A Novel Stator Coreless Disk Motor With Skewed Wave Winding for Shaftless Rim Thruster

Abstract

Disk motors characterized by a flat structure and high power density are suitable for use in shaftless rim thrusters. This study proposes a novel stator coreless disk motor with skewed wave winding, which is intended for use in shaftless rim thrusters of small underwater robots. It analyzes the generation mechanism of back electromotive force (EMF) and electromagnetic force for the skewed wave winding and designs three disk motors with different pole numbers (12 poles, 16 poles, and 24 poles) by varying the winding skewed angle. A positive correlation between motor efficiency and the number of poles is demonstrated through a finite element simulation on disk motors with different pole numbers. Finally, a prototype of the 16-pole motor is fabricated and tested to validate the effectiveness of the previous motor design.