Patent ID: 8274190

Claim:
An electric machine comprising: a plurality of rotor bars; a first coupling component configured to electrically couple the plurality of rotor bars together, wherein each rotor bar of the plurality of rotor bars comprises: a first metallic material having a first electrical resistivity, the first metallic material having a first end and a second end opposite the first end, wherein the first coupling component is coupled to the first end of the first metallic material; and a second metallic material cast about the first material and about portions of the first coupling component and having a second electrical resistivity greater than the first electrical resistivity; wherein the first metallic material comprises a copper bar and the second metallic material comprises aluminum; wherein each rotor bar of the plurality of rotor bars has a first end and a second end opposite the first end, and wherein the first coupling component is electrically coupled to the first end of each rotor bar of the plurality of rotor bars; wherein the electric machine further comprises a second coupling component coupled to the second end of each rotor bar of the plurality of rotor bars, wherein the second coupling component is configured to electrically couple the plurality of rotor bars together; and wherein the second metallic material is also cast about portions of the second coupling component.