Comparative investigation of rotary and linear motor feed drive systems for high precision machine tools

International competition calls for increased machining accuracy of machine tools in the near future. In precision machining a position accuracy of 0.01 /spl mu/m is a desired standard. A new control applying oversampling methods for the current measurement has been developed in order to use a linear motor as a high-precision feed drive for a submicrometer range machine tool. The performance of the new linear drive system has been compared with different rotary drive systems on a lathe with air bearings of the slides. The new direct drive yields better results than any rotary drive system with precision ball or roller screws.