JP2021069145A - Motor - Google Patents

Abstract

To provide a motor in which a brush is prevented from protruding from a brush accommodation part, without shortening an effective abrasion length of the brush.SOLUTION: A motor comprises: a rotor 20 including a rotary shaft 21; a rectifier 50 fitted to the rotary shaft 21; a brush 60 in contact with the rectifier 50; a brush holding member 90 in which an opening 91a is provided at the side of the rectifier 50 and which includes a brush accommodation part 91 for accommodating the brush 60 therein; a pigtail wire 70 which is a conductive wire connected to the brush 60; and a wall 92 which is a hook structure to which a portion of the pigtail wire 70 is hooked when the brush 60 accommodated in the brush accommodation part 91 is moved out of the opening 91a. The pigtail wire 70 includes a hard portion 71 which is harder than the other portion and in the pigtail wire 70, an exposed portion for a predetermined length from a connection location with the brush 60 includes a portion which is the hard portion 71 and hooked to the wall 92 when the brush 60 accommodated in the brush accommodation part 91 is moved out of the opening 91a.SELECTED DRAWING: Figure 4

Description

The present disclosure relates to an electric motor.

Electric motors are widely used in the field of electrical equipment such as automobiles, as well as in the field of household electric appliances such as vacuum cleaners. For example, in a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle, an electric motor is used to drive a cooling fan such as a radiator.

As an electric motor, a commutator electric motor using a brush and a commutator, or a brushless electric motor not using a brush and a commutator is known.

Of these, the commutator motor includes a rotor, a commutator attached to the rotating shaft of the commutator, and a brush in contact with the commutator (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2013-135493

In the commutator motor, the brush is stored in a brush storage portion such as a brush box. For example, in Patent Document 1, the brush is housed in a brush box integrally formed with the brush holding member.

In addition, a pigtail wire is connected to the brush to supply power to the brush. One end of the pigtail wire is embedded in the side surface of the brush, and the other end is connected to the power supply terminal.

Conventionally, the portion of the pigtail wire exposed from the brush has been made flexible so as not to become a resistance force when the brush moves to the commutator side. For this reason, the root portion of the pigtail wire on the brush side may be deformed and the pigtail wire may slip through the narrow portion at the exit of the brush storage portion, causing a problem that the brush pops out from the brush storage portion.

Therefore, it is conceivable to set the length of the pigtail wire as short as possible in order to prevent the brush from popping out from the brush housing, but shortening the length of the pigtail wire shortens the effective wear length of the brush. Will end up.

The present disclosure has been made to solve such a problem, and an object of the present invention is to provide an electric motor capable of suppressing the brush from popping out from the brush storage portion without shortening the effective wear length of the brush. ..

In order to achieve the above object, one aspect of the electric motor according to the present disclosure is a rotor having a rotating shaft, a commutator attached to the rotating shaft, a brush in contact with the commutator, and a commutator side. When a brush holding member having an opening and having a brush accommodating portion for accommodating the brush, a conductive wire connected to the brush, and the brush housed in the brush accommodating portion exit from the opening. The conductive wire has a hooking structure in which a part of the conductive wire is hooked, and the conductive wire has a hard portion harder than other portions, and has a predetermined length from a connection portion of the conductive wire with the brush. The exposed portion is the hard portion and includes the part of the conductive wire.

According to the electric motor according to the present disclosure, it is possible to prevent the brush from popping out from the brush storage portion without shortening the effective wear length of the brush.

It is a perspective view when the electric motor which concerns on embodiment is seen from obliquely above. It is a perspective view when the electric motor which concerns on embodiment is seen from diagonally below. It is sectional drawing of the electric motor which concerns on embodiment. It is a figure which shows the brush holding member, the brush and the cover plate in the electric motor which concerns on embodiment. It is a figure which shows the brush holding member, the brush and the cover plate in the electric motor which concerns on embodiment. It is a top view which shows the structure around the brush in the electric motor which concerns on embodiment. It is sectional drawing which shows the structure around the brush in the electric motor which concerns on embodiment. It is sectional drawing which shows the structure around the brush in the electric motor which concerns on embodiment. It is a figure which shows the structure of the pigtail wire in the electric motor which concerns on embodiment. It is a figure for demonstrating the state at the time of assembling a conventional electric motor. It is a figure for demonstrating the state at the time of assembling the electric motor which concerns on embodiment. It is sectional drawing which shows the structure around the brush in the electric motor which concerns on modification 1. FIG. It is a top view which shows the structure around the brush in the electric motor which concerns on modification 2. FIG. It is a top view which shows the structure around the brush in the electric motor which concerns on modification 3. It is a top view which shows the structure around the brush in another electric motor which concerns on modification 3. FIG. It is a perspective view which shows the structure around the brush in another electric motor which concerns on modification 4. FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The embodiments described below are specific examples of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions of the components, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components not described in the independent claims are described as arbitrary components.

It should be noted that each figure is a schematic view and is not necessarily exactly illustrated. Further, in each figure, the same reference numerals are given to substantially the same configurations, and duplicate description will be omitted or simplified.

Further, in the present specification and drawings, the X-axis, the Y-axis, and the Z-axis represent the three axes of the three-dimensional Cartesian coordinate system. That is, the X-axis and the Y-axis are orthogonal to each other and both are orthogonal to the Z-axis.

(Embodiment)
The overall configuration of the electric motor 1 according to the embodiment will be described with reference to FIGS. 1A to 3B. FIG. 1A is a perspective view of the electric motor 1 according to the embodiment when viewed from diagonally above. FIG. 1B is a perspective view of the electric motor 1 when viewed from diagonally below. FIG. 2 is a cross-sectional view of the electric motor 1 in the XZ cross section. 3A and 3B are views showing a brush 60, a brush holding member 90, and a cover plate 100 in the electric motor 1. In addition, in FIG. 3A and FIG. 3B, the brush spring 80 is omitted and the cover plate 100 is removed.

The electric motor 1 is a commutator electric motor, and as shown in FIGS. 1A to 3B, the stator 10 (stator), the rotor 20 (rotor), the first bearing 31, the second bearing 32, and the first bracket A 41 and a second bracket 42, a commutator 50, a brush 60, a pigtail wire 70, a brush spring 80, a brush holding member 90, and a cover plate 100 are provided.

The electric motor 1 in the present embodiment is a kind of DC motor (DC motor) driven by direct current, a magnet is used as the stator 10, and an armature winding 22 (rotor winding) is used as the rotor 20. ) Is used.

Further, as shown in FIGS. 1A and 1B, the electric motor 1 is a flat type brushed coreless motor (flat motor). Therefore, neither the stator 10 nor the rotor 20 has a core (iron core), and the electric motor 1 has a thin and light structure as a whole.

The stator 10 shown in FIG. 2 generates a magnetic force acting on the rotor 20. The stator 10 constitutes a magnetic circuit together with the rotor 20 which is an armature. The stator 10 has a donut shape as a whole, and is configured such that north poles and south poles are alternately present on the air gap surface with the rotor 20 along the circumferential direction. In the present embodiment, the stator 10 is a field that creates a magnetic flux for generating torque, and is composed of, for example, a plurality of magnets 11 (magnets). The magnet 11 is, for example, a permanent magnet having an S pole and an N pole.

The plurality of magnets 11 constituting the stator 10 are arranged so that the north pole and the south pole are alternately and evenly present in the circumferential direction. In the present embodiment, the direction of the main magnetic flux generated by the stator (magnet 11) is the direction along the axis C included in the rotating shaft 21 (the axial direction of the rotating shaft). The plurality of magnets 11 are fixed to the first bracket 41.

The rotor 20 generates a magnetic force acting on the stator 10. The rotor 20 has a rotating shaft 21 and rotates about the axis C of the rotating shaft 21. The rotor 20 generates a magnetic force acting on the stator 10. In the present embodiment, the direction of the main magnetic flux generated by the rotor 20 is along the direction in which the axis C included in the rotating shaft 21 extends.

As shown in FIG. 2, the rotor 20 is arranged via the stator 10 and the air gap. Specifically, there is a minute air gap between the surface of the rotor 20 and the surface of the stator 10. In the present embodiment, the rotor 20 faces the stator 10 in the direction of the axis C of the rotating shaft 21. That is, the stator 10 and the rotor 20 are aligned along the direction in which the axis C included in the rotating shaft 21 extends through the air gap.

The rotating shaft 21 included in the rotor 20 is a shaft that serves as a center when the rotor 20 rotates. The rotating shaft 21 is, for example, a metal rod. The first portion 21a, which is a portion on the output side of the rotating shaft 21, is supported by the first bearing 31. On the other hand, the second portion 21b, which is a portion on the opposite output side of the rotating shaft 21, is supported by the second bearing 32. That is, the first bearing 31 and the second bearing 32 rotatably support the rotating shaft 21 as a pair of bearings. As an example, the first bearing 31 and the second bearing 32 are bearings.

In the present embodiment, the end portion of the first portion 21a of the rotating shaft 21 protrudes from the first bracket 41 and the first bearing 31. A load such as a rotating fan is attached to the end of the first portion 21a of the rotating shaft 21. On the other hand, the end of the second portion 21b of the rotating shaft 21 does not protrude from the second bracket 42 and the second bearing 32.

The first bearing 31 is held by the first bracket 41. Specifically, the first bearing 31 is fixed to the recess provided in the first bracket 41. Further, the second bearing 32 is held by the second bracket 42. Specifically, the second bearing 32 is fixed to the recess provided in the second bracket 42.

The first bracket 41 and the second bracket 42 are made of, for example, a metal material. Specifically, the first bracket 41 and the second bracket 42 are formed into a predetermined shape by bending a metal plate such as a cold-rolled steel plate (SPC material). In the present embodiment, the first bracket 41 is an outer member of the electric motor 1 and is formed in a bottomed tubular shape having a bottom portion and a cylindrical side wall portion. The magnet 11 constituting the stator 10 is fixed to the bottom of the first bracket 41. Further, the armature winding 22 of the rotor 20 is surrounded by a side wall portion of the first bracket 41. The material of the first bracket 41 and the second bracket 42 is not limited to the metal material, and may be a resin material.

As shown in FIG. 2, the rotor 20 has an armature winding 22 (winding coil). A plurality of armature windings 22 are arranged so as to surround the rotating shaft 21. Specifically, the plurality of armature windings 22 are arranged in an annular shape along the rotation direction of the rotation shaft 21 in a top view. Each armature winding 22 is electrically connected to the commutator 50. Specifically, each armature winding 22 is connected to the commutator piece 51 of the commutator 50.

As an example, each of the plurality of armature windings 22 is a thin winding coil having a coil layer in which a conductive wire is wound in a plane. The conductive wire constituting each armature winding 22 is an electric wire having a core wire such as a copper wire and an insulating film covering the core wire. For example, each armature winding 22 is composed of one layer or a plurality of coil layers in which conductive wires are wound in a substantially fan-shaped quadrangle on the same plane. In the present embodiment, each armature winding 22 is a single coil composed of only one coil layer.

Each of the plurality of armature windings 22 is wound so as to generate a magnetic force acting on the stator 10 when an electric current flows. In the present embodiment, the direction of the main magnetic flux generated by each armature winding 22 is the direction along the axis C included in the rotating shaft 21. Specifically, the plurality of armature windings 22 are arranged in a plane so that the coil openings face the direction along the axis C included in the rotating shaft 21. Therefore, the plurality of armature windings 22 are arranged so as to face the stator 10 via an air gap in the direction of the axis C of the rotating shaft 21.

The plurality of armature windings 22 are integrally molded by the mold resin 23. The mold resin 23 is made of, for example, an insulating thermosetting resin. In the present embodiment, the plan-view shape of the molded resin 23 after molding is circular.

A commutator 50 is fixed to the rotating shaft 21 of the rotor 20. That is, the commutator 50 is attached to the rotating shaft 21. Therefore, the commutator 50 rotates together with the rotating shaft 21. The commutator 50 has a plurality of commutator pieces 51 (commutator segments) arranged in an annular shape so as to surround the rotating shaft 21.

The plurality of commutator pieces 51 are arranged along the circumferential direction of the rotation shaft 21. Specifically, the plurality of commutator pieces 51 are arranged in an annular shape at equal intervals so as to surround the rotation shaft 21. Each of the plurality of commutator pieces 51 is a conductive terminal made of a metal material such as copper, and is electrically connected to an armature winding 22 attached to the rotor 20. As an example, the commutator 50 is a molded commutator, and a plurality of commutator pieces 51 are resin-molded. In this case, the plurality of commutator pieces 51 are embedded in the mold resin so that the surface is exposed. Further, the plurality of commutator pieces 51 are insulated and separated from each other. For example, two adjacent commutator pieces 51 are connected to each other by an armature winding 22.

The brush 60 is in contact with the commutator 50. Specifically, the brush 60 is in contact with the commutator piece 51 of the commutator 50. The brush 60 is a power feeding brush (energizing brush) for supplying electric power to the armature winding 22 of the rotor 20.

The brush 60 is a conductive carbon brush made of carbon. Specifically, the brush 60 is a carbon brush containing a metal such as copper. The brush 60 is a long rod-shaped member. In the present embodiment, the brush 60 is an elongated rectangular parallelepiped. Such a brush 60 can be produced, for example, by crushing a kneaded product obtained by kneading graphite powder, copper powder, a binder resin, and a curing agent, compression molding into a substantially rectangular parallelepiped, and firing.

The brush 60 is arranged so that its longitudinal direction is orthogonal to the axis C included in the rotation shaft 21 (that is, the radial direction of rotation of the rotation shaft 21). Further, the brush 60 is arranged so as to be movable in a direction orthogonal to the axis C included in the rotation axis 21. As shown in FIGS. 3A and 3B, two brushes 60 are provided in the present embodiment.

A pigtail wire 70 is connected to the brush 60. The pigtail wire 70 is an example of a conductive wire, and a current supplied from the power supply terminal 65 flows through the pigtail wire 70. Therefore, when the brush 60 comes into contact with the commutator piece 51, the current (armature current) supplied to the brush 60 via the pigtail wire 70 is transferred to each armature winding 22 of the rotor 20 via the commutator piece 51. Flow to.

Further, as shown in FIG. 2, the brush 60 is attached so as to be in constant sliding contact with the commutator 50 by receiving a pressing force from the brush spring 80. That is, the brush 60 is pressed against the commutator 50 by the brush spring 80. As a result, the front end portion of the brush 60 in the longitudinal direction is in contact with the commutator piece 51.

The brush spring 80 applies pressure (spring pressure) to the brush 60 by a spring elastic force (spring restoring force), and urges the brush 60 toward the commutator 50. The brush spring 80 is in contact with the rear end of the brush 60. In the present embodiment, the brush spring 80 is a compression coil spring, and one end of the brush spring 80 in the expansion / contraction direction is in contact with the rear end surface of the brush 60. The brush 60 and the brush spring 80 are held by the brush holding member 90.

The brush holding member 90 is a brush holder that holds the brush 60. As shown in FIGS. 3A and 3B, the brush holding member 90 has a brush storage portion 91 in which the brush 60 is stored. Like the brush 60, the brush accommodating portion 91 is long in the direction orthogonal to the axis C included in the rotating shaft 21 (that is, the radial direction of rotation of the rotating shaft 21), and has a concave cross-sectional shape. There is. The brush storage unit 91 stores the brush spring 80 together with the brush 60. Therefore, the length of the brush accommodating portion 91 in the longitudinal direction is longer than the length of the brush 60. The brush 60 stored in the brush storage unit 91 slides in the brush storage unit 91 by being pressed by the brush spring 80. Therefore, an appropriate gap is provided between the brush accommodating portion 91 and the brush 60 so that the brush 60 can slide on the brush accommodating portion 91. The brush 60 pressed against the brush spring 80 moves the brush accommodating portion 91 toward the commutator 50 as the front end portion of the brush 60 wears due to friction with the commutator piece 51. The brush storage portion 91 is covered with a cover plate 100. That is, the cover plate 100 covers the brush 60 and the brush spring 80 stored in the brush storage unit 91.

The cover plate 100 is made of, for example, a metal plate, and is arranged so as to cover the brush accommodating portion 91. Further, the cover plate 100 has a plurality of locking claws 101 formed by bending a part of a metal plate. The cover plate 100 is fixed to the brush holding member 90 by inserting the locking claw 101 into the locking hole formed in the brush holding member 90 and locking the cover plate 100. As shown in FIGS. 1A, 1B and 2, in the present embodiment, the brush holding member 90 is an outer member of the electric motor 1 and covers the second bracket 42 from the outside. The brush holding member 90 is made of, for example, an insulating resin material. In the present embodiment, the brush holding member 90 is a resin molded product formed by integral molding using a resin material.

Here, with reference to FIGS. 3A and 3B, the detailed configurations of the brush 60, the pigtail wire 70, and the brush holding member 90 are described. This will be described with reference to FIGS. 4 to 7. FIG. 4 is a top view showing the configuration around the brush 60 in the electric motor 1 according to the embodiment. 5 is a cross-sectional view taken along the line VV of FIG. 4, and FIG. 6 is a cross-sectional view taken along the line VI-VI of FIG. FIG. 7 is a diagram showing the configuration of the pigtail line 70.

As described above, the brush holding member 90 is provided with a brush accommodating portion 91 for accommodating the brush 60. As shown in FIGS. 3A and 3B, since two brushes 60 are used in the present embodiment, the brush holding member 90 is provided with two brush storage portions 91.

As shown in FIG. 5, the brush accommodating portion 91 has a pair of side walls that sandwich the brush 60. Each of the pair of side walls has a side wall surface facing the side surface of the brush 60. In the present embodiment, one of the pair of side walls has a low height.

As shown in FIGS. 3A and 4, an opening 91a is provided on the commutator 50 side of each brush accommodating portion 91. The tip of the brush 60 stored in the brush storage portion 91 protrudes from the brush storage portion 91 through the opening 91a and is in contact with the commutator piece 51 of the commutator 50.

Further, as shown in FIGS. 3A, 3B and 4, a wall 92 is provided in the vicinity of the opening 91a of the brush accommodating portion 91. The wall 92 is provided on the side of the opening 91a. The wall 92 stands upright from the bottom surface of the brush accommodating portion 91, and has a first wall surface located on the commutator 50 side and a second wall surface located on the side opposite to the commutator 50 side. The first wall surface of the wall 92 on the commutator 50 side is flush with the opening 91a of the brush storage portion 91.

In this embodiment, the height of the wall 92 gradually decreases toward the opening 91a. Specifically, the upper end surface of the wall 92 is an inclined surface formed so as to be lowered toward the opening 91a. The wall 92 is provided integrally with the brush holding member 90.

The wall 92 is an example of a hooking structure in which a part of the pigtail wire 70 is hooked when the brush 60 stored in the brush storage portion 91 exits the opening 91a. For example, when assembling the electric motor 1, when the brush 60 tries to jump out of the brush storage portion 91 through the opening 91a, a part of the pigtail wire 70 is hooked on the wall 92 which is a hooking structure.

One end of the pigtail wire 70 is embedded in the brush 60. Specifically, one end of the pigtail wire 70 is embedded in the side surface of the brush 60. As shown in FIG. 5, the pigtail wire 70 embedded in the brush 60 is pulled out so as to straddle the lower side wall of the pair of side walls constituting the brush storage portion 91.

The pigtail wire 70 is a feeder for supplying power to the brush 60. As shown in FIG. 7, the pigtail wire 70 has a hard portion 71 that is harder than other portions (parts other than the hard portion 71). That is, the hard portion 71 is a portion that is less likely to be deformed than the other portion, and has higher strength than the other portion. Assuming that the cross section of the pigtail wire 70 cut in the width direction is the cross section, the shape of the cross section of the hard portion 71 is a flat shape as if the pigtail wire 70 was crushed.

In the present embodiment, the hard portion 71 is a welded portion hardened by welding. For example, by welding the end portion of the pigtail wire 70, a flat hard portion 71 can be formed at the end portion of the pigtail wire 70. As an example, the hard portion 71 can be formed by spot welding a predetermined range of the end portion of the pigtail wire 70. In this case, the portion of the pigtail wire 70 other than the hard portion 71 has the original hardness and width of the pigtail wire 70. Specifically, the portion of the pigtail wire 70 other than the hard portion 71 is flexible and can be freely deformed. As shown in FIG. 7, in the present embodiment, the hard portion 71 is provided at the end of the pigtail wire 70.

As shown in FIGS. 4 to 6, the exposed portion of the pigtail wire 70 having a predetermined length from the connection portion with the brush 60 is the hard portion 71. That is, the root portion of the pigtail wire 70 on the brush 60 side is the hard portion 71. In the present embodiment, the embedded portion of the pigtail wire 70 embedded in the brush 60 is also a hard portion 71. That is, the hard portion 71 provided at the end of the pigtail wire 70 is located across both the inside and the outside of the brush 60. Specifically, as shown in FIG. 6, the pigtail line 70 is embedded in the brush 60 in a state in which the longitudinal direction of the hard portion 71 in the cross section is along the direction orthogonal to the moving direction of the brush 60.

The brush 60, which is a carbon brush in which a part of the pigtail wire 70 shown in FIG. 7 is embedded, is, for example, a rectangular parallelepiped kneaded product obtained by kneading graphite powder, copper powder, a binder resin, and a curing agent. It can be produced by embedding a part of the hard portion 71 of No. 1 and then compression molding and firing.

As shown in FIG. 4, in the present embodiment, the angle at which the pigtail line 70 is embedded in the brush 60 is set with respect to the moving direction of the brush 60 when viewed from the direction of the axis C included in the rotating shaft 21. It is 90 degrees. Specifically, the longitudinal direction of the hard portion 71 of the pigtail wire 70 and the moving direction of the brush 60 are orthogonal to each other.

In the electric motor 1 configured as described above, the current supplied to the brush 60 flows as an armature current (drive current) to the armature winding 22 of the rotor 20 via the commutator 50, whereby the rotor 20 A current is generated in (armature winding 22). Then, the magnetic force generated by the interaction between the magnetic flux generated in the rotor 20 and the magnetic flux generated in the stator 10 becomes the torque for rotating the rotor 20. At this time, the direction in which the current flows is switched depending on the positional relationship when the commutator piece 51 and the brush 60 are in contact with each other. By switching the direction in which the current flows in this way, a rotational force in a certain direction is generated by the repulsive force and the attractive force of the magnetic force generated between the stator 10 and the rotor 20, and the rotor 20 rotates. It rotates around the shaft 21.

Next, the operation and effect of the electric motor 1 according to the present embodiment will be described with reference to FIG. 8, including the background to the present disclosure. FIG. 8 is a diagram for explaining a state when assembling a conventional electric motor.

When assembling an electric motor or the like, when the brush and the brush spring to which the pigtail wire is connected are stored in the brush storage portion, the brush may be pushed out from the brush storage portion due to the spring action of the brush spring or the like.

At this time, in the conventional electric motor, the entire portion of the pigtail wire exposed from the brush is made flexible so as not to become a resistance force when the brush moves to the commutator side. Therefore, the base portion of the pigtail line on the brush side is flexible and can be freely deformed.

As a result, as shown in FIG. 8, when the brush 60 is extruded from the brush accommodating portion 91 as described above, the root portion of the pigtail wire 70X on the brush 60 side is deformed and the pigtail wire 70X becomes the brush holding member 90. The narrow portion of the opening 91a of the brush storage portion 91 may be rubbed through, and the entire brush 60 may pop out from the opening 91a of the brush storage portion 91 and fall out.

In this case, by providing the wall 92 on the side of the opening 91a of the brush storage portion 91, the pigtail wire 70X can be hooked on the wall 92 when the brush 60 protrudes from the brush storage portion 91. It is possible to prevent the 60 from falling out of the brush storage portion 91. That is, the wall 92 is a stopper that prevents the brush 60 from falling out of the brush storage portion 91 due to a part of the pigtail wire 70 being caught on the wall 92.

Here, if the height of the wall 92 is made constant, the presence of the wall 92 makes it difficult to store the brush 60 and the brush spring 80 in the brush storage portion 91 when assembling the electric motor, and the periphery of the brush 60 and the brush 60. Assembling the members becomes complicated. As a result, the assembly efficiency of the electric motor is reduced.

Therefore, it is conceivable to provide the wall 92 so that the height of the wall 92 gradually decreases toward the opening 91a of the brush accommodating portion 91 by inclining the upper end surface of the wall 92 or the like. This makes it possible to reduce the complexity of assembling the brush 60 and the peripheral members of the brush 60.

However, if the upper end surface of the wall 92 is tilted, the function of the wall 92 as a stopper is reduced. That is, when the upper end surface of the wall 92 is tilted, the pigtail wire 70X is less likely to be caught on the wall 92 when the brush 60 tries to come out of the opening 91a, and eventually the brush 60 pops out of the brush storage portion 91 and falls off. It may end up.

On the other hand, in order to prevent the brush 60 from popping out from the brush storage portion 91, it is conceivable to set the length of the pigtail wire 70X to be short. However, if the length of the pigtail wire 70X is shortened, the effective wear length of the brush 60 will be shortened. That is, the original effective wear length of the brush 60 cannot be used up, and the practical life of the brush 60 is shortened. As a result, the life of the electric motor is shortened.

On the other hand, in the electric motor 1 of the present embodiment, as described above, the pigtail wire 70 has a hard portion 71 that is harder than other portions. When the exposed portion of the pigtail wire 70 having a predetermined length from the connection portion with the brush 60 is a hard portion 71 and the brush 60 stored in the brush storage portion 91 exits from the opening 91a. Includes a portion that hangs on the wall 92.

With this configuration, as shown in FIG. 9, when the brush 60 stored in the brush storage portion 91 tries to come out from the opening 91a, the hard portion 71 of the pigtail wire 70 comes into contact with the wall 92. As a result, the pigtail wire 70 is more likely to be caught on the wall 92 as compared with the case of FIG. 8, so that it is possible to prevent the pigtail wire 70 from slipping through the narrow portion of the opening 91a of the brush storage portion 91. As a result, it is possible to prevent the brush 60 from jumping out of the brush accommodating portion 91 and falling off without shortening the length of the pigtail wire 70. Therefore, it is possible to prevent the brush 60 from popping out of the brush accommodating portion 91 without shortening the effective wear length of the brush 60.

Further, in the present embodiment, the hard portion 71 of the pigtail wire 70 is a welded portion hardened by welding.

As a result, a part of the pigtail wire 70 can be easily cured to form the hard portion 71. Further, by welding the pigtail wire 70, it is possible to make it difficult to unravel the pigtail wire 70. When welding the end of the pigtail wire 70 on the side connected to the power supply terminal 65, it is preferable to weld the end of the pigtail wire 70 on the side connected to the brush 60 at the same time.

Further, in the present embodiment, the embedded portion of the pigtail wire 70 embedded in the brush 60 is a hard portion 71.

As a result, the hard portion 71 of the pigtail wire 70 can be provided straddling the inside and the outside of the brush 60, so that the strength when the hard portion 71 of the pigtail wire 70 comes into contact with the wall 92 can be improved. .. Therefore, it is possible to prevent the hard portion 71 of the pigtail wire 70 from being deformed when the hard portion 71 of the pigtail wire 70 comes into contact with the wall 92. As a result, it is possible to further prevent the pigtail wire 70 from being deformed and slipping through the narrow portion of the opening 91a of the brush storage portion 91. Therefore, it is possible to further prevent the brush 60 from jumping out of the brush accommodating portion 91 and falling out.

Further, in the present embodiment, the shape of the cross section of the hard portion 71 of the pigtail wire 70 is a flat shape, and as shown in FIG. 6, the pigtail line 70 has a brush in the longitudinal direction of the hard portion 71 in the cross section. It is embedded in the brush 60 in a state along a direction orthogonal to the moving direction of the 60.

As a result, when the brush 60 stored in the brush storage portion 91 tries to come out from the opening 91a, the hard portion 71 of the pigtail wire 70 is likely to be caught on the wall 92. Therefore, it is possible to further prevent the brush 60 from jumping out of the brush accommodating portion 91 and falling out.

As shown in FIG. 10, in the pigtail line 70, the longitudinal direction of the hard portion 71 in the cross section is not the direction orthogonal to the moving direction of the brush 60, but the longitudinal direction of the hard portion 71 in the cross section is the movement of the brush 60. It may be embedded in the brush along the direction.

With this configuration, it is possible to prevent the hard portion 71 of the pigtail wire 70 from coming into contact with the brush accommodating portion 91. Specifically, it is possible to prevent the hard portion 71 of the pigtail wire 70 from coming into contact with the upper surfaces of the pair of side walls constituting the brush accommodating portion 91. As a result, it is possible to prevent the pigtail wire 70 from interfering with the brush accommodating portion 91.

Further, in the present embodiment, when viewed from the direction of the axis C of the rotating shaft 21, the embedding angle of the pigtail wire 70 in the brush 60 is 90 degrees with respect to the moving direction of the brush 60. , Not limited to this. For example, as shown in FIG. 11, when viewed from the direction of the axis C of the rotating shaft 21, the embedding angle α of the pigtail line 70 in the brush 60 is less than 90 degrees with respect to the moving direction of the brush 60. You may.

When the hard portion 71 is provided on the pigtail wire 70 to harden the base portion of the brush 60 of the pigtail wire 70 as in the present embodiment, it becomes difficult to store the brush 60 to which the pigtail wire 70 is connected in the brush holding member 90. Therefore, the assembling property of the electric motor 1 may be deteriorated. However, as described above, by setting the embedding angle α of the pigtail wire 70 into the brush 60 to less than 90 degrees in advance with respect to the moving direction of the brush 60, the brush 60 to which the pigtail wire 70 is connected can be attached to the brush holding member. It can be easily stored in the 90, and it is possible to suppress the deterioration of the assembling property of the electric motor 1. As an example, the embedding angle α of the pigtail wire 70 into the brush 60 is 30 to 60 degrees (α = 45 ° in FIG. 11), but is not limited to this.

Further, by setting the embedding angle α of the pigtail wire 70 into the brush 60 to be less than 90 degrees with respect to the moving direction of the brush 60, the pigtail wire 70 can be easily bent into a V shape to hold the pigtail wire 70 as a brush holding member. It can be easily stored in a predetermined position of 90.

In this case, it is preferable that the brush holding member 90 is provided with a protrusion structure that is bent by contact with the pigtail wire 70 when the brush 60 is pushed into the brush storage portion 91 through the opening 91a. As a result, the pigtail wire 70 can be easily bent into a V shape by the protrusion structure to give the pigtail wire 70 a habit.

For example, as shown in FIG. 12, as a protrusion structure, it is preferable that the brush holding member 90A is provided with a pin-shaped protrusion 93A that protrudes in the direction of the axis C included in the rotating shaft 21. As a result, the pigtail wire 70 can be easily attached by pressing the pigtail wire 70 against the protrusion 93A. The protrusion 93A may be provided integrally with the brush holding member 90A. Thereby, the protrusion 93A can be provided as the protrusion structure without increasing the manufacturing process. Further, the protrusion 93A may be a pin separate from the brush holding member 90A.

Further, as shown in FIG. 13, the protrusion structure may be a part of the brush storage portion 91B of the brush holding member 90B. Specifically, as a protrusion structure, the brush storage portion 91B may be provided with a protrusion 93B extending in the moving direction of the brush 60. As a result, the pigtail wire 70 can be easily attached by pressing the pigtail wire 70 against the protrusion 93B.

(Modification example)
The electric motor according to the present disclosure has been described above based on the embodiment, but the present disclosure is not limited to the above embodiment.

For example, in the above embodiment, the brush accommodating portion 91 is composed of a pair of side walls, but the present invention is not limited to this. For example, as shown in FIG. 14, the brush accommodating portion 91C may have a structure having a substantially rectangular cross-sectional shape surrounded by top, bottom, left, and right. In this case, a slit for leading out the pigtail wire 70 is formed on the side surface of the brush box. Further, this slit is not formed over both ends in the longitudinal direction, and the side plate 92C is left on the opening 91a side. The side plate 92C is an example of a hooking structure in which a part of the pigtail wire 70 is hooked when the brush 60 stored in the brush storage portion 91C exits the opening 91a. That is, in the above embodiment, as a hooking structure in which a part of the pigtail wire 70 is hooked, a wall 92 is provided on the side of the opening 91a of the brush storage portion 91 separately from the brush storage portion 91. In this modification, the side plate 92C is provided on the brush accommodating portion 91C itself as a hooking structure in which a part of the pigtail wire 70 is hooked. As a result, when the brush 60 stored in the brush storage portion 91C is about to come out of the opening 91a, the hard portion 71 of the pigtail wire 70 comes into contact with the side plate 92C. As a result, it is possible to prevent the pigtail wire 70 from slipping through the narrow portion of the opening 91a of the brush storage portion 91C as in the above embodiment, so that the brush 60 does not pop out from the brush storage portion 91C. It can be suppressed.

Further, in the above embodiment, the brush storage portions 91, 91A, 91B are integrated with the brush holding members 90, 90A, 90B, but are not limited to this, and are separate from the brush holding members 90, 90A, 90B. There may be. For example, the brush storage portions 91, 91A, 91B may be a brush box having a substantially rectangular cross-sectional shape surrounded by the top, bottom, left, and right, and the entire brush box having a substantially rectangular parallelepiped shape. The brush accommodating portion 91C shown in FIG. 14 may also be a separate body from the brush holding member 90C.

Further, in the above embodiment, the hard portion 71 of the pigtail wire 70 may be formed by a method other than welding. For example, the end of the pigtail wire 70 may be hardened to form the hard portion 71 by applying solder, an adhesive, or impregnating a conductive material to the end of the pigtail wire 70. Alternatively, the hard portion 71 may be formed by contracting the end portion of the pigtail wire 70 with a heat shrinkable tube or the like.

Further, in the above embodiment, the hard portion 71 of the pigtail wire 70 is embedded in the brush 60, but the present invention is not limited to this. For example, the hard portion 71 of the pigtail wire 70 does not have to be embedded in the brush 60. In this case, the hard portion 71 of the pigtail wire 70 on which the hard portion 71 is formed in advance may be fixed to the side surface of the brush 60 with an adhesive, or the end portion of the pigtail wire 70 having no hard portion 71 may be fixed first. The hard portion 71 may be provided only on the exposed portion of the brush 60 by embedding it in the brush 60 and then welding the root portion of the pigtail wire 70 on the brush 60 side.

Further, in the above embodiment, when the pigtail wire 70 is embedded in the brush 60, a part of the pigtail wire 70 is embedded in a kneaded product obtained by kneading graphite powder, copper powder, or the like, and then compression molding is performed and firing is performed. However, it is not limited to this. For example, a brush 60 having a hole formed on the side surface may be produced, an end portion of the pigtail wire 70 may be inserted into the hole, and the pigtail wire 70 and the brush 60 may be fixed with an adhesive or the like.

Further, in the above embodiment, the direction of the main magnetic flux generated by each of the stator 10 and the rotor 20 is the direction of the axis C of the rotating shaft 21, but is not limited to this. The direction of the main magnetic flux generated by each of the stator 10 and the rotor 20 may be a direction orthogonal to the axis C of the rotating shaft 21. In this case, the stator 10 and the rotor 20 are configured to have an air gap in a direction orthogonal to the axis C of the rotating shaft 21.

Further, in the above embodiment, the electric motor 1 is a flat type brushed coreless motor, but the motor 1 is not limited to this. For example, the electric motor 1 may be a brushless motor, a motor in which one or both of the stator 10 and the rotor 20 have a core, or a non-flat type motor.

Further, in the above embodiment, the stator 10 is composed of a magnet, but the stator 10 is not limited to this. For example, the stator 10 may be composed of a stator winding and a stator core.

Further, the case where the electric motor 1 in the above embodiment is applied to a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle has been described, but the present invention is not limited to this. The electric motor 1 in the above embodiment can also be applied to other products such as household electric appliances such as vacuum cleaners.

In addition, it is realized by arbitrarily combining the components and functions in each embodiment within the range obtained by applying various modifications to the above-described embodiment and not deviating from the purpose of the present disclosure. Forms are also included in this disclosure.

The technology of the present disclosure can be widely used in various products equipped with electric motors, including products in the fields of electrical equipment such as automobiles and household electric appliances.

1 Motor 10 Stator 11 Magnet 20 Rotor 21 Rotating shaft 21a 1st part 21b 2nd part 22 Armature winding 23 Mold resin 31 1st bearing 32 2nd bearing 41 1st bracket 42 2nd bracket 50 Commutator 51 Commutator Child piece 60 Brush 65 Power terminal 70, 70X Pigtail wire 71 Hard part 80 Brush spring 90, 90A, 90B, 90C Brush holding member 91, 91B, 91C Brush storage part 91a Opening 92 Wall 92C Side plate 93A, 93B Protrusion 100 Cover plate 101 Stop claw

Claims (13)

A rotor with a rotation axis and
With the commutator attached to the rotating shaft,
The brush in contact with the commutator and
A brush holding member having an opening on the commutator side and a brush accommodating portion for accommodating the brush.
The conductive wire connected to the brush and
It is provided with a hooking structure in which a part of the conductive wire is hooked when the brush stored in the brush storage portion exits the opening.
The conductive wire has a hard portion that is harder than other portions, and has a hard portion.
The exposed portion of the conductive wire having a predetermined length from the connection point with the brush is the hard portion and includes the part of the conductive wire.
Electric motor. The hard part is a welded part hardened by welding.
The electric motor according to claim 1. The conductive wire is a pigtail wire,
The electric motor according to claim 2. The hooking structure is a wall provided on the side of the opening, and has a wall surface on the side opposite to the commutator side.
The electric motor according to any one of claims 1 to 3. The height of the wall gradually decreases toward the opening,
The electric motor according to claim 4. The hooking structure is provided integrally with the brush holding member.
The electric motor according to any one of claims 1 to 5. One end of the conductive wire is embedded in the brush.
The embedded portion of the conductive wire embedded in the brush is the hard portion.
The electric motor according to any one of claims 1 to 6. Assuming that the cross section when the conductive wire is cut in the width direction is a cross section,
The shape of the cross section of the hard portion is a flat shape.
The conductive wire is embedded in the brush in a state in which the longitudinal direction of the hard portion in the cross section is along the direction orthogonal to the moving direction of the brush.
The electric motor according to claim 7. Assuming that the cross section when the conductive wire is cut in the width direction is a cross section,
The shape of the cross section of the hard portion is a flat shape.
The conductive wire is embedded in the brush in a state where the longitudinal direction of the hard portion in the cross section is along the moving direction of the brush.
The electric motor according to claim 7. When viewed from the axial direction of the rotation axis, the embedding angle of the conductive wire in the brush is less than 90 degrees with respect to the moving direction of the brush.
The electric motor according to any one of claims 7 to 9. It has a protrusion structure that is bent by contact with the conductive wire when the brush is pushed into the brush storage portion through the opening.
The electric motor according to any one of claims 1 to 10. The protrusion structure protrudes in the axial direction of the rotation shaft and is provided integrally with the brush holding member.
The electric motor according to claim 11. The protruding structure is a part of the side wall of the brush accommodating portion.
The electric motor according to claim 11.

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