JP6723348B2 - Stator core and electric motor equipped with the stator core - Google Patents

Description

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

Generally, the stator core constitutes a stator used in an electric motor or a rotating machine. The stator core is formed by laminating a plurality of electromagnetic steel plates, and includes a ring-shaped core back portion and a plurality of teeth portions that extend inward from the core back portion. Insulation is applied to the teeth portion and the winding is wound.

For example, in the stator core disclosed in Patent Document 1, electromagnetic steel sheets adjacent to each other in the stacking direction are caulked at the core back portion and the teeth portion. However, in the stator core, due to the distortion due to the press-fitting of the caulking convex portion and the concave portion in the teeth portion, the influence of stress, the magnetic permeability is lowered, the insulation treatment is further destroyed, and the fracture surfaces of the electromagnetic steel sheets come into contact with each other. Eddy current is generated between the stacked layers, increasing iron loss and deteriorating magnetic characteristics, which adversely affects motor characteristics. On the other hand, the stator core is deformed as if it were crushed due to the winding shrinkage caused by the tension of the winding unless the teeth are caulked. When the winding shrinkage occurs, the winding cannot be wound at the target position, and manufacturing defects such as winding disorder occur, which affects the manufacturing quality.

Therefore, in the stator core disclosed in Patent Document 2, the electromagnetic steel sheets that are adjacent to each other in the stacking direction are caulked at the core back portion, and the electromagnetic steel sheets that are adjacent to each other in the stacking direction at the teeth portion are fitted together leaving a gap. It is configured to have parts. Further, the stator core disclosed in Patent Document 3 has a configuration in which a protrusion for a gap is provided on each laminated core plate to secure a minute gap between the 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 concavo-convex portions continuously in the laminating direction on each electromagnetic steel plate of the teeth portion, and a gap is formed between the laminations of the teeth portions to suppress shrinkage due to windings. It is a configuration that does. Further, Patent Document 3 has a configuration in which a minute gap is provided between the laminated iron core plates to reduce iron loss due to eddy current. However, the required gap between the laminated layers is 1 μm to 5 μm and is determined by the shape accuracy of the tip of the blade to be formed. Therefore, in order to form a gap between stacked layers by providing, for example, an emboss on each electromagnetic steel sheet, high-precision processing is required, and processing costs and maintainability of the blade become problems. 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 at the target position. However, manufacturing defects such as disordered winding occur.

The present invention has been made to solve the above problems, and is provided with a stator core that can suppress winding shrinkage due to windings without caulking the electromagnetic steel sheets of the teeth portion, and a stator core thereof. The purpose 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, and a plurality of teeth portions extending inward from the core back portion and windings wound around. , The core back portion has a caulking joint portion for fixing the electromagnetic steel sheets adjacent to each other in the stacking direction, and the electromagnetic steel sheet of the teeth portion is formed into a flat plate shape. The magnetic steel sheets are not joined to each other, and some of the plurality of gaps formed between the plurality of magnetic steel sheets in the teeth portion have a protrusion that abuts a flat surface of the magnetic steel sheet. A plurality of the protrusions are provided in parallel in the radial direction .

According to the present invention, the electromagnetic steel sheet of the tooth portion is formed in a flat plate shape, and the protrusion is provided in a part of the plurality of gaps formed between the plurality of electromagnetic steel sheets of the tooth portion. It is possible to make the lamination width of the core back portion equal to the lamination width of the teeth portion on which the tension is applied by winding the winding, and it is possible to suppress winding shrinkage.

It is a longitudinal cross-sectional view of an electric motor provided with a stator core according to an embodiment of the present invention. It is a top view showing a stator provided with a stator core concerning an embodiment of the invention. It is a longitudinal cross-sectional view of a stator core according to an embodiment of the present invention. It is a top view explaining the connecting structure of the segment which constitutes the stator core concerning the embodiment of the invention. It is a longitudinal cross-sectional view showing a stator core in which a protrusion is not provided on an electromagnetic steel plate of a tooth portion. FIG. 6 is a vertical cross-sectional view showing a state where tension is applied to the stator core shown in FIG. 5 by a winding. It is explanatory drawing which showed the relationship between the clearance gap between the lamination|stacking by the crimp joint part of the stator core which concerns on embodiment of this invention, and the clearance gap formed by a protrusion part. (A) is a partially enlarged view showing a caulking joint portion provided on an electromagnetic steel sheet of a core back portion, and (b) is a partially enlarged view showing a protrusion portion provided on an electromagnetic steel sheet of a tooth portion. (A) is a plan view of a segment showing a configuration in which protrusions are arranged in a radial direction in parallel with each other in a gap between the laminated stator cores according to the embodiment of the present invention; It is the XX sectional view taken. It is explanatory drawing which showed roughly the principal part of the metal mold|die for shape|molding the protrusion part of the stator core which concerns on embodiment of this invention.

Embodiment.
Below, the stator core 1 which concerns on embodiment of this invention, and the electric motor 100 provided with the stator core are demonstrated based on FIGS. FIG. 1 is a vertical cross-sectional view of an electric motor including a stator core according to an embodiment of the present invention. As shown in FIG. 1, the stator core 1 according to the present embodiment constitutes a stator 10 used in an electric motor 100. The electric motor 100 includes, for example, an annular stator 10 that is fixedly supported on the inner wall surface of the closed container 100a by shrink fitting, etc., and a rotor 20 that is rotatably attached to face the inner surface of the stator 10. Has been done.

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

FIG. 2 is a plan view showing a stator provided with a stator core according to the embodiment of the present invention. FIG. 3 is a vertical cross-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 case of the illustrated example) having a plate thickness of about 0.1 mm to 0.7 mm as an example. The core back portion 3 is formed and has an annular shape, and a plurality of teeth portions 4 extending inward from the core back portion 3 and around which the winding 8 is wound. Note that the number of the electromagnetic steel plates 2 shown is an example, and may be changed as needed.

FIG. 4 is a plan view illustrating a connecting structure of segments that form 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 the core back part 3 to nine substantially T-shaped segments 11 (split cores) that are divided into nine in the annular direction. .. The adjacent segments 11 are rotatably connected to the adjacent segment 11. Specifically, the electromagnetic steel sheets 2 in the core back portions 3 of the adjacent segments 11 are alternately overlapped at the end portion of the core back portion 3, a common pin hole is formed in the overlapped portion, and the pin is formed in the pin hole. It is inserted and pin-connected 7. Therefore, the stator core 1 according to the present embodiment is not limited to the annular shape shown in FIG. 2, but can be changed into various shapes such as an inverted annular shape or a linear shape by rotating each segment 11. it can. In addition, the adjacent segments 11 may be integrally formed by welding the edge portions of the adjacent core back portions 3. Alternatively, a configuration may be adopted in which a concavo-convex fitting portion where adjacent segments 11 are fitted to each other is provided at the end portion of the core back portion 3.

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

Here, the caulking structure will be described. In the stator core 1 of the present embodiment, the electromagnetic steel plate 2 is subjected to cutting and bending work, and the caulking joint portion 5 by V-caulking for fastening the plurality of electromagnetic steel plates 2 with the projections having a plate thickness or more is the core back portion. It is applied to 3. As another caulking structure, there is a structure in which a circular protrusion called a circular caulking is formed and magnetic plates adjacent to each other in the stacking direction are fastened to each other in a press-fitting relationship. Further, as a shape similar to the round caulking, there is a round V-shaped caulking structure in which a semicircle is obliquely deformed, and a corner caulking structure similar to the round caulking is used as the caulking having 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, but the gap between the stacked layers tends to increase. Further, any of the caulking structures described above is a fastening method using press-fitting of the caulking deformed portion, and there is a drawback that distortion and stress of the stator iron core due to press-fitting of the convex portion and the concave portion increase, and magnetic characteristics deteriorate.

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

FIG. 5 is a vertical cross-sectional view showing a stator core in which the protrusions are not provided on the electromagnetic steel plates of the teeth portion. FIG. 6 is a vertical cross-sectional view showing a state in which tension is applied to the stator core shown in FIG. 5 by windings. In the stator core 1, as shown in FIG. 5, the caulking joint portion 5 causes a gap between the core back portion 3 and the tooth portion 4 to be laminated. Therefore, as shown in FIG. 6, when the winding wire 8 is wound around the teeth portion 4, the gap between the laminated layers of the core back portion 3 is maintained at the caulking joint portion 5, but the teeth portion 4 is wound around the winding portion 8. The tension F causes it to shrink. This crimping bends from the core back portion 3 toward the tooth portion 4, and the tips on the inner diameter side of the tooth portions 4 adjacent in the stacking direction are deformed so that there is no gap between the adjacent tooth portions 4. .. When the shrinkage of the stator core 1 occurs, the winding 8 cannot be wound at a target position, and manufacturing defects such as winding disorder occur, which affects the manufacturing quality.

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

Therefore, the stator core 1 of the present embodiment has the configuration shown in FIGS. 3 and 4. Specifically, in the stator core 1, the electromagnetic steel plates 2 in the teeth portion 4 of each segment 11 are formed into a flat plate shape, and the electromagnetic steel plates 2 adjacent to each other in the stacking direction are not joined. Further, in the stator core 1, the dowel-shaped protrusions 9 are provided in some of the plurality of gaps formed between the electromagnetic steel plates 2 in the teeth portion 4 to form the lamination width D1 of the core back portion 3. , The lamination width D2 of the tooth portion 4 on which the tension F acts by the winding of the winding wire 8 is made equal. The protrusion 9 is integrally formed 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 sheet 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 stacks formed by the crimp joints of the stator core according to the embodiment of the present invention and the gap formed by the protrusions. In the protrusion 9, the dimension of the gap X2 formed by the protrusion 9 is equal to the product of the gap X1 of each gap between the laminated layers of the core back portion 3 and the number of laminated sheets n −1 of the electromagnetic steel plates 2. Formed in size. In the case of the stator core 1 of the embodiment shown in FIG. 7, as an example, the 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 equal. Is configured as follows.

FIG. 8A is a partially enlarged view showing a caulking joint portion provided on the electromagnetic steel plate of the core back portion. FIG. 8B is a partial enlarged view showing the protrusions provided on the electromagnetic steel plate of the teeth portion. 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 protrusions 9 provided on the electromagnetic steel plate 2 of the teeth 4 need to have a size such that the teeth 4 are not deformed by the 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 of the protrusion 9 and the inner diameter A of the recess 9b (outer diameter C−inner diameter). A) is set to be larger than 1/3 of the plate thickness t of the electromagnetic steel plate 2 to increase the strength of the protrusion 9 against the tension F of the winding 8.

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 plate 2. The side surface of the projecting portion 9 can also be configured by a spherical surface having an embossed shape or the like. However, if the side surface of the protruding portion 9 is made spherical, maintenance of the die blade is not performed by the conventional flat polishing, which causes 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 projection 9 is formed by a punch having a flat tip shape which is advantageous in terms of maintainability and cost.

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

FIG. 10: is explanatory drawing which showed roughly the principal part of the metal mold|die for shape|molding the protrusion part of the stator core which concerns on embodiment of this 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 plate 2 in the tooth portion 4, and a forming punch 402 that moves vertically with respect to the cam structure 401. It is molded by the mold 400. The mold 400 is configured such that the molding punch 402 can automatically switch between the presence and absence of the molding of the protrusion 9 by automatic control by a press machine, and the protrusion shape is intermittently formed at an arbitrary timing.

In the stator core 1 of the present embodiment, the protrusions 9 are intermittently provided at the target position of the teeth portion 4 by the automatic control of the press machine in the mold 400, for example, one for every six electromagnetic steel plates 2. Therefore, an arbitrary interval is configured in accordance with the actual measurement value of the gap between the laminated layers of the core back portion 3 (the difference between the product of the thickness of one electromagnetic steel sheet and the number of laminated sheets n and the actual laminated width). can do. Therefore, in the stator core 1, when the winding 8 is wound, the number of the electromagnetic steel plates 2 having the protrusion shape according to the shrinkage can be adjusted to the target interval even during press production. Further, in the stator core 1, the number of intermittences can be adjusted by remote control even during press production, depending on the state of the gap between the laminations of the crimp joints 5 of the core back portion 3, and a target lamination width can be obtained. ..

In addition, as a configuration for forming a gap between the adjacent electromagnetic steel plates 2 in the teeth portion 4, for example, the inner diameter side of the ring, which is the tip of the teeth portion 4, may be intermittently or continuously laser-welded inside the die 400. However, in terms of magnetic characteristics, eddy current is generated between the welding surface formed on the inner diameter side of the ring and the caulking joint portion 5 provided on the core back portion 3, and the performance deteriorates. It is preferable to provide the protrusion 9.

Further, a thin plate for adjusting the lamination width D1 of the core back portion 3 and the lamination width D2 of the teeth portion 4 may be sandwiched from the outside in the gap between the adjacent electromagnetic steel plates 2 in the teeth portion 4. However, since a new step of inserting the thin plate is required, equipment for that is required. Therefore, the dowel-shaped protrusion 9 that can be formed at the same time as being stacked inside the die 400 at high speed is advantageous in terms of manufacturing cost.

Therefore, in the stator core 1 of the present embodiment, since 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, the convex portions of caulking are formed. The permeability and the stress due to the press-fitting of the recesses do not lower the magnetic permeability and the insulation process is not destroyed. Further, in the stator core 1, since the protrusions 9 are provided in a part of the plurality of gaps formed between the plurality of electromagnetic steel plates 2 in the tooth portion 4, the lamination width D1 of the core back portion 3 is provided. And the lamination width D2 of the tooth portion 4 on which the tension F acts due to the winding of the winding wire 8 can be made equal, and the winding shrinkage can be suppressed. Therefore, the winding 8 can be wound at a target position, and manufacturing defects such as winding disorder can be reduced. In addition, the winding quality can be improved, and the number of repair work and in-process defects can be reduced, so that a high-quality electric motor can be provided. Furthermore, since the stator core 1 of the present embodiment can face the pressure when the electromagnetic steel plates 2 are stacked in the mold 400 by the protrusions 9, it is possible to suppress the stacking interval from being shortened. ..

Further, in the stator core 1 of the present embodiment, even if the winding 8 has a tension that varies depending on the diameter of the concentrated winding or the material of the winding 8, a protrusion having a size corresponding to the winding 8 is formed. By setting the portion 9, the laminated width D1 of the core back portion 3 and the laminated width D2 of the tooth portion 4 can be made equal to each other, so that the windings 8 can be stably arranged.

In addition, in the stator core 1 of the present embodiment, the protrusion 9 has the convex portion 9a formed on one surface of the electromagnetic steel plate 2 and the concave portion 9b formed on the other surface, and the outer diameter C of the convex portion 9a is C. And the inner diameter A of the recess 9b is larger than 1/3 of the thickness t of the electromagnetic steel plate 2, the strength of the protrusion 9 with respect to the tension F of the winding 8 can be increased.

In addition, the stator core 1 of the present embodiment is provided when the projections 9 are arranged in parallel in the radial direction and a plurality of the projections 9 are provided, so that the electromagnetic steel plate 2 has a small thickness or the teeth 4 have a long length. However, it is possible to suppress the bending deformation of the winding 8 due to the tension F.

Further, since the stator core 1 of the present embodiment is configured such that the segments 11 that are adjacent to each other in the annular direction are rotatably pin-connected to the adjacent segments 11, the segments 11 are rotated. Therefore, it can be changed into various shapes such as an inverted circular shape and a linear shape.

Further, in the stator core 1 of the present embodiment, the teeth portion 4 is configured to be insulated by the insulating material 6 made of a paper material or a resin sheet having an insulating function and wound around the winding wire 8. The insulation between the winding wire 8 and the tooth portion 4 is improved.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the configurations of the above-described embodiments. For example, although the core back portion 3 has been shown in the embodiment including a plurality of segments divided in the annular direction, the core back portion 3 may have a donut shape without being divided into the segments. Further, the dowel-shaped protrusion 9 can be applied in any shape such as a square shape other than the illustrated round shape. The protrusions 9 may be evenly arranged on the teeth 4 of each segment 11, but if the joint between the core back portions 3 is provided only on one side, the electromagnetic waves having the protrusions 9 may be formed. By increasing the number of the steel plates 2, it becomes possible to individually adjust the change in the stacking width between the tooth portions 4, and it is possible to suppress the difference between the tooth portions 4. As mentioned above, it should be noted that, in short, various modifications, applications, and utilization ranges that are required by those skilled in the art are included in the gist (technical range) of the present invention.

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

Claims (8)

A stator core comprising a plurality of laminated electromagnetic steel sheets, the stator core having an annular core back portion, and a plurality of teeth portions extending inward from the core back portion and around which windings are wound. hand,
The core back portion has a caulking joint portion in which the electromagnetic steel plates adjacent to each other in the stacking direction are fixed,
The electromagnetic steel plate of the teeth portion is formed in a flat plate shape, the electromagnetic steel plates are not joined ,
A part of the plurality of gaps formed between the plurality of electromagnetic steel plates in the tooth portion, a protrusion that abuts the flat surface of the electromagnetic steel plate is provided,
The said stator part is a stator iron core provided in parallel along with the radial direction . The stator core according to claim 1, wherein the protrusion has a convex portion formed on one surface of the electromagnetic steel plate and a concave portion formed on the other surface. The stator core according to claim 2, 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 plate thickness of the electromagnetic steel plate. The protrusions stator core according to any one of claims 1 to 3 which is formed integrally with the electromagnetic steel sheet. The core back portion is composed of a plurality of segments divided in the annular direction,
The segments adjacent in the annular direction, the stator core according to any one of claims 1 to 4 which is pivotally connected to the adjacent segments. The core back portion is composed of a plurality of segments divided in the annular direction,
Stator core according to any one of claims 1 to 4, wherein said segments to each other are connected by welding adjacent annular direction. The teeth portion is subjected to insulation treatment with an insulating material made of a paper material or a resin sheet having an insulating function,
The insulation treatment is decorated with stator core according to any one of claims 1 to 6, wherein the windings are wound around the teeth. Motor having a stator core according to any one of claims 1-7.

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