Blowing device and cleaner

Abstract

A blowing device includes a mixed flow impeller that rotates about a central axis extending vertically, a motor that drives the mixed flow impeller to rotate, and an impeller cover surrounding an outside of the mixed flow impeller in a radial direction. The mixed flow impeller includes a hub portion extending outwardly in the radial direction toward a lower side in an axial direction, and moving blades juxtaposed on an outer surface of the hub portion in a circumferential direction. A minimum dimension of a first gap between the moving blade and the impeller cover at a lower end portion of the moving blade is larger than a minimum dimension of a second gap between the moving blade and the impeller cover at an upper end portion of the moving blade.

What is claimed is: 
     
         1 . A blowing device comprising:
 a mixed flow impeller that rotates about a central axis extending vertically;   a motor that drives the mixed flow impeller to rotate; and   an impeller cover surrounding an outside of the mixed flow impeller in a radial direction; wherein   the mixed flow impeller includes:
 a hub portion that expands outwardly in the radial direction toward a lower side in an axial direction; and 
 a plurality of moving blades which are juxtaposed on an outer surface of the hub portion in a circumferential direction; and 
   a minimum dimension of a first gap between the moving blade and the impeller cover at a lower end portion of the moving blade is larger than a minimum dimension of a second gap between the moving blade and the impeller cover at an upper end portion of the moving blade.   
     
     
         2 . The blowing device according to  claim 1 , wherein the hub portion includes a lower surface recess portion that is recessed in the axial direction on a lower surface. 
     
     
         3 . The blowing device according to  claim 1 , wherein
 the motor is disposed below the mixed flow impeller;   a motor housing which surrounds an outside of the motor in the radial direction is provided; and   a minimum dimension of a third gap between the motor housing and the impeller is smaller than a minimum dimension of a fourth gap between the motor housing and the impeller cover.   
     
     
         4 . The blowing device according to  claim 2 , wherein the motor includes:
 a shaft extending along the central axis;   a rotor that is fixed to the shaft and rotates together with the shaft;   an upper bearing that rotatably supports the shaft; and   a lower bearing that is disposed below the upper bearing and rotatably supports the shaft; and   at least a portion of the upper bearing is disposed in the lower surface recess portion.   
     
     
         5 . The blowing device according to  claim 1 , wherein a lower end portion of the hub portion includes a notch portion obtained by removing a portion of the hub portion. 
     
     
         6 . The blowing device according to  claim 1 , wherein the mixed flow impeller is made of resin. 
     
     
         7 . A cleaner comprising:
 the blowing device according to  claim 1 .