Modeling and optimization of thermal characteristics for roll grinders

Abstract

The thermal deformation has a significant effect on the processing precision of the machine tool. In this paper, a simulation model and an experimental method of the thermal performance were proposed for a roll grinder. The calculation methods of thermal boundary conditions including the heat power caused by the spindle motor with water cooling, headstock motor with air cooling and hydrodynamic bearings, the convective heat transfer coefficients of the rotating surface at different spindle speeds, and machine tool contact resistance were provided to establish a high-precision FEM model. Based on the achieved key temperature points in the simulation, thermal characteristic experiments were carried out at different spindle speeds with 18 temperature sensors and three displacement sensors. The experimental results of the temperature field and thermal displacement were then compared with the simulation results to verify the effectiveness of the constructed finite element model. Finally, three kinds of optimization schemes of the roll grinder structure were discussed to further improve the thermal performance. The simulation results indicated that the thermal deformation of the spindle decreased in the X- and Y-axis directions.