Analysis of transient lubrication and wear coupling behaviors considering thermal effect and journal misalignment for main bearings under dynamic load

Abstract

This study developed a numerical model that coupled transient lubrication and wear in misaligned main bearings under dynamic loading conditions. This model accounts for variations in oil film thickness attributable to journal misalignment, elastic deformation, wear, and temperature fluctuations during the operational cycle of the bearing. Validation of the model's accuracy is achieved through comparisons of bearing temperature, and wear depth. An extensive analysis is conducted on the temporal evolution of temperature, contact pressure, oil film pressure and thickness, wear depth, and wear loss. Comparative assessments between misaligned and aligned bearings are performed. The findings reveal that in cases of journal misalignment, wear depth and contact pressure predominantly accumulate on the edge side, with the maximum wear depth, peak oil film pressure, peak asperity contact pressure, and temperature significantly exceeding those in aligned conditions. Furthermore, to underscore the importance of incorporating temperature in the coupling model, a comparative analysis of lubrication and wear characteristics between isothermal and thermal models across varying radius gaps is conducted. It indicates the necessity of factoring in temperature effects when assessing lubrication and wear properties. It is observed that bearing temperature tends to decrease correspondingly with wear progression.