Research On Rolling Bearing Operational Reliability Analysis Method Of Go Line Department In City Rail Train

ABSTRACT:Rolling bearings of go line department in city rail train play a role in absorbing and transmitting load, its reliability directly affects the overall performance of the train and its immediate failure will bring huge losses of life and property. Traditional reliability research did not consider the influence of the running state on reliability, and also ignored the difference between the individual and overall reliability. Therefore, it has important theoretical and practical significance to explore the relationship between running status and reliability and realize real-time reliability evaluation of rolling bearings in coordination with the available online condition monitoring technology.Proportional Hazards Model (PHM) establishes the connection between the equipment running status covariates and reliability statistics, so as to continuously update reliability index, and provide the basis for the decision-making of preventive maintenance. Accordingly, the main aim of this thesis is to design the PHM for rolling bearings of go line department which can be applied in the decision-making process of condition-based maintenance (CBM) and enriches reliability theory study in China at the same time, based on a general idea including data acquisition, covariate selection and calculation, model hypothesis testing and parameter estimation according to PHM theory. Specifically, the content can be abstracted as follows:(1) According to the failure life and vibration data obtained from the rolling bearing vibration test, based on the integration of traditional reliability modeling techniques and vibration signal characteristics analysis, the Kurtosis and RMS of vibration characteristics is picked as covariates of the proportional hazard model to form a new reliability evaluation model of rolling bearing-Weibull Proportional Hazards Model (WPHM) by taking Weibull as the benchmark distribution. The PH hypothesis test verifies the validity of this model. The parameters of WPHM are estimated by using maximum likelihood estimation (MLE) method to draw the operational reliability and failure rate curve of rolling bearings of go line department.(2) Aiming at the problem of complexity and difficulty of parameter estimation of multi-parameter WPHM, the faster convergence of the parameter estimation is realized and the efficient algorithm of reliability evaluation process and stability of the calculation results are achieved through improving constriction factor PSO (CFPSO) algorithm whose objective function is also the maximum likelihood function because of the advantage of maximum likelihood estimation method.(3) The operation reliability calculation is applied in the decision-making of CBM mainly. By taking maximum availability as objective, the threshold of fault rate and decision-making curve are calculated and drawn respectively based on the operation reliability evaluation of rolling bearings by using PHM, so as to determine whether or not the running status of rolling bearings satisfies the requirement of preventive maintenance and maximize the use value of rolling bearings.