Systems and methods for regulating fluid flow for internal cooling and lubrication of electric machines

Abstract

The invention provides systems and methods for cooling and lubrication of high power density electric machines with an enhanced fluid injection system. Multiple fluid flow passages may be provided within the electric machine, which may include one or more bearing fluid flow pathways and one or more rotor fluid flow pathways. The bearing fluid flow pathway may comprise one or more passages which may direct a fluid to contact one or more bearings for lubrication and cooling of the one or more bearings. The rotor fluid flow pathway may comprise one or more passages which may direct a fluid along the rotatable shaft toward the rotor and stator for cooling of the rotor and stator. The electric machine may also include a fluid flow passage leading to a junction, wherein the fluid flow pathway may split between the bearing fluid flow pathway and the rotor fluid flow pathway. Additionally, the electric machine may include a fluid flow metering device at the junction between the bearing fluid flow pathway and the rotor fluid flow pathway, wherein the metering device is configured to determine the relative amount of fluid that flows to the bearing and fluid that flows toward the rotor and stator.

1 .- 14 . (canceled) 
     
     
         15 . An electric machine having a heat exchange component, said machine comprising:
 a rotor fixed to a rotatable shaft and supported by means of one or more bearings;   a stator stationary in relation to the rotatable rotor and shaft with a gap between the rotor and the stator; and   one or more fluid flow passages within the machine, wherein at least one of the fluid flow passages directs fluid to contact the rotor or stator, wherein at least one of the fluid flow passages is in fluid communication with an exhaust sump, and wherein the exhaust sump functions as a heat exchanger, thereby cooling a fluid within the exhaust sump delivered by the one or more fluid flow passages to improve cooling of the electric machine.   
     
     
         16 . The machine of  claim 15  wherein the fluid flow passages are liquid flow passages and the fluid within the exhaust sump is a liquid. 
     
     
         17 . The machine of  claim 16  wherein the exhaust sump functions as a liquid-to-gas heat exchanger. 
     
     
         18 . The machine of  claim 16  wherein the exhaust sump functions as a liquid-to-liquid heat exchanger. 
     
     
         19 . The machine of  claim 15  wherein the electric machine comprises a plurality of fluid flow passages, which form one or more fluid flow pathways within the machine, and wherein the one or more fluid flow pathways are in fluid communication with the exhaust sump. 
     
     
         20 . The machine of  claim 15  wherein the exhaust sump does not comprise an outlet through which the fluid exits the machine, and the fluid within the exhaust sump is recirculated within the machine. 
     
     
         21 . The machine of  claim 15  wherein the exhaust sump comprises one or more outlets through which the fluid exits the machine. 
     
     
         22 . The machine of  claim 21  wherein a volume of fluid is collected within the exhaust sump prior to exiting the electric machine through the one or more outlets, and the volume of fluid remains in the exhaust sump for a period of time during which the fluid is cooled within the exhaust sump. 
     
     
         23 . The machine of  claim 15  wherein the exhaust sump has cooling fins formed thereon. 
     
     
         24 . The machine of  claim 23  wherein a fan blows a gas over the cooling fins. 
     
     
         25 . The machine of  claim 15  wherein one or more external heat sinks are applied to one or more exterior surfaces of the exhaust sump. 
     
     
         26 . The machine of  claim 15  wherein a fluid flows over one or more exterior surfaces of the exhaust sump. 
     
     
         27 . A method for cooling an electric machine comprising:
 providing a rotor fixed to a rotatable shaft and supported by means of one or more bearings;   providing a stator stationary in relation to the rotatable rotor and shaft with a gap between the rotor and the stator;   providing one or more fluid flow passages within the machine, wherein at least one of the fluid flow passages directs fluid to contact the rotor or stator, wherein at least one of the fluid flow passages is in fluid communication with an exhaust sump and delivers a fluid to the exhaust sump; and   cooling the fluid within the exhaust sump, which functions as a heat exchanger to improve cooling of the electric machine.   
     
     
         28 . The method of  claim 27  wherein the fluid flow passages are liquid flow passages and the fluid within the exhaust sump is a liquid. 
     
     
         29 . The method of  claim 28  wherein the exhaust sump functions as a liquid-to-gas heat exchanger. 
     
     
         30 . The method of  claim 28  wherein the exhaust sump functions as a liquid-to-liquid heat exchanger. 
     
     
         31 . The method of  claim 27  wherein the electric machine comprises a plurality of fluid flow passages, which form one or more fluid flow pathways within the machine, and wherein the one or more fluid flow pathways are in fluid communication with the exhaust sump. 
     
     
         32 . The method of  claim 27  wherein the exhaust sump does not comprise an outlet through which the fluid exits the machine, and the fluid within the exhaust sump is recirculated within the machine. 
     
     
         33 . The method of  claim 27  wherein the exhaust sump comprises one or more outlets through which the fluid exits the machine. 
     
     
         34 . The method of  claim 27  further comprising collecting a volume of fluid within the exhaust sump prior to exiting the electric machine through the one or more outlets, wherein the volume of fluid remains in the exhaust sump for a period of time during which the fluid is cooled within the exhaust sump. 
     
     
         35 . The method of  claim 34  further comprising permitting the fluid to exit the exhaust sump continuously. 
     
     
         36 . The method of  claim 34  further comprising collecting the fluid within the exhaust sump for a period of time without allowing the fluid to exit for the period of time; and subsequently permitting the fluid to exit the exhaust sump at various rates or intervals.