JP3177177B2 - Flat motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat motor used for a cassette tape recorder, a CD player, and the like, and more particularly to a flat motor having a reduced thickness while improving the performance of the motor.

[0002]

2. Description of the Related Art Conventionally, as this kind of flat motor, for example, there is one shown in FIG. In the flat motor 41, a wheel 46 is fixed to a rotating shaft 45 rotatably supported by a bearing 43 on the housing 42 side, and the wheel 46 has a multipole-magnetized disk-shaped first magnet 47. One back yoke 48 is fixed. Further, a second magnet 49 and a second back yoke 50 are arranged on the wheel 46 so as to face the first magnet 47 in the axial direction, and constitute the rotor 44.

[0003] The second back yoke 50 is driven by the attraction force of the first magnet 47 and the second magnet 49.
Is crimped. In a magnetic field generated between the first magnet 47 and the second magnet 49, a substrate 51 and a stator 51 having a plurality of coils 53 are located.
When a current is supplied to 3, the torque generated by the relative force between the first magnet 47 and the second magnet 49 is generated.

FIG. 11 is a plan view of the stator 51 of FIG. 10 as viewed from above. Six coils 53 are arranged on the substrate 52, and the terminal portions at the beginning and end of the winding of each coil 52 are connected to the wiring lands 54 of the wiring on the substrate 52.
55. Here, the six coils 53
An example is shown in which the coils at each diagonal form a pair and are driven in three phases.

[0005] Such a flat motor 41 is a highly efficient motor with little iron loss since there is no iron core in the coil 53 due to its structure. Further, there is essentially no torque unevenness based on the attraction force acting between the iron core in the coil and the NS magnetic pole of the magnet, that is, no coking because there is no iron core in the coil.

[0006]

However, although the conventional flat motor is excellent in structure as described above, when it is used in a portable device using a battery as a power source, the efficiency is further increased in order to extend the life of the battery. In addition, there is a demand for downsizing, and in particular, downsizing of motors in order to downsize equipment.

In this case, in the conventional example shown in FIG. 11, the gap of the magnetic circuit between the second magnet 49 and the coil 53 can be made sufficiently narrow because there is no obstacle between them. The gap between the coil 53 and the coil 52 is widened by the thickness of the substrate 52 located therebetween, which is a major obstacle to improving the efficiency. Further, the substrate 52 exists because of the structure of the stator 51 in which the coil is held and the wiring for energization is carried out. In the thickness direction.

The present invention provides a flat motor whose thickness is reduced while improving its performance by using a stator in which the shape of a board for coil connection is devised in order to solve such a conventional problem. The purpose is to do.

[0009]

In order to achieve this object, the present invention is configured as follows. First, the present invention has a multi-polarized disk-shaped magnet, a rotor rotatably supported by a bearing portion, and a plurality of coils arranged in a ring on a substrate in the axial direction of the magnet. And a fixedly arranged stator.

In the present invention, such a flat motor is provided with a substrate in the form of a ring which faces the magnet in the axial direction and has an inner diameter larger than the outer diameter of the magnet.
A substrate and a ring-shaped second substrate whose outer diameter is smaller than the inner diameter of the magnet, and the outer peripheral portions of the plurality of coils are fixed to the first substrate while the first substrate and the second substrate are concentrically arranged, and the inner peripheral portion is formed. It is characterized in that it is fixed to the second substrate and arranged in an annular shape, and further, the magnet is inserted into the hollow area between the first substrate and the second substrate and arranged close to the coil.

That is, in the flat motor according to the present invention, a portion facing the magnet of the rotor is removed while leaving an outer peripheral portion and an inner peripheral portion necessary for connection of the coil of the substrate as a substrate used for arranging coils of the stator. It has a double ring structure, and the magnet of the rotor is arranged in the space from which the substrate has been removed. For this reason, compared with the conventional structure, the magnet of the rotor corresponding to the thickness of the substrate can be made closer to the coil, and the gap of the magnetic circuit is narrowed by that amount, thereby improving the efficiency of the motor. Further, since the rotor is closer to the coil by the thickness of the substrate than in the conventional structure, the thickness of the motor is reduced by the thickness of the substrate.

As a specific structure of the flat motor of the present invention,
The rotor is composed of a multipolar magnetized disk-shaped first magnet and a first magnet.
A multipole-magnetized disk-shaped second magnet is disposed at a distance facing the magnet in the axial direction, and the stator is disposed between the first magnet and the second magnet in the axial direction. In addition, one of the first magnet and the second magnet is inserted into a hollow area between the first substrate and the second substrate, and is disposed close to the coil.

As another specific structure of the flat motor,
The rotor has a multi-pole magnetized disk-shaped magnet and an opposing yoke arranged at a distance facing the magnet in the axial direction, and the stator is arranged between the magnet and the opposing yoke in the axial direction. Then, a magnet is inserted into a hollow area between the first substrate and the second substrate, and is arranged close to the coil.

In the stator according to the present invention, the outer peripheral bottom side of the coil having a substantially isosceles triangle or a substantially isosceles trapezoidal shape is fixed to the first substrate, and the inner peripheral vertex sphere of the coil has the upper side attached to the second substrate. Fix it. The terminal part at the end of winding of the coil is arranged in a range in contact with the first substrate at or near the bottom of the coil and connected to wiring on the first substrate. Further, the terminal portion at the beginning of winding of the coil is arranged in the vertex or upper side portion of the coil or in a range in contact with the second substrate at the vicinity thereof and connected to the wiring on the second substrate.

Therefore, the first substrate of the stator is a single-sided wiring substrate, and the second substrate is a double-sided wiring substrate having through holes. The coil is a round conductive wire having a self-fusing layer or an air-core coil using a flat conductive wire having a self-fusing layer. Further, the plurality of coils arranged annularly between the first substrate and the second substrate arranged concentrically adhere and fix between isosceles portions of adjacent coils to increase the support strength for the substrate having the double ring structure. .

[0016]

FIG. 1 is a sectional view of a motor structure according to a first embodiment of a flat motor according to the present invention. In the flat motor 1, a wheel 6 is fixed to a rotating shaft 5 rotatably supported by a bearing 3 on the housing 2 side. A first back yoke 8 having a multipole-magnetized disk-shaped first magnet 7 is fixed to a lower portion of the wheel 6.

Further, a second back yoke 10 having a second magnet 9 is disposed above the wheel 6 so as to face the lower first magnet 7 in the axial direction. The second back yoke 10 is pressed against the wheel 6 by the attraction of the first magnet 7 and the second magnet 9. The wheel 6, the first magnet 7, the first back yoke 8, the second magnet 9, and the second back yoke 10 constitute the rotor 4 of the flat motor 1.

The stator 11 is located in a magnetic field generated between the first magnet 7 and the second magnet 9.
The stator 11 has a ring-shaped first substrate 12 supported by the housing 2 on the outer peripheral side and a ring-shaped second substrate 13 located on the inner peripheral side, concentrically arranged, and the stator 11 is disposed between the first substrate 12 and the second substrate 13. A plurality of coils 14 are annularly arranged in the circumferential direction.

For this reason, when the coil 14 of the stator 11 is energized, a rotational force is generated by the relative force between the first magnet 7 and the second magnet 9. First substrate 1 of stator 11
The second and second substrates 13 will be described in more detail. First, the first substrate 12 located on the outer peripheral side has a ring shape whose inner diameter is larger than the outer diameter of the first magnet 7. The second substrate 13 located on the inner peripheral side has the same ring shape whose outer diameter is smaller than the inner diameter of the first magnet 7.

The first substrate 12 and the second substrate 13 are arranged concentrically as shown in the figure, and the coils 14 are arranged in a ring shape, and the outer and inner sides of the coil are fixed and supported, respectively. A portion facing the first magnet 7 between the two substrates 13 is a hollow area where no substrate exists. For this reason, the first magnet 7 can be disposed so as to enter the hollow area between the first substrate 12 and the second substrate 13, whereby the first magnet 7 can be disposed.
The magnet 7 can be arranged as close to the coil 14 as possible, similarly to the upper second magnet 9.

FIG. 2 shows the stator 11 of FIG. In this embodiment, the stator 11 includes six coils 14 </ b> A to 14 </ b> F in a state in which the first substrate 12 on the outer peripheral side and the second substrate 13 on the inner peripheral side are concentrically arranged. The array is fixed in a ring between them. That is, the plurality of coils 14A to 14F have a substantially isosceles trapezoidal shape,
The coil bottom side located on the outer peripheral side is fixed to the first substrate 12, and the coil top side (apex) is fixed to the second substrate 13.

Each of the coils 14A to 14F is an air-core coil wound by using a round conductive wire or a flat conductive wire having a self-fusing layer, and a terminal portion at the inside of the coil at the beginning of winding is a second inner side. The terminal on the outer side of the coil is connected to the wiring of the first substrate 12 on the outer peripheral side. Six coils 1 provided on the stator 11
4A to 14F form a pair of coils located at diagonal positions,
An example in which three-phase driving is performed is shown. That is, coils 14A and 14D, coils 14B and 14E, coils 14C and 14F
Are driven in three phases.

FIG. 3 shows a coil 14A of the stator 11 of FIG.
14F shows the wiring patterns of the first substrate 12 and the second substrate 13 which are concentrically arranged except for 14F. Also, in FIG. 3, the positions of the coils 14A to 14F are indicated by imaginary lines. In the wiring of the first substrate 12 on the outer peripheral side, wiring lands 15 for connecting terminal portions of the six coils 14A to 14F at the end of coil winding are formed at six places.

The first three coils 14A to 14A
Although the wiring lands 15 of C are independent wirings, the wiring lands 15 of the latter three coils 14D to 14F are common wiring. Six wiring lands 16 for connecting winding start terminals inside the respective coils of the six coils 14A to 14F are provided on the second substrate 13 located on the inner peripheral side.
Is provided. Of the six wiring lands 16, the wiring connecting the opposing sets of coils is connected by through holes penetrating the second substrate 13.

That is, in the case of three-phase driving with six coils, the coils located diagonally are paired, but the paired coils are
When wiring is performed by the wiring of the substrate 13, the respective wirings cross each other. For this reason, the wiring between the wiring lands 16 connecting the coil winding start terminals located at the diagonal positions is performed by the through holes of the double-sided wiring board. Here the second
The substrate 13 uses a double-sided wiring board having through holes in order to reduce the outer diameter as much as possible. However, if the outer diameter is increased so as to allow wiring outside the wiring land 16 which is a land part for coil connection, In addition, even between single-sided wiring boards, connection between diagonal coils can be realized.

Next, the winding directions of the six coils connected and arranged by the first substrate 12 and the second substrate 13 are opposite if the winding directions of the paired coils are the same, and the motor cannot be formed. Therefore, the winding direction of the paired coils is reversed as shown by the arrow in FIG.
The current directions of A to 14F are all the same. For example, taking the pair of coils 14A and 14D as an example, the current is supplied from the coil end terminal connected to the wiring land 15 of the coil 14A, and is connected to the wiring land 16 provided on the inner second substrate 13. Starts to flow to the terminal part. Subsequently, the current flows from the coil winding start terminal portion connected to the wiring land 16 of the coil 14D at the diagonal position, and flows out to the coil winding end terminal portion connected to the outer peripheral side first substrate wiring land 15. .

As a result, a current flows through the coil 14A from the coil winding end terminal to the coil winding start terminal, and a current flows through the coil 14D from the coil winding start terminal to the coil winding end terminal. Therefore, by reversing the winding direction of the coil 14D with respect to the coil 14A, the current directions of the coils 14A and 14D can be made the same. This relationship also applies to the diagonally paired coils 14B and 1B.
The same applies to 4E and coils 14C and 14F.

Further, as shown in FIG. 2, simply fixing the outer peripheral side and the inner peripheral side of the coils 14A to 14F to the first substrate 12 and the second substrate 13 does not have sufficient rigidity, and causes chatter or the like when the motor is driven. In such a case, it is desirable to increase the rigidity by dropping an adhesive into a gap between isosceles portions of adjacent coils and fixing the coils to each other. FIG. 4 shows the stator 1 of FIG.
The first magnet 7 and the second magnet 7 shown in FIG.
The magnetized state of the magnet 9 is shown. That is, FIG. 4A shows the magnetized state of the first magnet 7, in which the S pole and the N pole are alternately formed while being divided into eight poles in the circumferential direction. FIG. 4 (b)
1 is a magnetized state of the second magnet 9 of FIG. 1, which is divided into eight poles in the circumferential direction to form N poles and S poles alternately, and is disposed facing the first magnet 7 in the axial direction. In this state, the N pole of the second magnet 9 is disposed so as to face the S pole of the first magnet 7.

In the flat motor according to the first embodiment of the present invention shown in FIGS. 1 to 4, as is apparent from FIG. Has a double ring structure in which the first substrate 12 and the second substrate 13 are concentrically arranged with the portion facing the first magnet 7 removed, and the first magnet 7 on the rotor 4 side is arranged in the space where the substrate is removed. By that, the thickness of the substrate,
By bringing the first magnet 7 closer to the coil 14, the gap of the magnetic circuit can be narrowed accordingly, and the motor efficiency can be improved. Further, since the first magnet 7 is closer to the coil 14 by the thickness of the substrate than in the conventional structure, the thickness of the motor can be reduced accordingly.

FIG. 5 shows a second embodiment of the present invention.
The second magnet 9 of the first embodiment is connected to the yoke plate 3.
It is characterized by being replaced with 0. In the flat motor 21, a wheel 26 is fixed to a rotating shaft 25 rotatably supported by a bearing 23 on the housing 22 side. A back yoke 28 having a multipolar magnetized disk-shaped magnet 27 is fixed to the lower side of the wheel 26.

On the upper part of the wheel 26, a magnet 2 is provided.
The opposing yoke 30 is arranged facing the shaft 7 in the axial direction. The opposing yoke 30 is pressed against the wheel 26 by the attraction force of the magnet 27. This wheel 26, magnet 2
7. The rotor 24 is constituted by the back yoke 28 and the opposing yoke 30. Magnet 27 and opposing yoke 3
0, a stator 31 having a first substrate 32, a second substrate 33 and a plurality of coils 34.
Is located, and when the coil 34 is energized, a rotational force is generated by a relative force with the magnet 27.

The first substrate 32 of the stator 31 has a ring shape whose inner diameter is larger than the diameter of the magnet 27, as in the first embodiment shown in FIGS. The inner substrate 13 has a ring shape whose outer diameter is smaller than the inner diameter of the magnet 27.
Since there is no substrate at the portion facing 7, the magnet 27 can be arranged as close as possible to the coil 34, similarly to the opposing yoke 30.

Therefore, even in the second embodiment shown in FIG.
The magnet 27 can be made to enter the hollow area between the first substrate 32 and the second substrate 33 so as to be close to the coil 34 by the thickness of the substrate. And the axial dimension of the motor can be reduced by the thickness of the substrate. FIG. 6 shows a third embodiment of the present invention, which is characterized in that the positional relationship between the coil and the substrate in the first embodiment of FIG. 1 is reversed. In the flat motor 21, the rotor 24 has a multi-polarized disk-shaped first magnet 27 fixed to a lower portion of a wheel 26 with a first back yoke 28, and faces the first magnet 27 on an upper portion of the wheel 26 in the axial direction. Then, the second magnet 29 is mounted on the second back yoke 30, and the second back yoke 30 is pressed against the coil 26 by the attraction of the first magnet 27 and the second magnet 29.

The stator 31 includes a first substrate 32 and a second substrate 3
3 and a plurality of coils 34. In this embodiment, the first substrate 32 has a ring shape in which the inner diameter is larger than the outer diameter of the second magnet 29 located on the upper side, and the second substrate 33 located on the inner periphery has the outer diameter of the second magnet 29. It has a ring shape smaller than the inner diameter of the second magnet 29, and there is no substrate at a portion facing the second magnet 29.

Therefore, the second magnet 29 can enter the hollow area of the substrate with respect to the coil 34 and be arranged as close as possible to the coil 34, similarly to the lower first magnet 27. For this reason, even in the third embodiment of FIG. 6, the second magnet 29 can be brought closer to the coil 34 by the thickness of the substrate, so that the gap of the magnetic circuit can be narrowed and the efficiency of the motor can be improved.
Further, the axial dimension of the motor can be reduced by the thickness of the substrate.

FIG. 7 shows a fourth embodiment of the present invention. The flat motor structure of the first embodiment shown in FIG. 1 is used as an example. In the fourth embodiment, nine coils are provided. In the stator 11 of FIG. 7, nine coils 14 are arranged in the circumferential direction as shown in a concentric arrangement of the first substrate 12 on the outer peripheral side and the second substrate 13 on the inner peripheral side.
A to 14I are arranged with the bottom portion on the outer periphery side and the apex portion on the inner periphery side fixed. In this 9-coil stator 11, since the coil interval in the circumferential direction is narrow, the coil 14
A to 14I have a substantially isosceles triangular coil shape.

FIG. 8 shows a coil 14A of the stator 11 of FIG.
FIG. 14 is an explanatory view of a state where １４14I is removed, and the first substrate 1
2 shows the wiring state of the second substrate 13. In addition, coil 1
4A to 14I are represented by imaginary lines. In the nine coils of the stator 11 shown in FIG. 7, three-phase driving is performed with three coils as a set at 120 ° intervals. That is, the coils 14A, 1
Three sets of coil groups including 4D, 14G, coils 14B, 14E, 14H, and coils 14C, 14F, 14I are formed.

The first substrate 12 and the second substrate 13 shown in FIG.
Wiring for supplying a current to each of three sets of coils arranged at intervals of 20 ° to perform three-phase driving is provided, the first substrate 12 is a single-sided wiring substrate, and the second substrate 13 is It is a double-sided wiring board using through holes.
In this case, the coil winding directions of the coils 14A to 14I are directions indicated by arrows.

For example, taking a set of coils 14A, 14D and 14G as an example, the coils 14A and 14G have the same winding direction, whereas the winding direction of the coil 14D is opposite. The wiring of the first substrate 12 and the second substrate 13 to the coils 14A, 14D, and 14G is performed using three wiring lands 15 of the first substrate 12 and three wiring lands 16 of the second substrate 13.

That is, the first wiring land 15 of the first substrate 12 is connected to the winding end terminal portion of the coil 14A,
The terminal portion at the beginning of winding inside 4 </ b> A is connected to the wiring land 16 of the second substrate 13. Subsequently, the coil 14 of the second substrate 13
A wiring land 16 of coil A to wiring land 16 of coil 14D
Is connected to the wiring start terminal inside the coil 14D, and the terminal end outside the coil 14D is connected to the wiring land 15 of the first substrate 12.

The wiring lands 15 connecting the winding end terminals of the coil 14D are connected to the wiring lands 15 of the coil 14G.
Is connected to the terminal portion at the end of the winding, and the winding start terminal portion inside the coil of the coil 14B is connected to the second substrate 13.
Are connected to the wiring lands 16. This relationship is based on the remaining two sets of coils 14B, 14E, 14H and coil 14C,
The same applies to 14F and 14I.

FIG. 9 shows the nine-coil stator 11 of FIG.
FIG. 3 shows the magnetic pole arrangement of the first magnet 7 and the second magnet 9 of FIG. That is, FIG. 9A shows the magnetic pole arrangement of the first magnet 7, and FIG.
Magnetic pole arrangement. Both the magnetic pole arrangement of the first magnet 7 and the magnetic pole arrangement of the second magnet 9 are divided into 14 poles in the circumferential direction, and the S poles and the N poles are alternately arranged.
The magnetic poles of the first magnet 7 and the second magnet 9 facing each other in the axial direction are formed so that if one is an S pole, the other is an N pole, and if one is an N pole, the other is an S pole. .

The 9 coils 1 shown in FIGS.
In the flat motor of the present invention having two poles, the first motor shown in FIG.
As in the embodiment, the first magnet 7 side enters the hollow area between the first substrate 12 and the second substrate 13 of the stator 11, and can be arranged as close as possible to the coil 14 as in the second magnet 9. Thus, the gap of the magnetic circuit can be narrowed to improve the efficiency of the motor, and at the same time, the motor thickness in the axial direction can be reduced by the thickness of the substrate.

In the above embodiment, a flat motor having six coils and eight poles and nine coils and twelve poles has been taken as an example. However, the present invention is not limited to the number of coils or the number of magnet poles, but may be applied to the first motor. It is possible to realize a structure in which a magnet or a yoke is inserted into a hollow area between the substrate 12 and the second substrate 13 and is arranged close to the coil.

[0045]

As described above, according to the present invention, as a substrate used for arranging the coils of the stator, the first and second ring-shaped portions having the outer peripheral portion and the inner peripheral portion necessary for connection with the coil are left. As a double ring structure with the substrate, the magnet or yoke on the rotor side is arranged by penetrating into the hollow area where the substrate is removed, so that the magnet or yoke can be brought close to the coil by the thickness of the substrate, Accordingly, the efficiency of the motor can be improved by reducing the gap of the magnetic circuit, and at the same time, the axial thickness of the motor can be reduced by the thickness of the substrate.

[Brief description of the drawings]

FIG. 1 is a sectional view showing the structure of a flat motor according to a first embodiment of the present invention;

FIG. 2 is a plan view showing an arrangement state of coils of the stator shown in FIG. 1;

FIG. 3 is a plan view showing a positional relationship between a wiring and a coil of the substrate of FIG. 2;

FIG. 4 is an explanatory diagram of a magnetized state of first and second magnets in FIG. 1;

FIG. 5 is a sectional view showing a structure of a flat motor according to a second embodiment of the present invention;

FIG. 6 is a sectional view showing the structure of a flat motor according to a third embodiment of the present invention;

FIG. 7 is a sectional view showing a stator of a flat motor according to a fourth embodiment of the present invention.

8 is a plan view showing the positional relationship between the wiring and the coil of the substrate of FIG. 7;

FIG. 9 is an explanatory view of a magnetized state of the first and second magnets of FIG. 7;

FIG. 10 is a sectional view showing the structure of a conventional flat motor.

FIG. 11 is a plan view showing an arrangement state of coils of the stator of FIG. 9;

[Explanation of symbols]

 1: Flat motor 2: Housing 3: Bearing part 4: Rotor 5: Rotating shaft 6: Wheel 7: First magnet 8: First back yoke 9: Second magnet 10: Second back yoke 11: Stator 12: First Substrate 13: Second substrate 14: Coil

Claims (8)

(57) [Claims] 1. A multi-pole magnetized disk-shaped magnet,
In a flat motor, comprising: a rotor rotatably supported by a bearing portion; and a stator in which a plurality of coils arranged in a ring on a substrate are fixedly arranged so as to face in the axial direction of the magnet. A ring-shaped first inner surface facing the magnet in the axial direction and having an inner diameter larger than the outer diameter of the magnet;
A substrate having a ring-shaped second substrate having an outer diameter smaller than the inner diameter of the magnet; and fixing the outer peripheral portions of the plurality of coils to the first substrate in a state where the first substrate and the second substrate are coaxially arranged. The inner peripheral portion is fixed to the second substrate and arranged in an annular shape.
The flat motor according to claim 1, wherein the magnet is inserted into a hollow area between the first substrate and the second substrate and is disposed close to the coil. 2. The flat motor according to claim 1, wherein the rotor is disposed with a multipole-magnetized disk-shaped first magnet and at a distance facing the first magnet in the axial direction. A multi-polarized disk-shaped second magnet, wherein the stator is disposed between the first and second magnets in an axially facing manner, and A flat motor characterized in that one of the first magnet and the second magnet is inserted into a hollow area between the coils and is disposed in proximity to the coil. 3. The flat motor according to claim 1, wherein the rotor has a multipole-magnetized disk-shaped magnet and an opposing yoke disposed at a distance from the magnet in the axial direction. The stator is disposed between the magnet and the opposing yoke in the axial direction, and the magnet is inserted into a hollow area between the first substrate and the second substrate to be disposed close to the coil. A flat motor, characterized in that: 4. The flat motor according to claim 1, wherein the stator includes a coil having a substantially isosceles triangular shape or a substantially isosceles trapezoid formed on the outer peripheral side bottom portion of the first substrate. And the inner peripheral apex or the upper side of the coil is fixed to the second substrate, and the terminal portion at the end of winding of the coil is disposed in the bottom side of the coil or in the vicinity thereof in a range in contact with the first substrate. And a terminal portion at the beginning of winding of the coil is arranged at a vertex or an upper side portion of the coil or in a vicinity thereof in a range in contact with the second substrate, and is connected to the wiring on the first substrate. A flat motor characterized by being connected to wiring. 5. The flat motor according to claim 1, wherein the first substrate is a single-sided wiring substrate, and the second substrate is a double-sided wiring substrate having through holes. Flat motor. 6. The flat motor according to claim 1, wherein said coil is an air-core coil using a round conductive wire having a self-fusing layer. 7. A flat motor according to claim 1, wherein said coil is an air-core coil using a flat conductive wire having a self-fusion layer. 8. The flat motor according to claim 1, wherein the plurality of coils arranged annularly between the concentrically arranged first substrate and the second substrate are arranged between the isosceles of adjacent coils. A flat motor characterized by being adhered and fixed.