Abstract: A rotary member is continually held suspended by a strong pinning force of oxide superconductors in a superconductive state. The magnetic field of magnets on the suspended rotary member is distributed concentrically about the center of the pinning force, so that the rotary member can be continually rotated in a non-contacting state while being lifted off the high temperature oxide superconductors. The rotary member is rotated in a high vacuum and is held to continually rotate for an extended period of time. Kinetic energy is stored in and recovered from the rotating member via an input/output device.