Centrifugal blower having auxiliary radial inlet

Abstract

A centrifugal blower includes a housing, a cover, and an impeller. The housing includes a peripheral wall delimiting an inner space. The peripheral wall further includes a first sidewall and a second sidewall respectively at two ends thereof. A radial air outlet is defined between the first sidewall and the second sidewall of the peripheral wall. A cover includes an axial air inlet communicated with the inner space of the housing. An impeller is rotatably mounted in the inner space of the housing and aligned with the axial air inlet. At least one auxiliary radial air inlet is defined in the peripheral wall and adjacent to one of the first sidewall and the second sidewall. When the impeller turns, an axial airflow is sucked into the inner space via the axial air inlet and an auxiliary radial airflow is sucked into the inner space via the auxiliary radial air inlet.

1 . A centrifugal blower comprising: 
 a housing comprising a peripheral wall delimiting an inner space, the peripheral wall further including a first sidewall and a second sidewall respectively at two ends thereof, a radial air outlet being defined between the first sidewall and the second sidewall of the peripheral wall;    a cover including an axial air inlet communicated with the inner space of the housing; and    an impeller rotatably mounted in the inner space of the housing and aligned with the axial air inlet;    at least one auxiliary radial air inlet being defined in the peripheral wall and adjacent to one of the first sidewall and the second sidewall;    wherein when the impeller turns, an axial airflow is sucked into the inner space via the axial air inlet and an auxiliary radial airflow is sucked into the inner space via said at least one auxiliary radial air inlet.    
   
   
       2 . The centrifugal blower as claimed in  claim 1  wherein: 
 a portion of the peripheral wall adjacent to the first sidewall delimiting the radial air outlet is an air-driving starting point;    another portion of the peripheral wall adjacent to the second sidewall delimiting the radial air outlet is an air-driving end point; and    said at least one auxiliary air inlet is adjacent to the air-driving starting point.    
   
   
       3 . The centrifugal blower as claimed in  claim 2  wherein the housing is a snail shell-like structure and wherein the impeller is eccentrically mounted in the inner space.  
   
   
       4 . The centrifugal blower as claimed in  claim 3  wherein the first sidewall delimiting the radial air outlet is closer to the impeller than the second sidewall delimiting the radial air outlet.  
   
   
       5 . The centrifugal blower as claimed in  claim 1  wherein said at least one auxiliary radial air inlet is a rectilinear slit.  
   
   
       6 . The centrifugal blower as claimed in  claim 1  wherein said at least one auxiliary radial air inlet is an inclined slit.  
   
   
       7 . The centrifugal blower as claimed in  claim 1  wherein said at least one auxiliary radial air inlet is delimited by two sidewalls that extend in a direction at an acute angle with a radial direction of the peripheral wall.  
   
   
       8 . The centrifugal blower as claimed in  claim 1  wherein said at least one auxiliary radial air inlet has a width that decreases inward.  
   
   
       9 . The centrifugal blower as claimed in  claim 2  wherein a plurality of equispaced auxiliary radial air inlets are defined in the peripheral wall and adjacent to the first sidewall delimiting the radial air outlet.  
   
   
       10 . The centrifugal blower as claimed in  claim 9  wherein each said auxiliary radial air inlet has a width that decreases inward.  
   
   
       11 . The centrifugal blower as claimed in  claim 9  wherein two sidewalls delimiting each of said auxiliary radial air inlets are parallel to each other.  
   
   
       12 . The centrifugal blower as claimed in  claim 9  wherein the peripheral wall further includes a plurality of extensions for the auxiliary radial air inlets, the extensions projecting from an inner face of the peripheral wall and extending along an air-driving direction of the impeller.