Influence of thermal effect on dynamic behavior of high-speed dry hobbing motorized spindle system

This paper is devoted to investigating the influence of thermal effect on the dynamic behavior of a motorized spindle system in high-speed dry hobbing machine tool. First, the thermal induced preloads of combined bearings were calculated by characterizing the uneven temperature rise under operational condition. Subsequently, the influence relationship of thermal induced preload on the stiffness of combined bearings was studied. The change rules of the dynamic behavior of motorized spindle system with respect to the temperature rise were analyzed by coupling bearing stiffness and spindle dynamic models. Finally, experimental measurements on bearing temperature rise and spindle dynamic behavior were implemented for validation. The results indicate that thermal effects have a significant impact on the stiffness of combined bearings and hence the operating stability of high-speed dry hobbing motorized spindle system. This study can provide a reference for thermal dynamic optimization of motorized spindle system for high performance high-speed dry hobbing.