SUPERCONDUCTING BEARINGS FOR HIGH-LOAD APPLICATIONS

Progress in the application of high temperature superconducting cerami c materials to magnetic bearings and the prospects for higher load dev ices is reviewed. In particular we present experimental evidence from two studies at Cornell. New measurements from a hybrid superconducting bearing show the possibility of peak magnetic pressures of 60 N/cm2 h igher in the temperature range of 20-degrees-40-degrees-K using a wire wound coil of Nb-Sn wire as the source of magnetic field and a melt-q uenched processed YBa2Cu3O7 bulk superconductor as the other half of t he bearing. In a second experiment we demonstrate an 0.85 kg levitated rotor at 28,000 RPM and 5 kJ stored energy. This experiment, conducte d at 78-degrees-K, demonstrates a six-component discrete-clement YBCO bearing with a rare earth ring magnet. Stiffness and spin-decay measur ements are reported. These experiments point the way to large rotor le vitation of 10-100 kg in the near term and 1000 kg rotors in the not t oo distant future.