Lubrication Effects on Rolling Bearing Dynamics: Modelling and Analysis

Rolling bearings, critical in various rotating machinery, significantly influence system performance including reliability. However, the impact of lubricating properties on bearing vibration characteristics remains inadequately explored despite its crucial importance in improving the performance and elucidating fault mechanisms. This paper introduces a dynamic model that incorporates lubrication effects, time-varying friction forces between rollers and raceways, as well as contact and friction forces between rollers and the cage. The model includes self-rotation and revolution of the roller, along with the revolution of the cage, enabling analysis of the bearing's slippage behaviour. Through a series of simulations involving various viscosity pressure coefficients, the study explores the effect of lubricant viscosity on oil film thickness, internal forces, dynamic responses and slip properties of the bearing. It has found that increasing viscosity leads to lower characteristic frequencies and more pronounced slippage. Moreover, higher viscosity levels result in more significant deviations between simulated characteristic frequencies and their theoretical values. This research offers new insights into bearing tribo-dynamics, offering a theoretical basis for bearing condition monitoring and fault diagnosis.