Thrust washer for universal joint having preloading thrust surfaces

Abstract

A thrust washer for use in a universal joint having a preloading thrust surface includes a center aperture, an outer surface and an inner surface. A portion of the inner surface defines a thrust surface which contacts the outer end of the trunnion in only a limited contact area. The thrust surface may be located adjacent the outer circumference of the center aperture in the thrust washer. The thrust surface contacts only that portion of the outer end of the trunnion which is adjacent the outer circumference of the lubricant passageway extending through each trunnion. In one embodiment, the inner surface is tapered outwardly such that the thrust surface is defined by the thickest portion of the tapered surface. In another embodiment, the inner surface includes a plurality of protuberances located around the circumference of the center aperture such that these protuberances define the thrust surface. In both embodiments, a small preloading force is applied at the limited contact area on the trunnion which helps to reduce and/or eliminate any radial movement or play between the universal joint components. However, because the contact area is limited, the mount of preloading force is minimized such that the flex effort or torque required to cause the cross member to rotate within its bearing cups is not excessive. In both embodiments, the thrust washer is made from a resilient, deformable material which may be subject to wear such that the thrust surface may wear away after a short period of operation.