WO2022202274A1 - Electric motor and electric blower - Google Patents

Abstract

Provided is an electric motor capable of reducing influence of magnetic flux, which is generated by an armature winding, on a constant force spring. A magnetic motor (1) comprises: a rotor (20) having a rotation shaft (21), and a commutator (30) attached to the rotation shaft (21); a brush (40) adjacent to the commutator (30); a plurality of armature windings (22) connected to the commutator (30); a constant force spring (110); and a soft magnetic member (second bracket (102)) which is disposed between the plurality of armature windings (22) and the constant force spring (110), and shields magnetic flux generated by the plurality of armature windings (22). The constant force spring (110) is formed by a band-like plate material, and presses the brush (40) against the commutator (30).

Description

Electric motor and electric blower

The present disclosure relates to electric motors and electric blowers.

Electric motors are widely used in the field of electrical equipment mounted on vehicles such as automobiles. For example, two-wheeled or four-wheeled vehicles use electric motors to drive cooling fans for cooling radiators and batteries.

As electric motors, brushed electric motors that use brushes and brushless electric motors that do not use brushes are known. Among them, the brushed motor consists of a stator, a rotor rotated by the magnetic force of the stator, a commutator attached to the rotating shaft of the rotor, brushes in sliding contact with the commutator, and brushes pushed against the commutator. and a spring for applying (see, for example, Patent Document 1). In such motors, the brushes wear and reduce in length as they operate. In the electric motor described in Patent Document 1, by using a constant load spring as a spring for pressing the brush against the commutator, the constant load spring pushes the brush against the commutator as the length of the brush decreases. It is trying to suppress the fluctuation of the force applied.

JP 2014-147171 A

The constant force spring described in Patent Document 1 is made of a strip-shaped wire rod. This strip-shaped wire is made of a non-magnetic material so as not to be affected by the magnetic flux generated by the armature winding. However, for example, even if the constant load spring is made of austenitic stainless steel, which is one of non-magnetic materials, it becomes magnetized due to processing stress when winding the strip-shaped wire rod. In particular, since the constant force spring has a belt-like shape, its surface area is large. Therefore, when the constant force spring is magnetized, the force received by the magnetic flux cannot be ignored. Therefore, the constant force spring is attracted toward the armature winding by the magnetic flux generated by the armature winding. As a result, the direction in which the constant force spring pushes the brush may vary, and the load may vary.

The present disclosure has been made to solve such problems, and aims to provide an electric motor and an electric blower equipped with the electric motor that can suppress the influence of the magnetic flux generated by the armature winding on the constant force spring. aim.

To achieve the above object, one aspect of the electric motor according to the present disclosure includes a rotor having a rotating shaft, a commutator attached to the rotor, brushes in contact with the commutator, and connections with the commutator. a plurality of armature windings, a constant force spring configured by a strip-shaped wire and pressing the brush against the commutator, and disposed between the plurality of armature windings and the constant force spring, and a soft magnetic member that shields magnetic flux generated by the plurality of armature windings.

In order to achieve the above object, one aspect of an electric blower according to the present disclosure includes the above electric motor and a fan attached to the rotating shaft.

According to the present disclosure, it is possible to realize an electric motor that can suppress the influence of the magnetic flux generated by the armature winding on the constant force spring, and an electric blower equipped with the electric motor.

FIG. 1 is an external perspective view of the electric motor according to the embodiment when viewed from below. FIG. 2 is an external perspective view of the electric motor according to the embodiment when viewed from above. FIG. 3 is a cross-sectional view of the electric motor according to the embodiment. FIG. 4 is a perspective view showing the internal structure of the brush holder in the electric motor according to the embodiment. FIG. 5 is a perspective view showing the configuration of the constant force spring according to the embodiment. FIG. 6 is an enlarged cross-sectional view of part of the electric motor according to the embodiment. FIG. 7 is a plan view showing a modification of the arrangement of the constant force spring 110 and the brush 40. As shown in FIG. FIG. 8 is a perspective view showing a fan attached to the electric motor according to the embodiment. FIG. 9 is a schematic diagram of an electric blower including a fan attached to an electric motor.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. It should be noted that each of the embodiments described below is a specific example of the present disclosure. Therefore, numerical values, shapes, materials, constituent elements, arrangement positions of constituent elements, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept of the present disclosure will be described as optional constituent elements.

It should be noted that each figure is a schematic diagram and is not necessarily strictly illustrated. Moreover, in each figure, the same code|symbol is attached|subjected to the substantially same structure, and the overlapping description is abbreviate|omitted or simplified. Also, in this specification, the terms "upper" and "lower" do not necessarily indicate upward (vertically upward) and downward (vertically downward) directions in absolute spatial recognition.

(Embodiment)
[1. overall structure]
First, the overall configuration of an electric motor 1 according to the embodiment will be described with reference to FIGS. 1 to 4. FIG. FIG. 1 is an external perspective view of an electric motor 1 according to the present embodiment when viewed from below. FIG. 2 is an external perspective view of the electric motor 1 viewed from above. FIG. 3 is a cross-sectional view of the electric motor 1. As shown in FIG. Specifically, FIG. 3 is a III-III cross-sectional view when the electric motor 1 shown in FIG. be. 4 is a perspective view showing the internal structure of the brush holder 50 in the electric motor 1. FIG. 3, only the portion appearing in the cross section of the electric motor 1 is illustrated. 4 shows a perspective view of the brush holder 50 from below with the cover plate 131 removed.

As shown in FIG. 3 , the electric motor 1 includes a stator 10 (stator) and a rotor 20 (rotor) rotated by the magnetic force of the stator 10 . The electric motor 1 according to the present embodiment is a brushed electric motor, and as shown in FIG. It has two brushes 40 in contact with 30 .

As shown in FIGS. 3 and 4 , the electric motor 1 further includes a brush holder 50 that holds the brushes 40 and a constant force spring 110 that presses the brushes 40 against the commutator 30 . The electric motor 1 also includes a bearing 91 , a first bracket 101 and a second bracket 102 .

The electric motor 1 according to the present embodiment is a type of direct-current electric motor (DC motor) driven by direct current, and uses a magnet 11 as a stator 10 and an armature winding 22 as a rotor 20 . child is used. In the present embodiment, the electric motor 1 is a flat type brushed coreless motor (flat motor) mounted on 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 as a whole is thin and light. In the present embodiment, the thickness of the electric motor 1 (that is, the dimension in the direction of the axis C of the rotating shaft 21) is smaller than the outer diameter (the dimension in the direction perpendicular to the direction of the axis C). Specifically, electric motor 1 according to the present embodiment is a small motor used as a cooling fan for a radiator in a vehicle, and the outer diameter (diameter) of electric motor 1 is 120 mm or less. As an example, the outer diameter of the electric motor 1 is 62 mm. The electric motor 1 is driven by an input voltage of DC 12V.

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

As shown in FIG. 3, the stator 10 is arranged with a minute air gap 12 between itself and the rotor 20 . The stator 10 generates magnetic force acting on the rotor 20 . The stator 10 is configured to generate magnetic flux on an air gap surface 12a with the rotor 20, and forms a magnetic circuit together with the rotor 20, which is an armature. Specifically, the stator 10 is generally donut-shaped as a whole, and N poles and S poles are alternately and evenly present on the air gap surface 12a with the rotor 20 along the circumferential direction of the rotating shaft 21. is configured as The stator 10 is a magnetic field that creates magnetic flux for generating torque, and in the present embodiment, is composed of a plurality of magnets 11 (magnets). Magnet 11 is, for example, a permanent magnet having an S pole and an N pole.

The plurality of magnets 11 that constitute the stator 10 are arranged so that N poles and S poles are alternately and evenly distributed over the circumferential direction. In the present embodiment, the direction of the main magnetic flux generated by stator 10 (magnet 11) is along the direction in which rotating shaft 21 extends. The direction of the main magnetic flux is generated in the direction corresponding to the magnetic poles of the magnet 11 . The stator 10 is fixed to the first bracket 101 .

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

The rotor 20 is arranged facing the stator 10 . In the present embodiment, rotor 20 faces stator 10 in the direction of axis C of rotating shaft 21 .

The rotating shaft 21 is a shaft having an axis C, and is a long rod-shaped member such as a metal rod. The axis C of the rotating shaft 21 is the center of rotation of the rotor 20 . The longitudinal direction of the rotating shaft 21, that is, the direction in which the rotating shaft 21 extends (stretching direction) is also referred to as the direction of the axis C (axis direction).

The rotating shaft 21 is supported by bearings 91 . As an example, the bearing 91 is a bearing such as a ball bearing.

In the present embodiment, the first end 21 a of the rotating shaft 21 is the output-side end (output shaft) and protrudes from the first bracket 101 and the bearing 91 . A load such as a fan is attached to the first end 21a. A second end 21 b of the rotary shaft 21 is an end (counter-output shaft) on the non-output side and protrudes from the second bracket 102 .

The bearing 91 is held by the first bracket 101 . Specifically, the bearing 91 is fixed to a recess provided in the first bracket 101 .

The first bracket 101 is a member that forms a housing together with the second bracket 102 . A stator 10 and a rotor 20 are arranged in a housing composed of a first bracket 101 and a second bracket 102 . In the present embodiment, the first bracket 101 is an outer shell member of the electric motor 1, and is formed in a bottomed tubular shape having a bottom portion and a cylindrical side wall portion. A magnet 11 forming the stator 10 is fixed to the bottom of the first bracket 101 . Also, the armature winding 22 of the rotor 20 is surrounded by the side wall portion of the first bracket 101 . The first bracket 101 is made of, for example, a metal material. For example, the first bracket 101 is made of iron-based material such as cold-rolled steel plate (SPC material) or metal such as aluminum. The material of the first bracket 101 is not limited to a metal material, and may be a resin material. I hope it is.

The second bracket 102 is a member that forms the housing together with the first bracket 101 . The second bracket 102 is made of a plate-like soft magnetic material. The second bracket 102 is an example of a soft magnetic member that is arranged between the multiple armature windings 22 and the constant force spring 110 and shields the magnetic flux generated by the multiple armature windings 22 . In the present embodiment, second bracket 102 is made of an iron plate. Note that the soft magnetic material forming the second bracket 102 is not limited to iron. For example, permalloy, silicon iron, etc. can be used as the soft magnetic material.

As shown in FIG. 3, the rotor 20 has a rotating shaft 21, a plurality of armature windings 22, and a mold resin 23 covering the plurality of armature windings 22.

Each of the plurality of armature windings 22 is composed of an electric wire, and is wound so as to generate magnetic force acting on the stator 10 when current flows. In this embodiment, 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 . That is, the magnets 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 .

Each armature winding 22 is composed of an insulating coated wire having a core wire made of metal such as copper or aluminum and an insulating film covering the core wire. In the present embodiment, each of the plurality of armature windings 22 is a thin winding coil having a coil layer in which conductive wires are wound in a plane. Specifically, each of the plurality of armature windings 22 is composed of, for example, one layer or a plurality of coil layers in which an insulated wire is wound in a generally fan shape in a plan view. A plurality of armature windings 22 configured in this way are arranged so as to surround the rotating shaft 21 when viewed from the direction of the axis C of the rotating shaft 21 .

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

The plurality of armature windings 22 are integrally molded together with the molding resin 23 by being covered with the molding resin 23 . The mold resin 23 is made of an insulating resin material such as phenol resin or unsaturated polyester (BMC).

As shown in FIG. 3, the commutator 30 is attached to the rotary shaft 21. Therefore, the commutator 30 rotates together with the rotating shaft 21 as the rotor 20 rotates. A commutator 30 attached to the rotating shaft 21 may be part of the rotor 20 .

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

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 plurality of commutator segments 31 are arranged insulated from each other, 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 .

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

As shown in FIG. 3, two brushes 40 are in contact with the commutator 30 . Specifically, each of the two brushes 40 is in contact with the commutator segment 31 of the commutator 30 . Since the commutator 30 rotates as the rotating shaft 21 rotates, the brush 40 keeps contacting all the commutator segments 31 sequentially. The number of brushes 40 is not limited to two, and may be four, for example.

As shown in FIG. 4, the two brushes 40 are arranged in a brush holder 50. Specifically, each of the two brushes 40 is arranged in the brush holder 50 such that its longitudinal direction is perpendicular to the axis C of the rotating shaft 21 (that is, the radial direction of rotation of the rotating shaft 21). there is

In the present embodiment, the angle formed by the longitudinal directions of the two brushes 40 is 180°. The angle formed by the longitudinal directions of the two brushes 40 may be less than 180°.

Each of the brushes 40 is a power supply brush (energization brush) that supplies power to the armature winding 22 by coming into contact with the commutator segment 31 . The brush 40 includes a first end 41 in contact with the commutator 30 and a second end 42 opposite the first end 41 . The brush 40 is a conductor having conductivity. As an example, the brush 40 is a long, substantially rectangular parallelepiped carbon brush made of carbon. In this embodiment, the brush 40 is preferably a carbon brush containing metal such as copper. Thereby, the contact resistance between the brushes 40 and the commutator segments 31 can be reduced. Such a brush 40 can be produced, for example, by pulverizing a kneaded product obtained by kneading graphite powder, copper powder, a binder resin, and a curing agent, compressing and molding the product into a rectangular parallelepiped, and firing the product.

As shown in FIGS. 3 and 4, the brush holder 50 is provided with the same number of constant force springs 110 as the number of brushes 40 . In this embodiment, two constant force springs 110 are arranged. The brush 40 is attached so as to always be in contact with the commutator segments 31 of the commutator 30 under the pressure of the constant force spring 110 . That is, the brush 40 is pressed against the commutator 30 by the constant force spring 110 .

As shown in FIG. 3 , the constant load spring 110 applies pressure (spring pressure) to the brush 40 by spring elastic force (spring restoring force) to urge the brush 40 toward the commutator 30 . The configuration of the constant force spring 110 will be described with reference to FIG. 5 as well. FIG. 5 is a perspective view showing the configuration of the constant force spring 110 according to this embodiment. As shown in FIG. 5, in the present embodiment, the constant force spring 110 is a spring that is made of a strip-shaped wire and presses the brush 40 against the commutator 30 . In other words, the constant force spring 110 is made of an elongated thin plate. The constant force spring 110 is positioned between the spiral portion 111 at one end, which is wound with a strip-shaped wire rod, and the fixed portion 112, which is located at the other end, between the spiral portion 111 and the fixed portion 112. , and a planar portion 113 in which the strip-shaped wire rod has a planar shape. As shown in FIG. 4, the spiral portion 111 contacts the second end 42 of the brush 40 . The fixed part 112 is fixed to the hooked part 60 of the brush holder 50 . In the present embodiment, the fixing portion 112 is fixed to the brush holder 50 by hooking the hook-shaped portion 60 on the opening 117 (see FIG. 5) formed in the fixing portion 112 .

A hook-shaped portion 60 to which the fixed portion 112 of the constant force spring 110 is hooked is arranged near the first end portion 41 of the brush 40 . As a result, the spiral portion 111 of the constant force spring 110 pushes the second end portion 42 of the brush 40 in a direction to approach the vicinity of the first end portion 41 of the brush 40 where the fixing portion 112 is arranged. Therefore, the pressing force of the constant force spring 110 keeps the first end 41 of the brush 40 in constant contact with the commutator segments 31 . Since the brushes 40 continue to be in contact with the commutator segments 31 in this manner, the brushes 40 wear due to friction as the commutator segments 31 rotate. Therefore, it moves in the direction (radial direction) toward the axis C of the rotating shaft 21 due to the pressing force from the constant load spring 110 . A metal material, for example, can be used as a material forming the constant force spring 110 . In this embodiment, constant force spring 110 is made of austenitic stainless steel, which is a non-magnetic material.

Electric power is supplied to the brushes 40 from an external power supply arranged outside the electric motor 1 . The external power supply is a power supply that exists outside the electric motor 1 and supplies the electric motor 1 with a predetermined input voltage. In the present embodiment, the external power supply is a DC power supply that supplies the electric motor 1 with an input voltage of DC 12V. Note that the DC power supply is not particularly limited as long as it outputs DC power, and examples thereof include a generator, a converter, and a battery.

In the electric motor 1 configured as described above, the current supplied to each of the two brushes 40 flows through the armature winding 22 via the commutator segment 31 of the commutator 30 as an armature current (driving current). As a result, magnetic flux is generated in the rotor 20 (armature winding 22). The magnetic force generated by the interaction between the magnetic flux generated in the rotor 20 and the magnetic flux generated from the stator 10 becomes the torque that rotates the rotor 20 . At this time, the direction in which the current flows is switched depending on the positional relationship when the commutator segments 31 of the commutator 30 and the two brushes 40 are in contact with each other. In this way, by switching the direction of current flow, the repulsive force and the attractive force of the magnetic force generated between the stator 10 and the rotor 20 generate a rotational force in a fixed direction, causing the rotor 20 to rotate. It rotates about axis 21 .

The brush holder 50 is a holding member that holds two brushes 40 . The brush holder 50 is made of, for example, an insulating resin material. In the present embodiment, the brush holder 50 is a resin molded product formed by integral molding using a resin material. As shown in FIG. 3, in the present embodiment, the brush holder 50 is an outer shell member forming the outer shell of the electric motor 1 and covers the second bracket 102 from the outside.

The brush holder 50 has a holder main body 50a and a hook-shaped portion 60. The holder main body 50a is a portion where the brushes of the brush holder 50 are arranged. In other words, the holder main body 50a is a portion of the brush holder 50 other than the hook-shaped portion 60. As shown in FIG. As shown in FIG. 4, the holder body 50a of the brush holder 50 has two brush storage portions 51. As shown in FIG. A brush 40 is housed in each of the two brush housing portions 51 . The brush housing portion 51 is formed in a concave shape on the inner surface side of the brush holder 50 . In this embodiment, the brush housing portion 51 has a concave shape, but may have a box-like shape in which the brush housing portion 51 and the cover plate 131 are integrated. The hook-shaped portion 60 is a portion that protrudes from the holder main body 50a along the rotating shaft 21 and is used to fix the constant force spring 110. As shown in FIG.

In the present embodiment, the brush housing portion 51 is elongated in a direction perpendicular to the axis C of the rotating shaft 21 (that is, in the radial direction of rotation of the rotating shaft 21) and has a concave cross-sectional shape. .

As shown in FIG. 4 , each of the two brush housings 51 housing the brushes 40 is covered with a cover plate 131 . The two cover plates 131 are made of brass plates, for example, and are arranged so as to cover the brush housing portion 51 respectively.

In addition, as shown in FIG. 4, the constant force spring 110 is housed in the brush housing portion 51 together with the brush 40 .

[2. effect]
Next, the effects of electric motor 1 according to the present embodiment will be described with reference to FIG. FIG. 6 is an enlarged cross-sectional view of part of the electric motor 1 according to this embodiment. In FIG. 6, the constant force spring 110, the armature winding 22, and their surroundings are shown in an enlarged manner in the cross section of the electric motor 1. As shown in FIG.

The armature winding 22 generates magnetic flux in the direction indicated by the block arrows in FIG. Further, as described above, the constant force spring 110 is made of austenitic stainless steel, which is a non-magnetic material. However, when the spiral portion 111 of the constant load spring 110 is formed from the strip-shaped wire rod made of austenitic stainless steel, the constant load spring 110 becomes magnetized due to processing stress. Therefore, if a member that shields magnetic flux is not interposed between the constant force spring 110 and the armature winding 22, the magnetic flux generated by the armature winding 22 causes the constant force spring 110 to become armature winding. A force is received in a direction approaching the line 22 (that is, the direction indicated by the dashed arrow in FIG. 6). That is, the constant force spring 110 is attracted to the armature winding 22 . In this case, the direction in which the constant force spring 110 pushes the brush 40 may vary, or the load may vary.

In this embodiment, since the second bracket 102 made of a soft magnetic material is arranged between the constant force spring 110 and the armature winding 22, the magnetic flux generated by the armature winding 22 is 2 bracket 102 shields. Therefore, the magnetic flux generated by the armature winding 22 and reaching the constant force spring 110 can be reduced. Thereby, the influence of the magnetic flux generated by the armature winding 22 on the constant force spring can be suppressed. In other words, it is possible to suppress fluctuations in the direction in which the constant force spring 110 pushes the brush 40 and fluctuations in the load.

Further, in the present embodiment, as shown in FIG. 6, the fixed portion 112 and the flat portion 113 of the constant force spring 110 are arranged on the opposite side of the brush 40 to the side on which the plurality of armature windings 22 are arranged. , are placed. In other words, in FIG. 6, the plurality of armature windings 22 are arranged below the brushes 40, whereas the fixed portion 112 and the flat portion 113 of the constant force spring 110 are arranged above. be done. The closer the plane portion 113 of the constant force spring 110 is to the armature windings 22 , the greater the force that the plane portion 113 receives from the magnetic flux generated by the armature windings 22 . Therefore, compared to the case where the flat portion 113 of the constant force spring 110 is arranged between the brush 40 and the plurality of armature windings 22 (that is, below the brush 40 in FIG. 6), Arranging on the side opposite to the side on which the plurality of armature windings 22 are arranged can reduce the force that the plane portion 113 receives from the magnetic flux generated by the plurality of armature windings 22 . Therefore, the influence of the magnetic flux generated by the armature winding 22 on the constant force spring 110 can be further suppressed.

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

For example, in the electric motor 1 according to the above embodiment, the second bracket 102 is a soft magnetic member. It may be a magnetic member. For example, the cover plate 131 may be a soft magnetic member.

Also, the flat portion 113 of the constant force spring 110 is arranged on the side opposite to the side where the plurality of armature windings 22 are arranged with respect to the brush 40, but the arrangement of the flat portion 113 is not limited to this. For example, the planar portion 113 may be arranged in the circumferential direction around the axial center C direction of the rotating shaft 21 with respect to the brush 40 as shown in FIG. 7 . In addition, the arrow in FIG. 7 indicates the circumferential direction centering on the axial center C direction of the rotating shaft 21 . 7 is a plan view showing a modification of the arrangement of the constant force spring 110 and the brush 40. FIG. Such an arrangement can also prevent the planar portion 113 of the constant force spring 110 from being attracted by the magnetic flux generated by the armature winding 22 .

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

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

Here, an example of applying the electric motor 1 according to the above embodiment to an electric blower will be described with reference to FIG. FIG. 8 is a perspective view showing fan 190 attached to electric motor 1 according to the above embodiment. FIG. 9 is a schematic diagram of an electric blower 600 including a fan 190 attached to the electric motor 1. FIG. Electric blower 600 can be realized by attaching fan 190 as shown in FIG. 8 to rotating shaft 21 of electric motor 1 according to the above embodiment. In other words, the electric blower according to the present disclosure includes the electric motor 1 of the above embodiment and the fan 190 attached to the rotation shaft 21 of the electric motor 1 . Note that the fan 190 shown in FIG. 8 is merely an example, and a fan or the like having another shape and structure may be attached to the electric motor 1 according to the above embodiment. Since such an electric blower includes the electric motor 1 according to the above embodiment, it has the same effects as the electric motor 1 according to the above embodiment.

In addition, it is realized by arbitrarily combining the constituent elements and functions of the embodiments and modifications without departing from the spirit of the present disclosure, as well as the forms obtained by applying various modifications that a person skilled in the art can think of to the above embodiments. Any form is also included in the present disclosure.

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

Reference Signs List 1 electric motor 10 stator 11 magnet 12 air gap 12a air gap surface 20 rotor 21 rotating shaft 21a first end 21b second end 22 armature winding 23, 32 mold resin 30 commutator 31 commutator piece 40 brush 41 First end 42 Second end 50 Brush holder 50a Holder main body 51 Brush storage part 60 Hook-shaped part 91 Bearing 101 First bracket 102 Second bracket 110 Constant force spring 111 Spiral part 112 Fixed part 113 Flat part 117 Opening 131 Cover Plate 190 Fan 600 Electric blower

Claims (6)

a rotor having a rotating shaft;
a commutator attached to the rotor;
a brush in contact with the commutator;
a plurality of armature windings connected to the commutator;
a constant force spring configured by a strip-shaped plate material and pressing the brush against the commutator;
A soft magnetic member disposed between the plurality of armature windings and the constant force spring and shielding magnetic flux generated by the plurality of armature windings,
Electric motor. The constant force spring has a spiral portion on which the plate-shaped wire rod is wound, positioned at one end, a fixed portion positioned at the other end, and positioned between the spiral portion and the fixed portion. , and a planar portion in which the strip-shaped plate material has a planar shape,
The planar portion is arranged in a position opposite to the plurality of armature windings when viewed from the brush, or in a circumferential direction centered on the axial direction of the rotating shaft with respect to the brush,
The electric motor according to claim 1. The soft magnetic member is composed of an iron plate,
The electric motor according to claim 1 or 2. Further comprising a mold resin covering the plurality of armature windings,
The electric motor according to any one of claims 1 to 3. The thickness of the electric motor is smaller than the outer diameter of the electric motor,
The electric motor according to any one of claims 1 to 4. The electric motor according to any one of claims 1 to 5;
a fan attached to the rotating shaft;
electric blower.

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