Induction rotor retention structure

A method of manufacturing an electric machine having a stator, the method comprising:

• providing a rotor body defining a rotational axis and having at least one slot extending between axial ends of the rotor body;
• providing a shorting ring support structure that includes an outer ring member having an axial end surface facing the rotor body, the axial end surface having a radially inner edge and a radially outer edge, the axial end surface being spaced apart from the rotor body at the radially inner edge and being engaged with the rotor body proximate the radially outer edge;
• and
• casting both at least one conductor bar in the slot and a shorting ring on the rotor body to thereby form a rotor wherein the outer ring member defines the outer radial limit of the shorting ring, whereby cast material secures the shorting ring support structure to the rotor body.

A method of manufacturing an electric machine having a stator, the method comprising:

• providing a rotor body defining a rotational axis and having a plurality of conductor slots extending between axial ends of the rotor body;
• providing first and second shorting ring support structures, each shorting ring support structure having an inner ring member, an outer ring member and a plurality of spokes radially extending between the inner and outer ring members;
• respectively positioning the first and second shorting ring support structures proximate opposite axial ends of the rotor body;
• and
• casting a plurality of conductor bars in corresponding ones of the plurality of conductor slots and casting first and second shorting rings at the opposite axial ends of the rotor body to thereby form a rotor wherein the first and second shorting ring support structures define inner and outer radial limits of the first and second shorting rings respectively and wherein the spokes of each of the first and second shorting ring support structures are spaced axially inwardly from opposing axial surfaces of the first and second shorting rings whereby each of the spokes is fully embedded in one of the first and second shorting rings.