| Axial piston pump,due to its unique structural characteristics,its has the advantages of high efficiency,strong self-priming capacity,coupled with the variable axial piston pump with a wide range of forms,can according to the different needs of users to transform the way of working,simple operation and long working life.In recent years for the reliability of the axial piston pump requirements with the development of science and technology and the market also gradually increase,but because the present domestic related reliability test is not enough to solid,sample information collection is not complete,energy consumption is too high,so the new type of axial piston pump reliability test is particularly necessary.This paper studies the reliability test and life evaluation of axial piston pump on the basis of the national key research and development program sub-project "Research on reliability and Life Experiment Evaluation Technology of High pressure Plunger pump/Motor" led by Weichai Power Co.,Ltd.,with Jilin University as the main responsible unit.In order to improve the reliability of hydraulic parts such as axial piston pump and motor,this paper provides a reference for the reliability test research and optimization of hydraulic parts in the future through the combination of theoretical research and test data analysis.Firstly,the failure cases of axial piston pump are collected and collected by using the failure tree analysis method and a large number of cooperative enterprises.Four typical failure modes of axial piston pump are obtained,and the failure reasons and corresponding improvement measures of the failure cases are also described in detail.On this basis,a failure case database of axial plunger pump is compiled in combination with programming language.The objectives and tasks of the failure case database are described,and the functional requirements and module realization are introduced in detail.The database is used to collect failure cases for a long time to facilitate weibull analysis with the support of a large number of axial piston pump failure data.Next several common laboratory on power recovery unit and accelerated life testing scheme were analyzed,this paper chose the recycling effect good electrical recycling way,and can better fit the actual loading condition of varying stress accelerated plan,formulated the corresponding testing scheme,according to design principle diagram of hydraulic system of the matching axial plunger pump accelerated life test equipment reliability,and play an important role in detail elaborated the auxiliary hydraulic system and real-time monitoring and control system,also made a selection for key parts.The power recovery principle of the system is analyzed,and the actual overall power recovery of the test bed is compared with the theoretical recovery value,which shows that the difference between the two is not big,which proves that the power recovery method selected in the test is feasible and effective,and the energy-saving effect is significant.Finally the measured in experiment and dismantling the axial plunger pump inspection,find the failure reason for local failure,after compared the characteristics of the probability distribution model of several common choice for the test failure characteristics of the two parameter weibull lifetime distribution,also selects the inverse power law model to analyze the characteristics of the measured axial plunger pump life and the relationship between the pressure stress;Based on volumetric efficiency determine the axial plunger pump failure,and by using maximum likelihood estimation method and in combination with three parameters test degradation data to solve the distribution function,which is obtained by Matlab software related to the reliability of the measured axial plunger pump function and curve,and calculate the test characteristics under the selected variable stress accelerated life expectancy and life expectancy,completed the life evaluation of the measured axial piston pump. |
