WO2017195249A1

WO2017195249A1 - Stator core and electric motor equipped with same

Info

Publication number: WO2017195249A1
Application number: PCT/JP2016/063749
Authority: WO
Inventors: 悠太森; 剛仙岩邊; 雄康平戸
Original assignee: 三菱電機株式会社
Priority date: 2016-05-09
Filing date: 2016-05-09
Publication date: 2017-11-16
Also published as: JP6723348B2; CN109075626A; JPWO2017195249A1; CN109075626B

Abstract

This stator core is formed by stacking a plurality of magnetic steel sheets, and is provided with: an annular core back; and a plurality of teeth that extend inwardly from the core back and each have a winding wound therearound. The core back has a caulked joint for fixing between magnetic steel sheets that are disposed adjacent to each other in a stacking direction. The magnetic steel sheets at the teeth are each formed in a flat plate shape. Protrusions are disposed in some of multiple gaps formed between the magnetic steel sheets at the teeth.

Description

Stator core and electric motor equipped with the stator core

The present invention relates to a stator core formed by laminating a plurality of electromagnetic steel sheets and an electric motor including the stator core.

Generally, a stator core constitutes a stator used for an electric motor or a rotating machine. The stator core is formed by laminating a plurality of electromagnetic steel plates, and includes an annular core back portion and a plurality of teeth portions extending inward from the core back portion. The teeth portion is subjected to insulation treatment and wound with a winding.

For example, in the stator core disclosed in Patent Document 1, electromagnetic steel sheets adjacent in the stacking direction are caulked and joined at the core back part and the tooth part, respectively. However, the stator iron core is affected by the distortion and stress caused by the press-fitting of the caulking convex part and concave part in the tooth part, the magnetic permeability decreases, the insulation treatment is further destroyed, and the fracture surfaces of the electrical steel sheets are in contact with each other. Eddy currents are generated between the layers, and the magnetic characteristics deteriorate due to an increase in iron loss, which adversely affects the motor characteristics. On the other hand, if the stator core is not caulked and joined to the teeth portion, the stator core is deformed so as to be crushed due to winding contraction. When the winding shrinkage occurs, the winding cannot be wound to the target position, and manufacturing defects such as winding disturbance occur, which affects the manufacturing quality.

Therefore, the stator core disclosed in Patent Document 2 is an uneven structure in which the electromagnetic steel sheets adjacent in the stacking direction are caulked and bonded in the core back part, and the electromagnetic steel sheets adjacent in the stacking direction are fitted in the tooth part leaving a gap. It is the structure which has a part. In addition, the stator core disclosed in Patent Document 3 has a configuration in which a gap protrusion is provided on each laminated iron core plate and a minute gap is secured between the iron core plates.

JP 2013-59262 A JP 2008-43102 A Japanese Patent Laid-Open No. 06-14481

The stator core disclosed in Patent Document 2 is provided with uneven portions continuously in the stacking direction on each electromagnetic steel sheet of the teeth portion, and a gap is formed between the stacks of the tooth portions to suppress winding shrinkage. It is the structure to do. Patent Document 3 is a configuration in which a minute gap is provided between laminated iron core plates to reduce iron loss due to eddy current. However, the required gap between the stacks is 1 μm to 5 μm, and is determined by the shape accuracy of the blade tip to be molded. For this reason, in order to form, for example, an emboss on each electromagnetic steel sheet to form a gap between the stacks, high-precision processing is required, and the processing cost and maintainability of the blades are problematic. In addition, when embossing is performed with an automatic press machine, the bottom dead center position during operation occurs due to temperature changes, etc., and the gap between the layers changes due to that effect, so the winding is wound to the target position. This is not possible and causes manufacturing defects such as turbulence.

The present invention has been made to solve the above-described problems, and includes a stator core that can suppress winding contraction due to winding without caulking and joining the electromagnetic steel sheet of the tooth portion, and the stator core. An object is to provide an electric motor.

The stator core according to the present invention is formed by laminating a plurality of electromagnetic steel sheets, an annular core back portion, a plurality of teeth portions extending inwardly from the core back portion, and windings are wound thereon. The core back part has a crimped joint part to which the electromagnetic steel sheets adjacent in the stacking direction are fixed, and the electromagnetic steel sheet of the teeth part is formed in a flat plate shape. The protrusion is provided in a part of the plurality of gaps formed between the plurality of electromagnetic steel sheets in the tooth portion.

According to the present invention, the electrical steel sheet of the teeth part is formed in a flat plate shape, and the protrusions are provided in some of the plurality of gaps formed between the plurality of electrical steel sheets in the tooth part. The laminated width of the core back portion and the laminated width of the teeth portion to which tension is applied by winding of the winding can be made equal, and winding shrinkage can be suppressed.

It is a longitudinal cross-sectional view of the electric motor provided with the stator core which concerns on embodiment of this invention. It is the top view which showed the stator provided with the stator core which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the stator core which concerns on embodiment of this invention. It is a top view explaining the connection structure of the segment which comprises the stator core which concerns on embodiment of this invention. It is the longitudinal cross-sectional view which showed the stator iron core by which the projection part is not provided in the electromagnetic steel plate of the teeth part. It is the longitudinal cross-sectional view which showed the state which the tension | tensile_strength by winding acted on the stator core shown in FIG. It is explanatory drawing which showed the relationship between the clearance gap between the lamination | stacking by the crimping junction part of the stator core which concerns on embodiment of this invention, and the clearance gap formed by a projection part. (A) is the elements on larger scale which showed the crimping junction part provided in the electromagnetic steel plate of a core back part, (b) is the elements on larger scale which showed the projection part provided in the electromagnetic steel plate of a teeth part. (A) is the top view of the segment which showed the structure which provided the protrusion part in parallel in radial direction in the clearance gap between lamination | stacking of the stator core which concerns on embodiment of this invention, (b) is directed to (a) FIG. It is explanatory drawing which showed schematically the principal part of the metal mold | die for shape | molding the projection part of the stator core which concerns on embodiment of this invention.

Embodiment.
Hereinafter, a stator core 1 according to an embodiment of the present invention and an electric motor 100 including the stator core will be described with reference to FIGS. FIG. 1 is a longitudinal sectional view of an electric motor provided with a stator core according to an embodiment of the present invention. A stator core 1 according to the present embodiment constitutes a stator 10 used in an electric motor 100, as shown in FIG. The electric motor 100 includes, for example, an annular stator 10 that is fixedly supported on the inner wall surface of the sealed container 100a by shrink fitting or the like, and a rotor 20 that is rotatably attached to the inner surface of the stator 10. Has been.

As shown in FIG. 1, the rotor 20 is inserted into a rotor core 21 configured by laminating a plurality of electromagnetic steel sheets punched into a predetermined shape, and a permanent hole inserted into an insertion hole provided in the rotor core 21. A magnet 22 is provided, and is fixed to a shaft portion 23 such as a compression mechanism portion by shrink fitting or the like. The rotor 20 rotates upon receiving a rotational force from the rotating magnetic field generated by the stator 10.

FIG. 2 is a plan view showing a stator including the stator core according to the embodiment of the present invention. FIG. 3 is a longitudinal sectional view of the stator core according to the embodiment of the present invention. As shown in FIG. 2, the stator 10 includes a stator core 1 and windings 8 wound around the stator core 1. As shown in FIGS. 2 and 3, the stator core 1 is formed by laminating a plurality of thin electromagnetic steel plates 2 (11 in the illustrated example) having a thickness of about 0.1 mm to 0.7 mm as an example. The core back portion 3 is formed in an annular shape, and includes a plurality of teeth portions 4 that extend inward from the core back portion 3 and can be wound with the winding 8. In addition, the number of the electromagnetic steel plates 2 illustrated is an example, and is appropriately changed as necessary.

FIG. 4 is a plan view illustrating a connecting structure of segments constituting the stator core according to the embodiment of the present invention. As shown in FIGS. 2 and 4, the stator core 1 is configured by connecting a substantially T-shaped segment 11 (divided core) obtained by dividing the core back portion 3 into nine in the annular direction. . The adjacent segments 11 are connected to the adjacent segments 11 so as to be rotatable. Specifically, the electromagnetic steel plates 2 in the core back portions 3 of the adjacent segments 11 are alternately overlapped at the end portions of the core back portions 3, and a common pin hole is formed at the overlapped portion, and the pin hole has a pin. It is inserted and pin-coupled 7. Therefore, the stator core 1 according to the present embodiment is not limited to the annular shape shown in FIG. 2, and can be changed to various shapes such as an inverted annular shape or a straight shape by rotating each segment 11. it can. The adjacent segments 11 may be configured to be integrated with each other by welding the edge portions of the adjacent core back portions 3. Or the structure which provided the uneven | corrugated fitting part which the adjacent segments 11 fit in in the edge part of the core back part 3 may be sufficient.

The core back part 3 of each segment 11 has a caulking joint part 5 by V caulking that fixes the electromagnetic steel sheets 2 adjacent to each other in the stacking direction at two positions, as shown in FIGS. Each segment 11 is subjected to insulation treatment by an insulating material 6 such as paper or resin sheet having an insulating function. A winding 8 (concentrated winding) is wound on the tooth portion 4 of each segment 11 from above the insulating material 6. A slot is formed between adjacent teeth 4, and the slot is a storage space for the winding 8. As the winding 8, a magnet wire or the like in which an insulating film is applied to the outside of the copper wire is used.

Here, the caulking structure will be described. In the stator core 1 of the present embodiment, a caulking joint portion 5 by V caulking that cuts and bends the electromagnetic steel plate 2 and fastens a plurality of electromagnetic steel plates 2 with projections having a thickness greater than or equal to the thickness is provided as a core back portion. 3 is given. As another caulking structure, there is a structure in which a circular protrusion called a round caulking is formed, and magnetic plates adjacent in the stacking direction are fastened in a press-fit relationship. Further, there are a round V-shaped caulking structure in which a semicircle is obliquely deformed as a similar shape of a round caulking, and a square caulking structure similar to a round caulking as a caulking of a plate thickness or less.

The V-caulking structure has a large fastening force in the same joint area as compared with the round caulking structure, etc., but there is a tendency for the gap between the layers to increase. In addition, any of the above caulking structures is a fastening method using press-fitting of the caulking deformed portion, and there is a drawback that distortion and stress of the stator core due to press-fitting of the convex portion and the concave portion are increased, and magnetic characteristics are deteriorated.

In the stator core 1 of the present embodiment, in view of the characteristics of the caulking structure, the electromagnetic steel plate 2 of the core back portion 3 of each segment 11 is joined by V caulking, and the electromagnetic steel plate 2 of the tooth portion 4 is formed in a flat plate shape. In this configuration, the number of crimps is reduced to suppress distortion and stress due to press-fitting of the convex portion and the concave portion. However, the joining in the core back part 3 of each segment 11 is not limited to V caulking, and may be round caulking, square caulking, or the like.

FIG. 5 is a longitudinal sectional view showing a stator core in which no protrusion is provided on the electromagnetic steel plate of the tooth portion. FIG. 6 is a longitudinal sectional view showing a state in which tension by winding acts on the stator core shown in FIG. As shown in FIG. 5, in the stator core 1, a gap is generated between the core back portion 3 and the teeth portion 4 by the caulking joint portion 5. Therefore, as shown in FIG. 6, when the winding 8 is wound around the tooth portion 4, the gap between the laminations of the core back portion 3 is maintained at the caulking joint portion 5. It is wound by the tension F. This winding shrinkage is bent from the core back part 3 toward the tooth part 4, and the tips on the inner diameter side of the tooth parts 4 adjacent in the stacking direction are deformed so that there is no gap between the adjacent tooth parts 4. . When the stator core 1 is wound and contracted, the winding 8 cannot be wound to a target position, and manufacturing defects such as winding disturbance occur, which affects the manufacturing quality.

Moreover, the outer diameter and inner diameter of the stator core 1 are deformed by winding and shrinking, and when the segments 11 are arranged in an annular shape, the outer diameter and inner diameter are barrel-shaped. As a result, the inner core roundness and cylindricity of the stator core 1 are deteriorated, the air gap between the rotor 20 and the stator 10 is non-uniform, and the motor characteristics are adversely affected.

Therefore, the stator core 1 of the present embodiment has the configuration shown in FIGS. Specifically, the stator iron core 1 forms the electromagnetic steel plate 2 in the teeth part 4 of each segment 11 in a flat plate shape, and the electromagnetic steel plates 2 adjacent to each other in the stacking direction are not joined. Further, the stator core 1 is provided with dowel-shaped protrusions 9 in some of the plurality of gaps formed between the electromagnetic steel plates 2 in the tooth portion 4, and the stacking width D 1 of the core back portion 3 The stacking width D2 of the tooth portion 4 to which the tension F is applied by winding the winding 8 is made equal. The protruding portion 9 is formed integrally with the electromagnetic steel plate 2 and has a configuration in which a convex portion 9a is formed on one surface of the electromagnetic steel plate 2 and a concave portion 9b is formed on the other surface.

FIG. 7 is an explanatory diagram showing the relationship between the gap between the stacked layers by the caulking joint of the stator core according to the embodiment of the present invention and the gap formed by the protrusion. The protrusion 9 has a size in which the dimension of the gap amount X2 formed by the protrusion 9 is equal to the product of the gap amount X1 of each gap between the laminations of the core back part 3 and the number n of laminations of the electromagnetic steel sheets 2. Formed with. In the case of the stator core 1 of the embodiment shown in FIG. 7, as an example, six electromagnetic steel plates 2 are set as one set, and the lamination width L1 of the core back portion 3 and the lamination width L2 of the teeth portion 4 are equivalent. It is configured as follows.

FIG. 8A is a partially enlarged view showing a caulking joint provided on the electromagnetic steel sheet in the core back part. FIG.8 (b) is the elements on larger scale which showed the projection part provided in the electromagnetic steel plate of a teeth part. As shown in FIG. 8A, in the caulking joint portion 5 of the core back portion 3, the difference α (outer diameter B−inner diameter A) between the outer diameter B of the convex portion and the inner diameter A of the concave portion may be 0 or less. . However, the protrusion 9 provided on the electromagnetic steel plate 2 of the tooth portion 4 needs to have such a size that the tooth portion 4 is not deformed by winding of the winding 8. This is because the lamination width D2 of the tooth portion 4 cannot be made equal to the lamination width D1 of the core back portion 3 if the protrusion 9 is deformed by the tension F of the winding 8. Therefore, in the stator core 1 of the present embodiment, as shown in FIG. 8B, the difference α between the outer diameter C of the protrusion 9a and the inner diameter A of the recess 9b (outer diameter C−inner diameter). A) is configured to be larger than 1/3 of the thickness t of the electromagnetic steel sheet 2, and the strength of the protrusion 9 against the tension F of the winding 8 is increased.

It is preferable that the side surface of the protruding portion 9 has a shape that is perpendicular or inclined with respect to the upper surface of the electromagnetic steel sheet 2. The side surface of the protruding portion 9 can also be constituted by an embossed spherical surface or the like. However, if the side surfaces of the protrusions 9 are spherical, maintenance of the mold blade is not performed by conventional planar polishing, and there is a problem in operation management. Therefore, in the stator core 1 of the present embodiment, the operation management in manufacturing is performed as usual, and the protruding portion 9 is formed with a flat tip-shaped punch that is advantageous in terms of maintainability and cost.

FIG. 9A is a plan view of a segment showing a configuration in which protrusions are provided in parallel in the radial direction in the gaps between the stacked stator cores according to the embodiment of the present invention. FIG. 9B is a cross-sectional view taken along the line XX indicated in FIG. As shown in FIG. 9, a plurality of protrusions 9 (two in the illustrated example) may be provided in parallel in the radial direction in the same electromagnetic steel sheet 2. The stator core 1 is provided with a plurality of protrusions 9 in the radial direction, so that even when the electromagnetic steel sheet 2 is thin or the teeth 4 are long, the stator core 1 is bent by the tension of the winding 8. Deformation can be suppressed. The arrangement and number of the protrusions 9 are not limited to the embodiment shown in FIG. For example, three or more protrusions 9 may be provided, or may be provided in parallel in the annular direction. However, it is preferable to provide a plurality of protrusions 9 in parallel in the radial direction because of the influence of magnetic flux density.

FIG. 10 is an explanatory view schematically showing the main part of a mold for forming the protrusions of the stator core according to the embodiment of the present invention. As shown in FIG. 10, the protruding portion 9 includes a cam structure 401 that forms a protruding shape at a target position of the electromagnetic steel sheet 2 in the tooth portion 4, and a forming punch 402 that operates up and down with respect to the cam structure 401. The mold 400 is formed. The mold 400 is configured such that the molding punch 402 can automatically switch the presence / absence of molding of the protruding portion 9 by automatic control by a press, and intermittently molds the protruding shape at an arbitrary timing.

In the stator core 1 according to the present embodiment, the protrusions 9 are intermittent at the target position of the teeth portion 4 such as one for every six magnetic steel plates 2 by automatic control of the press machine in the mold 400. The gap between the stacks of the core back portion 3 is formed in accordance with the actual measurement value (the difference between the product of the thickness of each electromagnetic steel sheet and the number of stacks n and the actual stacking width). can do. Therefore, when the winding 8 is wound, the stator core 1 can adjust the number of the electromagnetic steel plates 2 having a protruding shape according to the winding shrinkage to a target interval even during press production. In addition, the stator core 1 can adjust the number of intermittent operations by remote operation even during press production according to the state of the gap between the laminations of the caulking joints 5 of the core back part 3, and can obtain a target lamination width. .

In addition, as a structure which forms a clearance gap between the adjacent electromagnetic steel plates 2 in the tooth part 4, for example, the inner diameter side of the ring which is the tip of the tooth part 4 may be laser-welded intermittently or continuously inside the mold 400. However, in terms of magnetic characteristics, eddy currents are generated between the welded surface formed on the inner diameter side of the annular ring and the crimped joint 5 provided on the core back portion 3, and the performance deteriorates. Protrusions 9 are preferably provided.

Further, a thin plate for adjusting the stacking width D1 of the core back portion 3 and the stacking width D2 of the teeth portion 4 from the outside may be sandwiched between the adjacent electromagnetic steel plates 2 in the teeth portion 4. However, since the process of inserting a thin plate is newly required, the installation for that is needed. Therefore, the dowel-shaped protrusions 9 that can be formed at the same time as the lamination within the mold 400 are advantageous in terms of manufacturing cost.

Therefore, in the stator core 1 of the present embodiment, the electromagnetic steel plates 2 of the teeth portion 4 are formed in a flat plate shape, and the electromagnetic steel plates 2 adjacent to each other in the stacking direction are not joined to each other. The permeability does not decrease due to the distortion and stress caused by the press-fitting of the recess, and the insulation treatment is not destroyed. Further, since the stator core 1 is provided with the protruding portions 9 in some of the plurality of gaps formed between the plurality of electromagnetic steel plates 2 in the tooth portion 4, the laminated width D <b> 1 of the core back portion 3. And the lamination | stacking width | variety D2 of the teeth part 4 which tension F acted by winding of the coil | winding 8 can be made equivalent, and winding shrinkage can be suppressed. Therefore, the winding 8 can be wound to a target position, and manufacturing defects such as winding disturbance can be reduced. In addition, since the winding quality can be improved and the number of rework steps and in-process defects can be reduced, a high-quality electric motor can be provided. Furthermore, since the stator core 1 of this Embodiment can oppose the pressure at the time of laminating | stacking the electromagnetic steel plate 2 in the metal mold | die 400 with the projection part 9, it can suppress that a lamination | stacking space | interval shrinks. .

Further, in the stator core 1 according to the present embodiment, even when the tension of the winding 8 varies depending on the diameter of the concentrated winding or the material of the winding 8, the protrusion has a size corresponding to the winding 8. By setting the portion 9, the stacking width D <b> 1 of the core back portion 3 and the stacking width D <b> 2 of the tooth portion 4 can be made equal, so that stable winding 8 arrangement is possible.

Further, in the stator core 1 of the present embodiment, the protruding portion 9 has a convex portion 9a formed on one surface of the electromagnetic steel plate 2, and a concave portion 9b formed on the other surface, and the outer diameter C of the convex portion 9a. Since the difference between the inner diameter A of the recess 9b is larger than 1/3 of the thickness t of the electromagnetic steel sheet 2, the strength of the protrusion 9 against the tension F of the winding 8 can be increased.

Further, the stator core 1 according to the present embodiment is provided when the electromagnetic steel sheet 2 is thin or the teeth part 4 is long by providing a plurality of protrusions 9 arranged in parallel in the radial direction. Even so, it is possible to suppress the bending deformation of the winding 8 due to the tension F.

In addition, the stator core 1 according to the present embodiment has a configuration in which the segments 11 adjacent to each other in the annular direction are pin-coupled 7 so as to be rotatable with respect to the adjacent segments 11. Thus, it can be changed into various shapes such as an inverted annular shape and a straight shape.

Further, the stator core 1 of the present embodiment has a configuration in which the tooth portion 4 is subjected to an insulation treatment by an insulating material 6 made of a paper material or a resin sheet having an insulating function and wound by a winding 8. The insulation between the winding 8 and the tooth portion 4 is good.

Although the present invention has been described above based on the embodiment, the present invention is not limited to the configuration of the embodiment described above. For example, although the core back part 3 showed embodiment comprised by the some segment divided | segmented in the annular direction, it may be divided | segmented into a segment and may be donut shape. Further, the dowel-shaped protruding portion 9 can be applied to any shape other than the illustrated round shape, such as a square shape. Moreover, although the protrusion part 9 may be equally arrange | positioned at the teeth part 4 of each segment 11, especially when the junction part of the core back parts 3 is provided only in one side, the electromagnetic wave which has the protrusion part 9 is provided. By increasing the number of the steel plates 2, it is possible to individually adjust the change in the lamination width between the tooth portions 4, and the difference between the tooth portions 4 can be suppressed. In short, it should be noted that the scope (technical scope) of the present invention also includes the scope of various modifications, applications, and uses made by those skilled in the art as needed.

1 stator core, 2 electromagnetic steel plate, 3 core back part, 4 teeth part, 5 crimping joint, 6 insulation material, 7 pin connection, 8 winding, 9 protrusion, 9a protrusion, 9b recess, 10 stator, 11 segments, 20 rotors, 21 rotor cores, 22 permanent magnets, 23 shafts, 100 motors, 100a sealed containers, 400 molds, 401 cam mechanisms, 402 molding punches.

Claims

A stator core comprising a plurality of electromagnetic steel plates laminated and comprising an annular core back portion and a plurality of teeth portions extending inwardly from the core back portion and wound with windings. And
The core back portion has a crimped joint portion to which the electromagnetic steel plates adjacent in the stacking direction are fixed,
The electrical steel sheet of the teeth part is formed in a flat plate shape,
A stator core in which a protrusion is provided in a part of a plurality of gaps formed between the plurality of electromagnetic steel plates in the tooth portion.
The stator core according to claim 1, wherein the protrusion is formed integrally with the electromagnetic steel plate.
3. The stator core according to claim 2, wherein the protrusion has a convex portion formed on one surface of the electromagnetic steel sheet and a concave portion formed on the other surface.
The stator core according to claim 3, wherein a difference between an outer diameter of the convex portion and an inner diameter of the concave portion is larger than 1/3 of a thickness of the electromagnetic steel sheet.
The stator core according to any one of claims 1 to 4, wherein a plurality of the protrusions are arranged in parallel in the radial direction.
The core back part is composed of a plurality of segments divided in an annular direction,
The stator core according to any one of claims 1 to 5, wherein the segments adjacent in the annular direction are rotatably connected to the adjacent segments.
The core back part is composed of a plurality of segments divided in an annular direction,
The stator core according to any one of claims 1 to 5, wherein the segments adjacent in the annular direction are connected by welding.
The teeth portion is subjected to insulation treatment by an insulating material made of a paper material or a resin sheet having an insulating function,
The stator core according to any one of claims 1 to 7, wherein the winding is wound around the tooth portion that has been subjected to the insulation treatment.
An electric motor comprising the stator core according to any one of claims 1 to 8.