Title of the invention: Adhesive laminated core for stator, its manufacturing method and rotary electric machine
Technical field
[0001]
The present invention relates to an adhesive laminated core for a stator, a method for manufacturing the same, and a rotary electric machine.
This application claims priority based on Japanese Patent Application No. 2018-235869 filed in Japan on December 17, 2018, and the contents thereof are incorporated herein by reference.
Background technology
[0002]
Conventionally, as a core used in a rotary electric machine, a laminated core in which a plurality of electromagnetic steel sheets are laminated to each other is known. A plurality of steel plates are joined by a method such as welding, bonding, or caulking.
Patent Document 1 discloses a technique of using a two-component curable adhesive in a step of laminating a plurality of rotor steel plates constituting a rotor core.
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2017-046442
Outline of the invention
Problems to be solved by the invention
[0004]
However, the rotor core obtained by the technique of Patent Document 1 cannot sufficiently suppress the iron loss of the rotary electric machine.
[0005]
An object of the present invention is to provide an adhesive laminated core for a stator and a method for manufacturing the same, which can suppress iron loss of a rotary electric machine and have excellent productivity, and a rotary electric machine provided with the adhesive laminated core for a stator.
Means to solve problems
[0006]
One embodiment of the present invention has the following aspects.
[1] A plurality of electrical steel sheets laminated with each other and coated on both sides with an insulating coating,
It is provided with an adhesive portion that is arranged between the electromagnetic steel sheets that are adjacent to each other in the stacking direction and that adheres these electromagnetic steel sheets to each other.
All the sets of the electromagnetic steel sheets adjacent to each other in the laminating direction are adhered by the adhesive portion.
The adhesive forming the adhesive portion contains an acrylic compound, an oxidizing agent, and a reducing agent, and a part of the acrylic compound and the oxidizing agent are used as the first agent, and the rest of the acrylic compound and the reducing agent are used as the first agent. The agent is a two-part acrylic adhesive that is placed in the second agent.
Adhesive laminated core for stator in which the adhesive portion is partially provided between electromagnetic steel sheets adjacent to each other in the laminated direction.
[2] The acrylic compound contains at least one selected from the group consisting of methyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate.
The methyl methacrylate is 0 to 50% by mass, the phenoxyethyl methacrylate is 0 to 50% by mass, the 2-hydroxyethyl methacrylate is 0 to 50% by mass, and the 2-hydroxypropyl is 0 to 50% by mass with respect to the total mass of the acrylic adhesive. The adhesive laminated core for a stator according to the above [1], wherein the methacrylate is 0 to 50% by mass.
[3] A plurality of electrical steel sheets laminated on each other and coated on both sides with an insulating coating,
It is provided with an adhesive portion that is arranged between the electromagnetic steel sheets that are adjacent to each other in the stacking direction and that adheres these electromagnetic steel sheets to each other.
All the sets of the electromagnetic steel sheets adjacent to each other in the laminating direction are adhered by the adhesive portion.
The adhesive that forms the adhesive portion is an acrylic adhesive containing an acrylic compound.
Adhesive laminated core for stator in which the adhesive portion is partially provided between electromagnetic steel sheets adjacent to each other in the laminated direction.
[4] The adhesive laminated core for a stator according to the above [3], wherein the acrylic adhesive is an anaerobic adhesive.
[5] The adhesive laminated core for a stator according to the above [3], wherein the acrylic compound is a cyanoacrylate.
[6] The adhesive laminated core for the stator according to any one of the above [1] to [5], wherein the acrylic adhesive further contains an elastomer.
[7] The elastomer contains acrylonitrile butadiene rubber and contains.
The adhesive laminated core for a stator according to the above [6], wherein the acrylonitrile butadiene rubber is 1 to 20% by mass with respect to the total mass of the acrylic adhesive.
[8] The adhesive laminated core for a stator according to any one of the above [1] to [7], wherein the adhesive area ratio of the electromagnetic steel sheet by the adhesive portion between the respective electromagnetic steel sheets is 20 to 80%.
[9] The method for manufacturing an adhesive laminated core for a stator according to the above [1].
An operation in which the first agent and the second agent of the acrylic adhesive are applied to a part of the surface of the electromagnetic steel sheet at room temperature, and then the first agent and the second agent of the acrylic adhesive are applied and then pressure-bonded on another electromagnetic steel sheet to form the adhesive portion. A method for manufacturing an adhesive laminated core for a stator, which repeats the above steps.
[10] The method for manufacturing an adhesive laminated core for a stator according to the above [3].
At room temperature, the acrylic adhesive is applied to a part of the surface of the electrical steel sheet, and then the adhesive laminated core for a stator is repeatedly crimped on another electrical steel sheet to form the adhesive portion. Production method.
[11] A rotary electric machine provided with an adhesive laminated core for a stator according to any one of the above [1] to [8].
The invention's effect
[0007]
According to the present invention, it is possible to provide a rotary electric machine provided with an adhesive laminated core for a stator and a method for manufacturing the same, which can suppress iron loss of the rotary electric machine and is excellent in productivity, and the adhesive laminated core for a stator.
A brief description of the drawing
[0008]
FIG. 1 is a cross-sectional view of a rotary electric machine provided with an adhesive laminated core for a stator according to an embodiment of the present invention.
[Fig. 2] Fig. 2 is a side view of the laminated core for the same stator.
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2 showing an example of an arrangement pattern of an adhesive portion of the adhesive laminated core for the same stator.
FIG. 4 is a side view showing a schematic configuration of a manufacturing apparatus for an adhesive laminated core for a stator.
Mode for carrying out the invention
[0009]
Hereinafter, with reference to the drawings, the adhesive laminated core for the stator and the rotary electric machine provided with the adhesive laminated core for the stator according to the embodiment of the present invention will be described. In the present embodiment, an electric motor as a rotary electric machine, specifically an AC electric motor, more specifically a synchronous electric motor, and even more specifically, a permanent magnet field type electric motor will be described as an example. This type of electric motor is suitably used for, for example, an electric vehicle.
[0010]
[First Embodiment]
As shown in FIG. 1, the rotary electric machine 10 includes a stator 20, a rotor 30, a case 50, and a rotary shaft 60. The stator 20 and rotor 30 are housed in a case 50. The stator 20 is fixed in the case 50.
In the present embodiment, the rotor 30 is an inner rotor type in which the rotor 30 is located inside the stator 20 in the radial direction as the rotary electric machine 10. However, as the rotary electric machine 10, an outer rotor type in which the rotor 30 is located outside the stator 20 may be adopted. Further, in the present embodiment, the rotary electric machine 10 is a 12-pole 18-slot three-phase AC motor. However, the number of poles, the number of slots, the number of phases, and the like can be changed as appropriate.
The rotary electric machine 10 can rotate at a rotation speed of 1000 rpm by applying an exciting current having an effective value of 10 A and a frequency of 100 Hz to each phase, for example.
[0011]
The stator 20 includes an adhesive laminated core for a stator (hereinafter referred to as a stator core) 21 and a winding not shown.
The stator core 21 includes an annular core back portion 22 and a plurality of teeth portions 23. In the following, the direction of the central axis О of the stator core 21 (or the core back portion 22) is referred to as the axial direction, and the radial direction of the stator core 21 (or the core back portion 22) (the direction orthogonal to the central axis О) is referred to as the radial direction. The circumferential direction of the stator core 21 (or core back portion 22) (direction that orbits around the central axis О) is referred to as a circumferential direction.
[0012]
The core back portion 22 is formed in an annular shape in a plan view of the stator 20 when viewed from the axial direction.
The plurality of tooth portions 23 project from the inner circumference of the core back portion 22 toward the inside in the radial direction (toward the central axis О of the core back portion 22 along the radial direction). The plurality of tooth portions 23 are arranged at equal angular intervals in the circumferential direction. In the present embodiment, 18 tooth portions 23 are provided at every 20 degrees of the central angle centered on the central axis О. The plurality of tooth portions 23 are formed to have the same shape and the same size as each other. Therefore, the plurality of tooth portions 23 have the same thickness dimension as each other.
The winding is wound around the teeth portion 23. The winding may be a centralized winding or a distributed winding.
[0013]
The rotor 30 is arranged inside the stator 20 (stator core 21) in the radial direction. The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32.
The rotor core 31 is formed in an annular shape (annular ring) arranged coaxially with the stator 20. The rotating shaft 60 is arranged in the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31.
The plurality of permanent magnets 32 are fixed to the rotor core 31. In this embodiment, a set of two permanent magnets 32 form one magnetic pole. The plurality of sets of permanent magnets 32 are arranged at equal angular intervals in the circumferential direction. In the present embodiment, 12 sets (24 in total) of permanent magnets 32 are provided at a central angle of 30 degrees about the central axis О.
[0014]
In this embodiment, an embedded magnet type motor is adopted as a permanent magnet field type motor. The rotor core 31 is formed with a plurality of through holes 33 that penetrate the rotor core 31 in the axial direction. The plurality of through holes 33 are provided corresponding to the arrangement of 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 fixing of each permanent magnet 32 ​​to the rotor core 31 can be realized, for example, by adhering the outer surface of the permanent magnet 32 ​​and the inner surface of the through hole 33 with an adhesive. As the permanent magnet field type motor, a surface magnet type motor may be adopted instead of the embedded magnet type motor.
[0015]
Both the stator core 21 and the rotor core 31 are laminated cores. For example, as shown in FIG. 2, the stator core 21 is formed by laminating a plurality of electromagnetic steel sheets 40.
The product thickness (total length along the central axis О) of each of the stator core 21 and the rotor core 31 is, for example, 50.0 mm. The outer diameter of the stator core 21 is, for example, 250.0 mm. The inner diameter of the stator core 21 is, for example, 165.0 mm. The outer diameter of the rotor core 31 is, for example, 163.0 mm. The inner diameter of the rotor core 31 is, for example, 30.0 mm. However, these values ​​are examples, and the product thickness, outer diameter and inner diameter of the stator core 21, and the product thickness, outer diameter and inner diameter of the rotor core 31 are not limited to these values. Here, the inner diameter of the stator core 21 is based on the tip of the teeth portion 23 of the stator core 21. That is, the inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tips of all the teeth portions 23.
[0016]
Each of the electromagnetic steel sheets 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electromagnetic steel sheet as a base material. As the electromagnetic steel sheet 40, a known electrical steel sheet can be used. The chemical composition of the electrical steel sheet 40 is not particularly limited. In this embodiment, a non-oriented electrical steel sheet is used as the electrical steel sheet 40. As the non-oriented electrical steel sheet, for example, a non-oriented electrical steel strip of JIS C 2552: 2014 can be adopted.
However, as the electromagnetic steel sheet 40, it is also possible to use a grain-oriented electrical steel sheet instead of the non-oriented electrical steel sheet. As the grain-oriented electrical steel sheet, for example, a JIS C 2553: 2012 grain-oriented electrical steel strip can be adopted.
[0017]
Both sides of the electrical steel sheet 40 are covered with an insulating film in order to improve the workability of the electrical steel sheet and the iron loss of the laminated core. As the substance constituting the insulating film, for example, (1) an inorganic compound, (2) an organic resin, (3) a mixture of an inorganic compound and an organic resin, and the like can be adopted. Examples of the inorganic compound include (1) a complex of dichromate and boric acid, and (2) a complex of phosphate and silica. Examples of the organic resin include epoxy resin, acrylic resin, acrylic styrene resin, polyester resin, silicon resin, and fluororesin.
[0018]
Thickness of the insulating coating (flat per one side of the electrical steel sheet 40) in order to ensure the insulation performance between the electrical steel sheets 40 laminated to each other. The uniform thickness) is preferably 0.1 μm or more.
On the other hand, the insulating effect saturates as the insulating film becomes thicker. Further, as the insulating film becomes thicker, the ratio (occupancy ratio) of the magnetic steel sheet in the laminated core decreases, and the performance as the laminated core deteriorates. Therefore, the insulating coating should be as thin as possible to ensure the insulating performance. The thickness of the insulating film (thickness per one side of the electromagnetic steel sheet 40) is preferably 0.1 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 2 μm or less.
[0019]
As the thickness of the electromagnetic steel sheet 40 becomes thinner, the effect of improving iron loss gradually saturates. Further, as the electromagnetic steel sheet 40 becomes thinner, the manufacturing cost of the electrical steel sheet 40 increases. Therefore, the thickness of the electrical steel sheet 40 is preferably 0.10 mm or more in consideration of the effect of improving iron loss and the manufacturing cost.
On the other hand, if the electromagnetic steel sheet 40 is too thick, the press punching operation of the electrical steel sheet 40 becomes difficult. Therefore, considering the press punching work of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.65 mm or less.
Also, as the electromagnetic steel sheet 40 becomes thicker, iron loss increases. Therefore, considering the iron loss characteristics of the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.35 mm or less, more preferably 0.20 mm or 0.25 mm.
In consideration of the above points, the thickness of each electrical steel sheet 40 is, for example, 0.10 mm or more and 0.65 mm or less, preferably 0.10 mm or more and 0.35 mm or less, and more preferably 0.20 mm or 0.25 mm. .. The thickness of the electrical steel sheet 40 includes the thickness of the insulating coating.
[0020]
As shown in FIG. 2, in the stator core 21, an adhesive portion 41 for adhering these electromagnetic steel sheets 40 to each other is partially provided between all the sets of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction. All the sets of the electromagnetic steel sheets 40 adjacent to each other in the stacking direction are laminated via the adhesive portion 41 partially provided between them. The electromagnetic steel sheets 40 adjacent to each other in the stacking direction are not fixed by other means (for example, caulking).
[0021]
The adhesive portion 41 adheres the electromagnetic steel sheets 40 adjacent to each other in the laminating direction. The adhesive portion 41 is an adhesive that has been cured without being divided.
[0022]
The thickness of the adhesive portion 41 is preferably 1 μm or more in order to obtain stable and sufficient adhesive strength.
On the other hand, if the thickness of the adhesive portion 41 exceeds 100 μm, the adhesive force is saturated. Further, as the adhesive portion 41 becomes thicker, the space factor decreases, and the magnetic characteristics such as iron loss of the stator 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.
In the above, the thickness of the adhesive portion 41 means the average thickness of the adhesive portion 41. The average thickness of the adhesive portion 41 can be adjusted, for example, by changing the amount of the adhesive applied.
[0023]
The average thickness of the adhesive portion 41 is the average value of the laminated core as a whole. The average thickness of the bonded portion 41 is almost the same at the stacking position along the stacking direction and at the circumferential position around the central axis of the laminated core. Therefore, the average thickness of the adhesive portion 41 can be set as the average value of the numerical values ​​measured at 10 or more points in the circumferential direction at the upper end position of the laminated core.
[0024]
The adhesive forming the adhesive portion 41 is a second-generation acrylic adhesive (SGA: Second Generation Acrylic adhesive). It can be said that the adhesive portion 41 is made of a cured product of SGA.
SGA contains an acrylic compound, an oxidizing agent, and a reducing agent.
The SGA in this embodiment is a two-dose form and is composed of two agents, a first agent and a second agent. Further, among the above-mentioned components, a part of the acrylic compound and the oxidizing agent are arranged in the first agent, and the rest of the acrylic compound and the reducing agent are arranged in the second agent. When the first agent and the second agent come into contact with each other, the polymerization of the acrylic compound by the redox reaction proceeds and the compound is cured.
Since the curing of the two-agent type SGA proceeds rapidly at room temperature (for example, 20 to 30 ° C., further 20 to 25 ° C.), the heat treatment in the case of the thermosetting adhesive is used when forming the adhesive portion 41. It is not necessary to perform a curing process such as holding for a long time during natural curing, and the stator core 21 can be manufactured with excellent productivity. SGA will be described in detail later.
[0025]
Generally, when the adhesive is cured, curing shrinkage occurs. Due to this curing shrinkage, compressive stress and tensile stress are applied to the electrical steel sheet 40. When these stresses are applied to the electromagnetic steel sheet 40, strain occurs. In particular, in the case of a thermosetting adhesive, the stress applied increases due to the difference in the coefficient of thermal expansion between the electromagnetic steel plate 40 and the bonded portion. The strain of the electromagnetic steel sheet 40 increases the iron loss of the rotary electric machine 10. The effect of the distortion of the electromagnetic steel sheet 40 constituting the stator core 21 on the iron loss is larger than the effect of the distortion of the steel sheet forming the rotor core 31.
In the present embodiment, since the adhesive portion 41 is partially provided, the stress applied to the electrical steel sheet 40 due to curing shrinkage is reduced as compared with the case where the adhesive portion 41 is provided on the entire surface. Further, since the two-dosage form SGA is cured at room temperature, the stress due to the difference in the coefficient of thermal expansion is also reduced. Therefore, the strain of the electromagnetic steel sheet 40 can be suppressed, and the increase in iron loss can be suppressed.

The scope of the claims
[Claim 1]
With multiple electrical steel sheets laminated to each other and both sides covered with an insulating film,
It is provided with an adhesive portion that is arranged between the electromagnetic steel sheets that are adjacent to each other in the stacking direction and that adheres these electromagnetic steel sheets to each other.
All the sets of the electromagnetic steel sheets adjacent to each other in the laminating direction are adhered by the adhesive portion.
The adhesive forming the adhesive portion contains an acrylic compound, an oxidizing agent, and a reducing agent, and a part of the acrylic compound and the oxidizing agent are used as the first agent, and the rest of the acrylic compound and the reducing agent are used as the first agent. The agent is a two-part acrylic adhesive that is placed in the second agent.
Adhesive laminated core for stator in which the adhesive portion is partially provided between electromagnetic steel sheets adjacent to each other in the laminated direction.
[Claim 2]
The acrylic compound contains at least one selected from the group consisting of methyl methacrylate, phenoxyethyl methacrylate, 2-hydroxyethyl methacrylate and 2-hydroxypropyl methacrylate.
The methyl methacrylate is 0 to 50% by mass, the phenoxyethyl methacrylate is 0 to 50% by mass, the 2-hydroxyethyl methacrylate is 0 to 50% by mass, and the 2-hydroxypropyl is 0 to 50% by mass with respect to the total mass of the acrylic adhesive. The adhesive laminated core for a stator according to claim 1, wherein the methacrylate is 0 to 50% by mass.
[Claim 3]
With multiple electrical steel sheets laminated to each other and both sides covered with an insulating film,
It is provided with an adhesive portion that is arranged between the electromagnetic steel sheets that are adjacent to each other in the stacking direction and that adheres these electromagnetic steel sheets to each other.
All the sets of the electromagnetic steel sheets adjacent to each other in the laminating direction are adhered by the adhesive portion.
The adhesive that forms the adhesive portion is an acrylic adhesive containing an acrylic compound.
Adhesive laminated core for stator in which the adhesive portion is partially provided between electromagnetic steel sheets adjacent to each other in the laminated direction.
[Claim 4]
The adhesive laminated core for a stator according to claim 3, wherein the acrylic adhesive is an anaerobic adhesive.
[Claim 5]
The adhesive laminated core for a stator according to claim 3, wherein the acrylic compound is a cyanoacrylate.
[Claim 6]
The adhesive laminated core for a stator according to any one of claims 1 to 5, wherein the acrylic adhesive further contains an elastomer.
[Claim 7]
The elastomer contains acrylonitrile butadiene rubber
The adhesive laminated core for a stator according to claim 6, wherein the acrylonitrile butadiene rubber is 1 to 20% by mass with respect to the total mass of the acrylic adhesive.
[Claim 8]
The adhesive laminated core for a stator according to any one of claims 1 to 7, wherein the adhesive area ratio of the electromagnetic steel sheet by the adhesive portion between the respective electromagnetic steel sheets is 20 to 80%.
[Claim 9]
The method for manufacturing an adhesive laminated core for a stator according to claim 1.
An operation in which the first agent and the second agent of the acrylic adhesive are applied to a part of the surface of the electromagnetic steel sheet at room temperature, and then the first agent and the second agent of the acrylic adhesive are applied and then pressure-bonded on another electromagnetic steel sheet to form the adhesive portion. A method for manufacturing an adhesive laminated core for a stator, which repeats the above steps.
[Claim 10]
The method for manufacturing an adhesive laminated core for a stator according to claim 3.
At room temperature, the acrylic adhesive is applied to a part of the surface of the electrical steel sheet, and then the adhesive laminated core for a stator is repeatedly crimped on another electrical steel sheet to form the adhesive portion. Production method.
[Claim 11]
A rotary electric machine including the adhesive laminated core for a stator according to any one of claims 1 to 8.