A hydrostatic transmission system includes a fluid-driven motor and an integrated pump assembly connected to the fluid-driven motor to provide fluid to operate the fluid-driven motor. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The hydrostatic transmission system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the hydrostatic transmission system to an operational set point.

A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid-driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid-driven system to a flow set point and a pressure in the fluid-driven actuator system to a pressure set point and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid-driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid-driven system to a flow set point and a pressure in the fluid-driven actuator system to a pressure set point and concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A traveling hydraulic stepless transmission (“HST”), ensures stopping of a vehicle on a slope under high load conditions, maintains stopping the vehicle on flat ground under low load conditions, and enables smooth starting from a stop. The HST includes a neutral check valve (“NCV”) and an internal damping system (“IDS”). The NCV includes a first orifice that opens a first oil passage to a transaxle case when a pressure in the first oil passage is equal to or less than a predetermined pressure, and that connects the second oil passage to the transaxle case when a pressure in a second oil passage is equal to or less than the predetermined pressure. The IDS includes second orifices that connect a high pressure side of the oil passages to the transaxle case when a discharge rate of the hydraulic pump is equal to or less than a predetermined discharge rate.

A vent for a hydraulic drive device disposed in a housing includes a vent body having a closed first side, a second side having an opening, and a sidewall. An internal passageway in the vent body connects the second side opening to the atmosphere. The vent body is removably disposed in a vent opening in one of two positions. When the first side of the vent body is inserted into the vent opening, the closed first side prevents communication between the sump and atmosphere, and when the second side of the vent body is inserted into the vent opening, the internal passageway and the second side opening permit communication between the internal sump and atmosphere.

A hydraulic transaxle comprises an axial piston hydraulic pump having a variable displacement, and a transaxle casing incorporating the hydraulic pump. The hydraulic pump includes a movable swash plate and a pair of trunnion shafts. The transaxle casing includes a pair of side walls, and includes a pair of casing holes each of which penetrates each of the side walls between an inside and an outside of the transaxle casing. The pair of trunnion shafts are passed through the respective casing holes. The swash plate is formed with a pair of swash plate holes in the respective side portions facing the respective side walls in the inside of the transaxle casing. Proximal end portions of the respective trunnion shafts are inserted into the respective swash plate holes. A distal end portion of one of the trunnion shafts projects from the corresponding casing hole to the outside of the transaxle casing.

A hydraulic transaxle comprises an axial piston hydraulic pump having a variable displacement, and a transaxle casing incorporating the hydraulic pump. The hydraulic pump includes a movable swash plate and a pair of trunnion shafts. The transaxle casing includes a pair of side walls, and includes a pair of casing holes each of which penetrates each of the side walls between an inside and an outside of the transaxle casing. The pair of trunnion shafts are passed through the respective casing holes. The swash plate is formed with a pair of swash plate holes in the respective side portions facing the respective side walls in the inside of the transaxle casing. Proximal end portions of the respective trunnion shafts are inserted into the respective swash plate holes. A distal end portion of one of the trunnion shafts projects from the corresponding casing hole to the outside of the transaxle casing.

A modular porting manifold for a hydrostatic transmission that serves as an end cover for the hydraulic motor, and which may be modularly interfaced with multiple different pump configurations having the same or similar pump interface across the different pump configurations. A pump interfacing section of the porting manifold may have a mating surface that interfaces with a corresponding mating surface of an outwardly addressable manifold of the pump. The pump interfacing section of the porting manifold may have at least two ports for communication of hydraulic fluid with the pump, in which the at least two ports are laterally spaced apart in the same horizontal plane to align with at least two corresponding ports on the pump manifold that are also in the same horizontal plane, which may provide less complex and easier to manufacture flow passages for the porting manifold and/or pump end block.

A modular porting manifold for a hydrostatic transmission that serves as an end cover for the hydraulic motor, and which may be modularly interfaced with multiple different pump configurations having the same or similar pump interface across the different pump configurations. A pump interfacing section of the porting manifold may have a mating surface that interfaces with a corresponding mating surface of an outwardly addressable manifold of the pump. The pump interfacing section of the porting manifold may have at least two ports for communication of hydraulic fluid with the pump, in which the at least two ports are laterally spaced apart in the same horizontal plane to align with at least two corresponding ports on the pump manifold that are also in the same horizontal plane, which may provide less complex and easier to manufacture flow passages for the porting manifold and/or pump end block.

A hydrostatic transmission system includes a fluid-driven motor and an integrated pump assembly connected to the fluid-driven motor to provide fluid to operate the fluid-driven motor. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The hydrostatic transmission system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the hydrostatic transmission system to an operational set point.