Abstract: A hydraulic system includes a power source, a fluid displacement assembly, a plurality of actuators, a plurality of control valves and an electronic control unit. The fluid displacement assembly is coupled to the power source. The plurality of actuators is in selective fluid communication with the fluid displacement assembly. The plurality of control valves is adapted to provide selective fluid communication between the fluid displacement assembly and the plurality of actuators. The electronic control unit is adapted to actuate the plurality of control valves, the electronic control unit receives a rotational speed of the power source, determines a firing frequency of the power source based on the rotational speed, selects a frequency of the pulse width modulation signal for the plurality of control valves based on the firing frequency of the power source, and actuates the plurality of control valves in accordance with the frequency of the pulse width modulation signal.

Abstract: A hydraulic system includes a power source, a fluid displacement assembly, a plurality of actuators, a plurality of control valves and an electronic control unit. The fluid displacement assembly is coupled to the power source. The plurality of actuators is in selective fluid communication with the fluid displacement assembly. The plurality of control valves is adapted to provide selective fluid communication between the fluid displacement assembly and the plurality of actuators. The electronic control unit is adapted to actuate the plurality of control valves, the electronic control unit receives a rotational speed of the power source, determines a firing frequency of the power source based on the rotational speed, selects a frequency of the pulse width modulation signal for the plurality of control valves based on the firing frequency of the power source, and actuates the plurality of control valves in accordance with the frequency of the pulse width modulation signal.

Abstract: A hydrostatic pump-motor unit (35) including a clutch assembly (43) and a pump-motor portion (45) disposed within a housing assembly (51,55,57). An intermediate drive shaft (21) extends through the entire axial extent of the unit (35) and is surrounded by a hollow shaft member (63). The housing assembly (51,55,57) supports the drive shaft (21) by means of a pair of bearing sets (67,71), and the hollow shaft member (63) is supported relative to the housing assembly by means of a pair of bearing sets (75,79). The pump-motor portion (45) includes an axial piston cylinder barrel (115) surrounding the shaft member (63) and splined thereto. The clutch assembly (43) is operable to selectively clutch and de-clutch the drive shaft (21) and the hollow shaft member (63). Having the drive line extend through the pump-motor unit (35) substantially improves the packaging of the overall drive system.

Abstract: A hydrostatic transaxle is disclosed of the type including a hydrostatic transmission (11;221), a differential gear means (19;243), and first (21;213) and second (23;215) axle shafts. The hydrostatic transmission includes a transmission case (34;229,231) having a second case portion (31;231) including an output hub portion (97;235). The transaxle includes axle housing casing halves 133,135:209,211) joined together on a plane containing the axis of rotation of the axle shafts, and including an output portion (163,165;209,211) in tight engagement about the output hub portion. Another portion (173;229,231,249) of the transmission case cooperates with one of the axle casing halves to define a secondary mounting means and a torque reaction means which, together with the output hub portion, comprise the only portions of the transmission case operatively associated with the axle housing (131;208).

Abstract: A variable displacement, rotary fluid pressure pump (11) is disclosed of the type having a cam ring member (25) which is movable, in response to rotation of a control shaft (35), between a neutral position (FIG. 5) and a displaced position (FIG. 4). The pump housing (13, 15) includes a support member (25), and they cooperate to define a high-pressure fluid passage (51). In communication with the passage (51) is a recess (71), in which is disposed a dampening shoe (73). The dampening shoe is biased by high-pressure fluid in the passage (51) into engagement with an adjacent surface (77) of the cam ring (25). The surface (77) defines a neutral fluid passage (79), and the dampening shoe (73) defines a restricted opening (85).