motor

Abstract

To provide a motor that enables fail-safe operation while suppressing increases in manufacturing costs. [Solution] The motor body comprises a rotor rotatable about a central axis and a stator having a plurality of coils and facing the rotor with a gap between them; a control unit having a drive circuit capable of driving the motor body; a plurality of commutator members, each electrically connected to at least one coil; a first brush member that rotates with the rotor and can contact the commutator members; and a second brush member that rotates with the rotor and can contact a commutator member different from the commutator member that the first brush member contacts. The control unit switches the drive method for driving the motor body between a first drive method, which drives the motor body by supplying current to the plurality of coils via the drive circuit, and a second drive method, which drives the motor body by supplying current to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members.

Description

Technical Field

[0001] The present invention relates to a motor.

Background Art

[0002] In order to execute fail-safe driving to continue the rotation of a motor when a microcontroller that controls the motor fails, a motor control device including a plurality of microcontrollers is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the motor control device as described above, it is necessary to provide a plurality of microcontrollers. Therefore, there has been a problem that the manufacturing cost of the motor including the motor control device increases.

[0005] In view of the above circumstances, an object of the present invention is to provide a motor capable of realizing fail-safe driving while suppressing an increase in manufacturing cost.

Means for Solving the Problems

[0006] One embodiment of the motor of the present invention comprises a motor body having a rotor rotatable about a central axis and a stator having a plurality of coils and facing the rotor with a gap between them; a control unit having a drive circuit capable of driving the motor body; a plurality of commutator members, each electrically connected to at least one of the coils; a first brush member that rotates with the rotor and is capable of contacting the commutator members; and a second brush member that rotates with the rotor and is capable of contacting a commutator member different from the commutator member that the first brush member contacts. The control unit can switch between a first drive method for driving the motor body, in which the drive circuit supplies current to the plurality of coils to drive the motor body, and a second drive method for driving the motor body, in which current is supplied to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members to drive the motor body. [Effects of the Invention]

[0007] According to one aspect of the present invention, a fail-safe drive can be achieved in a motor while suppressing an increase in the manufacturing cost of the motor. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a cross-sectional view showing a part of the motor in the first embodiment. [Figure 2] Figure 2 is a perspective view showing a part of the motor in the first embodiment. [Figure 3] Figure 3 is a perspective view showing a part of the rotor, a part of the stator, a part of the rectifier, a first brush assembly, and a second brush assembly in the first embodiment. [Figure 4] Figure 4 is a view from above of a part of the motor in the first embodiment, showing the state in which the first brush member and the second brush member are in the first position. [Figure 5] Figure 5 is a view from above of a part of the motor in the first embodiment, showing the state in which the first brush member and the second brush member are in the second position. [Figure 6] Figure 6 is a circuit diagram showing a part of the motor in the first embodiment. [Figure 7] Figure 7 is a cross-sectional view showing a part of the motor in the first embodiment, illustrating the current flow in the second drive system. [Figure 8] Figure 8 is a perspective view showing a portion of the rotor, the first brush assembly, and the second brush assembly in the first embodiment. [Figure 9A] Figure 9A shows the case where the rotor rotation angle is 0° in the second drive system of the first embodiment. [Figure 9B] Figure 9B shows the case where the rotor rotation angle is 60° in the second drive system of the first embodiment. [Figure 9C] Figure 9C shows the case where the rotor rotation angle is 120° in the second drive system of the first embodiment. [Figure 9D] Figure 9D shows the case where the rotor rotation angle is 180° in the second drive system of the first embodiment. [Figure 9E] Figure 9E shows the case where the rotor rotation angle is 240° in the second drive system of the first embodiment. [Figure 9F] Figure 9F shows the case where the rotation angle of the rotor is 300° in the second drive system of the first embodiment. [Figure 10] Figure 10 is a flowchart showing an example of the processing procedure of the control unit when driving the motor body in the first embodiment. [Figure 11] Figure 11 is a circuit diagram showing a part of the motor in a modified example of the first embodiment. [Figure 12] Figure 12 is a perspective view showing a part of the motor in the second embodiment. [Figure 13] Figure 13 is a cross-sectional perspective view showing a part of the motor in the second embodiment. [Figure 14] Figure 14 is a perspective view showing multiple commutator members in the second embodiment. [Figure 15] FIG. 15 is an exploded perspective view showing a plurality of commutator members in the second embodiment. [Figure 16] FIG. 16 is a diagram schematically showing a plurality of commutator members, a first brush member, and a second brush member in the second embodiment.

Mode for Carrying Out the Invention

[0009] In the drawings, the central axis J of the motor in the embodiments described below is virtually shown as appropriate. In the following description, the axial direction of the central axis J is simply referred to as the "axial direction", the radial direction centered on the central axis J is simply referred to as the "radial direction", and the circumferential direction centered on the central axis J is simply referred to as the "circumferential direction". The Z-axis shown in each figure indicates the direction in which the central axis J extends. In the following description, the side (+Z side) in the axial direction toward which the arrow of the Z-axis points is referred to as the "upper side", and the side opposite to the side toward which the arrow of the Z-axis points (-Z side) in the axial direction is referred to as the "lower side". Note that the upper side and the lower side are merely names for explaining the relative positional relationship of each part, and the actual arrangement relationship, etc. may be an arrangement relationship, etc. other than the arrangement relationship indicated by these names.

[0010] Further, in the drawings, an arrow θ indicating the circumferential direction is shown as appropriate. In the following embodiments, the side (+θ side) in the circumferential direction toward which the arrow θ points is referred to as the "one side in the circumferential direction", and the side opposite to the side toward which the arrow θ points (-θ side) in the circumferential direction is referred to as the "other side in the circumferential direction". The one side in the circumferential direction is the side that advances clockwise around the central axis J when viewed from the upper side (+Z side). The other side in the circumferential direction is the side that advances counterclockwise around the central axis J when viewed from the upper side.

[0011] <First Embodiment> The motor 100 in this embodiment shown in Figure 1 is a multiphase motor. In this embodiment, the motor 100 is a three-phase motor. As shown in Figure 1, the motor 100 comprises a housing 100a, a motor body 100b, a rectifier 30, a first brush assembly 71, a second brush assembly 72, and a control unit 80. The housing 100a houses the motor body 100b, the rectifier 30, the first brush assembly 71, the second brush assembly 72, and the control unit 80. In Figure 1, the housing 100a is schematically shown by a dashed line.

[0012] The motor body 100b includes a rotor 10 and a stator 20. The rotor 10 is rotatable about a central axis J. The rotor 10 includes a shaft 11, a rotor core 12, and a magnet 13. The shaft 11 extends in the axial direction. The shaft 11 is cylindrical with respect to the central axis J. Although not shown in the figures, the shaft 11 is rotatably supported by bearings. The rotor core 12 is fixed to the outer circumferential surface of the shaft 11. The rotor core 12 is annular in shape, surrounding the shaft 11. In this embodiment, the upper end face of the rotor core 12 is located at the same axial position as the upper end face of the shaft 11. However, the upper end face of the shaft 11 and the upper end face of the rotor core 12 may be located at different axial positions.

[0013] The magnet 13 is fixed to the outer circumferential surface of the rotor core 12. The magnetization direction of the magnet 13 is radial. Multiple magnets 13 are provided. As shown in Figures 2 and 3, two magnets 13 are provided: magnet 13N and magnet 13S. Magnets 13N and 13S have a semicircular arc shape centered on the central axis J when viewed in the axial direction. Magnet 13N is a magnet 13 whose radially outer magnetic pole is the north pole. Magnet 13S is a magnet 13 whose radially outer magnetic pole is the south pole. In this embodiment, the rotor 10 has 2 poles. As shown in Figure 1, the upper end face of each magnet 13 is located above the upper end face of the rotor core 12. The lower end face of each magnet 13 is located below the lower end face of the rotor core 12. Note that the upper end face of each magnet 13 may be located at the same axial position as the upper end face of the rotor core 12, or it may be located below the upper end face of the rotor core 12. The lower end face of each magnet 13 may be located at the same axial position as the lower end face of the rotor core 12, or it may be located above the lower end face of the rotor core 12.

[0014] The stator 20 faces the rotor 10 with a gap between them. The stator 20 is located radially outward from the rotor 10. The stator 20 is annular in shape, surrounding the rotor 10. The stator 20 has a stator core 21, a plurality of coils 22, and an insulator 23. The stator core 21 is annular in shape, surrounding the rotor 10. The plurality of coils 22 are attached to the stator core 21 via the insulator 23. As shown in Figures 3, 4, and 5, the plurality of coils 22 are arranged in a circumferential direction. In this embodiment, there are three coils 22: coil 22U, coil 22V, and coil 22W. In other words, in this embodiment, the number of slots in the stator 20 is 3. Thus, the motor 100 of this embodiment is a 2-pole, 3-slot motor. The three coils 22U, 22V, and 22W are electrically connected to each other. As shown in Figure 6, in this embodiment, the three coils 22U, 22V, and 22W are connected to each other by a star connection. Alternatively, the three coils 22U, 22V, and 22W may be connected to each other by a delta connection. Coil 22U is a U-phase coil. Coil 22V is a V-phase coil. Coil 22W is a W-phase coil.

[0015] As shown in Figure 1, the rectifier 30 is located above the motor body 100b. The rectifier 30 includes a support member 31, a first insulating member 32, a second insulating member 33, a plurality of commutator members 40, a conductive member 50, and a ground member 60. In other words, the motor 100 comprises a support member 31, a first insulating member 32, a second insulating member 33, a plurality of commutator members 40, a conductive member 50, and a ground member 60. The support member 31 supports the plurality of commutator members 40. In this embodiment, the support member 31 is made of resin. The support member 31 is made, for example, by insert molding using the plurality of commutator members 40 as insert members. The support member 31 has a cylindrical portion 31a, an annular portion 31b, a plurality of arm portions 31c, and a holding portion 31d.

[0016] The cylindrical portion 31a is cylindrical, surrounding the central axis J. More specifically, the cylindrical portion 31a is cylindrical, with the central axis J as its center and opening on both sides in the axial direction. The cylindrical portion 31a is supported from below by the insulator 23. The lower end of the cylindrical portion 31a contacts the radial outer edge of the upper surface of the insulator 23.

[0017] The annular portion 31b is an annular shape surrounding the central axis J. More specifically, the annular portion 31b is a circular annular shape centered on the central axis J. The outer diameter of the annular portion 31b is smaller than the inner diameter of the cylindrical portion 31a. The annular portion 31b is located radially inward of the cylindrical portion 31a. More specifically, the annular portion 31b is located radially inward at the upper end of the cylindrical portion 31a.

[0018] Multiple arm portions 31c connect the cylindrical portion 31a and the annular portion 31b. Multiple arm portions 31c extend radially. As shown in Figure 2, multiple arm portions 31c are arranged at intervals in the circumferential direction. Multiple arm portions 31c are arranged at equal intervals around the circumference. In this embodiment, three arm portions 31c are provided. The radially outer end of each arm portion 31c connects to the upper end of the inner circumferential surface of the cylindrical portion 31a. The radially inner end of each arm portion 31c connects to the outer circumferential surface of the annular portion 31b.

[0019] The holding portion 31d is connected to the lower side of the annular portion 31b. The holding portion 31d is the part that holds the multiple commutator members 40. A part of each commutator member 40 is embedded in the holding portion 31d. The holding portion 31d is an annular shape surrounding the central axis J. More specifically, the holding portion 31d is a substantially circular annular shape centered on the central axis J. The outer diameter of the holding portion 31d is larger than the outer diameter of the annular portion 31b. As shown in Figure 1, the inner diameter of the holding portion 31d is the same as the inner diameter of the annular portion 31b. The inner circumferential surface of the holding portion 31d is located below the inner circumferential surface of the annular portion 31b and connects to the inner circumferential surface of the annular portion 31b without any step difference.

[0020] As shown in Figure 3, the multiple commutator members 40 are arranged with spacing in the circumferential direction. The multiple commutator members 40 are arranged at equal intervals around the circumference. As shown in Figure 4, in this embodiment, there are three commutator members 40: commutator member 40U, commutator member 40V, and commutator member 40W. Each commutator member 40 is a conductive material. Each of the multiple commutator members 40 has at least one contact portion 41 that can be contacted by the first brush member 71b and the second brush member 72b, which will be described later. In this embodiment, each commutator member 40 has one contact portion 41. In this embodiment, each commutator member 40 consists of one contact portion 41. The contact portion 41 of commutator member 40U is contact portion 41U. The contact portion 41 of commutator member 40V is contact portion 41V. The contact portion 41 of the commutator member 40W is a contact portion 41W. Each contact portion 41 is electrically conductive.

[0021] The multiple contact portions 41 included in the multiple commutator members 40 are arranged in a circumferential direction around the central axis J. The multiple contact portions 41 are arranged at equal intervals over a full rotation in the circumferential direction. When the number of phases of the motor 100 is N and the number of poles of the rotor 10 is P, the total number of multiple contact portions 41 included in the multiple commutator members 40 is expressed as N × P / 2. In this embodiment, the number of phases of the motor 100 is 3, so the total number of multiple contact portions 41 is expressed as 3 × P / 2. In this embodiment, the number of poles of the rotor 10 is 2, so the total number of multiple contact portions 41 is 3.

[0022] Each contact portion 41 is arc-shaped when viewed in the axial direction, with the central axis J as the center. Each of the multiple arm portions 31c is located above the circumferential center of each of the multiple contact portions 41. The circumferential dimension of each contact portion 41 is greater than the circumferential dimension of each arm portion 31c. The lower surface of each contact portion 41 and the circumferential surfaces on both sides of each contact portion 41 are covered by the holding portion 31d. The circumferential center of the upper surface of each contact portion 41 is covered by each arm portion 31c. As shown in Figure 1, each contact portion 41 is located radially outward from the outer circumferential surface of the shaft 11. Each contact portion 41 is located radially inward from the radially inward surface of the magnet 13. Each contact portion 41 overlaps with the rotor core 12 when viewed in the axial direction.

[0023] As shown in Figure 3, one second connecting member 22b is connected to each of the contact portions 41. The second connecting member 22b is connected to a first connecting member 22a that extends upward from the coil 22. The first connecting member 22a extends upward from each of the three coils 22U, 22V, and 22W. As shown in Figure 7, the first connecting member 22a is electrically connected to the control unit 80, which will be described later, on a substrate 81. The first connecting member 22a may be a coil lead wire formed by the end of the conductor that makes up the coil 22, or it may be a conductive member such as a busbar that is electrically connected to the coil 22.

[0024] Each second connecting member 22b has a portion that extends radially inward from each first connecting member 22a, and a portion that extends downward from the radially inward end of the radially inward portion and connects to each contact portion 41. As shown in Figure 3, the second connecting member 22b connected to the first connecting member 22a extending upward from the coil 22U is connected to the contact portion 41U. The second connecting member 22b connected to the first connecting member 22a extending upward from the coil 22V is connected to the contact portion 41V. The second connecting member 22b connected to the first connecting member 22a extending upward from the coil 22W is connected to the contact portion 41W. As a result, each of the multiple commutator members 40 is electrically connected to at least one coil 22 via the first connecting member 22a and the second connecting member 22b. In this embodiment, each commutator member 40 is connected to one coil 22 via a first connecting member 22a and a second connecting member 22b.

[0025] In the following description, the portion comprising the multiple contact portions 41, i.e., the multiple commutator members 40 and the holding portion 31d, is referred to as the commutator body portion 30a. The commutator body portion 30a is annular in shape with the central axis J at its center. The outer circumferential surface of the commutator body portion 30a is composed of the radially outer surfaces of the multiple contact portions 41 and the radially outer surfaces of the holding portion 31d located between adjacent contact portions 41 in the circumferential direction. The outer circumferential surface of the commutator body portion 30a is a cylindrical surface with the central axis J at its center. In the commutator body portion 30a, the multiple contact portions 41 are insulated from each other by the resin holding portion 31d.

[0026] The conductive member 50 is a conductive member. As shown in Figure 1, the conductive member 50 has a first conductive body 51 and a first connecting part 52. The first conductive body 51 is located below the plurality of commutator members 40 and the holding part 31d, that is, below the commutator body 30a. The first conductive body 51 is an annular shape surrounding the central axis J. More specifically, the first conductive body 51 is an annular shape centered on the central axis J. A first insulating member 32 is positioned between the first conductive body 51 and the holding part 31d in the axial direction. The first insulating member 32 has insulating properties. The first insulating member 32 is made of resin. The first insulating member 32 is plate-shaped with its plate surface facing the axial direction. The first insulating member 32 is an annular shape surrounding the central axis J. More specifically, the first insulating member 32 is an annular shape centered on the central axis J. The upper surface of the first insulating member 32 contacts the lower surface of the holding portion 31d. The lower surface of the first insulating member 32 contacts the upper surface of the first main body portion 51. The inner diameter of the first main body portion 51 is smaller than the inner diameter of the annular portion 31b, the inner diameter of the holding portion 31d, and the inner diameter of the first insulating member 32.

[0027] The first connecting portion 52 extends upward from a portion of the first main body 51 that is radially inward from the inner edge of the first insulating member 32, the inner edge of the holding portion 31d, and the inner edge of the annular portion 31b. In this embodiment, the first connecting portion 52 is cylindrical and extends in the axial direction. The first connecting portion 52 passes axially through the radially inward side of the first insulating member 32, the radially inward side of the holding portion 31d, and the radially inward side of the annular portion 31b. The first connecting portion 52 extends upward from the support member 31. The first connecting portion 52 is electrically connected to the control unit 80, which will be described later. As a result, the conductive member 50 is electrically connected to the control unit 80. As shown in Figure 7, the first connecting portion 52 is electrically connected to the power supply wiring portion 81a provided on the substrate 81. The power supply wiring portion 81a is wiring to which a power supply voltage is applied from an external power supply E. As a result, the power supply voltage is applied to the conductive member 50.

[0028] The ground member 60 is a conductive member. As shown in Figure 1, the ground member 60 has a second main body portion 61 and a second connecting portion 62. In this embodiment, the second main body portion 61 is circular in shape when viewed in the axial direction, with the central axis J as the center. The second main body portion 61 is located below the first main body portion 51. The second main body portion 61 is located above the rotor 10. The second main body portion 61 is located above the upper end face of the shaft 11 and above the upper end face of the rotor core 12.

[0029] A second insulating member 33 is positioned between the second main body portion 61 and the first main body portion 51 in the axial direction. The second insulating member 33 has insulating properties. The second insulating member 33 is made of resin. The second insulating member 33 is plate-shaped with its plate surface facing axially. The second insulating member 33 is annular in shape surrounding the central axis J. More specifically, the second insulating member 33 is annular in shape with the central axis J as its center. The upper surface of the second insulating member 33 contacts the lower surface of the first main body portion 51. The lower surface of the second insulating member 33 contacts the upper surface of the second main body portion 61. In this embodiment, the inner diameter of the second insulating member 33 is the same as the inner diameter of the first main body portion 51.

[0030] The second connecting portion 62 extends upward from the portion of the second main body 61 located radially inward from the inner edge of the second insulating member 33 and the inner edge of the first main body 51. In this embodiment, the second connecting portion 62 is cylindrical in shape and extends axially with respect to the central axis J. The second connecting portion 62 passes axially through the radially inward side of the second insulating member 33, the radially inward side of the first main body 51, the radially inward side of the first insulating member 32, the radially inward side of the holding portion 31d, and the radially inward side of the annular portion 31b. The second connecting portion 62 extends upward from the support member 31. As shown in Figure 7, the second connecting portion 62 is electrically connected to a ground portion 81b provided on the substrate 81 of the control unit 80, which will be described later. The ground portion 81b is the portion whose potential becomes the reference potential in the control unit 80. Although not shown, the ground portion 81b is grounded, for example, by being electrically connected to the housing 100a. The ground member 60 is connected to the ground section 81b of the control unit 80 and grounded.

[0031] Multiple commutator members 40 and conductive members 50 are fixed to each other via a holding portion 31d that holds the multiple commutator members 40 and a first insulating member 32. Conductive members 50 and ground members 60 are fixed to each other via a second insulating member 33. In other words, in this embodiment, conductive members 50, ground members 60 and multiple commutator members 40 are fixed to each other in an insulated state. The holding portion 31d and the first insulating member 32 are fixed to each other by, for example, an adhesive. The first insulating member 32 and the first main body portion 51 of the conductive member 50 are fixed to each other by, for example, an adhesive. The first main body portion 51 of the conductive member 50 and the second insulating member 33 are fixed to each other by, for example, an adhesive. The second insulating member 33 and the second main body portion 61 of the ground member 60 are fixed to each other by, for example, an adhesive.

[0032] The methods for fixing the holding portion 31d to the first insulating member 32, the method for fixing the first insulating member 32 to the first main body portion 51 of the conductive member 50, the method for fixing the first main body portion 51 of the conductive member 50 to the second insulating member 33, and the method for fixing the second insulating member 33 to the second main body portion 61 of the ground member 60 are not particularly limited. The multiple commutator members 40 and the first insulating member 32 may be fixed to each other without the holding portion 31d. The first insulating member 32 may not be provided. In this case, the multiple commutator members 40 and the conductive member 50 may be insulated from each other by the portion of the holding portion 31d that covers the lower surfaces of the multiple commutator members 40.

[0033] The first brush assembly 71 and the second brush assembly 72 rotate together with the rotor 10. As shown in Figure 4, in this embodiment, the first brush assembly 71 and the second brush assembly 72 are located radially outward from the multiple commutator members 40. As shown in Figure 8, the first brush assembly 71 and the second brush assembly 72 are located above the rotor core 12. The first brush assembly 71 is mounted on the rotor core 12 so as to be rotatable about an axially extending rotation axis R1. The second brush assembly 72 is mounted on the rotor core 12 so as to be rotatable about an axially extending rotation axis R2. The rotation axes R1 and R2 are located radially outward from the multiple commutator members 40. The rotation axes R1 and R2 are positioned radially across the central axis J when viewed in the axial direction.

[0034] The first brush assembly 71 and the second brush assembly 72 are movable between a state in which the first brush member 71b and the second brush member 72b, as described later, are in contact with the outer circumferential surface of the commutator body 30a from the radially outward direction, as shown in Figure 4, and a state in which the first brush member 71b and the second brush member 72b are moved radially outward from the outer circumferential surface of the commutator body 30a, as shown in Figure 5. In the following description of the positional relationships of the parts of each brush assembly, unless otherwise specified, the positional relationships of the parts of each brush member of each brush assembly are as they are in the state in which each brush member is in contact with the outer circumferential surface of the commutator body 30a, as shown in Figure 4.

[0035] As shown in Figure 8, the first brush assembly 71 includes a first holder member 71a and a first brush member 71b. In other words, the motor 100 comprises a first holder member 71a and a first brush member 71b. The first holder member 71a holds the first brush member 71b. A portion of the first brush member 71b is embedded in the first holder member 71a. The first holder member 71a is made of resin. The first holder member 71a is made, for example, by insert molding using the first brush member 71b as an insert member. The first holder member 71a extends in the circumferential direction. The first holder member 71a has a through hole 71f that penetrates the first holder member 71a in the axial direction. The through hole 71f is provided at one end of the first holder member 71a in the circumferential direction (+θ side). A first column portion 74a, which protrudes upward from the upper surface of the rotor core 12, is passed through the through hole 71f in the axial direction. The first holder member 71a extends from the first column portion 74a to the other side in the circumferential direction (-θ side).

[0036] The first column portion 74a is fixed to the upper surface of the rotor core 12. The material constituting the first column portion 74a is not particularly limited. The first column portion 74a may be fixed to the upper surface of the rotor core 12 by any means. The first column portion 74a has a large diameter portion 74c and a small diameter portion 74d. The large diameter portion 74c and the small diameter portion 74d are cylindrical in shape, extending axially with respect to the rotation axis R1. The lower end of the large diameter portion 74c is fixed to the rotor core 12. The small diameter portion 74d extends upward from the upper end of the large diameter portion 74c. The outer diameter of the small diameter portion 74d is smaller than the outer diameter of the large diameter portion 74c. The small diameter portion 74d is passed axially through the through hole 71f of the first holder member 71a. The small diameter portion 74d is fitted into the through hole 71f. As a result, the first holder member 71a is supported by the small-diameter portion 74d so as to be rotatable around the rotation axis R1.

[0037] The upper end of the small-diameter portion 74d is located above the upper surface of the first holder member 71a. The first retaining ring 76a is attached to the portion of the small-diameter portion 74d that is located above the upper surface of the first holder member 71a. The first retaining ring 76a surrounds the small-diameter portion 74d. The first retaining ring 76a is attached to the outer circumferential surface of the small-diameter portion 74d. The first retaining ring 76a prevents the first holder member 71a from moving upward relative to the small-diameter portion 74d. The first retaining ring 76a can be any type of retaining ring as long as it can prevent the first holder member 71a from moving upward. The first retaining ring 76a may be a C-type retaining ring or an E-type retaining ring.

[0038] The lower surface of one end of the first holder member 71a in the circumferential direction (+θ side) contacts the outer peripheral edge of the upper end of the large-diameter portion 74c. As a result, the first holder member 71a is supported from below by the large-diameter portion 74c. Thus, in this embodiment, the first holder member 71a is supported by the first column portion 74a so as to be rotatable around the rotation axis R1, and is also supported from below.

[0039] The first brush member 71b is partially embedded in the portion of the first holder member 71a on the other circumferential side (-θ side) and is held by the first holder member 71a. The first brush member 71b is a conductive material. In this embodiment, the first brush member 71b is plate-shaped with its plate surface facing radially. In this embodiment, the circumferential position of a portion of the first brush member 71b is the same as the circumferential position of the central part of the magnet 13S in the circumferential direction.

[0040] As shown in Figure 4, in this embodiment, the first brush member 71b is located radially outward from the commutator member 40. The first brush member 71b faces radially toward the radially outer surfaces of one or two commutator members 40. The first brush member 71b is contactable with the commutator member 40. Viewed axially, the first brush member 71b extends linearly from the radially inner surface of the portion of the first holder member 71a on the other circumferential side (-θ side) toward the other circumferential side. Viewed axially, the direction in which the first brush member 71b extends is tangential to the outer circumferential surface of the commutator body 30a. The other circumferential end of the first brush member 71b is located circumferentially toward the other circumferential side of the other circumferential end of the first holder member 71a.

[0041] As shown in Figure 8, the first brush member 71b has a first terminal portion 71c, a second terminal portion 71d, and a base portion 71e. The first terminal portion 71c and the second terminal portion 71d extend from the base portion 71e to the other side in the circumferential direction (-θ side) along the tangential direction in which the first brush member 71b extends when viewed in the axial direction. The first terminal portion 71c and the second terminal portion 71d are arranged side by side with a gap between them in the axial direction. The first terminal portion 71c is located above the second terminal portion 71d. As shown in Figure 1, the axial position of the first terminal portion 71c is the same as the axial position of the lower portion of the commutator member 40. The first terminal portion 71c can contact the radial outer surface of the commutator member 40. The axial position of the second terminal portion 71d is the same as the axial position of the first main body portion 51 of the conductive member 50. The second terminal portion 71d is capable of contacting the radially outer surface of the first main body portion 51. The first brush member 71b is capable of simultaneously contacting the conductive member 50 and the commutator member 40 via the first terminal portion 71c and the second terminal portion 71d.

[0042] As shown in Figure 8, the second brush assembly 72 includes a second holder member 72a and a second brush member 72b. In other words, the motor 100 comprises a second holder member 72a and a second brush member 72b. The second holder member 72a holds the second brush member 72b. A portion of the second brush member 72b is embedded in the second holder member 72a. The second holder member 72a is made of resin. The second holder member 72a is manufactured, for example, by insert molding using the second brush member 72b as an insert member. The second holder member 72a extends in the circumferential direction. The second holder member 72a has a through hole 72f that penetrates the second holder member 72a in the axial direction. The through hole 72f is provided at one end of the second holder member 72a in the circumferential direction (+θ side). A second column portion 74b, which protrudes upward from the upper surface of the rotor core 12, is passed through the through hole 72f in the axial direction. The second holder member 72a extends from the second column portion 74b to the other side in the circumferential direction (-θ side).

[0043] The second column portion 74b is fixed to the upper surface of the rotor core 12. The material constituting the second column portion 74b is not particularly limited. The second column portion 74b may be fixed to the upper surface of the rotor core 12 by any means. The shape of the second column portion 74b is the same as that of the first column portion 74a. The second holder member 72a is supported by the second column portion 74b so as to be rotatable around the axis of rotation R2 and is also supported from below, similar to how the first holder member 71a is supported by the first column portion 74a. A second retaining ring 76b is attached to the small diameter portion of the second column portion 74b that is located above the second holder member 72a. The second retaining ring 76b prevents the second holder member 72a from moving upward. The second retaining ring 76b may be any type of retaining ring as long as it can prevent the second holder member 72a from moving upward. The second retaining ring 76b may be a C-type retaining ring or an E-type retaining ring.

[0044] The second brush member 72b is partially embedded in the portion of the second holder member 72a on the other circumferential side (-θ side) and is held by the second holder member 72a. The second brush member 72b is a conductive material. In this embodiment, the second brush member 72b is plate-shaped with its plate surface facing radially. In this embodiment, the circumferential position of a portion of the second brush member 72b is the same as the circumferential position of the central part of the magnet 13N.

[0045] As shown in Figure 4, in this embodiment, the second brush member 72b is located radially outward from the commutator member 40. The second brush member 72b is radially opposite to the radially outer surface of one or two commutator members 40. The second brush member 72b is capable of contacting a commutator member 40 different from the commutator member 40 that the first brush member 71b contacts. The second brush member 72b extends linearly in the axial direction from the radially inner surface of the portion of the second holder member 72a on the other circumferential side (-θ side). In the axial direction, the direction in which the second brush member 72b extends is the tangential direction, tangent to the outer circumferential surface of the commutator body 30a. The other circumferential end of the second brush member 72b is located circumferentially further outward than the other circumferential end of the second holder member 72a.

[0046] As shown in Figure 8, the second brush member 72b has a third terminal portion 72c, a fourth terminal portion 72d, and a base portion 72e. The third terminal portion 72c and the fourth terminal portion 72d extend from the base portion 72e to the other side in the circumferential direction (-θ side) along the tangential direction in which the second brush member 72b extends when viewed in the axial direction. The third terminal portion 72c and the fourth terminal portion 72d are arranged side by side with an axial gap between them. The third terminal portion 72c is located above the fourth terminal portion 72d. The first terminal portion 71c and the third terminal portion 72c are provided at the same position in the axial direction. The fourth terminal portion 72d is located below the second terminal portion 71d. The axial distance between the third terminal portion 72c and the fourth terminal portion 72d is greater than the axial distance between the first terminal portion 71c and the second terminal portion 71d.

[0047] As shown in Figure 1, the axial position of the third terminal portion 72c is the same as the axial position of the lower portion of the commutator member 40. The third terminal portion 72c can contact the radially outer surface of the commutator member 40. The axial position of the fourth terminal portion 72d is the same as the axial position of the second main body portion 61 of the ground member 60. The fourth terminal portion 72d can contact the radially outer surface of the second main body portion 61. The second brush member 72b can simultaneously contact a commutator member 40 and the ground member 60 that are different from the commutator member 40 that the first brush member 71b contacts, via the third terminal portion 72c and the fourth terminal portion 72d.

[0048] In this embodiment, the first brush member 71b and the second brush member 72b are mounted on the rotor 10 so as to be movable between a first position P1 in contact with the commutator member 40 and a second position P2 away from the commutator member 40. The first brush member 71b is movable between the first position P1 and the second position P2 by the first brush assembly 71 rotating about the rotation axis R1. The second brush member 72b is movable between the first position P1 and the second position P2 by the second brush assembly 72 rotating about the rotation axis R2. Figures 1 to 4 and 7 show the state in which the first brush member 71b and the second brush member 72b are in the first position P1. Figures 5 and 8 show the state in which the first brush member 71b and the second brush member 72b are in the second position P2. As shown in Figures 4 and 5, the first position P1 and the second position P2 are positions where the radial positions of each brush member are different from each other. In this embodiment, the first position P1 is a position where each brush member is located radially inward from the second position P2.

[0049] As shown in Figure 8, the motor 100 includes an elastic member 75a that applies force to the first brush assembly 71 and an elastic member 75b that applies force to the second brush assembly 72. In this embodiment, the elastic members 75a and 75b are torsion coil springs wound around an axis extending in the axial direction. The elastic member 75a applies force to the first brush assembly 71 around the rotation axis R1. The elastic member 75b applies force to the second brush assembly 72 around the rotation axis R2.

[0050] The elastic member 75a surrounds the large-diameter portion 74c of the first column portion 74a. One end 75c of the elastic member 75a is inserted from above into a hole 12a provided on the upper surface of the rotor core 12. This prevents the one end 75c from moving around the rotation axis R1. The other end 75d of the elastic member 75a extends in the axial direction. The other end 75d is located radially outward of the first holder member 71a. The other end 75d contacts the radially outward surface of the first holder member 71a. When attached to the rotor 10, the elastic member 75a is compressively elastically deformed around the rotation axis R1, and applies a radially inward force to the first holder member 71a via the other end 75d. As a result, in the state shown in Figure 4, when the first brush member 71b is in contact with the commutator body 30a, the elastic member 75a presses the first brush member 71b against the commutator body 30a from the radially outward direction. In other words, the elastic member 75a applies a force to the first brush member 71b in a direction that presses it radially against the commutator member 40.

[0051] As shown in Figure 8, the elastic member 75b surrounds the large-diameter portion of the second column 74b. One end 75e of the elastic member 75b is inserted from above into a hole 12b provided on the upper surface of the rotor core 12. This prevents the one end 75e from moving around the rotation axis R2. The other end 75f of the elastic member 75b extends in the axial direction. The other end 75f is located radially outward of the second holder member 72a. The other end 75f contacts the radially outward surface of the second holder member 72a. When attached to the rotor 10, the elastic member 75b is compressively elastically deformed around the rotation axis R2, and applies a radially inward force to the second holder member 72a via the other end 75f. As a result, when the second brush member 72b is in contact with the commutator body 30a as shown in Figure 4, the elastic member 75b presses the second brush member 72b against the commutator body 30a from the radially outward direction. In other words, the elastic member 75b applies a force to the second brush member 72b that presses it radially against the commutator member 40.

[0052] The motor 100 is equipped with a support portion 73. In this embodiment, there are two support portions 73: a support portion 73a and a support portion 73b. The support portions 73a and 73b protrude upward from the upper surface of the rotor core 12. The lower ends of the support portions 73a and 73b are fixed to the radially outer edge of the upper surface of the rotor core 12. In this embodiment, the support portions 73a and 73b are plate-shaped with their plate surfaces facing radially. When viewed in the axial direction, the support portions 73a and 73b are curved in an arc shape with the central axis J as the center.

[0053] The support portion 73a is located radially outward of the first brush assembly 71. The support portion 73a is located radially outward of the other circumferential end (-θ side) of the first holder member 71a. As shown in Figure 5, when the first brush member 71b is in the second position P2, the radially inward surface of the support portion 73a contacts the radially outward surface of the first holder member 71a. This prevents the first brush member 71b from moving radially outward beyond the second position P2. In other words, the support portion 73a radially supports the first brush member 71b at the second position P2. In this embodiment, the support portion 73a supports the first brush member 71b from the radially outward direction via the first holder member 71a.

[0054] The support portion 73b is located radially outward of the second brush assembly 72. The support portion 73b is located radially outward of the other circumferential end (-θ side) of the second holder member 72a. When the second brush member 72b is in the second position P2, the radially inward surface of the support portion 73b contacts the radially outward surface of the second holder member 72a. This prevents the second brush member 72b from moving radially outward beyond the second position P2. In other words, the support portion 73b radially supports the second brush member 72b at the second position P2. In this embodiment, the support portion 73b supports the second brush member 72b from the radially outward direction via the second holder member 72a.

[0055] When the rotor 10 rotates around the central axis J, a radially outward centrifugal force is generated on the first brush assembly 71 and the second brush assembly 72. The centrifugal force generated on the first brush assembly 71 and the second brush assembly 72 increases as the rotational speed of the rotor 10 increases. When the rotor 10 rotates and a radially outward centrifugal force is generated on the first brush assembly 71, a rotational moment is generated in the first brush assembly 71 that causes it to rotate radially outward around the rotation axis R1. When this rotational moment becomes greater than the rotational moment around the rotation axis R1 applied to the first brush assembly 71 by the elastic member 75a, the first brush assembly 71 moves radially outward around the rotation axis R1. At this time, the first brush assembly 71 moves radially outward until the first holder member 71a contacts the support portion 73a and the position of the first brush member 71b reaches the second position P2. When the rotor 10 rotates and a radially outward centrifugal force is generated on the second brush assembly 72, a rotational moment is generated in the second brush assembly 72 that causes it to rotate radially outward around the rotation axis R2. When this rotational moment becomes greater than the rotational moment around the rotation axis R2 applied to the second brush assembly 72 by the elastic member 75b, the second brush assembly 72 moves radially outward around the rotation axis R2. At this time, the second brush assembly 72 moves radially outward until the second holder member 72a contacts the support portion 73b and the position of the second brush member 72b reaches the second position P2. Thus, in this embodiment, when the rotational speed of the rotor 10 exceeds a certain rotational speed, the first brush assembly 71 and the second brush assembly 72 automatically move radially outward, and the first brush member 71b and the second brush member 72b automatically move from the first position P1 to the second position P2.

[0056] The angle φ shown in Figure 4 is the circumferential angle around the central axis J between the portion of the first brush member 71b that contacts the commutator member 40 and the portion of the second brush member 72b that contacts the commutator member 40. When the number of phases of the motor 100 is N, the angle φ is equivalent to an angle expressed as 540 / N[°] in electrical angle terms. In this embodiment, the number of phases N of the motor 100 is 3, so the angle φ is equivalent to an angle that is 180° in electrical angle terms. In this embodiment, the number of poles P of the rotor 10 is 2, so the electrical angle and mechanical angle of the rotor 10 are equal to each other. The angle φ is 180° in mechanical terms. In this specification, "the angle φ is equivalent to an angle that is 180° in electrical angle terms" includes the case where the angle φ is exactly equivalent to an angle that is 180° in electrical angle terms, and the case where the angle φ is approximately equivalent to an angle that is 180° in electrical angle terms. The case where angle φ is approximately equivalent to an angle that is 180° in electrical angle terms includes cases where angle φ deviates within the tolerance range from an angle equivalent to an angle that is 180° in electrical angle terms.

[0057] For example, if motor 100 has 3 phases N and rotor 10 has 6 poles P, then the angles equivalent to an electrical angle of 180° during one rotation of rotor 10 are 180°, 540°, and 900°. When rotor 10 has 6 poles P, an electrical angle of 180° is a mechanical angle of 60°, an electrical angle of 540° is a mechanical angle of 180°, and an electrical angle of 900° is a mechanical angle of 300°. Therefore, when motor 100 has 3 phases N and rotor 10 has 6 poles P, the angle φ is a mechanical angle of 60°, 180°, or 300°.

[0058] The control unit 80 controls the motor body 100b. As shown in Figure 1, the control unit 80 has a substrate 81 located above the rectifier 30. The surface of the substrate 81 faces axially. The substrate 81 is positioned above and away from the rectifier 30. Although not shown, the substrate 81 is fixed to the housing 100a, for example. The substrate 81 may also be supported from below by a support member 31 of the rectifier 30, for example.

[0059] As shown in Figure 6, the control unit 80 includes a calculation unit 82, a drive circuit 83, and a switching element 84. The calculation unit 82, the drive circuit 83, and the switching element 84 are mounted on a substrate 81. The calculation unit 82 is the part of the control unit 80 that can perform various controls. The calculation unit 82 is a processor such as a CPU (Central Processing Unit). The calculation unit 82 is, for example, a microcontroller (MCU: Micro Controller Unit). The calculation unit 82 has a drive signal generation unit 82a. The drive signal generation unit 82a generates a drive signal for driving the drive circuit 83. The drive signal generation unit 82a is a pre-driver that drives the drive circuit 83.

[0060] The drive circuit 83 is a circuit capable of driving the motor body 100b. More specifically, the drive circuit 83 is an inverter circuit that supplies power to the motor body 100b. The drive circuit 83 is composed of a plurality of switching elements 83a. The switching elements 83a are transistors. For example, the switching elements 83a are MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). Note that the switching elements 83a may be other types of transistors such as IGBTs (Insulated Gate Bipolar Transistors). The drive circuit 83 is a three-phase inverter circuit composed of six switching elements 83a. The plurality of switching elements 83a constituting the drive circuit 83 are switched between an ON state and an OFF state by drive signals input to each switching element 83a from the calculation unit 82. By switching the state of each switching element 83a by the calculation unit 82, the drive circuit 83 supplies three-phase alternating current to the plurality of coils 22 of the motor body 100b. As a result, the motor body 100b is driven by the drive circuit 83. The drive circuit 83 is supplied with a power supply voltage from an external power supply E.

[0061] The switching element 84 is provided on the power supply wiring section 81a to which the first main body 51 of the conductive member 50 is connected. The switching element 84 is, for example, a MOSFET. However, the switching element 84 may be another type of transistor, such as an IGBT. The switching element 84 is a switching element that can switch between a connected state in which the external power supply E and the conductive member 50 are electrically connected via the power supply wiring section 81a, and a disconnected state in which the connection between the external power supply E and the conductive member 50 is interrupted. When the switching element 84 is in the ON state, the external power supply E and the conductive member 50 are electrically connected via the power supply wiring section 81a. When the switching element 84 is in the OFF state, a part of the power supply wiring section 81a is interrupted, and the connection between the external power supply E and the conductive member 50 is interrupted.

[0062] The control unit 80 can switch between a first drive method and a second drive method for driving the motor body 100b. The first drive method is a drive method in which the motor body 100b is driven by supplying current to a plurality of coils 22 by a drive circuit 83. In the first drive method, current is supplied from the drive circuit 83 to each coil 22 via each first connecting member 22a.

[0063] The second drive method is a drive method that drives the motor body 100b by supplying current to a plurality of coils 22 via a first brush member 71b, a second brush member 72b, and a plurality of commutator members 40. Therefore, even if, for example, an abnormality occurs in the drive circuit 83 or the drive signal generation unit 82a and the motor body 100b can no longer be driven by the first drive method, the control unit 80 can still drive the motor body 100b by the second drive method. The second drive method is a drive method for the motor body 100b via a first brush member 71b, a second brush member 72b, and a plurality of commutator members 40, and, similar to a brushed DC motor, is a drive method that can mechanically switch the current supplied to the plurality of coils 22. Therefore, there is no need to control the drive circuit 83 as in the first drive method, and there is no need to provide a control circuit in the control unit 80 for driving the motor body 100b by the second drive method. As a result, without providing multiple control units 80 or multiple drive circuits 83, if an abnormality occurs in the driving of the motor body 100b by the first drive method, the control unit 80 can perform fail-safe driving by continuing to drive the motor body 100b by the second drive method. Therefore, compared to the cases where multiple control units 80 and multiple drive circuits 83 are provided, the increase in the manufacturing cost of the motor 100 can be suppressed. Thus, according to this embodiment, in the motor 100, fail-safe driving can be achieved while suppressing an increase in the manufacturing cost of the motor 100.

[0064] Region Mc shown in Figure 6 represents the region used when the motor body 100b is driven by the first drive method. Region Ms shown in Figure 6 represents the region used when the motor body 100b is driven by the second drive method.

[0065] In this embodiment, as described above, the motor 100 includes a conductive member 50 electrically connected to the control unit 80 and to which a power supply voltage is applied, and a ground member 60 that is grounded. The first brush member 71b is capable of simultaneously contacting the conductive member 50 and the commutator member 40. The second brush member 72b is capable of simultaneously contacting a commutator member 40 different from the one that the first brush member 71b contacts, and the ground member 60. Therefore, when the control unit 80 drives the motor body 100b using the second drive method, it can suitably supply current to the motor body 100b. The flow of this current will be described in detail below.

[0066] Figure 7 shows an example of the current I that flows when the motor body 100b is driven by the second drive method. In the second drive method, the current I supplied from the external power supply E flows from the power wiring section 81a of the circuit board 81 to the first connection section 52 of the conductive member 50. The current I that flows through the first connection section 52 flows from the first body 51 to the second terminal section 71d of the first brush member 71b. The current I that flows through the second terminal section 71d flows from the first terminal section 71c of the first brush member 71b to the contact section 41 of one commutator member 40. The current I that flows through one contact section 41 flows to the second connecting member 22b connected to that contact section 41. The current I that flows through the second connecting member 22b flows through the first connecting member 22a and flows to the coil 22 connected to the first connecting member 22a. The current I flowing through coil 22 flows to other coils 22 that are electrically connected to the second brush member 72b via jumper wires 22c connecting the coils 22. The current I flowing to these other coils 22 flows through the first connecting member 22a connected to these other coils 22, and the second connecting member 22b connected to the first connecting member 22a, and flows to the contact portion 41 of the other commutator member 40 that the second brush member 72b contacts. The current I flowing to the contact portion 41 of the other commutator member 40 flows to the third terminal portion 72c of the second brush member 72b. The current I flowing to the third terminal portion 72c flows to the fourth terminal portion 72d of the second brush member 72b, and from the fourth terminal portion 72d flows to the second main body portion 61 of the ground member 60. The current I flowing through the second main body 61 flows to the second connection part 62 of the ground member 60, and from the second connection part 62 flows to the ground part 81b of the substrate 81. When the rotor 10 rotates, the commutator member 40 that each brush member contacts changes, so that the coil 22 through which the current I flows and the direction of the current I flowing through the coil 22 change. As a result, the poles of the electromagnet created by the power flowing through the coil 22 change, and the rotor 10 rotates. In this way, the control unit 80 can supply current to the multiple coils 22 via the first brush member 71b, the second brush member 72b, and the multiple commutator members 40, and can suitably drive the motor main body 100b by the second drive method.

[0067] In this embodiment, as described above, the conductive member 50, the ground member 60, and the multiple commutator members 40 are fixed in an insulated state from each other. The ground member 60 is connected to the ground section 81b of the control unit 80 and grounded. Since the conductive member 50 and the ground member 60 can be fixed together with the multiple commutator members 40, it is easy to make the first brush member 71b contact the conductive member 50 and the commutator members 40 simultaneously, and it is easy to make the second brush member 72b contact the ground member 60 and the commutator members 40 simultaneously. Furthermore, since the ground member 60 can be grounded by connecting it to the ground section 81b of the control unit 80, it is not necessary to rotate the ground member 60 together with the rotor 10, unlike, for example, when the ground member 60 is grounded via a rotating rotor 10. Therefore, the structure of the motor 100 can be simplified compared to the case where it is necessary to rotate the ground member 60.

[0068] In this embodiment, as described above, the motor 100 is a three-phase motor, and when the number of poles of the rotor 10 is P, the total number of contact portions 41 included in the multiple commutator members 40 is expressed as 3 × P / 2. The circumferential angle φ around the central axis J between the portion of the first brush member 71b that contacts the commutator member 40 and the portion of the second brush member 72b that contacts the commutator member 40 is an angle equivalent to an angle of 180° in electrical angle terms. By setting the angle φ to such an angle, the current flowing through the multiple coils 22 in the second drive system can be made to flow in the same way as the current flowing through the multiple coils 22 in the first drive system. The changes in the current flowing through the multiple coils 22 will be described in detail below.

[0069] Figures 9A to 9F show the contact state of each brush with the commutator member 40 when the rotor 10 rotates once while the motor body 100b is driven by the second drive method. In Figure 9A, the rotational position of the rotor 10 is set to the position where the rotation angle θm of the rotor 10 is 0°. The rotation angle θm increases as the rotor 10 rotates in one direction (+θ side) in the circumferential direction. The rotation angle θm is the mechanical angle.

[0070] As shown in Figure 9A, when the rotation angle θm is 0°, the first brush member 71b contacts the contact portion 41U of the commutator member 40U, and the second brush member 72b contacts the contact portion 41W of the commutator member 40W. In this case, current flows through coil 22U and coil 22W, and the direction of the current flowing through coil 22U and the direction of the current flowing through coil 22W are opposite to each other. In Figure 9A, the radially inner pole of the electromagnet produced by the current flowing through coil 22U is the north pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22W is the south pole.

[0071] As shown in Figure 9B, when the rotation angle θm is 60°, the first brush member 71b contacts the contact portion 41V of the commutator member 40V, and the second brush member 72b contacts the contact portion 41W of the commutator member 40W. In this case, current flows through coil 22V and coil 22W, and the direction of the current flowing through coil 22V and the direction of the current flowing through coil 22W are opposite to each other. In Figure 9B, the radially inner pole of the electromagnet produced by the current flowing through coil 22V is the north pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22W is the south pole.

[0072] As shown in Figure 9C, when the rotation angle θm is 120°, the first brush member 71b contacts the contact portion 41V of the commutator member 40V, and the second brush member 72b contacts the contact portion 41U of the commutator member 40U. In this case, current flows through coil 22U and coil 22V, and the direction of the current flowing through coil 22U and the direction of the current flowing through coil 22V are opposite to each other. In Figure 9C, the radially inner pole of the electromagnet produced by the current flowing through coil 22U is the south pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22V is the north pole.

[0073] As shown in Figure 9D, when the rotation angle θm is 180°, the first brush member 71b contacts the contact portion 41W of the commutator member 40W, and the second brush member 72b contacts the contact portion 41U of the commutator member 40U. In this case, current flows through coil 22U and coil 22W, and the direction of the current flowing through coil 22U and the direction of the current flowing through coil 22W are opposite to each other. In Figure 9D, the radially inner pole of the electromagnet produced by the current flowing through coil 22U is the south pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22W is the north pole.

[0074] As shown in Figure 9E, when the rotation angle θm is 240°, the first brush member 71b contacts the contact portion 41W of the commutator member 40W, and the second brush member 72b contacts the contact portion 41V of the commutator member 40V. In this case, current flows through coil 22V and coil 22W, and the direction of the current flowing through coil 22V and the direction of the current flowing through coil 22W are opposite to each other. In Figure 9E, the radially inner pole of the electromagnet produced by the current flowing through coil 22V is the south pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22W is the north pole.

[0075] As shown in Figure 9F, when the rotation angle θm is 300°, the first brush member 71b contacts the contact portion 41U of the commutator member 40U, and the second brush member 72b contacts the contact portion 41V of the commutator member 40V. In this case, current flows through coil 22U and coil 22V, and the direction of the current flowing through coil 22U and the direction of the current flowing through coil 22V are opposite to each other. In Figure 9F, the radially inner pole of the electromagnet produced by the current flowing through coil 22U is the north pole, and the radially inner pole of the electromagnet produced by the current flowing through coil 22V is the south pole.

[0076] As described above, by making the circumferential angle φ around the central axis J between the portion of the first brush member 71b that contacts the commutator member 40 and the portion of the second brush member 72b that contacts the commutator member 40 equivalent to an angle of 180° in electrical angle terms, in the second drive system, the contact between each brush member and each commutator member 40 can be sequentially switched during one rotation of the rotor 10, and the direction of the current flowing through the multiple coils 22 can be switched in the same way as in the first drive system. Therefore, in the second drive system using the first brush member 71b, the second brush member 72b, and the multiple commutator members 40, current can be suitably supplied to the motor body 100b, and the motor body 100b can be suitably driven.

[0077] In this embodiment, as described above, the first brush member 71b is movable between a first position P1 in contact with the commutator member 40 and a second position P2 away from the commutator member 40. Therefore, when the motor body 100b is driven using the first drive method, positioning the first brush member 71b at the second position P2 can suppress friction between the first brush member 71b and the commutator member 40. Consequently, wear of the first brush member 71b can be suppressed. Furthermore, when the motor body 100b is driven using the first drive method, positioning the first brush member 71b at the second position P2 prevents rotational resistance from being applied to the rotor 10 due to friction between the first brush member 71b and the commutator member 40. Consequently, the rotor 10 can be easily rotated using the first drive method. The same effect applies to the second brush member 72b.

[0078] In this embodiment, as described above, the first position P1 and the second position P2 are positions where the radial position of the first brush member 71b is different from that of the first brush member 71b. The motor 100 is equipped with an elastic member 75a that applies a force to the first brush member 71b in a direction that presses the first brush member 71b radially against the commutator member 40. Therefore, the elastic member 75a can ensure that the first brush member 71b is in stable contact with the commutator member 40. Furthermore, since the radial positions of the first position P1 and the second position P2 are different from that of the first brush member 71b, when the centrifugal force generated on the first brush member 71b becomes large enough to move the first brush member 71b against the elastic force applied to the first brush member 71b by the elastic member 75a, the centrifugal force can automatically move the first brush member 71b to the second position P2. Therefore, there is no need to provide a separate drive unit to move the first brush member 71b between the first position P1 and the second position P2, which further suppresses the increase in the manufacturing cost of the motor 100. The same effect applies to the second brush member 72b and the elastic member 75b.

[0079] In this embodiment, as described above, the motor 100 includes a support portion 73a that supports the first brush member 71b radially at the second position P2. Therefore, the first brush member 71b, which automatically moves radially due to centrifugal force, can be positioned at the second position P2. This prevents the first brush member 71b from moving too far radially and coming into contact with other members. In this embodiment, the support portion 73a supports the first brush member 71b, which automatically moves radially outward due to centrifugal force, from the radially outward side at the second position P2. Therefore, it is possible to prevent the first brush member 71b from moving too far radially outward. Consequently, it is possible to prevent the first brush member 71b from coming into contact with the stator 20 or the like. The same effect applies to the second brush member 72b and the support portion 73b.

[0080] In this embodiment, when the motor body 100b is driven by the first drive method, the control unit 80 turns off the switching element 84. When the switching element 84 is turned off, the connection between the external power supply E and the conductive member 50 is interrupted, and no current flows to the first brush member 71b, the second brush member 72b, and the multiple commutator members 40. In other words, in this embodiment, the switching element 84 is a switching element that can interrupt the supply of current to the multiple coils 22 via the first brush member 71b, the second brush member 72b, and the multiple commutator members 40. Therefore, by interrupting the supply of current to the multiple coils 22 via the first brush member 71b, the second brush member 72b, and the multiple commutator members 40 using the switching element 84, it is possible to suppress the flow of current other than the current from the drive circuit 83 to the multiple coils 22 when the motor body 100b is driven by the first drive method. Thus, the control unit 80 can suitably drive the motor body 100b by the first drive method. Furthermore, by using the switching element 84 to interrupt the supply of current to the first brush member 71b, the second brush member 72b, and the multiple coils 22 via the multiple commutator members 40, the control unit 80 can actively terminate the driving of the motor body 100b by the second driving method.

[0081] In this embodiment, if the control unit 80 detects an abnormality in the driving of the motor body 100b while driving the motor body 100b using the first driving method, it switches the driving method for the motor body 100b from the first driving method to the second driving method. Therefore, even if some abnormality occurs in the driving of the motor body 100b using the first driving method, the driving of the motor body 100b can be continued. Abnormalities that occur in the driving of the motor body 100b in the first driving method include, for example, abnormalities that occur in the drive circuit 83 and abnormalities that occur in the drive signal generation unit 82a.

[0082] As shown in Figure 6, in this embodiment, the calculation unit 82 has a monitoring unit 82b. The monitoring unit 82b monitors whether there is any abnormality in the driving of the motor body 100b when the motor body 100b is being driven by the first driving method. The monitoring unit 82b receives signals output from the drive signal generation unit 82a, as well as voltage and current in the drive circuit 83. If the monitoring unit 82b determines, based on the input information, that an abnormality has occurred in the motor body 100b in the first driving method, it stops the output of the drive signal from the drive signal generation unit 82a to the drive circuit 83. As a result, each switching element 83a of the drive circuit 83 turns OFF, and the supply of current from the drive circuit 83 to the multiple coils 22 is stopped. If the monitoring unit 82b determines, based on the input information, that an abnormality has occurred in the motor body 100b in the first driving method, it outputs a drive signal to turn on the switching element 84. As a result, the switching element 84 is turned ON, and current is supplied to the multiple coils 22 via the first brush member 71b, the second brush member 72b, and the multiple commutator members 40. In other words, the drive mode of the motor body 100b is switched from the first drive mode to the second drive mode.

[0083] As described above, in this embodiment, when the rotational speed of the rotor 10 exceeds a certain rotational speed, the first brush member 71b and the second brush member 72b automatically separate from the multiple commutator members 40. Therefore, in order to continue driving the motor body 100b in the second drive method, it is necessary to maintain the rotational speed of the rotor 10 below that certain rotational speed. The control unit 80, for example, uses a pulse signal to drive the switching element 84 and adjusts the duty cycle of the pulse signal to adjust the voltage value applied to the motor body 100b, thereby maintaining the rotational speed of the rotor 10 below that certain rotational speed. The smaller the duty cycle of the drive signal that drives the switching element 84, the smaller the voltage applied to the motor body 100b in the second drive method. The smaller the voltage applied to the motor body 100b in the second drive method, the smaller the rotational speed of the rotor 10.

[0084] Figure 10 is a flowchart showing an example of the processing procedure of the control unit 80 when driving the motor body 100b. In this embodiment, the control unit 80 executes the processing shown in the flowchart of Figure 10 by the calculation unit 82. As shown in Figure 10, the control unit 80 starts driving the motor body 100b using the second driving method (step S101). When the rotor 10 is not rotating, the first brush member 71b and the second brush member 72b are in contact with the commutator body 30a, so the control unit 80 can execute the second driving method. In step S101, the control unit 80 outputs a drive signal to the switching element 84, but does not output a drive signal to the drive circuit 83.

[0085] After starting to drive the motor body 100b using the second drive method, the control unit 80 determines whether the rotational speed of the rotor 10 is equal to or greater than a predetermined value (step S102). In step S102, the control unit 80 may acquire the rotational speed of the rotor 10 in any way. In step S102, the control unit 80 may acquire the rotational speed of the rotor 10 based on a rotation sensor capable of detecting the rotational position of the rotor 10, or based on the value of the current supplied to the motor body 100b, or based on the value of the back electromotive force generated in the motor body 100b. The predetermined value used for the determination in step S102 is a value less than or equal to the rotational speed of the rotor 10 at which the first brush member 71b and the second brush member 72b automatically separate from the commutator body 30a due to centrifugal force. This predetermined value is, for example, smaller than the rotational speed of the rotor 10 at which the first brush member 71b and the second brush member 72b automatically separate from the commutator body 30a due to centrifugal force.

[0086] If the control unit 80 determines in step S102 that the rotational speed of the rotor 10 is less than a predetermined value (step S102: NO), it continues to drive the motor body 100b using the second drive method. If the control unit 80 determines in step S102 that the rotational speed of the rotor 10 is greater than or equal to a predetermined value (step S102: YES), it switches the drive method of the motor body 100b to the first drive method (step S103). Thus, in this embodiment, the control unit 80 starts rotating the rotor 10 using the second drive method, and when the rotational speed of the rotor 10 becomes greater than or equal to a predetermined value, it switches the drive method for driving the motor body 100b from the second drive method to the first drive method. As described above, in the second drive method, the current supplied to the multiple coils 22 is switched mechanically via the first brush member 71b, the second brush member 72b, and the multiple commutator members 40. Therefore, by starting the motor body 100b drive using the second drive method, the control unit 80 can stably start rotating the rotor 10 regardless of the initial value of the rotor 10 when the motor body 100b is started. Furthermore, when the rotational speed of the rotor 10 stabilizes at or above a predetermined value, the motor body 100b can be efficiently driven by driving it using the first drive method with the drive circuit 83. Also, as described above in this embodiment, when the rotational speed of the rotor 10 exceeds a certain rotational speed, the first brush member 71b and the second brush member 72b automatically separate from the multiple commutator members 40. Therefore, by setting the predetermined value in step S102 to be below that certain rotational speed, the control unit 80 can switch the drive method of the motor body 100b from the second drive method to the first drive method when the first brush member 71b and the second brush member 72b separate from the multiple commutator members 40, or before they separate from the multiple commutator members 40. Therefore, the control unit 80 can reliably switch the drive mode of the motor body 100b from the second drive mode to the first drive mode.

[0087] In step S103, the control unit 80 switches the drive method from the second drive method to the first drive method by turning off the switching element 84 and outputting a drive signal to the drive circuit 83. Note that when the control unit 80 starts driving the motor body 100b using the second drive method in step S101, it may start the same calculations as when starting to drive the motor body 100b using the first drive method, even though it does not output a drive signal to drive the drive circuit 83. In this case, the control unit 80 can stably drive the motor body 100b using the first drive method immediately after switching the drive method of the motor body 100b from the second drive method to the first drive method in step S103.

[0088] After switching the drive mode of the motor body 100b to the first drive mode, the control unit 80 determines whether or not the monitoring unit 82b has detected an abnormality (step S104). If the control unit 80 determines in step S104 that the monitoring unit 82b has not detected an abnormality (step S104: NO), it continues monitoring by the monitoring unit 82b and continues driving the motor body 100b using the first drive mode. If the control unit 80 determines in step S104 that the monitoring unit 82b has detected an abnormality (step S104: YES), it switches the drive mode of the motor body 100b from the first drive mode to the second drive mode (step S105). In step S105, the control unit 80 stops the drive signal to the drive circuit 83 and outputs a drive signal to turn on the switching element 84, switching the drive mode of the motor body 100b to the second drive mode. In step S105, the control unit 80 outputs a signal to a higher-level device, such as one on which the motor 100 is mounted, to inform it that the monitoring unit 82b has detected an abnormality.

[0089] At least part of the functions of each component of the control unit 80 are realized, for example, by executing a program, i.e., software, stored in a storage unit (not shown). At least part of the functions of each component of the control unit 80 may be realized by hardware including circuit units such as LSI (Large Scale Integration), ASIC (Application Specific Integrated Circuit), FPGA (Field-Programmable Gate Array), and GPU (Graphics Processing Unit), or by the cooperation of software and hardware. The storage unit (not shown) in which the above-mentioned program is stored is realized by a storage medium such as RAM (Random Access Memory), ROM (Read Only Memory), HDD (hard disk drive), and flash memory. The storage unit is not particularly limited as long as it can store the above-mentioned program, and may be a microcomputer or a disk medium such as a CD-ROM. The storage unit may be provided separately from the control unit 80. In this case, the control unit 80 may communicate with the storage unit by wired communication or wireless communication and execute the program stored in the storage unit.

[0090] The control unit 80 may switch between the first and second drive modes in any manner. After starting to drive the motor body 100b using the second drive mode, the control unit 80 may switch the drive mode of the motor body 100b to the first drive mode when it detects that the first brush member 71b and the second brush member 72b have separated from the multiple commutator members 40. One method for detecting that the first brush member 71b and the second brush member 72b have separated from the multiple commutator members 40 is, for example, detection based on the value of a current sensor provided in the power supply wiring section 81a. After starting to drive the motor body 100b using the second drive mode, the control unit 80 may switch the drive mode of the motor body 100b to the first drive mode after a period of alternating switching between the first and second drive modes. After starting to drive the motor body 100b using the second drive method, the control unit 80 may switch the drive method of the motor body 100b to the first drive method based on the value of the current supplied to the motor body 100b or the value of the back electromotive force generated in the motor body 100b, regardless of the rotational speed of the rotor 10. When starting to drive the motor body 100b, the control unit 80 may drive the motor body 100b using the first drive method from the beginning.

[0091] Furthermore, the control unit 80 may be divided into multiple parts and configured as a control unit having the functions described above by these multiple parts. For example, the control unit 80 may be configured as the control unit 180 provided in the motor 101 shown in Figure 11. As shown in Figure 11, in the control unit 180 of the motor 101, a monitoring unit 182b is provided separately from the calculation unit 182. The monitoring unit 182b is, for example, a microcontroller (MCU). The monitoring unit 182b can communicate with the calculation unit 182. The monitoring unit 182b functions in the same way as the monitoring unit 82b described above. The calculation unit 182 is the same as the calculation unit 82 described above, except that the monitoring unit 182b is not provided.

[0092] The following describes embodiments that differ from those described above. In the following descriptions of each embodiment, components similar to those described in the section above may be omitted from the description by using the same reference numerals as appropriate. Also, for parts corresponding to the components described in the section above each embodiment, the same name and different reference numerals will be used to explain the differences from the above-described configuration, while the explanation of similar components may be omitted. Note that, within the scope of consistency, components similar to those described in the section above each embodiment may be adopted as components whose description is omitted.

[0093] <Second Embodiment> The motor 200 of this embodiment shown in Figures 12 and 13 is a three-phase motor. The motor 200 is an 8-pole, 12-slot motor. As shown in Figures 12 and 13, the rectifier 230 of the motor 200 of this embodiment has a plurality of commutator members 240. There are three commutator members 240: commutator member 240U, commutator member 240V, and commutator member 240W. As shown in Figure 14, commutator member 240U has a plurality of contact portions 241U and a connecting portion 242U. Commutator member 240V has a plurality of contact portions 241V and a connecting portion 242V. Commutator member 240W has a plurality of contact portions 241W and a connecting portion 242W.

[0094] The connecting parts 242U, 242V, and 242W are annular in shape, surrounding the central axis J. The connecting parts 242U, 242V, and 242W are arranged side by side with a gap in the axial direction. As shown in Figure 15, each of the connecting parts 242U, 242V, and 242W has an annular part 242a and a plurality of protrusions 242b. The annular part 242a is an annular shape, surrounding the central axis J. More specifically, the annular part 242a is a circular annular shape centered on the central axis J. The plurality of protrusions 242b project radially outward from the annular part 242a. The plurality of protrusions 242b are arranged with a gap in the circumferential direction. The plurality of protrusions 242b are arranged at equal intervals around the circumference in the circumferential direction. In each of the connecting sections 242U, 242V, and 242W of this embodiment, four protrusions 242b are provided. The connecting sections 242U, 242V, and 242W are offset from each other in the circumferential direction, but have similar shapes. The multiple protrusions 242b in the connecting section 242U, the multiple protrusions 242b in the connecting section 242V, and the multiple protrusions 242b in the connecting section 242W are positioned so as not to overlap each other when viewed in the axial direction.

[0095] Contact portions 241U are fixed to the radially outer ends of each of the multiple protrusions 242b in the connecting portion 242U. Contact portions 241V are fixed to each of the radially outer ends of each of the multiple protrusions 242b in the connecting portion 242V. Contact portions 241W are fixed to each of the radially outer ends of each of the multiple protrusions 242b in the connecting portion 242W.

[0096] As shown in Figure 14, the multiple contact portions 241U, 241V, and 241W are arranged at the same position in the axial direction. The multiple contact portions, including the multiple contact portions 241U, 241V, and 241W, are arranged at equal intervals around the circumference. In these multiple contact portions, one contact portion 241U, one contact portion 241V, and one contact portion 241W are arranged sequentially along the circumference. In this embodiment as well, the total number of multiple contact portions, including the multiple contact portions 241U, 241V, and 241W, is expressed as N × P / 2, where N is the number of phases of the motor 200 and P is the number of poles of the rotor. Since the number of phases N of the motor 200 is 3 and the number of poles P of the rotor is 8, the total number of multiple contact portions in this embodiment is 12.

[0097] As shown in Figure 13, the support member 231 has a holding portion 231d for holding each commutator member 240. In this embodiment, the support member 231 consists of a holding portion 231d. The support member 231 may have a cylindrical portion 31a, an annular portion 31b, and a plurality of arm portions 31c, similar to the support member 31 of the first embodiment. A portion of each commutator member 240 is embedded in the holding portion 231d. Each commutator member 240 is entirely embedded in the holding portion 231d, except for the upper surface and radially outer surface of each contact portion 241U, 241V, 241W. The holding portion 231d is an annular shape surrounding the central axis J. More specifically, the holding portion 231d is an annular shape centered on the central axis J. The holding portion 231d has a through hole 231f that penetrates the holding portion 231d in the axial direction. The through hole 231f is located radially outward from the inner circumferential surface of the retaining portion 231d. The other configurations of the retaining portion 231d are the same as those of the retaining portion 31d in the first embodiment.

[0098] The first insulating member 232 is the same as the first insulating member 32 of the first embodiment, except that it has a through hole 232a that penetrates the first insulating member 232 in the axial direction. The through hole 232a is located below the through hole 231f and connects to the through hole 231f. In this embodiment, the first connecting portion 52 of the conductive member 50 is passed through the through hole 232a and the through hole 231f in the axial direction.

[0099] As shown in Figure 16, the circumferential angle φ around the central axis J between the portion of the first brush member 271b that contacts the commutator member 240 and the portion of the second brush member 272b that contacts the commutator member 240 is 225° in mechanical terms. Since the rotor in this embodiment has 8 poles, a mechanical angle of 225° is equivalent to an electrical angle of 900°. An electrical angle of 900° is equivalent to an angle expressed as 540 / N[°], or 180°, when the number of phases N of the motor 200 is 3. Therefore, as the rotor rotates and the commutator member 240 that each brush member contacts changes sequentially, the motor body can be driven effectively, similar to the first embodiment.

[0100] In this embodiment, the second brush member 272b may be placed at any of the three locations shown by the dashed lines in Figure 16. The locations for the second brush member 272b shown by the dashed lines in Figure 16 are the location where the angle φ is 45° in mechanical angle, the location where the angle φ is 135° in mechanical angle, and the location where the angle is 315° in mechanical angle. Regardless of which of these three locations the second brush member 272b is placed at, the angle φ will be equivalent to an angle that is 180° in electrical angle terms. The other configurations of the motor 200 are the same as those of the motor 100 in the first embodiment.

[0101] The present invention is not limited to the embodiments described above, and other configurations and methods can be adopted within the scope of the technical idea of ​​the present invention. The structure of the motor may be any structure that can be driven by the first drive method and the second drive method, respectively. The number of poles of the rotor is not particularly limited.

[0102] If the first brush member and the second brush member are movable between a first position in contact with the commutator member and a second position away from the commutator member, each brush member may move automatically by centrifugal force as in the first embodiment described above, or it may be moved by a drive unit that drives each brush member. For example, a solenoid actuator can be used as the drive unit. In this case, the solenoid actuator switches the position of each brush member between the first position and the second position. Each brush member may be mounted on the rotor so as to be movable in the radial direction by a radially extending rail member or the like. In this case, each brush member may be configured to move automatically in the radial direction by centrifugal force, or it may be configured to be moved in the radial direction by the drive unit described above. The first position may be any position in which each brush member is in contact with the commutator member. The second position may be any position in which each brush member is away from the commutator member. The first position and the second position may be different positions in the axial direction. In this case, the second position is a position different from the commutator member in the axial direction.

[0103] Each brush member may be located radially inward of the multiple commutator members. In this case, each brush assembly may be configured to rotate around a rotation axis extending axially due to centrifugal force. In this case, each brush assembly may be configured to rotate with a fulcrum between the two circumferential ends, for example, and a weight portion may be provided at an end different from the circumferential end on which each brush member is located. As a result, when the weight portion moves radially outward due to centrifugal force, each brush member moves radially inward relative to it. Therefore, each brush member located radially inward of the multiple commutator members can be automatically moved radially inward and separated from the multiple commutator members by utilizing centrifugal force.

[0104] In this specification, "the brush members are capable of contacting the commutator members" means that there is a possibility that the brush members will contact the commutator members when the motor is in use. In other words, "the brush members are capable of contacting the commutator members" means that the brush members may always be in contact with the commutator members when the motor is in use, or it may include cases where the brush members are in contact with the commutator members and cases where they are not in contact with the commutator members when the motor is in use, or the brush members do not always have to be in contact with the commutator members when the motor is in use. For example, if the motor body is driven by the second drive method only when an abnormality is detected in the first drive method, then the brush members do not have to be in contact with the commutator members during use as long as no abnormality occurs when the motor is in use.

[0105] The applications of the motor to which the present invention applies are not particularly limited. The motor may be mounted on any equipment. The motor may be mounted on a vehicle. In this case, the motor may be used as a power source for the vehicle. The motor may be used in an electric pump or an electric actuator.

[0106] Furthermore, this technology can be configured as follows: (1) A motor comprising: a motor body having a rotor rotatable about a central axis and a stator having a plurality of coils and facing the rotor with a gap between them; a control unit having a drive circuit capable of driving the motor body; a plurality of commutator members, each electrically connected to at least one of the coils; a first brush member that rotates with the rotor and is capable of contacting the commutator members; and a second brush member that rotates with the rotor and is capable of contacting a commutator member different from the commutator member that the first brush member contacts, wherein the control unit can switch between a first drive method for driving the motor body, in which the drive circuit supplies current to the plurality of coils to drive the motor body, and a second drive method for driving the motor body, in which current is supplied to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members to drive the motor body. (2) The motor according to (1), comprising a conductive member electrically connected to the control unit and to which a power supply voltage is applied, and a ground member that is grounded, wherein the first brush member is capable of simultaneously contacting the conductive member and the commutator member, and the second brush member is capable of simultaneously contacting a commutator member different from the commutator member that the first brush member contacts and the ground member. (3) The motor according to (2), wherein the conductive member, the ground member, and the plurality of commutator members are fixed in an insulated state from each other, and the ground member is connected to the ground portion of the control unit and grounded. (4) A three-phase motor, wherein each of the plurality of commutator members has at least one contact portion that can be contacted by the first brush member and the second brush member, the plurality of contact portions included in the plurality of commutator members are arranged in a circumferential direction around the central axis, and when the number of poles of the rotor is P, the total number of the plurality of contact portions included in the plurality of commutator members is expressed as 3 × P / 2, and the circumferential angle around the central axis between the portion of the first brush member that contacts the commutator member and the portion of the second brush member that contacts the commutator member is equivalent to an angle that is 180° in electrical angle terms, as described in any one of (1) to (3). (5) The motor according to any one of (1) to (4), wherein the first brush member is movable between a first position in contact with the commutator member and a second position away from the commutator member. (6) The motor according to (5), wherein the first position and the second position are positions in which the radial position of the first brush member is different from each other, and the motor is further provided with an elastic member that applies a force to the first brush member in a direction that presses the first brush member radially against the commutator member. (7) The motor according to (6), further comprising a support portion that radially supports the first brush member at the second position. (8) The motor according to any one of (1) to (7), wherein the control unit has a switching element capable of interrupting the supply of current to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members. (9) The motor according to any one of (1) to (8), wherein the control unit detects an abnormality in the driving of the motor body when the motor body is being driven by the first driving method, and switches the driving method for driving the motor body from the first driving method to the second driving method. (10) The motor according to any one of (1) to (9), wherein the control unit starts rotating the rotor by the second drive method, and when the rotational speed of the rotor reaches a predetermined value or more, switches the drive method for driving the motor body from the second drive method to the first drive method.

[0107] The configurations and methods described herein can be combined as appropriate, within the bounds of non-inconsistency. [Explanation of Symbols]

[0108] 10...Rotor, 20...Stator, 22,22U,22V,22W...Coil, 40,40U,40V,40W,240,240U,240V,240W...Commutator components, 41,41U,41V,41W,241U,241V,241W...Contact parts, 50...Conductive components, 60...Ground components, 71b,271b...First brush components, 72b,27 2b...Second brush member, 73, 73a, 73b...Support part, 75a, 75b...Elastic member, 80, 180...Control unit, 81b...Ground part, 83...Drive circuit, 83a, 84...Switching element, 100, 101, 200...Motor, 100b...Motor body, I...Current, J...Center axis, P...Number of poles, P1...First position, P2...Second position, φ...Angle

Claims

1. A motor body comprising a rotor rotatable about a central axis, and a stator having multiple coils and facing the rotor with a gap between them, A control unit having a drive circuit capable of driving the motor body, A plurality of commutator members, each electrically connected to at least one of the coils, A first brush member that rotates together with the rotor and is capable of contacting the commutator member, A second brush member rotates together with the rotor and is capable of contacting a commutator member different from the commutator member that the first brush member contacts, Equipped with, The control unit is capable of switching the drive method for driving the motor body between a first drive method, in which the drive circuit drives the motor body by supplying current to the plurality of coils, and a second drive method, in which the drive circuit drives the motor body by supplying current to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members.

2. A conductive member electrically connected to the control unit and to which the power supply voltage is applied, Ground member to be grounded, Equipped with, The first brush member is capable of simultaneously contacting the conductive member and the commutator member, The motor according to claim 1, wherein the second brush member is capable of simultaneously contacting a commutator member different from the commutator member in contact with the first brush member, and the gland member.

3. The conductive member, the ground member, and the plurality of commutator members are fixed in an insulated state from each other. The motor according to claim 2, wherein the ground member is connected to and grounded to the ground portion of the control unit.

4. It is a three-phase motor. Each of the plurality of commutator members has at least one contact portion that can be contacted by the first brush member and the second brush member, The multiple contact portions included in the multiple commutator members are arranged in a circumferential direction around the central axis, When the number of poles of the rotor is P, The total number of contact portions included in the plurality of commutator members is expressed as 3 × P / 2, The motor according to claim 1, wherein the circumferential angle around the central axis between the portion of the first brush member that contacts the commutator member and the portion of the second brush member that contacts the commutator member is equivalent to an angle of 180° in electrical angle terms.

5. The motor according to claim 1, wherein the first brush member is movable between a first position in contact with the commutator member and a second position away from the commutator member.

6. The first position and the second position are positions where the radial position of the first brush member is different from each other. The motor according to claim 5, further comprising an elastic member that applies a force to the first brush member in a direction that presses the first brush member radially against the commutator member.

7. The motor according to claim 6, further comprising a support portion that radially supports the first brush member at the second position.

8. The motor according to claim 1, wherein the control unit has a switching element capable of interrupting the supply of current to the plurality of coils via the first brush member, the second brush member, and the plurality of commutator members.

9. The motor according to any one of claims 1 to 8, wherein the control unit detects an abnormality in the driving of the motor body when the motor body is being driven by the first driving method, and switches the driving method for driving the motor body from the first driving method to the second driving method.

10. The motor according to any one of claims 1 to 8, wherein the control unit starts rotating the rotor by the second drive method, and when the rotational speed of the rotor exceeds a predetermined value, switches the drive method for driving the motor body from the second drive method to the first drive method.

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