electric motor

Abstract

The utility model provides a kind of motor that can inhibit the position deviation of brush relative to commutator with cheap structure.The motor has: rotor, with rotating shaft extending along the axial direction;Commutator, installed on rotating shaft;Brush, contact with commutator;Brush holder, holding brush;And the second support, covering brush holder, brush holder has the recess of becoming the first positioning part, the second support has the convex part of becoming the second positioning part embedded into recess, recess and convex part limit brush holder moving in the width direction of brush on the plane orthogonal to axial direction by mutual embedding.

Description

Technical Field

[0001] This disclosure relates to an electric motor. Background Technology

[0002] Electric motors are primarily used in household appliances such as electric vacuum cleaners, and are also widely used in electronic devices such as automobiles. For example, electric motors are used in the electric fans of electric vacuum cleaners to rotate the rotary fans. Additionally, electric motors are used in two-wheeled or four-wheeled vehicles to drive cooling fans in radiators and other components.

[0003] As electric motors, brushed motors (commutator motors) that use brushes and brushless motors that do not use brushes are known. A brushed motor has: a stator; a rotor that rotates under the magnetic force of the stator; a commutator that is mounted on the rotating shaft of the rotor; brushes that are in contact with the commutator; and a brush holder that holds the brushes.

[0004] In recent years, in addition to cost reduction, motors used in vehicles have also required miniaturization and weight reduction. In particular, motors used in the cooling fans of radiators in two-wheeled vehicles require miniaturization and weight reduction. As such motors for vehicles, thinner, flat brushed motors have been proposed (see, for example, Patent Document 1).

[0005] However, existing electric motors suffer from the following drawback: the brushes deviate from their intended position relative to the commutator, leading to reduced motor performance and lifespan. To improve brush positioning accuracy and avoid this misalignment, considerations include employing complex structures for the motor components, complex machining processes, or adding specialized components. However, such methods increase the overall cost of the motor.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2006-149019 Utility Model Content

[0009] This disclosure was made to solve such a problem. The purpose of this disclosure is to provide an electric motor capable of suppressing the positional misalignment of the brushes relative to the commutator with an inexpensive construction.

[0010] To achieve the above objectives, a technical solution for an electric motor disclosed herein comprises: a rotor having a rotating shaft extending along an axial direction; a commutator mounted on the rotating shaft; a brush in contact with the commutator; a brush holder holding the brush; and a bracket covering the brush holder, the brush holder having a first positioning portion, and the bracket having a second positioning portion engaging with the first positioning portion, the first positioning portion and the second positioning portion restricting the movement of the brush holder along the width direction of the brush in a plane orthogonal to the axial direction by mutual engagement.

[0011] Preferably, the first positioning part is a recessed part, and the second positioning part is a convex part.

[0012] Preferably, the recess has a pair of walls facing the width direction of the brush, and the protrusion is sandwiched between the pair of walls.

[0013] Preferably, the support is a metal plate, and the protrusion is formed by partially lifting the metal plate.

[0014] Preferably, the first positioning part and the second positioning part are located in the outer peripheral region of the brush in a direction that intersects the axis and is radially centered on the axis.

[0015] Preferably, when viewed from the axial direction, the first positioning part and the second positioning part are located on the center line of the direction in which the brush slides.

[0016] Preferably, the brush is one of a pair of brushes, and the first positioning part and the second positioning part are each provided with two sets.

[0017] Preferably, the pair of brushes are arranged opposite each other with respect to the commutator.

[0018] Preferably, the motor also includes a bearing that supports the rotating shaft, and there is only one bearing.

[0019] According to this disclosure, it is possible to suppress brush position misalignment relative to the commutator with an inexpensive construction. Attached Figure Description

[0020] Figure 1 This is a perspective view of the electric motor in the embodiment, viewed from above.

[0021] Figure 2 This is a perspective view of the electric motor in the embodiment, viewed from below.

[0022] Figure 3 This is a cross-sectional view of the electric motor in an embodiment where the plane passing through the axis of rotation and the brush is cut.

[0023] Figure 4 This is an exploded perspective view of the electric motor in the embodiment.

[0024] Figure 5 yes Figure 4 An exploded perspective view of the brush holder and the various components arranged in the brush holder.

[0025] Figure 6 This is a perspective view of the brush holder of the electric motor according to the embodiment.

[0026] Figure 7 This is a perspective view of the second bracket of the electric motor in the embodiment, viewed from one side.

[0027] Figure 8 This is a perspective view of the second bracket of the electric motor in the embodiment, viewed from the other side.

[0028] Figure 9 This is a top view showing the positional relationship between the brush holder, in which the brushes are housed, and the second bracket in the electric motor of the embodiment.

[0029] Figure 10 This is a top view showing the positional relationship of the second bracket, the commutator mounted on the rotating shaft, and the brushes in the electric motor of the comparative example.

[0030] Figure 11 This is a top view showing the positional relationship between the brush holder housing the brushes and the second bracket in the electric motor of Modified Example 1.

[0031] Figure 12 This is a top view showing the positional relationship between the brush holder, which houses the brushes, and the second bracket in the electric motor of Modified Example 2.

[0032] Figure 13 This is a top view showing the positional relationship between the brush holder, which houses the brushes, and the second bracket in the electric motor of Modified Example 3. Detailed Implementation

[0033] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. The embodiments described below represent specific examples of the present disclosure. Therefore, the numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, and connection methods shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, constituent elements in the following embodiments that are not described in the independent claims representing the highest-level concept of the present disclosure will be described as arbitrary constituent elements.

[0034] In this specification and accompanying drawings, the X-axis, Y-axis, and Z-axis represent the three axes of a three-dimensional orthogonal coordinate system. The X-axis and Y-axis are mutually orthogonal and both orthogonal to the Z-axis. In this embodiment, the Z-axis direction is the direction in which the axis C of the rotation axis 21 extends.

[0035] Each figure is a schematic diagram and may not be a strict representation. In each figure, structures that are substantially the same as those in other figures are labeled with the same reference numerals, and repeated descriptions are omitted or simplified.

[0036] In this embodiment, the radial direction of the stator 10 and rotor 20 is defined as "radial," and the rotational direction of the rotor 20 is defined as "circumferential." That is, the direction extending from the axis C of the rotation shaft 21 is "radial," and the direction surrounding the axis C of the rotation shaft 21 is "circumferential." Therefore, "radial" becomes a direction orthogonal to the axis C direction of the rotation shaft 21 (also simply referred to as the "axial direction"). In this specification, terms such as "up" and "down" do not necessarily refer to the absolute spatial perception of upward (vertically above) and downward (vertically below) directions.

[0037] (Implementation Method)

[0038] use Figures 1-6 The overall structure of the electric motor 1 in the embodiment will be described. Figure 1 This is a perspective view of the electric motor 1 in the embodiment viewed from above. Figure 2 This is a perspective view of the electric motor 1 in the embodiment viewed from below. Figure 3 This is a cross-sectional view of the motor 1 in the embodiment when it is cut by a plane passing through the axis C of the rotating shaft 21 and through the brush 40. Figure 4 This is an exploded perspective view of the electric motor 1 according to the embodiment. Figure 5 yes Figure 4 An exploded perspective view of the brush holder 60 and the various components disposed in the brush holder 60. Figure 6 This is a perspective view of the brush holder 60 of the electric motor 1 according to the embodiment.

[0039] like Figure 3 As shown, the electric motor 1 includes a stator 10 and a rotor 20 that rotates under the magnetic force of the stator 10. The electric motor 1 is a brushed electric motor. The electric motor 1 includes: a commutator 30 mounted on a rotating shaft 21 of the rotor 20; at least one brush 40 in contact with the commutator 30; a brush spring 50 for pressing the brush 40 against the commutator 30; a brush holder 60 for holding the brush 40; and a cover plate 70 covering the brush 40. Figure 4 and Figure 5As shown, the motor 1 also includes a power supply terminal 80 electrically connected to the brush 40, a capacitor 90 connected to the power supply terminal 80, a bearing 100, a first bracket 111, and a second bracket 112. (As shown...) Figure 1 and Figure 2 As shown, a power supply line 2 for supplying power to the motor 1 is connected to the motor 1.

[0040] Electric motor 1 is a type of DC motor driven by direct current. It uses a magnet as the stator 10 and an armature with coils 22 as the rotor 20. Electric motor 1 is a flat-type brushed coreless motor (flat motor) mounted in two-wheeled or four-wheeled vehicles. Therefore, the stator 10 and rotor 20 do not have a core. Electric motor 1 has a thin and lightweight overall structure. Specifically, electric motor 1 is a small motor used in the cooling fan of a vehicle's radiator. The outer diameter (φ) of electric motor 1 is 120 mm or less. For example, the outer diameter φ of electric motor 1 is φ60 mm, φ70 mm, or φ90 mm, etc. Electric motor 1 is driven by power supplied from an external power source such as a battery. For example, electric motor 1 is driven by a DC 12V input voltage supplied via a power supply line 2 connected to an external power source.

[0041] The components of the electric motor 1 will be described in detail below.

[0042] like Figure 3 As shown, the stator 10 is disposed with a small air gap between it and the rotor 20. The stator 10 generates a magnetic force acting on the rotor 20. The stator 10 is structured such that magnetic flux is generated on the air gap surface opposite the rotor 20, separated by the air gap. The stator 10, together with the armature stator 10, forms a magnetic circuit. Specifically, the stator 10 is substantially annular in shape. The stator 10 is configured such that N poles and S poles are alternately and equally present on the air gap surface opposite the rotor 20, separated by the air gap, along the circumference of the rotation axis 21. The stator 10 is an excitation element that forms magnetic flux for generating torque. The stator 10 is composed of multiple magnets. The magnets constituting the stator 10 are, for example, permanent magnets. The direction of the main magnetic flux generated by the stator 10 (magnets) is the direction extending along the rotation axis 21. The stator 10 is fixed to the first support 111.

[0043] The rotor 20 has a rotating shaft 21 and a coil 22. The rotor 20 is a coreless rotor without a core.

[0044] The rotor 20 rotates about the axis C extending from the rotation shaft 21. The rotor 20 generates a magnetic force acting on the stator 10. In this embodiment, the direction of the main magnetic flux generated by the rotor 20 is along the axis C extending from the rotation shaft 21.

[0045] The rotor 20 is configured opposite to the stator 10. The rotor 20 is opposite to the stator 10 in the direction of the axis C extending from the rotation shaft 21. Specifically, the coils 22 of the rotor 20 and the stator 10 are opposite to each other in the direction of the axis C extending from the rotation shaft 21. That is, the coils 22 and the stator 10 are arranged in the direction of the axis C of the rotation shaft 21.

[0046] The rotating shaft 21 is a shaft with a center C. The rotating shaft 21 is a longitudinally elongated rod-shaped component. For example, the rotating shaft 21 is a metal rod made of a metal material such as SUS (Stainless Steel). The center C of the rotating shaft 21 becomes the center of rotation when the rotor 20 rotates. The length direction of the rotating shaft 21, that is, the direction in which the rotating shaft 21 extends (the extension direction), is the direction of the center C.

[0047] The rotating shaft 21 is supported by a bearing 100. There is only one bearing 100. That is, the rotating shaft 21 is supported by only one bearing 100. The bearing 100 supports the rotating shaft 21 for free rotation. The rotating shaft 21 is pressed into the bearing 100. The bearing 100 is held in place by the first support 111. Specifically, the bearing 100 is pressed into a recess provided in the first support 111 and thus fixed. As an example, the bearing 100 is a ball bearing. Specifically, the bearing 100 is a deep groove ball bearing.

[0048] The first end 21a of the rotating shaft 21 is the output-side end (output shaft). The first end 21a of the rotating shaft 21 protrudes from the first bracket 111 and the bearing 100. The first end 21a of the rotating shaft 21 is the end on the bearing 100 side of the rotating shaft 21 and the bearing 100 side of the commutator 30. A load, such as a rotary fan, is mounted on the first end 21a. The motor 1 with the rotary fan mounted on the rotating shaft 21 can be used, for example, as a cooling fan or an electric fan. The second end 21b of the rotating shaft 21 is the output-opposite end (output-opposite shaft). The second end 21b does not protrude from the second bracket 112.

[0049] The first support 111 and the second support 112 are made of metallic materials, for example. For instance, the first support 111 and the second support 112 are made of ferrous materials such as cold-rolled steel sheet (SPC (Steel Plate Cold) material) or metals such as aluminum. The first support 111 and the second support 112 form a housing. The stator 10 and the rotor 20 are disposed within this housing.

[0050] like Figure 1 and Figure 2 As shown, the first bracket 111 is the housing component of the electric motor 1. The first bracket 111 is formed into a bottomed cylindrical shape with a bottom and cylindrical sidewalls. The magnet constituting the stator 10 is fixed to the bottom of the first bracket 111. The coil 22 of the rotor 20 is surrounded by the sidewalls of the first bracket 111.

[0051] The second bracket 112 is configured to cover the brush holder 60. Specifically, the second bracket 112 is configured to cover the opening of the brush holder 60. The second bracket 112 is flat. That is, the second bracket 112 is a flat cover configured to cover the opening of the brush holder 60. The second bracket 112 is disposed between the first bracket 111 and the brush holder 60. Specifically, the second bracket 112 is sandwiched between the first bracket 111 and the brush holder 60.

[0052] The materials of the first bracket 111 and the second bracket 112 are not limited to metal. The materials of the first bracket 111 and the second bracket 112 may also be resin. From the viewpoint of suppressing noise generated from the motor 1, it is preferable that the first bracket 111 and the second bracket 112 are made of metal. Specifically, the first bracket 111 and the second bracket 112 are made of metal plates. The first bracket 111 is formed into a predetermined three-dimensional shape by performing a predetermined stamping process or the like on the metal plate. The second bracket 112 is a flat, plate-shaped metal plate.

[0053] Figure 3 The rotor 20 shown has coils 22, which are winding coils. The rotor 20 has multiple coils 22. Each coil 22 is an armature winding made of wire. Each coil 22 is wound in such a way that a magnetic force acting on the stator 10 is generated by the flow of current. The direction of the main magnetic flux generated by each coil 22 is along the axis C extending along the rotation axis 21. Specifically, each coil 22 is wound into a flat shape. The coil faces of each coil 22 are arranged in an orientation facing the axis C extending along the rotation axis 21.

[0054] Each of the multiple coils 22 is composed of an insulated wire having a core made of a metal such as copper or aluminum and an insulating film covering the core. Each of the multiple coils 22 is a thin winding coil having a coil layer formed by winding the insulated wire into a planar shape. Specifically, each of the multiple coils 22 is composed of one or more coil layers, for example, insulated wire wound into a substantially fan-shaped form when viewed from above. The multiple coils 22 thus configured are arranged to surround the rotation axis 21 when viewed along the axis C extending from the rotation axis 21.

[0055] Multiple coils 22 are electrically connected to the commutator 30. Specifically, each coil 22 is electrically connected to one of the multiple commutator segments 31 of the commutator 30. Therefore, current flows through the multiple coils 22 via the commutator segment 31 contacted by the brush 40.

[0056] Multiple coils 22 are covered by molding resin 23. That is, multiple coils 22 are resin molded. Therefore, the multiple coils 22 are integrally formed together with the molding resin 23 by being covered by it. The top view of the molding resin 23 after molding the multiple coils 22 is circular. The molding resin 23 can be, for example, an insulating resin material such as phenolic resin or unsaturated polyester resin (BMC (Bulk Molding Compound)). The molding resin 23 can be either a thermosetting resin or a thermoplastic resin.

[0057] Thus, the motor 1 is a coreless motor in which the rotor 20 does not have a core. In the motor 1, the multiple coils 22 of the rotor 20 are molded in a thin shape using resin molding. As a result, a thin motor 1 with low inductance and a flat shape can be realized.

[0058] like Figure 3 As shown, the commutator 30 is mounted on the rotating shaft 21. Therefore, the commutator 30 rotates together with the rotating shaft 21 as the rotor 20 rotates. The commutator 30 is mounted on the second end 21b of the rotating shaft 21. The commutator 30 mounted on the rotating shaft 21 may also be part of the rotor 20.

[0059] The commutator 30 has a plurality of commutator segments 31 arranged along the rotation direction of the rotation shaft 21. Specifically, the plurality of commutator segments 31 are arranged in a ring shape along the rotation direction of the rotation shaft 21 in a manner that surrounds the rotation shaft 21. Each commutator segment 31 is a longitudinally elongated member extending along the length direction of the rotation shaft 21.

[0060] Each commutator segment 31 is a conductive terminal made of a metal material such as copper. Each commutator segment 31 is electrically connected to a coil 22 of the rotor 20. The commutator segments 31 are arranged insulated and separate from each other. However, each commutator segment 31 is electrically connected to a coil 22 of the rotor 20.

[0061] As an example, the commutator 30 is a molded commutator. The commutator 30 is a structure formed by molding multiple commutator segments 31 with molding resin 23. In this case, the multiple commutator segments 31 are embedded in the molding resin 23 with their surfaces exposed. The molding resin 23 is the commutator body. The molding resin 23 is essentially a cylindrical member having a through hole for the insertion of a rotating shaft 21. The molding resin 23 is a resin molded body made of an insulating resin material such as a thermosetting resin.

[0062] At least one brush 40 is in contact with the commutator 30. Specifically, the front end of the brush 40 is in contact with the commutator segment 31 of the commutator 30. Since the commutator 30 rotates by the rotation of the rotating shaft 21, the brush 40 is in continuous contact with all the commutator segments 31 in sequence.

[0063] Brush 40 is a power supply brush used to supply power to coil 22. Specifically, brush 40 supplies power to coil 22 by contacting commutator segments 31 of commutator 30. Through the contact between brush 40 and commutator segments 31, armature current supplied from power terminal 80 to brush 40 flows through commutator segments 31 and into coil 22.

[0064] As an example, the brush 40 is a conductive carbon brush made of carbon. The brush 40 is a roughly rectangular parallelepiped. In this case, it is preferable that the brush 40 is a carbon brush containing metals such as copper. This reduces the contact resistance between the brush 40 and the commutator segment 31. For example, the brush 40 can be manufactured by crushing a mixture obtained by mixing graphite powder, copper powder, binder resin, and curing agent, compressing it into a rectangular parallelepiped, and then firing it.

[0065] In this embodiment, multiple brushes 40 are provided. Specifically, as shown in the figure... Figures 3-5 As shown, the motor 1 is provided with two brushes 40. The two brushes 40 are arranged opposite each other in a manner that sandwiches the commutator 30. That is, the two brushes 40 are arranged at a 180° interval along the rotation direction of the rotor 20. Therefore, the two brushes 40 are arranged in a straight line. The angle between the length directions of the two brushes 40 is 180°. Therefore, the commutator 30 is pressed in one axial direction by the two brushes 40 arranged in a straight line. Furthermore, the number of brushes 40 is not limited to two.

[0066] The brush 40 is pressed by the brush spring 50 and is always in contact with the commutator segments 31 of the commutator 30. That is, the brush 40 is pressed against the commutator 30 by the brush spring 50. Thus, the brush 40 is configured to slide in contact with the commutator 30 under the pressing force from the brush spring 50, and is capable of moving in a radial direction intersecting the axis C extending from the rotation shaft 21 as it wears with the commutator 30.

[0067] The number of brush springs 50 corresponds to the number of brushes 40. In this embodiment, since there are two brushes 40 in the motor 1, there are also two brush springs 50. The brushes 40 and brush springs 50 are housed in the brush holder 60 and covered by the cover plate 70.

[0068] The brush spring 50 applies pressure (spring force) to the brush 40 using its spring force (spring restoring force), exerting a force on the brush 40 toward the commutator 30. The brush spring 50 is a constant load spring. Therefore, the brush spring 50 applies a uniform load to the brush 40. In other words, the brush spring 50, as a constant load spring, applies a uniform pressing force to the brush 40.

[0069] The brush spring 50 is made of strip-shaped wire. The brush spring 50 is a disc spring. For example... Figure 3 and Figure 5 As shown, the brush spring 50 has a vortex portion 50a (coil portion) formed by winding a strip of wire into a vortex shape. The brush spring 50 is constructed using a strip of wire made of a metal material such as steel plate.

[0070] Specifically, the brush spring 50 is composed of a longitudinally elongated and strip-shaped metal plate. Therefore, the vortex section 50a is the portion of the brush spring 50 formed by repeatedly winding the longitudinally elongated and strip-shaped metal plate in one direction in a vortex shape. The brush spring 50 generates a force (spring restoring force) that returns to its original vortex shape by pulling one end of the wire out from the vortex section 50a.

[0071] like Figure 3 As shown, the brush spring 50 presses the brush 40 against the commutator 30 using the vortex portion 50a. Specifically, the brush spring 50 applies a load to the brush 40 by contacting the rear end of the brush 40 through the vortex portion 50a and utilizing the spring restoring force of the vortex portion 50a. In this case, it is preferable that the load applied by the brush spring 50 to press the brush 40 against the commutator 30 is more than twice the radial load generated during the rotation of the rotor 20.

[0072] The brush spring 50 is configured such that the vortex axis of the vortex portion 50a is in a torsional position relative to the axis C extending from the rotation shaft 21. In other words, the brush spring 50 is configured such that the vortex portion 50a is vertical. The vortex surface (coil surface) of the vortex portion 50a is parallel to the axis C of the rotation shaft 21.

[0073] The brush spring 50 is not limited to a constant load spring; it can also be a compression coil spring or a torsion spring, etc.

[0074] Power is supplied to the brushes 40 from an external power source located outside the motor 1 via power terminal 80. The external power source is a power source located outside the motor 1. The external power source supplies a predetermined input voltage to the motor 1. The external power source is a DC power source that supplies a DC 12V input voltage to the motor 1.

[0075] like Figure 3 and Figure 4 As shown, the brush 40 is disposed within the brush holder 60. The brush holder 60 is a retaining member that holds the brush 40. The brush holder 60 not only holds the brush 40, but also the cover plate 70, the power supply terminal 80, and the capacitor 90. Figures 1-3 As shown, the brush holder 60 is also a housing component constituting the housing of the motor 1. The brush holder 60 covers the second bracket 112 from the outside.

[0076] The brush holder 60 is made of an insulating resin material. The brush holder 60 is a resin molded article integrally formed from the insulating resin material. For example, the resin material constituting the brush holder 60 is phenolic resin. However, it is not limited to this.

[0077] like Figure 3 , Figure 5 and Figure 6 As shown, the brush holder 60 has a brush receiving portion 61 that serves as a spatial region for receiving the brushes 40. The brush receiving portion 61 is formed as a concave portion. The number of brush receiving portions 61 corresponds to the number of brushes 40. Two brush receiving portions 61 are formed in the brush holder 60. The two brush receiving portions 61 are each formed as a concave shape that is longitudinally elongated in a direction orthogonal to the axis C of the rotation shaft 21 (i.e., radially) and has a rectangular cross-sectional shape.

[0078] like Figure 3 As shown, the brush holder 61 houses both the brush 40 and the brush spring 50. Therefore, the length of the brush holder 61 in the longitudinal direction is longer than the length of the brush 40. Specifically, the brush spring 50 is positioned such that its vortex portion 50a is located behind the rear end of the brush 40; in other words, the vortex portion 50a is located within the brush holder 61 on the side opposite to the side where the commutator 30 is located, relative to the brush 40. In this case, the outer end of the brush spring 50 is led out from below the brush 40 toward the commutator 30 and fixed to a recess formed at the front bottom of the brush holder 60.

[0079] The brush 40, housed in the brush housing 61, slides within the brush housing 61 by being pressed by the brush spring 50. As the front end of the brush 40 wears due to friction with the commutator segment 31, the brush 40, pressed by the brush spring 50, moves toward the commutator 30 within the brush housing 61. In other words, as the brush 40 wears, its rear end moves radially toward the axis C of the rotating shaft 21.

[0080] like Figure 3 and Figure 4 As shown, a cover plate 70 is provided to cover the brush 40 housed in the brush housing 61. The cover plate 70 covers not only the brush 40 but also the brush spring 50. The cover plate 70 is fixed to the brush holder 60 by a portion of the cover plate 70 being pressed into it. The cover plate 70 is made of a metal material such as brass or stainless steel (SUS). The cover plate 70 is made of a plate-shaped metal sheet. The cover plate 70 is formed by sheet metal processing such as bending or stamping of a metal sheet cut to a predetermined shape.

[0081] like Figures 4-6As shown, a through hole 62 for the power supply line 2 to pass through is formed in the brush holder 60. Figure 2 As shown, a through hole 62 is located on the back side of the brush holder 60. The power supply line 2 passes through the through hole 62.

[0082] like Figures 4-6 As shown, two through holes 62 are formed in the brush holder 60. The two through holes 62 extend in parallel. That is, the openings of the two through holes 62 are arranged laterally.

[0083] like Figure 5 As shown, each through hole 62 is formed as a channel to connect the outside and inside of the brush holder 60. Each through hole 62 extends to the position of the power terminal 80. A power supply line 2 passes through the through hole 62, thereby connecting the power supply line 2 to the power terminal 80. That is, the power supply line 2 is electrically and mechanically connected to the power terminal 80. The power terminal 80 receives power from an external power source via the power supply line 2.

[0084] Power terminal 80 receives power from an external power source to supply power to brush 40. Therefore, power terminal 80 is electrically connected to brush 40. The power supplied to brush 40 is then supplied to coil 22 of rotor 20. In this embodiment, since the external power source is a DC power source, power terminal 80 receives DC voltage as input voltage via power supply line 2.

[0085] like Figure 4 As shown, the power terminal 80 and the brush 40 are electrically connected by a braided wire 41. The braided wire 41 is fixed to the brush 40. Specifically, one end of the braided wire 41 is fixed to the brush 40, and the other end is connected to the power terminal 80. The braided wire 41 is fixed to the brush 40, for example, by being led out from the side of the brush 40. In addition, the braided wire 41 and the power terminal 80 are joined, for example, by solder. Power is supplied to the power terminal 80 from an external power source via the power supply line 2, thereby supplying current to the brush 40 via the braided wire 41 connected to the power terminal 80.

[0086] like Figure 4 As shown, the power terminal 80 is fixed to the brush holder 60. Specifically, the power terminal 80 is fixed to the brush holder 60 by pressing the foot 83 into the insertion hole 63 provided in the brush holder 60.

[0087] like Figure 4 and Figure 5As shown, the motor 1 has two power supply terminals 80. The two power supply terminals 80 receive DC power from an external power source. In this case, one of the two power supply terminals 80 (the first power supply terminal) is a positive-side power supply terminal (high-voltage side terminal) connected to the positive side of the DC power supply. The other power supply terminal 80 (the second power supply terminal) is a negative-side power supply terminal (low-voltage side terminal) connected to the negative side of the DC power supply.

[0088] A capacitor 90, housed in a brush holder 60, is connected to both power supply terminals 80. For example, the two power supply terminals 80 are connected to the leads of the capacitor 90 using solder or similar materials. The capacitor 90 is connected to the two power supply terminals 80 in parallel. This allows for the suppression of noise generated by the motor 1. In other words, the capacitor 90 is a noise reduction capacitor.

[0089] Capacitor 90 is a leaded capacitor (capacitor with leads). Capacitor 90 has a main body and a pair of lead terminals (pins) extending from the main body. One of the pair of lead terminals of capacitor 90 is connected to one of a pair of power supply terminals 80. The other of the pair of lead terminals of capacitor 90 is connected to the other of the pair of power supply terminals 80. In this embodiment, two capacitors 90 are disposed in the brush holder 60. Two capacitors 90 connected in series are connected in parallel to the pair of power supply terminals 80. The two capacitors 90 are housed in a capacitor housing 64 formed in the brush holder 60. Figure 6 As shown, the capacitor housing 64 is a recess provided on the inner surface of the brush holder 60. (As indicated...) Figure 4 As shown, the capacitor storage section 64 is located between a pair of power supply terminals 80.

[0090] A power supply line 2 is connected to a pair of power terminals 80. For example... Figure 1 and Figure 2 As shown, power supply line 2 is a power supply line used to supply power to motor 1. Specifically, power supply line 2 supplies power to power terminal 80 for the application of power to coil 22.

[0091] like Figure 1 and Figure 2 As shown, the power supply line 2 has a power supply terminal (not shown), a wire body 4, a tube 5, a connector 6, and a waterproof plug 7.

[0092] The wire body 4 is a power wire (electrical line) through which supplied electricity passes. The wire body 4 is, for example, an insulated wire such as vinyl wire. The wire body 4 has a core wire made of a conductor such as copper and an insulating film covering the core wire. The power supply lines 2 are connected to two power terminals 80 respectively. Therefore, as... Figure 1 and Figure 2As shown, the power supply line 2 has two wire bodies 4. The wire body 4 connected to the power supply terminal 80, which serves as the high-voltage side terminal, is the high-voltage side power supply line (positive side wiring). The wire body 4 connected to the power supply terminal 80, which serves as the low-voltage side terminal, is the low-voltage side power supply line (negative side wiring).

[0093] Two electrical wires 4 are covered by a conduit 5. The conduit 5 is a cylindrical cover that covers the electrical wires 4. The conduit 5 is, for example, an insulating rubber tube. The two ends of the two electrical wires 4 are exposed from the conduit 5.

[0094] Although not shown in the diagram, each of the two main wire bodies 4 has a metal power supply terminal installed at one end, which connects to the connection portion 81 of the power supply terminal 80. The power supply terminal passes through the through hole 62 of the brush holder 60 and connects to the connection portion 81 of the power supply terminal 80. Figure 1 As shown, a connector 6 is installed at the other end of the two main wire bodies 4. The power supply line 2 is electrically connected to the external power source by connecting the connector 6 to the connector of another power supply line that is connected to an external power source. In other words, the motor 1 is connected to the external power source.

[0095] The waterproof plug 7 is an insulating cylindrical seal. It is also a rubber seal with rubber elasticity. For example, it may be made of an elastomer. The waterproof plug 7 is installed at the ends of both wire bodies 4. When the power supply wire 2 is connected to the motor 1, the power supply terminal of the power supply wire 2 passes through the through hole 62 of the brush holder 60, thereby pressing the waterproof plug 7 into and fitting it into the through hole 62. This prevents water from seeping into the interior of the motor 1 through the through hole 62 of the brush holder 60.

[0096] In the electric motor 1 configured as described above, when power is supplied to the power terminal 80 via the power supply line 2, the power is also supplied to the brushes 40 via the power terminal 80. As a result, the armature current (drive current) flows through the coil 22 via the commutator 30, which is in contact with the brushes 40, generating magnetic flux in the rotor 20 (coil 22). The magnetic force generated by the interaction between the magnetic flux generated in the rotor 20 and the magnetic flux generated by the stator 10 becomes the torque that rotates the rotor 20. At this time, the direction of the current flowing through the coil 22 is switched according to the positional relationship between the commutator segments 31 and the brushes 40. Thus, by switching the direction of current flow, a rotational force in a constant direction is generated by the repulsive and attractive forces of the magnetic forces generated between the stator 10 and the rotor 20, causing the rotor 20 to rotate around the axis C of the rotation shaft 21.

[0097] Here, refer to Figure 3 and Figure 6 Use Figures 7-9 The detailed structure of the brush holder 60 and the second bracket 112 is described below. Figure 7 This is a perspective view of the second bracket 112 of the motor 1 in the embodiment viewed from one side. Figure 8 This is a perspective view of the second bracket 112 of the motor 1 in the embodiment viewed from the other side. Figure 9 This is a top view showing the positional relationship between the brush holder 60, in which the brush 40 is housed, and the second bracket 112 in the electric motor 1 of the embodiment.

[0098] like Figure 6 As shown, the brush holder 60 has a recess 65 that serves as a first positioning portion. The recess 65 is a groove having a planar bottom surface and a pair of inner side surfaces. The pair of inner side surfaces of the recess 65 are a pair of wall surfaces 65a. The pair of wall surfaces 65a of the recess 65 face the width direction of the brush 40. The pair of wall surfaces 65a face the Y-axis direction. The pair of wall surfaces 65a are vertically erected from the bottom surface of the recess 65. That is, the angle between the pair of wall surfaces 65a and the bottom surface is 90°. The pair of wall surfaces 65a are parallel to the axis C direction of the rotation shaft 21. Specifically, the pair of wall surfaces 65a are parallel to the XZ plane.

[0099] In addition to a pair of inner surfaces (wall surface 65a) that serve as the first and second inner surfaces, the recess 65 also has a third inner surface that is vertically disposed on the bottom surface. The brush 40 side of the recess 65 is open. Therefore, as... Figure 9 As shown, when viewed from the axis C of the rotation axis 21, the inner surface of the recess 65 appears as a Japanese katakana character コ.

[0100] like Figure 9 As shown, the recess 65 is located in the outer peripheral region of the outer side of the brush 40. Specifically, the recess 65 is provided at a position opposite the rear end face of the brush 40 in the radial direction of the rotor 20 (a direction intersecting the axis C and centered on the axis C). That is, as... Figure 6 As shown, the recess 65 is provided on the outer side of the brush receiving portion 61 in the longitudinal direction of the outer peripheral region of the brush holder 60. Therefore, the recess 65 is arranged along the radial direction of the rotor 20 with the brush 40 housed in the brush receiving portion 61.

[0101] The number of recesses 65 is the same as the number of brushes 40. In this embodiment, since two brushes 40 are used, two recesses 65 are provided. Therefore, the recesses 65 are provided on the outer side of each of the two brush receiving portions 61. Furthermore, the two recesses 65 provided on the outer side of the brush receiving portions 61 are located at the outer peripheral end of the brush holder 60.

[0102] like Figure 3 , Figure 9As shown, the two brushes 40 are arranged opposite each other with the commutator 30 between them. Therefore, when viewed from the axis C of the rotating shaft 21, the two recesses 65 located on the outer side of the brush housing 61 in the longitudinal direction are located on the center line of the sliding direction of the brushes 40.

[0103] like Figure 7 and Figure 8 As shown, the second bracket 112 has a protrusion 112a that serves as a second positioning portion. The protrusion 112a is a protrusion formed in such a way that it protrudes from the main surface of the second bracket 112, which is formed as a flat plate. The protrusion 112a can be formed, for example, by processing to partially lift up the metal plate constituting the second bracket 112.

[0104] The amount of protrusion of the protrusion 112a is not particularly limited. For example, the amount of protrusion 112a can be the thickness of the metal plate constituting the second support 112. The amount of protrusion 112a is the same as the depth of the recess 65 of the brush holder 60. However, it is not limited to this. Furthermore, in this embodiment, the top view shape of the protrusion 112a is circular. However, it is not limited to this. For example, the top view shape of the protrusion 112a can also be a rectangle or other polygons; it can be not only a perfect circle but also an ellipse.

[0105] like Figure 3 As shown, the protrusion 112a of the second bracket 112 is embedded in the recess 65 of the brush holder 60. The protrusion 112a of the second bracket 112 and the recess 65 of the brush holder 60 determine the relative position of the brush holder 60 and the second bracket 112 by mutual engagement. The protrusion 112a of the second bracket 112 and the recess 65 of the brush holder 60 restrict the movement of the brush holder 60 along the width direction of the brush 40 by mutual engagement. That is, the movement of the brush holder 60 along the width direction of the brush 40 is restricted by the engagement of the protrusion 112a and the recess 65.

[0106] Thus, the relative position of the brush holder 60 and the second bracket 112 is determined by the engagement of the protrusion 112a of the second bracket 112 with the recess 65 of the brush holder 60, and the movement of the brush holder 60 along the width direction of the brush 40 is restricted in a plane orthogonal to the axis C of the rotation axis 21 (XY plane). In other words, the recess 65 of the brush holder 60 and the protrusion 112a of the second bracket 112 function as positioning portions determining the positions of the brush holder 60 and the second bracket 112, and also as movement restriction portions restricting the movement of the brush holder 60. Therefore, it is preferable that the protrusion 112a and the recess 65 engage with each other without any gap. Alternatively, they can be engaged with a small gap (e.g., less than 0.1 mm) between the protrusion 112a and the recess 65, which is equivalent to the dimensional tolerance.

[0107] like Figure 9 As shown, the protrusion 112a embedded in the recess 65 of the brush holder 60 is sandwiched by a pair of wall surfaces 65a of the recess 65. The pair of wall surfaces 65a face the width direction of the brush 40. Therefore, when the brush holder 60 is to be positioned along the width direction of the brush 40 (in... Figure 9 When the brush holder 60 moves along the Y-axis, the protrusion 112a abuts against a pair of wall surfaces 65a. This restricts the movement of the brush holder 60 along the width direction of the brush 40. In other words, it prevents the brush holder 60 from shifting from a predetermined position in the width direction of the brush 40. Thus, the pair of wall surfaces 65a function as limiting walls that restrict the movement of the brush holder 60 along the width direction of the brush 40.

[0108] Furthermore, by restricting the movement of the brush holder 60 along the width direction of the brush 40, the movement of the brush 40 housed in the brush holder 60 is also restricted along the width direction of the brush 40. In other words, the recess 65 and the protrusion 112a restrict the movement of the brush 40 along its width direction. In other words, the recess 65 and the protrusion 112a prevent the brush 40 from shifting from a predetermined position in the width direction of the brush 40.

[0109] The protrusions 112a of the second bracket 112 have the same number as the recesses 65 of the brush holder 60. In this embodiment, the brush holder 60 has two recesses 65. Therefore, as Figure 7 and Figure 8 As shown, the second bracket 112 has two protrusions 112a. That is, as Figure 9 As shown, the protrusion 112a and the recess 65 are provided in two sets.

[0110] like Figure 9 As shown, the two protrusions 112a and the recesses 65 of the brush holder 60 are also located in the outer peripheral region of the rotor 20 in the radial direction (the direction intersecting the axis C and centered on the axis C), further outward than the brush 40. Specifically, when viewed from the axis C of the rotating shaft 21, the two protrusions 112a and the recesses 65 are also positioned opposite the rear end face of the brush 40 in the radial direction of the rotor 20. That is, when viewed from the axis C of the rotating shaft 21, the two protrusions 112a are located outside the length direction of the brush receiving portion 61 in the outer peripheral region of the brush holder 60. Therefore, the protrusions 112a and the recesses 65 are also arranged along the radial direction of the rotor 20 and the brush 40. The two protrusions 112a and the two recesses 65 provided in the brush holder 60 are also located on the centerline of the sliding direction of the brush 40 when viewed from the axis C of the rotating shaft 21.

[0111] like Figure 7 and Figure 8As shown, the second bracket 112 is provided with a through hole 112b, through which a screw (not shown) for fixing the second bracket 112 to the brush holder 60 passes. There are two through holes 112b.

[0112] Next, the process of obtaining the technology disclosed herein will be included in the description of the effects of the electric motor 1 of this embodiment.

[0113] In recent years, there has been a pursuit of higher efficiency and longer lifespan for electric motors. For example, for motors used in automotive applications, such as those for cooling fans in radiators of two-wheeled vehicles, the pursuit is not only for miniaturization and weight reduction, but also for higher efficiency and longer lifespan. For instance, for motors used in vehicles, the goal is to achieve a lifespan far exceeding 1,000 hours (e.g., 2,000 hours).

[0114] In a brushed motor with brushes, the lifespan of the brushes is considered the lifespan of the motor. That is, the motor reaches the end of its lifespan when the brushes wear out and their lifespan is exhausted.

[0115] In this type of brushed motor, in order to obtain high efficiency, the brushes are configured in such a way that the attraction (gravity) and repulsion (repulsion) of the magnetic forces generated by the rotor and stator are in an ideal state (that is, a state with less loss), and the commutation timing is switched.

[0116] Therefore, if the position of the brushes deviates from the predetermined position (i.e., the designed position) relative to the commutator mounted on the rotating shaft, the efficiency of the motor decreases. Thus, components such as brush holders that hold the brushes are designed to minimize the deviation of the brushes' position relative to the commutator.

[0117] In this situation, to ensure high positional accuracy of the brushes and commutator, it is advisable to adopt complex structures for components that constitute the motor, such as brush holders, or to perform complex machining, or to add other special components. However, if complex structures are adopted for the components, complex machining is performed, or special components are added, the machining costs, material costs, and assembly costs will increase, and the overall cost of the motor will be higher.

[0118] To date, it has been believed that even if the position of the brush relative to the commutator deviates slightly from the predetermined position, it will not have a significant impact on the performance and lifespan of the motor.

[0119] Therefore, in order to control costs, brushed motors to date have been designed with a slight offset between the brushes and the commutator. In other words, brushed motors to date have allowed for a slight offset of the brushes relative to the commutator. Conversely, motors to date have been able to ensure the required lifespan even with this predetermined offset.

[0120] However, in the pursuit of further extending the lifespan of brushed motors, the inventors of this application conducted an experimental study on the effect of the brush's positional offset relative to the commutator. Using Figure 10 The experimental results are explained using the motor 1X shown as a comparative example. Figure 10 This is a top view showing the positional relationship of the second bracket 112X, the commutator 30 mounted on the rotating shaft 21, and the brush 40 in the electric motor 1X of the comparative example.

[0121] The comparative example motor 1X is constructed with an external dimension of φ60mm, and compared to the motor 1 of the above embodiment, it is constructed without a protrusion 112a in the second bracket 112X, and without a recess 65 in the brush holder (not shown).

[0122] In the comparative example motor 1X configured in this way, the two brushes 40 are moved parallel to each other from their predetermined position (designed position), i.e., the position of line L1, to the position of line L2, resulting in a positional offset of the brushes 40 relative to the commutator 30 (that is, an axial offset of the brushes 40). In other words, both brushes 40 are offset in the width direction. Specifically, the brush holder housing the brushes 40 is offset in the width direction of the brushes 40, resulting in a positional offset of the two brushes 40 relative to the commutator 30. Furthermore, the amount of this offset was measured and found to be only about 0.3 mm.

[0123] However, it is known that even a misalignment of only about 0.3mm generates residual brush current, significantly degrading the motor's performance. It is also known that if the position of brush 40 is misaligned, the ripple in the drive current flowing through the winding coils of rotor 20 via brush 40 and commutator 30 increases. In other words, if the position of brush 40 is misaligned, the ripple of the drive current increases, generating sparks between brush 40 and commutator 30, accelerating brush 40 wear, and reducing the motor's lifespan.

[0124] Thus, according to the experiments conducted by the inventors of this application, in the brushed motors of the present time, the performance of the motor decreases and the lifespan of the motor is reduced when the brush is offset in the width direction, even if the offset is only about 0.3 mm.

[0125] According to the research of the inventors of this application, the arrangement of the two brushes 40 also affects the positional offset of the brushes 40. Specifically, assuming that the two brushes 40 are arranged at an angle of 60°, it is believed that because the reaction force of the brush based on the brush spring is biased to one side, the brush holder is stable by leaning towards one side, and the position of the brush is not easily offset. In contrast, as Figure 10As shown, when the two brushes 40 are arranged in a straight line with an angle of 180° between them, the reaction force of the brushes 40 based on the brush spring does not deviate to one side, and the brush holder is prone to movement. As a result, it is assumed that the brushes 40 disposed in the brush holder move together with the brush holder, and the position of the brushes 40 is prone to displacement.

[0126] The inventors of this application conducted in-depth research on this problem and as a result, they discovered a structure that can suppress the positional deviation of the brush 40 with an inexpensive construction.

[0127] Specifically, in the motor 1, the brush holder 60 has a recess 65 that serves as a first positioning portion. The second bracket 112 has a protrusion 112a that serves as a second positioning portion, which is inserted into the recess 65 that serves as the first positioning portion. The recess 65 and the protrusion 112a restrict the movement of the brush holder 60 along the width direction of the brush 40 by interlocking with each other.

[0128] According to this structure, it is possible to suppress the movement of the brush 40 housed in the brush holder 60 along the width direction of the brush 40. As a result, it is possible to suppress the positional offset (axis offset) of the brush 40 relative to the commutator 30. For example, in the motor 1 with an external dimension of φ60mm, the positional offset of the brush 40 can be suppressed to less than 0.1mm (e.g., 0.01mm to 0.08mm).

[0129] Furthermore, in the electric motor 1 of this embodiment, the positional shift of the brush 40 is suppressed by utilizing the brush holder 60 and the second bracket 112, which are existing components. In other words, the positional shift of the brush 40 is suppressed without adding any additional dedicated components. Moreover, since the brush holder 60 is a resin molded product, the recess 65 can be formed in the brush holder 60 simply by slightly modifying the shape of the mold used to mold the brush holder 60. The protrusion 112a can be formed simply and at low cost by performing stamping or similar processing on the second bracket 112. Thus, the recess 65 and the protrusion 112a can be formed with high dimensional accuracy without incurring high costs. Therefore, the positional shift of the brush 40 can be suppressed with a low-cost structure and high precision.

[0130] Thus, the electric motor 1 according to this embodiment can suppress the positional misalignment of the brush 40 relative to the commutator 30 with an inexpensive construction. Consequently, it is possible to suppress the degradation of the motor's performance and lifespan caused by the positional misalignment of the brush 40. In other words, it is possible to achieve high performance and long lifespan of the electric motor.

[0131] Furthermore, in the electric motor 1 of this embodiment, the recess 65 of the brush holder 60 has a pair of wall surfaces 65a facing the width direction of the brush 40. The protrusion 112a of the second bracket 112 is sandwiched between the pair of wall surfaces 65a.

[0132] According to this structure, if the brush holder 60 is to move along the width direction of the brush 40, the protrusion 112a abuts against a pair of wall surfaces 65a. Therefore, movement of the brush holder 60 along the width direction of the brush 40 is restricted. This effectively suppresses the brush 40 held in the brush holder 60 from shifting in the width direction.

[0133] Furthermore, in the electric motor 1 of this embodiment, the protrusion 112a of the second bracket 112 is formed by partially lifting up the metal plate constituting the second bracket 112.

[0134] According to this structure, the protrusion 112a can be formed in the second bracket 112 in a low-cost and simple manner. Therefore, the positional displacement of the brush 40 relative to the commutator 30 can be suppressed with an inexpensive construction.

[0135] Furthermore, in the motor 1 of this embodiment, the recess 65 and the protrusion 112a are located in the outer peripheral region, which is further outward than the brush 40.

[0136] According to this structure, compared with the case where the recess 65 and the protrusion 112a are provided in the inner peripheral region on the inner side of the rear end face of the brush 40, the positional displacement of the brush 40 caused by the recess 65 and the protrusion 112a can be effectively suppressed.

[0137] Furthermore, in the electric motor 1 of this embodiment, when viewed from the axis C direction of the rotating shaft 21, the recess 65 and the protrusion 112a are located on the center line of the direction in which the brush 40 slides.

[0138] In this way, by providing the recess 65 and the protrusion 112a along the centerline of the brush 40's length, the angular tolerance will not be superimposed on the positional offset of the brush 40. Therefore, the positional offset of the brush 40 can be minimized. That is, the positional offset of the brush 40 can be suppressed with higher precision.

[0139] Furthermore, in the motor 1 of this embodiment, there are two brushes 40, and two recesses 65 and two protrusions 112a are provided corresponding to the number of brushes 40. That is, there are two sets of recesses 65 and protrusions 112a.

[0140] According to this structure, not only can the movement of the brush holder 60 along the width direction of the brush 40 be more effectively restricted, but also the movement of the brush holder 60 along the rotation direction can be restricted. Therefore, the positional offset of the brush 40 relative to the commutator 30 can be more effectively suppressed.

[0141] Furthermore, in the motor 1 of this embodiment, the two brushes 40 are arranged opposite each other with a gap between them and the commutator 30. The two brushes 40 are arranged in a straight line with an angle of 180° between them.

[0142] As described above, when the two brushes 40 are arranged in a straight line, the reaction force of the brushes 40 based on the brush spring 50 does not deviate to one side, and the brush holder 60 is prone to movement. However, in this embodiment, the recess 65 of the brush holder 60 engages with the protrusion 112a of the second bracket 112. Therefore, movement of the brush holder 60 can be suppressed. That is, even if the two brushes 40 are arranged in a straight line, positional displacement of the brushes 40 housed in the brush holder 60 can be effectively suppressed.

[0143] In addition, the electric motor 1 of this embodiment also includes a bearing 100 that supports the rotating shaft 21, but there is only one bearing 100.

[0144] If only one bearing 100 is used to support the rotating shaft 21, the rotating shaft 21 itself is more prone to positional displacement compared to the case where two bearings 100 are used. As a result, the brush 40 is also more prone to positional displacement relative to the rotating shaft 21. In contrast, in this embodiment, the recess 65 of the brush holder 60 engages with the protrusion 112a of the second bracket 112. Thus, even if only one bearing 100 supports the rotating shaft 21, positional displacement of the brush 40 can be effectively suppressed.

[0145] (Variation example)

[0146] The electric motor 1 of this disclosure has been described above based on the embodiments, but this disclosure is not limited to the above embodiments.

[0147] For example, in the above embodiment, when viewed from the axis C of the rotation axis 21, the recess 65 of the brush holder 60 and the protrusion 112a of the second bracket 112 are located in the outer peripheral region of the brush holder 60 opposite to the rear end face of the brush 40. However, it is not limited to this. Figure 11 This is a top view showing the positional relationship between the brush holder 60A, which houses the brush 40, and the second bracket 112 in the motor 1A of Modified Example 1. Specifically, it can also be like... Figure 11 As shown in the motor 1A, when viewed from the axis C of the rotating shaft 21, the recess 65 of the brush holder 60A and the protrusion 112a of the second bracket 112A are located in the outer peripheral region of the brush holder 60A, along the direction of arrangement of the two brushes 40 (in Figure 11 The direction orthogonal to the X-axis (in the middle) Figure 11 On a straight line (with the Y-axis in the middle).

[0148] Furthermore, in the above embodiment, the two brushes 40 are configured such that the angle between them is 180°. However, this is not the only limitation. Figure 12 This is a top view showing the positional relationship between the brush holder 60B, which houses the brush 40, and the second bracket 112B in the motor 1B of Modified Example 2. For example, it can also be like... Figure 12 As shown in the motor 1B, the two brushes 40 are configured at an angle of 60°. In this case, as... Figure 12 As shown, when viewed from the axis C of the rotation axis 21, it is preferable that the recess 65 of the brush holder 60B and the protrusion 112a of the second bracket 112B are located in the outer peripheral region of the brush holder 60B, opposite to the rear end face of the brush 40. Figure 13 This is a top view showing the positional relationship between the brush holder 60C, which houses the brush 40, and the second bracket 112C in the motor 1C of Modified Example 3. It can also be viewed as... Figure 13 As shown in the motor 1C, when viewed from the axis C of the rotating shaft 21, the recess 65 of the brush holder 60C and the protrusion 112a of the second bracket 112C are located in the outer peripheral region of the brush holder 60C, at positions opposite to the two brushes 40 respectively across the rotating shaft 21.

[0149] Furthermore, although not illustrated, the two brushes 40 can be arranged linearly symmetrically about the axis C of the rotation shaft 21, and the angle between the two brushes 40 is not limited to 180° or 60°. For example, the angle between the two brushes 40 can be 90° or 120°.

[0150] Furthermore, in the above embodiment, when viewed from the axis C of the rotation shaft 21, the recess 65 of the brush holder 60 and the protrusion 112a of the second bracket 112 are located in the outer peripheral region, which is further outward than the rear end face of the brush 40. However, this is not a limitation. For example, when viewed from the axis C of the rotation shaft 21, the recess 65 of the brush holder 60 and the protrusion 112a of the second bracket 112 may be located in the inner peripheral region, which is further inward than the rear end face of the brush 40. However, in this case, the recess 65 and the protrusion 112a need to be located in a position that does not interfere with the brush 40.

[0151] Furthermore, in the above embodiment, the recess 65 is composed of three inner surfaces, and when viewed from the axis C of the rotation axis 21, the inner surfaces of the recess 65 are shaped like Japanese katakana characters. However, it is not limited to this. For example, the recess 65 may be composed of only the two inner surfaces of a pair of wall surfaces 65a, or it may be composed of only one inner surface of a pair of wall surfaces 65a. Alternatively, the recess 65 may be composed of four inner surfaces, and when viewed from the axis C of the rotation axis 21, the inner surfaces of the recess 65 are rectangular in shape.

[0152] When viewed from the axis C of the rotation axis 21, the inner surface of the recess 65 may not be configured to form rectangular sides. For example, when viewed from the axis C of the rotation axis 21, the inner surface of the recess 65 may be configured to form polygonal sides such as triangles or pentagons. Alternatively, when viewed from the axis C of the rotation axis 21, the recess 65 may be circular. In this case, the inner surface of the recess 65 is formed into a cylindrical shape.

[0153] Furthermore, in the above embodiment, the recess that becomes the first positioning part is provided in the brush holder 60, and the protrusion 112a that is embedded in the first positioning part and becomes the second positioning part is provided in the second bracket 112. However, it is not limited to this. For example, the concave-convex structure can be reversed, with the protrusion that becomes the first positioning part provided in the brush holder 60, and the recess that is embedded in the first positioning part and becomes the second positioning part provided in the second bracket 112.

[0154] Furthermore, in the above embodiment, the protrusion 112a of the second bracket 112 is provided as part of the metal plate constituting the second bracket 112. However, it is not limited to this. For example, the protrusion 112a of the second bracket 112 may be separate from the metal plate constituting the second bracket 112. In this case, the protrusion 112a is fixed to the metal plate constituting the second bracket 112. For example, a screw may be screwed into the metal plate constituting the second bracket 112, and the screw head or screw shank may be provided as a protrusion.

[0155] Furthermore, in the above embodiment, the motor 1 has only one bearing 100. However, it is not limited to this. Specifically, the motor 1 may also have two bearings. In this case, for example, one of the two bearings can be mounted on the first end 21a of the rotating shaft 21, and the other of the two bearings can be mounted on the second end 21b of the rotating shaft 21. In this way, by using two bearings 100, the positional displacement of the rotating shaft 21 itself can be suppressed. Therefore, the positional displacement of the brush 40 relative to the rotating shaft 21 can be further suppressed.

[0156] Furthermore, in the above embodiment, the motor 1 is a coreless motor in which the stator 10 and rotor 20 do not have cores. However, it is not limited to this. For example, the motor 1 may also be a motor in which the stator 10 and rotor 20 have cores. However, as in the above embodiment, by making it a coreless motor, it is possible to achieve a motor 1 with lower inductance and a thinner profile.

[0157] Furthermore, in the above embodiment, the stator 10 is composed only of permanent magnets. However, it is not limited to this. For example, the stator 10 may be a stator composed of permanent magnets and an iron core, or it may be an armature composed of stator windings and an iron core without using permanent magnets.

[0158] Furthermore, in the above embodiment, the motor 1 is a flat motor with a thickness smaller than its outer diameter. However, it is not limited to this. The technology disclosed herein can also be applied, for example, to cylindrical motors with a cylindrical housing and a thickness larger than its outer diameter.

[0159] 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. However, it is not limited to this. Specifically, the direction of the main magnetic flux generated by the stator 10 and the rotor 20 can also be a direction orthogonal to the axis C of the rotating shaft 21 (the radial direction of the rotation of the rotating shaft 21). For example, the technology disclosed herein can also be applied to an inner rotor type motor in which the rotor 20 is disposed inside the stator 10.

[0160] Furthermore, in the above embodiment, the electric motor 1 is a vehicle motor for use in a vehicle. However, it is not limited to this. The technology disclosed herein can also be applied, for example, to electric motors used in various other electrical appliances, such as electric motors used in electric fans, electric vacuum cleaners, etc.

[0161] Furthermore, this disclosure also includes various modifications conceived by those skilled in the art to the above embodiments and variations, or methods implemented by arbitrarily combining the constituent elements and functions of the embodiments without departing from the spirit of this disclosure. Solutions obtained by arbitrarily combining two or more claims from the multiple claims recited in the claims at the time of filing this application, to the extent that they are not technically contradictory, are also included in this disclosure. For example, when a referenced claim in the claims at the time of filing this application is set as a reference to multiple claims or multiple referenced claims, to the extent that it is not technically contradictory, the combination of all claims included in such a referenced multiple claims or multiple referenced claims is also included in this disclosure.

[0162] Industrial availability

[0163] The technology disclosed herein is primarily applicable to products in the fields of electronic equipment such as automobiles and household appliances, and can be widely used in electric motors and various products equipped with electric motors.

[0164] Explanation of reference numerals in the attached figures

[0165] 1. 1A, 1B, 1C, Electric motor; 2. Power supply line; 4. Wire body; 5. Pipe; 6. Connector; 7. Waterproof plug; 10. Stator; 20. Rotor; 21. Rotating shaft; 21a. First end; 21b. Second end; 22. Coil; 23. Molded resin; 30. Commutator; 31. Commutator segment; 40. Brush; 41. Braided wire; 50. Brush spring; 50a. Swirl section; 60, 60A, 60B, 6 0C, Brush holder; 61, Brush storage part; 62, Through hole; 63, Insertion hole; 64, Capacitor storage part; 65, Recess (first positioning part); 65a, Wall surface; 70, Cover plate; 80, Power terminal; 81, Connecting part; 83, Foot; 90, Capacitor; 100, Bearing; 111, First bracket; 112, 112A, 112B, 112C, Second bracket; 112a, Protrusion (second positioning part).

Claims

1. An electric motor, characterized in that, This electric motor has the following features: A rotor having a rotating shaft extending along the axial direction; A commutator, which is mounted on the rotating shaft; The brush is in contact with the commutator; A brush holder that holds the brush; and A bracket that covers the brush holder. The brush holder has a first positioning part. The bracket has a second positioning part that fits into the first positioning part. The first positioning part and the second positioning part restrict the movement of the brush holder along the width direction of the brush in a plane orthogonal to the axis direction by interlocking with each other.

2. The electric motor according to claim 1, characterized in that, The first positioning part is a recess. The second positioning part is a convex part.

3. The electric motor according to claim 2, characterized in that, The recess has a pair of walls facing the brush in the width direction. The protrusion is sandwiched between the pair of walls.

4. The electric motor according to claim 2 or 3, characterized in that, The support is a metal plate. The protrusion is formed by partially lifting the metal plate.

5. The electric motor according to any one of claims 1 to 3, characterized in that, The first positioning part and the second positioning part are located in the outer peripheral region of the brush in a direction that intersects the axis and is radially centered on the axis.

6. The electric motor according to claim 5, characterized in that, When viewed from the axis, the first positioning part and the second positioning part are located on the center line of the direction in which the brush slides.

7. The electric motor according to any one of claims 1 to 3, characterized in that, The brush is one of a pair of brushes. The first positioning part and the second positioning part are each provided in two sets.

8. The electric motor according to claim 7, characterized in that, The pair of brushes are arranged opposite each other with respect to the commutator.

9. The electric motor according to any one of claims 1 to 3, characterized in that, The electric motor also includes bearings that support the rotating shaft. There is only one bearing.

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