Patent ID: 7337526

Claim:
A method for fabricating a squirrel cage rotor for use in an electrical machine, comprising the steps of: (a) forming at least one stack of metallic laminations affixed to either a shaft or a mandrel, each metallic lamination including a plurality of spaced-apart openings disposed around a periphery of the lamination and generally aligned in the at least one stack, so as to define slots that extend generally axially along the at least one stack; (b) applying a ceramic insulating coating to at least a portion of an internal surface of each of the slots, said ceramic insulating coating having both a thermal insulating characteristic and an electrical insulation characteristic that are substantially greater than thermal and electrical insulating characteristics of the metallic laminations; (c) providing at least one electrical conductor extending axially within each of at least a majority of the slots, the step of providing at least one electrical conductor including the steps of: (i) heating an electrically conductive metal to a molten state; (ii) casting an electrical conductor within each of the at least the majority of the slots using the electrically conductive metal that has been heated to the molten state and a consumable pattern; and (iii) enabling the electrically conductive metal cast as the electrical conductor within each of the at least the majority of the slots to cool to an ambient temperature; and (d) electrically interconnecting the electrical conductors extending axially within the slots in the at least one stack.