WO2005036717A1

WO2005036717A1 - Direct current motor and power supply method for the same

Info

Publication number: WO2005036717A1
Application number: PCT/JP2004/014923
Authority: WO
Inventors: Toshinori Sasaki
Original assignee: Aisin Seiki Kabushiki Kaisha
Priority date: 2003-10-09
Filing date: 2004-10-08
Publication date: 2005-04-21
Also published as: JP2005117822A

Abstract

A direct current motor whose rotor can be downsized and power supply method for the motor. A direct current motor (11) includes a stator (12) and a rotor (13). The stator (12) has a core (21), a coil (22) wound on the core (21), and a commutator (23) connected to the coil (22). The rotor (13) is rotatably placed on the inner periphery side of the stator (12) and includes a yoke (37) and a magnet (38) fixed to the yoke (37). Slip rings (31, 32) and brushes (44, 48) supply power that is supplied to the stator (12) to the rotor (13). Brushes (43, 47) arranged on the rotor (13) are connected to the slip rings (31, 32) and slide on the commutator (23).

Description

Specification

DC motor and power supply method thereof

Technical field

The present invention relates to a DC motor and a power supply method thereof.

Background art

Conventionally, as a DC motor, for example, DC motors described in Patent Documents 1 and 2 are known. The DC motors described in these patent documents include a stator having a magnet fixed to an inner wall surface of a motor case. Inside the stator, a rotor on which a core on which coils are wound, a commutator, and a shaft are integrally supported. The brush supported by the motor case is in sliding contact with the commutator. Therefore, when power is supplied from an external power supply to the DC motor, the power is supplied to the coil via the brush force commutator, and a magnetic field is generated in the coil. The action of the magnetic field generated in the coil and the magnetic force of the magnet facing the coil generates a rotational moment in the coil, and the rotor rotates. When the rotor rotates, the polarity of the supplied power is sequentially switched by the commutator, and the rotor continuously rotates in one direction.

[0003] In the DC motors described in Patent Documents 1 and 2, the magnet of the stator is disposed so as to face the rotor in the radial direction of the rotor having the core on which the coil is wound. The motor case to which the is fixed functions as a back yoke of the magnetic circuit. Therefore, it is preferable to secure a magnetic path space (cross-sectional area of the teeth orthogonal to the radial direction of the motor) in the teeth of the rotor core, which is proportional to the amount of magnetic flux generated by the magnet. On the other hand, between the adjacent teeth of the core, it is also necessary to secure a sufficient space (the cross-sectional area orthogonal to the motor radial direction in the space between the adjacent teeth) for winding the coil for the required performance. It is. Therefore, since both the magnetic path space and the winding space are concentrated on the rotor, both spaces must be sufficiently ensured, and there is a limit to the small diameter of the rotor.

Patent Document 1: Japanese Patent No. 3433370

Patent document 2: JP-A-2000-175402 Disclosure of the invention

[0004] The present invention provides a DC motor and a power supply method thereof that can realize a rotor with a small diameter.

According to a first aspect of the present invention, there is provided a stator including a core, a coil wound on the core, and a commutator connected to the coil, a rotatably disposed inside the stator, a yoke, and a fixation to the yoke. A DC motor including a rotor including the magnets provided, an intermediate member for supplying electric power supplied to the stator to the rotor, and a brush provided on the rotor and connected to the intermediate member and in sliding contact with the commutator. And

[0005] In the first embodiment of the present invention, the magnet has a plurality of segments, and adjacent segments may be magnetized to different polarities from each other!

In the first aspect of the present invention, the brush may be urged along the axial direction of the rotor so as to slide on the commutator.

[0006] In the first aspect of the present invention, the intermediary member includes a slip ring provided on one of the stator and the rotor, and an intermediary brush provided on one of the other of the stator and the rotor and in sliding contact with the slip ring. May be included. In this case, the intermediary brush may be urged along the axial direction of the rotor so as to be in sliding contact with the slip ring. Alternatively, the intermediary brush may be urged along the radial direction of the rotor so as to slide on the slip ring.

[0007] In the first aspect of the present invention, the stator includes a stator body that houses the coil and the core, a connector body that houses a terminal for supplying power to the DC motor, and a deviation between the stator body and the connector body. It may include a fitting projection provided on one side and interconnecting the stator main body and the connector main body. In this case, the DC motor may include a brush holder fixed to one end of the rotor, housed in the connector body, and holding the brush.

[0008] A second aspect of the present invention provides a core, a coil wound on the core, a stator body accommodating the coil and the core, a commutator connected to the coil, and a power supply to a DC motor. Including a connector main body for accommodating the terminal, and a fitting protrusion provided on one or the other of the stator main body and the connector main body for interconnecting the stator main body and the connector main body. A rotor rotatably disposed inside the stator and including a yoke and a magnet fixed to the yoke; a slip ring provided on one of the stator and the rotor; Or the other which is provided on the other

A DC motor comprising: one brush; and a second brush connected to one of a slip ring and a first brush provided on the rotor, provided on the rotor, and in sliding contact with a commutator.

[0009] A third aspect of the present invention is a power supply method for a DC motor including a stator, a rotor, a core on which a coil is wound, a commutator connected to the coil, and a magnet fixed to the yoke. In addition, the present invention is characterized by a method of supplying power to a DC motor, comprising temporarily supplying power supplied to a stator to a rotor, and supplying power supplied to the rotor to the stator.

[0010] (Action)

According to the first aspect of the present invention, the electric power supplied to the stator of the DC motor is once supplied to the rotor via the intermediate member. Then, the electric power supplied to the rotor is supplied again to the stator via the brush and the commutator connected to the intermediate member. At this time, electric power is supplied to the coil via the commutator, and a rotational moment is generated in the magnet due to the action of the magnetic field generated in the coil and the magnetic force of the magnet facing the coil, and the rotor rotates. When the rotor rotates, the commutator sequentially switches the polarity of the supplied power, and the rotor continuously rotates in one direction. In the DC motor driven in this manner, the rotor arranged on the inner peripheral side of the stator is constituted by a magnet fixed to the yoke. That is, since it is not necessary to secure a magnetic path space and a winding space in the rotor, the rotor is particularly reduced in diameter.

[0011] In the first aspect of the present invention, in the configuration in which the brush is urged along the axial direction of the rotor, in the configuration in which the stator and the rotor are axially assembled, the brush is attached along with the assembling operation. And the commutator are smoothly pressed against each other, so that the complexity of the assembling work is reduced.

[0012] In the first aspect of the present invention, the intermediate member includes a slip ring provided on one of the stator and the rotor, and an intermediary brush provided on one of the other and slidingly in contact with the slip ring. In the configuration, the intermediate member can be formed extremely easily. Change In a configuration in which the intermediate brush is urged along the axial direction of the rotor, the intermediate brush and the slip ring are smoothly pressed together with the operation of assembling the stator and the rotor along the axial direction, The complexity of the assembly operation is reduced.

[0013] According to the third aspect of the present invention, the electric power supplied to the stator is temporarily supplied to the rotor, and is again supplied to the stator. Therefore, the core and the commutator on which the coil is wound may be provided on the stator without the necessity of rotating the coil and the commutator connected to the coil. In this case, since the rotor may be provided with a magnet fixed to the yoke, it is not necessary to secure a magnetic path space and a winding space in the rotor, and in particular, the rotor can be reduced in diameter.

Brief Description of Drawings

FIG. 1 is a longitudinal sectional view showing a DC motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a cross-sectional view along the axial direction of a brush holder included in the DC motor in FIG. 1.

[Fig. 4] Diagram showing connection of DC motor in Fig. 1.

FIG. 5 is a longitudinal sectional view showing a DC motor according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a DC motor according to a third embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

Hereinafter, a DC motor 11 according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a longitudinal sectional view of the DC motor 11 of the first embodiment, and FIG. 2 is a sectional view taken along line 2-2 of FIG. As shown in FIG. 1, the DC motor 11 includes a stator 12 and a motor 13. The stator 12 includes a stator body 14 and a connector body 15.

The stator main body 14 includes a core 21 made of a laminated steel sheet, a coil 22, and a plurality of (12 in the first embodiment) commutator segments 23 a constituting a commutator (commutator) 23. The core 21, the coil 22, and the commutator segment 23 a are integrated by a housing part 24 which also has a resin material strength. As shown in FIG. 2, the core 21 includes an inner core 25 and a cylindrical outer core 26. The inner core 25 has a cylindrical inner race 25a, and a plurality (12) of teeth 25b radially extending from the inner race 25a at a predetermined angle (30 ° in the first embodiment). The base end of each tooth 25b is formed so as to gradually widen toward both adjacent teeth 25b as it is directed toward the inner ring portion 25a. Note that the outer surface of each tooth 25b is covered with a resin material forming the housing portion 24.

[0019] On the inner peripheral surface of the outer core 26, a plurality (12) of fitting recesses 26a are provided at predetermined angles (30 °) corresponding to the tips of the teeth 25b. The core 21 is formed by fitting each of the tips of the teeth 25b of the inner core 25 with the corresponding fitting recess 26a of the outer core 26, and assembling the inner core 25 and the outer core 26 integrally.

[0020] The coil 22 is wound around the teeth 25b by a lap winding with a short wire, which will be described later, between the inner race 25a of the inner core 25 and the outer core 26. In FIG. 2, the illustration of the coil 22 is omitted for convenience.

The commutator 23 has an inner diameter equal to the inner diameter of the core 21 (the inner ring portion 25a),

(Right side of FIG. 1), it is arranged coaxially with the core 21. The commutator 23 is embedded in the housing 24 so as to expose the commutator segment 23a inside the housing 24. Each commutator segment 23a of the commutator 23 is electrically connected to the winding of the coil 22.

The housing part 24 is formed in a substantially cylindrical shape having an inner diameter equivalent to the inner diameter of the core 21 and the commutator 23, and is provided in a state surrounding the core 21, the coil 22, and the commutator 23. The outer shape of the body 14 is formed. An annular fitting protrusion 24a is formed on one side (the right side in FIG. 1) of the housing portion 24 so as to protrude along the inner peripheral surface thereof in parallel with the axial direction. The fitting projection 24a is used for engaging the connector main body 15 with the stator main body 14 (no, the housing portion 24).

[0023] The connector body 15 includes two slip rings 31, 32 arranged on a coaxial line separated from each other in the axial direction, and a predetermined positional force on the outer peripheral surface of each of the slip rings 31, 32. And terminals 33 and 34 extending therefrom. The slip rings 31 and 32 and the terminals 33 and 34 are integrally formed by a connector housing 35 which also has a resin material. Slip ring 31 and 32 are made of a conductive material and have an inner diameter equivalent to the inner diameter of the commutator 23 (nozzling part 24) and formed in an annular shape. The slip rings 31 and 32 are embedded in the connector housing 35 so that the inner peripheral surfaces of the slip rings 31 and 32 are exposed inside the connector housing 35.

[0024] The connector housing portion 35 is formed in a substantially bottomed cylindrical shape having an inner diameter equivalent to the inner diameter of the slip rings 31 and 32, and base ends of the slip rings 31 and 32 and the terminals 33 and 34. The external shape of the connector main body 15 is formed in a manner to surround the connector body. The connector housing 35 is formed with a connector holder 35a so as to surround the ends of the terminals 33 and 34 exposed to the outside. An annular fitting recess 35b is formed at the opening side (left side in FIG. 1) end of the connector housing portion 35 in parallel with the axial direction corresponding to the fitting protrusion 24a of the nosing and housing portion 24. . The connector main body 15 (connector housing portion 35) is connected to the stator main body 14 by fitting the fitting projection 24a into the fitting recess 35b. In the stator 12, an inner space S having a substantially circular cross section is formed by the inner wall surfaces of the stator body 14 and the connector body 15.

[0025] The rotor 13 is rotatably accommodated in an internal space S formed in the stator 12. The rotor 13 includes a shaft 36, a yoke 37, a magnet 38, and a brush horn roller 39. The shaft 36 is arranged coaxially with the stator 12, and one side and the other side (the left and right sides in FIG. 1) of the shaft 36 are connected to ball bearings 41 and 42 mounted on the inner peripheral surface of the housing part 24. Each is pivotally supported. The ball bearings 41 and 42 are disposed substantially corresponding to the ends of one side and the other side (left and right sides in FIG. 1) of the core 21 in the axial direction. One end (left side in FIG. 1) of the shaft 36 penetrates the ball bearing 41 and protrudes to the outside. The other end (right side in FIG. 1) of the shaft 36 penetrates the ball bearing 42 and protrudes to near the bottom wall of the connector body 15 (connector housing 35).

The yoke 37 is arranged corresponding to the core 21 so as to be sandwiched between the ball bearings 41 and 42 in the axial direction. The yoke 37 is formed in a substantially cylindrical shape, and is fixed to the shaft 36 such that the shaft 36 passes through the yoke 37. A magnet 38 is fixed to the outer peripheral surface of the yoke 37. The magnet 38 is formed of, for example, Ne-Fe-B. Figure 2 As shown in FIG. 3, the magnet 38 is magnetized with alternate polarities (N and S poles) at predetermined angles (90 ° in the first embodiment). The outer diameter of the magnet 38 is set so that a slight gap exists between the outer peripheral surface of the magnet 38 and the inner peripheral surface of the core 21. The yoke 37 functions as a back yoke of the magnetic circuit.

[0027] The brush holder 39 has an outer diameter smaller than the inner diameter of the stator 12 (housing section 24, connector housing section 35), and is formed in a substantially cylindrical shape. The brush holder 39 is fixed to the shaft 36 such that the tip of a shaft 36 projecting from the ball bearing 42 to the bottom wall of the connector main body 15 (connector housing 35) passes through. The brush holder 39 also includes a plurality (four) of brush receiving holes 39a, 39b, 39c, 39d recessed radially outwardly toward the center in the radial direction.

As shown in FIG. 1, the brush housing holes 39a and 39b are arranged in the axial direction corresponding to the commutator 23. The brush housing hole 39c is arranged corresponding to the slip ring 31 in the axial direction. The brush housing hole 39d is arranged in the axial direction corresponding to the slip ring 32.

FIG. 3 is a schematic view of the brush holder 39 viewed from the axial direction. The brush accommodating holes 39a and 39b are recessed in the radial direction at an angle of about 90 ° to each other. The brush receiving hole 39c is formed to be concave in the radial direction at a predetermined angle (approximately 60 °) with respect to the brush receiving hole 39a. Further, the brush receiving hole 39d is formed to be concave in the radial direction at a predetermined angle (approximately 60 °) with respect to the brush receiving hole 39b and at a predetermined angle (substantially 90 °) with respect to the brush receiving hole 39c. That is, the brush receiving holes 39a and 39b, the brush receiving hole 39c, and the brush receiving hole 39d are formed at different positions in the circumferential direction.

[0030] A brush 43 that slides on the commutator 23 (commutator segment 23a) is housed in the brush housing hole 39a, and a brush 44 that slides on the slip ring 31 is housed in the brush housing hole 39c. These brushes 43, 44 are short-circuited by connection lines 45. As shown in FIG. 3, the torsion coil panel 46 is supported by a support portion 39e provided on the brush holder 39. The base end of the brush 43 contacts one end of the torsion coil panel 46, and the base end of the brush 44 contacts the other end of the torsion coil panel 46. In this state, the brushes 43 and 44 are moved by the torsion coil panel 46 in the radial direction of the rotor 13, that is, the shaft 3 of the rotor 13. It is biased away from 6. That is, the brush 43 is urged toward the commutator 23, and the brush 44 is urged toward the slip ring 31.

[0031] The brush accommodating portion 39b accommodates a brush 47 that is in sliding contact with the commutator 23 (commutator segment 23a), and the brush accommodating hole 39d accommodates a brush 48 that is in sliding contact with the slip ring 32. These brushes 47, 48 are short-circuited by connection lines 49. As shown in FIG. 3, the torsion coil panel 50 is supported by the brush holder 39. The base end of the brush 47 is in contact with one end of the torsion coil panel 50, and the base end of the brush 48 is in contact with the other end of the torsion coil panel 46. In such a state, the brushes 47 and 48 are urged radially outward by the torsion coil spring 50. That is, the brush 47 is urged toward the commutator 23, and the brush 48 is urged toward the slip ring 32.

With the above configuration, one terminal 33 irrespective of the rotational position of the rotor 13 is connected to the slip ring 31, the brush 44 slidably contacting the slip ring 31, the connection line 45, and the commutator 23 via the brush 43. Electrically connected to the commutator segment 23a. Similarly, the other terminal 34 is electrically connected to a corresponding commutator segment 23 a of the commutator 23 via a slip ring 32, a brush 48 slidingly contacting the slip ring 32, a connection line 49 and a brush 47.

Here, the winding connection mode of the DC motor 11 will be briefly described with reference to FIG. As described above, the core 21 of the first embodiment has twelve teeth 25b, and in FIG. 4, each tooth 25b is numbered 1 to 12. Further, the commutator 23 has twelve commutator segments 23a, and each commutator segment 23a is similarly assigned a number of 1 to 12!

[0034] Since the angle between the depth direction of the brush housing hole 39a and the depth direction of the brush housing hole 39b is approximately 90 °, three brushes 43 and 47 corresponding to the angle (= The commutator segments 23a are shifted from each other by 12Z (360 ° / 90 °;)). In FIG. 4, the brushes 43 and 47 are in sliding contact with the first and fourth commutator segments 23a, respectively.

[0035] The winding connected to the first commutator segment 23a forming the coil 22 is wound so as to straddle a plurality of (three in the first embodiment) teeth 25b sequentially, and Connected to data segment 23a! The same applies to the windings connected to the commutator segments 23a of other numbers. Also, the windings connected to each commutator segment 23a are short-circuited with the windings connected to the commutator segments 23a facing each other in the radial direction (for example, No. 1 is short-circuited to No. 7 and No. 4 Is short-circuited with number 10.) As described above, the coil 22 is wound around the core 21 in a lap winding with a short-circuit line.

Next, the operation of the DC motor 11 having such a configuration will be described. When power is supplied from an external power supply to the stator 12 of the DC motor 11 via the terminals 33 and 34, this power is supplied to the rotor 13 via the slip rings 31 and 32 and the brushes 44 and 48. Then, the electric power supplied to the rotor 13 is supplied to the stator 12 again via the connection lines 45 and 49, the brushes 43 and 47, and the commutator 23. At this time, electric power is supplied to the coil 22 via the commutator 23, and a magnetic field is generated in the coil 22. Due to the action of the magnetic field generated in the coil 22 and the magnetic force of the magnet 38 facing the coil 22, a rotational moment is generated in the magnet 38, and the rotor 13 rotates. When the rotor 13 rotates, the polarity of the supplied power is sequentially switched by the commutator 23 (commutator segment 23a), and the rotor 13 continuously rotates in one direction continuously.

As described in detail above, according to the DC motor 11 of the first embodiment, the following effects can be obtained.

(1) In the first embodiment, the rotor 13 disposed inside the stator 12 includes a coil for generating a magnetic field using force power including a shaft 38 and a magnet 38 fixed to a yoke 37. Not in. That is, since it is not necessary to secure a magnetic path space and a winding space in the rotor 13, the rotor 13 can be particularly reduced in diameter. Further, in the DC motor 11, the inertia of the rotor 13 can be significantly reduced as compared with a general conventional DC brush motor, and the responsiveness can be improved.

[0038] In a DC brushless motor in which a magnetic path space and a winding space are secured in the stator, a magnetic sensor for detecting a rotational position (three Hall elements) and a switching element for switching energization (six FETs) are provided. Is required. However, in the DC motor 11 of the first embodiment, since these magnetic sensors and switching elements are not required, the DC motor 11 as a whole Cost can be reduced by reducing the number of parts. Of course, the circuit configuration for driving the motor can be simplified.

(2) In the first embodiment, the slip rings 31 and 32 provided on the stator 12 and the rotor 13

The electric power supplied to the stator 12 can be supplied to the rotor 13 with a very simple configuration provided with the brushes 44 and 48 provided on the (brush holder 39) and slidingly contacting the slip rings 31 and 32.

(Second Embodiment)

Hereinafter, a DC motor 51 according to a second embodiment of the present invention will be described with reference to FIG. The DC motor 51 of the second embodiment has a configuration in which the slip ring is provided on the rotor and the brush that slides on the slip ring is provided on the stator in the first embodiment, and the same configuration is the same. The reference numerals are used and the description is partially omitted.

FIG. 5 is a longitudinal sectional view of a DC motor 51 according to the second embodiment. As shown in FIG. 5, the DC motor 51 includes a stator 52 and a rotor 53. The stator 52 includes a stator main body 54 and a connector main body 55.

[0042] The stator main body 54 includes the core 21, the coil 22, and a plurality of (12 in the second embodiment) commutator segments 56a constituting a commutator (commutator) 56. The core 21, the coil 22, and the commutator segment 56a are integrally formed by a housing 57 having a resin material strength.

The commutator 56 has an inner diameter that is equivalent to the inner diameter of the core 21, and is arranged coaxially with the core 21 on one side (left side in FIG. 5) of the core 21. The commutator 56 is embedded in the housing 57 so as to expose the commutator segment 56a inside the housing 57. Each commutator segment 56a of the commutator 56 is electrically connected to the winding of the coil 22 as in the first embodiment.

The housing portion 57 is formed in a substantially cylindrical shape having an inner diameter slightly larger than the inner diameters of the core 21 and the commutator 56, and extends around the core 21, the coil 22, and the commutator 56. Form the external shape of

[0045] The connector main body 55 includes two terminals 58 and 59 extending in the radial direction, and these are integrally formed by a connector housing portion 60 which also has a resin material strength. Terminal 5 9 is juxtaposed with the terminal 58 on the side orthogonal to the paper surface. The connector housing section 60 has an outer diameter equivalent to the inner diameter of the housing section 57 and is formed in a substantially cylindrical shape with a bottom. The connector housing section 60 extends around the base end of the terminal 58 (59) to form the connector housing 55. The outer shape is formed.

The connector housing section 60 has a connector holder section 60a formed so as to surround the distal end of the terminal 58 (59) exposed to the outside. The connector housing portion 60 is formed with a plurality (two) of wall portions 60b and 60c that protrude toward the center in the radial direction and extend in parallel with the axial direction. Brush housing holes 60d and 60e are formed respectively from the ends of the opening side (left side in FIG. 5) of the shaft 60 in parallel with the axial direction. The central axial force of the connector housing part 60 and the radial distance from the brush receiving hole 60d are set to be longer than the radial distance from the central axis of the connector housing part 60 to the brush receiving hole 60e.

A brush 61 and a coil panel 62 are accommodated in the brush accommodation hole 60d, and the brush 61 is urged outward by the coil panel 62 along the axial direction. The brush 61 is short-circuited to the terminal 58 by the connection line 63. Similarly, a brush 64 and a coil panel 65 are accommodated in the brush accommodation hole 60e, and the brush 64 is urged outward by the coil panel 65 along the axial direction. Note that the brush 64 is also short-circuited to the terminal (59) by a connection wire (the connection between the brush 64 and the terminal (59) is not shown).

The connector main body 55 (connector housing part 60) is connected to the stator main body 54 by press-fitting the peripheral wall of the connector main body 55 into the inner wall surface of the housing part 57. In the stator 52, an inner space S1 having a substantially circular cross section is formed by the inner wall surfaces of the stator body 54 and the connector body 55.

[0049] The rotor 53 is rotatably accommodated in an internal space S1 formed in the stator 52.

The rotor 53 includes a shaft 66, a yoke 67, a magnet 68, a slip ring holder 69, and a brush holder 70. The shaft 66 is arranged coaxially with the stator 52. One side and the other side (the left and right sides in FIG. 5) of the shaft 66 are provided with a ball bearing 71 and a connector housing mounted on the inner peripheral surface of the housing portion 57. Attached to the inner peripheral surface of part 60 The ball bearing 72 is supported by each. One end (left side in FIG. 5) of the shaft 66 penetrates the ball bearing 71 and protrudes to the outside, and the other end (right side in FIG. 5) of the shaft 66 is connected to the connector body 55 (connector housing section). Near the bottom wall of 60), it is pivotally supported by a ball bearing 72!

[0050] The yoke 67 is arranged corresponding to the core 21 so as to be sandwiched between the connector housing section 60 and the ball bearing 71 in the axial direction. The yoke 67 has a substantially cylindrical inner ring portion 67a and an outer ring portion 67b arranged concentrically with each other, and a substantially disk-shaped flange portion 67c connecting the inner ring portion 67a and the outer ring portion 67b. ing. The yoke 67 is fixed to the shaft 66 such that the shaft 66 passes through the inner ring portion 67a. A magnet 68 is fixed to the outer peripheral surface of the yoke 67. This magnet 68 is magnetized similarly to the magnet 38 of the first embodiment (see FIG. 2). The outer diameter of the magnet 38 is set so that a slight gap exists between the outer peripheral surface of the magnet 68 and the inner peripheral surface of the core 21. The yoke 67 functions as a back yoke of the magnetic circuit.

[0051] The slip ring holder 69 is arranged so as to be sandwiched between the yoke 67 and the connector housing section 60 in the axial direction. The slip ring holder 69 is provided with two annular slip rings 73 and 74 having different diameters arranged concentrically with each other, and these are integrally formed by a slip ring nosing portion 75 which also has a grease material. I have.

[0052] The slip ring 73 is formed in an annular shape from a conductive material, and has a radius equivalent to a radial distance from the central axis of the shaft 66 to the brush receiving hole 60d (brush 61). . The slip ring 73 is embedded in the slip ring nosing portion 75 so as to face the brush 61 so as to expose an annular end face thereof. Further, the slip ring 74 is formed in an annular shape by using a conductive material, and the central axial force of the shaft 66 has a radius equivalent to the radial distance to the brush receiving hole 60e (brush 64). The slip ring 74 is embedded in the slip ring housing portion 75 so as to face the brush 64 so as to expose an annular end face thereof.

The brushes 61 and 64 housed in the brush housing holes 60d and 60e are in sliding contact with the slip rings 73 and 74, respectively. The slip rings 73 and 74 have terminals 76 and 77 extending from the annular end surface to one side (the left side in FIG. 5, ie, the yoke 67 side) in parallel with the axial direction. Each is connected.

[0054] The slip ring housing 75 has an outer diameter equal to the outer diameter of the magnet 68 and is formed in an annular shape, and is provided outside the slip ring holder 69 so as to surround the slip rings 73 and 74. The shape is formed. The slip ring holder 69 (slip ring nozzle portion 75) is fixed to the shaft 66 so that the shaft 66 is passed through.

The brush holder 70 is disposed so as to be sandwiched between the yoke 67 and the ball bearing 71 in the axial direction. The brush holder 70 has a large-diameter portion 70a having an outer diameter smaller than the inner diameter of the stator 52 (core 21), and a small-diameter portion 70b having an outer diameter equal to the inner diameter of the outer ring portion 67b of the yoke 67 on the yoke 67 side. And is formed in a stepped cylindrical shape. The brush holder 70 is fixed to the shaft 66 in such a manner that the small diameter portion 70b is press-fitted into the outer ring portion 67b of the yoke 67 and the shaft 66 is passed through. The large-diameter portion 70a of the brush holder 70 is disposed in the axial direction so as to correspond to the commutator 56.

[0056] In the large diameter portion 70a of the brush holder 70, a plurality of (two) brush storage holes 70c and 70d are formed so as to face the radial center. These brush receiving holes 70c, 70d are recessed in the radial direction at substantially 90 ° to each other, similarly to the brush receiving holes 39a, 39b of the first embodiment (see FIG. 3).

The brush accommodating hole 70c accommodates a brush 78 and a coil panel 79 that are in sliding contact with the commutator 56 (commutator segment 56a). The brush 78 is urged toward the commutator 56 by a coil panel 79. Further, a cylindrical guide portion 70e is formed in the small diameter portion 70b of the brush holder 70 so as to extend parallel to the axial direction and penetrate the flange portion 67c of the yoke 67 so as to correspond to the brush receiving hole 70c. The terminal 76 extends into the inside along the guide portion 70e, and the distal end of the terminal 76 is connected to a terminal 80 electrically connected to the brush 78 in the brush receiving hole 70c via a connection line. ing.

[0058] On the other hand, the brush 81 and the coil panel 82 that are in sliding contact with the commutator 56 (commutator segment 56a) are housed in the brush housing hole 70d. The brush 81 is urged toward the commutator 56 by the coil panel 82. Further, a cylindrical guide portion 70f is formed in the small diameter portion 70b of the brush holder 70 so as to extend in parallel with the axial direction and pass through the flange portion 67c of the yoke 67 so as to correspond to the brush receiving hole 70d. Terminal 77 runs along this guide section 70f The tip of the terminal 77 is connected to a terminal 83 which is electrically connected to the brush 81 in the brush receiving hole 70d via a connection line.

[0059] With the above-described configuration, one terminal 58 irrespective of the rotational position of the rotor 53 is connected to the connection line 63, the brush 61, the slip ring 73 to which the brush 61 slides, the terminal 76, the terminal 80, and the brush 78. Is electrically connected to the corresponding commutator segment 56a of the commutator 56 via Similarly, the other terminal (59) is electrically connected to the corresponding commutator segment 56a of the commutator 56 via the brush 64, the slip ring 74 with which the brush 64 slides, the terminal 77, the terminal 83 and the brush 81. You.

[0060] Note that the winding configuration of the DC motor 51 of the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

Next, the operation of the DC motor 51 having such a configuration will be described. When the external power is also supplied to the stator 52 of the DC motor 51 via the terminal 58 (59), this power is supplied to the rotor 53 via the brushes 61, 64 and the slip rings 73, 74. Then, the electric power supplied to the rotor 53 is supplied to the stator 52 again via the terminals 76 and 77, the terminals 80 and 83, the brushes 78 and 81, and the commutator 56. At this time, power is supplied to the coil 22 via the commutator 56, and a magnetic field is generated in the coil 22. By the action of the magnetic field generated in the coil 22 and the magnetic force of the magnet 68 facing the coil 22, a rotational moment is generated in the magnet 68, and the rotor 53 rotates. When the rotor 53 rotates, the polarity of the supplied power is sequentially switched by the commutator 56 (commutator segment 56a), and the rotor 53 continuously rotates in one direction continuously.

As described in detail above, according to the DC motor 51 of the second embodiment, the following effects can be obtained in addition to the effects of the first embodiment.

(1) In the second embodiment, the brushes 61, 64 are urged along the axial direction with respect to the slip rings 73, 74 to make sliding contact with the slip rings 73, 74. Therefore, in the assembling work for assembling the stator 52 and the rotor 53 along the axial direction, the brushes 61 and 64 and the slip rings 73 and 74 are smoothly pressed into contact with each other, so that the complexity of the assembling work can be reduced.

(2) In the second embodiment, the commutator 56 is arranged on the opposite side to the connector main body 55 across the core 21 in the axial direction. Therefore, the commutator 56 is connected to the connector body 55. Since no space is required for disposing the DC motor 51, the amount of projection of the DC motor 51 toward one axial side (the right side in FIG. 5) is reduced, and the degree of freedom in design can be improved.

(Third Embodiment)

Hereinafter, a DC motor 91 according to a third embodiment of the present invention will be described with reference to FIG. The DC motor 91 according to the third embodiment has a configuration in which the positional relationship between the commutator and the brush that slides on the commutator in the second embodiment is changed. Is partially omitted.

FIG. 6 is a longitudinal sectional view of a DC motor 91 according to the third embodiment. As shown in FIG. 6, the DC motor 91 includes a stator 92 and a rotor 93. The stator body 94 included in the stator 92 includes the core 21, the coil 22, and a plurality (12 in the third embodiment) of commutator segments 95 a constituting a commutator (commutator) 95. The core 21, the coil 22, and the commutator segment 95 a are integrated by a housing part 96 that also has a resin material strength.

[0065] The commutator 95 is formed in an annular shape having an outer diameter equal to the inner diameter of the core 21, and is arranged coaxially with the core 21 on one side of the core 21 (left side in FIG. 6). I have. The commutator segment 95a is formed in such a manner that the annular end face of the commutator 95 is divided into fan shapes at predetermined angles (30 °). The commutator 95 is embedded in the nosing portion 96 such that the commutator segment 95a is exposed at the center of the nosing portion 96. Each commutator segment 95a of the commutator 95 is electrically connected to the winding of the coil 22 as in the second embodiment.

The housing part 96 is formed in a substantially cylindrical shape having an inner diameter equivalent to the inner diameter of the core 21, and is formed in an outer shape of the stator body 94 so as to surround the core 21, the coil 22, and the commutator 95. Shape. The connector main body 55 (connector housing portion 60) similar to that of the second embodiment is connected to the stator main body 94 by press-fitting the peripheral wall portion of the connector main body 55 into the inner wall surface of the housing portion 96. In the stator 92, an inner space S2 having a substantially circular cross section is formed by the inner wall surfaces of the stator body 94 and the connector body 55.

[0067] The rotor 93 is rotatably accommodated in an internal space S2 formed in the stator 92.

The rotor 93 has a shaft 101, a yoke 102, a magnet 103, a slip ring holder 104 and a brush holder 105. The shaft 101 is arranged coaxially with the stator 92. One side and the other side (the left and right sides in FIG. 6) of the shaft 101 are provided with a ball bearing 106 and a connector housing mounted on the inner peripheral surface of the housing portion 96. Each is supported by a ball bearing 107 mounted on the inner peripheral surface of the part 60. One end (left side in FIG. 6) of the shaft 101 penetrates the ball bearing 106 and protrudes to the outside, and the other end (right side in FIG. 6) of the shaft 101 is connected to the connector body 55 ( It is supported by a ball bearing 107 near the bottom wall of the connector housing 60).

[0068] The yoke 102 is arranged corresponding to the core 21 so as to be sandwiched between the connector housing section 60 and the ball bearing 106 in the axial direction. This yoke 102 is formed in a substantially cylindrical shape with a bottom opening to the connector main body 55 (connector housing part 60), and is fixed to the shaft 101 in such a manner that the shaft 101 passes through the bottom wall of the yoke 102. ing. The magnet 103 is fixed to the outer peripheral surface of the yoke 102. The magnet 103 is magnetized similarly to the magnets 38 and 68 of the first and second embodiments (see FIG. 2). The outer diameter of the magnet 103 is set so that a slight gap exists between the outer peripheral surface of the magnet 103 and the inner peripheral surface of the core 21. The yoke 102 functions as a back yoke of the magnetic circuit.

[0069] The slip ring holder 104 is arranged so as to be sandwiched between the yoke 102 and the connector housing portion 60 in the axial direction. The slip ring holder 104 is provided with two annular slip rings 108 and 109 having different diameters arranged concentrically with each other, and these are integrally formed by a slip ring nosing portion 110 which is also a resin material. ing.

[0070] Slip ring 108 is formed in an annular shape with a conductive material, and the central axial force of shaft 101 also has a radius equal to the radial distance to brush receiving hole 60d (brush 61). The slip ring 108 is embedded in the slip ring nosing portion 110 so as to face the brush 61 and expose the annular end face thereof. The slip ring 109 is formed in an annular shape with a conductive material, and the central axial force of the shaft 101 has a radius equivalent to the radial distance to the brush housing hole 60e (brush 64). The slip ring 109 is embedded in the slip ring housing portion 110 so as to face the brush 64 so as to expose an annular end face thereof. [0071] The brushes 61, 64 housed in the brush housing holes 60d, 60e are in sliding contact with these slip rings 108, 109, respectively. The slip rings 108 and 109 are formed with terminal portions 108a and 109a extending from the annular end surfaces to one side (the left side in FIG. 6, that is, the yoke 102 side) in parallel with the axial direction.

The slip ring housing portion 110 is formed in an annular shape having an outer diameter equivalent to the outer diameter of the magnet 103, and extends outside the slip ring holder 104 so as to extend around the slip rings 108 and 109. Form a shape! The slip ring holder 104 (slip ring housing portion 110) is fixed to the shaft 101 so that the shaft 101 is passed through.

[0073] The brush holder 105 is disposed inside the yoke 102 so as to be sandwiched between the slip ring holder 104 and the ball bearing 106 in the axial direction. The brush holder 105 is formed in an annular shape having an outer diameter equal to the inner diameter of the yoke 102. A plurality (two) of wall portions 105a, 105b extending in parallel with the axial direction are provided on the peripheral edge of the brush holder 105. Are formed.

[0074] The brush holder 105 has a configuration in which the wall portions 105a and 105b penetrate the bottom wall portion of the yoke 102 toward the commutator 95 and are pressed into the inner peripheral surface of the yoke 102 so that the shaft 101 is passed through. It is fixed to. The radial distance from the center axis of the brush holder 105 to the wall portions 105a, 105b is set such that the wall portions 105a, 105b correspond to the commutator 95.

[0075] Brush receiving holes 105c and 105d are formed in the wall portions 105a and 105b of the brush holder 105 so as to be recessed in parallel with the axial direction, respectively. These brush receiving holes 105c, 105d are arranged at substantially 120 ° apart from each other in the circumferential direction, similarly to the brush receiving holes 39a, 39b of the first embodiment (see FIG. 3, except that the brush receiving holes 105c, 105d). 105d is recessed in the direction perpendicular to the paper surface in FIG.

The brush 111 and the coil panel 112 that are in sliding contact with the commutator 95 (commutator segment 95a) are accommodated in the brush accommodation hole 105c. The brush 111 is urged toward the commutator 95 by the coil panel 112. The brush 111 is electrically connected to a slip ring 108 (terminal portion 108a) via a connection line 113 passing through a bottom wall of the brush holder 105. On the other hand, the brush 114 and the coil panel 115 that are in sliding contact with the commutator 95 (commutator segment 95a) are housed in the brush housing hole 105d. The brush 114 is urged toward the commutator 95 by the coil panel 115. The brush 114 is electrically connected to the slip ring 109 (terminal portion 109a) via a connection line 116 penetrating the bottom wall of the brush holder 105.

With the above-described configuration, one terminal 58 irrespective of the rotational position of the rotor 93 includes the connection line 63, the brush 61, the slip ring 108 (terminal portion 108 a) with which the brush 61 slides, the connection line 113, and the brush It is electrically connected to the corresponding commutator segment 95a of the commutator 95 via 111. Similarly, the other terminal (59) is electrically connected to the corresponding commutator segment 95a of the commutator 95 via the brush 64, the slip ring 109 (terminal section 109a) on which the brush 64 slides, the connecting line 116 and the brush 114. Connected.

[0079] The winding connection mode and operation of the DC motor 91 of the third embodiment are the same as those of the second embodiment, and therefore description thereof is omitted.

As described in detail above, according to the DC motor 91 of the third embodiment, the following effects can be obtained in addition to the effects similar to those of the second embodiment.

(1) In the third embodiment, the brushes 111 and 114 are urged along the axial direction with respect to the commutator 95 to slide on the commutator 95. Therefore, in the assembling work for assembling the stator 92 and the rotor 93 along the axial direction, the brushes 111 and 114 and the commutator 95 are smoothly pressed together, so that the complexity of the assembling work can be reduced.

[0081] The above embodiment may be modified as follows.

• The number of teeth (number of slots) of the core and the number of commutator segments of the commutator in each of the above embodiments are merely examples, and the number of teeth and the number of commutator segments may be changed as appropriate.

The number of poles of the magnet in each of the above embodiments is merely an example, and the number of poles of the magnet may be changed as appropriate.

• The winding connection mode of the DC motor in each of the above embodiments is an example. For example, the brush may be a brush that comes into sliding contact with a commutator that can be wound around the core in a concentrated winding manner.

Claims

The scope of the claims

[1] a stator including a core, a coil wound around the core, and a commutator connected to the coil;

A rotor rotatably disposed inside the stator and including a yoke, and a magnet fixed to the yoke;

An intermediary member for supplying power to the stator to the rotor,

A DC motor, comprising: a brush provided on the rotor, connected to the intermediary member, and slidably in contact with the commutator.

[2] The DC motor according to claim 1,

The DC motor, wherein the magnet has a plurality of segments, and adjacent segments are magnetized to polarities different from each other.

[3] The DC motor according to claim 1,

The brush is urged along the axial direction of the rotor so as to make sliding contact with the commutator! A DC motor characterized by:

[4] The DC motor according to claim 1,

The mediation member,

A DC motor comprising: a slip ring provided on one of the stator and the rotor; and an intermediate brush provided on one of the other of the stator and the rotor and slidably in contact with the slip ring.

[5] The DC motor according to claim 4,

The intermediary brush is urged along the axial direction of the rotor so as to make sliding contact with the slip ring! A DC motor characterized by:

[6] The DC motor according to claim 4,

The intermediary brush is urged along the radial direction of the rotor so as to make sliding contact with the slip ring! A DC motor characterized by:

[7] The DC motor according to claim 1,

The stator is

A stator body that houses the coil and the core; A connector main body accommodating a terminal for supplying power to the DC motor; and a fitting protrusion provided on one of the stator main body and the connector main body for interconnecting the stator main body and the connector main body. And a direct current motor.

[8] The DC motor according to claim 7,

A DC motor, comprising: a brush holder fixed to one end of the rotor, housed in the connector body, and holding the brush.

[9] Accommodates a core, a coil wound around the core, a stator body accommodating the coil and the core, a commutator connected to the coil, and a terminal for supplying power to the DC motor. A stator, comprising: a connector main body; and a fitting projection provided on one or the other of the stator main body and the connector main body and interconnecting the stator main body and the connector main body.

A slip ring provided on one of the stator and the rotor, a first brush provided on one of the other of the stator and the rotor and in sliding contact with the slip ring;

A DC motor connected to one of the slip ring and the first brush provided on the rotor, and a second brush provided on the rotor and slidably in contact with the commutator. .

[10] In a power supply method for a DC motor including a stator, a rotor, a core on which a coil is wound, a commutator connected to the coil, and a magnet fixed to a yoke, the coil is supplied to the stator. A power supply method for a DC motor, comprising: temporarily supplying power to the rotor; and supplying power supplied to the rotor to the stator.