Active Magnetic Bearing for Ultra Precision Plastic Electronics Production System – Mr Mathias Tantau

Mathias Tantau, a Masters student from Germany has designed an active magnetic bearing for the printing roll of the reel to reel platform – see Figure 1. The active motion control of magnetic bearings allows independent adjustment of bearing stiffness and damping, as well as compensation of machining inaccuracies in the whole spindle. The quick assembly of a magnetic bearing could expedite the change of printing rollers between different layers of the produced flexible electronics circuit.

The magnetic bearing shown introduces a novel technique to measure the radial position of the shaft; surface encoders count concentric fringes on the face of a reference disc and subsequent electronics generate incremental position information. This self-made scale utilises the high resolution and secure noise rejection of incremental systems compared with ordinary, absolute gap sensors, which are mostly used in active magnetic bearings.

If the proposed magnetic bearing is really reconcilable with ultra precision and if the performance of a magnetic bearing can compete with a hydrostatic bearing of the same size, this has to be further investigated in the research project. To achieve this objective a simpler prototype shall be designed, machined and assembled, programmed and tested in the remaining months of research project.

This Masters by Research projects is being undertaken at Cranfield University under the supervision of Paul Morantz.