Centrifugal multi-blade blower

Abstract

A centrifugal multi-blade blower includes an impeller, and a casing that accommodates the impeller, and draws in air at least from an inlet port of the casing which opens on one end side of a rotation shaft and blows out the air radially outward of the rotation shaft. The impeller includes a main plate that is joined to the rotation shaft, vanes which are arranged around the axis of the rotation shaft and the other end sides of which in the rotation axis direction are connected to the main plate, and a side plate that connects together the vanes on their one end sides in the rotation axis direction. The vanes are characterized in that an inlet angle on a cross-sectional surface crossing each inner peripheral edge part of the vanes on a meridian plane of the impeller in a predetermined direction is evenly made in the entire region from the side plate-side through the main plate-side, and that outer peripheral edge parts of the vanes are configured to be away from the axis of the rotation shaft from the main plate-side toward the side plate-side.

What is claimed is: 
     
         1 . A centrifugal multi-blade blower comprising:
 a rotation shaft;   an impeller that rotates with the rotation shaft as a center of the rotation and includes:   a main plate that is coupled with the rotation shaft;   a plurality of vanes that are arranged around an axis of the rotation shaft; and   a side plate that connects together the plurality of vanes on one end side of the rotation shaft; and   a casing that accommodates the impeller and includes an inlet port which opens at least on the one end side of the rotation shaft, wherein:   the blower draws in air through the inlet port and blows out the air radially outward of the rotation shaft;   the plurality of vanes on the other end side of the rotation shaft are connected to the main plate;   the plurality of vanes are configured such that an inlet angle on a cross-sectional surface crossing each inner peripheral edge part of the plurality of vanes on a meridian plane of the impeller in a predetermined direction is evenly made in an entire region from the side plate through the main plate;   outer peripheral edge parts of the plurality of vanes are configured to separate from the axis of the rotation shaft from the main plate toward the side plate;   a ratio of an outer peripheral diameter to an inner peripheral diameter of the impeller on the side plate-side is a side-plate side inner-outer diameter ratio;   a ratio of an outer peripheral diameter to an inner peripheral diameter of the impeller on the main plate-side is a main-plate side inner-outer diameter ratio; and   the impeller is configured such that the side-plate side inner-outer diameter ratio is smaller than the main-plate side inner-outer diameter ratio.   
     
     
         2 . The centrifugal multi-blade blower according to  claim 1 , wherein each of the plurality of vanes is configured such that a part of the inner peripheral edge part on the one end side of the rotation shaft is located on a front side of a part of the inner peripheral edge part on the other end side of the rotation shaft in a rotation direction of the impeller. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The centrifugal multi-blade blower according to  claim 1 , wherein the inlet angle of each of the plurality of vanes on each cross-section perpendicular to a direction of the rotation shaft is made evenly in the entire region from the side plate through the main plate. 
     
     
         7 . The centrifugal multi-blade blower according to  claim 1 , wherein:
 the each inner peripheral edge part of the plurality of vanes is divided into a predetermined number of portions whose lengths along the inner peripheral edge part are the same;   each of the outer peripheral edge parts of the plurality of vanes is divided into the predetermined number of portions whose lengths along the each of the outer peripheral edge parts are the same;   a line that connects together an inner division point at the each inner peripheral edge part and an outer division point at the each of the outer peripheral edge parts is an imaginary flow line, the inner division point and the outer division point being located in the same order; and   each of the plurality of vanes is configured such that the inlet angle on a cross-section along each imaginary flow line is made evenly in the entire region from the side plate through the main plate.   
     
     
         8 . (canceled)