Centrifugal fan

Abstract

A centrifugal fan according to an exemplary embodiment of the present invention includes: a hub penetrated by a rotational axis; a plurality of main blades extended in a radial direction from a predetermined point of the top of the hub; a bell mouth formed on a top of the exteriors of the plurality of main blades; and a plurality of auxiliary blades extended in the radial direction between the plurality of main blades, wherein a ratio (D1/D2) of an inner diameter D1 to an outer diameter D1 of each of the auxiliary blades is in the range of 07 to 0.9.

1 . A centrifugal fan, comprising:
 a hub penetrated by a rotational axis;   a plurality of main blades extended in a radial direction from a predetermined point of the top of the hub;   a bell mouth formed on a top of the exteriors of the plurality of main blades; and   a plurality of auxiliary blades extended in the radial direction between the plurality of main blades,   wherein a ratio (D 1 /D 2 ) of an inner diameter Dl to an outer diameter D 1  of each of the auxiliary blades is in the range of 07 to 0.9.   
     
     
         2 . The centrifugal fan of  claim 1 , wherein the auxiliary blade is extended on a bottom of the bell mouth and is spaced apart from the hub. 
     
     
         3 . The centrifugal fan of  claim 2 , wherein the width of the auxiliary blade is smaller than that of the main blade. 
     
     
         4 . The centrifugal fan of  claim 2 , wherein the length of the auxiliary blade is larger than that of the main blade. 
     
     
         5 . The centrifugal fan of  claim 2 , wherein one or plural main blades are positioned between the adjacent auxiliary blades. 
     
     
         6 . The centrifugal fan of  claim 2 , wherein a ratio (W 1 /W 2 ) of the width w 1  of the trailing edge of the auxiliary blade to the width W 2  of the trailing edge of the main blade is in the range of 0.45 to 0.65. 
     
     
         7 . The centrifugal fan of  claim 2 , wherein the inner diameter D 1  of the auxiliary blade is equal to or larger than the diameter of the bottom of the hub. 
     
     
         8 . The centrifugal fan of  claim 2 , wherein the inner diameter D 1  of the auxiliary blade is equal to or larger than the inner diameter of the bell mouth.