Torque Density Improvement in Transverse Flux Machine using Disc

Transverse flux machines are usually designed with either cylindrical rotor or disc rotor structure. In this paper, a disc rotor topology with single layer of permanent magnets per phase is proposed to improve the torque density. Unlike conventional transverse flux machine, the stator construction is simplified by joining c-cores of all phase stacks together in the proposed design. Analytical equations are derived for calculating the electromagnetic torque, magnetizing inductance, and leakage inductance. The disc rotor transverse flux machine is compared with an equivalent cylindrical rotor transverse flux machine using finite element analysis simulation. It is found that the transverse flux machine with disc rotor has higher torque density than that of cylindrical rotor topology.