The present invention relates to a laminated core and a rotary electric machine.
　The present application claims priority based on Japanese Patent Application No. 2018-235851 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 joined by both bonding and caulking methods.
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2015-136228
Outline of the invention
Problems to be solved by the invention
[0004]
　There is room for improvement in improving the magnetic characteristics of the conventional laminated core while ensuring the dimensional accuracy of the outer shape.
[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 while ensuring dimensional accuracy of the outer shape.
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 to each other, and the electromagnetic steel sheet located on the first side of the plurality of electromagnetic steel sheets along the stacking direction. And the electrical steel sheets located on the second side along the stacking direction are not crimped and bonded to each other, and the electrical steel sheets located in the center along the stacking direction are laminated cores that are not bonded to each other. be.
[0007]
　Joining by caulking can improve dimensional accuracy as compared with joining by bonding. Here, among the plurality of electromagnetic steel sheets, the electromagnetic steel sheet located on the first side along the laminating direction and the electromagnetic steel sheet located on the second side along the laminating direction are both crimped to each other. Therefore, it is possible to improve the accuracy of the shape of each part of the laminated core located on the first side and the second side in the laminated direction (each part located outside the laminated direction with respect to the center of the laminated direction). .. Each of these portions has a large influence on the outer shape of the laminated core with respect to the portion located at the center of the laminated core. Therefore, by increasing the accuracy of the shape of each of these portions, as a result, the accuracy of the outer shape of the laminated core can be improved. Therefore, the handleability of the laminated core can be ensured. For example, even when winding the winding around the laminated core, it can be wound with high accuracy.
　Bonding by bonding can suppress distortion generated in electrical steel sheets as compared with joining by caulking. Since the strain generated in the electrical steel sheet affects the iron loss of the electrical steel sheet and the magnetic characteristics of the laminated core, it is preferable that the strain is small. Here, among the plurality of electromagnetic steel sheets, the electromagnetic steel sheets located at the center along the laminating direction are bonded to each other. Therefore, the occurrence of strain can be suppressed as compared with the case where these electromagnetic steel sheets are crimped to each other. As a result, the magnetic properties of the laminated core can be improved.
[0008]
(2) In the laminated core according to (1), the number of the electrical steel sheets located at the center and bonded to each other is the number of the electrical steel sheets located on the first side and crimped to each other, and the number of the electrical steel sheets. It may be larger than the number of the electromagnetic steel sheets located on the second side and crimped to each other.
[0009]
　The number of electrical steel sheets located at the center and adhered to each other (hereinafter referred to as N3) is the number of electrical steel sheets located on the first side and crimped to each other (hereinafter referred to as N1), and the number of electrical steel sheets to be bonded to each other (hereinafter referred to as N1). It is larger than the number of electrical steel sheets that are positioned and crimped to each other (hereinafter referred to as N2). Therefore, the ratio of the number of electrical steel sheets joined by caulking can be reduced in the entire laminated core. As a result, the magnetic characteristics of the laminated core can be further improved.
[0010]
(3) In the laminated core according to the above (1) or (2), the number of the electromagnetic steel sheets located on the first side and crimped to each other and the electromagnetic steel located on the second side and crimped to each other. The number of steel sheets may be equal to.
[0011]
　N1 and N2 are equal. Therefore, in the laminated core, it is possible to suppress a difference between the dimensional accuracy on the first side and the dimensional accuracy on the second side in the laminating direction. As a result, the handleability of the laminated core can be further ensured.
[0012]
(4) In the laminated core according to any one of (1) to (3), the electromagnetic steel sheet protrudes from the annular core back portion and the core back portion in the radial direction of the core back portion. In addition, a plurality of teeth portions arranged at intervals in the circumferential direction of the core back portion may be provided.
[0013]
　The laminated core is a stator core including a core back portion and a teeth portion. Therefore, for example, when the winding is passed through the slots between the teeth portions adjacent to each other in the circumferential direction, the above-mentioned action and effect of ensuring the handleability is remarkably achieved. That is, if the dimensional accuracy of the slot is improved, it is possible to easily wind the winding around the teeth portion as designed. As a result, the winding space factor in the slot can be increased. As a result, the electrical load in the slot can be increased.
[0014]
(5) In the laminated core according to any one of (1) to (4), the average thickness of the bonded portion may be 1.0 μm to 3.0 μm.
[0015]
(6) In the laminated core according to any one of the above (1) to (5), the average tensile elastic modulus E of the bonded portion may be 1500 MPa to 4500 MPa.
[0016]
(7) In the laminated core according to any one of (1) to (6) above, the adhesive portion is a room temperature adhesive type acrylic adhesive containing SGA made of an elastomer-containing acrylic adhesive. You may.
[0017]
(8) A second aspect of the present invention is a rotary electric machine provided with the laminated core according to any one of the above (1) to (7).
The invention's effect
[0018]
　According to the present invention, it is possible to improve the magnetic characteristics while ensuring the dimensional accuracy of the outer shape.
A brief description of the drawing
[0019]
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 stator included in the rotary electric machine shown in FIG.
FIG. 4 is a plan view of an electromagnetic steel plate and an adhesive portion of a stator included in the rotary electric machine shown in FIG.
5 is a plan view of an electromagnetic steel plate and caulking of a stator included in the rotary electric machine shown in FIG. 1. FIG.
FIG. 6 is a cross-sectional view taken along the line VI-VI shown in FIG.
FIG. 7 is a cross-sectional view of a stator core according to a first modification of an embodiment of the present invention, which corresponds to the cross-sectional view shown in FIG.
FIG. 8 is a cross-sectional view of a stator core according to a second modification of the embodiment of the present invention, which corresponds to the cross-sectional view shown in FIG.
Mode for carrying out the invention
[0020]
　Hereinafter, the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an electric motor as a rotary electric machine, specifically an AC electric motor, more specifically a synchronous electric motor, and even more specifically, a permanent magnet field type electric motor will be described as an example. This type of motor is suitably adopted for, for example, an electric vehicle.
[0021]
　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 in which the rotor 30 is located inside the stator 20 is adopted. However, as the rotary electric machine 10, an outer rotor type in which the rotor 30 is located outside the stator 20 may be adopted. 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. The rotary electric machine 10 can rotate at a rotation speed of 1000 rpm by applying an exciting current having an effective value of 10 A and a frequency of 100 Hz to each phase, for example.
[0022]
　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. In the following, 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 the axial direction, and the radial direction of the stator core 21 (core back portion 22) (orthogonal to the central axis O of the stator core 21). The direction) is called the radial direction, and the circumferential direction of the stator core 21 (core back portion 22) (the direction that orbits around the central axis O of the stator core 21) is called the circumferential direction.
[0023]
　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 inward 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 shapes and sizes of the plurality of teeth portions 23 do not have to be the same.
　The winding is wound around the teeth portion 23. The winding may be a centralized winding or a distributed winding.
[0024]
　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 a central angle of 30 degrees about the central axis O. The intervals between the plurality of sets of permanent magnets 32 do not have to be the same.
[0025]
　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. Fixing of each permanent magnet 32 ​​to the rotor core 31 can be realized, for example, 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 adopted instead of the embedded magnet type motor.
[0026]
　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.
[0027]
　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 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. As the grain-oriented electrical steel sheet, for example, a grain-oriented electrical steel strip of JIS C 2553: 2012 can be adopted.
[0028]
　Insulating coatings are provided on both sides of the electrical steel sheet 40 in order to improve the workability of the electrical steel sheet and the iron loss of the laminated core. 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.
[0029]
　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, the insulating effect is saturated as the insulating film becomes thicker. 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.
[0030]
　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, 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, preferably 0.10 mm or more and 0.35 mm or less, more preferably 0.20 mm or 0.25 mm. be. The thickness of the electrical steel sheet 40 includes the thickness of the insulating coating.
[0031]
　A part of the plurality of electromagnetic steel sheets 40 forming the stator core 21 is adhered by the adhesive portion 41. The adhesive portion 41 is an adhesive that is provided between 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. As such an adhesive, a radical polymerization type adhesive or the like can be used in addition to a thermosetting type adhesive, and from the viewpoint of productivity, it is desirable to use a room temperature curing type adhesive. The room temperature curable adhesive cures at 20 ° C to 30 ° C. 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 a state before curing, and becomes an adhesive portion 41 after the adhesive is cured.
[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.
　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.
　Since the tensile elastic modulus obtained from the sample in this way is equal to the average value of the entire laminated core, 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 laminated core. 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 laminated core.
[0033]
　As the bonding method, for example, a method of applying an adhesive to the electromagnetic steel sheet 40 and then bonding by heating and / or pressure bonding can be adopted. The heating means may be any means such as heating in a high temperature bath or an electric furnace, or a method of directly energizing.
[0034]
　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 torque density when the laminated core is used as a motor decreases. Therefore, the thickness of the adhesive portion 41 is preferably 1 μm or more and 100 μm or less, 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.
[0035]
　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 laminated core 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 laminated core. 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 laminated core.
[0036]
　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.
[0037]
　In this embodiment, the plurality of electromagnetic steel sheets 40 forming the rotor core 31 are fixed to each other by caulking C (dowels). 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.
[0038]
　Here, as shown in FIGS. 3 and 4, in the stator core 21 of the present embodiment, all the sets of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are joined by either bonding or caulking. In the present embodiment, among the plurality of electrical steel sheets 40, the N1 electrical steel sheet 40 (hereinafter, also referred to as the first laminated body 76) located on the first side D1 along the stacking direction, and the second along the stacking direction. None of the N2 electrical steel sheets 40 (hereinafter, also referred to as the second laminated body 77) located on the side D2 are crimped and bonded to each other, and are not joined by a joining method other than crimping. Of the plurality of electrical steel sheets 40, the N3 electrical steel sheets 40 (hereinafter, also referred to as the third laminated body 78) located in the center along the stacking direction are not bonded to each other and are not bonded to each other. Not joined by the joining method.
[0039]
　Of both ends of the stator core 21 in the stacking direction, the end located on the first side D1 is referred to as the first end 21a, and the end located on the second side D2 is referred to as the second end 21b. The first end portion 21a is formed of the N1 sheet of electromagnetic steel sheet 40 (first laminated body 76). The second end portion 21b is formed of the N2 magnetic steel sheets 40 (second laminated body 77). In this embodiment, N1 and N2 are equal. Here, the equality of N1 and N2 includes not only the case where N1 and N2 are completely equal, but also the case where there is a slight difference (substantially equal) between N1 and N2. This slight difference means a difference in the number of sheets within 5% with respect to the total number of sheets of the stator core 21.
[0040]
　As shown in FIG. 5, crimps C1 and C2 are formed on the electrical steel sheets 40 (N1 and N2 electrical steel sheets 40, the first laminated body 76 and the second laminated body 77) that are crimped to each other. There is. The caulking C1 and C2 include a first caulking C1 provided on the core back portion 22 and a second caulking C2 provided on the teeth portion 23.
[0041]
　A plurality of first caulking C1s are arranged at equal intervals along the circumferential direction. In the illustrated example, the first caulking C1 is arranged so as to be offset from the teeth portion 23 along the circumferential direction. The first caulking C1 is arranged in the middle of the adjacent teeth portions 23 along the circumferential direction. The first caulking C1 is arranged at the center of the core back portion 22 along the radial direction.
　The second caulking C2 is provided in all the teeth portions 23. The second caulking C2 is arranged at the center of each tooth portion 23 in the circumferential direction. Two second caulking C2s are arranged side by side in the radial direction on each tooth portion 23.
[0042]
　As shown in FIG. 6, the first caulking C1 includes a convex portion C11 and a concave portion C12 provided on each electrical steel sheet 40. The convex portion C11 protrudes from the electromagnetic steel sheet 40 in the stacking direction. The concave portion C12 is arranged in a portion of each electrical steel sheet 40 located on the back side of the convex portion C11. The recess C12 is recessed in the stacking direction with respect to the surface (first surface) of the electromagnetic steel sheet 40. The convex portion C11 and the concave portion C12 are formed by, for example, pressing each of the electromagnetic steel sheets 40.
　Here, in each of the N1 electrical steel sheet 40 (first laminated body 76) and the N2 electrical steel sheet 40 (second laminated body 77), one of the two electrical steel sheets 40 adjacent to each other in the stacking direction is the first. 1 is called the electromagnetic steel sheet 40, and the other is called the second electrical steel sheet 40. The first caulking C1 is formed by fitting the convex portion C11 of the first electromagnetic steel sheet 40 into the concave portion C12 of the second electrical steel sheet 40. By fitting the convex portion C11 into the concave portion C12 and forming the first caulking C1, the relative displacement between the two electromagnetic steel sheets 40 adjacent to each other in the stacking direction is regulated.
[0043]
　The second caulking C2 has the same configuration as the first caulking C1. The second caulking C2 includes the convex portion C11 and the concave portion C12 provided on each of the electromagnetic steel sheets 40. The second caulking C2 is formed by fitting the convex portion C11 of the first electromagnetic steel sheet 40 into the concave portion C12 of the second electrical steel sheet 40. By fitting the convex portion C11 into the concave portion C12 and forming the second caulking C2, the relative displacement between the two electromagnetic steel sheets 40 adjacent to each other in the stacking direction is regulated.
[0044]
　The shapes of the convex portion C11 and the concave portion C12 are not particularly limited.
　Further, the direction in which the convex portion C11 protrudes and the direction in which the concave portion C12 is recessed may be either the first side D1 or the second side D2 in the stacking direction.
　For example, as in the stator core 21 of the present embodiment shown in FIG. 6, in both the N1 electrical steel sheet 40 (first laminated body 76) and the N2 electrical steel sheet 40 (second laminated body 77). The convex portion C11 may protrude to the second side D2, and the concave portion C12 may be recessed to the second side D2. In this case, in each of the N1 sheet of electromagnetic steel sheet 40 (first laminated body 76) and the N2 sheet of electromagnetic steel sheet 40 (second laminated body 77), the electromagnetic steel sheet 40 located on the second side D2 is convex. A portion C11 and a recess C12 may be formed. However, in the illustrated example, the through hole C13 is formed in the electromagnetic steel sheet 40 located on the second side D2 in place of the convex portion C11 and the concave portion C12. In this case, the convex portion C11 of the electromagnetic steel sheet 40 adjacent to the electromagnetic steel sheet 40 on which the through hole C13 is formed is fitted into the through hole C13. As a result, in each of the N1 electrical steel sheet 40 (first laminated body 76) and the N2 electrical steel sheet 40 (second laminated body 77), the two electrical steel sheets 40 located on the second side D2 are formed. , Squeezed each other.
　Further, for example, in the N1 magnetic steel sheet 40 (first laminated body 76), the convex portion C11 protrudes to the second side D2 and the concave portion C12 becomes the second, as in the stator core 21A of the first modification shown in FIG. It may be recessed on the side D2. On top of that, in the N2 electrical steel sheets 40 (second laminated body 77), the convex portion C11 may protrude to the first side D1 and the concave portion C12 may be recessed to the first side D1. In the illustrated example, in the N1 sheet of electromagnetic steel sheet 40 (first laminated body 76), a through hole C13 is formed in the electromagnetic steel sheet 40 located on the secondmost side D2 in place of the convex portion C11 and the concave portion C12. Has been done. Further, in the N2 electrical steel sheets 40 (second laminated body 77), through holes C13 are formed in the electrical steel sheets 40 located on the first side D1 in place of the convex portions C11 and the concave portions C12. ..
　Further, for example, in the N1 magnetic steel sheet 40 (first laminated body 76), the convex portion C11 protrudes to the first side D1 and the concave portion C12 becomes the first, as in the stator core 21B of the second modified example shown in FIG. It may be recessed on the side D1. On top of that, in the N2 magnetic steel sheets 40 (second laminated body 77), the convex portion C11 may protrude to the second side D2, and the concave portion C12 may be recessed to the second side D2. In the illustrated example, in the N1 sheet of electromagnetic steel sheet 40 (first laminated body 76), a through hole C13 is formed in the electromagnetic steel sheet 40 located on the first side D1 instead of the convex portion C11 and the concave portion C12. Has been done. Further, in the N2 electrical steel sheets 40 (second laminated body 77), through holes C13 are formed in the electrical steel sheets 40 located on the secondmost side D2 in place of the convex portions C11 and the concave portions C12. ..
　Although not shown, the convex portion C11 protrudes to the first side D1 in both the N1 electrical steel sheet 40 (first laminated body 76) and the N2 electrical steel sheet 40 (second laminated body 77). , The recess C12 may be recessed in the first side D1.
[0045]
　As shown in FIG. 3, among the plurality of electrical steel sheets 40, the N3 electrical steel sheets 40 (third laminated body 78) located at the center along the stacking direction are the N1 electrical steel sheets 40 (first laminated body). 76), the N2 magnetic steel sheets 40 (second laminated body 77) are sandwiched from both sides in the laminating direction. The N3 electrical steel sheets 40 (third laminated body 78) form the central portion 21c of the stator core 21. Assuming that the total number of electrical steel sheets 40 is N0, N0 is obtained as the sum of N1, N2, and N3.
[0046]
　As shown in FIG. 4, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction bonded by the bonding portion 41 are not completely bonded to each other. These electromagnetic steel sheets 40 are locally bonded to each other.
[0047]
　In the present embodiment, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are adhered to each other by an adhesive portion 41 provided along the peripheral edge of the electromagnetic steel sheets 40. Specifically, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are adhered to each other by a first adhesive portion 41a and a second adhesive portion 41b. The first adhesive portion 41a is provided along the outer peripheral edge of the electromagnetic steel sheet 40 in a plan view of the electromagnetic steel sheet 40 when viewed from the stacking direction. The second adhesive portion 41b is provided along the inner peripheral edge of the electromagnetic steel sheet 40 in a plan view of the electromagnetic steel sheet 40 when viewed from the stacking direction. The first and second adhesive portions 41a and 41b are formed in a strip shape in a plan view, respectively.
[0048]
　Here, the band shape also includes a shape in which the width of the band changes in the middle. For example, a shape in which round points are continuous in one direction without being divided is also included in a band shape extending in one direction. Further, along the peripheral edge includes not only the case where it is completely parallel to the peripheral edge but also the case where it has an inclination of, for example, 5 degrees or less with respect to the peripheral edge.
[0049]
　The first adhesive portion 41a is arranged along the outer peripheral edge of the electromagnetic steel sheet 40. The first adhesive portion 41a extends continuously over the entire circumference in the circumferential direction. The first adhesive portion 41a is formed in an annular shape in a plan view of the first adhesive portion 41a when viewed from the stacking direction.
　The second adhesive portion 41b is arranged along the inner peripheral edge of the electromagnetic steel sheet 40. The second adhesive portion 41b extends continuously over the entire circumference in the circumferential direction.
[0050]
　The second adhesive portion 41b includes a plurality of tooth portions 44 and a plurality of core back portions 45. The plurality of tooth portions 44 are provided at intervals in the circumferential direction, and are arranged in each tooth portion 23. The plurality of core back portions 45 are arranged in the core back portion 22, and connect the tooth portions 44 adjacent to each other in the circumferential direction.
　The tooth portion 44 includes a pair of a first portion 44a and a second portion 44b. The first portion 44a is arranged at intervals in the circumferential direction. The first portion 44a extends along the radial direction. The first portion 44a extends in a radial direction in a strip shape. The second portion 44b connects a pair of first portions 44a to each other in the circumferential direction. The second portion 44b extends in a band shape in the circumferential direction.
[0051]
　In the present embodiment, the plan-view shapes of all the adhesive portions 41 provided between the electromagnetic steel sheets 40 are the same. The plan view shape of the adhesive portion 41 means the overall shape of the adhesive portion 41 in a plan view of the electromagnetic steel sheet 40 provided with the adhesive portion 41 when viewed from the stacking direction. The fact that all the adhesive portions 41 provided between the electromagnetic steel sheets 40 have the same plan view shape means that the plan view shapes of all the adhesive portions 41 provided between the electromagnetic steel sheets 40 are completely the same. It does not include only certain cases, but includes substantially the same cases. In the case of substantially the same, it is a case where all the adhesive portions 41 provided between the electromagnetic steel sheets 40 have a common plan view shape of 95% or more.
[0052]
　In the present embodiment, the adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion 41 is 1% or more and 40% or less. In the illustrated example, the adhesive area ratio is 1% or more, 20% or less, and specifically 20%. The adhesive area ratio of the electromagnetic steel sheet 40 by the adhesive portion 41 is the adhesive portion 41 of the first surface of the electromagnetic steel plate 40 with respect to the area of ​​the surface facing the stacking direction (hereinafter referred to as the first surface of the electromagnetic steel sheet 40). Is the ratio of the area of ​​the region (adhesive region 42) provided with. The region provided with the adhesive portion 41 is a region (adhesive region 42) of the first surface of the electrical steel sheet 40 in which the adhesive cured without being divided is provided. The area of ​​the region where the adhesive portion 41 is provided can be obtained, for example, by photographing the first surface of the magnetic steel sheet 40 after peeling and analyzing the imaged result.
[0053]
　In the present embodiment, the bonding area ratio of the electromagnetic steel sheets 40 by the bonding portion 41 between the electromagnetic steel sheets 40 is 1% or more and 20% or less. In both electrical steel sheets 40 adjacent to each other in the stacking direction, the adhesive area ratio of the electrical steel sheets 40 by the adhesive portion 41 is 1% or more and 20% or less. When the adhesive portions 41 are provided on both sides in the stacking direction with respect to one electrical steel sheet 40, the adhesive area ratios on both sides of the electrical steel sheet 40 are 1% or more and 20% or less.
　By adhering the electromagnetic steel sheet 40 with the adhesive portion 41, it is possible to easily secure the adhesive area (bonding area) as compared with the case where the electromagnetic steel sheet 40 is crimped.
[0054]
　In the present embodiment, the electromagnetic steel sheets 40 (N1 and N2 electrical steel sheets 40, the first laminated body 76, and the second laminated body 77) that are crimped to each other are not adhered to each other. In other words, the adhesive portion 41 is not provided between the electromagnetic steel sheets 40 that are crimped to each other.
　Further, in the present embodiment, the electromagnetic steel sheets 40 (N3 electrical steel sheets 40) bonded to each other are not crimped. In other words, in the electromagnetic steel sheets 40 bonded to each other, the convex portion C11 and the concave portion C12 (or the through hole C13) are not fitted. That is, the regulation of the relative displacement of the electromagnetic steel sheets 40 bonded to each other is not realized by at least the fitting of the convex portion C11 and the concave portion C12 (or the through hole C13).
[0055]
　In the present embodiment, the caulking C1 and C2 and the adhesive portion 41 are arranged at positions where they do not overlap in a plan view and avoid each other. The caulking C1 and C2 and the adhesive portion 41 are arranged so as to be offset in a plan view. The total area of ​​the caulking C1 and C2 in the plan view is smaller than the total area of ​​the bonded portion 41.
[0056]
　Here, a joining method at the boundary (hereinafter referred to as the first boundary B1) between the N1 magnetic steel sheet 40 on the first side D1 joined by caulking and the central N3 electrical steel sheet 40 joined by adhesion. May be crimped or glued. In other words, of the N1 electrical steel sheets 40 located on the first side D1, the electrical steel sheet 40 located on the second side D2 and the N3 electrical steel sheets 40 located in the center, the most first side D1 The electromagnetic steel sheet 40 located in may be joined to each other by caulking, or may be joined by adhesion.
[0057]
　Further, the joining method at the boundary (hereinafter referred to as the second boundary B2) between the N2 electromagnetic steel sheets 40 on the second side D2 joined by caulking and the central N3 electrical steel sheets 40 joined by adhesion is , Caulking or adhesive. In other words, of the N2 electrical steel sheets 40 located on the second side D2, the electrical steel sheet 40 located on the first side D1 and the N3 electrical steel sheet 40 located in the center, the second side D2. The electromagnetic steel sheet 40 located in may be joined to each other by caulking, or may be joined by adhesion.
[0058]
　In the stator core 21 shown in FIG. 6, the stator core 21A shown in FIG. 7, and the stator core 21B shown in FIG. 8, electromagnetic steel sheets 40 adjacent to each other are joined by adhesion at both the first boundary B1 and the second boundary B2. ..
　Here, one of the electromagnetic steel sheets 40 adjacent to each other at the first boundary B1 and the second boundary B2 is referred to as a third electromagnetic steel sheet 40, and the other is referred to as a fourth electromagnetic steel sheet 40. In the third electromagnetic steel sheet 40, a convex portion C11, a concave portion C12, or a through hole C13 is formed on the surface (first surface) facing the fourth electromagnetic steel sheet 40. In the fourth electrical steel sheet 40, none of the convex portion C11, the concave portion C12, and the through hole C13 is formed on the surface (first surface) facing the third electromagnetic steel sheet 40. The surface of the fourth electrical steel sheet 40 is substantially flat. In addition, the fact that it is substantially flat here includes, for example, a case where a concave-convex shape that may be unavoidably generated in manufacturing is formed on the surface of the electrical steel sheet 40.
[0059]
　In both the first boundary B1 and the second boundary B2, it is basically superior that the electromagnetic steel sheet 40 is joined. However, the electrical steel sheets 40 may not be joined at the boundaries B1 and B2 in anticipation of the fastening force due to the winding.
[0060]
　Joining by caulking can improve dimensional accuracy as compared with joining by bonding. Here, among the plurality of electrical steel sheets 40, the electrical steel sheets 40 (N1 magnetic steel sheets 40, the first laminated body 76) located on the first side D1 along the stacking direction and the second side D2 along the stacking direction The positioned electromagnetic steel sheets 40 (N2 electrical steel sheets 40, second laminated body 77) are all crimped to each other. Therefore, in the stator core 21, the accuracy of the shape of each portion located on the first side D1 and the second side D2 in the stacking direction (each portion located outside the stacking direction with respect to the center of the stacking direction) is improved. Can be done. Each of these portions has a large influence on the outer shape of the stator core 21 with respect to the portion located at the center of the stator core 21. Therefore, by increasing the accuracy of the shape of each of these portions, as a result, the accuracy of the outer shape of the stator core 21 can be improved. Therefore, the handleability of the stator core 21 can be ensured. For example, even when winding the winding around the stator core 21, it can be wound with high accuracy.
　In the present embodiment, when the winding is passed through the slots between the teeth portions 23 adjacent to each other in the circumferential direction, the above-mentioned action and effect of ensuring the handleability is remarkably achieved. That is, if the dimensional accuracy of the slot is improved, the winding can be easily wound around the teeth portion 23 as designed. As a result, the winding space factor in the slot can be increased. As a result, the electrical load in the slot can be increased.
[0061]
　The bonding by bonding can suppress the strain generated in the electrical steel sheet 40 as compared with the bonding by caulking. Since the strain generated in the electromagnetic steel sheet 40 affects the iron loss of the electrical steel sheet 40 and the magnetic characteristics of the stator core 21, it is preferable that the strain is small. Here, among the plurality of electrical steel sheets 40, the electrical steel sheets 40 (N3 electrical steel sheets 40, third laminated body 78) located at the center along the stacking direction are bonded to each other. Therefore, the occurrence of distortion can be suppressed as compared with the case where these electromagnetic steel sheets 40 are crimped to each other. As a result, the magnetic characteristics of the stator core 21 can be improved.
[0062]
　As shown in FIG. 3, N3 is larger than N1 and N2. Therefore, the ratio of the number of electrical steel sheets 40 joined by caulking can be reduced in the entire stator core 21. As a result, the magnetic characteristics of the stator core 21 can be further improved.
　N1 and N2 are equal. Therefore, in the stator core 21, it is possible to suppress a difference between the dimensional accuracy on the first side D1 and the dimensional accuracy on the second side D2 in the stacking direction. As a result, the handleability of the stator core 21 can be further ensured.
[0063]
　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.
[0064]
　In the above embodiment, the caulking C1 and C2 and the adhesive portion 41 are arranged at positions where they do not overlap in a plan view and avoid each other. However, the caulking C1 and C2 and the adhesive portion 41 may overlap in a plan view.
[0065]
　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 between the circumferential direction and the radial direction of the teeth portion 23, the dimensional ratio in the radial direction between the teeth portion 23 and the core back portion 22, etc. Can be arbitrarily designed according to the desired characteristics of the rotating electric machine.
[0066]
　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.
[0067]
　In the above-described embodiment, the permanent magnet field type motor 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, and various publicly known not to be exemplified below. Structure 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, but 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, but the present invention is not limited to this. For example, the rotary electric machine may be an induction motor.
　In the above-described embodiment, the AC motor has been described as an example of the motor, but the present invention is not limited to this. For example, the rotary electric machine may be a DC motor.
　In the above-described embodiment, the electric machine has been described as an example of the rotary electric machine, but the present invention is not limited to this. For example, the rotary electric machine may be a generator.
[0068]
　In the above embodiment, the case where the laminated core according to the present invention is applied to the stator core has been illustrated, but it can also be applied to the rotor core.
[0069]
　In addition, it is possible to replace the components in the embodiment with well-known components as appropriate without departing from the spirit of the present invention, and the above-mentioned modifications may be appropriately combined.
[0070]
　Next, a verification test was conducted to verify the above-mentioned effects. This verification test was carried out by simulation using software. As the software, JMAG, a finite element method electromagnetic field analysis software manufactured by JSOL Corporation, was used.
　As the verification test, a first verification test and a second verification test were carried out.
[0071]
(First Verification Test) In
　the first verification test, the action and effect based on the fact that the electromagnetic steel sheets on both sides in the laminating direction are crimped and the central electromagnetic steel sheet is adhered are verified.
　In this verification test, simulations were carried out for the stators of Comparative Examples 1 and 2 and the stator of Example 1.
[0072]
　Common to both the stators of Comparative Examples 1 and 2 and the stator of the first embodiment, the stator 20 according to the embodiment shown in FIGS. 1 to 6 is used as the basic structure, and the following points are changed with respect to the stator 20. bottom. That is, the thickness of the electrical steel sheet was 0.25 mm, the stacking thickness of the laminated core was 50 mm, and the number of electrical steel sheets was 200.
[0073]
　Then, in the stator of Comparative Example 1, 200 electromagnetic steel sheets were joined by caulking in all layers. In the stator of Comparative Example 2, 200 magnetic steel sheets were joined by adhesion in all layers. In the stator of the first embodiment, out of 200 electrical steel sheets, 30 sheets (15% of the total number of sheets) located on both sides in the stacking direction are joined by caulking, and 140 sheets (all) located in the center of the stacking direction. 70% of the number of sheets) was bonded by adhesion.
[0074]
　For each of the stators of Comparative Examples 1, 2 and Example 1, the iron loss per magnetic steel sheet and the dimensional accuracy as the stator core were confirmed. The iron loss was calculated by a simulation using the above software. The dimensional accuracy was evaluated by the amount of deviation from the target dimension when five stator cores were manufactured in each example.
[0075]
　The results are shown in Table 1 below.
[0076]
[table 1]

[0077]
　From the above, in Example 1, the iron loss was improved by 8.8% (= (27.4-25.0) /27.4) as compared with Comparative Example 1, and the dimensional accuracy was improved. Good results were obtained.
[0078]
(Second verification test) In
　the second verification test, the difference in effect based on the difference in the number of crimped sheets and the number of sheets to be adhered was verified.
　In this verification test, simulations were carried out for the stators of Examples 11 to 14.
[0079]
　Common to all of the stators of Examples 11 to 14, the stator 20 according to the embodiment shown in FIGS. 1 to 6 is used as the basic structure, and the following points are changed with respect to the stator 20. That is, the thickness of the electrical steel sheet was 0.25 mm, the stacking thickness of the laminated core was 50 mm, and the number of electrical steel sheets was 200.
[0080]
　Then, the stators of Examples 11 to 14 were set as follows.
　In the stator of the eleventh embodiment, out of 200 electrical steel sheets, 20 sheets (10% of the total number of sheets) located on both sides in the stacking direction are joined by caulking, and 160 sheets (all) located in the center of the stacking direction. 80% of the number of sheets) was bonded by adhesion.
　In the stator of Example 12, of the 200 electrical steel sheets, 40 sheets (20% of the total number of sheets) located on both sides in the stacking direction are joined by caulking, and 120 sheets (all) located in the center of the stacking direction. 60% of the number of sheets) was bonded by adhesion.
　In the stator of Example 13, of the 200 electrical steel sheets, 60 sheets (30% of the total number) located on both sides in the stacking direction are joined by caulking, and 80 sheets (all) located in the center of the stacking direction. 40% of the number of sheets) was bonded by adhesion.
　In the stator of Example 14, 80 out of 200 electrical steel sheets located on both sides in the stacking direction (40% of the total number) are joined by caulking, and 40 sheets (all) located in the center of the stacking direction. 20% of the number of sheets) was bonded by adhesion.
[0081]
　The results are shown in Table 2 below.
[0082]
[Table 2]

[0083]
　From the above, it was confirmed that the iron loss was improved from Examples 14 to 11. For example, in Example 11, an improvement in iron loss of 7.5% (= (26.7-24.7) / 26.7) was observed as compared with Example 14. Also in Example 12, an improvement in iron loss of 4.9% (= (26.7-25.4) / 26.7) was observed as compared with Example 14.
　On the other hand, in Examples 12 to 14, good results were obtained regarding the dimensional accuracy.
[0084]
　From this result, the number N1 of the number of electromagnetic steel sheets (first laminated body) located on the first side in the laminating direction and crimped to each other and the electromagnetic steel sheets (second laminated body) located on the second side in the laminating direction and crimped to each other It was confirmed that it is preferable that the number of sheets N2 of) and the number of sheets N0 of the whole electromagnetic steel sheet have the following relationship. That is, it is confirmed that it is preferable that each ratio (N1 / N0 and N2 / N0) of N1 and N2 to N0 is preferably 10% or more and 40% or less when N1 and N2 are equal (N1 = N2). Was done. Furthermore, it was confirmed that it is more preferable that each of the above ratios is 20% or more and 40% or less.
Industrial applicability
[0085]
　According to the present invention, it is possible to improve the magnetic characteristics while ensuring the dimensional accuracy of the outer shape. Therefore, the industrial applicability is great.
Code description
[0086]
10 Rotating electric
machines 21, 21A, 21B Stator core (laminated core)
22 Core back part
23 Teeth part
40 Electrical steel sheet
The scope of the claims
[Claim 1]
　A laminated core including a plurality of electromagnetic steel sheets laminated to each other, the electromagnetic steel sheet
　located on the first side along the stacking direction and the second side located along the stacking direction among the plurality of electromagnetic steel sheets. None of the electrical steel sheets are crimped and bonded to each other, and the electrical steel sheets located at the center along the stacking direction are laminated cores that are not bonded to each other.
[Claim 2]
　The number of the electrical steel sheets located at the center and adhered to each other is the number of the electrical steel sheets located on the first side and crimped to each other, and the number of the electrical steel sheets located on the second side and crimped to each other. The laminated core according to claim 1, which is larger than the number of sheets.
[Claim 3]
　The laminated core according to claim 1 or 2, wherein the number of the electrical steel sheets located on the first side and crimped to each other is equal to the number of the electrical steel sheets located on the second side and crimped to each other.
[Claim 4]
　The electrical steel sheet has an annular core back portion and a plurality of teeth portions that protrude from the core back portion in the radial direction of the core back portion and are arranged at intervals in the circumferential direction of the core back portion. The laminated core according to any one of claims 1 to 3.
[Claim 5]
　The laminated core according to any one of claims 1 to 4, wherein the average thickness of the bonded portion is 1.0 μm to 3.0 μm.
[Claim 6]
　The laminated core according to any one of claims 1 to 5, wherein the average tensile elastic modulus E of the bonded portion is 1500 MPa to 4500 MPa.
[Claim 7]
　The laminated core according to any one of claims 1 to 6, wherein the adhesive portion is a room temperature adhesive type acrylic adhesive containing SGA made of an elastomer-containing acrylic adhesive.
[Claim 8]
　A rotary electric machine comprising the laminated core according to any one of claims 1 to 7.