Design and optimization of a special magnetic levitated drive with unbalance robustness

This paper deals with the design of a passively damped magnetic bearing system in a special construction form powered by a BLDC Motor. Special attention was given to the optimization of the mechanical system in order to minimize oscillation amplitudes due to unbalanced excitation and decay times. In addition, the main components of the presented drive, the magnetic bearings and the BLDC-motor, were optimized for the determined construction space. The internal rotor is stabilized with passive magnetic bearings in radial and tilt directions and by an active magnetic bearing in axial direction. For the damping of the system, the stator is supported by elastomer rings. These damping elements lead to a significant reduction of rotor vibration, because the passive magnetic bearings show negligible damping. Rotor-dynamic effects were examined at the built magnetic bearing system and the theoretical models were verified.