Reduction of Toque Ripple and Unbalanced Magnetic Force of a Rotatory Axial Two-Phase Transverse Flux Machine by Using Herringbone Teeth

헤링본 치를 이용한 축방향 이상 횡자속형 전동기의 토크 리플과 불평형 자기력 저감

Transverse flux machine (TFM) has been considered as a promising driving machine especially at the low-speed applications because it has higher power density, torque and efficiency than the conventional electrical motors. However, it has complicated structure, large torque ripple and sometimes unbalanced magnetic force due to its inherent structure. This paper investigates the characteristics of torque ripple and unbalanced magnetic force of a rotatory two-phase TFM due to the teeth geometry by using the 3-dimensional finite element method, and it develops a rotatory two-phase TFM with herringbone teeth to reduce the torque ripple as well as to eliminate the unbalanced magnetic force.