A brushless motor, comprising: a stator including a stator core and a plurality of winding teeth evenly distributed on the stator core; and a rotor rotatably disposed within the stator with the winding teeth facing the rotor, the rotor including a rotor core and a plurality of magnets evenly distributed around the rotor core, wherein a first symmetry axis of the rotor is defined passing through a center of a first one of the magnets to a center of the rotor, and a second symmetry axis of the rotor is defined passing between adjacent ones of the magnets to the center of the rotor, and wherein a first distance between the outer surface of the rotor to a surface of a first one of the winding teeth when the first symmetry axis is aligned with the first winding tooth is smaller than a second distance between the outer surface of the rotor to the surface of the first winding tooth when the second symmetry axis is aligned with the first winding tooth, wherein the radially outer surface of the rotor includes alternating curved outward circular arc segments and curved inward V-shaped segments that are smoothly connected, wherein the first symmetry axis passes through a center of a curved outward circular arc segment from said curved outward circular arc segments, and the second symmetry axis passes through a center of a curved inward V-shaped segment from said curved inward V-shaped segments, wherein each of the curved outward circular arc segments has a radius R1, and the distance along the first symmetry axis axis R2 from the radially outer surface to a center of the rotor is such that R1 < R2 wherein each winding tooth includes a coil wound portion and a front portion facing the rotor at an end of the coil wound portion, wherein a surface of the front portion has an arc segment, curved towards the rotor, at a center part and two straight line segments connected to respective circumferential ends of the arc segment, and wherein the length of each straight line segment, the width of the winding portion, and the width of the front portion are configured to satisfy: c − b / 2 ≤ a ≤ c / 2 where 'a' is the length of each straight line segment, 'b' is the width of the winding portion, and 'c' is the width of the front portion, wherein the length 'a' and the widths 'b' and 'c' are indicated in tangential direction. a stator including a stator core and a plurality of winding teeth evenly distributed on the stator core; and a rotor rotatably disposed within the stator with the winding teeth facing the rotor, the rotor including a rotor core and a plurality of magnets evenly distributed around the rotor core, wherein a first symmetry axis of the rotor is defined passing through a center of a first one of the magnets to a center of the rotor, and a second symmetry axis of the rotor is defined passing between adjacent ones of the magnets to the center of the rotor, and wherein a first distance between the outer surface of the rotor to a surface of a first one of the winding teeth when the first symmetry axis is aligned with the first winding tooth is smaller than a second distance between the outer surface of the rotor to the surface of the first winding tooth when the second symmetry axis is aligned with the first winding tooth, wherein the radially outer surface of the rotor includes alternating curved outward circular arc segments and curved inward V-shaped segments that are smoothly connected, wherein the first symmetry axis passes through a center of a curved outward circular arc segment from said curved outward circular arc segments, and the second symmetry axis passes through a center of a curved inward V-shaped segment from said curved inward V-shaped segments, wherein each of the curved outward circular arc segments has a radius R1, and the distance along the first symmetry axis axis R2 from the radially outer surface to a center of the rotor is such that R1 < R2 wherein each winding tooth includes a coil wound portion and a front portion facing the rotor at an end of the coil wound portion, wherein a surface of the front portion has an arc segment, curved towards the rotor, at a center part and two straight line segments connected to respective circumferential ends of the arc segment, and wherein the length of each straight line segment, the width of the winding portion, and the width of the front portion are configured to satisfy: c − b / 2 ≤ a ≤ c / 2 where 'a' is the length of each straight line segment, 'b' is the width of the winding portion, and 'c' is the width of the front portion, wherein the length 'a' and the widths 'b' and 'c' are indicated in tangential direction.