EA041718B1 - GLUE-SLATED CORE FOR STATOR AND ELECTRIC MOTOR - Google Patents

Description

The field of technology to which the invention belongs

The present invention relates to a glued laminated core for a stator and to an electric motor.

The application for this invention claims priority to Japanese Patent Application No. 2018-235863 filed December 17, 2018, the contents of which are incorporated herein by reference.

Prerequisites for the creation of the invention

In a laminated core used for an electric motor, when the thickness of the electrical steel sheet is reduced, the stiffness per electrical steel sheet is reduced. Therefore, although the number of their layers increases, the stiffness of the entire laminated core also decreases. In this case, when the motor is running, deformation of the stator or displacement of the laminated core may occur due to rotation of the rotor. Further, when the number of layers is increased, processing during production of the laminated core becomes difficult, and problems such as deformation of the laminated core and difficulty in the winding procedure arise.

In order to solve these problems, for example, as in the motor core (laminated core) described in Patent Document 1 below, increasing the mechanical strength of the laminated core can be performed by fixing the shape of the laminated core with an adhesive material. Those. in the motor core described in Patent Document 1, layers of room temperature-curable instant adhesive are placed in all tooth portions so as to extend in the directions (radial directions) in which the tooth portions extend. Additionally, a plurality of layers of thermosetting organic adhesive material are placed in the circumferential direction of the substantially annular electrical steel sheets. In addition, adjacent sheets of electrical steel are bonded to each other by layers of room temperature-curable instant adhesive material and layers of thermosetting organic adhesive material.

List of bibliographic references

Patent Documents.

Patent document 1.

Unexamined Patent Application (Japan), First Publication No. 2016-171652.

The essence of the invention

Problems Solved by the Invention

However, if the strength of the adhesive materials in the tooth portions is too high, a compressive force due to shrinkage when the adhesive materials are cured is applied to the tooth portions, which adversely affects their magnetic properties. In the method described in Patent Document 1, this problem is not recognized and, of course, steps are not taken to solve this problem.

The present invention has been made in view of the above circumstances, and its object is to provide a glued-laminated core for a stator including an adhesive structure that does not adversely affect the magnetic properties of the tooth portions while increasing their mechanical strength, and an electric motor including a glued laminated core for the stator.

Troubleshooter

In order to solve the above problem, the present invention uses the following means.

(1) A glued-laminated stator core according to one aspect of the present invention includes a plurality of electrical steel sheets coaxially overlapping each other and each having a back portion of the core and a tooth portion; and a plurality of adhesive layers that bond the electrical steel sheets together, wherein between the respective electrical steel sheets, the partial adhesive strength provided by the adhesive layers, which is an average adhesive strength per unit area in the tooth portion, is lower than the partial adhesive strength provided by the adhesive layers, which is an average adhesive strength per unit area in the back of the core.

(2) In the aspect according to the above (1), the following configuration may be used: the average value of the adhesive strength ratios obtained by dividing the partial adhesive strength in the tooth portion by the partial adhesive strength in the back portion of the core is in the range of 0.1 or more and less than 1, 0.

(3) In the aspect according to the above (1) or (2), the following configuration may be used: the average value S1 of the partial bonding strength in the tooth portion is 1-15 MPa; the average value S2 of the partial bonding strength in the back portion of the core is 15-50 MPa; and the mean value of S1 is lower than the mean value of S2.

(4) In the aspect according to the above (1) or (2), the following configuration may be used: each of the adhesive layers is made of an adhesive material having the same chemical

- 1 041718 composition; the average value A1 of the area share of the adhesive layers in the tooth portion is 10-50%; the average value A2 of the proportion of the area of the adhesive layers in the back part of the core is 50-100%; and the A1 mean is below the A2 mean.

(5) In the aspect according to any of the above (1) to (4), the average thickness of the adhesive layers may be 1.0-3.0 µm.

(6) In the aspect according to any of the above (1) to (5), the average tensile modulus E of the adhesive layers may be 1500-4500 MPa.

(7) In an aspect according to any of the above (1) to (6), the adhesive layers may be a room temperature curable acrylic-based adhesive containing an SGA made of an elastomer-containing acrylic-based adhesive.

(8) An electric motor according to one aspect of the present invention includes a bonded laminated core for a stator according to any of the above (1) to (7).

Benefits of the Invention

According to each aspect of the present invention, it is possible to provide a glued laminated core for a stator including an adhesive structure that does not adversely affect the magnetic properties of the tooth portions while increasing their mechanical strength, and a motor including a glued laminated core for stator.

Brief description of the drawings

Fig. 1 is a cross-sectional view of an electric motor including a bonded-laminated core for a stator according to an embodiment of the present invention.

Fig. 2 is a side view of a glued laminated core for a stator.

Fig. 3 is a cross-sectional view taken along line A-A in FIG. 2, showing many examples of schemes for the formation of adhesive layers in a glued-laminated core for a stator.

Fig. 4 is a side view of a manufacturing apparatus used to manufacture examples of a bonded-laminated stator core.

Fig. 5 is a diagram showing the examples shown in table. 1A and 1B, and is a graph showing the relationship between the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core.

Fig. 6 is a diagram showing the examples shown in table. 2A and 2B and is a graph showing the relationship between the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core.

Fig. 7 is a diagram showing the examples shown in table. 3A and 3B and is a graph showing the relationship between the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core.

Fig. 8 is a diagram showing the examples shown in table. 3A and 3B, and is a graph showing the relationship between the area ratio at the position of the tooth portion and the area ratio at the position of the back portion of the core.

Embodiments for carrying out the invention

Hereinafter, with reference to the drawings, a bonded-laminated stator core and a motor including a bonded-laminated stator core according to one embodiment of the present invention will be described. In addition, in the present embodiment, as a motor, a motor, namely an AC motor, more specifically a synchronous motor, and more specifically a permanent magnet motor, is described as an example. This type of electric motor is suitably used for an electric vehicle, for example.

As shown in FIG. 1, motor 10 includes a stator 20, a rotor 30, a housing 50, and a rotary shaft 60. Stator 20 and rotor 30 are housed in housing 50. Stator 20 is attached to the inside of housing 50.

In the present embodiment, the motor 10 is an internal rotor motor in which the rotor 30 is radially disposed in the stator 20. However, the motor 10 may be an external rotor motor in which the rotor 30 is located outside the stator 20. Additionally, in the present embodiment, motor 10 is a three-phase AC motor having 12 poles and 18 slots. However, the number of poles, the number of slots, the number of phases, etc. can be changed appropriately.

The electric motor 10 may be rotated at 1000 rpm, for example, by applying a drive current having an effective value of 10 A and a frequency of 100 Hz to each phase.

Stator 20 includes a bonded core for stator 21 (hereinafter referred to as stator core) and windings (not shown).

The stator core 21 includes an annular back portion 22 and a plurality of tooth portions 23. Hereinafter, the direction along the central axis O of the stator core 21 (or back portion 22) is referred to as the axial direction, the radial direction

- 2 041718 of the stator core 21 (or core back part 22) (i.e., the direction orthogonal to the central axis O) is called the radial direction, and the circumferential direction of the stator core 21 (or core back part 22) (i.e., the direction of rotation around the central axis O) is called the circumferential direction.

The back portion 22 of the core has a circular shape when viewed from the top of the stator 20 along the axial direction.

A plurality of tooth portions 23 extend inwardly in the radial direction (towards the central axis O of the core back portion 22 in the radial direction) from the inner periphery of the core back portion 22. A 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 every 20° relative to a central angle centered on the central axis O. A plurality of tooth portions 23 are formed to be identical in shape and size to each other. Thus, the plurality of tooth portions 23 have the same thickness dimension to each other.

The windings are wound around the tooth portions 23. The windings may be concentrated windings or distributed windings.

The rotor 30 is located in 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 to have an annular shape (encircling the annular shape) disposed coaxially with the stator 20. The rotation shaft 60 is disposed in the rotor core 31. The rotation shaft 60 is attached to the core 31 of the rotor.

A plurality of permanent magnets 32 are attached to the rotor core 31. In the present embodiment, a set of two permanent magnets 32 form one magnetic pole. A 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 every 30° of the central angle centered on the central axis O.

In the present embodiment, an internal permanent magnet motor is used as a permanent magnet excited motor. A plurality of through holes 33 that extend through the rotor core 31 in the axial direction are formed in the rotor core 31 . The plurality of through holes 33 are provided so that they correspond to the arrangement of the plurality of permanent magnets 32. Each permanent magnet 32 is attached to the rotor core 31 in the state in which it is located in the corresponding through hole 33. The attachment of each permanent magnet 32 to the rotor core 31 can be realized for example, by providing an adhesive between the outer surface of the permanent magnet 32 and the inner surface of the through hole 33 with an adhesive material or the like. In addition, as a permanent magnet motor, a surface permanent magnet motor can be used instead of an internal permanent magnet motor.

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 electrical steel sheets 40 in the axial direction.

Further, the lamination thickness (total length along the central axis O) of each of the stator core 21 and the rotor core 31, for example, is 50.0 mm. The outer diameter of the stator core 21, for example, is 250.0 mm. The inner diameter of the stator core 21, for example, is 165.0 mm. The outer diameter of the rotor core 31, for example, is 163.0 mm. The inner diameter of the rotor core 31, for example, is 30.0 mm. However, these values are examples, and the layering thickness, outer diameter and inner diameter of the stator core 21 and the layering 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 measured with the tops of the tooth portions 23 of the stator core 21 as reference members. Thus, the inner diameter of the stator core 21 is the diameter of a virtual circle inscribed in the tops of all tooth parts 23.

Each electrical steel sheet 40 forming the stator core 21 and the rotor core 31 is formed, for example, by punching an electrical steel sheet serving as a base material. As the electrical steel sheet 40, a known electrical steel sheet may be used. The chemical composition of the electrical steel sheet 40 includes 2.5 to 3.9% Si as shown below in units of mass%. The ranges of components other than Si are not particularly limited, but the desirable ranges in the present embodiment are indicated below. By setting the chemical composition in these ranges, the yield strength YP of each electrical steel sheet 40 can be set to 380 MPa or more and 540 MPa or less.

Si: 2.5-3.9%,

Al: 0.001-3.0%,

Mn: 0.05-5.0%,

- 3 041718 residue: Fe and impurities.

In the present embodiment, a grain-oriented electrical steel sheet is used as the electrical steel sheet 40 . As the non-grain-oriented electrical steel sheet, for example, a non-grain-oriented electrical steel strip according to JIS C 2552:2014 can be used. However, as the electrical steel sheet 40, it is also possible to use a grain-oriented electrical steel sheet instead of a grain-oriented electrical steel sheet. As the grain-oriented electrical steel sheet, JIS C 2553:2012 grain-oriented electrical steel strip can be used.

Insulating coatings are provided on both surfaces of the electrical steel sheet 40 in order to improve the usability of the electrical steel sheet 40 and iron loss of the stator core 21 (hereinafter, may simply be referred to as a laminated core). As the insulating coating material, for example, (1) an inorganic compound, (2) an organic polymer, (3) a mixture of an inorganic compound and an organic polymer, and the like can be used. Among them, in the case where the insulating coating is (1) an inorganic compound or (3) a mixture of an inorganic compound and an organic resin, it is possible to greatly suppress deterioration in magnetic properties due to curing shrinkage of each of the adhesive layers. As an inorganic compound, for example, (1) a complex compound of dichromate and boric acid, (2) a complex compound of phosphate and silica, and the like. may be given as an example. As the organic resin, epoxy resin, acrylic resin, acrylic styrene resin, polyester resin, silicone resin, and fluorine resin can be roughly illustrated.

In order to ensure insulation performance between the electrical steel sheets 40 laminated to each other, the upper limit of the average thickness of the insulation coating (average thickness per surface of the electrical steel sheet 40) is preferably 1.5 µm, more preferably 1.2 µm.

On the other hand, the insulation effect becomes saturated when the insulation coating becomes thicker. Additionally, as the insulating coating becomes thicker, the fill factor of the electrical steel sheet 40 in the laminated core decreases and the performance of the laminated core deteriorates. Therefore, the insulation coating can be as thin as possible within the range in which the performance of the insulation can be maintained. The lower limit of the average thickness of the insulating coating (thickness per surface of the electrical steel sheet 40) is preferably 0.3 µm, more preferably 0.5 µm. As an average thickness of the insulating coating, for example, 0.8 µm can be applied in the above-mentioned upper and lower limit ranges.

The average thickness of the insulating coating is the average value of the entire laminated core. The thickness of the insulating coating barely varies throughout their layered positions in the axial direction and angular position around the central axis of the laminated core. For this reason, the average thickness of the insulating coating may be set as a value measured at the top end position of the laminated core.

As the thickness of the electrical steel sheet 40 becomes thinner, the steel loss reducing effect gradually becomes saturated. Further, as the electrical steel sheet 40 becomes thinner, the manufacturing cost of the electrical steel sheet 40 increases. For this reason, the thickness of the electrical steel sheet 40 is preferably 0.10 mm or more in view of the steel loss improvement effect and manufacturing cost.

On the other hand, if the electrical steel sheet 40 is too thick, the press punching operation of the electrical steel sheet 40 becomes difficult. For this reason, considering the operation of punching the electrical steel sheet 40, the thickness of the electrical steel sheet 40 is preferably 0.65 mm or less. In addition, the thickness of the electrical steel sheet 40 includes the thickness of the insulating coating.

The average thickness of each electrical steel sheet 40 is the average of the entire laminated core. The thickness of each electrical steel sheet 40 barely changes over the lamination positions in the axial direction and the angular position around the central axis of the laminated core. For this reason, the average thickness of each electrical steel sheet 40 can be set as the value measured at the top end position of the laminated core.

A plurality of electrical steel sheets 40 forming the stator core 21 are layered, for example, through a plurality of dot-shaped adhesive layers 41 . Each of the adhesive layers 41 is formed from an adhesive material that is cured without separation. For adhesive layer 41 is used,

- 4 041718 for example, thermosetting adhesive material by polymer bonding and the like. As the adhesive material for forming the adhesive layer 41, an adhesive material that contains any of (1) acrylic resin, (2) epoxy resin, and (3) epoxy resin acrylic each having oil adhesiveness can be used.

For the adhesive material for forming the adhesive layer 41, the radically curable adhesive material or the like. can be used in addition to the thermosetting adhesive, and from the performance point of view, a room temperature curing adhesive is preferably used. Room temperature curing (room temperature adhesive) adhesive is cured at 20-30°C. As a room temperature-curing adhesive, an acrylic-based adhesive is preferable. A typical acrylic-based adhesive includes a second-generation acrylic-based (SGA) adhesive and the like. Any of the anaerobic adhesive, the instant adhesive, and the acrylic-based elastomeric adhesive can be used within a range where the benefits of the present invention are not impaired. In addition, the adhesive material mentioned herein is the adhesive material in the state before curing, and becomes the adhesive layer 41 after the adhesive material is cured.

The average tensile modulus E of the adhesive layer 41 at room temperature (2030°C) is in the range of 1500-4500 MPa. If the average tensile modulus of the adhesive layer 41 is less than 1500 MPa, a problem arises that the rigidity of the laminated core is lowered. For this reason, the lower limit of the average tensile modulus of the adhesive layer 41 is 1500 MPa, more preferably 1800 MPa. On the contrary, if the average tensile modulus of the adhesive layer 41 exceeds 4500 MPa, there will be a problem that the stress and tension applied to the electrical steel sheet 40 increase and the magnetic properties of the core deteriorate. For this reason, the upper limit of the average tensile modulus of the adhesive layer 41 is 4500 MPa, more preferably 3650 MPa. The average tensile modulus of each adhesive layer 41 can be adjusted by changing one or both of: the heating and pressurization conditions applied during bonding; and type of curing agent.

Additionally, the average tensile modulus E is measured by a resonance method. In particular, the average tensile modulus is measured in accordance with JIS R 1602:1995.

More specifically, a measurement sample (not shown) is first made. This test is obtained by providing adhesion between two electrical steel sheets 40 using an adhesive material that is the target of measurements, and curing them so as to form an adhesive layer 41. In the case in which the adhesive material is thermosetting, curing is performed by heating and pressurizing it under heating conditions and pressurizing it in the actual processing. On the other hand, in the case where the adhesive material is of the room temperature-curable type, curing is performed by pressurizing at room temperature.

In addition, the tensile modulus of this sample is measured using a resonance method. As described above, the method for measuring tensile modulus using the resonance method is performed in accordance with JIS R 1602:1995. Further, the tensile modulus of only the adhesive layer 41 is obtained by removing the effect of the electrical steel sheet 40 itself from the tensile modulus (measured value) of the sample by calculation.

Since the tensile modulus obtained from the sample in this way is equal to the average value for the entire laminated core, this value is considered to be the average tensile modulus. The composition is set such that the average tensile modulus barely changes over the layered positions in the axial direction or in the angular position around the central axis of the laminated core. For this reason, the average tensile modulus may be set to the value obtained by measuring the adhesive layer 41 after curing at the top end position of the laminated core.

As a method of bonding the electrical steel sheets 40 together, a bonding method in which an adhesive material is applied to the bottom surfaces (surfaces on one side) of the electrical steel sheets 40, then they are overlapped, and then one or both of heating and pressure stacking is performed to cure the adhesive material to form the adhesive layer 41. In addition, the means in the case of heating may be any means, such as means for heating the stator core 21 in a high temperature bath or electric furnace, or a method for directly supplying power and heating the core 21 stators. On the other hand, in the case in which a room temperature-curing adhesive material is used, they are only bonded by compression stacking without heating.

In order to obtain a stable and sufficient adhesive strength, the thickness of the adhesive layer 41 is preferably 1 µm or more.

On the other hand, if the thickness of the adhesive layer 41 exceeds 100 µm, the bonding strength is saturated. Further, as the adhesive layer 41 becomes thick, the spatial coefficient decreases and the magnetic properties such as loss in the laminated core steel decrease. Thus, the thickness of the adhesive layer 41 is preferably 1 µm or more and 100 µm or less, more preferably 1 µm or more and 10 µm or less.

Additionally, in the above description, the thickness of the adhesive layer 41 means the average thickness of the adhesive layer 41.

The average thickness of the adhesive layer 41 is more preferably 1.0 µm or more and 3.0 µm or less. If the average thickness of the adhesive layer 41 is less than 1.0 µm, sufficient adhesive strength cannot be ensured as described above. For this reason, the lower limit of the average thickness of the adhesive layer 41 is 1.0 µm, more preferably 1.2 µm. Conversely, if the average thickness of the adhesive layer 41 becomes thicker than 3.0 μm, problems such as a significant increase in the tension amount of the electrical steel sheet 40 due to shrinkage during solidification occur. For this reason, the upper limit of the average thickness of the adhesive layer 41 is 3.0 µm, more preferably 2.6 µm.

The average thickness of the adhesive layer 41 is the average value of the entire laminated core. The average thickness of the adhesive layer 41 hardly changes at the lamination positions in the axial direction and the circumferential position around the central axis of the laminated core. For this reason, the average thickness of the adhesive layer 41 may be set as the average of numerical values measured at 10 or more points in the circumferential direction at the upper end position of the laminated core.

In addition, the average thickness of the adhesive layers 41 can be adjusted by changing, for example, the amount of adhesive applied.

Fig. 3 shows an example of schemes for the formation of the adhesive layer 41. In FIG. 3, two shaping patterns 41A and 41B are shown together in one drawing with a line with alternating long and short dashes as a boundary. In the case of applying the formation pattern 41A, the entire surface of the electrical steel sheet 40 is formed in such a coating pattern. On the other hand, in the case of applying the formation pattern 41B, the entire surface of the electrical steel sheet 40 is formed in such a coating pattern.

First, in the case of the formation scheme 41A, the adhesive layer 41 is formed such that its average area fraction in the core back portion 22 and its average area fraction in the tooth portions 23 are equal to each other at each position of the laminated core in the axial direction, but the components of the core itself used adhesive material differ from each other. In the core back portion 22, a plurality of dot-shaped adhesive layers 41 are placed in an annular shape. Each of the adhesive layers 41 on the core back portion 22 are arranged to overlap an imaginary straight line EL1 connecting the center position of each tooth portion 23 in the transverse direction and the center axis O of the electrical steel sheet 40 .

On the other hand, in the tooth portion 23, two adhesive layers 41 are placed side by side to overlap an imaginary straight line EL1 for each tooth portion 23. The size of the diameter of the adhesive layer 41 in the core back portion 22 is larger than the diameter of the adhesive layer 41 in the tooth portion 23. For this reason, the number of adhesive layers 41 in the back portion 22 is smaller than the number of adhesive layers 41 in the tooth portion 23, but the area fractions are the same. Those. the ratio of the sum of the areas of each adhesive layer 41 on the core back portion 22 to the total area of the back of the core portion 22 and the ratio of the sum of the areas of each adhesive layer 41 on the tooth portion 23 to the total area of the tooth portion 23 are the same.

In the case of considering the total bonding area between the electrical steel sheets 40 that overlap each other as the partial strength divided into the core back portion 22 and the tooth portion 23, if the adhesive materials used are the same, the partial bonding strength of the core back portion 22 and the partial strength the bonding of the tooth portion 23 are the same. However, in this formation scheme 41A, the adhesive strength of the adhesive material used to form the adhesive layers 41 formed on the back portion 22 is higher than the adhesive strength of the adhesive material used to form the adhesive layers 41 formed on the tooth portion 23.

As a result, between the respective electrical steel sheets 40, the average bonding strength per unit area in the tooth portions 23 due to each of the adhesive layers 41 is lower than the average bonding strength per unit area in the core back portion 22. More specifically, the average bonding strength ratio obtained by dividing the partial bonding strength of each unit area in the tooth portions 23 by the partial bonding strength of each unit area in the back portion 22 is in the range of 0.1 or more to less than 1.0. The upper limit of the average bonding strength ratio is preferably 0.8, more preferably 0.6. Additionally, the lower limit of the average strength ratio

- 6 041718 bonding is preferably 0.15, more preferably 0.2.

Then, in the case of the generation circuit 41B shown in FIG. 3, the average value of the partial bonding strength or the average value of the area fraction differs between the core back portion 22 and the tooth portions 23 at each position of the laminated core in the axial direction.

Specifically, in the case of comparison by the average value of the partial bonding strength, the average value S1 of the partial bonding strength in the tooth portions 23 is 1-15 MPa, and the average value S2 of the partial bonding strength in the core back portion 22 is 15-50 MPa. In addition, the average value of S1 is lower than the average value of S2.

The lower limit of the average S1 is preferably 2 MPa, more preferably 3 MPa. The upper limit of the average S1 is preferably 10 MPa, more preferably 8 MPa. On the other hand, the lower limit of the average S2 is preferably 20 MPa, more preferably 30 MPa. Also, the upper limit of the average value of S2 is preferably 45 MPa, more preferably 40 MPa. However, the fact that the average value of S1 is lower than the average value of S2 remains unchanged.

On the other hand, in the case of comparison by the average value of the area ratio, the average value A1 of the area ratio of each adhesive layer 41 in the tooth portions 23 is 10-50%, and the average value A2 of the area ratio of each adhesive layer 41 in the back-core portion 22 is 50-100 %. In addition, the average value of A1 is lower than the average value of A2. Also, the average adhesive strength per unit area of each adhesive layer 41 is 5 to 50 MPa, which is common to each position of the tooth portions 23 and the back portion 22 of the core.

Additionally, the lower limit of the average A1 is preferably 10%. Also, the upper limit of the average A1 is preferably 30%, more preferably 20%. On the other hand, the lower limit of the average A2 is preferably 60%, more preferably 70%. Also, the upper limit of the average A2 is preferably 90%, more preferably 80%. However, the fact that the average value of A1 is lower than the average value of A2 remains unchanged.

Thus, the average value of the partial bond strength or the average value of the area ratio is determined as described above between the back core portion 22 and the tooth portions 23, whereby the average bond strength per unit area of each adhesive layer 41 in the tooth portions 23 can be made lower compared to the average bonding strength per unit area in the back portion 22 of the core.

Considering the arrangement of each adhesive layer 41 in the core back portion 22, a plurality of adhesive layers 41 in the form of round dots are arranged in an annular shape. Each of the adhesive layers 41 of the core back portion 22 is arranged to overlap an imaginary straight line EL2 connecting the center position of each tooth portion 23 in the transverse direction and the center axis O of the electrical steel sheet 40 .

On the other hand, in the tooth portion 23, one adhesive layer 41 is placed to overlap the imaginary straight line EL2 for each tooth portion 23. The size of the diameter of the adhesive layer 41 in the back portion 22 is larger than the diameter size of the adhesive layer 41 in the tooth portion 23. Thus, the average value the partial bond strength of the tooth portion 23 is restrained to become lower than the average value of the partial strength of the core back portion 22 at each position of the laminated core in the axial direction. In other words, the average value of the area ratio of the tooth portion 23 is suppressed to become lower than the average value of the partial strength of the core back portion 22 at each position of the laminated core in the axial direction. As a result, between the electrical steel sheets 40, the average bonding strength per unit area in the tooth portion 23 due to each adhesive layer 41 is lower than the average bonding strength per unit area in the back portion 22 of the core.

In the present embodiment, a plurality of electrical steel sheets forming the rotor core 31 are fastened together with fasteners 42 (dowels) shown in FIG. 1. However, the plurality of electrical steel sheets forming the rotor core 31 may also have a laminar structure bonded with an adhesive similar to the stator core 21.

Additionally, laminated cores for the stator core 21, the rotor core 31, and the like. can be formed by so-called coiling.

Examples

Using the manufacturing apparatus 100 shown in FIG. 4, the stator core 21 is manufactured by changing various manufacturing conditions.

First, the manufacturing apparatus 100 will now be described. In the manufacturing apparatus 100, at the time of feeding the electrical steel sheet P from the coil C (coil) in the direction of the arrow F, punching is performed many times by the molds placed in each step to gradually form the shapes of the electrical steel sheets 40, an adhesive material is applied to the bottom surfaces of the electrical steel sheets 40 and the punched electrical steel sheets 40 are layered, pressed and glued during the temperature rise, thereby forming each adhesive layer 41.

- 7 041718

As shown in FIG. 4, the manufacturing apparatus 100 includes a first-stage punching station 110 at a position proximal to the coil C, a second-stage punching station 120 adjacent on the exit side in the conveying direction of the electrical steel sheet P from the punching station 110, and a station 130 for applying adhesive coating, located nearby on the exit side even further from the cutting station 120.

The punching station 110 includes a stationary mold 111 located below the electrical steel sheet P and a movable mold 112 located above the electrical steel sheet P.

The punching station 120 includes a stationary mold 121 located below the electrical steel sheet P and a movable mold 122 located above the electrical steel sheet P.

Depending on the flat design of the motor, more cutting stations can be arranged.

The adhesive coating station 130 includes an applicator 131 including a plurality of injectors arranged in accordance with an adhesive coating pattern. Those. each injector is placed in a position corresponding to the formation position of each adhesive layer 41 shown in FIG. 3. The diameters of the nozzles of the injectors differ from each other depending on the size of the adhesive layers 41 to be formed. Further, in the case of the formation circuit 41A, the adhesive material flow path leading to the injector for applying the adhesive material to the core back portion 22 and the adhesive material flow path leading to the other injector for applying the adhesive material to the tooth portion 23 can be separated independently from each other. friend. In this case, the chemical components of the adhesive material applied to the core back portion 22 and the chemical components of the adhesive material applied to the tooth portion 23 can be separated independently from each other.

Moreover, instead of a configuration in which multiple types of adhesives are simultaneously applied by a single adhesive coating station 130 as described above, a plurality (e.g., two) of adhesive coating stations 130 may be provided to separately apply adhesives. In this case, the first type of adhesive material is applied to one of the tooth portion 23 and the core back portion 22 in the first adhesive coating station 130, and the second type of adhesive material is applied to the other in the second adhesive coating station 130.

The manufacturing apparatus 100 further includes a stacking station 140 at an underlying position relative to the adhesive coating station 130 . The stacking station 140 includes a heating device 141, a stationary outer shaping mold 142, a thermal insulation member 143, a movable outer shaping mold 144, and a spring 145.

The heating device 141, the stationary external mold 142, and the heat-insulating member 143 are disposed below the electrical steel sheet P. On the other hand, the movable external mold 144 and the spring 145 are disposed above the electrical steel sheet P. In addition, reference number 21 indicates the stator core.

In the manufacturing apparatus 100 of FIG. 4 having the configuration described above, first, the electrical steel sheet P is sequentially sent from the coil C in the direction of the arrow F. Then, the electrical steel sheet P is firstly punched by the punching station 110. Then, the electrical steel sheet P is punched by the punching station 120 Through these punching processes, the shape of the electrical steel sheet 40 having the core back portion 22 and the plurality of tooth portions 23 shown in FIG. 3 is obtained for electrical steel sheet P. However, since it is not completely punched out at this point, the process proceeds to the next step in the direction of arrow F. In the adhesive coating station 130, in the next step, the adhesive material supplied from each of the injectors of the applicator 131 is applied in a dotted form. At this time, the amounts or types of applied adhesive materials differ between the core back portion 22 and the tooth portion 23.

Thereafter, finally, the electrical steel sheet P is sent to the stacking station 140, punched out by the movable outer-shaping die 144, and layered with high precision. During this laying, the electrical steel sheet 40 receives a constant pressing force from the spring 145.

By successively repeating the punching process, the adhesive coating process, and the stacking process as described above, a predetermined number of electrical steel sheets 40 can be laminated. Further, the laminated core formed by stacking the electrical steel sheets 40 in this way is heated, for example, to a temperature of 200°C by the heating device 141 in the case of a thermoset adhesive. This heating cures the adhesives to form the adhesive layers 41. In the case of a room temperature curing adhesive, the adhesive cures over time to form the adhesive layers 41.

The stator core 21 is fully prepared by each of the above steps.

Using the manufacturing apparatus 100 described above, the stator cores 21 shown in Nos. 1-13 in Table 1 are manufactured. 1A and 1B. In addition, in order to create a comparative example, the stator core 21 shown in No. 14 was also manufactured using a different apparatus.

First, the thickness of the roll sheet (coil C) was traditionally set to 0.25 mm. A liquid insulating coating containing a metal phosphate and an acrylic resin emulsion was applied to small sections and fired at 300° C. to form a 0.8 μm insulating coating on one surface thereof.

Then, the coil was formed by punching into a single core sheet (electrical steel sheet 40) which is ring-shaped with an outer diameter of 300 mm and an inner diameter of 240 mm and is provided with 18 rectangular tooth portions having a length of 30 mm and a width of 15 mm on the side of its inner diameter. , using the device 100 for manufacturing.

Then, during successive feeding of the punched single sheet core, the adhesive material was applied in dotted form at each position shown in FIG. 3 (except for Comparative Example No. 14).

The chemical components of the electrical steel sheet 40 used in the manufacture of each stator core 21 are standardized as follows. In addition, each component value indicates wt.%:

Si: 3.1

Al: 0.7

Mn: 0.3, residue: Fe and impurities.

Table 1A

No. Part Adhesive material used to form the adhesive layer Area share Name Strength Attitude share Relative adhesive gluing strengths area shares material i (MPa) gluing (%) area (- (-) ) 1 Toothed part Chloroprene 2.0 0.40 60 1.00 rubber Back part Cyanoacrylate A 5.0 60 core 2 Toothed part Cyanoacrylate A 5.0 0.33 60 1.00 Back part Anaerobic 15.0 60 core 3 Toothed part Anaerobic 15.0 0.63 60 1.00 Back part Cyanoacrylate B 24.0 60 core 4 Toothed part Cyanoacrylate A 5.0 0.10 60 1.00 Back part SGA 48.0 60 core 5 Toothed part Cyanoacrylate B 24.0 0.50 60 1.00 Back part SGA 48.0 60 core 6 Toothed part Cyanoacrylate B 24.0 0.75 60 1.00 Back part Epoxy 32.0 60

- 9 041718

core resin A 7 Toothed part Cyanoacrylate B 24.0 0.57 60 1.00 Part of the back of the core Epoxy resin B 42.0 60 8 Toothed part Epoxy resin B 42.0 0.88 60 1.00 Part of the back of the core SGA 48.0 60 9 Toothed part Cyanoacrylate B 24.0 4.80 60 1.00 Part of the back of the core Cyanoacrylate A 5.0 60 10 Toothed part Epoxy resin B 42.0 1.31 60 1.00 Part of the back of the core Epoxy resin A 32.0 60 AND Toothed part Epoxy resin B 42.0 1.75 60 1.00 Part of the back of the core Cyanoacrylate B 24.0 60 12 Toothed part SGA 48.0 1.50 60 1.00 Part of the back of the core Epoxy resin A 32.0 60 13 Toothed part Chloroprene rubber 2.0 0.06 60 1.00 Part of the back of the core Epoxy resin A 32.0 60 14 Toothed part (Fixed with fasteners) - Part of the back of the core (Fixed with fasteners) -

- 10 041718

IB table

No. Total strength gluing Rigidity of laminated core Magnetic properties of the tooth part Example/comparative example Partial adhesive strength (MPa) Bond strength ratio (-) impact test Solution Relative not increased IA steel losses Solution 1 1.2 0.40 2 Good 105 Excellent Example 3.0 2 3.0 0.33 2 Good 103 Excellent Example 9.0 3 9.0 0.63 2 Good 106 Good Example 14.4 4 3.0 0.10 1 Excellent 110 Good Example 28.8 5 14.4 0.50 1 Excellent 104 Excellent Example 28.8 6 14.4 0.75 2 Good 105 Excellent Example 19.2 7 14.4 0.57 1 Excellent 104 Excellent Example 25.2 8 25.2 0.88 1 Excellent 109 Good Example 28.8 9 14.4 4.80 5 bad 126 bad Comparative example 3.0 10 25.2 1.31 3 satisfaction 128 bad Comparator

- 11 041718

19.2 rhetorical ny example AND 25.2 1.75 3 satisfaction rhetorical 131 bad Comparative example 14.4 12 28.8 1.50 3 satisfaction rhetorical 127 bad Comparative example 19.2 13 1.2 0.06 3 satisfaction rhetorical 112 Satisfactory Example 19.2 14 0.3 0.60 5 bad 125 bad Comparative example 0.5

On the other hand, the adhesive material for forming each adhesive layer 41 was selected from the following and used in an appropriate combination. Specific combinations are as shown in Table. 1A.

Adhesive material based on chloroprene rubber (bonding strength: 2 MPa).

Cyanoacrylate adhesive (bonding strength: 5 MPa).

Anaerobic adhesive material (gluing strength: 15 MPa).

Adhesive based on cyanoacrylate B (bonding strength: 24 MPa).

Epoxy adhesive (bonding strength: 32 MPa).

Epoxy resin adhesive B (bonding strength: 42 MPa).

Adhesive material based on epoxy resin C (bonding strength: 64 MPa).

SGA (gluing strength: 48 MPa).

Also in the examples in Table. 1A and 1B, the area ratio of the adhesive layer 41 in the tooth portion 23 is in all cases equal to the area ratio of the adhesive layer 41 in the back portion 22 of the core. For this reason, as shown in Table. 1A, the bonding strength ratio obtained by dividing the partial bonding strength of the tooth portion 23 by the partial bonding strength of the core back portion 22 is equal to the bonding strength ratio (Comparative Example No. 14 is omitted in the above). The partial adhesive strength indicates the adhesive strength (adhesion strength) of the tooth portion 23 as a single portion or the core back portion 22 as a single portion.

Sheets 40 electrical steel stacked package after applying adhesives; and thereafter, each adhesive layer 41 was formed by heating and curing while being subjected to a predetermined pressurization. The same work was repeated for 130 single sheet cores to make a laminated core (stator core 21).

On the other hand, in the stator core 21 of No. 14, the adhesive material was not used for bonding between the electrical steel sheets 40, and the electrical steel sheets 40 were mechanically fastened by fasteners. These fasteners have been formed on both the core back portion 22 and the tooth portions 23. In addition, the dimensions of the fasteners in the tooth portions 23 are made smaller than those of the fastener in the core back portion 22. As a result, partial bonding strength, i.e. the average bonding strength per unit area in the tooth portions 23 was adjusted to be lower than the partial bonding strength, i. e. the average bonding strength per unit area in the back portions 22 of the core.

The stiffness (mechanical strength) of the laminated core was evaluated for each of the laminated cores for No. 1-14 made using the method described above. The mechanical strength rating was determined by impact testing. In the column, the stiffness of the laminated core in Table. 1B, excellent indicates that high mechanical strength is achieved, good indicates that the necessary and sufficient mechanical strength is provided, and poor indicates that the minimum required mechanical strength is not achieved. Here, excellent is 1, good is 2, fair is 3, and bad is 4 or 5.

Impact test (noise assessment).

The outer circumferential end portion of the core back portion 22 of the laminated core was vibrated in the radial direction by an impact hammer, and modal vibration analysis was performed with the top of the tooth portion 23 and the central back portion 22 in a 180° direction around the axis with respect to the vibration source as measurement points. Additionally,

- 12 041718 for the case in which the central part of the core back part 22 in the radial direction was vibrating in the axial direction by means of an impact hammer, the modal vibration analysis was also performed with the top of the tooth part 23 and the core back part 22 in the direction of 180° around the axis relative to the source vibrations as measuring points.

The assessment (decision) was made in accordance with the following criteria. A smaller value indicates that vibration is prevented and the mechanical strength is higher.

(Excellent): Only one or two vibration peaks are detected.

(good): Several vibration peaks are detected.

(Fair): 10 or more vibration peaks are detected depending on the vibration direction.

(poor): There is a main peak, but 10 or more vibration peaks are detected.

(poor): There is no main peak, and 10 or more vibration peaks are detected.

In addition, the magnetic properties of the laminated core are also evaluated. The magnetic properties were evaluated by measuring steel loss with a rotary iron loss simulator (not shown) having a rotor-shaped detector having a diameter of 239.5 mm. In the column, the magnetic properties of the toothed part in Table. 1B excellent indicates that very high magnetic properties can be achieved. Additionally, Good indicates that high magnetic properties are provided. Satisfactory indicates that the necessary and sufficient magnetic properties are provided. Additionally, poor indicates that the magnetic properties are lower than the minimum required magnetic properties.

Here, first, a steel loss value measured at a magnetic flux density of 1.5 T against the electrical steel sheet 40 before gluing was obtained as a reference value. Then the steel losses were measured similarly for each of the laminated cores at a magnetic flux density of 1.5 T. Then, the steel loss of each laminated core was divided by a reference value and was shown by 100% indication to obtain an increase ratio. For example, in No. 1 in Table. 1B, the iron loss increase ratio is 105%, which indicates that the iron loss has increased by 5% relative to the reference value.

The case in which the steel loss increase ratio thus obtained is 5% or less (the numerical value in the table is 105% or less) was determined to be excellent; the case in which it is greater than 5 and equal to 10% or less (the numerical value in the table is greater than 105 and equal to 110% or less) was determined as good; the case in which it is greater than 10 and equal to 20% or less (the numerical value in the table is greater than 110 and less than 120%) was determined to be satisfactory; and the case in which it is greater than 120% (the numerical value in the table is greater than 120%) was determined to be bad.

As shown in Table. 1A and 1B, in the comparative example shown in No. 9, the partial bonding strength in the tooth portion 23 was significantly higher compared to the partial strength in the core back portion 22, and thus the magnetic property of the tooth portion 23 was lowered. Additionally, since the partial bonding strength in the core back portion 22 was too low, the stiffness of the laminated core also decreases.

Also in the Comparative Examples shown in Nos. 10-12, since the partial bonding strength in the tooth portion 23 is higher than the partial strength in the core back portion 22, the magnetic property of the tooth portion 23 was lowered.

Also in the comparative example using the fastener shown in No. 14, since a compressive force was applied to the tooth portion 23 due to the formation of the fastener, the magnetic properties were greatly reduced.

On the other hand, in Examples of Nos. 1 to 8 and 13, it was confirmed that the laminated core has high rigidity (mechanical strength), high magnetic properties, and desirable performance.

Additionally, Fig. 5 shows the relationship between the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core shown in Table. 1A. In FIG. 5, the ratios below the boundary line B1, in which the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core are equal, are comparative examples for No. 9-12. Although No. 14 is above the boundary line B1, the electrical steel sheets 40 are fastened to each other by fastening instead of gluing, and thus, as described above, desirable properties have not been obtained, in particular in terms of magnetic properties.

The boundary line B2 indicates a state in which the bonding strength ratio is 0.1. Although the example of No. 13, which deviates to the left of the boundary line B2 on paper, was satisfactory in terms of the rigidity and magnetic properties of the laminated core, the bonding strength of the tooth portion 23 was low, and the rigidity of the laminated core was slightly insufficient in some cases, and thus thus, she did not reach the superlative. On the other hand, in the examples shown in Nos. 1-8, excellent case results and equivalents were obtained in terms of either the stiffness or the magnetic properties of the laminated core. From this result, it can be said that the bond strength ratio is more preferably 0.1 or more, in addition to being less than 1.0.

Then, using the device 100 for manufacturing the stator cores 21 shown in No. 15-29 in Table. 2A and 2B have been made. In the present embodiment, although the adhesive material was changed in each case, the adhesive material applied to the tooth portion 23 and the adhesive material applied to the core back portion 22 were the same. For this reason, the bonding strength ratios have all been unified to 1.00.

On the other hand, with regard to the area ratio, the coating amount of adhesive material applied to the tooth portion 23 and the coating amount of adhesive material applied to the core back portion 22 are different, and as a result, the area ratio was changed in each case.

Also in Table. 2B, each threshold value for excellent, good, fair, and poor in terms of laminated core stiffness is described in Table 2B. 1b. Likewise, each threshold value for excellent, good, fair, and poor in terms of tooth portion magnetic properties is also described in Table 1. 1b.

Table. 2A

No. Part Adhesive used for Area share adhesive layer formation Bond strength ratio (-) Name of the adhesive Adhesion strength (MPa) Area share (%) Relative area fractions () 15 Toothed part Cyanoacrylate B 24.0 1.00 20 0.33 Back part Cyanoacrylate B 24.0 60 core 16 Toothed part Cyanoacrylate B 24.0 1.00 40 0.73 Back part Cyanoacrylate B 24.0 55 core 17 Toothed part Epoxy 42.0 1.00 10 0.18 resin B Back part Epoxy 42.0 55 core resin B 18 Toothed part Epoxy 42.0 1.00 45 0.64 resin B Back part Epoxy 42.0 70 core resin B 19 Toothed part SGA 48.0 1.00 15 0.17 Back part SGA 48.0 90 core 20 Toothed part SGA 48.0 1.00 thirty 0.40 Back part SGA 48.0 75 core 21 Toothed part Cyanoacrylate B 24.0 1.00 5 0.05 Back part Cyanoacrylate B 24.0 95 core 22 Toothed part Cyanoacrylate B 24.0 1.00 5 0.13

- 14 041718

Part of the back of the core Cyanoacrylate B 24.0 40 23 Toothed part Cyanoacrylate B 24.0 1.00 80 1.07 Part of the back of the core Cyanoacrylate B 24.0 75 24 Toothed part Epoxy C 32.0 1.00 75 1.25 Part of the back of the core Cyanoacrylate B 24.0 60 25 Toothed part Cyanoacrylate B 24.0 1.00 70 2.00 Part of the back of the core Cyanoacrylate B 24.0 35 26 Toothed part Epoxy resin B 42.0 1.00 3 0.04 Part of the back of the core Epoxy resin B 42.0 80 27 Toothed part Epoxy resin B 42.0 1.00 thirty 0.60 Back part core Epoxy resin B 42.0 50 28 Toothed part Epoxy C 64.0 1.00 55 0.69 Part of the back of the core Epoxy resin C 64.0 80 29 Toothed part Epoxy C 64.0 1.00 10 oh and Part of the back of the core Epoxy C 64.0 90

- 15 041718

Table. 2B No. Total strength Rigidity Magnetic Example / compare gluing laminated core tooth properties parts yarn example Partial adhesive strength (MPa) Bond Strength Ratio (-) percussion trial Solution Ratio of increase in steel loss Solution 15 4.8 0.33 2 Good 105 Excellent bottom Example 14.4 16 9.6 0.73 2 Good 106 Good Example 13.2 17 4.2 0.18 1 Excellent bottom 103 Excellent bottom Example 23.1 18 8.4 0.29 1 Excellent bottom 109 Good Example 29.4 19 7.2 0.17 1 Excellent bottom 104 Excellent bottom Example 43.2 20 14.4 0.40 1 Excellent bottom 108 Good Example 36.0 21 1.2 0.05 3 I am satisfied 110 Good Example 22.8 22 1.2 0.13 3 I am satisfied 110 Good Example 9.6 23 19.2 1.07 3 I am satisfied 123 bad Comparative example 18.0

- 16 041718

24 24.0 1.67 3 I am satisfied 121 bad Comparative example 14.4 25 16.8 2.00 3 I am satisfied 131 bad Comparative example 8.4 26 1.3 0.04 3 I am satisfied 112 Satisfactory Example 33.6 27 12.6 0.60 1 Excellent 106 Good Example 21.0 28 35.2 0.69 1 Excellent 114 Satisfactory Example 51.2 29 6.4 oh and 1 Excellent 110 Good Example 57.6

In the comparative examples of No. 23-25 shown in table. 2A and 2B, the partial bonding strength in the tooth portion 23 was higher than the partial strength in the core back portion 22, and thus the magnetic property of the tooth portion 23 deteriorated.

Additionally, Fig. 6 shows the relationship between the partial bonding strength in the position of the tooth portion and the partial bonding strength in the back portion of the core shown in Table. 2A. In FIG. 6, the ratios below the boundary line VB, in which the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core are equal, are comparative examples for Nos. 23-25.

On the other hand, as shown in Table. 2B, it was confirmed that, in Examples for Nos. 15-22 and 26-29, the laminated cores had high rigidity (mechanical strength), high magnetic properties, and desirable performance.

In addition, the examples of Nos. 17-20 and 27, surrounded by a boundary line B4 forming a square frame, were excellent in both rigidity and magnetic properties of the laminated core. From this result, it was found that it is more preferable that the average value S1 of the partial bonding strength in the tooth portion 23 is 3-15 MPa; the average value S2 of the partial bonding strength in the core back portion 22 is 15-50 MPa; and the mean value of S1 is lower than the mean value of S2.

Then, using the device 100 for manufacturing the stator cores 21 shown in No. 30-47 in Table. 3A and 3B have been made.

Also in Table. 3B, each threshold value for excellent, good, fair, and poor in terms of laminated core stiffness is described in Table 3B. 1b. Likewise, each threshold value for excellent, good, fair, and poor in terms of tooth portion magnetic properties is also described in Table 1. 1b.

In Nos. 30-46, although the adhesive material used was changed in each case, the adhesive material applied to the tooth portion 23 and the adhesive material applied to the core back portion 22 were the same (the adhesive material has the same chemical components). For this reason, the bonding strength ratios have all been unified to 1.00. Further, with regard to the area ratio, the coating amount of adhesive material applied to the tooth portion 23 and the coating amount of adhesive material applied to the core back portion 22 were different, and as a result, the area ratio was changed in each case.

On the other hand, in No. 47, the adhesive material applied to the tooth portion 23 and the adhesive material applied to the core back portion 22 were different. In addition, in No. 47, the combination of both adhesives was chosen such that the adhesive strength for the adhesive in the tooth portion 23 was lower than the adhesive strength for the adhesive in the back portion 22 of the core. Also, with regard to the area ratio, the coating amount of adhesive material applied to the tooth portion 23 was less than the coating amount of adhesive material applied to the back portion 22 of the core. As a result, the area ratio in the tooth portion 23 was less than the area ratio in the back portion 22

- 17 041718 core.

Table 3A

No. Part Adhesive material used to form the adhesive layer Area share Name of the adhesive Adhesion strength (MPa) Bond strength ratio (-) Area share (%) Relative area fractions () thirty Toothed part Epoxy C 64.0 1.00 thirty 0.43 Part of the back of the core Epoxy C 64.0 70 31 Toothed part Epoxy resin A 32.0 1.00 40 0.44 Part of the back of the core Epoxy resin A 32.0 90 32 Toothed part Epoxy C 64.0 1.00 35 0.58 Part of the back of the core Epoxy C 64.0 60 33 Toothed part SGA 48.0 1.00 40 0.73 Part of the back of the core SGA 48.0 55 34 Toothed part Cyanoacrylate B 24.0 1.00 15 0.23 Part of the back of the core Cyanoacrylate B 24.0 65 35 Toothed part Epoxy resin B 42.0 1.00 20 0.29 Part of the back of the core Epoxy resin B 42.0 70 36 Toothed part SGA 48.0 1.00 15 0.17 Part of the back of the core SGA 48.0 90 37 Toothed part SGA 48.0 1.00 15 0.20 Part of the back of the core SGA 48.0 75 38 Toothed part Cyanoacrylate B 24.0 1.00 5 0.05 Part of the back of the core Cyanoacrylate B 24.0 95 39 Toothed part Cyanoacrylate B 24.0 1.00 5 0.13 Back part Cyanoacrylate B 24.0 40

- 18 041718

core 40 Toothed part Cyanoacrylate B 24.0 1.00 80 1.07 Part of the back of the core Cyanoacrylate B 24.0 75 41 Toothed part Anaerobic 15.0 1.00 80 1.33 Part of the back of the core Anaerobic 15.0 60 42 Toothed part Cyanoacrylate B 24.0 1.00 70 2.00 Part of the back of the core Cyanoacrylate B 24.0 35 43 Toothed part Epoxy resin B 42.0 1.00 3 0.04 Part of the back of the core Epoxy resin B 42.0 80 44 Toothed part Epoxy resin B 42.0 1.00 3 0.09 Part of the back of the core Epoxy resin B 42.0 35 45 Toothed part Epoxy resin C 64.0 1.00 55 0.69 Part of the back of the core Epoxy C 64.0 80 46 Toothed part Epoxy C 64.0 1.00 8 0.09 Part of the back of the core Epoxy C 64.0 90 47 Toothed part Anaerobic 15.0 0.36 20 0.57 Part of the back of the core Epoxy C 42.0 45

- 19 041718

SR table

No. Total strength gluing Rigidity of laminated core Magnetic properties of the tooth part Example/comparative example Partial adhesive strength (MPa) Bonding strength ratio O impact test Solution Ratio of increase in steel loss Solution thirty 19.2 0.43 1 Excellent 105 Excellent Example 44.8 31 12.8 0.44 1 Excellent 105 Excellent Example 28.8 32 22.4 0.58 1 Excellent 107 Good Example 38.4 33 19.2 0.73 1 Excellent 108 Good Example 26.4 34 3.6 0.23 1 Excellent 109 Good Example 15.6 35 8.4 0.29 1 Excellent 103 Excellent Example 29.4 36 7.2 0.17 1 Excellent 107 Good Example 43.2 37 7.2 0.20 1 Excellent 106 Good Example 36.0 38 1.2 0.05 2 Good 110 Good Example 22.8 39 1.2 0.13 2 Good 105 Excellent Example

-20041718

9.6 bottom 40 19.2 1.07 2 Good 127 bad Comparative example 18.0 41 12.0 1.33 3 satisfaction rhetorical 128 bad Comparative example 9.0 42 16.8 2.00 3 satisfaction rhetorical 131 bad Comparative example 8.4 43 1.3 0.04 3 satisfaction rhetorical 111 Satisfactory Example 33.6 44 1.3 0.09 3 satisfaction rhetorical 115 Satisfactory Example 14.7 45 35.2 0.69 1 Excellent FROM Satisfactory Example 51.2 46 5.1 0.09 1 Excellent 112 Satisfactory Example 57.6 47 h, o 0.16 3 satisfaction rhetorical 103 Excellent Example 18.9

As a result, in the comparative examples for No. 40-42 shown in table. 3A and 3B, the partial bonding strength in the tooth portion 23 was higher than the partial strength in the core back portion 22, and thus the magnetic property of the tooth portion 23 decreased.

On the other hand, as shown in Table. 3A and 3B, it was confirmed that, in Examples for Nos. 30-39 and 43-47, the laminated cores had high rigidity (mechanical strength), high magnetic properties, and desirable performance.

Additionally, Fig. 7 shows the relationship between the partial bonding strength in the position of the tooth portion and the partial bonding strength in the back portion of the core shown in Table. 3A. In FIG. 7, the ratios below the boundary line B5, in which the partial bonding strength at the position of the tooth portion and the partial bonding strength at the position of the back portion of the core are equal, are comparative examples for Nos. 40-42.

Additionally, Fig. 8 shows the relationship between the area ratio at the position of the tooth portion and the area ratio at the position of the back portion of the core shown in Table. 3A.

The examples for Nos. 30-37 surrounded by border line B6 forming a square box in FIG. 8 obtained an excellent or equivalent result in terms of stiffness and magnetic properties of the laminated core. From this result, it was found that it is more preferable that the average value A1 of the area fraction of each of the adhesive layers in the tooth portion 23 is 10-50%; the average value A2 of the area ratio of each of the adhesive layers in the core back portion 22 is 50-100%; and the A1 mean is below the A2 mean.

The embodiment and examples of the present invention have been described above. However, the technical scope of the present invention is not limited to the above-described embodiment and examples, and various modifications can be added without departing from the gist of the present invention.

For example, the shape of the stator core 21 is not only limited to the shape shown in the above embodiment. In particular, the dimensions of the outer diameter and the inner diameter of the stator core 21, the lamination thickness, the number of slots, the size ratio of the tooth portion 23 between the circumferential direction and the radial direction, the size ratio in the radial direction between the tooth portion 23 and the core back portion 22, etc. P. can be freely calculated according to the required properties of the motor.

- 21 041718

In the rotor 30 of the above embodiment, a set of two permanent magnets 32 forms one magnetic pole, but the present invention is not limited to this. For example, one permanent magnet 32 may form one magnetic pole, or three or more permanent magnets 32 may form one magnetic pole.

In the above-described embodiment, the permanent magnet motor is described as an example of the motor 10, but as illustrated below, the structure of the motor 10 is not limited to this, and various well-known structures not illustrated below can also be used.

In the above-described embodiment, the permanent magnet motor is described as an example of the motor, but the present invention is not limited thereto. For example, motor 10 may be a reluctance motor or an electromagnetic field motor (double winding motor).

In the above embodiment, the synchronous motor is described as an example of an AC motor, but the present invention is not limited thereto. For example, motor 10 may be an induction motor.

In the above embodiment, the AC motor is described as an example of the motor 10, but the present invention is not limited thereto. For example, motor 10 may be a DC motor.

In embodiments, a motor is described as an example of a motor, but the present invention is not limited thereto. For example, motor 10 may be a generator.

In addition, within the range without departing from the gist of the present invention, components in the embodiment can be appropriately replaced with known components, and the above modified examples can be combined with each other appropriately.

Industrial Applicability

According to the present invention, a bonded-laminated stator core including an adhesive structure that does not adversely affect magnetic properties while increasing its mechanical strength, and a motor including a bonded-laminated stator core can be provided. . Hence, it provides wide industrial applicability.

Brief description of links with numbers:

- electric motor,

- glued laminated core for the stator,

- part of the back of the core,

- tooth part

- sheet of electrical steel,

- adhesive layer.

Claims (8)

CLAIM 1. A glued-laminated core for a stator, comprising a plurality of electrical steel sheets coaxially overlapping each other, each of which has an annular back portion of the core and a plurality of tooth portions each of which extends inwardly in the radial direction from the inner periphery of the back portion of the core; and a plurality of adhesive layers that bond the electrical steel sheets together, respectively, in the back portion of the core and the tooth portions, the adhesive layers being a plurality of areas placed on each of the tooth portions and at positions on the back portion of the core that are adjacent in the radial direction. with each of said tooth portions, and at the same time between the respective sheets of electrical steel, the average bonding strength per unit area in the tooth portions is less than the average bonding strength per unit area in the back portion of the core. 2. The glued-laminated stator core according to claim 1, wherein the ratio obtained by dividing the average adhesive strength per unit area in the tooth portions by the average adhesive strength per unit area in the back portion of the core is in the range of 0.1 or more and less 1.0. 3. Glued-laminated core for the stator according to claim 1 or 2, where the average value S1 of the average bonding strength per unit area in the tooth parts is equal to 1-15 MPa; the average value S2 of the average bonding strength per unit area in the back portion of the core is 15-50 MPa; the mean value of S1 is lower than the mean value of S2. - 22 041718 4. Glued-laminated core for the stator according to claim 1 or 2, where each of the adhesive layers is made of an adhesive material having the same chemical composition; the average value A1 of the proportion of the area of the adhesive layers in the toothed parts is 10-50%; the average value A2 of the proportion of the area of the adhesive layer in the back portion of the core is 50-100%; the mean value of A1 is lower than the mean value of A2. 5. A glued-laminated stator core according to any one of claims 1 to 4, wherein the average thickness of the adhesive layers is 1.0-3.0 µm. 6. A glued-laminated stator core according to any one of claims 1 to 5, wherein the average tensile modulus E of the adhesive layers is 1500-4500 MPa. 7. A bonded-laminated stator core according to any one of claims 1 to 6, wherein the adhesive layers are a room temperature bondable acrylic-based adhesive including an SGA made from an elastomer-containing acrylic-based adhesive. 8. An electric motor containing a glued laminated core for a stator according to any one of claims 1 to 7.