Patent ID: 8485322

Claim:
A brake or clutch assembly comprising a housing surrounding and supporting an actuating piston which is non-rotatable relative to the housing, a pair of coupling members which are rotatable relative to the housing and coupling members which are non-rotatable relative to the housing, the rotatable and non-rotatable coupling members being brought into engagement on actuation of the piston to engage the brake or clutch assembly, the piston being provided with fully enclosed internal radially inwardly extending cooling oil passages which receive cooling oil from passages in the surrounding housing to direct cooling oil radially inwardly within the piston, the oil exiting from the radial passages in the piston via axially orientated openings facing the rotatable coupling members to provide cooling oil to the rotatable coupling members, wherein said pair of rotatable coupling members are provided with an intermediate non-rotatable member therebetween, one rotatable coupling member being pressed by the piston against the intermediate member and the other rotatable coupling member being pressed against a non-rotatable member when the piston is actuated.