Development of Non-Contact Levitated Rotating Machine Using HTS Bulks and Permanent Magnets

We have studied a non-contact magnetic levitation system using ring-shaped higherature superconducting (HTS) bulks and ring-shaped permanent magnets (PMs). Because the HTS bulks were magnetized by PMs fixed between the HTS bulks, this PMs levitated with strong restoring force. We used a stator coil to rotate the iron shaft combined with PMs. In order to rotate the shaft stable, restoring the force of radial direction is very important. Therefore, the ring-shaped PMs magnetized in the radial direction were fitted to the shaft. In this rotating system, we focused on two parameters, i.e., the rotation and the control. In the rotation, we measured the maximum rotating speed and the axial vibration due to the rotating speed. The three types of stator coils were designed by electromagnetic analysis, and these stators were tested experimentally.