Experiments of a Very Simple Radial-Passive Magnetic Bearing Based on Eddy Currents

We developed a very simple new-type passive radial magnetic bearing system which consists of an axisymmetric magnetic gap and a spinning copper disc inserted in the gap. Restoring radial forces are generated by interaction between eddy currents due to radial displacement of the disc and magnetic flux of the gap. Most important feature is no drag force and no heat problem during no radial displacement of the disc. Main purpose of the experiment was to determine how much the copper disc peripheral of the rotor should be inserted in the magnetic gap of the stator. Results concerning radial restoring component force and its perpendicular one vs rotational speed were shown. Approximate analysis of distributed eddy currents using distributedparameter model was given.