Patent ID: 8584633

Claim:
A camshaft phaser for controllably varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine, comprising: a harmonic gear drive unit including a circular spline and a dynamic spline, a flexspline disposed within said circular spline and said dynamic spline, a wave generator disposed within said flexspline, and a rotational actuator connected to said wave generator; and a sprocket connectable to the crankshaft of said internal combustion engine; a sprocket housing supportive of said sprocket and attached to said harmonic gear drive unit; and a hub attached to said harmonic gear drive unit and connectable to a camshaft of said internal combustion engine; wherein one of said circular spline and said dynamic spline is attached to said sprocket housing and the other of said circular spline and said dynamic spline is attached to said hub.