STELLEINRICHTUNG IN INTEGRIERTER ODER KONZENTRIERTER BAUWEISE

An integrated electro hydraulic actuator package for remotely controlling the position of an aircraft control surface has both its input power and its input command signals supplied solely by wires from remote locations. The package encloses an electric motor running wet in the hydraulic fluid and driving a reversible variable displacement pump connected directly to a differential piston and cylinder actuator and is designed to be completely manifolded. A differential piston and cylinder reservoir carries fluid to make up for any losses of fluid from the actuator to the outside of the package. An auxiliary pump supplies fluid to a servo motor circuit for control purposes, the circuit being governed by an electro-hydraulic servo valve whereby a servo motor system adjusts the displacement of the main pump. Loss of fluid from the package or mechanical failure in a pump causes loss of delivery pressure at the auxiliary pump and actuates a bypass valve to bypass the actuator allowing make-up of fluid from the reservoir. Overload protection is provided in the servo motor circuit by a pair of pressure responsive dumping valves. A linearly variable differential transformer provides a signal indicating the position of the actuator which is combined with a command signal from a remote location to govern the electro-hydraulic servo valve. The position of the displacement adjuster of the main pump is also fed to the electro-hydraulic servo valve providing a signal indicative of the velocity of the actuator. A heat exchanger surrounds the electric motor and carries the fluid returning from the pump housing to the reservoir. An auxiliary electric motor driven fan cools the heat exchanger.