An investigation on the occurrence of stable cage whirl motions in ball bearings based on dynamic simulations

The occurrence of stable cage whirl in ball bearings with outer ring guided cage under solid lubrication conditions is investigated based on dynamic simulations. The roles of the cage forces in stable whirls and the ball spacing characteristics under stable and unstable conditions are investigated. Results show that the stable whirl motion significantly depends on the ball-cage pocket contact force and the cage-guiding ring forces. Unequal ball spacing is important to the increase of the whirl radius for stable whirl. Furthermore, the ball cannot drive the cage continuously under severe skidding conditions, and thus increase the cage instability.