Study Of New Type Electro-Hydraulic Actuator For Industry Valve

In recent years, the hydraulic actuator has developed quickly accompany with the high demand of industry automation. The major trend of hydraulic actuator development is miniaturization、light weight、high efficiency、energy conservation and high reliability. Especially in the petrochemical industry, we need hydraulic actuator work reliability in the small area、high temperature、high pressure、inflammable、explosive、 poisonous and harmful environment to control the valve. These environment need high quality hydraulic actuator. Currently, there is one type of actuator only can be used acccompany with a hydraulic pressure station or a set of servo valve, this made the actuator with problem such as a high volume、 high throttle loss、 sensitive with the oil contaminate、 the servo valve need high machining accuracy、 expensive、 hard to maintain and so on. Another type of actuator use the volume control circuit, this system use servo motor and variable-stroke pump. It’s principle is change the swashplate’s angle to change the pump’s output and use this to control the speed of actuator. This loop without overflow and throttling loss so the system’s efficiency is high. This system could be used in high-power system. But this system also has it’s weak point. First, the variable-stroke pump’s swashplate’s angle is limited, and this restrict the system’s speed governing range. Second, the noise of variable-stroke pump is too loud and the system’s ability of resistance pollution is weak. Finally, in all working condition the servo motor’s speed is invariability, most of time the system is working under load. And so the motor provide power always more than the actuator need. So the efficiency is low, waste of energy and make the pump abrasion.New type hydraulic actuator use the constant rate pump and servo motor, control the servo motor to control the displacement of actuator. In order to improve the performance of the actuator, reduce the volume of the actuator, first, we need to make better the hydraulic actuator’s hydraulic principle, count and select the hydraulic component. Analyse the matching of the hydraulic component. Second, Build a hydraulic system model use the AMESim software, simulation analyse on different frequency signal input, different servo motor speed and different pipe length. Also need to Select a appropriate control strategy to achieve a more efficient and reliable control of the hydraulic actuator.Finally, rational design the appearance of the actuator configuration for a small volume and convenient to install.