Patent ID: 7316620

Claim:
A constant velocity universal joint comprising: an outer joint member having three track grooves each having circumferentially-opposed roller guideways; a tripod member having three radially-projecting trunnions; rollers inserted into said track grooves; and rings fitted onto said trunnions for supporting said rollers rotatably, wherein said rings have a circular cross section and said trunnions are so shaped in cross section as to contact inner peripheries of said rings in directions perpendicular to an axis of the joint and create clearances with the inner peripheries of said rings in the axial direction of the joint; said rollers being capable of moving along said roller guideways in the axial direction of said outer joint member, wherein the ratio of the pitch circle diameter T PCD of said track grooves to the pitch circle diameter S PCD of a spline hole formed in said tripod member, or T PCD /S PCD , is set within the range of 1.7-2.1, the ratio of the diameter D J of said trunnions to the pitch circle diameter S PCD of said spline hole, or D J /S PCD , is set within the range of 0.6-1.0, and the ratio of the outer diameter D R of said rollers to the pitch circle diameter S PCD of said spline hole, or D R /S PCD , is set within the range of 1.4-2.3.