Thermoelectrically tempered motorised spindle for high-precision machine tools

在高精度（HP）和超精密（UP）加工领域，对零件的尺寸精度提出了极高的要求，小到亚微米范围。这种高精度部件的一个重要应用领域是医疗技术、航空航天工业和工具制造。用于机床HP和UP加工的电主轴的热性能对实现所需的工作精度起着至关重要的作用。高达75%的几何误差是由刀具中心点的热诱发位移引起的。由于电机和轴承的电气和机械功率损失，热流被诱导，例如，进入轴和主轴的外壳。这些导致温度升高，从而导致相应部件的热诱导变形。诱导热流的变化是不可避免的，例如由于工具或工件的变化以及转速的调整。为了在HP和UP加工领域保持所需的公差，这导致机床需要长时间的预热，直到达到热稳定状态。使用珀尔帖技术进行温度控制的目的是增加电主轴的热稳定性，并减少其预热期相比，最先进的状态。为此，将开发一种新型热电冷却系统，该系统基于管状珀尔帖模块，并将其集成在电动铣削主轴的热源和散热器之间。这将使从轴承和主轴电机的热量控制去除。

In the field of high-precision (HP) and ultra-precision (UP) machining, high demands are placed on the dimensional accuracy of the components down to the submicrometer range. An important field of application for such high-precision components is medical technology, the aerospace industry and toolmaking. The thermal behavior of the motorised spindles used for HP and UP machining in machine tools plays a crucial role in achieving the required working accuracy. Up to 75 % of geometrical errors are caused by thermally induced displacements of the tool center point. As a result of electrical and mechanical power losses of the motor and the bearings, heat flows are induced, for example, into the shaft and the housing of the spindles. These lead to increasing temperatures and consequently to thermally induced deformation of the corresponding components. Variations in the induced heat flow are unavoidable, e.g. due to the change of tool or workpiece as well as adjustments to the rotational speed. In order to maintain the required tolerances in the area of HP and UP machining, this leads to long warm-up periods of the machine tools until a thermal steady state is reached. The use of Peltier technology for temperature control is intended to increase the thermal stability of a motorized spindle and reduce its warm-up period compared to the state of the art. For this purpose, a novel thermoelectric cooling system based on tubular Peltier modules is to be developed and integrated between the heat sources and sinks of a motorized milling spindle. This will enable a controlled removal of heat from the bearings and the motor of the spindle.