Magnetic wedge and rotating electric machine

Abstract

To provide a low-loss and high-strength magnetic wedge and a rotary electric machine using the same.SOLUTION: The magnetic wedge is used for a rotary electric machine in which a stator and a rotor oppose to each other across a gap surface. The magnetic wedge is composed of a first member and a second member provided between the first member and the gap surface. The first member has a first magnetic metallic phase including at least one first element selected from the group consisting of Fe, Co, and Ni. The second member has a second magnetic metallic phase including at least one second element selected from the group consisting of Fe, Co, and Ni. The ratio of the first magnetic metallic phase to the first member is greater than the ratio of the second magnetic metallic phase to the second member.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a magnetic wedge and a rotating electric machine. [Background technology]

[0002] Typically, the coil windings of a rotating electric machine are housed in core slots and supported and fixed by wedges installed at the slot openings. Non-magnetic materials are generally used for these wedges, but the magnetic resistance in the gap between the stator core and rotor core becomes discontinuous, causing pulsation in the magnetic flux distribution on the surface of the core facing the gap, resulting in increased harmonic loss. To reduce this harmonic loss, magnetic wedges (magnetic wedges) have long been used. Figure 1 is a schematic diagram of how a magnetic wedge is used and its effects. Figure 1 shows a radial gap-type rotating electric machine as an example.

[0003] In FIG. 1, magnetic wedges 100, coils 230, core teeth 250, and core slots 260 are shown.

[0004] The magnetic wedge is typically made of a soft magnetic material that has been compressed into powder. However, the strength of such a wedge is insufficient. Furthermore, when a magnetic wedge with low electrical resistance is used, loss increases in the high-frequency range, limiting the operating band. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 63-161834

[0006] [Patent Document 2] Japanese Patent Application Laid-Open No. 2000-166156 Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a magnetic wedge with low loss and high strength, and a rotating electric machine using the same. [Means for solving the problem]

[0008] The magnetic wedge of the embodiment is a magnetic wedge used in a rotating electric machine in which a stator and a rotor face each other via a gap surface, and the magnetic wedge comprises a first member and a second member provided between the first member and the gap surface, the first member having a first magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni, the second member having a second magnetic metal phase containing at least one second element selected from the group consisting of Fe, Co, and Ni, and the ratio of the first magnetic metal phase to the first member is greater than the ratio of the second magnetic metal phase to the second member. The first member has a higher bending strength than the second member. . [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing the use of a magnetic wedge and the effect of the magnetic wedge. [Figure 2] 1 is a schematic diagram of a radial gap type rotating electric machine according to a first embodiment. [Figure 3] 1 is a schematic diagram of an axial gap type rotating electric machine according to a first embodiment. [Figure 4] FIG. 2 is a schematic cross-sectional view of a magnetic wedge according to the first embodiment. [Figure 5] FIG. 3 is a schematic view showing an example of a first member of the first embodiment. [Figure 6] FIG. 3 is a schematic view showing an example of a second member of the first embodiment. [Figure 7] FIG. 2 is a schematic cross-sectional view of a magnetic wedge according to the first embodiment. [Figure 8] 2 is a schematic diagram illustrating a main surface of the magnetic body of the first embodiment. FIG. [Figure 9] 2 is a schematic diagram showing a state in which a magnetic wedge is used in the radial gap type rotating electric machine of the first embodiment. FIG. [Figure 10]2 is a schematic diagram showing a state in which a magnetic wedge is used in the axial gap type rotating electric machine according to the first embodiment. FIG. [Figure 11] 3A to 3C are diagrams illustrating the effects of the magnetic wedge of the first embodiment. [Figure 12] FIG. 6 is a schematic diagram illustrating an example of a radial gap type rotating electric machine according to a second embodiment. [Figure 13] FIG. 6 is a schematic diagram illustrating an example of an axial gap type rotating electric machine according to a second embodiment. [Figure 14] FIG. 4 is a schematic diagram illustrating an example of a generator according to a second embodiment. [Figure 15] FIG. 6 is a schematic diagram illustrating an example of a linear motor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) The magnetic wedge of the embodiment is a magnetic wedge used in a rotating electric machine in which a stator and a rotor face each other via a gap surface, and the magnetic wedge comprises a first member and a second member arranged between the first member and the gap surface, the first member having a first magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni, and the second member having a second magnetic metal phase containing at least one second element selected from the group consisting of Fe, Co, and Ni, and the proportion of the first magnetic metal phase in the first member is greater than the proportion of the second magnetic metal phase in the second member.

[0011] In this specification, the terms "axial direction," "rotational direction," and "radial direction" are defined relative to the rotor of the rotating electric machine. That is, "axial direction" refers to the direction along the rotational axis of the rotor, "rotational direction" refers to the direction around the rotational axis of the rotor (or the tangential direction thereof), and "radial direction" refers to the direction perpendicular to the rotational axis of the rotor.

[0012] The "gap surface" is defined by the gap between the rotor and the stator. The "gap surface" of a radial gap type rotating electric machine and an axial gap type rotating electric machine will be explained using Fig. 2 and Fig. 3. Fig. 2 is a schematic diagram of a radial gap type rotating electric machine of this embodiment. Fig. 3 is a schematic diagram of an axial gap type rotating electric machine of this embodiment.

[0013] In FIG. 2, a rotating electric machine 200, a rotor 210, a stator core 220, a coil 230, and an air gap surface 240 are shown.

[0014] In FIG. 3, a rotating electric machine 200, a rotor 210, a coil 230, an air gap surface 240, iron core teeth 250, a stator 270, and a shaft 280 are shown.

[0015] In the case of a radial gap rotating electric machine, the stator is positioned opposite the rotor at a certain radial distance, so the "gap surface" is a surface parallel to the cylindrical surface centered on the rotor's rotation axis, as shown in Figure 2. Therefore, the radial direction is perpendicular to the gap surface, and the axial direction and rotation direction are parallel to the gap surface.

[0016] On the other hand, in the case of an axial gap rotating electric machine, the stator is arranged facing the rotor at a certain axial distance, so the "gap plane" is a plane perpendicular to the rotation axis of the rotor, as shown in Figure 3. Therefore, the axial direction is perpendicular to the gap plane, and the rotation direction and radial direction are parallel to the gap plane.

[0017] In the magnetic wedge of this embodiment, it is preferable that there be a difference between the magnetic permeabilities in the three directions, i.e., the axial permeability, the rotational permeability, and the radial permeability. More preferably, the difference is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. This is preferable because it suppresses the increase in leakage flux caused by the use of the magnetic wedge and fully enjoys the effect of improving the efficiency of the rotating electric machine. Furthermore, by increasing the effective magnetic flux (main magnetic flux), it is expected that the torque of the rotating electric machine will also be improved.

[0018] The difference in magnetic permeability is determined based on the lowest magnetic permeability. For example, the difference between the radial magnetic permeability μr and the rotational magnetic permeability μθ is calculated as (μr - μθ) / μθ×100(%) when the rotational magnetic permeability is low, and as (μθ - μr) / μr×100(%) when the radial magnetic permeability is low.

[0019] FIG. 4 is a schematic cross-sectional view of the magnetic wedge of this embodiment.

[0020] The magnetic wedge 100 includes a first member (first sintered portion) 60 and a second member (compressed powder portion) 70. In Fig. 4, the magnetic wedge 100, the first member 60, the second member 70, the coil 230, the gap surface 240, and the core teeth 250 are shown.

[0021] The first member 60 preferably has a first magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni, and the ratio of the first magnetic metal phase to the first member is greater than the ratio of the second magnetic metal phase to the second member. The ratio of the magnetic metal phase may be determined by structural observation using SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy) or TEM-EDX (Transmission Electron Microscope-Energy Dispersive X-ray Spectroscopy), or may be estimated from the saturation magnetization value by cutting out a member and evaluating its magnetic properties using a VSM (Vibrating Sample Magnetometer). As an example, in the case of a member made of Fe, the saturation magnetization of Fe is 2.2 T, so if the saturation magnetization of the member is 2.0 T, the proportion of the magnetic metal phase in the member is 2.0 / 2.2×100=approximately 90.9%. A comprehensive judgment may also be made by combining the results of structure observation and magnetic measurement. The proportion of the first magnetic metal phase is preferably 90% or more of the first member 60, more preferably 95% or more. Furthermore, the relative density is preferably 90% or more, more preferably 95% or more. FIG. 5 is a schematic diagram showing an example of the first member of the first embodiment. The first member preferably has precipitate particles containing Ta and C. FIG. 5 shows a first member 60 and precipitate particles 10. When such precipitate particles are included in a magnetic material, the precipitation strengthening mechanism significantly improves mechanical properties such as strength and thermal stability. The precipitate particles preferably also contain Co. More preferably, they contain at least one of Fe and Si, and even more preferably, they contain both Fe and Si. Furthermore, the precipitate particles preferably contain elements contained in the matrix in which the precipitate particles are arranged (excluding, for example, obvious impurity elements less than 0.1%). This makes the compositions of the precipitate particles and the matrix similar, which is preferable because it improves thermal stability and mechanical properties such as strength and hardness.

[0022] The first member 60 is preferably a sintered portion (first sintered portion) made of sintered material. The manufacturing method of the first member 60 is not particularly limited, and it is preferably manufactured by a normal sintering method. More preferably, the following methods can be mentioned. The first step is a preparation step for molding. For example, a magnetic metal ribbon is manufactured, heat-treated, pulverized, and molded. In this case, the magnetic metal ribbon is manufactured using a film-forming device such as a roll quenching device or a sputtering device. A roll quenching device is desirable because it is suitable for mass synthesis. A single-roll quenching device is particularly preferable because it is simple. Furthermore, when heat-treating the magnetic metal ribbon, the ribbon may be cut to an appropriate size to make it easier to place in an electric furnace for heat treatment. For example, cutting to an appropriate size may be done using a mixer or the like. Heat treatment is preferable because it improves pulverizability. The heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and more preferably a reducing atmosphere such as H2 (hydrogen), CO (carbon monoxide), or CH4 (methane). The reason for this is that even if the magnetic metal ribbon is oxidized, heat treatment in a reducing atmosphere can reduce the oxidized metal and return it to metal. This can also reduce the oxidized magnetic metal ribbon, which has lost its saturation magnetization, and restore the saturation magnetization. The heat-treated magnetic metal ribbon is pulverized to produce flat magnetic metal particles. Prior to this pulverization, the magnetic metal ribbon or thin film may be cut to an appropriate size using a mixer or similar device. The pulverization is carried out using a pulverizer such as a bead mill, planetary mill, or mixer. Any type of pulverizer is acceptable. Examples include planetary mills, bead mills, mixer rotary ball mills, vibration ball mills, stirring ball mills (attritors), jet mills, centrifuges, and methods that combine mills and centrifugation. The resulting flat magnetic metal particles are molded. For example, molding is carried out using uniaxial press molding, hot press molding, CIP molding, HIP molding, etc. A high pressing pressure is preferable, preferably 10,000 kgf / cm. 2 It is preferable that the temperature is more than 1000°C. After pressing once, heat treatment (for example, heat treatment at 1000°C in an H2 atmosphere) and pressing again is carried out multiple times (for example, two or more times) to achieve densification (higher density and improved saturation magnetization). This produces a molded body. The second step is a step of heat-treating the obtained molded body. At this time, it is preferable to perform the heat treatment in a vacuum. At this time, it is preferable to place the molded body on a Ta foil when performing the heat treatment in a vacuum. The heat treatment temperature is preferably 1100°C or higher, more preferably 1200°C or higher. It is preferable that the degree of vacuum is high, and 10 -1 Pa or less, and more preferably 10 -2 Pa or less, more preferably 10 -3 The pressure is below 100 Pa. Furthermore, it is preferable that carbon be present in the furnace where the heat treatment is performed. As a result, sintering proceeds while Fe, Co, Si, and other elements partially evaporate during vacuum heat treatment. Because Fe and Co evaporate more readily than Si (due to their higher vapor pressure), the sintered composition deviates from the raw material composition (becoming slightly Si-rich and Fe- and Co-poor). The surface of the material is particularly slightly Si-rich and Fe- and Co-poor compared to the center. Furthermore, during vacuum heat treatment, Ta diffuses from the Ta foil into the material, and carbon in the furnace also diffuses into the material. This behavior only occurs when the material is placed on Ta foil and heat treated at high temperatures in a vacuum with carbon present in the furnace. This vacuum heat treatment results in the formation of Ta-Co-C (including Fe and Si) precipitate particles in the matrix. While it is preferable for the raw material composition to contain Ta and C, even if they are not present in the raw material composition, Ta and C can be incorporated during the process and form precipitate particles. Furthermore, by setting an appropriate degree of vacuum and heat treatment temperature, precipitated particles (containing Fe and Si) with a cubic crystal structure of Ta3Co3C are generated. The precipitated particles are oriented relative to the matrix, resulting in a low lattice mismatch. It is preferable to appropriately remove lattice distortion from the resulting molded body (magnetic material) by heat treatment. This heat treatment is preferably carried out in an inert atmosphere or a reducing atmosphere, more preferably in a reducing atmosphere such as H2, CO, or CH4.

[0023] The second component 70 is disposed between the first component 60 and the gap surface 240. The second component 70 has a second magnetic metal phase containing at least one second element selected from the group consisting of Fe, Co, and Ni. The second component 70 preferably has a plurality of flat magnetic metal particles containing flat surfaces and the second magnetic metal phase, and an intervening phase present between the flat magnetic metal particles and containing at least one third element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). The proportion of the second magnetic metal phase is preferably less than 90% of the second component 70. The relative density is preferably less than 90%. Figure 6 is a schematic diagram showing an example of the second component of the first embodiment. The magnetic material (flat magnetic metal particles) 2 and the intervening phase 20 are shown.

[0024] The flat magnetic metal particles preferably have a coercive force difference depending on the direction within the flat surface. The larger the directional coercive force difference ratio, the more preferable, and it is preferably 1% or more. More preferably, the coercive force difference ratio is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. The coercive force difference ratio here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), where Hc(max) is the maximum coercive force and Hc(min) is the minimum coercive force within the flat surface. Note that coercive force can be evaluated using a vibrating sample magnetometer (VSM) or the like. When the coercive force is low, a coercive force of 0.1 Oe or less can be measured by using a low magnetic field unit. Measurements are performed by changing the direction within the flat surface relative to the direction of the measurement magnetic field.

[0025] The phrase "having a coercive force difference" means that when a magnetic field is applied in a 360-degree direction within the flat surface and the coercive force is measured, there is a direction in which the coercive force is maximum and a direction in which the coercive force is minimum. For example, when the coercive force is measured while changing the direction every 22.5 degrees around a 360-degree angle within the flat surface, if a coercive force difference appears, that is, if there are angles where the coercive force is greater and angles where the coercive force is smaller, then the material is considered to "have a coercive force difference."

[0026] The second member 70 comprises a plurality of flat magnetic metal particles and an intervening phase, and the plurality of flat magnetic metal particles have an average thickness of 10 nm or more and 100 μm or less, have flat surfaces, and it is preferable that the average ratio of the average length within the flat surfaces to the thickness is 5 or more and 10,000 or less.

[0027] The flat surface of the second member 70 is preferably oriented parallel to the plane of the second member 70, and has a difference in coercive force depending on the direction in the plane.

[0028] By having a coercive force difference within the plane of the second member 70, the minimum coercive force value becomes smaller, which is preferable, compared to an isotropic material with almost no coercive force difference. A material with magnetic anisotropy within the plane has a difference in coercive force depending on the direction within the plane, and the minimum coercive force value becomes smaller compared to a magnetically isotropic material. This reduces hysteresis loss and improves magnetic permeability, which is preferable.

[0029] By having a coercive force difference within the plane of the second member 70, the minimum coercive force value becomes smaller, which is preferable, compared to an isotropic material with almost no coercive force difference. A material with magnetic anisotropy within the plane has a difference in coercive force depending on the direction within the plane, and the minimum coercive force value becomes smaller compared to a magnetically isotropic material. This reduces hysteresis loss and improves magnetic permeability, which is preferable.

[0030] Within the plane of the second member 70 (within a plane parallel to the flat surfaces of the flat magnetic metal particles), the larger the percentage of the coercive force difference due to direction, the better, and it is preferably 1% or more. More preferably, the percentage of the coercive force difference is 10% or more, even more preferably, the percentage of the coercive force difference is 50% or more, and even more preferably, the percentage of the coercive force difference is 100% or more. The percentage of the coercive force difference here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), where Hc(max) is the maximum coercive force and Hc(min) is the minimum coercive force within the flat surface.

[0031] The second member 70 is preferably a compressed powder portion made of a compressed powder material. The method for manufacturing the second member 70 is not particularly limited, and it is preferably manufactured by a normal powder compacting method. More preferably, the following methods can be mentioned.

[0032] The first step is to produce a magnetic metal ribbon containing at least one first element selected from the group consisting of Fe, Co, and Ni. This step involves producing a ribbon or thin film using a film-forming device such as a roll quenching device or a sputtering device. In this case, when using a film-forming device, it is desirable to form a film with uniaxial anisotropy in the film plane by magnetic field deposition or rotational deposition. When using a film-forming device, the thickness can be reduced, the structure tends to be refined, and rotational magnetization is likely to occur. Therefore, when producing a material with rotational magnetization, it is desirable to use a film-forming method. A roll quenching device is suitable for mass synthesis and is therefore desirable when synthesizing bulk materials. When using a roll quenching device, a single-roll quenching device is simple and preferable.

[0033] The second step is heat-treating the magnetic metal ribbon at a temperature of 50°C to 800°C. In this step, the ribbon may be cut to an appropriate size to facilitate placement in an electric furnace for heat treatment. For example, cutting to an appropriate size may be performed using a mixer or similar device. This step is desirable because it facilitates improved pulverization in the subsequent third step, the crushing step. The heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and more preferably a reducing atmosphere such as H2 (hydrogen), CO (carbon monoxide), or CH4 (methane). This is because even if the magnetic metal ribbon is oxidized, heat treatment in a reducing atmosphere can reduce the oxidized metal and return it to metal. This also makes it possible to reduce a magnetic metal ribbon that has been oxidized and has a reduced saturation magnetization, thereby restoring the saturation magnetization. Furthermore, if the crystallization of the magnetic metal ribbon progresses significantly due to heat treatment, the properties will deteriorate (coercive force increases, magnetic permeability decreases), so it is preferable to select conditions to suppress excessive crystallization. Furthermore, it is more preferable to perform the heat treatment in a magnetic field. The stronger the applied magnetic field, the better, but it is preferable to apply a magnetic field of 1 kOe or more, and even more preferably 10 kOe or more. This is preferable because it allows magnetic anisotropy to be expressed in the plane of the magnetic metal ribbon, achieving excellent magnetic properties.

[0034] The third step is to pulverize the heat-treated magnetic metal ribbon to produce flat magnetic metal particles. Prior to this pulverization, the magnetic metal ribbon or thin film may be cut to an appropriate size using a mixer or other device. In this step, pulverization is performed using a pulverizer such as a bead mill or planetary mill. Any type of pulverizer is acceptable. Examples include a planetary mill, bead mill, rotary ball mill, vibrating ball mill, stirring ball mill (attritor), jet mill, centrifuge, or a combination of a mill and centrifugation. During pulverization, cooling at a temperature below 0°C is preferred, as this facilitates pulverization. Cooling to liquid nitrogen temperature (77 K) or dry ice temperature (194 K) is particularly desirable, with cooling to liquid nitrogen temperature being even more desirable. This makes the magnetic metal ribbon more susceptible to low-temperature embrittlement, facilitating pulverization. This is preferred because pulverization can be performed efficiently without applying excessive stress or strain to the magnetic metal ribbon. However, in many cases, the powder can be sufficiently pulverized without cooling, and in such cases, cooling is not necessary.

[0035] In the third step, the thickness of the flat magnetic metal particles can be reduced by combining rolling with simple pulverization. If the desired thickness is achieved by the second step, the rolling process can be omitted. Rolling can be performed simultaneously, or after pulverization, or after rolling. In this case, a device capable of applying a strong gravitational acceleration is preferred, such as a planetary mill, bead mill, rotary ball mill, vibrating ball mill, stirring ball mill (attritor), jet mill, centrifuge, or a combination of milling and centrifugation. For example, a high-power planetary mill is preferred because it can easily apply gravitational accelerations of several tens of g. In the case of a high-power planetary mill, an inclined planetary mill is more preferred, in which the direction of the rotational gravitational acceleration and the direction of the revolutionary gravitational acceleration are not collinear but are angled. In a normal planetary mill, the direction of the gravitational acceleration due to rotation and the direction of the gravitational acceleration due to revolution are on the same line, but in an inclined planetary mill, the container rotates while tilted, so the direction of the gravitational acceleration due to rotation and the direction of the gravitational acceleration due to revolution are not on the same line but at an angle. This is preferable because it allows power to be transmitted to the sample efficiently, allowing for efficient milling and rolling. Furthermore, when considering mass production, a bead mill is preferable as it is easy to process large quantities.

[0036] It is desirable to carry out the above cutting, pulverization and rolling (rolling is carried out as necessary, and not carried out if not necessary), and in some cases to repeat the cutting, pulverization and rolling processes to obtain flat magnetic metal particles 10 with a predetermined thickness and aspect ratio. In this case, it is preferable to carry out pulverization and rolling so that the thickness is 10 nm or more and 100 μm or less, more preferably 10 nm or more and 1 μm or less, and even more preferably 10 nm or more and 100 nm or less, as this results in particles that are prone to rotational magnetization.

[0037] It is also desirable to appropriately remove lattice distortion from the obtained flat magnetic metal particles by heat treatment. This heat treatment, like the second step, is preferably carried out at a temperature of 50°C or higher and 800°C or lower, and the heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and more preferably a reducing atmosphere such as H2, CO2, or CH4. It is even more desirable to carry out the heat treatment in a magnetic field. The reasons and details for these are the same as those for the second step, so a detailed explanation will be omitted here.

[0038] The flat magnetic metal particles obtained by the above steps are compacted together with the intervening phase. For example, molding is performed by uniaxial press molding, hot press molding, CIP molding, HIP molding, etc. At this time, it is preferable to perform molding while applying a magnetic field, as this will impart magnetic anisotropy. Thereafter, it is preferable to heat treat the obtained compact. Furthermore, it is preferable to apply a magnetic field during the heat treatment in order to impart magnetic anisotropy. By the above steps, a compacted powder material can be obtained.

[0039] The electrical resistivity of the first member 60 is 10 -8 Ωm or more 10 -4 The electrical resistivity of the second member 70 is preferably less than 10 Ωm. -4 It is preferable that the electrical resistivity is Ωm or more. The electrical resistivities of the first member 60 and the second member 70 can be measured by, for example, a DC four-terminal method or a DC two-terminal method.

[0040] The bending strength (three-point bending strength) of the first member 60 is preferably 200 MPa or more, more preferably 300 MPa or more, and even more preferably 500 MPa or more. The bending strength of the first member 60 and the bending strength of the second member 70 can be measured in accordance with a three-point bending test method defined in standards such as JIS-R1601.

[0041] The saturation magnetization of the first member 60 is preferably 1.7 T or more, and more preferably 1.8 T or more. The saturation mass magnetization is preferably 180 emu / g or more, and more preferably 190 emu / g or more. The saturation magnetization of the first member 60 and the saturation magnetization of the second member 70 can be measured by, for example, VSM.

[0042] of the first member 60 in a direction perpendicular to the gap surface 240 Thickness is the magnetic wedge 100 in the direction perpendicular to the gap surface 240 Thickness It is preferable that the ratio is 30% or more and 70% or less.

[0043] FIG. 7 is a schematic cross-sectional view of the magnetic wedge of this embodiment.

[0044] 7(a) is a schematic cross-sectional view of the magnetic wedge 100 of this embodiment. The second member 70 preferably has a first recess 72. The first member 60 is preferably provided on the first recess 72 of the second member 70. In other words, a portion of the first member 60 is preferably provided in the first recess 72. By providing the first recess 72, the first member 60 can be fixed to the second member 70. This makes it easier to install the magnetic wedge 100 inside the rotating electric machine 200.

[0045] 7(a), for example, when magnetic flux flows in a direction perpendicular to the gap surface 240, eddy currents are generated in the first member 60 in a direction that cancels out the flow of magnetic flux, as shown in FIG. 7(a). If too strong eddy currents flow, the amount of heat generated in the first member 60 increases (loss increases), which becomes a problem.

[0046] FIG. 7(b) is a schematic cross-sectional view of a magnetic wedge 110 according to a modified example of this embodiment. The magnetic wedge 110 includes a plurality of first members 60a, 60b, and 60c. The first members 60a, 60b, and 60c are arranged in the direction shown in FIG. 7(b), which is parallel to the gap surface 240. This reduces the area occupied by each of the first members 60a, 60b, and 60c in the direction perpendicular to the magnetic flux compared to the first member 60 shown in FIG. 7(a). This reduces the magnitude of eddy currents generated in each of the first members 60a, 60b, and 60c. This reduces the heat generation (loss) of the entire first member 60.

[0047] FIG. 7(c) is a schematic cross-sectional view of a magnetic wedge 120 that is a modified example of this embodiment.

[0048] Preferably, the magnetic wedge 120 further includes a third member 80 provided between the first member 60 and the second member 70 and having a second recess 82. Here, the second member 70 preferably has the first recess 72 provided between the first member 60 and the second member 70. Furthermore, the second recess 82 is preferably provided between the first member 60 and the third member 80. Furthermore, it is preferable that a portion of the third member 80 is provided in the first recess 72, and a portion of the first member 60 is provided in the second recess 82. Furthermore, it is preferable that the third member 80 is a sintered portion (second sintered portion). This is because the strength of the first member 60 is greater than that of the second member 70, and therefore the first recess 72 (second member 70) wears out each time the manufacturing process of the rotating electric machine is repeated. Therefore, a portion of the third member 80, which is a sintered portion (second sintered portion), is provided in the first recess 72, and further, a portion of the first member 60 is provided in the second recess 82 of the third member. As a result, the first member 60, which is removed more frequently, repeatedly comes into contact with and out of contact with the third member 80, which is the sintered portion (second sintered portion). In other words, the first member 60, which is removed more frequently, is prevented from repeatedly coming into contact with and out of contact with the second member 70, which is the compacted portion. This makes it possible to suppress wear of the first recess 72 (second member).

[0049] The magnetic wedge includes a magnetic material with a planar structure having a main surface. The planar structure magnetic material includes at least one selected from the group consisting of flat particles, ribbons, thin films, thick films, and plate-like members. The flat particles are flaky particles (flattened particles) with a flaky shape. A ribbon refers to a ribbon-like object with a thickness of about several μm to about 100 μm, a thin film refers to a thin film with a thickness of about several nm to about 10 μm, a thick film refers to a thick film with a thickness of about several μm to about several hundred μm, and a plate-like member refers to a plate-like object with a thickness of about 100 μm to about several hundred mm, but these are not strictly defined, and thicknesses may deviate slightly from the range. In any case, it is preferable that the average length within the main surface (defined as (a+b) / 2, where a is the maximum length and b is the minimum length; details will be described later) is greater than the thickness. The thickness ranges and classifications described above are merely guidelines, and whether a magnetic material includes flat particles, ribbons, thin films, thick films, or plate-like members is determined comprehensively, including information such as appearance and shape.

[0050] The "main surface" of a magnetic body refers to a surface corresponding to a plane in a planar structure. FIG. 8 is a schematic diagram illustrating the main surface of the magnetic body of this embodiment. For example, in the case of a prismatic column, the main surface is the surface with the largest area, as shown in FIG. 8(a), or the surface opposite thereto. In the case of a prismatic column, the first surface 2a or the second surface 2b is the main surface. In the case of a cylinder, the main surface refers to the bottom surface, as shown in FIG. 8(b). In the case of a cylinder, the first surface 2a or the second surface 2b is the main surface. In the case of an oblate ellipsoid, the main surface is the cross section with the largest area, as shown in FIG. 8(c). In the case of an oblate ellipsoid, the first surface 2a is the main surface. In the case of a rectangular parallelepiped, the main surface refers to the surface with the largest area, as shown in FIG. 8(d). In the case of a rectangular parallelepiped, the first surface 2a or the second surface 2b is the main surface. In other words, in the case of a flat particle, it refers to the flat surface, in the case of a ribbon or plate, it refers to the plate surface, and in the case of a thin film or thick film, it refers to the film surface. In the rectangular prism of Fig. 8(a), the cylinder of Fig. 8(b), and the oblate ellipsoid of Fig. 8(c), the surface with the largest area is defined as the first surface 2a. The second surface 2b is defined as the surface opposite to the first surface 2a. The main surface is the first surface 2a or the second surface 2b. When the magnetic material is a flat magnetic metal particle, the main surface is the flat surface of the flat magnetic metal particle.

[0051] Furthermore, it is preferable that the average length within the main surface is greater than the thickness. More preferably, the ratio of the average length within the main surface to the thickness is 5 or greater. This is preferable because it makes it easier to create differences in the magnetic permeability of the magnetic wedges (increasing anisotropy). From the perspective of reducing loss, it is also preferable because it can reduce eddy current loss.

[0052] The average length within the main surface is defined as (a+b) / 2, where a is the maximum length and b is the minimum length. The maximum length a and minimum length b are determined as follows: Draw a line perpendicular to the tangent at each point on the contour line of the main surface and measure the length to the point where it intersects with the opposite contour line. Do this for all points on the contour line to determine the maximum length a and minimum length b. The thickness t is defined as the length perpendicular to the main surface. Furthermore, the ratio of the average length within the main surface to the thickness is defined as ((a+b) / 2) / t, where a is the maximum length a, minimum length b, and thickness t.

[0053] From the viewpoint of suppressing leakage flux, it is preferable that the magnetic bodies be arranged so that they are approximately perpendicular to the gap surface. While some of the magnetic bodies may not be perpendicular, the definition of "approximately perpendicular" in this embodiment is that the main surfaces of more than half of the magnetic bodies are within a range of ±20° from the plane perpendicular to the gap surface, and it is preferable that "approximately perpendicular" as defined herein is satisfied. More preferably, it is preferable that the main surfaces of more than half of the magnetic bodies are within a range of ±10° from the plane perpendicular to the gap surface. This configuration is preferable because the magnetic permeability of the magnetic wedge is high in the direction perpendicular to the gap surface and low in the direction parallel to the gap surface, thereby suppressing the increase in leakage flux due to the use of the magnetic wedge and fully enjoying the effect of improving the efficiency of the rotating electric machine. Furthermore, it is possible to increase the effective magnetic flux (main magnetic flux) and improve the torque of the rotating electric machine.

[0054] The magnetic permeability in this embodiment refers to the true magnetic permeability, which is not affected by the shape. In other words, it is the true magnetic permeability that is not affected by the demagnetizing field. The effective magnetic permeability changes as the shape changes because the degree of influence of the demagnetizing field changes. However, the true magnetic permeability is the magnetic permeability that eliminates the influence of the demagnetizing field, and can be determined by forming a completely closed magnetic circuit and measuring it. For example, if the sample (magnetic wedge) is ring-shaped, it forms a completely closed magnetic circuit, making it easy to determine the true magnetic permeability. Even if the sample (magnetic wedge) is not ring-shaped, the true magnetic permeability can be determined by forming a closed magnetic circuit using a yoke. By using a yoke, a closed magnetic circuit is formed in each of the three directions, and thus the true magnetic permeability in each of the three directions can be determined. However, it may be difficult to accurately measure the magnetic permeability in the three directions: axial permeability μz, rotational permeability μθ, and radial permeability μr. In such cases, the magnetic permeability may be estimated by measuring the coercive force in the three directions. Generally, coercivity and permeability depend on the magnitude of magnetic anisotropy. When magnetic anisotropy is small, coercivity also becomes small, and conversely, permeability becomes large. Conversely, when magnetic anisotropy is large, coercivity becomes large, and conversely, permeability becomes small. Therefore, coercivity and permeability are correlated via magnetic anisotropy, and the magnitude of permeability can be estimated from the value of coercivity.

[0055] However, care must be taken because even if the coercivity is the same, the magnetic permeability may not be the same. For example, even if the coercivity is the same, if the magnetic material contained in the magnetic wedge has a rod-like shape, the magnetic permeability will be large in the direction parallel to the rod due to the effect of shape magnetic anisotropy, and small in the direction perpendicular to the rod. Also, even if the coercivity is the same, if the magnetic material contained in the magnetic wedge has a flat shape, the magnetic permeability will be large in the direction parallel to the flat surface due to the effect of shape magnetic anisotropy, and small in the direction perpendicular to the flat surface. Based on the above, when determining the relationship between coercivity and magnetic permeability, it is possible to first estimate the magnetic permeability based on the magnitude of coercivity, then observe the shape of the magnetic material contained in the magnetic wedge, estimate the effect of shape magnetic anisotropy from that shape, and comprehensively determine the relationship between magnetic permeability.

[0056] It is preferable to arrange the magnetic material so that the radial permeability μr is higher than the rotational permeability μθ and the axial permeability μz. This is particularly preferable for a radial gap type rotating electric machine. This effect will be explained in detail using FIG. 9. FIG. 9 is a schematic diagram showing the use of a magnetic wedge in a radial gap type rotating electric machine of this embodiment. In a radial gap type rotating electric machine, the magnetic wedge is attached so as to bridge between the iron core teeth arranged at a predetermined interval in the rotational direction, and closes the slot opening extending along the axial direction.

[0057] Therefore, from the viewpoint of reducing leakage flux flowing between the core teeth via the magnetic wedge, it is preferable that the rotational permeability μθ is lower than the radial permeability μr. On the other hand, from the viewpoint of reducing leakage flux flowing from the gap ends to the outside of the core in the axial direction, it is preferable that the axial permeability μz is lower than the radial permeability μr.

[0058] In summary, arranging the magnetic material so that the radial permeability μr is higher than the rotational permeability μθ and the axial permeability μz is preferable because it minimizes the increase in leakage flux. This makes it possible to fully enjoy the effect of improving the efficiency of the rotating electric machine by using magnetic wedges. It is even more preferable that the permeability increases in the order of radial, rotational, and axial (radial permeability μr > rotational permeability μθ > axial permeability μz). If the rotational permeability μθ is greater than the axial permeability μz, the magnetic flux passing from the core teeth through the wedge to the air gap increases, and harmonic loss can be reduced, which is also preferable. In other words, it is possible to further improve the efficiency of the rotating electric machine by using magnetic wedges.

[0059] In Figure 9, the magnetic wedge fills the entire space between the coil and the core surface in the core slot, but it does not necessarily have to fill the entire space. The magnetic wedge may occupy only a portion of the space between the coil and the core surface.

[0060] 9 shows the magnetic wedge 100, coil 230, and core teeth 250. Fig. 9 also shows a schematic representation of the first member 60, second member 70, and third member 80 collectively as the magnetic wedge 100. It is preferable that the first member, second member, and third member all have the above-described magnetic permeability relationship, but it is also preferable that any one or any two of them have the above-described magnetic permeability relationship.

[0061] It is preferable to arrange the magnetic material so that the axial permeability μz is higher than the rotational permeability μθ and the radial permeability μr. This is particularly preferable in the case of an axial gap type rotating electric machine. This effect will be explained in detail using FIG. 10. FIG. 10 is a schematic diagram showing the use of a magnetic wedge in an axial gap type rotating electric machine. In an axial gap type rotating electric machine, the magnetic wedge is attached so as to bridge between the iron core teeth arranged at a predetermined interval in the rotational direction, and closes the slot opening extending along the radial direction.

[0062] 10 shows the magnetic wedge 100, the coil 230, and the core teeth 250. In FIG. 10, the first member 60, the second member 70, and the third member 80 are collectively shown as the magnetic wedge 100.

[0063] Therefore, from the viewpoint of reducing the leakage flux flowing between the core teeth via the magnetic wedge, it is preferable that the rotational permeability μθ is lower than the axial permeability μz. On the other hand, from the viewpoint of reducing the leakage flux flowing from the gap end to the radial outside of the core, it is preferable that the radial permeability μr is lower than the axial permeability μz.

[0064] In summary, arranging the magnetic body so that the axial permeability μz is higher than the rotational permeability μθ and the radial permeability μr is preferable because it minimizes the increase in leakage flux. This makes it possible to fully enjoy the effect of improving the efficiency of the rotating electric machine by using magnetic wedges. It is even more preferable that the permeability increases in the axial, rotational, and radial directions (axial permeability μz > rotational permeability μθ > radial permeability μr). If the rotational permeability μθ is greater than the radial permeability μr, the magnetic flux passing from the core teeth through the wedge to the air gap increases, and harmonic loss can be reduced, which is also preferable. In other words, it is possible to further improve the efficiency of the rotating electric machine by using magnetic wedges. It is preferable that all of the first, second and third members have the above-mentioned relationship in magnetic permeability, but it is also preferable that any one or any two of them have the above-mentioned relationship in magnetic permeability.

[0065] In order to reduce the leakage magnetic flux flowing through the core teeth via the magnetic wedges, the magnetic bodies are preferably arranged so that their main surfaces are oriented approximately perpendicular to the direction of rotation. This is preferable for both radial gap type rotating electric machines and axial gap type rotating electric machines. This configuration significantly reduces the leakage magnetic flux flowing between the core teeth via the magnetic wedges. This allows the rotating electric machine to fully utilize the improved efficiency achieved by using magnetic wedges.

[0066] It is preferable that the magnetic body has a difference in magnetic permeability depending on the direction in the main plane. More preferably, the direction in which the magnetic permeability of the magnetic body is highest (the direction of the easy axis of magnetization) is aligned in one direction. This configuration is preferable because it makes it easier to create differences in the magnetic permeability of the magnetic wedge (increasing anisotropy). Even more preferably, the direction of the easy axis of magnetization of the magnetic body is aligned in a direction perpendicular to the gap surface. That is, in the case of a radial gap type rotating electric machine, it is preferable that the direction of the easy axis of magnetization of the magnetic body is aligned in the radial direction, and in the case of an axial gap type rotating electric machine, it is preferable that the direction of the easy axis of magnetization of the magnetic body is aligned in the axial direction. This configuration makes it easier for the magnetic wedge to have high magnetic permeability in a direction perpendicular to the gap surface and low anisotropy in a direction parallel to the gap surface. This is preferable because it suppresses the increase in leakage flux due to the use of a magnetic wedge and fully enjoys the effect of improving the efficiency of the rotating electric machine. It also increases the effective magnetic flux (main magnetic flux) and improves the torque of the rotating electric machine.

[0067] The magnetic material preferably includes at least one selected from the group consisting of flat particles, ribbons, thin films, thick films, and plate-like members. Such a configuration facilitates manufacturing, improves manufacturing yield, and reduces manufacturing costs. The magnetic material is particularly preferably a ribbon or plate-like member. This is because manufacturing is facilitated, manufacturing yield is improved, and manufacturing costs can be particularly reduced.

[0068] The magnetic material is preferably flat particles. This configuration makes it possible to reduce eddy current loss generated in the magnetic wedge. This makes it possible to fully enjoy the effect of improving the efficiency of a rotating electric machine by using a magnetic wedge. Furthermore, when manufacturing magnetic wedges with complex shapes, manufacturing is easy because it only requires solidifying powder, which improves manufacturing yield and reduces manufacturing costs.

[0069] The magnetic material preferably contains at least one magnetic element selected from the group consisting of iron (Fe), cobalt (Co), and nickel (Ni), has a thickness of 10 nm to 100 μm, and has a ratio of the average length within the main surface to the thickness of 5 to 10,000. When the magnetic material is a flat particle, it is a flaky particle having a flaky shape.

[0070] The magnetic material contains Fe and Co, and the amount of Co is preferably 10 atomic % or more and 60 atomic % or less, more preferably 10 atomic % or more and 40 atomic % or less, based on the total amount of Fe and Co. This is preferable because it is easy to impart a moderately large magnetic anisotropy. In addition, Fe-Co systems are preferable because they easily achieve high saturation magnetization. Furthermore, by keeping the composition range of Fe and Co within the above range, it is preferable because a higher saturation magnetization can be achieved.

[0071] The magnetic material preferably contains at least one non-magnetic metal selected from the group consisting of Mg, Al, Si, Ca, Zr, Ti, Hf, Zn, Mn, Ba, Sr, Cr, Mo, Ag, Ga, Sc, V, Y, Nb, Pb, Cu, In, Sn, and rare earth elements. This enhances the thermal stability and oxidation resistance of the magnetic material. Among these, Al and Si are particularly preferred because they readily form solid solutions with Fe, Co, and Ni, the main components of the magnetic material, and contribute to improving thermal stability and oxidation resistance.

[0072] The thickness of the magnetic material and the ratio of the average length within the main surface to the thickness can be determined by observing the magnetic material with a transmission electron microscope (TEM) or a scanning electron microscope (SEM), and the average value of 10 or more values ​​is used.

[0073] The thickness of the magnetic material is preferably 10 nm to 100 μm, more preferably 1 μm to 100 μm. Furthermore, the ratio of the average length in the main surface to the thickness is preferably 5 to 10,000, more preferably 10 to 1,000. When multiple magnetic materials are included in the magnetic wedge, the thickness and the ratio of the average length in the main surface to the thickness are determined for each magnetic material, and the average value is preferably within the above range. A thin thickness and a large ratio of the average length in the main surface to the thickness are preferable from the viewpoint of easily reducing eddy current loss, but on the other hand, the coercive force tends to be somewhat large. Therefore, from the viewpoint of reducing coercive force, it is preferable to have a moderate thickness and a moderate ratio of the average length in the main surface to the thickness. A thickness and a ratio of the average length in the main surface to the thickness within the above ranges result in a material that is well-balanced in terms of eddy current loss and low coercive force (enabling low hysteresis loss).

[0074] It is preferable to have an intervening phase between the magnetic particles that contains at least one element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). This increases the electrical resistance of the intervening phase, thereby reducing eddy current loss in the magnetic wedge. From this perspective, it is preferable that the electrical resistance of the intervening phase is higher than that of the magnetic particles. Since the intervening phase surrounds the magnetic particles, it is preferable that the oxidation resistance and thermal stability of the flat particles can be improved. Among these, those containing oxygen are more preferable from the viewpoints of high oxidation resistance and high thermal stability. Since the intervening phase also plays a role in mechanically bonding the magnetic particles together, it is also preferable from the viewpoint of high strength.

[0075] The intervening phase also plays a role in mechanically bonding magnetic materials together, and therefore it is preferable to mix in at least one reinforcing material selected from glass fiber, carbon fiber, silicon carbide fiber, boron fiber, alumina fiber, aramid fiber, PBO fiber, polyarylate fiber, polyethylene fiber, polyolefin fiber, vinylon fiber, polyester fiber, and nylon fiber.

[0076] Furthermore, in the magnetic wedge of this embodiment, by disposing a non-magnetic material inside the magnetic wedge, the magnetic permeability in the rotational direction can be reduced, and the leakage magnetic flux flowing between the iron core teeth via the magnetic wedge can be further reduced.

[0077] Furthermore, the mechanical strength of the magnetic wedge of this embodiment can be further increased by covering the surface of the magnetic wedge with a resin. In this case, the resin is not particularly limited, but examples include polyester resin, polyethylene resin, polystyrene resin, polyvinyl chloride resin, polyvinyl butyral resin, polyvinyl alcohol resin, polybutadiene resin, Teflon resin, polyurethane resin, cellulose resin, ABS resin, nitrile-butadiene rubber, styrene-butadiene rubber, silicone resin, other synthetic rubber, natural rubber, epoxy resin, phenol resin, allyl resin, polybenzimidazole resin, amide resin, polyimide resin, polyamide-imide resin, and copolymers thereof. In particular, silicone resin and polyimide resin, which have high heat resistance, are preferably used.

[0078] Next, the effects of this embodiment will be described.

[0079] FIG. 11 is a diagram illustrating the effects of this embodiment. The graph shown on the left side of FIG. 11 is a graph of an example in which the second member 70 is arranged on the gap side. In other words, the graph shown on the left side of FIG. 11 is a graph of an example in which the second member 70 is arranged between the first member 60 and the gap surface 240. The graph shown on the right side of FIG. 11 is a graph of a comparative example in which the first member (sintered portion) 60 is arranged on the gap side. In other words, the graph shown on the right side of FIG. 11 is a graph of a comparative example in which the first member 60 is arranged between the second member 70 and the gap surface 240. In both graphs, the horizontal axis represents the thickness of the first member 60. Thickness The ratio is changed from 0 (when the entire magnetic wedge 100 is made of the second member 70) to 1 (when the entire magnetic wedge 100 is made of the first member 60).

[0080] Here, the second member 70 has a higher electrical resistivity than the first member 60, a lower bending strength than the first member 60, and a lower saturation magnetization than the first member 60. Specifically, the first member 60 has a magnetization of 1.86 T, a relative magnetic permeability of 500, and an electrical resistivity of 10 -7 The second member 70 has a magnetization of 1 T, a relative magnetic permeability of 120, and an electrical resistivity of 10 -3 The tensile strength is 90 Ωm and the bending strength is 90 MPa. The proportion of the magnetic metal phase is 50 Vol%.

[0081] First, in the embodiment (where the second member 70 is disposed on the air gap side), the "harmonic magnetic flux" which is important from the viewpoint of high efficiency is Thickness is the magnetic wedge Thickness In addition, when the eddy current loss of the magnetic wedge is 20% or more of the above, it is sufficiently small and favorable results are obtained. Thickness is the magnetic wedge Thickness When the eddy current loss is 70% or less of the above, the eddy current loss is sufficiently small and favorable results are obtained. From the viewpoint of high efficiency, it is necessary to reduce both the "harmonic magnetic flux" and the "eddy current loss of the magnetic wedge". Thickness The magnetic wedge Thickness On the other hand, it was found that the "load capacity of the magnetic wedge" which is important from the viewpoint of high reliability, Thickness When the ratio is 30% or more, the load capacity is sufficiently high and preferable characteristics are obtained. From the above, in order to achieve both high efficiency and high reliability (achieving both low loss and high load capacity), the first member 60 Thickness The magnetic wedge Thickness It was found that the required level was between 30% and 70%.

[0082] On the other hand, in the comparative example (where the first member 60 is disposed on the air gap side), the "harmonic magnetic flux" which is important from the viewpoint of high efficiency is Thickness is the magnetic wedge ThicknessIn addition, when the eddy current loss of the magnetic wedge is about 5% or more of the eddy current loss of the first member 60, which is important from the viewpoint of high efficiency, Thickness is the magnetic wedge Thickness When the eddy current loss is less than about 5% of the eddy current loss, the eddy current loss is sufficiently small and favorable results are obtained. From the viewpoint of high efficiency, it is necessary to reduce both the "harmonic magnetic flux" and the "eddy current loss of the magnetic wedge", but it was found that it is difficult to reduce both at the same time. In the comparative example, the first member 60 is arranged on the air gap side, and the eddy current loss of the first member 60 is smaller than that of the example. Thickness Although it is easy to reduce the harmonic magnetic flux even if the magnetic resistance is small, the electrical resistivity is low and the eddy current loss increases dramatically, which has a large effect, and it was found that it is difficult to effectively reduce both the "harmonic magnetic flux" and the "eddy current loss of the magnetic wedge" at the same time. Thickness is 30% or more, the withstand load becomes sufficiently high, which is the same as in the example. From the above, it was found that in the comparative example, unlike the example, it is difficult to achieve both high efficiency and high reliability (to achieve both low loss and high withstand load).

[0083] From the above, it is preferable that the magnetic wedge 100 has the first member 60 and the second member 70 provided between the first member 60 and the gap surface 240. It is also preferable that the electrical resistivity of the second member 70 is higher than that of the first member 60, the bending strength of the first member 60 is higher than that of the second member 70, and the saturation magnetization of the first member 60 is higher than that of the second member 70. It is also preferable that the magnetic resistance of the first member 60 in the direction perpendicular to the gap surface 240 is higher than that of the second member 70. Thickness is the magnetic wedge 100 in the direction perpendicular to the gap surface 240 Thickness It is preferable that the ratio is 30% or more and 70% or less.

[0084] The electrical resistivity of the first member 60 is 10 -8 Ωm or more 10 -4 The electrical resistivity of the second member 70 is less than 10 -4The resistivity is Ωm or more, and the bending strength of the first member 60 is preferably 200 MPa or more, more preferably 300 MPa or more, and even more preferably 500 MPa or more. The saturation magnetization of the first member 60 is preferably 1.7 T or more, and more preferably 1.8 T or more. This makes it possible to obtain a magnetic wedge with low loss and high strength.

[0085] The ratio of the first magnetic metal phase to the first member 60 is preferably greater than the ratio of the second magnetic metal phase to the second member 60. This is because the above electrical resistivity, bending strength, and saturation magnetization can be easily satisfied.

[0086] It is preferable that the first member 60 is a sintered portion made of a sintered material, and the second member 70 is a compacted portion made of a compacted powder material, because the above electrical resistivity, bending strength, and saturation magnetization can be easily satisfied.

[0087] According to the magnetic wedge of this embodiment, it is possible to obtain a magnetic wedge with low loss and high strength.

[0088] (Second embodiment) The rotating electric machine of this embodiment is characterized by including the magnetic wedge of the first embodiment. Therefore, description of the same content as in the first embodiment will be omitted. In this specification, the rotating electric machine is a concept that includes all of an electric motor (motor), a generator (generator), and a motor-generator that functions as both a motor and a generator as needed.

[0089] The radial gap motor of this embodiment is characterized by having a magnetic wedge in which a magnetic body having a main surface is arranged so that the main surface is approximately perpendicular to the gap surface, and which has differences in magnetic permeability in three directions: axial permeability, rotational permeability, and radial permeability.

[0090] FIG. 12 is a schematic diagram showing an example of a radial gap type rotating electric machine according to this embodiment. FIG. 12 shows an example of a radial gap type motor according to this embodiment. The radial gap type rotating electric machine has a rotor and a stator disposed radially opposite the rotor with a predetermined gap therebetween. In FIG. 12, the rotor is disposed inside the stator, but it may be disposed outside. The rotor includes a rotor core and a shaft and is supported for rotation. Meanwhile, the stator includes a stator core, field coils inserted into slots in the stator core, and magnetic wedges held in wedge grooves at the slot openings. FIG. 12 shows, as an example, a case in which the magnetic wedges are disposed so that the radial permeability μr is higher than the rotational permeability μθ and the axial permeability μz, but this is not limiting.

[0091] In this way, by creating differences in the magnetic permeability in the three directions of the magnetic wedge (axial permeability μz, rotational permeability μθ, and radial permeability μr), it is possible to reduce harmonic loss that occurs on the rotor surface while suppressing an increase in leakage flux. Furthermore, because the magnetic flux passing through the air gap increases, the torque of the radial gap motor is increased. High efficiency can be achieved by either or both of the above loss reduction effect and torque increase effect.

[0092] The material of the iron core may be any of a laminated core made of magnetic thin plates, a powder core made by compressing and molding magnetic particles, a ferrite core, and the like.

[0093] In particular, in radial gap motors that use laminated cores made of magnetic thin plates, it is particularly preferable to arrange the main surfaces of the magnetic material contained in the magnetic wedge parallel to the main surfaces of the magnetic thin plates that form the laminated core, as this reduces eddy current loss.

[0094] Furthermore, the radial gap motor may be one having a conductor in the rotor (induction motor), one having a permanent magnet (permanent magnet motor), or one having a magnetic material (reluctance motor).

[0095] The axial gap motor of this embodiment is characterized by having a magnetic wedge in which a magnetic body having a main surface is arranged so that the main surface is approximately perpendicular to the gap surface, and which has differences in magnetic permeability in three directions: axial permeability, rotational permeability, and radial permeability.

[0096] FIG. 13 is a schematic diagram showing an example of an axial gap rotating electric machine according to this embodiment. FIG. 13 shows an example of an axial gap motor according to this embodiment. The axial gap motor has a rotor and a stator arranged opposite the rotor across a predetermined air gap in the axial direction. The stator includes a stator core, field coils inserted into slots in the stator core, and magnetic wedges held in wedge grooves at the slot openings. FIG. 13 shows an example in which the magnetic wedges are arranged so that their axial permeability μz is higher than their radial permeability μr and rotational permeability μθ. However, this is not limiting. By providing differences in the three-directional permeability μz, rotational permeability μθ, and radial permeability μr in the magnetic wedges, it is possible to reduce harmonic loss generated on the rotor surface while suppressing an increase in leakage magnetic flux. Furthermore, the increased magnetic flux passing through the air gap increases the torque of the axial gap motor. As a result, high efficiency can be achieved.

[0097] In FIG. 13, the rotor is disposed between two stators, but it may be disposed on one side or both sides of one stator.

[0098] The iron core material may be any of a laminated core made of magnetic thin plates, a powder core made by compressing magnetic particles, a ferrite core, etc. In particular, in an axial gap type motor using a laminated core made of magnetic thin plates, it is particularly preferable to arrange the main surfaces of the magnetic material contained in the magnetic wedge parallel to the main surfaces of the magnetic thin plates that form the laminated core, as this reduces eddy current loss.

[0099] The generator of this embodiment is characterized by having a magnetic wedge in which a magnetic body having a main surface is arranged so that the main surface is approximately perpendicular to the gap surface, and which has a difference in magnetic permeability in three directions: axial, rotational, and radial.

[0100] FIG. 14 is a schematic diagram showing an example of a generator according to this embodiment. A generator typically includes a rotor with excitation coils housed in slots in the rotor core (although a rotor using permanent magnets as an excitation source may also be used) and a stator with armature coils housed in slots in the stator core. By rotating the rotor and passing an excitation current through the excitation coils, electric power is generated in the armature coils. The rotor includes a rotor core, field coils inserted into the slots in the rotor core, and magnetic wedges held in wedge grooves at the slot openings, and is supported for rotation by bearings. FIG. 14 shows, as an example, a case in which the magnetic wedges are arranged so that their radial permeability μr is higher than their rotational permeability μθ and axial permeability μz, but this is not limiting.

[0101] In this way, by creating differences in the magnetic permeability in the three directions of the magnetic wedge (axial permeability μz, rotational permeability μθ, and radial permeability μr), it is possible to reduce harmonic loss that occurs on the surface of the stator while suppressing an increase in leakage flux. In addition, the magnetic flux that passes through the air gap and interlinks with the armature coil increases, thereby increasing the generated voltage induced in the armature coil. As a result, high efficiency can be achieved.

[0102] In Figure 14, magnetic wedges are placed at the slot openings of the rotor core, but they may also be placed at the slot openings of the stator core. Also, while the figure shows a wound-type generator with an excitation coil in the rotor, a permanent magnet generator with a permanent magnet in the rotor may also be used. In this case, the magnetic wedges are placed at the slot openings of the stator core.

[0103] The iron core may be made of any material, such as a laminated core made of magnetic thin plates, a powder core made by compressing magnetic particles, a ferrite core, etc. In particular, in a generator using a laminated core made of magnetic thin plates, it is particularly preferable to arrange the main surfaces of the magnetic material contained in the magnetic wedge and the main surfaces of the magnetic thin plates that form the laminated core in parallel, as this reduces eddy current loss.

[0104] Since a linear motor is a flat-plate structure developed from a radial gap motor, the magnetic wedge of the present invention can also be applied to a linear motor. That is, the stator may include a stator core and a field coil inserted into slots in the stator core, with a magnetic wedge provided at the slot opening. Figure 15 is a schematic diagram showing an example of a linear motor of this embodiment. In a linear motor, the moving direction of the mover, the direction perpendicular to the moving direction of the mover, and the direction perpendicular to the stator correspond to the rotational direction, axial direction, and radial direction of a radial gap motor, respectively.

[0105] In this case, as shown in FIG. 15, it is preferable that the magnetic characteristics of the magnetic wedge have differences in three directions: magnetic permeability μz in the direction perpendicular to the stator, magnetic permeability μx in the moving direction of the mover, and magnetic permeability μy in the direction perpendicular to the moving direction. In FIG. 15, the magnetic wedge is arranged so that the magnetic permeability μz in the direction perpendicular to the stator is higher than the magnetic permeability μx in the moving direction of the mover and the magnetic permeability μy in the direction perpendicular to the moving direction, but this is not limited to this. This makes it possible to reduce harmonic loss occurring on the surface of the mover while suppressing an increase in leakage flux. Furthermore, since the magnetic flux passing through the air gap increases, the thrust of the linear motor is improved. As a result, high efficiency can be achieved. FIG. 15 shows a mover 290.

[0106] According to the rotating electric machine of this embodiment, the increase in leakage flux due to the use of magnetic wedges can be suppressed, and pulsation of the magnetic flux distribution on the surface of the iron core can be effectively alleviated, thereby achieving high efficiency.

[0107] The slot shape of the rotating electrical machine of this embodiment may be a semi-closed slot, but is preferably an open slot, which is preferable because it can significantly reduce harmonic loss.

[0108] The rotating electric machine of this embodiment can be applied to transportation systems such as railways, electric vehicles, and hybrid cars; social systems such as elevators and air conditioners; industrial systems such as robots, pumps, compressors, and fans; energy systems such as thermal power generators, hydroelectric generators, wind power generators, nuclear power generators, and geothermal power generators; and home appliances such as washing machines, thereby enabling high system efficiency. In particular, large-capacity industrial machines generally employ open slots, and therefore are preferably provided with the magnetic wedge of the first embodiment. Furthermore, traction motors for railways use form-wound coils due to the need to withstand high voltages and vibrations, and therefore employ open slots, and therefore are preferably provided with the magnetic wedge of the first embodiment.

[0109] In particular, in railways, the loss in the rotating electrical machine accounts for about half of the power consumed when the train is running, so reducing the loss in the rotating electrical machine has a significant effect on improving efficiency. Also, in electric vehicles and hybrid cars, the efficiency of the main motor can be improved by using the magnetic wedge of the first embodiment, thereby extending the cruising range.

[0110] Although several embodiments and examples of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments and examples can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments, examples, and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

[0111] The above-described embodiments can be summarized as the following technical proposals. Technical proposal 1 A magnetic wedge used in a rotating electric machine in which a stator and a rotor face each other via an air gap surface, The magnetic wedge is A first member; a second member provided between the first member and the gap surface, the first member has a first magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni; A magnetic wedge, wherein the second member has a second magnetic metal phase containing at least one second element selected from the group consisting of Fe, Co, and Ni, and the ratio of the first magnetic metal phase to the first member is greater than the ratio of the second magnetic metal phase to the second member. Technical proposal 2 A magnetic wedge according to Technical Solution 1, wherein the second member has a higher electrical resistivity than the first member, and the first member has a higher bending strength and a higher saturation magnetization than the second member. Technical proposal 3 The electrical resistivity of the first member is 10 -8 Ωm or more 10 -4 The magnetic wedge according to Technical Scheme 1 or 2, wherein the resistance is less than Ωm. Technical proposal 4 A magnetic wedge according to any one of Technical Schemes 1 to 3, wherein the bending strength of the first member is 200 MPa or more. Technical proposal 5 A magnetic wedge according to any one of Technical Schemes 1 to 4, wherein the saturation magnetization of the first member is 1.7 T or more. Technical plan 6 of the first member in a direction perpendicular to the gap surface Thickness is the magnetic wedge's magnetic field in a direction perpendicular to the gap surface. Thickness The magnetic wedge according to any one of Technical Schemes 1 to 5, wherein the magnetic wedge has a thickness of 30% or more and 70% or less. Technical proposal 7 The magnetic wedge according to any one of Technical Schemes 1 to 6, wherein the first member is a first sintered portion and the second member is a compacted powder portion. Technical proposal 8 the second component comprises a plurality of flat magnetic metal particles and an intervening phase; A magnetic wedge described in any one of Technical Proposals 1 to 7, wherein the flat magnetic metal particles have an average thickness of 10 nm or more and 100 μm or less, have flat surfaces, and the average ratio of the average length within the flat surfaces to the thickness is 5 or more and 10,000 or less, and the intervening phase is present between the flat magnetic metal particles and contains at least one third element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F). Technical proposal 9 A magnetic wedge as described in Technical Solution 8, wherein the flat surface of the second member is oriented parallel to the plane of the second member and has a difference in coercive force depending on the direction within the plane. Technical proposal 10 The magnetic wedge according to any one of Technical Schemes 1 to 9, wherein the first member has precipitated particles containing Ta and C. Technical proposal 11 A rotating electric machine using the magnetic wedge described in any one of Technical Schemes 1 to 10. [Explanation of symbols]

[0112] 2 Magnetic material (flat magnetic metal particles) 2a First side 2b Second side 10 Precipitated particles 20 Intervening phase 60 First sintered portion (first member) 60a First member 60b First member 60c First member 70 Powder compression section (second member) 72 First recess 80 Second sintering section (third member) 82 Second recess 100 magnetic wedge 110 Magnetic wedge 120 Magnetic wedge 200 Rotating Electric Machine 200a radial gap type rotating electric motor 200b Axial gap type rotating electric motor 210 Rotor 220 Stator core 230 coil 240 Void surface 250 Iron Core Teeth 260 Core slot 270 Stator 280 axes 290 Mover RP reference plane

Claims

1. A magnetic wedge used in a rotating electric machine in which a stator and a rotor face each other via an air gap surface, The magnetic wedge is A first member; a second member provided between the first member and the gap surface, the first member has a first magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni; the second member has a second magnetic metal phase containing at least one second element selected from the group consisting of Fe, Co, and Ni; a ratio of the first magnetic metal phase to the first member is greater than a ratio of the second magnetic metal phase to the second member; The first member has a higher bending strength than the second member. magnetic wedge.

2. 2. The magnetic wedge according to claim 1, wherein the second member has a higher electrical resistivity than the first member, and the first member has a higher saturation magnetization than the second member.

3. The electrical resistivity of the first member is 10 －８ Ωm or more 10 －４ 3. The magnetic wedge according to claim 1, wherein the magnetic resistance is less than Ωm.

4. The magnetic wedge according to claim 1 , wherein the first member has a bending strength of 200 MPa or more.

5. 5. The magnetic wedge according to claim 1, wherein the saturation magnetization of the first member is 1.7 T or more.

6. 6. The magnetic wedge according to claim 1, wherein the film thickness of the first member in a direction perpendicular to the gap surface is 30% or more and 70% or less of the film thickness of the magnetic wedge in a direction perpendicular to the gap surface.

7. The magnetic wedge according to claim 1 , wherein the first member is a first sintered portion and the second member is a compacted powder portion.

8. the second component comprises a plurality of flat magnetic metal particles and an intervening phase; A magnetic wedge described in any one of claims 1 to 7, wherein the plurality of flat magnetic metal particles have an average thickness of 10 nm or more and 100 μm or less, have flat surfaces, and the average ratio of the average length within the flat surfaces to the thickness is 5 or more and 10,000 or less, and the intervening phase is present between the plurality of flat magnetic metal particles and contains at least one third element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N) and fluorine (F).

9. The magnetic wedge according to claim 8 , wherein the flat surface of the second member is oriented parallel to a plane of the second member, and the second member has a coercive force that varies depending on the direction in the plane.

10. The magnetic wedge according to claim 1 , wherein the first member has precipitated particles containing Ta and C.

11. The ratio of the first magnetic metal phase to the first member is 90% or more, and the ratio of the second magnetic metal phase to the second member is less than 90%. A magnetic wedge according to any one of claims 1 to 10.

12. The ratio of the first magnetic metal phase to the first member is 95% or more. The magnetic wedge of claim 11.

13. A rotating electric machine using the magnetic wedge according to any one of claims 1 to 12.

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