JPH08163844A - Ac miniature motor - Google Patents

Abstract

PURPOSE: To reduce the thickness of a motor by arranging a coil, comprising a large number of mutually continuous loops, along one imaginary plane while shifting the position of each loop sequentially along that loop to obtain a sheet- like structure for forming a stator coil. CONSTITUTION: When an AC current is fed to the coil A2 of a stator A, magnetic flux is induced in the coil A2 and a rotor B is rotated. The coil A2 comprises a large number of mutually continuous loops each arranged along one imaginary plane P2 while being shifted sequentially. Since a sheet-like structure is employed, a quite thin motor can be realized. With such structure, radial thickness of the stator A can be reduced and thereby the thickness of motor can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a small AC motor,
Specifically, by applying an alternating current to the stator coil,
The present invention relates to a small AC motor in which a rotor provided inside a stator and having magnetic poles around it rotates in synchronization with the AC.

[0002]

2. Description of the Related Art As shown in FIG. 14, a stator Af is provided with a plurality of magnetic pole cores 61 facing the outer peripheral surface of a rotor Bf across a gap G on the inner peripheral portion thereof so as to be aligned in the circumferential direction. There is. A coil A2f for magnetizing them is attached to each magnetic pole core 61. On the other hand, the rotor Bf has a plurality of magnetic poles 15f on the outer peripheral surface. In the motor having such a configuration, when an alternating current is applied to the coil A2f, the magnetic pole cores 61 are magnetized, respectively, and are attracted to the rotor Bf by the attractive force and the repulsive force between the core 61 and the magnetic pole 15f of the rotor Bf. Powered. Core for each magnetic pole
Since the magnetization of 61 is reversed with the plus / minus reversal of the alternating current, the rotor Bf rotates at a rotation speed synchronized with the frequency of the alternating current. Such rotation of the rotor can be used for various purposes.

[0003]

In this conventional small AC motor, since the inner peripheral wall surface of the stator is constituted by the surface of the core facing the rotor and the coil is arranged outside the inner peripheral wall surface. Stator thickness T (radial dimension)
However, there is a problem that the size of the motor is required to be small and the size of the motor cannot be reduced.

The small AC motor of the present invention is provided to solve the above-mentioned problems (technical problems) of the prior art. The first purpose is to make it possible to rotate the rotor by applying an alternating current to the coil, and to use the rotation for various purposes. A second object is to provide a motor capable of achieving a significant reduction in thickness. Other objects and advantages will be readily apparent from the drawings and the following description related thereto.

[0005]

In order to achieve the above object, a small AC motor according to the present invention comprises a cylindrical stator and a rotor adapted to rotate inside the stator. In a small AC motor equipped with a coil for generating a magnetic flux for rotating the rotor,
The coil consists of a number of loops that are continuous with each other, the loops being arranged along one virtual plane and with each loop being sequentially displaced along that plane. And the coil is electrically divided into the required number of magnetic poles, and the virtual surface is the cylindrical inner peripheral surface of the stator. Is.

[0006]

When the coil is energized, each of the electrically separated portions of the coil forms a magnetic pole. Rotational force is exerted on the rotor by the attractive force and the repulsive force between the magnetic pole and the magnetic pole of the rotor. The magnetic poles N and S of each portion are reversed with the plus or minus inversion of the alternating current. Therefore, the rotor rotates at the number of revolutions synchronized with the frequency of the alternating current. The coil of the stator is a thin coil in which a large number of loops are arranged along the cylindrical inner peripheral surface of the stator. This enables the stator to be formed with a very small radial thickness, and enables the motor to have a small thickness.

[0007]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and 2, A is a stator, and B is a rotor rotatable with respect to the stator A, respectively. First, the stator A will be described. A1 is a case for accommodating various members and rotatably supporting the rotor B. A2 is a coil provided in the case A1 for giving a magnetic flux for rotating the rotor to the rotor.

The case A1 will be described. The case A1 is formed to be extremely small, and has an outer diameter of 4 mm and a length of 15 mm, for example. Reference numeral 1 denotes a case body, which may be formed of a non-magnetic material such as brass so as to prevent the rotation of the rotor from being damped by a magnetic action. Reference numerals 2 and 3 denote end members for closing the openings at both ends of the main body 1. The former is made of, for example, a resin material, and the latter is made of metal, such as brass, for the reason described later. The latter may also be made of a resin material.
Numerals 4 and 5 are fitting portions of the respective members, which are portions which are fixed to the openings of the respective ends of the main body 1 by press fitting. After fitting the end portion of the main body 1, the end portion may be fixed by caulking. Reference numerals 6 and 7 are bearing holes provided in each of the end members 2 and 3. Each end member serves as a bearing by providing the bearing hole. Reference numerals 8 and 9 are terminals provided on the end member 2 and are provided by insert means. Since the terminals 8 and 9 are provided, the end member 2 also serves as a terminal block. In order to provide the terminals 8 and 9, the end member 2 is made of an insulating material such as the above resin material. A rotor B stop position regulating member 10 is made of a magnetic material such as steel.

Next, the coil A2 is formed in an extremely thin tubular shape with a structure which will be described in detail later. 12, 13
Indicates a lead wire.

Next, the rotor B will be described. B1 is a rotary shaft, which shows an example of being formed by a stainless wire material from the viewpoint of having high strength, and the thickness is, for example, 0.8 to 1 mm.
Something is used. B2 is a rotor main body fixed to the rotating shaft B1, and is composed of permanent magnets, and has a plurality of magnetic poles on the outer peripheral surface, for example, four magnetic poles including N pole and S pole in this example.
Equipped with 15. The magnetic pole 15 has N poles and S poles alternately arranged in the circumferential direction. Corresponding to this number of poles, the motor of this example has 4
It is called a pole motor. The number of the magnetic poles 15 may be 2 or 6, and in that case, a 2-pole motor and a 6-pole motor are used. The rotor body B2 is small in size and has a strong magnetic force, for example, a neodymium magnet, a barium ferrite magnet,
A strontium ferrite magnet or the like is used. 17, 18
Shows a collar and a washer which are illustrated as members for positioning the rotor B in the axial direction, respectively.

Next, the coil A2 will be described with reference to FIGS. The coil A2 has a sheet shape. In order to make the configuration easy to understand, description will be given in a state of being expanded in the circumferential direction as shown in FIG. The coil A2 is a sheet-shaped coil A2 'having a shape as shown in FIG. 21 is the above-mentioned cylindrical coil A2
In the case of, the reference numeral 22 indicates the unfolding direction (in the state of the tubular coil A2, the circumferential direction). Reference numerals 23 and 23 indicate portions where the cylindrical coil A2 is superposed on each other. The sheet-shaped coil A2 'is formed by continuously winding a wire, and has a large number of loops continuous with each other.
Composed of 24. The loops 24 are arranged along one virtual plane, and the loops 24 are sequentially displaced along the plane. In the state of the sheet-shaped coil A2 ′ of FIG. 3, the above-mentioned virtual surface is a plane P1 forming the paper surface of FIG.
In the state of the tubular coil A2, it is the tubular inner peripheral surface P2 of the stator A as shown in FIGS. In the state of the sheet-shaped coil A2 ', the direction of the positional deviation is the unfolding direction 22
The direction is parallel to, and is the circumferential direction in the state of the tubular coil A2. The displacement dimension is, for example, approximately the wire diameter of the strand. If the number of loops 24 in the coil A2 may be small, the coils may be displaced by a dimension larger than the above wire diameter. The above-mentioned tubular coil A2 can be formed by forming the above-mentioned sheet-shaped coil A2 'and then forming it into a tubular shape.
However, it is also possible to form the element wire by winding it in the shape of the cylindrical coil A2 from the beginning.

The coil A2 is electrically divided into the required number of magnetic poles. Reference numerals A21 to A24 denote a plurality of divided magnetic pole coils. Although they are mechanically polymerized in parts, they are completely separated electrically. The number of the magnetic pole coils corresponds to the number of the magnetic poles 15 of the rotor B,
In this example, since the motor is a four-pole motor, the number of magnetic pole coils is four. In the coil A2 ', 25 is a lead wire at the winding start end and 29 is a lead wire at the winding end end. 26,
27 and 28 are lead wires provided at the above-mentioned electrically separated boundaries. Therefore, in the magnetic pole coil A21, the lead wires 25 and 26 are electrically one end and the other end. Similarly, in the magnetic pole coil A22, the lead wires 26 and 27, in the magnetic pole coil A23, the lead wires 27 and 28, and in the magnetic pole coil A24, the lead wires 28 and 29 are electrical one end and the other end, respectively. ing. The above-mentioned lead wires 25, 27, 29 are combined to form the above-mentioned lead wire 12, and the lead wires 26, 28
Are combined to form the lead wire 13 described above.

In the above coil, each loop 24
The intermediate portion 31 is formed parallel to the axial direction 21 as shown in the figure. Both ends 32 have a shape in which the overlap between the loops 24 is averaged in order to minimize the thickness in the state of the cylindrical coil A2. In this example, the angle θ in the figure is designed as a mountain shape of 45 °, for example. are doing. The length 33 in the axial direction 21 of each loop 24 is preferably designed corresponding to the length of the rotor body B2, and the width 34 in the expansion direction 22 is, for example, a cylinder in order to keep the efficiency of magnetic flux generation high. The entire circumference of the coil A2 is preferably 1 to 1.5 times the width corresponding to a value obtained by dividing the entire circumference by 360 ° by the number of magnetic pole coils. For example, a fusion wire is used as an element wire for forming the magnetic pole coil. As shown in FIG. 8, the fusion wire has an insulating coating 37 around the copper wire 36.
Is further covered with an adhesive 38 which exhibits an adhesive action by heating, for example. Therefore, by heating the sheet-shaped coil A2 ′ as described above, the adhesives 38 are fused and integrated with each other so that the sheet-shaped coil is held. The diameter D1 of the copper wire 36 is 0.06 mm, and the thickness T1 of the coil A2 is 0.2 mm.
It is a degree.

The assembly of the motor having the above structure is as follows. First, the stop position regulating member 10 is fixed to the case body 1 by, for example, an adhesive means. The position in the circumferential direction may be set at a position described later. Next, the cylindrical coil A2 is housed in the case body 1 and fixed to the inner peripheral surface of the case body 1 by an adhesive means. Then connect the lead wires 12 and 13 to the ends 8 of the terminals 8 and 9.
Connect to a and 9a, for example, by soldering. Next, the end member 2 is attached to the case body 1. On the other hand, the collar 17 and the washer 18 are attached to the rotating shaft B1 to which the rotor body B2 is fixed, the housing 17 is housed in the case body 1, and the rotating shaft B1 is inserted into the bearing hole 6.
Next, the end member 3 is attached to the case body 1 with the rotation shaft B1 inserted through the bearing hole 7. The assembly is completed as described above.

Next, the operation of the motor having the above structure will be described with reference to FIGS. 9 and 10. In these drawings, the magnetic pole coils are displayed with different types of wires. See also FIG.
In, the magnetic flux generated by each magnetic pole coil is indicated by the arrow of the same kind of line as the magnetic pole coil. Further, in both figures, the direction of the magnetic flux is indicated by the direction of the arrow, and the strength of the magnetic flux is indicated by the length of the arrow. An AC power supply 40 (for example, 60 Hz, 10 V) is connected to the terminals 8 and 9. When the AC power supply 40 has the illustrated polarity, the magnetic pole coils A21 to A24 generate the magnetic flux shown in FIG. 9, respectively. The strength of the magnetic flux of each part in each magnetic pole coil is as illustrated. That is, the magnetic flux is strongest in each central portion where the loops 24 are most overlapped, and becomes weaker toward the edges. When the magnetic pole coils generate the magnetic flux as described above, the combined magnetic flux of the coil A2 as a whole is as shown in FIG.
Therefore, in the coil A2, the portions indicated by reference numerals 41 and 42 are N
It becomes a pole, and the portions indicated by reference numerals 43 and 44 become S poles. Then, those N and S poles and the N and S poles of the rotor body B2
Due to the well-known magnetic attraction and repulsion with the pole, a rotational force in the direction of arrow 45 is applied to the rotor body B2, and the rotor B rotates in the direction of arrow 45.

When the polarity of the AC power supply 40 is reversed at the next time point, the direction of the magnetic flux generated by the coil A2 is reversed. Therefore, parts 41 and 42 become south poles, and part 4
3,44 is the north pole. At this point, if the S pole of the rotor body B2 rotated in the direction of the arrow 45 passes through the portions 41 and 42 and the N pole passes through the portions 43 and 44, respectively, the rotor body B2 also moves in the direction of the arrow 45 in the same manner. Rotational force is applied, and the rotor B has an arrow
Continue turning in 45 directions. Since the polarity of the AC power supply 40 is periodically inverted as described above, the rotor B continues to rotate at a rotational speed at which the inversion and the movement of the magnetic pole of the rotor B are synchronized.

When the energization of the coil A2 is stopped, the application of the turning force to the rotor body B2 disappears and the rotor B stops rotating. In this case, since the magnetic pole 15 of the rotor body B2 emits magnetic flux, the magnetic pole 15 causes the magnetic pole 15 to stop the stop position regulating member 10 of the stator A.
The rotor B stops at a position magnetically attracted to the magnetic pole 15, that is, at a position where the magnetic pole 15 is close to the member 10. Therefore, the stop position regulating member
The coil 10 is provided at a position corresponding to a substantially intermediate position of any two adjacent parts of the magnetic pole parts 41 to 44 in the coil A2 (position overlapping the intermediate position when viewed in the axial direction of the coil). It is preferable that the motor can be started smoothly.

In the non-energized state, there is no member other than the stop position regulating member 10 that magnetically attracts the magnetic pole 15 around the rotor body B2, so that the member 10 and the magnetic pole 15 are slightly magnetically attracted to each other. It suffices to generate a suction force, and therefore a very small member is sufficient. This prevents the size of the motor from increasing. Further, the small magnetic attraction between the magnetic poles 15 allows the rotor B to be started smoothly, and also becomes a load against the rotation of the rotor during rotation. The loss can be reduced with respect to the rotational force given to the rotor body B2 by the coil A2. It also facilitates the rotation of the rotor.

As described above, the fact that there is no member other than the stop position restricting member 10 that magnetically attracts the magnetic pole 15 of the rotor body B2 makes it possible to use a magnet having a very strong magnetic force such as a rare earth magnet as the rotor body B2. (Regarding the suction force with the member 10, the member 10 may be made smaller as described above). This makes it possible to generate the required torque with the small rotor body B2, and as a result, it is possible to further reduce the size of the motor.

Next, FIGS. 11 to 13 showing another embodiment of the present invention will be described. In this example, the efficiency of rotation output of the rotor with respect to the electric power applied to the coil is increased, and magnetic interference between the magnetic body and the rotor can be prevented even if there is a magnetic body around the motor in use. An example of doing so is shown. In the figure, 51 is a bush for attaching the rotor yoke to the rotating shaft B1e, which is made of, for example, a synthetic resin material and is attached to the rotating shaft B1e by an adhesive, for example. Reference numeral 52 denotes a rotor yoke, which is made of iron as an example of a magnetic material so that magnetic flux can easily pass therethrough, but may be made of magnetic stainless steel. The yoke is formed to have a thickness that allows a cross-sectional area to pass the entire amount of magnetic flux from the rotor body B2e without being saturated. For example, it is about 0.2 mm. The inner diameter is formed so that it can surround the outer circumference of the coil A2e. The yoke 52 is fixed to the bush 51 by, for example, insert molding means, but a fixing means such as an adhesive may be used. Incidentally, 53 is a coil mounting groove formed in the end member 2e, 54 is a lack portion for circumferentially positioning the end member 2e with respect to the case body 1e, and 55 is a fitting formed corresponding to the lack portion 54 It's a piece.

In assembling the above-mentioned structure, one end of the coil A2e is fitted into the coil mounting groove 53 and bonded. Next, the end member 2e is attached to the case body 1e. The other parts are assembled in the same manner as in the above embodiment.

When the motor having the above construction is rotated, the magnetic flux generated from the N pole magnetic pole 15e of the rotor body B2e passes through the rotor yoke 52 as shown by reference numeral 56 in FIG. 13 and the S pole magnetic pole of the rotor body B2e. Up to 15. Therefore, when the rotor Be is rotated by energizing the coil A2e, the attractive force and the repulsive force due to the interaction between the magnetic flux generated from the coil A2e and the magnetic flux generated from the magnetic pole 15e are increased as compared with the above-described embodiment. You can get great turning power. Further, during the rotation, the magnetic flux of the rotor body B2e is changed to the rotor yoke.
The rotor yoke 52 blocks the leakage through the 52 and to the outside. Therefore, even if there is a magnetic material around the installation location of the motor, magnetic interference between the magnetic material and the rotor body B2e does not occur, and the rotor rotates stably. This allows the motor to be used anywhere. The blocking of the magnetic flux by the rotor yoke 52 makes it possible to use a magnetic material such as steel as the case body 1e.
In addition, for the parts which are functionally the same as or equivalent to those in the previous figure and are considered to be redundant, the same reference numerals as those in the previous figure are appended with the letter e, and the redundant description is omitted.

[0023]

As described above, according to the present invention, when an alternating current is applied to the coil A2, the rotor B can be rotated by the magnetic flux generated from the coil, and the rotation can be used for various purposes. it can. Moreover, the coil A2 is composed of a number of loops 24 that are continuous with each other, and each of the loops 24 is along one virtual plane P2, and each loop 24 is sequentially along the plane P2. Since they are arranged so as to be displaced, and the whole is in the form of a sheet, it can be formed extremely thin. This has the effect of making it possible to form the stator A with a very small thickness in the radial direction and to make the thickness of the motor extremely small.

[Brief description of drawings]

FIG. 1 is a vertical sectional view in a direction parallel to an axis.

FIG. 2 is an exploded perspective view.

FIG. 3 is a diagram showing a developed state of a coil.

FIG. 4 is an enlarged view of a coil end portion in a developed state.

5 is a diagram showing a state where the coil end portion of FIG. 4 is viewed from a direction of an arrow V. FIG.

6 is a cross-sectional view taken along the line VI-VI in FIG.

FIG. 7 is an enlarged view of a VII portion stator in FIG. 6 (a part of a coil loop is omitted).

FIG. 8 is a cross-sectional view showing a cross section of a wire of a coil and a connection between the wires.

FIG. 9 is a diagram showing magnetic flux generated by each magnetic pole coil.

FIG. 10 is a diagram showing a synthetic magnetic flux.

FIG. 11 is a vertical cross-sectional view showing another embodiment.

12 is a partially cutaway exploded perspective view of the embodiment of FIG.

13 is a diagram showing the magnetic flux of the embodiment of FIG.

FIG. 14 is a cross-sectional view of the conventional motor in a direction perpendicular to the axis.

[Explanation of symbols]

 A stator B rotor A2 coil 24 loops

Claims (2)

[Claims] 1. A small AC motor comprising a cylindrical stator and a rotor adapted to rotate inside the stator, the stator comprising a coil for generating a magnetic flux for rotating the rotor, The coil consists of a number of loops that are continuous with each other, the loops being arranged along one virtual plane and with each loop being sequentially displaced along that plane. And
The whole is in the form of a sheet, the coil is electrically divided into the required number of magnetic poles, and the virtual surface is the cylindrical inner peripheral surface of the stator. Small AC motor. 2. The small AC motor according to claim 1, wherein a rotor yoke made of a magnetic material that surrounds an outer peripheral side of the coil is attached to the rotor so as to be integrally rotatable.