Heat dissipation device having passive fan

Abstract

The present invention relates to a heat dissipation device including a power fan for driving air to flow. The driven air flow drives the impeller of the passive fan to rotate on a support shaft of the heat dissipation seat, thereby generating a sideward wind supply. Therefore, the passive fan may be rotated without needing a power supply, and the passive itself will not generate high temperature and high heat, thereby further increasing the cooling and heat dissipating efficiency thereof on a heat emitting member.

What is claimed is:  
     
         1 . A heat dissipation device having a passive fan, comprising: 
 a power fan ( 1 ), for driving air to flow; and    a passive fan ( 2 ), including a heat dissipation seat ( 21 ) provided with a support shaft ( 25 ) for supporting an impeller ( 22 ) to rotate, the impeller ( 22 ) being driven to rotate by an air flow supplied by the power fan ( 1 ), thereby generating a sideward wind supply.    
     
     
         2 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the power fan ( 1 ) is provided with a connecting pipe ( 11 ) for guiding air to an air inlet port of the passive fan ( 2 ).  
     
     
         3 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the heat dissipation seat ( 21 ) of the passive fan ( 2 ) is provided with heat dissipation pieces ( 23 ) whose surrounding region defines a receiving space ( 24 ) provided with the support shaft ( 25 ) for allowing rotation of the impeller ( 22 ).  
     
     
         4 . The heat dissipation device having a passive fan as claimed in  claim 3 , wherein the heat dissipation pieces ( 23 ) of the heat dissipation seat ( 21 ) are arranged in a radiating manner, or an annular manner, or an inclined manner, or a flow guiding arc-shaped manner.  
     
     
         5 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the receiving space ( 24 ) is provided with heat dissipation posts ( 26 ) therein without hindering rotation of the impeller ( 22 ).  
     
     
         6 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the passive fan ( 2 ) includes flat plate shaped blades, or multi-wing shaped blades, or centrifugal typed blades.  
     
     
         7 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the support shaft ( 55 ) is provided in the receiving space ( 54 ) at a non-central position thereof.  
     
     
         8 . The heat dissipation device having a passive fan as claimed in  claim 1 , wherein the impeller ( 22 ) of the passive fan ( 2 ) includes a central hub ( 27 ) provided with a plurality of blades ( 28 ), and the blades ( 28 ) having a distal end provided with auxiliary blades ( 29 ) extending downward.  
     
     
         9 . A heat dissipation device having a passive fan, comprising: 
 a power fan ( 4 ), including a base ( 41 ) provided with a rotation shaft ( 44 ) and stator coils ( 42 ), the stator coils ( 42 ) being energized to drive an impeller ( 43 ) to rotate on the rotation shaft ( 44 ), to introduce the air into a wind inlet opening ( 45 ) and output the air through a wind outlet opening ( 46 ); and    a passive fan ( 7 ), including a heat dissipation seat ( 71 ) combined with the power fan ( 4 ), the heat dissipation seat ( 71 ) provided with a support shaft ( 75 ) for supporting an impeller ( 72 ) to rotate, the impeller ( 72 ) driven to rotate by an air flow supplied by the power fan ( 4 ), thereby generating a sideward wind supply.    
     
     
         10 . The heat dissipation device having a passive fan as claimed in  claim 9 , wherein the base ( 41 ) of the power fan ( 4 ) includes a plurality of stator coils ( 42 ), and the impeller ( 43 ) of the power fan ( 4 ) is provided with a magnet ring ( 47 ).  
     
     
         11 . The heat dissipation device having a passive fan as claimed in  claim 9 , wherein the impeller ( 43 ) of the power fan ( 4 ) includes blades having an outer periphery connected with an auxiliary blade ( 48 ) for producing a sideward wind supply, the auxiliary blade ( 48 ) extending into an inside of the heat dissipation seat ( 71 ).  
     
     
         12 . The heat dissipation device having a passive fan as claimed in  claim 11 , wherein the auxiliary blade ( 48 ) is a multi-wing shaped blade, or a flat plate shaped blade, or a centrifugal typed blade.  
     
     
         13 . A heat dissipation device having a passive fan, comprising: 
 a power fan ( 6 ), having a center provided with a hub ( 63 ) which includes stator coils and a magnet ring therein, so that an impeller ( 62 ) may be rotated to drive an air flow by blades ( 64 ), to introduce the air into a wind inlet opening ( 65 ) and output the air through a wind outlet opening ( 66 ); and    a passive fan ( 2 ), including a heat dissipation seat ( 21 ) combined with the power fan ( 6 ), the heat dissipation seat ( 21 ) provided with a support shaft ( 25 ) for supporting an impeller ( 22 ) to rotate, the impeller ( 22 ) driven to rotate by an air flow supplied by the power fan ( 6 ), thereby generating a sideward wind supply.    
     
     
         14 . The heat dissipation device having a passive fan as claimed in  claim 13 , wherein the impeller ( 22 ) of the passive fan ( 2 ) includes a central hub ( 27 ) provided with a plurality of blades ( 28 ), and the blades ( 28 ) having a distal end provided with auxiliary blades ( 29 ) extending downward.