Theoretical Study on the Thermal Contact Resistance of a Space-Use Deep Groove Ball Bearing

Abstract

The thermal contact resistance between the balls and the inner and outer rings of a space-use deep groove ball bearing is analyzed assuming that heat transfer between smooth contacting elements occurs through the elastic contact areas. It is also assumed that the stationary bearing sustains axial and/or radial loads under steady-state temperature condition. The shapes and sizes of the contact areas are calculated using the Hertzian theory. The thermal analysis is based on an isolated isothermal elliptic contact area supplying heat to an insulated half-space. The formulation of the resistance is given as a function of a geometric factor of the contact area and the thermal conductivity of the bearing. In particular, an expression for the axial load is derived with careful consideration of changes in contact angle induced by elastic deformation at the contact area.