In a steam valve driving apparatus according to an embodiment, a control valve permits or blocks a flow of hydraulic oil from a supply port to an opening direction piston chamber. A dump valve blocks or permits the flow of the hydraulic oil from the opening direction piston chamber to a discharge port. A blocking valve permits or blocks a flow of the hydraulic oil from an accumulator to a closing direction piston chamber. The control valve permits the flow of control oil from the closing direction piston chamber to the discharge port in a state where the flow of hydraulic oil from the supply port to the opening direction piston chamber is permitted.

A regeneration control hydraulic system for an excavator, including at least one hydraulic pump, an actuator, a regeneration oil path, and a regeneration cut-off oil path. The regeneration oil path is configured to send a return oil as a regeneration oil to a cavity having a negative pressure of the actuator. The regeneration oil path is provided with a regeneration valve and a first control valve. The first control valve is configured to control the regeneration oil to enter the cavity having the negative pressure of the actuator when a working device of the excavator retracts inwards, or to control the oil to be discharged from the actuator to the regeneration cut-off oil path when the working device swings outwards. The regeneration cut-off oil path is configured to send the regeneration oil passing through the regeneration valve or the oil discharged from the actuator to other destinations.

A regeneration control hydraulic system for an excavator, including at least one hydraulic pump, an actuator, a regeneration oil path, and a regeneration cut-off oil path. The regeneration oil path is configured to send a return oil as a regeneration oil to a cavity having a negative pressure of the actuator. The regeneration oil path is provided with a regeneration valve and a first control valve. The first control valve is configured to control the regeneration oil to enter the cavity having the negative pressure of the actuator when a working device of the excavator retracts inwards, or to control the oil to be discharged from the actuator to the regeneration cut-off oil path when the working device swings outwards. The regeneration cut-off oil path is configured to send the regeneration oil passing through the regeneration valve or the oil discharged from the actuator to other destinations.

A combined valve for insertion into an elongated bore of a power unit body of a hydraulic power unit may have an elongated carrier for receiving a relief and a check valve. The valve may also have a register arranged at a first axial position of a longitudinal axis of the carrier for calibration of the relief valve. The valve may also have a check valve coupled to the carrier at a second axial position along the longitudinal axis of the carrier. The valve may also have a relief valve coupled to the carrier at a third axial position along the longitudinal axis of the carrier. A minimal distance between the first and the second axial position may be less than a minimal distance between the first and the third axial position.

An aircraft hydraulic actuation system for retracting an aircraft landing gear. The actuation system includes a supply line arranged to carry hydraulic fluid pressurized by a pump, a return line arranged to return hydraulic fluid to a reservoir, and a hydraulic actuator 128. In a first mode of operation, a first chamber 130 of the actuator 128 is supplied with pressurized hydraulic fluid from the supply line such that a piston 134 is moved in a first direction so as to move a load such as a landing gear. In a second mode of operation, the first chamber 130 is taken out of fluid communication with the supply line and a second chamber 132 is in fluid communication with the return line, such that the piston 134 is able to be moved under the influence of the load, for example when the landing gear extends under gravity.

A hydraulic machinery may include: a boom actuator including a large chamber and a small chamber; a tank; and an energy recovery circuit provided between the boom actuator and the tank, wherein the energy recovery circuit includes: a discharge valve provided between the large chamber and the tank to allow or block the flow of fluid from the former to the latter; a regeneration valve connecting the large chamber and the small chamber to allow or block the flow of fluid from the former to the latter; a recovery part for recovering energy; and a first valve provided between the large chamber and the recovery part to allow or block the flow of fluid from the former to the latter.

Provided is a work machine which can increase the operation speed of an actuator by a regeneration function while securing the position control accuracy of the actuator. A controller is configured to calculate a regeneration flow rate on the basis of an input amount of an operation lever and a target actuator flow rate, subtract the regeneration flow rate from the target actuator flow rate to calculate a target actuator supply flow rate, calculate a target flow rate control valve opening amount on the basis of the target actuator supply flow rate, calculate a target pump flow rate that is equal to or higher than a total target actuator supply flow rate, control a selector valve on the basis of the input amount of the operation lever, control a flow rate control valve according to the target flow rate control valve opening amount, and control a hydraulic pump according to the target pump flow rate.

A hydraulic system for a working machine includes a hydraulic actuator having a first fluid chamber and a second fluid chamber, an accumulator, an outputting fluid tube to output an operation fluid, and a switching valve to be switched between a first position and a second position. The first position allows the first fluid chamber and the second fluid chamber to be communicated with the outputting fluid tube and thereby allowing a floating operation. The second position allows the first fluid chamber and the accumulator to be communicated with each other, allows the second fluid chamber and the outputting fluid tube to be communicated with each other, and thereby allows an anti-vibration operation.

Disclosed is a valve assembly with: a valve body defining valve inlet and outlet ports; a manifold connected to the valve outlet port, the manifold includes: a manifold inlet body portion defining: a manifold internal surface forming a manifold channel; and a first manifold external surface defining a manifold inlet opening that opens to the manifold channel, the manifold channel is fluidly coupled to the valve outlet port via the manifold inlet opening; a manifold outlet port, and a manifold outlet conduit extending from the manifold inlet body portion to the manifold outlet port; a manifold exhaust port, and a manifold exhaust conduit extending from the manifold inlet body portion to the manifold exhaust port, the manifold exhaust and outlet conduits are fluidly coupled to each other via the manifold channel, heat fins extend from the manifold exhaust conduit; and a eutectic plug disposed within the manifold exhaust conduit.

An apparatus includes a hydraulic circuit that is configured to selectively open fluid communication between one portion of the hydraulic circuit and another portion of the hydraulic circuit, such as a reservoir, based on the flow of the hydraulic fluid in the one portion. When the flow of hydraulic fluid exceeds a selected threshold in the one portion of the hydraulic circuit, the flow of fluid urges the opening of a hydraulic component of the hydraulic circuit to allow fluid communication between the one portion and the reservoir to discharge fluid from the one portion.