Superconducting bearing device

Abstract

A superconducting bearing device comprising a superconductor mounted on a stationary member and a magnet section to be mounted on a rotating member, the superconductor and the magnet section being disposed to oppose each other with a gap therebetween. Also disclosed is a method for producing the magnet section thereof, wherein the magnet section consists of a plurality of annular permanent magnets which are concentric with the axis of the rotating member and also include at least one soft magnetic yoke disposed between these annular permanent magnets. Each annular magnet, in turn, may be comprised of a plurality of arcuate magnet portions whose joint surfaces may be concentrically or axially staggered to disperse nonuniform flux densities observed at their junction surfaces. The joint surfaces between the annular and magnets and the interposing rings may be curved or slanted to reduce axial displacement when the magnet section is rotated. Also, the yoke members may protrude towards the superconductor relative to the permanent magnets comprising the magnet section, and these yokes may be optimally shaped to concentrate and direct magnetic flux to the opposing superconductor in conjunction with curled magnetization of the permanent magnets. Finally, one or more restraining members or wedge portions may be fitted to the magnet section to radially and circumferentially compress the permanent magnets sections and prevent their displacement and breakage at high rotational speeds.