A harmonic gear like motor

The harmonic gear is among the more interesting mechanical devices for amplifying torque. This gear has zero backlash with high gear ratios. The number of teeth on the rotor is typically two less than that on the stator. An electromechanical motor equivalent to this device is discussed and analyzed. By contrast to its mechanical equivalent, this electromechanical cousin has no deforming components, and produces torque to weight ratios 28% in excess of its induction motor and permanent magnet counterparts. The cogging torque is less than 0.6% of full rated torque. Among its more unique features is a rotation opposite to the stator field excitation rotation.