Novel compensation of axial thermal expansion in ball screws

Novel functional materials in the field of machine tools such as shape memory alloys are capable to convert thermal energy into mechanical energy by generating work. Besides, their self-sensing properties and high energy density make them suitable to compensate thermal deformations. Manufacturing requirements concerning machine tools and machining centers can be summarized in a high productivity, a high reliability (low-maintenance) and a high accuracy/precision. The latter machine design parameter depends almost on linear drive systems, which are responsible for the relative distance between workpiece and tool center point. Their positioning performance is limited, among others, to changes in thermal conditions; even with cooling systems that represent about 90 % of the overall energy consumption of the machine. Therefore, thermal errors in machine tools are currently an issue to overcome. Within the scope of this work, shape memory alloys have been integrated in ball screw drives in order to achieve a thermal stable machine transmission component.