Electric motor having armature coated with a thermally conductive plastic

An armature for an electric motor, comprising:

• a lamination stack;
• an armature shaft extending coaxially through said lamination stack;
• a plurality of magnet wires wound around said lamination stack;
• a commutator disposed on said armature shaft to which ends of said magnet wires are electrically coupled;
• and
• a thermally conductive plastic coating molded over said armature, a portion of said coating forming an integrally formed fan adjacent said armature.

An electric motor for use with a power tool, said electric motor comprising:

• a stator;
• an armature disposed within said stator;
• a thermally conductive plastic at least partially encasing a plurality of magnet wires of said armature;
• and
• a molded fan formed from said thermally conductive plastic and disposed adjacent one end of said armature to provide a cooling airflow over said armature during use of said motor.

A method for forming an electric motor, said method comprising:

• providing a stator;
• providing an armature having a plurality of magnet wires wound therearound;
• molding a thermally conductive plastic over at least a portion of said armature to at least partially encase said magnet wires;
• and
• molding a fan at one end of said armature from said thermally conductive plastic.

A method for forming an armature for an electric motor, said method comprising:

• providing a lamination stack;
• providing an armature shaft for supporting said lamination stack;
• providing a commutator disposed on said armature;
• winding a plurality of magnet wires around said lamination stack and securing ends of said magnet wires to said commutator;
• performing a molding step to mold a thermally conductive coating over a substantial portion of said lamination stack to at least substantially encase said magnet wires therewithin, and to form a fan adjacent one end of said lamination stack from said thermally conductive coating.

A method for forming an armature for an electric motor, comprising:

• providing a lamination stack;
• providing an armature shaft for supporting said lamination stack;
• providing a commutator disposed on said armature;
• winding a plurality of magnet wires around said lamination stack and securing ends of said magnet wires to said commutator;
• molding a thermally conductive plastic coating over a substantial portion of said lamination stack to at least substantially encase said magnet wires therewithin, and to form a fan adjacent one end of said lamination stack from said thermally conductive plastic coating, and wherein said thermally conductive plastic coating has a density approximately equal to said magnet wires, to thereby substantially eliminate the need to balance said armature prior to assembling said armature to form said electric motor.

An electric motor comprising:

• a stator;
• an armature having an armature shaft and being disposed within said stator, wherein said armature includes a plurality of slots;
• a plurality of magnet wires formed in a plurality of coils and disposed in said slots to at least partially occupy said slots;
• and
• a flowable plastic having a density substantially similar to said magnet wires for at least substantially filling a remainder of an area of each of said slots to balance said armature.

An electric motor comprising:

• a stator;
• an armature including a plurality of axial slots;
• a plurality of magnet wires formed in a plurality of coils and disposed in said slots to at least partially occupy said slots;
• and
• an injectable resin injected into said slots to at least substantially fill said slots, said resin having a density substantially similar to said magnet wires to balance said armature.

A method for forming an armature for an electric motor, said method comprising:

• providing a lamination stack having a plurality of axial slots arranged circumferentially therearound;
• disposing a plurality of magnet wires in said axial slots;
• and
• filling said axial slots with a resin having a density substantially similar to a density of said magnet wires to thereby balance said lamination stack.