Blower

Abstract

This invention is designed to reduce a harsh noise, by suppressing a wind noise generated at a wind-receiving end, which is caused by forming the wind-receiving end of an outlet port for air so as to be parallel to a side extending along the direction of the rotation axis of a vane of an impeller. For the purpose of reducing the harsh noise, the wind-receiving end ( 1 d 1 ) of the outlet port ( 1 d ) is provided in the form of steps or with inclination with respect to a side ( 3 a 1 ) extending along the direction of the rotation axis of a vane ( 3 a ) of the impeller ( 3 ) so that the wind sent and blown out by the vanes ( 3 a ) of the impeller ( 3 ) is prevented from blowing against the wind-receiving end ( 1 d 1 ) all at once throughout its entire width.

What is claimed is:  
     
         1 . A blower having a motor and an impeller which are housed within a casing provided with inlet ports and an outlet port, said impeller being rotated by said motor so that air is sucked from the inlet ports of said casing and discharged from said outlet port of said casing to send air, wherein 
 a wind-receiving end of said outlet port located on the inward side of an air flow is formed with inclination with respect to a side extending along the direction of the rotation axis of each vane of said impeller.    
     
     
         2 . The blower according to  claim 1 , wherein the maximum value of the inclination of said wind-receiving end of said outlet port is the value obtained by dividing a pitch of a vane of said impeller by the length of the side extending along the direction of the rotation axis of each vane of said impeller.  
     
     
         3 . A blower having a motor and an impeller which are housed within a casing provided with inlet ports and an outlet port, said impeller being rotated by said motor so that air is sucked from said inlet ports of said casing and discharged from said outlet port of said casing to send air, wherein 
 a wind-receiving end of said outlet port located on the inward side of an air flow is provided in the form of steps, including upper and lower steps each parallel to the side extending along the direction of the rotation axis of said vane of said impeller, and having a level difference in its middle.    
     
     
         4 . The blower according to  claim 3 , wherein the dimension of a vane pitch of said impeller is set as the maximum amount of the level difference in said wind-receiving end of said outlet port.