An improved model of motorized spindle for transient thermo-structural analysis

The prediction of the temperature distribution and thermal deformation for motorized spindle dependent on time is critical in its design process. The thermo-structural model of a grinding motorized spindle is developed with accurate thermal boundary conditions of the spindle-bearing system based on experimental data and numerical calculation. The following thermal boundary conditions are improved: the heat transfer coefficient of natural convection between spindle surface and ambient air through heat flux measurement, the heat transfer coefficient of forced convection of cooling water by the simulation analysis. In addition, a method of heat distribution applied to the bearing model is proposed. The thermo-structural model with structural deformation constraints is validated experimentally based on the transient temperature of typical regions, the axial thermal deformation of the shaft and the thermal equilibrium time.