非工作状态下电液伺服机构运动分析

Kinematic Analysis of Electro-Hydraulic Servo Mechanism under Non-Working Condition

针对电液伺服机构安装到运载火箭后存在非工作状态下承受外力并产生被动运动的现状,分析伺服机构的受力情况并构建内部液体流动回路,研究非工作状态下伺服机构在外力作用时的运动特性。发现伺服阀零位特性以及伺服机构高压回路密封性能是影响伺服机构非工作状态下运动特性的主要因素。在外力作用下发生运动时油缸某一侧往往处于抽真空状态。使用零位特性良好的伺服阀以及高压回路泄漏小的伺服机构,在外力作用下将处于双向不动或单向可动的状况。利用典型产品开展了物理试验,验证了结论的有效性。

The electro-hydraulic servo mechanism bears external force and generates passive motion under the nonworking condition after being installed into a launch vehicle. A thorough analysis of the motion characteristics of a servo mechanism under the action of external force in the non-working state is presented. The results show that the zero position characteristic of the servo valve and the sealing performance of the high-pressure loop of a servo mechanism are the main factors affecting the motion characteristics of the servo mechanism under the non-working condition. When the motion occurs under the action of external force,one side of the cylinder is often in the state of vacuum pumping. The servo valve with good zero position characteristics,and the servo mechanism with small leakage in the high-pressure loop will be in bidirectional immobility or unidirectional movability state under the action of external force. The validity of the conclusion is verified by the physical test of typical products.