JPH10191614A - Pulse motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of torque decrease, thermal strain, and efficiency degradation in a pulse motor. SOLUTION: At the secondary scale of a pulse motor, teeth parts and a groove parts 2 are disposed alternately, and permanent magnets 13 are disposed so that the polarities of adjacent ones may be opposite to each other, and are inserted in respective grooves 2 respectively. Insulation covering 15 which covers a permanent magnet body 14 and an adhesive layer 16 which covers the inner surface of the groove 2 are formed between the inner surface of the groove part 2 and the surface of a permanent magnet body 14 and are insulated electrically to each other. It is thus possible to prevent the groove part or a spacer and the permanent magnet from coming into direct contact with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a pulse motor suitable for use in factory automation (FA) equipment requiring a relatively large thrust, such as an industrial robot.

[0002]

2. Description of the Related Art As a conventional example of the pulse motor, Japanese Patent Publication No. 7-59143 or Japanese Patent Publication No.
No. 44 is known. 2 and 3 show examples of the configuration of a secondary scale in a conventional rotary pulse motor. Reference numeral 1 denotes cores, and these cores 1 are provided with grooves 2 along the rotation direction, and permanent magnets 3 are inserted into these grooves 2 respectively. A spacer 5 is arranged between the outer yoke 4 and the permanent magnet 3, and the spacer 5 is fixed to the yoke 4 by a weld 6. The spacer 5 is in contact with the permanent magnet 3 and positions the permanent magnet 3 at a predetermined position.

[0003]

The permanent magnet 3 is made of a rare-earth metal having a high magnetic permeability, for example, a samarium-cobalt-based, neodymium-based or cerium-based metal. It is structured to be insulated by processing or the like. In such a structure, if the insulating coating is peeled off for some reason or if there is a pinhole in the aluminum chromate treatment layer, the permanent magnet 3 is connected to the secondary side because the ferromagnetic material is conductive. The conductive state is established with the metal components such as the core 1 and the spacer 5 that constitute the scale, and for example, the following problems occur.

More specifically, when the permanent magnet 3 comes into contact with the inner surface of the groove 2 and the spacer 5 and becomes electrically conductive, the dashed arrow in FIG. As shown in the figure, a one-turn coil is formed through the permanent magnet 3, the spacer 5, the welded portion 6, the yoke 5, the welded portion 6, the spacer 5, and the permanent magnet 3, and the induced current flowing through the one-turn coil Various problems occur. In addition to the above, the inner end of the core 1, the end or the side of the permanent magnet 3, the outer end of the core 1, the yoke 4, the outer end of the core 1, and the permanent magnet A phenomenon in which a one-turn coil is formed through the end or side of the coil 3 or a phenomenon in which the permanent magnet 3 and the spacer 5 are conducted to act as a cage coil is also considered.
A similar problem occurs.

[0005] As a result of the short-circuit of the permanent magnet 3, the following problems to be solved arise. I. Since the current that should be converted to magnetic force is consumed as the induced current, the torque decreases. B. Since the insulation failure of the permanent magnet 3 is a phenomenon that occurs at random positions, it causes local heat generation, and as a result, thermal strain is generated and mechanical accuracy is reduced due to the thermal strain. C. When the current flowing through the short-circuit portion is large, the efficiency of the motor itself decreases.

[0006]

In order to achieve the above object, a pulse motor according to the present invention comprises a secondary scale having a number of teeth spaced from each other along a predetermined direction; And a primary magnetic flux generator supported movably in the predetermined direction with respect to the side scale, formed between each magnetic pole of the primary magnetic flux generator and each tooth of the secondary scale. A pulse motor that sequentially moves the primary-side magnetic flux generation unit relative to a secondary-side scale by sequentially generating a magnetic flux through each of the gaps, wherein the secondary-side scale includes the tooth part and the groove part. Are arranged alternately, and permanent magnets are arranged so that adjacent magnets have opposite polarities and inserted into the respective groove portions, and between the inner surface of the groove portion and the surface of the permanent magnet main body. Communicate these with each other. Manner, wherein an insulating insulating layer is provided. Further, the insulating layer includes an insulating coating formed at least in a contact area with the groove in the permanent magnet main body, and an insulating adhesive layer interposed between the permanent magnet main body and the groove and bonding them together. It is characterized by becoming. Further, the insulating coating is formed on the surface of the permanent magnet main body by any one of epoxy resin coating, aluminum chromate treatment, and electrodeposition coating. Furthermore, the adhesive layer is made of any one of an epoxy resin, a thermoplastic resin, and an acrylate resin, and a fitting dimension between the groove and the permanent magnet is a loose fitting. According to the above configuration, since the insulating layer on the surface of the permanent magnet main body and the adhesive are doubly insulated, the permanent magnet does not contact the core or the spacer. Further, since the permanent magnet main body is fixed by the adhesive force of the adhesive, the fitting between the groove of the core and the permanent magnet may be loose, and therefore, the possibility that the insulating layer is broken at the time of mounting is small.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In the figure, the same components as those of the conventional example are denoted by the same reference numerals, and the description will be simplified. Reference numeral 13 denotes a permanent magnet. The permanent magnet 13 includes a permanent magnet main body 14 made of a rare-earth metal having a high magnetic permeability, such as a samarium-cobalt-based, neodymium-based, or cerium-based metal, and a And an insulating coating 15 provided.

The insulating coating 15 includes, for example, a. Aluminum chromate treatment as in the past, b. An epoxy resin coating formed by spray coating an epoxy resin, or c. Processing such as insulating resin coating by electrodeposition coating is employed.

On the other hand, the groove 2 into which the permanent magnet 13 is inserted
An adhesive is applied in advance on the inner surface of the substrate to form an adhesive layer 16. The adhesive constituting this adhesive layer is d.
Epoxy resin, e. An anaerobic thermoplastic resin having a property of being cured by blocking air (for example, an adhesive that is commercially available as a screw lock, Loctite, and the like under a trade name for preventing a screw from loosening), or f. Adhesives having good electrical insulation such as acrylate resins are employed. These adhesives d to e are appropriately selected according to the surface treatments a to c described above. As a specific combination example, the neodymium magnet is subjected to aluminum chromate treatment, and is preferably obtained by using an anaerobic adhesive. High adhesiveness can be obtained.

The secondary scale of the pulse motor configured as described above is assembled by applying an adhesive in the groove 2 in advance and inserting the permanent magnet 13 therein. Here, the insulating coating 1 is applied to the surface of the permanent magnet 13.
5 and the electrically insulating adhesive layer 16 are provided, so that the permanent magnet 13 is electrically connected to the core 1 or the spacer 5 unless both the insulating coating 15 and the adhesive layer 16 are broken at the same position. Therefore, a one-turn coil as described in the related art cannot be formed, and torque reduction, heat generation, or efficiency reduction due to eddy current passing through the permanent magnet 13 does not occur. .

If the dimensional tolerance between the groove 2 and the permanent magnet 13 is set to a loose fit in consideration of the adhesive force of the adhesive layer 16, when the permanent magnet 13 is inserted into the groove 2, an excessively large Since no force is applied or a large frictional force acts between the surface of the permanent magnet 13 and the inner surface of the groove 2, the insulating coating 15 is less likely to be broken. Further, in the illustrated embodiment, since an anaerobic adhesive is used as the adhesive, the adhesive is hardened only by inserting the permanent magnet 13 into the groove 2. Can be fixed.

The specific shape and structure of the secondary scale of the pulse motor including the permanent magnet are not limited to those shown in the drawings. The technology of the present invention can be applied not only to a rotary pulse motor but also to a linear pulse motor.

[0013]

As described above, according to the present invention,
The secondary scale, the tooth portion and the groove portion are alternately arranged, and permanent magnets are arranged in such a manner that adjacent magnets have opposite polarities and inserted into each of the groove portions. Since an insulating coating layer is provided between the inner surface of the groove and the surface of the permanent magnet body to electrically insulate them from each other, the permanent magnet body is doubled by the insulating layer and the adhesive layer on the surface. Because the permanent magnet body does not contact the core or spacer, these permanent magnets, body, core, and spacer form a series of circuits and do not become a one-turn coil. Generation of distortion or reduction in efficiency can be reliably prevented. If the insulating coating is formed in a contact area of the permanent magnet main body with the groove and the spacer, the insulating coating is interposed between the permanent magnet main body and the groove and between the permanent magnet and the spacer to insulate them. can do. The insulating coating is formed on the surface of the permanent magnet main body by any of epoxy resin coating, aluminum chromate treatment, or electrodeposition coating, and the adhesive layer is formed of an epoxy resin, a thermoplastic resin, or an acrylate resin. As a result, an induced current due to a core short circuit does not flow, and a stable pulse motor with low heat generation and high efficiency can be obtained. Further, since the fitting dimension between the groove and the permanent magnet main body is loosely fitted, the insulating layer and the adhesive on the surface of the permanent magnet are double insulated, and the permanent magnet contacts the core and the spacer. There is no.
Further, since the permanent magnet is fixed by the adhesive force of the adhesive, the fitting between the groove of the core and the permanent magnet may be loose, and therefore, the possibility of the insulating layer being broken at the time of attachment is small.

[Brief description of the drawings]

FIG. 1 is a front view of an embodiment of the present invention.

FIG. 2 is a perspective view of a conventional example.

FIG. 3 is a sectional view taken along line III-III of FIG. 2;

[Explanation of symbols]

Reference Signs List 1 core 2 groove 13 permanent magnet 14 permanent magnet main body 15 insulating coating 16 adhesive layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masaaki Naruhisa 100 Takegahana-cho, Ise-shi, Mie Shinko Electric Co., Ltd. (72) Inventor Mitsuji Kanda 100 Takegahana-cho, Ise-shi, Mie Shinko Electric Co., Ltd. Inside Ise Works (72) Inventor Motoharu Nakajima 100 Takegahana-cho, Ise City, Mie Prefecture Shinko Electric Co., Ltd.

Claims (5)

[Claims] 1. A secondary scale having a number of teeth arranged at intervals in a predetermined direction, and a primary side supported to be relatively movable in the predetermined direction with respect to the secondary scale. A magnetic flux generating portion, by sequentially generating magnetic flux through each gap formed between each magnetic pole of the primary magnetic flux generating portion and each tooth portion of the secondary scale,
In a pulse motor that relatively moves the primary-side magnetic flux generation unit with respect to a secondary-side scale, the secondary-side scale has the tooth portions and the groove portions arranged alternately, and permanent magnets adjacent to each other are mutually connected. Arranged so as to have opposite polarities and inserted into each of the grooves, and an insulating layer for electrically insulating these from each other is provided between the inner surface of the groove and the surface of the permanent magnet main body. A pulse motor characterized in that: 2. The insulating layer according to claim 1, wherein the insulating layer is formed at least in an area of contact with the groove in the permanent magnet main body, and an insulating bond interposed between the permanent magnet main body and the groove and bonding them together. The pulse motor according to claim 1, wherein the pulse motor comprises an agent layer. 3. The method according to claim 2, wherein the insulating coating is an epoxy resin coating,
The pulse motor according to claim 2, wherein the pulse motor is formed on the surface of the permanent magnet holding main body by one of an aluminum micrometer treatment and an electrodeposition coating. 4. The pulse motor according to claim 2, wherein the adhesive layer is made of any one of an epoxy resin, a thermoplastic resin, and an acrylate resin. 5. The pulse motor according to claim 2, wherein a fitting dimension between the groove and the permanent magnet is a loose fitting.