Heatsink fan structure

Abstract

A heatsink fan structure includes an impeller having a hub provided with a pivot portion rotatably mounted on the pivot portion of the housing. The hub of the impeller has a periphery provided with multiple blades that are arranged in a radiating manner. A circular fixing frame is mounted on an outer periphery of the blades. The fixing frame has a permanent magnet. The upper and lower ends of each of the blades are not protruded from the fixing frame.

What is claimed is:  
     
         1 . A heatsink fan structure, comprising: 
 a housing, provided with a pivot portion, multiple poles, a circuit board, and an air outlet;    an outer frame, combined with the housing, the outer frame having an air inlet, the air inlet having a periphery formed with an annular lip; and    an impeller, having a hub provided with a pivot portion rotatably mounted on the pivot portion of the housing, the hub of the impeller having a periphery provided with multiple blades that are arranged in a radiating manner, a circular fixing frame mounted on an outer periphery of the blades, the fixing frame having a permanent magnet, and upper and lower ends of each of the blades being not protruded from the fixing frame.    
     
     
         2 . The heatsink fan structure as claimed in  claim 1 , wherein the fixing frame has a diameter greater than that of the air inlet of the outer frame.  
     
     
         3 . The heatsink fan structure as claimed in  claim 1 , wherein at least one of the upper end and the lower end of the inner periphery of the fixing frame is formed with a horn-shaped arcuate edge.  
     
     
         4 . The heatsink fan structure as claimed in  claim 3 , wherein the lip of the outer frame is extended downward, and has a curvature the same as that of the arcuate edge of the fixing frame.  
     
     
         5 . A heatsink fan structure, comprising: 
 a housing, having a receiving space provided with a base board and an air outlet, the base board provided with a stator seat, the stator seat having a pivot portion; and    an impeller, having a hub provided with a pivot portion rotatably mounted on the pivot portion of the housing, the hub having a permanent magnet that is repulsive to a magnetic field produced by the stator seat of the housing, the hub of the impeller having a periphery provided with multiple blades, a fixing frame mounted on an outer periphery of the blades, and upper and lower ends of each of the blades being not protruded from the fixing frame.