Patent ID: 7553136

Claim:
An electric fan comprising: a fan base having a base plate, an annular first rail attached to the base plate; a stator mounted on the base plate, the stator comprising a pole member, a winding and a printed circuit board electrically connected with wires of the winding; and a rotor comprising a hub with a plurality of fan blades formed on the hub, the hub comprising a top wall and a peripheral sidewall extending from the top wall, a permanent magnet attached to an inside of the top wall of the hub and cooperating with the pole member to define therebetween an axial magnetic flux gap, and an annular second rail attached to the hub, the second rail axially facing to the first rail and movably cooperating with the first rail to define a rotation path of the rotor with respect to the stator; wherein the pole member is in a form of a unitary plate, comprising a plurality of pole arms and a plurality of positioning posts extending perpendicularly from the pole arms respectively, the winding comprises a plurality of coils respectively wound around the positioning posts, the base plate defines a plurality of positioning holes therein, and the positioning posts of the pole member extend through the coils of the winding and engage into the positioning holes to position the stator on the base plate.