Method of fabricating an injected molded motor assembly

A method of producing an electrical motor comprising the steps of:

• constructing a rotor assembly on a rotor shaft, the rotor assembly having a central rotor adapted for support by bearings located near the ends of the rotor shaft;
• forming an intermediate stator assembly having stator poles and means for magnetizing the stator poles;
• placing the intermediate stator assembly into a mold fixture that includes an internal cavity shaped to define a rear end cap for the stator assembly and a mandrel projecting through the center of the intermediate stator assembly to form a central bore;
• unitizing the stator assembly by injecting molten plastic under pressure into the mold fixture, whereby the molten plastic is forced into the intermediate stator assembly to encapsulate the stator poles, fill interior voids, and fill the mold cavity to form a unitary rear end cap;
• cooling the assembly to solidify the molten plastic into a plastic mass, the plastic mass forming a central bore extending between the formed rear end cap and another end cap, the central bore being of a size adequate to closely receive the rotor of the rotor assembly;
• forming bearing support surfaces in the end caps, the bearing surfaces being sized to receive the bearings adapted to support the rotor;
• and
• mounting the rotor assembly into the stator assembly by inserting the rotor assembly into the continuous bore and engaging the rotor bearings with the mounting surfaces.