Influence of design parameters on magnetic gear´s torque capability

Magnetic gear design parameters have been previously investigated individually. This paper presents a comprehensive study of the influence of individual and combined design parameters on the optimal torque capacity and performance of the magnetic gear. Parameters considered include the combination of pole pair numbers of inner and outer permanent magnets and ferromagnetic pieces, ferromagnetic geometry, and permanent magnet thicknesses. Finite element analysis has shown that there is a compromise between gear ratio and torque capacity and a maximum capacity of torque exists that can be coupled in a gear with fixed outer diameter. It reveals that increasing the volume of PM material the minimum inner and outer PM thickness ratio should be increased in order to avoid partial demagnetisation, which will inhibit the selection of PM thickness ratio for optimal torque coupling capacity.