Assemblies and Methods for Cooling Electric Machines

Abstract

Cooling assemblies and methods, including, for example, at least one bar (e.g., electrically insulated and/or thermally conductive bar(s)), members (e.g., i-beams, rectangular members, and the like), stator laminations, rotor laminations, and/or combinations thereof, such as those configured to cool electric machines (e.g., electric motors and generators).

1 . A cooling assembly for an electric machine, comprising:
 a rotor core comprising a plurality of laminations and having:   a first end;   a second end;   a bore extending from the first end to the second end of the rotor core and configured to accommodate at least a portion of a rotor shaft, the bore characterized by a longitudinal axis;   an end plate disposed at the first end; and   an end plate disposed at the second end;   where at least some laminations in the plurality of laminations comprise at least one opening positioned at least between the first end and the second end of the rotor core; and   at least one bar disposed in the at least one opening, where the at least one bar is electrically insulated from the at least some laminations.   
     
     
         2 . The cooling assembly of  claim 1 , where the at least one opening extends from the first end to the second end, and the at least one bar disposed in the at least one opening extends from the first end to the second end. 
     
     
         3 . The cooling assembly of  claim 1 , further comprising:
 a plurality of openings in at least some laminations in the plurality of laminations positioned at least between the first end and the second end of the rotor core; and   a bar disposed in each of the plurality of openings, where the bar is electrically insulated from the at least some laminations;   where each opening in the plurality of openings is substantially equidistant from the longitudinal axis of the bore of the rotor core.   
     
     
         4 . The cooling assembly of  claim 1 , where the thermal conductivity of the at least one bar is equal to or greater than 20 W/m-K. 
     
     
         5 . The cooling assembly of  claim 1 , where the dielectric strength of the at least one bar is equal to or greater than 40 V/mil. 
     
     
         6 . The cooling assembly of  claim 1 , where the at least one bar comprises ceramic. 
     
     
         7 . The cooling assembly of  claim 1 , further comprising:
 an end plate disposed at the first end; and   an end plate disposed at the second end;   where the end plates are configured to prevent the at least one bar from moving longitudinally with respect to the plurality of openings.   
     
     
         8 . The cooling assembly of  claim 1 , further comprising:
 a plurality of members disposed between at least two adjacent laminations such that the at least two adjacent laminations form at least one channel that extends at least partially around the rotor core.