Abstract: A compact hydraulic motor 10 in which a pressurized sleeve bearing 20 is coaxial with a commutator 16, all positioned in the output housing 14. The commutator housing provides fluids to a rotary valve plate 48 and to chambers 52 formed between rotating inner member 30 and orbiting outer member 32. The sleeve bearing 20 is pressurized with fluid from the gear set 30, 32 and is in fluid communication with a rear needle bearing 24. The seals are protected from overpressurization through channels 25 and 46 and pressurization valves. In an alternate embodiment of the invention, dual gear sets 80, 82, and 81, 83, (FIG. 7) are positioned within a housing for either series or parallel operation. Fluid directed to the two gear sets by a manifold 112 can run the gear sets in parallel or series in order to provide either high speed low torque or low speed high torque operation.

Abstract: A fluid actuated device of the type wherein the controlled supply and discharge of fluid medium actuates a member for movement through an orbital path in which the flow of the fluid medium is controlled solely by a valve structure rotating in synchronism with a member rotatively driven by said orbitably moving member and which control selectively permits the supply of fluid medium to bypass the orbitably movable member.