A pneumatic chamber 20 is configured to include a first pneumatic chamber 21 pressurizing a first piston 11 and a second pneumatic chamber 22 pressurizing a second piston 12. The first pneumatic chamber 21 communicates with the second pneumatic chamber 22. The hydraulic pressure generating unit 55 is internally provided with a hydraulic chamber 30, and the hydraulic chamber 30 is configured to have a first hydraulic chamber 31 pressurized by the first pneumatic chamber 21 via the first piston 11 and a second hydraulic chamber 32 pressurized by the second pneumatic chamber 22 via the second piston 12. The hydraulic pressure generating unit 55 is movable in a thrust direction in a cylinder 2, and the second hydraulic chamber 32 has a function of fixing the moving hydraulic pressure generating unit 55 in the cylinder 2 by causing a thin portion 15 to be elastically deformed in a radial direction due to hydraulic pressure. The first hydraulic chamber 31 outputs hydraulic pressure of the first hydraulic chamber 31, which is increased by the fixing, to an output rod 7.

An apparatus includes a plurality of pneumatic linear actuator modules, a dynamic actuator linkage, and a static actuator linkage. Each of the plurality of pneumatic linear actuator modules includes a static portion and a dynamic portion. The dynamic portion is movable in a linear fashion relative to the static portion. The dynamic actuator linkage connects the dynamic portion of each of the plurality of pneumatic linear actuator modules to a moveable portion of a device. The static actuator linkage connects the static portion of each of the plurality of pneumatic linear actuator modules to an immoveable portion of the device. A number of pneumatic linear actuator modules one less than the plurality of pneumatic linear actuator modules are able to provide linear actuation to the device. Each of the plurality of actuator modules is configured to selectively couple and decouple to the dynamic actuator linkage and the static actuator linkage.

A valve controller for controlling a valve and a valve comprising the valve controller are disclosed. The valve has an actuator and a flow controlling unit. The valve controller is configured to execute a setup process and comprises a first pilot valve that can energize the actuator by allowing a first pressurized fluid to enter the actuator and de-energizing the actuator by allowing the fluid to leave the actuator. The valve controller further has an input device by which the setup process can be initiated, and a memory unit for storing setup parameter values. The setup process comprises: determining parameter values indicative of the functionality of at least one of the valve controller, the actuator and the flow controlling unit, and storing the parameter values as setup parameter values in the memory unit.

A landing gear system for an aircraft includes a retractable landing gear assembly, a hydraulic actuator for actuating movement part, for example a bogie of the landing gear assembly, and an accumulator associated with the actuator. The accumulator comprises a volume of pressurised gas separated from hydraulic fluid by a separator piston. Travel of the separator piston beyond a certain position is indicative of a fault. The accumulator includes a snubbing device that acts to slow movement of the separator piston beyond that position. A monitoring system measures the time taken for the movement of the landing gear part effected by the hydraulic actuator. If the measured time is longer than a threshold time, that is indicative of a possible fault in the accumulator, that might, without the snubbing, remain undetected and/or hidden from view.

The invention relates to a hydraulic device for driving an actuator to be hydraulically controlled or actuated, comprising a motor arranged in a motor housing, a compensating tank (31) for accommodating hydraulic fluid, and a hydraulic pump, which is arranged in a pump housing and driven by the motor, wherein the hydraulic pump is designed in such a way that the hydraulic pump permits conveyance of hydraulic fluid in two directions, namely in the forward direction and in the backward direction.

An agricultural machine including a frame, at least one operating unit connected to the frame, at least one wheel or crawler track rotatably attached to the frame to allow the movement of the machine on a supporting surface and a lifting unit operatively interposed between the frame and the wheel or between the frame and the operating unit, configured to vary the height of the operating unit with respect to the supporting surface of the machine. The lifting unit includes at least one hydraulic cylinder provided with a liner, a first and a second piston both slidingly housed inside the liner and arranged in series to define at least a first and a second chamber inside the liner, wherein the first and the second piston can be controlled independently of each other.

The present disclosure relates to a radial piston hydraulic device distributing flow by pilot operated check valves and an operating method thereof. The radial piston hydraulic device includes a housing, a plurality of piston assemblies, a main shaft, first pilot operated check valves, second pilot operated check valves, and a valve plate. The first pilot operated check valves have a same number as the plurality of piston assemblies and are one-to-one corresponding to the plurality of piston assemblies. The second pilot operated check valves have a same number as the plurality of piston assemblies and are one-to-one corresponding to the plurality of piston assemblies. The radial piston hydraulic device can be used not only as the hydraulic motor, but also as a hydraulic pump, and can be used in a hydraulic system that need to realize power recovery functions.

A first piston (4) which is coupled to an output rod (2) and which is inserted in a housing (3) is driven upward by a pressurized fluid. A second piston (6) which is arranged above the first piston (4) is driven downward. This causes a wedge-type force multiplier (M), arranged above the first piston (4), to carry out force multiplication driving with respect to the output rod (2).

The present invention regards an elongated fluid actuator arrangement comprising a first and second cylinder housing (3, 5) extending in a longitudinal direction (X), respective housing (3, 5) encompasses a first respective a second piston body (7, 9). The respective piston body (7, 9) divides the respective cylinder housing (3, 5) in a first and second cylinder chamber (11, 13). The arrangement (1) is adapted for connection to a valve member means (15) of a fluid supply device (17). A piston rod member (19) extending through said respective first and second piston bodies (7, 9). The first piston device (7) comprises a piston rod engagement and disengagement means (29), which is adapted to engage or disengage the first piston device (7) to/from the piston rod member (19), wherein an engagement area (A2), defined by an engagement zone between the first piston body (7) and the piston rod member (19), is larger than a cross-sectional piston area (A1) of the first piston body (7).

A de-linking assembly includes an actuator defining a chamber and an inlet, a piston slideably disposed within the chamber, link coupled to the actuator, and a ram disposed between the piston and the link. The link defines a stress concentration features and a load point on a side of the link on a side of the stress concentration feature opposite the actuator. The ram is seated to the piston and against the load point such that air introduced into the chamber through the inlet applies force to the piston and ram sufficient to sever the link by inducing stress in the stress concentration feature.