Numerical and experimental investigation on ball motion with oil rheology and thermal effect in high speed ball bearings

Dynamic behavior of rolling elements determines the performance including the extent of skidding and wear in ball bearings, which are influenced by many factors. A comprehensive investigation of dynamic behaviors of high speed ball bearings has been conducted both numerically and experimentally. The dynamic model of high speed ball bearings applicable to a wide range of shaft speeds has been developed, taking into account rheological behavior of lubricating oil, curvature effect, collision between balls and cage and thermal effect. Analyses of ball speeds and interaction forces, as well as sliding speed within ball -raceway contact ellipse have been carried out. The ball -to -race ratio (BRR) of speed has been studied specifically under various operating conditions to reflect the cage speed with high precision. A set of experiments have accordingly been performed on a test rig where optic fiber transducer was employed to obtain the orbital speed of ball. The increase of orbital speed of ball with shaft speed was observed in experiments under different axial load. Numerical results from dynamic simulations also agree with the experimental results based on the investigated ball bearing. The present model is versatile over a wide range of operating conditions.