Centrifugal pump impeller with inverted expulsion chambers

Abstract

An impeller for a centrifugal pump includes a shroud, wherein the shroud is a substantially planar circular section of material. The impeller includes a hub portion disposed in the center of the shroud; the hub configured to connect the impeller to a driveshaft for rotation in a preferred direction. The impeller also includes a plurality of inverted expulsion chambers, wherein each inverted expulsion chamber comprises a channel-shaped relief in the shroud extending radially towards an outer perimeter of the shroud.

What is claimed is: 
     
         1 . An impeller for a centrifugal pump, the impeller comprising: 
 a shroud comprising a substantially planar circular section of material;   a hub disposed in the center of the shroud, the hub configured to connect the impeller to a driveshaft for rotation in a preferred direction; and   a plurality of inverted expulsion chambers, wherein each inverted expulsion chamber comprises a channel-shaped relief in the shroud extending from a location proximate to the center of the shroud toward an outer perimeter of the shroud.   
     
     
         2 . The impeller of  claim 1 , wherein the plurality of inverted expulsion chambers comprises less than six inverted expulsion chambers. 
     
     
         3 . The impeller of  claim 1 , wherein the plurality of inverted expulsion chambers comprises six or more inverted expulsion chambers.  
     
     
         4 . The impeller of  claim 1 , wherein a cross section of each of the plurality of inverted expulsion chambers has a backward leaning geometry. 
     
     
         5 . The impeller of  claim 1 , wherein a cross section of each of the plurality of inverted expulsion chambers comprises a trough point, a leading edge, and a trailing edge. 
     
     
         6 . The impeller of  claim 5 , wherein the leading edges and trailing edges are symmetrical relative to the trough point. 
     
     
         7 . The impeller of  claim 5 , wherein the leading edges and trailing edges are asymmetrical relative to the trough point. 
     
     
         8 . The impeller of  claim 1 , wherein a cross section of two or more of the plurality of inverted expulsion chambers embody more than one cross-sectional geometry.  
     
     
         9 . The impeller of  claim 1 , wherein at least one of the plurality of inverted expulsion chambers has a cross-sectional geometry that varies along a length of the at least one of the plurality of inverted expulsion chambers. 
     
     
         10 . The impeller of  claim 1 , comprising a first one or more of the plurality of inverted expulsion chambers embodies a first cross-sectional geometry and a second one or more of the plurality of inverted expulsion chambers embodies a second cross-sectional geometry. 
     
     
         11 . A centrifugal pump including the impeller of  claim 1 , wherein the shroud comprises a first shroud and wherein the impeller further comprises: 
 a second shroud; and   a sidewall portion extending between the first shroud and the second shroud,   wherein the centrifugal pump further comprises: 
 a casing within which the impeller is rotatably mounted, the casing including an intake opening and a discharge opening; and 
 a motor connected to rotate the impeller in the preferred direction. 
   
     
     
         12 . A method of manufacturing an impeller for a centrifugal pump, the method comprising: 
 forming a shroud comprising a substantially planar circular section of material; and   disposing a hub in the center of the shroud, the hub configured to connect the impeller to a driveshaft for rotation in a preferred direction,   wherein an outer surface of the shroud includes a plurality of inverted expulsion chambers, wherein each inverted expulsion chamber comprises a channel-shaped relief in the shroud extending from a location proximate to the center of the shroud toward an outer perimeter of the shroud.   
     
     
         13 . The method of  claim 12 , wherein the plurality of inverted expulsion chambers comprises less than six inverted expulsion chambers. 
     
     
         14 . The method of  claim 12 , wherein the plurality of inverted expulsion chambers comprises six or more inverted expulsion chambers.  
     
     
         15 . The method of  claim 12 , wherein a cross section of each of the plurality of inverted expulsion chambers has a backward leaning geometry. 
     
     
         16 . The method of  claim 12 , wherein a cross section of each of the plurality of inverted expulsion chambers comprises a trough point, a leading edge, and a trailing edge. 
     
     
         17 . The method of  claim 16 , wherein the leading edges and trailing edges are symmetrical relative to the trough point. 
     
     
         18 . The method of  claim 16 , wherein the leading edges and trailing edges are asymmetrical relative to the trough point. 
     
     
         19 . The method of  claim 12 , wherein a cross section of two or more of the plurality of inverted expulsion chambers embody more than one cross-sectional geometry.  
     
     
         20 . The method of  claim 12 , wherein at least one of the plurality of inverted expulsion chambers has a cross-sectional geometry that varies along a length of the at least one of the plurality of inverted expulsion chambers.