Stability Improvement of Passively Stabilized Degrees of Freedom in Magnetically Levitated Systems

The passive degrees of freedom of magnetically levitated devices are prone to external disturbance forces and torques as there is no possibility to adapt the bearing stiffness or to introduce damping actively. In the case of bearingless disk drives, this concerns the axial and tilt deflections. A novel stabilization coil presented in this work helps to stabilize the tilt deflections. After the introduction of the electrodynamic working principle, the measurement results conducted at a high speed bearingless disk drive prototype are presented. To the knowledge of the authors, this work represents the first publication on such a stabilization device.