Torque of Tapered Roller Bearings

Abstract

An analytic tapered roller bearing torque model is presented along with laboratory test data. Initial results of this proposed model are favorable. An accurate general purpose torque prediction tool could be obtained by extending the concepts presented in conjunction with a more comprehensive analysis of actual bearing operating conditions. By using EHL (Elastohydrodynamic Lubrication) theory and micro-macro contact analysis, the bearing torque can be determined by predicting each torque component for each roller due to raceway rolling, raceway moments due to EHL pressure distribution, and frictional force of rib-roller end contact. The roughness effect of contact surfaces, effect of EHL film thickness parameter (the ratio of film thickness to composite surface roughness), and thermal EHL effects are also included. A bearing torque test rig, which can measure the torque of cup race, cone race, and rib separately, was built and used to provide test data. Good agreement between the experimentally measured bearing torques and the predictions of the new torque model has been obtained. This torque model will provide a greater fundamental understanding and is more versatile over a wide range of operating conditions.