Abstract

A phaser for adjusting the timing between a camshaft and a crankshaft. The phaser consists of an outer housing having internal and external teeth and an inner housing connected to the camshaft. The outer teeth couple to the cam drive—the timing chain, timing belt or timing gears. A worm mounted on the inner housing is meshed with the internal teeth of the outer housing. The worm gear is connected to one or two drive wheels, which are rotated by contact with stationary plates. The plates are moved by electromagnetic coils to contact the drive wheel or wheels, and turn them in one direction or the other. The actuators are activated by an engine control unit. The plates can be mounted concentrically on one side of the phaser, or on opposite sides.