Life Prediction And Predictive Replacement Decision Research Of Piston Pump Based On Nonlinear Wiener Process

As a key component of hydraulic system,piston pump is called the "heart" of hydraulic system because of its high load and high power.Because of its characteristics of small flow fluctuation,high volume efficiency,long life and economy,it is widely used in aerospace,military industry,heavy duty machinery and other fields.The oil suction and discharge process of the piston pump is completed by the relative movement of the components,The friction of the components in this process cannot be ignored.The most important three pairs of friction pair are the piston pump slipper parts and swash plate composed of the slipper pair,piston pump plate and cylinder block composed of the distribution pair,piston pump piston and piston hole composed of the piston pair.Because the friction pair is in the environment of high pressure and high specific pressure,the friction pair is one of the fault points of the piston pump,and its performance is good or bad,directly affect the life of the piston pump.However,the safety,economy and reliability of piston pump can be improved effectively if proper maintenance strategy is adopted.Predictive maintenance and replacement decisions are concerned because they are more forward-looking and more adaptable to production.Therefore,this paper takes the axial piston pump as the research object,and USES the leakage return oil flow rate characterizing the degradation process to conduct predictive maintenance and replacement research,which can provide the premise foundation for the health management of the axial piston pump.The main contents of the paper include:Firstly,the theoretical methods used in this paper are introduced as the knowledge background,mainly including the establishment of Wiener process,the detailed introduction of parameter estimation method,the introduction of the optimal benign test method of model optimal benign selection,and the introduction of the update process and the update reward process.Secondly,the structure,working principle and failure mechanism of axial piston pump are introduced.According to the Wiener process in background knowledge,the degradation model of piston pump was established by using the external characteristic quantity of piston pump,and the optimal degradation model was obtained by the optimal benign test.At the same time,on the basis of the optimal degradation model to construct the axial piston pump remaining service life prediction model,and will build the remaining service life prediction model for example,it is concluded that with stochastic effect power function of the structure of the linear and nonlinear Wiener process model predicted results is better than the other two kinds of nonlinear Wiener process model,closer to the axial piston pump degradation in the process of actual life.Finally,the predictive maintenance and replacement research is carried out on the basis of the prediction model of the service life of the piston pump in the nonlinear Wiener process with random effect power function structure.Predictive maintenance and replacement planning is based on the renewal compensation model to maximize.The process is to use the current equipment observation data to predict the remaining service life of the equipment,substitute the remaining service life into the predictive maintenance and replacement model,and obtain the optimal predictive maintenance and replacement point of the equipment under the long-term operation by finding the maximum unit average return rate under the remaining service life.Finally,the feasibility of predictive maintenance replacement model is proved by an example,and the sensitivity analysis of the key parameters of the model is carried out,and the influence of parameters on the average unit return rate is obtained.