A motor comprising: a first E-shaped stator core; and a second E-shaped stator core independently provided from the first stator core, wherein each of the first and second E-shaped stator cores (110A, 110B) comprises, a yoke extended in a yoke length direction; a center tooth extended in a tooth extension direction from a center of the yoke; and two outer teeth extended in a tooth extension direction from upper and lower ends of the yoke, respectively, the outer teeth being longer than the center teeth, wherein the center teeth and outer teeth form a cylindrical opening suitable for accommodating a ring shaped rotor core between the first and the second E-shaped stator core (110A, 110B), wherein the rotor rotates around an axis and, wherein a center tooth pole shoe is formed in an end of the each center tooth and is extended from the end of the center tooth in both opposite circumferential directions, wherein an outer tooth pole shoe is formed in an end of the each outer tooth and is extended from the end of the outer tooth in both opposite circumferential directions, wherein the yoke is perpendicular to the tooth extension direction of the center and outer teeth (112a, 112b), and the center and outer teeth (112a, 112b) are extended linearly, and a slot is formed between the center tooth and the outer tooth in an outer surface of the outer tooth, characterized in that a ratio (G/F) of a height to a length is 0.27∼0.33, wherein the length is defined as the length in the tooth extension direction of the outer tooth between the yoke and the pole shoe and the height is defined as the height in the yoke length direction of a polar extension of the outer tooth pole shoe that extends from the outer tooth towards the center tooth, and/or a ratio (H/I) of a height to a length is 0.55∼0.67, wherein the length is defined as the length in the tooth extension direction of the center tooth between the yoke and the pole shoe, and the height is defined as the height in the yoke length direction of a polar extension of the center tooth pole shoe that extends from the center tooth towards the outer tooth. a first E-shaped stator core; and a second E-shaped stator core independently provided from the first stator core, wherein each of the first and second E-shaped stator cores (110A, 110B) comprises, a yoke extended in a yoke length direction; a center tooth extended in a tooth extension direction from a center of the yoke; and two outer teeth extended in a tooth extension direction from upper and lower ends of the yoke, respectively, the outer teeth being longer than the center teeth, wherein the center teeth and outer teeth form a cylindrical opening suitable for accommodating a ring shaped rotor core between the first and the second E-shaped stator core (110A, 110B), wherein the rotor rotates around an axis and, wherein a center tooth pole shoe is formed in an end of the each center tooth and is extended from the end of the center tooth in both opposite circumferential directions, wherein an outer tooth pole shoe is formed in an end of the each outer tooth and is extended from the end of the outer tooth in both opposite circumferential directions, wherein the yoke is perpendicular to the tooth extension direction of the center and outer teeth (112a, 112b), and the center and outer teeth (112a, 112b) are extended linearly, and a slot is formed between the center tooth and the outer tooth in an outer surface of the outer tooth, characterized in that a ratio (G/F) of a height to a length is 0.27∼0.33, wherein the length is defined as the length in the tooth extension direction of the outer tooth between the yoke and the pole shoe and the height is defined as the height in the yoke length direction of a polar extension of the outer tooth pole shoe that extends from the outer tooth towards the center tooth, and/or a ratio (H/I) of a height to a length is 0.55∼0.67, wherein the length is defined as the length in the tooth extension direction of the center tooth between the yoke and the pole shoe, and the height is defined as the height in the yoke length direction of a polar extension of the center tooth pole shoe that extends from the center tooth towards the outer tooth.