Electronic devices with a motor that includes a stator with a non-uniform radius of curvature

A fan motor suitable for use in an electronic device, such as a consumer electronic device, is disclosed. The fan motor includes a stator and a rotor. In order to minimize a varying torque applied to the rotor, the stator includes modifications. For example, the stator includes stator teeth, each with an arc defined by a radius of curvature that varies. The radius (from a reference point to the arc) can vary in accordance with a sinusoidal curve. Furthermore, the corners of each stator tooth may be rounded. The rounded corners of the stator teeth may include a uniform (or constant, non-varying) radius of curvature. These enhancement are designed to provide a more uniform torque by the stator to the rotor. As a result, the rotation of the rotor is subject to smaller fluctuations, and the fan motor undergoes less vibration and generates less acoustical noise.