Design And Key Technology Research Of Friction And Wear Testing Machine Based On Friction Pair Of Plunger Pump

In recent years,people have higher requirements for the stability and friction quality of metal materials testing.Whether the actual working conditions of the service workpiece can be simulated more truly is the key factor to determine the depth and accuracy of tribology research.At present,most of wear testing machines are used to provide stable static load for friction test,but it is obviously not suitable for some parts with special service conditions,such as port plate and sliding shoe for plunger pump.The actual working condition of such parts is variable load,high seed,high temperature,lubrication,etc.So it is important to design a wear testing machine that can provide variable load.Based on the analysis of the variable load theory and the working principle of the electromagnetic exciter,the mechanical system of the variable load test machine is designed in detail with the stress of the key friction pairs of the swashplate axial piston pump as the design standard of the test machine.The static simulation and response analysis of the key components of the test machine system are carried out through the ANSYS Workbench,and the dynamics of the damping design mechanism is carried out by Adams Simulation analysis.The main work of this paper is as follows:(1)The movement form of the plunger in the swashplate axial piston pump,the force analysis of the plunger and the force mode between the port plate and the cylinder block in the swashplate axial piston pump were established.The main force factors affecting the wear failure of the above friction pairs were analyzed.The heat treatment process of slipper and valve plate,which were the friction pair materials under the testing machine,was explored,and the mechanical properties of complex brass were analyzed,which provided theoretical basis for the design of variable load testing machine.(2)A kind of friction and wear testing machine which can provide periodic variable load was designed.The working principle of the variable load testing machine was introduced.The measuring mechanism of friction coefficient under the condition of variable load and the measuring methods of some key parameters were given.The test machine can achieve the following technical indicators: 10-500 N loading force,40-400 Mpa friction stress,1000-3000 rpm speed,17-50 Hz frequency,oil lubrication,heating temperature of 0-100℃.(3)The three-dimensional assembly model of the variable load wear tester was established by UG,and the two-dimensional assembly drawing of the tester was given.The peripheral motion system,load changing system,clamping system and measurement and control system of the whole testing machine system were designed in detail,and the main body of the testing machine was designed.(4)Through the software ANSYS Workbench,the static simulation of the whole machine,the rotating spindle and the support platform was carried out.The total deformation,the deformation in the X,Y and Z directions of the above three mechanisms were analyzed,and the equivalent effect variation nephogram and the equivalent stress nephogram of the three mechanisms were given.The harmonic response analysis and response spectrum analysis of the whole machine mechanism were carried out,and the strength and rigidity check were completed.(5)The vibration characteristics of the electromagnetic exciter were analyzed.The equivalent stiffness and mass of the damping rod were calculated.The modal neutral file was generated by ANSYS,and the flexible bar model was generated by the joint simulation with ADAMS/view.The multi-body dynamics simulation of the damper was carried out by ADAMS.