Patent ID: 6851537

Claim:
A power transmission device comprising: a rotary input member adapted to receive drive torque from a source of torque; a rotary output member adapted to provide drive torque to an output device; and a torque transfer mechanism operable for transferring drive torque from said input member to said output member, said torque transfer mechanism including a friction clutch assembly operably disposed between said input member and said output member and a clutch actuator operable for applying a clutch engagement force to said friction clutch assembly, said clutch actuator including an operator for selectively rotating a first threaded member relative to a second threaded member, said first threaded member and said second threaded member each being partially disposed within a space radially inward of said friction clutch assembly and between said friction clutch assembly and one of said input member and said output member, said clutch actuator having a plurality of balls disposed within said threads between said first and second threaded members, said second threaded member being restricted from rotation and operable to linearly translate in response to rotation of said first threaded member.