JPS6159060B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a self-starting small synchronous motor, and more particularly to a coil, a permanent magnet, and a magnetic flux on the surface of the permanent magnet that effectively transforms the magnetic flux of the alternating magnetic field generated by the excitation coil. It has a circular soft magnetic body with AC poles shaped to be interlinked with each other, and a magnetic yoke that minimizes magnetic loss in the air gap in the AC magnetic circuit. It concerns a small synchronous motor that generates rotational force.

Many various synchronous motors have been proposed and are already well known. However, although this type of electric motor has a self-starting function, it can start rotating in any direction, so the direction of rotation is not determined, so it must be controlled by some mechanical method to achieve the desired rotation. It must be controlled so that it rotates in the same direction. However, when using such a mechanical structure, there are many problems such as wear and tear, and there is a great possibility that this will cause a failure in the operation of the electric motor, such as an inability to start.

Furthermore, in order to achieve smooth rotation, known electric motors must use a rotor with a relatively large moment of inertia and a relatively large weight. As described above, since the moment of inertia and weight of conventional electric motors are relatively large, the self-starting ability is significantly reduced. That is, as is known, a small electric motor equipped with a rotor having a relatively large weight and moment of inertia is significantly affected by starting power and operating power, resulting in extremely low operating efficiency, and at the same time, generates undesirable heat.

There is a tendency for the magnet to be characterized by multi-pole magnetization, but this is incorrect. All conventional inductor synchronous motors are destined to have the same number of dead points as the number of poles. The present invention has absolutely no dead points, regardless of the number of poles.

Furthermore, this type of known electric motor has the disadvantage that permanent magnets cannot be used effectively because north and south poles occur between the stator and the rotor.

The present invention has been developed in view of these points, and at the same time eliminates all the drawbacks of conventional products, it also has a self-starting ability, rotates reliably in a fixed direction when supplied with electricity, and has a mechanical The present invention aims to provide a lightweight, compact synchronous motor that can rotate in a desired direction without using any structure. Furthermore, the synchronous motor of the present invention does not have a particularly large moment of inertia, making it possible to use a relatively lightweight rotor that can rotate smoothly, and also having a relatively small magnetic force. The desired rotational motion can be obtained by using Furthermore, it is another object of the present invention to provide a compact synchronous motor that can prevent generation of undesirable heat in this type of machine, obtain relatively high efficiency, and utilize permanent magnets extremely effectively. This is one of the purposes.

That is, in the present invention, a self-starting synchronous motor is provided with motors each having the same diameter and surrounding a common axis, and occupying positions close to each other on both sides of a plane perpendicular to the axis, and each having the same diameter and surrounding the common axis. It has a series of N and S poles distributed alternately around the circumference as a center, with the number of N and S poles on one being equal to the number of N and S poles on the other, but between both poles. A pair of circular permanent magnets are provided with an angular shift that establishes a constant phase shift relationship. The mutual magnetic pole phase difference angle of each row together with the magnetic side path generates a self-starting directional rotational force. The pair of permanent magnets are surrounded by coils located close to each other on both sides of a plane perpendicular to the axis, and these pair of permanent magnets are located close to each other on both sides of the plane. occupying a position. The coil has a diameter larger than that of the permanent magnet. A magnetic bypass is also formed by a circular soft magnetic body located close to the coil.

Further, a circular soft magnetic body is provided that surrounds the axis in a coaxial relationship and includes a cylindrical wall extending between a pair of permanent magnets, a coil, and the circular soft magnetic body. The cylindrical wall of this circular soft magnetic material has alternating current poles distributed on the circumference around the axis, and separated by alternating current poles of the cylindrical wall, which are also distributed evenly on the circumference around the axis. A plurality of axially extending cutout windows are formed. The number of magnetic poles of the permanent magnet is preferably twice the number of AC poles of the circular soft magnetic material.
In addition, when the excitation coil is not energized, the relative position of the circular soft magnetic body and the permanent magnet is such that the AC pole coincides with the middle of the magnetic pole boundary line of the first pole column and the magnetic pole boundary line of the second magnetic pole column. It is designed to actively exist in the world. The circular soft magnetic body has an annular yoke at one end of its cylindrical wall, and the stator has a part thereof parallel to the annular yoke of the circular soft magnetic body, with a small distance between the two. Contains a casing that defines a narrow gap. The upper and lower parts of the circular soft magnetic body form an alternating current magnetic circuit by maintaining a sufficient area and a small gap with the annular yoke and the flat surface of the casing.

That is, in the electric motor of the present invention, a coil and a pair of permanent magnets are provided, and an alternating current pole extending in the axial direction is provided in a circular soft magnetic body having a cylindrical cross section, and the annular yoke is provided with magnetic resistance relative to the fixed yoke portion. the shape of the alternating current pole is appropriately selected so as to effectively link the magnetic flux of the alternating current magnetic field formed by the coil with the magnetic flux of the direct current magnetic field existing on the cylindrical peripheral surface of the permanent magnet, At the same time, by arranging both ends of the circular soft magnetic body in a narrow gap formed in the AC magnetic circuit, loss of AC magnetic flux can be suppressed to a minimum.

A major feature of the synchronous motor of the present invention is that it is equipped with a magnetic bypass that provides directional rotational force using only a single coil. It is possible to obtain a stable and strong directional rotational force that works together with the angular deviation of the two-stage magnetization by providing a magnetic flux shunt above or below the extended plane of the plane that separates the two-stage magnets. I can do it. Furthermore, the present invention
The present invention aims to provide a new synchronous motor that does not use any conventional direction regulating means such as a shaded coil, a check mechanism, or a two-coil system.

The present invention will be described in more detail below with reference to a preferred embodiment shown in the drawings.

In the following embodiments, a case is shown in which a circular soft magnetic body is used as a rotor.

The embodiment of the small synchronous motor according to the invention illustrated in FIGS. 1 and 2 includes a casing 1 and a base plate 2. The casing 1 and the substrate 2 are made of soft magnetic material and serve not only as a casing but also as a yoke. The casing 1 has a cylindrical outer wall and a flat end wall as shown in FIG.
is a circular plate whose outer peripheral edge is fixed to the inner surface of the cylindrical side wall of the casing 1. A soft magnetic material 3A is placed between the substrate 2 and the flat end wall of the casing 1 in parallel to both.
Place. This soft magnetic material 3A constitutes a magnetic bypass to the substrate 2. The soft magnetic body 3A has an annular shape, and the distance from the substrate is determined experimentally. Further, the soft magnetic material 3A may be applied all over the circumference, or may be applied to a part of the periphery. Further, the soft magnetic bodies 3A are arranged in a coaxial relationship around a common axis that coincides with the axis of the shaft 6. Furthermore, the soft magnetic body 3B shown in FIG. 3 is a magnetic bypass similar to the soft magnetic body 3A shown in FIG.
This soft magnetic body 3B is arranged parallel to the axis and perpendicular to the substrate 2, and is arranged on a circumference coaxial with the axis, with an air gap parallel to the rotor circumferential surface all around or part of the circumference. position. The height in the axial direction is determined as appropriate.

The shaft 6 forms part of a support means that cooperates with the rotor 8 and rotatably supports the rotor. Therefore, the shaft 6 is rotatably supported by a bearing 5 made of a non-magnetic material whose center is fixed to the substrate 2.
The bearing 5, which rotatably supports the shaft 6, also supports a pair of circular permanent magnets 9a and 9b made of barium ferrite magnets via a non-magnetic ring 12. The pair of permanent magnets 9a and 9b each include a series of N and S poles distributed on the circumference around the axis of the shaft 6. That is, as is clear from FIGS. 1, 2 and 4B, the series of N and S poles of each of the permanent magnets 9a and 9b are staggered, with the poles of one permanent magnet intersecting with those of the other permanent magnet. It is offset from the pole by an angular distance α as shown in FIG. 4B. This angular shift establishes a certain phase shift relationship between the magnetic poles of the pair of permanent magnets 9a and 9b,
This phase shift forms a synchronous motor with no dead points regardless of the number of poles, and is a factor in generating directional torque. As is clear from FIG. 4B, each pole of the individual permanent magnet lies on a line parallel to the axis of the shaft 6 and located between a pair of adjacent poles of the other permanent magnet. Therefore, a constant phase angle α is established between the poles of the pair of permanent magnets 9a and 9b. In the example shown in 10 on Figures 1 and 2 and Figure 4B, each of the permanent magnets 9a and 9b is provided with 8 S poles and 8 N poles alternated with these poles, and these poles all form a pair. so that the permanent magnets are evenly distributed on the circumference around the common axis. FIG. 4B shows a permanent magnet in which the plate 10 of FIGS. 1 and 2 is omitted and integral magnetization is performed.

A pair of permanent magnets 9a and 9b are arranged so as to be adjacent to each other on both sides of a plane perpendicular to their common axis. A plate 10 made of a soft magnetic material is arranged to prevent an undesirable reaction between the two.

In addition, in place of the above-mentioned permanent magnets 9a and 9b, the magnets shown in FIG.
It is also possible to use a magnet 9 shown in FIG. This is obtained by giving a phase angle β instead of the above-mentioned phase angle α. This is a 16-pole single-stage magnetization. A pair of permanent magnets 9a together with a support structure 11 for winding the coil.
and 9b coaxially and spaced apart in a circular manner to form a cylindrical gap having a substantially uniform width and extending in the axial direction between the inner surface of the coil support structure 11 and the outer surface of the pair of permanent magnets 9a and 9b. limit. The diameter of the inner peripheral edge of the disc-shaped soft magnetic body 3A that extends along a circle centered on the axis of the shaft 6 is slightly smaller than the diameter of the inner surface of the coil support structure 11. That is, the series of magnetism of the pair of permanent magnets 9a and 9b is connected to the coil support structure 1.
1 and so as to generate a necessary magnetic field together with the disk-shaped soft magnetic body 3A as in the post-surgical procedure.

In particular, as is clear from Figures 1 and 2, the rotor 8
has a cylindrical shape and a circular cross-sectional shape, and its cylindrical wall surrounds the axis of the shaft 6 coaxially therewith, and a pair of permanent magnets 9a and 9b, a coil 4, and a disc-shaped soft magnetic body. 3A into a thin annular gap of uniform width. Note that all the elements except the rotor 8 are fixed elements forming part of the stator. A plurality of uniformly distributed notched windows are formed in the cylindrical wall of the rotor 8, and these notched windows are generally elliptical except for the straight ends, and the common axis of all circular elements is Ensure that it is evenly distributed around the heart. The AC poles 8e that separate these axially extending cut-out windows from each other are also uniformly distributed around the rotor axis, and each has a shape with a narrow portion in the center. That is, the individual alternating current poles 8e of the rotor extend parallel to the axis of the shaft 6,
The width is the narrowest in the plane occupied by the disc-shaped magnetic body 10. As is clear from FIGS. 2 and 5A and 5B, the individual alternating current poles 8e become progressively wider on both sides of this plane as they move away from the plane. That is, the widest part of the AC pole 8e joins the annular end portions 8c and 8d of the rotor. Therefore,
The central portion of the AC pole 8e forms a narrow portion.

As shown in FIG. 1, the upper end of the shaft 6 is fixed to a circular non-magnetic boss 7 made of a light alloy or synthetic resin and fixed in a center hole formed in an annular yoke 8a of a rotor 8. It is surrounded by the boss 7. This annular yoke 8a, 8b of the rotor
The casing 1 and the substrate 2 have a sufficient facing area and a small distance from each other, and a very highly efficient alternating current magnetic circuit is formed with a narrow gap between them. In the embodiment shown in FIG. 2, the rotor 8 has an annular yoke 8a
On the opposite side thereof, it is provided with an outwardly directed flat flange 8b, which flange 8b occupies a position close to the base plate 2 of the casing 1 so as to define a narrow gap therebetween. Since a narrow gap is provided between the annular yokes 8a and 8b of the rotor and the transverse wall portions of the casing 1 and the base plate 2, a flange 8 extending parallel to the base plate 2 and the transverse wall of the casing 1 is provided.
An alternating current magnetic circuit is formed in these narrow gaps, which are limited to a relatively wide area provided by the annular yoke 8a and the annular yoke 8a. Figure 6A shows the magnetic circuit of the soft magnetic body (magnetic side path) 3A in Figure 1. _φ1 passes through the S part of the AC pole 8, and the S part of the AC pole 8 is Because of its existence, φ ₁ −φ _3A passes.

That is, in the AC pole 8, (φ ₁ of S part)>(
S part φ ₁ −φ _3A ). FIG. 6B shows the magnetic circuit of the magnetic bypass 3B of FIG. This is similar to the above-mentioned magnetic side path 3A, and in the AC pole (S
Part φ ₁ )>(S part φ ₁ −φ _3B ), and both 3A and 3B form a magnetic bypass of the AC pole. The arrangement of the magnetic bypasses 3A and 3B is arranged concentrically with the rotor axis and around it, and can be over the entire circumference or over a part of the circumference. Soft magnetic material 3A is perpendicular to the AC pole, 3B
are arranged parallel to the alternating current pole. These soft magnetic bodies 3A and 3B are installed at positions close to the alternating current poles with a gap in between.

FIG. 7 illustrates the manner in which the synchronous motor according to the present invention generates the necessary torque. First of all, the 6th
As shown in Figure A, the upper S is the upper permanent magnet 9a.
and the upper half of the rotor, and the lower S includes the lower permanent magnet 9b and the lower half of the rotor and the magnetic bypass 3A. The magnetic circuit when power is supplied is shown in Figure 6A. The alternating current pole of S has magnetic flux φ ₁ , and S
The alternating current pole has a magnetic flux of φ ₁ −φ _3A . That is, (S
It is clear that there is a relationship of (magnetic flux φ ₁ −φ _3A )<(magnetic flux φ ₁ of IS). Similarly in FIG. 6B, (S magnetic flux φ ₁ )>(S magnetic flux φ ₁ −φ _3B ).

In the explanation of torque generation below, the magnetic flux of the AC pole S has a higher magnetic flux density than the magnetic flux of S, and the permanent magnet 9
Note that there is an angular deviation α between a and 9b.

T ₀ When no power is supplied. The AC pole 8e is located positively on the boundary line of the magnetic poles. It exists in magnetic equilibrium at the center of the deviation angle α.

When energized at position T ₁ T ₀ . The AC pole 8e was polarized and rotated to this position in search of opposite polarity of the permanent magnets 9a and 9b. As mentioned above, φ ₁ > φ ₂
From the relationship = (S of S) > (N of S), α ₁
Magnetic equilibrium is achieved at the position <α ₂ . The alternating current pole N, which is shifted by α ₂ from the center of the magnetic pole _SC , is already related to the area of the magnetic pole N _D.

When the power supply becomes zero at the position T ₂ T ₁ . AC pole 8
e is rotated to this position. At the position T ₁ , the AC pole 8e of S is already in the area of the magnetic pole N _D , and at the same time when the power supply becomes zero, the magnetic poles N _D and S _C and the magnetic pole S ₄
Actively rotate in search of the boundary of N ₃ and take a relative position similar to T ₀ .

When power is supplied at the position T ₃ T ₂ and the alternating current pole 8e has polarity, the alternating current pole 8e rotates to this position to seek the isomerism of 9a and 9b. The rotation from T ₀ to T ₁ and the operation from T ₂ to T ₃ are exactly the same.

T ₄ One cycle is completely completed by rotating to this position, and the rotation continues repeatedly.

8 and 9 show other embodiments of the electric motor of the present invention. The casing 11 is made of soft magnetic material and also serves as a yoke. The casing 11 has a cylindrical outer wall and an inner wall 11b, the outer wall and the inner wall 11b are continuous at the bottom, and the cross section is U-shaped and annular.
The outer wall and the inner wall 11b are coaxial with the shaft 16. The magnetic side path 13B is a coaxial annular soft magnetic body, and the excitation coil 14 disposed at the upper opening of the cylindrical inner wall 11b is annular and housed in the U-shaped cross section of the casing 11. The shaft 16 works in conjunction with the rotor 18 to rotatably support the rotor.
Further, the shaft 16 is rotatably supported by a bearing 15 made of a non-magnetic material fixed on the same axis to the inner wall 11b. An annular magnet 119 made of a ferrite magnet is fitted into the upper end opening of the casing 11 . The magnet consists of a pair of magnets 19a and 19b. The outer diameter of the magnet 19b is fitted into the inner diameter of the magnet 19a. These magnets each have a series of north and south poles, offset by an angular distance α. 19a and 1
9b may be magnetized separately or integrally in two stages. Of course, it is also possible to obliquely magnetize the disk-shaped magnet at an angle of β in the direction of rotation as shown in FIG. 4A. As is clear from FIGS. 8 and 9, the rotor 18 has a disk shape, and the yoke 1 on its outer periphery
The yoke 8b surrounds the axis of the shaft 16 coaxially and faces the inner periphery of the outer wall of the casing 11 with a narrow annular gap in between, and the yoke 18a surrounds the inner periphery of the inner wall 11b with a narrow annular gap in between. The yokes constitute yoke means, and are provided with annular yokes 18b and 18c, respectively. The disc-shaped portion of the rotor 18 is the shaft 1
an alternating current pole 18 that is perpendicular to 6 and forms 8 cutout windows radially and separates the cutout windows from each other;
Eight e are distributed radially at equal angular intervals. The AC pole 18e is narrowest at the center of the annular yokes 18b and 18c, forming a narrow part, and is widest at the part where the annular yokes 18b and 18c merge. The rotor 18 is connected to the circular boss 1 by its annular yoke 18a.
It is fixed to the shaft 16 via 7. Rotor 1
8 forms a highly efficient magnetic circuit between the annular yokes 18b and 18c and the casing with a sufficient opposing area and a small gap. Furthermore, magnetic side path 13B
is installed in the upper part of the casing inner wall 11b in the direction perpendicular to the axis as an extension of the magnetic circuit. This is made of the same disc-shaped soft magnetic material as the axis, and is arranged parallel to the rotor AC pole 18e with appropriate dimensions and gaps. Moreover, this may be the entire circumference of the inner wall 11b or a part of the circumference. Finally, the soft magnetic body 13A in FIG. 10 and the soft magnetic body 13B in FIG. 9 are replaced by the soft magnetic body (magnetic bypass) 3 in FIG.
This corresponds to the soft magnetic body (magnetic side path) 3B in FIGS. A and 6B, and the explanation of the generation of directional rotational force in FIGS. 9 and 10 will be omitted since it overlaps with FIG. 7. In Figure 5 A, the polarity due to smooth magnetic flux is AC pole 8.
This shows the state that occurs at e. FIG. 5B also shows that it is possible to generate a difference in magnetic flux density due to the presence of the magnetic side paths 3A, 3B, 13A, and 13B.

As is clear from the above explanation, in the present invention, the sixth,
As a result of the magnetic effects described in connection with FIG. 7, the rotor generates a rotational force.

In known small synchronous motors of this type, it was inevitable that the rotor would be quite heavy, but in the present invention, even if the moment of inertia and weight are minimized, the relatively weak magnetic force that exists in the motor can be avoided. However, these magnetically cooperate to enable self-directed rotation.

Generally, a rotor with a large moment of inertia and a large weight will have a negative effect on starting power and operating power, resulting in poor operating efficiency and temperature rise.However, according to the present invention, maximum efficiency can be achieved by forming an AC magnetic circuit with an annular yoke. I can do it. Therefore, a strong magnetic flux can be generated between the permanent magnet and the AC pole of the circular soft magnetic material, and highly efficient rotational force can be generated.

In addition, in conventional products, permanent magnets could not be used effectively because N and S poles were generated between the fixed part and the rotating part, but in the present invention, permanent magnets can be placed simultaneously on the same peripheral surface of the circular soft magnetic body. It is possible to provide a synchronous motor that generates N and S poles, enables effective interlinkage of magnetic flux with permanent magnets, and has an extremely large magnetic effect. In addition, in conventional electric motors, it was common sense to use a mechanical check mechanism, a shaded wire, a two-phase system, etc. to regulate the direction of rotation; Accidents were extremely common, there was a time delay in forward rotation, and the shaded type had major drawbacks such as reverse rotation when the voltage changed, and the two-phase type had a big problem in terms of price.

As mentioned above, the present invention eliminates all of the above drawbacks,
Using a single coil, we succeeded in generating a strong directional rotational force through the cooperative action of a simple magnetic bypass and the angular deviation of two-stage magnetization. Also, a major drawback of all conventional induct-type synchronous motors is that they have dead points equal to the number of magnet poles, but induct-type synchronous motors that feature multi-pole magnetization have friction points at the dead points. If the magnet stops due to load or load, it will not be able to start even if the next energization occurs, and a large number of magnet poles also means that there are many dead points, which is not desirable. In contrast, the two-stage magnetized and obliquely magnetized permanent magnet of the present invention can provide phase angles α and β and provide a synchronous motor with no dead points, which is unprecedented. It is an excellent synchronous motor that does not look like anything else.

[Brief explanation of the drawing]

Figures 1 and 2 show a first embodiment of the present invention; Figure 1 is a cross-sectional view, Figure 2 is a diagram showing the relationship between the stator and the circular soft magnetic body, and Figures 3 and 4 are other figures. Figure 3 is a cross-sectional view, Figure 4 is a diagram showing the method of magnetizing a magnet, Figure 5 is a diagram showing how magnetic poles are generated in a circular soft magnetic body, and Figure 6 is a diagram showing a magnetic pole. FIG. 7 is a diagram showing a mode of generating torque, and FIGS. 8 to 10 are diagrams showing still other embodiments. 1... Casing, 2... Board, 3A, 3B,
13A, 13B...Soft magnetic material (magnetic bypass), 6...
... Shaft, 8 ... Circular soft magnetic body, 9 ... Permanent magnet, 11 ... Support structure.

Claims (1)

[Claims] 1. A casing that also serves as a yoke made of a soft magnetic material that surrounds the coil described below, and a circular soft magnetic material that is formed by providing a cutout window and uniformly distributing a plurality of alternating current poles with a narrow part in the center. a coil disposed so as to sandwich the alternating current pole of the circular soft magnetic material and face a circular permanent magnet described later; a magnetic side path disposed opposite the alternating current pole and shunting part of the magnetic flux along the way; It consists of a circular permanent magnet arranged opposite to an AC pole, and the circular permanent magnet is composed of circular permanent magnets in which N and S poles are arranged alternately, and there is an angular difference above and below the circular permanent magnet. A small synchronous motor in which each magnetic pole has a fixed angle with respect to the direction of rotation.