A new driving method for superconducting levitated stepping motor

A magnetically levitated stepping motor using high T/sub c/ superconductor has been studied. The levitated stepping motor consists of a cylindrical rotor with superconductors and a stator with eight electromagnets. The rotor measures 10 mm in diameter, 46 mm in length, and 18 g in mass. The superconductors of the rotor are field-cooled in liquid nitrogen with various field-cooling currents. The levitated rotor is driven by an four-phase excitation with various driving currents. The rotation angle by each step is 45 deg. The rotor spins for every step as the excitation phase shifts. This paper discusses the dynamics of the motor driven by a new driving method.