Induction rotor having improved conductor bar profiles and method for forming the same

A rotor, for an induction motor, comprising:

• a rotor core having a body that at least:
• extends radially inward from an outer surface of the body toward a central axis;
• extends axially from a first axial end to a second axial end;
• and
• defines a plurality of internal grooves;
• wherein each of the internal grooves at least:
• includes an opening, having an opening profile width, at the outer surface of the body;
• is defined by two opposing walls;
• extends from the first axial end to the second axial end;
• extends radially between the opening at the outer surface and a radially-inward end;
• and
• includes a body section;
• and
• wherein the two opposing walls comprise:
• opposing first straight and parallel segments extending radially inward, from the opening, forming a neck portion having a neck profile width equivalent to the opening profile width;
• opposing second straight and parallel segments extending radially inward, from the neck portion, forming a first primary portion having a first primary profile width being greater than the neck profile width;
• opposing extended segments, extending radially inward from the first primary portion, forming an extended portion having an extended profile width being greater than the first primary profile width;
• opposing curved segments meeting at the radially-inward end, forming an inward-end portion of the groove;
• and
• opposing third straight and parallel segments extending radially between the inward-end portion and the extended portion, forming a second primary portion, having a second primary profile width equivalent to the first primary profile width.

A rotor bar, for use in a rotor core of a rotor, comprising:

• an opening surface having an opening profile width;
• and
• two opposing walls extending from the opening surface to a point at which the walls meet;
• wherein the two opposing walls comprise:
• opposing first straight and parallel segments extending from the opening, surface, forming a neck portion having a neck profile width equivalent to the opening profile width;
• opposing second straight and parallel segments extending from the neck portion, forming a first primary portion having a first primary profile width being greater than the neck profile width;
• opposing extended segments, extending from the first primary portion toward the point at which the walls meet, forming an extended portion having an extended profile width being greater than the first primary profile width;
• opposing curved segments meeting at the said point, forming an end portion;
• and
• opposing third straight and parallel segments extending between the end portion and the extended portion, forming a second primary portion having a second primary profile width equivalent to the first primary profile width.