Research On Life Evaluation Method Of Axial Piston Pump Based On Degradation Test

As the power source in the hydraulic system,the hydraulic pump always occupies a pivotal position.Among all types of hydraulic pumps,axial piston pumps stand out in high-pressure and high-power systems because of their better sealing performance,high rated pressure,and easy flow adjustment.The life of the axial piston pump is related to the smooth operation of the entire system,and its degradation state is also related to the performance.In this paper,the life evaluation method of the axial piston pump is researched.Firstly,the failure mechanism is analyzed theoretically and the experimental research is carried out.Secondly,the analysis model of the whole pump life is determined and deduced.Finally,on the basis of the above research,the life test and analysis of the whole pump are carried out.The evaluation method adopted for the life of the axial piston pump is the degradation test method,and different life analysis models are established for the life failure of the axial piston pump products in different periods.And through the whole pump life degradation test,the life of the axial piston pump is evaluated.An important step before life analysis is the study and analysis of failure mechanism.Nowadays,domestic and foreign scholars have generally believed that wear is one of the main reasons that restrict the life of the axial piston pump.Therefore,the friction and wear analysis of the three friction pairs in the axial piston pump is carried out by using the wear theory at first,so as to obtain the expression of the wear quantity of the three friction pairs,determine the sensitive stress affecting the wear,and provide a theoretical basis for the subsequent life analysis.The friction and wear test is carried out for the valve pair.The influence of relevant factors on the wear was obtained by orthogonal tests,and the microscopic properties of the material surface are observed through the electron microscope photos,and the wear mechanism under rated conditions are analyzed.After that,the ultimate wear test is carried out to explore the changes in the wear mechanism under the extreme conditions,and the limit PV value of the material was tested to ensure the unity of failure mechanism in the life test.Finally,the degradation model of the axial piston pump is established.Considering the different situations encountered in the actual test,the competition model of sudden failure and degradation failure,the fusion model of degradation data and life data and the accelerated degradation model are established,respectively;and then in combination,the degradation test of the entire axial piston pump is carried out to evaluate the life of the axial piston pump.The whole pump test also indirectly proves the validity of the model.