WO2023135955A1

WO2023135955A1 - Electric motor and electrical device

Info

Publication number: WO2023135955A1
Application number: PCT/JP2022/043681
Authority: WO
Inventors: 圭策中野; 和雄遠矢
Original assignee: パナソニックＩｐマネジメント株式会社
Priority date: 2022-01-17
Filing date: 2022-11-28
Publication date: 2023-07-20

Abstract

The present invention achieves both the life extension of and the size reduction of an electric motor using an auxiliary brush. An electric motor (1) comprises a rotor (20) having a shaft (21) and a plurality of coils (22), a commutator (30) attached to the shaft (21), an energization brush (40), and an auxiliary brush (50). The plurality of coils (22) are electrically connected to the commutator (30). The commutator (30) has a plurality of commutator segments (31) including a first commutator segment and a second commutator segment along the circumferential direction of the shaft (21). The first commutator segment is adjacent to a commutator segment (31) making contact with the energization brush (40) and located in front of the commutator segment (31) in the rotation direction of the rotor (20). The second commutator segment is electrically connected to the first commutator segment via at least one of the plurality of coils (22). The auxiliary brush (50) makes contact with the second commutator segment.

Description

Electric motors and electrical equipment

The present disclosure relates to electric motors and electrical equipment.

Electric motors are used in various products such as electric blowers mounted on vacuum cleaners. As electric motors, a commutator motor (commutator motor) using brushes and a commutator and a brushless electric motor using neither brushes nor a commutator are known.

A commutator motor, for example, includes a stator, a rotor rotated by the magnetic force of the stator, a commutator attached to a rotating shaft (shaft) of the rotor, and energized brushes in sliding contact with the commutator. The commutator has a plurality of commutator segments provided along the circumferential direction of the rotation axis of the rotor. A plurality of coils wound around a rotor core are electrically connected to each of the plurality of commutator segments.

In a commutator motor, each of a plurality of coils of a rotor is energized by an energizing brush and a commutator. In this case, sparks may occur between the current-carrying brushes and the commutator segments when the energized coils are switched by the rotation of the commutator. The generation of such sparks accelerates wear of the current-carrying brushes, shortening the life of the motor.

Therefore, conventionally, in order to suppress the spark and extend the life of the current-carrying brush, there has been proposed a technique of providing an auxiliary brush to which an electronic component that absorbs the arc voltage caused by the spark is connected (for example, Patent Documents 1 to 3). ).

JP 2013-179807 A Japanese Unexamined Patent Application Publication No. 2011-4582 Japanese Patent No. 6512981

However, in the technique disclosed in Patent Document 1, since the auxiliary brush and the current-carrying brush are positioned at a short distance, brush abrasion powder accumulates between the current-carrying brush and the auxiliary brush, generating an abnormal spark. There is a risk that the current-carrying brushes will wear out, or that brush abrasion dust will adhere to the current-carrying brushes, hindering the movement of the current-carrying brushes and causing energization failure. As a result, extension of the life of the electric motor is hindered.

Further, in the technique disclosed in Patent Document 2, the current-carrying brush and the auxiliary brush are integrally configured. Poor contact may occur without contacting the child segment. As a result, extension of the life of the electric motor is hindered.

In addition, in the technique disclosed in Patent Document 3, the auxiliary brushes and the current-carrying brushes are arranged to be shifted in the axial direction of the shaft, so the commutator segment becomes longer in the axial direction of the shaft. For this reason, miniaturization of the electric motor is hindered.

As described above, conventional commutator motors using auxiliary brushes have the problem that it is difficult to achieve both long life and miniaturization.

The present disclosure has been made to solve such problems, and an electric motor and an electric device having the same that can achieve both a long life and a small size even when an auxiliary brush is used. intended to provide

In order to achieve the above object, one aspect of the electric motor according to the present disclosure includes a rotor having a rotating shaft and a plurality of coils, a commutator attached to the rotating shaft, current-carrying brushes in contact with the commutator, and the and an auxiliary brush in contact with the commutator. The plurality of coils are electrically connected to the commutator. The commutator has a plurality of commutator segments provided along the circumferential direction of the rotating shaft. The plurality of commutator segments has a first commutator segment and a second commutator segment. The first commutator segment is adjacent to the commutator segment in contact with the current-carrying brush and positioned ahead of the commutator segment in the rotational direction of the rotor. The second commutator segment is electrically connected to the first commutator segment via at least one of the plurality of coils. The auxiliary brush is arranged in contact with the second commutator segment.

Also, one aspect of the electrical equipment according to the present disclosure is an electrical equipment using the electric motor described above.

According to the present disclosure, even when the auxiliary brush is used, both long life and miniaturization can be achieved.

FIG. 1 is a cross-sectional view of an electric motor according to an embodiment. FIG. 2 is a diagram schematically showing a commutator, current-carrying brushes, auxiliary brushes, etc. in the motor of FIG. FIG. 3A is a diagram for explaining how the current-carrying brushes and the commutator segments are in sliding contact with each other due to the rotation of the commutator in the motor of FIG. It is a diagram. 3B is a diagram for explaining how the current-carrying brushes and the commutator segments are in sliding contact with each other due to the rotation of the commutator in the electric motor of FIG. FIG. 10 is a diagram showing a state in which only the commutator segments located at are in contact; FIG. 4 is a diagram schematically showing connection relationships among a plurality of coils, a commutator, current-carrying brushes, auxiliary brushes, etc. in the electric motor of FIG. FIG. 5 is another diagram schematically showing connection relationships among a plurality of coils, a commutator, current-carrying brushes, auxiliary brushes, etc. in the electric motor of FIG. FIG. 6 is a graph showing measurement results of voltages between current-carrying brushes and auxiliary brushes in the electric motor according to the comparative example. FIG. 7 is a graph showing measurement results of voltages between current-carrying brushes and auxiliary brushes in the motor of FIG. FIG. 8 is a graph showing measurement results of currents between current-carrying brushes and auxiliary brushes in the motor of FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In addition, the embodiment described below shows a specific example of the present disclosure. Therefore, numerical values, shapes, materials, components, arrangement positions of components, connection forms, and the like shown in the following embodiments are examples and are not intended to limit the present disclosure. Therefore, among constituent elements in the following embodiments, constituent elements not described in independent claims 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.

(Embodiment)
First, the overall configuration of the electric motor 1 according to the embodiment will be described with reference to FIGS. 1 to 3B. FIG. 1 is a cross-sectional view of electric motor 1 according to the embodiment. FIG. 2 is a diagram schematically showing the commutator 30, the current-carrying brushes 40, the auxiliary brushes 50, etc. in the electric motor 1 of FIG. FIG. 3A and FIG. 3B are diagrams for explaining how the commutator segment 31 slides with the current-carrying brush 40 due to the rotation of the commutator 30 in the electric motor 1 of FIG. FIG. 3A is a diagram showing a state in which one current-carrying brush 40 is in contact with both of two commutator segments 31. FIG. FIG. 3B is a diagram showing a state in which the current-carrying brush 40 is in contact with only the commutator segment 31 located rearward in the rotational direction among the two adjacent commutator segments 31 .

As shown in FIGS. 1 and 2, the electric motor 1 is a commutator motor including a stator 10, a rotor 20 rotated by the magnetic force of the stator 10, a commutator 30 attached to a shaft 21 of the rotor 20, and a commutator. It is provided with current-carrying brushes 40 in contact with the child 30 , auxiliary brushes 50 in contact with the commutator 30 , and a frame 60 housing the stator 10 and the rotor 20 .

Electric motor 1 in the present embodiment is a direct-current electric motor (DC motor) driven by direct current, and magnet 11 is used as stator 10, and an armature having a plurality of coils 22 is used as rotor 20. .

It should be noted that the electric motor 1 according to the present embodiment can be used in various electric devices. For example, the electric motor 1 can be used as an electric blower mounted on a vacuum cleaner, an air towel, or the like. The electric motor 1 can also be used for electrical equipment mounted on an automobile, an electric tool, or the like. Each component of the electric motor 1 will be described in detail below.

The stator 10 (stator) generates magnetic force acting on the rotor 20 . The stator 10 is configured such that N poles and S poles alternately exist on the air gap surface with the rotor 20 along the circumferential direction. In the present embodiment, stator 10 is composed of a plurality of magnets 11 (magnets). Magnet 11 is a magnetic field that creates magnetic flux for generating torque, and is, for example, a permanent magnet having an S pole and an N pole. Each of the plurality of magnets 11 has an arc shape with a substantially constant thickness when viewed from above. A plurality of magnets 11 are fixed to the frame 60 .

A plurality of magnets 11 constituting the stator 10 are arranged so that N poles and S poles are alternately and evenly distributed along the circumferential direction. Therefore, the direction of the main magnetic flux generated by the stator 10 (magnet 11 ) is a direction intersecting with the direction of the axis C of the shaft 21 . In the present embodiment, the plurality of magnets 11 are arranged at equal intervals along the circumferential direction so as to surround the rotor 20 and are positioned on the radially outer peripheral side of the rotor core 23 of the rotor 20 . Specifically, a plurality of magnets 11 magnetized with N poles and S poles are arranged so that the magnetic pole centers of the N poles and the magnetic pole centers of the S poles are equidistantly spaced along the circumferential direction.

The rotor 20 (rotor) generates magnetic force acting on the stator 10 . In the present embodiment, the direction of the main magnetic flux generated by the rotor 20 is a direction intersecting with the direction of the axis C of the shaft 21 . The rotor 20 has a shaft 21 that is a rotating shaft. Also, the rotor 20 is an armature and has a plurality of coils 22 , a rotor core 23 and a plurality of insulators 24 . In the present embodiment, rotor 20 is an inner rotor and is arranged inside stator 10 . Specifically, rotor 20 is surrounded by a plurality of magnets 11 forming stator 10 . Further, the rotor 20 is arranged with the stator 10 through an air gap. Specifically, a minute air gap exists between the outer peripheral surface of the rotor 20 (rotor core 23 ) and the inner surface of each magnet 11 .

The shaft 21 is a rotating shaft having an axis C, and is an elongated rod-shaped member that serves as the center when the rotor 20 rotates. The longitudinal direction (stretching direction) of the shaft 21 is the direction of the axis C (axial direction). The shaft 21 is rotatably held by bearings such as bearings. Although details are not shown, for example, one end of the shaft 21, that is, the first end 21a, is held by a bracket fixed to the frame 60, or is held directly on the frame 60 by a first bearing. , and the other end of the shaft 21, the second end 21b, is supported by a second bearing held by a bracket fixed to the frame 60 or directly held by the frame 60. The bracket is fixed to the frame 60 so as to cover the opening of the frame 60, for example.

The shaft 21 is fixed at the center of the rotor 20. Shaft 21 is, for example, a metal rod, and is fixed to rotor core 23 while penetrating rotor core 23 . For example, the shaft 21 is fixed to the rotor core 23 by being press-fitted into the center hole of the rotor core 23 or by shrink fitting.

A plurality of coils 22 (rotor coils) are wound so as to generate a magnetic force acting on the stator 10 when current flows. Each of the plurality of coils 22 is wound around rotor core 23 via insulator 24 . The insulator 24 is made of an insulating resin material or the like, and electrically insulates the coil 22 and the rotor core 23 from each other. A plurality of coils 22 are provided for each slot of the rotor 20 and electrically connected to the commutator 30 . Specifically, the multiple coils 22 are electrically connected to the commutator segments 31 of the commutator 30 . As will be described later, for example, the rotor core 23 has a plurality of teeth arranged in the circumferential direction of the shaft 21, and the plurality of coils 22 correspond to the plurality of teeth on a one-to-one basis. Each of the plurality of coils 22 is wound around a corresponding one of the plurality of teeth.

The rotor core 23 is a laminate in which a plurality of electromagnetic steel sheets are laminated in the longitudinal direction of the shaft 21 . Rotor core 23 has, for example, a plurality of teeth. As described above, the coil 22 is wound around each of the teeth. The rotor core 23 is not limited to a laminate of electromagnetic steel sheets, and may be a bulk body made of a magnetic material.

The commutator 30 is attached to the shaft 21. Therefore, the commutator 30 rotates together with the shaft 21 as the rotor 20 rotates. In this embodiment, the commutator 30 is attached to the first end 21 a of the shaft 21 .

The commutator 30 has a plurality of commutator segments 31 and mold resin 32 . A plurality of commutator segments 31 are provided along the circumferential direction of the shaft 21 . Specifically, the plurality of commutator segments 31 are arranged in an annular shape at equal intervals so as to surround the shaft 21 . In this embodiment, the commutator 30 has 17 commutator segments 31 .

Each of the plurality of commutator segments 31 is a commutator piece extending in the longitudinal direction of the shaft 21 . Each of the multiple commutator segments 31 is a conductive terminal made of, for example, a metal material such as copper, and is electrically connected to the multiple coils 22 of the rotor 20 . As an example, the commutator 30 is a molded commutator, and has a configuration in which a plurality of commutator segments 31 are resin-molded. In this case, the multiple commutator segments 31 are embedded in the mold resin 32 so that their surfaces are exposed.

Also, the plurality of commutator segments 31 are insulated and separated from each other, but the plurality of commutator segments 31 are electrically connected to each other. Although details will be described later, the plurality of commutator segments 31 are electrically connected to each other via the plurality of coils 22 .

A conductive brush 40 and an auxiliary brush 50 are in contact with the commutator 30 . Specifically, each of the current-carrying brush 40 and the auxiliary brush 50 is in sliding contact with the commutator segment 31 of the commutator 30 . Although not shown, each of the current-carrying brush 40 and the auxiliary brush 50 is held by a corresponding brush holder. For example, each of the current-carrying brush 40 and the auxiliary brush 50 is housed in a brush holder. In this case, each of the current-carrying brush 40 and the auxiliary brush 50 slides inside the brush holder. Although not shown, electric motor 1 is provided with brush springs such as coil springs or torsion springs for pressing each of current-carrying brushes 40 and auxiliary brushes 50 against commutator 30 . Each brush spring applies a pressing force to the corresponding energizing brush 40 or auxiliary brush 50 using spring elasticity. Each of the current-carrying brushes 40 and the auxiliary brushes 50 is in a state where the surfaces of the tip portions are always in contact with the commutator segments 31 of the commutator 30 under pressure from the corresponding brush springs. The surface where each of the current-carrying brush 40 and the auxiliary brush 50 rubs against the commutator segment 31 serves as a sliding surface. Although one brush spring is provided for each of the current-carrying brush 40 and the auxiliary brush 50, the present invention is not limited to this.

Each of the current-carrying brush 40 and the auxiliary brush 50 is a conductive body. As an example, each of the current-carrying brush 40 and the auxiliary brush 50 is a long, substantially rectangular parallelepiped carbon brush made of carbon. Specifically, each of current-carrying brush 40 and auxiliary brush 50 is a carbon brush containing metal such as copper. For example, each of the current-carrying brush 40 and the auxiliary brush 50 can be produced by pulverizing a kneaded material obtained by kneading graphite powder, copper powder, binder resin, and a curing agent, and compressing and molding it into a rectangular parallelepiped, followed by firing. can.

The current-carrying brushes 40 are power-supplying brushes that supply power to the rotor 20 by coming into contact with the commutator 30 . Specifically, the tip portion of the current-carrying brush 40 contacts the commutator segment 31 of the commutator 30 . Therefore, the current-carrying brush 40 is connected to an electric wire through which a current supplied from a power source 70 (see FIG. 4) flows. FIG. 4 is a diagram schematically showing connection relationships among the plurality of coils 22, the commutator 30, the current-carrying brushes 40, the auxiliary brushes 50, etc. in the electric motor 1 of FIG. For example, the current-carrying brush 40 is electrically connected to an electrode terminal that receives power from the power supply 70 via an electric wire such as a pigtail wire. Specifically, the other end of the pigtail wire having one end connected to the electrode terminal is connected to the rear end of the current-carrying brush 40 , and the current-carrying brush 40 contacts the commutator segment 31 . , the armature current supplied to the current-carrying brushes 40 through the pigtail wires flows through the coils 22 of the rotor 20 through the commutator segments 31 .

The current-carrying brush 40 is configured so that there is a contact state across two adjacent commutator segments 31 . That is, the length of the width of the current-carrying brush 40 in the rotation direction of the rotor 20 is greater than the length of the interval between two adjacent commutator segments 31 . This allows the current-carrying brush 40 to short-circuit the coil 22 connected between the two commutator segments 31 .

For example, as shown in FIG. 2, the 17 commutator segments 31 are numbered 1 to 17 in order along the circumferential direction of the shaft 21, and the commutator segments 31 to 17 are numbered 17. Assume that shaft 21 rotates in a direction towards segment 31 . In this case, for example, as shown in FIG. The rotation advances the rotation of the commutator 30 . Then, as shown in FIG. 3B, the current-carrying brush 40 (the first current-carrying brush 41) is cut off from the 17th commutator segment 31 and positioned behind the two adjacent commutator segments 31 in the rotational direction. Only the first commutator segment 31 is contacted. As a result, one or more coils 22 connected to the wiring path between the 17th commutator segment 31 and the 1st commutator segment 31 can be short-circuited.

As shown in FIGS. 1 and 2, in this embodiment, a plurality of conductive brushes 40 are provided. Each of the plurality of current-carrying brushes 40 is in contact with the commutator 30 . Specifically, the plurality of conductive brushes 40 includes a first conductive brush 41 and a second conductive brush 42 as a pair of conductive brushes 40 . The first current-carrying brush 41 and the second current-carrying brush 42 are arranged to face each other so as to sandwich the commutator 30 . That is, the first conductive brush 41 and the second conductive brush 42 are arranged line-symmetrically about the axis C of the shaft 21 . Each of the first conductive brush 41 and the second conductive brush 42 is in contact with the commutator segment 31 of the commutator 30 in a direction perpendicular to the axis C of the shaft 21 (radial direction). The first conductive brush 41 and the second conductive brush 42 are connected to a power source 70 (see FIG. 4). In this embodiment, power supply 70 is a DC power supply. As an example, the first conducting brush 41 is an anode-side brush, and the second conducting brush 42 is a cathode-side brush.

The auxiliary brush 50 is a spark suppressing brush for suppressing sparks generated when the current-carrying brush 40 and the commutator segment 31 are separated. The electric current supplied from the power supply 70 does not directly flow through the auxiliary brush 50 , and a part of the electric current supplied from the power supply 70 flows through the current-carrying brush 40 and the commutator segment 31 .

In this embodiment, a plurality of auxiliary brushes 50 are provided. Each of the multiple auxiliary brushes 50 is in contact with the commutator 30 . Specifically, the plurality of auxiliary brushes 50 includes a first auxiliary brush 51 and a second auxiliary brush 52 as a pair of auxiliary brushes 50 . Each of the first auxiliary brush 51 and the second auxiliary brush 52 is in contact with the commutator 30 .

In this embodiment, the electric motor 1 includes a plurality of spark absorbers 80. Specifically, the plurality of spark absorbers 80 includes first spark absorbers 81 and second spark absorbers 82 . The current-carrying brush 40 and the auxiliary brush 50 are electrically connected via the spark absorber 80 . The spark absorber 80 is a member for absorbing sparks generated when the current-carrying brush 40 and the commutator segment 31 are separated. For example, the spark absorber 80 can be a Zener diode, or a capacitor. In this embodiment, spark absorber 80 is a Zener diode.

Specifically, the first auxiliary brush 51 is electrically connected to the first conducting brush 41 via the first spark absorber 81 . That is, the first spark absorber 81 is inserted in the wiring path between the first auxiliary brush 51 and the first conductive brush 41 . Specifically, one terminal of the first spark absorber 81 is connected to the first auxiliary brush 51 , and the other terminal of the first spark absorber 81 is connected to the first conductive brush 41 . . Each of the first auxiliary brush 51 and the first conductive brush 41 and the first spark absorber 81 are connected by wiring such as a conductive wire, for example.

The second auxiliary brush 52 is electrically connected to the second conductive brush 42 via the second spark absorber 82 . That is, the second spark absorber 82 is inserted in the wiring path between the second auxiliary brush 52 and the second conductive brush 42 . Specifically, one terminal of the second spark absorber 82 is connected to the second auxiliary brush 52 , and the other terminal of the second spark absorber 82 is connected to the second conductive brush 42 . . Each of the second auxiliary brush 52 and the second conductive brush 42 and the second spark absorber 82 are connected by wiring such as a conductive wire, for example.

Although the details will be described later, the auxiliary brushes 50 are adjacent to the commutator segment 31 in contact with the current-carrying brushes 40 among the plurality of commutator segments 31 and positioned in front of the commutator segment 31 in the rotational direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected to one commutator segment through at least one of the plurality of coils 22 . Specifically, the first auxiliary brush 51 is adjacent to the commutator segment 31 that is in contact with the first current-carrying brush 41 among the plurality of commutator segments 31 and is located in front of this commutator segment 31 in the rotational direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected via at least one of the plurality of coils 22 to the first commutator segment located thereon. The second auxiliary brush 52 is adjacent to the commutator segment 31 in contact with the second current-carrying brush 42 among the plurality of commutator segments 31 and positioned in front of this commutator segment 31 in the rotational direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected to one commutator segment through at least one of the plurality of coils 22 .

The frame 60 is a housing (case) that houses the parts that make up the electric motor 1 such as the stator 10 and the rotor 20 . Frame 60 has, for example, a cylindrical portion. Frame 60 is made of, for example, a metal material such as aluminum. Stator 10 (magnet 11 ) is attached to frame 60 along the inner peripheral surface of frame 60 . Note that the frame 60 may have a cylindrical shape with a bottom.

Next, the electrical connections between the commutator segments 31 and the commutator segments 31 with which the auxiliary brushes 50 are in contact will be described with reference to FIGS. 4 and 5. FIG. FIG. 4 is a diagram schematically showing connection relationships among the plurality of coils 22, the commutator 30, the current-carrying brushes 40, the auxiliary brushes 50, etc. in the electric motor 1 of FIG. FIG. 5 is another diagram schematically showing connection relationships among the plurality of coils 22, the commutator 30, the current-carrying brushes 40, the auxiliary brushes 50, etc. in the electric motor 1 of FIG.

As shown in FIGS. 4 and 5, each of the multiple coils 22 is connected to two commutator segments 31 out of the multiple commutator segments 31 . For example, regarding the coil 22a connected to the commutator segment 31 of the number 17 and the commutator segment 31 of the number 6 among the plurality of coils 22, one end of the coil 22a is connected to the commutator segment 31 of the number 17. The other end of the coil 22 a is connected to the No. 6 commutator segment 31 . Further, for example, regarding the coil 22b connected to the 11th commutator segment 31 and the 17th commutator segment 31 among the plurality of coils 22, one end of the coil 22b is connected to the 11th commutator segment. 31, and the other end of this coil 22b is connected to the 17th commutator segment 31. For example, coil 22a and coil 22b may be formed by one winding. In this case, for example, one end of coil 22a is connected to commutator segment 31 of number 17 by hooking the winding on commutator segment 31 of number 17, and the other end of coil 22b is connected to commutator segment 31 of number 17. may be connected to commutator segment 31 numbered 17 . The same applies to other coils 22 as well.

As described above, the auxiliary brush 50 is the first commutator segment 31 adjacent to the commutator segment 31 in contact with the current-carrying brush 40 among the plurality of commutator segments 31 and located in front of this commutator segment 31 in the rotation direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected to the commutator segment via at least one of the plurality of coils 22 . That is, the auxiliary brush 50 is the second commutator electrically connected to the commutator segment 31 immediately after the current-carrying brush 40 is separated from the plurality of commutator segments 31 via at least one of the plurality of coils 22 . It is arranged so as to touch the segment.

Specifically, the first auxiliary brush 51 is adjacent to the commutator segment 31 that is in contact with the first current-carrying brush 41 among the plurality of commutator segments 31 and is located in front of this commutator segment 31 in the rotational direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected via at least one of the plurality of coils 22 to the first commutator segment located thereon.

The second auxiliary brush 52 is adjacent to the commutator segment 31 in contact with the second current-carrying brush 42 among the plurality of commutator segments 31 and positioned in front of this commutator segment 31 in the rotational direction of the rotor 20 . It is arranged in contact with a second commutator segment electrically connected to one commutator segment through at least one of the plurality of coils 22 .

For example, in the state shown in FIGS. 4 and 5, the first auxiliary brush 51 is adjacent to the first commutator segment 31 in contact with the first conductive brush 41 among the plurality of commutator segments 31, and the rotor 20 is rotating. 6th commutator segment 31 electrically connected via at least one of the plurality of coils 22 to the 17th commutator segment 31 located in front of the 1st commutator segment 31 in the direction. are placed. That is, in this state, the 17th commutator segment 31 corresponds to the first commutator segment, and the 6th commutator segment 31 corresponds to the second commutator segment.

In this embodiment, the second commutator segment is electrically connected to the first commutator segment through one of the multiple coils 22 . That is, in this embodiment, the plurality of coils 22 includes one coil 22 connected to the first commutator segment and the second commutator segment.

For example, in the state shown in FIGS. 4 and 5, the 17th commutator segment 31 corresponds to the first commutator segment, and the 6th commutator segment 31 corresponds to the second commutator segment. The 6th commutator segment 31 is electrically connected to the 17th commutator segment 31 through one coil 22 a of the plurality of coils 22 . In the present embodiment, the commutator segment 31 of No. 6 is electrically connected to the commutator segment 31 of No. 17 even through the 16 coils 22 other than the coil 22a of the plurality of coils 22. It is connected to the. Thus, in the present embodiment, the 6th commutator segment 31 is electrically connected to the 17th commutator segment 31 through only one coil 22a of at least the plurality of coils 22. . That is, in this embodiment, the second commutator segment is electrically connected to the first commutator segment through at least one of the plurality of coils 22 .

In the present embodiment, the second commutator segment is any one of the commutator segments 31 shown below. That is, the commutator segment 31 electrically connected to the first commutator segment of the plurality of coils 22 via the first coil of the plurality of coils 22, and the plurality of coils 22 of the commutator segments 31 electrically connected to the first commutator segment via the second coil of one of the commutator segments 31, the commutator having a smaller potential difference between the current-carrying brush 40 and the auxiliary brush 50 segment 31; That is, when the current-carrying brush 40 is in contact with one commutator segment 31 and the auxiliary brush 50 is in contact with the commutator segment 31 electrically connected to the first commutator segment via one first coil, It is smaller than the potential difference between the current-carrying brush 40 and the auxiliary brush 50 in the following cases. That is, the potential difference between the current-carrying brush 40 and the auxiliary brush 50 is such that the current-carrying brush 40 is in contact with one commutator segment 31 and the auxiliary brush 50 is electrically connected to the first commutator segment via one second coil. is smaller than the potential difference between the current-carrying brush 40 and the auxiliary brush 50 when in contact with the commutator segment 31 connected to the .

For example, in the state shown in FIGS. 4 and 5, the 17th commutator segment 31 corresponds to the first commutator segment, and the 6th commutator segment 31 corresponds to the second commutator segment. The 6th commutator segment 31 is one of the commutator segments shown below among the plurality of commutator segments 31 . That is, the 6th commutator segment electrically connected to the 17th commutator segment 31 via one coil 22a of the plurality of coils 22, and one coil 22b of the plurality of coils 22 of the 11th commutator segments electrically connected to the 17th commutator segment 31 via segment 31; That is, when the first conductive brush 41 is in contact with the commutator segment 31 of No. 1 and the first auxiliary brush 51 is in contact with the commutator segment 31 of No. 6, the relationship between the first conductive brush 41 and the first auxiliary brush 51 is The potential difference between the first conducting brush 41 and the first auxiliary brush when the first conducting brush 41 is in contact with the first commutator segment 31 and the first auxiliary brush 51 is in contact with the eleventh commutator segment 31 51 is smaller than the potential difference between 4 and 5, coil 22a corresponds to the first coil, coil 22b corresponds to the second coil, and commutator segment number 31 is at least one of the plurality of coils 22. 22a only, and the 11th commutator segment 31 is electrically connected to the 17th commutator segment 31 only through at least one coil 22b of the plurality of coils 22. 31 is electrically connected.

In this embodiment, the second commutator segment has a lower potential than the first commutator segment. In other words, the auxiliary brush 50 is arranged so as to be in contact with another commutator segment 31 that is separated from the current-carrying brush 40 and has a lower potential than the commutator segment 31 in which the spark is generated. For example, in the state shown in FIGS. 4 and 5, commutator segment 31 numbered 17 corresponds to the first commutator segment, commutator segment 31 numbered 6 corresponds to the second commutator segment, and commutator segment number 6 corresponds to the commutator segment numbered 6. The child segment 31 is at a lower potential than the 17th commutator segment 31 .

In this embodiment, the conductive brush 40 and the auxiliary brush 50 configured in this manner are arranged on the same plane. Specifically, the conductive brush 40 and the auxiliary brush 50 are arranged on the same plane perpendicular to the direction of the axis C of the shaft 21 . In the present embodiment, the first conductive brush 41, the second conductive brush 42, the first auxiliary brush 51, and the second auxiliary brush 52 are arranged within the frame 60 without shifting in the direction of the axis C of the shaft 21. arranged on the same plane.

Next, the measurement results of the voltage between the energizing brush 40 and the auxiliary brush 50 and the measurement results of the current between the energizing brush 40 and the auxiliary brush 50 will be described with reference to FIGS. 6 to 8. FIG. FIG. 6 is a graph showing measurement results of voltages between current-carrying brushes and auxiliary brushes in the electric motor according to the comparative example. FIG. 7 is a graph showing measurement results of voltages between the current-carrying brushes 40 and the auxiliary brushes 50 in the electric motor 1 of FIG. FIG. 8 is a graph showing measurement results of the current between the current-carrying brush 40 and the auxiliary brush 50 in the electric motor 1 of FIG.

In the electric motor according to the comparative example shown in FIG. 6, the spark absorber 80 is not connected between the current-carrying brushes and the auxiliary brushes. In such a motor, an arc voltage of about 10 [V] to 15 [V] is measured with the generation of a spark.

On the other hand, as described above, in the electric motor 1 , the spark absorber 80 is connected between the current-carrying brushes 40 and the auxiliary brushes 50 . As shown in FIG. 7, in the electric motor 1, the arc voltage of about 10 [V] to 15 [V] is not measured, and it can be seen that the generation of sparks is suppressed. As shown in FIG. 8, it can be seen that a current of about 0.4 [A] to 0.8 [A] flows through the spark absorber 80 between the current-carrying brush 40 and the auxiliary brush 50 . It is considered that the current flowing through the spark absorber 80 in this manner suppresses the generation of sparks.

Thus, it has been found that spark generation can be suppressed by bringing the auxiliary brush 50 into contact with the second commutator segment electrically connected to the first commutator segment through at least one of the plurality of coils 22. rice field.

The electric motor 1 according to the embodiment has been described above.

The electric motor 1 according to the embodiment includes a rotor 20 having a shaft 21 and a plurality of coils 22, a commutator 30 attached to the shaft 21, current-carrying brushes 40 in contact with the commutator 30, and auxiliary brushes in contact with the commutator 30. 50. A plurality of coils 22 are electrically connected to a commutator 30 . The commutator 30 has a plurality of commutator segments 31 provided along the circumferential direction of the shaft 21 . Among the plurality of commutator segments 31, the auxiliary brushes 50 are arranged in a first commutator segment adjacent to the commutator segment 31 in contact with the current-carrying brush 40 and positioned in front of this commutator segment 31 in the rotational direction of the rotor 20. is placed in contact with a second commutator segment which is electrically connected through at least one of the coils 22 of the .

According to this configuration, since the auxiliary brush 50 is in contact with the second commutator segment electrically connected to the first commutator segment in which a spark can occur between the energizing brush 40 and the energizing brush 40, the auxiliary brush 50 contacts the energizing brush 40. It is possible to suppress the occurrence of sparks with the first commutator segment. As a result, the life of the current-carrying brush 40 can be extended. Further, since the second commutator segment is electrically connected to the first commutator segment through at least one of the plurality of coils 22, a separate voltage equalizing wire or the like is used to separate the second commutator segment and the first commutator segment. Since there is no need to electrically connect the commutator segments, it is possible to suppress an increase in the number of commutator segments and to achieve a size reduction. Thus, even when the auxiliary brushes 50 are used, it is possible to achieve both a longer life and a smaller size of the electric motor 1 .

Also, in the electric motor 1 according to the embodiment, the second commutator segment is electrically connected to the first commutator segment via one of the multiple coils 22 .

According to this, since the energizing brushes 40 and the auxiliary brushes 50 can be arranged closer to each other, it is possible to simplify the routing of the wires connected to the energizing brushes 40 and the auxiliary brushes 50, and furthermore, the electric motor 1 miniaturization can be achieved.

In the electric motor 1 according to the embodiment, the second commutator segment is the commutator segment 31 having a smaller potential difference between the current-carrying brush 40 and the auxiliary brush 50 among the commutator segments 31 shown below. be. That is, the commutator segment 31 electrically connected to the first commutator segment of the plurality of coils 22 via the first coil of the plurality of coils 22, and the plurality of coils 22 of the commutator segments 31 electrically connected to the first commutator segment via the second coil of one of the commutator segments 31, the commutator having a smaller potential difference between the current-carrying brush 40 and the auxiliary brush 50 segment 31;

According to this, it is possible to suppress the potential difference between the current-carrying brush 40 and the auxiliary brush 50 from increasing, so that the spark can be absorbed more efficiently and the generation of the spark can be suppressed more efficiently.

Also, in the electric motor 1 according to the embodiment, the second commutator segment has a lower potential than the first commutator segment.

According to this, the second commutator segment electrically connected to the first commutator segment is assisted so as to have a lower potential than the first commutator segment where sparks can occur between the current-carrying brushes 40 . Since the brushes 50 are in contact with each other, the auxiliary brushes 50 can suppress the occurrence of sparks between the current-carrying brushes 40 and the first commutator segments. As a result, the life of the electric motor 1 can be further extended.

Also, in the electric motor 1 according to the embodiment, the current-carrying brushes 40 and the auxiliary brushes 50 are electrically connected via the spark absorbers 80 .

According to this, the spark absorber 80 can absorb the arc voltage due to the spark generated between the current-carrying brush 40 and the first commutator segment. As a result, it is possible to effectively suppress wear of the energizing brush 40 due to sparks, thereby suppressing a reduction in the life of the energizing brush 40 . Therefore, it is possible to further extend the life of the electric motor 1 .

Also, the electrical equipment according to the embodiment is an electrical equipment using the electric motor 1 described above.

According to this, even when the auxiliary brush 50 is used in the electric device, it is possible to achieve both a longer life and a smaller size of the electric device.

(Other embodiments, etc.)
As described above, the electric motor 1 according to the present disclosure has been described based on the embodiment, but the present disclosure is not limited to the above embodiment.

In the above-described embodiment, the case where the second commutator segment is electrically connected to the first commutator segment via one of the multiple coils 22 has been described, but the present invention is not limited to this. For example, the second commutator segment may not be electrically connected to the first commutator segment through one of the plurality of coils 22 . That is, for example, the second commutator segment may be electrically connected to the first commutator segment only through two or more of the plurality of coils 22 .

Further, in the above-described embodiment, the second commutator segment is electrically connected to the first commutator segment via one first coil, and the second commutator segment via one second coil. The case where the commutator segment 31 having the smaller potential difference between the current-carrying brush 40 and the auxiliary brush 50 among the commutator segments 31 electrically connected to the first commutator segment has been described. It is not limited to this. For example, the second commutator segment includes commutator segment 31 electrically connected to the first commutator segment via one first coil and to the first commutator segment via one second coil. Of the commutator segments 31 that are electrically connected, the commutator segment 31 may be the commutator segment 31 that has a larger potential difference between the current-carrying brush 40 and the auxiliary brush 50 .

Also, in the above-described embodiment, the case where the current-carrying brush 40 and the auxiliary brush 50 are electrically connected via the Zener diode that is the spark absorber 80 has been described, but the present invention is not limited to this. For example, the current-carrying brush 40 and the auxiliary brush 50 may be electrically connected via an electronic component or the like capable of absorbing sparks other than a Zener diode.

Also, in the above-described embodiment, the case where the electric motor 1 includes two energizing brushes 40 and two auxiliary brushes 50 corresponding to the two energizing brushes 40 has been described, but the present invention is not limited to this. For example, the electric motor 1 may include four current-carrying brushes 40 and four auxiliary brushes 50 corresponding to the four current-carrying brushes 40 .

Also, in the above-described embodiment, the stator 10 is configured by the magnets 11, but the present invention is not limited to this. For example, stator 10 may be composed of a stator core and coils wound around the stator core.

Also, in the above-described embodiment, the case where the rotor 20 has the rotor core 23 has been described, but the present invention is not limited to this. For example, the electric motor 1 can also be applied to a coreless motor that does not have a core. For example, the electric motor 1 can be applied to a flat coreless motor in which the magnetic flux of the stator 10 and the rotor 20 is generated in the direction of the axis C of the shaft 21 .

In addition, it is realized by arbitrarily combining the constituent elements and functions of the embodiments without departing from the scope of the present disclosure. Forms are also included in this disclosure.

The present disclosure can be used for various products equipped with electric motors, such as vacuum cleaners and automobiles.

1 electric motor 10 stator 11 magnet 20 rotor 21 shaft 21a first end 21b

second end

22, 22a, 22b coil 23 rotor core 24 insulator 30 commutator 31 commutator segment 32 mold resin 40 current-carrying brush 41 first current-carrying brush 42 second 2 current-carrying brush 50 auxiliary brush 51 first auxiliary brush 52 second auxiliary brush 60 frame 70 power supply 80 spark absorber 81 first spark absorber 82 second spark absorber

Claims

a rotor having a rotating shaft and a plurality of coils;
a commutator attached to the rotating shaft;
a current-carrying brush in contact with the commutator;
and an auxiliary brush in contact with the commutator,
the plurality of coils are electrically connected to the commutator;
The commutator has a plurality of commutator segments provided along the circumferential direction of the rotating shaft,
The plurality of commutator segments has a first commutator segment and a second commutator segment, and the first commutator segment is adjacent to the commutator segment in contact with the current-carrying brush and in the direction of rotation of the rotor. in front of the commutator segment, wherein the second commutator segment is electrically connected to the first commutator segment via at least one of the plurality of coils;
The auxiliary brush is arranged to contact the second commutator segment,
Electric motor.
the second commutator segment electrically connected to the first commutator segment through one of the plurality of coils;
The electric motor according to claim 1.
The second commutator segment is electrically connected to the first commutator segment of the plurality of commutator segments via a first coil of one of the plurality of coils. , and among the commutator segments electrically connected to the first commutator segment via a second coil of one of the plurality of coils, the potential difference between the current-carrying brush and the auxiliary brush is is the smaller commutator segment,
The electric motor according to claim 2.
the second commutator segment is at a lower potential than the first commutator segment;
The electric motor according to any one of claims 1 to 3.
The current-carrying brush and the auxiliary brush are electrically connected via a spark absorber.
The electric motor according to any one of claims 1 to 4.
An electric device using the electric motor according to any one of claims 1 to 5.