Arrangement for preloading bearings

• US 3,900,232 A
• Filed: 09/26/1973
• Issued: 08/19/1975
• Est. Priority Date: 09/26/1973
• Status: Expired due to Term

• Current Assignee: John E. Rode
• Original Assignee: John E. Rode
• Inventors: Rode, John E.
• Primary Examiner(s): Wood, Jr., M. Henson
• Assistant Examiner(s): Church, Gene A.
• Application Number:
  US05/401,117
• Time in Patent Office: 692 Days
• Field of Search: 308/189R,189A,190,1R,27R,27A,2B,227 29/149.5,148.4
• US Class Current: 384/517
• CPC Class Codes: F16C 19/54 Systems consisting of a plurality of bearings with rolling friction spindle bearings F16C35/08
• CPC Class Codes: F16C 2300/02 General use or purpose, i.e. no use, purpose, special adaptation or modification indicated or a wide variety of uses mentioned
• CPC Class Codes: F16C 25/083 with resilient means acting axially on a race ring to preload the bearing
• CPC Class Codes: F16C 41/02 Arrangements for equalising the load on a plurality of bearings or their elements
• CPC Class Codes: F16F 1/02 made of steel or other material having low internal friction characterised by their special construction from fibre-reinforced plastics F16F1/366; spring units consisting of several springs F16F3/02; making springs from wire B21F35/00; Wound, torsion, leaf, cup, ring or the like springs, the material of the spring not being relevant
• CPC Class Codes: Y10T 29/497 Pre-usage process, e.g., preloading, aligning

Abstract

An arrangement for preloading a pair of axially spaced thrust sustaining antifriction bearings which are interposed in tandem between a pair of members in which one race of each bearing is abutted on one side by abutment means stationary on one of the members, while moveable abutment means on the other member are arranged in opposed relation to the other sides of the other races of the bearings. Load elements are interposed between the other races of the bearings and the moveable abutments and adjusted to compress the load elements axially and thereby exert a predetermined preload on the bearings. A feature of the present invention resides in the specific load elements and each of which is arranged so that axial compression thereof will cause the load element to undergo a first period of resilient deformation at increasing compressive force followed by a second period of plastic deformation at substantially constant compression force. In applying the preload to the bearings, the load elements are first compressed within the range of plastic deformation thereof and are then clamped in place between the bearings and the abutments therefor in a condition of resilient deformation. Precise and accurate preloading of the bearings can thus be accomplished without the necessity of resorting to expensive, highly accurate machining of the members in respect of the bearing engaging surfaces thereof.

Claims

1. In combination;

first and second relatively rotatable members, at least two thrust sustaining antifriction bearings interposed between said members in axially spaced relation and each bearing having first and second races pertaining to and nonrotatable relative to said first and second members respectively, first abutment means stationary on said first member and engaging one axial side of said first races, second abutment means axially slidable on said second member and in opposed relation to the other axial sides of said second races, axially compressible load element means interposed between said second abutment means and said second races, and clamp means on said other member clamping said second abutment means thereto with said load element means between said second abutment means and the said second races of said bearings, each said load element being axially compressible at a predetermined force thereby to impart a predetermined axial load on each said bearing when the load element means are axially compressed.

2. A combination according to claim 1 in which each load element means comprises at least one ring convoluted in axial cross section and formed of a work hardening metallic material, each ring when subjected to an axial compressing force deforming resiliently up to a predetermined amount of axial compression and deforming plastically under substantially the same axial force upon further axial compression and springing back the amount of the resilient compression when the axial compressing force is released.

3. A combination according to claim 1 in which each load element means is in the form of a plurality of rings in coaxial nested relation, each ring being convoluted in axial cross section and formed of a work hardening metallic material, each ring when subjected to an axial compressing force deforming resiliently up to a predetermined amount of axial compression and deforming plastically under substantially the same axial force upon further axial compression and springing back the amount of the resilient compression when the axial compressing force is released.

4. A combination according to claim 1 in which at least one said load element means is in the form of a ring of sintered powdered metal having a density substantially less than theoretical density.

5. A combination according to claim 1 in which each of said load element means is in the form of a ring of sintered powdered metal having a density substantially less than theoretical density.

6. A combination according to claim 1 in which said clamp means comprises a clamp element adapted to be fixed to said other member to confine said second abutment means between said load element means and said clamp element, and means for first fixing said clamp element to said other member in a first axial position in which botH of said load element means are in a state of plastic deformation and for thereafter fixing said clamp element to said other member in a second axial position spaced axially farther from said second races than when the clamp element was in said first axial position.

7. A combination according to claim 6 in which said load element means are compressed into a state of resilient deformation when said clamp element is in said second axial position.

8. A combination according to claim 1 in which said second abutment means comprises sleeve means slidable on said second member and having shoulders facing said second races and between which shoulders and second races the said load element means are disposed.

9. A combination according to claim 8 in which said sleeve means comprise a pair of sleeves in tandem, each sleeve having one radial side engaging said second member and the other radial side engaging the adjacent radial side of a respective second race.

10. A combination according to claim 8 in which said sleeve means is a single sleeve member having one radial side slidably engaging said second member and on the other radial side slidably engaging the adjacent radial sides of said second races.

11. A combination according to claim 1 in which the first abutment means on said first member comprise shoulders thereon engaging said one axial side of said first races.

12. A combination according to claim 11 in which said shoulders are integral with said first member and said first races are of different diameters.

13. A combination according to claim 1 in which said first abutment means comprises sleeve means having one radial side engaging said first member and the other radial side engaging the adjacent radial side of said first races and having shoulders engaging the said one axial side of said first races, said first member comprising abutment means axially engaging said sleeve means and operable to sustain the thrust of said load element means on said bearings.

14. A combination according to claim 1 in which said bearings are radial thrust bearings.

15. A combination according to claim 1 in which said bearings are thrust bearings, and a further radial bearing interposed between said members.

16. A method of providing for proportional preloading of tandem thrust sustaining antifriction bearings interposed between first and second members with each bearing having a race pertaining to each member which comprises;

providing stationary abutment means on one of said members abutting one axial side of the pertaining races of the bearings, providing axially moveable abutment means on the other members disposed in opposed relation to the other axial sides of the other races of the bearings, placing a load element between said other race of each bearing and said moveable abutment means, said load elements when arranged in tandem and axially compressed by the application of an axial compressing force undergoing a first period of resilient deformation during which the compressing force increases substantially linearly followed by a second period of plastic deformation during which the compressing force remains substantially constant and equal on each load element and each load element springing back the amount of said resilient deformation upon release of said compressing force, moving said moveable abutment means toward said other races to a predetermined first axial position wherein said load elements are compressed to within the range of plastic deformation thereof, then moving said moveable abutment means away from said other races to a predetermined second axial position, and clamping the moveable abutment means to said other member in said second axial position.

17. The method according to claim 16 in which said load elements are confined between said moveable abutment means and said other races in a state of resilient compression when said second abutment means is in said second axial position.

18. The method according to claim 16 which inCludes interposing at least two rings in nested relation as a load element between said moveable abutment means and each said other race.

19. The method according to claim 15 which includes clamping said moveable abutment means to said other member by a clamp element which abuts said moveable abutment means from the opposite side that the moveable abutment means is abutted by said load elements, said clamping element having first and second predetermined axial positions on said other member, said clamp element in said first position compressing said load elements axially at least to the point of plastic deformation thereof, and in said second position compressing said load elements axially within the range of resilient deformation thereof.

20. In combination;

a pair of relatively rotatable members, a pair of thrust sustaining antifriction bearings interposed in tandem between said members and having first races pertaining to one member and second races pertaining to the other member, at least one abutment on each member, said abutments in opposed relation and on opposite sides of said pair of bearings, and axially collapsible load element means serially arranged with said bearings between said abutments and operable to divide thrust loads between said bearings, each load element means comprising at least one ring convoluted in axial cross section and formed of a work hardening metallic material, each ring when subjected to an axial compressing force deforming resiliently up to a predetermined amount of axial compression and deforming plastically under substantially the same axial force upon further axial compression and springing back the amount of the resilient compression when the axial compressing force is released.

21. The combination according to claim 20 in which one abutment engages one end of one race of one bearing and the other abutment engages the other end of the other race of the other bearing and said load element means comprises a first load element interposed between the first races of the bearings and a second load element interposed between the second races of the bearings.

22. The combination according to claim 21 in which said bearings are disposed to sustain thrust in the same direction.

23. The combination according to claim 20 in which said bearings are of different size, and ring members interposed between corresponding races of said bearings in serial arrangement with said load element means.

24. The combination according to claim 23 in which each ring member is slidably supported as a respective one of said pair of members.

25. The combination according to claim 23 in which each ring member has one of the radially inner and outer sides slidably engaging a respective one of said pair of members and the other radial side notched and engaging one radial side and an end of one race of a respective bearing.

26. The combination according to claim 25 in which the other end of the other race of each bearing engages a respective one of said abutments.

27. The combination according to claim 23 in which each of said load element means has a stiffness in conformity with the size of the bearing pertaining thereto.

28. The combination according to claim 23 in which said bearings are substantially coplanar.