A Mathematical Model of Elastohydrodynamic Lubrication in a Rolling Bearing

Abstract

There is always a demand in the industry sector to increase the efficiency of machine components to reduce wear and tear. Most machines operate under fluid film lubrication, which is known as elastrohydrodynamic lubrication (EHL). Thermal behavior is also an important aspect since most machines operate under heavy loads, high speeds, and rough surfaces. Previous research on Thermal Elastrohydrodynamic lubrication (TEHL) under full film lubrication has focused on Newtonian lubricants. The present study focuses on developing a realistic model for a non-Newtonian lubricant of rolling bearing capable of mathematical simulation of the lubrication regime. The mathematical model consists of the Reynolds-Eyring and film thickness equations, density and viscosity equations for the rheology of lubricant, which depends on pressure and temperature, and the energy equation due to friction, which leads to thermal effects of the lubricant. These equations are discretized using the finite different method and simulated by Matlab. The film thickness, pressure and temperature profiles are also presented on how various parameters affect them. The results provide insight into the effective design of the bearing and lubricating fluid. This research indicates that the viscosity, density radius of rolling elements and speed affect the lubricant film thickness and pressure. Moreover, the lubricant is affected by changes in its temperature. Furthermore, the research forms a foundation for further research in Elastohydrodynamic Lubrication of bearings and proposes an efficient and reliable model for thermal Elastohydrodynamic lubrication for rolling bearing that can reduce friction and wear.