A pneumatically controlled flow booster includes a booster valve plug position sensor that enables control of the flow booster in a feedback loop, for example by a pneumatic valve positioner, thereby providing accurate, high speed, high flow control of both small and large actuator adjustments. Embodiments can accurately control a surge suppression valve over extended valve adjustment ranges and can fully open a surge suppression valve during a trip. The flow booster valve can include a spool and sleeve valve and/or a poppet valve. Embodiments provide bimodal flow boosting, whereby the output flow is less dependent on the valve plug position in a first position range, and more strongly dependent on the valve plug position in a second range.

An electrical power generation system includes a hydraulic pump configured to be switchable between operating in a first pump direction and in a second pump direction opposite the first pump direction and a hydraulic motor operably connected to the hydraulic pump to convert hydraulic flow into electrical power. The hydraulic motor has a motor inlet passage and a motor outlet passage. A hydraulic block is located in flow communication with the hydraulic pump and with the hydraulic motor. The hydraulic block is configured such that hydraulic fluid flow exiting the hydraulic block toward the hydraulic motor is directed through the motor inlet passage, regardless of whether the hydraulic pump is operating in the first pump or the second pump direction.

An electrical power generation system includes a hydraulic pump configured to be switchable between operating in a first pump direction and in a second pump direction opposite the first pump direction and a hydraulic motor operably connected to the hydraulic pump to convert hydraulic flow into electrical power. The hydraulic motor has a motor inlet passage and a motor outlet passage. A hydraulic block is located in flow communication with the hydraulic pump and with the hydraulic motor. The hydraulic block is configured such that hydraulic fluid flow exiting the hydraulic block toward the hydraulic motor is directed through the motor inlet passage, regardless of whether the hydraulic pump is operating in the first pump or the second pump direction.

A sub-system 200 for an aircraft hydraulic system 20 that includes a first inlet 202 for receiving fluid from a supply 22 of hydraulic fluid, a system valve 210 for controlling fluid flow from the sub-system 200 to a hydraulically-operable system 24 of the aircraft hydraulic system 20, a check valve 220 for permitting fluid flow from the sub-system 200 and preventing or hindering fluid flow into the sub-system 200, a second inlet 240 for receiving fluid from a second supply 28 of hydraulic fluid, and a selector 230. The selector 230 configured to place the system valve 210 in fluid communication with the first inlet 202 when the selector 230 is in a first state, and to place the system valve 210 in fluid communication with the check valve 220 and the second inlet 240 when the selector 230 is in a second state different from the first state.

An articulated work vehicle has front and rear frames coupled. The work vehicle includes a hydraulic actuator driven by hydraulic pressure to change a vehicle body frame angle of the front frame with respect to the rear frame, a lever rotatable to change the body frame angle, a control valve that controls a flow rate of oil supplied to the hydraulic actuator, and a controller. The controller sets a target angle of the vehicle body frame angle with respect to an input angle of the lever, and controls the control valve such that an actual angle of the vehicle body frame angle matches the target angle of the vehicle body frame angle.

A pressure booster having arranged therein drive cylinders on both sides of a boosting cylinder is provided with a pair of pilot valves that are actuated when pistons of the drive cylinders abut against the moving ends thereof. A pair of actuation valves switch the supply state of a pressure fluid to pressure chambers of the drive cylinders. When the pilot valves are actuated, the pressure fluid passes through the pilot valves and is supplied to the pair of actuation valves, and the supply state of the pressure fluid is switched.

A hydraulic system includes a first output fluid tube connecting between a hydraulic pump to output operation fluid and a first operation valve to change a first pilot pressure of the operation fluid, a second output fluid tube connected between the hydraulic pump and a second operation valve to change a second pilot pressure of the operation fluid, a switching valve provided in the second output fluid tube, and a warm-up fluid tube connected between the first operation valve and the switching valve, wherein the switching valve is switched between a first position allowing the operation fluid to be drained through the first output fluid tube, the first operation valve, the warm-up fluid tube and the switching valve, and a second position allowing the operation fluid to be supplied through second output fluid tube to the second operation valve.

Proposed is a hydraulic cylinder rod in which a rod eye is robustly coupled to a hybrid round rod for weight reduction. To this end, the hydraulic cylinder rod is configured with a hybrid round rod including a metal tube and a composite material round rod provided for weight reduction inside the metal tube, wherein a side of the metal tube is formed to be relatively longer than the length of the composite material round rod to thereby provide a space defined by a length difference therebetween; and a rod eye is coupled to the space.

A proportional control fluid actuator that is used as a positioning device in applications such as a hydraulic directional control valve. The activating device has a cylinder body attachable to a valve body and has a bore carrying a piston that is coaxially secured to an end of a valve spool. The device is provided with spaced openings in the cylinder body that communicate with the bore therein to introduce fluid to act on opposite sides of the piston. Factory pre-compressed spring means are provided for normally urging the piston and spool to a center position. Since the areas of the fluid pressure applied on both sides of the piston are different (due to a spool on one side of the piston), two pre-compressed springs are used to compensate the area difference to achieve a proportional movement of the spool.

A vehicle door positioning holder includes a hydraulic cylinder connected to the door and a vehicle chassis, and a brake hydraulically connected in a loop. The cylinder pushes hydraulic fluid in the loop when the door is moved. The brake includes first and second chambers hydraulically connected to the loop and a third chamber connected in the loop at respective ends to the first and second chambers. The brake has a ball element in the third chamber when the hydraulic fluid is still, moved towards the first chamber as the hydraulic fluid flows in a first direction, and moved towards the second chamber as the hydraulic fluid flows in a second direction. A flow resistance of the hydraulic fluid is larger when the ball is positioned in the third chamber than when the ball is moved towards the first or the second chambers.