An electrohydraulic system for use under water includes an electrohydraulic actuator and a container. A hydraulic cylinder or a hydraulic motor and a hydraulic machine are arranged in an internal space of the container. The hydraulic machine is mechanically coupled to a rotary drive unit for a common rotary movement, and the hydraulic machine adjusts the hydraulic cylinder or the hydraulic motor. The rotary drive unit is arranged outside the container and is configured to couple to and decouple from the hydraulic machine. A device in one embodiment includes the electrohydraulic system.

A method to use hydraulic pressure to power a vehicle includes providing a hydraulic fluid power system having a motor in communication with a hydraulic pump; a hose in communication with the hydraulic pump, the hose having a one way valve; a gear motor in fluid communication with the hose to receive hydraulic fluid therefrom; and an alternator to receive power from the gear motor and to transfer power to a battery for storage; operating the hydraulic pump via the motor such that hydraulic fluid is pumped through the hose to the gear motor; charging the battery with power generated by the gear motor and alternator; and using the battery for one or more components of the vehicle.

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.

A hydraulic cylinder assembly having a free-floating motor and pump, comprising a motor, and a hydraulic fluid reservoir coupled to the motor. There is a reservoir base plate having a pair of fluid path holes therein which run there through. The base plate has a mounting stud. There is a meshed gear fluid pump having a pair of downwardly directed inflow/outflow holes. The single mounting tab allows the easy placement or removal of the assembly into an operating location.

A hydraulic control unit that delivers hydraulic fluid to a limited slip differential includes a hydraulic control unit housing, a motor and a pump. The hydraulic control unit housing has a manifold housing portion and an accumulator housing portion. The manifold housing portion defines a fluid pathway arrangement for communicating fluid along at least a first fluid pathway. The accumulator housing portion houses an accumulator assembly having a biasing assembly and a piston. The accumulator housing portion and manifold housing portion cooperate to form an accumulator chamber that houses the biasing assembly. The motor is disposed on the first side of the manifold housing portion. The pump is disposed on a second side of the manifold portion, opposite the first side. The pump is configured to pump fluid into the accumulator chamber of the accumulator housing portion.

A pneumatic actuator (240), comprising: a pressure reducer (270) for delivering gas under a reduced pressure to a control valve; the control valve (280) selectively supplying gas to a pneumatic cylinder (290) or discharging gas from the cylinder (290) to the environment; a replaceable gas capsule (260) for supplying the gas under increased pressure; where the actuator has a first mode of operation for moving the piston (293) to the extended position, and has a second mode of operation for retracting the piston (293). A method for assembling a pneumatic actuator. A portable tool, a clamping device, a screw clamp comprising such a pneumatic actuator. A method for assembling the screw clamp. A method for repairing the screw clamp.

A hydraulic propulsion system converts heat or thermal energy into hydraulic energy, and such hydraulic energy into mechanical work. The hydraulic propulsion system includes a thermal unit, a hydraulic cylinder with pistons and springs mounted therein, one or more hydraulic motors, one or more hydraulic accumulators, and one or more electrical energy generators, as well as a plurality of flow control valves to control the flow of hydraulic fluid between the various components. The hydraulic propulsion system may be enhanced by an energy transmission unit including a wave generator.

A movable-blade operation system for a hydraulic machine according to an embodiment includes an oil hydraulic cylinder installed within a rotational shaft, a bidirectional pump, a pump drive motor, a control unit, and an oil head installed in the hydraulic machine. The bidirectional pump selectively feeds pressurized hydraulic oil to one of a first cylinder chamber and a second cylinder chamber. The oil head couples the rotational shaft rotatably, and the hydraulic oil fed from the bidirectional pump to the first cylinder chamber and the second cylinder chamber flows through the oil head. The bidirectional pump, the pump drive motor, and the control unit are installed outside the hydraulic machine.

A hydraulically-actuated device comprises a self-contained fluid reservoir comprising a tank for receiving a fluid, a reservoir port, and a flexible diaphragm. An actuation member comprises a hydraulically actuated piston in a cylinder. A pump case comprises an inlet port and an outlet port, the inlet port in fluid communication with the reservoir port, and the outlet port in fluid communication with the actuation member. A pump is within the pump case. The pump can be a reversible pump. The flexible diaphragm can flex in to the fluid reservoir when the pump transfers a fluid from the fluid reservoir to the actuation member and can flex away from the fluid reservoir when the pump transfers fluid from the actuation member to the fluid reservoir. The flexible diaphragm can hermetically seal a fluid within the fluid reservoir and have a second side in communication with atmospheric pressure.

A hydraulic reservoir (10), for use for example in a marine pleasure craft, comprises a vortex chamber (16), a hydraulic fluid return line (18) and a hydraulic fluid suction line (20) respective entering and exiting substantially tangentially to an internal wall surface of the vortex chamber. An upper chamber (26) is disposed above the vortex chamber (16) and in fluid communication with the vortex chamber. The upper chamber is capable of expansion and/or contraction in use in order to adjust continuously to the volume of the hydraulic fluid to be accommodated in the hydraulic reservoir. Also disclosed is a method of operating such a hydraulic reservoir, in which hydraulic fluid is directed into the vortex chamber (16) along the hydraulic fluid return line (18) and extracting hydraulic fluid from the vortex chamber along the hydraulic fluid suction line (20), to thereby generate a vortex flow in the vortex chamber. Dissolved air, if present, becomes entrained into bubbles which rise to the upper chamber (26). Expansion and/or contraction of the upper chamber (26) is provided in order to adjust continuously to the volume of the hydraulic fluid to be accommodated in the hydraulic reservoir (10).