Study on hydraulic servo system which uses magnetic fluid as working fluid.

我们研制了一种磁控层流比例放大器(MCLPA)，它在供应喷嘴的出口处安装了两个电磁铁。用磁流体代替传统的石油作为MCLPA液压系统的工质，可以实现无运动部件的电-机换能器，MCLPA喷嘴宽度为1 mm，长宽比为0.5和1。在电流为1A的情况下，MCLPA的电磁铁产生的最大磁场强度为0.1T，在没有任何电源电流的情况下，MCLPA的压力恢复率与修正的雷诺数成正比。最大压力恢复率为37%，证实了MCLPA的形状和尺寸适合于这种应用。在电磁铁上施加恒定电流，即1A，MCLPA两个出口之间的压差与修正的雷诺数成正比增加。在修正雷诺数为850时，最大压差为74.7kPa.输出压差与提供给电磁铁的电流的第二次功率成正比。

We developed a magnetic controlled laminar proportional amplifier (MCLPA) which has two electromagnets installed at the outlet of a supply nozzle. Using a magnetic fluid as the working fluid of a hydraulic system of the MCLPA instead of conventional petroleum, an electrical to mechanical transducer having no moving parts can be realized.Width of the nozzle of the MCLPA was 1 mm and aspect ratio were 0.5 and 1. In this study , we examined the characteristics of the MCLPA. The maximum strength of the magnetic field which was generated by the electromagnet of the MCLPA with a current of 1 A was 0.1 T. Without any supply current, pressure recovery of the MCLPA increased in proportion to the modified Reynolds number. The maximum pressure recovery was 37 % It was confirmed that the shape and dimensions of the MCLPA was adequate for this application. Applying a constant current, i.e., 1 A, to the electromagnet, the pressure difference between two outlet ports of the MCLPA increased in proportion to the modified Reynolds number. The maximum pressure difference was 74.7 KPa at the modified Reynolds number of 850. The output pressure difference increased aproximately in proportion to the second power of the supply current to the electromagnet.