Electric machine end turn cooling apparatus

An electric machine comprising:

• a stator having an end turn potted in a potting material having a thermal conductivity greater than about 0.4 W/m/° C.;
• and
• a cooling structure in thermal contact with the end turn, the cooling structure comprising a plurality of layers, and
• a first layer of the plurality of layers having an opening forming a portion of a first fluid passage.

A cooling structure comprising:

• a plurality of layers, each layer being:
• an annular lamination, or
• an annular or cylindrical turn of a wound strip;
• a first manifold having a first manifold channel;
• and
• a second manifold having a second manifold channel,
• each of the plurality of layers having a plurality of openings,
• the plurality of openings of the plurality of layers forming:
• a plurality of substantially azimuthal fluid passages in fluid communication with the first manifold channel and the second manifold channel, and
• a plurality of substantially axial fluid passages in fluid communication with the first manifold channel and the second manifold channel, or
• a plurality of substantially radial fluid passages each being in fluid communication with the first manifold channel and the second manifold channel,
• each substantially azimuthal fluid passage connecting:
• a pair of substantially axial fluid passages, or
• a pair of substantially radial fluid passages,
• at least one fluid path connecting the first manifold channel and the second manifold channel including at least one of the substantially azimuthal fluid passages, and
• the structure being configured to cool an end turn of an electric machine.