초록 ▼

A hydraulic coupling is disclosed for use in motor vehicle driveline applications to rotatively couple a pair of rotary members. The hydraulic coupling includes a multi-plate clutch assembly operatively connecting the two rotary members and an actuator assembly for actuating the clutch assembly in r

A hydraulic coupling is disclosed for use in motor vehicle driveline applications to rotatively couple a pair of rotary members. The hydraulic coupling includes a multi-plate clutch assembly operatively connecting the two rotary members and an actuator assembly for actuating the clutch assembly in response to and as a function of speed differentiation between the two rotary members. The actuator assembly includes a hydraulic pump, a piston disposed in a piston chamber, and a fluid control system for controlling the fluid pressure supplied to the piston chamber by the hydraulic pump to control the clutch engagement force exerted by the piston on the clutch assembly. The fluid control system includes a pressure relief valve operable for limiting the fluid pressure in the piston chamber to a predetermined maximum pressure value. The fluid control system also includes a thermal unload valve operable for releasing the fluid pressure within the piston chamber when the fluid temperature exceeds a predetermined maximum temperature value.

대표청구항 ▼

[ What is claimed is:] [1.] A hydraulic coupling for use in a motor vehicle driveline apparatus to rotatively couple first and second rotary members, the hydraulic coupling comprising:a cover assembly fixed for rotation with the first rotary member and surrounding the second rotary member to define

[ What is claimed is:] [1.] A hydraulic coupling for use in a motor vehicle driveline apparatus to rotatively couple first and second rotary members, the hydraulic coupling comprising:a cover assembly fixed for rotation with the first rotary member and surrounding the second rotary member to define a clutch chamber and a supply chamber;a transfer clutch located in said clutch chamber and including a clutch pack having a first clutch plate fixed for rotation with said cover assembly and a second clutch plate fixed for rotation with the second rotary member;a piston housing defining a piston chamber;a piston disposed in said piston chamber for movement relative to said clutch pack for exerting a clutch engagement force thereon the magnitude of which is a function of the fluid pressure in said piston chamber;a hydraulic pump operative for pumping fluid from said supply chamber to said piston chamber in response to a speed differential between the first and second rotary members;first and second flow paths between said piston chamber and said clutch chamber;a pressure relief valve associated with said first flow path for permitting fluid flow from said piston chamber into said clutch chamber when the fluid pressure in said piston chamber reaches a predetermined pressure value; anda thermal unload valve associated with said second flow path for permitting fluid flow from said piston chamber to said clutch chamber when the fluid temperature in said piston chamber exceeds a predetermined temperature value.