A hydrostatic piston machine unit, which is in particular designed as a hydrostatic axial piston machine unit, comprises at least two driving mechanisms that can be driven synchronously and have displacement pistons which each perform a reciprocating motion in operation and are provided for delivery into a common pressure line. The hydrostatic piston machine unit has a jointly assigned precompression volume for the at least two driving mechanisms.

A hydraulic engine with hydraulic pumps that moves the oil filled in the body thereof through the hydraulic pumps to allow rotational load bodies to be driven by means of the reciprocation of pistons, thereby obtaining a rotational force required for driving, includes: a power supply adapted to supply power to a driving part and to charge the power generated from rotational load bodies through the driving of a power driving part; the driving part driven through the power supplied from the power supply; a pair of hydraulic pumps adapted to pump a fluid through the rotation of the driving part; and the power driving part adapted to generate a driving force through the reciprocation of a driving piston.

A hydrostatic actuator and an arrangement for attaching it to a receiving component are provided. The hydrostatic actuator has a master cylinder containing a housing and a piston movable axially within the housing which acts on a pressure chamber filled with a pressurizing agent. The piston is driven by a rotary-driven electric motor having a stator and a rotor, by a rolling planetary transmission that converts the rotary drive to an axial motion. In order to be able to produce such a hydrostatic actuator with little need for construction space, cost-effectively and with better quality, a supporting of the rolling planetary transmission is simplified, and the cooling and shielding of an electronic controller and the pressure behavior of the hydrostatic actuator is improved.

A fluid machine for a pneumatic or hydraulic drive system, said fluid machine being able to work as a fluid motor or as a fluid pump, comprising: at least two piston assemblies each comprising a piston means (110a-c), the at least two piston assemblies being operable to cause sequential reciprocating movement of the pistons means (110a-c); a drive member (120) rotatable about an axis and providing an annular, wave-like surface (122) extending at least partially radially to the axis, towards which the piston means (110a-c) project, wherein, in case of working as a fluid motor, the pistons means (110a-c) are arranged to drive rotation of the drive member (120) about the axis at least by a pushing action on said wave-like surface (122) or, in the case of working as a fluid pump, the piston means (110a-c) are arranged to cooperate with said wave-like surface (122) so that rotation of the drive member (120) drives sequential reciprocating motion of the piston means (110a-c).

At least one pressure exchange unit with a hollow cylindrical body, a piston sliding in the body, the piston including a piston head separating the interior of the cylindrical body into a downstream chamber and an upstream chamber, the downstream chamber being provided with a device for the admission and discharge of water to be treated, the upstream chamber being provided with a five-way distributor linkage including, for hydraulic balancing, two pressurized liquid supply orifices, two orifices for the evacuation of the liquid and an opening in communication with the upstream chamber.

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 system to a flow set point and a pressure in the fluid system to pressure set point and a 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 system to a flow set point and a pressure in the fluid system to pressure set point and a 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 hydrostatic piston machine unit, which is in particular designed as a hydrostatic axial piston machine unit, comprises at least two driving mechanisms that can be driven synchronously and have displacement pistons which each perform a reciprocating motion in operation and are provided for delivery into a common pressure line. The hydrostatic piston machine unit has a jointly assigned precompression volume for the at least two driving mechanisms.

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 system to a flow set point and a pressure in the fluid system to pressure set point and a 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 low-energy and high pressure, hydraulic, pneumatic engine contains: a casing device, two main-cylinder devices, a holder device, two main-crankshaft devices, two recycle-valve devices, two swing-arm devices, two movable-valve devices, two recycle-cylinder devices, two recycle-crankshaft devices, and two umbrella-shaped gear devices. The engine operates without using gasoline or diesel, thus avoiding discharge of harmful substance or gas and pollution. The high pressure gas forces the hydraulic oil without using gasoline or diesel so as to start the engine, and the hydraulic oil recycles and reuses repeatedly, thus obtaining environmental protection. And the high pressure gas forces the hydraulic oil so as to circulate the hydraulic oil, and the communication of the low-energy and high pressure and the low pressure matches with the circulation space of the fluid operation to produce the torque, hence four strokes cycle of intake, compression, combustion and exhaust are not required.