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US 2016/0254735 A1Published application
Brushless dc electric motor
AssigneeAmerican Axle & Manufacturing, Inc.
InventorCurt D. Gilmore
Life of this patent
Estimating the term…
Abstract
A brushless DC electric motor having a rotor with a single bearing, a multi-pole oriented magnet, an output coupling and a rotor shell. The rotor shell is formed of an electrically insulating material and can be overmolded onto the magnet, the bearing and the output coupling.
Claims41
A method for forming a brushless DC electric motor comprising:
- providing a hollow magnet having a multi-pole configuration;
- overmolding a plastic material onto an interior surface of the hollow magnet;
- coupling an output member to the hollow magnet;
- and
- inserting a rotor into a stator, the rotor comprising the hollow magnet, the output member and the plastic material that is overmolded onto the interior surface of the hollow magnet.
2 more elements
A brushless DC motor comprising:
- a stator with a plurality of windings;
- and
- a rotor that is received in the stator and rotatable relative to the stator about a rotational axis, the rotor having an output member, a hollow magnet and a plastic material disposed between an interior surface of the hollow magnet and the output member, the hollow magnet having a multi-pole configuration, the plastic material being overmolded to the interior surface, wherein an exterior surface of the hollow magnet is disposed concentrically about the rotational axis of the rotor and wherein the interior surface is not centered about the rotational axis of the rotor such that a center of mass of the hollow magnet is radially offset from the rotational axis of the rotor.
A method for forming a rotor, the method comprising:
- providing an injection mold having a collet and first and second mold members, the collet being received between the first and second mold members, each of the first and second mold members defining a portion of a mold cavity;
- installing a motor output member into one of the portions of the mold cavity;
- installing a hollow cylindrical magnet into the collet;
- positioning the first and second mold members in a closed position to locate an outer surface of the hollow cylindrical magnet relative to a rotational axis of the motor output member and to apply a compressive force onto the outer surface of the hollow cylindrical magnet;
- injecting molten plastic under pressure between hollow cylindrical magnet and the motor output member;
- and
- cooling the injected molten plastic to secure the motor output member to the hollow cylindrical magnet.
4 more elements
A method for forming a rotor, the method comprising:
- providing an injection mold having first and second mold members, each of the first and second mold members defining a portion of a mold cavity;
- installing a motor output member into one of the portions of the mold cavity;
- coupling a hollow cylindrical magnet to one of the first and second mold members;
- positioning the first and second mold members in a closed position to align a longitudinal axis of the motor output member coincidently with a rotational axis of a rotor that is defined by the first and second mold members, to locate the outer surface of the hollow cylindrical magnet concentrically about the rotor axis and to apply a compressive force to the outer surface of the hollow cylindrical magnet;
- injecting molten plastic under pressure between hollow cylindrical magnet and the motor output member;
- and
- cooling the injected molten plastic to secure the motor output member to the hollow cylindrical magnet.
4 more elements
Dependencies are inferred from the claim text.