SEGMENTED ROLLING ELEMENT BEARING
A rocker arm assembly including a rocker arm, a bearing support member, and a bearing assembly. The bearing assembly is supported on the support member and engages the rocker arm. The bearing assembly includes a race defining a raceway having a stop member coupled thereto, and a plurality of rolling elements positioned on the raceway such that the movement of the rolling elements on the raceway is limited by the stop member.
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This application claims the benefit of U.S. Provisional Application No. 60/946,620 filed Jun. 27, 2007. The prior application listed in this paragraph is hereby incorporated by reference in its entirety.
BACKGROUNDThe present invention relates to bearings.
SUMMARYRocker arms are one example of an application in which bearings are used to support an oscillating member. Typically, the bearings contain a full complement of rolling elements to support the oscillating member and to provide the desired anti-friction capabilities.
In one embodiment, the invention provides a rocker arm assembly that includes a rocker arm, a bearing support member, and a bearing assembly. The bearing assembly is supported on the bearing support member and engages the rocker arm. The bearing assembly includes a race defining a raceway having a stop member coupled thereto, and a plurality of rolling elements positioned on the raceway such that the movement of the rolling elements on the raceway is limited by the stop member.
The invention also provides a rocker arm assembly that includes a rocker arm, a bearing support member that has two support arms extending in opposite directions along an axis, and two bearing assemblies. One bearing assembly is supported on each support arm and engages the rocker arm. Each bearing assembly includes a cylindrical race defining a raceway and a plurality of rolling elements positioned on the raceway. The raceway has a stop member coupled thereto that defines an extent of travel of the rolling elements on the raceway that is less than three-hundred-sixty degrees.
The invention also provides a bearing assembly including a cylindrical race which contains a complement of rolling elements with a limited travel pathway. The number of rolling elements is chosen in order to be sufficient to support a generally unidirectional radial load. Less than a full complement of rolling elements is used, thereby reducing the number of rolling elements in comparison to typical prior art bearings used in similar applications, resulting in lower production costs and lower weight while still providing suitable anti-friction capabilities.
For convenience, a rocker arm will be described in the remainder of this application, though it is contemplated that such a roller bearing could be used for a wide range of other applications.
Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings.
Referring to
Both the bearing assemblies 10 shown in
The illustrated outer race 20 is substantially cylindrical and cup-shaped, and includes a shaped opening 25 (e.g., generally D-shaped) operable to receive a like shaped protrusion or support arm 26 of the bearing support member 8 (see
In the illustrated embodiment, the outer raceway 21 includes at least one stop member 22 coupled thereto, located in the rolling element 23 pathway, and operable to limit the extent of travel of the rolling elements 23 along the outer raceway 21.
In the illustrated embodiment, the stop members 22a and 22b define therebetween an included angle, in which the rollers are located, of about two-hundred-ten degrees. Based on the illustrated diameter of the rollers, the number of rollers used, and the diameters of the raceways 21 and 30, this correlates to between about eighteen and about twenty degrees (18.8 degrees as illustrated) of possible oscillation of the outer race 20 relative to the inner race 28. In other embodiments, the included angle may be between two-hundred and two-hundred-twenty degrees. In yet other embodiments, the included angle can be any desired angle such that the extent of travel of the rollers around the raceways 21 and 30 is less than three-hundred-sixty degrees to achieve the desired oscillation capabilities.
The outer race 20 can be manufactured in a variety of ways including machining, forming or drawing to produce the general configuration shown in
The invention is not limited to cylindrical raceways and could be practiced with a radial segment of race that is less than 360 degrees. Also,
Thus, the invention provides, among other things, a bearing assembly capable of supporting a unidirectional oscillatory load with a less than full annular complement of rolling elements contained by at least one stopping element or member coupled to a race.
Various features and advantages of the invention are set forth in the following claims.
Claims
1. A rocker arm assembly comprising:
- a rocker arm;
- a bearing support member; and
- a bearing assembly supported on the bearing support member and engaging the rocker arm, the bearing assembly including: a race defining a raceway, the raceway having a stop member coupled thereto; and a plurality of rolling elements positioned on the raceway such that the movement of the rolling elements on the raceway is limited by the stop member.
2. The rocker arm assembly of claim 1, wherein the bearing assembly further comprises a second race, the plurality of rolling elements positioned between the two races.
3. The rocker arm assembly of claim 1, wherein the stop member is positioned and configured to center the bearing support member with respect to the first race.
4. The rocker arm assembly of claim 1, wherein the bearing assembly further comprises a second stop member coupled to the raceway, positioned and configured to center the bearing support member with respect to the first race.
5. The rocker arm assembly of claim 1, wherein the stop member is integrally formed with the race.
6. The rocker arm assembly of claim 5, wherein the stop member is a projection formed in the raceway.
7. The rocker arm assembly of claim 1, wherein the stop member is a plug secured to the raceway.
8. The rocker arm assembly of claim 1, wherein the bearing assembly further comprises a second stop member, the first and second stop members defining extents of travel of the rolling elements positioned therebetween.
9. The rocker arm assembly of claim 8, wherein the first stop member and the second stop member define an included angle of between about 200 degrees and about 220 degrees to limit the extent of travel of the rolling elements around the raceway.
10. The rocker arm assembly of claim 1, wherein the race is substantially cup-shaped.
11. The rocker arm assembly of claim 1, wherein the plurality of rolling elements is less than a full complement of rolling elements relative to the raceway.
12. The rocker arm assembly of claim 1, wherein the bearing support member includes two support arms extending in opposite directions along an axis, and wherein the rocker arm assembly includes two bearing assemblies, one bearing assembly on each support arm.
13. A rocker arm assembly comprising:
- a rocker arm;
- a bearing support member having two support arms extending in opposite directions along an axis; and
- two bearing assemblies, one bearing assembly on each support arm and engaging the rocker arm, each bearing assembly including: a cylindrical race defining a raceway, the raceway having a stop member coupled thereto; and a plurality of rolling elements positioned on the raceway;
- wherein the stop member defines an extent of travel of the rolling elements on the raceway that is less than three-hundred-sixty degrees.
14. A bearing assembly comprising:
- a cylindrical race defining a raceway, the raceway having a stop member coupled thereto; and
- a plurality of rolling elements positioned on the raceway such that the movement of the rolling elements on the raceway is limited by the stop member.
15. The bearing assembly of claim 14, further comprising a second race, the plurality of rolling elements positioned between the two races.
16. The bearing assembly of claim 15, wherein the stop member is positioned and configured to center the second race with respect to the first race.
17. The bearing assembly of claim 15, wherein the raceway includes a second stop member coupled thereto, positioned and configured to center the second race with respect to the first race.
18. The bearing assembly of claim 14, wherein the stop member is integrally formed with the race.
19. The bearing assembly of claim 18, wherein the stop member is a projection formed in the raceway.
20. The bearing assembly of claim 14, wherein the stop member is a plug secured to the raceway.
21. The bearing assembly of claim 14, further comprising a second stop member, the first and second stop members defining the extents of travel of the rolling elements positioned therebetween.
22. The bearing assembly of claim 21, wherein the first stop member and the second stop member define an included angle of between about 200 degrees and about 220 degrees to limit the extent of travel of the rolling elements around the raceway.
23. The bearing assembly of claim 14, wherein the race is substantially cup-shaped.
24. The bearing assembly of claim 14, wherein the plurality of rolling elements is less than a full complement of rolling elements relative to the raceway.
Type: Application
Filed: Jun 20, 2008
Publication Date: Jan 1, 2009
Applicant: THE TIMKEN COMPANY (Canton, OH)
Inventors: Ian D. Baynes (Merrimac, MA), William A. Dammers (Greenville, SC), Richard D. Kraus (Simpsonville, SC)
Application Number: 12/142,871
International Classification: F01L 1/18 (20060101);