The Effect of Surface Morphology of Tapered Rolling Bearings in High-Speed Train on Grease Lubrication

Abstract

With the extensive coverage of the rail transit system, ensuring the safe operation of rail vehicles is an important prerequisite. Insufficient lubrication will cause friction and wear of axle box bearings, which is directly related to ensured safety of high-speed trains. A non-Newtonian elastohydrodynamic lubrication(EHL) between tapered rolling elements and inner ring of axle box bearing in high-speed trains was established by numeric simulation. The input parameters of working conditions, including velocity, acceleration and plastic viscosity, were changed, considering the actual application and their influence trends on film-forming characteristics were analyzed. As a result, a phase of acceleration of starting or a process of braking at a low speed tends to occur mixed lubrication. Therefore, a method of optimizing surface morphology of rolling elements was adopted to improve lubrication. Based on comparison experiments, it was recommended that RMS roughness was greater than 0.03 μm and less than 0.1 μm and kurtosis was three and skewness was negative in a range of −1 to −0.5 and texture direction was parallel to rotation direction. The optimized surface promotes the transition from mixed-lubrication to full film lubrication, which alleviated the problem of surface damage due to insufficient lubrication and prolongated the service life.

An improved TEHL analysis of textured roller bearings consider various texture parameters and slip

“…Rosenkranz et al(2019) summarized the state of the art of surface texturing applied to machine elements, focused on surface texturing to sliding and rolling parts. A method of optimizing surface morphology of rolling bearing was adopted by Wang et al(2020) to improve lubrication; the optimized surface promotes the transition from mixed lubrication to full film lubrication, which alleviated the problem of surface damage because of insufficient lubrication and prolongated the service life. By integrating the micro-texture model and HL method, Han et al(2020) built the oil film pressure distribution and load capacity analysis model, and then the pressure distribution and oil film load capacity of the textured rolling bearing under the various texture dimension and texture type are analyzed; however, the analysis of temperature distribution is missing.…”