Development Of Testing Device For Port Pair And Plunger Pair Of Axial Piston Pump

Axial piston pump is an extremely complex,which requires accurate cooperation between friction pairs to ensure stable energy conversion.The port pair and plunger pair are the most important friction pairs of axial piston pump.The two friction pairs achieve volumetric periodic oil absorption and oil discharge functions through mutual cooperation,and their performance determines the efficiency and service life of the pump,Therefore,the premise of developing excellent performance axial piston pump is to have a complete and advanced testing device to measure and evaluate the dynamic oil film parameters of friction pair.Aiming at a military axial piston pump,this paper first analyzes the distribution law of oil film thickness and pressure of port pair and plunger pair under different working conditions through modeling and simulation,and then designs a special oil film test device to test the oil film parameters of two friction pairs of piston pump,so as to accurately and comprehensively evaluate and optimize the performance of piston pump.According to the structural form and working principle of piston pump,the solution models of oil film thickness and pressure distribution of two friction pairs are established respectively.The pressure control equation is deduced through Reynolds equation and Navier-Stokes equation.It is discretized by difference grid method and finite volume method,solved by SOR iteration method,and the oil film distribution law under different working conditions is obtained.Based on the idea of model pump,the mechanical structure of the test-bed of two friction pairs is designed respectively.The test-bed of port pair adopts the structure of port plate and friction plate.The testbed of plunger pair designs the structure of single plunger cylinder body and balance plunger pair,and plans the measuring points,selects and installs sensors.The hydraulic system of the test device is designed.The power pump station adopts the pump controlled hydraulic circuit.The system parameters are calculated and verified according to the principle of volume speed regulation.The oil supply pump station meets the two-way oil supply demand of the test bench,and the key components are selected at the same time.Design the measurement and control system software,calculate the sampling frequency of a single channel of the test system based on Nyquist-Shannon theorem,select the data acquisition card,design the data acquisition program,allocate the sampling channel,control the sampling process,design the visual working interface of the test software according to the functional requirements,and design the filtering and storage mode in detail.Finally,the working performance of the test device is verified through experiments,and the oil film thickness and pressure parameters of the two friction pairs under different pressure conditions are tested.Through the analysis results,the influence law of pressure conditions on the oil film characteristics of the two friction pairs is obtained,and the correctness of the oil film characteristic simulation model is verified.