Patent ID: 7462106

Claim:
A constant velocity universal joint comprising: an outer joint member including a cylindrical body whose inner peripheral face is formed with three guide grooves at even intervals, each guide groove extending in parallel with a central axis of the cylindrical body; an inner joint member including three tripod shafts extending radially outwardly at even intervals from a boss portion, each tripod shaft being formed with a tripod spherical face at a tip end portion; three roller units each including an outer peripheral face and a cylindrical inner peripheral face coaxially formed with each other, the inner peripheral face slidably engaging with the tripod spherical face, the outer peripheral face engaging with the guide groove in a rolling manner along with a longitudinal direction of the guide groove; the guide groove including a pair of strip-shaped inner side faces facing in parallel with each other relative to a plane radially extending from the central axis and a guide projection provided substantially centrally in the guide groove between the pair of inner side faces, wherein the guide projection has a substantially half arc shape in cross section whose diameter is smaller than a height of the guide groove; and an annular recess formed on a substantially center portion in a height direction of the outer peripheral face of the roller unit so as to extend in a circumferential direction and engaging with the guide projection in a rolling manner and rotatable relative to a central axis of the guide projection.