JPH11308837A - Surface-opposed motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of magnetic flux from the boundary part between a north pole and a south pole, to suppress parallel magnetic flux. and to prevent the generation of noise, by providing a modulating element which modulates a magnetic field strength to a low magnetic field strength side, at the boundary part between a north pole and a south pole of a magnet. SOLUTION: A back yoke 2 having a discoidal magnet 1 magnetized into multiple poles is fitted to a rotor 24 fixed to a shaft 22. Moreover, a rotor yoke 3 arranged to be opposed to the magnet 1 in the axial direction is press- fitted to a rotor 24 on its peripheral side by the attracting force of the magnet 1, and a stator coil 4 having driving coils 5 between the magnet 1 and the rotor yoke 3 is arranged. Here, a modulating element which modulates the magnetized waveform of the magnet 1 to a low magnetic field side at the boundary part between a north pole and a south pole is provided, and the change of a magnetic field strength L1 is slowed compared with its change before and after that, and made smaller than a magnetic field strength L2 in the case of sinusoidal magnetization. Consequently, it becomes possible to decrease parallel magnetic flux, and to reduce noise.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a face-to-face motor used for VCRs, headphones, CDs and the like, and to a face-to-face motor capable of reducing audible noise generated by vibration of a motor coil.

[0002]

2. Description of the Related Art Conventionally, for example, a motor shown in FIG. 23 is known as a surface facing motor used for VCRs, headphones, CDs and the like. That is, the bearing 5 on the housing 51 side
The rotor 54 is fixed to the rotating shaft 52 rotatably supported by the rotating shaft 3. A back yoke 55 having a multipole-magnetized disk-shaped magnet 56 is fixed to the rotor 54, and a rotor yoke 57 is disposed on the rotor 54 so as to face the magnet 56 in the axial direction. The rotor yoke 57 is
Due to the attraction force of the magnet 56, the rotor 5
4 is crimped.

A plurality of driving coils 60 are provided between the magnet 56 and the rotor yoke 57,
The stator coil 59 fixed to 1 is located. The stator coil 59 includes the magnet 56 and the rotor yoke 5.
7 is disposed in a magnetic field generated between the rotor 7 and the drive coil 60. When the drive coil 60 is energized, a rotational force is generated according to Fleming's law, and the rotor 54 rotates.

[0004] The motor having such a configuration is an efficient motor having little iron loss since there is no iron core in the driving coil.

[0005]

However, the above-mentioned surface-facing motor has the following problems. This problem will be described with reference to FIG.

FIG. 24 is a view for explaining a magnetic circuit of the surface facing motor. In this motor, the back yoke 55
Is formed by a disk-shaped magnet 56 which is fixed by magnetic attraction and is multipolar magnetized, and a rotor yoke 57 which faces the magnet 56 in the axial direction and is fixed by crimping while maintaining a minute gap by the attractive force of the magnet 56. It constitutes a magnetic circuit. The magnetic lines of force of this magnetic circuit are determined by the magnetic resistance or the magnetic permeability of the rotor yoke 57, the back yoke 55, and the air.
Line of magnetic force G from the pole to rotor yoke 57 via air
1, a magnetic line of force G2 flowing in the rotor yoke 57, a magnetic line of force G3 flowing to the S-pole magnet 56 via air, and a magnetic line of force G4 flowing through the back yoke 2. At this time, the magnetic lines of force G1 and G3 in the gap are so-called linkage magnetic fluxes that are perpendicular to the magnet 56. However, NS
Then, the direction of the magnetic field lines is reversed.

In the case of the minute gap, most of the magnetic lines of force in the gap are formed by the magnet 56 and the stator coil 59.
Although it is an effective magnetic flux that generates a rotational force in a direction perpendicular to the (drive coil 60), a parallel magnetic flux H that does not contribute to rotation is generated at the boundary between the N and S poles of the magnet 56. This parallel magnetic flux H is a magnetic flux parallel to the magnet 56 and the stator coil 59, and
9 through the radial direction of the coil pattern and the parallel magnetic flux H according to Fleming's law.
Is generated, that is, the vibration force of the coil is generated, and motor noise is generated.

In recent years, in magnetic recording devices, higher recording densities have been required.
In many cases, the motor is used at a high rotation speed with the downsizing of the device. However, as the rotation speed of the motor increases, the motor noise caused by the vibration of the stator coil 59 increases.
Further, in the surface-facing motor, since the shape of the stator coil 59 having the driving coil 60 is a flat disk shape, the stator coil 59 has vibration and vibration like a cone paper of a speaker.
Since it works as a noise source, loud noise is easily generated in principle.

Further, in order to improve the efficiency of the motor, in view of the effective use of the coil pattern, there has been a tendency in recent years to magnetize the magnet with multiple poles. Since the magnetic flux increases, the above-mentioned noise becomes a serious problem.

Therefore, a configuration shown in FIG. 25 is known as a surface facing motor for reducing this noise (Japanese Patent Laid-Open No. Hei 8
No. 163849).

Here, the rotor 34 of the surface facing motor is
A multipole-magnetized disk-shaped first magnet 36 and a multipole-magnetized disk-shaped second magnet 38 that is axially opposed to the first magnet 36 and disposed at an appropriate distance from the first magnet 36 are provided. And is rotatably supported by the bearing portion 33. Further, the stator coil 39 has a driving coil 40, and faces the first magnet 36 and the second magnet 38 in the axial direction, and the first magnet 36 and the second magnet 3
8 are arranged. In such a surface-facing motor, since the second magnet 38 is used instead of the rotor yoke, a vibration / noise source in a magnetic field generated between the first magnet 36 and the second magnet 38 is used. The magnetic flux in the direction parallel to the stator coil 39 can be reduced. Therefore, vibration and radiation noise can be reduced.

However, in this surface facing motor, the first
And the use of the second two magnets, the cost is higher than that of a normal motor. In particular, in a small flat motor, expensive rare earth magnets to obtain desired characteristics,
For example, since a sintered neodymium magnet is required, the cost is further increased. Although the second magnet is used in place of the rotor yoke, a second back yoke (37 in FIG. 25) is required to stably maintain a small amount of leakage magnetic flux of the second magnet. For this reason, the thickness of all the motors is about the same as the thickness of the magnet as compared with a normal motor, and cannot be reduced in thickness.

As another conventional surface facing motor,
The thing described in Japanese Patent Publication No. 04-44504 is known. Here, an auxiliary pole region having an inverse property to the main pole is provided at a position where the electric angle of the multi-pole magnetized magnet is 60, 120, 240, or 300 degrees to suppress fluctuation of the rotational force and noise. In the surface facing motor described in Japanese Patent Publication No. Hei 05-184108, the magnetic field strength distribution curve of the multi-pole magnetized magnet is formed by the fundamental wave and the third harmonic component, so that the rotational force is increased. Fluctuations and noise.

However, in these surface-facing motors, the fluctuation of the rotational force is suppressed by appropriately setting the magnetic field intensity distribution of the multi-polar magnetized magnet. The characteristics deteriorate. In addition, it is a force in the plane of the coil and has little effect on reducing noise generated by coil vibration.

The present invention has been made in order to eliminate these disadvantages, and has as its object to provide a surface-facing motor that can suppress noise even when a multi-pole magnetized coil is provided.

[0016]

According to a first aspect of the present invention, there is provided a surface-facing motor, comprising: a stator having a plurality of coils; a multi-pole magnetized magnet on one side of the coils; A face-facing motor including a yoke disposed on the opposite side of the magnet, comprising a modulator for modulating a magnetic field strength to a lower magnetic field strength side at an N / S pole boundary of the magnet. .

According to a second aspect of the present invention, in the surface facing motor according to the first aspect, the modulating section comprises a non-magnetized region provided at the boundary between the N and S poles. .

According to a third aspect of the present invention, in the surface facing motor according to the second aspect, the non-magnetized region includes:
The magnet comprises a recess provided on the stator side of the magnet.

According to a fourth aspect of the present invention, in the surface facing motor according to the first aspect, the modulating section is provided at a boundary between the N and S poles and opposite to a main pole of the magnet. It consists of a region of opposite polarity.

According to a fifth aspect of the present invention, there is provided a surface-facing motor having a stator having a plurality of coils, a multi-pole magnetized magnet on one side of the stator coil, and a magnet opposite to the magnet with respect to the coil. And a yoke arranged thereon, wherein a convex portion projecting toward the coil is formed at an N / S pole boundary of the magnet in the yoke.

According to a sixth aspect of the present invention, there is provided a surface-facing motor having a stator having a plurality of coils, a multi-pole magnetized magnet on one side of the stator coil, and a magnet opposite to the magnet with respect to the coil. And a yoke arranged in the surface-facing motor, comprising: a magnetic flux guiding portion for guiding a magnetic flux at an N / S pole boundary portion of the magnet.

According to a seventh aspect of the present invention, there is provided the surface facing motor according to the sixth aspect, wherein the magnetic flux guiding portion comprises:
The magnet is made of a magnetic material or a shielding material provided on a side facing the stator.

According to another aspect of the present invention, there is provided a surface-facing motor having a stator having a plurality of coils, a magnet multi-polarized on one side of the coil, and an opposite side of the coil with respect to the magnet. A face-to-face motor provided with:
They are arranged with a gap therebetween.

Hereinafter, the operation of the present invention will be described.

The present invention focuses on the fact that a parallel magnetic flux that does not contribute to the rotational force is generated from the NS boundary of the magnet, and the magnetic flux from the boundary does not contribute to the rotational force and has little effect on the motor efficiency. With the above configuration, N
・ Reduce the generation of magnetic flux from the S boundary, or
The direction of the magnetic flux from that part is changed. This allows
It suppresses the parallel magnetic flux that affects the coil, thereby preventing the generation of noise.

[0026]

(Embodiment 1) FIG. 2 is a schematic cross-sectional view for explaining the configuration of a surface-facing motor according to the present embodiment, and FIG. 3 is an explanatory view showing a main part thereof. Figures 2 and 3
In, the rotor 24 is fixed to the rotatable rotation shaft 22. A back yoke 2 having a multipolar magnetized disk-shaped magnet 1 is fixed to the rotor 24, and a rotor yoke 3 is arranged on the rotor 24 so as to face the magnet 1 in the axial direction. The rotor yoke 3 is pressed against the rotor 24 on the outer peripheral side by the attractive force of the magnet 1.

A stator coil 4 having a plurality of drive coils 5 is located between the magnet 1 and the rotor yoke 3. Since the stator coil 4 is disposed in the magnetic field generated between the magnet 1 and the rotor yoke 3, when the drive coil 5 is energized, a rotational force is generated according to Fleming's law, and the rotor 24 is driven. Will rotate.

In such a configuration, in the conventional surface-facing motor, the magnetized waveform of the multipolar magnetized magnet 1 is as follows.
Sinusoidal or trapezoidal wave magnetization as shown in FIG. 4A or 4B is obtained. These magnetized waveforms are properly used depending on the motor specification and motor application, but in any case, the magnetic field strength changes near the boundary between the N and S poles (boundary portion) as in the other portions.

In this embodiment, different from the above-mentioned conventional example, a modulation section for modulating the magnetized waveform of the magnet 1 to the low magnetic field side at the NS boundary is provided. For example, as shown in FIG. 1 (a), from the position where the N-pole or S-pole of the multi-polarized magnet 1 is almost maximally magnetized to the position where the S-pole or N-pole is approximately maximally magnetized. Within the range in which the magnetic field strength changes, a weak magnetization region (modulation section) is provided at the boundary between the N and S poles, where the change in the magnetic field strength becomes gentler than changes before and after the boundary. FIG. 1B is a diagram showing the magnetic field strength at the modulation section in FIG. 1A. As shown in FIG. 1B, the magnetic field strength L1 of the present embodiment shown by a solid line is shown by a dotted line. The magnetic field intensity L2 is set smaller than the conventional (sinusoidal magnetization, trapezoidal magnetization) magnetic field strength L2.

The operation of the main surface facing motor configured as described above will be briefly described with reference to FIG. First,
A disk-shaped magnet 1 in which a back yoke 2 is fixed by magnetic attraction and magnetized in multiple poles, and a rotor yoke which faces the magnet 1 in the axial direction and is crimped and fixed with a small gap maintained by the attraction of the magnet 1 3 constitute a magnetic circuit. The lines of magnetic force of this magnetic circuit are
Back yoke 2, from the magnetic resistance or permeability of air,
A magnetic line of force 7 from the N pole to the rotor yoke 3 via air, a magnetic line of force 8 flowing in the rotor yoke 3, a magnetic line of force 9 toward the magnet 1 of the S pole via air, and a magnetic line of force 10 flowing through the back yoke 2. At this time,
The lines of magnetic force 7, 9 in the gap are so-called linkage magnetic fluxes that are perpendicular to the magnet 1. However, the direction of the line of magnetic force is reversed in NS.

A stator coil 4 having a plurality of driving coils 5 and fixed to a housing is arranged in the gap. A plurality of spiral patterns are formed in the stator coil 4, and when an electric current is applied to the coil, a rotational force is generated by a radial portion of the pattern and the interlinkage magnetic flux.
The direction of the rotational force is determined by Fleming's law, and the magnitude of the rotational force is uniquely determined by the product of the magnetic field strength, the current, and the radial length of the pattern. The desired rotation direction and torque can be obtained by controlling with an external circuit according to the direction of rotation.

In such a surface-facing motor, conventionally, the presence of the parallel magnetic flux H shown in FIG.
The motor noise was generated by the vibration of.

However, in the surface-facing motor according to the present embodiment, as described above (see FIG. 1), the change in the magnetic field strength at the boundary between the N and S poles is smaller than before and after that, that is, N ·
Since the magnetic field strength at the south pole boundary is reduced, the parallel magnetic flux can be reduced, and the motor noise can be reduced.

As described above, in the present embodiment, the magnetic field strength is reduced at the boundary between the N and S poles. However, even in this case, the boundary hardly contributes to the rotational force, so that the influence on the motor efficiency is reduced. Is less.

As described above, in the surface-facing motor according to the present embodiment, the magnetic field strength is reduced at the boundary between the N and S poles.
Both noise suppression can be realized.

The boundary between the N and S poles for reducing the magnetic field strength is set within a range where the rotational efficiency of the motor can be maintained. Specifically, it is desirable to set the area to be equal to or less than 1/5 of the width of the main pole in the circumferential direction.

Further, in the embodiment shown in FIG.
At the boundary of the S-pole, a modulation unit composed of a weakly magnetized region where the magnetic field intensity is small (the intensity change is gradual) is provided, but the modulation unit is in the non-magnetized region (see FIG. 5) or opposite to the main pole. It may be a reverse polarity region (see FIG. 6) which becomes a property.

In the case where a non-magnetized region is provided, FIG.
As shown in (1), the magnet 1 may be a combination of a plurality of magnets with a gap maintained at the boundary between the N and S poles (N and S magnetic poles arranged with a gap therebetween). In this case, the parallel magnetic flux H can be reduced as compared with the magnetic circuit shown in FIG.

Further, as shown in FIG. 21, the modulation section may be a groove of a concave portion provided at the boundary between the N and S poles of the magnet 1. According to the configuration of FIG. 21, the same effect as in the case where the boundary portion is not magnetized can be obtained, the level of the parallel magnetic flux 11 is reduced, and the coil vibration and noise can be reduced.

The weakly magnetized area and the non-magnetized area are NS
It may be provided on a part of the pole boundary on the stator coil side.

Next, the result of verifying the effect of the surface facing motor of the present invention by simulation will be described.
The case where the boundary is non-magnetized and the case where the boundary is reverse-polarized will be described separately. Although the simulation does not describe the case where the boundary portion is a weakly magnetized region, the effect of noise suppression can be obtained in this case as in the above case.

FIG. 8 is a view for explaining a model used in this simulation, and is a cross-sectional view of a surface facing motor at a certain radial position. In this figure, the same parts as those in FIGS. In this model, the space around the surface facing motor was assumed to be air 12. In addition, for verification,
As shown in FIG. 5, the magnet 1 used was a non-magnetized region at the boundary between the N and S poles. For comparison, verification was also performed on a case where the surface magnetic field intensity distribution of the magnet 1 was a conventional sinusoidal magnetization shown in FIG.

First, the case of conventional sine wave magnetization will be described. FIG. 9 is a diagram showing a simulation result of a magnetic flux vector at the NS pole boundary in the case of sine wave magnetization. FIG. 10 shows a vector extracted from the result of FIG. 9 which is 1/10 or more of the magnetization level of the magnet 1. FIG. 11 shows only components parallel to the magnet 1 and the like in FIG.

From the results shown in FIG. 9, it is understood that the magnet 1 has a large amount of vertical magnetic flux linked to the drive coil 5 at the center of each pole, and has a large amount of parallel magnetic flux parallel to the magnet 1 near the boundary. 10 and 11 that the parallel magnetic flux has a high magnetization level (a level of 1/10 or more of the magnet 1).

Next, the case of the present invention (non-magnetized) will be described. FIG. 12 is a diagram showing a simulation result of a magnetic flux vector at the NS pole boundary in this case. FIG. 13 shows the magnet 1 in the result of FIG.
Is extracted and shown as a vector of 1/10 or more of the magnetization level of FIG. FIG. 14 shows only components parallel to the magnet 1 and the like in FIG.

By comparing FIG. 12 with FIG. 9, it can be seen that there is no change in the magnetic flux level at the center of each pole of both. Also,
Comparison of FIGS. 13 and 14 with FIGS. 10 and 11 shows that the magnetic flux level of the parallel magnetic flux at the NS boundary is smaller in the case of non-magnetization of the present invention.

As described above, it can be seen from the simulation result that the parallel magnetic flux can be suppressed by the surface facing motor of the present invention.

Next, the results of an experiment that has demonstrated the effects of the present invention will be described. Here, the experiment was conducted using the format of a consumer digital VCR (“Specifications of Digit”) that realized high video quality and high sound quality proposed by the HD Digital VCR Council.
al VCR for Consumer-Use ":
HD Digital VCR Conference
e. 1994. Dec. ). In this specification, the tape width is 6.35 (mm), the track width is 10 (μm), and the recording density is 2.44 (μm ² / bi).
At t), the recommended parameter is the drum diameter φ21.7.
(Mm), and the drum rotation speed is 150 (min ^-1 ). The conventional sine-wave magnetized surface-facing motor and the (non-magnetized) surface-facing motor of the present invention are incorporated in a rotary cylinder, and the noise level at a certain distance is measured by a sound level meter. Was subjected to frequency analysis. In this experiment, other factors such as a bearing incorporated in the same rotating cylinder were removed.

As a result, as compared with the conventional surface facing motor,
It has been found that the noise is reduced by 3 dB with the surface facing motor of the present embodiment. FIG. 15 (conventional) and FIG. 16 (this embodiment) show the frequency analysis results of noise during this experiment.
From these, it can be seen that so-called cogging noise (here, 5.4 kHz) or noise due to motor rotation (here, harmonics of 150 Hz) is reduced. 15 and 16, the vertical axis represents the noise level, and the horizontal axis represents the noise frequency.

Next, a description will be given of a simulation result in a case where a reverse polarity magnetized region is provided at the boundary between the N and S poles of the multipolar magnetized magnet 1. Here, a case where the surface magnetic flux distribution of the magnet 1 is as shown in FIG. 6 will be described.

FIG. 17 is a diagram showing a simulation result of a magnetic flux vector at the boundary between the NS poles in this case. FIG. 18 shows extracted vectors of 1/10 or more of the magnetization level of the magnet 1 in the result of FIG. FIG. 19 shows only components parallel to the magnet 1 and the like in FIG.

FIGS. 9 and 1 show the results of the conventional surface-facing motor.
As compared with 0 and 11, the direction of the magnetic flux on the magnet surface near the boundary is changed by providing the reverse polarity magnetized region as shown in FIG. That is, a large amount of parallel magnetic flux is generated on the surface of the magnet 1, and the level of the parallel magnetic flux near the middle of the gap where the coil is located is as shown in FIGS.
As shown in FIG. 9, it is smaller than the conventional one. Therefore,
It is possible to suppress generation of noise.

In the embodiment described above,
Regarding the non-magnetized area and the weakly magnetized area, even if they are provided only in a part of the boundary portion (for example, in the vicinity of the surface of the magnet 1 facing the stator coil 4), the effect of reducing the coil vibration and noise is similarly reduced. Can be expected. Furthermore, even if the widths of the non-magnetized area and the weakly magnetized area are changed according to the diameter, the effect of reducing coil vibration and noise can be expected.

Regarding the method of magnetizing the non-magnetized area, weakly magnetized area or reverse-polarized magnetized area of the magnet, the magnet is covered with a shield material near the boundary between the N and S poles of the magnet. Or the magnet groove width of the magnetized yoke,
There is a method of magnetizing by appropriately setting the groove shape and the coil position, or a method of simply magnetizing by sandwiching a spacer between the magnetizing yoke and the magnet.

(Second Embodiment) In the first embodiment, the magnetic field intensity of the magnet is modulated at the boundary in order to reduce the parallel magnetic flux at the boundary between the N and S poles of the magnet. The parallel magnetic flux is reduced by changing the shape of the components of the surface facing motor.

FIG. 20 shows a face-to-face motor in which a portion 8 of the rotary yoke 3 corresponding to the boundary of the magnet 1 is deformed in the direction of the magnet 1 in order to reduce the parallel magnetic flux at the boundary between the N and S poles of the magnet. FIG. 3 is an explanatory diagram showing a configuration. According to the configuration shown in FIG. 20, since the parallel magnetic flux H is directed toward the rotating yoke 3, the parallel component of the magnetic flux is reduced, and coil vibration and noise can be suppressed.

FIG. 22 is a diagram showing another configuration example of the present embodiment. Here, a magnetic flux guiding member such as an iron piece or a shield material (for example, lead) is attached to the surface of the N / S pole boundary portion of the magnet 1. As a result, the magnetic flux at the boundary passes through the magnetic flux guiding member.
And the vibration and noise of the coil are reduced. The magnetic flux guiding member is not limited to the above, and may be a material containing an iron component coated on the surface of the magnet 1.

In the above embodiment, the weakly magnetized area, the non-magnetized area or the reverse magnetized area, or the area in which the direction of the magnetic flux is changed are the N and S poles of the multipolar magnetized magnet. Is preferably provided in a region of 1/10 or less of the width of the main pole in the circumferential direction at the boundary of.

It is desirable that the magnetic flux level in the weakly magnetized region be equal to or less than 1/20 of the maximum residual magnetic flux density of the main pole.

In the above embodiment, the rotary yoke type surface facing motor has been described. However, the present invention can be similarly applied to a fixed yoke type. That is, in a fixed yoke-type surface-facing motor having a stator having a plurality of coils, a multipolar magnetized magnet, and a back yoke covering the magnet, at the N / S pole boundary of the magnet, The present invention described in Embodiments 1 and 2 may be applied.

[0061]

According to the surface facing motor of the present invention, the parallel magnetic flux at the coil existing position can be suppressed, and the noise caused by the vibration of the stator can be suppressed.

[Brief description of the drawings]

FIG. 1 is a magnetic field intensity distribution diagram and an enlarged view of a boundary portion of a magnet of a surface-facing motor according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a surface-facing motor according to an embodiment of the present invention.

FIG. 3 is an explanatory view showing a main part of the surface facing motor of FIG. 2;

FIG. 4 is a magnetic field strength distribution diagram of a magnet of a conventional surface facing motor.

FIG. 5 is a magnetic field intensity distribution diagram of a magnet of a surface-facing motor having a non-magnetized region.

FIG. 6 is a magnetic field intensity distribution diagram of a magnet of a surface facing motor having a reverse polarity region.

FIG. 7 is a diagram illustrating a magnetic circuit of a magnet of a surface-facing motor having a non-magnetized region.

FIG. 8 is a diagram illustrating a model of a simulation performed according to the present invention.

FIG. 9 is an enlarged view of a boundary part of a simulation result of a sine wave magnetized surface facing motor.

FIG. 10 is a diagram showing only the simulation result of FIG. 9 having a high magnetic flux level.

11 is a diagram showing only a parallel magnetic flux component in the simulation results of FIG. 10;

FIG. 12 is an enlarged view of a boundary portion of a simulation result of a non-magnetized surface facing motor.

FIG. 13 is a diagram showing only those having a high magnetic flux level as a result of the simulation of FIG. 12;

FIG. 14 is a diagram showing only a parallel magnetic flux component among the simulation results of FIG.

FIG. 15 is a diagram illustrating a noise frequency analysis result of a sine wave magnetized rotating cylinder.

FIG. 16 is a diagram showing a noise frequency analysis result of a non-magnetized rotating cylinder.

FIG. 17 is an enlarged view of a boundary part of a simulation result of a surface-opposed motor of reverse polarity magnetization.

18 is a diagram showing only the result of the simulation of FIG. 17 having a high magnetic flux level.

FIG. 19 is a diagram showing only a parallel magnetic flux component among the simulation results of FIG. 18;

FIG. 20 is a diagram illustrating a configuration of another surface facing motor of the present invention.

FIG. 21 is a diagram illustrating a configuration of still another surface facing motor of the present invention.

FIG. 22 is a diagram illustrating a configuration of still another surface facing motor of the present invention.

FIG. 23 is a diagram illustrating a configuration of a conventional surface facing motor.

24 is a diagram illustrating a magnetic circuit of the surface facing motor of FIG.

FIG. 25 is a diagram illustrating a configuration of another conventional surface facing motor.

[Explanation of symbols]

 Reference Signs List 1 magnet 2 back yoke 3 rotor yoke 4 stator coil 5 driving coil 6 air gap

Claims (8)

[Claims] 1. A surface comprising: a stator having a plurality of coils; a multi-polarized magnet on one side of the coil; and a yoke disposed on the opposite side of the coil with respect to the coil. A face-to-face motor, comprising: a modulator for modulating a magnetic field strength to a lower magnetic field strength side at an N / S pole boundary of the magnet. 2. The surface facing motor according to claim 1, wherein the modulating unit comprises a non-magnetized region provided at the boundary between the N and S poles. 3. The surface facing motor according to claim 2, wherein the non-magnetized region comprises a concave portion provided on the stator side of the magnet. 4. The surface facing motor according to claim 1, wherein the modulating section is provided at a boundary between the N and S poles and has a reverse polarity region opposite to a main pole of the magnet. Features a facing motor. 5. A stator having a plurality of coils, a multi-pole magnetized magnet on one side of the stator coil, and a yoke disposed on the side opposite to the magnet with respect to the coil. In the surface facing motor, a protrusion protruding toward the coil is formed at an N / S pole boundary portion of the magnet in the yoke. 6. A stator having a plurality of coils, a magnet multipolarly magnetized on one side of the stator coil, and a yoke disposed on the opposite side of the magnet with respect to the coil. A surface-facing motor, comprising: a magnetic flux guiding portion for guiding a magnetic flux at an N / S pole boundary portion of the magnet. 7. The rotating yoke type according to claim 6, wherein the magnetic flux guide is made of a magnetic material or a shield material provided on a side of the magnet facing the stator. Surface facing motor. 8. A surface comprising: a stator having a plurality of coils; a magnet multipolarly magnetized on one side of the coil; and a yoke disposed on the side opposite to the magnet with respect to the coil. In a facing motor, the N and S magnetic poles of the magnet are arranged with a gap therebetween.