Analysis Of Flow Pulsation And Flow Field Dynamic Characteristics Of Internal Gear Pump

There are many advantages at the internal gear pumps(such as compact structure,convenient processing and flexible space layout),Therefore it can be widely used in various hydraulic systems,however,the stability of the whole hydraulic system and the pump as well as the size of the noise,which is largely determined by the amount of flow pulsation generated by the gear pump when it is operating.Hence,the key to the research of the internal gear pump is how to reduce its flow pulsation effectively,at present.In this paper,a certain type of internal gear pump is taken as the research subject.The instantaneous flow,displacement and flow pulsation of the pump are studied,and the internal flow field of this pump is studied.The research is carried out to lay the foundation for the study of internal gear pumps.The main works of this paper are divided into the following points:1.According to the analysis of the structure mechanisms and working mechanisms of the internal gear pump,the calculation formulas of the basic parameters of the gear pair are obtained,then the mathematical model of the instantaneous flow rate,displacement and flow pulsation coefficient of the pump is established based on the calculation formulas.2.Two dynamic simulation models of the instantaneous flow rate,displacement and flow pulsation are built by MATLAB/simulink,and then the influence of the gear pair parameters on the instantaneous flow rate,displacement and flow pulsation coefficient of the pump is analyzed.3.According to measure the actual dimensions internal gear pump and the basic parameters of the gear pair,drawing and assembling of the internal gear pump model is completed.The changing situations of the pressure and velocity in internal flow filed of the gear pump are analyzed from the pump starting to work to getting stable situation by the dynamic mesh.The results show that the pressure and velocity in internal flow filed are gradually increasing until they reach a stable working state during this process.4.Fluid-structure interaction analysis are done for the gear pair and the Intermediate pump body,and modal analysis is done for the Intermediate pump body,the results of fluid-structure interaction interaction show that the maximum deformation and force of the gear pump and the medial pump body are much less than the yield limit of the gear pair and the medial pump body,therefore,they won't affect the performance of the pump.The results of modal analysis show that the natural frequency of the pump body are different from the frequency of the flow pulsation generated by the internal gear pump when it is working,thus there won't generate the resonance.There are 84 pictures,2 tables and 53 references in this article.