Manual hydraulic override pumps for use with actuators are described herein. An example apparatus includes a manifold including a reservoir port to be fluidly coupled to a reservoir of fluid, a pump port to be fluidly coupled to a pump, a first actuator port to be fluidly coupled to a first chamber of an actuator, and a second actuator port to be fluidly coupled to a second chamber of the actuator. The example apparatus also includes a rotor disposed in a cavity formed in the manifold. The rotor is rotatable between a first actuating position in which the rotor fluidly couples the first actuator port and the pump port, and a second actuating position in which the rotor fluidly couples the second actuator port and the pump port.

There is provided an hydraulic actuation system for an aircraft, the hydraulic actuation system includes an actuator (A), a primary actuation arrangement to provide hydraulic fluid to control the actuator (A), wherein the hydraulic actuation system is configured to detect a fault in the actuator (A). The hydraulic actuation system also includes a secondary actuation arrangement to provide hydraulic fluid to control the actuator (A) in response to a detection of a fault in the actuator (A).

An actuator assist apparatus for use with an actuator has a housing and a piston member slidably disposed in the housing. The piston member divides the interior of the housing into a first fluid chamber and a second fluid chamber. The actuator assist apparatus is configurable between a first, primed, configuration and an activated configuration. A force applicator is configured to store energy when the apparatus is in the primed configuration and release the energy to move the piston member relative to the housing. Movement of the piston member applies a force which assists in urging the actuator towards an extended configuration, thereby reducing the minimum operating pressure of the 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 linear drive system, in particular for a closure unit of a blow mold installation, with a simpler and more compact structure, a higher retraction and expansion speed in rapid mode, higher forces in power mode, and reduced energy consumption, than the prior art includes a cylinder arrangement which brings about a retraction and extension movement in rapid mode by separate hydraulically active faces which are independent of a larger hydraulically active face which is acted on with pressurized hydraulic fluid only in power mode. During the extension movement in power mode, however, the hydraulically active faces cooperate which contributes to high forces with a compact structure of the drive system.

An example valve includes a sleeve having a plurality of openings. A spool is rotatable within the sleeve and includes a respective plurality of openings corresponding to the plurality of openings of the sleeve. A rotary actuator coupled to the spool is configured for rotating the spool within the sleeve to one of at least eight rotary positions. The rotary actuator can rotate the spool to a given rotary position in a clockwise or a counter-clockwise direction to cause at least a partial alignment between a subset of the respective plurality of openings of the spool and a subset of the plurality of openings of the sleeve.

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.

An actuator control arrangement includes a hydraulic actuator having a housing and a piston rod axially moveable within the housing, a stop disposed within the housing to limit the extent of movement of the piston rod into the housing, and a solenoid valve arranged between a pressure source and the actuator. The solenoid valve is switchable between a first mode and a second mode in response to an electric control signal, wherein, in the first mode, the solenoid valve creates a fluid flow path from the pressure source to the actuator so as to locate the stop in its neutral position and in the second mode, the solenoid valve creates a fluid flow path to release pressure from the actuator to permit the stop to move to its retracted position. In the event of electrical failure, the stop will set the actuator to its neutral position.

A servo-control. The servo-control comprises at least one body as well as a power shaft and a control piston arranged in each body, the at least one body and the power shaft respectively forming two power members. One of the power members bears at least on end-stop member and the power member without an end-stop member bears a passivation actuator. The passivation actuator comprises a passivation shaft which bears an end-stop and a passivation piston, the passivation piston being arranged to be mobile in longitudinal translation in an enclosure, an elastic system being arranged between the passivation piston and the enclosure.

An electrohydraulic system includes a hydraulic load and at least one closed hydraulic circuit. The hydraulic circuit includes at least one control mechanism, a hydraulic machine, and a closed hydraulic reservoir. The closed hydraulic circuit is filled with degassed hydraulic fluid. A method, in one embodiment, includes filling the electrohydraulic system with degassed hydraulic fluid. In one embodiment, equipment is provided for filling the electrohydraulic system with the degassed hydraulic fluid