A servocontrol for controlling the position of a moving part of an aircraft includes a piloting device configured to control a power device according to a displacement control, the piloting device including a piloting unit further including a set of electronic, mechanical and/or hydraulic accessories in fluidic communication with the hydraulic cylinder and a body delimiting a network of tubular cavities fluidically connecting the electronic, mechanical and/or hydraulic accessories. The body includes an external surface, at least a first coupling portion between the network and a hydraulic cylinder and at least a second coupling portion between the network and the hydraulic cylinder and a neutral axis being defined for each tubular cavity. The neutral axis of at least one tubular cavity is curved.

An electro-hydraulic circuit includes a supply line that connects between a hydraulic supply device that supplies hydraulic fluid and a driving part to be driven by a hydraulic pressure of the hydraulic fluid; a switching valve disposed in the supply line to switch between switching lines for the hydraulic fluid supplied to the driving part; a pilot hydraulic line connected to the switching valve to supply the hydraulic fluid for switching between the switching lines; a check valve disposed in the pilot hydraulic line; a solenoid valve disposed in the pilot hydraulic line to change a supply state of the hydraulic fluid to the switching valve; a sealing material disposed in the switching valve to seal the hydraulic fluid; and a relief valve disposed in the pilot hydraulic line to release the pilot hydraulic pressure

In general, certain embodiments of the present disclosure provide an electro-hydrostatic actuator comprising a piston assembly and a hydraulic cylinder. The piston assembly, having a piston head and a piston rod extending from the piston head, is located and movable within the hydraulic cylinder. The hydraulic cylinder includes a hydraulic fluid chamber region including a piston side chamber and a rod side chamber, a reservoir for storing hydraulic fluid located within the hydraulic cylinder which is in fluid communication with the hydraulic fluid chamber region. The electro-hydrostatic actuator includes a hydraulic pump system for moving hydraulic fluid in the reservoir and the hydraulic fluid chamber region, the hydraulic pump system in fluid communication with a flow control network in a hydraulic cylinder boss for controlling a direction and flow magnitude of hydraulic fluid within the hydraulic fluid chamber region, and an electric motor for driving the hydraulic pump system.

A hydraulic system of an aircraft may include a system pump configured to provide hydraulic fluid to the hydraulic system at a first working pressure. The hydraulic system may further include a booster pump configured to supply hydraulic fluid to at least one boostable actuator at a second working pressure higher than the first working pressure. The boostable actuator may be operatively coupled to and configured to actuate at least one flight control surface of an aircraft.

An electro hydrostatic actuator comprising a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator, the pump comprising an inlet and an outlet for the hydraulic fluid and an active flow path configured therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path configured to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet. The hydraulic pump is a rotary piston pump comprising a pump barrel driven to rotate by a motor shaft.

Methods and apparatus for controlling aircraft flight control surfaces are disclosed. An example apparatus includes a flight control surface controller to move a control surface of an aircraft to a target position via at least one of a first actuator or a second actuator associated with the control surface based on a command input received by the flight control surface controller. The flight control surface controller to: obtain a flight characteristic of the aircraft; compare the flight characteristic to a flight characteristic threshold; in response to a first comparison result, cause the first actuator to move the control surface to the target position based on the command input without moving the second actuator; and in response to a second comparison result, cause the first actuator and the second actuator to move the control surface to the target position based on the command input.

The invention concerns a method for estimating an external force acting on an electrohydrostatic actuator, the actuator comprising a ram including a first chamber, a second chamber and a piston located between the first chamber and the second chamber, a pump capable of injecting fluid into the chambers for controlling a movement of the piston, and an electric motor driving the pump, the method comprising steps of: estimating, by means of at least one state observer (21, 22), a dynamic component and a static component of a difference in equivalent fluid pressure between the first chamber and the second chamber from a rotational speed of the electric motor, a position of the piston and a supply current of the electric motor, estimating the external force by means of a post-processing module (23) as a combination of the estimated dynamic component and static component of the difference in fluid pressure.

An electro hydrostatic actuator (EHA) comprises a hydraulic pump and an electric motor driving the hydraulic pump. The hydraulic pump comprises an inlet and an outlet for hydraulic fluid and an active fluid flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The hydraulic pump further comprises a bypass flow path arranged between the pump inlet and outlet, such that, in a damping mode of operation, hydraulic fluid is able to freely flow between the inlet and outlet in either direction.

A switching valve includes a sleeve on which a plurality of ports are disposed; a spool that is disposed inside the sleeve to move in an axial direction by a pilot hydraulic pressure to switch between switching lines each serving as a flow channel for hydraulic fluid that is formed by a combination of the ports; a first energizing unit that energizes the spool against the pilot hydraulic pressure; a relief hole that is disposed on the spool to discharge the hydraulic fluid with the pilot hydraulic pressure; a valve body that closes the relief hole; and a second energizing unit that energizes the valve body toward the relief hole of the spool against the pilot hydraulic pressure, and when the pilot hydraulic pressure exceeds a predetermined value, opens the relief hole.

Electro-hydraulic servo-valves and related methods are disclosed herein. An example electro-hydraulic servo-valve includes an inlet to receive a fluid from a reservoir, a torque motor, a chamber, the fluid to return to the reservoir via the chamber, and a flexure tube coupled to the torque motor. At least a portion of the flexure tube is disposed in the chamber. The flexure tube includes a nozzle to deliver the fluid to an actuator. The example electro-hydraulic servo-valve includes a damper operatively coupled to the flexure tube. The damper is disposed in the chamber.