Meissner motor using high-T/sub c/ ceramic superconductors

The authors developed a superconducting motor using high-T/sub c/ ceramic superconductors. This motor, which utilizes the repulsive force caused by the Meissner effect that appears below T/sub c/, is called the Meissner motor. The motor rotated at a maximum speed of 40 rpm. Though the repulsive force to drive the motor increased with the decrease of temperature or the increase of the gradient magnetic field, it was only about 1.1 gf/g at 77 K in 3500 G/cm. The motor has a maximum torque of 5.0 gf-cm theoretically, but actually had a torque below 0.66 gf-cm, because it took some time to be cooled below T/sub c/. The rotating speed of the motor was limited by heating ability, and its torque was limited by cooling ability.<
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