Performance Degradation Modeling And Maintenance Strategy Optimization Of Hump Vehicle Retarder Gear Pump

As an important speed regulating equipment in marshalling station,hump vehicle retarder plays an important role in vehicle deceleration marshalling.The gear pump is the core power component in the vehicle retarder system,and its running state is very important to the normal operation of the retarder.With the increasing workload of marshalling station and the increasing axle load of vehicles,the requirements for the reliability and safety of the retarder are becoming higher and higher.However,at present,there is no specific operation and maintenance strategy for gear pump in the operation and maintenance strategy of vehicle retarder,so it is necessary to formulate correct maintenance strategy to enable vehicle retarder to obtain higher reliability and better economic benefits during operation and maintenance.Therefore,the main work of this thesis is as follows:（1）Combined with the structure and working principle of vehicle retarder and gear pump,the performance degradation mechanism and leakage of gear pump are analyzed,and the influencing factors of gear pump degradation are determined.Through the combination of mechanical library and hydraulic Library in AMESim,the braking process of vehicle retarder is simulated,and the influence of the performance degradation of gear pump on the performance of vehicle retarder is obtained.（2）According to the requirements and data characteristics of data acquisition,a complete set of gear pump data acquisition system is designed by using G language programming language and NI Lab VIEW software graphical programming environment.The collected original data of gear pump are preprocessed,and the performance degradation models of three retarder gear pumps are established through Wiener process.Through step-by-step estimation,the least square method and maximum likelihood method are used to estimate the parameters respectively.The optimal model is found through statistical calculation,and the corresponding distribution function is given.It provides a reference for the degradation modeling of gear pump.（3）Analyzed the current operation and maintenance strategy of hump vehicle retarder and put forward the disadvantages of the existing operation and maintenance strategy.Based on this problem and combined with the degradation process model established for vehicle retarder gear pump,the preventive replacement strategy model of gear pump is established to obtain the long-term operation cost rate function and calculate the minimum value of the cost rate function,That is,the preventive replacement time point of the gear pump when the operating cost is the minimum（the yield is the maximum）,that is,the start and stop times of the gear pump.And for additional cost₀)and preventive replacement costconducted a sensitivity analysis and concluded that the preventive replacement costand additional cost₀)effect on cost rate function.The research results provide a certain reference value for the operation and maintenance strategy of hump vehicle retarder.