Simulation-Based Design of a Thermoelectrically Temperature-Controlled Motorized Spindle

The precision and efficiency of modern manufacturing processes are critically dependent on the thermal stability of the machine tool. As one of the most crucial components, the motorized spindle is of particular importance. By thermally stabilizing the bearings, the thermal expansion of the shaft can be reduced. A second advantage of the thermal stabilization of motorized spindles is the significant reduction of warm-up times after tool change down-times and the warm-up time at the start of the machining process. This study focuses on the simulation-based design of a thermoelectrically tempered motorized spindle that is using a novel design of tubular Peltier modules. The tubular design was chosen for its efficiency in providing a uniform and precise temperature control around the cylindrical surface of the bearing. In a first step, the thermal behavior of a functional prototype of a motorized spindle was measured under various operating conditions and compared to a simulation model using Comsol MultiphyicsTM. The FEM simulation validated by measurements was subsequently applied to the geometry of a real spindle to determine the optimized shape of the thermoelectric modules as well as their optimal number and placement around the bearings.