A system for detecting and controlling the position of a spoiler of an aircraft wing is described herein comprising: a hydraulic actuator having a piston rod operably connected to the spoiler, the piston rod being moveable between a retracted position, a neutral position and an extended position; and means for providing power to said hydraulic actuator; and a mechanical device for detecting whether the piston rod is in the retracted position, the neutral position or the extended position; and means, operatively connected to the mechanical device, that is configured to provide a change in a load applied to said hydraulic actuator, wherein said means is configured to change said load based on whether said piston rod is detected as being in said retracted position or said extended position.

Provided is a joint device which can be connected by quick and simple operation while being subjected to high-pressure high-flow-rate pressurized operating oil. The present invention comprises: a closed chamber 27 provided in a hydraulic circuit on which pressurized fluid acts, the pressurized fluid circuit having an upstream side and a downstream side, which are closed by an upstream-side stop valve 211 and a downstream-side stop valve 212; a male joint 30 provided at a position in communication with the closed chamber 27; and a female joint 40 connectable to the male joint 30 and provided in an emergency hydraulic circuit connected to the hydraulic circuit. The present invention is configured so that the female joint 40 is connected to the male joint 30 while the closed chamber 27 is closed by the upstream-side stop valve 211 and the downstream-side stop valve 212.

A power unit with manual override control for a hydraulic system having an initial state and at least one operational state is provided, comprising: a tank for storing hydraulic fluid that moves between a first chamber and a second chamber of a hydraulic cylinder; a pump that routes the hydraulic fluid in and out of the tank; a first relief valve; a first solenoid valve configured to shift between a plurality of positions based on the at least one operational state of the hydraulic system; a first check valve connected to the first solenoid valve; a manual override control unit comprising: a second check valve; and a second solenoid valve configured to shift between a plurality of positions based on activation of a manual override control, wherein the activation of the manual override control returns the hydraulic system from the at least one operational state to the initial state.

An example aircraft includes (i) a landing gear having a chassis, an axle, and wheels mounted to ends of the axle; (ii) a hydraulic actuator including a cylinder, a first piston coupled to the chassis, and a second piston coupled to the axle; and (iii) a directional control valve including: inlet ports configured to be fluidly coupled to a source of pressurized fluid, tank ports configured to be fluidly coupled to a tank, and workports configured to be fluidly coupled to the hydraulic actuator.

In one or more embodiments, a system for predicting health of a hydraulic pump comprises a reservoir tank temperature sensor to measure a temperature of a reservoir tank. The system further comprises a hydraulic pump temperature sensor to measure a temperature of the hydraulic pump. Also, the system comprises a differential pressure sensor to measure a differential pressure across a filter associated with the hydraulic pump. Further, the system comprises a processor(s) to determine a differential temperature by subtracting the temperature of the reservoir tank from the temperature of the hydraulic pump, to compare the differential temperature to a differential temperature threshold, to compare the differential pressure to a differential pressure threshold, and to generate an alert signal indicating failure of the hydraulic pump, when the processor(s) determines that the differential temperature exceeds the differential temperature threshold and the differential pressure exceeds the differential pressure threshold.

A hydraulic system of a vehicle includes a first pump for supplying at least one first hydraulic circuit and at least one second pump for supplying at least one second hydraulic circuit with hydraulic medium. The second pump supplies the first hydraulic circuit with hydraulic medium in an emergency mode or when an output pressure of the first pump fails.

A power unit with manual override control for a hydraulic system having an initial state and at least one operational state is provided, comprising: a tank for storing hydraulic fluid that moves between a first chamber and a second chamber of a hydraulic cylinder; a pump that routes the hydraulic fluid in and out of the tank; a first relief valve; a first solenoid valve configured to shift between a plurality of positions based on the at least one operational state of the hydraulic system; a first check valve connected to the first solenoid valve; a manual override control unit comprising: a second check valve; and a second solenoid valve configured to shift between a plurality of positions based on activation of a manual override control, wherein the activation of the manual override control returns the hydraulic system from the at least one operational state to the initial state.

A hydraulic elevator may comprise a bidirectional pump that controls up and down motion of an elevator car. A VVVF drive may cause the bidirectional pump to provide working fluid in a controlled manner to a hydraulic jack that supports the elevator car. A control valve may be disposed between the bidirectional pump and the hydraulic jack so that the control valve can be closed when the elevator car needs to be held in place. To avoid pressure waves that propagate when the control valve is opened with disparate pressures on the pump and jack sides of the control valve, the bidirectional pump may adjust the pressure on the pump side of the closed control valve to the pressure on the jack side of the control valve before the control valve is opened.

A spoiler actuator can be operated by applying high pressure to a first chamber of the actuator on receipt of a command to extend the spoiler; applying high pressure to a second chamber of the actuator on receipt of a command to retract the spoiler; and on failure of a supply of the high pressure actuating an anti-extension valve to prevent extension of the spoiler; disengaging the anti-extension valve to permit extension if pressure applied to the anti-extension valve exceeds a predetermined force of a spring biasing the anti-extension valve to the engaged position, wherein additional force is applied to the anti-extension valve if the spoiler is retracted beyond a neutral position.

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.