electric motor

Abstract

This electric motor comprises: a brush holder; a first terminal having a first exposure portion exposed from the outer surface side of the brush holder; a second terminal having a second exposure portion exposed from the outer surface side of the brush holder; and a capacitor having a first lead joined to the first exposure portion and a second lead joined to the second exposure portion. The brush holder has a recessed portion formed on the outer surface side of the brush holder. The recessed portion has: a first recessed portion where the first exposure portion is positioned; a second recessed portion where the second exposure portion is positioned; and a third recessed portion located between the first recessed portion and the second recessed potion and formed integrally with the first recessed portion and the second recessed portion. The body portion of the capacitor is housed in the third recessed portion.

Description

[Technical Field]

[0001] The present disclosure relates to electric motors. [Background technology]

[0002] Electric motors are also widely used in the field of electrical equipment mounted on vehicles such as automobiles. For example, electric motors are used in two-wheeled and four-wheeled vehicles to drive cooling fans that cool the radiator and battery.

[0003] Known electric motors include brushed motors, which use brushes, and brushless motors, which do not use brushes. Of these, brushed motors include a stator, a rotor that rotates due to the magnetic force of the stator, a commutator attached to the rotor's rotating shaft, and brushes that slide against the commutator. Power is supplied to the brushes from an external power source via a pair of power terminals (e.g., a positive terminal and a negative terminal connected to a DC power source) attached to a brush holder or the like.

[0004] There are cases where it is required to reduce noise generated by electric motors. For example, in the case of an electric motor used in a cooling fan of a radiator in a vehicle, it is required to reduce noise at a certain frequency.

[0005] In this case, noise is reduced in brushed motors by reducing sparks between the brushes and commutator, which are a source of noise, and by using metal brackets and other parts to block noise.

[0006] Also, a technique has been proposed for reducing noise by connecting a capacitor in parallel between a pair of power supply terminals (see, for example, Patent Document 1). In this case, the capacitor is housed inside the motor, for example, by being mounted on a circuit board disposed inside the housing of the motor, or is placed between a pair of power supply wires (harness) connected to the pair of power supply terminals.

[0007] In recent years, there has been a demand for thinner electric motors, and in particular, electric motors used in cooling fans for radiators in vehicles are required to be extremely thin overall.

[0008] As a result, even if a noise-reducing capacitor is installed inside the motor, there is currently little space for it, making it difficult to accommodate it. Even if a capacitor can be installed inside the motor, the limited installation space reduces the capacitor's heat dissipation. This results in an increase in the capacitor's temperature, reducing its short-circuit failure mode functionality and reducing its capacitance, thereby reducing the noise reduction effect of the capacitor. In particular, when a flat motor has an outer diameter of 120 mm or less, the space inside the motor becomes too narrow to accommodate a capacitor, or even if a capacitor can be installed inside the motor, its heat dissipation ability is significantly reduced.

[0009] One method for placing a capacitor between a pair of power supply lines is to use a film capacitor and connect the conductive part of the capacitor to the power supply lines by crimping it. However, this method requires processing the capacitor so that the coating of the power supply line is removed and the leads, which are the conductive parts of the capacitor, are connected to the conductors of the power supply lines, which makes it difficult to mass-produce electric motors. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2018-198475 Summary of the Invention

[0011] The present disclosure has been made to solve these problems, and aims to provide an electric motor that can be easily made thin, has excellent heat dissipation properties for the capacitor, and is suitable for mass production, even when a noise-reducing capacitor is used.

[0012] In order to achieve the above object, one aspect of the electric motor according to the present disclosure includes a commutator, a first brush and a second brush in contact with the commutator, and a brush for connecting the first brush and the second brush. On the inside a brush holder for holding the brush; and a first exposed portion exposed from an outer surface side of the brush holder, a brush holder having a through hole extending from the inner surface side to the outer surface side; a first terminal electrically connected to the first brush and a second exposed portion exposed from an outer surface side of the brush holder; a brush holder having a through hole extending from the inner surface side to the outer surface side; a second terminal electrically connected to the second brush, a first electric wire joined to the first exposed portion of the first terminal, a second electric wire joined to the second exposed portion of the second terminal, and a capacitor having a first lead joined to the first exposed portion of the first terminal and a second lead joined to the second exposed portion of the second terminal, wherein the brush holder has a recess formed on the outer surface side of the brush holder, the recess having a first recess in which the first exposed portion of the first terminal is located, a second recess in which the second exposed portion of the second terminal is located, and a third recess located between the first recess and the second recess and formed integrally with the first recess and the second recess, and the main body of the capacitor is housed in the third recess.

[0013] According to the present disclosure, even when a noise-reducing capacitor is used, it is possible to realize an electric motor that is easy to make thin, has excellent heat dissipation properties from the capacitor, and is suitable for mass production. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is an external perspective view of an electric motor according to an embodiment when viewed from above. [Figure 2] FIG. 2 is an external perspective view of the electric motor according to the embodiment as viewed from below. [Figure 3] FIG. 3 is a cross-sectional view of the electric motor according to the embodiment. [Figure 4] FIG. 4 is a rear view of the electric motor according to the embodiment. [Figure 5]FIG. 5 is a perspective view showing the internal structure of a brush holder in the electric motor according to the embodiment. [Figure 6] FIG. 6 is a plan view showing a brush holder in which a first brush and a second brush are housed in the electric motor according to the embodiment. [Figure 7] FIG. 7 is a plan view of the electric motor according to the embodiment when the sealing material is omitted, as viewed from the rear side. [Figure 8] FIG. 8 is a perspective view of the electric motor according to the embodiment when the sealing material is omitted, as viewed from the rear side. [Figure 9] FIG. 9 is a perspective view of a first terminal used in the electric motor according to the embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing the positional relationship between a first wire disposed in a first exposed portion of a first terminal and a first lead of a capacitor in an electric motor according to an embodiment. [Figure 11A] FIG. 11A is an enlarged plan view of a recess of the brush holder and its surroundings in a step of attaching the first terminal and the second terminal to the brush holder. [Figure 11B] 11B is an enlarged perspective view of the recess of the brush holder and its surroundings in the step of FIG. 11A. [Figure 12A] FIG. 12A is an enlarged plan view of the recess of the brush holder and its surroundings in the process of placing the capacitor in the recess of the brush holder. [Figure 12B] 12B is an enlarged perspective view of the recess of the brush holder and its surroundings in the step of FIG. 12A. [Figure 13A] FIG. 13A is an enlarged plan view of the recess of the brush holder and its surroundings in a step of arranging the first electric wire and the second electric wire in the recess of the brush holder. [Figure 13B] 13B is an enlarged perspective view of the recess of the brush holder and its surroundings in the step of FIG. 13A. [Figure 14A]FIG. 14A is an enlarged plan view of a recess in the brush holder and its surroundings in a process of crimping and joining a first wire, a first lead of the capacitor, and a first terminal, and crimping and joining a second wire, a second lead of the capacitor, and a second terminal. [Figure 14B] 14B is an enlarged perspective view of the recess of the brush holder and its surroundings in the step of FIG. 14A. [Figure 15A] FIG. 15A is an enlarged plan view of the recess of the brush holder and its surroundings in a step of filling the recess of the brush holder with a sealing material. [Figure 15B] 15B is an enlarged perspective view of the recess of the brush holder and its surroundings in the step of FIG. 15A. [Figure 16] FIG. 16 is a cross-sectional view showing the configuration of a first exposed portion of a first terminal according to a modified example. [Figure 17A] FIG. 17A is an enlarged perspective view showing the configuration of a recess in an electric motor according to a modified example. [Figure 17B] FIG. 17B is a cross-sectional view of a main part corresponding to the cross section 17B-17B of FIG. 17A. [Figure 18] FIG. 18 is a plan view showing a first modified example of the recess in the brush holder. [Figure 19] FIG. 19 is a plan view showing a second modified example of the recess in the brush holder. [Figure 20] FIG. 20 is a plan view showing a third modified example of the recess in the brush holder. [Figure 21] FIG. 21 is a plan view showing a fourth modified example of the recess in the brush holder. [Figure 22] FIG. 22 is a plan view showing a fifth modified example of the recess in the brush holder. [Figure 23] FIG. 23 is a plan view showing a sixth modified example of the recess in the brush holder. [Figure 24] FIG. 24 is a plan view showing a seventh modified example of the recess in the brush holder. [Figure 25A] FIG. 25A is a plan view showing an eighth modified example of the recess in the brush holder. [Figure 25B]FIG. 25B is a plan view showing a ninth modified example of the recess in the brush holder. [Figure 25C] FIG. 25C is a plan view showing a tenth modified example of the recess in the brush holder. [Figure 25D] FIG. 25D is a plan view showing an eleventh modified example of the recess in the brush holder. [Figure 25E] FIG. 25E is a plan view showing a twelfth modified example of the recess in the brush holder. [Figure 25F] FIG. 25F is a plan view showing a thirteenth modified example of the recess in the brush holder. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that each of the embodiments described below represents a specific example of the present disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions and connection forms of the components, etc. shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concept of the present disclosure will be described as optional components.

[0016] Note that each figure is a schematic diagram and is not necessarily a precise illustration. Furthermore, in each figure, substantially the same configuration is assigned the same reference numeral, and duplicate explanations are omitted or simplified. Furthermore, in this specification, the terms "up" and "down" do not necessarily refer to the upward direction (vertically upward) and downward direction (vertically downward) in absolute spatial recognition.

[0017] (Embodiment) First, the overall configuration of an electric motor 1 according to an embodiment will be described with reference to Figs. 1 to 6. Fig. 1 is an external perspective view of the electric motor 1 according to an embodiment, as viewed from above. Fig. 2 is an external perspective view of the electric motor 1, as viewed from below. Fig. 3 is a cross-sectional view of the electric motor 1, and Fig. 4 is a rear view of the electric motor 1. Fig. 5 is a perspective view showing the internal structure of a brush holder 50 in the electric motor 1. Fig. 6 is a plan view showing the brush holder 50 in the electric motor 1, in which a first brush 41 and a second brush 42 are housed. Note that Fig. 3 shows only the parts that appear in the cross section of the electric motor 1. Figs. 5 and 6 show the brush holder 50 with the first cover plate 131 and the second cover plate 132 removed.

[0018] As shown in Fig. 3, the electric motor 1 includes a stator 10 and a rotor 20 that rotates due to the magnetic force of the stator 10. The electric motor 1 is a brushed electric motor. As shown in Fig. 3, the electric motor 1 includes a commutator 30 attached to a rotating shaft 21 of the rotor 20. As shown in Figs. 5 and 6, the electric motor 1 includes a first brush 41 and a second brush 42 that contact the commutator 30.

[0019] 1 to 6, the electric motor 1 further includes a brush holder 50 that holds the first brush 41 and the second brush 42, a first terminal 61 electrically connected to the first brush 41, a second terminal 62 electrically connected to the second brush 42, a first electric wire 71 connected to the first terminal 61, a second electric wire 72 connected to the second terminal 62, and a capacitor 80 connected to the first terminal 61 and the second terminal 62. The electric motor 1 also includes a first bearing 91, a second bearing 92, a first bracket 101, and a second bracket 102.

[0020] The electric motor 1 is a type of direct current motor (DC motor) driven by direct current. The electric motor 1 uses a magnet 11 as a stator 10. The electric motor 1 uses an armature having an armature winding 22 as a rotor 20. The electric motor 1 is a flat-type brushed coreless motor (flat motor) mounted on a vehicle such as a two-wheeled or four-wheeled vehicle. Therefore, the stator 10 and the rotor 20 do not have a core (iron core), and the electric motor 1 has a thin and lightweight configuration overall. Specifically, the electric motor 1 is a small motor used in a cooling fan for a radiator in a vehicle. The outer diameter (diameter) φ of the electric motor 1 is 120 mm or less. For example, the outer diameter φ of the electric motor 1 is 70 mm. The electric motor 1 is driven by an input voltage of DC 12V.

[0021] Each component of the electric motor 1 will be described in detail below.

[0022] As shown in FIG. 3, the stator 10 is disposed with a small air gap between it and the rotor 20. The stator 10 generates a magnetic force that acts on the rotor 20. The stator 10 is configured to generate magnetic flux on the air gap surface with the rotor 20, and forms a magnetic circuit together with the rotor 20, which is an armature. Specifically, the stator 10 is substantially doughnut-shaped as a whole, and is configured so that north and south poles are alternately and evenly present on the air gap surface with the rotor 20 along the circumferential direction of the rotating shaft 21. The stator 10 is a field magnet that creates magnetic flux for generating torque, and is composed of a plurality of magnets 11. The magnets 11 are, for example, permanent magnets having south and north poles.

[0023] The multiple magnets 11 that make up the stator 10 are arranged so that N poles and S poles alternate evenly around the circumferential direction. The direction of the main magnetic flux generated by the stator 10 (magnets 11) is along the direction in which the rotation shaft 21 extends. The direction of the main magnetic flux is generated in a direction according to the magnetic poles of the magnets 11. The stator 10 is fixed to a first bracket 101.

[0024] As shown in Fig. 3, rotor 20 has rotating shaft 21 and rotates around axis C of rotating shaft 21. Rotor 20 generates a magnetic force that acts on stator 10. The direction of main magnetic flux generated by rotor 20 is along the direction in which rotating shaft 21 extends. The direction of main magnetic flux is generated in a direction corresponding to the direction of current flowing through armature winding 22.

[0025] The rotor 20 faces the stator 10 in the direction of the axis C of the rotating shaft 21 .

[0026] Rotating shaft 21 is a shaft having an axis C, and is a long rod-shaped member such as a metal rod. Axis C of rotating shaft 21 serves as the center of rotation of rotor 20. The longitudinal direction of rotating shaft 21, i.e., the direction in which rotating shaft 21 extends (extension direction), is also referred to as the direction of axis C (axial direction).

[0027] A first end 21a, which is one end of the rotating shaft 21, is supported by a first bearing 91. On the other hand, a second end 21b, which is the other end of the rotating shaft 21, is supported by a second bearing 92. As an example, the first bearing 91 and the second bearing 92 are bearings such as ball bearings.

[0028] The first end 21a of the rotating shaft 21 is the output side end (output shaft) and protrudes from the first bracket 101 and the first bearing 91. A load such as a rotary fan is attached to the first end 21a. The second end 21b of the rotating shaft 21 is the counter-output side end (counter-output shaft) and does not protrude from the second bracket 102 and the second bearing 92.

[0029] The first bearing 91 is held by the first bracket 101. Specifically, the first bearing 91 is fixed to a recess provided in the first bracket 101. The second bearing 92 is held by the second bracket 102. Specifically, the second bearing 92 is fixed to a recess provided in the second bracket 102.

[0030] The first bracket 101 and the second bracket 102 are made of, for example, a metal material. For example, the first bracket 101 and the second bracket 102 are made of an iron-based material such as cold-rolled steel plate (SPC material) or a metal such as aluminum. The first bracket 101 and the second bracket 102 form a housing, and the stator 10 and the rotor 20 are arranged inside this housing.

[0031] In this embodiment, the first bracket 101 is an outer casing member of the electric motor 1 and is formed in a bottomed cylindrical shape having a bottom and a cylindrical sidewall. The magnets 11 that constitute the stator 10 are fixed to the bottom of the first bracket 101. The armature winding 22 of the rotor 20 is surrounded by the sidewall of the first bracket 101. The material of the first bracket 101 and the second bracket 102 is not limited to a metal material and may be a resin material. However, from the perspective of suppressing noise generated by the electric motor 1, it is preferable that the first bracket 101 and the second bracket 102 are made of a metal material.

[0032] As shown in FIG. 3, the rotor 20 has a rotating shaft 21, a plurality of armature windings 22, and a molding resin 23 that covers the armature windings 22.

[0033] The multiple armature windings 22 are made of electric wire. The multiple armature windings 22 are wound so that a magnetic force acting on the stator 10 is generated when a current flows through them. The direction of the main magnetic flux generated by each armature winding 22 is the direction of the axis C of the rotating shaft 21. In other words, the magnet 11 of the stator 10 and the armature windings 22 of the rotor 20 are aligned in the direction of the axis C of the rotating shaft 21.

[0034] Each armature winding 22 is configured from an insulating-coated wire having a core wire made of a metal such as copper or aluminum and an insulating film coating the core wire. Each of the multiple armature windings 22 is a thin winding coil having coil layers in which conductive wire is wound in a planar manner. Specifically, each of the multiple armature windings 22 is configured, for example, from one layer or multiple coil layers in which insulating-coated wire is wound in a substantially fan-like shape in a planar view. The multiple armature windings 22 configured in this manner are arranged to surround the rotating shaft 21 when viewed from the direction of the axis C of the rotating shaft 21.

[0035] Each of the multiple armature windings 22 is electrically connected to the commutator 30. Specifically, each of the multiple armature windings 22 is electrically connected to one of the multiple commutator segments 31 of the commutator 30.

[0036] The multiple armature windings 22 are covered with molded resin 23 and are integrally molded together with the molded resin 23. The molded resin 23 is made of an insulating resin material such as phenol resin or unsaturated polyester (BMC).

[0037] 3, the commutator 30 is attached to the rotating shaft 21. Therefore, the commutator 30 rotates together with the rotating shaft 21 as the rotor 20 rotates. In this embodiment, the commutator 30 is attached to the second end 21b side of the rotating shaft 21. The commutator 30 attached to the rotating shaft 21 may be a part of the rotor 20.

[0038] The commutator 30 has a plurality of commutator pieces 31 (commutator segments) arranged along the rotation direction of the rotating shaft 21. Specifically, the plurality of commutator pieces 31 are arranged in an annular shape along the rotation direction of the rotating shaft 21 so as to surround the rotating shaft 21. Each commutator piece 31 is an elongated member extending in the longitudinal direction of the rotating shaft 21.

[0039] Each of the multiple commutator segments 31 is a conductive terminal made of a metal material such as copper, and is electrically connected to the armature winding 22 of the rotor 20. The multiple commutator segments 31 are arranged insulated and separated from one another, but are electrically connected by the armature winding 22 of the rotor 20. For example, two adjacent commutator segments 31 are electrically connected by the armature winding 22.

[0040] As an example, the commutator 30 is a molded commutator, and is configured such that a plurality of commutator segments 31 are molded in a molded resin 32. In this case, the plurality of commutator segments 31 are embedded in the molded resin 32 so that their surfaces are exposed. The molded resin 32 is the commutator main body, and is a substantially cylindrical member having a through hole into which the rotating shaft 21 is inserted. The molded resin 32 is a resin molded body made of an insulating resin material such as a thermosetting resin.

[0041] 3, a first brush 41 contacts the commutator 30. Although not shown, a second brush 42 also contacts the commutator 30. Specifically, the first brush 41 and the second brush 42 contact the commutator segments 31 of the commutator 30. As the commutator 30 rotates due to the rotation of the rotary shaft 21, the first brush 41 and the second brush 42 continue to contact all of the commutator segments 31 in sequence.

[0042] 5 and 6, the first brush 41 and the second brush 42 are arranged in a brush holder 50. Specifically, the first brush 41 and the second brush 42 are arranged in the brush holder 50 so that their longitudinal directions are perpendicular to the axis C of the rotating shaft 21 (i.e., the radial direction of the rotation of the rotating shaft 21).

[0043] In this embodiment, the first brush 41 and the second brush 42 are arranged so that the angle between the longitudinal direction of the first brush 41 and the longitudinal direction of the second brush 42 is less than 180°. That is, the first brush 41 and the second brush 42 are arranged in a positional relationship that forms a V shape when viewed from above. Specifically, the angle between the longitudinal direction of the first brush 41 and the longitudinal direction of the second brush 42 is 90° or less, and in this embodiment, it is approximately 60°. The angle between the longitudinal direction of the first brush 41 and the longitudinal direction of the second brush 42 may also be 180°. That is, the first brush 41 and the second brush 42 may be arranged line-symmetrically with respect to the axis C of the rotation shaft 21.

[0044] The first brush 41 and the second brush 42 are power supply brushes (conductive brushes) that contact the commutator segments 31 to supply power to the armature windings 22. The first brush 41 and the second brush 42 are conductive materials. As an example, each of the first brush 41 and the second brush 42 is a long, substantially rectangular parallelepiped carbon brush made of carbon. The first brush 41 and the second brush 42 may be a carbon brush containing a metal such as copper. This reduces the contact resistance between each of the first brush 41 and the second brush 42 and the commutator segments 31. The first brush 41 and the second brush 42 can be produced, for example, by kneading graphite powder, copper powder, a binder resin, and a curing agent, pulverizing the mixture, compression-molding the mixture into a rectangular parallelepiped, and firing the mixture.

[0045] 5 and 6, a first brush spring 111 and a second brush spring 112 are disposed in the brush holder 50. The first brush 41 receives a pressing force from the first brush spring 111 and is attached so as to be in constant contact with the commutator segments 31 of the commutator 30. In other words, the first brush 41 is pressed against the commutator 30 by the first brush spring 111. Similarly, the second brush 42 receives a pressing force from the second brush spring 112 and is attached so as to be in constant contact with the commutator segments 31 of the commutator 30. In other words, the second brush 42 is pressed against the commutator 30 by the second brush spring 112.

[0046] The first brush spring 111 and the second brush spring 112 apply a pressure (spring pressure) to the first brush 41 and the second brush 42, respectively, by means of a spring elastic force (spring restoring force), and urge the first brush 41 and the second brush 42 toward the commutator 30. The first brush spring 111 and the second brush spring 112 are each a compression coil spring. The first brush spring 111 and the second brush spring 112 may also be a torsion spring or the like.

[0047] The first brush spring 111 is disposed rearward of the first brush 41 so that one end of the first brush spring 111 in the expansion / contraction direction contacts the rear end surface of the first brush 41. As a result, the pressing force of the first brush spring 111 causes the front end of the first brush 41 in the longitudinal direction to always contact the commutator segments 31. Similarly, the second brush spring 112 is disposed rearward of the second brush 42 so that one end of the second brush spring 112 in the expansion / contraction direction contacts the rear end surface of the second brush 42. As a result, the pressing force of the second brush spring 112 causes the front end of the second brush 42 in the longitudinal direction to always contact the commutator segments 31. In this way, as the first brush 41 and the second brush 42 wear due to friction with the commutator segments 31, the pressing forces from the first brush spring 111 and the second brush spring 112 move in a direction toward the axis C of the rotating shaft 21 (radial direction).

[0048] Electric power is supplied to the first brush 41 and the second brush 42 from an external power supply located outside the electric motor 1 via a first terminal 61 and a second terminal 62, respectively. The external power supply is a power supply that exists outside the electric motor 1 and supplies a predetermined input voltage to the electric motor 1. The external power supply is a DC power supply that supplies an input voltage of DC 12 V to the electric motor 1.

[0049] The first terminal 61 and the second terminal 62 receive electric power to be applied to the armature winding 22 of the rotor 20 via the first brush 41 and the second brush 42, respectively. In the present embodiment, since the external power supply is a DC power supply, the first terminal 61 and the second terminal 62 receive a DC voltage from the DC power supply as an input voltage. In this case, for example, the first terminal 61 is a high-voltage terminal (positive terminal), and the second terminal 62 is a low-voltage terminal (negative terminal). As will be described in detail later, the first terminal 61 and the second terminal 62 are attached to the brush holder 50. A first electric wire 71 and a second electric wire 72 are electrically connected to the first terminal 61 and the second terminal 62, respectively, and the first terminal 61 and the second terminal 62 receive electric power from the external power supply via the first electric wire 71 and the second electric wire 72, respectively.

[0050] The first electric wire 71 and the second electric wire 72 are power supply lines for supplying power to the first terminal 61 and the second terminal 62, respectively. For example, the first electric wire 71 and the second electric wire 72 are a harness. When the first terminal 61 is a high-voltage side terminal and the second terminal 62 is a low-voltage side terminal, the first electric wire 71 connected to the first terminal 61 is a high-voltage side power supply line (positive side wiring). The second electric wire 72 connected to the second terminal 62 is a low-voltage side power supply line (negative side wiring). Each of the first electric wire 71 and the second electric wire 72 is an insulated wire made of vinyl wire or the like, and has a core wire made of a conductor such as copper and an insulating coating that covers the core wire.

[0051] 5 and 6, the first brush 41 and the first terminal 61 are connected by a first pigtail wire 121. Specifically, one end of the first pigtail wire 121 is joined to the first brush 41. The other end of the first pigtail wire 121 is joined to the first terminal 61. Similarly, the second brush 42 and the second terminal 62 are connected by a second pigtail wire 122. Specifically, one end of the second pigtail wire 122 is joined to the second brush 42. The other end of the second pigtail wire 122 is joined to the second terminal 62.

[0052] Power is supplied from an external power source to the first terminal 61 and the second terminal 62 via the first electric wire 71 and the second electric wire 72, and current is supplied to the first brush 41 and the second brush 42 via the first pigtail wire 121 connected to the first terminal 61 and the second pigtail wire 122 connected to the second terminal 62.

[0053] In the electric motor 1 configured as described above, the current supplied to the first brush 41 and the second brush 42 flows as an armature current (drive current) through the armature winding 22 via the commutator segments 31 of the commutator 30. This generates magnetic flux in the rotor 20 (armature winding 22). The magnetic flux generated in the rotor 20 interacts with the magnetic flux generated from the stator 10, generating a magnetic force that serves as torque to rotate the rotor 20. At this time, the direction of the current flow is switched depending on the positional relationship between the commutator segments 31 of the commutator 30 and the first brush 41 and the second brush 42 when they come into contact. By switching the direction of the current flow in this way, a rotational force in a fixed direction is generated by the magnetic repulsive and attractive forces generated between the stator 10 and the rotor 20, causing the rotor 20 to rotate about the rotation shaft 21.

[0054] Next, as a characteristic structure of the electric motor 1 according to this embodiment, the detailed structure of the brush holder 50 together with the first terminal 61 and the second terminal 62 will be described using Figs. 7 to 9 with reference to Figs. 3 to 6. Fig. 7 is a plan view of the electric motor 1 according to this embodiment when viewed from the rear side, with the sealing material 140 omitted. Fig. 8 is a perspective view of the electric motor 1 when viewed from the rear side. Fig. 9 is a perspective view of the first terminal 61 used in the electric motor 1.

[0055] The brush holder 50 is a holding member that holds the first brush 41 and the second brush 42. The brush holder 50 is made of, for example, an insulating resin material. In this embodiment, the brush holder 50 is a resin molded product that is formed by integral molding using a resin material. As shown in FIG. 3, in this embodiment, the brush holder 50 is an outer casing member that forms the outer casing of the electric motor 1, and covers the second bracket 102 from the outside.

[0056] 5 and 6, the brush holder 50 has a first brush housing section 51 that houses the first brush 41 and a second brush housing section 52 that houses the second brush 42. The first brush housing section 51 and the second brush housing section 52 are formed in a concave shape on the inner surface side of the brush holder 50.

[0057] In this embodiment, the first brush storage section 51 and the second brush storage section 52 are elongated in a direction perpendicular to the axis C of the rotating shaft 21 (i.e., in the radial direction of rotation of the rotating shaft 21) and have a concave cross-sectional shape.

[0058] 3 and 5, the first brush housing 51 housing the first brush 41 is covered by a first cover plate 131. Similarly, the second brush housing 52 housing the second brush 42 is covered by a second cover plate 132. The first cover plate 131 and the second cover plate 132 are made of, for example, a metal plate, and are arranged to cover the first brush housing 51 and the second brush housing 52, respectively.

[0059] 5 and 6, the first brush housing 51 houses a first brush spring 111 together with the first brush 41. Similarly, the second brush housing 52 houses a second brush spring 112 together with the second brush 42. Therefore, the longitudinal lengths of the first brush housing 51 and the second brush housing 52 are longer than the lengths of the first brush 41 and the second brush 42, respectively.

[0060] As described above, power is supplied to the first brush 41 and the second brush 42 via the first terminal 61 and the second terminal 62, respectively.

[0061] 7 and 8, the first terminal 61 and the second terminal 62 are attached to the brush holder 50 so that a portion of each is exposed on the outer surface side of the brush holder 50. Specifically, the first terminal 61 has a first exposed portion 61a exposed from the outer surface side of the brush holder 50. The second terminal 62 has a second exposed portion 62a exposed from the outer surface side of the brush holder 50.

[0062] The first terminal 61 and the second terminal 62 are electrode terminals that receive power from an external power source via a first electric wire 71 and a second electric wire 72, respectively. The first electric wire 71 is joined to a first exposed portion 61a of the first terminal 61. The second electric wire 72 is joined to a second exposed portion 62a of the second terminal 62.

[0063] As shown in FIG. 9, the pair of first exposed portions 61a of the first terminal 61 are plate-shaped side plates, each extending from both ends of a plate-shaped bottom plate 61b. Therefore, the first terminal 61 has a substantially U-shaped cross section as a whole. A pair of protrusions is formed at the tip of each of the pair of first exposed portions 61a. One of the pair of first exposed portions 61a is wider (plate width) than the other. Therefore, the distance between the pair of protrusions of the wider first exposed portion 61a is narrower than the distance between the pair of protrusions of the narrower first exposed portion 61a.

[0064] 5 and 6, when the first terminal 61 is attached to the brush holder 50, the bottom plate 61b of the first terminal 61 is located on the inner surface side of the brush holder 50. The pair of first exposed portions 61a of the first terminal 61 are inserted from the inside to the outside of the brush holder 50 through a pair of slit-shaped through-holes formed in the brush holder 50, and are exposed on the outer surface side of the brush holder 50. At this time, the pair of first exposed portions 61a are pushed into the slits of the brush holder 50. As a result, the first terminal 61 is fixed to the brush holder 50 by locking portions formed on the side surfaces of the pair of first exposed portions 61a locking with the inner surface of the brush holder 50.

[0065] The second terminal 62 has the same shape as the first terminal 61, and includes a bottom plate 62b and a pair of second exposed portions 62a. The second terminal 62 is fixed to the brush holder 50 in the same manner as the first terminal 61. The first terminal 61 and the second terminal 62 are made of a conductive material such as a metal material.

[0066] 7 and 8, a first electric wire 71 is joined to the first exposed portion 61a of the first terminal 61. Specifically, the first electric wire 71 is joined to the first exposed portion 61a of the first terminal 61 by being crimped to a part of the first exposed portion 61a of the first terminal 61.

[0067] The first terminal 61 has a pair of first exposed portions 61a. A first portion 71a (exposed core portion) where the core wire is exposed at the tip side of the first electric wire 71 is crimped to one of the pair of first exposed portions 61a of the first terminal 61. As a result, the first terminal 61 and the first electric wire 71 are electrically connected and fixed to each other at the first portion 71a of the first electric wire 71. Specifically, the first portion 71a of the first electric wire 71 is disposed in a recess between a pair of protrusions at the tip of the narrower first exposed portion 61a of the pair of first exposed portions 61a of the first terminal 61 (in this embodiment, the inner first exposed portion 61a). The first portion 71a of the first electric wire 71 is joined to the first terminal 61 by crimping this pair of protrusions.

[0068] Furthermore, the second portion 71b (non-exposed core portion) of the first electric wire 71, where the core wire is not exposed, is crimped to the other of the pair of first exposed portions 61a of the first terminal 61. This allows the first terminal 61 and the first electric wire 71 to be fixed also at the second portion 71b of the first electric wire 71. That is, the first terminal 61 and the first electric wire 71 can be fixed at a portion other than the first portion 71a of the first electric wire 71. This allows the first electric wire 71 to be fixed to the first terminal 61, for example, even if the first electric wire 71 is pulled after the first electric wire 71 is fixed to the first terminal 61, the stress can be absorbed by the portion where the first exposed portion 61a and the second portion 71b are fixed, and is hardly transmitted to the joint portion between the first exposed portion 61a and the first portion 71a. This prevents the first terminal 61 and the first electric wire 71 from being broken at the first portion 71a of the first electric wire 71.

[0069] The second portion 71b of the first electric wire 71 is a portion where the core wire is covered with an insulating coating in the first electric wire 71. Therefore, in the second portion 71b of the first electric wire 71, the first terminal 61 and the first electric wire 71 are fixed to each other but are not electrically connected.

[0070] Furthermore, in the first electric wire 71, the second portion 71b, where the core wire is covered with an insulating coating, has a wire diameter larger than that of the first portion 71a by the amount of the insulating coating. Therefore, the second portion 71b of the first electric wire 71 is disposed in a recess between a pair of protrusions at the tip of the wider first exposed portion 61a of the pair of first exposed portions 61a of the first terminal 61 (in this embodiment, the outer first exposed portion 61a), and is joined to the first terminal 61 by crimping this pair of protrusions.

[0071] Similarly, for the second terminal 62, a second electric wire 72 is joined to the second exposed portion 62a of the second terminal 62. Specifically, the second electric wire 72 is joined to the second exposed portion 62a of the second terminal 62 by being crimped to a part of the second exposed portion 62a of the second terminal 62.

[0072] The second terminal 62 has a pair of second exposed portions 62a. A first portion 72a (exposed core portion) at the tip end of the second electric wire 72, where the core wire is exposed, is crimped to one of the pair of second exposed portions 62a of the second terminal 62. As a result, the second terminal 62 and the second electric wire 72 are electrically connected and fixed to each other at the first portion 72a of the second electric wire 72. Specifically, the first portion 72a of the second electric wire 72 is disposed in a recess between a pair of protrusions at the tip end of the narrower second exposed portion 62a of the pair of second exposed portions 62a of the second terminal 62 (in this embodiment, the inner second exposed portion 62a). The pair of protrusions are crimped to join the second terminal 62.

[0073] The second portion 72b (non-exposed core portion) of the second electric wire 72, where the core wire is not exposed, is crimped to the other of the pair of second exposed portions 62a of the second terminal 62. This allows the second terminal 62 and the second electric wire 72 to be fixed at the second portion 72b of the second electric wire 72 as well. That is, the second terminal 62 and the second electric wire 72 can be fixed at a portion other than the first portion 72a of the second electric wire 72. This allows the second electric wire 72 to be fixed at a portion other than the first portion 72a of the second electric wire 72. Even if the second electric wire 72 is pulled after the second electric wire 72 is fixed to the second terminal 62, the stress can be absorbed by the portion where the second exposed portion 62a and the second portion 72b are fixed. Therefore, the stress is hardly transmitted to the joint portion between the second exposed portion 62a and the first portion 72a. This prevents the second terminal 62 and the second electric wire 72 from being broken at the first portion 72a of the second electric wire 72.

[0074] The second portion 72b of the second electric wire 72 is a portion where the core wire is covered with an insulating coating in the second electric wire 72. Therefore, in the second portion 72b of the second electric wire 72, the second terminal 62 and the second electric wire 72 are fixed to each other but are not electrically connected.

[0075] In the second electric wire 72, the second portion 72b, where the core wire is covered with an insulating coating, has a wire diameter larger than that of the first portion 72a by the amount of the insulating coating. Therefore, the second portion 72b of the second electric wire 72 is disposed in a recess between a pair of protrusions at the tip of the wider second exposed portion 62a of the pair of second exposed portions 62a of the second terminal 62 (in the present embodiment, the outer second exposed portion 62a), and is joined to the second terminal 62 by crimping this pair of protrusions.

[0076] As shown in Figures 7 and 8, the brush holder 50 further has a recess 53 formed in a concave shape on the outer surface side of the brush holder 50. In this embodiment, the recess 53 is formed by providing a wall portion 54 that protrudes outward on the outer surface of the brush holder 50. The wall portion 54 is a partition formed in the shape of a screen on the outer surface of the brush holder 50. The recess 53 is a portion surrounded by the wall portion 54 formed in one continuous piece. Note that the recess 53 is not limited to this structure as long as it has a concave cross-sectional shape. For example, the recess 53 may be formed by recessing the outer surface of the brush holder 50 inward.

[0077] The recess 53 has three regions: a first recess 53a, a second recess 53b, and a third recess 53c.

[0078] The first recess 53a is a region where the first exposed portion 61a of the first terminal 61 is located. That is, the first recess 53a functions as a first arrangement space in which the first exposed portion 61a is arranged. Specifically, the wall 54 constituting the first recess 53a surrounds the first exposed portion 61a. In this embodiment, a pair of first exposed portions 61a are located in the first recess 53a. That is, the wall 54 constituting the first recess 53a surrounds the pair of first exposed portions 61a. In this case, since one of the pair of first exposed portions 61a is wider, the width of the first recess 53a is wider at the portion of the wider first exposed portion 61a. The first recess 53a is formed so that the outer portion is wider than the inner portion. Specifically, the first recess 53a is oval-shaped in a plan view. That is, the wall 54 constituting the first recess 53a is oval-shaped.

[0079] A first recess 54a is provided in a portion of the wall 54 that constitutes the first recess 53a, through which the first electric wire 71 connected to the first terminal 61 is drawn out. In the present embodiment, the first electric wire 71 is disposed in the first recess 54a and is sandwiched between the wall 54 on both sides of the first recess 54a. For example, the first electric wire 71 is lightly press-fitted into the first recess 54a. This prevents the first electric wire 71 from coming off the first terminal 61 even if a tensile force is applied to the first electric wire 71 or the first electric wire 71 vibrates.

[0080] The second recess 53b is a region where the second exposed portion 62a of the second terminal 62 is located. That is, the second recess 53b functions as a second arrangement space in which the second exposed portion 62a is arranged. Specifically, the wall 54 constituting the second recess 53b surrounds the second exposed portion 62a. A pair of second exposed portions 62a is located in the second recess 53b. That is, the wall 54 constituting the second recess 53b surrounds the pair of second exposed portions 62a. In this case, since one of the pair of second exposed portions 62a is wider, the second recess 53b is wider at the portion of the wider second exposed portion 62a. The second recess 53b is formed so that the outer portion is wider than the inner portion. Specifically, the second recess 53b is oval-shaped in a plan view. That is, the wall 54 constituting the second recess 53b is oval-shaped.

[0081] A second recess 54b is provided in a portion of the wall 54 that constitutes the second recess 53b, through which the second electric wire 72 connected to the second terminal 62 is drawn out. In the present embodiment, the second electric wire 72 is disposed in the second recess 54b and is sandwiched between the wall 54 on both sides of the second recess 54b. For example, the second electric wire 72 is lightly press-fitted into the second recess 54b. This prevents the second electric wire 72 from coming off the second terminal 62 even if a tensile force is applied to the second electric wire 72 or the second electric wire 72 vibrates.

[0082] As shown in FIG. 8 , the first recess 53a and the second recess 53b are located within an area of ​​less than 180° around the rotary shaft 21 in a plan view of the brush holder 50 seen from the outer surface side. That is, in the plan view, the angle formed by the line connecting the axis C of the rotary shaft 21 to the center of the first recess 53a and the line connecting the axis C of the rotary shaft 21 to the center of the second recess 53b is less than 180°. In this case, the angle formed by the line connecting the axis C of the rotary shaft 21 to the center of the first recess 53a and the line connecting the axis C of the rotary shaft 21 to the center of the second recess 53b is preferably less than 90°, and is approximately 60° in this embodiment. That is, the first recess 53a and the second recess 53b are positioned in a V-shaped relationship around the rotary shaft 21.

[0083] The second recess 53b has the same shape as the first recess 53a. Specifically, the first recess 53a and the second recess 53b are formed at positions that are line-symmetrical with respect to the third recess 53c.

[0084] The positional relationship between the first terminal 61 and the second terminal 62 is similar to that between the first recess 53a and the second recess 53b. That is, the first exposed portion 61a of the first terminal 61 arranged in the first recess 53a and the second exposed portion 62a of the second terminal 62 arranged in the second recess 53b are located within an area of ​​less than 180° about the rotating shaft 21 in a plan view of the brush holder 50 viewed from the exterior. For example, in the plan view, the angle formed by the line connecting the axis C of the rotating shaft 21 to the narrower first exposed portion 61a and the line connecting the axis C of the rotating shaft 21 to the narrower second exposed portion 62a is less than 180°, preferably less than 90°, and in this embodiment, is approximately 60°. That is, the first terminal 61 and the second terminal 62 are attached to the brush holder 50 in a positional relationship that resembles a V shape with the rotating shaft 21 as the center.

[0085] As shown in Figures 7 and 8, the third recess 53c is a region located between the first recess 53a and the second recess 53b and formed integrally with the first recess 53a and the second recess 53b. In other words, the third recess 53c is spatially connected to each of the first recess 53a and the second recess 53b. The recess 53 is a single recessed spatial region formed by the first recess 53a, the second recess 53b, and the third recess 53c being continuously formed integrally. Therefore, the wall portions 54 constituting the first recess 53a, the second recess 53b, and the third recess 53c are continuous.

[0086] In this embodiment, the third recess 53c has a bridge portion formed in a bridge shape so as to bridge between the first recess 53a and the second recess 53b. Specifically, the third recess 53c has a substantially rectangular shape in plan view and is formed at a position offset outward between the first recess 53a and the second recess 53b. That is, the third recess 53c has a protruding portion formed to protrude outward from the bridge portion in plan view. As a result, the shape of the recess 53 in plan view is based on an H-shape formed by the bridge portion of the first recess 53a, the second recess 53b, and the third recess 53c, with a protruding portion protruding outward from the bridge portion.

[0087] The capacitor 80 is disposed in the third recess 53c. That is, the third recess 53c functions as a third arrangement space in which the capacitor 80 is disposed. Specifically, the main body 81 of the capacitor 80 is housed in the third recess 53c. That is, the third recess 53c functions as a capacitor housing portion for housing the capacitor 80. The third recess 53c may have any shape as long as it can house the main body 81 of the capacitor 80. In this embodiment, the main body 81 of the capacitor 80 is housed in the third recess 53c in an orientation such that it does not protrude from the upper end surface of the wall portion 54 of the third recess 53c.

[0088] The capacitor 80 is a lead-type capacitor (capacitor with leads) and has a main body 81 and a pair of leads, a first lead 82a and a second lead 82b. The main body 81 has a pair of anodes and cathodes, an electrolyte and a dielectric disposed between the pair of anodes and cathodes, and an insulating outer casing member that covers the pair of anodes and cathodes and the electrolyte and dielectric. The first lead 82a and the second lead 82b are lead pins (lead terminals) drawn out from the main body 81 and are made of conductive wire such as a metal wire. Each of the first lead 82a and the second lead 82b is connected to the anode or cathode of the main body 81.

[0089] Capacitor 80 is a noise reduction capacitor, and is connected in parallel between first terminal 61 and second terminal 62. The capacitance of capacitor 80 is, for example, 0.001 μF. This makes it possible to effectively reduce noise in the frequency band of 30 to 100 MHz. Furthermore, capacitor 80 is preferably one with excellent heat resistance, and one example is a ceramic capacitor. Note that the capacitance of capacitor 80 is not limited to 0.001 μF, and is set according to the frequency of the noise to be reduced.

[0090] The first lead 82a of the capacitor 80 is bent so as to be housed within the recess 53 and joined to the first exposed portion 61a of the first terminal 61. That is, the first lead 82a of the capacitor 80 is routed so as to pass from the third recess 53c through the first recess 53a that surrounds the first terminal 61. In this embodiment, the base portion of the first lead 82a is located in the third recess 53c, and the tip portion of the first lead 82a is located in the first recess 53a.

[0091] In the first recess 53a, the first lead 82a of the capacitor 80 is joined to the first exposed portion 61a of the first terminal 61 by being crimped together with the first electric wire 71 to a part of the first exposed portion 61a of the first terminal 61. In the present embodiment, the tip end of the first lead 82a of the capacitor 80 is crimped together with the first portion 71a of the first electric wire 71 to one of the pair of first exposed portions 61a of the first terminal 61. As a result, the first lead 82a of the capacitor 80 is electrically connected to the first terminal 61 together with the first electric wire 71 at the first portion 71a of the first electric wire 71 and is fixed to each other.

[0092] Specifically, the first lead 82a of the capacitor 80, like the first electric wire 71, is disposed in a recess between a pair of protrusions at the tip of the narrower first exposed portion 61a of the pair of first exposed portions 61a of the first terminal 61 (in the present embodiment, the inner first exposed portion 61a), and is joined to the first terminal 61 together with the first electric wire 71 by crimping the pair of protrusions. In this case, as shown in Fig. 10, the first lead 82a of the capacitor 80 and the first portion 71a of the first electric wire 71 are preferably disposed in this order in the recess between the pair of protrusions of the first exposed portion 61a in the vertical direction.

[0093] Although not shown, the tip of the first lead 82a and the first portion 71a of the first electric wire 71 are further joined to the first exposed portion 61a by soldering. In other words, the tip of the first lead 82a, the first portion 71a of the first electric wire 71, and the first terminal 61 are joined not only by crimping but also by soldering.

[0094] Similarly, second lead 82b of capacitor 80 is bent so as to be housed within recess 53 and joined to second exposed portion 62a of second terminal 62. In other words, second lead 82b of capacitor 80 is routed so as to pass from third recess 53c through second recess 53b surrounding second terminal 62. In this embodiment, the base portion of second lead 82b is located in third recess 53c, and the tip portion of first lead 82a is located in second recess 53b.

[0095] In the second recess 53b, the second lead 82b of the capacitor 80 is joined to the second exposed portion 62a of the second terminal 62 by being crimped together with the second electric wire 72 to a part of the second exposed portion 62a of the second terminal 62. The tip end of the second lead 82b of the capacitor 80 is crimped together with the first portion 72a of the second electric wire 72 to one of the pair of second exposed portions 62a of the second terminal 62. As a result, the second lead 82b of the capacitor 80 is electrically connected to the second terminal 62 together with the second electric wire 72 at the first portion 72a of the second electric wire 72 and is fixed to each other.

[0096] Specifically, the second lead 82b of the capacitor 80, like the second electric wire 72, is disposed in a recess between a pair of protrusions at the tip of the narrower second exposed portion 62a of the pair of second exposed portions 62a of the second terminal 62 (in the present embodiment, the inner second exposed portion 62a), and is joined to the second terminal 62 together with the second electric wire 72 by crimping the pair of protrusions. In this case, the second lead 82b of the capacitor 80 and the first portion 72a of the second electric wire 72 may be disposed in this order in the vertical direction in the recess between the pair of protrusions of the second exposed portion 62a, like the first lead 82a and the first electric wire 71 shown in FIG.

[0097] Although not shown, the tip of the second lead 82b and the first portion 72a of the second electric wire 72 are further joined to the second exposed portion 62a by soldering. In other words, the tip of the second lead 82b, the first portion 72a of the second electric wire 72, and the second terminal 62 are joined not only by crimping but also by soldering.

[0098] As shown in FIG. 4, the recesses 53 are filled with a sealant 140. Specifically, the first recess 53a, the second recess 53b, and the third recess 53c are filled with the sealant 140. The sealant 140 ensures the dielectric strength of the live parts (the first exposed part 61a of the first terminal 61, the second exposed part 62a of the second terminal 62, the first part 71a of the first electric wire 71, the first part 72a of the second electric wire 72, and the first lead 82a and the second lead 82b of the capacitor 80) exposed on the outer surface of the brush holder 50, and also serves to waterproof the live parts. Therefore, the sealant 140 is made of an insulating resin material whose main component is a resin material such as silicone. The sealant 140 can be formed by applying a liquid insulating resin material to the recesses 53 and then solidifying it.

[0099] In the present embodiment, the sealant 140 is filled into the recess 53 until it is flush with the upper end surface of the wall 54 that defines the recess 53, but this is not limited to this. The sealant 140 only needs to be formed so that at least the charging portion is not exposed from the sealant 140. A portion of the main body 81 of the capacitor 80 may be exposed from the sealant 140.

[0100] Next, a method for joining the first and second terminals 61 and 62, the first and second electric wires 71 and 72, and the capacitor 80 will be described with reference to FIGS. 11A to 15B. FIGS. 11A to 15B are diagrams for explaining a method for joining the first and second terminals 61 and 62, the first and second electric wires 71 and 72, and the capacitor 80. FIG. 11A is an enlarged plan view of the recess 53 of the brush holder 50 and its periphery in the step of attaching the first and second terminals 61 and 62 to the brush holder 50. FIG. 11B is an enlarged perspective view of the recess 53 of the brush holder 50 and its periphery in the step of FIG. 11A. FIG. 12A is an enlarged plan view of the recess 53 of the brush holder 50 and its periphery in the step of placing the capacitor 80 in the recess 53 of the brush holder 50. FIG. 12B is an enlarged perspective view of the recess 53 of the brush holder 50 and its periphery in the step of FIG. 12A. Fig. 13A is an enlarged plan view of the recess 53 of the brush holder 50 and its periphery in the step of arranging the first electric wire 71 and the second electric wire 72 in the recess 53 of the brush holder 50. Fig. 13B is an enlarged perspective view of the recess 53 of the brush holder 50 and its periphery in the step of Fig. 13A. Fig. 14A is an enlarged plan view of the recess 53 of the brush holder 50 and its periphery in the step of crimping and joining the first electric wire 71, the first lead 82a of the capacitor 80, and the first terminal 61, and also crimping and joining the second electric wire 72, the second lead 82b of the capacitor 80, and the second terminal 62. Fig. 14B is an enlarged perspective view of the recess 53 of the brush holder 50 and its periphery in the step of Fig. 14A. Fig. 15A is an enlarged plan view of the recess 53 of the brush holder 50 and its periphery in the step of filling the recess 53 of the brush holder 50 with a sealant 140. FIG. 15B is an enlarged perspective view of the recess 53 of the brush holder 50 and its surroundings in the step of FIG. 15A.

[0101] 11A and 11B, the first terminal 61 and the second terminal 62 are attached to the brush holder 50. The first terminal 61 and the second terminal 62 are attached to the brush holder 50 so that the first exposed portion 61a of the first terminal 61 and the second exposed portion 62a of the second terminal 62 are exposed on the outer surface side of the brush holder 50.

[0102] Specifically, the pair of first exposed portions 61a of the first terminal 61 are inserted from the inside to the outside of the brush holder 50 into a pair of through-holes formed in the first recess 53a of the brush holder 50. This allows the first terminal 61 to be attached to the brush holder 50 with the pair of first exposed portions 61a exposed on the outer surface side of the brush holder 50 in the first recess 53a.

[0103] Similarly, the pair of second exposed portions 62a of the second terminal 62 are inserted from the inside to the outside of the brush holder 50 into a pair of through holes formed in the second recess 53b of the brush holder 50. This allows the second terminal 62 to be attached to the brush holder 50 with the pair of second exposed portions 62a exposed on the outer surface side of the brush holder 50 in the second recess 53b.

[0104] 12A and 12B, capacitor 80 is set in brush holder 50. In this embodiment, capacitor 80 is set in brush holder 50 so that capacitor 80 is housed in recess 53 of brush holder 50.

[0105] Specifically, the capacitor 80 is set in the recess 53 such that the main body 81 is housed in the third recess 53c of the recess 53, the tip of the first lead 82a is located between the pair of protrusions on the narrower of the pair of first exposed portions 61a of the first terminal 61, and the tip of the second lead 82b is located between the pair of protrusions on the narrower of the pair of second exposed portions 62a of the second terminal 62. At this time, it is preferable to bend the first lead 82a and the second lead 82b of the capacitor 80 in advance so that they can be housed in the recess 53.

[0106] 13A and 13B, the first electric wire 71 and the second electric wire 72 are set in the brush holder 50. The first electric wire 71 and the second electric wire 72 are set in the brush holder 50 so that the tip ends of the first electric wire 71 and the second electric wire 72 are positioned in the recesses 53 of the brush holder 50.

[0107] Specifically, the first electric wire 71 is set in the first recess 53a so that the first portion 71a is located between the pair of protrusions on the narrower of the pair of first exposed portions 61a of the first terminal 61, and the second portion 71b is located between the pair of protrusions on the wider of the pair of first exposed portions 61a of the first terminal 61. At this time, the first lead 82a of the capacitor 80 has already been placed on one of the pair of first exposed portions 61a, so that the first portion 71a of the first electric wire 71 is placed on the first lead 82a of the capacitor 80, as shown in FIG.

[0108] In this step, a portion of the first electric wire 71 is pressed into the first recess 54a formed in the wall 54 that constitutes the first recess 53a, thereby lightly press-fitting the portion of the first electric wire 71 into the first recess 54a. As a result, the first electric wire 71 is set in the brush holder 50 in a state where it is fixed in the first recess 54a and pulled out from the first recess 53a.

[0109] Similarly, the second electric wire 72 is set in the second recess 53b so that the first portion 72a is located between the pair of protrusions on the narrower of the pair of second exposed portions 62a of the second terminal 62, and the second portion 72b is located between the pair of protrusions on the wider of the pair of second exposed portions 62a of the second terminal 62. At this time, the second lead 82b of the capacitor 80 has already been placed on one of the pair of second exposed portions 62a, so the first portion 72a of the second electric wire 72 is placed on the second lead 82b of the capacitor 80.

[0110] Similarly to the first electric wire 71, a portion of the second electric wire 72 is pressed into the second recess 54b formed in the wall 54 that constitutes the second recess 53b, thereby lightly press-fitting the portion of the second electric wire 72 into the second recess 54b. As a result, the second electric wire 72 is set in the brush holder 50 in a state where it is fixed in the second recess 54b and pulled out from the second recess 53b.

[0111] 14A and 14B , the first electric wire 71 and the capacitor 80 are joined to the first terminal 61, and the second electric wire 72 and the capacitor 80 are joined to the second terminal 62. For the first electric wire 71, the first portion 71a of the first electric wire 71 and the first lead 82a of the capacitor 80 are joined to one of the pair of first exposed portions 61a of the first terminal 61, and the second portion 71b of the first electric wire 71 is joined to the other of the pair of first exposed portions 61a of the first terminal 61. For the second electric wire 72, the first portion 72a of the second electric wire 72 and the second lead 82b of the capacitor 80 are joined to one of the pair of second exposed portions 62a of the second terminal 62, and the second portion 72b of the second electric wire 72 is joined to the other of the pair of second exposed portions 62a of the second terminal 62.

[0112] Specifically, in the first recess 53a, the first portion 71a of the first electric wire 71 and the first lead 82a of the capacitor 80 are arranged between a pair of protrusions on the narrower first exposed portion 61a of the pair of first exposed portions 61a of the first terminal 61, and the pair of protrusions on the narrower first exposed portion 61a are crimped to fix the first portion 71a of the first electric wire 71 and the first lead 82a of the capacitor 80 to the narrower first exposed portion 61a. Also, the second portion 71b of the first electric wire 71 is arranged between the pair of protrusions on the wider first exposed portion 61a of the pair of first exposed portions 61a of the first terminal 61, and the pair of protrusions on the wider first exposed portion 61a are crimped to fix the second portion 71b of the first electric wire 71 to the wider first exposed portion 61a.

[0113] Similarly, in the second recess 53b, with the second portion 72b of the second electric wire 72 and the second lead 82b of the capacitor 80 arranged between a pair of protrusions on the narrower second exposed portion 62a of the pair of second exposed portions 62a of the second terminal 62, the pair of protrusions on the narrower second exposed portion 62a are crimped to fix the first portion 71a of the second electric wire 72 and the second lead 82b of the capacitor 80 to the narrower second exposed portion 62a. Also, with the second portion 72b of the second electric wire 72 arranged between the pair of protrusions on the wider second exposed portion 62a of the pair of second exposed portions 62a of the second terminal 62, the pair of protrusions on the wider second exposed portion 62a are crimped to fix the second portion 72b of the second electric wire 72 to the wider second exposed portion 62a.

[0114] Although not shown, the joint between the narrower first exposed portion 61a of the first terminal 61 and the narrower second exposed portion 62a of the second terminal 62 is further joined by soldering after this crimping joint.

[0115] Specifically, solder is applied and cured to the portion where the first portion 71a of the first electric wire 71 and the first lead 82a of the capacitor 80 are crimped by the narrower first exposed portion 61a of the first terminal 61. Solder is also applied and cured to the portion where the first portion 72a of the second electric wire 72 and the second lead 82b of the capacitor 80 are crimped by the narrower second exposed portion 62a of the second terminal 62.

[0116] 15A and 15B, a sealant 140 is formed in the recessed portion 53 of the brush holder 50. In this embodiment, the sealant 140 is filled into each of the first recessed portion 53a, the second recessed portion 53b, and the third recessed portion 53c.

[0117] Specifically, a liquid insulating resin material is applied to the recess 53, thereby filling the first recess 53a, the second recess 53b, and the third recess 53c with the liquid insulating resin material. At this time, since the first recess 53a, the second recess 53b, and the third recess 53c are continuous spaces, the liquid insulating resin material may be poured into any one of the first recess 53a, the second recess 53b, and the third recess 53c to fill the entire recess 53 with the liquid insulating resin material. For example, the liquid insulating resin material may be poured only into the third recess 53c, so that the liquid insulating resin material flows from the third recess 53c into the first recess 53a and the second recess 53b, thereby filling the entire recess 53 with the liquid insulating resin material. Alternatively, the liquid insulating resin material may be simultaneously injected into two or all of the first recess 53a, the second recess 53b, and the third recess 53c, thereby filling the entire recess 53 with the liquid insulating resin material. After filling the recess 53 with the liquid insulating resin material, the liquid insulating resin material is dried and hardened. This allows the sealing material 140 filled in the recess 53 to be formed.

[0118] As described above, in the electric motor 1 according to this embodiment, the lead-type capacitor 80 connected in parallel between the first terminal 61 and the second terminal 62 is housed in the recess 53 formed on the outer surface of the brush holder 50. Specifically, the recess 53 of the brush holder 50 has a first recess 53a formed to surround the first exposed portion 61a of the first terminal 61, a second recess 53b formed to surround the second exposed portion 62a of the second terminal 62, and a third recess 53c located between the first recess 53a and the second recess 53b and formed integrally with the first recess 53a and the second recess 53b. The main body 81 of the capacitor 80 is housed in the third recess 53c. The first lead 82a of the capacitor 80 is joined to the first exposed portion 61a of the first terminal 61, and the second lead 82b of the capacitor 80 is joined to the second exposed portion 62a of the second terminal 62.

[0119] In this way, by storing capacitor 80 in recess 53 formed on the outer surface of brush holder 50 to which first terminal 61 and second terminal 62 are attached, rather than storing capacitor 80 inside motor 1, a thin motor can be easily realized. Also, electric motor 1 having capacitor 80 can be realized without changing the external dimensions of the electric motor. For example, an electric motor 1 that can reduce noise can be realized without changing the external dimensions of an ultra-thin electric motor 1.

[0120] Furthermore, by arranging the capacitor 80 on the outside of the brush holder 50 rather than inside the brush holder 50, it is not necessary to provide a space inside the brush holder 50 to store the capacitor 80, and it is possible to prevent the temperature of the capacitor 80 from rising when the capacitor 80 is arranged inside the brush holder 50. Furthermore, by arranging the capacitor 80 on the outer surface side of the resin brush holder 50, it is possible to improve the heat dissipation performance of the capacitor 80 compared to when the capacitor 80 is arranged on the inner surface side of the brush holder 50. This makes it possible to prevent a rise in the temperature of the capacitor 80 from reducing the functionality of the capacitor 80 in a short-circuit failure mode or a decrease in the capacitance of the capacitor 80, which would reduce the noise reduction effect of the capacitor.

[0121] Furthermore, a lead-type capacitor is used as the capacitor 80, and the first lead 82a and the second lead 82b of the capacitor 80 can be joined to the first terminal 61 and the second terminal 62 from outside the brush holder 50, so that the capacitor 80 can be connected in parallel between the first terminal 61 and the second terminal 62 without requiring complex processing. This makes it possible to realize an electric motor 1 that is suitable for mass production even when the capacitor 80 is used.

[0122] Thus, with the electric motor 1 according to this embodiment, even when a noise-reducing capacitor 80 is used, it is possible to realize an electric motor 1 that is easy to make thin, has excellent heat dissipation properties for the capacitor 80, and is easy to mass-produce.

[0123] Furthermore, with the electric motor 1 according to this embodiment, the capacitor 80 can be easily selected according to the frequency of the noise to be reduced without changing the internal structure of the electric motor. For example, if the capacitor is housed inside the electric motor, changing the capacitance of the capacitor would require redesigning the internal structure of the electric motor. However, as with the electric motor 1 according to this embodiment, by housing the capacitor 80 in the recess 53 formed on the outer surface of the brush holder 50, the capacitance of the capacitor 80 can be easily changed according to the frequency of the noise to be reduced. For example, while EMC (Electro Magnetic Compatibility) measurements for vehicle motors for Japan typically focus on reducing noise in the FM (Frequency Modulation) band of approximately 30 to 100 MHz, other countries around the world may require the reduction of noise in different frequency bands. In this case, with the electric motor 1 according to this embodiment, it is possible to select and replace the capacitor 80 with a capacitance according to the frequency of the noise to be reduced without changing the internal structure of the electric motor 1.

[0124] Furthermore, in the electric motor 1 according to this embodiment, a lead-type capacitor is used as the capacitor 80, with the first lead 82a of the capacitor 80 directly connected to the first terminal 61 and the second lead 82b of the capacitor 80 directly connected to the second terminal 62. The capacitor 80 used in this embodiment is a commercially available (standard) product, and the first lead 82a and the second lead 82b of the capacitor 80 are used with the same length as the commercially available product. Therefore, the inter-terminal distance between the first terminal 61 and the second terminal 62 attached to the brush holder 50 is a distance that the first lead 82a and the second lead 82b of the commercially available capacitor 80 can reach. In other words, in this embodiment, the inter-terminal distance between the first terminal 61 and the second terminal 62 is short. For example, the first terminal 61 and the second terminal 62 are attached to the brush holder 50 in a positional relationship that forms a V shape with the rotation shaft 21 as the center.

[0125] Furthermore, by shortening the inter-terminal distance between the first terminal 61 and the second terminal 62 in this way, the inter-wire distance between the first electric wire 71 and the second electric wire 72 can also be shortened. This makes it easy to bring the first electric wire 71 drawn out from the first recess 53a and the second electric wire 72 drawn out from the second recess 53b closer to each other. In other words, it becomes easy to route the first electric wire 71 and the second electric wire 72. This makes it possible to shorten the lead time of the manufacturing process and facilitates automation of the manufacturing process.

[0126] As described above, the electric motor 1 according to this embodiment includes the commutator 30, the first brush 41 and the second brush 42 in contact with the commutator 30, the brush holder 50 that holds the first brush 41 and the second brush 42, the first terminal 61 having the first exposed portion 61a exposed from the outer surface of the brush holder 50 and electrically connected to the first brush 41, the second terminal 62 having the second exposed portion 62a exposed from the outer surface of the brush holder 50 and electrically connected to the second brush, the first electric wire 71 joined to the first exposed portion 61a of the first terminal 61, the second electric wire 72 joined to the second exposed portion 62a of the second terminal 62, and the capacitor 80 having the first lead 82a joined to the first exposed portion 61a of the first terminal 61 and the second lead 82b joined to the second exposed portion 62a of the second terminal 62. The brush holder 50 has a recess 53 formed on the outer surface of the brush holder 50. The recess 53 has a first recess 53a in which the first exposed portion 61a of the first terminal 61 is located, a second recess 53b in which the second exposed portion 62a of the second terminal 62 is located, and a third recess 53c located between the first recess 53a and the second recess 53b and formed integrally with the first recess 53a and the second recess 53b. The main body 81 of the capacitor 80 is housed in the third recess 53c.

[0127] This makes it possible to realize an electric motor that is easy to make thin, has excellent heat dissipation properties for the capacitor, and is suitable for mass production, even when a capacitor for reducing noise is used.

[0128] In the electric motor 1, the brush holder 50 forms the outer shell of the electric motor 1.

[0129] This configuration can further improve the heat dissipation of the capacitor 80 disposed on the outer surface side of the brush holder 50. Therefore, problems caused by an increase in the temperature of the capacitor 80 can be further suppressed.

[0130] In the electric motor 1, the third recess 53c has a bridge portion formed in a bridge shape.

[0131] With this configuration, the first recess 53a and the second recess 53b can be connected by the third recess 53c, which allows the first lead 82a and the second lead 82b of the capacitor 80 to be stored in the recess 53, and also makes it possible to easily route the first lead 82a and the second lead 82b from the third recess 53c to the first recess 53a and the second recess 53b.

[0132] Furthermore, even if a conventional electric motor has a brush holder that does not have the third recess 53c and is provided only with the first recess 53a and the second recess 53b, the brush holder 50 is a resin molded product, so the bridge-shaped third recess 53c can be easily added between the first recess 53a and the second recess 53b. This makes it easy to obtain the brush holder 50 having the structure of this embodiment based on the brush holder of a conventional electric motor that has only the first recess 53a and the second recess 53b. Therefore, even if the third recess 53c is added to accommodate the capacitor 80, it is possible to avoid complicated routing of the first electric wire 71 drawn out from the first recess 53a and the second electric wire 72 drawn out from the second recess 53b. In other words, even if the third recess 53c is added to accommodate the capacitor 80, the first electric wire 71 and the second electric wire 72 can be easily routed without changing the configuration of the conventional electric motor.

[0133] In the electric motor 1, the first electric wire 71 and the first lead 82a of the capacitor 80 are joined to the first exposed portion 61a of the first terminal 61 by being crimped to a portion of the first exposed portion 61a. The second electric wire 72 and the second lead 82b of the capacitor 80 are joined to the second exposed portion 62a of the second terminal 62 by being crimped to a portion of the second exposed portion 62a.

[0134] This configuration allows for strong bonding between the first wire 71, the first lead 82a of the capacitor 80, and the first exposed portion 61a of the first terminal 61. Also, the second wire 72, the second lead 82b of the capacitor 80, and the second exposed portion 62a of the second terminal 62 can be strongly bonded.

[0135] In this case, in the electric motor 1 according to the present embodiment, the first electric wire 71 and the first terminal 61 are fixed by crimping at two locations, and the second electric wire 72 and the second terminal 62 are fixed by crimping at two locations.

[0136] Specifically, the first terminal 61 has a pair of first exposed portions 61a. The second terminal 62 has a pair of second exposed portions 62a. The first electric wire 71 and the second electric wire 72 each have a core wire made of a conductor and an insulating coating that covers the core wire. A first portion 71a (exposed core wire portion) where the core wire is exposed at the tip side of the first electric wire 71 and a first lead 82a are crimped to one of the pair of first exposed portions 61a. A second portion 72b (insulating coating portion) of the first electric wire 71 where the core wire is not exposed is crimped to the other of the pair of first exposed portions 61a. The first portion 72a where the core wire is exposed at the tip side of the second electric wire 72 and a second lead 82b are crimped to one of the pair of second exposed portions 62a. A second portion 72b of the second electric wire 72 where the core wire is not exposed is crimped to the other of the pair of second exposed portions 62a.

[0137] In this way, the first electric wire 71 is crimped to the first exposed portion 61a of the first terminal 61 at two locations, the exposed core portion and the insulating coating portion of the first electric wire 71, and the second electric wire 72 is crimped to the second exposed portion 62a of the second terminal 62 at two locations, the exposed core portion and the insulating coating portion of the second electric wire 72, so that the first electric wire 71 and the second electric wire 72 can be firmly fixed to the first terminal 61 and the second terminal 62, respectively. This makes it possible to prevent disconnection between the first electric wire 71 and the first terminal 61, and also to prevent disconnection between the second electric wire 72 and the second terminal 62, even if a tensile force is applied to the first electric wire 71 and the second electric wire 72.

[0138] In the electric motor 1, the first lead 82a of the capacitor 80 and the first electric wire 71 are joined to the first exposed portion 61a of the first terminal 61 by solder, and the second lead 82b of the capacitor 80 and the second electric wire 72 are joined to the second exposed portion 62a of the second terminal 62 by solder.

[0139] In this way, by joining the first lead 82a and the first electric wire 71 by soldering and joining the second lead 82b and the second electric wire 72 by soldering, the reliability of the electrical and mechanical connection between the first lead 82a and the first electric wire 71 is improved, and the reliability of the electrical and mechanical connection between the second lead 82b and the second electric wire 72 is improved.

[0140] In this case, the first lead 82a and the first electric wire 71 may be further joined by soldering to the portion where the first lead 82a and the first electric wire 71 are crimped at the first exposed portion 61a. Similarly, the second lead 82b and the second electric wire 72 may be further joined by soldering to the portion where the second lead 82b and the second electric wire 72 are crimped at the second exposed portion 62a. This further improves the reliability of the electrical and mechanical connection between the first lead 82a and the first electric wire 71, and also further improves the reliability of the electrical and mechanical connection between the second lead 82b and the second electric wire 72.

[0141] In the electric motor 1, the first recess 53a, the second recess 53b, and the third recess 53c are filled with the sealing material 140. Specifically, the entire recess 53 is filled with the sealing material 140.

[0142] With this configuration, in the first recess 53a, the joint portion between the first terminal 61, the first lead 82a, and the first electric wire 71 is covered with the seal material 140. In the second recess 53b, the joint portion between the second terminal 62, the second lead 82b, and the second electric wire 72 is covered with the seal material 140. In the third recess 53c, the main body 81 of the capacitor 80 is covered with the seal material 140. This can improve waterproofing and dielectric strength.

[0143] In particular, in the electric motor 1 according to the present embodiment, the third recess 53c is formed integrally and continuously with the first recess 53a and the second recess 53b. That is, the first recess 53a and the second recess 53b are connected by the third recess 53c.

[0144] This makes it easier to apply the liquid insulating resin material to the first recess 53a and the second recess 53b when forming the sealant 140, compared to when the first recess 53a and the second recess 53b are separated. For example, by applying the liquid insulating resin material to one of the first recess 53a, the second recess 53b, and the third recess 53c, the liquid insulating resin material flows into the remaining portions of the first recess 53a, the second recess 53b, and the third recess 53c, making it easier to apply the liquid insulating resin material to the entire recess 53.

[0145] 10, in the electric motor 1, the first lead 82a of the capacitor 80 and the first portion 71a of the first electric wire 71 are arranged in this order in the vertical direction in the recess of one of the pair of first exposed portions 61a of the first terminal 61. The second lead 82b of the capacitor 80 and the first portion 72a of the second electric wire 72 are arranged in this order in the vertical direction in the recess of one of the pair of second exposed portions 62a of the second terminal 62.

[0146] In this way, by placing the first portion 71a of the first electric wire 71 on the first lead 82a of the capacitor 80 and the first portion 72a of the second electric wire 72 on the second lead 82b of the capacitor 80, the first lead 82a and the first portion 71a of the first electric wire 71 can be easily crimped by the pair of protrusions on the first exposed portion 61a of the first terminal 61. Furthermore, the second lead 82b and the first portion 72a of the second electric wire 72 can be easily crimped by the pair of protrusions on the second exposed portion 62a of the second terminal 62. This improves the crimping quality.

[0147] FIG. 16 is a cross-sectional view showing the configuration of the first exposed portion 61a of the first terminal 61 according to a modified example. In this case, as in the first exposed portion 61a of the first terminal 61A shown in FIG. 16, a recess 61c for accommodating the first lead 82a of the capacitor 80 may be formed in the bottom between a pair of protrusions at the tip of the first exposed portion 61a. This makes it easier to crimp the first lead 82a and the first portion 71a of the first electric wire 71 by the pair of protrusions of the first exposed portion 61a of the first terminal 61A. Although not shown, the second terminal 62 may also have a recess for accommodating the second lead 82b of the capacitor 80 in the bottom between the pair of protrusions at the tip of the first exposed portion 61a.

[0148] (Variation) Although the electric motor 1 according to the present disclosure has been described above based on the embodiment, the present disclosure is not limited to the above embodiment.

[0149] FIG. 17A is an enlarged perspective view showing the configuration of the recess 53 in an electric motor 1 according to a modified example. FIG. 17B is a cross-sectional view of a main portion corresponding to the cross section 17B-17B in FIG. 17A. For example, as in the brush holder 50A shown in FIGS. 17A and 17B, a portion of the wall 54 defining the recess 53 may have a tapered portion 54c, where a portion of the inner wall surface of the wall 54 is tapered. In FIGS. 17A and 17B, the tapered portion 54c is formed on the wall 54 defining the third recess 53c. In this case, the tapered portion 54c may be formed in a position facing the portion where the first lead 82a and the second lead 82b of the capacitor 80 are bent outward from the main body 81 (the portion extending along the longitudinal direction of the bridge portion of the third recess 53c). This makes it easier to determine the positions of the first lead 82a and the second lead 82b when placing the capacitor 80 in the recess 53, thereby facilitating the insertion of the capacitor 80 into the recess 53.

[0150] In the above embodiment, the planar shape of the recess 53 formed in the brush holder 50 was an H-shape formed by the bridge portion of the first recess 53a, the second recess 53b, and the third recess 53c, with a protruding portion protruding outward from the bridge portion, but this is not limited to this.

[0151] For example, as in the recess 53A shown in FIG. 18, the third recess 53c may be formed only by a bridge portion, and the recess 53A, which is formed by the first recess 53a, the second recess 53b, and the third recess 53c, may have an H-shape in plan view. FIG. 18 is a plan view showing a first modified example of the recess 53A in the brush holder 50A. FIG. 19 is a plan view showing a second modified example of the recess 53B in the brush holder 50A. Alternatively, as in the recess 53B shown in FIG. 19, the H-shaped recess 53A shown in FIG. 18 may be used as a base, with the bridge portion of the third recess 53c shifted to one end of the first recess 53a and the second recess 53b. In other words, as shown in FIG. 19, the recess 53B may have a U-shape in plan view.

[0152] In this case, the main body 81 of the capacitor 80 accommodated in the third recess 53c may be arranged vertically in the third recess 53c as shown in Figures 18 and 19, rather than being arranged flat in the third recess 53c as in the above embodiment. That is, the main body 81 of the capacitor 80 may be arranged in the third recess 53c in a position where it stands upright on the outer surface of the brush holder 50. Note that in the above embodiment and other modified examples as well, the main body 81 of the capacitor 80 may be arranged vertically in the third recess 53c, rather than being arranged flat.

[0153] In this way, by making the planar shape of recess 53A H-shaped or U-shaped, the volume of sealing material 140 to be filled can be reduced compared to recess 53 in the above embodiment. Furthermore, by making the planar shapes of recesses 53A and 53B, including recess 53 in the above embodiment, based on an H-shape, sealing material 140 can be stably filled. In other words, by forming third recess 53c having a bridge portion between first recess 53a and second recess 53b, liquid insulating resin material can be easily applied to the entire recess 53, and sealing material 140 can be stably filled.

[0154] FIG. 20 is a plan view showing a third modified example of the recess 53 in the brush holder 50. FIG. 21 is a plan view showing a fourth modified example of the recess 53 in the brush holder 50. Like the recess 53C shown in FIG. 20, the recess 53C may have a shape in which the entire width of the bridge portion of the third recess 53c is widened to one end of the first recess 53a and the second recess 53b. Alternatively, like the recess 53D shown in FIG. 21, the bridge portion of the third recess 53c may have a shape in which part or the entire width is widened beyond one end of the first recess 53a and the second recess 53b. The recess 53D shown in FIG. 21 has a curved shape in which one end of the bridge portion of the third recess 53c bulges outward. For example, the recess 53 shown in FIG. 21 has a frog-like shape in plan view. FIG. 22 is a plan view showing a fifth modified example of the recess 53 in the brush holder. As shown in Fig. 22, the recess 53E may have a shape in which the entire width of the bridge portion of the third recess 53c on both sides is expanded to both ends of the first recess 53a and the second recess 53b. The recess 53E shown in Fig. 22 has a rectangular shape with rounded corners in a plan view. In other words, the three-dimensional shape of the recess 53E shown in Fig. 22 is substantially a rectangular box shape.

[0155] In this way, by widening the width of the bridge portion of the third recess 53c, the main body 81 of the capacitor 80 can be placed flat in the third recess 53c, and therefore the entire capacitor 80 can be easily covered with the sealing material 140 without increasing the height of the wall portion 54. Furthermore, since the volume of the third recess 53c is increased, a capacitor 80 with a large main body 81 can be easily accommodated therein.

[0156] Fig. 23 is a plan view showing a sixth modified example of recess 53 in the brush holder. Like recess 53F shown in Fig. 23, a shape having third recess 53c large enough to accommodate multiple capacitors 80 may be used. The planar shape of recess 53F shown in Fig. 23 is a shape obtained by widening the width of the bridge portion of third recess 53c in recess 53 in the above embodiment.

[0157] In this way, by making the third recess 53c sized to accommodate multiple capacitors 80, one or multiple capacitors 80 can be selected and stored in the third recess 53c depending on the capacitance required for the noise to be reduced. That is, the third recess 53c may store multiple capacitors 80, or may store one capacitor 80 having a large main body 81. When multiple capacitors 80 are stored in the third recess 53c, all of the multiple capacitors 80 are connected in parallel between the first terminal 61 and the second terminal 62.

[0158] Furthermore, although the planar shape of recess 53 in the above-described embodiment has rounded corners, this is not limiting. Fig. 24 is a plan view showing a seventh modified example of recess 53 in a brush holder. For example, as in recess 53G shown in Fig. 24, in recess 53 in the above-described embodiment, each corner of first recess 53a, second recess 53b, and third recess 53c may have an angular shape. Figs. 25A to 25F are plan views showing eighth to thirteenth modified examples of recess 53 in a brush holder, respectively. Similarly, in recesses 53A, 53B, 53C, 53D, 53E, and 53F shown in Figures 18 to 23, the corners of each of the first recess 53a, the second recess 53b, and the third recess 53c may be angular, as in recesses 53H, 53I, 53J, 53K, 53L, and 53M shown in Figures 25A to 25F, respectively.

[0159] In the above embodiment, the electric motor 1 is a coreless motor in which the stator 10 and the rotor 20 do not have cores, but this is not limiting. For example, the electric motor 1 may be an electric motor in which the stator 10 and the rotor 20 have cores.

[0160] In the above embodiment, the stator 10 is composed of only permanent magnets, but this is not limiting. For example, the stator 10 may be a stator composed of permanent magnets and an iron core, or a stator composed of stator windings and an iron core without using permanent magnets.

[0161] In the above embodiment, the electric motor 1 is a flat motor having an outer size in which the thickness is smaller than the outer diameter, but this is not limited to this. The technology of the present disclosure can also be applied to, for example, a cylindrical electric motor having a cylindrical housing having an outer size in which the thickness is larger than the outer diameter.

[0162] Furthermore, in the above embodiment, the direction of the main magnetic flux generated by the stator 10 and the rotor 20 is the direction of the axis C of the rotating shaft 21, but this is not limited thereto. Specifically, the direction of the main magnetic flux generated by the stator 10 and the rotor 20 may be a direction perpendicular to the direction of the axis C of the rotating shaft 21 (the radial direction of the rotation of the rotating shaft 21). For example, the technology of the present disclosure can also be applied to an inner rotor type motor in which the rotor 20 is arranged inside the stator 10.

[0163] In the above embodiment, the electric motor 1 is a vehicle motor used in a vehicle, but the present disclosure is not limited to this. The technology of the present disclosure can also be applied to electric motors used in various other electrical devices, such as electric blowers mounted on electric vacuum cleaners.

[0164] In addition, the present disclosure also includes forms obtained by applying various modifications to the above embodiments that a person skilled in the art would conceive, or forms realized by arbitrarily combining the components and functions of each embodiment within the scope that does not deviate from the intent of the present disclosure. [Industrial Applicability]

[0165] The technology disclosed herein can be widely used in a variety of products equipped with electric motors, including products in the electrical equipment field such as automobiles and the household electrical appliance field. [Explanation of symbols]

[0166] 1 electric motor 10 Stator 11 Magnet 20 rotor 21 Rotation axis 21a First end 21b Second end 22 Armature winding 23, 32 Mold resin 30 commutator 31 Commutator piece 41 First Brush 42 Second Brush 50, 50A Brush Holder 51 First brush storage section 52 Second brush storage section 53, 53A, 53B, 53C, 53D, 53E, 53F, 53G, 53H, 53I, 53J, 53K, 53M Recess 53a First recess 53b Second recess 53c Third recess 54 Wall 54a First recess 54b Second recess 54c tapered section 61, 61A 1st terminal 61a 1st exposed part 61b, 62b bottom plate 61c Recess 62 2nd terminal 62a 2nd exposed part 71 First Electric Wire 71a, 72a 1st part 71b, 72b 2nd part 72 Second Electric Wire 80 capacitors 81 Main body 82a 1st lead 82b 2nd lead 91 First bearing 92 Second bearing 101 First Bracket 102 Second Bracket 111 First brush spring 112 Second brush spring 121 First pigtail wire 122 Second pigtail wire 131 First cover plate 132 Second cover plate 140 Sealing material

Claims

1. A commutator and a first brush and a second brush in contact with the commutator; a brush holder that holds the first brush and the second brush on an inner surface thereof; a first terminal having a first exposed portion exposed from an outer surface side of the brush holder, penetrating the inner surface side and the outer surface side of the brush holder, and electrically connected to the first brush; a second terminal having a second exposed portion exposed from an outer surface side of the brush holder, penetrating the inner surface side and the outer surface side of the brush holder, and electrically connected to the second brush; a first electric wire joined to the first exposed portion of the first terminal; a second wire joined to the second exposed portion of the second terminal; a capacitor having a first lead joined to the first exposed portion of the first terminal and a second lead joined to the second exposed portion of the second terminal, The brush holder has a recess formed on an outer surface side of the brush holder, the recess includes a first recess in which the first exposed portion of the first terminal is located, a second recess in which the second exposed portion of the second terminal is located, and a third recess located between the first recess and the second recess and formed integrally with the first recess and the second recess, The main body of the capacitor is housed in the third recess.

2. 2. The electric motor according to claim 1, wherein the brush holder forms an outer shell of the electric motor.

3. The electric motor according to claim 1 or 2, wherein the third recess has a bridge portion formed in a bridge shape.

4. The electric motor according to any one of claims 1 to 3, wherein the first electric wire and the first lead are joined to the first exposed portion by being crimped to a portion of the first exposed portion, and the second electric wire and the second lead are joined to the second exposed portion by being crimped to a portion of the second exposed portion.

5. the first terminal has a pair of the first exposed portions, the second terminal has a pair of the second exposed portions, The first electric wire and the second electric wire each have a core wire made of a conductor and an insulating coating that covers the core wire, a first portion where the core wire is exposed at a tip end side of the first electric wire and the first lead are crimped to one of the pair of first exposed portions; a second portion of the first electric wire where the core wire is not exposed is crimped to the other of the pair of first exposed portions, a first portion where the core wire is exposed at a tip end side of the second electric wire and the second lead are crimped to one of the pair of second exposed portions; a second portion of the second electric wire where the core wire is not exposed is crimped to the other of the pair of second exposed portions; 5. The electric motor according to claim 4.

6. the first lead and the first portion of the first electric wire are arranged in this order in a vertical direction in a recess of one of the pair of first exposed portions, the second lead and the first portion of the second electric wire are arranged in this order in a vertical direction in a recess of one of the pair of second exposed portions; 6. The electric motor according to claim 5.

7. the first lead and the first electric wire are joined to the first exposed portion by soldering, the second lead and the second electric wire are joined to the second exposed portion by soldering; The electric motor according to any one of claims 1 to 6.

8. the first recess, the second recess, and the third recess are filled with a sealing material; The electric motor according to any one of claims 1 to 7.

9. The electric motor is a flat type, The outer diameter of the motor is 120 mm or less. The electric motor according to any one of claims 1 to 8.

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