Direct current motor using magnets with extensions
AssigneeAsmo Co., Ltd.
InventorsHiroyuki Harada, Takeshi Tanaka
Life of this patent
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Abstract
A direct current motor is comprised of an armature, magnets arranged to face each other through the armature, a commutator and brushes. The armature has a core and a plurality of coils wound on the core. Each magnet has a main part and an extension extending form the main part. The main part has an angular interval which corresponds to an interval of winding each coil, so that the extension is positioned outside the coil in the circumferential direction. During the commutation period of the coil, that is, during shorting of the coil by the brush, the amount of magnetic flux passing through the coil is changed by the extension of the magnet. Thus, an induction voltage is generated in the coil to counteract to a reactance voltage of the coil.
Claims20
A direct current motor comprising:
- an armature having a core and coils wound on the core;
- magnets arranged to face each other through the armature;
- a commutator operatively connected to the coils;
- and
- a brush disposed in sliding contact with the commutator for shorting each coil during a commutation period to reverse a direction of current in the coil,
- wherein each magnet has an extension at an end thereof to generate in the coil an induction voltage which counteracts to the reactance voltage.
A direct current motor comprising:
- an armature having a core and coils wound on the core;
- magnets shaped arcuately and arranged to face each other through the armature, each magnet having a main part and an extension, the main part extending over a predetermined angular interval corresponding to an angular interval of winding each coil, and the extension being provided outside of the main part;
- and
- a commutator fixed to the armature and operatively connected to the coils.
Dependencies are inferred from the claim text.