Control of axial tool displacement in a motorized milling spindle by means of a thermoelectric temperature control system

In high-precision manufacturing, thermal shifts of machine tools account for a significant portion of geometrical errors. To improve its thermomechanical behavior a motorized milling spindle is equipped with a thermoelectric temperature control system. This system allows different temperatures to be set inside the spindle, enabling a new approach to control the axial tool displacement. A closed-loop control is designed using the temperature at the front bearings as manipulated variable. As a result, this study demonstrates the ability to reach and hold constant setpoint values of axial tool displacements for rotational speeds between 15,000 1/min and 55,000 1/min.