A hydraulic fluid pressure amplifier system includes a boost cylinder assembly, an energy storage device in fluid communication with the boost cylinder assembly, and a working cylinder assembly. The boost cylinder assembly includes a boost cylinder and a boost cylinder piston movable relative to the boost cylinder between a retracted position and an extended position, wherein movement of the boost cylinder piston from the retraced position to the extended position compresses a hydraulic fluid in a blind side volume of the boost cylinder from a nominal fluid pressure to an amplified high fluid pressure greater than the nominal fluid pressure. The energy storage device receives the hydraulic fluid compressed from the nominal fluid pressure to the amplified high fluid pressure. The working cylinder assembly is operatively connected with the boost cylinder assembly and is selectively operable for effecting the movement of the boost cylinder piston.

A hydraulic pressure amplifier arrangement (1) comprising a supply port (IN), a return port (R), a high pressure port (H1), and a pressure amplifier unit (2) having a low pressure inlet (3) connected to the supply port (IN) and a high pressure outlet (4) connected to the high pressure port (H1) is described, wherein the pressure amplifier unit (2) comprises an amplification factor. In such a hydraulic pressure amplifier arrangement it should be possible to allow simply releasing off pressure at the high pressure port while keeping small unnecessary energy consumption. To this end a control valve (8) is arranged in a connection between the high pressure port (H1) and the return port (R).

A pressure-booster output stabilizer includes: a first cylinder having therein a first chamber and a second chamber separated by a first piston; a second cylinder having therein a third chamber and a fourth chamber separated by a second piston; and a piston rod configured to couple the first piston and the second piston. The primary pressure of a pressure booster is supplied to the first chamber, the secondary pressure of the pressure booster is supplied to the fourth chamber, and the pressurized fluid is taken out from the fourth chamber.

A pressurizing device includes: a pressurizing unit that pressurizes a pressurized object by supplying a working fluid; a first cylinder mechanism that supplies the working fluid in a first cylinder to the pressurizing unit by output of a first drive source; a second cylinder mechanism that supplies the working fluid in a second cylinder to the pressurizing unit by output of a second drive source; and a control device that controls the first drive source and the second drive source, in which the control device performs transition control to transition to a second supply state of supplying the working fluid from the second cylinder mechanism to the pressurizing unit when satisfying a remaining amount condition of the working fluid in the first cylinder of the first cylinder mechanism in a first supply state of supplying the working fluid from the first cylinder mechanism to the pressurizing unit.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

A hydraulic actuator arrangement (1) is described comprising a hydraulic actuator having a pressure chamber (2), a cylinder (3) in a cylinder housing (4), and a piston (5) connected to a piston rod, a hydraulic pump (7) connected to the pressure chamber (2) and an electric motor (8) driving the hydraulic pump (7), wherein the pump (7) and the motor (8) are arranged within the actuator. Such an actuator arrangement should have many application possibilities. To this end, a hydraulic pressure amplifier (10) is arranged between the hydraulic pump (7) and the pressure chamber (2).

A hydrostatic drive system (1) has a hydrostatic pump (3) driven by a drive motor (2) and connected in a closed circuit with a hydrostatic motor (4). The hydrostatic motor (4) drives a consumer (5) and the closed circuit is formed by a first hydraulic connection (6a) and a second hydraulic connection (6b). A hydrostatic accumulator (30) can be connected with at least one of the two hydraulic connections (6a, 6b). A hydrostatic drive unit is located in an accumulator flow path (21) between one of the two hydraulic connections (6a, 6b) and the hydrostatic accumulator (30) and an additional hydrostatic drive unit is located in a tank flow path (22) between the other of the two hydraulic connections (6a, 6b) and a tank (17). The hydrostatic drive unit and the additional hydrostatic drive unit are a hydrostatic dual-flow double drive unit (20) provided in the accumulator flow path (21) and in the tank flow path (22).

A control system for a hydraulic system including an accumulator and a hydraulic transformer coordinates flow sharing within the hydraulic system. The hydraulic transformer includes first and second variable displacement pump/motor units mounted on a rotatable shaft. The rotatable shaft has an end adapted for connection to a first external load. The first variable displacement pump/motor unit includes a first side that fluidly connects to a pump and a second side that fluidly connects to a tank. The second variable displacement pump/motor unit includes a first side that fluidly connects to the accumulator and a second side that fluidly connects with the tank. A second external load may be hydraulically connected to the hydraulic system. Energy may be transferred to/from the pump, the accumulator, the first external load, and/or the second external load, as directed by the control system.

In a hydraulic shield support system, a plurality of pressure intensifiers are respectively provided for a plurality of hydraulic props. Each pressure intensifier is operated to increase a system pressure to an increased pressure for supplying fluid at the increased pressure to a pressure chamber of the associated hydraulic prop. The plurality of pressure sensors measure the pressures of the fluid supplied to the respective hydraulic props. A control unit sets a plurality of desired pressures for the plurality of hydraulic props, and stops operation of the respective pressure intensifiers when the set desired pressure has been reached.

A power transfer unit includes a first hydraulic circuit, a second hydraulic circuit fluidly connected to the first hydraulic circuit, a pump and motor assembly fluidly connected between the first hydraulic circuit and the second hydraulic circuit, an isolation valve arranged along the first hydraulic circuit and fluidly connected to an inlet of the pump and motor assembly. The isolation valve is movable between a closed position and an open position to prevent and enable high-pressure fluid flow to the inlet, respectively. An unloader valve is arranged along the second hydraulic circuit and fluidly connected to an outlet of the pump and motor assembly, and an orifice is arranged along the second hydraulic circuit and fluidly connected to the unloader valve to reduce back pressure in the second hydraulic circuit.