Pulsation Test and Analysis of Internal Gear Pump Used in Electro-hydraulic Actuator

Abstract

The linear conjugate internal gear pump is widely used in the Electro-hydraulic Actuator (EHA) system because of its high efficiency and low noise, especially in the ship domain where vibration and noise requirements are very strict. To find out the reason, the calculation method of flow fluctuation and pressure pulsation at the pump outlet is obtained theoretically. First, the method of obtaining the two characteristic values of pump source flow pulsation Qs and pump source impedance Zs, and the data calculation and processing program are compiled by Matlab. Then the test platform was built, as well as the computer simulation and data collection. According to the theoretical method, the actual flow fluctuation and pressure pulsation at the pump outlet under different working conditions are measured and calculated respectively. The data of each working condition can be summarized and analyzed as: the test platform is reasonable and the data obtained from the test and calculation are reasonable; under the same frequency spectrum, the amplitude corresponding to the fundamental frequency of the motor pump is much larger than that of the pump tooth; under different working conditions, the variation trend of flow fluctuation and pressure pulsation corresponding to the fundamental frequency and the frequency doubling of the internal gear pump is obtained by testing; the specific values are smaller and suitable for the use in a silent system.