WO2016129247A1 - Rectifier, rectifier motor and method for manufacturing rectifier - Google Patents

Abstract

This rectifier (1) is formed into a cylindrical shape along a shaft center (1a), and comprises a conductive layer (2), a resin layer (4) and an intermediate layer (3). The conductive layer (2) contains a conductive material and a polishing material (18). The conductive layer (2) is provided with a plurality of rectifier pieces (2a) that extend from the outer circumferential surface (1b) toward the direction opposite to the shaft center (1a). The resin layer (4) contains an electrically insulating resin material. The intermediate layer (3) contains a conductive material and an electrically insulating resin material in combination. In the intermediate layer (3), the content ratio of the conductive material decreases from the conductive layer (2) side toward the resin layer (4) side, while the content ratio of the resin layer increases in that direction.

Description

Commutator, commutator motor, and commutator manufacturing method

The present invention relates to a commutator motor used for an electric device attached to a household vacuum cleaner or a vehicle.

Commutator motors are used in household vacuum cleaners and electrical equipment attached to vehicles. In recent years, in these devices, a commutator motor is required to be small and have high durability.

In a commutator motor including a commutator, a driving current is supplied to a rotor having a commutator through a brush. In the following description, a commutator motor including a commutator is also simply referred to as a motor.

The commutator is composed of a plurality of commutator pieces. The commutator is molded with an electrically insulating resin.

The motor has a contact portion where the brush and the commutator piece are in mechanical contact. The brush and the commutator piece are also electrically connected at the contact portion.

The motor rectifies the drive current supplied to the rotor using a brush and a commutator piece. When the drive current is rectified, a spark discharge is generated between the brush and the commutator piece at the contact portion that is in mechanical contact. Therefore, when the drive current is rectified, the ambient temperature is high near the contact portion that is in mechanical contact.

FIG. 7 is an enlarged view of a main part of a conventional commutator.

As shown in FIG. 7, since the commutator piece 42a and the electrically insulating resin 43 that molds the commutator 41 are made of different materials, they have different thermal expansion coefficients.

Therefore, if the ambient temperature in the vicinity of the contact portion that is in mechanical contact increases, thermal strain due to thermal stress concentrates on the boundary surface 44 located between the commutator piece 42a and the electrically insulating resin 43.

Also, when the rotor rotates at high speed, centrifugal force acts on the commutator 41. This centrifugal force reaches the boundary surface 44 where thermal strain is concentrated. The boundary surface 44 on which the centrifugal force is applied peels from the commutator piece 42a and swells to the outer peripheral side. Therefore, the commutator piece 42a may partially swell and unevenness may occur on the outer peripheral surface of the commutator piece 42a. When irregularities are generated on the outer peripheral surface, the spark discharge generated between the commutator piece 42a and the brush may be further increased. Eventually, the spark discharge generated between the commutator piece 42a and the brush grows into a ring fire. When ring fire occurs, the brushes may wear abnormally. Alternatively, the commutator piece 42a may be damaged.

As a result, the motor stops.

In order to cope with the above-described problems, Patent Document 1 discloses a motor using a commutator formed of a functionally gradient material.

FIG. 8A is a partial cross-sectional view showing an outline of a conventional motor. FIG. 8B is a cross-sectional view of a conventional commutator.

8A and 8B, a functionally gradient material is used for the commutator 41 shown in Patent Document 1. The commutator 41 includes a plurality of commutator pieces 42a.

In the commutator 41, no boundary surface is generated between the commutator piece 42 a and the electrically insulating resin that molds the commutator 41. Therefore, the commutator 41 shown in Patent Document 1 can disperse thermal stress even when the ambient temperature near the contact portion that is in mechanical contact increases. Therefore, even when a centrifugal force acts on the commutator 41 when the rotor 51 rotates at a high speed, the commutator piece 42a is unlikely to be peeled off or cracked.

Japanese Patent Laid-Open No. 4-109847

The commutator targeted by the present invention is formed in a cylindrical shape along the axis and has a conductive layer, a resin layer, and an intermediate layer.

The conductive layer is located on the outer peripheral side in the direction orthogonal to the axis. The conductive layer includes a conductive material and an abrasive. In the conductive layer, a plurality of commutator pieces are formed from the outer peripheral surface toward the opposite side of the axis.

The resin layer is located on the inner peripheral side in the direction orthogonal to the axis. The resin layer includes an electrically insulating resin material.

The intermediate layer is located between the conductive layer and the resin layer in the direction orthogonal to the axis. The intermediate layer includes a mixture of a conductive material and an electrically insulating resin material. In the intermediate layer, the content of the conductive material decreases and the content of the resin material increases from the conductive layer toward the resin layer.

FIG. 1A is a cross-sectional view showing an outline of a motor according to Embodiment 1 of the present invention. FIG. 1B is a cross-sectional view showing an outline of the commutator according to Embodiment 1 of the present invention. FIG. 1C is a front view of the commutator according to Embodiment 1 of the present invention. FIG. 2A is an enlarged view of a main part for explaining a use state of the commutator in Embodiment 1 of the present invention. FIG. 2B is an enlarged view of a main part for explaining another usage state of the commutator in Embodiment 1 of the present invention. FIG. 3 is a conceptual diagram for explaining the composition change of the commutator in the first embodiment of the present invention. FIG. 4 is a conceptual diagram illustrating another composition change of the commutator in the first embodiment of the present invention. FIG. 5A is a characteristic diagram showing the driving time and brush length of a motor using a commutator compared with the present invention. FIG. 5B is a characteristic diagram showing a drive time and a brush length of the motor using the commutator in Embodiment 1 of the present invention. FIG. 6 is a flowchart showing a commutator manufacturing method according to Embodiment 2 of the present invention. FIG. 7 is an enlarged view of a main part of a conventional commutator. FIG. 8A is a partial cross-sectional view showing an outline of a conventional motor. FIG. 8B is a cross-sectional view of a conventional commutator.

The commutator according to the embodiment of the present invention can always maintain a good state when the brush and the commutator are in a conductive state by the configuration described later. Therefore, the commutator in the embodiment of the present invention can be expected to further extend the life of the brush.

In other words, the conventional commutator had the following points to be improved.

That is, in the conventional motor 40 shown in FIG. 8A, the brush 47 and the commutator 41 are in contact with each other on a sliding contact surface 47a where the brush 47 and the commutator 41 slide. When the brush 47 and the commutator 41 slide against each other, the brush 47 is worn. If the brush 47 is worn, brush powder is generated in the vicinity of the sliding contact surface 47a. When brush powder adheres to the sliding contact surface 47a, poor conduction occurs between the brush 47 and the commutator piece 42a formed on the commutator 41. When poor conduction occurs between the brush 47 and the commutator piece 42a, spark discharge occurs on the sliding contact surface 47a. When spark discharge occurs on the sliding contact surface 47a, an oxide film that is an insulator is formed on the commutator piece 42a. When an oxide film is generated on the commutator piece 42 a, the conduction failure further proceeds between the commutator piece 42 a and the brush 47. Therefore, the motor 40 is prevented from extending the life of the brush 47.

That is, in a conventional motor, the brush that has been subjected to a predetermined driving time is rapidly worn. Therefore, with a conventional motor, the brush length of a brush that has passed a predetermined driving time is accelerated.

Therefore, the commutator which is an embodiment of the present invention to be described later further extends the life of the brush while maintaining a good conduction state between the brush and the commutator.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.

(Embodiment 1)
FIG. 1A is a cross-sectional view showing an outline of a motor according to Embodiment 1 of the present invention. FIG. 1B is a cross-sectional view showing an outline of the commutator according to Embodiment 1 of the present invention. FIG. 1C is a front view of the commutator according to Embodiment 1 of the present invention.

FIG. 2A and FIG. 2B are enlarged views of main parts for explaining the use state of the commutator in the first embodiment of the present invention.

3 and 4 are conceptual diagrams for explaining the composition change of the commutator in Embodiment 1 of the present invention.

FIG. 5A is a characteristic diagram showing the drive time and brush length of a motor using a commutator compared with the present invention. FIG. 5B is a characteristic diagram showing a drive time and a brush length of the motor using the commutator in Embodiment 1 of the present invention.

As shown in FIG. 1A, commutator 1 in Embodiment 1 of the present invention is used inside motor 30. In the following description, the motor 30 is exemplified by a DC motor.

The motor 30 includes a rotor 31 and a stator 32.

The rotor 31 includes the commutator 1, the shaft 11, and the rotor core 14. The commutator 1 will be described in detail later. The shaft 11 has a central axis 11 a located on the axis 1 a of the commutator 1. The commutator 1 is attached to the shaft 11. The rotor core 14 is attached to the shaft 11.

The stator 32 is positioned facing the rotor 31.

The motor 30 having this configuration can enjoy the effects exhibited by the commutators 1 and 101 described later.

As shown in FIG. 1B, commutator 1 in Embodiment 1 of the present invention is formed in a cylindrical shape along axis 1a, and has conductive layer 2, resin layer 4, and intermediate layer 3. .

The conductive layer 2 is located on the outer peripheral side in the direction orthogonal to the axis 1a. The conductive layer 2 includes a conductive material and an abrasive 18. In the conductive layer 2, a plurality of commutator pieces 2a are formed from the outer peripheral surface 1b toward the opposite side of the shaft center 1a.

The resin layer 4 is located on the inner peripheral side in the direction orthogonal to the axis 1a. The resin layer 4 includes an electrically insulating resin material.

The intermediate layer 3 is located between the conductive layer 2 and the resin layer 4 in a direction orthogonal to the axis 1a. The intermediate layer 3 includes a mixture of a conductive material and an electrically insulating resin material. In the intermediate layer 3, the content of the conductive material decreases from the conductive layer 2 toward the resin layer 4, and the content of the resin material increases.

According to this configuration, as shown in FIGS. 2A and 2B, the commutator piece 2 a includes the abrasive 18. The abrasive 18 polishes the oxide film 20 generated on the surface of the commutator piece 2a. Therefore, the oxide film 20 does not increase in thickness. Therefore, poor conduction between the brush 17 and the commutator piece 2a is reduced.

As a result, the occurrence of spark discharge, which has occurred due to poor conduction between the brush 17 and the commutator piece 2a, is suppressed.

Therefore, since the commutator 1 according to the first embodiment can suppress the wear of the brush 17, the life of the brush 17 can be extended.

By the way, if a material that does not bond to copper is used as the abrasive 18, the abrasive 18 can be easily separated from the commutator piece 2a. Therefore, the abrasive 18 is less likely to remain on the sliding contact surface 17a.

That is, when a material that combines with copper is used as the abrasive, the abrasive remains on the sliding surface side of the commutator piece. In this case, conduction failure may occur between the brush and the commutator piece.

Therefore, if a material that is not bonded to copper is used as the abrasive 18, the abrasive 18 can be prevented from remaining on the sliding contact surface 17a side of the commutator piece 2a. Therefore, a good conduction state is maintained between the brush 17 and the commutator piece 2a. Therefore, the occurrence of spark discharge is reduced between the brush 17 and the commutator piece 2a. As a result, the commutator 1 can further extend the life of the brush 17.

In particular, the configuration that exhibits remarkable effects is as follows.

That is, as shown in FIG. 1B, in the commutator 1, the conductive material is copper. Specifically, the commutator 1 can be formed of copper powder. Alternatively, the conductive material is silver. Other conductive metals can be used as the conductive material.

The intermediate layer 3 is a functionally graded material containing a mixture of a conductive material and a resin material.

The intermediate layer 3 is formed of a plurality of first intermediate layers 3a and second intermediate layers 3b in a direction orthogonal to the axis 1a.

Particularly, the first intermediate layer 3a and the second intermediate layer 3b, which are a plurality of layers, have different mixing ratios of the conductive material and the resin material.

Also, the abrasive 18 is harder than copper. Specifically, the abrasive 18 is a ceramic material. Alternatively, the abrasive 18 is tungsten.

2A and 2B, the abrasive 18 can be added to the sliding contact surface 17a side of the inclined commutator piece 2a. Therefore, the outer peripheral surface 2b of the commutator piece 2a is polished by the abrasive 18 harder than copper forming the commutator 1 on the outer peripheral surface 2b. That is, the non-conductive layer generated on the outer peripheral surface 2b of the commutator piece 2a is polished.

Moreover, the abrasive 18 is a spherical particle. The shape of the particles includes not only a true sphere but also a substantially spherical shape having a substantially elliptical cross-sectional shape.

The particles of the abrasive 18 are also located on the outer peripheral surface 2b side of the inclined commutator piece 2a. If the brush 17 is in sliding contact with the commutator piece 2a, the outer peripheral surface 2b of the commutator piece 2a is worn by friction. When the outer peripheral surface 2b of the commutator piece 2a is worn, particles of the abrasive 18 are taken out from the copper molecules constituting the commutator piece 2a.

With the above configuration, when the particles of the abrasive 18 are taken out from the commutator piece 2a, the particles are taken out more smoothly. As shown in FIG. 2A, the particles of the abrasive 18 taken out are substantially spherical. Therefore, the abrasive 18 rolls between the brush 17 and the outer peripheral surface 2b of the commutator piece 2a. The particles of the abrasive 18 contribute to the polishing of the outer peripheral surface 2b of the commutator piece 2a.

Furthermore, it explains in detail using a drawing.

As shown in FIG. 1A, the field magnet 13 is attached to the motor 30 along the inner peripheral surface 12a of the frame 12 formed in a cylindrical shape. In the motor 30, the rotor 31 is located on the inner peripheral side of the field magnet 13.

The rotor 31 has a shaft 11, an armature 10, and a commutator 1.

The armature 10 includes a rotor core 14, an insulator 15, and a winding 16. In the first embodiment, the rotor core 14 is configured by laminating steel plates. The rotor core 14 can be formed in another configuration as long as the same effect as that of the stacked steel plates can be obtained. A winding 16 is wound around the rotor core 14 via an insulator 15. The insulator 15 electrically insulates the rotor core 14 and the winding 16 from each other. The insulator 15 can be formed of resin.

The armature 10 and the commutator 1 are attached to the shaft 11. The shaft 11 is rotatable about the central axis 11a as a rotation center.

As shown in FIG. 1B, the commutator 1 is formed with a plurality of commutator pieces 2a. As shown in FIG. 1A, in the first embodiment, commutator 1 is a plurality of commutator pieces (2a) and contacts a pair of brushes 17. The pair of brushes 17 are in contact with the plurality of commutator pieces (2a) from a direction orthogonal to the central axis 11a. The direction orthogonal to the central axis 11a is also referred to as a radial direction. The surface on which each of the plurality of commutator pieces (2a) and each of the pair of brushes 17 slide is also referred to as a sliding contact surface 17a. Each of the pair of brushes 17 can be realized by using a carbon material.

A drive current is supplied to each of the plurality of commutator pieces (2a) from each of the pair of brushes 17 via the sliding contact surface 17a. The direction in which the drive current flows is switched depending on the positional relationship when the commutator piece (2a) and the brush 17 are in contact with each other. Since the direction in which the drive current flows is switched, the armature 10 rotates. Switching the direction in which the drive current flows is also referred to as commutation.

Next, as shown in FIG. 1B and FIG. 1C, the commutator 1 according to the first embodiment is cylindrical. In the direction crossing the axis 1a, the commutator 1 includes a conductive layer 2 positioned on the outer peripheral side, a resin layer 4 positioned on the inner peripheral side, and an intermediate layer positioned between the conductive layer 2 and the resin layer 4 3.

The conductive layer 2 is formed of a conductive material. Copper or copper alloy can be used as the conductive material. In the first embodiment, the conductive layer 2 is formed of copper powder (19). In the conductive layer 2, a commutator piece 2a is formed toward the opposite side of the axis 1a.

Resin layer 4 is formed of a resin material having electrical insulation. As the resin material, a thermosetting resin such as an epoxy resin or a phenol resin can be used.

The intermediate layer 3 has a composition in which a conductive material and a resin material are mixed. The intermediate layer 3 includes a first intermediate layer 3a and a second intermediate layer 3b. The first intermediate layer 3a and the second intermediate layer 3b have different compositions.

Further, the commutator 1 is disposed between the adjacent pair of commutator pieces 2a among the plurality of commutator pieces 2a on the surface orthogonal to the axis 1a from the outer peripheral surface 1b toward the axis 1a. The slit 7 including the concave slit 7 has a depth reaching the resin layer 4. The slit 7 electrically separates a pair of adjacent commutator pieces 2a.

3, the right side shows the outer peripheral side of the commutator 1 and the left side shows the inner peripheral side of the commutator 1 in the figure. As shown in FIG. 3, in the commutator 1, the ratio of the main composition continuously changes from the conductive material 2c to the resin material 4a from the outer peripheral side to the inner peripheral side. More specifically, the main composition of the commutator 1 changes from the conductive material 2c to the resin material 4a through a mixed state of the conductive material 2c and the resin material 4a. This change gradually changes as the conductive material 2c and the resin material 4a enter and mix as shown in the enlarged view in the figure.

That is, the intermediate layer 3 which is a mixture of the conductive material 2c and the resin material 4a functions as a functionally gradient material.

Therefore, the composition of the commutator 1 continuously changes without forming a boundary surface between the materials. Therefore, in the commutator 1, when a clear boundary surface is formed, a micro void or the like that is considered to be generated on the boundary surface does not occur.

With this configuration, the commutator 1 made of a plurality of materials can disperse the thermal stress as if it were an integrated body made of a single material. Therefore, when the rotor (31) rotates at a high speed, even if centrifugal force acts on the commutator 1, the commutator piece 2a or the like does not peel or crack. Further, the commutator 1 can prevent unevenness as described above. Therefore, the commutator 1 has improved reliability.

The commutator 1 can be formed using a discharge plasma sintering method, for example, as shown in a second embodiment described later.

It should be noted that the composition change of the commutator in the first embodiment is also possible in the following form.

That is, as shown in FIG. 4, the commutator 101 has a region made of a single material. Specifically, commutator 101 includes a region 2d made of conductive material 2c and a region 4b made of resin material 4a from the outer peripheral side to the inner peripheral side of commutator 101.

These regions 2d and 4b are intended to be actively composed of a single material. These regions 2d and 4b do not exclude the mixing of other unintended materials.

With this configuration, the commutator 101 can obtain a desired capacitance or the like according to the required specifications.

Next, characteristic actions and effects of the first embodiment will be described below.

As shown in FIG. 2A, the commutator (1) includes an abrasive 18 in the commutator piece 2a formed outside the conductive layer (2). For example, a ceramic material is used for the abrasive 18. The abrasive 18 removes the oxide film 20 generated on the surface of the commutator piece 2a, that is, the sliding contact surface 17a. Therefore, the oxide film 20 removed by the abrasive 18 cannot be thickened.

That is, as shown in FIG. 2B, the surface of the commutator piece 2a is polished with the oxide film 20 that caused the conduction failure between the commutator piece 2a and the brush 17. Therefore, the conduction state between the commutator piece 2a and the brush 17 is maintained in a good state.

As a result, the occurrence of the spark discharge generated on the sliding contact surface 17a where the commutator piece 2a and the brush 17 are in sliding contact with each other is suppressed. Therefore, the commutator 1 according to the first embodiment can extend the life of the brush 17.

Further, the abrasive 18 is not bonded to the copper powder 19. Therefore, the abrasive 18 is easily separated from the commutator piece 2 a made of the copper powder 19. In other words, it is possible to suppress the abrasive 18 from remaining only on the sliding contact surface 17a where the commutator piece 2a and the brush 17 slide independently.

Therefore, it is possible to suppress the abrasive 18 from remaining on the sliding contact surface 17a independently, so that poor conduction between the commutator piece 2a and the brush 17 is reduced. When the conduction failure is reduced between the commutator piece 2 a and the brush 17, the occurrence of spark discharge can be reduced between the commutator piece 2 a and the brush 17. As a result, the life of the brush 17 is further extended.

Here, the relationship between the drive time and the brush length will be described for the brush 17 in the first embodiment and the brush of the comparative example.

As shown in FIG. 5A, when a conventional brush, which is a comparative example, is used, when the brush length reaches a predetermined driving time T1, the wear proceeds rapidly. That is, the conventional brush has two wear speeds with a predetermined drive time T1 as a boundary.

As shown in FIG. 5B, when the brush 17 according to the first embodiment is used, the brush length is gradually shortened in proportion to the driving time. That is, the brush 17 advances at a substantially constant speed in proportion to the driving time.

That is, as is clear from the comparison between FIG. 5A and FIG. 5B, the brush 17 in the first embodiment has a long life.

Incidentally, in general, in a motor having a large inductance, spark discharge tends to be large between the brush and the commutator piece. If a large spark discharge occurs, the brush will be damaged. In addition, when a large spark discharge occurs, the thickness of the oxide film generated on the surface of the commutator piece increases. Therefore, when the thickness of the oxide film generated on the surface of the commutator piece is increased, poor conduction is likely to occur between the brush and the commutator piece.

Therefore, if the brush according to the first embodiment is used for a motor having a large inductance, the oxide film can be polished, so that a conduction failure occurring between the brush and the commutator piece can be suppressed. Therefore, the brush in the first embodiment can be expected to have a remarkable effect, particularly with a motor having a large inductance.

In addition, each component of Embodiment 1 mentioned above can be set as the following forms.

That is, the abrasive 18 can be a ceramic material and a compound of tungsten in addition to the ceramic material and tungsten. As the abrasive 18, other materials having characteristics similar to those of a ceramic material and tungsten can be used.

(Embodiment 2)
FIG. 6 is a flowchart showing a commutator manufacturing method according to Embodiment 2 of the present invention.

In addition, about the structure similar to the commutator in this Embodiment 1, the same code | symbol is attached | subjected and description is used.

As shown in FIG. 6, the commutator manufacturing method according to the second embodiment of the present invention includes the following steps.

That is, in the preparing step, a conductive material and a resin material are prepared (step 1).

In the filling step, the conductive material and the resin material are filled, respectively. In the filling step, the conductive material and the resin material are mixed and filled (step 2).

The step of energizing performs pulse-shaped energization while applying pressure to the filled conductive material, the mixed and filled conductive material and resin material, and the filled resin material (step 3).

Through the above steps, commutators 1 and 101 described in the first embodiment are manufactured.

According to the method of manufacturing a commutator shown in the second embodiment, functionally graded material can be manufactured in a short time with power saving. Thus, the manufacturing method described in Embodiment 2 can improve production efficiency and reduce manufacturing costs.

It should be noted that a discharge plasma sintering method can be used for the commutator manufacturing method shown in the second embodiment. The commutator manufactured by the manufacturing method shown in the second embodiment becomes a functionally graded material in which the content ratios of the conductive material and the resin material sequentially change.

Therefore, the composition of the commutator manufactured by the manufacturing method shown in the second embodiment changes continuously without forming a boundary surface between the materials. Therefore, in this commutator, when a clear boundary surface is formed, a microscopic void that is considered to be generated on the boundary surface does not occur.

Further, when the discharge plasma sintering method is used, it is possible to manufacture an abrasive having low conductivity and a metal having high conductivity in an integrated manner.

The commutator of the present invention can be used for a commutator motor used in an electric device attached to a household vacuum cleaner or a vehicle. In particular, when the commutator of the present invention is applied to a commutator motor that is used for applications in which a large current flows and rotates at high speed, a remarkable effect can be obtained.

1, 41, 101 Commutator 1a Axes 1b, 2b Outer peripheral surface 2 Conductive layer 2a, 42a Commutator piece 2c Conductive material 2d, 4b Region 3 Intermediate layer 3a First intermediate layer (layer)
3b Second intermediate layer (layer)
DESCRIPTION OF SYMBOLS 4 Resin layer 4a Resin material 7 Slit 10 Armature 11 Shaft 11a Center axis 12 Frame 12a Inner peripheral surface 13 Field magnet 14 Rotor core 15 Insulator 16 Winding 17, 47 Brush 17a, 47a Sliding surface 18 Polishing material 19 Copper powder 20 Oxide film 30, 40 Motor (commutator motor)
43 Resin 44 Interface 31, 51 Rotor 32 Stator

Claims (12)

1. Formed in a cylindrical shape along the axis, in a direction perpendicular to the axis,
   A conductive layer that is located on the outer peripheral side and includes a conductive material, and includes a polishing material, and a plurality of commutator pieces are formed from the outer peripheral surface toward the opposite side of the axis, and
   Located on the inner periphery side, a resin layer containing an electrically insulating resin material,
   The conductive material and the resin material are mixed and included between the conductive layer and the resin layer, and the content of the conductive material decreases from the conductive layer toward the resin layer. An intermediate layer in which the content of the resin material increases;
   Commutator with
2. The commutator according to claim 1, wherein the conductive material is copper.
3. The commutator according to claim 1, wherein the conductive material is silver.
4. The commutator according to claim 1, wherein the intermediate layer is a functionally gradient material including a mixture of the conductive material and the resin material.
5. The commutator according to claim 1, wherein the intermediate layer is formed of a plurality of layers in a direction perpendicular to the axis.
6. The commutator according to claim 5, wherein the plurality of layers have different mixing ratios of the conductive material and the resin material.
7. The commutator according to claim 1, wherein the abrasive has higher hardness than copper.
8. The commutator according to claim 7, wherein the abrasive is a ceramic material.
9. The commutator according to claim 7, wherein the abrasive is tungsten.
10. The commutator according to claim 1, wherein the abrasive is a spherical particle.
11. The commutator according to any one of claims 1 to 4,
    A shaft on which the commutator is mounted, the central axis of which is located on the axis;
    A rotor core attached to the shaft;
    A rotor having
    A stator positioned opposite the rotor;
    A commutator motor comprising:
12. Preparing the conductive material and the resin material;
    Filling each of the conductive material and the resin material, and mixing and filling the conductive material and the resin material;
    Conducting the pulsed energization while applying pressure to the filled conductive material, the filled resin material, and the mixed and filled conductive material and the resin material;
    A method of manufacturing a commutator that manufactures the commutator according to any one of claims 1 to 4.

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