Wear ring for spring of friction coupling

Abstract

A power drive assembly having a housing, a drive mechanism removably installed in the housing, an annular biasing spring installed in the housing for biasing the mechanism, and a wear ring arrangement including an undercut annular groove in the mechanism opening coaxially toward an end of the biasing spring and a wear ring removably installed in the groove to engage the end of the biasing spring in the assembled arrangement of the power drive assembly. The wear ring has a cross section complementary to the undercut groove cross section whereby the mechanism may be installed in the housing with the groove opening downwardly and the wear ring maintained in the groove for facilitated assembly of the power drive.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
       1. In a power drive assembly having a housing, a drive mechanism removably installed in said housing, and an annular biasing spring installed in said housing for biasing said mechanism, an improved wear ring arrangement comprising: means on said mechanism defining an undercut annular groove opening coaxially toward an end of the biasing spring; and   a .Iadd.split .Iaddend.wear ring removably installed in said groove to engage said end of the biasing spring in the assembled arrangement of the power drive assembly, said wear ring having a cross section complementary to the undercut groove cross section whereby the mechanism may be installed in the housing with the groove opening downwardly and the wear ring maintained therein to removably engage said end of the biasing spring.   
     
     
       2. The power drive assembly of claim 1 wherein said housing is provided with an annular groove receiving a second wear ring to axially engage the opposite end of the biasing spring in the assembled arrangement of the power drive assembly. 
     
     
       3. The power drive assembly of claim 1 wherein said housing is provided with an annular groove receiving a second wear ring to axially engage the opposite end of the biasing spring in the assembled arrangement of the power drive assembly, said housing groove being undercut and said second wear ring being complementary thereto to be releasably maintained therein. 
     
     
       4. The power drive assembly of claim 1 wherein said biasing spring comprises a Belleville spring. 
     
     
       5. The power drive assembly of claim 1 wherein said biasing spring comprising a plurality of coaxially stacked Belleville spring elements. 
     
     
       6. The power drive assembly of claim 1 wherein said undercut groove defines a right circularly cylindrical side surface and an opposite frustoconical side surface. 
     
     
       7. The power drive assembly of claim 1 wherein said undercut groove defines a radially inner right circularly cylindrical side surface and an outer frustoconical side surface. 
     
     
       8. The power drive assembly of claim 1 wherein said undercut groove defines an undercut frustoconical sidewall extending at an angle of approximately 5° to 10° to the axis of operation of the annular groove. 
     
     
       9. The power drive assembly of claim 1 wherein said wear ring .[.comprises a split ring having.]. .Iadd.has .Iaddend.at least one frustoconical radially facing side surface. 
     
     
       10. The power drive assembly of claim 1 wherein said drive mechanism comprises a clutch assembly. 
     
     
       11. The power drive assembly of claim 1 wherein said drive mechanism comprises a brake assembly. .Iadd. 12. In a power drive assembly having a housing, a drive mechanism removably installed in said housing, and an annular biasing spring installed in said housing for biasing said mechanism, an improved wear ring arrangement comprising: means on said housing defining an undercut annular groove opening coaxially toward an end of the biasing spring; and   a split wear ring removably installed in said groove to engage said end of the biasing spring in the assembled arrangement of the power drive assembly, said wear ring having a cross section complementary to the undercut groove cross section whereby the housing may be installed about the mechanism with the groove opening downwardly and the wear ring maintained therein to removably engage said end of the biasing spring. .Iaddend..Iadd. 13. The power drive assembly of claim 12 wherein said biasing spring comprises a Belleville spring. .Iaddend..Iadd. 14. The power drive assembly of claim 12 wherein said biasing spring comprises a plurality of coaxially stacked Belleville spring elements. .Iaddend..Iadd. 15. The power drive assembly of claim 12 wherein said undercut groove defines a right circularly cylindrical side surface and an opposite frustoconical side surface. .Iaddend. .Iadd. 16. The power drive assembly of claim 12 wherein said undercut groove defines a radially inner right circularly cylindrical side surface and an outer frustoconical side surface. .Iaddend..Iadd. 17. The power drive assembly of claim 12 wherein said undercut groove defines an undercut frustoconical sidewall extending at an angle of approximately 5° to 10° to the axis of operation of the annular groove. .Iaddend..Iadd. 18. The power drive assembly of claim 12 wherein said wear ring has at least one frustoconical radially facing side surface. .Iaddend..Iadd. 19. The power drive assembly of claim 12 wherein said drive mechanism comprises a clutch assembly. .Iaddend..Iadd. 20. The power drive assembly of claim 12 wherein said drive mechanism comprises a brake assembly. .Iaddend.