Design of a Transverse Flux Spoke-Type Permanent Magnet Motor With Step Skew Crossed Teeth

This paper proposes a novel crossed teeth transverse flux permanent magnet motor. Differing from existing transverse flux permanent magnet motors (TFPMMs), the proposed motor features step skew crossed stator teeth. This unique structure can reduce the cogging torque and torque ripple. The structure of the stator teeth is also a prominent feature of this motor. Additionally, after evaluating several rotor shapes, axial segmentation of the rotor can reduce interphase leakage. The concentrated circle coils can simplify winding design and assembly, as they eliminate the need for end coils. Then, the theoretical analysis of the no-load back electromotive force (back-EMF) and output torque with step-skewed stator teeth is presented. The effects of the pole-pair numbers and rotor types are also evaluated. Based on the 3D finite element method (FEM) results, a prototype was designed and manufactured. Finally, no-load and load experimental platforms were established to obtain the back-EMF and torque performance of the prototype. The experimental results verified the simulation analysis, demonstrating improvements in torque and power density, as well as a reduction in cogging torque compared to existing TFPMMs.