Thermal contact resistance for stationary and moving heat sources in angular contact ball bearings

Abstract

Sliding friction is a common tribological effect that occurs between the contact surfaces of the inner components (inner race, outer race and balls) of a spindle rolling bearing during operation. This friction generally generates heat, which can affect the performance of the rolling bearing. To date, numerous studies have assumed that the contact surface between the inner components of the bearing is circular and stationary. While this assumption has yielded adequate results, it is not sufficient in the case of angular contact ball bearings, where the contact surfaces are elliptical and could be treated as either stationary or moving heat sources. This paper presents solutions for both, stationary and moving heat sources for elliptical contact surfaces in a spindle rolling bearing. The primary objective is to find the thermal contact resistances which are dependent on the shape of contact, the loads, the rotational speed and the material properties thereof, applying the mathematical expressions developed by Muzychka and Yovanovich. These expressions were used to calculate various thermal resistances, providing results applicable to the analysis of thermal models in spindle rolling elements. Through finite element analysis (FEA) performed in Ansys Workbench, the stationary and moving heat sources were compared, finding the heat distribution along the elements of the bearing. The findings herein are suitable for the creation of thermal networks in rolling bearings, which are essential to predict their thermal behaviour.