Abstract: A hydraulically actuated friction coupling comprises a hollow case, an output shaft drivingly connected to the case, a friction clutch pack for selectively engaging and disengaging the case and the output shaft, and a hydraulic clutch actuator. The hydraulic actuator includes a hydraulic pump for generating a hydraulic pressure to frictionally load the clutch pack, and a piston assembly disposed within the case between the pump and the clutch pack. The piston assembly includes an annular pressure plate adjacent to the pump, an annular thrust plate axially spaced from the pressure plate and adjacent to the clutch pack, and a pair of concentric radially spaced resilient annular seal members bonded to the pressure and thrust plates so as to define an annular cavity within the piston assembly. The annular cavity in the piston assembly is in fluid communication with an output port of the hydraulic pump.

Abstract: A novel arrangement of a limited slip differential assembly comprising a differential case housing a friction clutch assembly provided within a differential case for selectively restricting differential action and a hydraulic actuator assembly including a piston assembly and a bi-directional gerotor pump. The piston assembly includes a hydraulic piston disposed in a piston housing forming a pressure chamber. The piston housing is provided with a removable bleed plug defining a flow restricting bleed passage. The bleed plug is accessible from the outside of the differential assembly without disassembling thereof through an access hole in the differential case. By appropriately selecting a flow area of the bleed passage, the limited slip differential assembly may be tuned to define application rate of torque transfer of the friction clutch assembly.

Abstract: An air bleed device for a rigid closed housing having a vent hole in a vehicle power transmission system has a baffle portion and a vent portion, connected through a neck portion. In use, the baffle portion is positioned inside the housing and is significantly larger than the vent hole, so it may not be deformed sufficiently to pass through the vent hole. The baffle portion is a pair of planar pieces held in spaced apart relationship by a wall portion which runs along the periphery of the planar pieces and leaves an opening to give access to a plenum between the planar pieces. An outer surface of one of the planar pieces rests against the inner wall of the housing. The vent portion has a collar with a decreasing diameter which may be pulled through the vent hole in a deformed manner and a lower flange-like surface of the collar rests against the outer wall of the housing. When installed in the vent hole, the neck portion provides a frictional fit due to its outside diameter.