Heat exchangers for liquid-free cooling of rotating shafts

Heat reduces the performance of machine tool spindles. In particular, the heating of the shaft leads to numer-ous undesirable effects. Fluid-based shaft cooling systems exist but are expensive and energy-intensive. For this reason, a novel, liquid-free shaft cooling concept is researched. Heat is transferred from a rotating heat exchanger to a non-rotating and cooled structure through a narrow air gap. In this paper, the cooling poten-tial of this concept is identified simulatively and experimentally by quantifying the heat transfer coefficients as well as the generated air friction. For the first time, a suitable simulation setup for the modelling of such heat exchangers is presented, providing a fundamental contribution to the design of liquid-free cooling sys-tems.& COPY; 2023 CIRP. Published by Elsevier Ltd. All rights reserved.