Cooling fan for refrigerant cooled motor

Abstract

An electric motor for a vapor compression system is disclosed. The electric motor is provided with a working fluid. The electric motor includes a housing forming cavity therein. The housing includes a rotor, a stator, and a shaft. The rotor is secured to the shaft and the stator surrounds at least a portion of the rotor. An airgap is formed between the rotor and the stator. An inlet of the housing receives the working fluid and is in fluid communication with the airgap. An outlet of the housing is in fluid communication with the airgap and receives the working fluid from the airgap. The electric motor further includes an impeller that induces flow of the working fluid between the inlet and the outlet.

What is claimed is: 
     
         1 . An electric motor for a vapor compression system, the electric motor being provided with a working fluid, the electric motor comprising:
 a housing forming cavity therein, the housing including:
 a rotor, a stator, and a shaft, wherein the rotor is secured to the shaft and the stator surrounds at least a portion of the rotor; 
 an airgap formed between the rotor and the stator; 
 an inlet that receives the working fluid and is in fluid communication with the airgap; 
 an outlet that is in fluid communication with the airgap and receives the working fluid from the airgap; and 
 an impeller that induces flow of the working fluid between the inlet and the outlet. 
   
     
     
         2 . The electric motor according to  claim 1 , wherein the impeller is disposed on an upstream side of the rotor and the stator and is configured to push the working fluid from the inlet to the outlet. 
     
     
         3 . The electric motor according to  claim 1 , wherein the impeller is disposed on a downstream side of the rotor and the stator and is configured to pull the working fluid from the inlet to the outlet. 
     
     
         4 . The electric motor according to  claim 1 , further comprising a second impeller, wherein the impeller is disposed on an upstream side of the rotor and the stator. 
     
     
         5 . The electric motor according to  claim 4 , wherein the second impeller is disposed on a downstream side of the rotor and the stator. 
     
     
         6 . The electric motor according to  claim 1 , wherein the impeller is disposed on the shaft. 
     
     
         7 . A heating, ventilation, and air conditioning (HVAC) system, comprising:
 a compressor; and   an electric motor coupled to the compressor, wherein the electric motor provides a mechanical power to the compressor, the electric motor including:   a housing forming cavity therein, the housing including:
 a rotor, a stator, and a shaft, wherein the rotor is secured to the shaft and the stator surrounds at least a portion of the rotor, an airgap being formed between the rotor and the stator, the shaft being coupled with the compressor; 
 an inlet that receives the working fluid and is in fluid communication with the airgap; 
 an outlet that is in fluid communication with the airgap and receives the working fluid from the airgap; and 
 an impeller that induces flow of the working fluid between the inlet and the outlet. 
   
     
     
         8 . The HVAC system according to  claim 7 , further comprising a condenser, an evaporator, and an expansion device. 
     
     
         9 . The HVAC system according to  claim 7 , wherein the impeller is configured to push the working fluid from the inlet to the outlet. 
     
     
         10 . The HVAC system according to  claim 7 , wherein the impeller is configured to pull the working fluid from the inlet to the outlet. 
     
     
         11 . The HVAC system according to  claim 7 , wherein the impeller is disposed on the shaft. 
     
     
         12 . The HVAC system according to  claim 7 , wherein the impeller is disposed on the rotor. 
     
     
         13 . The HVAC system according to  claim 7 , wherein the electric motor further comprises a spray nozzle disposed near windings of the stator. 
     
     
         14 . The HVAC system according to  claim 7 , further comprising a second impeller, wherein the impeller is disposed on an upstream side of the rotor and the stator. 
     
     
         15 . The HVAC system according to  claim 14 , wherein the second impeller is disposed on a downstream side of the rotor and the stator. 
     
     
         16 . A method for cooling an electric motor in a vapor compression system, the electric motor including a housing forming cavity therein, the housing including a rotor, a stator, and a shaft, wherein the rotor is secured to the shaft and the stator surrounds at least a portion of the rotor, an airgap being formed between the rotor and the stator, the method comprising:
 providing a working fluid to an inlet of the housing;   cooling the electric motor by moving the working fluid from the inlet of the housing through the airgap, the working fluid receiving heat from the electric motor; and   discharging the working fluid from an outlet of the housing.   
     
     
         17 . The method according to  claim 16 , wherein moving the working fluid from the inlet of the housing through the airgap includes pulling the working fluid from the inlet toward the outlet with an impeller disposed on the shaft, the impeller being on a downstream side of the rotor and the stator. 
     
     
         18 . The method according to  claim 16 , wherein moving the working fluid from the inlet of the housing through the airgap includes pushing the working fluid from the inlet toward the outlet with an impeller disposed on the shaft, the impeller being on an upstream side of the rotor and the stator. 
     
     
         19 . The method according to  claim 16 , wherein the working fluid is moved through the airgap at a desired mass flowrate. 
     
     
         20 . The method according to  claim 19 , wherein the desired mass flowrate is from at or about 1 to at or about 2 percent of a mass flow of the compressor in the vapor compression system.