Centrifugal fan

Abstract

A centrifugal fan includes a fan frame, an impeller and a motor. The fan frame includes a base plate, a sidewall and a plurality of air deflectors. The sidewall and the air deflectors are disposed on the base plate. The base plate, the sidewall and the air deflectors form an accommodating space and an air outlet. The impeller is disposed in the accommodating space. There is a flow channel between the impeller and the sidewall. The motor is connected with the impeller and drives the impeller to rotate. The air deflectors are set separately along the extension direction of the flow channel and toward to the air outlet. The distance between the air deflector which is closer to the air outlet and the impeller is larger.

What is claimed is: 
     
         1 . A centrifugal fan comprising:
 a fan frame comprising a base plate, a sidewall and a plurality of air deflectors, the sidewall and the air deflectors are disposed on the base plate, an accommodating space and an air outlet disposed by the base plate, the sidewall and the air deflector;   an impeller received in the accommodating space, a flow channel disposed between the impeller and the sidewall of the fan frame; and   a motor connected with the impeller and driving the impeller to rotate;   wherein the deflectors are set separately along the extension direction of the flow channel and toward to the air outlet, a distance is disposed between the air deflector and the impeller, and the distance increases when the air deflector is closer to the air outlet.   
     
     
         2 . The centrifugal fan of  claim 1 , wherein the two adjacent air deflectors are partially overlapped along a predetermined direction. 
     
     
         3 . The centrifugal fan of  claim 2 , wherein the impeller comprises a rotation center, an air deflector comprises an end adjacent to an additional air deflector, and the predetermined direction is a direction from the rotation center to the end of the air deflector. 
     
     
         4 . The centrifugal fan of  claim 1 , wherein the air deflectors at least comprises a first air deflector and a second air deflector, a distance between the second air deflector and the air outlet is smaller than a distance between the first air deflector and the air outlet, and the second air deflector and the impeller are separately disposed two opposite sides of the air deflector. 
     
     
         5 . The centrifugal fan of  claim 1 , wherein a gap is disposed between the adjacent two air deflectors, an outside airflow flows into the centrifugal fan via the gap, and the flow direction of the outside airflow is along an extension direction of the flow channel. 
     
     
         6 . The centrifugal fan of  claim 1 , wherein the sidewall comprises a throat part, and the air deflectors and the throat part are disposed at two opposite sides of the impeller, respectively. 
     
     
         7 . The centrifugal fan of  claim 1 , wherein the air deflectors are arc-shaped. 
     
     
         8 . The centrifugal fan of  claim 1 , wherein dusts in the centrifugal fan are exhausted from the centrifugal fan via a space between the two adjacent air deflectors when the impeller is driven to rotate reversely by the motor.