Coupled Vibration Of Flexible Wheel-rail Under The Irregularity And Lubrication Analysis Of Bearing

Railway transportation is currently the main tools of transport in china, playing a key role in economic and social development. With the rapid development of china’s economy, the timeliness of railway transportation has been unable to meet the growing demand. Thus, development of high-speed and heavy technology has become an inevitable trend, and railway vehicle and track technology made further higher requirements. Railway bearing system is one of the most important components of a railway vehicle system. In the course of the vehicle’s work, because of the irregularity of the rail excitation and other factors, the wheel-rail system is subject to strong vibratory shock, while it’s the one cause of fatigue damage. And large vibration will directly affect the operation safety and stability of vehicle. Secondly, grease lubrication usually is made for railway bearing system, with its good lubricating performance and long life, which is directly affecting the service life of bearing system. Therefore, the study about vibration characteristic and lubrication property of the railway bearing system, is not only a study that has academic value, but also a research that has important practical significance and broad application prospect.In this paper, with the numerical calculation and analysis tool MATLAB for simulation, based on the theory in structural dynamics and fluid mechanics, the railway bearing system used as the research object, researching railway bearing system’s frequency response and random vibration response etc. On this basis, further study about lubrication performance of railway bearing system considering temperature effects was made. Culminating in the actual project cases, verifying the validity of the theoretical model in the method. This paper’s work will provide a theoretical basis and reference for the structure optimization design of railway bearing system, vehicle stability and dynamics performance evaluation. The main research work are as follows:Firstly, based on the bearing coupling contact model and wheel-rail dynamic space coupling contact model, wheel-axle-rail system’s coupled dynamic model was made with using the way of combining lumped parameter method and the finite element method. The model takes fully account of the shaft’s flexible deformation, nonlinear time-varying contact bearing load, rail’s vibration and other factors, through the analysis of the mechanical characteristic of each subsystem, using the basic principles of Newton, establishing the equations of wheel-axle-rail. And comparing with the rigid wheel-rail model, Analysis of the influence of the shaft’s flexible deformation on wheel-shaft-rail’s system was made.Secondly, based on the basic theory of grease lubrication, structural parameters and kinematics of railway bearing system, considering thermal effect, the lubrication analysis model of double tapered roller bearings was established. And the analysis of the influence of working parameters and temperature effect on the lubricating properties.Finally, to illustrate the accuracy of the present theory model and the method, take a railway truck bearing as the research object, instances show that the wheel-axle-rail system dynamics model and lubricating properties analysis method has a high reliability, which can provide reference for the wheel-rail system’s design, verification and reliability analysis.