Design of a Measurement Setup and First Experiments on the Influence of CO2-cooling on the Thermal Displacements on a Machine Tool

The paper investigates the thermal influences of CO2- and oil-cooling on the precision of a machine tool. If CO2 is used for process cooling instead of oil, a different temperature distribution in the machine is observed. Different temperature distributions lead to different tool center point (TCP)-displacements. To measure TCP-displacements under real process conditions with CO2 and oil, a special measurement setup is designed, built and applied. A representative process for the machine is chosen to compare the different process coolings. The results show that the choice of coolant has a crucial influence on the TCP-displacements. It is shown that the thermally induced displacements can be reduced by 15 μm in y-direction, but increase about 4 μm in x-direction, when the coolant is changed from oil to CO2.