Patent ID: 6809457
Filing Date: 2004-10-26
Classification: H02K

Abstract:
A brushless DC motor comprising:a pole plate formed by means of punching a magnetically conductive plate made of a single metal sheet, the pole plate including a plurality of pole faces and a magnetically conductive tube, the pole faces of the pole plate being annularly located around the magnetically conductive tube of the pole plate; a magnetic pole base formed by means of punching another magnetically conductive plate made of a single metal sheet, the magnetic pole base including a plurality of pole faces and a magnetically conductive tube, the pole faces of the magnetic pole base being annularly located around the magnetically conductive tube of the magnetic pole base; a coil assembly directly mounted on the magnetic pole base and situated in a space between the pole plate and the magnetic pole base; a circuit board also mounted on the magnetic pole base; and a rotor including a shaft and a permanent magnet; and a holder ring mounted around the shaft of the rotor; the magnetically conductive tube of the magnetic pole plate being received in the magnetically conductive tube of the pole base to form an axle tube, at least one bearing being received in the axle tube for rotatably holding the shaft of the rotor such that said holder ring is sandwiched between an end face of the magnetically conductive tube of the magnetic pole base and an end face of the bearing; and the pole faces of the magnetic pole base and the pole faces of the pole plate being alternately disposed and located around the axle tube.