Structural optimization of ball bearings with three-point contact at high-speed.

• The dynamic transition of FCPBB's contact states was revealed under high-speed conditions. • Three-point contact state of FCPBB for specific conditions was optimized. • Eccentricity has a substantial effect on the FCPBB performance. • A smaller curvature coefficient or larger eccentricity can reduce bearing sliding. Three-point contact state is a common state for four-point contact ball bearings (FPCBB), significantly improving the performance in high-speed and light-load conditions. However, in this case, the internal contact state is in a dynamic transition between two-point and three-point contact, with substantial frictional losses. To this end, a nonlinear dynamic model of FPCBB, considering the lubrication traction and the bearing assemblies' dynamic features, is proposed to optimize the FPCBB's performance for three-point contact state. The dynamic changes of contact states under high-speed and light-load conditions are revealed, and four sets of conditions are picked as optimization conditions. Beside, groove curvature coefficient and curvature center eccentricity, depending on outer ring structure, are selected as optimized structural parameters. On this basis, the behavior performance in three-point contact state is optimized for specific operating conditions. The results show that with the gradual growth of eccentricity, the bearing fatigue life first extends slowly and then reduces rapidly, where an optimum value exists; for bearings possibly serving in skidding condition, it is better to prefer a larger eccentricity or a smaller curvature coefficient to reduce sliding damage. [Display omitted] [ABSTRACT FROM AUTHOR]