| In recent years,our country’s high-speed rail industry has developed rapidly.As of February 2022,the operating mileage of our country’s high-speed rail has exceeded40,000 kilometers,which puts forward higher requirements for the safe and stable operation of high-speed rail.The bogie is an independent running device supporting the car body,which directly determines the running stability of the high-speed train.The traction motor is installed in it to provide power for the high-speed train.Bearings and rotors,as key components in traction motors,play an important role in motor operation.At present,the research and manufacturing capacity of high-performance high-speed train motor bearings in our country is insufficient.Therefore,it is necessary to improve the design and evaluation technology of reliability and fatigue life of traction motor bearings.In recent years,the research on high-speed train traction motor bearings has mainly focused on the fault diagnosis of the bearing,compared with less research on the damage mechanism of the bearing.The research on dynamic simulation fault simulation and life estimation of bearings can be helpful in bearing manufacturing and processing.It can also provide theoretical basis and foundation for fault diagnosis and online real-time monitoring of rolling bearings to a certain extent.In this paper,the surface stress,subsurface stress and deformation of the contact area generated by the surface of the rolling element and the ring under static load are first calculated according to the Hertzian contact theory,so as to infer the load distribution of the bearing under different clearance,and calculate the rated value of load without permanent deformation.Secondly,the rotational speed and friction torque of the bearing during rotation,the centrifugal force and gyroscopic moment of the bearing at high rotational speed,and the lubrication state of the rings and rollers are considered to build a motion calculation model of the bearing during operation.In addition,a onedimensional bearing-rotor system model was built in COMSOL to simulate the operating states of two types of bearings in high-speed train traction motors,and to explore the influence of bearing clearance on the rotor and bearing trajectories,vibrations,and torques.Aiming at the deep groove ball bearings and cylindrical roller bearings installed on the traction motors of high-speed trains,three-dimensional modeling and finite element analysis of the two kinds of bearings are carried out in this paper.For the cylindrical roller bearing,the stress and deformation calculation of the contact area under the ideal line contact form is established.This paper realizes the bearing simulation of four different shapes of rollers through ANSYS to explore the influence of the roller shape on the contact stress and deformation of the cylindrical roller bearing.The load-deformation relationship considering centrifugal force at high speed is established,and it is confirmed by finite element simulation.For the simulation of deep groove ball bearings,the theoretical calculation of the stress and deformation of the point contact form of the steel ball-raceway contact area of the ball bearing is carried out in this paper.Modeling analysis of deep groove ball bearings under load,and using finite element method to carry out dynamic simulation analysis of bearings under different loads,different speeds and bearing damage at high speeds to explore their motion states under various working conditions and stress changes.Finally,starting from the bearing surface contact fatigue,this paper analyzes the influence of bearing load on bearing life,applies damage accumulation theory,introduces stress-life coefficient,and considers multiple influencing factors to correct the calculation of life.Estimate and analyze the life of different cylindrical roller bearings and ball bearings under different working conditions. |
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