US Patent 11296572 Electric machine with variable cross-sectional area constant perimeter trapezoidal teeth

A radial flux electric machine includes a rotor configured to rotate about an axis of rotation and a stator fixedly positioned proximate the rotor. At least one of the rotor or the stator may include a plurality of teeth annularly arranged about the axis of rotation. Each tooth of the plurality of teeth may extend in a radial direction such that a plurality of cross-sectional areas of each tooth in a plurality of planes perpendicular to the radial direction may vary. And perimeters of the plurality of cross-sections may be substantially the same across the plurality of perpendicular planes.