Patent ID: 8749110

Claim:
A permanent magnet motor comprising a stator and a rotor rotatably mounted to the stator, the stator comprising a substantially polygonal housing having n convex side portions and n connecting portions distributed alternately, wherein the connecting portions are arranged at corners of the housing, n is an integer equal to or greater than 3, adjacent convex side portions are connected by a respective one of the connecting portions, each of said n convex side portions has a convex outer surface and a convex inner surface, the radial cross section of each convex side portion is convex outwardly relative to a straight line passing through two circumferential ends of the convex side portion; a plurality of permanent magnets fixed to an inner surface of the housing, each of the permanent magnets being in proximity to one of said n connecting portions; and an end cap mounted to one end of the housing, the end cap comprising a bottom and n convex side walls extending from edges of the bottom and corresponding to said n convex side portions of the housing, wherein one flat mounting surface facing radially is formed at the outer surface of a first one of said n convex side walls of the end cap and located outside the housing when the end cap is mounted to the housing.