wherein at least one of the inner raceway and the outer raceway includes,
a central region that is in contact with the plurality of rolling elements during normal operation, and
at least one recessed side region that is not in contact with the plurality of rolling elements during normal operation; and

wherein the at least one recessed side region has longitudinal micro-grooves oriented generally parallel to a travel direction of the rolling elements.

2. The bearing assembly of claim 1 , wherein the at least one recessed side region has a surface roughness greater than a surface roughness of the central region.

3. The bearing assembly of claim 2 , wherein the at least one recessed side region improves lubrication performance of the bearing assembly by increasing the retention of lubricant due to a greater surface roughness.

4. The bearing assembly of claim 1 , wherein the central region is located between two recessed side regions.

5. The bearing assembly of claim 1 , wherein both the inner raceway and the outer raceway each include the central region and the at least one recessed side region.

6. The bearing assembly of claim 1 , wherein the ratio of roughness between the at least one recessed side region and the central region is greater than 1 and up to about 40.

7. The bearing assembly of claim 1 , wherein the at least one recessed side region has average roughness value of about 10 microinches to about 40 microinches.

8. The bearing assembly of claim 7 , wherein the central region has average roughness value of about 4 microinches to about 10 microinches.

9. The bearing assembly of claim 1 , wherein central region has a width W 1 that is 0-25% wider than an expected maximum contact length between the rolling elements and the at least one of the inner raceway and the outer raceway on which the central region is formed.

10. The bearing assembly of claim 9 , wherein the at least one recessed side region has a width W 2 smaller than the width W 1 of the central region.

11. The bearing assembly of claim 1 , wherein the at least one recessed side region has a depth D measured from an average roughness line defined by a roughness of the central region and extended along a central region curvature through the at least one side region, the side region depth D being greater than a maximum roughness peak-to-valley height within the central region.

12. A method of forming a bearing assembly comprising:
creating a bearing assembly having an inner race defining an inner raceway and an outer race defining an outer raceway;
performing a first finishing operation to form a rough surface profile on at least one of the inner raceway and the outer raceway, the rough surface profile including at least one rough recessed side region and a rough central region, the at least one rough recessed side region being recessed relative to the rough central region; and
performing a second finishing operation to decrease the roughness of the rough central region to produce a central region that is smoother than the rough recessed side region.

13. The method of claim 12 , wherein the first finishing operation is a first grinding operation and the second finishing operation is a second grinding operation.

14. The method of claim 12 , wherein one of the first finishing operation and the second finishing operation includes one of the group consisting of a mechanical, electrical, optical/laser-assisted, or chemical finishing operation.

15. The method of claim 12 , further comprising retaining lubricant in the at least one recessed side region to improve lubrication performance of the bearing assembly.

16. The method of claim 12 , wherein the central region is located between two recessed side regions.

17. The method of claim 12 , wherein the first finishing operation and the second finishing operation are performed on both the inner raceway and the outer raceway.

18. The method of claim 12 , wherein performing the second finishing operation creates a ratio of roughness between the at least one recessed side region and the central region that is greater than 1 and up to about 40.

19. The method of claim 12 , wherein performing the first finishing operation creates an average roughness value on the at least one rough recessed side region of about 10 microinches to about 40 microinches.

20. The method of claim 19 , wherein performing the second finishing operation creates an average roughness value on the central region of about 4 microinches to about 10 microinches.

21. The method of claim 12 , wherein the at least one recessed side region has a depth D measured from an average roughness line defined by a roughness of the central region and extended along a central region curvature through the at least one side region, the side region depth D being greater than a maximum roughness peak-to-valley height within the central region.

22. The method of claim 21 , wherein the first finishing operation creates longitudinal micro-grooves in the at least one recessed side region and oriented generally parallel to a travel direction of the rolling elements.

23. A bearing assembly comprising:
an inner race ring defining an inner raceway;
an outer race ring defining an outer raceway;
a plurality of rolling elements in rolling contact with the inner raceway and the outer raceway;
wherein at least one of the inner raceway and the outer raceway includes,
a central region that is in contact with the plurality of rolling elements during normal operation, and
at least one recessed side region that is not in contact with the plurality of rolling elements during normal operation, the at least one recessed side region having a surface roughness greater than a surface roughness of the central region to improve lubrication performance of the bearing assembly by increasing retention of lubricant in the at least one recessed side region due to the greater surface roughness;

wherein the at least one recessed side region has a depth D measured from an average roughness line defined by a roughness of the central region and extended along a central region curvature through the at least one side region, the side region depth D being greater than a maximum roughness peak-to-valley height within the central region; and
wherein the at least one recessed side region has longitudinal micro-grooves oriented generally parallel to a travel direction of the rolling elements.

24. The bearing assembly of claim 23 , wherein the central region is located between two recessed side regions.

25. The bearing assembly of claim 23 , wherein both the inner raceway and the outer raceway each include the central region and the at least one recessed side region.

26. The bearing assembly of claim 23 , wherein the ratio of roughness between the at least one recessed side region and the central region is greater than 1 and up to about 40.

27. The bearing assembly of claim 23 , wherein the at least one recessed side region has average roughness value of about 10 microinches to about 40 microinches.

28. The bearing assembly of claim 27 , wherein the central region has average roughness value o

Assignees

• Timken Co

Inventors

• Ai Xiaolan
• Evans Ryan D
• Houpert Luc

Classifications

• F16C33/6651 Primary

  in recesses or cavities provided in retainers, races or rolling elements · CPC title

• F16C2223/06

  polishing · CPC title

• F16C19/00

  Bearings with rolling contact, for exclusively rotary movement (adjustable bearings F16C23/00, F16C25/00 {; electrically insulating bearings H02K5/173}) · CPC title

• B23P9/02

  Treating or finishing by applying pressure, e.g. knurling (B23P9/04 takes precedence) · CPC title

• F16C33/585

  of raceways, e.g. ribs to guide the rollers · CPC title