Impeller pump

Abstract

A centrifugal pump includes a motor with a shaft and an adapter mounted to the motor. A volute housing mounted to the adapter defines a volute chamber. The adapter and volute housing define a pumping chamber therebetween. The volute housing includes an impeller inlet wall having an orifice. An impeller is disposed within the pumping chamber and a hub of the impeller is mounted on the shaft while a shroud portion coincides with the impeller orifice. An inducer is coupled to the shaft and extends into the inlet dogleg. A first portion of the inducer resides within the shroud portion of the impeller and a second portion of the inducer resides within the inlet orifice. The inducer includes helical blades whereby, upon rotation of the shaft, a fluid within the inlet dogleg is acted upon by the helical blades of the inducer before the fluid enters the impeller shroud portion.

What is claimed is: 
     
         1 . A centrifugal pump, comprising:
 a) a motor with a shaft rotatably extending therefrom;   b) an adapter configured to be mounted to the motor at a first side, the adapter defining an opening for permitting passage of the shaft therethrough;   c) a volute housing configured to be mounted to a second side of the adapter wherein the volute housing defines an inlet dogleg and the adapter and volute housing define a pumping chamber therebetween, wherein the volute housing includes an impeller inlet wall delineating the inlet dogleg from the pumping chamber, wherein the impeller inlet wall defines an impeller inlet orifice whereby the volute chamber is in fluid communication with the pumping chamber;   d) an impeller configured to be disposed within the pumping chamber, wherein a hub of the impeller is rotatably mounted on the shaft, and wherein the impeller includes a shroud portion configured to coincide with the impeller inlet orifice; and   e) an inducer having an inducer body with a first end configured to be coupled to a distal end of the shaft and a second end configured to extend into the volute chamber, whereby a first portion of the inducer resides within the shroud portion of the impeller and a second portion of the inducer resides within the inlet orifice, wherein the inducer includes at least two helical blades extending a length of the inducer proximate the first end to proximate the second end whereby, upon rotation of the shaft, a fluid within the inlet dogleg is acted upon by the helical blades along the second portion of the inducer before the fluid enters the impeller shroud portion.   
     
     
         2 . The centrifugal pump of  claim 1  wherein each of the helical blades has a variable pitch wherein the pitch decreases linearly from the first end to the second end. 
     
     
         3 . The centrifugal pump of  claim 1 , wherein the shroud portion of the impeller includes a wear ring configured to be encompassed by the volute housing and coincide with the impeller inlet orifice whereby a leakage flow path is defined between volute housing and the wear ring whereby a high pressure leakage flow exits the leakage flow path into the volute chamber along the second portion of the inducer. 
     
     
         4 . A centrifugal pump, comprising:
 a) a motor with a shaft rotatably extending therefrom;   b) an adapter configured to be mounted to the motor at a first side, the adapter defining an opening for permitting passage of the shaft therethrough;   c) a volute housing configured to be mounted to a second side of the adapter wherein the volute housing defines a volute chamber and the adapter and volute housing define a pumping chamber therebetween, wherein the volute housing includes an impeller inlet wall delineating the inlet dogleg from the pumping chamber, wherein the impeller inlet wall defines an impeller inlet orifice whereby the inlet dogleg is in fluid communication with the pumping chamber;   d) an impeller configured to be disposed within the pumping chamber, wherein a hub of the impeller is rotatably mounted on the shaft, and wherein the impeller includes a shroud portion having a wear ring configured to be encompassed by the volute housing and coincide with the impeller inlet orifice; and   e) an inducer having an inducer body with a first end configured to be coupled to a distal end of the shaft and a second end configured to extend into the volute chamber, whereby a first portion of the inducer resides within the shroud portion of the impeller and a second portion of the inducer resides within the inlet orifice, wherein the inducer includes at least two helical blades extending a length of the inducer proximate the first end to proximate the second end, wherein each of the helical blades has a variable pitch wherein the pitch decreases linearly from the first end to the second end whereby, upon rotation of the shaft, a fluid within the volute chamber is acted upon by the helical blades along the second portion of the inducer before the fluid enters the impeller shroud portion,   wherein a leakage flow path is defined between volute housing and the wear ring whereby a high pressure leakage flow exits the leakage flow path into the volute chamber along the second portion of the inducer.   
     
     
         5 . An impeller assembly for use within a centrifugal, wherein the centrifugal pump includes a motor with a shaft rotatably extending therefrom, the impeller assembly comprising:
 a) an adapter configured to be mounted to the motor at a first side, the adapter defining an opening for permitting passage of the shaft therethrough;   b) a volute housing configured to be mounted to a second side of the adapter wherein the volute housing defines an inlet dogleg and the adapter and volute housing define a pumping chamber therebetween, wherein the volute housing includes an impeller inlet wall delineating the inlet dogleg from the pumping chamber, wherein the impeller inlet wall defines an impeller inlet orifice whereby the volute chamber is in fluid communication with the pumping chamber;   c) an impeller configured to be disposed within the pumping chamber, wherein a hub of the impeller is rotatably mounted on the shaft, and wherein the impeller includes a shroud portion configured to coincide with the impeller inlet orifice; and   d) an inducer having an inducer body with a first end configured to be coupled to a distal end of the shaft and a second end configured to extend into the volute chamber, whereby a first portion of the inducer resides within the shroud portion of the impeller and a second portion of the inducer resides within the inlet orifice, wherein the inducer includes at least two helical blades extending a length of the inducer proximate the first end to proximate the second end whereby, upon rotation of the shaft, a fluid within the inlet dogleg is acted upon by the helical blades along the second portion of the inducer before the fluid enters the impeller shroud portion.