Experimental Investigations on Passively Levitated Electrodynamic Thrust Self-Bearing Motors

Recent researches have revealed that electrodynamic thrust bearings can gather, within one single armature winding, both the passive axial restoring force and the driving torque, thus yielding a new passively levitated electrodynamic thrust self-bearing (EDTSB) motor. Although their operation principle and the model describing their axial and spin dynamics have already been corroborated, experimental results still lack to properly characterize these machines. In this context, this paper is devoted to an in-depth experimental investigation of an EDTSB motor. Measurements performed on the prototype endorse the assumptions regarding the linearization of the flux linkages as well as the negligible impact of the magnetic field harmonic content. They also disclose that suspension currents are induced even when the rotor is centered. Finally, the thrust bearing and self-bearing motor behaviors are studied in quasi-static and dynamic conditions, validating the dynamical model.