Development and Analysis of a Homopolar Consequent Pole Transverse Flux Magnetic Gear

Magnetic gears perform the same function as mechanical gears but rely on noncontact operation to transfer power, producing many potential advantages over mechanical gears. This paper proposes two new topologies of transverse flux magnetic gear (TFMG). The new topologies are parametrically evaluated using 3D finite element analysis (FEA). The homopolar consequent pole TFMG offers simple assembly with only a single magnet but suffers from a low volumetric torque density (VTD) based on preliminary studies and a proof-of-concept prototype. The doubly magnetized consequent pole TFMG requires more magnets but could produce a higher VTD, but that VTD is still relatively low for a coaxial magnetic gear. A prototype of the homopolar consequent pole TFMG gear was built. Its measured slip torque agreed well with simulations, but it experienced relatively significant bearing losses. Although the VTD of this new topology is low, its simplicity with only a single permanent magnet could be advantageous for small-torque applications where manufacturing complexity can drive cost.