CHARACTERISTICS OF A SUPERCONDUCTING MAGNETIC BEARING

Both repulsive and attractive forces caused by the pinning state in wh ich the magnetic field is trapped in a superconductor are capable of n oncontact steady support of an object in all directions. In this paper , we describe the levitation force characteristics, the force relaxati on caused by flux creep, and the bearing loss under high rotational sp eed, of a disk-type superconducting bearing ata temperature of 77 K, a s well as the rotational characteristics of pinning-type superconducti ng radial bearings, The bearing consists of Y1Ba2Cu3Ox (YBCO) oxide su perconductors fabricated using quench melt growth (QMG) process and ra re-earth permanent magnets, The rotor in which a permanent magnet is s upported by the pinning force in the superconductor can be safely oper ated at high rotational speeds.