Patent ID: 6104114
Filing Date: 2000-08-15
Classification: H02K

Abstract:
A brushless motor comprising:a base plate having a cylindrical member;a shaft inserted into the cylindrical member;a rotor fixed to the shaft and being rotatable relative to the base plate, the rotor including a cup-shaped member having a circumferential wall surrounding the outer periphery of the cylindrical member and a rotor hub attached to the outer peripheral surface of the cup-shaped member;a pair of bearings interposed between the base plate and the rotor, one of the bearing being disposed between the inner peripheral surface of the cup-shaped member and the outer peripheral surface of the cylindrical member and the other one of the bearing being disposed between the inner peripheral surface of the cylindrical member and the outer peripheral surface of the shaft, the latter bearing being located inside of the former bearing so that both bearing axially overlap with each other;an annular rotor magnet secured to the inner surface of the rotor hub;a stator including a stator core having a plurality of teeth and coils respectively wound around each of the teeth, the stator disposed on the base plate so as to oppose the inner peripheral surface of the rotor magnet, the base plate being provided with a plurality of through holes to correspond to the teeth, and a part of the coils being accommodated within the through holes; anda sheet member fitted on the outer surface of the base plate to close the lower openings of the through holes, and wherein the base plate is provided with a plurality of recesses which extend in a radially inward direction at the position between the adjacent teeth, and coil leads led from the coils are electrically connected with a flexible printed circuit board within the recesses.