Direct current motor, coil winding method for direct-current motor, and method for manufacturing direct-current motor
A direct-current motor includes a yoke having six magnetic poles, an iron core having nine teeth, first and second coils wound about each tooth in directions different from each other, a commutator for being rotated integrally with the iron core and having eighteen commutator pieces, and three pairs of brushes. The brush having the positive pole electrically connected to the first coil is different from the brush having the positive pole electrically connected to the second coil, the brush having the negative pole electrically connected to the first coil is different from the brush having the negative pole electrically connected to the second coil, or the brush having the positive pole and the brush having the negative pole that are electrically connected to the first coil are respectively different from the brush having the positive pole and the brush having the negative pole that are electrically connected to the second coil.
1. A direct-current motor, comprising:
a cylindrical yoke having six magnetic poles;
an iron core rotationally provided inside the yoke, the iron core having nine teeth arranged in a rotation direction;
a first coil wound about each tooth in a forward direction;
a second coil wound about each tooth in a reverse direction with respect to the first coil;
a commutator for being rotated integrally with the iron core, the commutator having eighteen commutator pieces arranged in the rotation direction; and
three sets of brushes retained inside the yoke, each set having a pair of brushes, wherein each set of the brushes supplies electricity to the first and second coils by sliding against corresponding commutator pieces,
wherein the first and second coils provided on a same tooth are connected to the commutator pieces of a same phase such that the first and second coils are electrically connected to an arbitrary one of the brushes having a positive pole and an arbitrary one of the brushes having a negative pole simultaneously,
wherein,
the first coil has ends respectively connected to two commutator pieces,
the second coil has ends respectively connected to two commutator pieces,
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the first coil,
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the second coil, and
the brush having the positive pole electrically connected to the first coil is different from the brush having the positive pole electrically connected to the second coil, or
the brush having the negative pole electrically connected to the first coil is different from the brush having the negative pole electrically connected to the second coil, or
the brush having the positive pole and the brush having the negative pole that are electrically connected to the first coil are respectively different from the brush having the positive pole and the brush having the negative pole that are electrically connected to the second coil.
2. The direct-current motor according to claim 1 , wherein the ends of the first coil are respectively connected to two commutator pieces the phases of which are shifted by at least 180° in a rotation direction of the commutator.
3. The direct-current motor according to claim 1 , wherein another second coil is provided on a tooth that is different from the same tooth in which the first coil is provided, said other second coil is connected to one of the commutator pieces to which the first coil is connected, and the first coil and said other second coil are configured by a single conducive wire.
4. The direct-current motor according to claim 1 , wherein the ends of the first coil are symmetrically arranged with respect to the same tooth, and the ends of the second coil are symmetrically arranged with respect to the same tooth.
5. A coil winding method for a direct-current motor, wherein
the direct-current motor includes:
a cylindrical yoke having six magnetic poles;
an iron core rotationally provided inside the yoke, the iron core having nine teeth arranged in a rotation direction;
a first coil wound about each tooth in a forward direction;
a second coil wound about each tooth in a reverse direction with respect to the first coil;
a commutator for being rotated integrally with the iron core, the commutator having eighteen commutator pieces arranged in the rotation direction; and
three sets of brushes retained in the yoke, each set having a pair of brushes, wherein each set of the brushes supplies electricity to the first and second coils by sliding against corresponding commutator pieces, the method comprising:
continuously winding each of the first and second coils such that the first and second coils provided on a same tooth are connected to the commutator pieces of a same phase such that the first and second coils are electrically connected to an arbitrary one of the brushes having a positive pole and an arbitrary one of the brushes having a negative pole simultaneously, and such that:
the brush having the positive pole electrically connected to the first coil is different from the brush having the positive pole electrically connected to the second coil, or
the brush having the negative pole electrically connected to the first coil is different from the brush having the negative pole electrically connected to the second coil, or
the brush having the positive pole and the brush having the negative pole that are electrically connected to the first coil are respectively different from the brush having the positive pole and the brush having the negative pole that are electrically connected to the second coil,
wherein,
the first coil has ends respectively connected to two commutator pieces,
the second coil has ends respectively connected to two commutator pieces,
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the first coil, and
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the second coil.
6. A method for manufacturing a direct-current motor, comprising:
providing a cylindrical yoke having six magnetic poles;
providing an iron core rotationally provided inside the yoke, the iron core having nine teeth arranged in a rotation direction;
providing a first coil wound about each tooth in a forward direction;
providing a second coil wound about each tooth in a reverse direction with respect to the first coil;
providing a commutator for being rotated integrally with the iron core, the commutator having eighteen commutator pieces arranged in the rotation direction; and
providing three sets of brushes retained inside the yoke, each set having a pair of brushes, wherein each set of the brushes supplies electricity to the first and second coils by sliding against corresponding commutator pieces,
wherein the first and second coils provided on a same tooth are connected to the commutator pieces of a same phase such that the first and second coils are electrically connected to an arbitrary one of the brushes having a positive pole and an arbitrary one of the brushes having a negative pole simultaneously,
wherein,
the brush having the positive pole electrically connected to the first coil is different from the brush having the positive pole electrically connected to the second coil, or
the brush having the negative pole electrically connected to the first coil is different from the brush having the negative pole electrically connected to the second coil, or
the brush having the positive pole and the brush having the negative pole that are electrically connected to the first coil are respectively different from the brush having the positive pole and the brush having the negative pole that are electrically connected to the second coil, and
wherein,
the first coil has ends respectively connected to two commutator pieces,
the second coil has ends respectively connected to two commutator pieces,
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the first coil, and
the same tooth on which the first and second coils are provided corresponds to a circumferential midpoint between the ends of the second coil.