Direct current motor

Patent metadata

Field	Value
Publication number	US-9985401-B2
Application number	US-201514980960-A
Country	US
Kind code	B2
Filing date	Dec 28, 2015
Priority date	Mar 13, 2015
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

A brush holder has a core side position regulator engaged with a first connection plate to regulate a relative position. The core side position regulator has a projection part projected toward an armature core in the axial direction, and a fitting groove portion defined on both sides of the projection part in a circumferential direction. The relative position in the circumferential direction is regulated by an engagement between the projection part and a slit of the first connection plate. The relative position in the axial direction is regulated by an engagement between sides of the slit and the fitting groove portion. A width of the projection part in the circumferential direction is larger than a width of a brush in the circumferential direction.

First claim

What is claimed is:

1. A direct current motor having at least four poles comprising:
a commutator having a cylindrical shape on an axis of an armature;
a brush arranged on an outer circumference of the commutator;
a brush holder holding the brush and having insulating properties and;
a pressure component arranged in the brush holder to press the brush to the commutator;
a first connection plate having conductive properties and arranged adjacent to a core of the armature in an axial direction, all of plus side brushes or all of minus side brushes of the brush being electrically connected to the first connection plate through a respective pigtail; and
a second connection plate having conductive properties and arranged opposite from the core of the armature through the first connection plate in the axial direction, all of the minus side brushes or all of the plus side brushes being electrically connected to the second connection plate through a respective pigtail, wherein
the brush holder has an inner circumference opening opposing to the commutator in a radial direction, and an outer circumference wall surface that regulates an outer circumference position of the pressure component in the radial direction,
the first connection plate and the second connection plate are arranged in the axial direction in parallel without electrically contacting, the brush holder being held between the first connection plate and the second connection plate,
the first connection plate has a slit extending from the inner circumference or the outer circumference in the radial direction,
the brush holder has a core side position regulator engaged with the first connection plate to regulate a relative position,
the core side position regulator has
a projection part projected toward the core of the armature in the axial direction, and
a fitting groove portion defined on both sides of the projection part in a circumferential direction,

the relative position in the circumferential direction is regulated by an engagement between the projection part and the slit,
the relative position in the axial direction is regulated by an engagement between at least a part of sides of the slit in the circumferential direction and the fitting groove portion,
a width of the projection part in the circumferential direction is larger than a width of the brush in the circumferential direction, and
the first connection plate overlaps with an end portion of the brush adjacent to the core of the armature in the axial direction in a state where the brush holder that holds the brush is attached to the first connection plate.

2. The direct current motor according to claim 1 , wherein
the commutator includes
a plurality of commutator segments insulated from each other and arranged in a cylindrical state, and
a connector portion that is an end of the respective commutator segments, the connector portion being located adjacent to the core of the armature in the axial direction, an armature coil of the armature being electrically connected to the connector portion, and

the first connection plate has a spreading part which connects the sides of the slit with each other in the circumferential direction at a position on an outer side of an outer circumference of the connector portion in the radial direction.

3. The direct current motor according to claim 2 , wherein
all of the plus side brushes are electrically connected to the first connection plate which has the spreading part, and
all of the minus side brushes are electrically connected to the second connection plate.

4. The direct current motor according to claim 3 , wherein
the second connection plate is directly fixed to a motor case which forms a part of ground circuit, and is electrically connected with the motor case.

5. The direct current motor according claim 1 , further comprising:
an armature in which a coil is wave-wound around a core, and
a magnetic field coil connected to the coil of the armature in series or serial-parallel, the magnetic field coil being energized to form magnetic field poles, wherein
the number of the brushes connected to the first connection plate through the pigtail is less than one half of the number of the magnetic field poles, and
the magnetic field coil and the first connection plate are electrically connected.

6. The direct current motor according to claim 1 , further comprising:
a plurality of magnetic field coil that are energized to form magnetic field poles, wherein
the magnetic field coils are connected in series or two-parallel, and
the magnetic field coils and the first connection plate are electrically connected with each other.

7. A direct current motor having at least four poles comprising:
a commutator having a cylindrical shape on an axis of an armature;
a brush arranged on an outer circumference of the commutator;
a brush holder holding the brush and having insulating properties and;
a pressure component arranged in the brush holder to press the brush to the commutator;
a first connection plate having conductive properties and arranged adjacent to a core of the armature in an axial direction, all of plus side brushes or all of minus side brushes of the brush being electrically connected to the first connection plate through a respective pigtail; and
a second connection plate having conductive properties and arranged opposite from the core of the armature through the first connection plate in the axial direction, all of the minus side brushes or all of the plus side brushes being electrically connected to the second connection plate through a respective pigtail, wherein
the brush holder has an inner circumference opening opposing to the commutator in a radial direction, and an outer circumference wall surface that regulates an outer circumference position of the pressure component in the radial direction,
the first connection plate and the second connection plate are arranged in the axial direction in parallel without electrically contacting, the brush holder being held between the first connection plate and the second connection plate,
the first connection plate has a slit extending from the inner circumference or the outer circumference in the radial direction,
the brush holder has a core side position regulator engaged with the first connection plate to regulate a relative position,
the core side position regulator has
a projection part projected toward the core of the armature in the axial direction, and
a fitting groove portion defined on both sides of the projection part in a circumferential direction,

the relative position in the circumferential direction is regulated by an engagement between the projection part and the slit,
the relative position in the axial direction is regulated by an engagement between at least a part of sides of the slit in the circumferential direction and the fitting groove portion,
a width of the projection part in the circumferential direction is larger than a width of the brush in the circumferential direction,
the commutator includes
a plurality of commutator segments insulated from each other and arranged in a cylindrical state, and
a connector portion that is an end of the respective commutator segments, the connector portion being located adjacent to the core of the armature in the axial direction, an armature coil of the armature being electrically connected to the connector portion,

the first connection plate has a spreading part which connects the sides of the slit with each other in the circumferential direction at a position on an outer side of an outer circumference of the connector portion in the radial direction,
the brush holder has a step part located on an outer side of the projection part in the radial directi

Assignees

• Denso Corp

Inventors

• Hirabayashi Takashi

Classifications

• H02K23/02 Primary

  characterised by arrangement for exciting · CPC title

• H01R39/41

  cartridge type · CPC title

• H01R39/381 Primary

  characterised by the application of pressure to brush · CPC title

• H01R39/38

  Brush holders · CPC title

• H02K5/148

  Slidably supported brushes · CPC title