Pressure-boosting axial-flow heat-dissipating fan

Abstract

A pressure-boosting axial-flow heat-dissipating fan includes a housing and an impeller. The housing includes an annular wall including an air inlet in a first end thereof and an air outlet in a second end thereof. A base and a pressure-boosting device are mounted in the air outlet. The impeller is rotatably mounted to the base. The impeller includes a hub and a plurality of blades on an outer periphery of the hub. Two of the blades adjacent to each other partially overlap with each other along an axis parallel to a rotating axis of the impeller. The number of the blades on the impeller is increased such that the overall air-driving area of the blades is increased, improving the overall heat-dissipating efficiency.

1 . A pressure-boosting axial-flow heat-dissipating fan comprising: 
 a housing including an annular wall, the annular wall including an air inlet in a first end thereof and an air outlet in a second end thereof, a base and a pressure-boosting device being mounted in the air outlet; and    an impeller rotatably mounted to the base, the impeller including a hub and a plurality of blades on an outer periphery of the hub, two of the blades adjacent to each other partially overlapping with each other along an axis parallel to a rotating axis of the impeller.    
   
   
       2 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the hub is substantially inverted U-shaped and includes an arcuate portion adjacent to the air inlet side.  
   
   
       3 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein each said blade includes an air-inlet-side tip substantially flush with an end face of the housing that is adjacent to the air inlet of the housing.  
   
   
       4 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the hub extends out of the air inlet of the housing.  
   
   
       5 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the blades suck axial airflow and ambient radial airflow into the housing.  
   
   
       6 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 5  wherein the hub and the blades extend out of the air inlet of the housing.  
   
   
       7 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein each said blade includes an air-inlet-side tip at a level higher than the hub.  
   
   
       8 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the air inlet of the housing is circular.  
   
   
       9 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the pressure-boosting device includes a plurality of radially extending plates each having a first end fixed to the base and a second end fixed to the annular wall.  
   
   
       10 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein each said plate has a slant opposite to that of the blades with respect to the rotating axis of the impeller.  
   
   
       11 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 1  wherein the pressure-boosting device includes a plurality of parallel plates.  
   
   
       12 . The pressure-boosting axial-flow heat-dissipating fan as claimed in  claim 11  wherein each said plate is substantially triangular in section.