Rotor die casting method

A method for die casting end rings and conductor bars on motor rotors comprising the steps of:

• providing a compensator mechanism comprising a compensator sleeve having a breech opening in a side thereof and a compensator received in the sleeve for reciprocal movement along a first axis,
• providing a die plate closing off one end of the compensator sleeve to form a die cavity, the die plate and compensator sleeve being axially separable,
• storing a plurality of stacks of motor laminations, each stack held together by a stacking pin, on a loading rack positioned laterally on one side of the compensator mechanism and the first axis,
• causing one of the stacks to roll by gravity from the loading rack into the compensator sleeve through the breech opening thereof,
• pushing the stack forward in the compensator sleeve by the compensator into abutment with the die plate,
• injecting a charge of molten metal into the die cavity formed by the compensator, compensator sleeve and die plate on and through the stack to form end rings and conductor bars on the stack to thereby form a rotor,
• then axially separating the die plate and compensator sleeve,
• moving a retriever laterally from said one side of the first axis and perpendicularly toward said first axis to an unload position interposed between the compensator sleeve and die plate, the retriever having an opening aligned with the compensator sleeve when it is moved to its unload position,
• pushing the cast rotor out of the compensator sleeve and into the retriever opening and holding the rotor in the retriever opening,
• then retracting the retriever to a position on said one side of said compensator mechanism and said first axis,
• while the rotor is in the retriever and when the retriever has been retracted, pressing the stacking pin out of the rotor along a second axis substantially parallel to the first axis and ejecting the rotor out of the retriever opening along said second axis,
• after the retriever has retracted away from the compensator sleeve and die plate, bringing the die plate and compensator sleeve together, and
• subsequent to clearing of the retriever from between the compensator sleeve and die plate and prior to the injection of the rotor from the retriever opening, rolling another stack into the compensator sleeve and pushing the last mentioned stack forward in the compensator sleeve.