Experimental Validation and Characterisation of a Passively Levitated Electrodynamic Thrust Self-Bearing Motor

Recent researches have revealed that electrodynamic thrust bearings (EDTBs) can gather, within a 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. However, to date, experimental results still lack to corroborate the operation principle as well as the model describing the axial and rotational dynamics of these motors. In this context, this paper is devoted to the experimental validation and characterisation of an EDTSB motor. Measurements performed on the prototype endorse the assumptions regarding the linearisation of the flux linkages as well as the negligible impact of the magnetic field harmonic content. Nevertheless, they also disclose that suspension currents are induced even when the rotor is centred. Despite this, the thrust bearing and self-bearing motor behaviours are studied in quasi-static and dynamic conditions, validating the operation principle as well as the electromechanical model.