Patent ID: 7431138

Claim:
A start-up clutch assembly comprising: a disk clutch having an outer disk carrier and an inner disk carrier with a multi-disk clutch pack disposed therebetween, said multi-disk clutch pack adapted to engage to provide torque translation between said inner and said outer carriers; a piston adapted to be actuated by fluid pressure to cause said multi-disk clutch pack to engage; a disk-return spring defining a spring force and adapted to prevent actuation of said piston; a first cavity adapted to be selectively supplied with pressurized fluid to actuate said piston; a second cavity adapted to be selectively supplied with pressurized fluid to provide cooling to said multi-disk clutch pack; a first fluid passage adapted to provide pressurized fluid to said first cavity; a second fluid passage adapted to provide pressurized fluid to said second cavity, said first and second passages being branches of a main passage; and a separator plate operatively disposed between said first and second cavities to isolate said first cavity from said second cavity, including a compensating opening, and juxtaposed to said piston so as to create a gap between said piston and said separator plate, wherein said compensating opening and said gap cooperate to form compensating cavities that are fed by a portion of said pressurized cooling fluid from said second cavity through said compensating opening and partially act against movement of said piston to provide compensation for additional centrifugal-force pressure in said first cavity and wherein said compensating opening and said gap further are adapted to control actuation of said piston toward said separator plate and compensate for centrifugal forces of drive components of said disk clutch upon said piston by controlling how fast said pressurized cooling fluid is forced out of said compensating cavities.