Stacked core

Abstract

To provide an electromagnetic steel sheet that has sufficient adhesive strength and higher magnetic properties by balancing the size of each of bonded portions, the spacing between these bonded portions, and the thickness of the electrical steel sheet to a higher order, and a laminated core formed by laminating a plurality of these electromagnetic steel sheets.SOLUTION: An electromagnetic steel sheet includes a base steel plate 2, and an insulating coating 3 having adhesive ability formed on one side or both sides of the base steel plate 2, and the insulating coating 3 includes a plurality of bonded portions 3a having an average circle-equivalent diameter d of 1.0 mm to 5.0 mm, and the average area ratio AR obtained by dividing the total surface area of each bonded portion 3a by the surface area of the base steel plate 2 is 4% or more and 80% or less.SELECTED DRAWING: Figure 6

Description

[[TECHNICAL FIELD]]

[0001] The present invention relates to Stacked core . [[BACKGROUND ART]]

[0002] A rotating electrical machine uses a laminated core formed by laminating a plurality of electromagnetic steel sheets. These electromagnetic steel sheets are integrated in a laminated state by methods such as caulking, welding, and adhesion. However, when laminated by caulking or welding, the magnetic properties of each electromagnetic steel sheet deteriorate due to mechanical stress and thermal stress applied during processing, as well as interlayer short-circuiting, and the performance of the laminated core may not be fully exhibited. Lamination by adhesion is extremely effective in solving this problem.

[0003] For example, Patent Document 1 discloses a configuration in which a plurality of dot-shaped adhesive portions are arranged in a staggered pattern on the adhesive surface of a non-oriented electromagnetic steel sheet. That is, an X axis and a Y axis are defined along the adhesive surface, and adhesive portions are arranged on respective grid points of an A grid and a B grid having intervals of Px in the X axis direction and Py in the Y axis direction, respectively. Between the A grid and the B grid, the positions of the respective grids are shifted from each other by Px / 2 and Py / 2, thereby forming a staggered arrangement. This Patent Document 1 exemplifies a configuration in which insulating coatings are formed on both surfaces of a non-oriented electromagnetic steel sheet. Then, a plurality of non-oriented electromagnetic steel sheets are laminated via an adhesive layer made of a composition exhibiting adhesive ability. Examples of the composition include acrylic resins, epoxy resins, and the like. The adhesive layer is composed of a plurality of dot-shaped adhesive portions arranged in a staggered pattern.

[0004] On the other hand, unlike the configuration of Patent Document 1, it is also practiced to impart adhesive ability to the insulating coating itself to bond a plurality of electromagnetic steel sheets together. That is, when manufacturing a laminated core, a plurality of electromagnetic steel sheets each having an adhesive insulating coating on one or both surfaces are laminated, and at least one of pressure and heat is applied. Thereby, the insulating coating of each electromagnetic steel sheet melts, and the electromagnetic steel sheets adjacent to each other in the lamination direction are bonded together. [[PRIOR ART DOCUMENTS]] [[PATENT DOCUMENTS]]

[0005] [Patent Document 1] Japanese Patent Publication No. 2017-011863 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] Both the configuration disclosed in Patent Document 1 and the configuration in which adhesive properties are imparted to the insulating coating are superior in terms of magnetic properties compared to lamination by crimping or welding. However, in recent years, even higher magnetic properties have been required for further performance improvements. To meet this demand, one could consider reducing the size of each point-like adhesive area and increasing the spacing between adhesive areas (the shortest distance between the edges of adjacent adhesive areas), but this may not provide sufficient adhesive strength. Therefore, one could consider increasing the size of each adhesive area to some extent, narrowing the spacing between adhesive areas, or doing both, but an optimal solution regarding the extent to which this is acceptable in order to achieve the objective of obtaining higher magnetic properties has not been found. In particular, when the thickness of the electrical steel sheet is thin, the influence of the stress added to the steel sheet as the adhesive hardens becomes significant, which hindered the determination of the optimal solution.

[0007] This invention was made in view of the above circumstances, and by balancing the size of each adhesive part, the spacing between these adhesive parts, and the thickness of the electromagnetic steel sheet in a high order, it is possible to achieve higher magnetic properties while having sufficient adhesive strength. The resulting electrical steel sheet Constructed by stacking multiple sheets Stacked core The purpose is to provide it. [Means for solving the problem]

[0008] In order to solve the above problems and achieve the above objectives, the present invention employs the following embodiments. (1) One aspect relating to the present invention Stacked core teeth, A laminated core made by stacking three or more electromagnetic steel sheets, wherein each of the electromagnetic steel sheets isThe device comprises a base steel sheet and an insulating coating having adhesive properties formed on one or both sides of the base steel sheet, wherein the insulating coating has a plurality of adhesive portions with an average circular equivalent diameter d (mm) of 1.0 mm to 5.0 mm, and the average area ratio AR, obtained by dividing the sum of the surface areas of each adhesive portion by the surface area of ​​the base steel sheet, is 4% to 80%. As described in (1) above Stacked core According to this method, the conditions of having an average equivalent circle diameter d of 1.0 mm to 5.0 mm and an average area ratio AR of 4% to 80% are combined to achieve a balance between the size of each adhesive part and the average spacing between these adhesive parts. This results in higher magnetic properties while maintaining sufficient adhesive strength. This laminated core is constructed from electromagnetic steel sheets that provide sufficient adhesive strength while also achieving higher magnetic properties, thus enabling reduced iron loss. In this context, "having adhesive properties" means that the insulating coating melts and exhibits adhesive properties when subjected to at least one of heating and / or pressurization.

[0009] (2) The same as described in (1) above Stacked core The average separation ratio g / d, obtained by dividing the average separation distance g (mm) between adjacent adhesive parts by the average circle equivalent diameter d (mm), may be between 1.0 and 3.0. As described in (2) above Stacked core According to this method, by setting the average separation ratio g / d to 1.0-3.0, the average area ratio AR can be optimized to be between 5% and 20%. As a result, the balance between the size of each adhesive joint and the average separation is optimized. This makes it possible to more reliably obtain sufficient adhesive strength and high magnetic properties.

[0010] (3) The items described in (1) or (2) above Stacked core The above each The value α of Equation 1, which is calculated using the thickness t0 (mm) of the electrical steel sheet, the average circle equivalent diameter d (mm), and the average area ratio AR (%), may be 430 or less. α = AR / d / t0 2 ...(Formula 1) As described in (3) above Stacked coreAccording to the above, by setting the value of α obtained by Equation 1 to 430 or less, the balance among the size of each adhesive portion, the average spacing, and the thickness of the electromagnetic steel sheet is optimized. This makes it possible to more reliably obtain sufficient adhesive strength and high magnetic properties.

[0012] (4) Any one of the above items (1) to (3) The laminated core described in the above may have the following configuration: each of the electromagnetic steel sheets includes a core back portion and a tooth portion; W / d obtained by dividing the average width dimension W (mm) of the tooth portion by the average equivalent circular diameter d (mm) is 1.0 or more and 30.0 or less. The above (4) According to the laminated core described in the above, in the tooth portions where the balance between adhesive strength and magnetic properties is particularly required, the adhesive state between the mutually laminated electromagnetic steel sheets can be made favorable.

Effects of the Invention

[0013] According to the above aspects of the present invention, the size of each adhesive portion, the spacing between these adhesive portions, and further the thickness of the electromagnetic steel sheet are balanced in a high order, whereby higher magnetic properties can be obtained while maintaining sufficient adhesive strength Electrical steel sheet formed by laminating a plurality of stacked core it becomes possible to provide.

Brief Description of Drawings

[0014] [Figure 1] It is a cross-sectional view of a rotating electric machine including a laminated core according to an embodiment of the present invention. [Figure 2] It is a side view of the laminated core. [Figure 3] It is a plan view of an electromagnetic steel sheet constituting the laminated core. [Figure 4] It is a plan view of a strip-shaped steel sheet that is a material of the electromagnetic steel sheet. [Figure 5] It is a cross-sectional view showing the material, and is a view taken along line A-A in FIG. 4. [Figure 6] It is a view explaining the arrangement of each adhesive portion in the electromagnetic steel sheet, and is an enlarged view of part B in FIG. 4. [Figure 7]Both (a) and (b) are diagrams showing modified examples of the arrangement of the adhesive parts, and are enlarged partial views corresponding to Figure 6. [Figure 8] (a) is a cross-sectional view of CC in Figure 6, and (b) is a modified version thereof. [Figure 9] This is a side view showing an example of a manufacturing apparatus for producing laminated cores by obtaining electrical steel sheets from the same material. [Figure 10] This figure shows an example from Table 1, and is a graph showing the relationship between the average spacing ratio g / d and the average area ratio AR. [Modes for carrying out the invention]

[0015] The following description will refer to the drawings and explain a laminated core according to one embodiment of the present invention, a rotating electric machine equipped with this laminated core, and the material (electromagnetic steel sheet) used to form this laminated core. In this embodiment, an electric motor, specifically an AC motor, more specifically a synchronous motor, and even more specifically a permanent magnet field motor will be used as an example of the rotating electric machine. This type of electric motor is suitably used, for example, in electric vehicles.

[0016] (Rotating electric machine 10) As shown in Figure 1, the rotating electric machine 10 comprises a stator 20, a rotor 30, a case 50, and a rotating shaft 60. The stator 20 and rotor 30 are housed within the case 50. The stator 20 is fixed within the case 50. In this embodiment, the rotating electric machine 10 is an inner rotor type in which the rotor 30 is located radially inward of the stator 20. However, the rotating electric machine 10 may also be an outer rotor type in which the rotor 30 is located outside of the stator 20. Furthermore, in this embodiment, the rotating electric machine 10 is a 12-pole, 18-slot three-phase AC motor. However, the number of poles, the number of slots, the number of phases, etc., can be changed as appropriate. The rotating electric machine 10 can rotate at a rotational speed of 1000 rpm by applying an excitation current with an effective value of 10 A and a frequency of 100 Hz to each phase, for example.

[0017] The stator 20 comprises a stator laminated core (hereinafter referred to as the stator core) 21 and windings (not shown). Each of the multiple electromagnetic steel sheets 40 constituting the stator core 21 comprises an annular core back portion 22 and multiple teeth portions 23. Hereinafter, the direction of the central axis O of the stator core 21 (or core back portion 22) will be referred to as the axial direction, the radial direction (direction perpendicular to the central axis O) of the stator core 21 (or core back portion 22) will be referred to as the radial direction, and the circumferential direction (direction around the central axis O) of the stator core 21 (or core back portion 22) will be referred to as the circumferential direction.

[0018] The core back portion 22 is formed in an annular shape in a plan view of the stator 20 as seen from the axial direction. Multiple teeth portions 23 protrude radially inward from the inner circumference of the core back portion 22 (towards the central axis O of the core back portion 22 along the radial direction). The multiple teeth portions 23 are arranged at equal angular intervals in the circumferential direction. In this embodiment, 18 teeth portions 23 are provided at central angle intervals of 20 degrees around the central axis O. The multiple teeth portions 23 are formed to be of the same shape and size as each other. Therefore, the multiple teeth portions 23 have the same thickness dimension as each other. The windings are wound around each tooth portion 23. The windings may be concentrated windings or distributed windings.

[0019] The rotor 30 is positioned radially inward relative to the stator 20 (stator core 21). The rotor 30 comprises a rotor core 31 and a plurality of permanent magnets 32. The rotor core 31 is formed in an annular (ring-shaped) form and is arranged coaxially with the stator 20. The rotating shaft 60 is located inside the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31. Multiple permanent magnets 32 are fixed to the rotor core 31. In this embodiment, pairs of permanent magnets 32 form one magnetic pole. Multiple pairs of permanent magnets 32 are arranged at equal angular intervals in the circumferential direction. In this embodiment, 12 pairs (24 in total) of permanent magnets 32 are provided at 30-degree intervals around the central axis O.

[0020] In this embodiment, an embedded magnet type motor is used as the permanent magnet field motor. The rotor core 31 has 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 arrangement of the plurality of permanent magnets 32. Each permanent magnet 32 ​​is fixed to the rotor core 31 while positioned within the corresponding through hole 33. Fixing each permanent magnet 32 ​​to the rotor core 31 can be achieved, for example, by bonding the outer surface of the permanent magnet 32 ​​to the inner surface of the through hole 33 with an adhesive. Note that a surface magnet type motor may be used instead of the embedded magnet type as the permanent magnet field motor.

[0021] Both the stator core 21 and the rotor core 31 are laminated cores. For example, as shown in Figure 2, the stator core 21 is formed by laminating multiple electromagnetic steel sheets 40 in the lamination direction. The lamination direction is the axial direction.

[0022] The stacking thickness (total length along the central axis O) of the stator core 21 and 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 just examples, and the stacking thickness, outer diameter, and inner diameter of the stator core 21, and the stacking 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 tooth portion 23 in the stator core 21. That is, the inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tip of all the tooth portions 23.

[0023] Figure 3 shows one of the multiple electromagnetic steel sheets 40 that constitute the stator core 21. This electromagnetic steel sheet 40 comprises a base steel sheet 2 and an insulating coating 3 having adhesive and insulating properties formed on one or both sides of the base steel sheet 2. The insulating coating 3 consists of a base insulating coating 3b that completely covers the surface of the base steel sheet 2 and a plurality of adhesive portions 3a arranged in a point-like manner on the base insulating coating 3b. Details of the adhesive portions 3a and the base insulating coating 3b will be described later. In this embodiment, the case in which the insulating coating 3 is formed only on the upper surface of the base steel sheet 2 will be described. The insulating coating 3 is formed only on the upper surface of the core back portion 22 and the upper surface of each tooth portion 23, and is not formed on the lower surfaces of the core back portion 22 and each tooth portion 23. Note that the insulating coating 3 may also cover the sides of the core back portion 22 and the sides of each tooth portion 23. The side surfaces referred to here, in the case where the electromagnetic steel sheet 40 is formed by punching out a material, refer to the cut surface formed after punching, and include the outer peripheral side surfaces that form the outer shape of the core back portion 22, and the side surfaces that form the outer shape of the teeth portion 23 and the inner shape of the core back portion 22. In this embodiment, the case in which the insulating coating 3 is formed only on the upper surface of the core back portion 22 and the upper surface of each teeth portion 23 is illustrated, but the configuration is not limited to this. The insulating coating 3 may also be formed on both the upper and lower surfaces of the core back portion 22 and each teeth portion 23.

[0024] Each electrical steel sheet 40 is formed, for example, by punching out material 1 as shown in Figures 4 to 6. Material 1 is a steel sheet (electrical steel sheet) that serves as the base material for the electrical steel sheet 40. Examples of material 1 include strip-shaped steel sheets and cut sheets. Although the explanation of the stator core 21 is still in progress, the following will describe material 1. In this specification, the strip-shaped steel sheet that serves as the base material for the electromagnetic steel sheet 40 may be referred to as material 1. The steel sheet that has been punched out from material 1 to form the shape used for the laminated core may be referred to as electromagnetic steel sheet 40.

[0025] (Material 1) If material 1 is a strip of steel, it is handled, for example, in a state wound onto coil 1A (see Figure 9). In this embodiment, non-oriented electrical steel sheet is used as material 1. As non-oriented electrical steel sheet, non-oriented electrical steel strip of JIS C 2552:2014 can be used. However, grain-oriented electrical steel sheet may be used as material 1 instead of non-oriented electrical steel sheet. In this case, grain-oriented electrical steel strip of JIS C 2553:2019 can be used as grain-oriented electrical steel sheet. Also, as material 1, non-oriented thin electrical steel strip or grain-oriented thin electrical steel strip of JIS C 2558:2015 can be used.

[0026] The upper and lower limits of the average plate thickness t0 of material 1 are set, for example, as follows: As material 1 becomes thinner, the manufacturing cost of material 1 increases. Therefore, considering the manufacturing cost, the lower limit of the average plate thickness t0 of material 1 is 0.10 mm, preferably 0.15 mm, and more preferably 0.18 mm. On the other hand, if material 1 is too thick, the manufacturing cost will be good, but when material 1 is used as electrical steel sheet 40, eddy current loss will increase and core iron loss will deteriorate. Therefore, considering core iron loss and manufacturing cost, the upper limit of the average sheet thickness t0 of material 1 is 0.65 mm, preferably 0.35 mm, and more preferably 0.30 mm. As an example of an average plate thickness t0 of material 1 that satisfies the above range, 0.20 mm can be used.

[0027] The average plate thickness t0 of material 1 includes not only the thickness of the base steel plate 2 described later, but also the thickness of the insulating coating 3 (the sum of the average thickness of the base insulating coating 3b and the average thickness of each adhesive part 3a). Furthermore, the method for measuring the average plate thickness t0 of material 1 is, for example, the following method. For example, if material 1 is a strip of steel sheet wound into the shape of a coil 1A (see Figure 9), at least a portion of material 1 is unwound into a flat plate shape. On the flat plate shape of material 1, a predetermined position in the longitudinal direction of material 1 is selected (for example, a position 10% of the total length of material 1 from the longitudinal edge of material 1). At this selected position, material 1 is divided into five regions along its width direction. The plate thickness of material 1 is measured at four locations that form the boundaries of these five regions. The average value of the plate thicknesses at these four locations can be taken as the average plate thickness t0 of material 1.

[0028] The upper and lower limits for the average plate thickness t0 of material 1 can also be used as the upper and lower limits for the average plate thickness t0 of the electrical steel sheet 40. The method for measuring the average plate thickness t0 of the electrical steel sheet 40 is, for example, the following method: For example, the stacked thickness of the laminated core is measured at four locations with equal spacing in the circumferential direction (i.e., at 90-degree intervals around the central axis O). The thickness per sheet is calculated by dividing each of the four measured stacked thicknesses by the number of laminated electrical steel sheets 40. The average value of the four thicknesses can be taken as the average plate thickness t0 of the electrical steel sheet 40. The average plate thickness t0 measured in this electrical steel sheet 40 state is equal to the average plate thickness t0 measured in the material 1 state.

[0029] As shown in Figures 5 and 6, the material 1 comprises a base steel sheet 2 and an insulating coating 3. That is, in this embodiment, the material 1 has an insulating coating 3 that is thinner than the base steel sheet 2 laminated on the upper surface, which is one side of the strip-shaped base steel sheet 2. If necessary, the insulating coating 3 may also be laminated on the lower surface in addition to the upper surface of the base steel sheet 2. Alternatively, an undercoat insulating coating 3b may be formed on both the upper and lower surfaces of the base steel sheet 2, and each adhesive portion 3a may be formed only on the upper surface of the base steel sheet 2.

[0030] The chemical composition of the base steel sheet 2 contains 2.5% to 4.5% Si by mass, as shown below in mass percent. By setting the chemical composition within this range, the yield strength of material 1 (electrical steel sheet 40) can be set to, for example, 380 MPa to 540 MPa.

[0031] Si: 2.5%~4.5% Al: 0.001%~3.0% Mn: 0.05%~5.0% Remainder: Fe and impurities

[0032] When material 1 is used as electrical steel sheet 40, the insulating coating 3 provides insulation between adjacent electrical steel sheets 40 in the lamination direction. Furthermore, the insulating coating 3 has adhesive properties (self-fusing function) and bonds adjacent electrical steel sheets 40 in the lamination direction. More specifically, the insulating coating 3 fuses together when subjected to at least one of pressure and / or heat.

[0033] As shown in Figure 6, the insulating coating 3 consists of a base insulating coating 3b that completely covers the surface of the base steel plate 2, and multiple point-shaped adhesive portions 3a arranged on the base insulating coating 3b. Each bonded portion 3a has an average equivalent diameter d of 1.0 mm to 5.0 mm. Furthermore, for each bonded portion 3a, if the average spacing between adjacent portions on the surface of the base steel plate 2 is g (mm), the average spacing ratio g / d obtained by dividing this average spacing g (mm) by the average equivalent diameter d (mm) is between 1.0 and 3.0. The shape of each adhesive portion 3a may be circular, elliptical, triangular, quadrilateral, polygonal, or a combination thereof, when viewed from the front of the surface of the material 1. The arrangement of each adhesive portion 3a may be such that, when viewed from the front of the surface of the material 1, the direction along the surface is defined as the X direction, and the direction along the surface and perpendicular to the X direction is defined as the Y direction, the adhesive portions 3a are equally spaced at an average spacing g1 in the X direction and equally spaced at an average spacing g2 in the Y direction. The average spacing g1 is the average of the shortest spacing lengths formed between the outer edges of adjacent adhesive portions 3a in the X direction. Similarly, the average spacing g2 is the average of the shortest spacing lengths formed between the outer edges of adjacent adhesive portions 3a in the Y direction. If the average spacing g1 and average spacing g2 are different, their average value is used as the average spacing g.

[0034] It is preferable that the mean spacing g1 and mean spacing g2 are equal to each other. In that case, mean spacing g1 and mean spacing g2 are both treated as equal mean spacing g. The arrangement of each adhesive portion 3a is not limited to the grid-like arrangement described above; other arrangements, such as the staggered arrangement shown in Figure 7(a), may also be adopted. Furthermore, as shown in Figure 7(b), adhesive portions 3a of two or more different sizes (equivalent to a circle diameter) may be mixed and arranged.

[0035] The insulating coating 3 may have a multi-layer structure or a single-layer structure. In the multi-layer configuration of this embodiment, as shown in Figure 8(a), the insulating film 3 is composed of a base insulating film 3b with excellent insulating performance and adhesive portions 3a that form a top insulating film with excellent adhesive performance. The base insulating film 3b is formed to cover the bare surface of the base steel plate 2 without any gaps, and the adhesive portions 3a are formed overlapping the surface of the base insulating film 3b. Since insulating performance is ensured by the base insulating film 3b, the adhesive portions 3a do not need to have insulating performance. However, the configuration is not limited to this, and both the base insulating film 3b and the adhesive portions 3a may have insulating performance. In this case as well, the base insulating film 3b may not have adhesive performance, and only the adhesive portions 3a may have adhesive performance.

[0036] The coating composition for forming the underlying insulating film 3b is not particularly limited, and general treatment agents such as chromic acid-containing treatment agents and phosphate-containing treatment agents can be used. Each adhesive portion 3a, which is an insulating coating with adhesive properties, is formed by applying a coating composition for electrical steel sheets onto a base insulating coating 3b. Before heat bonding during the manufacturing of the laminated core, each adhesive portion 3a is in an uncured or semi-cured state (Stage B), and the curing reaction proceeds due to heating during heat bonding, resulting in the development of adhesive properties.

[0037] On the other hand, as shown in the modified example in Figure 8(b), a single-layer structure can also be adopted as the insulating coating 3. That is, each adhesive portion 3a may be formed intermittently along the surface of the base steel sheet 2 directly on the surface, as long as the required insulating performance is ensured. In this case, each adhesive portion 3a has both adhesive and insulating properties. The insulating properties of each adhesive portion 3a ensure insulation between adjacent electromagnetic steel sheets 40 when they are laminated. Furthermore, the adhesive properties of each adhesive portion 3a bond the electromagnetic steel sheets 40 together.

[0038] In both cases, whether the insulating coating 3 is a multi-layer or single-layer structure, the average area ratio AR, obtained by dividing the sum of the surface areas of each adhesive portion 3a by the surface area of ​​the material (base steel sheet) 1, is between 4% and 80%. For example, in Figure 6, the area of ​​the rectangle indicated by the dashed line is the surface area A0 (mm²) of the material 1. 2 ) and further, the total area of ​​the nine adhesive parts 3a contained within this quadrilateral region is A1 (mm²). 2 In this case, the average area ratio AR is calculated as AR(%) = (A1 / A0) × 100. If any of the bonded parts 3a are located at the edge of material 1 and are partially cut, these shall also be included in the total surface area of ​​each bonded part 3a.

[0039] According to material 1 having the configuration described above, by combining the conditions that the average equivalent circle diameter d is 1.0 mm to 5.0 mm and the average area ratio AR is 4% to 80%, the size of each adhesive part 3a and the average spacing g between these adhesive parts 3a are balanced to a high degree. As a result, sufficient adhesive strength and high magnetic properties are achieved simultaneously.

[0040] Here, it is more preferable that the average spacing ratio g / d, obtained by dividing the average spacing g (mm) between adjacent adhesive parts 3a by the average equivalent circle diameter d (mm), is between 1.0 and 3.0. By setting the average spacing ratio g / d to between 1.0 and 3.0 in this way, the average area ratio AR can be optimized to between 5% and 20%. As a result, the balance between the size of each adhesive part 3a and the average spacing g is optimized, so sufficient adhesive strength and high magnetic properties can be obtained more reliably. Furthermore, it is preferable that the value α in Equation 1, which is calculated using the thickness t0 (mm), average circle equivalent diameter d (mm), and average area ratio AR (%) of each electrical steel sheet 40, be 430 or less. By setting the value of α calculated in Equation 1 to 430 or less, the balance between the size of each adhesive portion 3a, the average separation distance g (mm), and the thickness t0 (mm) of each electrical steel sheet 40 is optimized. This makes it possible to more reliably obtain sufficient adhesive strength and high magnetic properties. α = AR / d / t0 2 ...(Formula 1) The value of α is preferably 360 or less. The lower limit of α is not particularly limited, but considering the average circle equivalent diameter d (mm), the average area ratio AR (%), and the arrangement of each adhesive part 3a within a practical range, the lower limit of α is preferably 17, and more preferably around 30.

[0041] The coating composition for the electrical steel sheet used to form each adhesive portion 3a is not particularly limited, and examples include compositions containing an epoxy resin and an epoxy resin curing agent. That is, an example of an insulating film having adhesive properties is a film containing an epoxy resin and an epoxy resin curing agent.

[0042] As the epoxy resin, any general epoxy resin can be used, and specifically, any epoxy resin having two or more epoxy groups in one molecule can be used without particular restriction. Examples of such epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, alicyclic epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, hydantoin type epoxy resin, isocyanurate type epoxy resin, acrylic acid modified epoxy resin (epoxy acrylate), phosphorus-containing epoxy resin, and halogens thereof (brominated epoxy resin, etc.) and hydrogenated products. As the epoxy resin, one type may be used alone, or two or more types may be used in combination.

[0043] The coating composition for electrical steel sheets may also contain acrylic resin. The acrylic resin is not particularly limited. Examples of monomers used in the acrylic resin include unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, and hydroxypropyl (meth)acrylate. Note that (meth)acrylate means acrylate or methacrylate. The acrylic resin may be used alone or in combination of two or more types.

[0044] Acrylic resins may have constituent units derived from monomers other than acrylic monomers. Examples of other monomers include ethylene, propylene, and styrene. These other monomers may be used individually or in combination of two or more.

[0045] When using acrylic resin, it may be used as an acrylic-modified epoxy resin obtained by grafting acrylic resin onto an epoxy resin. In coating compositions for electrical steel sheets, it may be included as a monomer that forms the acrylic resin.

[0046] As epoxy resin curing agents, latent, heat-curing types can be used, such as aromatic polyamines, acid anhydrides, phenolic curing agents, dicyandiamides, boron trifluoride-amine complexes, and organic acid hydrazides. Examples of aromatic polyamines include metaphenylenediamine, diaminodiphenylmethane, and diaminodiphenylsulfone. Examples of phenolic curing agents include phenol novolac resins, cresol novolac resins, bisphenol novolac resins, triazine-modified phenol novolac resins, and phenol resol resins. Among these, phenolic curing agents are preferred as epoxy resin curing agents, and phenol resol resins are more preferred. As epoxy resin curing agents, one type may be used alone, or two or more types may be used in combination.

[0047] The amount of epoxy resin curing agent in the coating composition for electrical steel sheets is preferably 5 to 35 parts by mass, and more preferably 10 to 30 parts by mass, per 100 parts by mass of epoxy resin.

[0048] The coating composition for electrical steel sheets may contain additives such as curing accelerators (curing catalysts), emulsifiers, and defoamers. Only one additive may be used, or two or more may be used in combination.

[0049] The upper and lower limits of the average thickness t1 of the insulating film 3 are set, for example, as follows: When material 1 is used as an electrical steel sheet 40, the average thickness t1 of the insulating coating 3 (thickness per side of the electrical steel sheet 40 (material 1)) is adjusted to ensure insulation performance and adhesive properties between the electrical steel sheets 40 that are laminated together. In the multi-layered insulating coating 3 shown in Figure 8(a), the average thickness of the base insulating coating 3b can be, for example, 0.3 μm or more and 1.2 μm or less. Preferably, the average thickness of the base insulating coating 3b is 0.7 μm or more and 0.9 μm or less. The average thickness of each adhesive portion 3a forming the top insulating coating can be, for example, 1.5 μm or more and 8.0 μm or less. On the other hand, in the case of the single-layer insulating coating 3 shown in Figure 8(b), the average thickness t1 of the insulating coating 3 (thickness per side of the electromagnetic steel sheet 40 (material 1)) can be, for example, 1.5 μm or more and 8.0 μm or less. Furthermore, the method for measuring the average thickness t1 of the insulating coating 3 on material 1 is the same as for the average plate thickness t0 of material 1; for example, the thickness can be determined at 10 points on the insulating coating 3 and the average of these values ​​can be used to determine the average thickness t1.

[0050] The upper and lower limits for the average thickness t1 of the insulating coating 3 in this material 1 can also be used as the upper and lower limits for the average thickness t1 of the insulating coating 3 in the electromagnetic steel sheet 40. The method for measuring the average thickness t1 of the insulating coating 3 in the electromagnetic steel sheet 40 is, for example, the following measurement method. For example, among the multiple electromagnetic steel sheets 40 that form the laminated core, select the electromagnetic steel sheet 40 located on the outermost side in the lamination direction (the electromagnetic steel sheet 40 whose surface is exposed in the lamination direction). On the surface of the selected electromagnetic steel sheet 40, select a predetermined position in the radial direction (for example, the position exactly midway (center) between the inner and outer edges of the electromagnetic steel sheet 40). At the selected position, determine the thickness of the insulating coating 3 at, for example, 10 points. Measure this at four locations in the circumferential direction of the electromagnetic steel sheet 40 at equal intervals (i.e., every 90 degrees around the central axis O). The average value of the thicknesses measured at the four locations can be taken as the average thickness t1 of the insulating coating 3. The reason why the average thickness t1 of the insulating film 3 was measured on the outermost electrical steel sheet 40 in the lamination direction is that the insulating film 3 is manufactured in such a way that its thickness hardly changes at the lamination position along the lamination direction of the electrical steel sheet 40.

[0051] Multiple sheets of electromagnetic steel 40 are produced by punching material 1 as described above multiple times, and a laminated core (stator core 21 or rotor core 31) is produced by laminating these electromagnetic steel sheets 40. This laminated core is made up of electromagnetic steel 40 that has sufficient adhesive strength while also providing higher magnetic properties, thus enabling reduced iron loss. Here, it is preferable that for each electromagnetic steel sheet 40, the W / d (dimensionless value) obtained by dividing the average width dimension W (see Figure 3) of each tooth portion 23 by the average circle equivalent diameter d is between 1.0 and 30.0. In this case, the bonding state between the electromagnetic steel sheets 40 laminated together can be made favorable in each tooth portion 23 where a balance between adhesive strength and magnetic properties is particularly required.

[0052] (Layer stacking method for stacked cores) The following is a description of the laminated core. The multiple electromagnetic steel sheets 40 that form the stator core 21 are laminated with an insulating coating 3 in between, as shown in Figure 2. Adjacent electrical steel sheets 40 in the lamination direction are locally bonded by each adhesive portion 3a of the insulating coating 3. That is, on the surface of the electrical steel sheet 40 facing the lamination direction (hereinafter referred to as the first surface; the back surface of the first surface is referred to as the second surface), as shown in Figure 6 for example, there is a mixture of bonded regions formed by each adhesive portion 3a and non-bonded regions formed between these bonded portions 3a.

[0053] The adhesive region refers to the area on the first surface of the electromagnetic steel sheet 40 where the insulating coating 3 is adhered to the second surface of an adjacent electromagnetic steel sheet 40. On the other hand, the non-adhesive region refers to the area on the first surface of the electromagnetic steel sheet 40 where the insulating coating 3 is not adhered to the second surface of an adjacent electromagnetic steel sheet 40. In other words, in the non-adhesive region, the electromagnetic steel sheets 40 adjacent to each other in the lamination direction are not adhered to each other. In the non-adhesive region, there are no adhesive portions 3a, and the underlying insulating coating 3b is exposed. The non-adhesive region is insulated from the second surface of an adjacent electromagnetic steel sheet 40 in the lamination direction by the insulating properties of the underlying insulating coating 3b. Furthermore, if insulating coatings 3 are formed on both the first and second surfaces of the electromagnetic steel sheet 40, the adhesive region refers to the area on the first surface of the electromagnetic steel sheet 40 where the insulating coating 3 is integrally and seamlessly bonded to the insulating coating 3 of an adjacent electromagnetic steel sheet 40. On the other hand, the non-adhered region refers to the area on the first surface of the electromagnetic steel sheet 40 where the insulating coating 3 is not bonded to the insulating coating 3 of an adjacent electromagnetic steel sheet 40.

[0054] A method for confirming the adhesive and non-adhered areas on the first surface of the electrical steel sheet 40 is, for example, the following method. That is, two electrical steel sheets 40 that are bonded together via an insulating coating 3 are separated. The first surface of the separated electrical steel sheets 40 is observed, and the area where adhesive residue of the insulating coating 3 remains due to the peeling of the adhesive area is determined to be the adhesive area, and the area where no adhesive residue remains is determined to be the non-adhered area (no adhesive residue remains in areas that are fixed by tackiness). Image processing using a computer or artificial intelligence may be used for this determination.

[0055] In this embodiment, the multiple electromagnetic steel sheets forming the rotor core 31 are fixed to each other by the crimping 42 (dowels) shown in Figure 1. However, the multiple electromagnetic steel sheets forming the rotor core 31 may also have a laminated structure fixed by an insulating coating 3, similar to the stator core 21. Furthermore, laminated cores such as the stator core 21 and rotor core 31 may be formed by a so-called spiral stacking method.

[0056] (Method of manufacturing a laminated core) Next, we will explain the manufacturing method (hereinafter also simply referred to as the manufacturing method) for the laminated core that produces the stator core 21 configured as described above. Figure 9 shows a side view of a laminated core manufacturing apparatus 100 (hereinafter simply referred to as manufacturing apparatus 100) that is preferably used in this manufacturing method. In the manufacturing apparatus 100, the material 1 is fed from the coil 1A (hoop) in the direction of arrow F, and multiple punching operations are performed by dies positioned at each stage to gradually form the shape of the electromagnetic steel sheet 40. Then, the punched electrical steel sheets 40 are stacked on top of several already stacked electrical steel sheets 40, and then pressurized while the temperature is increased. As a result, adjacent electrical steel sheets 40 in the stacking direction are bonded (or fused) together by their respective adhesive parts 3a.

[0057] As shown in Figure 9, the manufacturing apparatus 100 has multiple punching stations. These punching stations may have two stages, or three or more stages. To illustrate with an example of a three-stage punching station, the manufacturing apparatus 100 includes a first-stage punching station 110 located closest to the coil 1A, a second-stage punching station 120 located adjacent to the first-stage punching station 110 downstream along the material 1 transport direction, and a third-stage punching station 130 located adjacent to the first-stage punching station 120 downstream along the material 1 transport direction. The punching station 110 includes a female die 111 positioned below the material 1 and a male die 112 positioned above the material 1. The punching station 120 includes a female die 121 positioned below the material 1 and a male die 122 positioned above the material 1. The punching station 130 includes a female die 131 positioned below the material 1 and a male die 132 positioned above the material 1.

[0058] The manufacturing apparatus 100 further includes a stacking station 140 located downstream of the second-stage punching station 120. This stacking station 140 includes, for example, a heating device 141, an outer-circumferential female punching die 142, a heat insulating member 143, an outer-circumferential male punching die 144, and a spring 145. The heating device 141, the outer peripheral punching female die 142, and the heat insulating member 143 are located below the material 1. On the other hand, the outer peripheral punching male die 144 and the spring 145 are located above the material 1. Reference numeral 21 indicates the stator core.

[0059] In this embodiment, in addition to lamination, pressure and heating are also performed to bond the electromagnetic steel sheets 40, but the present invention is not limited to the apparatus and method of this embodiment. For example, the manufacturing apparatus 100 may perform the lamination of the electromagnetic steel sheets 40, and the bonding between each electromagnetic steel sheet 40 may be performed in a later process by a separate apparatus. In this case, the heating device 141 and the heat insulating member 143 are not required in the manufacturing apparatus 100 and will be equipped in the separate apparatus. In this case, before moving the stator core 21 in an unbonded state from the manufacturing apparatus 100 to the separate apparatus, it is preferable to fix the electromagnetic steel sheets 40 together with a jig (not shown) to prevent misalignment between them.

[0060] In the manufacturing apparatus 100 having the configuration described above, first, material 1 is sequentially fed from coil 1A in the direction of arrow F in Figure 9. Then, punching is performed on this material 1 by punching station 110. Next, punching is performed on this material 1 by punching station 120. Furthermore, punching is performed on this material 1 by punching station 130. By sequentially performing these punching processes, the material 1 is given the shape of an electromagnetic steel sheet 40 having a core back portion 22 and multiple tooth portions 23 as shown in Figure 3. However, since it is not completely punched at this point, the process proceeds to the next step along the direction of arrow F.

[0061] Finally, material 1 is sent to the lamination station 140, where it is punched out by the outer peripheral punching die 144 and laminated with precision. During this lamination, the electromagnetic steel sheets 40 are subjected to a constant pressure by the spring 145. By sequentially repeating the punching process and the lamination process as described above, a predetermined number of electromagnetic steel sheets 40 can be stacked. Furthermore, the laminated core formed by stacking the electromagnetic steel sheets 40 in this way is heated to, for example, 200°C by the heating device 141. This heating hardens each adhesive portion 3a of the insulating coating 3, and the electromagnetic steel sheets 40 are bonded together. At this time, if the insulating coating 3 is formed on only one side of each electromagnetic steel sheet 40, the insulating coating 3 formed on one of the electromagnetic steel sheets 40 adjacent in the lamination direction will be bonded to the surface of the other electromagnetic steel sheet 40. On the other hand, if the insulating coating 3 is formed on both sides of each electrical steel sheet 40, the insulating coating 3 formed on one of the electrical steel sheets 40 adjacent to the other electrical steel sheet 40 will adhere to the insulating coating 3 formed on the other electrical steel sheet 40. The laminated core is completed through the above steps. [Examples]

[0062] [Example 1] Using the manufacturing apparatus 100 shown in Figure 9, the above-mentioned stator core 21 (hereinafter referred to as "stator core") was manufactured using non-oriented electrical steel sheets with a thickness of 0.25 mm while varying various manufacturing conditions, and the iron loss and peel strength of the stator core were evaluated. The heating conditions for all stator cores were kept the same, with a heating temperature of 200°C and a heating time of 30 minutes. The evaluation results are summarized in Table 1. In Table 1, the stator core iron loss is the energy loss generated within the stator core, and was evaluated by the energy loss in a rotating magnetic field using the method described in Japanese Patent Publication No. 2740553. Specifically, search coils were placed at four different locations in the circumferential direction of the core back, and the energy loss was determined when the core was magnetized to obtain a magnetic flux density of 1.5T as the average value of the four locations. This energy loss was then divided by the weight of the stator core to convert it to units of W / kg, and this was used as the stator core iron loss. The above energy loss was calculated from the difference in induced torque when the stator core was rotated at 300 rpm and an excitation current was applied to an excitation yoke located in the center of the stator core, and when it was not. That is, the relationship that the product of the induced torque and the rotational speed is equal to the energy generated within the stator core was used to determine the energy loss. In Table 1, a smaller iron loss value in the stator core is preferable as it indicates higher magnetic properties. In Table 1, the criteria for judging the iron loss of the stator core were as follows: "Excellent" if the iron loss value is less than 2.40 W / kg, "Good" if it is between 2.40 W / kg and less than 2.60 W / kg, "Acceptable" if it is between 2.60 W / kg and less than 3.3 W / kg, and "Unacceptable" if it is 3.30 W / kg or more.

[0063] On the other hand, the delamination strength of the stator core was measured by the maximum load at which the laminations separated and the iron core was separated by pressing a wedge into the center of the lamination surface. Here, a wedge with a tip angle of 7 degrees was used. This wedge was then pressed into the center height position in the lamination direction of the stator core. In Table 1, a higher peel strength of the stator core is preferable, as it indicates higher rigidity of the stator core. In Table 1, the criteria for judging the rigidity of the stator core were as follows: "Excellent" if the maximum load is 1450N or more, "Good" if it is 980N or more but less than 1450N, "Acceptable" if it is 780N or more but less than 980N, and "Unacceptable" if it is less than 780N.

[0064] [Table 1]

[0065] As shown in Table 1, in No. 1, the average equivalent circle diameter d was too small and the average area ratio AR was too high, resulting in "unacceptable" iron loss in the stator core. In No. 2, although the iron loss of the stator core was "good," the average equivalent diameter d was too small and the average area ratio AR was also too low, resulting in the stator core's peel strength being "unacceptable." In No. 3, although the stator core's peel strength was rated as "excellent," the average area ratio AR was too high, resulting in the stator core's iron loss being rated as "unacceptable." In No. 4, both the average equivalent diameter d and the average area ratio AR were of a high degree of suitability, resulting in a "good" rating for both the stator core's peeling strength and iron loss. In No. 5, although the iron loss of the stator core was "good," the peel strength of the stator core was "unacceptable" because the average area ratio AR was too low.

[0066] In No. 6, both the average equivalent diameter d and the average area ratio AR were of a high degree of suitability, resulting in a "good" peel strength and a "good" iron loss in the stator core. In No. 7, both the average equivalent circle diameter d and the average area ratio AR were of a high degree of suitability, resulting in a "good" peel strength and "excellent" iron loss of the stator core. In No. 8, although the stator core's peel strength was rated as "excellent," the average area ratio AR was too high, resulting in the stator core's iron loss being rated as "unacceptable." In No. 9, both the average equivalent diameter d and the average area ratio AR were of a high degree of suitability, resulting in a "good" rating for both the stator core's peeling strength and iron loss. No. 10 also achieved a "good" rating in both stator core peel strength and iron loss because both the average equivalent diameter d and the average area ratio AR were of a high order of suitability.

[0067] For No. 11, both the average equivalent diameter d and the average area ratio AR were appropriate, resulting in a stator core peel strength of "excellent" and iron loss of "good". For No. 12, both the average equivalent diameter d and the average area ratio AR were appropriate, resulting in a "good" peel strength and "excellent" iron loss for the stator core. In No. 13, although the stator core's peel strength was rated as "excellent," the iron loss of the stator core was rated as "unacceptable" because the average equivalent diameter d was too large and the average area ratio AR was too high. In No. 14, both the average equivalent diameter d and the average area ratio AR were of a high degree of suitability, resulting in a "good" rating for both the stator core's peeling strength and iron loss. In No. 15, the average equivalent circle diameter d was too large and the average area ratio AR was too low, resulting in a "failure" peel strength for the stator core.

[0068] Figure 10 shows a graph of the relationship between the average separation ratio g / d (dimensionless value) and the average area ratio AR (%) for Nos. 1 to 15. As shown in the figure, by setting the average separation ratio g / d to 1.0 to 3.0, the average area ratio AR can be optimized to be between 5% and 20%. As a result, the balance between the size of each bonded area and the average separation is optimized. Nos. 4, 9, 10, and 14, which satisfy this condition, were confirmed to be "excellent" and optimized in terms of both the peel strength and iron loss of the stator core.

[0069] From the above, the basic trend is that when the average equivalent diameter d is appropriate, increasing the average area ratio AR improves the peel strength while decreasing iron loss. Furthermore, it was found that when the average equivalent diameter d is small, increasing the average area ratio AR does not significantly improve the peel strength. This is thought to be because the adhesive area of ​​each bonded part is small, making it easier for peeling to progress even with a high average area ratio AR. Conversely, it was found that when the average equivalent diameter d is large, iron loss does not increase significantly even when the average area ratio AR is lowered. This is thought to be because the stress applied to each adhesive joint on the base steel plate becomes non-uniform.

[0070] From the above, it was confirmed that a high-order balance between the rigidity and iron loss of the stator core can be achieved by setting the average equivalent diameter d to 1.0 mm to 5.0 mm and the average area ratio AR to 4% or more and 80% or less. Furthermore, it was confirmed that the stiffness and iron loss of the stator core can be optimized by setting the average spacing ratio g / d to 1.0 to 3.0.

[0071] [Example 2] Using the manufacturing apparatus 100 shown in Figure 9, stator cores 21 (hereinafter referred to as stator cores) were manufactured using non-oriented electrical steel sheets of different thicknesses while varying various manufacturing conditions, and the iron loss and peel strength of the stator cores were evaluated. The heating conditions for all stator cores were kept the same, with a heating temperature of 180°C and a heating time of 20 minutes. The arrangement of the bonded parts was standardized to a square grid pattern as shown in Figure 6. The evaluation results are summarized in Table 2. The evaluation method and other details were the same as those used in Example 1 above.

[0072] [Table 2]

[0073] In this embodiment, the iron loss, which is the evaluation index, is strongly influenced by the thickness of the electrical steel sheet. Assuming all other factors are equal, the thinner the sheet, the lower the iron loss. Therefore, the results in Table 2 will be explained for each average sheet thickness of the material. First, regarding peel strength, all samples in Table 2 satisfy the conditions that the average equivalent circle diameter d of the bonded area is 1.0 mm to 5.0 mm and the average area ratio AR is 4% to 80%, indicating sufficient strength. The effects of the invention will be explained below, focusing on iron loss. We compare No. 21 and No. 22, both of which have an average plate thickness of 0.10 mm. In these cases, No. 22, where Equation 1 satisfies α ≤ 430, has lower iron loss compared to No. 21, where Equation 1 does not satisfy α ≤ 430. We compare samples No. 23 to No. 25, where the average plate thickness of the material is 0.15 mm. In these samples, the iron loss is lower in No. 24 and No. 25, where Equation 1 satisfies α ≤ 430, compared to No. 23, where Equation 1 does not satisfy α ≤ 430. We compare samples No. 26 to No. 29, where the average plate thickness of the material is 0.20 mm. In these samples, No. 28 and No. 29, where Equation 1 satisfies α ≤ 430, have lower iron loss compared to No. 26 and No. 27, where Equation 1 does not satisfy α ≤ 430.

[0074] From the above, it was confirmed that when the average equivalent diameter d is 1.0 mm to 5.0 mm and the average area ratio AR is 4% to 80%, the above-mentioned equation 1 satisfies α ≤ 430, thereby enabling a high-order balance between the rigidity of the stator core and iron loss.

[0075] Although one embodiment of the present invention and its examples have been described in detail above, the specific configuration is not limited to the configurations of these embodiments and examples, and may also include modifications, combinations, deletions, etc. of the configuration that do not depart from the spirit of the present invention. For example, the shape of the stator core 21 is not limited to the form shown in the above embodiment. Specifically, the outer and inner diameters of the stator core 21, the stacking thickness, the number of slots, the circumferential and radial dimensional ratios of the teeth portion 23, and the radial dimensional ratio between the teeth portion 23 and the core back portion 22 can be arbitrarily designed according to the desired characteristics of the rotating electric machine. In the rotor 30 of the above embodiment, a pair of permanent magnets 32 form one magnetic pole, but the present invention is not limited to this form. For example, one permanent magnet 32 ​​may form one magnetic pole, or three or more permanent magnets 32 may form one magnetic pole.

[0076] In the above embodiment, a permanent magnet field type motor was used as an example to describe the rotating electric machine 10, but the present invention is not limited to this. For example, the rotating electric machine 10 may be a reluctance type motor or an electromagnet field type motor (wound field type motor). In the above embodiment, a synchronous motor was used as an example of an AC motor, but the present invention is not limited thereto. For example, the rotating electric machine 10 may be an induction motor. In the above embodiment, an AC motor was used as an example of the rotating electric machine 10, but the present invention is not limited thereto. For example, the rotating electric machine 10 may be a DC motor. In the above embodiment, an electric motor was used as an example of the rotating electric machine 10, but the present invention is not limited thereto. For example, the rotating electric machine 10 may be a generator. [Explanation of Symbols]

[0077] 2 Base steel plate 3. Insulating coating 3a Adhesive part 21 Stator core (stacked core) 22 Core back section 23 Teeth Department 31. Rotor core (multilayered core) 40 Electrical steel sheet

Claims

1. A laminated core made by stacking three or more electromagnetic steel sheets, Each of the aforementioned electrical steel sheets, Base material steel plate and An insulating coating having adhesive properties formed on one or both sides of the base steel plate, Equipped with, The insulating film has a plurality of adhesive portions having an average circular equivalent diameter d (mm) of 1.0 mm to 5.0 mm. The average area ratio AR obtained by dividing the sum of the surface areas of each adhesive portion by the surface area of ​​the base steel plate is 4% or more and 80% or less. A laminated core characterized in that the value α of Equation 1, which is obtained using the thickness t0 (mm) of each electrical steel sheet, the average circle equivalent diameter d (mm), and the average area ratio AR (%), is 430 or less. α=AR / d / t0 2 ... (Formula 1)

2. The average spacing ratio g / d, obtained by dividing the average spacing g (mm) between adjacent adhesive parts by the average equivalent circle diameter d (mm), is between 1.0 and 3.

0. The laminated core according to feature 1.

3. Each of the aforementioned electrical steel sheets comprises a core back portion and a teeth portion, The ratio W / d, obtained by dividing the average width dimension W (mm) of the teeth portion by the average equivalent diameter d (mm), is between 1.0 and 30.

0. A laminated core according to claim 1 or 2, characterized by the above.

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