每日一词｜飞行控制伺服阀Flightcontrolservovalves

飞行控制伺服阀
Flight control servo valves

Nature and Purpose
A servo valve is an electrically- operated valve that uses feedback to precisely control the position of an internal device (either flapper nozzle or jet pipe) to control the fluid flow. The term electrohydraulic servo valve is often used because servo valves are controlled through an electrical signal and are usually used in hydraulic systems. Servo valves operate with very high accuracy, very high repeatability, very low hysteresis, and very high frequency response. Servo valve systems feature high response characteristics, high reliability, accurate position control, velocity control and force control.
Servo valves are used when accurate position control is required, such as control of a primary flight control surface. Position control is achieved through a closed loop control system, consisting of command sensor, feedback sensor, digital or analog controller, and the servo valve. Servo valves can be used to control hydraulic actuators or hydraulic motors. A servo valve and actuator combination are referred to as a servo- actuator. The main advantage of a servo valve is that a low power electrical signal can be used to accurately position an actuator or motor.