The invention relates to a hydraulic device for a hydraulic system (12). The hydraulic device includes a chamber arrangement including at least one high-pressure chamber for connection to a high-pressure side of the hydraulic system, and at least one low-pressure chamber for connection to a low-pressure side of the hydraulic system; and a movable member arranged to reciprocate at least partly inside the chamber arrangement in response to pressure variations within the at least one high-pressure chamber and within the at least one low-pressure chamber. The chamber arrangement further includes at least one tank chamber for connection to a tank-pressure side of the hydraulic system.

An air supply device control system may include a sensor configured to detect a trailer to be provided in an eco-friendly commercial vehicle, an air supply device configured to compress and supply air, and a controller electrically connected to the air supply device and configured to control rotation speed of the air supply device to control the air of the air supply device, wherein the controller increases the rotation speed of the air supply device based on whether the trailer is provided in the eco-friendly commercial vehicle, which is detected by the sensor.

Disclosed techniques include energy storage and buffering using multiple pressure containers. Liquid and gas are pumped into a subterranean container. The liquid and gas are pressurized in the subterranean container. A pump is coupled to the subterranean container to accomplish the pressurizing of the subterranean container. The pump and the subterranean container are coupled to an above-ground pressure vessel. The above-ground pressure vessel is pressurized using the pump. The above-ground pressure vessel receives excess flow from the pump beyond the flow provided to the subterranean container. The above-ground pressure vessel provides buffering for pressure flowing into or out of the subterranean container. The gas includes air and the liquid includes water. Pressure is extracted from the first subterranean container to drive a turbine. The pressure from the above-ground pressure vessel supplements pressure from the subterranean container to drive the turbine at a substantially constant rate.

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.

Systems, methods and devices are described providing a selective hydraulic or electrically powered prime mover that is a bi-directional power unit system, including movement within a device used to compress and/or expand a fluid and provide fluid movement. The use of a hydraulic power unit is involved and comprises at least a pump or other fluid moving device, a first set of selective control valves delivering pressurized fluid to the device(s), and a second set of selective control valves returning unpressurized fluid from the device(s), a reservoir comprising a compensator tank, a port for operation at ambient pressure, and a pressure measuring device measuring ambient pressure allowing for unbalanced flow to and from the device as well as thermal expansion or compression. The use of a multiport and in some cases a swashplate pump that incorporates the features and functions of several valves for the system is also described.

An aircraft assembly having: a first part; a second part, the second part being movably mounted with respect to the first part; an electro-hydraulic actuator coupled between the second part and a first anchor point, the actuator comprising a cylinder defining a bore and a piston and rod assembly slidably mounted within the bore and an active chamber within which an increase in fluid pressure causes the actuator to change during a first phase between first and second extension states to move the second part relative to the first part. The electro-hydraulic actuator further includes a hydraulic fluid supply circuit comprising a piezo-electric pump operable to supply pressurised fluid to the active chamber to change the actuator between first and second extension states.

An equalization device is, in particular, in the form of a tank. The housing (2) of the tank has at least one inlet (8) and one outlet (10) for receiving and discharging fluid, respectively, at least in one of the housing walls (4) of the housing, which housing can be filled with the fluid. At least one equalization body (14) is arranged within the housing (2). The equalization body is at least partly provided with an elastically compliant separating wall (20). The interior of the equalization body is delimited, and is at least partly in pressure-equalizing connection (32) with the surroundings at a passage (12, 32) through one of the housing walls (4).

The self-contained energy efficient hydraulic actuator system of the present invention includes a hydraulic cylinder, a servo motor that is configured to produce rated torque from zero RPM to maximum rated RPM with rotor speed/position feedback to a servo motor, a pump, and a solenoid valve that enables the hydraulic cylinder to maintain its position without the motor running. The system has the ability to hold a load in place without motor operation via the use of the solenoid valve, and therefore saves energy and extends the motor lifetime by minimizing the motor running time.

A hydraulic energy handling system for a working machine includes a high-pressure side; a low-pressure side; a hydraulic machine for mechanically driving, and being mechanically driven by, a mechanical driveline of the working machine; at least one high-pressure hydraulic energy storage connected to the high-pressure side; a hydraulic motor; a hydraulic pump arranged to supply hydraulic fluid to an inlet side of the hydraulic motor; and a return line for conducting hydraulic fluid to a hydraulic tank. The system further includes a pressure relief valve between the high-pressure side and the return line and arranged to discharge excess hydraulic energy from the high-pressure side to the return line to provide a braking force on the mechanical driveline; and a priority valve arrangement connected to an outlet side of the hydraulic motor to direct a prioritized flow of hydraulic fluid to the low-pressure side.

The invention relates to an underwater-based, depth-compensable accumulator system which is adapted to produce hydraulic power for underwater operations, and which consists of one or more gas-free accumulator units. An accumulator unit according to the invention has only one movable part, but interaction with a switching device enables switching between multiple modes so that an accumulator unit can be configured to generate a desired hydraulic pressure at any sea depth.