There is provided a hybrid stepping motor including a rotor including a plurality of rotor small teeth arranged on an outer circumferential surface thereof, and a stator including a plurality of salient poles, each including a plurality of stator small teeth. In inner fan, within the inner air duct, moves air in one direction, while an outer fan, in the outer air duct, moves air in the other direction. In another embodiment, one or more ESAM layers may have air pockets dispersed therein.