Second Paper: Analysis of Spin/Roll Conditions and the Frictional-Energy Dissipation in Angular-Contact Thrust Ball Bearings

Abstract

In current analyses of the contact conditions in angular-contact ball bearings it is assumed that sliding occurs in all regions where tangential surface tractions are operative. Other work in similar rolling-contact situations has, however, demonstrated that some of this slip requirement may be accommodated by the elastic surface deformations. This type of analysis leads to areas of sliding and sticking coexisting within the contact areas. These concepts are here applied to angular-contact thrust ball bearings and lead to some interesting deviations from the results obtained using the complete slip analysis. In particular, these concepts of microslip enable the determination of the spin/roll ratio at each race contact. Detailed calculations for conical ball thrust bearings illustrate the main discrepancy of the full slip analysis in over-estimating the frictional-energy losses, such discrepancies being most marked with decreasing contact angle, increasing pitch/ball radii, and increasing coefficient of sliding friction.