Patent attributes
An electric fan includes a frame (10) having a central tube (12) extending therefrom, a bearing (30) received in the central tube, a stator (50) mounted around the central tube, and a rotor (70) being rotatably supported by the bearing. The frame defines an air inlet (19) and an air outlet (17) at two different sides thereof. The stator includes a stator core (52) having a central cylinder (520). A plurality of radial posts (522) extends from the central cylinder. A plurality of magnetic poles (524) is formed at free ends of the posts. A plurality of stator coils (54) is wound around the posts. Each magnetic pole includes a lower portion (700) adjacent to the air outlet and an upper portion (60) adjacent to the air inlet. The upper portions expand radially along a direction from the air inlet to the air outlet.
