Electric machine stator cooling systems and methods

An electric machine comprising:

• a rotor;
• a stator comprising a plurality of radially positioned electromagnets, wherein an electromagnet comprises;
• a core comprising a stack of laminations defining a tooth and a yoke segment;
• an insulating bobbin surrounding a portion of the tooth of each lamination;
• and
• electrically conductive windings surrounding a portion of the bobbin, wherein each lamination in the stack of laminations is held against adjacent laminations by the bobbin, and
• a stator encapsulant encapsulating the electromagnets;
• and
• a housing supporting the rotor and the stator, wherein the housing comprises;
• a perimeter portion;
• a first end plate at one end of the perimeter portion;
• and
• a second end plate at the opposite end of the perimeter portion, wherein the stator encapsulant is in thermal contact with the first end plate and the second end plate, and wherein the yoke segments of a plurality of electromagnets are in direct physical contact with a shoulder structure extending from the first end plate, and wherein the shoulder structure supports each electromagnet at a select distance away from the first end plate such that there is no physical contact between the windings of any electromagnet and the first end plate.

A method of cooling a stator comprising:

• providing an electric machine comprising:
• a rotor;
• a stator comprising;
• a plurality of radially positioned electromagnets
• a stator encapsulant encapsulating the electromagnets;
• and
• a housing supporting the rotor and the stator, wherein the housing comprises;
• a perimeter portion;
• a first end plate at one end of the perimeter portion;
• and
• a second end plate at the opposite end of the perimeter portion, wherein the stator encapsulant contacts the first end plate and the second endplate such that a central region of the first end plate, a central region of the second end plate, and an interior stator surface define an enclosed cylindrical rotor cavity having substantially no voids extending from the interior stator surface, the central region of the first end plate, and the central region of the second end plate toward the perimeter portion;
• and
• causing heat to be conducted from the stator encapsulant to the first end plate and the second end plate.