Patent attributes
A constant velocity universal joint has an outer joint member having eight curved track grooves axially extending along an inner circumferential surface, an inner joint member having eight curved track grooves axially extending along an outer circumferential surface, eight balls respectively arranged in eight ball tracks provided as pairs of the track grooves of the outer and inner joint members. The center of each track groove of the outer joint member is axially displaced a predetermined distance from the spherical center of the inner circumferential surface. The center of each track groove of the inner joint member is axially displaced the same distance from the spherical center of the outer circumferential surface in the direction opposite to that of the outer joint member. A PCD gap in the ball track is in the range of 5 μm to 50 μm.
