JPH09149568A - Stator and rotating electric machine using that stator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator which does not need accuracy in manufacture of an iron core and is small in magnetic resistance of the junction of splitted iron cores. SOLUTION: This stator is attached within the housing of a rotating electric machine, and has a stator iron core, which has a plurality of slots, being made by stacking a specified number of sheets of thin plates consisting of magnetic substance, and a plurality of stator coils which are accommodated in each slot. In this case, the stator iron core 3A is divided into a plurality of stacked iron core pieces 31 at the rear parts and a plurality of stacked iron cores 320 at the tooth parts, and magnetic coating 34 is applied on the end face of at least one iron core of both iron core pieces 310 and 320, and a DC magnetic field is applied to the applied film to coordinate the arrangement for magnetization, and these are put in circular form so that the coordination faces may join each other.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary electric machine such as an induction motor or a synchronous machine, and more particularly to a motor suitable for a general-purpose induction motor having a relatively small capacity.

[0001]

2. Description of the Related Art A rotary electric machine such as a general-purpose induction motor having a relatively small capacity which has been generally used in the past will be described with reference to FIG. FIG. 8 is a schematic explanatory view including a partial cross-sectional view of a conventional rotary electric machine, and FIG. 9 is a schematic explanatory view of a stator core of the conventional rotary electric machine. In FIG. 8, the upper half is a cross-sectional view and the lower half is an external view.

In FIG. 8, reference numeral 1 denotes a housing, which is also called a frame or a frame, and is formed into a substantially cylindrical shape by casting an iron-based material such as cast iron, and constitutes a casing of an electric motor. 1
Reference numeral a denotes a radiation fin, which has a strip shape extending in the axial direction, is integrally cast with the housing 1, and is radially formed on the outer periphery thereof. 2A and 2B are end brackets, also called bearing brackets, which house the bearings 4A and 4B.
The spigots are fitted to both ends of each to be attached. Reference numeral 3'denotes a stator, which is a stator core 3A 'made by laminating thin silicon steel plates, and a stator coil wound around a plurality of slots provided in an inner peripheral portion of the stator core 3A'. 3B and 3B. Reference numeral 5 denotes a rotor, which has a rotary shaft 6, which is end brackets 2A, 2
By being rotatably held by the B bearings 4A and 4B, it is configured to rotate at a predetermined position inside the stator 3 and at a position facing the stator 3.

In such a conventional electric motor, the stator 3'is previously inserted into the housing 1 and attached to the inner peripheral wall thereof, and then the rotor 5 is inserted into the stator 3 '. Then, the bearings 4A and 4B are fitted to the rotary shaft 6, so that the end brackets 2A and 2B are fitted to both ends of the housing 1, respectively, and the housing 1 is fitted to the housing 1 by a plurality of bolts (not shown). It is designed to be fixedly attached and assembled. One end side (right side in the figure) of the rotary shaft 6 is a bearing 4B of the end bracket 2A.
The output shaft is formed by inserting the shaft into the bearing 4 of the end bracket 2A on the other end side (the left side in the figure).
An external cooling fan 9 (hereinafter referred to as an external fan) is attached to a portion protruding from A. Reference numeral 10 denotes an end cover, which forms a cover for covering the outer fan 9. The end cover 10 is provided with an opening 10a (hereinafter referred to as a ventilation inlet) for taking in outside air with the external fan 9. Further, the opposite side of the opening 10a is formed into an open cylindrical shape or a deformed cylindrical shape, so that a ventilation opening including a radial gap portion 10b is formed between the end bracket 2A and the outer diameter portion of the housing 1. To be formed.

Therefore, when the outer fan 9 is rotated by the rotor 5, the outside air is sucked from the ventilation inlet 10a of the end cover 10 and blown out from the gap portion 10b, whereby the end bracket 2A and the housing. 1
And ventilating outside air to the outer surface of the end bracket 2B,
A cooling effect is obtained. The rotor 5 is mounted in the housing 1 of the rotary shaft 6 at a position facing the stator 3'as described above.
A secondary conductor bar (not shown) and an end ring 7 are provided, and an internal cooling fan 8 (hereinafter referred to as an inner fan) is formed integrally with the end ring 7.

The inner fan 8 is composed of a plurality of blade blades axially protruding from both end surfaces of the end ring 7, and circulates air inside the electric motor to obtain a cooling action. That is, the air flow generated by the inner fan 8 passes through the rotor 5, the end ring 7, the stator coil 3B, and the both end surfaces of the stator core 3A ′ while being cooled, and then relatively flows in comparison with the housing 1. Heat is obtained when passing along the inner surfaces of the end brackets 2A, 2B having a low temperature rise. By the way, in the rotating electric machine as described above, miniaturization and weight reduction are always a big subject, and therefore various miniaturization means are taken.

[0005]

In the miniaturizing means described above, the number of coils housed in the stator slot is increased, in other words, the coil space factor (ratio of the slot volume to the housed coil volume) is conventionally reduced. There is a method of further improving the size of the rotating electric machine. In order to improve the coil space factor, the back portion and the tooth portion of the stator iron core are formed of separate iron core pieces, and the stator coil is previously arranged at a position to be a slot,
After that, there is a method of using a so-called split core, in which both core pieces are joined to form a slot portion to form a stator core.

However, when the stator core is divided and the divided core pieces are joined together, a slight gap is generated in the joined portion. When the air gap exists in the magnetic circuit of the rotary electric machine, a large magnetomotive force is required to pass the magnetic flux through the air gap. This is because the air gap generated in the joint has a much higher magnetic resistance than the inside of the iron core, has a large amount of leakage magnetic flux, and is hard for the magnetic flux to pass through. Therefore, the larger the number of voids formed by the split cores in the magnetic circuit, the higher the magnetic resistance and the larger the magnetomotive force required. As a result, the exciting current of the rotating electric machine has to be increased, which causes a decrease in power factor, resulting in a drawback that the performance of the rotating electric machine deteriorates as compared with the conventional one.

In order to suppress the exciting current of the rotating electric machine and maintain the performance of the rotating electric machine, which is the above-mentioned drawback, there has been proposed a method of interposing a magnetic film material on the joint surface of the split core pieces to reduce the magnetic resistance. ing. However, simply interposing the magnetic film material causes a problem that the magnetized spin molecules of the magnetic film material are random and the effect is not sufficient. Further, as another means, it is conceivable to reduce the voids in the joint portion. For that purpose, the working accuracy must be made ultra-precision, so-called "zero-zero" accuracy, which causes a problem of high cost. The first object of the present invention is to solve the above problems, and to align the magnetized spin molecules of the magnetic material,
Another object of the present invention is to provide a stator core having a small magnetic resistance and a small leakage magnetic flux generated at the joints of the split cores without improving the manufacturing accuracy of the core. A second object of the present invention is to provide a small and lightweight rotating electric machine that uses the stator core and has good performance.

[0008]

In order to achieve the above first object, the structure of the stator according to the first invention is such that a thin iron core piece made of a magnetic material is attached to an inner peripheral wall of a housing of a rotating electric machine. In a stator having a stator core having a predetermined number of laminated layers and a plurality of slots, and a stator coil housed in each slot, the stator core includes a plurality of back laminated core pieces and a plurality of tooth laminated cores. Divide into pieces and form a ferromagnetic powder film on at least one end face of the both laminated iron core pieces, apply a DC magnetic field to the film to match the magnetization arrangement,
The two laminated core pieces are annularly engaged so that their magnetization matching surfaces are joined. According to a second aspect of the present invention, there is provided a rotating electric machine, which comprises a stator core attached to an inner peripheral wall of a housing of the rotating electric machine, having a predetermined number of thin plates made of a magnetic material, and having a plurality of slots. In a rotating electric machine using a stator having a stator coil, the above stator is used.

The above structure will be described in more detail. The stator according to the present invention is configured such that the stator iron core has a plurality of sets of laminated iron core pieces formed by laminating a predetermined number of thin plates of at least two kinds of magnetic materials, respectively.
The iron core pieces are thinly joined to the end face of at least one of the iron core pieces in the cross-sectional direction of the magnetic flux circuit, for example, approximately 0.
A magnetic film material is formed to a thickness of 01 to 0.05 mm.

As the magnetic film material, it is desirable to use a magnetic material having a high magnetic permeability (for example, permalloy), and the particle size of iron contained in the magnetic material is preferably 10 μm or less. Then, in order to facilitate the formation of a film on the one end surface of the iron core by the magnetic material, it is desirable to use it together with an epoxy or silicone adhesive. Further, the ferritic iron powder and the adhesive may be used, but the iron powder particle size is 1 as described above.
0 μmm or less is preferable. The magnetic material is composed of the above-mentioned materials, and the magnetic flux is satisfactorily passed through, so that the iron loss represented by hysteresis loss is significantly smaller than that of the silicon steel sheet.

Then, a magnetic film material used in combination with the adhesive material is applied and adhered to one or both end surfaces of the two iron cores, and then a DC voltage is applied to the magnetic film material before the adhesive material is fixed. A magnetic field is applied to arrange the magnetized spin molecules inside the magnetic field so that the magnetic flux can easily pass in a predetermined direction. After that, the core pieces are annularly array-bonded so that the magnetic film surfaces are bonded to form a stator core. Since the adhesive is attached to the end faces of the core pieces, the core pieces can be easily joined to each other. Therefore, in the magnetic circuit of the rotating electric machine, when the iron core pieces are arranged in an annular shape so that the magnetic film surfaces are joined, the voids formed in the joint portions of the respective iron core pieces are filled with the magnetic material and become small. It will be.
Moreover, in the magnetic film material, since the magnetized spin molecules are aligned by the application of the DC magnetic field, the magnetic resistance is reduced, the magnetic flux is easily passed, and the increase of the exciting current can be prevented. As described above, the present invention is configured such that even if the magnetic circuit of the rotary electric machine is formed by the split iron core, the electric characteristics are hardly disturbed and good characteristics can be obtained.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. [Embodiment 1] FIG. 1 is a schematic explanatory view of an induction motor using a stator according to the present invention, FIG. 2 is a schematic explanatory view of a stator according to the present invention, and FIG. FIG. 4 is an explanatory view of a back stator core piece that constitutes the stator, FIG. 4 is an explanatory view of a tooth stator core piece that constitutes the stator of FIG. 2, and FIG. 5 is a view of the tooth stator core piece of FIG. 6 is a perspective view of the stator core of FIG. 2, and FIG. 7 is a magnetic circuit explanatory diagram of the stator of FIG.

The induction motor shown in FIG. 1 is different from the induction motor shown in FIG. 8 only in the stator and has the same structure as the others, so that the detailed description is complicated, and the parts related to the present invention. Only briefly explained. Further, the same reference numerals are the same parts, and thus the repetitive description is omitted. Only new main symbols will be described. 3 is a stator and 3A is a stator core. In FIG. 1, an induction motor has a stator 3 attached to an inner peripheral wall of a housing 1, and the stator 3 is a fixed member formed by laminating a predetermined number of magnetic materials such as silicon steel plates in an axial direction. It has a child core 3A and a stator coil 3B housed in a slot 3C of the stator core 3A.

The stator core 3A comprises a back laminated core piece 310.
And the tooth portion laminated core piece 320 are divided and formed, and a plurality of these are alternately arranged in an annular shape. In FIG. 2, the laminated iron core piece 310 is not shown in its entirety, but the iron core pieces 31 constituting the laminated iron core piece 310 are shown. Therefore, the iron core piece 31 will be described. Each of the plurality of iron core pieces 31 includes a back portion 31a and a back portion 3a.
It is formed in a T shape from a small piece portion 31b projecting in the center of the inner side of 1a in the radial center direction of the ring.

Referring to FIG. 3 in more detail, the core piece 31 includes a back portion 31a and the back portion 31a.
Small piece part 3 protruding in the center of the inside of
1b is left, and both sides in the circumferential direction of the small piece portion 31b are cut out to form a cutout portion 31c which will later become a slot 3C, and is formed in a T shape. Further, on the back portion 31a of the iron core piece 31, protrusions 31d that engage with the iron core piece 32 are formed on both sides in the radial direction, and chamfers 31e are provided on both sides of the circumferential outer edge portion of the back portion 31a. ing.
Then, by laminating a predetermined number of the iron core pieces 31 in the axial direction of the rotary shaft 6, the laminated iron core piece 310 is formed.

Next, the magnetic member 34 will be described. In the back portion 31a of the back laminated core piece 310, from the ends of the chamfers 31e on both sides thereof, to the end portions of the chamfers 31e on the both end portions in the radial direction of the back laminated portion 31a, the chamfers 31e are continuously magnetized to the end portions so as to cover the protrusion 31d. The member 34 is formed. The magnetic member 34 is formed by mixing a magnetic material powder having a high magnetic permeability such as permalloy and an iron component having a particle size of 10 μmm or less, and forming a coating film on both radial end surfaces of the back portion 31a of the iron core piece. It is preferable to use it in combination with an epoxy or silicone adhesive for the sake of easy handling. In this case, magnetic powder and 1
It is not always necessary to mix with iron of 0 μmm or less, and 1
A magnetic material powder of 0 μm or less or an iron content of 10 μm or less may be used alone.

The magnetization of the magnetic film material 34 will be described with reference to FIG. In FIG. 5, 11 is a magnetizing device. As shown in the figure, the magnetizing device 11 is configured such that a magnetizing coil 11b is wound around a rectangular magnetic path 11a, a part of the magnetizing coil 11b serves as a magnetic pole to form an open circuit, and a direct current power supply 11c is connected to the magnetizing coil 11b. A laminated iron core piece 31 in which the magnetic film material 34 is formed between the magnetic poles in the open portion of the rectangular magnetic path 11a.
Zero is placed in the adhesive material that it contains without solidifying.
Then, when a DC magnetic field is applied to the magnetic film material 34 by the magnetizing device 11, the magnetization direction inside the magnetic film material 34 becomes
They are arranged in a fixed direction as shown by the arrow B in the figure.

Next, the tooth laminated core piece 320 will be described. FIG. 4 does not show the entire tooth portion laminated core piece 320, but shows the constituent core pieces 32, which will be described with reference to this. As shown in the figure, the core piece 32 is
Radial length of the iron core piece 31, that is, the back portion 31a
The upright portion 32 having the same length as the combined length of the small piece portion 31b and the same width as the small piece portion 31b of the iron core piece 31.
a is formed. The upright portion 32a has an end portion 35 formed on both sides in the width direction thereof, an end edge portion 32b provided with a tongue piece 32c protruding in the width direction at one end thereof, and both end portions on both ends in the other end thereof. Is chamfered 32e like the core piece 31
Is provided, and the back portion 3 is provided near the chamfer 32e.
A concave groove 32d that can be engaged with the protrusion 31d of 1a is formed. Then, by laminating a predetermined number of the iron core pieces 32 in the axial direction of the rotary shaft 6, the laminated iron core pieces 320 are formed.

With reference to FIGS. 6 and 7, the laminated core piece 31 described above is used.
The formation of the stator 3 and the stator core 3A by engaging 0 with the laminated core piece 320 will be described. Laminated iron core piece 310
(In FIG. 7, the iron core piece 31 is shown.) A predetermined number of preformed stator coils 3B are provided in each space formed by the notch portion 31c and the small piece portion 31b by a jig (not shown). They are arranged annularly at the positions. After that, the laminated core piece 320 (the core piece 32 is shown in FIG. 7) is attached to the surface of the laminated core piece 310 on both sides in the radial direction on which the magnetic film material 34 is provided, on the radial center side of the stator core 3A. Then, it is moved along the radial direction by the moving means (not shown) to be engaged.

At this time, the groove 32 of each laminated core piece 320
d is assembled to each other by engaging the protrusions 31d of the iron core piece 31, and the magnetic film material 34 and the iron core piece 32 are attached.
End face 35 of the laminated core piece 320, the end edge portion 32b of the laminated core piece 320, the small piece portion 31b of the laminated core piece 310, and the cutout portion 3
With 1c, a slot 3C is formed so as to surround the coil 3B already arranged. In this way,
The stator coil 3B can be housed in the slot 3C. The slot 3C is a semi-closed type due to the protruding tongue piece 32c.

At this time, the width of the back portion 31a of each laminated core piece 310 in the annular circumferential direction is sandwiched between the widths of the two slots 3C and the two slots 3C when the core pieces 32 are engaged. It has a combined size with the small piece portion 31b. The stator coil 3B is formed in advance so as to have a shape that can be stored in the slot 3C. That is,
In the stator coil 3B, a plurality of conducting wires are wound in a toroidal shape, and the portion inserted into the slot 3C is formed at an angle according to the angular position of the slot 3C.

Further, as shown in FIG. 6, the stator coil 3
When the stator coil 3B is inserted into the slot 3C of the stator core 3A, the coil end portions 33c and 33d of B are exposed at the upper and lower portions of the stator core 3A in the rotation axis direction. At that time, when the coil end portions 33c and 33d of the stator coil 3B are inserted into the slot 3C, the stator coil 3 inserted into the adjacent slot 3C is inserted.
In order to avoid interference with the coil end portion of B, it is desirable to form it into a curved shape having an appropriate radius, although not shown.

In the prior art, since there are manufacturing dimensional errors and assembly errors in each of the laminated core pieces, when the two stator cores are assembled as described above, there is a slight difference in the engaging portions of both laminated core pieces. There was a gap. That is, as shown in FIG. 7, the magnetic circuit 50 has eight engaging portions. When the engaging portion becomes a gap, a gap similar to the gap between the stator and the rotor of the induction motor is newly added, and a large magnetomotive force is required to pass the magnetic flux through the gap. As a result, the exciting current increases abnormally. According to the present embodiment, with a slight thickness approximately corresponding to the manufacturing error,
Since the magnetic materials are sandwiched and engaged, the magnetic resistance of the air gap is reduced, and since the magnetic field arrangement inside the magnetic materials is well arranged, the magnetic flux can pass through better, and the increase in the exciting current as in the past can be prevented. . Moreover, since the magnetic material is made of a material having a high magnetic permeability and an iron particle size of 10 μmm or less, which is very small, the magnetic material is not laminated like an iron core piece but is integrated in the axial direction. Even one
The effect of iron loss due to eddy currents is not a problem. The hysteresis loss of the high magnetic permeability material is about 1/5 that of electrolytic iron.

Further, according to the above embodiment, the case where the magnetic film material 34 is formed on the joint end surface of the laminated core piece 310 has been described, but it may be formed on the end surface of the laminated core 320. Further, the shapes of the two laminated core pieces 310 and 320 are not limited to those in the above-mentioned embodiment, and the joint end faces when the both core pieces are engaged can be magnetized. Further, depending on the standard of the rotating electric machine, the ferrite-based iron powder and the adhesive may be used, but it goes without saying that the iron powder particle size is as described above. When the magnetic material is made of the above-mentioned materials, the magnetic flux passes well, but the iron loss represented by the hysteresis loss is significantly smaller than that of the silicon steel sheet. With the configuration as described above, it is possible to provide a small and lightweight rotating electric machine having good electric characteristics.

[0025]

As described in detail above, according to the structure of the present invention, a stator core attached to an inner peripheral wall of a housing of a rotating electric machine and formed by laminating a predetermined number of thin plates made of a magnetic material, In a stator having a stator coil housed in each slot of an inner peripheral portion of the stator core, a plurality of sets of laminated core pieces formed by laminating a predetermined number of the thin plates for at least two kinds of In a stator core configured in an annular arrangement, a magnetic film material is formed on the end surface of at least one of the core pieces to which the core pieces are joined, and a DC magnetic field is applied to align the directions of the magnetized spin molecules. By doing so, the effects listed below can be obtained. (1) To provide a stator having a small magnetic resistance and a small magnetic flux leakage generated at the joint portion of the split iron cores, although the split iron cores are used to reduce the size and weight, without improving the manufacturing accuracy of the iron cores. can do. (2) A rotating electric machine having good electric characteristics can be provided with no reduction in efficiency or power factor even though a split iron core is used to reduce the size and weight.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an induction motor using a stator according to the present invention.

FIG. 2 is a schematic explanatory view of a stator according to the present invention.

3 is an explanatory view of a back stator core piece that constitutes the stator of FIG. 2. FIG.

FIG. 4 is an explanatory diagram of a tooth portion stator core piece that constitutes the stator of FIG. 2;

5 is an explanatory diagram of a DC magnetic field application of the tooth stator core piece of FIG. 3. FIG.

6 is a perspective view of the stator core of FIG. 2. FIG.

FIG. 7 is an explanatory diagram of a magnetic circuit of the stator of FIG.

FIG. 8 is a schematic explanatory view including a partial cross-sectional view of a conventional rotating electric machine.

FIG. 9 is a schematic explanatory view of a stator core of a conventional rotating electric machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Housing 3 ... Stator 3A ... Stator iron core 3B ... Stator coil 3C ... Slot 11 ... Magnetizing device 31 ... Back iron core piece 31a ... Iron core piece 31 back 31b ... Iron core piece 31 small piece 31c ... Iron core piece 31 Notch part 32 ... Tooth part iron core piece 32a ... Upright part 32b of iron core piece 32b ... End edge part 32c of iron core piece 32 ... Tongue piece 34 ... Magnetic film material 50 ... Magnetic circuit 310 ... Back laminated iron core piece 320 ... Tooth part Laminated iron core piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Tsukio Sekine, 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Izumi Shimizu 4-6-Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. In-house (72) Inventor Yukio Endo 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (72) Inventor Matsuri 4--6 Kanda Surugadai, Chiyoda-ku, Tokyo In Hitachi, Ltd. (72) Inventor Ryuichi Iwata 4-6 Kanda Surugadai, Chiyoda-ku, Tokyo Hitachi, Ltd. (72) Inventor Takahiro Takeda 7-1 Higashi Narashino-cho, Narashino, Chiba Prefecture Hitachi Industrial Equipment Division

Claims (2)

[Claims] 1. A stator core, which is attached to an inner peripheral wall of a housing of a rotating electric machine, has a plurality of thin iron core pieces laminated of a magnetic material, and has a plurality of slots, and a stator coil housed in each slot. In a stator having, the stator core is divided into a plurality of back laminated core pieces and a plurality of tooth laminated core pieces, a ferromagnetic powder film is formed on at least one end face of the both laminated core pieces, A stator characterized in that a direct-current magnetic field is applied to the film to match the magnetization arrangement, and the two laminated core pieces are annularly engaged so that their magnetization matching surfaces are joined. 2. A stator core, which is attached to an inner peripheral wall of a housing of a rotating electric machine, has a plurality of thin plates made of a magnetic material and has a plurality of slots, and a stator coil housed in each slot. A rotary electric machine using a stator, wherein the stator according to claim 1 is used.