A hydraulic drive unit includes: a pump; a pair of supply-discharge lines; a valve block; a sealed tank; a suction line that leads hydraulic oil in the sealed tank to the pump; a connecting line that connects an air vent port of the pump to the suction line; and a gas-liquid separator that separates air and the hydraulic oil flowing through the connecting line from each other. The pump is disposed upward of the valve block and the sealed tank in a vertical direction.

A safety device includes a connection point (21) for a pressure accumulator (1) that is connected to a bursting unit (55) at the gas end via the connection point (21). The bursting unit (55) can be triggered by a controllable force element (73). In the triggered state, the bursting unit allows the pressure accumulator (1) to be emptied at the gas end.

A method and system providing a pressurized fluid includes a pump having a pump inlet and a pump outlet, the pump to provide a fluid flow, a bypass path to direct the fluid flow from the pump outlet to the pump inlet, a load path having a load path pressure, the load path including: a fluid accumulator to accumulate a fluid volume, and at least one load device, a bypass regulator valve in fluid communication with the pump outlet, the bypass path, and the load path, and a controller to direct the fluid flow to the load path in response to the load path pressure being less than a low load path threshold pressure via the bypass regulator valve and to direct the fluid flow to the bypass path in response to the load path pressure being greater than a high load path threshold pressure via the bypass regulator valve.

A valve system includes: a valve; a hydraulic cylinder attached to at least a portion of the valve; and at least a first accumulator in fluid communication with the hydraulic cylinder. The first accumulator includes: (i) a first end having a fluid inlet and a fluid outlet; (ii) a second end having a gas inlet; and (iii) a body positioned between the first end and the second end and which includes a fluid chamber and a gas chamber separated by a flexible separating member. The hydraulic cylinder is configured to close the valve in response to pressure provided by fluid distributed from the first accumulator.

Venting of gaseous fuel during operation and after shutdown of an internal combustion engine increases emissions. A vent handling apparatus for a gaseous fuel system of an internal combustion engine comprises an accumulator for storing gaseous fuel; a first valve selectively enabling fluid communication between the accumulator and one of a gaseous fuel communication passage and a gaseous fuel storage vessel, the gaseous fuel communication passage delivering gaseous fuel to the internal combustion engine for combustion; and an apparatus for selectively returning the gaseous fuel from the accumulator to the internal combustion engine for combustion.

A method for the production of a bladder accumulator (10) that separates two media chambers (16, 18) from one another in a storage housing (12) by a bladder body (14). The following production steps include extruding a plastic tube over the bladder body (14), shaping the plastic tube with the integrated bladder body (14) in a molding tool that corresponds to a predeterminable plastic core container (20), and winding at least one plastic fiber from the outside on the plastic core container (20) for the purpose of creating the storage housing (12).

Presented herein are systems and methods that allow for adapting at least one dimension of an accumulator in a hydraulic system when faced with certain dimensional constraints and to vary the compliance or stiffness of an accumulator.

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 hydropneumatic pressure accumulator, in particular a pulsation damper, includes an accumulator housing (2) and a movable separating element (20), which separates a pressurized working gas-containing gas working space (24) from a fluid chamber (22) in the accumulator housing (2). A gas storage chamber (12) is provided, which contains an additional volume of the pressurized working gas, and is connected via a connecting path (30) having a throttle point to the gas working space.

The invention relates to the automatic reloading of the gas space of a hydropneumatic accumulator. An apparatus for readjusting the load of the gas space includes a pressurized gas source connected via an air system to a loading check-valve and a reinjection valve controlled by a unit for calculating a cycle for reinjecting gas into the gas space.