Method and apparatus for transfer molding of electric motor cores and magnetizable inserts

A method of securing magnetizable inserts within cores of an electric converter, the method comprising:

• placing an assembly of rotor cores in a transfer molding press, the magnetizable inserts being disposed within cavities of the rotor cores and the cavities of the rotor cores being in fluid communication;
• placing a polymer preform proximate a central portion of the assembly of rotor cores;
• displacing the polymer preform such that the polymer preform changes state and flows radially and then axially through the cavities of the rotor cores;
• removing the assembly of rotor cores from the transfer molding press;
• and
• removing polymer waste from the assembly of rotor cores,
• wherein the assembly of rotor cores is weighed before being placed into the transfer molding press and is weighed after being removed from the transfer molding press, wherein a difference in weight is compared with a predefined weight value to determine a fill volume of the cavities.