Heat dissipation device and centrifugal fan thereof

Abstract

A centrifugal fan includes a housing and a plurality of blades received in the housing. The housing includes a base wall and a sidewall surrounding the base wall. The sidewall defines a first air outlet and a second air outlet adjacent to the first air outlet. An elongated air guiding plate is located between the first air outlet and the second air outlet. The air guiding plate includes an outer end away from the blades and an inner end adjacent to the blades. A height of the inner end of the air guiding plate in an axial direction of the centrifugal fan is smaller than a height of the outer end of the air guiding plate.

1 . A centrifugal fan comprising:
 a plurality of blades;   a housing for receiving the blades therein, the housing comprising a base wall and a sidewall surrounding the base wall, the sidewall defining a first air outlet and a second air outlet adjacent to the first air outlet; and   an elongated air guiding plate being located between the first air outlet and the second air outlet, the air guiding plate comprising an outer end away from the blades and an inner end adjacent to the blades, a height of the inner end of the air guiding plate in an axial direction of the centrifugal fan being smaller than a height of the outer end of the air guiding plate.   
   
   
       2 . The centrifugal fan as described in  claim 1 , wherein a maximal height of the air guiding plate is smaller than a height of the sidewall. 
   
   
       3 . The centrifugal fan as described in  claim 1 , wherein a distance between the inner end of the air guiding plate and distal ends of the blades is no smaller than one millimeter. 
   
   
       4 . The centrifugal fan as described in  claim 1 , wherein an outline of the base wall comprises an arced section, a first linear section and a second linear section connected between two opposite ends of the arced section, the first and second linear sections corresponding to the first and second air outlets, respectively, the air guiding plate extending inwardly from a junction of the two linear sections towards the blades. 
   
   
       5 . The centrifugal fan as described in  claim 4 , wherein an airflow generated by the blades first reaches the first linear section and then the second linear section, and an angle formed between the air guiding plate and the first linear section is smaller than 45 degrees. 
   
   
       6 . The centrifugal fan as described in  claim 1 , wherein the height of the outer end of the air guiding plate is constant, while the height of the inner end of the air guiding plate decreases gradually from the outer end towards the blades. 
   
   
       7 . The centrifugal fan as described in  claim 6 , wherein the air guiding plate comprises a first lateral surface facing and adjacent to the first air outlet and a confronting second lateral surface facing and adjacent to the second air outlet, the first lateral surface being parallel to the second lateral surface. 
   
   
       8 . The centrifugal fan as described in  claim 1 , wherein a size of a transverse section of the air guiding plate gradually increases along a longitudinal direction from a topmost end of the air guiding plate towards a bottommost end thereof. 
   
   
       9 . The centrifugal fan as described in  claim 8 , wherein the air guiding plate comprises a first lateral surface facing and adjacent to the first air outlet and a confronting second lateral surface facing and adjacent to the second air outlet, the first and second lateral surfaces intersect with each other and thus forms a side edge at the inner end of the air guiding plate. 
   
   
       10 . A heat dissipation device comprising:
 a centrifugal fan comprising a housing and a plurality of blades received in the housing, the housing comprising a base wall and a sidewall surrounding the base wall, the sidewall defining a first air outlet and a second air outlet adjacent to the first air outlet, an elongated air guiding plate being located between the first air outlet and the second air outlet, the air guiding plate comprising an outer end which is adjacent to a side edge of the base wall and an inner end which is adjacent to the blades, a height of the inner end of the air guiding plate in an axial direction of the centrifugal fan being smaller than the height of the outer end of the air guiding plate; and   a first fin unit and a second fin unit received in the first air outlet and the second fin unit, respectively.   
   
   
       11 . The heat dissipation device as described in  claim 10 , wherein a minimal distance between the inner end of the air guiding plate and the blades is one millimeter. 
   
   
       12 . The heat dissipation device as described in  claim 10 , wherein the height of the air guiding plate decreases gradually from the outer end towards the inner end, a maximal height of the air guiding plate is smaller than a height of the sidewall. 
   
   
       13 . The heat dissipation device as described in  claim 12 , wherein the air guiding plate comprises a first lateral surface facing and adjacent to the first air outlet and a confronting second lateral surface facing and adjacent to the second air outlet, the first lateral surface being parallel to the second lateral surface. 
   
   
       14 . The heat dissipation device as described in  claim 12 , wherein a size of a transverse section of the air guiding plate gradually increases along a longitudinal direction from a topmost end of the air guiding plate towards a bottommost end thereof. 
   
   
       15 . The heat dissipation device as described in  claim 10 , wherein a distance between the inner end of the air guiding plate and the blades is gradually increased along the axial direction of the centrifugal fan from a bottom to a top thereof.