Research On Life Prediction Of Axial Piston Pump With Three Parameter Weibull Distribution

The hydraulic pump is the core power component of the hydraulic system,especially the axial piston pump is widely used in the field of industry and engineering.The life prediction of axial piston pump is of great help to the plan of maintenance and support for the whole machine.At present,research on hydraulic reliability engineering is much more in the domain of aerospace,military,as against less in civil area.Therefore,Combined with engineering practice,the life prediction of civil axial piston pump is studied,and the three parameter Weibull distribution model is put forward to calculate the life of axial piston pump.The dissertation does the failure analysis for axial piston pump by means of FTA and gets the main failure mechanisms and stresses of hydraulic pump,then,reveals the cavitation characteristics and internal leakage mechanism.Establishing a three parameter Weibull lifetime distribution model by comparing several common probability distribution models.In view of the genera parameter estimations of Weibull distribution,a combination of correlation coefficient method and genetic algorithm is proposed to estimate the parameters.And the mathematical model is established and the mathematical deduction is carried out.Finally,the estimated value of three parameters is obtained.This dissertation uses 6 test samples.In view of the life prediction test power and timeconsuming problem,the experiment scheme is designed for axial piston pump life prediction on the basis of recovery technology,and two hydraulic systems of the same principle life prediction test device are designed.Based on volumetric efficiency degradation data,nonlinear least squares method is used to get the optimal degradation model search strategy,simultaneously,the pseudo failure life of axial piston pump is obtained through the optimal degradation model.The three parameter Weibull distribution is used to predict the life of axial piston pump.Finally,the life prediction model,reliability function model and failure rate model of the three parameter Weibull distribution of the axial piston pump is obtained,and the life of the axial piston pump in 35 MPa is calculated according to the life prediction model.