Abstract: A power transmission device includes a rotatable input member, a rotatable output member, a friction clutch to selectively transfer torque between the input member and the output member, an actuator providing an actuating force to the friction clutch and a controller. The actuator includes an electric motor having an output shaft drivingly coupled to a gerotor. The gerotor is operable to supply pressurized fluid to a piston acting on the friction clutch. The controller controls the actuator in response to a four-wheel lock request to provide one of a minimum output torque and an output torque greater than a vehicle requested torque to operate the friction clutch in a locked mode.

Abstract: A drive train having an axle assembly with a differential and a multi-speed transmission outputs rotary power to an input pinion of the differential. The multi-speed transmission includes a positive or dog clutch with teeth having staggered heights. The staggered tooth height configuration provides a larger effective engagement area with less tooth lash.

Abstract: A power transmission device includes a friction clutch operable to selectively transfer torque between an input member and an output member. An actuator is operable to provide an actuating force to the friction clutch. The actuator includes an electric motor having an output shaft drivingly coupled to a gerotor. The gerotor is operable to provide pressurized fluid to a piston acting on the friction clutch.

Abstract: The present invention includes a positive clutch having a first clutch ring and a second clutch ring. The positive clutch further includes a first plurality of teeth connected to the first clutch ring. The first plurality of teeth includes a first set of teeth and a second set of teeth. The first set of teeth is taller than said second set of teeth. The staggered tooth height configuration provides a larger effective engagement area with less tooth lash.