基于挤压油膜理论的二维电液压力伺服阀稳定性分析

针对飞机液压刹车系统，设计了一种2D电液压力伺服阀，以2D伺服螺旋机构为导阀，通过弹簧与主阀联动，采用直线位移传感器形成闭环位置反馈，精确控制出口压力；基于挤压油膜理论设计阀体结构，增大系统阻尼比，提高系统稳定性；在建立阀和油膜缓冲数学模型的基础上，仿真分析了主阀正开口量与弹簧变形量和主阀输出压力之间的关系，确保该阀具有良好的电流-压力特性；对初始系统、减小开环放大系数和增大系统阻尼比三种情况进行了稳定性仿真分析，验证了引入油膜阻尼缓冲设计的必要性。

Stability Analysis of 2D Electro-hydraulic Pressure Servo Valve Based on Squeeze Oil Film Theory

A new kind of 2D electro-hydraulic pressure servo valve (EPSV) was designed for aircraft hydraulic braking system herein. Using LVDT to form a closed loop position feedback, servo spiral mechanism was taken as pilot valve, the pressures were accurately controlled through mutual movements among 2D pilot valve, spring and master valve. Based on the squeeze oil film theory, the valve structures were designed to increase the system damping ratio and improve system stability. A mathematical model of the valve and the squeeze oil film theory were built, the relationship among positive opening amounts of the master valve, spring deflections and the output pressures of master valve was simulated to ensure its current-pressure characteristics. Three kinds of conditions, initial system, decreasing open loop gains and increasing system damping ratios, were comparatively analyzed by software MATLAB, simulation results show that: it is necessary to design the valve based on the squeeze oil film theory, the valves stability is improved much after increasing its damping ratios.