A Multiphysics Model of a Lubricated Ball-on-Flat’s Thermal Resistance

Post date: July 13, 2020
Student: Indronil Ghosh
Faculty: Timothy S. Fisher
Sponsor: The Aerospace Corporation

Summary: Ball bearings are commonly used to reduce the friction in rotating mechanical systems. The thermal constriction resistance between ball and raceways produces poor heat removal rates, so that in most terrestrial applications, convection dominates the cooling process. In the vacuum of space, air is not present, and thus convection cooling is not available; consequently, the bearings themselves provide the primary thermal conduction pathway between shaft and housing. Developing a clear understanding of thermal conductance through a bearing is important for prediction of spacecraft bearing temperatures, which in turn affect life considerations for the mechanism. The present work reports an improved analytical technique to model bearing thermal conductance.