Brushless motor

DETAILED DESCRIPTION The present invention has been made in order to solve the above-mentioned problems inherent in the conventional technology and the primary object of the present invention is to provide a brushless motor which can be improved in wow/flutter characteristic by balancing the magnetic attraction force between the driving magnet and the stator core through the contrivance of the configuration of the salient-pole umbrella portions of the stator core and the resulting decrease in torque ripple.
In accordance with the invention, a brushless motor comprises a rotor, a driving magnet which is rotated integrally with the rotor and a stator core disposed so as to oppose the driving magnet and being wound therearound with a coil.
The stator core has salient poles with umbrella portions except for notched portions thereof.
A magnetic sensor is disposed in the vicinity of the stator core in a first notched portion prepared by partly removing two corresponding adjacent salient-pole umbrella portions of the stator core for detecting a magnetic pole of the driving magnet.
A second notched portion is formed by partly removing two corresponding adjacent salient-pole umbrella portions in a zone of the whole circumferential area of the stator core.
The second notched portion is magnetically balanced with the first notched portion.
A brushless motor according to an embodiment of the present invention will now be described with reference to the drawings.
Note that common reference numerals are used to denote constituent portions corresponding to those of a conventional brushless motor shown in FIG.
8.