Impeller bearings for pumps

Abstract

Impeller bearings for pumps are disclosed. An example fluid pump includes a motor, a shaft coupled to a rotor of the motor, an impeller coupled to the shaft forward of the motor, the impeller including expeller vanes, a first radial bearing positioned around the shaft aft of the motor, wherein the first radial bearing is a first foil bearing through which fluid flows in a first direction, and a second radial bearing positioned around the impeller, wherein the second radial bearing is a second foil bearing through which fluid flows in the first direction.

What is claimed is: 
     
         1 . A fluid pump comprising:
 a motor;   a shaft coupled to a rotor of the motor;   an impeller coupled to the shaft forward of the motor, the impeller including expeller vanes;   a first radial bearing positioned around the shaft aft of the motor, wherein the first radial bearing is a first foil bearing through which fluid flows in a first direction; and   a second radial bearing positioned around the impeller, wherein the second radial bearing is a second foil bearing through which the fluid flows in the first direction.   
     
     
         2 . The fluid pump of  claim 1 , wherein the fluid contacts the expeller vanes after flowing through the second radial bearing and before flowing out of the fluid pump. 
     
     
         3 . The fluid pump of  claim 1 , further including:
 a housing including a primary inlet and a secondary inlet aft of the primary inlet; and   a thrust bearing coupled to the shaft aft of the first radial bearing, wherein the fluid that enters the housing via the secondary inlet flows through the thrust bearing, wherein a first portion of the fluid that flows through the thrust bearing subsequently flows between the first radial bearing and the shaft towards a forward end of the pump, wherein a second portion of the fluid that flows through the thrust bearing subsequently flows through a bore of the shaft towards the forward end of the pump.   
     
     
         4 . The fluid pump of  claim 3 , wherein the second portion of the fluid exits the shaft forward of the motor. 
     
     
         5 . The fluid pump of  claim 1 , further including a backplate positioned between the motor and the impeller in an axial direction, wherein a portion of the fluid driven by the impeller flows between the backplate and the impeller. 
     
     
         6 . The fluid pump of  claim 5 , further including a motor housing positioned around the motor aft of the backplate, wherein the portion of the fluid flows into the motor housing. 
     
     
         7 . The fluid pump of  claim 6 , wherein the portion of the fluid is a first portion, wherein the motor housing includes a secondary inlet and a secondary outlet, wherein the secondary inlet receives a second portion of the fluid, wherein the secondary outlet directs the first portion and the second portion of the fluid into a recirculating passageway. 
     
     
         8 . A fluid pump comprising:
 a housing including a primary inlet and a secondary inlet aft of the primary inlet;   a motor;   a shaft coupled to a rotor of the motor;   an impeller coupled to the shaft forward of the motor, the impeller including expeller vanes to drive fluid that flows through the primary inlet;   a first radial bearing positioned around the shaft aft of the motor; and   a thrust bearing coupled to the shaft aft of the first radial bearing, wherein the fluid that enters the housing via the secondary inlet flows through the thrust bearing, wherein a first portion of the fluid that flows through the thrust bearing subsequently flows between the first radial bearing and the shaft towards a forward end of the fluid pump, wherein a second portion of the fluid that flows through the thrust bearing subsequently flows through a bore of the shaft towards the forward end of the fluid pump.   
     
     
         9 . The fluid pump of  claim 8 , further including a second radial bearing positioned around the impeller. 
     
     
         10 . The fluid pump of  claim 9 , wherein the fluid flows towards the forward end of the pump in the second radial bearing. 
     
     
         11 . The fluid pump of  claim 8 , wherein the second portion of the fluid exits the shaft forward of the motor. 
     
     
         12 . The fluid pump of  claim 11 , wherein the impeller includes a nose forward of the expeller vanes, wherein the second portion of the fluid flows through the nose. 
     
     
         13 . The fluid pump of  claim 8 , wherein the second portion of the fluid exits the shaft aft of the impeller. 
     
     
         14 . The fluid pump of  claim 8 , wherein the expeller vanes are first expeller vanes extending from a forward side of the impeller, wherein the impeller includes second expeller vanes that extend from an aft side of the impeller. 
     
     
         15 . The fluid pump of  claim 14 , wherein the second expeller vanes drive at least one of the first portion or the second portion of the fluid radially outward. 
     
     
         16 . A fluid pump comprising:
 a motor;   a shaft coupled to a rotor of the motor;   an impeller coupled to the shaft forward of the motor, the impeller including expeller vanes;   a first radial bearing positioned around the shaft aft of the motor; and   a second radial bearing positioned around the impeller, wherein a first portion of fluid driven by the impeller flows through the second radial bearing before exiting the fluid pump, wherein a second portion of the fluid driven by the impeller flows through an outlet of the fluid pump.   
     
     
         17 . The fluid pump of  claim 16 , wherein the first radial bearing is a first foil bearing through which fluid flows in a first direction, and wherein the second radial bearing is a second foil bearing through which the fluid flows in the first direction. 
     
     
         18 . The fluid pump of  claim 16 , further including:
 a housing including a primary inlet and a secondary inlet aft of the primary inlet; and   a thrust bearing coupled to the shaft aft of the first radial bearing, wherein the fluid that enters the housing via the secondary inlet flows through the thrust bearing, wherein a third portion of the fluid that flows through the thrust bearing subsequently flows between the first radial bearing and the shaft towards a forward end of the pump, wherein a fourth portion of the fluid that flows through the thrust bearing subsequently flows through a bore of the shaft towards the forward end of the pump.   
     
     
         19 . The fluid pump of  claim 16 , wherein the expeller vanes are first expeller vanes extending from a forward side of the impeller, wherein the impeller includes back expeller vanes that extend from an aft side of the impeller. 
     
     
         20 . The fluid pump of  claim 16 , further including:
 an impeller housing positioned around the impeller; and   a motor housing positioned around the motor, wherein a third portion of the fluid driven by the impeller flows from the impeller housing into the motor housing before exiting the fluid pump.