Comparison of coaxial magnetic gears with different topologies

This paper quantitatively compares two coaxial magnetic gears (CMGs) with different topologies, namely, the CMG installed with radially magnetized permanent magnets (CMGRM) and the CMG installed with Halbach magnetized permanent magnets (CMGHM). By using the 3D finite element method, the end-effect and the performances of both CMGs are investigated. Analysis results show that the CMGHM can offer higher pull-out torque, lower torque ripple and lower iron losses than the CMGRM. Experimental results are also given for verification. Index Terms—Finite element method, Halbach arrays, magnetic gears, permanent magnet, torque transmission. I