Characteristics of the magnetic gear using a bulk high-Tc superconductor

A magnetic gear which can transmit force without contact has operational benefits of requiring neither vibration, noise, nor lubrication. Still, its transmission force is considerably smaller than a mechanical gear. Strong magnets are needed to improve magnetic gear transmission force. For this purpose, a magnet formed by the pinning effect in a bulk superconductor might have magnetic flux density several times stronger than rare-earth permanent magnets. We propose a noncontact magnetic gear using a bulk high-Tc superconductor. In this paper, a three-dimensional electromagnetic field analysis program has been developed to analyze characteristics of the proposed gear. Two superconducting magnetic gears with different magnet configuration are manufactured, and their characteristics are measured. The analysis and the experiment explore the possibility of a magnetic gear using the pinning magnet formed in the superconductor.