Patent ID: 8608578

Claim:
A constant velocity joint for a drive system comprising: a hollow housing having a plurality of guide grooves therein, the guide grooves extending in an axial direction of the housing and spaced equally apart in a circumferential direction of the housing; a tripod having a plurality of trunnions, each trunnion positioned in a corresponding one of the guide grooves of the hollow housing; and a roller assembly disposed on each trunnion, the roller assembly including an outer roller for rollably receiving in the corresponding guide groove; wherein the outer roller includes a convex outer surface, the convex outer surface having a first radius (Rry) seen from a cross section taken in an orthogonal direction relative to a central axis of the outer roller, the convex outer surface having a second radius (Rrx) seen from a cross section taken along the central axis of the outer roller, the convex outer surface of the second radius (Rrx) formed throughout an entire side surface of the outer roller, a center of the second radius (Rrx) displaced outwardly from a center of the first radius (Rry), and the second radius (Rrx) being shorter than the first radius (Rry); wherein each of the guide grooves of the housing includes a concave surface for mating with the convex outer surface of the outer roller, the concave surface having a length (L) and a radius (Rg) seen from a cross section taken along the central axis of the housing, a center of the radius (Rg) being the same as the center of the second radius (Rrx) of the outer roller, and the second radius (Rrx) of the outer roller being shorter than the radius (Rg) of the housing by a clearance margin throughout an entire length (L) of the concave surface, wherein the guide groove further includes an upper recess area and a lower recess area respectively recessed from the concave surface of the groove, and thereby defining widened spaces between the guide groove of the housing and its corresponding upper and lower portions of the convex outer roller.