Micro fan

Abstract

The present invention relates to a micro fan, including an impeller, a fan seat and a bottom cover plate, wherein the impeller has a shaft seat stationarily disposed at one end of a spindle and a plurality of blades extended from a periphery of the shaft seat, a top ring and a bottom ring are disposed on a top and a bottom ends of an outer rim of each blade, and a permanent magnet is disposed on a periphery of each blade and is positioned between the top and bottom rings. The impeller of the present invention requires only a single bearing to rotate the impeller therein, and thus there will be no concentricity alignment issue. Furthermore, an air inlet on the fan seat has no impediment at all and is subjected to no blockage, thereby not only increasing the air supply rate and smoothening the air flow field.

1 . A micro fan, comprising:
 an impeller having a spindle, a shaft seat stationarily disposed at one end of said spindle, a plurality of blades extended from an outer periphery of said shaft seat, and a permanent magnet disposed on an outer rim of each said blade;   a fan seat having an angular wall for said impeller to be centrally inserted therein, a stator containing slot located beside an outer periphery of said angular wall for accommodating a stator set, and an air inlet disposed on a top side of said fan seat; and   a bottom cover plate having an air outlet disposed centrally, a plurality of support rods located inside said air outlet and linked with a shaft tube, a bearing located inside said shaft tube for said spindle of said impeller to be centrally inserted in said bearing in a rotational manner.   
   
   
       2 . The micro fan of  claim 1 , wherein an air guiding flange is disposed at said air inlet and has an inner edge formed by inclined inwardly, and an inner hole of said air inlet is slightly smaller than a maximum outer diameter of said impeller. 
   
   
       3 . The micro fan of  claim 1 , wherein a top ring and a bottom ring are disposed on a top end and a bottom end on an outer edge of each said blade, and said permanent magnet is fixed between said top ring and said bottom ring. 
   
   
       4 . The micro fan of  claim 3 , wherein a snap protrusion is disposed on one side of said top ring and located in the proximity of said permanent magnet. 
   
   
       5 . The micro fan of  claim 3 , wherein a snap protrusion is disposed on one side of said bottom ring and located in the proximity of said permanent magnet. 
   
   
       6 . The micro fan of  claim 1 , wherein a fitting edge is disposed on an outer periphery of said air outlet for said angular wall to be inserted in, a magnetic absorption positioning plate is disposed on an inner side of said fitting edge and is snapped and positioned while said angular wall is fitted with said fitting edge. 
   
   
       7 . A micro fan, comprising:
 an impeller having a spindle, a shaft seat stationarily disposed at one end of said spindle, a plurality of blades extended from an outer periphery of said shaft seat, and a permanent magnet disposed on an outer rim of each said blade and is fixed between a top ring and a bottom ring;   a fan seat having an angular wall for said impeller to be centrally inserted therein, a stator containing slot located beside an outer periphery of said angular wall for accommodating a stator set, an air inlet disposed on a top side of said fan seat, and an air guiding flange disposed at said air inlet and having a diameter of an inner hole of said air guiding flange is less than a maximum outer diameter of said impeller; and   a bottom cover plate having an air outlet disposed centrally, a plurality of support rods located inside said air outlet and linked with a shaft tube, a bearing located inside said shaft tube for said spindle of said impeller to be centrally inserted in said bearing in a rotational manner.   
   
   
       8 . The micro fan of  claim 7 , wherein said air guiding flange has an inwardly-inclined inner edge. 
   
   
       9 . The micro fan of  claim 7 , wherein said top ring and said bottom ring are positioned at a top end and a bottom end of each said blade of said impeller. 
   
   
       10 . The micro fan of  claim 7 , wherein a snap protrusion is disposed on one side of said permanent magnet in the proximity of said top ring. 
   
   
       11 . The micro fan of  claim 7 , wherein a snap protrusion is disposed on one side of said permanent magnet in the proximity of said bottom ring. 
   
   
       12 . The micro fan of  claim 7 , wherein a fitting edge is disposed on a periphery of said air outlet for said angular wall to be inserted therein, a magnetic absorption positioning plate is provided on an inner side of said fitting edge to be snapped and positioned while said angular wall is inserted in said fitting edge.