Impeller blade with uneven spacing

Abstract

An impeller assembly configured to produce low noise is provided. In one embodiment, an impeller assembly is provided having a hollow cylindrical hub body with a sleeve extending therethrough. The sleeve is configured to receive a driveshaft of a motor to couple the impeller assembly to the motor. The impeller assembly includes a plurality of impeller blades extending radially outward therefrom. Each blade of the plurality of impeller blades is unevenly distributed around a circumference of the hub body.

What is claimed is: 
     
         1 . An impeller assembly, comprising:
 a generally cylindrical hollow hub body;   a sleeve extending through the hub body, the sleeve includes a central bore therethrough configured to receive a driveshaft for coupling the impeller assembly to a motor;   a plurality of vanes extending between the sleeve and the hub body; and   a plurality of impeller blades extending radially outward from the hub body and being unevenly distributed around a circumference of the hub body.   
     
     
         2 . The impeller assembly of  claim 1  wherein each impeller blade of the plurality of impeller blades is angled relative to a longitudinal axis of the hub body. 
     
     
         3 . The impeller assembly of  claim 1  wherein the plurality of impeller blades comprises an odd number of impeller blades. 
     
     
         4 . The impeller assembly of  claim 1  wherein each blade of the plurality of impeller blades includes an outer rim having a first vertex and a second vertex, and wherein a first distance between the first vertex of each impeller blade and a corresponding first vertex of a consecutive impeller blade in the clockwise direction differs from a second distance between the first vertex of each impeller blade and a corresponding first vertex of a consecutive impeller blade in the counterclockwise direction. 
     
     
         5 . The impeller assembly of  claim 1  wherein a center of mass of the impeller assembly is positioned along a longitudinal axis of the hub body. 
     
     
         6 . The impeller assembly of  claim 1 , wherein rotation of the hub body is configured to cause the plurality of impeller blades to create a pressure wave, and wherein at least two of plurality of impeller blades create pressure waves at different frequencies. 
     
     
         7 . The impeller assembly of  claim 1 , further comprising a cylindrical covering disposed around the plurality of impeller blades. 
     
     
         8 . The impeller assembly of  claim 7 , wherein the cylindrical covering includes a plurality of diffusing apertures. 
     
     
         9 . An impeller assembly comprising:
 a hub body including an inner surface and an outer surface, wherein the inner surface comprises a recess;   a sleeve extending through a center of the hub body, wherein the sleeve is configured to receive a driveshaft to physically couple the impeller assembly to a motor;   a plurality of vanes extending from the sleeve to the inner surface; and   a plurality of impeller blades extending radially outward from the outer surface and spaced around a circumference of the outer surface, wherein each blade of the plurality of impeller blades includes an outer edge having a first vertex and a second vertex, and wherein a first distance between the first vertex of each blade and a corresponding first vertex of an immediately adjacent blade in the clockwise direction differs from a second distance between the first vertex of each blade and a corresponding first vertex of an immediately adjacent blade in the counterclockwise direction.   
     
     
         10 . The impeller assembly of  claim 9 , wherein each of the plurality of impeller blades is angled related to a longitudinal axis of the sleeve. 
     
     
         11 . The impeller assembly of  claim 9 , wherein a center of mass of the impeller assembly is positioned along a longitudinal axis of the hub body. 
     
     
         12 . The impeller assembly of  claim 9 , wherein rotation of the hub body is configured to cause the plurality of impeller blades to create a pressure wave, and wherein at least two of plurality of impeller blades have pressure waves that differ from one. 
     
     
         13 . The impeller assembly of  claim 9 , wherein rotation of the hub body is configured to cause the plurality of impeller blades to produce a blade passage frequency with a magnitude in the sound pressure level range of 55 to 65 dB(A) when measured at 1 meter away from the plurality of impeller blades. 
     
     
         14 . The impeller assembly of  claim 9 , wherein the plurality of impeller blades comprises an uneven number of impeller blades. 
     
     
         15 . The impeller assembly of  claim 9 , further comprising a cylindrical covering disposed around the plurality of impeller blades. 
     
     
         16 . The impeller assembly of  claim 15 , wherein the cylindrical covering includes a plurality of diffusing apertures. 
     
     
         17 . The impeller assembly of  claim 9 , wherein each of the plurality of vanes is spaced equidistant from each other around the sleeve.