Research on dynamic characteristics of motorized spindle based on comprehensive stiffness of angular contact ball bearing

Abstract. In order to study the dynamic performance of a motorized spindle system more accurately and to consider the centrifugal effect, thermal effect of the angular contact ball bearing (ACBB) caused by high speed and influence of temperature rise on the dynamic viscosity of lubricating oil, a comprehensive stiffness model of a motorized spindle support bearing is established. Second, on this basis, combined with the Timoshenko beam theory and rotor dynamics, the dynamic model of the motorized spindle system is proposed using the finite element method. Finally, the influence of various factors on the dynamic characteristics of the high-speed motorized spindle system is studied and verified by experiments. The results show that the increase in the ball bearing preload and axial load could effectively improve the stability of the motorized spindle system, and the increase in the speed and thermal deformation of the ball bearing make the natural frequency and critical speed of the system decrease.