DIRECT LIQUID COOLING SYSTEMS AND METHODS FOR MAGNETS OF INTERIOR PERMANENT MAGNET ELECTRIC MACHINES

Presented are direct liquid cooling systems for regulating magnet temperature of electric machines, methods for making/using such systems, and motor vehicles equipped with traction motors having magnets cooled by such systems. An electric machine includes a stator assembly that is located inside a protective outer housing. The stator assembly includes one or more electromagnetic windings mounted onto a stator core. A rotor assembly is rotatably attached to the housing, coaxial with and spaced from the stator assembly. The rotor assembly includes one or more permanent magnets mounted to a rotor core. The rotor core includes one or more radially elongated feed grooves that are fluidly connected to one or more axially elongated feed channels. The rotor feed groove(s) fluidly connect to a direct liquid cooling system to receive therefrom a liquid coolant. Each rotor feed channel transports the liquid coolant into direct contact with a target surface of a magnet.