Research On Influence Mechanism Of Lubrication Technological For Wheelset Press-fit Quality And Its Experiment

The interference connection of wheelset press-fit process is the friction under normal load. The asperities size of wheelset contact surface is much larger than that of molecular, lubricant film produced in a State of extreme pressure play a major role in lubrication and friction reduce function. The analysis on the lubricant medium to the quality of wheelset press fit not only seeking the best technological lubrication state, but also studying the fundamental theory of lubrication mechanism. This paper carry out comprehensive and systematic researching on the friction and lubrication theory of interference fit, the lubrication forming mechanism of wheelset press fit, the microcosmic property influence factor analyzing of wheelset press fit, macroscopic analysis of experiments and technological priority of wheelset press fit.Firstly, the lubrication state is judged according to the state and properties of lubricant film, the forming mechanism of lubricant film,oil analysis properties,and the technological parameters of contact surface. The relevance of friction and lubrication theory of wheelset contact surface is established to analyze the lubrication state of different working condition parameters. This paper also analyzes the failure mode of the boundary lubricant film and different lubrication medium.Secondly, wheelset press-fit mathematical model is established to simulating the lubrication state of lubrication medium under the normal load and studying the process of fluid lubrication transform to boundary lubricant on the wheelset contact surface. The contact surface of HXN5's hub hole is calculated on the basis of elastic mechanism to analyze the bearing mechanism when the thread curve enter the wheel seat, at the same time, the lubrication state is divided in this process. Considering the condition of HXD2 and RE2 B wheelset contact surface, this paper put forward an idea of lubricant lube in the asperity scallops releasing the function of secondary lubricating and normal load bearing. MATLAB simulation is used to verifying the lubrication mechanism of contact surface and the stress bearing form.Finally, some experiments have been carried out to study the influence of lubricant and technological parameters to the wheelset press-fit process. Based on the measured relationship between the technological parameters and friction coefficient,a Stribeck curve chart is draw to illustrate the lubrication state. At the same time, the correlation between strain of wheelset contact surface and lubrication state is studied. The purpose of experiments is amended for acquiring the range application of lubrication technological, estimating the effect lubricating effect of the lubrication medium and putting forward appropriate measures for lubrication technological improvement.