Multiblade fan

Abstract

To provide a multiblade fan that enables an improvement in noise characteristics or blowing performance. The multiblade fan includes a scroll type casing that has a bell-mouthed inlet and an impeller housed in the casing. The impeller includes a plurality of blades and a rotation axis m oriented toward the inlet of the casing. The blades are annularly arranged. In the multiblade fan, a center axis of the inlet and the rotation axis of the impeller are arranged at a tilt angle to each other and in any one of an intersecting positional relationship and a skew-lines positional relationship so that a space between the inlet and the impeller increases from the rotation axis of the impeller toward an outlet of the casing.

1 . A multiblade fan comprising:
 a scroll type casing that includes a bell-mouthed inlet; and   an impeller that includes a plurality of annularly arranged blades and a rotation axis oriented toward the inlet and that is housed in the casing, wherein   a center axis of the inlet and the rotation axis of the impeller are arranged to make a tilt angle and in either one of a mutually intersecting positional relationship and a mutually skewed positional relationship, so that a space between the inlet and the impeller is increased from the rotation axis of the impeller toward an outlet of the casing.   
     
     
         2 . The multiblade fan according to  claim 1 , wherein a positional relationship between the center axis of the inlet and the rotation axis of the impeller is adjusted by arranging the center axis of the inlet to be tilted relative to a main body of the casing. 
     
     
         3 . The multiblade fan according to  claim 1 , wherein a positional relationship between the center axis of the inlet and the rotation axis of the impeller is adjusted by arranging the rotation axis of the impeller to be tilted relative to a main body of the casing.