Patent ID: 8684850

Claim:
A constant velocity universal joint comprising: an outer joint member having an inner surface provided with track grooves; an inner joint member having an outer surface provided with track grooves; a plurality of torque transmitting balls arranged in torque transmitting ball tracks formed by cooperation between the track grooves of the outer joint member and the track grooves of the inner joint member, the track grooves of the inner joint member corresponding to the track grooves of the outer joint member; and a cage for holding the torque transmitting balls, wherein at least one of each of the track grooves of the outer joint member and each of the track grooves of the inner joint member is formed by cold-forging finishing, wherein a track groove bottom side of the at least one of each of the track grooves of the outer joint member and each of the track grooves of the inner joint member is formed into a Gothic arch shape in horizontal cross-section, wherein track groove opening sides of the at least one of each of the track grooves of the outer joint member and each of the track grooves of the inner joint member are each formed into an elliptical shape in horizontal cross-section, and wherein a continuous position of the Gothic arch shape and the elliptical shape is located on a groove opening side within a range of from 30 degrees to 45 degrees with respect to a straight line connecting a ball center and a track groove bottom center.