Axially compact coupling for a camshaft phaser actuated by electric motor

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 including an input member, an output member, a wave generator disposed within said input member and said output member, and a rotational actuator connected to said wave generator such that rotation of said wave generator causes relative rotation between said input member and said output member;
• 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.

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 gear drive unit disposed within said housing, said gear drive unit having an input gear member and an output gear member, the input gear member being attachable to said crankshaft and being attached to an output shaft of an electric motor, the output gear being attachable to said camshaft such that rotation of said input gear member by said electric motor causes relative rotation between said crankshaft and said camshaft;
• a coupling adapter fixed to said input gear member, 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 said output shaft of said electric motor, said output 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.