The use of high temperature superconductor bulk in a co-axial magnetic gear

The torque transmission and angular speed change in machine mechanisms are provided by mechanical gear systems. Recent advances in magnetic system designs, developments in quality of the permanent magnetic and ferromagnetic materials led to possibilities of replacing magnetic gears with their mechanical counterparts. Magnetic gears are free from damages during the overloaded operation since they have no physical contact. However, the torque density in magnetic gears is lower compared to mechanical gears due to the limited magnetic flux densities of the permanent magnets. In this respect, the design alternatives are important from the point of enhancing the torque density in the magnetic gear development. For the design considerations in this paper, the effect of the gear depth on the torque efficiency and the use of high temperature superconductors in the pole pieces are investigated. The finite element analysis performed in COMSOL indicated that the torque values established on the rotors of the magnetic gear increased with increasing the depth without changing the efficiency of the gear mechanism. It was also determined that the use of superconductor in the pole pieces increased the torque transfer. High ripple on the amplitude of the torque values suggests the necessity of the experimental verification and more advance analysis.