2015 Volume 23 Issue 1 Pages 86-92
Compared to mechanical bearings, superconducting magnetic bearings (SMB) have various merits, because they are able to support a rotor without physical contact. However, SMBs have a problem of making the rotor amplitude larger near the critical rotational speed because of their low damping. Therefore, it is necessary to reduce the amplitude with considering effect of the nonlinearity on dynamics in passing through the critical rotational speed in applications.
We proposed a new method of reducing the resonant amplitude of a rotor supported by a SMB using axial translation of the rotor. We adopted an idea that the distance between the superconductor and the rotor can be tuned variably using electromagnetic force exerted by an electromagnet so that the natural frequency of the rotor in the horizontal direction can be changed. Tuning the electromagnetic force when the rotational speed is near the critical rotational speed, it is expected to reduce the resonant amplitude of the system.
