Study On Reliability Test Method For Short-time Axial Plunger Pump

Axial piston pump used widely in engineering vehicles,aeronautics and Astronautics,ship heavy industry and other engineering fields,as the core power element of hydraulic transmission and the advantages of high power density,easy realization of high speed regulation,large speed range,quick action and easy manufacture and use.The axial piston pump is used as the core element to ensure the normal operation of the equipment,and to meet the demand of higher and higher reliability of the market,therefore,it has important practical application value for the reliability analysis of axial piston pump.But the axial piston pump has the characteristics of large power and long life,and its reliability test has always been the problem of long test cycle,high energy consumption and high cost.For this reason,a short-time reliability life test rig is set up in combination with actual conditions,and the short-time reliability parameters of the domestic A4 VS axial piston pump are analyzed.Based on the principle of mechanical compensation power recovery,the reliability experiment platform is designed and debugged by the calculation and analysis,the test scheme for the short-time reliability test of the axial piston pump was determined,at the same time,the state monitoring signals were selected,and the matching calculation of the speed and the flow rate was carried out,the theoretical analysis of the effect of power recovery was also carried out.According to Weibull life data statistical analysis method,the test data were processed,and volume efficiency was chosen as the basis of failure judgement.Based on the degradation data,the reliability life distribution model of axial piston pump was obtained based on the conventional mathematical statistics method,by comparing the reliability data of the test with the conventional reliability parameters,the feasibility of the short-time reliability test method was verified by the test results,which saved hundreds of hours of the test time under rated pressure.Finally,based on the performance degradation theory of axial piston pump and the volume efficiency degradation data,we get the volume efficiency degradation model of the tested sample by programming quickly and accurately.The mixed Weibull method was introduced,and the degradation model was optimized.By mixing Weibull graph and least square method and combining with expanding the failure time of sample test,we got the unknown parameters of mixed Weibull distribution function.At last,the accuracy of the hybrid Weibull graph method and the least square method were verified by the K-S nonparametric hypothesis test,and the accuracy of the least square method of mixed Weibull was verified by comparison.