Dynamic Modeling and Experimental Validation of Axial Electrodynamic Bearings

Eddy current effects are the base of electrodynamic bearings principle. They arise when a conductor moves in a magnetic field. As they are passive by nature, no additional instrumentation such as sensor or power electronics are needed, and this implies several advantages such as the reduced complexity, improved reliability and smaller size and cost. Electrodynamic bearings have also drawbacks such as the difficulty in ensuring a stable levitation in a wide speed range, therefore the bearing design must be based on a dynamic analysis to investigate the stability issue. A prediction of the dynamic performance of rotating systems equipped with axial/radial electrodynamic bearings needs a model able to describe the dynamic behavior. The present paper is devoted to describe and validate experimentally the quasi static and the dynamic model of axial electrodynamic bearings.