Apparatus and method of making a rotor core with elimination of outer periphery machining

An apparatus for making a rotor core, the apparatus comprising:

• a support for a lamina stack having a radially-outer surface and having therein openings, the support having an axis extending along the lamina stack;
• an inner surface movable radially inward toward the radially-outer surface of the lamina stack, the inner surface being defined by a plurality of collets each having an inner surface portion;
• a mold to receive casting material that flows into the openings in the lamina stack and that is cast to the lamina stack while the inner surface is positioned against the radially-outer surface of the lamina stack, such that the inner surface substantially prevents the casting material from flowing onto the radially-outer surface of the lamina stack;
• and
• a moving mechanism operable to move the inner surface radially inward to mate with the radially-outer surface of the lamina stack, the moving mechanism including a collar that slides axially along the collets.

An apparatus for making a rotor core, the apparatus including:

• a support for supporting a lamina stack that has an axis extending along the stack;
• a plurality of collets, the collets positioned to engage the support;
• a collet moving mechanism for moving the collets radially inward against the lamina stack, the moving mechanism positioned to cam the collets radially inward when a portion of the moving mechanism moves axially toward the support;
• and
• an arrangement to receive casting material that is cast to the lamina stack while the collets are against the lamina stack.