Multilayer magnets and motors

Abstract

This invention provides a technology for improving the strength of a multilayer magnet while suppressing an increase in the eddy current loss ratio. [Solution] The stacked magnet comprises a plurality of stacked magnets and an intermediate layer disposed between adjacent magnets, having an insulating portion and two conductive portions that are positioned so as to sandwich the insulating portion and are in contact with each of the adjacent magnets. In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, the outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides. If the conductive portion consists of one conductive region formed of a conductive material, each of the pair of long sides is the outline of the conductive region. If the conductive portion has a plurality of conductive regions and an insulating region disposed between adjacent conductive regions among the plurality of conductive regions, the plurality of conductive regions are arranged in a line along the long sides, and the ratio of the volume of the conductive region to the volume of the intermediate layer is 14% or more and 35% or less.

Description

Technical Field

[0001] The present invention relates to a laminated magnet and a motor.

Background Art

[0002] Conventionally, a laminated magnet in which a plurality of magnets are laminated has been known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even with the prior art such as Patent Document 1, there is still room for improvement in the technology of improving the strength while suppressing an increase in the eddy current loss ratio in the laminated magnet.

[0005] An object of the present invention is to provide a technology for improving the strength while suppressing an increase in the eddy current loss ratio in a laminated magnet.

Means for Solving the Problems

[0006] The present invention has been made to solve at least a part of the above problems and can be realized in the following forms.

[0007] (1) According to one embodiment of the present invention, a laminated magnet is provided. This laminated magnet comprises a plurality of stacked magnets and an intermediate layer disposed between adjacent magnets among the plurality of magnets, the intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions, the two current-carrying portions being arranged so as to sandwich the insulating portion and in contact with each of the adjacent magnets, and in a cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, the outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides, each of the pair of long sides is The current-carrying portion is an outline of the current-carrying portion, and the current-carrying portion consists of one current-carrying region formed of a conductive material, and each of the pair of long sides is an outline of the current-carrying region, and the intermediate layer has a plurality of current-carrying regions formed of a conductive material and an insulating region arranged between adjacent current-carrying regions, and in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the plurality of current-carrying regions are arranged in a line along the long side, and the ratio of the volume of the current-carrying region to the volume of the intermediate layer is 14% or more and 35% or less.

[0008] In this configuration, the intermediate layer, positioned between adjacent magnets among multiple magnets, has two conductive sections that are positioned so as to sandwich an insulating section made of an insulating material. Since each of these two conductive sections is in contact with each of the adjacent magnets in the intermediate layer, the bonding strength between adjacent magnets can be improved. When the conductive section consists of a single conductive region made of a conductive material, each of the pair of long sides of the outer outline of the rectangular intermediate layer forms the outline of the conductive region. Furthermore, when the conductive section has multiple conductive regions made of a conductive material and an insulating region positioned between adjacent conductive regions among the multiple conductive regions, the multiple conductive regions are arranged along the long sides of the outer outline of the intermediate layer. As a result, the increase in eddy current loss due to the conductive regions is suppressed. Therefore, the laminated magnet can improve its strength while suppressing an increase in the eddy current loss ratio.

[0009] (2) According to another embodiment of the present invention, a laminated magnet is provided. This laminated magnet comprises a plurality of stacked magnets and an intermediate layer disposed between adjacent magnets among the plurality of magnets, the intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions, the two current-carrying portions being arranged so as to sandwich the insulating portion and in contact with each of the adjacent magnets, and in a cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, the outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides, each of the pair of short sides is The current-carrying portion is an outline of the current-carrying portion, and when the current-carrying portion consists of one current-carrying region formed of a conductive material, each of the pair of short sides is the outline of the current-carrying region. When the intermediate layer has a plurality of current-carrying regions formed of a conductive material and an insulating region arranged between adjacent current-carrying regions, in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the plurality of current-carrying regions are arranged in a line along the short sides, and the ratio of the volume of the current-carrying region to the volume of the intermediate layer is 14% or more and 20% or less. With this configuration, the intermediate layer arranged between adjacent magnets among a plurality of magnets has two current-carrying portions arranged so as to sandwich an insulating portion formed of an insulating material. Since each of these two current-carrying portions is in contact with each of the adjacent magnets in the intermediate layer, the bonding strength between adjacent magnets can be improved. When the current-carrying portion consists of one current-carrying region formed of a conductive material, each of the pair of short sides of the outline of the outer circumference of the rectangular intermediate layer is the outline of the current-carrying region. Furthermore, when the energized portion has multiple energized regions formed of a conductive material and insulating regions positioned between adjacent energized regions, the multiple energized regions are arranged along the short side of the outline of the intermediate layer. This suppresses the increase in eddy current loss due to the energized regions. Therefore, the laminated magnet can improve its strength while suppressing an increase in the eddy current loss ratio.

[0010] (3) According to yet another embodiment of the present invention, a laminated magnet is provided. This laminated magnet comprises a plurality of stacked magnets and an intermediate layer disposed between adjacent magnets among the plurality of magnets, the intermediate layer having an insulating portion formed of an insulating material and an energizing portion formed of a conductive material, wherein the energizing portion is in contact with each of the adjacent magnets, and in a cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, the energizing portion is formed to include the center of the outline of the intermediate layer at a position away from the outline formed by the outer circumference of the intermediate layer, and the ratio of the volume of the energizing portion to the volume of the intermediate layer is 14% or more and 35% or less. With this configuration, the intermediate layer disposed between adjacent magnets among the plurality of magnets has an energizing portion in contact with each of the adjacent magnets. This makes it possible to improve the bonding strength between adjacent magnets. Furthermore, since the energizing portion is formed to include the center of the outline of the outer circumference of the rectangular intermediate layer at a position away from the outline of the outer circumference of the intermediate layer, the increase in eddy current loss due to the energizing portion is suppressed. This allows the stacked magnet to improve its strength while suppressing an increase in the eddy current loss ratio.

[0011] (4) According to yet another embodiment of the present invention, a motor is provided. This motor comprises a rotor having the above-described stacked magnets and a stator having coils. In this configuration, the rotor of the motor has, in the stacked magnets, an intermediate layer located between adjacent magnets among the multiple magnets, having energizing portions that are in contact with each of the adjacent magnets. Because the energizing portions are located at specific locations in the intermediate layer, the increase in eddy current loss due to the energizing portions is suppressed in the stacked magnets, and the strength is improved. As a result, the rotational speed of the motor can be increased, and the output of the motor can be improved.

[0012] Furthermore, the present invention can be realized in various forms, for example, in the form of a method for manufacturing a laminated magnet, a method for manufacturing an intermediate layer of a laminated magnet, an apparatus including a laminated magnet, a method for manufacturing an apparatus including a laminated magnet, and a method for controlling an apparatus including a laminated magnet.

Brief Description of the Drawings

[0013] [Figure 1] It is a perspective view of the laminated magnet of the first embodiment. [Figure 2] It is a cross-sectional view taken along line A-A of FIG. 1. [Figure 3] It is a cross-sectional view of a motor including the laminated magnet of the first embodiment. [Figure 4] It is a cross-sectional view of a rotor including the laminated magnet of the first embodiment. [Figure 5] It is a cross-sectional view of the intermediate layer included in the laminated magnet of the first embodiment. [Figure 6] It is a cross-sectional view of a modification of the intermediate layer included in the laminated magnet of the first embodiment. [Figure 7] It is a diagram showing the evaluation result regarding the intermediate layer of the first embodiment. [Figure 8] It is a cross-sectional view of the intermediate layer included in the laminated magnet of the second embodiment. [Figure 9] It is a cross-sectional view of a modification of the intermediate layer included in the laminated magnet of the second embodiment. [Figure 10] It is a diagram showing the evaluation result regarding the intermediate layer of the second embodiment. [Figure 11] It is a cross-sectional view of the intermediate layer included in the laminated magnet of the third embodiment. [Figure 12] It is a diagram showing the evaluation result regarding the intermediate layer of the third embodiment. [Figure 13] It is a perspective view of a modification of the laminated magnet of the first embodiment.

Modes for Carrying Out the Invention

[0014] <First Embodiment> FIG. 1 is a perspective view of the laminated magnet 10 of the present embodiment. FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1. FIG. 3 is a cross-sectional view of the motor 100 including the laminated magnet 10 of the present embodiment. FIG. 4 is a cross-sectional view of the rotor 110 including the laminated magnet 10 of the present embodiment. The laminated magnet 10 of the present embodiment is used in a motor 100 that generates rotational torque by electricity supplied from an external power source not shown. As shown in FIG. 1, the laminated magnet 10 includes a plurality of magnets 11 that are laminated and an intermediate layer 12. Note that the technical field in which the laminated magnet 10 of the present embodiment is used is not limited to motors.

[0015] The motor 100 of the present embodiment includes a rotor 110, a stator 120, and a motor case 130. The rotor 110 includes a rotor member 110a having a substantially cylindrical shape and a laminated magnet 10. In the motor 100 of the present embodiment, the laminated magnet 10 is provided on the rotor 110 such that the lamination direction of the plurality of magnets 11 and the intermediate layer 12 in the laminated magnet 10 is parallel to the rotation axis C1 of the rotor 110 in the motor 100 (see FIG. 3). The laminated magnet 10 is inserted into an insertion hole 110b formed in the rotor 110.

[0016] Magnet 11 contains rare earth elements. Examples of rare earth elements include one or more selected from the group consisting of neodymium (Nd), praseodymium (Pr), terbium (Tb), dysprosium (Dy), samarium (Sm), yttrium (Y), scandium (Sc), lanthanum (La), cerium (Ce), europium (Eu), gadolinium (Gd), holmium (Ho), ytterbium (Yb), and lutetium (Lu). Among these, it is desirable that the magnet contains one or more of Nd, Pr, Dy, and Tb as rare earth elements, and it is more desirable that it contains Nd as the main component. Note that "containing Nd as the main component" means that the Nd content (mass%) is the highest among the rare earth elements contained in magnet 11. In addition to rare earth elements, magnet 11 may also contain transition metal elements and boron. In the stacked magnet 10 of this embodiment, a plurality of magnets 11 are stacked with an intermediate layer 12 in between. The magnetization directions of each of the plurality of magnets 11 are arranged parallel to each other, for example, in the x-axis direction in the perspective view of the stacked magnet 10 shown in Figure 1. In this embodiment, the magnets 11 have a rectangular parallelepiped shape.

[0017] The intermediate layer 12 is placed between adjacent magnets 11 among the multiple stacked magnets 11. The intermediate layer 12 has an insulating portion formed of an insulating material and two conductive portions.

[0018] Figure 5 is a cross-sectional view of the intermediate layer 12 of the stacked magnet 10 of this embodiment, and is a cross-sectional view taken along line BB in Figure 2. As shown in Figure 5, the intermediate layer 12 has an insulating portion 121 formed of an insulating material and two current-carrying portions 122. The thickness of the intermediate layer 12 in the stacking direction of this embodiment is 10 μm. It is desirable that the thickness of the intermediate layer 12 be 30 μm or less. The thickness of the intermediate layer can be, for example, 1 μm or more.

[0019] The insulating portion 121 is formed of an insulating material. In this embodiment, the insulating portion 121 is formed of ceramics. It is desirable that the insulating portion 121 contains one or more selected from the group consisting of CaF2, BaF2, SrF2, MgF2, Al2O3, ZrO2, Dy2O3, Tb2O3, Nd2O3, TbF3, DyF3, LiF, SiO2, BN, ZrB2, Si3N4, TiB2, Pr2O3, and SiC. It is desirable that the insulating portion 121 contains at least a fluoride of Group IIA of the periodic table. It is even more desirable that the insulating portion 121 contains at least one fluoride of Group IIA of the periodic table selected from the group consisting of CaF2, BaF2, SrF2, and MgF2. In this embodiment, the insulating portion 121 contains CaF2.

[0020] The two current-carrying sections 122 are positioned so as to sandwich the insulating section 121 and are in contact with each of the adjacent magnets 11. In the stacked magnet 10, as shown in Figure 5, in the cross-section of the intermediate layer 12 along a direction perpendicular to the stacking direction (z-axis direction) of the multiple magnets 11, the outline L12 formed by the outer circumference of the intermediate layer 12 has a rectangular shape consisting of a pair of short sides L12a and a pair of long sides L12b. Of the outline L12 formed by the outer circumference of the intermediate layer 12, each of the pair of long sides L12b forms the outline of the current-carrying section 122. The current-carrying section 122 consists of one current-carrying region 122a formed of a conductive material. That is, each of the pair of long sides L12b of the outline L12 of the intermediate layer 12 is part of the outline of the current-carrying region 122a. In this embodiment, the current-carrying region 122a is formed of the same type of magnetic material as the material forming each of the multiple magnets 11. In the stacked magnet 10 of this embodiment, the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 is 14% or more and 35% or less. It is even more desirable that the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 is 30% or less.

[0021] In the laminated magnet 10 of this embodiment, the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 is calculated as follows. First, the peeled surface of the intermediate layer 12 formed when the laminated magnet 10 is peeled at the intermediate layer 12 is observed, and the area ratio of the insulating portion 121 to the energized region 122a at the peeled surface is calculated. Next, assuming that the respective thicknesses of the insulating portion 121 and the energized region 122a in the intermediate layer 12 are constant, the respective volume ratios of the insulating portion 121 and the energized region 122a are calculated, and the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 is calculated. If peeling at the intermediate layer 12 of the laminated magnet 10 is difficult, instead of peeling at the intermediate layer 12, a cross section corresponding to the peeled surface of the intermediate layer 12 may be formed by processing such as cutting, and the cross section formed by processing may be observed.

[0022] Figure 6 is a cross-sectional view of a modified intermediate layer 13 of the stacked magnet 10 of this embodiment. Similar to Figure 5, Figure 6 shows a cross-section of the intermediate layer 13 along a direction perpendicular to the stacking direction (z-axis direction) of the multiple magnets 11. The intermediate layer 13 shown in Figure 6 is positioned between adjacent magnets 11 among the multiple magnets 11 and has an insulating portion 121 formed of an insulating material and two current-carrying portions 132.

[0023] Each of the two current-carrying portions 132 of the intermediate layer 13 shown in Figure 6 has a plurality of current-carrying regions 132a formed of a conductive material, and an insulating region 132b positioned between adjacent current-carrying regions 132a. In a cross-section of the intermediate layer 13 along a direction perpendicular to the stacking direction of the plurality of stacked magnets 11, the plurality of current-carrying regions 132a are arranged along the long side L13b of the outline L13 formed by the outer circumference of the intermediate layer 13. Each of the plurality of current-carrying regions 132a in this embodiment is formed of the same type of magnetic material as the material forming each of the plurality of magnets 11. In the stacked magnet 10 of this embodiment, the ratio of the total volume of the plurality of current-carrying regions 132a to the volume of the intermediate layer 13 is 14% or more and 35% or less. It is even more desirable that the ratio of the volume of the current-carrying regions 132a to the volume of the intermediate layer 13 is 30% or less. As shown in Figures 5 and 6 below, an intermediate layer having a rectangular shape in which each of the pair of long sides of the outline formed by the outer circumference of the intermediate layer is the outline of the energized part of the intermediate layer is called a "long-side conductive intermediate layer".

[0024] The stator 120 has a stator core 120a and a coil 120b. The stator 120 is located outside the rotor 110 and is fixed to the motor case 130 inside the motor case 130, which will be described later. The stator core 120a is formed to have a substantially cylindrical shape and has a plurality of protrusions 120c on its inside. The coil 120b is a conductive wire covered with an insulator and is wound around each of the plurality of protrusions 120c on the stator core 120a. When electricity supplied from outside the motor 100 flows through the coil 120b, it generates a magnetic field.

[0025] The motor case 130 is a hollow component that houses the rotor 110 and the stator 120 inside. The motor case 130 is provided with two bearings 130a and 130b. Each of the two bearings 130a and 130b rotatably supports the rotor 110.

[0026] Next, the manufacturing method of the stacked magnet 10 of this embodiment will be described. In the manufacturing of the stacked magnet 10, first, a strip-cast alloy (SC alloy) powder is prepared (preparation step). In this embodiment, the composition of the SC alloy is Nd2Fe 14 This is represented by B. SC alloys are prepared by mixing the main raw materials of Nd / Pr alloys, alloys containing Co, Al, Cu, Ga, and Zr, and elemental metals, under an argon atmosphere. Next, the SC alloy is subjected to hydrogen absorption using a hydrogen furnace (hydrogen atmosphere, temperature: 200°C, time: 2 hours) to embrittle the grain boundaries (neodymium-rich phase) of the SC alloy (hydrogen decomposition process), thereby producing SC alloy powder.

[0027] Following the hydrogenation process, a lubricant is added to the SC alloy powder (first lubricant addition step). Methyl caprylate is used as the lubricant. The mixing ratio of the lubricant to the amount of SC alloy is, for example, 0.03% to 0.07% by mass. Specifically, the SC alloy powder is coarsely ground under a nitrogen or argon atmosphere while adding the lubricant using a stirrer (coarse grinding step). The average particle size D50 of the SC alloy powder after coarse grinding is, for example, 50 μm to 500 μm.

[0028] Following the coarse grinding process, the coarsely ground SC alloy powder is finely ground using a jet mill under a nitrogen atmosphere while adding a lubricant (fine grinding process). The average particle size D50 after fine grinding is, for example, 2.0 μm to 3.5 μm. Next, a lubricant is added to the finely ground SC alloy powder (second lubricant addition process). Methyl laurate is used as the lubricant. The mixing ratio of the lubricant to the amount of SC alloy is, for example, 0.05 mass% to 0.1 mass%.

[0029] Following the second lubricant addition step, SC alloy powder is filled into each of the multiple molding spaces of a mold equipped with multiple partition plates in a nitrogen atmosphere (powder filling step). Each of the multiple molded bodies formed in each of the multiple molding spaces corresponds to the magnets that will be stacked in the temporary fixing step described later. After the powder filling step, an external magnetic field of, for example, 2T to 4T (Tesla) is applied to the mold filled with SC alloy powder in the planar direction (perpendicular to the thickness direction) of each of the multiple molded bodies to align the orientation of the SC alloy powder (orientation step). Next, the SC alloy powder filled in the mold is pressurized to form the SC alloy molded body (molding step). The conditions for pressurized molding in the molding step are, for example, a pressure of 5MPa to 20MPa and a filling density of 3.0g / cm³. 3 ~4.0g / cm 3 The relative density is 40% to 52%.

[0030] Following the molding process, the outer frame is removed from the mold, and the fired product, in which the molded body and partition plates are alternately connected, is removed (removal process). The fired product, including the partition plates, is heated in an argon atmosphere at a temperature of 500°C for 3 to 4 hours to dehydrogenate it. The dehydrogenated fired product, including the partition plates, is held at a temperature of 930°C to 1050°C for 3 hours and fired in a vacuum atmosphere (first firing process). This produces the magnet 11.

[0031] Following the first firing process, the partition plate is removed from the manufactured magnet 11, and the insulating material 121 is applied to the surface of the magnet 11 before lamination (insulating material application process). A mixture of CaF2 powder and a solvent is used as the insulating material 121. The insulating material 121 is applied, for example, by spraying in the atmosphere. The insulating material 121 is applied to the rectangular surface of the rectangular parallelepiped magnet 11, at a position away from a pair of long sides, along the longitudinal direction of the surface of the magnet 11. In the manufacturing method of the laminated magnet 10 of this embodiment, the ratio of the volume of the energized area 122a to the volume of the intermediate layer 12, or the ratio of the total volume of multiple energized areas 132a to the volume of the intermediate layer 13, is adjusted by adjusting the amount of insulating material 121 applied to the surface of the magnet 11 before lamination. Note that the method of applying the insulating material 121 is not limited to this. The insulating material 121 may be applied to a desired location, for example, on the rectangular surface of the magnet 11, at a position away from the pair of long sides, using a mask for applying the material to a specific location, along the longitudinal direction of the surface of the magnet 11.

[0032] Following the insulating material coating process, multiple magnets 11 coated with the insulating material 121 are stacked in the atmosphere and temporarily fixed (temporary fixing process). Following the temporary fixing process, the temporarily fixed stack is placed in a hot press mold and subjected to uniaxial hot pressing (hot pressing process). In the hot pressing process, for example, a pressure of 5 × 10 -2 Pa~1×10 -4 The process is carried out under a vacuum atmosphere of approximately Pa, or under an inert atmosphere (such as a nitrogen or argon atmosphere). The hot press temperature is, for example, 700°C to 1100°C, and the hot press press duration is, for example, 1 second to 1 hour. The hot press pressure is, for example, 3 MPa to 100 MPa, and the hot press heat treatment duration is, for example, 3 minutes to 20 hours. In the manufacturing method of the laminated magnet 10 of this embodiment, during such a hot press process, the magnetic material forming the magnet 11 diffuses into the material of the insulating portion 121, and an energizing region 122a or energizing region 132a is formed. The laminated magnet 10 of this embodiment is manufactured in this manner. However, the manufacturing method of the laminated magnet 10 is not limited to this.

[0033] Next, the evaluation test of the stacked magnet in this embodiment will be described. In this evaluation test, multiple stacked magnets (hereinafter referred to as "samples") with different ratios of the volume of the energized region to the volume of the intermediate layer were prepared, and for each of the multiple samples, the "volume ratio of the energized region," "residual magnetic flux density," "eddy current loss ratio," and "intensity" were measured or calculated.

[0034] Figure 7 illustrates the evaluation results of the laminated magnet of this embodiment. The five types of samples used in this evaluation test were manufactured by a method similar to the manufacturing method of the laminated magnet 10 of this embodiment. Sample 1 has no intermediate layer and has a structure in which multiple magnets are simply stacked. The intermediate layer of each of Samples 2 to 4 has an insulating part formed of an insulating material and an energizing part. The insulating part of each of Samples 2 to 4 contains CaF2, and the energizing part is formed of the same material as the magnet. Sample 5 has an intermediate layer that contains only an insulating part containing CaF2. The size of the magnets in the samples used in this evaluation test is 6 mm in the magnetization direction × 2 mm in the stacking direction × 20 mm, and the size of the part of the laminated magnet excluding the intermediate layer is 6 mm in the magnetization direction × 40 mm in the stacking direction × 20 mm.

[0035] The "Volume Ratio of Conductive Area (%)" shown in Figure 7 represents the ratio of the volume of the conductive area to the volume of the intermediate layer for each of Samples 1 to 5. The method for calculating the "Volume Ratio of Conductive Area (%)" is the same as the method for calculating the ratio of the volume of the conductive area 122a to the intermediate layer 12, or the ratio of the total volume of multiple conductive areas 132a to the intermediate layer 13, in the laminated magnet 10 of this embodiment. As mentioned above, Sample 1 does not have an intermediate layer, but since adjacent magnets are connected, the "Volume Ratio of Conductive Area (%)" is conveniently set to 100%. In Sample 2, where the "Volume Ratio of Conductive Area (%)" is 33.0%, and in Sample 3, where it is 28.0%, two conductive areas are arranged such that, similar to the intermediate layer 12 (Figure 5) of this embodiment, each of the two conductive areas is formed by one of the long sides of the outline of the intermediate layer. In Sample 4, where the "volume ratio of the conductive area (%)" is 30.0%, the conductive area in the intermediate layer is positioned independently of the outline of the intermediate layer. In Sample 5, the intermediate layer is formed of insulating material, so the "volume ratio of the conductive area (%)" is 0%.

[0036] The "Residual Magnetic Flux Density (T)" shown in Figure 7 represents the results of comparing the residual magnetic flux densities for each of the samples from Sample 1 to Sample 5. The "Residual Magnetic Flux Density (T)" shown in Figure 7 was measured using a pulsed BH tracer for each of the samples from Sample 1 to Sample 5. In this evaluation test, the "Residual Magnetic Flux Density (T)" scores were set as follows, according to the magnitude of the measured values ​​of the residual magnetic flux density. 1.40T: 5 points 1.37T or more and less than 1.40T: 3 points Less than 1.37T: 0 points

[0037] The "Eddy Current Loss Ratio (%)" shown in Figure 7 represents the results of comparing the eddy current losses for each of the samples from Sample 1 to Sample 5. Here, we will explain the calculation method for the "Eddy Current Loss Ratio (%)" shown in Figure 7. First, each of the samples from Sample 1 to Sample 5 was placed between the magnetic poles of a C-type core, and the eddy current loss was measured using a power meter under conditions of 25°C, 500kHz frequency, and 0.01T magnetic flux density. Next, using the measured eddy current losses for each of the samples from Sample 1 to Sample 5, the ratio of the measured eddy current losses for each of the samples from Sample 2 to Sample 5 was calculated, with the measured eddy current loss for Sample 1 set to 100. In this evaluation test, the "Eddy Current Loss Ratio (%)" score was set as follows, according to the magnitude of the numerical value calculated using the eddy current loss measurement results. Less than 75%: 5 points 75% to less than 85%: 3 points 85% or higher: 0 points

[0038] The "Strength (MPa)" shown in Figure 7 represents the results of comparing the strength of the stacked magnets for each of the samples from Sample 1 to Sample 5. For each of the samples from Sample 1 to Sample 5, a three-point bending test was performed, and the bending stress value was calculated based on the maximum load until the sample broke. In this evaluation test, the "Strength (MPa)" score was set as follows, according to the magnitude of the calculated bending stress value. 50 MPa or higher: 5 points 30 MPa to less than 50 MPa: 3 points Less than 30 MPa: 0 points

[0039] The "evaluation" shown in Figure 7 was determined for each of Samples 2 to 5 using the sum of the scores for "residual magnetic flux density (T)", "eddy current loss ratio (%)", and "intensity (MPa)". In this evaluation test, for each of Samples 2 to 5, the "evaluation" groups were set up as follows, according to the magnitude of the sum of the scores for "residual magnetic flux density (T)", "eddy current loss ratio (%)", and "intensity (MPa)". The numbers in parentheses in Figure 7 represent the sum of the scores for each sample, and the sum of the scores for Sample 1, which is a comparative example in this evaluation test, is 10 points. 12 points or more: A 11 points:B 10 points or less: C

[0040] As shown in Figure 7, the residual magnetic flux density (T) of each of the samples 2 to 4, which have an energized portion as part of the intermediate layer, was confirmed not to decrease significantly compared to sample 1, which has a structure in which multiple magnets are simply stacked. Specifically, the difference between the residual magnetic flux density of each of the samples 2 to 4 and the residual magnetic flux density of sample 1 was within the tolerance range of ±0.03 (T) of the teslameter used for measurement, confirming that the residual magnetic flux density of each of the samples 2 to 4 was about the same as that of sample 1. In order for the residual magnetic flux density (T) to be about the same as that of sample 1, it is desirable that the volume ratio of the energized region (%) be 14% or more.

[0041] As shown in Figure 7, the "eddy current loss ratio (%)" confirms that samples 2 to 4, which have a current-carrying portion as part of the intermediate layer, do not show a significant increase in eddy current loss compared to sample 5, which has only an insulating portion containing CaF2 in the intermediate layer. Specifically, the "eddy current loss ratio (%)" of samples 2 to 4 is 85% or less compared to sample 1, where adjacent magnets are connected. In other words, if the "volume ratio of the current-carrying region (%)" is within 35%, the increase in the current loss ratio is suppressed even if a current-carrying portion is included in the intermediate layer.

[0042] As shown in Figure 7, the "Strength (MPa)" indicates that samples 2 to 4, which have conductive parts as part of the intermediate layer, show improved strength compared to sample 5, which has only an insulating part containing CaF2 in the intermediate layer, due to the inclusion of conductive parts in the intermediate layer that are in contact with each adjacent magnet. Furthermore, among samples 2 to 4, which have conductive parts in the intermediate layer, samples 2 and 3, which have conductive intermediate layers along the long side, show improved strength compared to sample 4, where the conductive parts are arranged independently of the outline of the intermediate layer.

[0043] As shown in the "Overall Evaluation" in Figure 7, it was confirmed that Sample 2 and Sample 3, respectively, exhibited superior characteristics in terms of residual magnetic flux density and eddy current loss compared to Sample 1 and Sample 5. Furthermore, it was confirmed that Sample 2 and Sample 3, which have an intermediate layer with conduction along the long side, exhibit improved strength as a laminated magnet without significant changes in residual magnetic flux density or eddy current loss compared to Sample 4, which has an intermediate layer without conduction along the long side. As a result, when the laminated magnet of Sample 2 or Sample 3 is used in a motor, it is less likely to break even when the motor rotation speed is increased, allowing for a further increase in motor output.

[0044] As described above, in the stacked magnet 10 of this embodiment, the intermediate layers 12 and 13, which are arranged between adjacent magnets 11 among the multiple stacked magnets 11, have two current-carrying parts 122 and 132 that are arranged so as to sandwich an insulating part 121 made of an insulating material. Each of these two current-carrying parts 122 and 132 is in contact with each of the adjacent magnets 11 in the intermediate layers 12 and 13, so that the bonding strength between adjacent magnets 11 can be improved. The current-carrying part 122 consists of one current-carrying region 122a made of a conductive material, and each of the pair of long sides L12b of the outer outline L12 of the rectangular intermediate layer 12 forms the outer outline of the current-carrying region 122a. Furthermore, the energizing section 132 has a plurality of energizing regions 132a formed of a conductive material and insulating regions 132b arranged between adjacent energizing regions 132a, with the plurality of energizing regions 132a arranged along the long side L13b of the outline L13 of the intermediate layer 13. As a result, the increase in eddy current loss due to the energizing regions 122a and 132a is suppressed. Therefore, the laminated magnet 10 can improve its strength while suppressing an increase in the eddy current loss ratio.

[0045] Furthermore, according to the motor 100 of this embodiment, the rotor 110 of the motor 100 has a laminated magnet 10 having an intermediate layer 12 having an insulating portion 121 formed of an insulating material and an energizing portion 122 which is at least partly formed of an energizing material. With this configuration, the rotor 110 of the motor 100 has energizing regions 122a and 132a in the intermediate layers 12 and 13, which are located between adjacent magnets 11 of the multiple stacked magnets 11, and which are in contact with each of the adjacent magnets 11. Since the energizing regions 122a and 132a are located in specific places in the intermediate layers 12 and 13, the increase in eddy current loss due to the energizing regions 122a and 132a is suppressed in the laminated magnet 10, and the strength is improved. As a result, the rotational speed of the motor 100 can be increased, and the output of the motor 100 can be improved.

[0046] <Second Embodiment> Figure 8 is a cross-sectional view of the intermediate layer of the laminated magnet 20 of the second embodiment. Compared with the laminated magnet 10 of the first embodiment (Figure 1), the positional relationship between the insulating portion and the energizing portion in the intermediate layer of the laminated magnet 20 of the second embodiment is different.

[0047] The stacked magnet 20 of this embodiment comprises a plurality of stacked magnets 11 and an intermediate layer 22. The intermediate layer 22 is positioned between adjacent magnets 11 among the plurality of magnets 11. The intermediate layer 22 has an insulating portion 221 formed of an insulating material and two current-carrying portions 222.

[0048] The insulating portion 221 is formed of an insulating material. The insulating portion 221 in this embodiment contains CaF2.

[0049] The two current-carrying sections 222 are positioned so as to sandwich the insulating section 221 and are in contact with each of the adjacent magnets 11. In the stacked magnet 20, as shown in Figure 8, in the cross-section of the intermediate layer 22 along a direction perpendicular to the stacking direction (z-axis direction) of the multiple magnets 11, the outline L22 formed by the outer circumference of the intermediate layer 22 has a rectangular shape consisting of a pair of short sides L22a and a pair of long sides L22b. Of the outline L22 formed by the outer circumference of the intermediate layer 22, each of the pair of short sides L22a forms the outline of the current-carrying section 222. The current-carrying section 222 consists of one current-carrying region 222a formed of a conductive material. That is, each of the pair of short sides L22a of the outline L22 of the intermediate layer 22 is part of the outline of the current-carrying region 222a. In this embodiment, the current-carrying region 222a is formed of the same type of magnetic material as the material forming each of the multiple magnets 11. In the stacked magnet 20 of this embodiment, the ratio of the volume of the energized region 222a to the volume of the intermediate layer 22 is 14% or more and 20% or less. It is even more desirable that the ratio of the volume of the energized region 222a to the volume of the intermediate layer 22 is 15% or less. The method for calculating the ratio of the volume of the energized region 222a to the volume of the intermediate layer 22 is the same as the method for calculating the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 in the first embodiment.

[0050] Figure 9 is a cross-sectional view of a modified intermediate layer of the stacked magnet 20 of this embodiment. Similar to Figure 8, Figure 9 shows a cross-section of the intermediate layer 23 along a direction perpendicular to the stacking direction (z-axis direction) of the stacked magnets 11. The intermediate layer 23 shown in Figure 9 is positioned between adjacent magnets 11 among the multiple magnets 11 and has an insulating portion 221 formed of an insulating material and two current-carrying portions 232.

[0051] Each of the two current-carrying portions 232 of the intermediate layer 23 shown in Figure 9 has a plurality of current-carrying regions 232a formed of a conductive material, and an insulating region 232b located between adjacent current-carrying regions 232a. In the plurality of current-carrying regions 232a, in the cross-section of the intermediate layer 23 along the direction perpendicular to the stacking direction of the plurality of stacked magnets 11, the plurality of current-carrying regions 232a are arranged along the short side L23a of the outline line L23 formed by the outer circumference of the intermediate layer 23. Each of the plurality of current-carrying regions 232a in this embodiment is formed of the same type of magnetic material as the material forming each of the plurality of magnets 11. In the stacked magnet 20 of this embodiment, the ratio of the total volume of the plurality of current-carrying regions 232a to the volume of the intermediate layer 23 is 14% or more and 20% or less. It is even more desirable that the ratio of the volume of the current-carrying regions 232a to the volume of the intermediate layer 23 is 15% or less. As shown in Figures 8 and 9 below, an intermediate layer having a rectangular shape in which each of the pair of short sides of the outline formed by the outer circumference of the intermediate layer is the outline of the energized part of the intermediate layer is called a "short-side conductive intermediate layer".

[0052] Next, the manufacturing method of the laminated magnet 20 of this embodiment will be described. The manufacturing method of the laminated magnet 20 differs from the insulating material coating step of the manufacturing method of the laminated magnet 10 of the first embodiment. The insulating material 221 material used in the insulating material coating step is applied to the rectangular surface of the magnet 11, which has a rectangular parallelepiped shape, at a position away from the pair of short sides, and along the short direction of the surface of the magnet 11. In the manufacturing method of the laminated magnet 20 of this embodiment, the ratio of the volume of the energized area 222a to the volume of the intermediate layer 22, or the ratio of the total volume of multiple energized areas 232a to the volume of the intermediate layer 23, is adjusted by adjusting the amount of insulating material 221 applied to the surface of the magnet 11 before lamination. Note that the method of applying the insulating material 221 is not limited to this. A mask may be used to apply the material to the rectangular surface of the magnet 11, at a position away from the pair of short sides, and along the short direction of the surface of the magnet 11.

[0053] Next, the evaluation test of the stacked magnet in this embodiment will be described. In this evaluation test, multiple stacked magnets (hereinafter referred to as "samples") with different ratios of the volume of the energized region to the volume of the intermediate layer were prepared, and for each of the multiple samples, the "volume ratio of the energized region," "residual magnetic flux density," "eddy current loss ratio," and "intensity" were measured or calculated.

[0054] Figure 10 illustrates the evaluation results of the laminated magnet of this embodiment. The six types of samples used in this evaluation test were manufactured by a method similar to the manufacturing method of the laminated magnet 20 of this embodiment. Samples 1, 4, and 5 are the same samples as those shown in Figure 7, which shows the results of the evaluation test described in the first embodiment. The intermediate layer of each of samples 6 to 8 has an insulating portion formed of an insulating material and two conductive portions. The size of the magnets in the samples used in this evaluation test is 6 mm in the magnetization direction × 2 mm in the stacking direction × 20 mm, and the size of the portion of the laminated magnet excluding the intermediate layer is 6 mm in the magnetization direction × 40 mm in the stacking direction × 20 mm.

[0055] The "Volume Ratio of Conductive Area (%)" shown in Figure 10 indicates the ratio of the volume of the conductive area to the volume of the intermediate layer for each of the samples 1, 4, 5, 6, 7, and 8. In each of the samples where the "Volume Ratio of Conductive Area (%)" is 28.0%, 20.0%, and 15.0%, the two conductive sections are arranged such that each of the pair of short sides of the outline of the intermediate layer forms the outline of the two conductive sections, similar to the intermediate layer 22 (Figure 8) in this embodiment. The "Residual Magnetic Flux Density (T)", "Eddy Current Loss Ratio (%)", "Intensity (MPa)", and "Evaluation" shown in Figure 10 were measured or calculated using the same method as the evaluation test in the first embodiment.

[0056] As shown in Figure 10, the residual magnetic flux density (T) of samples 4, 6 to 8, each of which has an energized portion as part of the intermediate layer, was confirmed not to decrease significantly in residual magnetic flux density compared to sample 1, which has a structure in which multiple magnets are simply stacked. Specifically, the difference between the residual magnetic flux density of samples 4, 6 to 8 and the residual magnetic flux density of sample 1 was within the tolerance range of ±0.03 (T) of the teslameter used for measurement, confirming that the residual magnetic flux density of samples 4, 6 to 8 was about the same as that of sample 1. In order for the residual magnetic flux density (T) to be about the same as that of sample 1, it is desirable that the volume ratio of the energized region (%) be 14% or more.

[0057] As shown in Figure 10, the "eddy current loss ratio (%)" confirms that samples 7 and 8, which have a current-carrying section as part of the intermediate layer, do not experience a significant increase in eddy current loss compared to sample 5, which has only an insulating section containing CaF2 in the intermediate layer. Specifically, the "eddy current loss ratio (%)" for samples 7 and 8 is 85% or less compared to sample 1, where adjacent magnets are connected. On the other hand, sample 6, with a "volume ratio (%) of current-carrying area (%)" of 28.0%, had a relatively large "eddy current loss ratio (%)" of 99.2%. In other words, if the "volume ratio (%) of current-carrying area (%)" is within 20%, the increase in the current loss ratio is suppressed even if a current-carrying section is included in the intermediate layer.

[0058] As shown in Figure 10, the "Strength (MPa)" indicates that samples 4, 6 to 8, which have conductive parts as part of the intermediate layer, show improved strength compared to sample 5, which has only an insulating part containing CaF2 in the intermediate layer, due to the inclusion of conductive parts in the intermediate layer that are in contact with each adjacent magnet. Furthermore, among samples 4, 6 to 8, which have conductive parts in the intermediate layer, samples 6 to 8, which have an intermediate layer with short-side conductivity, show improved strength compared to sample 4, where the conductive parts are arranged independently of the outline of the intermediate layer.

[0059] As shown in the "Overall Evaluation" in Figure 10, it was confirmed that Sample 7 and Sample 8 each exhibited superior characteristics compared to Sample 1 and Sample 5. Specifically, among Samples 4, 6, and 8, Samples 6 through 8, each having an intermediate layer with short-side conductivity, were found to have improved strength as a laminated magnet without significant changes in residual magnetic flux density or eddy current loss compared to Sample 4, which has an intermediate layer without short-side conductivity. Furthermore, among Samples 6 through 8, Samples 7 and 8, with a "volume ratio of the conductive region (%)" of 20% or less, were found to have relatively small eddy current losses. As a result, when the laminated magnet of Sample 7 or Sample 8 is used in a motor, it is less likely to break even when the motor speed is increased, allowing for further increases in motor output.

[0060] As described above, according to the stacked magnet 20 of this embodiment, the intermediate layers 22 and 23, which are arranged between adjacent magnets 11 among the multiple stacked magnets 11, have two current-carrying parts 222 and 232 that are arranged so as to sandwich an insulating part 221 made of an insulating material. Each of these two current-carrying parts 222 and 232 is in contact with each of the adjacent magnets 11 in the intermediate layers 22 and 23, so that the bonding strength between adjacent magnets 11 can be improved. The current-carrying part 222 consists of one current-carrying region 222a made of a conductive material, and each of the pair of short sides L22a of the outer outline L22 of the rectangular intermediate layer 22 forms the outer outline of the current-carrying region 222a. Furthermore, the energizing portion 232 has a plurality of energizing regions 232a formed of a conductive material and insulating regions 232b arranged between adjacent energizing regions 232a, with the plurality of energizing regions 232a arranged along the short side L23a of the outline L23 of the intermediate layer 23. As a result, the increase in eddy current loss due to the energizing regions 222a, 232a is suppressed. Therefore, the laminated magnet 20 can improve its strength while suppressing an increase in the eddy current loss ratio.

[0061] <Third Embodiment> Figure 11 is a cross-sectional view of the intermediate layer of the laminated magnet 30 of the third embodiment. Compared with the laminated magnet 10 of the first embodiment (Figure 1), the laminated magnet 30 of the third embodiment has a different positional relationship between the insulating portion and the energizing portion in the intermediate layer.

[0062] The stacked magnet 30 of this embodiment comprises a plurality of stacked magnets 11 and an intermediate layer 32. The intermediate layer 32 is positioned between adjacent magnets 11 among the plurality of magnets 11. The intermediate layer 32 has an insulating portion 321 formed of an insulating material and an energizing portion 322.

[0063] The insulating portion 321 is formed of an insulating material. The insulating portion 321 in this embodiment contains CaF2.

[0064] The energizing portion 322 is in contact with each of the adjacent magnets 11. In the cross-section of the intermediate layer 32 along a direction perpendicular to the stacking direction of the multiple stacked magnets 11, the energizing portion 322 is formed at a position away from the outline L32 formed by the outer circumference of the intermediate layer 32, and includes the center of the outline L32 of the intermediate layer 32. Specifically, in Figure 11, if the center C32 is defined as the point where the diagonals DL1 and DL2 intersect in the outline L32 of the rectangular intermediate layer 32, the energizing portion 322 is formed to include the center C32. The energizing portion 322 in this embodiment is made of the same type of magnetic material as the material forming each of the multiple magnets 11. In the stacked magnet 30 of this embodiment, the ratio of the volume of the energizing portion 322 to the volume of the intermediate layer 32 is 14% or more and 35% or less. Hereinafter, as shown in Figure 11, an intermediate layer in which the energized portion is formed at a position away from the outline formed by the outer circumference of the rectangular intermediate layer, and which includes the center of the outline of the intermediate layer, is referred to as a "centrally conductive intermediate layer." The method for calculating the ratio of the volume of the energized portion 322 to the volume of the intermediate layer 32 is the same as the method for calculating the ratio of the volume of the energized region 122a to the volume of the intermediate layer 12 in the first embodiment. In Figure 11, the energized portion 322 is formed to have a circular shape, but the shape of the energized portion 322 is not limited to this.

[0065] Next, the manufacturing method of the laminated magnet 30 of this embodiment will be described. The manufacturing method of the laminated magnet 30 differs from the insulating material coating step of the manufacturing method of the laminated magnet 30 of the first embodiment. The insulating material used in the insulating material coating step is applied along the outer circumference of the rectangular surface of the magnet 11, which has a rectangular parallelepiped shape, thereby forming an intermediate layer 32. In the manufacturing method of the laminated magnet 30 of this embodiment, the ratio of the volume of the energized portion 322 to the volume of the intermediate layer 32 is adjusted by adjusting the amount of insulating material 321 applied to the surface of the magnet 11 before lamination. Note that the method of applying the insulating material 321 is not limited to this. It may also be applied along the outer circumference of the magnet 11 on the rectangular surface of the magnet 11 using a mask.

[0066] Next, the evaluation test of the stacked magnet in this embodiment will be described. In this evaluation test, multiple stacked magnets (hereinafter referred to as "samples") with different ratios of the volume of the energized part to the volume of the intermediate layer were prepared, and for each of the multiple samples, the "volume ratio of the energized part," "residual magnetic flux density," "eddy current loss ratio," and "intensity" were measured or calculated.

[0067] Figure 12 illustrates the evaluation results of the laminated magnet of this embodiment. The five types of samples used in this evaluation test were manufactured by a method similar to the manufacturing method of the laminated magnet 30 of this embodiment. Samples 1, 4, and 5 are the same samples as those shown in Figure 7, which shows the results of the evaluation test described in the first embodiment. The intermediate layers of samples 9 and 10 each have an insulating portion and an energizing portion formed of an insulating material. The size of the magnets in the samples used in this evaluation test is 6 mm in the magnetization direction × 2 mm in the stacking direction × 20 mm, and the size of the portion of the laminated magnet excluding the intermediate layer is 6 mm in the magnetization direction × 40 mm in the stacking direction × 20 mm.

[0068] The "Volume Ratio of Conductive Area (%)" shown in Figure 12 indicates the ratio of the volume of the conductive area to the volume of the intermediate layer for each of the samples 1, 4, 5, 9, and 10. For sample 9, which has a "Volume Ratio of Conductive Area (%)" of 33.0%, and sample 10, which has a "Volume Ratio of Conductive Area (%)" of 28.0%, the conductive area is positioned to include the center of the outline of the intermediate layer, similar to the intermediate layer 32 (Figure 11) in this embodiment. The "Residual Magnetic Flux Density (T)", "Eddy Current Loss Ratio (%)", "Intensity (MPa)", and "Evaluation" shown in Figure 12 were measured or calculated using the same method as the evaluation test in the first embodiment.

[0069] As shown in Figure 12, the residual magnetic flux density (T) of samples 4, 9, and 10 does not decrease significantly compared to sample 1, which has a structure in which multiple magnets are simply stacked. Specifically, the difference between the residual magnetic flux density of samples 4, 9, and 10 and the residual magnetic flux density of sample 1 is within the tolerance range of ±0.03 (T) of the teslameter used for measurement, confirming that the residual magnetic flux density of samples 4, 9, and 10 is about the same as that of sample 1. In order for the residual magnetic flux density (T) to be about the same as that of sample 1, it is desirable that the volume ratio of the energized part (%) be 14% or more.

[0070] As shown in Figure 12, the "eddy current loss ratio (%)" confirms that samples 4, 9, and 10, which have a current-carrying section as part of the intermediate layer, do not experience a significant increase in eddy current loss compared to sample 5, which has only an insulating section containing CaF2 in the intermediate layer. Specifically, the "eddy current loss ratio (%)" for samples 4, 9, and 10 is 85% or less compared to sample 1, where adjacent magnets are connected. In other words, if the "volume ratio of the current-carrying section (%)" is 35% or less, the increase in the current loss ratio is suppressed even if a current-carrying section is included in the intermediate layer.

[0071] As shown in Figure 12, the "Strength (MPa)" indicates that samples 4, 9, and 10, which have conductive parts as part of the intermediate layer, exhibit improved strength compared to sample 5, which has only an insulating layer containing CaF2, due to the inclusion of conductive parts in the intermediate layer that are in contact with each adjacent magnet. Furthermore, among samples 4, 9, and 10, which have conductive parts in the intermediate layer, samples 9 and 10, which have a centrally conductive intermediate layer, exhibit improved strength compared to sample 4, where the conductive parts are arranged independently of the outline of the intermediate layer.

[0072] As shown in the "Overall Evaluation" in Figure 12, it was confirmed that samples 9 and 10, respectively, exhibited superior characteristics in terms of residual magnetic flux density and eddy current loss compared to samples 1 and 5. Furthermore, it was confirmed that samples 9 and 10, which have a centrally conductive intermediate layer, exhibit improved strength as laminated magnets without significant changes in residual magnetic flux density or eddy current loss compared to sample 4, which has an intermediate layer that is not centrally conductive. As a result, when the laminated magnets of sample 9 or sample 10 are used in a motor, they are less likely to break even when the motor rotation speed is increased, allowing for a further increase in motor output.

[0073] As described above, in the laminated magnet 30 of this embodiment, the intermediate layer 32, which is placed between adjacent magnets 11 among the multiple stacked magnets 11, has an energizing portion 322 that is in contact with each of the adjacent magnets 11. This improves the bonding strength between adjacent magnets 11. Furthermore, since the energizing portion 322 is formed at a position away from the outer outline L32 of the rectangular intermediate layer 32, and includes the center C32 of the outer outline L32 of the intermediate layer 32, the increase in eddy current loss due to the energizing portion 322 is suppressed. As a result, the laminated magnet 30 can improve its strength while suppressing an increase in the eddy current loss ratio.

[0074] <Modified form of this embodiment> The present invention is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit, for example, the following modifications are also possible.

[0075] [Example 1] In the first and second embodiments, the current-carrying region was formed of the same type of magnetic material as the material forming each of the multiple magnets. In the third embodiment, the current-carrying portion was formed of the same type of magnetic material as the material forming each of the multiple magnets. However, the material forming the current-carrying region or current-carrying portion is not limited to these, and may be any conductive material.

[0076] [Differentiation 2] In the above-described embodiment, in the method for manufacturing a laminated magnet, an insulating material is applied to the surface of the magnet 11 before lamination, and in the hot-pressing process, the magnetic material that will form the magnet is diffused into the insulating material to form an intermediate layer having an insulating portion and an electrically conductive portion. The method for forming the intermediate layer is not limited to this. In the insulating material application process, an insulating material that will form the insulating portion and an electrically conductive material that will form the electrically conductive portion may be applied to the surface of the magnet to form the intermediate layer.

[0077] [Difference 3] In the embodiment described above, the stacked magnet was assumed to be rectangular in shape, as shown in Figure 1. However, the shape of the stacked magnet is not limited to this.

[0078] Figure 13 is a perspective view of a modified example of the stacked magnet 10 of the first embodiment. The stacked magnet 10 shown in Figure 13 has a shape when viewed from the z-axis direction that is the unfolded side of a frustocone. As a result, in the cross-section of the intermediate layer 12 along the direction perpendicular to the stacking direction (z-axis direction) of the multiple magnets 11, the outline formed by the outer circumference of the intermediate layer 12 has a rectangular shape consisting of a pair of short sides and a pair of long sides. Even in a stacked magnet 10 of this shape, by providing an intermediate layer 12 having an insulating part 121 made of an insulating material and an energizing part 122 made of a conductive material, it is possible to improve strength while suppressing an increase in the eddy current loss ratio compared to when the intermediate layer is made of an insulating material.

[0079] [Differentiation Example 4] In the embodiments described above, the stacked magnet was assumed to be applied to an IPM motor. However, the motor to which the stacked magnet is applied is not limited to an IPM motor. It may also be applied to an SPM motor or an axial gap motor.

[0080] The embodiments of this specification have been described above based on the embodiments and modifications described above. The embodiments described above are for the purpose of facilitating understanding of this specification and do not limit it. This specification may be modified and improved without departing from its spirit and the scope of the claims, and equivalents thereof are included in this specification. Furthermore, any technical features that are not described as essential in this specification may be deleted as appropriate.

[0081] <Application Example 1> It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions, The two current-carrying parts are arranged so as to sandwich the insulating part and are in contact with each of the adjacent magnets. In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides. Each of the pair of long sides is the outline of the energized portion, The energized section is, When it consists of one current-carrying region formed of a conductive material, each of the pair of long sides is the outline of the current-carrying region. In the case where there are multiple current-carrying regions formed of a conductive material and insulating regions disposed between adjacent current-carrying regions, in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the multiple current-carrying regions are arranged side by side along the long side. The ratio of the volume of the current-carrying region to the volume of the intermediate layer is characterized by being 14% or more and 35% or less. Stacked magnets. <Application Example 2> It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions, The two current-carrying parts are arranged so as to sandwich the insulating part and are in contact with each of the adjacent magnets. In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides. Each of the pair of short sides is the outline of the energized portion, The energized section is, When it consists of one current-carrying region formed of a conductive material, each of the pair of short sides is the outline of the current-carrying region. In the case where there are multiple current-carrying regions formed of a conductive material and insulating regions disposed between adjacent current-carrying regions, in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the multiple current-carrying regions are arranged side by side along the short side. The ratio of the volume of the current-carrying region to the volume of the intermediate layer is characterized by being 14% or more and 20% or less. Stacked magnets. <Application Example 3> It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an insulating portion formed of an insulating material and an energizing portion formed of a conductive material. The energizing portion is in contact with each of the adjacent magnets, In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The current-carrying portion is formed at a position away from the outline formed by the outer circumference of the intermediate layer, and includes the center of the outline of the intermediate layer. The ratio of the volume of the current-carrying section to the volume of the intermediate layer is characterized by being 14% or more and 35% or less. Stacked magnets. <Application Example 4> It is a motor, A rotor having a stacked magnet as described in any one of Application Examples 1 to 3, A stator having a coil, characterized by comprising Motor. [Explanation of symbols]

[0082] 10, 20, 30…Stacked magnets 11…Magnets 110...Stator 12, 13, 22, 23, 32… Middle class 120... Rotor 120b... Coil 121,221,321…Insulation part 122, 132, 222, 232, 322… Power supply section 122a,132a,222a,232a...Electricity area 132b, 232b… Insulation regions L12, L13, L22, L23, L32… (Outline of the intermediate layer) L12a, L22a, L23a... Short side L12b, L13b, L22b... Longer side

Claims

1. It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions. The two current-carrying parts are arranged so as to sandwich the insulating part and are in contact with each of the adjacent magnets. In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides. Each of the pair of long sides is the outline of the energized portion, The energized section is, When it consists of one current-carrying region formed of a conductive material, each of the pair of long sides is the outline of the current-carrying region. In the case where there are multiple current-carrying regions formed of a conductive material and insulating regions disposed between adjacent current-carrying regions, in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the multiple current-carrying regions are arranged side by side along the long side. The ratio of the volume of the current-carrying region to the volume of the intermediate layer is characterized by being 14% or more and 35% or less. Stacked magnets.

2. It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an intermediate layer having an insulating portion formed of an insulating material and two current-carrying portions. The two current-carrying parts are arranged so as to sandwich the insulating part and are in contact with each of the adjacent magnets. In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The outline formed by the outer circumference of the intermediate layer has a rectangular shape consisting of a pair of short sides and a pair of long sides. Each of the pair of short sides is the outline of the energized portion, The energized section is, When it consists of one current-carrying region formed of a conductive material, each of the pair of short sides is the outline of the current-carrying region. In the case where there are multiple current-carrying regions formed of a conductive material and insulating regions disposed between adjacent current-carrying regions, in the cross-section of the intermediate layer along a direction perpendicular to the lamination direction, the multiple current-carrying regions are arranged side by side along the short side. The ratio of the volume of the current-carrying region to the volume of the intermediate layer is characterized by being 14% or more and 20% or less. Stacked magnets.

3. It is a stacked magnet, Multiple magnets stacked on top of each other, An intermediate layer is disposed between adjacent magnets among the plurality of magnets, and comprises an insulating portion formed of an insulating material and an energizing portion formed of a conductive material. The energizing portion is in contact with each of the adjacent magnets, In the cross-section of the intermediate layer along a direction perpendicular to the stacking direction of the plurality of magnets, The current-carrying portion is formed at a position away from the outline formed by the outer circumference of the intermediate layer, and includes the center of the outline of the intermediate layer. The ratio of the volume of the current-carrying portion to the volume of the intermediate layer is characterized in that it is 14% or more and 35% or less. Stacked magnets.

4. It is a motor, A rotor having a stacked magnet according to any one of claims 1 to 3, A stator having a coil, characterized by comprising Motor.

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