Patent ID: 6140726
Filing Date: 2000-10-31
Classification: H02K

Abstract:
A motor structure including a rotor having a field magnet and being held rotatably between two flanges fixed at ends of a yoke, and stator poles having salient poles opposed to the field magnet of the rotor, comprising:a magnetic flux density adjusting yoke formed in a cylindrical shape using a soft magnetic material and having salient poles having a sectional square, half the number of the salient poles being projected as upper salient poles on an inner upper edge of the yoke inwardly at an equal angel and the remaining half of the salient poles being projected as lower salient poles on an inner lower edge of the yoke inwardly at an equal angle so as not to overlap the upper salient poles vertically and horizontally;an upper stator yoke formed in the shape of a cup using a soft magnetic material and having inwardly projecting salient poles having a sectional square formed on the bottom thereof, the upper stator yoke being superimposed on the upper side of the magnetic flux density adjusting yoke so that the salient poles thereof are aligned with the upper salient poles of the magnetic flux density adjusting yoke;a lower stator yoke formed in the shape of a cup using a soft magnetic material and having inwardly projecting salient poles having a sectional square formed on the bottom thereof, the lower stator yoke being superimposed on the lower side of the magnetic flux density adjusting yoke so that the salient poles thereof are aligned with the lower salient poles of the magnetic flux density adjusting yoke;a rectangular pole plate composed to the top of the salient poles; anddriving coils wound respectively around the superimposed portions of the upper salient poles and the superimposed portions of the lower salient poles.