Influence of bearing kinematics hypotheses on ball bearing heat generation

Abstract

Spindle dynamics is a key issue in machining. Thermo-mechanical models of spindle need to be developed to understand and predict the complex behavior of spindles at high speed. Accurate bearing stiffness model is required, since it is a boundary condition of the shaft. Besides, bearings also play an important role in heat generation in the spindle. Bearing models rely on kinematics hypotheses at the ball-race contacts. The aim of the paper is to study the influence of these kinematics hypotheses on bearing heat generation. The different kinematics hypotheses that can be found in literature are presented and implemented into the bearing friction model. Simulations of bearing dynamics are performed and contact force and torque at ball-race contacts are compared. Behavior of the bearing models with different kinematic models is studied using a coupled thermo-mechanical model of a specialized test bed. Loss torque and temperatures simulated are compared and validated by experiments.