Patent ID: 7175557

Claim:
A power transmission device for use in a motor vehicle having a powertrain and first and second drivelines, comprising: an input member driven by the powertrain; a first output member coupled to the first driveline; a second output member coupled to the second driveline; a torque distributing drive mechanism for transmitting drive torque from said input member to said first and second output members and including a differential, a speed changing unit and first and second torque couplings, said differential having an input component driven by said input member and first and second output components respectively driving said first and second output members, said speed changing unit having a first shaft driven by said input component, a second shaft, and a gearset for changing the rotary speed of said second shaft relative to said first shaft, said first torque coupling including a first clutch disposed between said second shaft and said first output component and first electric actuator means for controlling engagement of said first clutch by shifting between a motor mode and a brake mode, and said second torque coupling including a second clutch disposed between said second shaft and said second output component and second electric actuator means for controlling engagement of said second clutch by shifting between a motor mode and a brake mode; and a control system for selectively switching said first and second electric actuator means between their respective motor and brake modes.