A device for the deaeration of a hydraulic fluid of a hydraulic system has at least one hydraulic motor arrangement and a hydraulic fluid storage which is hydraulically coupled with this hydraulic motor arrangement. A suction device for sucking out the hydraulic fluid is associated with the at least one hydraulic motor arrangement such that the suction device guides hydraulic fluid out of the hydraulic motor arrangement into the hydraulic fluid storage by means of vacuum pressure (p). The suction device is constructed as a jet pump and is integrated in the return line between the hydraulic motor arrangement and hydraulic fluid storage.

A hydraulic transaxle includes a transaxle casing including an upper transaxle housing and a lower casing, hydrostatic transmission (HST), and an axle. The HST has a hydraulic pump and a hydraulic motor that are fluidly connected to each other. The hydraulic motor has a motor shaft that is drivingly connected to the axle through a reduction gear train that is disposed between the hydraulic pump and the axle. Reduction gear train has a gear shaft supported by the upper transaxle housing via a ball bearing. At least a part of the upper transaxle housing is formed by a gear top cover made of metal and covering the reduction gear train. Ball bearing is supported by the upper transaxle housing and the gear top cover.

A hydrostatic transmission for a working machine having a frame, an engine on the frame, and at least one wheel driven by the hydrostatic transmission is disclosed. The hydrostatic transmission includes a housing, a hydraulic pump, the hydraulic pump driven by an output shaft from the engine, a hydraulic motor for driving an output shaft connected to the at least one wheel, a first fluid line fillable with hydraulic fluid to be maintained under a first pressure, a second fluid line fillable with hydraulic fluid to be maintained under a second pressure, a first check valve for allowing hydraulic fluid to enter the first fluid line, a second check valve for allowing hydraulic fluid to enter the second fluid line, and an entrained air deflector for preventing hydraulic fluid entrained with air from entering the first check valve and the second check valve.

A hydrostatic transmission for a working machine having a frame, an engine on the frame, and at least one wheel driven by the hydrostatic transmission is disclosed. The hydrostatic transmission includes a housing, a hydraulic pump, the hydraulic pump driven by an output shaft from the engine, a hydraulic motor for driving an output shaft connected to the at least one wheel, a first fluid line fillable with hydraulic fluid to be maintained under a first pressure, a second fluid line fillable with hydraulic fluid to be maintained under a second pressure, a first check valve for allowing hydraulic fluid to enter the first fluid line, a second check valve for allowing hydraulic fluid to enter the second fluid line, and an entrained air deflector for preventing hydraulic fluid entrained with air from entering the first check valve and the second check valve.

A method for driving a transmission mechanism output power in response to an anticipated fluid-pressure gradient field is provided. The method includes sensing the change of direction of pressure gradient field at a desired location from the different area of the transmission mechanism within fluid. The method further includes constructing fluid-pressure gradient field based upon isolation-fluid apparatus or low-density fluid space installed on a transmission mechanism within fluid.

A method for driving a transmission mechanism output power in response to an anticipated fluid-pressure gradient field is provided. The method includes sensing the change of direction of pressure gradient field at a desired location from the different area of the transmission mechanism within fluid. The method further includes constructing fluid-pressure gradient field based upon isolation-fluid apparatus or low-density fluid space installed on a transmission mechanism within fluid.

Degasifying apparatus for eliminating gases, such as ambient air, from fluids, such as oil, said apparatus consisting of at least one permeable membrane (26) which lets the gas to be eliminated from the fluid (22) penetrate therethrough and retains the liquid moiety of the fluid.

Degasifying apparatus for eliminating gases, such as ambient air, from fluids, such as oil, said apparatus consisting of at least one permeable membrane (26) which lets the gas to be eliminated from the fluid (22) penetrate therethrough and retains the liquid moiety of the fluid.

A hydrostatic transmission for a working machine having a frame, an engine on the frame, and at least one wheel driven by the hydrostatic transmission is disclosed. The hydrostatic transmission includes a housing, a hydraulic pump, the hydraulic pump driven by an output shaft from the engine, a hydraulic motor for driving an output shaft connected to the at least one wheel, a first fluid line fillable with hydraulic fluid to be maintained under a first pressure, a second fluid line fillable with hydraulic fluid to be maintained under a second pressure, a first check valve for allowing hydraulic fluid to enter the first fluid line, a second check valve for allowing hydraulic fluid to enter the second fluid line, and an entrained air deflector for preventing hydraulic fluid entrained with air from entering the first check valve and the second check valve.

A hydrostatic transmission for a working machine having a frame, an engine on the frame, and at least one wheel driven by the hydrostatic transmission is disclosed. The hydrostatic transmission includes a housing, a hydraulic pump, the hydraulic pump driven by an output shaft from the engine, a hydraulic motor for driving an output shaft connected to the at least one wheel, a first fluid line fillable with hydraulic fluid to be maintained under a first pressure, a second fluid line fillable with hydraulic fluid to be maintained under a second pressure, a first check valve for allowing hydraulic fluid to enter the first fluid line, a second check valve for allowing hydraulic fluid to enter the second fluid line, and an entrained air deflector for preventing hydraulic fluid entrained with air from entering the first check valve and the second check valve.