Fan structure with externally connected circuit

Abstract

A fan structure with externally connected circuit includes a frame body, a stator, a fan impeller and a circuit board. The stator and the fan impeller are disposed in the frame body. The circuit board is disposed on an outer face of the frame body in contact with ambient air. Therefore, the room for the circuit board is increased without increasing the thickness of the frame body. Moreover, the heat dissipation effect of the circuit board is enhanced.

What is claimed is: 
     
         1 . A fan structure with externally connected circuit, comprising:
 a frame body having an air inlet end, an air outlet end, an inner wall, an outer wall, an axial flow passage and a seat section, the air inlet end and the air outlet end being respectively formed on two sides of the frame body, the axial flow passage being defined by the inner wall to pass through the frame body, the seat section being positioned in the axial flow passage and connected to the inner wall via multiple support sections, a hollow bearing cup protruding from the seat section;   a stator fitted around the bearing cup and disposed on the seat section;   a fan impeller disposed on the seat section of the frame body corresponding to the stator, the fan impeller having multiple blades annularly arranged on an outer circumference of the fan impeller; and   a circuit board disposed on the outer wall and electrically connected to the stator.   
     
     
         2 . The fan structure with externally connected circuit as claimed in  claim 1 , wherein the circuit board has a connection side snugly attached to a part of the surface of the outer wall or the entire surface of the outer wall and an outer side exposed to ambient environment. 
     
     
         3 . The fan structure with externally connected circuit as claimed in  claim 1 , wherein a solid body is formed between the inner wall and the outer wall.