Motor frame cooling with hot liquid refrigerant and internal liquid

Abstract

This invention presents the device and method for cooling electric machines with hot liquid refrigerant in a floating refrigerant loop and using an internal liquid such as oil for enhancing the cooling effects. The electric machine cooling apparatus has at least one refrigerant tube disposed in the electric machine. The refrigerant tube is in thermal communication with the electric machine. An internal liquid is disposed inside the frame of the electric machine. The internal liquid is in thermal communication with the electric machine and at least one refrigerant tube. The refrigerant is at least partially a hot liquid refrigerant supplied from a floating refrigerant loop.

1 . An electric machine cooling apparatus comprising; 
 an electric machine having a frame, stator, and rotor,    at least one refrigerant tube disposed in said electric machine, said refrigerant tube in thermal communication with said electric machine,    an internal liquid disposed inside the frame of said electric machine, said internal liquid in thermal communication with said electric machine and said at least one refrigerant tube,    wherein the refrigerant in,said at least one refrigerant tube is at least partially a hot liquid refrigerant supplied from a floating refrigerant loop.    
   
   
       2 . An electric machine cooling apparatus according to  claim 1  wherein said internal liquid is selected from the group consisting of transmission oil and lubrication oil.  
   
   
       3 . An electric machine cooling apparatus according to  claim 1  wherein said refrigerant tube material is at least one material selected from the group consisting of copper and aluminum.  
   
   
       4 . An electric machine cooling apparatus according to  claim 1  wherein said at least one refrigerant tube further comprises at least one surface enhancement selected from the group consisting of fins, pins, and re-entrant cavities.  
   
   
       5 . An electric machine cooling apparatus according to  claim 1  wherein said frame further comprises ribs.  
   
   
       6 . An electric machine cooling apparatus according to  claim 1  wherein said tubes are disposed having a gap between said tubes and said frame.  
   
   
       7 . An electric machine cooling apparatus according to  claim 1  wherein said rotor further comprises at least one end piece to sling internal liquid droplets into contact with internal surfaces of said electric machine.  
   
   
       8 . An electric machine cooling apparatus according to  claim 7  wherein said at least one end piece further comprises at least one scooper.  
   
   
       9 . An electric machine cooling apparatus according to  claim 7  wherein said at least one end piece further comprises at least one scooper with grooves.  
   
   
       10 . An electric machine cooling apparatus according to  claim 7  wherein said at least one end piece further comprises a wavy surface.  
   
   
       11 . An electric machine cooling apparatus according to  claim 7  wherein said at least one end piece further comprises a wavy surface with grooves.  
   
   
       12 . An electric machine cooling apparatus according to  claim 1  wherein said internal liquid is in communication with a transmission sump.  
   
   
       13 . An electric machine cooling apparatus according to  claim 12  wherein communication between said internal liquid and said transmission sump is controlled using a ball valve.  
   
   
       14 . A method for cooling an electric machine comprising; 
 flowing refrigerant through at least one refrigerant tube disposed in an electric machine having a frame, stator, and rotor; said refrigerant tube in thermal communication with said electric machine,    slinging an internal liquid disposed inside the frame of said electric machine, said internal liquid in thermal communication with said electric machine and said at least one refrigerant tube,    wherein the refrigerant in said at least one refrigerant tube is at least partially a hot liquid refrigerant supplied from a floating refrigerant loop.    
   
   
       15 . A method according to  claim 14  wherein said internal liquid is selected from the group consisting of transmission oil and lubrication oil.  
   
   
       16 . A method according to  claim 14  wherein said refrigerant tube material is at least one material selected from the group consisting of copper and aluminum.  
   
   
       17 . A method according to  claim 14  wherein said at least one refrigerant tube further comprises at least one surface enhancement selected from the group consisting of fins, pins, and re-entrant cavities.  
   
   
       18 . A method according to  claim 14  wherein said frame further comprises ribs.  
   
   
       19 . A method according to  claim 14  wherein said tubes are disposed having a gap between said tubes and said frame.  
   
   
       20 . A method according to  claim 14  wherein said rotor further comprises at least one end piece disposed to sling internal liquid droplets into contact with internal surfaces of said electric machine.  
   
   
       21 . A method according to  claim 20  wherein said at least one end piece further comprises at least one scooper.  
   
   
       22 . A method according to  claim 20  wherein said at least one end piece further comprises at least one scooper with grooves.  
   
   
       23 . A method according to  claim 20  wherein said at least one end piece further comprises a wavy surface.  
   
   
       24 . A method according to  claim 20  wherein said at least one end piece further comprises a wavy surface with grooves.  
   
   
       25 . A method according to  claim 14  wherein said internal liquid is in fluid communication with a transmission sump.  
   
   
       26 . A method according to  claim 25  wherein fluid communication between said internal liquid and said transmission sump is controlled using a ball valve.