JP2001008387A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance motor characteristics by magnetically isolating first and second pole teeth contiguous to each other in the circumferential direction, thereby suppressing flux leakage. SOLUTION: A brush motor 1 has a rotary shaft 20 supported by a motor case 11 and ball bearings 13, 14 secured to an end plate 12. First and second cores 31, 32 are placed fixedly on the rotary shaft 20 and applied, respectively with coils 33, 34. The first and second cores 31, 32 are extended along the motor case 11 to first pole teeth 35, 36 and second pole teeth 37, 38, respectively. First and second pole teeth 35, 37 are arranged alternately in the first core 31, and first and second pole teeth 36, 38 are arranged alternately in the second core 32. The magnetic path connecting the first and second pole teeth 35, 37 and the magnetic path connecting the first and second pole teeth 36, 38 pass through the coils 33, 34, respectively. According to the structure, satisfactory motor characteristics can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor in which pole teeth of a core face a driving magnet. More specifically, it relates to the structure of the core.

[0002]

2. Description of the Related Art Among various motors, a motor having a so-called PM type single-turn inductor structure is disclosed in Japanese Utility Model Application Laid-Open No. 1-17.
No. 1582 is disclosed. Conventionally, any of these single-turn inductor structure motors
As shown in FIGS. 9A and 9B, a core 130 is formed with respect to a permanent magnet 141 having an N pole and an S pole formed in the circumferential direction.
Has the structure in which the first pole teeth 135 and the second pole teeth 137 face each other. Here, the first and second pole teeth 13
5, 137 are formed downward and upward, respectively, and the downward first polar tooth 135 and the upward second polar tooth 1
37 are alternately arranged around the core 130. Also,
The core 130 is entirely formed of a magnetic material, and the magnetic path connecting the first and second pole teeth 135 and 137 is
It passes through 33.

Here, as an index indicating the rotational performance of the motor, a characteristic value (T / N value) corresponding to the reciprocal of the heat loss when the same torque is generated is given by the following equation: / N = P ² · Φ ² · HA · A / L P: Number of magnetic poles Φ: Effective magnetic flux H: Number of parallel coils A: Coil cross section L: Coil length per turn Therefore, as the number of magnetic poles is increased, the motor characteristics are improved. Also, the motor characteristics are improved by reducing the coil length per turn.

[0004]

However, in the conventional motor, when the number of magnetic poles is increased, as shown by an arrow Y in FIG. The effective magnetic flux shown does not increase. Here, to increase the effective magnetic flux, it is necessary to narrow the interval between the pole teeth,
When the interval between the pole teeth is reduced, the reluctance between the adjacent pole teeth is reduced. Therefore, when a current is applied to the coil 133, as shown by an arrow W in FIG. And the core 130 immediately saturates, and the effective magnetic flux indicated by the arrow W cannot be increased. Therefore, there is a problem that the maximum torque is small. Also,
There is also a problem that the time constant becomes electrically large and the high-speed response becomes poor.

[0005] In view of the above problems, an object of the present invention is to provide:
An object of the present invention is to provide a motor capable of improving motor characteristics by improving the structure of a core and suppressing leakage of magnetic flux.

[0006]

In order to solve the above-mentioned problems, the present invention provides a core having first and second pole teeth extending alternately in the circumferential direction from both sides in the axial direction.
An armature including a single-turn coil in which a magnetic path connecting the first magnetic pole and the second magnetic pole passes inside;
In the motor having the first pole tooth and the second pole tooth and the driving magnet opposed to the second pole tooth, of the first pole tooth and the second pole tooth, the pole teeth adjacent in the circumferential direction are magnetically It is characterized by being separated.

According to the present invention, the first pole teeth and the second pole teeth arranged in the circumferential direction are not connected to the adjacent pole teeth by a magnetic material and are magnetically separated. Even if the pole teeth of adjacent different poles are close to each other, the magnetic resistance to the leakage magnetic flux is large between the adjacent pole teeth. Therefore, even in a configuration in which adjacent pole teeth are close to each other due to an increase in the number of magnetic poles, the effective magnetic flux that can flow with the same magnetic path cross-sectional area increases because the leakage magnetic flux is reduced and the ratio of the effective magnetic flux is improved. The limit torque can be greatly increased. In addition, since the leakage magnetic flux is reduced and the self-inductance is reduced, good motor characteristics can be obtained such that the rise of current is increased and the high-speed response is improved by the reduction of the electric time constant.

In the present invention, the core is, for example,
Formed by three magnetically separated core pieces;
In each of the two core pieces, the first magnetically coupled
The second pole tooth and the second pole tooth are formed at positions where the angular directions are shifted by 120 ° or more, so that adjacent pole teeth are magnetically separated on the core.

In the present invention, the core is formed of a plurality of magnetically separated core pieces having the same number as the number of the first pole teeth and the number of the second pole teeth. In each of the core pieces, the first magnetically coupled
The second pole tooth and the second pole tooth may be shifted from each other by three magnetic pole pitches or more, so that adjacent pole teeth may be magnetically separated on the core.

In the present invention, a core having two or more phases to which currents having different phases are supplied to the coil may be used as the core. In this case, a spacer made of a non-magnetic material is provided between the cores of two or more phases.
Alternatively, it is preferable to form a gap. With this configuration, it is possible to prevent adjacent pole teeth from being connected via the other core, even in a structure in which the cores are stacked in two stages.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a motor with a brush to which the present invention is applied will be described with reference to the drawings.

FIG. 1 is a sectional view of a motor with a brush to which the present invention is applied, which is cut along the motor axis direction.

(Overall Configuration) In FIG. 1, a brushed motor 1 of the present embodiment has a PM type single-turn inductor structure, and a motor housing 10 is formed by a cylindrical motor case 11 and an end plate 12. Have been. In the motor 1 with a brush, the rotating shaft 20 is rotatably supported around the axis by ball bearings 13 and 14 fixed to the motor case 11 side and the end plate 12 side, respectively. First and second cores 31 and 32 for two phases are fixed around the rotation shaft 20 in the axial direction. Inside the first and second cores 31 and 32, coils 33 and 32 of each phase are fixed. 34 are wound. From the outer peripheral edges of the first and second cores 31 and 32, along the inner peripheral surface of the motor case 11, the first pole teeth 35 and 36 and the second
Are extended respectively. Here, the first
The first pole teeth 35, 36 extend downward toward FIG. 1 and the second pole teeth 37, 38 extend upward toward FIG. 1 and are located between the first pole teeth 35, 36. I have. For this reason,
In the first core 31, the first pole teeth 35 and the second pole teeth 37 are alternately arranged in the circumferential direction, and in the second core 32,
In the circumferential direction, the first pole teeth 36 and the second pole teeth 38 are alternately arranged. Here, the first and second pole teeth 35,
37 and first and second pole teeth 36, 3
The magnetic path connecting 8 passes through the coils 33 and 34. In this manner, in the present embodiment, the first core 31 including the first pole teeth 35 and the second pole teeth 37, the first pole teeth 36 and the second
Core 32 with pole teeth 38 and coil 3
The rotor 30 is constituted by 3 and 34.

On the other hand, the inner peripheral surface of the motor case 11 has a permanent magnet 41 in which N poles and S poles are alternately arranged in the circumferential direction.
(The driving magnet) is fixed to the stator 40.

(Structure of the core) In the brushed motor 1 thus constructed, the first and second cores 31, 3
2 is configured as described below with reference to FIGS. 2, 3 and 4. Here, FIGS. 2A and 2B are a plan view and a side view, respectively, showing one of three core pieces constituting the first and second cores 31 and 32, respectively. is there. 3 (A), (B),
(C) is a plan view of the state in which three core pieces constituting the first core 31 are connected by a connecting piece when viewed from the output shaft (output end of the rotating shaft 20) shown in FIG. In order to show the positional relationship between the three core pieces constituting one core 31, the positional relationship between the first flat plate portions of the three core pieces is viewed from the output shaft side shown in FIG. 1 core 3
FIG. 2 is a plan view showing the positional relationship of each second flat plate portion of the three core pieces as viewed from the output shaft side shown in FIG. FIG. 4 (A),
(B) and (C) are plan views of a state in which three core pieces constituting the second core 32 are connected by connecting pieces when viewed from the output shaft side shown in FIG. 1, respectively. In order to show the positional relationship between the three core pieces, the first flat plate portion of the three core pieces is viewed from the output shaft side shown in FIG. Make up 3
FIG. 2 is a plan view showing the positional relationship between each second flat plate portion of three core pieces in order to show the positional relationship between three core pieces when viewed from the output shaft side shown in FIG. 1.

In this embodiment, the first and second cores 31,
In constructing the 32, three core pieces 39 shown in FIGS. 2A and 2B are used. Each of these core pieces 39 has a configuration in which the first and second cores 31 and 32 are divided into three in the circumferential direction, and these three core pieces 39 are plastic connection pieces 300 at the center side. (Nonmagnetic portion) and are magnetically separated.

The connecting piece 300 is composed of a shaft hole 301 through which the rotary shaft 20 passes, and a projection 302 protruding from the cylindrical portion constituting the shaft hole 301 to the outer peripheral side at an equiangular interval of 120 °. The center side 390 (base end side) of the core piece 39 is held in the space sandwiched by the protrusions 302.
Here, the protrusion 302 is formed with a small protrusion 303 protruding in the circumferential direction for preventing the coming off.

Further, the coil 3 is attached to any of the core pieces 39.
First plate teeth 392 extending from the center side to the outer peripheral side and sandwiching first polar teeth 35, 36 downward from the outer peripheral edge, and second polar teeth from the outer peripheral edge, respectively A second flat plate portion 394 is formed in which 37 and 38 extend upward. Also, the first flat plate portion 392
And the second flat plate portion 394 are connected to the protrusion 302 of the connection piece 300.
The first pole teeth 35 and 36 and the second pole teeth 37 and 38 magnetically coupled on the same core piece 39 have a structure connected by a connecting portion 396 having a shape fitted between the first pole teeth 35 and 36. Are connected by a magnetic material, and the magnetic path connecting the first pole teeth 35 and 36 and the second pole teeth 37 and 38 to the magnetic poles passes through the coils 33 and 34. A groove 397 in which the small projection 303 of the connecting piece 300 fits extends vertically in the connecting portion 396. In each of the core pieces 39, the side of the first flat plate portion 392 and the side of the second flat plate portion 394 are vertically moved by the connecting portion 396 by two.
It has a split structure, and these boundary portions 397 have a bent shape.

Further, in each of the core pieces 39,
The first flat plate portion 392 and the second flat plate portion 394 are configured such that they are completely displaced in the circumferential direction and do not overlap at all. Therefore, the first pole teeth 35 and 36 and the second pole teeth 37 and 38 magnetically coupled on the same core piece 39 are 120 °.
As described above, they are located in shifted angular directions and do not adjoin each other.

That is, in the first core 31, as shown in FIGS. 3A, 3B and 3C, three core pieces 39 (39A, 39B, 39C) are connected via the connecting piece 300. In the connected state, overlapping with the first flat plate portion 392 of the first core piece 39A is caused by the second core piece 39B of the second core piece 39B.
And the second flat plate portion 394 of the third core piece 39C overlaps with the remaining small area, and the first core piece 394 overlaps the first flat plate portion 392 of the first core piece 39A. The second flat plate portion 394 of 39A does not overlap at all. Also,
The second flat plate portion 394 of the third core piece 39C almost overlaps with the first flat plate portion 392 of the second core piece 39B, and the second flat plate portion 394 of the first core piece 39A is provided in a small remaining area. The flat plate portions 394 overlap and the second flat plate portion 3 of the second core piece 39B is opposed to the first flat plate portion 392 of the second core piece 39B.
94 does not overlap at all. Further, the first core piece 39A overlaps the first flat plate portion 392 of the third core piece 39C.
And the second flat plate portion 394 of the second core piece 39B overlaps with the remaining small area, and the third flat plate portion 392 of the third core piece 39C overlaps with the third flat plate portion 392 of the third core piece 39C. The second flat plate portion 394 of the core piece 39C does not overlap at all.

Also, in the second core 32, FIG.
As shown in (A), (B) and (C), three core pieces 3
9 (39A, 39B, 39C) connected via the connecting piece 300, the first flat plate portion 392 of the first core piece 39A overlaps with the second flat plate portion of the second core piece 39B. 394, the second flat plate portion 394 of the third core piece 39C overlaps with the remaining small area, and the first core piece 3 overlaps the first flat plate portion 392 of the first core piece 39A.
The 9A second flat plate portions 394 do not overlap at all. Also, overlapping with the first flat plate portion 392 of the second core piece 39B is as follows.
The second flat plate portion 394 of the third core piece 39C is almost the same as the second flat plate portion 394 of the first core piece 39A. 392 with respect to the second flat plate portion 39 of the second core piece 39B.
4 does not overlap at all. Further, most of the second flat plate portion 394 of the first core piece 39A overlaps with the first flat plate portion 392 of the third core piece 39C, and the second flat plate portion 394 of the second core piece 39B is provided in a small remaining area. The second flat plate portions 394 overlap,
The second flat plate portion 394 of the third core piece 39C does not overlap the first flat plate portion 392 of the third core piece 39C at all.

Therefore, in the present embodiment, in each of the first and second cores 31 and 32, the first and second pole teeth 35, 36, 37 and 38 have poles formed on different core pieces 39. Such a different pole tooth, which only overlaps with the tooth, means a connecting piece 90 made of a non-magnetic material on the cores 31, 32.
Since they are separated by 0, adjacent pole teeth are not connected by a magnetic material and are magnetically separated.

Further, in this embodiment, as shown in FIG.
A plastic spacer 16 is arranged between the first core 31 and the second core 32. Therefore, FIG.
By using the core piece 39 described with reference to
The configuration in which adjacent pole teeth are not connected by a magnetic material can be maintained even when the two cores 31 and 32 are stacked. Instead of the spacer 16, a slight gap may be provided between the first core 31 and the second core 32.

The cores 31 and 32 having such a structure are provided with connecting pieces 300 inside coils 33 and 34 which have been wound in advance.
After passing through, the groove 397 on the first flat plate portion 342 side of the core piece 39 divided vertically and the groove 397 on the second flat plate portion 394 side of the same core piece 39 are connected to the small projections 3 of the connecting piece 300.
03, the core piece 39 is shifted in the axial direction as it is, and the projection 303 of the connecting piece 300 is inserted into the groove 39 of the core piece 39.
7, the core piece 39 becomes 1 with respect to the connection piece 300.
Fixed. Next, the second core piece 39 is fixed at a position deviated by 120 ° from the previously fixed core piece with respect to the circumference of the connection piece 300, and thereafter, the first 3 between the two core pieces 39 fixed to
When the second core piece 39 is fixed, the three core pieces 39 are fixed via the connecting piece 300 made of a nonmagnetic material.

As described above, the motor 1 with a brush according to the present embodiment
In the first and second cores 31 and 32 used for the first step, the first pole teeth 35 and 36 and the second pole teeth 37
No. 8 has no magnetic material connected to the adjacent pole teeth, so that even if the adjacent pole teeth of different polarities are close to each other, the magnetic resistance is large between the adjacent pole teeth. For this reason,
Even if the number of magnetic poles is increased, the leakage of magnetic flux described with reference to FIG. 9D does not occur. Therefore, even in a configuration in which adjacent pole teeth are close to each other due to an increase in the number of magnetic poles, the effective magnetic flux that can flow with the same magnetic path cross-sectional area increases because the leakage magnetic flux is reduced and the ratio of the effective magnetic flux is improved. The limit torque can be greatly increased. In addition, since the leakage magnetic flux is reduced and the self-inductance is reduced, good motor characteristics can be obtained such that the rise of current is increased and the high-speed response is improved by the reduction of the electric time constant.

In the motor 1 with a brush according to the present embodiment,
The cores 31 and 32 have a two-tier structure.
Since the spacer 16 is arranged between the cores 31 and 32 to secure a magnetic gap, even in a structure in which the cores 31 and 32 are stacked in two stages, the adjacent pole teeth are interposed via the other core. The connection can be prevented.

(Structure of Commutator) FIGS. 5A and 5B are perspective views of a brush formed on the rotor side of the brushed motor 1 of the present embodiment, and a commutator formed on the stator side. It is a perspective view of. FIG. 6 is a cross-sectional view showing the configuration around the commutator-brush by cutting the brushed motor 1 along a direction orthogonal to the motor axis. FIG.
FIG. 3 is an explanatory diagram showing a commutator of the brushed motor 1 in a developed state.

In the motor 1 according to the present embodiment, power is supplied to the coils 33 and 34 from the outside as shown in FIG.
(A), (B) and the commutator 50 and the brush 60 shown in FIG.

In this embodiment, as shown in FIGS. 5B and 6, electrode surfaces 51 and 52 for two poles are formed on the inner peripheral surface of the open end side of the motor case 11 along the circumferential direction. The commutator 50 divided into the above (24 in the example shown here)
It has. In the commutator 50, the electrode surfaces 51 and 52 for two poles are formed by commutator pieces 53 and 54 made of an integrally pressed thin copper plate. That is, each of the commutator pieces 53 and 54 for two poles is provided with feeding portions 55 and 56 extending in the circumferential direction on the inner peripheral surface of the motor case 11, and a rectangular shape is formed from these feeding portions 55 and 56. The electrode portions 51 and 52 alternately protrude in the circumferential direction toward the other pole commutator pieces.
Therefore, if power is supplied from the outside only to the end portions of the power supply portions 55 and 56, power can be supplied to the entire commutator pieces 53 and 54.

On the other hand, as shown in FIGS. 5A and 6, four brushes 60 are formed on the end face of the rotor 30, and these four brushes 60 are formed as a pair. And the DC voltage supplied from the outside to the electrode surfaces 51, 5 of the commutator 50.
2 and is supplied to the coils 33 and 34 for two phases. In configuring such a brush 60 in the rotor 30, in the present embodiment, four brush holding portions 61 extend in an X-shape from the center of the end surface of the rotor 30. An electrode 65 having a connection portion 62 on the center side is also disposed inside the electrode 65, and a brush 60 is formed as a small protrusion at the tip of the electrode 65.
The electrode 65 has a small-diameter portion 66 and a large-diameter portion 67 on the base end side and the distal end side, respectively.
A coil spring 69 that is hooked on a step formed at the boundary portion is mounted around the periphery of the coil 6 in a compressed state. Accordingly, the electrode 65 is urged by the coil spring 69 so as to always push the brush 60 to the outer peripheral side, and the commutator 5 is pressed.
0 is elastically contacted.

Thus, the electrode 65 is connected to the coil spring 6
9, the brush 6
0 is in contact with the electrode surfaces 51 and 52 of the commutator 50, and
When rotated integrally with the rotor 30, the brush 60 slides on the electrode surfaces 51 and 52 of the commutator 50. Here, the position of the brush 60 and the electrode surfaces 51, 5
The positional relationship with 2 at a certain timing is represented as shown in FIGS. That is, two sets of brushes 6
0, the brushes 60 belonging to one phase have the positive pole of the commutator 50 when the brushes 60 belonging to the other phase are both located between the electrode surfaces 51 and 52. And another brush 60 is in contact with the commutator 50.
The negative electrode surface 52 is in contact with the negative electrode surface 52. Therefore, power is supplied to the coil 34 on the side electrically connected to these brushes 60 by wiring. In addition, any of the brushes 60 slides on the electrode surfaces 51 and 52 of the commutator 50 as the rotor 30 rotates.
The combinations and polarities of the brushes 60 that supply power to the brushes 4 are switched. Therefore, the rotor 30 includes the coils 33, 3
4 rotates around an axis by magnetic force between the permanent magnet 41 generated by the power supply to the motor 4.

As described above, the brushed motor 1 of the present embodiment
Here, the brush 60 is arranged on the side of the rotor 30 arranged inside the motor case 11 (stator 40), and the commutator 50 is arranged inside the motor case 11 (stator 40). Therefore, even when the commutator 50 is further finely divided in the circumferential direction to increase the number of magnetic poles, the commutator 50 is divided on the inner peripheral surface of the motor case 11 having a long peripheral length. Even in the case of dividing into 24 pieces, high accuracy can be obtained in the positions and shapes of the electrode surfaces 51 and 52. In other words, the commutator 50 becomes longer in the circumferential direction in proportion to the distance from the center to the position where the commutator 50 is arranged.
Accuracy of the angle of division of 1 and 52 and the arrangement angle of the brush 60 can be easily obtained.

Further, since the stator 40 is located on the outside, the stator 40 can be formed integrally with the motor case 11, so that the structure is simple and suitable for miniaturization. Further, the rotor 3 around which the coils 33 and 34 are wound
0 is located inside, so coil 3 per turn
The length of 3, 34 is short. Further, since the pole teeth 35 and 36 face the permanent magnet 41 at a position away from the center, the facing area can be expanded as compared with a configuration in which the pole teeth 35 and 36 face at a position near the center. Therefore, the motor characteristics can be significantly improved.

Further, such a commutator 50-brush 6
When a stepping motor with a brush is applied to the structure around 0, a stepper motor having an inner rotor structure in which the rotor 30 is disposed inside with the coils 33 and 34 and the stator 40 is disposed outside with the permanent magnet 41 can be configured. . Such a stepping motor having an inner rotor structure has a wide variety of applications, such as being compatible with a conventional stepping motor, unlike a stepping motor having an outer rotor structure.

[Other Embodiments] In the above embodiment, the adjacent magnetic poles are not connected to each other by a magnetic material on the core due to the positional relationship between the three core pieces 39. FIG. As schematically shown in FIG.
4A sets the first and second pole teeth 35 and 37 to 1
The plurality of core pieces 39C formed individually are made not to be connected by the magnetic part by interposing a magnetic part such as plastic, and the first pole teeth 35 are formed on any of the plurality of core pieces 39. And the second pole teeth 37 may be formed at positions displaced in the circumferential direction (the direction indicated by the arrow C). That is, the core 34A is
Are formed from a plurality of core pieces 39C magnetically separated from each other by the same number as the number of the pole teeth 35 and the number of the second pole teeth 37, and are magnetically coupled to each of the plurality of core pieces 39C. Since the first pole teeth 35 and the second pole teeth 37 are shifted by three magnetic pole pitches or more, adjacent pole teeth are magnetically separated on the core 39.

In this case, the first and second pole teeth 35, 3 formed on the different core pieces 39C are also provided.
7 are adjacent to each other, the adjacent pole teeth are not connected to each other on the core 34 by the magnetic portion. Therefore, even if adjacent pole teeth are close to each other, magnetic flux rarely leaks between adjacent pole teeth.

The core structure according to the present invention can be applied to a brushless motor, a stepping motor and a brushless motor.

[0038]

As described above, in the motor according to the present embodiment, the first pole teeth and the second pole teeth arranged in the circumferential direction are:
In any case, since the magnetic material is not connected to the adjacent pole teeth, the leakage of magnetic flux does not occur between the adjacent pole teeth even if the adjacent pole teeth are present. Therefore, even if the configuration is such that adjacent pole teeth are close to each other due to the increased number of magnetic poles,
Good motor characteristics can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a brushed motor to which the present invention is applied, which is cut along a motor axis direction.

FIGS. 2A and 2B each show a core 3
It is the top view which extracts and shows one of two core pieces, and its side view.

FIGS. 3A, 3B, and 3C are plane views of a state in which three core pieces constituting a first core are connected by a connecting piece when viewed from an output shaft side shown in FIG. 1; FIG. 1 is a plan view showing the positional relationship between each first flat plate portion of three core pieces in order to show the positional relationship between three core pieces constituting a first core, as viewed from the output shaft side shown in FIG. FIG. 2 is a plan view showing the positional relationship between each of the second flat plate portions of the three core pieces as viewed from the output shaft side shown in FIG. 1 in order to show the positional relationship between the three core pieces constituting the first core. .

FIGS. 4A, 4B, and 4C are plane views of a state in which three core pieces constituting a second core are connected by a connecting piece when viewed from an output shaft side shown in FIG. 1; FIG. 2 is a plan view showing the positional relationship between the first flat plate portions of the three core pieces in order to show the positional relationship between the three core pieces constituting the second core, as viewed from the output shaft side shown in FIG. FIG. 2 is a plan view showing the positional relationship between each second flat plate portion of the three core pieces as viewed from the output shaft side shown in FIG. 1 in order to show the positional relationship between three core pieces constituting the second core. .

FIGS. 5A and 5B are a perspective view on the brush side and a perspective view on the commutator side of the motor with a brush shown in FIG. 1, respectively.

FIG. 6 is a cross-sectional view showing the configuration around the commutator and the brush by enlarging the configuration of the area around the commutator and the brush by cutting the motor with a brush shown in FIG. 1 along a direction perpendicular to the motor axis.

FIG. 7 is an explanatory view showing a developed commutator of the motor with a brush shown in FIG. 1;

FIG. 8 shows a brushed motor to which the present invention is applied.
It is explanatory drawing which shows typically the structure at the time of using the core piece in which 1st pole tooth and 2nd pole tooth were formed one by one.

FIG. 9 (A), (B), (C), (D)
FIG. 7 is a plan view of a main part of a conventional motor, a longitudinal sectional view thereof, an explanatory diagram showing leakage of magnetic flux between magnetic poles, and an explanatory diagram showing leakage of magnetic flux between pole teeth.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brushed motor 10 Motor housing 11 Motor case 12 End plate 13, 14 Ball bearing 16 Spacer 20 Rotating shaft 30 Rotor 31 First core 32 Second core 33, 34 Coil 35, 36 First pole tooth 37, 38 Second pole teeth 39, 39A, 39B, 39C Core piece 40 Stator 41 Permanent magnet (drive magnet) 51, 52 Electrode surface 53, 54 Commutator piece 55, 56 Feeding part 61 Brush holding part 65 Electrode 66 Small-diameter portion 67 Large-diameter portion of electrode 69 Coil spring 300 Plastic connection piece (non-magnetic portion) 392 First flat plate portion of core piece 394 Second flat plate portion of core piece 396 First flat plate portion and second flat plate portion Connection with flat plate

Claims (4)

[Claims] A core having first and second polar teeth extending alternately in the circumferential direction from both sides in the axial direction;
An armature including a single-turn coil in which a magnetic path connecting the first magnetic pole and the second magnetic pole passes inside;
And a driving magnet opposed to the second pole tooth, wherein, of the first pole tooth and the second pole tooth, pole teeth adjacent in the circumferential direction are magnetically A motor characterized by being separated. 2. The method according to claim 1, wherein the core is formed by three magnetically separated core pieces, wherein each of the three core pieces has the first pole tooth magnetically coupled to the first pole tooth. The angle direction is 120 ° with the second pole tooth
The motor is characterized in that adjacent pole teeth are magnetically separated on the core by being formed at the shifted positions. 3. The core according to claim 1, wherein the core is formed of a plurality of magnetically separated core pieces having the same number as the number of the first pole teeth and the number of the second pole teeth. In each of the plurality of core pieces, the first pole teeth and the second pole teeth that are magnetically coupled are displaced from each other by three magnetic pole pitches or more, so that adjacent pole teeth are located on the core. A motor characterized by being magnetically separated. 4. The method according to claim 1, wherein
The core includes two or more phases of cores to which currents of different phases are supplied to the coil.
A motor, wherein a spacer or a gap made of a non-magnetic material is formed between cores equal to or larger than a phase.