Laminated core and rotating motor

Abstract

The stacked core includes: a plurality of electromagnetic steel plates stacked on each other; and a bonding portion, which is provided between the electromagnetic steel plates adjacent to each other in the stacking direction, and the bonding portion bonds the electromagnetic steel plates to each other respectively, the electromagnetic steel plates having an annular core back and a plurality of tooth portions, the plurality of tooth portions extending from the core back along the radial direction of the core back and arranged at intervals in the circumferential direction of the core back, the tooth portion of the electromagnetic steel plate having a bonding area provided with a band-shaped bonding portion extending in the circumferential direction.

Description

Technical Field

[0001] The present disclosure relates to a laminated core and a rotating electric machine.

[0002] This application claims priority based on Japanese Patent Application No. 2018-235857 filed in Japan on December 17, 2018, and the contents are incorporated herein by reference. Background Art

[0003] Conventionally, there is known a laminated core 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.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-023523 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned conventional laminated core, there is room for improvement in terms of improving magnetic properties.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the magnetic properties of a laminated core.

[0010] Technical solutions for solving technical problems

[0011] (1) One embodiment of the present invention is a laminated core, comprising: a plurality of electromagnetic steel sheets stacked on each other; and a bonding portion, which is provided between the electromagnetic steel sheets adjacent to each other in the stacking direction, and bonds the electromagnetic steel sheets to each other, the electromagnetic steel sheets having an annular core back and a plurality of tooth portions, the plurality of tooth portions extending from the core back in a radial direction of the core back and arranged at intervals in a circumferential direction of the core back, the tooth portions of the electromagnetic steel sheets having a bonding area provided with a band-shaped bonding portion extending in a circumferential direction.

[0012] According to the above configuration, the tooth portion of the electromagnetic steel sheet has a bonding area provided with a band-shaped bonding portion. The band-shaped bonding portion is along one direction, so that the bonding area of ​​the bonding portion can be increased and the bonding strength can be improved compared with the case where dot-shaped bonding portions are intermittently provided in the same range.

[0013] Distortion caused by the curing shrinkage of the adhesive occurs in the area of ​​the electromagnetic steel sheet in contact with the bonding portion, and the iron loss of the electromagnetic steel sheet in this area increases. Here, the area of ​​the electromagnetic steel sheet in contact with the bonding portion and where the iron loss increases due to distortion is referred to as a "degraded area". According to the above-mentioned structure, the bonding portion is in the shape of a band extending in the circumferential direction and is provided on the tooth portion, so that the degraded area extends circumferentially on the tooth portion. Since the magnetic flux flowing through the tooth portion is radial, the degraded area extends circumferentially, thereby shortening the path length of the magnetic flux passing through the degraded area. Therefore, the magnetic resistance to each magnetic flux in the magnetic circuit becomes smaller, and the degradation of the magnetic properties of the laminated core can be suppressed.

[0014] (2) In the laminated core of (1) above, the bonding region may be formed on the core back side relative to the vicinity of the front end of the tooth portion.

[0015] The magnetic flux spreads and extends from the front end of the tooth portion to both sides in the circumferential direction. Therefore, near the front end of the tooth portion, the magnetic flux tends to concentrate at both ends in the circumferential direction. If a degraded region is set in the area where the magnetic flux is concentrated, the increase in iron loss tends to become significant. Therefore, if the degraded region is set near the front end of the tooth portion, the iron loss tends to become larger. According to the above-mentioned structure, since the bonding area is located closer to the core back side than near the front end of the tooth portion, the degraded region can be separated from the area with higher magnetic flux density, and the increase in iron loss can be suppressed.

[0016] (3) In the laminated core of (1) or (2), the radial width dimension of the bonding region may increase from the circumferential center of the tooth portion toward the circumferential end portion of the tooth portion.

[0017] The magnetic flux spreads and extends from the front end of the tooth portion to both sides in the circumferential direction. In addition, the magnetic flux has a tendency to flow in a manner that passes through the shortest distance. Therefore, the magnetic flux density of the tooth portion increases as it moves toward the circumferential end side. If the deviation of the magnetic flux density of the tooth portion in the circumferential direction becomes larger, the magnetic properties of the laminated core may be reduced. According to the above-mentioned structure, the radial width dimension of the bonding area increases as it moves from the central part of the tooth portion toward the circumferential end side. That is, the radial length of the degraded area becomes longer as it moves from the central part of the tooth portion toward the circumferential end side. Therefore, the magnetic resistance of the tooth portion increases as it moves toward the circumferential outer side, and it is difficult for the magnetic flux to flow on the circumferential end side. As a result, the deviation of the magnetic flux density of the tooth portion can be suppressed, the magnetic flux density in the tooth portion can be made close to the same, and the magnetic properties of the laminated core can be improved.

[0018] (4) In the laminated core described in (1) or (2), the bonding region may extend in an arc shape along the circumferential direction.

[0019] According to the above configuration, since the adhesive portion can be applied uniformly along the circumferential direction, the manufacturing process can be simplified.

[0020] (5) In the laminated core described in (1) to (4) above, the bonding portion may extend over the entire width of the tooth portion.

[0021] According to the above configuration, since the bonding portion extends over the entire width of the tooth portion, it is easy to ensure the bonding strength between the tooth portions.

[0022] (6) In the laminated core according to any one of (1) to (5), the average thickness of the adhesive portion may be 1.0 μm to 3.0 μm.

[0023] (7) In the laminated core according to any one of (1) to (6), the average tensile elastic modulus E of the adhesive portion may be 1500 MPa to 4500 MPa.

[0024] (8) In the laminated core described in any one of (1) to (7), the adhesive portion may be a room temperature adhesive type acrylic adhesive containing SGA composed of an acrylic adhesive containing an elastomer.

[0025] (9) In the laminated core described in any one of (1) to (8), the melting point of the adhesive portion may be 180° C. or higher.

[0026] (10) A rotating electrical machine according to one aspect of the present invention includes the laminated core described in any one of (1) to (9).

[0027] According to the rotating electrical machine having the above configuration, since it includes the laminated core having excellent magnetic characteristics, it is possible to improve the energy efficiency of the rotating electrical machine.

[0028] Effects of the Invention

[0029] According to the present invention, the magnetic characteristics of the laminated core can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a cross-sectional view of a rotating electrical machine according to an embodiment of the present invention.

[0031] Figure 2 yes Figure 1 FIG. 1 is a top view of a stator included in the rotating electrical machine shown.

[0032] Figure 3 yes Figure 1 A front view of a stator included in the rotating electrical machine shown.

[0033] Figure 4 yes Figure 2 and Figure 3 Schematic diagram of the electromagnetic steel plates and bonding areas of the stator shown.

[0034] Figure 5 This is a schematic diagram of the bonding area of ​​the stator according to Modification Example 1.

[0035] Figure 6 It is a schematic diagram of the bonding area of ​​the stator of Modification Example 2.

[0036] Figure 7 This is a schematic diagram of the bonding area of ​​the stator of Modification 3.

[0037] Figure 8 This is a schematic diagram of the bonding area of ​​the stator of Modification Example 4.

[0038] Fig. 9 It is a schematic diagram of the bonding area of ​​the stator of Modification Example 5.

[0039] Fig.10 This is a graph showing the simulation results of the iron loss of Model No. 1 to Model No. 4.

[0040] Fig.11 It is a schematic diagram of the stator core of model No. 4 which is a comparative example. DETAILED DESCRIPTION

[0041] 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.

[0042] like Figure 1 and Figure 2 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.

[0043] In the rotating electrical machine 10 of the present embodiment, for example, an exciting current having an effective value of 10A and a frequency of 100 Hz is applied to each phase of the stator 20 , and accordingly the rotor 30 and the rotating shaft 60 rotate at a rotation speed of 1000 rpm.

[0044] In the present embodiment, an inner rotor type in which the rotor 30 is located inside the stator 20 is adopted as the rotating electrical machine 10. However, an outer rotor type in which the rotor 30 is located outside the stator 20 may be adopted as the rotating electrical machine 10. In addition, in the present embodiment, the rotating electrical machine 10 is a 12-pole 18-slot three-phase AC motor. However, for example, the number of poles, the number of slots, the number of phases, etc. may be appropriately changed.

[0045] The stator 20 includes a stator core (laminated core) 21 and a winding (not shown).

[0046] The stator core 21 includes an annular core back portion 22 and a plurality of teeth 23. Hereinafter, the axial direction (the direction of the central axis O of the stator core 21) of the stator core 21 (core back portion 22) is referred to as the axial direction, the radial direction (the direction orthogonal to the central axis O of the stator core 21) of the stator core 21 (core back portion 22) is referred to as the radial direction, and the circumferential direction (the direction surrounding the central axis O of the stator core 21) of the stator core 21 (core back portion 22) is referred to as the circumferential direction.

[0047] The core back portion 22 is formed in an annular shape in a plan view of the stator 20 viewed from the axial direction.

[0048] The plurality of teeth 23 extend radially inward from the core back portion 22 (along the central axis O of the core back portion 22 in the radial direction). The plurality of teeth 23 are arranged at equal intervals in the circumferential direction. In the present embodiment, 18 teeth 23 are provided at a center angle of 20 degrees centered on the central axis O. The plurality of teeth 23 are formed into shapes and sizes that are equal to each other.

[0049] The winding is wound around the teeth 23. The winding may be concentratedly wound or distributedly wound.

[0050] 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 .

[0051] 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.

[0052] 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 provided at a central angle of 30 degrees with the central axis O as the center.

[0053] 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.

[0054] <Laminated Core>

[0055] like Figure 3As shown in FIG. 1 , the stator core 21 is a laminated core. The stator core 21 is formed by laminating a plurality of electromagnetic steel sheets 40. That is, the stator core 21 includes a plurality of electromagnetic steel sheets 40 laminated in a laminating direction.

[0056] In addition, 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. The outer diameter of the rotor core 31 is, for example, 163.0 mm. However, these values ​​are only examples, and the stacking thickness, outer diameter, and inner diameter of the stator core 21 are not limited to these values. 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. That is, 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.

[0057] Each electromagnetic steel sheet 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electromagnetic steel sheet as a base material. As the electromagnetic steel sheet 40, a known 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.

[0058] However, a oriented electromagnetic steel sheet may be used instead of a non-oriented electromagnetic steel sheet as the electromagnetic steel sheet 40. As the oriented electromagnetic steel sheet, for example, a oriented electrical steel strip according to JIS C 2553:2012 may be used.

[0059] In order to improve the workability of the electromagnetic steel sheet and the iron loss of the laminated core, 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.

[0060] 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.

[0061] 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 stator core 21 increases, and the magnetic properties of the stator core 21 decrease. 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.

[0062] 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.

[0063] On the other hand, if the electromagnetic steel sheet 40 is too thick, the press punching operation of the electromagnetic steel sheet 40 becomes difficult.

[0064] Therefore, considering the press punching work of the electromagnetic steel sheet 40 , the thickness of the electromagnetic steel sheet 40 is preferably 0.65 mm or less.

[0065] In addition, if the thickness of the electromagnetic steel sheet 40 increases, 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.

[0066] 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.

[0067] The plurality of electromagnetic steel sheets 40 forming the stator core 21 are bonded 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 scope 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.

[0068] 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.

[0069] The average tensile modulus E is measured by a resonance method. Specifically, the tensile modulus is measured in accordance with JIS R 1602:1995.

[0070] More specifically, a sample for measurement (not shown) is first prepared. The sample is obtained by bonding two electromagnetic steel plates 40 with an adhesive of the measurement object and curing the adhesive to form a bonding portion 41. The curing is performed by heating and pressing under actual heating and pressing conditions when the adhesive is a thermosetting type. On the other hand, when the adhesive is a room temperature curing type, it is performed by pressing at room temperature.

[0071] Then, the tensile modulus of the sample is measured by the resonance method. The method for measuring the tensile modulus of the sample 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 can be obtained by calculating the tensile modulus of the sample (measured value) by removing the influence of the electromagnetic steel sheet 40 itself.

[0072] 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 be set to a value obtained by measuring the cured adhesive portion 41 at the upper end position of the laminated core.

[0073] The electric motor generates heat when driven. Therefore, if the melting point of the adhesive portion 41 is low, the heat generated by the engine causes the adhesive portion 41 to melt, thereby changing the shape of the adhesive region 42 and failing to achieve the desired effect. Generally, an insulating coating (enamel coating) is provided on the surface of the winding wound on the stator core 21. The heat-resistant temperature of the coating is, for example, about 180°C. Therefore, a general electric motor is driven in a manner below 180°C. That is, the engine can be heated to about 180°C. In the present embodiment, the melting point of the adhesive portion 41 is preferably above 180°C. Furthermore, considering the safety factor of the local presence of a high-temperature portion, the melting point of the adhesive portion 41 is further preferably above 200°C.

[0074] 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.

[0075] In order to obtain stable and sufficient adhesive strength, the thickness of the adhesive portion 41 is preferably 1 μm or more.

[0076] 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 space factor decreases, and the magnetic properties such as the iron loss of the laminated core decrease. Therefore, the thickness of the adhesive portion 41 is preferably 1 μm or more and 100 μm or less, and more preferably 1 μm or more and 10 μm or less.

[0077] Furthermore, in the above description, the thickness of the adhesive portion 41 refers to the average thickness of the adhesive portion 41 .

[0078] 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 exceeds 3.0 μm and becomes thicker, undesirable conditions such as a significant increase in the amount of distortion of the electromagnetic steel sheet 40 caused by 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.

[0079] The average thickness of the adhesive portion 41 is the average value of the entire laminated core. The average thickness of the adhesive 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 adhesive portion 41 can be set to the average value of the values ​​measured at the upper end position of the laminated core at more than 10 points in the circumferential direction.

[0080] 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.

[0081] Next, based on Figure 4 , the relationship between the electromagnetic steel sheet 40, the bonding portion 41, and the bonding region 42 will be described.

[0082] like Figure 4 As shown, the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are not bonded to each other over their entire surfaces. These electromagnetic steel sheets 40 are partially bonded to each other. The bonding portion 41 is provided on the plurality of teeth 23 of the electromagnetic steel sheet. The teeth 23 are bonded by the bonding portion 41. That is, the plurality of electromagnetic steel sheets 40 are bonded to each other by the bonding portion 41.

[0083] 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), an adhesive region 42 and a non-adhesive region (blank region) are formed. The adhesive region 42 refers to the region on the first surface of the electromagnetic steel sheet 40 where the adhesive portion 41 is provided. More specifically, the adhesive region 42 refers to the region on the first surface of the electromagnetic steel sheet 40 where the cured adhesive is provided. The non-adhesive region refers to the region on the first surface of the electromagnetic steel sheet where the adhesive portion 41 is not provided.

[0084] One bonding portion 41 is provided per tooth portion 23. According to the present embodiment, the bonding portions 41 are provided on the plurality of teeth portions 23. Therefore, the plurality of bonding portions 41 are discretely provided in the circumferential direction as a whole of the electromagnetic steel sheet 40. Thus, the electromagnetic steel sheets 40 can be fixed to each other in a well-balanced manner.

[0085] The bonding portion 41 is formed into a strip extending linearly along the circumferential direction. Therefore, the bonding region 42 is also formed into a strip extending linearly along the circumferential direction, similarly to the bonding portion 41. That is, the bonding region 42 extends in a direction orthogonal to the direction in which the tooth portion 23 extends. The width dimension of the bonding region 42 is the same over the entire length of the bonding region 42. In addition, the bonding region 42 is located near the front end of the tooth portion 23. Here, the front end of the tooth portion 23 refers to the range from the front end of the tooth portion 23 along the radial direction of the tooth portion 23 to 1 / 10 of the radial length of the tooth portion 23.

[0086] In this specification, the direction in which the tooth portion 23 extends (ie, radial direction) may be referred to as the length direction of the tooth portion 23 , and the direction orthogonal to the length direction may be referred to as the width direction of the tooth portion 23 .

[0087] In addition, in this specification, the "belt shape" as the shape in which the bonding portion 41 extends refers to a shape extending in one direction, and the width is 1.5% or more of the outer diameter of the stator core 21. When the width of the bonding portion 41 is 1.5% or more of the outer diameter of the stator core 21, the bonding strength between the electromagnetic steel sheets 40 can be sufficiently ensured.

[0088] In addition, in this embodiment, the width dimension of the adhesive region 42 is described as being the same over the entire length of the adhesive region 42. However, the width dimension of the adhesive region 42 may not necessarily be the same. As an example, both ends of the adhesive region 42 in the width direction may be curved and extend along the length direction.

[0089] The bonding portion 41 is in a generally rectangular shape with the direction perpendicular to the radial direction as the long side direction when viewed from above. According to this embodiment, by setting the bonding portion 41 in a shape extending in one direction, the bonding area of ​​the bonding portion 41 can be increased and the bonding strength can be improved compared to the case where the dot-shaped bonding portions 41 are intermittently provided within the same range.

[0090] By increasing the width dimension d1 of the bonding portion 41, the bonding portion 41 can be easily formed in the manufacturing process. In addition, by reducing the width dimension d1 of the bonding portion 41, the electromagnetic steel sheet 40 is not locally deformed significantly due to the compressive stress of the adhesive, and degradation of the iron loss of the electromagnetic steel sheet 40 as a whole can be suppressed.

[0091] In addition, the width dimension d1 of the bonding portion 41 refers to the dimension in the short side direction of the bonding portion 41 formed in a strip shape, and in the present embodiment, it is the dimension in the radial direction of the bonding portion 41. In the present embodiment, the bonding region 42 refers to the region where the bonding portion 41 is provided on the first surface of the electromagnetic steel sheet 40, and therefore the width dimension of the bonding region 42 is the same as the width dimension of the bonding portion 41.

[0092] The bonding portion 41 extends over the entire width of the tooth portion 23. According to the present embodiment, since the bonding portion 41 is formed in a strip shape extending over the entire width of the tooth portion 23, it is easy to ensure bonding strength between the teeth portions 23.

[0093] In the present embodiment, the adhesive shrinks when it is cured. Therefore, a distortion caused by the curing shrinkage of the adhesive occurs in the area of ​​the electromagnetic steel sheet 40 in contact with the adhesive area 42, and the iron loss of the electromagnetic steel sheet 40 in this area increases. Here, the area on the first surface of the electromagnetic steel sheet 40 that contacts the adhesive portion 41 and causes the iron loss to increase due to distortion is referred to as a degraded area 29. The degraded area 29 is an area that overlaps with the adhesive area 42 when viewed from the stacking direction. The degraded area 29 has a higher magnetic resistance than other areas (non-degraded areas).

[0094] In addition, in this specification, the increase in the value of iron loss may be referred to as "deterioration of iron loss".

[0095] When current flows through the winding (not shown) of the stator 20, magnetic flux B is formed in the electromagnetic steel sheet 40. The magnetic flux B forms a magnetic path passing through the teeth 23 and the core back 22. The magnetic flux B extends on the teeth 23 in the radial direction.

[0096] According to the present embodiment, the bonding region 42 is formed in a band shape extending in the circumferential direction on the tooth portion 23. Therefore, the deteriorated region 29 is formed in a band shape extending in the circumferential direction on the tooth portion 23. As described above, the magnetic flux B flows in the radial direction on the tooth portion 23. Therefore, by forming the band-shaped bonding region 42 extending in the circumferential direction on the tooth portion 23, the path length of the magnetic flux B passing through the deteriorated region 29 is shortened. As a result, the magnetic resistance to the magnetic flux B in the magnetic circuit becomes smaller, and the magnetic characteristics of the stator core 21 can be improved compared to the case where the electromagnetic steel sheets are fixed to each other by caulking.

[0097] In the present embodiment, the rotor core 31 is the same as the stator core 21 and is a laminated core. That is, the rotor core 31 has a plurality of electromagnetic steel plates laminated in the thickness direction. In the present embodiment, the laminated thickness of the rotor core 31 is equal to that of the stator core 21, 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. However, these values ​​are only examples, and the laminated thickness, outer diameter, and inner diameter of the rotor core 31 are not limited to these values.

[0098] In this embodiment, the plurality of electromagnetic steel sheets forming the rotor core 31 are connected by caulking C (pins, see Figure 1 However, the plurality of electromagnetic steel sheets 40 forming the rotor core 31 may be bonded to each other via bonding portions.

[0099] In addition, the stator core 21, the rotor core 31 and other laminated cores may be formed by so-called rotational stacking.

[0100] (Variant 1)

[0101] Next, based on Figure 5 The adhesive portion 141 and the adhesive region 142 of Modification 1 that can be adopted in the above embodiment will be described. Note that the same reference numerals are given to components having the same form as those in the above embodiment, and description thereof will be omitted.

[0102] As in the above embodiment, the tooth 23 has an adhesive region 142 provided with a band-shaped adhesive portion 141 extending in the circumferential direction. The adhesive portion 141 of this modification differs from the above embodiment mainly in that the adhesive region 142 is arranged near the base end of the tooth 23.

[0103] As in the above-mentioned embodiment, the bonding region 142 is formed in a strip shape extending linearly in the circumferential direction. The width dimension of the bonding region 142 is the same over the entire length of the bonding region 142. A region (deteriorated region 129) is formed in the electromagnetic steel sheet 40, which contacts the bonding region 142 and causes increased iron loss due to distortion. According to this modified example, since the path length of the magnetic flux B passing through the deteriorated region 129 is shortened, the magnetic resistance to the magnetic flux B in the magnetic circuit is reduced, and the magnetic properties of the stator core 21 can be improved.

[0104] The magnetic flux B diffuses and extends from the front end of the tooth portion 23 to both sides in the circumferential direction. Therefore, near the front end of the tooth portion 23, the magnetic flux is concentrated at both ends in the circumferential direction and the magnetic flux density tends to increase. If a degraded region is set in an area with a higher magnetic flux density, the increase in iron loss tends to become significant. Therefore, if the degraded region 129 is set near the front end of the tooth portion 23, the iron loss tends to become larger. The bonding region 142 of this modified example is formed near the base end of the tooth portion 23. That is, the bonding region 142 is formed on the side of the core back 22 than near the front end of the tooth portion 23. Therefore, the degraded region 129 can be configured separately from the area with a higher magnetic flux density, and the increase in iron loss can be suppressed. As a result, the magnetic resistance to the magnetic flux B in the magnetic circuit becomes smaller, and the magnetic properties of the stator core 21 can be improved. The above effect can be obtained if the adhesion region 142 is arranged closer to the base end than 1 / 2 of the total length of the tooth portion 23. Furthermore, the above effect can be obtained more significantly if the adhesion region 142 is arranged closer to the base end than 1 / 3 of the total length of the tooth portion 23.

[0105] (Variant 2)

[0106] Next, based on Figure 6 The adhesive portion 241 and the adhesive region 242 of Modification 2 that can be adopted in the above embodiment will be described. Note that the same reference numerals are given to components having the same form as those in the above embodiment, and description thereof will be omitted.

[0107] As in the above embodiment, the tooth 23 has an adhesive region 242 provided with a band-shaped adhesive portion 241 extending in the circumferential direction. The adhesive portion 241 of this modification differs from the above embodiment mainly in that the adhesive region 242 is formed substantially at the center of the tooth 23 in the longitudinal direction.

[0108] As in the above embodiment, since the adhesion region 242 is formed in a strip shape extending linearly in the circumferential direction, the path length of the magnetic flux B passing through the deteriorated region 229 can be shortened. As a result, the magnetic resistance to the magnetic flux B in the magnetic circuit is reduced, and the magnetic characteristics of the stator core 21 can be improved.

[0109] In addition, the adhesion region 242 of the present modification example is uniform over the entire length of the adhesion region 242 .

[0110] In addition, the adhesion region 242 of this modification is located closer to the core back portion 22 than the front end of the tooth portion 23, similarly to the adhesion region 242 of modification 1, so that the increase of iron loss can be suppressed. As a result, the magnetic resistance to the magnetic flux B in the magnetic circuit is reduced, and the magnetic characteristics of the stator core 21 can be improved.

[0111] (Variant 3)

[0112] Next, based on Figure 7 The adhesive portion 341 and the adhesive region 342 of Modification 3 that can be adopted in the above embodiment will be described. Note that the same reference numerals are given to components having the same form as those in the above embodiment, and description thereof will be omitted.

[0113] As in the above-described embodiment, the tooth portion 23 has an adhesive region 342 provided with a band-shaped adhesive portion 341 extending in the circumferential direction. The adhesive region 342 of this modification is similar in structure to the adhesive region 242 of Modification 2. According to the stator core 21 having the adhesive portion 341 of this modification, the same effect as that of the stator core 21 having the adhesive portion 241 of Modification 2 can be obtained. The difference between the adhesive region 342 of this modification and the adhesive region 242 of Modification 2 is that the width of the adhesive region 342 is different over the entire length.

[0114] The two ends of the adhesive region 342 in the present modification have a curved shape in the width direction. The two ends of the adhesive region 342 in the width direction are separated from each other as they move from the circumferential center of the tooth portion 23 toward the circumferential end side of the tooth portion 23. Therefore, the radial width dimension of the adhesive region 342 increases as it moves from the circumferential center of the tooth portion 23 toward the circumferential end side of the tooth portion 23. The width dimension of the adhesive region 342 is the smallest at the circumferential center of the tooth portion 23.

[0115] like Figure 4As shown, the magnetic flux B spreads and extends from the front end of the tooth portion 23 to both sides in the circumferential direction. In addition, the magnetic flux B has a tendency to flow in a manner that passes through the shortest distance. Therefore, the magnetic flux density of the tooth portion 23 tends to increase toward the circumferential end side. If the deviation of the magnetic flux density of the tooth portion 23 in the circumferential direction becomes larger, the magnetic properties of the stator core 21 may be reduced.

[0116] According to this modification, the radial width dimension of the bonding area 342 increases as it moves from the central portion of the tooth portion 23 toward the circumferential end side. That is, the radial length of the deteriorated area 391 increases as it moves from the central portion of the tooth portion 23 toward the width direction end side. Therefore, the magnetic resistance of the tooth portion 23 increases as it moves toward the circumferential end side, and the magnetic flux B is difficult to flow on the circumferential end side. As a result, the deviation of the magnetic flux density in the circumferential direction of the tooth portion 23 can be suppressed, and the magnetic flux density in the tooth portion 23 is made close to the same. As a result, the magnetic properties of the laminated core can be improved.

[0117] (Variant 4)

[0118] Next, based on Figure 8 The adhesive portion 441 and the adhesive region 442 of Modification 4 that can be adopted in the above-mentioned embodiment will be described. Note that the same reference numerals are given to the same components as those in the above-mentioned embodiment, and description thereof will be omitted.

[0119] As in the above embodiment, the tooth portion 23 is provided with an adhesive region 442, and the adhesive region 442 is provided with a strip-shaped adhesive portion 441 extending linearly along the circumferential direction. In addition, the adhesive portion 441 of this modification is different from the above embodiment mainly in that a plurality of (three) adhesive regions 442 arranged along the extension direction are formed on the tooth portion 23. The plurality of adhesive regions 442 are arranged from the center of the length direction of the tooth portion 23 toward the base end side.

[0120] As shown in this modification, in the above-mentioned embodiment and each modification, a plurality of bonding regions 441 may be provided for each tooth portion 23. Even in this case, the effects of the embodiment and the modification can be exerted, and the bonding strength between the electromagnetic steel sheets 40 can be improved.

[0121] Furthermore, when a plurality of bonding regions 442 are provided on one tooth portion 23, the width dimension of the bonding region 442 is preferably smaller than the spacing dimension between adjacent bonding regions 442. Thus, it is possible to suppress the distortion of the electromagnetic steel sheet caused by the plurality of bonding regions 442, thereby suppressing the degradation (increase) of the iron loss of the electromagnetic steel sheet.

[0122] (Variant 5)

[0123] Next, based on Fig. 9The adhesive portion 541 and the adhesive region 542 of the fifth modification example that can be adopted in the above embodiment will be described. Note that the same reference numerals are given to the same components as those in the above embodiment, and the description thereof will be omitted.

[0124] As in the above embodiment, the tooth portion 23 is provided with an adhesive region 542, and the adhesive region 542 is provided with a band-shaped adhesive portion 541 extending in the circumferential direction. The adhesive portion 541 of this modification is different from the above embodiment in that the adhesive region 542 extends in an arc shape in the circumferential direction. The adhesive portion 541 of this modification can be evenly coated in the circumferential direction, so that the manufacturing process can be simplified.

[0125] In addition, the technical scope of the present invention is not limited to the above-described embodiment and its modified examples, and various changes can be added without departing from the gist of the present invention.

[0126] In the stator core of the above-mentioned embodiment and its modified example, a plurality of electromagnetic steel sheets are fixed to each other at the bonding portion provided at the tooth portion. However, the electromagnetic steel sheets may be fixed to each other at the core back portion in addition to the tooth portion. In this case, rivets may be provided at the core back portion, and a bonding portion may be provided at the core back portion. Furthermore, in addition to bonding and fixing by the bonding portion, the electromagnetic steel sheets may be fixed to each other by welding. That is, the effect of the present embodiment can be obtained regardless of the fixing method of the core back portion.

[0127] The shape of the stator core is not limited to the form shown in the above embodiment. Specifically, the outer diameter and inner diameter of the stator core, the stacking thickness, the number of slots, the circumferential and radial dimension ratios of the teeth, the radial dimension ratios of the teeth and the core back, etc. can be arbitrarily designed according to the desired characteristics of the rotating motor.

[0128] 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.

[0129] In the above-described embodiment, a permanent magnet excitation type motor is described as an example of a rotating electrical machine. However, the structure of the rotating electrical machine is not limited to this as exemplified below, and various known structures not exemplified below may be adopted.

[0130] 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).

[0131] 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.

[0132] 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.

[0133] 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.

[0134] In the above-described embodiment, the case where the laminated core of the present invention is applied to the stator core is exemplified, but it may also be applied to the rotor core.

[0135] Furthermore, components in the above-described embodiment and its modified examples may be appropriately replaced with well-known components without departing from the gist of the present invention, and the above-described modified examples may be appropriately combined.

[0136] [Example]

[0137] A verification test was carried out to verify the suppression of the degradation of the iron loss of the electromagnetic steel sheet caused by the compressive stress in the bonding portion. In addition, this verification test was carried out by simulation using software. As software, JMAG, a finite element method electromagnetic field analysis software manufactured by JSOL Co., Ltd. was used. As the model used in the simulation, the stator core (laminated core) of Model No. 1 to Model No. 4 described below is assumed. The electromagnetic steel sheet used in each model is an electromagnetic steel sheet produced by punching a thin plate with a plate thickness of 0.25 mm and a plate thickness of 0.20 mm. The shape of the electromagnetic steel sheet and Figure 2 The shapes shown are the same.

[0138] The stator cores of models No. 1 to No. 3 and model No. 4 have different structures for fixing the electromagnetic steel sheets to each other. In the stator cores of models No. 1 to No. 3, bonding portions are provided between the electromagnetic steel sheets, and the electromagnetic steel sheets are bonded and fixed to each other. On the other hand, the stator core of model No. 4 fixes the electromagnetic steel sheets to each other by caulking.

[0139] The bonding area of ​​model No.1 is equivalent to Figure 4 The bonding area 42 shown. The bonding area of ​​model No. 1 is formed on a plurality of teeth, and each bonding area is formed in a strip shape extending linearly in the circumferential direction near the tip of the tooth.

[0140] The bonding area of ​​model No.2 is equivalent to Figure 5The adhesive region 142 shown. The adhesive region of model No. 2 is formed on a plurality of teeth, and each adhesive region is formed in a strip shape extending linearly in the circumferential direction near the base end of the tooth.

[0141] The bonding area of ​​model No.3 is equivalent to Figure 6 The bonding area 242 shown. The bonding area of ​​model No. 3 is formed on a plurality of teeth, and each bonding area is formed in a strip shape extending linearly along the circumferential direction at the center in the longitudinal direction of the tooth.

[0142] The stator core 1021 of model No. 4 is shown in Fig.11 The stator core 1021 is formed by stacking electromagnetic steel sheets 40 of the same shape as the stator core 21 of the above embodiment in the thickness direction. The stator core 1021 is different from the stator core 21 of the above embodiment in that the electromagnetic steel sheets 40 are fixed to each other by rivets 1042 (pins). The rivets 1042 are located at the teeth 23.

[0143] The calculation results of the iron loss of the electromagnetic steel sheet calculated by the simulation software for each model are shown in FIG. Fig.10 .in addition, Fig.10 In the iron loss (vertical axis) of the calculation results shown, the iron loss of model No. 4 is set to 1.0, and the iron loss of other models is expressed as a ratio to the iron loss of model No. 4.

[0144] like Fig.10 As shown, it was confirmed that the stator cores of Model No. 1 to Model No. 3 had smaller iron loss values ​​than the stator core of Model No. 4.

[0145] The stator core of model No.1 has a larger iron loss than the stator cores of models No.2 and No.3. Figure 4 As shown in FIG. 1 , in the stator core of model No. 1, the bonding area is arranged near the tip of the tooth portion, so it is considered that the iron loss increases because the deterioration area is provided in the area with high magnetic flux density. Figure 5 and Figure 6 As shown, in the stator cores of Model No. 2 and Model No. 3, the deteriorated region and the region with high magnetic flux density can be arranged separately, and it is considered that the increase in iron loss can be suppressed.

[0146] Industrial Availability

[0147] According to the present invention, magnetic properties can be improved, and thus the industrial applicability is great.

[0148] Description of Reference Numerals

[0149] 10…rotating electric machine, 20…stator, 21…stator core (laminated core), 22…core back, 23…tooth portion, 40…electromagnetic steel sheet, 41, 141, 241, 341…bonding portion, 42, 142, 242, 342…bonding region, d1…width dimension, B…magnetic flux.

Claims

1. A laminated core comprising: A plurality of electromagnetic steel sheets stacked one on top of another, and a bonding portion provided between the electromagnetic steel sheets adjacent to each other in a stacking direction and bonding the electromagnetic steel sheets to each other; The electromagnetic steel plate has: The annular core back, and a plurality of teeth extending from the core back portion in a radial direction of the core back portion and arranged at intervals in a circumferential direction of the core back portion; The tooth portion of the electromagnetic steel sheet has a bonding region provided with a band-shaped bonding portion extending in the circumferential direction, The radial width dimension of the bonding region increases from the circumferential center portion of the tooth portion toward the circumferential end portion side of the tooth portion.

2. A laminated core comprising: A plurality of electromagnetic steel sheets stacked one on top of another, and a bonding portion provided between the electromagnetic steel sheets adjacent to each other in a stacking direction and bonding the electromagnetic steel sheets to each other; The electromagnetic steel plate has: The annular core back, and a plurality of teeth extending from the core back portion in a radial direction of the core back portion and arranged at intervals in a circumferential direction of the core back portion; The tooth portion of the electromagnetic steel sheet has a bonding region provided with a band-shaped bonding portion extending in the circumferential direction, The bonding area extends in an arc shape along the circumferential direction.

3. The laminated core according to claim 1 or 2, wherein: The bonding region is formed on the core back side relative to the vicinity of the front end of the tooth portion.

4. The laminated core according to claim 1 or 2, wherein: The adhesive bond extends over the entire width of the toothing.

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

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

7. The laminated core according to claim 1 or 2, wherein: 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 laminated core according to claim 1 or 2, wherein: The melting point of the adhesive portion is 180° C. or higher.

9. The laminated core according to claim 1 or 2, wherein: The bonding region is provided in a region of the tooth portion that is closer to the base end than the center in the longitudinal direction.

10. A rotating electric machine comprising the laminated core according to any one of claims 1 to 9.

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