Ball joint with improved upper bearing and method of construction thereof

1. A ball joint, comprising:

a housing;

a stud having a spherical bearing surface disposed in said housing;

a bearing having a concave spherical bearing surface brought into sliding abutment with said spherical bearing surface of said stud; and

said bearing being a monolithic piece of fiber-reinforced polyamide material including a plurality of individual carbon fibers, substantially all of said individual carbon fibers being substantially oriented in a circumferential direction.

2. The ball joint as set forth in claim 1 wherein said fiber-reinforced polyamide material includes glass fibers and bronze flakes both extending circumferentially about said concave spherical bearing surface.

3. The ball joint as set forth in claim 2 wherein said fiber-reinforced polyamide material has a composition including greater than about 57% nylon; greater than 0% and less than about 30% glass fiber; greater than 0% and less than about 10% carbon fiber, and greater than 0% and less than about 10% bronze flake.

4. The ball joint as set forth in claim 3 wherein said fiber-reinforced polyamide material includes greater than 0% and less than about 3% white pigment.

5. The ball joint as set forth in claim 1 wherein said bearing is an upper bearing and further including a lower bearing.

6. The ball joint as set forth in claim 5 wherein said upper bearing is received in said lower bearing.

7. The ball joint as set forth in claim 5 wherein at least one of said upper and lower bearings is provided with lubrication grooves.

8. The ball joint as set forth in claim 5 wherein said lower bearing is provided with a low-friction coating.

9. The ball joint as set forth in claim 5 further including an end cap and a washer spring captured between said upper bearing and said end cap.

10. The ball joint as set forth in claim 1 wherein said stud has an end with threads opposite of said spherical bearing surface.

11. A method of constructing a ball joint, comprising:

injection molding a polyamide material with carbon fibers into a bearing with a concave spherical bearing surface wherein during the injection molding process the polyamide material flows circumferentially to substantially orient the carbon fibers within the polyamide material in a circumferential direction throughout the bearing; and

inserting the fiber-reinforced polyamide bearing with the substantially circumferentially aligned carbon fibers into a metal housing and bringing the concave spherical bearing surface into sliding abutment with a metal spherical bearing surface of a stud.

12. The method of claim 11 further including providing the fiber-reinforced polyamide material including glass and bronze flake both extending circumferentially about the concave spherical bearing surface.

13. The method of claim 12 further including providing the fiber-reinforced polyamide material having a composition including greater than about 57% nylon; greater than 0% and less than about 30% glass fiber; greater than 0% and less than about 10% carbon fiber, and greater than 0% and less than about 10% bronze flake.

14. The method of claim 13 further including providing the fiber-reinforced polyamide material includes greater than 0% and less than about 3% white pigment.

15. The method as set forth in claim 11 further including the step of injection molding a bearing before the step of inserting the bearing into sliding abutment with the metal spherical surface of the stud.