JP2000197289A - Motor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily assemble permanent magnets being kept in an engaged state into the body of a rotor and to keep the positional relationship between the basic magnets and the auxiliary magnets even after assembling jig is removed, by forming an even number of first permanent magnets in and the same even number of second permanent magnets in such a shape that they may be engaged with each other. SOLUTION: 2M (M is a positive even number) basic magnets 2 are formed with a recessed section 2b which allows the basic magnets 2 to engage with auxiliary magnets 3. On the inner side of the basic magnets 2 and the auxiliary magnets 3, the body 1a of a rotor and a rotary shaft 1x of a rotor are formed. Due to this structure, a rotor 1 can be assembled with the minimum influence from a repulsive force or an attractive force between the magnetized permanent magnets caused by their magnetic forces. Even after an assembling jig is removed, the permanent magnets never deviate in position and therefore the position of the combined magnet rotor can be kept as it is.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor comprising a rotor and a stator and a method for manufacturing the same. More specifically, the present invention relates to a method for manufacturing a motor having a rotor in which basic magnets and auxiliary magnets are alternately arranged in order.

[0002]

2. Description of the Related Art Generally, in order to improve the efficiency of a motor by forming an efficient magnetic field structure, for example, a permanent magnet is generated by a permanent magnet in a motor having a structure in which a permanent magnet is embedded in a rotor made of a material having high magnetic permeability. It is conceivable to increase the amount of magnetic flux and to use the magnet torque more efficiently to maximize the torque generated with the same current. A motor based on this idea has been proposed in, for example, Japanese Patent Application Laid-Open No. Hei 10-191585. ing.

According to the above publication, as shown in FIG. 3, each permanent magnet in a permanent magnet embedded motor having a structure in which a main magnet 87 and an auxiliary magnet 88 are embedded as permanent magnets inside a rotor 86 is shown in FIG. Regarding the arrangement of magnets,
Assuming that the direction from S to N is the polarity direction,
It is described that an auxiliary magnet 88 having a polarity direction perpendicular to the polarity direction of the main magnet 87 is arranged to form a magnetic field, and the amount of magnetic flux generated by the permanent magnet is increased.

[0004] In addition, high permeability materials such as silicon steel plates used in the motor described in the above-mentioned publication generally have a high specific gravity and a heavy rotor weight. There is a problem that efficiency is hindered by the weight, and to solve such a problem, it is conceivable to reduce the weight of the material of the rotor, and a material having a small magnetic permeability (relative magnetic permeability) is used for the rotor body. Has been proposed by the present applicant as follows, in which the motor can be reduced in weight, the magnetic force is not reduced, and the efficiency and the power are improved.

[0005] In the motor in which the rotor is reduced in weight, a rotor body which is a main part of the rotor is constituted by using a material having a small magnetic permeability, and a magnetic flux is not distributed to a portion constituted by this material. A rotor is formed by arranging permanent magnets on the outer peripheral portion of the portion so as not to generate leakage magnetic flux and short circuit so as to form a magnetic field structure.

An example of a motor having such a magnetic field structure will be described. FIG. 4 is an explanatory plan sectional view conceptually showing an example of the structure of the lightened inner rotor type motor described above, and FIG. 5 is a view including the direction of the polarity of the permanent magnet used in the inner rotor type motor. FIG. 6 is an explanatory plan sectional view conceptually showing the arrangement of the configuration described above, and FIG. 6 is an explanatory plan sectional view showing an example of the structure of an outer rotor type motor.

In the inner rotor type motor, the rotor body 1a is made of a low magnetic permeability material having a small magnetic permeability and a small electric conductivity, and permanent magnets 2 and 3 are arranged around the rotor body 1a. The low magnetic permeability material is also provided on the outer peripheral side as the rotor yoke 1b.

In the above example, as shown in FIG.
The permanent magnets include eight rectangular permanent magnets (hereinafter, referred to as basic magnets) 2a and 2b as first permanent magnets, and eight trapezoidal permanent magnets (hereinafter, referred to as auxiliary magnets) 3a as second permanent magnets. And 3b are arranged alternately, and the basic magnets 2a and 2b are equally spaced around the outer periphery of the rotor body 1a, with the N pole facing outward (2a) and the S pole facing outward (2b) alternately. The auxiliary magnets 3a and 3b are arranged so as to be repeated, and the basic magnets 2a and 2b
And the polarity of the auxiliary magnet is along the outer periphery of the rotor main body 1a, and the polarity of the magnetic pole of the outer pole of the basic magnet and the magnetic pole of the auxiliary magnet opposed thereto are the same. And are arranged so as to be adjacent to each other.

Hereinafter, in this specification, a rotor constituted by such an arrangement of the basic magnet 2 and the auxiliary magnet 3 in accordance with the above positional relationship is referred to as a "combination magnet rotor".

Also, in the case of the outer rotor type, as shown in FIG. 7, the basic magnet 7 and the auxiliary magnet 8 are arranged on the rotor body 6a in the same manner as in the case of the inner rotor type. 9
Are disposed so as to be opposed. Since the configuration of the "combination magnet rotor" is the same in the outer rotor type, the following description will be made in accordance with the example of the inner rotor type.

The shape of the basic magnet 2 and the shape of the auxiliary magnet 3 are not limited to the above-mentioned shapes. For example, both the basic magnet 2 and the auxiliary magnet 3 may be rectangular or trapezoidal. The shape and the above-described arrangement can be determined by changing the positional relationship with the stator 4 within a range that satisfies the requirements for magnetic flux distribution described later. At this time, the intervals between the permanent magnets may be close to each other, or a predetermined interval may be adopted. The number M of the basic magnets 2 and the number M of the auxiliary magnets 3 (M is a positive even number) can be arbitrarily set as long as they can be arranged symmetrically in a plan view.

In the "combination magnet rotor", the low magnetic permeability material is provided as a rotor yoke 1b on the outer peripheral side of the basic magnets 2a and 2b and the auxiliary magnets 3a and 3b. It is configured to be disposed in a low magnetic permeability material. still,
Reference numeral 1x indicates a rotor rotation axis.

The low-permeability material is a non-magnetic material having a low magnetic permeability other than a material conventionally known as a so-called high-permeability material, and an insulating material having a low conductivity, such as resin or rubber. Etc. can be used.
That is, in the low magnetic permeability material, the magnetic flux generated by the basic magnet and the auxiliary magnet is hardly distributed. Moreover, a material having a small specific gravity is preferable. With the configuration described above, the weight of the rotor is reduced, and an excellent motor with improved efficiency can be obtained.

The above-described "combination magnet rotor"
A method for manufacturing a motor using a motor will be described according to an example of an inner rotor type motor. The stator is manufactured according to a conventionally known technique. In this example, a case in which a permanent magnet is embedded in a synthetic resin will be described. FIG. 8 is a perspective explanatory view conceptually showing a manufacturing method in which a permanent magnet is integrally embedded in a synthetic resin.

As shown in FIG. 8, the basic magnets 2a and 2b and the auxiliary magnet 3a are formed in a predetermined shape.
And 3b are set with an appropriate jig or the like, and are formed integrally with the permanent magnet by injecting a synthetic resin into the periphery thereof by an injection molding method using a predetermined mold or the like. To obtain the rotor 1. At this time, the resin injection may be divided into two steps, and the jig and the like may be omitted. Thereafter, a stator (not shown) and the rotor 1 are assembled. By adopting the manufacturing method of integrally molding in this way,
The process of assembling the rotor 1 by hand is unnecessary, and an inexpensive motor can be provided by reducing the manufacturing cost.

FIG. 9 shows a concave portion 11 (only one portion is shown in FIG. 9) into which permanent magnets of the basic magnets 2a and 2b and the auxiliary magnets 3a and 3b formed in the predetermined shape can be inserted. After the molded body of the synthetic resin is formed in advance, the permanent magnet 2a 'is inserted into the concave portion 11 after the formation, and the upper rotor 1c and the rotor are disc-shaped members made of the synthetic resin from the upper surface and the lower surface. It is a perspective explanatory view notionally showing the manufacturing method of the assembly type which attaches undergarment 1d and makes rotor 1. According to this manufacturing method, the permanent magnet can be attached to the concave portion 11 by performing any one of various methods such as bonding, press-fitting, and filling according to the design of the permanent magnet and the entire rotor. .

As described above, by adopting the manufacturing method in which the recessed portion 11 is provided in the molded body and the permanent magnet is inserted and attached, the rotor main body is formed by a mold that is less expensive than the case of integrally molding. Therefore, it is possible to produce a small number of motors of various kinds in a short delivery time by an assembling process.

FIG. 10 is an explanatory perspective view showing a manufacturing method of obtaining a rotor by attaching a ring-shaped member 12 around the permanent magnet after attaching a permanent magnet to the rotor 1 main body. As shown in FIG. 10, when fitting the ring-shaped member 12,
A filler may be interposed between the ring-shaped member 12 and the permanent magnet, or may be bound by the rubber-shaped ring-shaped member 12.

According to the manufacturing method using the ring-shaped member 12, the rotor 1 can be formed without preparing a special rotor mold. When attaching the permanent magnet to the rotor body, it is necessary that the permanent magnet does not fall off during rotation as the rotor, and the permanent magnet may be adhered to the rotor body or attached so as to fit. Can also.

[0020]

In the motor proposed above, the magnetized permanent magnets are mounted or inserted into the rotor body one by one, so that a considerable amount of manpower is required for assembly. There is a problem that workability is low due to a repulsive force or an attractive force due to the magnetic force between the permanent magnets.

Further, when assembling such a permanent magnet, there is a possibility that the polarity of the permanent magnet is erroneously assembled, and if it is incorrect, a desired rotational characteristic cannot be obtained.

Further, when the permanent magnet is attached to the rotor body by using the above-described jig, if the jig is removed after the permanent magnet is attached to the rotor body, even if a slight displacement of the permanent magnets occurs, Due to the repulsive force and attractive force of the magnetic force between the permanent magnets, the positional relationship between the permanent magnets is
There is a problem that the arrangement of the "combination magnet rotor" is lost.

The present invention has been made in order to solve such a problem. In a rotor in which the above-described basic magnets and auxiliary magnets are arranged alternately in order,
An object of the present invention is to provide a motor having a structure that can be easily attached to a rotor main body while maintaining such an arrangement, and can maintain the arrangement of a basic magnet and an auxiliary magnet even after an assembly jig is removed, and a method of manufacturing the same.

[0024]

In order to solve the above-mentioned problems, a motor according to a first aspect of the present invention has a rotor body 1 on which 2M (M is a positive even number) permanent magnets are mounted.
a, and a stator 4, and each of the M first permanent magnets 2 of the 2M permanent magnets is maintained at a predetermined distance from each other, and each of the polarities is directed outward in the radial direction. And inward in the radial direction are sequentially attached to the rotor body 1a so as to be opposite to each other.
A second permanent magnet 3 is provided between each of the first permanent magnets 2, and the polarity of the second permanent magnet 3 is changed along the circumferential direction of the outer magnetic poles of the first permanent magnet 2. In a motor mounted so as to have the same polarity as the polarity, the M first permanent magnets 2 and the M second permanent magnets 3 are formed into shapes that can mesh with each other. It is characterized by the following.

According to the above configuration, the rotor can be assembled from the magnetized permanent magnets while minimizing the influence of the repulsive force or the attractive force due to the magnetic force between the permanent magnets. Even after removing the central member, which is a part, the arrangement of the “combination magnet rotor” can be maintained without any displacement. Furthermore, the shape of the interlocking portion between the first permanent magnet 2 and the second permanent magnet 3 is, for example,
By adopting a structure that does not separate easily, such as a wraparound shape (wedge shape, undercut), the position of the “combination magnet rotor” can be maintained without displacement even after the outer peripheral member of the assembly jig is removed.

In the motor according to claim 2 of the present invention, the shape of the M second permanent magnets 3 is rectangular,
Since the first permanent magnet 2 is formed with a recess so as to be meshed with the second permanent magnet 3, the recess can be easily formed.

According to a third aspect of the present invention, in the method of manufacturing a motor according to the first aspect, the M jigs are provided in an assembly jig 20 corresponding to the shape of the rotor body 1a. The first permanent magnet 2 and the M second permanent magnets 3 are inserted, and a synthetic resin is directly injected into the assembly jig 20 into which the first permanent magnet 2 has been inserted, thereby forming a rotor main body. Therefore, the assembly jig 20 can be prepared with a simple configuration using an inexpensive material.

[0028]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiment 1 FIG. 1A is a top view showing the shape of the basic magnet 2 and the shape of the auxiliary magnet 3 and the arrangement of both in the rotor of the inner rotor type "combination magnet rotor" in this embodiment. It is a figure, (b) and (c) of FIG.
FIG. 2 is an explanatory top view schematically showing only an interlocking portion in another example of the combination of the basic magnet 2 and the auxiliary magnet 3. FIG. 2 is a view for assembling the rotor of the “combination magnet rotor”. FIG. 2 is a perspective explanatory view conceptually showing the assembling jig.

In the example shown in FIG. 1A, the auxiliary magnet 3 is formed in the same rectangular shape as the conventional one, but the basic magnet 2 can mesh with the auxiliary magnet 3. As described above, the concave portion 2h is formed in a groove shape. The other points are the same as those of the conventional rotor. The rotor main body 1a and the rotor rotating shaft 1x are formed on the inner peripheral side of the basic magnet 2 and the auxiliary magnet 3.

The concave portion 2h is formed so as to form a groove along the direction perpendicular to the paper of FIG. 1 (a) (hereinafter also referred to as the longitudinal direction of the rotor).
The shape of h is not limited to the shape of the present example as long as the shape can be meshed with the shape of the auxiliary magnet 3 in the longitudinal direction of the rotor. For example, contrary to this example, the shape of the basic magnet 2 may be rectangular, and the shape of the auxiliary magnet 3 may mesh with the basic magnet 2. Furthermore, both may have a gear-like structure provided with gear-shaped unevenness or a wraparound shape (wedge shape, undercut) as shown in FIG. 1 (b) or (c). Then, the positional relationship between the basic magnet 2 and the auxiliary magnet 3 may be opposite to that in the illustrated example.

The recess 2h shown in FIG. 1 (a) is formed by cutting the groove-like recess into the side surface (the surface in the direction perpendicular to the paper) of the basic magnet 2 once having a substantially trapezoidal bottom surface. It may be provided, or may be formed into a shape including a groove-shaped concave portion from the beginning.

In the latter case, a powder of a barium ferrite magnet, a rare earth magnet, or the like can be compression molded, fired, and magnetized. Thus, the auxiliary magnet 3
Is rectangular, and the basic magnet 2 is provided with a concave portion so that the shape of the basic magnet 2 can be meshed with the auxiliary magnet 3. Therefore, the basic magnet 2 having such a concave portion can be easily formed. it can. Therefore, there is an effect of obtaining a low-cost motor.

Here, the arrangement of the permanent magnets in the aforementioned "combination magnet rotor" will be described.

In other words, in this arrangement, when 2M permanent magnets are mounted, of the 2M permanent magnets, each of the M basic magnets 2 is maintained at a predetermined interval, and the direction of each polarity is the diameter. The direction of the outer direction and the direction of the radial direction are arranged in the rotor main body 1a in such a manner that the direction of the direction is opposite to the direction of the radial direction, and the auxiliary magnet 3 is provided between each two adjacent basic magnets 2. Magnet 3
Are arranged in such a manner that the polarities of the magnetic poles are the same as the polarities of the magnetic poles outside the basic magnet 2 along the circumferential direction.

The rotor main body 1a is formed on the inner peripheral side of the basic magnet 2 and the auxiliary magnet 3 having the above-described configuration, and the rotor yoke 1b is formed on the outer peripheral side if necessary. According to the above configuration, the magnetized permanent magnet can be assembled with the rotor by minimizing the influence of the repulsive force or the attractive force due to the magnetic force between the permanent magnets. The arrangement of the "combination magnet rotor" can be maintained without the magnet being displaced.
Therefore, there is an effect of obtaining a motor which is easy to assemble and has a low assembly operation cost.

In the motor according to the present invention using the "combination magnet rotor", the number of permanent magnets can be set in the same manner as the conventional one.

The rotor body 1a and the rotor yoke 1b
Can be formed by a method such as an insert molding method or a molding method using the above-described low magnetic permeability material, particularly, a synthetic resin or the like.

Next, such a "combination magnet rotor"
The method of manufacturing the rotor described above will be described. As shown in FIG. 2, the assembling jig 20 includes a central member 21 formed in the same shape as the rotor main body 1a, an outer peripheral member 22 surrounding the outer peripheral portion and forming a box shape at the bottom. Consists of The assembling jig 20 can be divided so that the assembling jig 20 can be easily separated from the permanent magnet after assembly, for example, by the inner bottom surface 22 a of the outer peripheral member 22. ing. As a material of the assembly jig 20, a material that is not affected by the magnetic force of the permanent magnet is used.

The basic magnet 2 and the auxiliary magnet 3 are assembled using the assembly jig 20 described above. First,
In the assembly jig 20 shown in FIG. 2, the basic magnets 2 molded and magnetized as described above are inserted one by one into a predetermined position of the basic magnet 2 from above the assembly jig 20, and then similarly. The formed and magnetized auxiliary magnet 3 is similarly inserted into a predetermined position.

Thereafter, the center member 21 is removed from the assembly jig 20, and the rotor body 1a is formed on the inner peripheral side of the basic magnet 2 and the auxiliary magnet 3, and if necessary,
A rotor is obtained by forming a rotor yoke 1b on the outer peripheral side.

At this time, the center member 21 of the assembling jig 20 is detached, and instead, another center member having a shape conforming to the shape of the rotor main body 1a and having a shape capable of fixing the rotor rotation shaft is inserted and combined. It can also be used for injection of resin and the like.

In consideration of the biting shapes of the basic magnet 2 and the auxiliary magnet 3, both of them are provided with gear-shaped irregularities, or with a biting structure provided with the aforementioned wraparound shape (wedge shape, undercut), etc. If the shape of the outer peripheral member 22 is not easily separated,
Also, the rotor can be obtained by an insert molding method using a synthetic resin or the like.

Thereafter, a motor is manufactured by combining the rotor and the stator.

By using the assembling jig 20 described above, the rotor can be assembled by assembling the magnetized permanent magnet by minimizing the influence of the repulsive force or the attractive force due to the magnetic force between the permanent magnets during the assembling operation. In addition, the arrangement of the permanent magnets is not distorted by a slight displacement. Therefore, the assembling jig 20 can be prepared with a simple configuration and using inexpensive materials, and the motor can be manufactured with reduced assembling work costs.

Second Embodiment In the description of the first embodiment, the case where the present invention is applied to an inner rotor type rotor is shown. However, the present invention can be similarly applied to an outer rotor type rotor. For example, an assembly jig may be manufactured by changing the dimensions of the other central member so that the stator can be disposed at the center of another central member that matches the shape of the rotor main body 1a described above.

[0047]

As described above, the motor according to the present invention has the following features in accordance with the arrangement of the "combination magnet rotor".
Since the basic magnet and the auxiliary magnet are formed in a shape that can mesh with each other, the magnetized permanent magnet is
The rotor can be assembled while minimizing the effect of the repulsive force or attractive force due to the magnetic force between the permanent magnets. Even after the assembly jig is removed, the position of the "combination magnet rotor" is maintained without displacement. I can do it. Therefore, there is an effect of obtaining a motor having a "combination magnet rotor" which is easy to assemble and has a low assembling work cost.

In the motor according to the present invention, the shape of the auxiliary magnet is rectangular, and the basic magnet is formed with a concave portion so as to be meshed with the auxiliary magnet, so that the concave portion is easily formed. This has the effect of obtaining a low-cost motor.

In the method of manufacturing a motor according to the present invention, a basic magnet and an auxiliary magnet are inserted into an assembling jig conforming to the shape of the rotor body, and these are directly inserted into the assembling jig into which they are inserted. Since the rotor is obtained by forming the rotor body by injecting a synthetic resin or the like, an assembling jig can be prepared with a simple configuration using an inexpensive material. Therefore, the motor can be manufactured with low assembly work costs.

[Brief description of the drawings]

FIG. 1A is an explanatory top view showing a shape of a basic magnet 2, a shape of an auxiliary magnet 3, and an arrangement of both in a rotor of an inner rotor type “combination magnet rotor” according to an embodiment of the present invention; , (B) and (c)
FIG. 5 is an explanatory top view conceptually showing only an engagement portion in another example of the combination of the basic magnet 2 and the auxiliary magnet 3 in an enlarged manner.

FIG. 2 is a perspective explanatory view showing an assembly jig according to the embodiment of the present invention.

FIG. 3 is an explanatory plan sectional view showing the structure of a conventional motor.

FIG. 4 is an explanatory plan sectional view showing a configuration of an inner rotor type motor having a conventional “combination magnet rotor”.

5 is an explanatory plan sectional view showing an arrangement of permanent magnets in the motor shown in FIG. 4;

FIG. 6 is an explanatory plan sectional view showing a configuration of an outer rotor type motor having a conventional “combination magnet rotor”.

FIG. 7 is an explanatory perspective view conceptually showing a manufacturing method in which a permanent magnet is integrally embedded in a synthetic resin.

FIG. 8 shows a method of forming a synthetic resin molded body having a concave portion in advance,
FIG. 9 is a perspective explanatory view showing a manufacturing method of inserting a permanent magnet into the recess to form a rotor.

FIG. 9 is a perspective explanatory view showing a manufacturing method of obtaining a rotor by attaching a ring-shaped member around the permanent magnet after attaching the permanent magnet to the rotor body.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Rotor, 2 ... Basic magnet, 3 ... Auxiliary magnet, 4 ... Stator, 20 ... Assembly jig

Claims (3)

[Claims] 1. A rotor body (1a) on which 2M (M is a positive even number) permanent magnets are mounted, and a stator (4). Of the 2M permanent magnets, M-th Each of the 1 permanent magnets (2) is held at a predetermined distance from each other,
The rotor body (1a) such that the directions of the polarities are radially outward and radially inward in order.
And a second permanent magnet (3) is provided between two adjacent first permanent magnets (2), and the polarity of the second permanent magnet (3) is set in the circumferential direction. A motor mounted along the outer periphery of the first permanent magnet (2) so as to have the same polarity as the polarity of the magnetic pole outside the first permanent magnet (2), the M first permanent magnets (2) and the M A motor characterized in that the second permanent magnet (3) and the second permanent magnet (3) are formed in a shape that can mesh with each other. 2. The shape of the M second permanent magnets (3) is rectangular, and the first permanent magnets (2) can mesh with the second permanent magnets (3). 2. The motor according to claim 1, wherein the motor is formed by providing a concave portion. 3. The method for manufacturing a motor according to claim 1, wherein the M first permanent magnets (2) are provided in an assembling jig (20) conforming to the shape of the rotor body (1a). And the M
After inserting the second permanent magnets (3), the rotor body
A method for manufacturing a motor, characterized in that a rotor is obtained by forming (1a).