A hydrostatic transmission which utilizes a combination of a multiple planetary gear pump and a multiple planetary gear motor encased within one compact unit sealed so as to direct passage of hydraulic fluid between the combination thereof. The hydrostatic transmission comprises a power component provided with a plurality of planetary gears that can provide power to at least one load delivered by at least one of the plurality of planetary gears. The power component is configured with an integrated oil-switching mechanism that controls the rotational speed delivered to the load. The hydrostatic transmission is provided in one compact, sealed casing suitable for use in vehicles, having an output shaft optionally mechanically connected directly to the wheels of a vehicle drive. The inventive hydrostatic transmission operates without the need for lengthy pressure hoses and related connectors and fittings for cycling hydraulic fluid along needed flow paths.

A hydrostatic transmission which utilizes a combination of a multiple planetary gear pump and a multiple planetary gear motor encased within one compact unit sealed so as to direct passage of hydraulic fluid between the combination thereof. The hydrostatic transmission comprises a power component provided with a plurality of planetary gears that can provide power to at least one load delivered by at least one of the plurality of planetary gears. The power component is configured with an integrated oil-switching mechanism that controls the rotational speed delivered to the load. The hydrostatic transmission is provided in one compact, sealed casing suitable for use in vehicles, having an output shaft optionally mechanically connected directly to the wheels of a vehicle drive. The inventive hydrostatic transmission operates without the need for lengthy pressure hoses and related connectors and fittings for cycling hydraulic fluid along needed flow paths.

A control ring for controlling the flow of a pressure medium in a displacement pump is provided. The control extends along a first rotational axis, and includes a first and a second axial surface. The first axial surface has an interface section provided with at least a first and a second opening, which first and second openings are arc shaped and are separated by a first and a second land. The first land is provided with a first tapered groove extending from the first opening into the first land, and having its broader edge in a direction of the first opening and its tip in a direction of the second opening. The first tapered groove extends into the first land such that an angular distance between the first and second openings over the first land is different at different radial distances.

A control ring for controlling the flow of a pressure medium in a displacement pump is provided. The control extends along a first rotational axis, and includes a first and a second axial surface. The first axial surface has an interface section provided with at least a first and a second opening, which first and second openings are arc shaped and are separated by a first and a second land. The first land is provided with a first tapered groove extending from the first opening into the first land, and having its broader edge in a direction of the first opening and its tip in a direction of the second opening. The first tapered groove extends into the first land such that an angular distance between the first and second openings over the first land is different at different radial distances.

A hydrostatic transmission which utilizes a combination of a multiple planetary gear pump and a multiple planetary gear motor encased within one compact unit sealed so as to direct passage of hydraulic fluid between the combination thereof. The hydrostatic transmission comprises a power component provided with a plurality of planetary gears that can provide power to at least one load delivered by at least one of the plurality of planetary gears. The power component is configured with an integrated oil-switching mechanism that controls the rotational speed delivered to the load. The hydrostatic transmission is provided in one compact, sealed casing suitable for use in vehicles, having an output shaft optionally mechanically connected directly to the wheels of a vehicle drive. The inventive hydrostatic transmission operates without the need for lengthy pressure hoses and related connectors and fittings for cycling hydraulic fluid along needed flow paths.

A hydrostatic transmission which utilizes a combination of a multiple planetary gear pump and a multiple planetary gear motor encased within one compact unit sealed so as to direct passage of hydraulic fluid between the combination thereof. The hydrostatic transmission comprises a power component provided with a plurality of planetary gears that can provide power to at least one load delivered by at least one of the plurality of planetary gears. The power component is configured with an integrated oil-switching mechanism that controls the rotational speed delivered to the load. The hydrostatic transmission is provided in one compact, sealed casing suitable for use in vehicles, having an output shaft optionally mechanically connected directly to the wheels of a vehicle drive. The inventive hydrostatic transmission operates without the need for lengthy pressure hoses and related connectors and fittings for cycling hydraulic fluid along needed flow paths.

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 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.