Invention title: Laminated core and rotary electric machine
Technical field
[0001]
The present invention relates to a laminated core and a rotary electric machine.
The present application claims priority based on Japanese Patent Application No. 2018-235861 filed in Japan on December 17, 2018, the contents of which are incorporated herein by reference.
Background technology
[0002]
Conventionally, a laminated core as described in Patent Document 1 below has been known. In this laminated core, electromagnetic steel sheets adjacent to each other in the laminated direction are adhered by an adhesive layer.
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2015-142453
Outline of the invention
Problems to be solved by the invention
[0004]
There is room for improvement in improving the magnetic properties of the conventional laminated core.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to improve magnetic characteristics.
Means to solve problems
[0006]
In order to solve the above problems, the present invention proposes the following means.
(1) The first aspect of the present invention is a laminated core including a plurality of electromagnetic steel sheets laminated in the thickness direction, the electromagnetic steel sheet having an annular core back portion, and the outer periphery of the core back portion. An adhesive region is formed on the side, a non-adhesive region is formed on the inner peripheral side of the core back portion, and a plurality of caulking portions are formed at intervals in the circumferential direction in the non-adhesive region of the core back portion. It is a laminated core provided.
[0007]
Generally, the adhesive shrinks as it cures. Therefore, when an adhesive is provided on the electrical steel sheet, compressive stress is applied to the electrical steel sheet as the adhesive cures. When compressive stress is applied, the magnetic steel sheet is distorted. Further, when the crimped portion is provided on the electromagnetic steel sheet, the electromagnetic steel sheet is deformed, so that the electromagnetic steel sheet is distorted. The crimped portion and the adhesive region form a fixed portion. The fixing portion fixes the electromagnetic steel sheets adjacent to each other in the laminating direction. As the area of ​​the fixed portion increases, the strain of the electrical steel sheet increases.
According to this configuration, an adhesive region in which, for example, an adhesive portion, which is an adhesive, is provided is formed only on the outer peripheral side of the core back portion. Therefore, the core back portions of the electromagnetic steel sheets adjacent to each other in the stacking direction are partially adhered to each other. Therefore, for example, the area of ​​the adhesive region formed in the core back portion is reduced as compared with the case where the adhesive region extends inward in the radial direction to the crimped portion. Therefore, the area of ​​the fixed portion in the plan view in the stacking direction is reduced. As a result, the strain generated in the entire laminated core can be reduced. As a result, the iron loss generated in the laminated core can be reduced, and the magnetic characteristics of the laminated core can be improved.
[0008]
(2) In the laminated core according to (1), the outer peripheral side of the core back portion is the outside of the outer peripheral edge of the caulked portion, and the inner peripheral side of the core back portion is the outer peripheral edge of the caulked portion. It may be inside.
According to this configuration, the most inner peripheral portion of the adhesive region does not overlap with the crimped portion at all. Therefore, by fixing the stacking direction at the crimped portion, it is possible to prevent further strain from being applied by providing and fixing the adhesive portion in the region where the magnetic steel sheet is distorted. Therefore, the area of ​​the fixed portion becomes smaller. As a result, the strain generated in the laminated core can be further reduced.
[0009]
(3) In the laminated core according to (2), the outer peripheral side of the core back portion is the outer circumference of the virtual circle formed on the outer peripheral side of the outer peripheral edge of the caulking portion, and the inner circumference of the core back portion. The side may be inside the virtual circle.
According to this configuration, for example, even when the electromagnetic steel sheet has a tooth portion, the adhesive region is not provided in the tooth portion. Therefore, the area of ​​the fixed portion becomes smaller. As a result, the strain generated in the laminated core can be further reduced.
[0010]
(4) In the laminated core according to any one of (1) to (3), the adhesive region may be formed at least in the vicinity of the crimped portion of the outer peripheral edge of the core back portion.
According to this configuration, the adhesive portions are not continuously provided over the entire circumference of the outer edge of the core back portion, but are provided discontinuously (intermittently) at intervals. Therefore, for example, the area of ​​the adhesive region formed in the core back portion is reduced as compared with the case where the adhesive region is formed over the entire circumference. This reduces the area of ​​the fixed portion. Therefore, the strain generated in the entire laminated core can be made smaller.
[0011]
(5) In the laminated core according to any one of (1) to (4), the electromagnetic steel sheets adjacent to each other in the laminated direction are provided in the adhesive region of the core back portion, and the laminated core is provided in the laminated direction. An adhesive portion for adhering the core back portions adjacent to each other may be provided.
According to this configuration, it is possible to reliably bond the electromagnetic steel sheets adjacent to each other in the stacking direction by using the bonding portion.
[0012]
(6) In the laminated core according to (5) above, the average thickness of the bonded portion may be 1.0 μm to 3.0 μm.
[0013]
(7) In the laminated core according to (5) or (6), the average tensile elastic modulus E of the bonded portion may be 1500 MPa to 4500 MPa.
[0014]
(8) In the laminated core according to any one of (5) to (7), the adhesive portion may be a room temperature adhesive type acrylic adhesive containing SGA made of an elastomer-containing acrylic adhesive. ..
[0015]
(9) A second aspect of the present invention is a rotary electric machine including the laminated core according to any one of (1) to (8) above.
According to this configuration, the magnetic characteristics of the rotating electric machine can be improved.
The invention's effect
[0016]
According to the present invention, the magnetic characteristics can be improved.
A brief description of the drawing
[0017]
FIG. 1 is a cross-sectional view of a rotary electric machine according to an embodiment of the present invention.
FIG. 2 is a plan view of a stator included in the rotary electric machine shown in FIG.
FIG. 3 is a side view of a laminated core according to an embodiment of the present invention.
FIG. 4 is a plan view of a first surface of an electromagnetic steel sheet in a laminated core according to an embodiment of the present invention.
FIG. 5 is a plan view of a first surface of an electromagnetic steel sheet in a laminated core according to an embodiment of the present invention.
FIG. 6 is a plan view of a first surface of an electromagnetic steel sheet in a laminated core of a comparative example.
FIG. 7 is a diagram showing relative values ​​of iron loss of laminated cores of Examples 1 and 2 when the iron loss of the laminated cores of Comparative Example is 1.
Mode for carrying out the invention
[0018]
Hereinafter, the laminated core and the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings.
In this embodiment, an electric motor as a rotary electric machine, specifically, an AC electric motor will be described as an example. The AC motor is more specifically a synchronous motor, and more specifically a permanent magnet field type motor. This type of electric motor is suitably used for, for example, an electric vehicle.
[0019]
As shown in FIGS. 1 and 2, the rotary electric machine 10 includes a stator 20, a rotor 30, a case 50, and a rotary shaft 60. The stator 20 and rotor 30 are housed in a case 50. The stator 20 is fixed to the case 50.
In the present embodiment, as the rotary electric machine 10, an inner rotor type rotary electric machine in which the rotor 30 is located inside the stator 20 is used. However, as the rotary electric machine 10, an outer rotor type rotary electric machine in which the rotor 30 is located outside the stator 20 may be used. Further, in the present embodiment, the rotary electric machine 10 is a 12-pole 18-slot three-phase AC motor. However, for example, the number of poles, the number of slots, the number of phases, and the like can be changed as appropriate.
[0020]
The stator 20 includes a stator core 21 and a winding (not shown).
The stator core 21 includes an annular core back portion 22 and a plurality of teeth portions 23. The core back portion 22 is a region surrounded by the outer peripheral edge 22a of the core back portion and the inner peripheral edge 22b (broken line shown in FIG. 2) of the core back portion. Hereinafter, the axial direction of the stator core 21 (core back portion 22) (the central axis O direction of the stator core 21) is referred to as an axial direction. The radial direction of the stator core 21 (core back portion 22) (the direction orthogonal to the central axis O of the stator core 21) is referred to as the radial direction. The circumferential direction of the stator core 21 (core back portion 22) (direction that orbits around the central axis O of the stator core 21) is referred to as a circumferential direction.
[0021]
The core back portion 22 is formed in an annular shape in a plan view of the stator 20 when viewed from the axial direction.
The plurality of tooth portions 23 project from the core back portion 22 in the radial direction (toward the central axis O of the core back portion 22 along the radial direction). The plurality of tooth portions 23 are arranged at equal intervals in the circumferential direction. In the present embodiment, 18 tooth portions 23 are provided at every 20 degrees of the central angle centered on the central axis O. The plurality of tooth portions 23 are formed to have the same shape and the same size as each other.
The winding is wound around the teeth portion 23. The winding may be a centralized winding or a distributed winding.
[0022]
The rotor 30 is arranged inside the stator 20 (stator core 21) in the radial direction. The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32.
The rotor core 31 is formed in an annular shape (annular ring) arranged coaxially with the stator 20. The rotating shaft 60 is arranged in the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31.
The plurality of permanent magnets 32 are fixed to the rotor core 31. In this embodiment, a set of two permanent magnets 32 form one magnetic pole. The plurality of sets of permanent magnets 32 are arranged at equal intervals in the circumferential direction. In the present embodiment, 12 sets (24 in total) of permanent magnets 32 are provided at every 30 degrees of the central angle centered on the central axis O.
[0023]
In this embodiment, an embedded magnet type motor is adopted as a permanent magnet field type motor.
The rotor core 31 is formed with a plurality of through holes 33 that penetrate the rotor core 31 in the axial direction. The plurality of through holes 33 are provided corresponding to the plurality of permanent magnets 32. Each permanent magnet 32 ​​is fixed to the rotor core 31 in a state of being arranged in the corresponding through hole 33. For example, each permanent magnet 32 ​​is fixed to the rotor core 31 by adhering the outer surface of the permanent magnet 32 ​​and the inner surface of the through hole 33 with an adhesive or the like. As the permanent magnet field type motor, a surface magnet type motor may be used instead of the embedded magnet type motor.
[0024]
Both the stator core 21 and the rotor core 31 are laminated cores. The laminated core is formed by laminating a plurality of electromagnetic steel sheets 40.
The product thickness of each of the stator core 21 and the rotor core 31 is, for example, 50.0 mm. The outer diameter of the stator core 21 is, for example, 250.0 mm. The inner diameter of the stator core 21 is, for example, 165.0 mm. The outer diameter of the rotor core 31 is, for example, 163.0 mm. The inner diameter of the rotor core 31 is, for example, 30.0 mm. However, these values ​​are examples, and the product thickness, outer diameter and inner diameter of the stator core 21, and the product thickness, outer diameter and inner diameter of the rotor core 31 are not limited to these values. Here, the inner diameter of the stator core 21 is based on the tip of the teeth portion 23 of the stator core 21. The inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tips of all the teeth portions 23.
[0025]
Each of the electromagnetic steel sheets 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electromagnetic steel sheet as a base material. As the electromagnetic steel sheet 40, a known electrical steel sheet can be used. The chemical composition of the electrical steel sheet 40 is not particularly limited. In this embodiment, a non-oriented electrical steel sheet is used as the electrical steel sheet 40. As the non-oriented electrical steel sheet, for example, a non-oriented electrical steel strip of JIS (Japanese Industrial Standards) C 2552: 2014 can be adopted.
However, as the electromagnetic steel sheet 40, it is also possible to use a grain-oriented electrical steel sheet instead of the non-oriented electrical steel sheet. For the grain-oriented electrical steel sheet, a JIS C 2553: 2012 grain-oriented electrical steel strip can be adopted.
[0026]
To improve the workability of electrical steel sheets and the iron loss of laminated cores Insulating coatings are provided on both sides of the electromagnetic steel sheet 40. As the substance constituting the insulating film, for example, (1) an inorganic compound, (2) an organic resin, (3) a mixture of an inorganic compound and an organic resin, and the like can be applied. Examples of the inorganic compound include (1) a complex of dichromate and boric acid, and (2) a complex of phosphate and silica. Examples of the organic resin include epoxy-based resin, acrylic-based resin, acrylic-styrene-based resin, polyester-based resin, silicon-based resin, and fluorine-based resin.
[0027]
In order to ensure the insulating performance between the electromagnetic steel sheets 40 laminated with each other, the thickness of the insulating film (thickness per one side of the electromagnetic steel sheets 40) is preferably 0.1 μm or more.
On the other hand, as the insulating film becomes thicker, the insulating effect saturates. Further, as the insulating film becomes thicker, the space factor decreases, and the performance as a laminated core deteriorates. Therefore, the insulating coating should be as thin as possible to ensure the insulating performance. The thickness of the insulating film (thickness per one side of the electromagnetic steel sheet 40) is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 2 μm or less.
[0028]
As the electromagnetic steel sheet 40 becomes thinner, the effect of improving iron loss gradually saturates. Further, as the electromagnetic steel sheet 40 becomes thinner, the manufacturing cost of the electrical steel sheet 40 increases. Therefore, the thickness of the electrical steel sheet 40 is preferably 0.10 mm or more in consideration of the effect of improving iron loss and the manufacturing cost.
On the other hand, if the electromagnetic steel sheet 40 is too thick, the press punching operation of the electrical steel sheet 40 becomes difficult.
Therefore, considering the press punching work of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.65 mm or less.
Further, as the electromagnetic steel sheet 40 becomes thicker, the iron loss increases. Therefore, considering the iron loss characteristics of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.35 mm or less. The thickness of the electromagnetic steel sheet 40 is more preferably 0.20 mm or 0.25 mm.
In consideration of the above points, the thickness of each electrical steel sheet 40 is, for example, 0.10 mm or more and 0.65 mm or less. The thickness of each electrical steel sheet 40 is preferably 0.10 mm or more and 0.35 mm or less, and more preferably 0.20 mm or 0.25 mm. The thickness of the electrical steel sheet 40 includes the thickness of the insulating coating.
[0029]
As shown in FIG. 3, the plurality of electromagnetic steel sheets 40 forming the stator core 21 are laminated in the thickness direction. The thickness direction is the thickness direction of the electromagnetic steel sheet 40. The thickness direction corresponds to the stacking direction of the electromagnetic steel sheets 40. The plurality of electromagnetic steel sheets 40 are arranged coaxially with respect to the central axis O. The electromagnetic steel sheet 40 includes a core back portion 22 and a plurality of teeth portions 23.
As shown in FIG. 4, the plurality of electromagnetic steel sheets 40 forming the stator core 21 are fixed to each other by the adhesive portion 41 and the caulking portion 25 provided on the surface (first surface) 40a of the electromagnetic steel sheet 40.
For example, although not shown, the caulking portion 25 is composed of convex portions (dowels) and concave portions formed on the electromagnetic steel plate 40. The convex portion protrudes from the electromagnetic steel sheet 40 in the stacking direction. The concave portion is arranged in a portion of the electromagnetic steel sheet 40 located on the back side of the convex portion. The recess is recessed in the stacking direction with respect to the surface of the electromagnetic steel sheet 40. The convex portion and the concave portion are formed by, for example, pressing the electromagnetic steel plate 40.
Of the pair of electrical steel sheets 40 overlapping in the stacking direction, the convex portion of the crimped portion 25 of one electrical steel sheet 40 fits into the concave portion of the crimped portion 25 of the other electrical steel sheet 40.
[0030]
The adhesive portion 41 adheres the core back portions 22 (electrical steel sheets 40) adjacent to each other in the stacking direction. The plurality of electrical steel sheets 40 forming the stator core 21 are bonded by the bonding portion 41.
The adhesive portion 41 is an adhesive that is provided between the electromagnetic steel sheets 40 that are adjacent to each other in the stacking direction and is cured without being divided. As the adhesive, for example, a thermosetting adhesive by polymerization bonding is used.
As the composition of the adhesive, (1) an acrylic resin, (2) an epoxy resin, (3) a composition containing an acrylic resin and an epoxy resin, and the like can be applied.
[0031]
As the adhesive, in addition to a thermosetting type adhesive, a radical polymerization type adhesive or the like can also be used. From the viewpoint of productivity, a room temperature curing type (normal temperature adhesive type) adhesive is desirable. The room temperature curing type adhesive is an adhesive that cures at 20 ° C to 30 ° C. In the present specification, the numerical range represented by using "-" means a range including the numerical values ​​before and after "-" as the lower limit value and the upper limit value.
As the room temperature curing type adhesive, an acrylic adhesive is preferable. Typical acrylic adhesives include SGA (second generation acrylic adhesives, Second Generation Acrylic Adhesive) and the like. An anaerobic adhesive, an instant adhesive, and an elastomer-containing acrylic adhesive can be used as long as the effects of the present invention are not impaired.
The adhesive referred to here refers to the state before curing. When the adhesive is cured, it becomes an adhesive portion 41.
[0032]
The average tensile elastic modulus E of the bonded portion 41 at room temperature (20 ° C. to 30 ° C.) is in the range of 1500 MPa to 4500 MPa. If the average tensile elastic modulus E of the bonded portion 41 is less than 1500 MPa, there will be a problem that the rigidity of the laminated core is lowered. Therefore, the lower limit of the average tensile elastic modulus E of the adhesive portion 41 is 1500 MPa, more preferably 1800 MPa. On the contrary, if the average tensile elastic modulus E of the adhesive portion 41 exceeds 4500 MPa, a problem occurs in which the insulating film formed on the surface of the electromagnetic steel sheet 40 is peeled off. Therefore, the upper limit of the average tensile elastic modulus E of the adhesive portion 41 is 4500 MPa, more preferably 3650 MPa.
[0033]
The average tensile elastic modulus E is measured by the resonance method. Specifically, the tensile elastic modulus is measured in accordance with JIS R 1602: 1995.
More specifically, first, a sample for measurement (not shown) is produced. This sample is obtained by adhering two electromagnetic steel sheets 40 together with an adhesive to be measured and curing them to form an adhesive portion 41. When the adhesive is a thermosetting type, this curing is performed by heating and pressurizing under the heating and pressurizing conditions in actual operation. On the other hand, when the adhesive is a room temperature curing type, it is performed by pressurizing at room temperature.
Then, the tensile elastic modulus of this sample is measured by the resonance method. As described above, the method for measuring the tensile elastic modulus by the resonance method is performed in accordance with JIS R 1602: 1995. After that, the tensile elastic modulus of the bonded portion 41 alone can be obtained by removing the influence of the electromagnetic steel sheet 40 itself from the tensile elastic modulus (measured value) of the sample by calculation.
The tensile elastic modulus thus obtained from the sample is equal to the average value of the stator core 21 as a whole, which is a laminated core. Therefore, this value is regarded as the average tensile elastic modulus E. The composition of the average tensile elastic modulus E is set so that it hardly changes at the stacking position along the stacking direction or at the circumferential position around the central axis of the stator core 21. Therefore, the average tensile elastic modulus E can be set to a value obtained by measuring the cured bonded portion 41 at the upper end position of the stator core 21.
[0034]
As a bonding method using a thermosetting adhesive, for example, a method of applying an adhesive to the electromagnetic steel plate 40 and then bonding by heating and / or pressure bonding can be adopted.
As the heating means, for example, heating in a high-temperature tank or an electric furnace, or a method of directly energizing is used. The heating means may be any means.
[0035]
In order to obtain stable and sufficient adhesive strength, the thickness of the adhesive portion 41 is preferably 1 μm or more. On the other hand, when the thickness of the adhesive portion 41 exceeds 100 μm, the adhesive force is saturated. Further, as the adhesive portion 41 becomes thicker, the space factor decreases, and the magnetic properties such as iron loss of the laminated core decrease.
Therefore, the thickness of the adhesive portion 41 is 1 μm or more and 100 μm or less. The thickness of the adhesive portion 41 is more preferably 1 μm or more and 10 μm or less.
In the above, the thickness of the adhesive portion 41 means the average thickness of the adhesive portion 41.
[0036]
The average thickness of the bonded portion 41 is more preferably 1.0 μm or more and 3.0 μm or less. If the average thickness of the adhesive portion 41 is less than 1.0 μm, sufficient adhesive strength cannot be secured as described above. Therefore, the lower limit of the average thickness of the adhesive portion 41 is 1.0 μm, more preferably 1.2 μm. On the contrary, if the average thickness of the bonded portion 41 becomes thicker than 3.0 μm, problems such as a large increase in the amount of strain of the electromagnetic steel sheet 40 due to shrinkage during thermosetting occur. Therefore, the upper limit of the average thickness of the adhesive portion 41 is 3.0 μm, more preferably 2.6 μm.
The average thickness of the bonded portion 41 is an average value of the stator core 21 as a whole. The average thickness of the adhesive portion 41 is almost the same at the stacking position along the stacking direction and the circumferential position around the central axis of the stator core 21. Therefore, the average thickness of the adhesive portion 41 can be set as the average value of the numerical values ​​measured at 10 or more points in the circumferential direction at the upper end position of the stator core 21.
[0037]
The average thickness of the adhesive portion 41 can be adjusted by changing, for example, the amount of the adhesive applied. Further, the average tensile elastic modulus E of the adhesive portion 41 should be adjusted, for example, in the case of a thermosetting type adhesive by changing one or both of the heating and pressurizing conditions applied at the time of adhesion and the type of curing agent. Can be done.
[0038]
In the present embodiment, the plurality of electrical steel sheets 40 forming the rotor core 31 are fixed to each other by a caulking 42 (dove, see FIG. 1).
However, a plurality of electrical steel sheets 40 forming the rotor core 31 may be bonded to each other by the bonding portion 41.
The laminated cores such as the stator core 21 and the rotor core 31 may be formed by so-called rotating stacking.
[0039]
As shown in FIG. 4, a plurality of caulking portions 25 are provided on the core back portion 22 of the electrical steel sheet 40 at intervals in the circumferential direction. As will be described later, the plurality of caulking portions 25 are each provided on the non-adhesive region 43. The plurality of caulking portions 25 are arranged on the same circle centered on the central axis O. Each caulking portion 25 is displaced with respect to the teeth portion 23 along the circumferential direction.
On the surface (hereinafter referred to as the first surface of the electromagnetic steel sheet 40) 40a of the electromagnetic steel sheet 40 facing the stacking direction, the adhesive region 42 of the electromagnetic steel sheet 40 provided with the adhesive portion 41 and the electromagnetic steel having no adhesive portion 41 provided. A non-adhesive region 43 of the steel plate 40 is formed. More specifically, the adhesive region 42 of the electromagnetic steel sheet 40 provided with the adhesive portion 41 is provided with an adhesive (adhesive portion 41) cured without being divided from the first surface 40a of the electromagnetic steel plate 40. Means the area that is being used. Further, the non-adhesive region 43 of the electromagnetic steel sheet 40 in which the adhesive portion 41 is not provided means a region of the first surface 40a of the electrical steel sheet 40 in which the adhesive cured without being divided is not provided. ..
The bonded region 42 and the non-bonded region 43 are different regions from each other and do not overlap each other.
[0040]
In the present embodiment, the adhesive region 42 is formed on the outer peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. In other words, the adhesive portion 41 is provided on the outer peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. In other words, the adhesive is applied to the outer peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40.
[0041]
The outer peripheral side of the core back portion 22 is preferably outside the outer peripheral edge 25a of the caulking portion 25 (the outer peripheral edge 25a of the caulking portion 25 is located on the outermost side of the caulking portion 25 along the radial direction. Means part).
Further, it is more preferable that the outer peripheral side of the core back portion 22 is the outer side of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25. The virtual circle 27 can have the same diameter as the virtual circumscribed circle that circumscribes the plurality of caulking portions 25.
In FIG. 4, an adhesive portion 41 is continuously provided over the entire circumference of the outer edge of the core back portion 22 on the outside of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25.
In other words, in FIG. 4, the caulking part On the outside of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the 25, the adhesive region 42 is continuously formed over the entire circumference of the outer edge of the core back portion 22.
[0042]
As shown in FIG. 4, the adhesive portion 41 is not provided on the inner peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. In other words, no adhesive is applied to the inner peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. In other words, a non-adhesive region 43 is formed on the inner peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. The non-adhesive region 43 is provided with a plurality of caulking portions 25 at intervals in the circumferential direction.
The inner peripheral side of the core back portion 22 is preferably inside the outer peripheral edge 25a of the caulking portion 25. Further, it is more preferable that the inner peripheral side of the core back portion 22 is inside the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25. In other words, the portion of the core back portion 22 located inside the circumscribed circle in the radial direction is preferably the non-adhesive region 43. In FIG. 4, a non-adhesive region 43 is provided over the entire inner region of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25 in the core back portion 22.
The non-adhesive region 43 is also provided on the portion of the first surface 40a of the electrical steel sheet 40 corresponding to the plurality of teeth portions 23.
[0043]
The outside of the outer peripheral edge 25a of the caulking portion 25 refers to a region of the core back portion 22 outside the outer peripheral edge 25a of the caulking portion 25. The inside of the outer peripheral edge 25a of the caulking portion 25 refers to a region of the core back portion 22 inside the outer peripheral edge 25a of the caulking portion 25 and a region along the outer peripheral edge 25a of the caulking portion 25. Similarly, the outside of the virtual circle 27 refers to a region of the core back portion 22 outside the virtual circle 27. The inside of the virtual circle 27 means an area inside the virtual circle 27 and an area along the virtual circle 27 in the core back portion 22.
[0044]
It is assumed that the adhesive portion 41 is provided as shown in FIG. 4 between all the sets of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction. In this case, the ratio of the area of ​​the adhesive region 42 to 100% of the area of ​​the core back portion 22 of the first surface 40a of the electrical steel sheet 40 is, for example, 20%.
[0045]
Further, as shown in FIG. 5, the adhesive portion 41 is provided on the outer peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40 and at least in the vicinity of the caulking portion 25 of the outer edge of the core back portion 22. It may have been. The term "near the crimped portion 25" as used herein means, for example, a range of three times the length of the crimped portion 25 in the circumferential direction with the crimped portion 25 as the center in the circumferential direction.
In the example shown in FIG. 5, the adhesive portion 41 is provided intermittently over the entire circumference. The adhesive portion 41 is provided only in the vicinity of the caulking portion 25 on the outer edge of the core back portion 22. In other words, the adhesive portion 41 is also displaced from the teeth portion 23 along the circumferential direction, similarly to the caulking portion 25. Of the outer edge of the core back portion 22, the adhesive portion 41 is not provided on the portion located on the outer side in the radial direction of the tooth portion 23. In other words, of the outer edge of the core back portion 22, a non-adhesive region 43 is formed instead of the adhesive region 42 at a portion located on the outer side in the radial direction of the teeth portion 23.
The size of the adhesive region 42 in the circumferential direction is larger than the size of the crimped portion 25 in the circumferential direction. The caulking portion 25 is arranged at the central portion of the adhesive region 42 along the circumferential direction. The size of the adhesive region 42 in the circumferential direction is larger than the distance between the adhesive regions 42 adjacent to each other in the circumferential direction.
[0046]
A case will be described in which the adhesive portion 41 is provided as shown in FIG. 5 between all the sets of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction. In this case, the ratio of the area of ​​the adhesive region 42 to 100% of the area of ​​the core back portion 22 of the first surface 40a of the electrical steel sheet 40 is, for example, 12%.
[0047]
In this embodiment, it is assumed that the non-adhesive region 43 is formed in the plurality of tooth portions 23 included in the electromagnetic steel plate 40. In this case, a plurality of caulking portions 25 may be provided in the non-adhesive region 43 of the core back portion 22 and the non-adhesive region 43 of the plurality of teeth portions 23 at intervals in the circumferential direction.
[0048]
Generally, the adhesive shrinks as it cures. Therefore, when an adhesive is provided on the electrical steel sheet, compressive stress is applied to the electrical steel sheet as the adhesive cures. When compressive stress is applied, the magnetic steel sheet is distorted. Further, when the crimped portion is provided on the electromagnetic steel sheet, the electromagnetic steel sheet is deformed, so that the electromagnetic steel sheet is distorted. The crimped portion and the adhesive region form a fixed portion. The fixing portion fixes the electromagnetic steel sheets adjacent to each other in the laminating direction. As the area of ​​the fixed portion increases, the strain of the electrical steel sheet increases.
In the stator core 21 (laminated core) according to the present embodiment described above, a plurality of caulking portions 25 are provided on the core back portion 22 at intervals in the circumferential direction. An adhesive portion 41 is provided on the outer peripheral side of the core back portion 22 of the first surface 40a of the electromagnetic steel sheet 40. The adhesive portion 41 is not provided on the inner peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40.
In other words, in the stator core 21 (laminated core) according to the present embodiment, the core back portion 22 is provided with a plurality of caulking portions 25 at intervals in the circumferential direction. An adhesive region 42 is formed on the outer peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40. A non-adhesive region 43 is formed on the inner peripheral side of the core back portion 22 of the first surface 40a of the electrical steel sheet 40.
[0049]
With this configuration, an adhesive region 42 in which the adhesive portion 41 is provided is formed only on the outer peripheral side of the core back portion 22. The core back portions 22 of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are partially bonded to each other. Therefore, for example, the area of ​​the adhesive region formed on the core back portion 22 is reduced as compared with the case where the adhesive region extends inward in the radial direction to the crimped portion. Therefore, the area of ​​the fixed portion in the plan view in the stacking direction is reduced. As a result, the strain generated in the entire stator core 21 can be reduced. As a result, the iron loss generated in the stator core 21 can be reduced, and the magnetic characteristics of the stator core 21 can be improved.
[0050]
A caulking portion 25 is provided in a non-adhesive region 43 different from the adhesive region 42.
If an attempt is made to manufacture a stator core in which a crimped portion is provided in an adhesive region, the following problems occur. For example, in order to provide a crimped portion in the bonded region, an adhesive is applied to the convex portion of the crimped portion of the electromagnetic steel sheet. When trying to fit the convex part coated with the adhesive into the concave part of the caulked part of another electrical steel sheet, the adhesive gets in between the convex part and the concave part, and the convex part does not fit to the back of the concave part. There is a risk. In this case, there is a problem that the convex portion and the concave portion do not fit accurately and the pair of electromagnetic steel sheets are not laminated in parallel with each other.
A similar problem occurs when the adhesive is applied to the concave portion of the crimped portion of the electromagnetic steel sheet.
On the other hand, in the stator core 21 of the present embodiment, the caulking portion 25 is provided in the non-adhesive region 43. Therefore, the adhesive does not enter between the convex portion and the concave portion, and even if the crimped portion 25 is provided on the electromagnetic steel sheet 40, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction can be laminated in parallel.
[0051]
In the stator core 21 of the present embodiment, an adhesive region 42 is formed on the outer peripheral side of the core back portion 22. Therefore, not only the adhesive is applied to the first surface 40a of the electromagnetic steel sheet 40 to provide the adhesive portion 41, but also the adhesive portion can be provided by the following method.
That is, the adhesive is arranged on the radial outer side of the plurality of laminated electromagnetic steel sheets 40. When the pressure of the air inside the plurality of electromagnetic steel sheets 40 in the radial direction is reduced, the adhesive is impregnated between the plurality of electrical steel sheets 40. This adhesive can be cured to provide an adhesive portion.
[0052]
In the stator core 21 (laminated core) according to the present embodiment, the outer peripheral side of the crimped portion 25 in the core back portion 22 is the outer side of the outer peripheral edge 25a of the crimped portion 25. Then, the inner peripheral side of the crimped portion 25 in the core back portion 22 is set to the inside of the outer peripheral edge 25a of the crimped portion 25.
With this configuration, the most inner peripheral side portion of the adhesive region 42 does not overlap with the caulking portion 25 at all. Therefore, by fixing the stacking direction with the caulking portion 25 and fixing the electromagnetic steel sheet 40 by providing the adhesive portion 41 in the region where the strain is generated, it is possible to avoid further strain. Therefore, the area of ​​the fixed portion becomes smaller. As a result, the strain generated in the entire stator core 21 can be further reduced.
[0053]
In the stator core 21 (laminated core) according to the present embodiment, the outer peripheral side of the core back portion 22 is the outer side of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25. Then, the inner peripheral side of the core back portion 22 is set to the inside of the virtual circle 27 formed on the outer peripheral side of the outer peripheral edge 25a of the caulking portion 25.
With this configuration, the adhesive region 42 is not provided in the tooth portion 23. Therefore, the area of ​​the fixing portion composed of the caulking portion 25 and the adhesive portion 41 (adhesive region 42) for fixing the electromagnetic steel sheets 40 adjacent to each other in the stacking direction becomes smaller. As a result, the strain generated in the entire stator core 21 can be further reduced.
[0054]
In the stator core 21 (laminated core) according to the present embodiment, the adhesive portion 41 is provided at least in the vicinity of the crimped portion 25 on the outer edge of the core back portion 22.
As a result, the adhesive portion 41 is not continuously provided over the entire circumference of the outer edge of the core back portion 22, but is provided discontinuously (intermittently) at intervals. Therefore, for example, the area of ​​the adhesive region 42 formed on the core back portion 22 is reduced as compared with the case where the adhesive region is formed over the entire circumference of the core back portion. This reduces the area of ​​the fixed portion. Therefore, the strain generated in the entire stator core 21 can be made smaller.
[0055]
The stator core 21 (laminated core) according to the present embodiment includes an adhesive portion 41 provided in the adhesive region 42 of the core back portion 22. Therefore, the bonding portions 41 can be used to reliably bond the electromagnetic steel sheets 40 adjacent to each other in the stacking direction.
In the stator core 21 (laminated core) according to the present embodiment, the electromagnetic steel sheet 40 includes a plurality of tooth portions 23 on which the non-adhesive region 43 is formed. As a result, the area of ​​the non-adhesive region 43 in the electrical steel sheet 40 increases. Therefore, it is possible to increase the region where distortion does not occur in the stator core 21.
[0056]
The rotary electric machine 10 according to the present embodiment includes a stator core 21 (laminated core) according to the present embodiment. Therefore, the magnetic characteristics of the rotary electric machine 10 can be improved.
[0057]
The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
[0058]
The shape of the stator core is not limited to the form shown in the above embodiment. Specifically, the dimensions of the outer diameter and inner diameter of the stator core, the product thickness, the number of slots, the dimensional ratio in the circumferential direction and the radial direction of the teeth portion, the dimensional ratio in the radial direction between the teeth portion and the core back portion, etc. are desired. It can be arbitrarily designed according to the characteristics of the rotating electric machine.
[0059]
In the rotor of the above embodiment, a set of two permanent magnets 32 form one magnetic pole, but the present invention is not limited to this. For example, one permanent magnet 32 ​​may form one magnetic pole, or three or more permanent magnets 32 may form one magnetic pole.
[0060]
In the above-described embodiment, the permanent magnet field electric machine has been described as an example of the rotary electric machine, but the structure of the rotary electric machine is not limited to this as illustrated below. As the structure of the rotary electric machine, various known structures not illustrated below can also be adopted.
In the above-described embodiment, the permanent magnet field type motor has been described as an example as the synchronous motor. However, the present invention is not limited to this. For example, the rotary electric machine may be a reluctance type electric machine or an electromagnet field type electric machine (winding field type electric machine).
In the above-described embodiment, the synchronous motor has been described as an example of the AC motor. However, the present invention is not limited to this. for example,

The scope of the claims
[Claim 1]
A laminated core including a plurality of electrical steel sheets laminated in the thickness direction.
The electromagnetic steel sheet includes an annular core back portion and has an annular core back portion.
An adhesive region is formed on the outer peripheral side of the core back portion.
A non-adhesive region is formed on the inner peripheral side of the core back portion.
A laminated core in which a plurality of crimped portions are provided at intervals in the circumferential direction in the non-adhesive region of the core back portion.
[Claim 2]
The outer peripheral side of the core back portion is outside the outer peripheral edge of the caulked portion.
The laminated core according to claim 1, wherein the inner peripheral side of the core back portion is inside the outer peripheral edge of the caulked portion.
[Claim 3]
The outer peripheral side of the core back portion is the outer side of the virtual circle formed on the outer peripheral side of the outer peripheral edge of the caulked portion.
The laminated core according to claim 2, wherein the inner peripheral side of the core back portion is inside the virtual circle.
[Claim 4]
The laminated core according to any one of claims 1 to 3, wherein the adhesive region is formed at least in the vicinity of the crimped portion on the outer peripheral edge of the core back portion.
[Claim 5]
Claims 1 to 4 include an adhesive portion between the electromagnetic steel sheets adjacent to each other in the stacking direction, which is provided in the adhesive region of the core back portion and adheres the core back portions adjacent to each other in the stacking direction. The laminated core according to any one of the above items.
[Claim 6]
The laminated core according to claim 5, wherein the average thickness of the bonded portion is 1.0 μm to 3.0 μm.
[Claim 7]
The laminated core according to claim 5 or 6, wherein the average tensile elastic modulus E of the bonded portion is 1500 MPa to 4500 MPa.
[Claim 8]
The laminated core according to any one of claims 5 to 7, wherein the adhesive portion is a room temperature adhesive type acrylic adhesive containing SGA made of an elastomer-containing acrylic adhesive.
[Claim 9]
A rotary electric machine comprising the laminated core according to any one of claims 1 to 8.