Research On Instantaneous Flow Characteristics Of Swash Plate Axial Piston Variable Pump With Cross Porting Valve Plate Based On Compressible Media

Swash plate axial piston pump is widely used in various fields of industry because of its compact structure,fast variable response,high power density and efficiency.In order to improve the stability of the pump as much as possible,the opening valve plate is often used.In this paper,the swash plate axial piston variable pump with cross porting valve plate is taken as the research object,and the influence of compressible medium on the instantaneous flow characteristics of the pump is studied by the method of theoretical analysis and numerical simulation.In the first chapter,the research background and significance of this paper are summarized.The development of piston pump structure,the research status of compressible medium and the main content of this paper are introduced.In the second chapter,based on the comprehensive consideration of the angle of swash plate,the cross angle of swash plate and the angle of piston,the general model of piston kinematic model is established by using coordinate transformation method,and the kinematic characteristics of piston under different structure combinations are analyzed.In the third chapter,the existing models of compressible media are analyzed and compared,and the most suitable variable bulk modulus compressible model of media is selected.In the fourth chapter,the instantaneous characteristic equation of the pressure in the single piston chamber is established,the transient transition process of the pressure in the single piston chamber and the instantaneous flow characteristics of the piston pump are analyzed and compared based on the constant bulk modulus model and the variable bulk modulus model,and the instantaneous flow characteristics of the pump under the variable working conditions are studied.Finally,the paper analyzes and summarizes the content of the article,points out the shortcomings of this paper and the direction of further research in the future.The main conclusions of this paper are as follows:1)The angle of swash plate,the cross angle of swash plate and the angle of piston all affect the movement characteristics of piston and the flow characteristics of piston pump;2)Considering the leakage between the three friction pairs and the flow loss of the triangular groove of the swash plate axial piston variable pump with cross porting valve plate,the volume efficiency of the swash plate axial piston variable pump with cross porting valve plate is mainly affected by the flow loss from the triangulargroove;3)When the pressure in the piston chamber is lower,the change gradient of the instantaneous pressure in the piston chamber from the constant bulk modulus model is bigger than that from the variable bulk modulus model;4)The minimum value of instantaneous flow of the piston pump from the constant bulk modulus model is larger than that from the variable bulk modulus model.