An exemplary hybrid accumulator includes a piston slidably disposed in a cylinder and separating a reservoir from a pressure chamber, in use, a hydraulic fluid disposed in the reservoir and a spring disposed in the pressure chamber to act on the piston and pre-charge the hydraulic fluid to a first pressure, and a heating element in communication with the pressure chamber to increase pressure in the pressure chamber when the heating element is initiated.

A hydraulic device includes a housing and a closure element arranged thereon. The closure element is connected to the housing by torsional welding.

An actuator assist apparatus for use with an actuator has a housing and a piston member slidably disposed in the housing. The piston member divides the interior of the housing into a first fluid chamber and a second fluid chamber. The actuator assist apparatus is configurable between a first, primed, configuration and an activated configuration. A force applicator is configured to store energy when the apparatus is in the primed configuration and release the energy to move the piston member relative to the housing. Movement of the piston member applies a force which assists in urging the actuator towards an extended configuration, thereby reducing the minimum operating pressure of the actuator.

A system filled with a fluid, designed for underwater applications, in which the interior of a housing and/or tank forms a fluid region which is sealed with respect to the surrounding seawater region, includes at least one hydraulic pressure compensation device, which at least raises the pressure level of the fluid region to the ambient pressure prevailing in the seawater region. The pressure compensation device is constructed in two stages in such a way that at least one store having a flexible wall region and at least one piston store having a displaceable piston are arranged in series. The use of the pressure compensation device to pressurize at least one housing filled with fluid for a hydraulic actuating shaft is also proposed.

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 accumulator including an energy storage apparatus with a first piston face configured to reversibly compress an energy storage medium and a second piston face forming at least part of an inner surface of a corresponding second fluid chamber reversibly expandable by movement of the second piston face. A third piston face forms at least part of an inner surface of a corresponding third fluid chamber reversibly expandable by the third piston face. The first, second and third piston faces are coupled together.

A self-contained pressure compensation system and a control method thereof are provided, wherein the self-contained pressure compensation system comprises an oil supply device, a pressure compensation device, a power unit associated with the pressure compensation device, and a switch control device, the pressure compensation device supplies oil to the power unit and detects a change in a chamber pressure of itself in real time, the switch control device triggers the oil supply device to supply oil to the pressure compensation device if the chamber pressure is less than a predetermined first threshold and triggers the oil supply device to stop supplying oil to the pressure compensation device if the chamber pressure is greater than a predetermined second threshold. The invention can detect a chamber pressure of the pressure compensation device in real-time and can achieve automatic oil refilling, and can provide pressure compensation for the power unit effectively.

An energy storage system is provided. The system comprises an energy storage device comprising: a pressure vessel configured to store pressurised fluid; and one or more resilient elements, wherein the resilient elements comprise a plurality of filaments of resilient material braided to form the resilient elements, wherein the resilient elements are arranged within or about the pressure vessel, and wherein the energy storage device is configured such that storing pressurised fluid within the pressure vessel acts to tension or compress the resilient elements.

A hydraulic lifting device for a chassis of a mobile device has a valve block, a pump, a tank, a first cylinder device and a second cylinder device. The first cylinder device and the second cylinder device can be selectively pressurized by the pump or connected to tank via the valve block. The first cylinder device is connected to the pump via at least one primary non-return valve disposed in the valve block. The second cylinder device is connected to the pump via at least one secondary non-return valve disposed in the valve block. The valve block has at least one pressure accumulator downstream of the at least one secondary non-return valve in the flow direction from the pump to the second cylinder device. Furthermore, a chassis with such a lifting device and to a mobile device with a chassis is provided.

An accumulator assembly for providing hydraulic fluid to an actuator. That assembly includes an accumulator for containing a supply of hydraulic fluid, the accumulator having an exit port via which hydraulic fluid can flow, in use, to the actuator. The assembly also includes a coupling comprising a first coupling part configured to be located at an inlet port of the actuator and a second coupling part arranged at the exit port of the accumulator. The first and second coupling parts are configured to matingly engage to form an open passage for flow of the fluid-between the accumulator and the actuator, and to close the first coupling part when the first second coupling parts are not engaged, so as to prevent flow from the actuator and to prevent air and pollution ingress the actuator.