Patent ID: 7527133

Claim:
A power transmission device comprising: a rotary input member adapted to receive drive torque from a power source; a rotary output member adapted to provide drive torque to an output device; a torque transfer mechanism operable for transferring drive torque from said input member to said output member, said torque transfer mechanism including a clutch assembly operably disposed between said input member and said output member and a clutch actuator assembly for applying a clutch engagement force to said clutch assembly, said clutch actuator assembly including an electric motor driving a geared drive unit for controlling said clutch engagement force applied to said clutch assembly by a clutch apply operator, said geared drive unit includes a pinion gear driven by said electric motor and a face gear in meshed engagement with said pinion gear, said clutch apply operator including a first cam plate fixed against rotation, a second cam plate fixed for rotation with said face gear and rollers engaging a cam surface provided between said first and second cam plates, wherein said face gear includes a ramp angle adapted to accommodate axial movement of said second cam plate relative to said pinion gear; and a control system for actuating said electric motor so as to control the direction and amount of rotation of said face gear which, in turn, controls the direction and amount of translational movement of said second cam plate relative to said clutch assembly.