Patent ID: 7791245

Claim:
An electric machine comprising: a plurality of magnets for generating a first magnetic field; a non-magnetic magnet holder for retaining the plurality of magnets, the magnet holder having a circular configuration with the plurality of magnets being positioned around the circular configuration of the magnet holder; a first stator disposed radially outward from the plurality of magnets for generating a second magnetic field, the magnet and the first stator having a first air gap formed therebetween, the first stator including a plurality of stator poles separated by slots with each of the stator poles having a concentrated winding with a respective number of turns formed around each respective stator pole, each respective concentrated winding within the first stator comprising non-overlapping phases; and a second stator disposed radially inward from the plurality of magnets for generating a third magnetic field, the magnet and the second stator having a second air gap formed between, the second stator having a plurality of stator poles separated by slots with each of the stator poles having a concentrated winding with a respective number of turns formed around each respective stator pole, each respective concentrated winding within the second stator comprising non-overlapping phases; wherein the magnet holder and magnets retained therein are rotatable between the first stator and second stator, wherein the concentrated windings of the first stator and the second stator increase an active length of the windings of each respective stator, and wherein the concentrated winding reduces an overhang of each respective winding with respect to each stator pole of each stator for improving torque efficiency.