Electromagnetic Characteristics of Stacked Superconductors and Permanent Magnets Applying for Magnetic Bearings

This paper discusses magnetic bearings made of permanent magnets（ PM） and ring-shape stacked superconductors. We evaluate basic electromagnetic characteristics such as thrust force and rotation characteristics via experiments. The thrust force using a cylindrical PM and the ring-shape stacked superconductors are compared with the PM and a ring-shape bulk superconductor. The experimental results showed that both thrust forces are almost the same as 14 N. On the other hand, the rotation stability of the bearings using the 1- or 3-stacked superconductors, or a bulk superconductor is evaluated via time constant. The experimental results indicated that the time constants of the magnetic bearing using 3-stacked superconductors and using a bulk superconductor are 3.85 s and 2.92 s, respectively. The results showed that 3-stacked superconducting magnetic bearing have a competitive with the magnetic bearings using bulk superconductors.