INTERNAL PERMANENT MAGNET MOTOR WITH AN OUTER ROTOR

Provided is an electric motor comprising: a stator comprising stator poles arranged radially and a rotor comprising rotor poles, each comprising: a substrate comprising a magnetically permeable material and at least a first magnet and a second magnet. The magnets can comprise a respective proximal end proximal to the stator and a respective distal end opposite the respective proximal end, and distal from the stator. A distance between respective proximal ends of the magnets can be equal to or greater than a distance between respective distal ends of the magnets. Each rotor pole also comprise first and second proximal cavities, each cavity extending from the respective proximal end of a magnet for a given length along about the circumferential direction and away from the proximal end of the other magnet. Sum of the lengths of the proximal cavities can be about equal to a width of each stator pole.