Spiral flux motor with torus coils

Low-cost and high-reliability are important for electric vehicle (EV) motors. Armature windings make it more difficult to manufacture motors automatically. Thus, to obtain a motor with low-cost and high-reliability, we investigated a transverse-flux motor containing a torus coil. In this study, we propose a spiral flux motor (SFM) and discuss its principle and basic characteristics. The stator has axial C-shaped cores and torus coils, and the rotor has circumferential permanent magnets. The flux due to the permanent magnets and due to armature current flow spirally. Our analysis confirms that the SFM produces a high torque of 57.2 kN·m/m³. Thus, the spiral-flowing flux produces high torque with small torque ripple.