A torque transfer mechanism having a multi-plate friction clutch connecting a
pair
of rotary members and a electrohydraulic clutch actuator for controlling engagement
of the friction clutch. The clutch actuator includes a hydraulic pump, a hydraulically-actuated
rotary operator, and a thrust mechanism. The hydraulic pump draws low pressure
fluid from a sump and selectively delivers high pressure fluid to a series of actuation
chambers and return chambers defined between coaxially aligned first and second
components of the rotary operator. The magnitude of the fluid pressure delivered
to the actuation chamber controls angular movement of the second component relative
to the first component for energizing the thrust mechanism. The thrust mechanism
applies a clutch engagement force on the friction clutch, thereby transferring
drive torque from the first rotary member to the second rotary member. An electrohydraulic
control system regulates the fluid pressure delivered to the actuation and return chambers.