Patent ID: 7055657

Claim:
An interleaved wet friction plate braking device comprising, a stationary housing which carries a plurality of annular stationary brake plates and which has a stationary fluid reservoir containing coolant; a rotatable shaft, a plurality of annular friction plates mounted to rotate with the shaft, said friction plates having friction lining attached thereto, the friction lining having grooves; an actuator adapted to axially press the friction plates into braking engagement with the brake plates; a plurality of impeller vanes extending from the outer periphery of the friction plates and adapted to impact the stationary reservoir during a part of the rotation of the friction plates, the brake plates having a diameter greater than that of the friction plates including the impeller vanes but disposed axially closely adjacent to the vanes, wherein, during said part of the rotation of the friction plates, the brake plates, in combination with an area rotationally between adjacent impelle vanes, define a pressure chamber so as to impart inward flow of coolant through the grooves of the friction lining as the impeller vanes pass through the coolant in the stationary reservoir, and wherein during a remaining part of the rotation of the friction plates, coolant is permitted to flow radially outward by centrifugal force.