Abstract: An electro hydrostatic actuator includes an actuator body, a hydraulic pump driven to supply operation oil to the actuator body, and an electric motor configured to drive the hydraulic pump. Each of the hydraulic pump and the electric motor is placed so as to surround the outer periphery of the actuator body, and the hydraulic pump and the electric motor are arranged in a direction along a center axis.

Abstract: A landing gear retraction/extension device includes a hydraulic actuator, a hydraulic circuit, a hydraulic pump, an electric motor, and a driver. Part of the hydraulic circuit is provided such that heat is exchangeable between operation oil and each of the electric motor and the driver. The driver supplies power to the electric motor before landing of an aircraft such that an operation oil temperature is higher than a predetermined temperature upon the landing of the aircraft.

Abstract: A landing gear assembly includes a control system configured to output an amount of operation corresponding to an operated physical amount; a wheel; a landing gear supported by a frame of the aircraft, and configured to rotatably support the wheel; a steering system configured to steer the wheel using the amount of operation as a command value; and a detection sensor configured not to output a detection signal when the aircraft flies in air, and to output the detection signal when the aircraft stays on ground. When the detection sensor does not output the detection signal, or when speed of the aircraft is higher than first limitation speed, the steering system orients rotation of the wheel in a longitudinal direction of the aircraft in disregard of the amount of operation.

Abstract: A landing gear assembly includes a control system configured to output an amount of operation corresponding to an operated physical amount; a wheel; a landing gear supported by a frame of the aircraft, and configured to rotatably support the wheel; a steering system configured to steer the wheel using the amount of operation as a command value; and a detection sensor configured not to output a detection signal when the aircraft flies in air, and to output the detection signal when the aircraft stays on ground. When the detection sensor does not output the detection signal, or when speed of the aircraft is higher than first limitation speed, the steering system orients rotation of the wheel in a longitudinal direction of the aircraft in disregard of the amount of operation.

Abstract: A landing gear retraction/extension device includes a hydraulic actuator, a hydraulic circuit, a hydraulic pump, an electric motor, and a driver. Part of the hydraulic circuit is provided such that heat is exchangeable between operation oil and each of the electric motor and the driver. The driver supplies power to the electric motor before landing of an aircraft such that an operation oil temperature is higher than a predetermined temperature upon the landing of the aircraft.

Abstract: An electro hydrostatic actuator includes an actuator body, a hydraulic pump driven to supply operation oil to the actuator body, and an electric motor configured to drive the hydraulic pump. Each of the hydraulic pump and the electric motor is placed so as to surround the outer periphery of the actuator body, and the hydraulic pump and the electric motor are arranged in a direction along a center axis.