Brushless motor and disk drive including the same

Abstract

A brushless motor includes a rotor position detecting device disposed between stator teeth, rather than directly below a rotor magnet, so that the distance between a lower end of a rotor magnet and a stationary frame is minimized. This results in a thinner brushless motor than conventional designs. In the preferred embodiment of the present invention, the rotor position detecting device is a Hall device.

1 - 13 . Cancelled.  
     
     
         14 . A disk drive having a disk for reading and/or writing information, comprising: 
 a housing;    a brushless motor fixed to said housing; and    information access means for writing and/ or reading information in and/or from a predetermined position on said disk,    said brushless motor comprising:    a frame;    a rotor rotatably supported by said frame;    a rotor magnet fixed to said rotor;    a stator fixed onto said frame, said stator is spaced away from said rotor magnet to define a gap therebetween, said stator comprising a substantially annular base portion and a plurality of teeth circumferentially adjacent to each other and projecting from said annular base portion toward said rotor magnet with stator windings wound over each of the teeth; and    a rotor rotational position detecting device fixed onto or over said frame and disposed between the adjacent teeth of said stator;    wherein said stator windings are unevenly wound over said teeth to define a space in which said rotor rotational position detecting device is to be disposed.    
     
     
         15 . The disk drive according to  claim 14 , wherein said rotor rotational position detecting device is disposed away from an area directly below said rotor magnet.  
     
     
         16 . The disk drive according to  claim 14 , wherein said rotor rotational position detecting device is located in a place where a magnetic flux change caused by the rotor rotation is sufficient for a stator current to be switched to make the rotor rotate accurately.  
     
     
         17 . The disk drive according to  claim 14 , wherein said rotor rotational position detecting device is a Hall device.  
     
     
         18 . The disk drive according to  claim 17 , wherein said Hall device has a magnetic-flux sensitive surface inclined with respect to a surface of said frame.  
     
     
         19 . The disk drive according to  claim 17 , wherein said Hall device has a magnetic-flux sensitive surface inclined at an angle with respect to a surface of said frame, and the angle is determined by selecting an angle value where a magnetic flux change caused by the rotor rotation is sufficient for a stator current to be switched to make the rotor rotate accurately.  
     
     
         20 . The disk drive according to  claim 14 , wherein said stator windings are wound in less number over a distal end portion of said teeth in a radial direction.