Technical field
[0001]
The present invention relates to a laminated core and a rotary electric machine.
This application claims priority based on Japanese Patent Application No. 2018-235857 filed in Japan on December 17, 2018, the contents of which are incorporated herein by reference.
Background technology
[0002]
Conventionally, a laminated core as described in Patent Document 1 below has been known. In this laminated core, electromagnetic steel sheets adjacent to each other in the laminated direction are adhered.
Prior art literature
Patent documents
[0003]
Patent Document 1: Japanese Patent Application Laid-Open No. 2011-023523
Outline of the invention
Problems to be solved by the invention
[0004]
There is room for improvement in improving the magnetic characteristics of the conventional laminated core.
[0005]
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.
Means to solve problems
[0006]
(1) One aspect of the present invention includes a plurality of electromagnetic steel sheets laminated to each other and an adhesive portion provided between the electromagnetic steel sheets adjacent to each other in the stacking direction and adhering the electromagnetic steel sheets to each other. The electrical steel sheet has an annular core back portion and a plurality of teeth portions extending from the core back portion in the radial direction of the core back portion and arranged at intervals in the circumferential direction of the core back portion. The teeth portion of the electrical steel sheet is a laminated core having an adhesive region provided with a strip-shaped adhesive portion extending along the circumferential direction.
[0007]
According to the above configuration, the tooth portion of the electrical steel sheet has an adhesive region provided with a strip-shaped adhesive portion. Since the band-shaped adhesive portion extends in one direction, the adhesive area of ​​the adhesive portion can be increased to increase the adhesive strength as compared with the case where the dotted adhesive portions are intermittently provided in the same range. ..
Distortion due to curing shrinkage of the adhesive occurs in the region of the electrical steel sheet that comes into contact with the bonded portion, and the iron loss of the electrical steel sheet increases in that region. Here, the region of the electrical steel sheet in which the iron loss increases due to strain in contact with the adhesive region is referred to as a “deteriorated region”. According to the above configuration, since the adhesive portion has a band shape extending in the circumferential direction and is provided in the teeth portion, the deteriorated region extends in the circumferential direction in the teeth portion. Since the magnetic flux flowing through the teeth portion is along the radial direction, the deteriorated region extends in the circumferential direction, so that the path length of the magnetic flux passing through the deteriorated region is shortened. Therefore, the magnetic resistance to each magnetic flux in the magnetic circuit is reduced, and deterioration of the magnetic characteristics of the laminated core can be suppressed.
[0008]
(2) In the laminated core according to the above (1), the adhesive region may be formed on the core back portion side from the vicinity of the tip of the teeth portion.
[0009]
The magnetic flux diffuses and extends from the tip of the tooth part to both sides in the circumferential direction. Therefore, magnetic flux tends to concentrate at both ends in the circumferential direction near the tip of the tooth portion. If a deteriorated region is provided in the region where the magnetic flux is concentrated, the increase in iron loss tends to be remarkable. Therefore, if the deteriorated region is provided near the tip of the tooth portion, the iron loss tends to increase. According to the above configuration, since the adhesive region is located closer to the core back portion than the vicinity of the tip of the tooth portion, the deteriorated region can be arranged away from the region having a high magnetic flux density, and an increase in iron loss can be suppressed.
[0010]
(3) In the laminated core according to (1) or (2), the adhesive region has a radial width dimension from the circumferential central portion of the teeth portion toward the circumferential end side of the teeth portion. It may be a structure that becomes large.
[0011]
The magnetic flux diffuses and extends from the tip of the tooth part to both sides in the circumferential direction. Also, the magnetic flux tends to flow through the shortest distance. Therefore, the magnetic flux density of the teeth portion increases toward the end side in the circumferential direction. If the variation in the magnetic flux density of the teeth portion becomes large in the circumferential direction, the magnetic characteristics of the laminated core may deteriorate. According to the above configuration, the radial width dimension of the adhesive region increases from the central portion of the tooth portion toward the peripheral end portion side. That is, the radial length of the deteriorated region becomes longer from the central portion of the tooth portion toward the peripheral end portion side. For this reason, the magnetic resistance of the teeth portion increases toward the outside in the circumferential direction, and it becomes difficult for magnetic flux to flow on the peripheral end side. As a result, variations in the magnetic flux density of the teeth portion can be suppressed, the magnetic flux densities in the teeth portion can be brought close to each other uniformly, and the magnetic characteristics of the laminated core can be improved.
[0012]
(4) In the laminated core according to the above (1) or the above (2), the adhesive region may be configured to extend in an arc shape along the circumferential direction.
[0013]
According to the above configuration, the adhesive portion can be uniformly applied along the circumferential direction, so that the manufacturing process can be simplified.
[0014]
(5) In the laminated core according to the above (1) to (4), the adhesive portion may be configured to extend over the entire width of the teeth portion.
[0015]
According to the above configuration, since the adhesive portion extends over the entire width of the teeth portion, it is easy to secure the adhesive strength between the teeth portions.
[0016]
(6) In the laminated core according to any one of the above (1) to (5), the average thickness of the bonded portion may be 1.0 μm to 3.0 μm.
[0017]
(7) In the laminated core according to any one of the above (1) to (6), the average tensile elastic modulus E of the bonded portion may be 1500 MPa to 4500 MPa.
[0018]
(8) In the laminated core according to any one of (1) to (7) above, the adhesive portion is a room temperature adhesive type acrylic adhesive containing SGA made of an elastomer-containing acrylic adhesive. You may.
[0019]
(9) In the laminated core according to any one of the above (1) to (8), the melting point of the bonded portion may be 180 ° C. or higher.
[0020]
(10) The rotary electric machine according to one aspect of the present invention is a rotary electric machine including the laminated core according to any one of the above (1) to (9).
[0021]
According to the rotary electric machine having the above configuration, since it has a laminated core having excellent magnetic characteristics, the energy efficiency of the rotary electric machine can be improved.
The invention's effect
[0022]
According to the present invention, the magnetic characteristics of the laminated core can be improved.
A brief description of the drawing
[0023]
FIG. 1 is a cross-sectional view of a rotary electric machine according to an embodiment of the present invention.
FIG. 2 is a plan view of a stator included in the rotary electric machine shown in FIG.
FIG. 3 is a front view of a stator included in the rotary electric machine shown in FIG.
FIG. 4 is a schematic view of an electromagnetic steel sheet and an adhesive region of the stator shown in FIGS. 2 and 3.
FIG. 5 is a schematic view of an adhesive region of the stator of the modified example 1.
FIG. 6 is a schematic view of an adhesive region of the stator of the modified example 2.
FIG. 7 is a schematic view of an adhesive region of the stator of the modified example 3.
FIG. 8 is a schematic view of an adhesive region of the stator of the modified example 4.
FIG. 9 is a schematic view of an adhesive region of the stator of the modified example 5.
[Fig. 10] Model No. 1-Model No. It is a graph which shows the simulation result of the iron loss of 4.
[Fig. 11] Model No. as a comparative example. It is a schematic diagram of the stator core of 4.
Mode for carrying out the invention
[0024]
Hereinafter, the rotary electric machine according to the embodiment of the present invention will be described with reference to the drawings. In the present embodiment, an electric motor as a rotary electric machine, specifically an AC electric motor, more specifically a synchronous electric motor, and even more specifically, a permanent magnet field type electric motor will be described as an example. This type of electric motor is suitably used for, for example, an electric vehicle.
[0025]
As shown in FIGS. 1 and 2, the rotary electric machine 10 includes a stator 20, a rotor 30, a case 50, and a rotary shaft 60. The stator 20 and rotor 30 are housed in a case 50. The stator 20 is fixed to the case 50.
[0026]
In the rotary electric machine 10 of the present embodiment, for example, an exciting current having an effective value of 10 A and a frequency of 100 Hz is applied to each phase of the stator 20, and the rotor 30 and the rotating shaft 60 rotate at a rotation speed of 1000 rpm accordingly.
[0027]
In this embodiment, the rotor 30 is an inner rotor type in which the rotor 30 is located inside the stator 20 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, for example, the number of poles, the number of slots, the number of phases, and the like can be changed as appropriate.
[0028]
The stator 20 includes a stator core (laminated core) 21 and windings (not shown).
The stator core 21 includes an annular core back portion 22 and a plurality of teeth portions 23. In the following, the axial direction of the stator core 21 (core back portion 22) (the central axis O direction of the stator core 21) is referred to as the axial direction, and the radial direction of the stator core 21 (core back portion 22) (perpendicular to the central axis O of the stator core 21). The direction) is called the radial direction, and the circumferential direction of the stator core 21 (core back portion 22) (the direction that orbits around the central axis O of the stator core 21) is called the circumferential direction.
[0029]
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 extend inward in the radial direction (toward the central axis O of the core back portion 22 along the radial direction) from the core back portion 22. The plurality of tooth portions 23 are arranged at equal intervals in the circumferential direction. In the present embodiment, 18 tooth portions 23 are provided at every 20 degrees of the central angle centered on the central axis O. The plurality of tooth portions 23 are formed to have the same shape and the same size as each other.
The winding is wound around the teeth portion 23. The winding may be a centralized winding or a distributed winding.
[0030]
The rotor 30 is arranged inside the stator 20 (stator core 21) in the radial direction. The rotor 30 includes a rotor core 31 and a plurality of permanent magnets 32.
The rotor core 31 is formed in an annular shape (annular ring) arranged coaxially with the stator 20. The rotating shaft 60 is arranged in the rotor core 31. The rotating shaft 60 is fixed to the rotor core 31.
The plurality of permanent magnets 32 are fixed to the rotor core 31. In this embodiment, a set of two permanent magnets 32 form one magnetic pole. The plurality of sets of permanent magnets 32 are arranged at equal intervals in the circumferential direction. In the present embodiment, 12 sets (24 in total) of permanent magnets 32 are provided at a central angle of 30 degrees about the central axis O.
[0031]
In this embodiment, an embedded magnet type motor is adopted as a permanent magnet field type motor. The rotor core 31 is formed with a plurality of through holes 33 that penetrate the rotor core 31 in the axial direction. The plurality of through holes 33 are provided corresponding to the plurality of permanent magnets 32. Each permanent magnet 32 ​​is fixed to the rotor core 31 in a state of being arranged in the corresponding through hole 33. Fixing of each permanent magnet 32 ​​to the rotor core 31 can be realized, for example, by adhering the outer surface of the permanent magnet 32 ​​and the inner surface of the through hole 33 with an adhesive or the like. As the permanent magnet field type motor, a surface magnet type motor may be adopted instead of the embedded magnet type.
[0032]

As shown in FIG. 3, 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 the stacking direction.
[0033]
The product 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. However, these values ​​are examples, and the product 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 tip of the teeth portion 23 of the stator core 21. The inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tips of all the teeth portions 23.
[0034]
Each electromagnetic steel sheet 40 forming the stator core 21 and the rotor core 31 is, for example,