Centrifugal Fan

Abstract

A centrifugal fan includes a housing and a blade assembly, wherein the blade assembly comprises a driving device and fan blades, and the fan blades have a rotation center; the housing is provided with an air inlet and an air outlet, and the housing covers the blade assembly to form a flow channel therein; the flow channel comprises a supercharging area and an opening area, wherein the first boundary between the supercharging area and the opening area is a line connecting the tongue and the center, and the second boundary between the supercharging area and the opening area is a line connecting the center and the end point of the arc-shaped side wall of the flow channel, and the opening area has a central angle greater than 180° with the center, so the centrifugal fan has a wider air outlet range and a larger air outlet volume.

What is claimed is: 
     
         1 . A centrifugal fan, comprising a housing and a blade assembly, wherein the blade assembly comprises a driving device and fan blades, and the fan blades have a rotation center; the housing is provided with an air inlet and an air outlet, and the housing covers the blade assembly to form a flow channel therein; the flow channel comprises a supercharging area and an opening area, wherein a first boundary between the supercharging area and the opening area is a line connecting the tongue and the center, and a second boundary between the supercharging area and the opening area is a line connecting the center and the end point of the arc-shaped side wall of the flow channel, and the opening area has a central angle greater than 180° with the center. 
     
     
         2 . A centrifugal fan according to  claim 1 , wherein the air outlet at least comprises an arc-shaped portion. 
     
     
         3 . A centrifugal fan according to  claim 1 , wherein the air outlet comprises an arc-shaped portion and a straight portion. 
     
     
         4 . A centrifugal fan according to any one of  claim 1 , wherein at least one air guide plate is provided near the air outlet of the flow channel. 
     
     
         5 . A centrifugal fan according to  claim 4 , wherein the extension direction of at least one of the air guide plates is the same as the extension direction of the flow channel at the air guide plate. 
     
     
         6 . A centrifugal fan according to  claim 1 , wherein the tongue is one end of the arc-shaped side wall of the flow channel, and the distance from the tongue to the center is smaller than the distance from other points on the arc-shaped side wall to the center. 
     
     
         7 . A centrifugal fan according to  claim 1 , wherein the outer shape of the housing is a combination of the semicircle and the rectangle, and chamfers are performed on four sides of the housing. 
     
     
         8 . A centrifugal fan according to  claim 7 , wherein the air outlet comprises an arc-shaped portion and a straight portion, the arc-shaped portion of the air outlet is located on the semicircular portion of the housing, and the straight portion of the air outlet is located on the rectangular portion of the housing. 
     
     
         9 . A centrifugal fan according to  claim 8 , wherein when the fan blade assembly is installed on the housing, the center of the fan blades coincides with the center of the semicircular part of the housing.