Patent ID: 6945375

Claim:
A power transmission device for use in a motor vehicle having a powertrain and first and second drivelines, comprising: a first rotary member adapted to transmit drive torque from the powertrain to the first driveline; a second rotary member coupled to the second driveline; a torque transfer mechanism for transmitting drive torque from said first rotary member to said second rotary member and including a transfer clutch operably disposed between said first and second rotary members and a clutch actuator for controlling engagement of said transfer clutch, said clutch actuator including an operator unit operable to exert a clutch engagement force on said transfer clutch and an electric motor operable in a motor mode and a brake mode for generating an output torque that is converted by said operator unit into said clutch engagement force; and a control system for selectively switching said electric motor between its motor mode and its brake mode based on the rotary speed of one of said first and second rotary members.