The disclosure provides a blowout preventer system including: a hydraulic circuit, a blowout preventer including a ram having an open port and a close port, a hydraulic fluid tank, a hydraulic fluid pump, and a control valve. The hydraulic circuit includes: a first accumulator, a first valve, and a second valve. The control valve is coupled to the open port, the close port, and the hydraulic fluid tank. The first accumulator is coupled to the control valve by way of the first valve and to the close port by way of the second valve. The first valve allows hydraulic fluid to flow from the control valve to the first accumulator but prevents hydraulic fluid from flowing back to the control valve. When the control valve is in the open position, the second valve is closed, and when the control valve is in the close position, the second valve is open.

A hydraulic assembly for a vehicle transmission includes a hydraulic pump for providing a system pressure within a hydraulic circuit, a pressure accumulator for temporarily supplying pressure to the hydraulic circuit, and a valve assembly for charging the pressure accumulator after a predetermined pressure threshold value of the system pressure has been reached or exceeded. The valve assembly is hydraulically connected between the pump and the pressure accumulator.

A closed-circuit, self-contained hydraulic axis includes an electric motor, a hydraulic cylinder configured to be connected to a load and a main pump driven by the electric motor to pump hydraulic fluid through the circuit. Pressure connections of the pump are connected to the respective chambers of the cylinder such that the cylinder rod is configured to extend and retract depending on a direction of flow of the hydraulic fluid through the main pump. The hydraulic axis includes a main accumulator connected to the pump via first control valve, an energy storage accumulator connected to the pump via a second control valve, and a charge pump. The hydraulic axis is switchable between a first operating mode that is free of energy storage in the energy storage accumulator, and a second operating mode in which energy is stored in the energy storage accumulator.

A hydraulic machine is provided. A boom actuator includes a large chamber and a small chamber. A recovery unit receives fluid discharged from the large chamber and then recovers energy. A recovery line connects the large chamber and the recovery unit. An accumulator is connected to the recovery line. A jack-up assist line connects the accumulator and the small chamber. A jack-up assist valve is disposed on the jack-up assist line to block flow of fluid from the accumulator to the small chamber in a first position and allow the flow of fluid from the accumulator to the small chamber in a second position. A controller controls movement of the jack-up assist valve. The controller may determine whether or not the hydraulic machine is in a jack-up condition, and when the hydraulic machine is determined to be in the jack-up condition, moves the jack-up assist valve to the second position.

A hydraulic machine. A boom actuator includes a large chamber and a small chamber. A recovery unit receives fluid discharged from the large chamber and then recovers energy. A recovery line connects the large chamber and the recovery unit. An accumulator is connected to a first point on the recovery line. A discharge valve is disposed on the recovery line between the first point and the recovery unit. A first sensor measures a pressure in the accumulator. A controller controls opening and closing of the discharge valve. The controller performs anti-bouncing control of: determining a target pressure in the accumulator corresponding to a load pressure applied to fluid in the large chamber by a load according to a predetermined correspondence; and controlling the opening and closing of the discharge valve such that the pressure in the accumulator measured by the first sensor reaches the target pressure.

The object of the present invention resides in provision of a construction machine in which a hydraulic cylinder can be driven in a high efficiency by an accumulator. To this end, the construction machine including: a hydraulic cylinder; a first accumulator that accumulates return fluid from the hydraulic cylinder with a first set pressure; a tank that stores hydraulic fluid therein; a first hydraulic pump that delivers the hydraulic fluid sucked from the tank; a hydraulic actuator that is driven by the first hydraulic pump; and a second accumulator that accumulates return fluid from the hydraulic actuator with a second set pressure, includes a first control valve placed in a first hydraulic line that connects the first accumulator and the hydraulic cylinder to each other, and a second control valve placed in a second hydraulic line that connects the second accumulator and the hydraulic cylinder to each other. The second set pressure is set to a value higher than that of the first set pressure.

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 is configured to selectively receive a plunger member into a boost cylinder, wherein movement of the plunger member received in the boost cylinder compresses a charge fluid within a blind side volume of the boost cylinder from a first fluid pressure to an amplified fluid pressure greater than the first pressure. The working cylinder assembly is selectively operable responsive to receiving a source hydraulic fluid having a nominal fluid pressure less than the amplified fluid pressure for effecting the movement of the plunger member into the boost cylinder. The energy storage device is operable to selectively receive and store a portion of the charge fluid compressed to the amplified fluid pressure.

A renewable energy and waste heat harvesting system 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 collects energy from a renewable energy source and transfers the collected energy using the pressurized hydraulic fluid. The system further includes one 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 one 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 machine. A boom actuator includes a large chamber and a small chamber. A recovery unit receives fluid discharged from the large chamber and then recovers energy. A recovery line connects the large chamber and the recovery unit. An accumulator is connected to a first point on the recovery line. A discharge valve is disposed on the recovery line between the first point and the recovery unit. A first sensor measures a pressure in the accumulator. A controller controls opening and closing of the discharge valve. The controller performs anti-bouncing control of: determining a target pressure in the accumulator corresponding to a load pressure applied to fluid in the large chamber by a load according to a predetermined correspondence; and controlling the opening and closing of the discharge valve such that the pressure in the accumulator measured by the first sensor reaches the target pressure.

A high-pressure unit (HPU) skid for greasing and actuating a frac tree valve includes one or more hydraulic pumps, a grease pump, a hydraulic reservoir, and two or more accumulators all of which are mounted on a portable frame. The HPU skid further includes fluidic connections to connect the frac tree valve to an output of the grease pump and fluidic connections to connect the frac tree valve to at least one of the two or more accumulators. The hydraulic pumps are configured to withdraw hydraulic fluid from the hydraulic reservoir for charging the accumulators, operating the grease pump, or charging the accumulators and operating the grease pump at a same time.