Patent ID: 8800513

Claim:
A camshaft phaser for controllably varying the phase relationship between a crankshaft and a camshaft in an internal combustion engine, said camshaft phaser comprising: a housing having a housing bore with a longitudinal axis; a harmonic gear drive unit disposed within said housing, said harmonic gear drive unit comprising a circular spline and an axially adjacent dynamic spline, a flexspline disposed within said circular spline and said dynamic spline, a wave generator disposed within said flexspline, and a rotational actuator connectable to said wave generator such that rotation of said wave generator causes relative rotation between said circular spline and said dynamic spline, wherein one of said circular spline and said dynamic spline is fixed to said housing in order to prevent relative rotation therebetween; a hub rotatably disposed within said housing axially adjacent to said harmonic gear drive unit and attachable to said camshaft and fixed to the other of said circular spline and said dynamic spline in order to prevent relative rotation therebetween; a coupling adapter coaxial with said housing bore and fixed to said wave generator, said coupling adapter being rotatable about a coupling adapter rotational axis and being supported in said housing by a bearing which is press fit onto a bearing surface of said coupling adapter, said coupling adapter having a coupling adapter bore with opposing drive lugs extending radially inward therefrom which are axially coincident with said bearing surface; and a coupling fixed to a shaft of said rotational actuator, said shaft being rotatable about a rotational actuator rotational axis, said coupling being disposed within said coupling adapter bore and having opposing drive slots for receiving said opposing drive lugs, thereby transmitting rotary motion from said coupling to said coupling adapter; wherein said coupling is sized to allow linear movement of said coupling within said coupling adapter bore along a first misalignment axis that is substantially perpendicular to said coupling adapter rotational axis wherein each of said opposing drive lugs includes opposing lug sidewalls that extend axially and are substantially parallel to each other.