Electrically insulating, thermally conductive coatings for electrical systems and deposition methods thereof

Abstract

An electric machine includes a rotor assembly having a rotor core that extends in an axial direction and a stator assembly surrounding and coaxial with the rotor assembly. The stator assembly includes a stator core having slots extending in a radial direction into an inner surface of the stator core and extending axially from a first end surface to a second end surface of the stator core. The stator assembly includes stator coil windings disposed within the respective slots of the stator core and a first electrically insulating conformal coating disposed between the stator core and the stator coil windings. The conformal coating includes a polymer matrix impregnated with an effective amount of thermally conductive ceramic materials, above a percolation threshold, that form continuous thermal pathways across a thickness of the first coating.

1 .- 10 . (canceled) 
     
     
         11 . A rotor assembly, comprising:
 a rotor core, wherein the rotor core comprises:   rotor slots extending in a radial direction into an outer surface of the rotor core and extending axially from a first end surface to a second end surface of the rotor core;   rotor coil windings disposed within the rotor slots of the rotor core; and   an electrically insulating conformal coating disposed on one or more portions of the rotor core, the rotor coil windings, or both,   wherein the conformal coating includes a polymer matrix impregnated with an effective amount of thermally conductive ceramic materials above a percolation threshold that form continuous thermal pathways across a thickness of the conformal coating.   
     
     
         12 . The rotor core of  claim 11 ,
 wherein the rotor core is configured to be surrounded by and coaxial with a stator assembly,   wherein the stator assembly comprises:
 a stator core having stator slots extending in a radial direction into an inner surface of the stator core and extending axially from a third end surface to a fourth end surface of the stator core; 
 stator coil windings disposed within the respective stator slots of the stator core; and 
 an additional electrically insulating conformal coating disposed on one or more portions of the stator core, the stator coil windings, or both, 
   wherein the additional conformal coating includes a polymer matrix impregnated with an effective amount of thermally conductive ceramic materials, above a percolation threshold, that form continuous thermal pathways across a thickness of the additional conformal coating.   
     
     
         13 . The rotor core of  claim 11 , wherein the conformal coating is disposed on the surfaces of the rotor slots. 
     
     
         14 . The rotor core of  claim 11 , wherein the conformal coating is disposed on the first end surface, the second end surface, or both. 
     
     
         15 . The rotor core of  claim 11 , wherein the conformal coating is disposed on a surface of the rotor coil. 
     
     
         16 . An electric machine component, comprising:
 an electrophoretically deposited conformal coating disposed along at least a portion of an outer surface of the component, wherein the conformal coating is electrically insulating and thermally conductive, and wherein the conformal coating includes a polymer matrix impregnated with about 6% to about 60%, by volume, thermally conductive ceramic materials that form continuous thermal pathways within the conformal coating, wherein the amount of the thermally conductive ceramic materials depends at least in part on aspect ratios and/or alignment of the thermally conductive ceramic materials.   
     
     
         17 . The electric machine component of  claim 16 ,
 wherein the electric machine component comprises a rotor assembly,   wherein the rotor assembly comprises:   a rotor core that extends in an axial direction, wherein the rotor core comprises:
 rotor slots extending in a radial direction into an outer surface of the rotor core and extending axially from a third end surface to a fourth end surface of the rotor core; 
 rotor coil windings disposed within the rotor slots of the rotor core; and 
   wherein the conformal coating is disposed on one or more portions of the rotor slots, the rotor coil, or both.   
     
     
         18 . The electric machine component of  claim 17 , comprising a stator assembly surrounding and coaxial with the rotor assembly, the stator assembly comprises:
 a stator core having stator slots extending in a radial direction into an inner surface of the stator core and extending axially from a first end surface to a second end surface of the stator core;   stator coil windings disposed within the respective stator slots of the stator core; and   an additional conformal coating disposed on one or more portions of the stator core, the stator coil windings, or both.   
     
     
         19 . The electric machine component of  claim 18 , wherein the conformal coating is disposed on the surfaces of the rotor slots, the additional conformal coating is disposed on a surface of the stator coil windings, or both. 
     
     
         20 . The electric machine component of  claim 18 , wherein the conformal coating is disposed on a surface of the rotor coil windings, the additional conformal coating is disposed on the surfaces of the stator slots, or both.