Resilient bushing with long fatigue life

Abstract

A resilient bushing with long fatigue life comprises an outer rigid member having curvilinear inner surface portions and inner rigid member having curvilinear outer surface portions. At least one of said surface portions has a surface roughness height rating measured by SAE Standard J448a. Said surface roughness height rating is provided by sandblasting said surface portions of a metal member, and thereafter forming on said surface portions a phosphate coating. An elastomeric insert is compressively positioned between said inner surface portions of the outer member and said outer surface portions of the inner member.

What is claimed is: 
     
       1. A resilient bushing comprising: an outer rigid member having curvilinear inner surface portions;   an inner rigid member having curvilinear outer surface portions;   at least one of said surface portions being provided as a sandblasted surface with a phosphate coating of selected weight of at least about 2,000 milligrams per square foot formed on said surface to define an effective roughness surface height rating selected between about 170 RMS and 260 RMS in accordance with SAE Standard J488a; and   an elastomeric insert compressively positioned between said inner surface portions of the outer member and said outer surface portions of the inner member.   
     
     
       2. A resilient bushing comprising: an outer rigid member having curvilinear inner surface portions;   an inner rigid member having curvilinear outer surface portions;   at least one of said surface portions being provided as a sandblasted surface with an effective phosphate coating formed on said surface to define an effective roughness surface height rating selected in accordance with SAE Standard J448a; and   an elastomeric insert compressively positioned between said inner surface portions of the outer member and said outer surface portions of the inner member.   
     
     
       3. A resilient bushing as set forth in claim 2 wherein at least said outer portions of said inner rigid member is provided to define said roughness surface height rating. 
     
     
       4. A resilient bushing as set forth in claim 2 wherein said roughness height rating is selected to be at least about 170 RMS. 
     
     
       5. A resilient bushing as set forth in claim 2 wherein the weight of said effective phosphate coating is at least about 2,000 milligrams per square foot. 
     
     
       6. A resilient bushing as set forth in claim 2 wherein said roughness height rating is selected between about 170 RMS and 260 RMS. 
     
     
       7. A resilient bushing as set forth in claim 3 wherein said roughness height rating is selected to be at least about 170 RMS. 
     
     
       8. A resilient bushing as set forth in claim 7 wherein the weight of said effective phosphate coating is at least about 2,000 milligrams per square foot. 
     
     
       9. A resilient bushing as set forth in claim 3 wherein said roughness height rating is selected between about 170 RMS and 260 RMS. 
     
     
       10. A resilient bushing as set forth in claim 4 wherein the weight of said effective phosphate coating is at least about 2,000 milligrams per square foot. 
     
     
       11. A resilient bushing as set forth in claim 5 wherein said roughness height rating is selected between about 170 RMS and 260 RMS. 
     
     
       12. A resilient bushing as set forth in claim 11 wherein at least said outer portions of said inner rigid member is provided to define said roughness surface height rating. 
     
     
       13. A resilient bushing as set forth in claim 1 wherein: at least said outer surface portions of the inner rigid member have said surface roughness height rating.