A hydraulic apparatus includes a first valve manifold that provides a shutdown capability and a second valve manifold that provides an overspeed control capability. The hydraulic apparatus advantageously further employs a hydraulic appliance that includes a check valve and a bypass apparatus. The hydraulic appliance enables the second valve manifold to additionally provide as an alternative function a redundant shutdown capability, thereby obviating the need to have three separate valve manifolds.

Distributed trailing edge wing flap systems are described. An example wing flap system for an aircraft includes a flap and an actuator. The flap is movable between a deployed position and a retracted position relative to a fixed trailing edge of a wing of the aircraft. The actuator is to move the flap relative to the fixed trailing edge. The actuator is hydraulically drivable via first pressurized hydraulic fluid to be supplied by a hydraulic system of the aircraft. The actuator is also hydraulically drivable via second pressurized hydraulic fluid to be supplied by a local power unit. The local power unit is selectively connectable to an electrical system of the aircraft. The electrical system is to power the local power unit to supply the second pressurized hydraulic fluid.

A fluid pressure control device includes a first switching valve provided on a downstream of a first travel control valve in the first main passage and having an open position and a priority position, a second switching valve provided on a downstream of a second travel control valve in the second main passage and having an open position and a priority position, and a merging passage connecting a downstream of the first switching valve and a downstream of the second switching valve. In a state where first work control valves and second work control valves are not operated and the first travel control valve is operated, the first switching valve is at a priority position, and in a state where the first work control valves and the second work control valves are not operated and the second travel control valves is operated, the second switching valve is at a priority position.

A control valve assembly for indirect pneumatic control and method for controlling a working fluid pressure, which enable precise, sensitive and speed-variable controlling. The assembly includes two valve units, a working fluid inlet, and a control fluid inlet. A working fluid channel connects the working fluid inlet through the two valve units to an outlet. A valve piston arranged within a valve cylinder of the valve units is movable between open and closed positions. A spring element biases the valve piston toward the closed position, and a control pressure chamber applies a control pressure counteracting the spring element's bias. When a control pressure is applied in the first chamber, the first valve piston is moved to the open position. Two opposite valve surfaces form a valve opening opened at varying widths when the valve piston is moved in the valve cylinder because of a changing control pressure, and the working pressure can be finely adjusted corresponding to the valve opening width depending on the control pressure.

A system for recovering energy from a hydraulic actuator and to a method of operating the system are described. The system may have a hydraulic actuator and a source of hydraulic pressure, comprising a hydraulic pump, in fluid communication with the hydraulic actuator for pressurizing the hydraulic actuator. The system may also have a hydraulic accumulator assembly for selectively absorbing energy from the hydraulic actuator or via the hydraulic actuator. The system may also have a first one-way valve configured to provide fluid communication between the hydraulic actuator and the hydraulic accumulator assembly. The first one-way valve may be configured to permit a flow of fluid through the first one-way valve from the hydraulic actuator to the hydraulic accumulator assembly. The first one-way valve may also be configured to block a flow of fluid through the first one-way valve from the hydraulic accumulator assembly to the hydraulic actuator.

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.

A hydraulic unit is provided with: a manifold which forms a hydraulic circuit; a tank which is joined to the manifold; and a hydraulic pump which suctions hydraulic fluid in the tank and supplies the hydraulic fluid to the manifold, wherein the base end portion of a suction strainer is fitted into the hydraulic pump, and the suction strainer has such a shape that the base end portion of the suction strainer is not separated from the hydraulic pump in a state where the leading end portion of the suction strainer is in contact with the tank and an opening through which the hydraulic fluid is introduced from the tank is provided at the leading end portion.

A fluid pressure circuit for controlling a rod of a cylinder controlled in accordance with an operation command includes a tank, a fluid pressure actuator configured to pressurize fluid supplied from the tank for extending and retracting the cylinder, a flow control valve arranged between the fluid pressure actuator and the cylinder device configured to switch a flow passage of pressurized fluid and discharge via a first throttle return fluid from the cylinder, a variable regeneration switching valve configured to discharge return fluid from the cylinder to the flow control valve upon non-regeneration and upon regeneration, branch part of the return fluid and discharge via a second throttle the fluid branched, a regenerative motor configured for regeneration by fluid branched by the variable regeneration switching valve, and a third throttle connected in series with the first throttle upon the regeneration to limit flow of return fluid.

A cylinder driving device includes: an electric motor; a pump; a main passage and a main passage; a hydraulic cylinder; an operation check valve and an operation check valve; and a restriction valve and a restriction valve configured to restrict a flow of the working oil directed to the operation check valve and an operation check valve, wherein an opening area of the restriction valve and the restriction valve is reduced in response to an increase in a flow rate of the working oil discharged from the hydraulic cylinder to the main passage and a main passage.

A hydraulic device is provided. Working fluid stored in a fluid storage portion is supplied by a fluid supply portion to a power output portion. The fluid supply portion is driven by a brushless motor. A bypass flow path portion can be switched between a first state of supplying the working fluid from the fluid supply portion to the fluid storage portion and a second state of blocking the fluid supply portion from the fluid storage portion. A control to switch the bypass flow path portion from the first state to the second state after the brushless motor is started and a control to switch the bypass flow path portion from the second state to the first state when the brushless motor is stopped is performed. Backflow of the working fluid from the power output portion to the bypass flow path portion is prevented by a backflow prevention valve.