A hydro-pneumatic accumulator includes a housing defining a gas chamber for a compressible gas and a fluid chamber within the housing. A gas valve is in communication with the gas chamber via a gas passage. A check valve is provided within the gas passage and prevents gas from releasing from the gas chamber when the gas valve is removed, wherein the check valve is mechanically actuated to an open position by the gas valve in communication with the gas passage.

A sensor system for a dual bottle accumulator utilized with a subsea blowout preventer that monitors piston position with a position sensor in the hydraulic bottle, the gas pressure in the associated gas bottle with one or more pressure sensors, and sensors and remote actuators for associated valves.

A center biased actuator having an outer cylinder, a slave cylinder linearly transposed within the outer cylinder, a rod assembly with a piston linearly transposed within the slave cylinder and a rod extending from the outer cylinder, one or more first dynamic seals arranged to act on a sidewall of the rod to inhibit hydraulic fluid leaking from the outer cylinder, one or more second dynamic seals arranged to act on a sidewall of the slave cylinder or an inner surface of the outer cylinder to inhibit hydraulic fluid leaking from the outer cylinder, and a gas chamber comprising a sealed expandable chamber containing gas. The expandable chamber is arranged to act on hydraulic fluid within the center biased actuator to bias the center biased actuator to assume an intermediate condition which lies between a compressed condition and an extended condition.

A piston accumulator has an accumulator housing and a separating piston (8) guided for longitudinal motion in the accumulator housing. The separating piston separates a liquid side (4) from a gas side (10) in the accumulator housing. Liquid unintentionally transitions from the liquid side (4) to the gas side (10) despite a piston seal on the separating piston (8). By a return device (28), the transitioned liquid is at least partially returned from the gas side (10) of the accumulator housing to the liquid side (4) of the accumulator housing.

A hydrostatic cylinder with a gas pressure accumulator, which is preferably designed as a piston accumulator, and which is arranged concentrically on the outer circumference of the cylinder is disclosed. A gas pressure is produced via a constant pressure source and is limited or is essentially constant in the gas pressure accumulator and also a constant pressure medium pressure is independent of the degree of filling of the gas pressure accumulator.

The present disclosure relates to a miniature pressure compensating device (10), for balancing pressure fluctuations in a hydraulic system, comprising at least one shell (12), at least one hollow hydraulic cylinder (16), at least one reciprocating piston (26) and at least one non-return valve (NRV) (28). The hydraulic cylinder (16) comprises at least one dual charging valve port (22) for facilitating charging of both said compressible and incompressible fluid and at least one built-in two-tier scaling mechanism (24) comprising at least one metal-to-metal seal (24a) and at least one secondary seal (24b) to achieve effective isolation of the incompressible and compressible fluids. The present miniature pressure compensating device (10) has a volume below 13 cc.

A piston accumulator having an accumulator housing (4) and a separating piston (10), which is guided longitudinally displaceable therein, which separates two media chambers (12, 14) from each other and which has a dual sealing system (16), wherein one of the sealing systems (18) faces one media chamber (12) and the other sealing system (20) faces the other media chamber (14), wherein at the location (58) a compensation device is at least partially accommodated in the separating piston (10) between the two sealing systems (18, 20), which compensation device enables hydrostatic pressure compensation between the two sealing systems (18, 20) to prevent an undesirable pressure buildup during operation.

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 fluidic control system (1) for controlling a vehicle, which includes a controller (2) and a closed fluidic circuit. The circuit includes a pump (3) for pressurizing fluid in the circuit, valve means (40, 50, 60), an actuator (4, 5, 6) and a precharge accumulator (7). The valve means (40, 50, 60) is fluidly connected to the inlet and outlet of the pump (3) and the actuator (4, 6) is fluidly connected to the valve means (40, 50, 60) for selectively receiving pressurized fluid therefrom. The precharge accumulator (7) includes a movable member (73, FIG. 2) that describes a variable volume (71) fluidly connected to the circuit between the valve means (40, 50, 60) and the inlet of the pump (3). The system (1) also includes a sensor (70) for determining the position of the movable member (73) for estimating the quantity of fluid and/or detecting an abnormal pressure variation within the circuit.

The present disclosure is an accumulator that has an oil chamber, a first piston separating a first gas chamber from the oil chamber, and a second piston separating a second gas chamber from the oil chamber. The first and second piston are independently movable to alter the volume of the oil chamber.