Rotational Test of an Integrated Magnetic Bearing Using Multiple HTS Cubic Bulk Units

For magnetic bearings combining multiple cubic superconducting bulks, placement is a crucial factor. In this paper, the magnetic bearing surface constructed by arrangement optimization was composed of eight superconducting cubic bulk units. The combined arrangement of cubic superconducting bulks was determined by optimizing the spatial uniformity of the magnetic bearing's trapped magnetic flux distribution. We constructed a physical model in which a permanent magnet in the form of a floating rotor was sandwiched from above and below by an integrated magnetic bearing surface. Using rotation test equipment and an encoder, we investigated the influence of an optimal arrangement index on rotation loss that occurs due to magnetic flux distribution nonuniformity. In addition, the rotation axis tilt angle due to nonuniform magnetic flux distribution was measured using a laser displacement meter. The advantage of the method proposed in this research is that the magnetic distribution can be controlled optimally depending on the arrangement of the cubic bulk when it is incorporated in various bulk applications, not limited to SMB.