Core block, laminated core, and rotating electrical machine

Abstract

An iron core block in which a plurality of iron core blocks are annularly connected to constitute a laminated iron core, the iron core block comprising: a plurality of electromagnetic steel sheet pieces laminated to each other; and a bonding part that is provided between the electromagnetic steel sheet pieces adjacent to each other in the lamination direction and that bonds the electromagnetic steel sheet pieces to each other, the bonding area ratio of the bonding part to the electromagnetic steel sheet pieces being 1%-60% (inclusive).

Description

[0001] This application is a divisional application of the invention patent application with application date of June 22, 2020, application number 2020800449851, and invention name “Core block, laminated core and rotating motor”. Technical Field

[0002] The present disclosure relates to a core block, a laminated core, and a rotating electric machine.

[0003] This application claims priority based on Japanese Patent Application No. 2019-118337 filed in Japan on June 26, 2019, and the contents are incorporated herein by reference. Background Art

[0004] Conventionally, there is known a laminated core as described in the following Patent Document 1. In this laminated core, electromagnetic steel sheets adjacent to each other in the lamination direction are bonded together.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2011-023523 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] In the above-mentioned conventional laminated core, there is room for improvement in terms of improving magnetic characteristics.

[0010] The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the magnetic characteristics of a laminated core.

[0011] Technical means for solving technical problems

[0012] In order to solve the technical problem, the present invention proposes the following means.

[0013] (1) A first embodiment of the present invention is a core block that forms a laminated core by connecting a plurality of them in an annular shape, comprising: a plurality of electromagnetic steel sheets stacked on each other; and a bonding portion that is provided between the electromagnetic steel sheets that are adjacent to each other in the stacking direction and bonds the electromagnetic steel sheets to each other, wherein a bonding area ratio of the bonding portion to the electromagnetic steel sheets is greater than 1% and less than 60%.

[0014] If the electromagnetic steel sheets adjacent to each other in the stacking direction are not fixed by any means, they will be relatively displaced. On the other hand, if the electromagnetic steel sheets adjacent to each other in the stacking direction are fixed by, for example, riveting, plastic strain is applied to a part of the electromagnetic steel sheets, and the magnetic properties of the core blocks are deteriorated.

[0015] In the core block of the above-mentioned structure, the electromagnetic steel sheets adjacent to each other in the stacking direction are bonded to each other by the bonding portion. Therefore, among the plurality of electromagnetic steel sheets as a whole, the relative displacement of the electromagnetic steel sheets adjacent to each other in the stacking direction can be suppressed. Since the bonding area ratio of the bonding portion provided in the electromagnetic steel sheet is 1% or more, the bonding of the electromagnetic steel sheets to each other by the bonding portion is reliable, and the relative displacement of the electromagnetic steel sheets adjacent to each other in the stacking direction can be effectively restricted even during winding, etc. In addition, the method of fixing the electromagnetic steel sheets to each other is not fixing by riveting as described above, but fixing by bonding, so the strain generated in the electromagnetic steel sheets can be suppressed. Based on the above, the magnetic properties of the core block can be ensured.

[0016] However, as the adhesive portion solidifies, compressive stress is generated in the electromagnetic steel sheet. Therefore, even with the bonding by the adhesive portion, strain may be generated in the electromagnetic steel sheet. In the core block of the above-mentioned structure, the bonding area ratio of the adhesive portion to the electromagnetic steel sheet is 60% or less. Therefore, the strain generated in the electromagnetic steel sheet due to the adhesive portion can be suppressed to a low level. Therefore, the magnetic properties of the core block can be further ensured.

[0017] (2) In the core block described in (1) above, the bonding area ratio may be 1% or more and 20% or less.

[0018] According to this configuration, the strain generated in the electromagnetic steel sheet due to the bonding portion can be suppressed to a lower level.

[0019] (3) In the core block described in (1) or (2), it can also be constructed to have an arc-shaped core back and a tooth portion protruding from the core back to one side of the radial direction of the core back, and the bonding portion has: a pair of first parts extending along the circumferential edges of the tooth portion on both sides of the circumference; a second part extending along the circumferential edge of the front end of the tooth portion and connecting the front ends of a pair of the first parts to each other; a pair of third parts extending from the base end of the first part along the circumferential edge of one side of the radial direction of the core back to both sides of the circumference; a fourth part 45b extending circumferentially along the circumferential edge of the other side of the radial direction of the core back; and a pair of fifth parts extending along the circumferential edges of both sides of the circumference of the core back and connecting the third part and the fourth part respectively.

[0020] (4) In the core block described in (3) above, the widths of the second portion and the fifth portion may be narrower than the width of the fourth portion.

[0021] (5) In the core block described in any one of (1) to (4), the bonding portion may be provided on at least a portion of a peripheral edge of the electromagnetic steel sheet.

[0022] By arranging the bonding portion at the periphery of the electromagnetic steel sheet, for example, it is possible to suppress the electromagnetic steel sheet from curling up, etc. This makes it possible to facilitate the winding process and further ensure the magnetic properties of the laminated core.

[0023] (6) In the core block described in any one of (1) to (4), a non-bonding area of ​​the electromagnetic steel sheet where the bonding portion is not provided is formed between a bonding area of ​​the electromagnetic steel sheet where the bonding portion is provided and a peripheral edge of the electromagnetic steel sheet.

[0024] The electromagnetic steel sheets forming the core block are manufactured by punching out the electromagnetic steel sheets as the base material. During the punching process, a strain caused by the punching process is applied to a width corresponding to the thickness of the electromagnetic steel sheets from the periphery of the electromagnetic steel sheets to the inside of the electromagnetic steel sheets. The periphery of the electromagnetic steel sheets is work-hardened by the strain, so it is difficult to cause deformation such as the periphery of the electromagnetic steel sheets curling up locally. Therefore, even if the periphery of the electromagnetic steel sheets is not joined, it is difficult to cause deformation of the electromagnetic steel sheets. Therefore, even if a non-bonding area is formed at the periphery of the electromagnetic steel sheets, the deformation of the electromagnetic steel sheets can be suppressed. Moreover, by forming the non-bonding area in this way, it is possible to suppress the application of excess strain to the electromagnetic steel sheets. Therefore, the magnetic properties of the core block can be further ensured.

[0025] (7) In the core block described in (6), the width of the non-bonded region may be 1 to 10 times the thickness of the electromagnetic steel sheet.

[0026] (8) In the core block described in (1) or (2), it can also be constructed to have an arc-shaped core back and a tooth portion radially protruding from the core back toward the core back, and in the electromagnetic steel sheet, a non-bonding area of ​​the electromagnetic steel sheet where the bonding portion is not provided is formed at the front end of the tooth portion and the circumferential ends of the core back.

[0027] In the core block, the magnetic flux diffuses and extends from the front end of the tooth portion to both circumferential sides. Therefore, the magnetic flux at the front end of the tooth portion is easily concentrated. In addition, the magnetic flux invades the adjacent core block from both circumferential ends of the core back. Therefore, the magnetic flux is easily concentrated at both circumferential ends of the core back. If a bonding area is provided in the area where the magnetic flux is concentrated, the increase in iron loss is likely to become significant. Therefore, if the bonding area is provided at the front end of the tooth portion and the circumferential ends of the core back, the iron loss is likely to increase. According to the above-mentioned structure, since the non-bonding area without a bonding portion is located at the front end of the tooth portion and the circumferential ends of the core back, the bonding area can be arranged away from the area with high magnetic flux density, and the increase in iron loss can be suppressed.

[0028] (9) In the core block described in (1) or (2), it can also be constructed to have an arc-shaped core back and a tooth portion radially protruding from the core back toward the core back, and the bonding area of ​​the bonding portion to the core back is greater than the bonding area of ​​the bonding portion to the tooth portion.

[0029] When the width of the tooth (circumferential dimension) is narrower than the width of the core back (radial dimension), the magnetic flux is concentrated in the tooth and the magnetic flux density of the tooth tends to increase. Therefore, when the electromagnetic steel sheet is strained by the bonding portion, the magnetic properties of the tooth are more affected than the magnetic properties of the core back if the strain is the same.

[0030] The bonding area of ​​the bonding part to the core back is greater than the bonding area of ​​the bonding part to the teeth. Therefore, the influence of the deterioration of the magnetic properties in the teeth due to the strain of the bonding part can be suppressed, and the bonding strength of the laminated core as a whole can be ensured in the core back.

[0031] (10) In the laminated iron core described in any one of (1) to (9), the average thickness of the bonding portion may be 1.0 μm to 3.0 μm.

[0032] (11) In the laminated iron core described in any one of (1) to (10), the average tensile modulus E of the bonding portion may be 1500 MPa to 4500 MPa.

[0033] (12) In the laminated iron core described in any one of (1) to (11), the bonding portion may be a room temperature bonding type acrylic adhesive including SGA composed of an acrylic adhesive containing an elastomer.

[0034] (13) A second aspect of the present invention is a laminated core formed by annularly connecting a plurality of core blocks according to any one of (1) to (12).

[0035] (14) A second aspect of the present invention is a rotating electrical machine including the laminated iron core described in (13).

[0036] Effects of the Invention

[0037] According to the present invention, the magnetic characteristics of the laminated core can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a top view of the rotating electrical machine according to one embodiment of the present invention.

[0039] Figure 2 yes Figure 1 The side view of the core block provided in the rotating electrical machine shown.

[0040] Figure 3 yes Figure 1 A top view of a core block included in the rotating electrical machine shown.

[0041] Figure 4 It is a top view of the core block of Modification Example 1.

[0042] Figure 5 It is a top view of the core block of Modification Example 2.

[0043] Figure 6 It is a top view of the core block of Modification 3.

[0044] Figure 7 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 100%.

[0045] Figure 8 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 90%.

[0046] Fig. 9 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 85%.

[0047] Fig.10 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 70%.

[0048] Fig.11 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 60%.

[0049] Fig.12 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 50%.

[0050] Fig.13 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 40%.

[0051] Fig.14 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 30%.

[0052] Fig.15 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 20%.

[0053] Fig.16 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 15%.

[0054] Fig.17 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 10%.

[0055] Fig.18 It is a top view of a stator used as a simulation object of iron loss in a verification test, and is a top view showing a state where the bonding area ratio is 0%.

[0056] Fig.19 It is a plan view of a comparative stator used as a simulation object of iron loss in a verification test, and is a plan view showing a state where electromagnetic steel sheets are caulked and joined.

[0057] Fig. 20 It is a graph showing the results of the verification test.

[0058] Fig.21 This is a top view of a stator used as a simulation object for iron loss in a verification test.

[0059] Fig. 22 This is a top view of a stator used as a simulation object for iron loss in a verification test. DETAILED DESCRIPTION

[0060] Hereinafter, a rotating electrical machine according to an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, in this embodiment, an electric motor is cited as the rotating electrical machine, specifically an AC motor, more specifically a synchronous motor, and more specifically a permanent magnet excitation type motor as an example for description. Such an electric motor is suitable for use in, for example, electric vehicles, etc.

[0061] like Figure 1 As shown, the rotary electric machine 10 includes a stator 20, a rotor 30, a housing 50, and a rotating shaft 60. The stator 20 and the rotor 30 are accommodated in the housing 50. The stator 20 is fixed to the housing 50.

[0062] In the present embodiment, as the rotating electrical machine 10, an inner rotor type in which the rotor 30 is located inside the stator 20 is adopted. However, as the rotating electrical machine 10, an outer rotor type in which the rotor 30 is located outside the stator 20 may also be adopted. In addition, in the present embodiment, the rotating electrical machine 10 is a three-phase AC motor with 12 poles and 18 slots. However, for example, the number of poles, the number of slots, the number of phases, etc. may be appropriately changed. In addition, the rotating electrical machine 10 can be rotated at a speed of 1000 rpm by applying an excitation current of an effective value of 10A and a frequency of 100 Hz to each phase, for example.

[0063] The stator 20 includes a stator core (laminated core) 21, a connecting ring 29, and a winding (not shown). Hereinafter, the direction along the central axis O of the stator core 21 is referred to as the axial direction, the direction passing through the central axis O of the stator core 21 and being orthogonal to the central axis O is referred to as the radial direction, and the direction around the central axis O of the stator core 21 is referred to as the circumferential direction. In addition, in this specification, the "radial inner side" is sometimes referred to as the "radial one side".

[0064] The rotor 30 is arranged radially inward of the stator 20 (stator core 21 ). The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32 .

[0065] The rotor core 31 is formed in an annular shape (ring shape) 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.

[0066] A plurality of permanent magnets 32 are fixed to the rotor core 31. In the present embodiment, a group of two permanent magnets 32 forms a magnetic pole. The plurality of groups of permanent magnets 32 are arranged at equal intervals in the circumferential direction. In the present embodiment, 12 groups (24 in total) of permanent magnets 32 are arranged at intervals of 30 degrees with the central axis O as the center.

[0067] In the present embodiment, an embedded magnet type motor is used as a permanent magnet excitation type motor. A plurality of through holes 33 are formed on the rotor core 31, which 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. The fixation of each permanent magnet 32 ​​relative 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. In addition, as a permanent magnet excitation type motor, a surface magnet type motor can be used instead of an embedded magnet type motor.

[0068] The rotor core 31 is a laminated core. That is, the rotor core 31 is formed by laminating a plurality of electromagnetic steel sheets. The lamination thickness of the rotor core 31 is, for example, 50.0 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.

[0069] In the present embodiment, the plurality of electromagnetic steel sheets forming the rotor core 31 are fixed to each other by the caulking portions C (pins). However, the plurality of electromagnetic steel sheets forming the rotor core 31 may be bonded to each other.

[0070] Next, the stator core 21 will be described in more detail.

[0071] The stacking thickness of the stator core 21 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. Here, the inner diameter of the stator core 21 is based on the front end of the tooth portion 23 in the stator core 21. The inner diameter of the stator core 21 is the diameter of an imaginary circle inscribed in the front end of all the tooth portions 23.

[0072] The stator core 21 is a split core. Therefore, the stator core 21 has a plurality of core blocks 24. The plurality of core blocks 24 are connected in a ring shape to form the stator core 21. A connecting ring 29 is arranged radially outside the plurality of core blocks 24. The plurality of core blocks 24 are fixed to each other by being embedded in the connecting ring 29.

[0073] Next, the core blocks 24 will be described.

[0074] The core block 24 has an arc-shaped core back 22 and a tooth portion 23 extending in the circumferential direction. Figure 1 , the figure shows the boundary line 24BL between the core back 22 and the tooth portion 23. The core block 24 has a pair of corner portions 24c, which are provided between the radially inner surface and the circumferential surface of the outer surface. The boundary line 24BL is an arc centered on the central axis O and passing through the pair of corner portions 24c.

[0075] The core back 22 is formed in an arc shape centered on the central axis O when the stator 20 is viewed from above in the axial direction.

[0076] The teeth 23 protrude radially inward from the core back 22 (in the radial direction toward the center axis O of the core back 22). The stator core 21 is formed by arranging a plurality of core blocks 24 in an annular shape in the circumferential direction, so that the plurality of teeth 23 are arranged at equal intervals in the circumferential direction. In the stator 20 of the present embodiment, 18 teeth 23 are provided at intervals of 20 degrees with the center axis O as the center. The plurality of teeth 23 are formed in the same shape and size as each other.

[0077] The winding is wound around the teeth 23. The winding may be concentratedly wound or distributedly wound.

[0078] The core block 24 is formed by stacking a plurality of electromagnetic steel sheets 40 in the axial direction, wherein the electromagnetic steel sheets 40 are formed by punching an electromagnetic steel sheet. That is, the core block 24 has a plurality of electromagnetic steel sheets 40 stacked on each other. Therefore, the stator core 21 is a laminated core. The plurality of electromagnetic steel sheets 40 are each T-shaped when viewed from the axial direction.

[0079] Each electromagnetic steel sheet 40 forming the core block 24 is formed, for example, by punching an electromagnetic steel sheet as a base material. As the electromagnetic steel sheet 40, a known electromagnetic steel sheet can be used. The chemical composition of the electromagnetic steel sheet 40 is not particularly limited. In the present embodiment, a non-oriented electromagnetic steel sheet is used as the electromagnetic steel sheet 40. As the non-oriented electromagnetic steel sheet, for example, a non-oriented electrical steel strip of JIS C 2552:2014 can be used. However, as the electromagnetic steel sheet 40, a directional electromagnetic steel sheet can also be used instead of the non-oriented electromagnetic steel sheet. As the directional electromagnetic steel sheet, for example, a directional electrical steel strip of JIS C2553:2012 can be used.

[0080] In order to improve the workability of the electromagnetic steel sheet 40 and the iron loss of the core block 24, an insulating film is provided on both sides of the electromagnetic steel sheet 40. As a material 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, etc. can be applied. As an inorganic compound, for example, (1) a complex of dichromate and boric acid, (2) a complex of phosphate and silicon dioxide, etc. can be cited. As an organic resin, epoxy resin, acrylic resin, acrylic styrene resin, polyester resin, silicon resin, fluorine resin, etc. can be cited.

[0081] In order to ensure the insulation performance between the electromagnetic steel sheets 40 stacked on each other, the thickness of the insulating film (the thickness per single surface of the electromagnetic steel sheet 40 ) is preferably 0.1 μm or more.

[0082] On the other hand, as the insulating coating becomes thicker, the insulating effect is saturated. In addition, as the insulating coating becomes thicker, the proportion of the insulating coating in the core block 24 increases, the magnetic properties of the core block 24 decrease, and the performance as a laminated core decreases. Therefore, the insulating coating is preferably thinner within a range that can ensure the insulating performance. The thickness of the insulating coating (the thickness of each single surface 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.

[0083] As the electromagnetic steel sheet 40 becomes thinner, the iron loss improvement effect gradually saturates. In addition, as the electromagnetic steel sheet 40 becomes thinner, the manufacturing cost of the electromagnetic steel sheet 40 increases. Therefore, considering the iron loss improvement effect and the manufacturing cost, the thickness of the electromagnetic steel sheet 40 is preferably 0.10 mm or more.

[0084] On the other hand, if the electromagnetic steel sheet 40 is too thick, it becomes difficult to punch the electromagnetic steel sheet 40. Therefore, considering the punching work of the electromagnetic steel sheet 40, the thickness of the electromagnetic steel sheet 40 is preferably 0.65 mm or less.

[0085] In addition, if the electromagnetic steel sheet 40 is thicker, the iron loss increases. Therefore, considering the iron loss characteristics of the electromagnetic steel sheet 40, the thickness of the electromagnetic steel sheet 40 is preferably 0.35 mm or less, and more preferably 0.20 mm or 0.25 mm.

[0086] Considering the above point, the thickness of each electromagnetic steel sheet 40 is, for example, 0.10 mm to 0.65 mm, preferably 0.10 mm to 0.35 mm, and more preferably 0.20 mm or 0.25 mm. The thickness of the electromagnetic steel sheet 40 also includes the thickness of the insulating film.

[0087] The plurality of electromagnetic steel sheets 40 forming the core block 24 are bonded together by bonding portions 41. The bonding portions 41 are provided between the electromagnetic steel sheets 40 adjacent to each other in the stacking direction and are adhesives that are cured without being cut. Among adhesives, for example, thermosetting adhesives based on polymerization bonding are used. As adhesive compositions, those containing (1) acrylic resins, (2) epoxy resins, (3) compositions containing acrylic resins and epoxy resins, etc. can be used. As such adhesives, in addition to thermosetting adhesives, free radical polymerization adhesives, etc. can also be used. From the perspective of productivity, it is preferred to use room temperature curing adhesives. Room temperature curing adhesives cure at 20°C to 30°C. As room temperature curing adhesives, acrylic adhesives are preferred. Representative acrylic adhesives include SGA (Second Generation Acrylic Adhesive). Any of anaerobic adhesives, quick-drying adhesives, and acrylic adhesives containing elastomers can be used within the range that does not impair the effects of the present invention. The adhesive referred to here refers to the state before curing, and the adhesive becomes the adhesive portion 41 after curing.

[0088] The average tensile modulus E of the bonding portion 41 at room temperature (20°C to 30°C) is in the range of 1500MPa to 4500MPa. If the average tensile modulus E of the bonding portion 41 is less than 1500MPa, the rigidity of the laminated core is reduced. Therefore, the lower limit of the average tensile modulus E of the bonding portion 41 is 1500MPa, and more preferably 1800MPa. On the contrary, if the average tensile modulus E of the bonding portion 41 exceeds 4500MPa, the insulating coating formed on the surface of the electromagnetic steel sheet 40 is peeled off. Therefore, the upper limit of the average tensile modulus E of the bonding portion 41 is 4500MPa, and more preferably 3650MPa.

[0089] The average tensile modulus E is measured by a resonance method. Specifically, the tensile modulus is measured in accordance with JIS R 1602:1995.

[0090] More specifically, a sample for measurement (not shown) is first prepared. The sample is obtained by bonding two electromagnetic steel sheets 40 with an adhesive of the object to be measured and curing them to form a bonding portion 41. In the case where the adhesive is a thermosetting type, the curing is performed by heating and pressing under the heating and pressing conditions in actual operation. On the other hand, in the case where the adhesive is a room temperature curing type, the curing is performed by pressing at room temperature.

[0091] Then, the tensile modulus of the sample is measured by the resonance method. The method for measuring the tensile modulus by the resonance method is performed in accordance with JIS R 1602: 1995 as described above. Then, the tensile modulus of the bonding portion 41 alone is obtained by calculating the tensile modulus of the sample (measured value) by removing the influence of the electromagnetic steel sheet 40 itself.

[0092] Since the tensile modulus obtained from the sample is equal to the average value of the laminated core as a whole, this value is regarded as the average tensile modulus E. The composition is set so that the average tensile modulus E is almost unchanged at the stacking position along the stacking direction and the circumferential position around the central axis of the laminated core. Therefore, the average tensile modulus E can also be measured at the upper end of the laminated core and the cured bonding portion 41.

[0093] As a bonding method, for example, a method of applying an adhesive to the electromagnetic steel sheet 40 and then bonding by heating or pressing or both can be adopted. In addition, the heating means can be various means such as heating in a high temperature tank or electric furnace, or directly energizing.

[0094] In order to obtain stable and sufficient adhesive strength, the thickness of the adhesive portion 41 is preferably 1 μm or more.

[0095] On the other hand, if the thickness of the adhesive portion 41 exceeds 100 μm, the adhesive force is saturated. In addition, as the thickness of the adhesive portion 41 increases, the proportion of the adhesive portion in the core block 24 increases, and the magnetic properties such as the iron loss of the core block 24 decrease. Therefore, the thickness of the adhesive portion 41 is preferably greater than 1 μm and less than 100 μm, and more preferably greater than 1 μm and less than 10 μm.

[0096] Furthermore, in the above description, the thickness of the adhesive portion 41 refers to the average thickness of the adhesive portion 41 .

[0097] The average thickness of the adhesive portion 41 is more preferably not less than 1.0 μm and not more than 3.0 μm. If the average thickness of the adhesive portion 41 is less than 1.0 μm, sufficient bonding strength cannot be ensured as described above. Therefore, the lower limit of the average thickness of the adhesive portion 41 is 1.0 μm, and more preferably 1.2 μm. On the contrary, if the average thickness of the adhesive portion 41 increases and exceeds 3.0 μm, undesirable conditions such as a significant increase in the strain of the electromagnetic steel sheet 40 due to shrinkage during thermal curing occur. Therefore, the upper limit of the average thickness of the adhesive portion 41 is 3.0 μm, and more preferably 2.6 μm.

[0098] The average thickness of the bonding portion 41 is the average value of the entire laminated core. The average thickness of the bonding portion 41 is almost constant 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 bonding portion 41 can be the average value of the values ​​measured at the upper end position of the laminated core and at more than 10 positions in the circumferential direction.

[0099] In addition, the average thickness of the adhesive portion 41 can be adjusted by, for example, changing the amount of adhesive applied. In addition, the average tensile elastic modulus E of the adhesive portion 41 can be adjusted by, for example, changing the heating and pressurizing conditions applied during bonding and one or both of the types of curing agents in the case of a thermosetting adhesive.

[0100] like Figure 2 As shown, in this embodiment, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are bonded by bonding portions 41. In the example shown in the figure, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are fixed only by bonding, and are not fixed by other means (for example, riveting, etc.).

[0101] exist Figure 3 In the figure, the bonding portion 41 is emphasized by a dot pattern. Figure 3 As shown, the electromagnetic steel sheet pieces 40 adjacent to each other in the stacking direction are not bonded to each other over their entire surfaces. These electromagnetic steel sheet pieces 40 are partially bonded to each other.

[0102] In the present embodiment, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are bonded to each other by the bonding portion 41 provided at the periphery of the electromagnetic steel sheet 40. According to the present embodiment, the bonding portion 41 is provided at the entire periphery of the electromagnetic steel sheet 40. However, the bonding portion 41 may be provided at least at a portion of the periphery of the electromagnetic steel sheet 40.

[0103] The adhesive portions 41 are formed in a strip shape when viewed from above. Here, the strip shape also includes a shape in which the width of the strip changes along the way. For example, a shape in which circular points are not divided but continuous in one direction is also included in the strip shape extending in one direction. In addition, along the periphery of the electromagnetic steel sheet 40, not only the case of being completely parallel to the periphery, but also the case of being inclined within 5 degrees with respect to the periphery, for example.

[0104] The bonding portion 41 includes a tooth portion 44 disposed on the tooth portion 23 and a core back portion 45 disposed on the core back 22. The tooth portion 44 of the bonding portion 41 includes a pair of first portions 44a and a second portion 44b. The core back portion 45 of the bonding portion 41 includes a pair of third portions 45a, a fourth portion 45b, and a pair of fifth portions 45c. That is, the bonding portion 41 includes a pair of first portions 44a, a second portion 44b, a pair of third portions 45a, a fourth portion 45b, and a pair of fifth portions 45c.

[0105] A pair of first portions 44a extend along the circumferential edges of the tooth portion 23 on both sides. A pair of first portions 44a are arranged at intervals in the circumferential direction. A second portion 44b extends along the circumferential edge of the front end of the tooth portion 23 and connects the front ends of the pair of first portions 44a. A pair of third portions extend from the base end of the first portion 44a along the circumferential edge of the radial inner side (one side in the radial direction) of the core back 22 to both sides in the circumferential direction. The fourth portion 45b extends circumferentially along the circumferential edge of the radial outer side (the other side in the radial direction) of the core back 22. A pair of fifth portions 45c extend along the circumferential edges of the core back 22 on both sides in the circumferential direction and connect the third portion 45a and the fourth portion 45b, respectively.

[0106] According to the present embodiment, the first portion 44a, the second portion 44b, the third portion 45a, the fourth portion 45b, and the fifth portion 45c of the bonding portion 41 are formed to have the periphery that constitutes the outer shape of the electromagnetic steel sheet 40. Therefore, the electromagnetic steel sheet 40 stacked near the periphery of the bonding portion 41 can be firmly held. As a result, the curling that is likely to occur near the periphery of the electromagnetic steel sheet 40 can be effectively suppressed, and the bonding area ratio can be reduced while firmly fixing the electromagnetic steel sheet 40 to each other.

[0107] In addition, in the present embodiment, in the plan view of the electromagnetic steel sheet 40, the adhesive portion 41 is provided without a gap from the periphery of the electromagnetic steel sheet 40, but the present invention is not limited thereto. Figure 4As shown in the core block 124 of the first modification, in the plan view of the electromagnetic steel sheet 40, the bonding portion 141 may be provided with a gap relative to the periphery of the electromagnetic steel sheet 40. That is, between the bonding region 142 of the electromagnetic steel sheet 40 provided with the bonding portion 141 and the periphery of the electromagnetic steel sheet 40, a non-bonding region 143 of the electromagnetic steel sheet 40 not provided with the bonding portion 141 may be formed. In addition, the bonding region 142 of the electromagnetic steel sheet 40 provided with the bonding portion 141 refers to a region on the surface of the electromagnetic steel sheet 40 facing the stacking direction (hereinafter referred to as the first surface of the electromagnetic steel sheet 40) where the adhesive is not divided and solidified. The non-bonding region 143 of the electromagnetic steel sheet 40 not provided with the bonding portion 141 refers to a region on the first surface of the electromagnetic steel sheet 40 where the adhesive is not divided and solidified.

[0108] In addition, for example Figure 5 As in the core block 224 of the second modification shown in FIG. 1 , the bonding portion 241 may be configured not to have the portions corresponding to the second portion 44b and the fifth portion 45c in the bonding portion 41 of the above-mentioned embodiment. That is, in the electromagnetic steel sheet 40, a non-bonded region 243 of the electromagnetic steel sheet 40 without the bonding portion 241 may be formed at the front end of the tooth portion 23 and at both ends of the core back 22 in the circumferential direction. In addition, in this modification, the bonding portion 241 includes: a pair of first portions 244a arranged at intervals in the circumferential direction on the tooth portion 23 and extending in the radial direction; a pair of third portions 245a extending along the radial inner edge of the core back 22; and a fourth portion 245b extending along the radial outer edge of the core back 22.

[0109] Furthermore, if Figure 6 As shown in the modification 3 of the iron core block 324, the width dimension of each part of the bonding part 341 can also be set to a different configuration from the above-mentioned embodiment. The bonding part 341 of the modification 3 has a pair of first parts 344a, a second part 344b, a pair of third parts 345a, a fourth part 345b, and a pair of fifth parts 345c, as in the above-mentioned embodiment. In this modification, the widths of the first part 344a, the second part 344b, the third part 345a, and the fifth part 345c are approximately equal. On the other hand, the width of the fourth part 345b is wider than the widths of the other parts (the first part 344a, the second part 344b, the third part 345a, and the fifth part 345c) of the bonding part 341.

[0110] In addition, in this specification, the "width" of each part of the bonding portion 341 refers to the dimension in the direction orthogonal to the direction in which the part extends. For example, the width of the second part 344b, the third part 345a, and the fourth part 345b is the dimension along the radial direction of each part. In addition, the width of the first part 344a and the fifth part 345c is the dimension along the circumferential direction of each part.

[0111] In this specification, the width of each portion of the bonding portion 41 is 1.5% or more of the outer diameter of the stator core 21. When the width of each portion of the bonding portion 41 is 1.5% or more of the outer diameter of the stator core 21, sufficient bonding strength between the electromagnetic steel sheets 40 can be ensured.

[0112] like Figure 2 As shown, in the present embodiment, the top view shapes of all the bonding portions 41 provided between the electromagnetic steel sheets 40 are the same. The top view shape of the bonding portion 41 refers to the overall shape of the bonding portion 41 when the electromagnetic steel sheet 40 provided with the bonding portion 41 is viewed from the stacking direction. The top view shapes of all the bonding portions 41 provided between the electromagnetic steel sheets 40 are the same, which includes not only the case where the top view shapes of all the bonding portions 41 provided between the electromagnetic steel sheets 40 are completely the same, but also the case where the top view shapes of all the bonding portions 41 provided between the electromagnetic steel sheets 40 are substantially the same with 95% or more of the parts being common.

[0113] Furthermore, in the present embodiment, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 is greater than 1% and less than 60%. In the illustrated example, the bonding area ratio is greater than 1% and less than 20%, specifically, 20%. In addition, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 refers to the ratio of the area of ​​the region (bonding region 42) on the first surface where the bonding portion 41 is provided to the area of ​​the first surface of the electromagnetic steel sheet 40. The region where the bonding portion 41 is provided refers to the region (bonding region 42) on the first surface of the electromagnetic steel sheet 40 where the adhesive that is not cut and solidified is provided. The area of ​​the region where the bonding portion 41 is provided is obtained, for example, by photographing the first surface of the electromagnetic steel sheet 40 after peeling and performing image analysis on the photographing result.

[0114] In the present embodiment, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 is 1% or more and 20% or less between the electromagnetic steel sheet pieces 40. In the two electromagnetic steel sheet pieces 40 adjacent to each other in the stacking direction, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet pieces 40 is 1% or more and 20% or less. In the case where the bonding portion 41 is provided on both sides of one electromagnetic steel sheet piece 40 in the stacking direction, the bonding area ratio of both sides of the electromagnetic steel sheet piece 40 is 1% or more and 20% or less.

[0115] Furthermore, in the present embodiment, it is preferred that the bonding area of ​​the bonding portion 41 to the core back 22 (hereinafter referred to as the "first bonding area S1") is greater than or equal to the bonding area of ​​the bonding portion 41 to the tooth portion 23 (hereinafter referred to as the "second bonding area S2".). S2.

[0116] Here, the first bonding area S1 is the area of ​​the core back portion 45 where the bonding portion 41 is provided on the first surface of the electromagnetic steel sheet 40. Similarly, the second bonding area S2 is the area of ​​the tooth portion 44 where the bonding portion 41 is provided on the first surface of the electromagnetic steel sheet 40. In addition, like the area of ​​the area where the bonding portion 41 is provided, the first bonding area S1 and the second bonding area S2 are obtained by, for example, photographing the first surface of the electromagnetic steel sheet 40 after peeling and performing image analysis on the photographed result.

[0117] In the core block 24, if the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are not fixed by any means, the two are relatively displaced. On the other hand, when the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are fixed by, for example, riveting, plastic strain is applied to a part of the electromagnetic steel sheet 40, and the magnetic properties of the core block 24 are deteriorated. Riveting is a method of restricting the relative displacement of the electromagnetic steel sheet 40 by plastically deforming a part of the electromagnetic steel sheet 40 and biting in the stacking thickness direction. If plastic strain is applied to the electromagnetic steel sheet 40, the magnetic properties are deteriorated. Therefore, if riveting is used as a method for fixing the electromagnetic steel sheet 40, the magnetic properties of the core block 24 as a whole are also deteriorated.

[0118] In contrast, in the core block 24 of the present embodiment, the electromagnetic steel sheets 40 adjacent in the stacking direction are bonded to each other by the bonding portion 41. Therefore, in the entirety of the plurality of electromagnetic steel sheets 40, the relative displacement of the electromagnetic steel sheets 40 adjacent in the stacking direction can be suppressed. Here, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheets 40 is 1% or more. Therefore, the bonding by the bonding portion 41 is made reliable, and the relative displacement of the electromagnetic steel sheets 40 adjacent in the stacking direction can be effectively suppressed even when the teeth 23 of the core block 24 are wound. In addition, the fixing method of the electromagnetic steel sheets 40 is not the fixing by caulking as described above, but the fixing by bonding, so the strain generated in the electromagnetic steel sheets 40 can be suppressed. As described above, the magnetic properties of the core block 24 can be ensured. In addition, when it is desired to further increase the bonding strength so as to suppress the separation of the electromagnetic steel sheets 40 even when an impact is applied, it is more preferable to set the bonding area ratio to 10% or more.

[0119] Furthermore, if adhesive is applied to the electromagnetic steel sheet 40 , compressive stress is generated in the electromagnetic steel sheet 40 as the adhesive cures. Therefore, when the adhesive is applied to the electromagnetic steel sheet 40 to form the bonding portion 41 , strain may be generated in the electromagnetic steel sheet 40 .

[0120] However, in the core block 24 of the present embodiment, the bonding area ratio of the bonding portion 41 to the electromagnetic steel plate 40 is 60% or less. Therefore, the strain generated in the electromagnetic steel plate 40 due to the adhesive can be suppressed to a low level. Therefore, the magnetic properties of the core block 24 can be further ensured.

[0121] Furthermore, the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 is 20% or less. Therefore, the strain generated in the electromagnetic steel sheet 40 due to the adhesive can be suppressed to a lower level.

[0122] The bonding portion 41 is provided on a bonding region 42 formed on at least a portion of the periphery of the electromagnetic steel sheet 40. Therefore, for example, the electromagnetic steel sheet 40 adjacent to each other in the stacking direction can be prevented from curling up. Thus, the winding of the teeth 23 of the core block 24 can be facilitated, and the magnetic properties of the core block 24 can be further ensured. Therefore, the magnetic properties of the core block 24 can be further ensured.

[0123] When the width W1 (circumferential dimension) of the tooth portion 23 is narrower than the width W2 (radial dimension) of the core back 22, the magnetic flux is concentrated on the tooth portion 23, and the magnetic flux density of the tooth portion 23 tends to increase. Therefore, when the steel plate is strained by the adhesive, the magnetic properties of the tooth portion 23 are more affected than the magnetic properties of the core back 22 if the strain is the same.

[0124] In this embodiment, the first bonding area S1 is preferably equal to or larger than the second bonding area S2. In this case, the influence of deterioration of magnetic properties of the teeth 23 due to strain of the adhesive can be suppressed, and the bonding strength of the core block 24 as a whole can be ensured in the core back 22.

[0125] Furthermore, the electromagnetic steel sheet 40 forming the core block 24 is manufactured by punching an electromagnetic steel sheet as a base material. During the punching process, a strain caused by the punching process is applied to a width corresponding to the thickness of the electromagnetic steel sheet 40 from the periphery of the electromagnetic steel sheet 40 toward the inner side of the electromagnetic steel sheet 40. The periphery of the electromagnetic steel sheet 40 is work-hardened by the above-mentioned strain, so it is difficult to cause deformation such as partial curling of the periphery of the electromagnetic steel sheet 40. Therefore, even if the periphery of the electromagnetic steel sheet 40 is not bonded, it is difficult to cause deformation of the electromagnetic steel sheet 40. Therefore, if Figure 4Even if the non-bonding region 143 is formed on the periphery of the electromagnetic steel sheet 40 as in the core block 124 of the modified example 1 shown in the figure, the deformation of the electromagnetic steel sheet 40 can be suppressed. Furthermore, by forming the non-bonding region 143 in this way, it is possible to suppress the application of unnecessary strain to the electromagnetic steel sheet 40. Therefore, the magnetic properties of the core block 24 can be further ensured.

[0126] In addition, if Figure 4 As shown in the figure, by providing the non-contact area 143 between the periphery of the electromagnetic steel sheet 40 and the adhesive portion 141, it is possible to suppress the uncured adhesive from being squeezed out from the periphery of the electromagnetic steel sheet 40 when the electromagnetic steel sheet 40 is stacked. If the adhesive is cured in a state of being squeezed out from the front end of the tooth portion 23, it may interfere with the rotating rotor 30. In addition, if the adhesive is cured in a state of being squeezed out from the side of the tooth portion 23, the cross-sectional area of ​​the groove between the teeth 23 is compressed, and the space factor of the coil may be reduced.

[0127] The width of the non-adhesive region 143 is preferably 1 or more and 10 or less times the thickness of the electromagnetic steel sheet 40. By setting the width of the non-adhesive region 143 to 1 or more, the squeeze-out of the adhesive can be effectively suppressed. In addition, by setting the width of the non-adhesive region 143 to 10 or less times, it is expected that the effect of suppressing the curling of the electromagnetic steel sheet 40 due to work hardening from the periphery of the electromagnetic steel sheet 40 can be obtained.

[0128] In this specification, the "width" of the non-adhesive region 143 refers to the dimension in the direction perpendicular to the direction in which each part of the non-adhesive region 143 extends. The width of the non-adhesive region 143 is preferably within the above range over the entire length of the non-adhesive region 143.

[0129] In the core block 24, the magnetic flux spreads and extends from the front end of the tooth portion 23 to both sides in the circumferential direction. Therefore, the magnetic flux at the front end of the tooth portion 23 is easily concentrated. In addition, the magnetic flux invades the adjacent core block 24 from both ends of the core back 22 in the circumferential direction. Therefore, the magnetic flux is easily concentrated at both ends of the core back 22 in the circumferential direction. If the bonding area 42 is provided in the area where the magnetic flux is concentrated, the increase in iron loss is likely to become significant. Therefore, if Figure 5 As shown in the second modification, by providing the non-bonding area 243 at the front end of the tooth portion 23 and at both circumferential ends of the core back 22, the bonding area 242 can be arranged away from the area with high magnetic flux density, thereby suppressing the increase of iron loss.

[0130] The magnetic flux B tends to flow through the shortest distance with low magnetic resistance. Therefore, in the core back 22, the magnetic flux density decreases as it moves from the radial inner side (radial one side) connected to the tooth portion 23 to the radial outer side (radial other side) away from the tooth portion 23. On the other hand, as described above, the magnetic flux tends to concentrate at the front end of the tooth portion 23 and the circumferential ends of the core back 22. Figure 6 In the third modification, the widths of the second portion 344b and the fifth portion 345c located at the front end of the tooth portion 23 and the circumferential ends of the core back 22 are narrower than the width of the fourth portion 345b extending along the radially outer peripheral edge of the core back 22. That is, according to the third modification, the widths of the second portion 344b and the fifth portion 345c where the magnetic flux density is easy to increase are narrowed, and the increase in iron loss can be suppressed. In addition, according to the third modification, by increasing the width of the fourth portion 345b where the magnetic flux density is difficult to increase, the bonding strength between the electromagnetic steel sheets 40 can be improved while reducing the influence of the bonding portion 341 on the iron loss.

[0131] In addition, the protective scope of the present invention is not limited to the above-described embodiments, and various modifications can be added without departing from the gist of the present invention.

[0132] The shape of the core block 24 is not limited to the form shown in the above embodiment. The dimensions of each part of the core block 24, the thickness of the electromagnetic steel plate 40, etc. can be arbitrarily designed according to the desired characteristics of the rotating electrical machine.

[0133] In addition, in the core block, a convex shape may be provided on one circumferential end face of the core back, and a concave shape may be provided on the other circumferential end face. In this case, the convex shape can be inserted into the concave shape to suppress positional deviation when connecting multiple core blocks in the circumferential direction.

[0134] In addition, the core block may have two or more teeth for one core back. Furthermore, the core block may have a core back and teeth that are separate from each other.

[0135] In the rotor of the embodiment, a set of two permanent magnets 32 forms one magnetic pole, but the present invention is not limited thereto. For example, one permanent magnet 32 ​​may form one magnetic pole, or three or more permanent magnets 32 may form one magnetic pole.

[0136] In the above-described embodiment, a permanent magnet excitation type motor is described as an example of a rotating electrical machine, but the structure of the rotating electrical machine is not limited to this as exemplified below, and various well-known structures not exemplified below may be adopted.

[0137] In the above embodiment, a permanent magnet excitation type motor is exemplified as a synchronous motor, but the present invention is not limited thereto. For example, the rotating electric machine may be a reluctance type motor or an electromagnetic excitation type motor (winding excitation type motor).

[0138] In the above embodiment, a synchronous motor is described as an example of an AC motor, but the present invention is not limited to this. For example, the rotating electrical machine may be an induction motor.

[0139] In the above embodiment, an AC motor is described as an example of a motor, but the present invention is not limited to this. For example, the rotating electrical machine may be a DC motor.

[0140] In the above embodiment, an electric motor is described as an example of a rotating electrical machine, but the present invention is not limited to this. For example, the rotating electrical machine may be a generator.

[0141] In the above-described embodiment, the laminated iron core of the present invention is applied to a stator core, but it can also be applied to a rotor core. In addition, the laminated iron core of the present invention can also be applied to laminated iron cores other than rotating electrical machines such as transformers.

[0142] Furthermore, the components in the above-described embodiments may be appropriately replaced with well-known components without departing from the gist of the present invention, and the above-described modifications may be appropriately combined.

[0143] For example, the core block may also combine the configuration of Modification Example 1 and the configuration of Modification Example 2. Figure 4 As shown in the first modification example, a non-contact area 143 is provided between the periphery of the electromagnetic steel sheet 40 and the bonding portion 141, and further Figure 5 As in the second modified example shown, non-bonding regions 243 are provided at the front end of the teeth 23 and at both ends in the circumferential direction of the core back 22 .

[0144] Similarly, the core block may also combine the configuration of Modification Example 1 and the configuration of Modification Example 3. Figure 4 As in the first modification shown in FIG. 1 , a non-contact region 143 is provided between the periphery of the electromagnetic steel sheet 40 and the bonding portion 141, and Figure 6 As in the third modified example shown, the widths of the second portion 344b and the fifth portion 345c of the adhesive portion 341 are configured to be narrower than the width of the fourth portion 345b.

[0145] Example

[0146] Next, verification tests (first to third verification tests) were carried out to verify the above-mentioned effects. In addition, this verification test was carried out by simulation using software. As software, finite element method electromagnetic field analysis software JMAG manufactured by JSOL Corporation was used.

[0147] (First verification test)

[0148] Figures 7 to 18 12 types of stator cores 21A to 21L are shown in the figure. Figure 3The stator core 21 of the embodiment shown is a basic structure, and the following points are changed about the stator core 21. The stator cores 21A to 21L respectively have a plurality of core blocks 24A to 24L. In addition, the plate thickness of the electromagnetic steel plate 40 is set to 0.25 mm. And the bonding area ratio of the bonding portion 41 to each electromagnetic steel plate 40 is made different from each other in the range of 0% to 100%. More specifically, the bonding area ratio of the stator core 21A is 100%. The bonding area ratio of the stator core 21B is 90%. The bonding area ratio of the stator core 21C is 85%. The bonding area ratio of the stator core 21D is 70%. The bonding area ratio of the stator core 21E is 60%. The bonding area ratio of the stator core 21F is 50%. The bonding area ratio of the stator core 21G is 40%. The bonding area ratio of the stator core 21H is 30%. The bonding area ratio of the stator core 21I is 20%.

[0149] The bonding area ratio of the stator core 21J is 15%. The bonding area ratio of the stator core 21K is 10%.

[0150] The bonding area ratio of the stator core 21L is 0%.

[0151] The iron losses of 12 types of stator cores 21A to 21L were obtained through the simulation. Fig.19 As shown, the iron loss of the comparative stator core 21X in which multiple electromagnetic steel sheets 40 are riveted in full layers is also calculated. The comparative stator core 21X has multiple core blocks 24X. The plate thickness of the electromagnetic steel sheets 40 of the comparative stator core 21X is also 0.25 mm. In the core blocks of the comparative stator core 21X, a first riveted portion C1 provided on the core back 22 and two second riveted portions C2 provided on the tooth portion 23 are respectively provided. The first riveted portion C1 is located at the circumferential center of the core back 22. The two second riveted portions C2 are arranged radially at the circumferential center of the tooth portion 23. The ratio of the area occupied by the riveted portions C1 and C2 on the first surface of the electromagnetic steel sheet 40 is about 3.2%.

[0152] The results are shown in Fig. 20 . Fig. 20 In the graph, the horizontal axis is the bonding area ratio of the electromagnetic steel sheet 40 of the stator cores 21A to 21L. In addition, the vertical axis is the iron loss suppression rate Rt expressed as a percentage of the value obtained by dividing the difference between the iron loss of each stator core 21A to 21L and the iron loss of the comparative stator core 21X by the iron loss of the comparative stator core 21X. That is, Fig. 20 The iron loss suppression rate Rt on the vertical axis of the graph is expressed by the following equation (1) when the iron loss of each stator core 21A to 21L is represented by W and the iron loss of the comparative stator core 21X is represented by Worg.

[0153] [Formula 1]

[0154]

[0155] If the iron loss of the electromagnetic steel sheet 40 in each stator core 21A to 21L is equal to the iron loss in the comparative stator core 21X, the value of the vertical axis is 0%. The smaller the iron loss suppression rate, the smaller the iron loss, indicating that the magnetic characteristics as the stator core are excellent.

[0156] according to Fig. 20 The graph shown in FIG. 1 shows that by setting the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 to 60% or less, it is confirmed that the iron loss is smaller than that of the comparative stator core 21X of the prior art. In addition, it is confirmed that by setting the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 to 40% or less, the iron loss can be improved by 3% or more compared to the comparative stator core 21X of the prior art. Furthermore, it is confirmed that by setting the bonding area ratio of the bonding portion 41 to the electromagnetic steel sheet 40 to 20% or less, the iron loss can be improved by 5% or more compared to the comparative stator core 21X of the prior art.

[0157] (Second verification test)

[0158] Next, the bonding strength of the electromagnetic steel sheets was verified when the bonding area ratio was changed.

[0159] First, core blocks were prepared in which electromagnetic steel sheets with a bonding area ratio of 0% (i.e., no bonding) were stacked, core blocks were stacked in which electromagnetic steel sheets with a bonding area ratio of 0.5%, core blocks were stacked in which electromagnetic steel sheets with a bonding area ratio of 1%, and core blocks were stacked in which electromagnetic steel sheets with a bonding area ratio of 10%. Then, the teeth of these core blocks were wound to confirm whether the winding could be smoothly performed. The inspection results are shown in Table 1.

[0160] [Table 1]

[0161] Bonding area ratio Can winding be done 0％ × 0.5％ × 1％ ○ 10％ ○

[0162] In Table 1, "×" means that the core block collapsed due to the force applied to the core block during winding. In addition, "○" means the end of winding. According to this verification, it is confirmed that the bonding strength required for winding can be ensured by setting the bonding area ratio of the electromagnetic steel sheet to 1% or more. In addition, the bonding strength of the samples with the bonding area ratio set to 1% and 10% was confirmed, and it was confirmed that the strength of the sample with the bonding area ratio set to 10% was high. From the viewpoint of obtaining sufficient bonding strength in order to suppress peeling of the bonding portion during falling, it is preferred to set the bonding area ratio to 10% or more.

[0163] (3rd verification test)

[0164] This verification test is a verification test related to the width of each part of the adhesive portion. In addition, the conditions of the simulation and the conditions of the dimensions are the same as those of the first verification test.

[0165] Fig.21 and Fig. 22 The two types of stator cores 21M and 21N simulated in this verification test are shown. Figure 3 The stator core 21 of the illustrated embodiment is a basic structure.

[0166] Fig.21 The width of the second portion 44b and the fifth portion 45c of the bonding portion 41M of the stator core 21M shown is wider than the width of the other portions. Fig. 22 The width of the fourth portion 45b of the bonding portion 41N of the stator core 21N shown is wider than the width of other portions. In addition, the areas of the bonding portions 41N of the stator cores 21M and 21N are equal to each other. Therefore, the bonding strengths of the stator cores 21M and 21N are equal to each other.

[0167] Through simulation calculation of the iron loss of the stator cores 21M and 21N, the iron loss of the stator core 21N is 98% of the iron loss of the stator core 21M. That is, the iron loss of the stator core 21N is improved by 2% compared with the stator core 21M. This is considered to be because the widths of the second portion 44b and the fifth portion 45c in the stator core 21N are narrower than the width of the fourth portion 45b, so that the magnetic flux easily flows in the stator core 21N.

[0168] Description of Reference Numerals

[0169] 10...Rotary motor

[0170] 21…Stator core (laminated core)

[0171] 22…Core back

[0172] 23…Gear

[0173] 24, 124, 224, 324… iron core block

[0174] 40…Electromagnetic steel sheet

[0175] 41, 141, 241, 341…bonding part

[0176] 42, 142, 242…bonding area

[0177] 143, 243…Non-bonding area

[0178] 44a, 244a, 344a…Part 1

[0179] 44b, 344b…Part 2

[0180] 45a, 245a, 345a…Part 3

[0181] 45b, 245b, 345b…Part 4

[0182] 45c, 345c…Part 5

Claims

1. A core block is a core block formed by connecting a plurality of core blocks in a ring shape to form a laminated core, comprising: A plurality of electromagnetic steel sheets stacked on top of each other; as well as a bonding portion provided between the electromagnetic steel sheets adjacent to each other in the stacking direction and bonding the electromagnetic steel sheets to each other, The electromagnetic steel sheet has an arc-shaped core back and a tooth portion protruding from the core back toward one side in a radial direction of the core back. The bonding portion has: a pair of first portions extending along the peripheral edges of both sides of the tooth portion in the circumferential direction; a pair of third portions extending from a base end of the first portion to both sides in the circumferential direction along a peripheral edge of one side in the radial direction of the core back; and a fourth portion extending circumferentially along the peripheral edge of the other radial side of the core back, The bonding area ratio of the bonding portion to the electromagnetic steel sheet is 1% or more and 60% or less. The width of the fourth portion is wider than the widths of the first portion and the third portion, An area where the bonding portion is bonded to the core back is larger than an area where the bonding portion is bonded to the teeth.

2. The core block according to claim 1, wherein: The bonding area ratio is 1% or more and 20% or less.

3. The core block according to claim 1 or 2, wherein: The bonding portion has: a second portion extending along the periphery of the front end of the tooth portion and connecting the front ends of the pair of first portions; as well as A pair of fifth portions extending along the peripheral edges of both sides of the core back in the circumferential direction and respectively connecting the third portion and the fourth portion.

4. The core block according to claim 3, wherein: The widths of the second portion and the fifth portion are narrower than the width of the fourth portion.

5. The core block according to claim 1 or 2, wherein: The average thickness of the adhesive portion is 1.0 μm to 3.0 μm.

6. The core block according to claim 1 or 2, wherein: The average tensile elastic modulus E of the bonding portion is 1500 MPa to 4500 MPa.

7. A core block is a core block formed by connecting a plurality of core blocks in a ring shape to form a laminated core, comprising: A plurality of electromagnetic steel sheets stacked on top of each other; as well as a bonding portion provided between the electromagnetic steel sheets adjacent to each other in the stacking direction and bonding the electromagnetic steel sheets to each other, The electromagnetic steel sheet has an arc-shaped core back and a tooth portion protruding from the core back toward one side in a radial direction of the core back. The bonding portion has: a pair of first portions extending along the peripheral edges of both sides of the tooth portion in the circumferential direction; a pair of third portions extending from a base end of the first portion to both sides in the circumferential direction along a peripheral edge of one side in the radial direction of the core back; and a fourth portion extending circumferentially along the peripheral edge of the other radial side of the core back, The bonding area ratio of the bonding portion to the electromagnetic steel sheet is 1% or more and 60% or less. The adhesive portion is an acrylic adhesive of a room temperature adhesive type including SGA composed of an acrylic adhesive containing an elastomer.

8. The core block according to claim 7, wherein: The bonding area ratio is 1% or more and 20% or less.

9. The core block according to claim 7 or 8, wherein: The bonding portion has: a second portion extending along the periphery of the front end of the tooth portion and connecting the front ends of the pair of first portions; as well as A pair of fifth portions extending along the peripheral edges of both sides of the core back in the circumferential direction and respectively connecting the third portion and the fourth portion.

10. The core block according to claim 9, wherein: The widths of the second portion and the fifth portion are narrower than the width of the fourth portion.

11. The core block according to claim 7 or 8, wherein: The average thickness of the adhesive portion is 1.0 μm to 3.0 μm.

12. The core block according to claim 7 or 8, wherein: The average tensile elastic modulus E of the bonding portion is 1500 MPa to 4500 MPa. 13 . A laminated core, comprising a plurality of core blocks according to claim 1 connected in an annular shape.

14. A rotating electric machine comprising the laminated core according to claim 13.

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