US Patent 7160193 Constant velocity universal joint

In a no-flange type outer joint member, the amount of abrasion in a large inner diameter portion formed for a track groove is intended to be restrained. In a tripod type constant velocity universal joint including: a no-flange type outer joint member; and a roller assembly including a roller, being attached to a trunnion so as to be capable of oscillating, hardened layers are formed on portions of a large inner diameter portion of the outer joint member, which are in contact with an inclined roller assembly. In this case, a value of F/D is set equal to or less than 0.45, where a distance from a center of the track groove of the outer joint member to the ends of both the hardened layers on the side of the center of the track groove is F, and a diameter of an outer circumference of the roller assembly is D.