Plunging constant velocity universal joint

摘要

Unpleasant vibration and muffled sound are restrained. A constant velocity universal joint includes: an outer joint part 10 having a plurality of track grooves 14 formed on its cylindrical inner circumferential surface 12 and extending in an axial direction; an inner joint part 20 having a plurality of track grooves 24 formed on its spherical outer circumferential surface 22 and extending in the axial direction; six torque transmitting balls 30, each being put in a ball track formed by a pair of the track groove 14 of the outer joint part 10 and the track groove 24 of the inner joint part 20; and a cage 40 having pockets 46 for retaining the torque transmitting balls 30. The center Oo of curvatures of the spherical outer circumferential surface 42 and the center Oi of the spherical inner circumferential surface 44 of the cage 40 are offset by the same distance in the opposite directions along the axis about the center of the joint O. A circumferential arrangement of the ball tracks is made with a uniform pitch, and a circumferential arrangement of the pockets of the cage is made with a random and non-uniform pitch of 55° or more.