Abstract: The present invention is an apparatus and method for capturing a hydrodynamic film between two working surfaces whereby the hydrodynamic film separates the two working surfaces while transmitting mechanical energy between the two thereby greatly reducing wear while dissipating thermal energy produced from the transfer of mechanical energy.

Abstract: A rotor disc assembly of a wet disc brake is driven from a shaft with discs thereof movable axially along the shaft. Stator discs are splined to a stationary housing and are interleaved with members of the rotor assembly. Stator disc structure between each adjacent pair of rotor discs each has low impedance flow channels radially extending from the outer to inner peripheries of the stator discs for return flow of oil pumped from the region of the shaft to the periphery.

Abstract: A reversible power transmission having a pair of axially spaced selectively actuable brakes each including fixed stator disks and rotor disks. Two ring gears each have gear teeth on inner and outer surfaces with the outer teeth enmeshed with inner teeth on the rotor disks. An input shaft carries a driving sun gear. An output shaft is aligned with the input shaft. A cage carried by the output shaft has two arrays of idler pinion gears journaled in the cage with the first array driven by the sun gear and driving the second array. Each pinion of the first array is enmeshed with teeth on the inside of one of the ring gears, and each pinion of the second array is enmeshed with teeth on the inside of the other ring gear.