Abstract: A rotary fluid pressure device is disclosed of the type utilizing a gerotor gear set (13) and an output shaft assembly (45) including a spool valve (49). The device includes a housing (11) defining inlet and outlet ports (21 and 23). The spool valve and housing cooperate to define a lubrication fluid chamber (59). Torque is transmitted from the gerotor set to the output shaft by a dogbone shaft (61) having a rearward spline connection (65, 69) to the gerotor, and a forward spline connection (63, 67) to the output shaft. The spool valve defines a pair of annular grooves (71, 73) in communication with the ports and a pair of check valve assemblies (91, 93) to permit flow of lubrication fluid from the lubrication chamber into whichever of the annular grooves is in communication with the outlet port.

Abstract: A fluid pressure operated wheel motor is disclosed of the type including a stationary housing assembly (11) and a rotatable housing assembly (13), which includes a gerotor displacement mechanism (29). The gerotor ring (47) is part of the rotatable housing assembly and rotates, while the gerotor star (49) is connected by a dogbone shaft (57) to the stationary housing assembly and only orbits. The dogbone shaft defines an axial bore (67), and the stationary housing defines a pair of main fluid passages (71 and 73) which cooperate with a plurality of fluid passages (91 and 93) defined by the rotatable housing assembly to form commutating valving. In either direction of operation, the system fluid flows through the chamber (19) in which the dogbone is disposed. The system fluid is divided into two portions, with one portion flowing through one spline connection (59 and 63), and the other portion flowing through the axial bore and the other spline connection (61 and 65).

Abstract: A fluid pressure operated motor is disclosed of the type utilizing a gerotor gear set and an internal output shaft and spool valve. The motor includes a housing defining a fluid inlet port and an endcap defining a fluid output port. The motor further includes a dogbone shaft defining an axial bore and having a spline connection to the output shaft at one end and a spline connection to the externally-toothed member of the gerotor at its other end. In one direction of operation of the motor, the fluid exhausted from the contracting volume chambers passes through a radial passage of the spool valve into the interior of the spool valve. A portion of this system fluid flows through the forward spline connection, then through the bore in the dogbone shaft toward the endcap, while the other portion of the system fluid flows through the rear spline connection. The two portions recombine and flow through the fluid port in the endcap.