Abstract: A phase change device of the type wherein an axially displaceable advancing plate drivingly interconnects input and output members through angled or helical, surfaces formed on interfacing portions of the input and output members. In accordance with the invention a plurality of balls of the type used in antifriction bearings are carried by the advancing plate and the interfacing portions of the input and output members are formed as angled or helical grooves in which said balls are received.

Abstract: A combination bearing and apparatus for maintaining the relative axial location of the input and output members of a camshaft phase change device. Peripheral grooves are formed in the members to receive a plurality of balls which support the input member for rotation on the output member. Radial slots are formed in the output member for insertion of the balls, and the angular position of the balls is maintained by fingers formed on a retention member which has spoke members received in the slots, and which is held in engagement with the output member by a retaining ring.