Abstract: Considering the influence of axial passive stiffness, the dynamic characteristics of hybrid magnetic suspending flywheel with oblate external rotor were investigated using theoretical and numerical methods for static suspension and steady rotation states. The results show that the variations of axial and radial stiffnesses mainly and respectively affect the frequencies of radial swing and translation for static suspension state. In modes exchange zone, the vibration modes are the superposition of swing and translation. When the flywheel rotates steadily, the variations of radial and axial stiffnesses mainly and respectively affect the frequencies of cylindrical whirling and low\|speed conical whirling.

Key words: MaGnetic suspension flywheel, Dynamics characteristic, Axial stiffness, Radial stiffness, Mode exchange zone