Modeling of high-pressure external gear pump

Hydraulic systems provide good dynamic behaviour and therefore are one of the main design concept for industrial applications, such as the example of drives for machine tools. The most important part of the hydraulic system is the pump. The main task of the pump is the converting mechanical energy from the prime mover into hydraulic energy, or the flow and pressure, with as high efficiency as possible. The paper shows the experimental determination of the actual flow rate of one type of the external gear pump, depending on the load condition. The analysis of test results shows the linear dependence of the actual flow rate of the pump and the discharge pressure. On the basis of the mathematical model, the volumetric efficiency values of the pump are obtained. They deviate from about 1 % of the experimentally determined values, which justifies the applied model. The presented model can be the basis for the simulation as in the example shown in this paper, while the experimental model can also be applied in exploitation conditions. Namely, the experimental model of the pump can be employed for diagnostic purposes and for the simulation of the hydraulic device.