Pump-motor assembly

Abstract

A pump-motor assembly includes a motor housing, a motor disposed substantially within the motor housing, and a pumping element driven by the motor. A pressurized region is filled with a fluid pressurized by the pumping element, and a fluid passage is in fluid communication with the pressurized region and the motor housing. Fluid flows from the pressurized region to the motor housing and at least partially submerges the motor.

1 . A pump-motor assembly, comprising:
 a motor housing;   a motor disposed substantially within the motor housing;   a pumping element driven by the motor;   a pressurized region filled with a fluid pressurized by the pumping element; and   a fluid passage in fluid communication with the pressurized region and the motor housing, such that the fluid flows from the pressurized region to the motor housing and at least partially submerges the motor.   
     
     
         2 . The pump-motor assembly of  claim 1 , further comprising:
 a transfer shaft configured to transfer power between the motor and the pumping element; and   wherein the fluid passage is adjacent to the transfer shaft.   
     
     
         3 . The pump-motor assembly of  claim 2 , further comprising:
 one of a bushing and a bearing configured to carry the transfer shaft; and   wherein the fluid passage is incorporated into the one of the bushing and the bearing.   
     
     
         4 . The pump-motor assembly of  claim 2 , further comprising:
 a shaft seal disposed about the transfer shaft; and   wherein the fluid passage is incorporated into the shaft seal.   
     
     
         5 . The pump-motor assembly of  claim 2 , further comprising:
 an orifice disposed non-adjacent to the transfer shaft; and   wherein the fluid passage is incorporated into the orifice.   
     
     
         6 . The pump-motor assembly of  claim 5 ,
 wherein the orifice includes a bleed valve; and   wherein the bleed valve provides a proportional flow rate between the pressurized region and the motor housing based upon the pressure of the fluid in the pressurized region.   
     
     
         7 . The pump-motor assembly of  claim 6 , further comprising:
 an exit port in the motor housing; and   wherein the exit port is located to allow the fluid to form a pool in the motor housing.   
     
     
         8 . The pump-motor assembly of  claim 7 , further comprising:
 wherein the fluid flows from the pressurized region to the motor housing with an inlet flow pressure;   wherein the exit port includes a restrictor; and   wherein the restrictor provides an exit flow pressure which limits flow from the motor housing, such that fluid pressure builds in the motor housing.   
     
     
         9 . A pump-motor assembly, comprising:
 a motor housing;   a motor disposed substantially within the motor housing;   a pumping element driven by the motor;   a pressurized region filled with a fluid pressurized by the pumping element;   a fluid passage in fluid communication with the pressurized region and the motor housing, such that the fluid flows from the pressurized region to the motor housing and at least partially submerges the motor; and   an exit port in the motor housing, wherein the exit port is located to allow the fluid to form a pool in the motor housing.   
     
     
         10 . The pump-motor assembly of  claim 9 , further comprising:
 a transfer shaft configured to transfer power between the motor and the pumping element; and   wherein the fluid passage is adjacent to the transfer shaft.   
     
     
         11 . The pump-motor assembly of  claim 10 , further comprising:
 one of a bushing and a bearing configured to carry the transfer shaft; and   wherein the fluid passage is incorporated into the one of the bushing and the bearing.   
     
     
         12 . The pump-motor assembly of  claim 9 , further comprising:
 an orifice disposed non-adjacent to the transfer shaft; and   wherein the fluid passage is incorporated into the orifice.