Magnetic wedges and rotating electric machines

Abstract

To provide a magnetic wedge that combines excellent electromagnetic and mechanical properties. [Solution] The magnetic wedge of the embodiment comprises a first portion including a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, and a second portion provided in contact with the first portion and including a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to magnetic wedges and rotating electric machines. [Background technology]

[0002] Typically, the coil windings of a rotating electric machine are housed within a core slot and supported and fixed by wedges provided at the slot opening. While non-magnetic materials are generally used for these wedges, the discontinuity in the magnetic resistance of the air gap between the stator and rotor cores causes pulsation in the magnetic flux distribution on the core surface facing the wedge across the gap, resulting in increased harmonic losses. To reduce these harmonic losses and improve the efficiency of rotating electric machines, wedges with moderate magnetism (magnetic wedges) have long been available. Figure 1 is a schematic diagram illustrating the use and effects of magnetic wedges. Figure 1 shows a radial gap type rotating electric machine as an example. Figure 1 shows a magnetic wedge 100, a coil 230, core teeth 250, and a core slot 260.

[0003] It goes without saying that the higher the magnetic permeability of the magnetic wedge, the lower the harmonic losses. However, as shown in Figure 1, magnetic wedges are positioned to bridge adjacent core teeth, which has the disadvantage of increasing the leakage flux flowing between the core teeth through the magnetic wedge. On the other hand, considering the direction along the rotor's rotation axis, magnetic wedges are positioned to short-circuit multiple electromagnetic steel sheets used as the core material, which has the disadvantage of increasing the possibility of short-circuit current flow. To compensate for these shortcomings, composite materials consisting of magnetic particles (mainly magnetic metal particles) and intervening phases are generally used for magnetic wedges. However, many of these have low saturation magnetization and are prone to magnetic saturation, and the losses (especially hysteresis losses due to coercivity) are large, so the improvement in the efficiency of rotating electric machines is limited. In addition, the mechanical properties (strength, etc.) are inferior to wedges made of non-magnetic materials, raising concerns about the impact on reliability. Thus, it has not yet been achieved to achieve both the electromagnetic and mechanical properties required for magnetic wedges. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Utility Model Publication No. 58-6572 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The problem that this invention aims to solve is to provide a magnetic wedge having excellent electromagnetic and mechanical properties, and a rotating electric machine equipped therewith. [Means for solving the problem]

[0006] The magnetic wedge of the embodiment comprises a first portion including a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, and a second portion provided in contact with the first portion and including a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram illustrating the usage and effects of magnetic wedges. [Figure 2] This is a schematic diagram of the external appearance of the magnetic wedge according to the first embodiment. [Figure 3] This is a schematic partial cross-sectional view of the magnetic wedge according to the first embodiment. [Figure 4] This is a conceptual diagram illustrating how to determine the orientation angle of the second flattened magnetic metal particle in the first embodiment. [Figure 5] This is a conceptual diagram illustrating how to determine the orientation angle of the second flattened magnetic metal particle in the first embodiment. [Figure 6] This is a conceptual diagram illustrating how to determine the orientation angle of the second flattened magnetic metal particle in the first embodiment. [Figure 7]In the first embodiment, it is a conceptual diagram showing an example of a method for obtaining the thickness of flat magnetic metal particles. [Figure 8] In the first embodiment, it is a conceptual diagram for explaining a method for obtaining the maximum length and minimum length within the flat plane of flat magnetic metal particles. [Figure 9] In the first embodiment, it is a conceptual diagram for explaining a method for obtaining the maximum length and minimum length within the flat plane of flat magnetic metal particles in another example. [Figure 10] In the first embodiment, it is a schematic diagram showing the directions when measuring the coercive force while changing the direction every 22.5 degrees with respect to the 360 - degree angle within the flat plane of flat magnetic metal particles. [Figure 11] It is a schematic diagram of flat magnetic metal particles of the first embodiment. [Figure 12] It is an example of a microscope photograph of a fiber aggregate (glass fiber mat) in which a plurality of glass fiber bundles are formed into a mat shape. [Figure 13] In the first embodiment, it is a graph showing the relationship between the weight of fibers contained per 100 cm2 of the second part and the bending strength. [Figure 14] It is a schematic diagram showing the manufacturing process of the magnetic wedge of the first embodiment. [Figure 15] It is a schematic diagram showing an example of a radial - gap type rotating electric machine of the second embodiment. [Figure 16] It is a schematic diagram showing an example of an axial - gap type rotating electric machine of the second embodiment. [Figure 17] It is a schematic diagram showing an example of a generator of the second embodiment. [Figure 18] It is a schematic diagram showing an example of a linear motor of the second embodiment.

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings. In the drawings, the same or similar parts are denoted by the same or similar reference numerals. In this specification, unless otherwise specified, measurements are made at 25°C.

[0009] In this specification, the "axial direction," "rotational direction," and "radial direction" are defined with respect to the rotor of the rotating electric machine. That is, the "axial direction" means the direction along the rotor's axis of rotation, the "rotational direction" means the circumferential direction (or tangential direction) around the rotor's axis of rotation, and the "radial direction" means the direction perpendicular (perpendicular) to the rotor's axis of rotation.

[0010] (First Embodiment) The magnetic wedge of the embodiment comprises a first portion including a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, and a second portion provided in contact with the first portion and including a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers.

[0011] The magnetic wedge of this embodiment is used, for example, in a rotating electric machine. In other words, the rotating electric machine of this embodiment is equipped with the magnetic wedge of this embodiment.

[0012] Figure 2 is a schematic diagram of the external appearance of the magnetic wedge of this embodiment. As shown in Figure 2, magnetic wedges can be made in various shapes, not just simple rectangular parallelepiped shapes (rectangular cross-sections), but also trapezoidal, hexagonal, and convex shapes. The closer the magnetic wedge is placed to the air gap between the rotor and stator, the more effective it becomes (improving the efficiency of the rotating electric machine). From this viewpoint, trapezoidal, convex, and hexagonal shapes are preferable to rectangular shapes. Also, from the viewpoint of "a shape that easily draws magnetic flux towards the magnetic wedge (which improves the efficiency of the rotating electric machine)," trapezoidal and convex shapes are preferable to hexagonal shapes. On the other hand, from the viewpoint of ease of manufacture and high reliability as a material (mechanical properties, thermal properties), the rectangular shape is the most preferred, followed by the trapezoidal and hexagonal shapes. In that sense, the trapezoidal shape is very preferable because it is easy to position close to the air gap between the rotor and stator, the trapezoidal shape makes it easier to draw magnetic flux towards the magnetic wedge, and furthermore, it is easy to manufacture and the reliability of the material (mechanical properties, thermal properties) is easily improved.

[0013] Regardless of the shape, three axial directions that intersect each other orthogonally or perpendicularly are defined as the width direction, thickness direction, and longitudinal direction. The longitudinal direction of a magnetic wedge is the direction in which the length of the magnetic wedge is longer. For example, if the shape of the magnetic wedge in question is approximately a rectangular parallelepiped, the direction along the longest side of this approximately rectangular parallelepiped shape is determined as the longitudinal direction of the magnetic wedge. The thickness direction and width direction of a magnetic wedge are directions perpendicular to the longitudinal direction of the magnetic wedge. The thickness direction and width direction of a magnetic wedge can be distinguished as follows: If the magnetic wedge in question is installed inside a rotating electric machine, the magnetic wedge is removed from inside the rotating electric machine. Here, the direction of rotation of the rotating electric machine becomes the width direction of the magnetic wedge. The thickness direction is perpendicular to the width direction. On the other hand, if the magnetic wedge in question is not installed inside a rotating electric machine, the width direction is the direction closest to the average orientation direction of the flattened magnetic metal particles at the center of the cross-section perpendicular to the longitudinal direction. The thickness direction is perpendicular to the width direction. Note that the end face of the magnetic wedge in question should be avoided for the cross-section perpendicular to the longitudinal direction. For such cross-sections, the magnetic wedge is cut perpendicular to its longitudinal direction so that the length of the cross-section is at least one-tenth of the longitudinal length of the magnetic wedge. Furthermore, for both magnetic wedges extracted from rotating electric machines and magnetic wedges not installed on rotating electric machines, the central part of the cross-section formed by cutting is, for example, a region containing as many flattened magnetic metal particles as possible at the geometric center of the cross-section. Next, regarding the average orientation direction of the flattened magnetic metal particles, it is possible to observe the flattened magnetic metal particles within the cross-section formed by cutting in the target magnetic wedge using an optical microscope, scanning electron microscope (SEM), or transmission electron microscope (TEM), and measure the orientation direction by the direction of the longer side of the rectangle with the smallest area among the rectangles circumscribing each flattened magnetic metal particle. However, some flattened magnetic metal particles may have unclear contours during observation, making evaluation difficult. In other words, there are cases where the contour of the particle cannot be clearly identified by image analysis, and in such cases, it is excluded from observation.

[0014] Figure 3 is a schematic partial cross-sectional view of the magnetic wedge according to the first embodiment.

[0015] The central part of the cross-section is composed of a first part 12. The first part 12 includes a plurality of first flattened magnetic metal particles 10a and a first resin 16a provided between the plurality of first flattened magnetic metal particles 10a. The second part 14 is provided in contact with the first part 12 and includes a plurality of fibers 18, a plurality of second flattened magnetic metal particles 10b provided between the plurality of fibers 18 and a second resin 16b provided between the plurality of fibers 18. By combining flattened magnetic metal particles, resin, and fibers in this way, excellent electromagnetic and mechanical properties can be achieved simultaneously. Here, the planes of the magnetic wedge refer to, for example, the planes provided on the surface of the magnetic wedge shown in Figure 2.

[0016] Furthermore, the second part 14 does not need to be in direct contact with the first part 12; it may be in indirect contact via the fibers 18 or the intervening phase.

[0017] In this embodiment, the magnetic wedge has a number density of a plurality of second flattened magnetic metal particles 10b in the second portion 14 that is lower than the number density of a plurality of first flattened magnetic metal particles 10a in the first portion 12. From the viewpoint of easily obtaining the electromagnetic and mechanical properties required for a magnetic wedge, it is preferable that there be 1 to 1000 second flattened magnetic metal particles 10b in any cross-section, more preferably 2 to 1000, even more preferably 2 to 100, particularly preferably 2 to 50, and especially preferably 10 to 50. In order to contain the above number of second flattened magnetic metal particles 10b, it is preferable that the thickness of the second portion 14 is equal to or greater than the average thickness of the second flattened magnetic metal particles.

[0018] Furthermore, the second flattened magnetic metal particle 10b is oriented along the nearby first flattened magnetic metal particle 10a. Here, "nearby" means the range that is geographically close to the target second flattened magnetic metal particle 10b, and usually includes a range that includes up to 10 first flattened magnetic metal particles 10 centered on the second flattened magnetic metal particle 10b. More specifically, for example, the second flattened magnetic metal particle 10b is oriented along 10 first flattened magnetic metal particles 10a that are geographically close to the second flattened magnetic metal particle 10b. The orientation angle of the second flattened magnetic metal particle 10b is preferably 30 degrees or less, more preferably 20 degrees or less, and even more preferably 10 degrees or less with respect to the average orientation direction of the nearby first flattened magnetic metal particles 10a. These conditions allow the magnetic flux to flow smoothly through the magnetic wedge. Figures 4, 5, and 6 are conceptual diagrams illustrating how to determine the orientation angle of the second flattened magnetic metal particle 10b in the first embodiment. Ten first flattened magnetic metal particles 10a are selected from the second flattened magnetic metal particle 10b, starting with those closest in distance from their centers of gravity, and are shown in the figures with labels (numbers) from 1 to 10. The inclination of the orientation direction of the second flattened magnetic metal particle 10b is measured relative to the orientation direction of each selected first flattened magnetic metal particle 10a, and the average value is adopted as the orientation angle of the second flattened magnetic metal particle 10b. Here, if any obvious abnormalities are found among the selected first flattened magnetic metal particles 10a, they may be excluded from the measurement. Obvious abnormalities include, for example, bending or orientation disorder. In the cross-section shown in Figure 6, the first flattened magnetic metal particle 10a labeled 5 represents an example of a first flattened magnetic metal particle 10a that clearly deviates from the surrounding orientation characteristics due to a localized anomaly, and such particles are excluded from the measurement. The centroid and orientation direction of the flattened magnetic metal particle 10 can be determined in the same manner as described above, by image analysis of optical microscope, SEM, or TEM images.

[0019] From the viewpoint of making the orientation angle of the second flattened magnetic metal particles 10b 30 degrees or less, the thickness of the second portion 14 is preferably 5 μm or more and 2 mm or less, more preferably 10 μm or more and 1 mm or less, and even more preferably 50 μm or more and 500 μm or less.

[0020] Furthermore, in this embodiment, the magnetic wedge has a higher number density of the multiple second flattened magnetic metal particles 10b in the second portion 14 in the region closer to the first portion 12 than in the region further away from the first portion 12. In other words, in this embodiment, the magnetic wedge has a lower number density of the multiple second flattened magnetic metal particles 10b in the second portion 14 in the region further away from the first portion 12 than in the region closer to the first portion 12. This improves the surface electrical resistance, resulting in a magnetic wedge that is less likely to electrically short-circuit the multiple electromagnetic steel sheets forming the core when used in a rotating electric machine.

[0021] Here, a flattened magnetic metal particle is a flattened particle with a flaky or flattened shape.

[0022] The average thickness of the flattened magnetic metal particles is preferably 10 nm to 100 μm. More preferably 10 nm to 1 μm, and even more preferably 10 nm to 100 nm. This is preferable because it allows for sufficiently small eddy current losses when a magnetic field is applied in a direction parallel to the flattened plane. Furthermore, a smaller thickness is preferable because the magnetic moment is confined in a direction parallel to the flattened plane, making it easier for magnetization to proceed through rotational magnetization. When magnetization proceeds through rotational magnetization, the magnetization tends to proceed reversibly, resulting in a smaller coercivity, which is preferable because it reduces hysteresis losses. Average thickness refers to the average value of the thicknesses of multiple flattened magnetic metal particles and is distinct from mere "thickness". When determining the average thickness, it is preferable to use the average value obtained over 20 or more flattened magnetic metal particles. It is preferable to determine the average thickness from as many flattened magnetic metal particles as possible in order to obtain average information. Furthermore, if it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and adopt the average value obtained from them.

[0023] Note that the thickness of a flattened magnetic metal particle refers to the average thickness of a single flattened magnetic metal particle. Any method that can determine the average thickness of a single flattened magnetic metal particle is acceptable. For example, one may observe a cross-section perpendicular to the flattened plane of the flattened magnetic metal particle using a TEM, SEM, or optical microscope, select 10 or more arbitrary locations in the direction within the flattened plane of the observed cross-section, measure the thickness at each selected location, and use the average value. Alternatively, one may select 10 or more locations at equal intervals in the direction within the flattened plane of the observed cross-section of the flattened magnetic metal particle (in this case, it is preferable not to select the ends and other ends as they are special locations), measure the thickness at each selected location, and use the average value. Figure 7 is a conceptual diagram showing an example of how to determine the thickness of a flattened magnetic metal particle in the first embodiment. Figure 7 specifically shows how to determine the thickness in this case. Select 10 points (excluding the ends) at equal intervals in the direction from one end to the other within the flattened plane, and define the thickness at each point as t1, t2, ..., t 10 In this case, the thickness of the flattened magnetic metal particles is (t1 + t2 + ... + t 10 ) / 10. It is preferable to measure as many points as possible during measurement, as this allows for obtaining average information. Furthermore, if the cross-sectional contour is highly irregular or the surface contour is rough, making it difficult to determine the average thickness in its current state, it is preferable to smooth the contour with an average straight line or curve, as appropriate depending on the situation, before performing the above method.

[0024] Furthermore, in multiple flattened magnetic metal particles, the average length of the flattened surface is preferably 100 μm or more and 500 μm or less. The average length is defined as (a+b) / 2, using the maximum length a and minimum length b within the flattened surface of the flattened magnetic metal particle. The maximum length a and minimum length b can be determined as follows. For example, consider the rectangle with the smallest area among the rectangles circumscribing the flattened surface. Then, the length of the longer side of that rectangle is taken as the maximum length a, and the length of the shorter side is taken as the minimum length b. Figure 8 is a conceptual diagram illustrating how to determine the maximum and minimum lengths within the flattened surface of a flattened magnetic metal particle in the first embodiment. Figure 8 is a schematic diagram showing the maximum length a and minimum length b determined by the above method, using several flattened magnetic metal particles as examples. The maximum length a and minimum length b, like the average thickness, can be determined by observing the flattened magnetic metal particle with a TEM, SEM, or optical microscope. It is also possible to determine the maximum length a and minimum length b by performing image analysis of a microscope image on a computer. In all cases, it is preferable to determine the values ​​from 20 or more flattened magnetic metal particles. Furthermore, it is preferable to determine the values ​​from as many flattened magnetic metal particles as possible in order to obtain average information. If it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and adopt the average value obtained from them. Furthermore, since it is preferable to obtain the average value as much as possible, it is preferable to perform observation or image analysis with the flattened magnetic metal particles in a uniformly dispersed state (a state in which multiple flattened magnetic metal particles with different maximum and minimum lengths are dispersed as randomly as possible). For example, it is preferable to perform observation or image analysis by thoroughly mixing multiple flattened magnetic metal particles and sticking them onto a tape, or by dropping multiple flattened magnetic metal particles from above and sticking them onto a tape.

[0025] However, depending on the type of flattened magnetic metal particle, the method used to determine the maximum length a and minimum length b may not capture the essence of the particle. Figure 9 is a conceptual diagram illustrating another example of how to determine the maximum and minimum lengths of a flattened magnetic metal particle within a flattened plane in the first embodiment. For example, in the case shown in Figure 9, the flattened magnetic metal particle is elongated and curved, but in this case, the maximum and minimum lengths of the flattened magnetic metal particle are essentially the lengths a and b shown in Figure 9. Thus, the method for determining the maximum length a and minimum length b is not entirely unique, and basically, it is acceptable to "consider the rectangle with the smallest area among the rectangles circumscribing the flattened plane, and set the length of the longer side of that rectangle as the maximum length a and the length of the shorter side as the minimum length b." However, depending on the shape of the particle, if this method does not capture the essence, the maximum length a and minimum length b should be determined flexibly to capture the essence. Note that the thickness t is defined as the length perpendicular to the flattened plane. The ratio A of the average length within a flattened plane to its thickness is defined as A = ((a+b) / 2) / t, where a is the maximum length, b is the minimum length, and t is the thickness.

[0026] The average value of the ratio of the average length within the flattened plane to the thickness of the flattened magnetic metal particles is preferably between 2 and 10000. This is because it increases the magnetic permeability. It also allows for a higher ferromagnetic resonance frequency, thereby reducing ferromagnetic resonance loss. The average value of the ratio of the average length within the flattened plane to the thickness is used. Preferably, the average value obtained over 20 or more flattened magnetic metal particles is used. It is also preferable to obtain average information by examining as many flattened magnetic metal particles as possible. If it is not possible to observe 20 or more flattened magnetic metal particles, it is preferable to observe as many flattened magnetic metal particles as possible and use the average value obtained over them. For example, if there are particles Pa, Pb, and Pc, and their respective thicknesses are Ta, Tb, and Tc, and their average lengths within the flattened plane are La, Lb, and Lc, then the average thickness is calculated as (Ta + Tb + Tc) / 3, and the average value of the ratio of the average length within the flattened plane to the thickness is calculated as (La / Ta + Lb / Tb + Lc / Tc) / 3.

[0027] The ratio of the maximum length a to the minimum length b within the flattened plane, a / b, is preferably between 1.1 and 10. This improves the fluidity and packing properties of the particles, making it easier to obtain high-strength magnetic wedges.

[0028] It is preferable that the flattened magnetic metal particles have a difference in coercivity depending on the direction within the flattened plane. The larger the percentage of the difference in coercivity depending on the direction, the better, preferably 1% or more. More preferably, the percentage of the difference in coercivity is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. The percentage of the difference in coercivity referred to here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), using the maximum coercivity Hc(max) and minimum coercivity Hc(min) within the flattened plane. The coercivity can be evaluated using a vibrating sample magnetometer (VSM) or the like. If the coercivity is low, it is possible to measure coercivity of 0.1Oe or less by using a low magnetic field unit. Measurement is performed by changing the direction within the flattened plane with respect to the direction of the measurement magnetic field.

[0029] "Having a coercivity difference" means that when a magnetic field is applied in all 360 degrees within a flattened plane and the coercivity is measured, there is a direction in which the coercivity is maximum and a direction in which the coercivity is minimum. For example, when measuring the coercivity by changing the direction every 22.5 degrees within a 360-degree angle within a flattened plane, a coercivity difference appears; that is, there is an angle in which the coercivity is greater and an angle in which the coercivity is smaller. In this case, it is said that "a coercivity difference exists." Figure 10 is a schematic diagram showing the directions in the first embodiment when measuring the coercivity by changing the direction every 22.5 degrees within a 360-degree angle within the flattened plane of a flattened magnetic metal particle. In Figure 10, the flattened plane of the flattened magnetic metal particle is shown as viewed from above. Having a coercivity difference within a flattened plane is preferable because it reduces the minimum coercivity value compared to the isotropic case where there is almost no coercivity difference. In materials exhibiting magnetic anisotropy within a flattened plane, the coercivity differs depending on the direction within the plane, resulting in a smaller minimum coercivity value compared to magnetically isotropic materials. This reduces hysteresis loss and improves permeability, which is desirable. Figure 10 shows flattened magnetic metal particles 10 and a flattened plane 6.

[0030] Furthermore, the flattened magnetic metal particles have a magnetic metal phase containing at least one first element selected from the group consisting of Fe, Co, and Ni. It is preferable to select a composition that can achieve a higher saturation magnetization.

[0031] Elements can be easily analyzed using methods such as EDX (Energy Dispersive X-ray spectroscopy) and ICP (Inductively Coupled Plasma) emission spectroscopy.

[0032] The flattened magnetic metal particles preferably contain 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 flattened magnetic metal particles. Among these, Al and Si are particularly preferred because they readily form solid solutions with Fe, Co, and Ni, which are the main components of the flattened magnetic metal particles, and contribute to improving thermal stability and oxidation resistance.

[0033] Furthermore, in order to induce magnetic anisotropy, there is also a method of making the crystallinity of the flattened magnetic metal particles as amorphous as possible and inducing magnetic anisotropy in one direction in the plane by a magnetic field or strain. In this case, it is desirable to have a composition that makes it easy to make the flattened magnetic metal particles as amorphous as possible. From this viewpoint, it is preferable that the magnetic metal contained in the flattened magnetic metal particles contains at least one additive element selected from B (boron), Si (silicone), Al (aluminum), C (carbon), Ti (titanium), Zr (zirconium), Hf (hafnium), Nb (niobium), Ta (tantalum), Mo (molybdenum), Cr (chromium), Cu (copper), W (tungsten), P (phosphorus), N (nitrogen), Ga (gallium), and Y (yttrium). It is preferable that the additive element has a large difference in atomic radius from at least one first element selected from the group consisting of Fe, Co, and Ni. Furthermore, it is preferable that the additive element is such that the mixed enthalpy of at least one first element selected from the group consisting of Fe, Co, and Ni is negatively large. It is also preferable that the system consists of a total of three or more elements, including the first element and the additive element. In addition, metalloid additive elements such as B and Si are advantageous when mixed into the system because they have a slow crystallization rate and are prone to amorphous formation. From the above viewpoint, B, Si, P, Ti, Zr, Hf, Nb, Y, Cu, etc. are preferred, and it is more preferable that the additive element contains one of B, Si, Zr, Hf, or Y. For example, it is preferable that the magnetic metal phase contains Fe and Co as the first elements and Si and B as the additive elements. Furthermore, it is preferable that the total amount of the additive element is 0.001 at% or more and 80 at% or less relative to the total amount of the first element and the additive element. More preferably, it is 5 at% or more and 80 at% or less, and even more preferably, 10 at% or more and 40 at% or less. While a larger total amount of the aforementioned additive elements is preferable because it promotes amorphization and facilitates the imparting of magnetic anisotropy (i.e., it is preferable from the viewpoint of low loss and high permeability), it is also undesirable because it reduces the proportion of the magnetic metal phase, resulting in a lower saturation magnetization. Therefore, it is important to select the composition and amount of additive elements by considering all factors, including high saturation magnetization, low loss, and high permeability.

[0034] It is preferable that at least a portion of the surface of the flattened magnetic metal particles is covered with a coating layer with a thickness of 0.1 nm to 1 μm.

[0035] Figure 11 is a schematic diagram of flattened magnetic metal particles in the first embodiment. The coating layer 9 and the flattened magnetic metal particles 10 are shown.

[0036] The coating layer preferably contains at least one nonmagnetic 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, and more preferably contains at least one second element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). As nonmagnetic metals, Al and Si are particularly preferred from the viewpoint of thermal stability. If the flattened magnetic metal particles contain at least one nonmagnetic 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, it is more preferable that the coating layer contains at least one of the same nonmagnetic metals as one of the nonmagnetic metal components of the flattened magnetic metal particles. Among oxygen (O), carbon (C), nitrogen (N), and fluorine (F), the coating preferably contains oxygen (O), and is preferably an oxide or a composite oxide. This is from the viewpoint of ease of coating layer formation, oxidation resistance, and thermal stability. As a result, the adhesion between the flat magnetic metal particles and the coating layer can be improved, and the thermal stability and oxidation resistance of the magnetic wedge, described later, can be improved. The coating layer can not only improve the thermal stability and oxidation resistance of the flat magnetic metal particles, but also improve the electrical resistance of the flat magnetic metal particles. By increasing the electrical resistance, eddy current losses can be suppressed and the frequency characteristics of the magnetic permeability can be improved. For this reason, the coating layer is preferably electrically high-resistive, and preferably has a resistance value of 1 mΩ·cm or more.

[0037] Furthermore, the presence of a coating layer is also preferable from a magnetic standpoint. Since the thickness of the flattened magnetic metal particles is small relative to the size of the flattened surface, they can be considered as a pseudo-thin film. In this case, when a coating layer is formed on the surface of the flattened magnetic metal particles and integrated, it can be considered as a pseudo-layered thin film structure, and the magnetic domain structure is energetically stabilized. This makes it possible to reduce coercivity (which reduces hysteresis loss), which is preferable. At this time, the permeability is also increased, which is preferable. From this viewpoint, it is even more preferable that the coating layer is non-magnetic (as this makes it easier to stabilize the magnetic domain structure).

[0038] From the viewpoint of thermal stability, oxidation resistance, and electrical resistance, a thicker coating layer is preferable. However, if the coating layer is too thick, the saturation magnetization decreases, and the "effect of stabilizing the magnetic domain structure, resulting in lower coercivity, lower loss, and higher permeability" is also reduced, which is undesirable from a magnetic standpoint. Considering the above, the preferred thickness of the coating layer is 0.1 nm to 1 μm, more preferably 0.1 nm to 100 nm.

[0039] The resin constitutes part or all of the intervening phase surrounding a plurality of flattened magnetic metal particles. This is preferable because it not only reduces eddy current loss but also protects the flattened magnetic metal particles from oxidation and corrosion, thereby suppressing deterioration of magnetic properties. Specific resins include, for example, thermoplastic resins, thermosetting resins, polyester resins, vinyl ester resins, polyethylene resins, polystyrene resins, polyvinyl chloride resins, polyvinyl butyral resins, polyvinyl alcohol resins, polybutadiene resins, Teflon® resins, polyurethane resins, cellulose resins, ABS resins, nitrile-butadiene rubbers, styrene-butadiene rubbers, silicone resins, other synthetic rubbers, natural rubbers, epoxy resins, phenolic resins, allyl resins, polybenzimidazole resins, amide resins, polyimide resins, polyamideimide resins, bismaleimide resins, or copolymers thereof. In particular, to achieve high thermal stability, it is preferable to include at least one resin selected from the group consisting of highly heat-resistant silicone resins, polyimide resins, imide resins, and bismaleimide resins. Epoxy resins, phenolic resins, and polyester resins are versatile resins with relatively high heat resistance and strength, and their inclusion provides a magnetic wedge with an excellent balance of durability and cost. Furthermore, to achieve high adhesion with flattened magnetic metal particles, it is preferable to include at least one resin selected from the group consisting of bismaleimide resins, polyimide resins, phenolic resins, and epoxy resins. The intervening phase may be a resin composition that includes additives such as fillers, plasticizers, and stabilizers in addition to the resin. The intervening phase may also consist only of resin. Furthermore, it is preferable that the weight increase rate after exposure to air at room temperature for one week following exposure to air at 120°C for 30 minutes is 1% or less, and more preferably 0.1% or less. Also, it is preferable that the water absorption rate, as defined in ISO 62:1999 (JIS K7209:2000), is 1% or less, and more preferably 0.1% or less. These factors contribute to improved long-term reliability. The type of resin can be identified by methods such as IR (Infrared Spectroscopy) and NMR (Nuclear Magnetic Resonance).

[0040] The fiber 18 is, for example, an insulating fiber. The fiber 18 may be formed from single fibers, or it may be a fiber bundle of multiple fibers. Preferably, the fiber 18 is a glass fiber, silicon carbide fiber, silicon nitride fiber, alumina fiber, silicon carbide fiber, boron fiber, aromatic polyamide fiber, aramid fiber, polyethylene fiber, poly(p-phenylenebenzoxazole) (PBO) fiber, polyphenylene sulfide fiber, polyester fiber, acrylic fiber, nylon fiber, Zylon fiber, polyethylene fiber, etc. However, the fiber 18 is not limited to these. For example, the fiber 18 may be a carbon fiber. The fiber bundles are preferably glass fiber bundles, silicon carbide fiber bundles, silicon nitride fiber bundles, alumina fiber bundles, silicon carbide fiber bundles, boron fiber bundles, aromatic polyamide fiber bundles, aramid fiber bundles, polyethylene fiber bundles, poly(p-phenylenebenzoxazole) (PBO) fiber bundles, polyphenylene sulfide fiber bundles, polyester fiber bundles, acrylic fiber bundles, nylon fiber bundles, Zylon fiber bundles, polyethylene fiber bundles, etc. However, the fiber bundles are not limited to these. For example, the fiber bundles may be carbon fiber bundles.

[0041] Fig. 12 is an example of a microscopic photograph of a fiber aggregate in which a plurality of glass fiber bundles are formed into a mat (non-woven fabric) shape. Such a fiber aggregate is preferable because it is easy to obtain a magnetic wedge having a cross section shown in Fig. 3 and because the gap between fibers can be easily controlled by referring to the basis weight. Note that the photograph shown in Fig. 12(a) is a microscopic photograph of a glass fiber mat having a basis weight of 100 g / m 2 , that is, 1 g of weight per 100 cm 2 . The photograph shown in Fig. 12(b) is a microscopic photograph of a glass fiber mat having a basis weight of 300 g / m 2 , that is, 3 g of weight per 100 cm 2 . The photograph shown in Fig. 12(c) is a microscopic photograph of a glass fiber mat having a basis weight of 600 g / m 2 , that is, 6 g of weight per 100 cm 2 . Note that the fiber aggregate of the present embodiment is not limited to a fiber bundle formed into a mat shape. For example, the fiber aggregate of the present embodiment may be a fiber bundle formed into a cross (plain weave).

[0042] Fig. 13 is a graph showing the relationship between the weight of fibers contained per 100 cm 2 in the second portion of the magnetic wedge of the present embodiment and the bending strength. The mechanical strength of the magnetic wedge increases with the weight of fibers contained per 100 cm 2 in the second portion, but decreases when it reaches 6 g. Although not shown, the bending strength of a magnetic wedge in which the weight of fibers contained per 100 cm 2 in the second portion is less than 1 g is lower than the bending strength of a magnetic wedge in which the weight of fibers contained per 100 cm 2 in the second portion is 1 g. This is because when the weight of fibers contained per 100 cm 2 in the second portion is less than 1 g, the spatial overlap between the fibers and the flat magnetic metal particles becomes small, and it becomes difficult to sufficiently relieve the stress concentrated on the flat magnetic metal particles. Although not shown, the bending strength of a magnetic wedge in which the weight of fibers contained per 100 cm 2 in the second portion is more than 6 g is lower than the bending strength of a magnetic wedge in which the weight of fibers contained per 100 cm 2The weight of the fibers contained per unit area is lower than the bending strength of a magnetic wedge with 6g of fiber. This is because the gaps between the fibers are small, and resin and flat magnetic metal particles do not penetrate between the fibers. Thus, it is preferable that the multiple fibers form appropriate gaps between them, and the content of the multiple fibers in a plane parallel to the plane of the magnetic wedge is 100g / m². 2 More than 600g / m 2 The following, or 100cm 2 It is preferable that the amount is between 1g and 6g per serving.

[0043] The method for manufacturing the magnetic wedge of this embodiment will now be described. Note that the manufacturing method is not particularly limited and is described merely as an example.

[0044] The first step is to set multiple fibers on the surface that contacts the lower or middle mold of the die. Multiple fibers are obtained by cutting long fibers to a predetermined length. The average fiber length of the cut fibers is preferably 0.1 mm to 10,000 mm, more preferably 1 mm to 1,000 mm, and even more preferably 5 mm to 200 mm. If the average fiber length of the multiple fibers is 1 mm or more, it is easier to obtain a magnetic wedge with excellent mechanical properties such as bending strength and tensile strength. Furthermore, it is preferable that the multiple fibers are formed into a sheet shape in advance by intertwining the fibers together or solidifying them with an adhesive. This makes it easier to uniformly distribute the multiple fibers in the second part of the magnetic wedge. In addition, when using a fiber aggregate that has been formed into a sheet shape in advance, it is preferable to combine two or more types with different gaps between the fibers. This makes it easier to obtain a magnetic wedge with a gradient in the number density of multiple second flattened magnetic metal particles, as shown in Figure 3. In other words, it is easier to obtain a magnetic wedge in which the number density of the multiple second flattened magnetic metal particles within the second part is higher in the region closer to the first part than in the region further away from the first part. The long fibers may be single threads (single fibers) or fiber bundles in which multiple short fibers are combined to form a single thread.

[0045] After the first step of this embodiment, the weight of the multiple fibers is measured in a plane parallel to the surface in contact with the lower or middle mold of the mold, in a distance of 1 m 2100g to 600g per unit, or 100cm 2 It is preferable that the amount per fiber is between 1g and 6g. This makes it easier for flattened magnetic metal particles to penetrate between the fibers in a subsequent process, thereby obtaining "second flattened magnetic metal particles 10b," and improving the magnetic and mechanical properties of the resulting magnetic wedge. When using fiber assemblies that have been formed into a sheet in advance, the weight of the multiple fibers can be adjusted by referring to the basis weight of the fiber assemblies. This adjustment may be performed with a single fiber assembly or by stacking two or more fiber assemblies.

[0046] The second step is to place multiple flattened magnetic metal particles and an intervening phase substrate into the mold.

[0047] The plurality of flattened magnetic metal particles in this embodiment are preferably produced by crushing a magnetic metal ribbon containing at least one first element selected from the group consisting of Fe, Co, and Ni. The magnetic metal ribbon can be produced, for example, using a film deposition apparatus such as sputtering or a roll quenching apparatus. Film deposition apparatuses have the advantage of being able to produce thin films and a refined structure, making it easy to obtain magnetic metal ribbons with a rotational magnetization type magnetization reversal mechanism. On the other hand, roll quenching apparatuses have the advantage of being able to produce large quantities of magnetic metal ribbons necessary for the synthesis of bulk materials. In particular, single-roll quenching apparatuses are excellent for mass production due to their simple operation.

[0048] The average thickness of the magnetic metal ribbon is preferably 20 μm or less. If it exceeds 20 μm, it is thinned by rolling. The rolling method may be cold rolling, hot rolling, or both. Before rolling, the magnetic metal ribbon may be cut into appropriate sizes or crushed.

[0049] The grinding of magnetic metal ribbons is not limited to any particular method. For example, it can be done using grinding equipment such as mixers, planetary mills, bead mills, rotary ball mills, vibrating ball mills, agitated ball mills (attritors), jet mills, and centrifuges. It is preferable to pre-heat treat the magnetic metal ribbons at a temperature of 50°C to 1500°C before grinding. This improves the pulverability of the magnetic metal ribbon. Furthermore, the heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, and among these, a reducing atmosphere with H2 (hydrogen), CO (carbon monoxide), CH4 (methane) is particularly preferred. This is because even if the magnetic metal ribbon is oxidized, heat treatment in a reducing atmosphere can reduce the oxidized metal back to its original metal state. This also allows for the reduction of oxidized magnetic metal ribbons, which have reduced saturation magnetization, thereby restoring saturation magnetization. In the case of amorphous compositions, if the crystallization of the magnetic metal ribbon progresses significantly due to heat treatment, the coercivity increases and the permeability decreases, so it is preferable to select conditions that suppress excessive crystallization. Preferably, the heat treatment is performed in a magnetic field. In this case, the larger the applied magnetic field, the better, but it is preferable to apply 1 kOe or more, and more preferably 10 kOe or more. This makes it possible to induce magnetic anisotropy within the plane of the magnetic metal ribbon, thereby achieving excellent magnetic properties. During grinding, it is preferable to perform the grinding while cooling at a temperature below 0°C, as this facilitates the grinding process. In particular, cooling to liquid nitrogen temperature (77K) or dry ice temperature (194K) is desirable, and cooling to liquid nitrogen temperature is especially desirable. This makes the magnetic metal ribbon more susceptible to low-temperature embrittlement, facilitating grinding. In other words, it is preferable because grinding can be performed efficiently without applying excessive stress or strain to the magnetic metal ribbon. However, in many cases, sufficient grinding can be achieved without cooling, in which case cooling is not necessary.

[0050] The above cutting, crushing, and rolling processes are performed (rolling is done as needed; it is omitted if unnecessary), and if necessary, the cutting, crushing, and rolling processes are repeated to obtain flattened magnetic metal particles with an average thickness of 10 nm to 100 μm, an average length of the flattened surface of 100 μm to 500 μm, and an average ratio of the average length within the flattened surface to the thickness of 2 to 10000. This makes it possible to improve the magnetic and mechanical properties. In order to achieve the degree of orientation of flattened magnetic metal particles as in this embodiment, it is effective to improve the slipperiness of the flattened magnetic metal particles and increase their fluidity. Therefore, the average thickness of the flattened magnetic metal particles is preferably 10 μm to 30 μm, and more preferably 10 μm to 20 μm. Furthermore, the average ratio of the average length to the thickness of the flattened magnetic metal particles is preferably 10 to 100, and more preferably 10 to 50.

[0051] The flattened magnetic metal particles may be heat-treated before being placed in the mold. This moderately removes lattice distortion and improves magnetic properties. The heat treatment temperature is preferably between 50°C and 1500°C. The heat treatment atmosphere is preferably a vacuum atmosphere with a low oxygen concentration, an inert atmosphere, or a reducing atmosphere, with a reducing atmosphere of H2, CO, CH4 being particularly preferred. Preferably, the heat treatment is performed in a magnetic field. The reasons and details for these are the same as for magnetic metal ribbons, so they will not be explained here. In addition, the flattened magnetic metal particles may be coated with hydrolysis products of silane compounds. This makes it easier to obtain magnetic wedges in which the flattened magnetic metal particles and the intervening phase are firmly attached or bonded. The coating method is not particularly limited and can be carried out by dry or wet methods.

[0052] Examples of substrates for the intervening phase in this embodiment include thermoplastic resins, thermosetting resins, polyester resins, vinyl ester resins, polyethylene resins, polystyrene resins, polyvinyl chloride resins, polyvinyl butyral resins, polyvinyl alcohol resins, polybutadiene resins, Teflon® resins, polyurethane resins, cellulose resins, ABS resins, nitrile-butadiene rubbers, styrene-butadiene rubbers, silicone resins, other synthetic rubbers, natural rubbers, epoxy resins, phenolic resins, allyl resins, polybenzimidazole resins, amide resins, polyimide resins, polyamideimide resins, bismaleimide resins, etc., and it is preferable to select the method of introduction according to the state at room temperature. For example, by preparing a mixed powder with flattened magnetic metal particles from a solid and then introducing it into a mold, it is easy to obtain a magnetic wedge in which multiple flattened magnetic metal particles are uniformly dispersed in the intervening phase. Alternatively, by adding a liquid dropwise to a mold containing multiple flattened magnetic metal particles, it is easy to obtain a magnetic wedge with a high degree of orientation of the flattened magnetic metal particles. The substrate of the intervening phase may also contain organic peroxides or silane coupling agents.

[0053] The third step is to align the upper mold with the mold. If necessary, multiple fibers may be placed between the multiple flattened magnetic metal particles and the substrate of the intervening phase. The multiple fibers are obtained by cutting long fibers to a predetermined length, as in the first step. The average fiber length of the cut fibers is preferably 0.1 mm to 10,000 mm, more preferably 1 mm to 1,000 mm, and even more preferably 5 mm to 200 mm. If the average fiber length of the multiple fibers is 1 mm or more, a magnetic wedge with excellent mechanical properties such as bending strength and tensile strength is easily obtained. Furthermore, it is preferable that the multiple fibers are formed into a sheet shape in advance by intertwining the fibers with each other or solidifying them with an adhesive. This makes it easier to uniformly distribute the multiple fibers in the second part of the magnetic wedge. The long fibers may be single threads (single fibers) or fiber bundles in which multiple short fibers are combined to form a single thread.

[0054] The weight of multiple fibers arranged in a plane parallel to the surface in contact with the upper die of the mold is 1 m 2 100g to 600g per unit, or 100cm 2 The weight per fiber is preferably between 1g and 6g. This allows flat magnetic metal particles to easily penetrate between the fibers in subsequent processes, improving the magnetic and mechanical properties of the resulting magnetic wedge. When using fiber assemblies that have been pre-formed into a sheet, the weight of multiple fibers can be adjusted by referring to the basis weight of the fiber assemblies. This adjustment can be done with a single fiber assembly or by stacking two or more fiber assemblies. In addition, if necessary, mechanical vibration may be applied to the mold before and after the third process. Methods for applying mechanical vibration include manually shaking the mold, striking the mold with a hammer, or any other method as desired.

[0055] The fourth step is to apply pressure to the mold to form the multiple flattened magnetic metal particles, multiple fibers, and intervening phase into the desired shape. Preferably, the molding is performed in a magnetic field. Heat treatment may also be performed before, during, or after molding as needed. The device used to apply pressure to the mold is not particularly limited, but a device capable of applying pressure in a uniaxial direction, such as a hydraulic press, hot press, or electrostatic processing device, is preferred. The pressure may be applied continuously at a constant pressure, but preferably, pressure is applied intermittently by repeatedly applying and depressurizing pressure in the range of 0.1 MPa to 100 MPa. This causes the intervening phase substrate and multiple flattened magnetic metal particles to penetrate between the fibers, resulting in a "second flattened magnetic metal particle 10b" that has penetrated between the fibers, and a magnetic wedge with excellent magnetic and mechanical properties is obtained. The magnetic wedge thus obtained comprises a first portion including a plurality of flattened magnetic metal particles and an intervening phase, and a second portion provided in contact with the first portion and including a plurality of fibers, a plurality of flattened magnetic metal particles and an intervening phase. Furthermore, since the multiple flattened magnetic metal particles move from the center outward while pushing out the air present between the multiple fibers along with the substrate of the intervening phase, the number of flattened magnetic metal particles located near the surface of the magnetic wedge can be reduced compared to existing magnetic wedges consisting of multiple flattened magnetic metal particles and an intervening phase. This makes it possible to improve the surface electrical resistance of the magnetic wedge.

[0056] Furthermore, if necessary, a surface coating layer may be formed on the surface of the magnetic wedge (this step can be omitted if not necessary). The surface coating layer may be made of organic or inorganic material. The coating method is not particularly limited, and any method can be used as appropriate. For example, in the case of organic materials such as resins, impregnation or dipping methods can be used, and in some cases, it is preferable to press the coating with a hot press after application. When coating with inorganic materials, for example, gas-phase methods such as physical vapor deposition or liquid-phase methods such as sol-gel methods can be used, and in some cases, it is preferable to press the coating with a hot press after application. It is also preferable to perform heat treatment after coating to form a strong coating layer. This makes it possible to improve the surface electrical resistance of the magnetic wedge. On the other hand, since the non-magnetic region expands, it is preferable to keep the surface coating layer to a minimum.

[0057] Figure 14 is a schematic diagram showing part of the manufacturing process of a magnetic wedge according to the first embodiment. For example, as shown in Figure 14(a), in the mold 30, fibers 18, such as a glass fiber mat, are placed above and below the substrate of the flat magnetic metal particles and intervening phase. Then, as shown in Figure 14(b), the process of applying pressure to the mold at room temperature and then releasing the pressure to return to atmospheric pressure is repeated. Furthermore, as shown in Figure 14(c), heat is applied to the mold using, for example, a heater 32, and it is maintained at a predetermined temperature and pressure, and then slowly cooled. In this way, a magnetic wedge containing the fibers 18 is manufactured.

[0058] When measuring the coercivity with respect to direction in a plane parallel to the flattened plane of the flattened magnetic metal particles of a magnetic wedge, for example, the coercivity is measured by changing the direction every 22.5 degrees for a 360-degree angle within the plane.

[0059] Having a difference in coercivity within the plane of the magnetic wedge is preferable because it reduces the minimum coercivity value compared to the isotropic case where there is almost no difference in coercivity. In materials that have magnetic anisotropy within a plane, there is a difference in coercivity depending on the direction within the plane, and the minimum coercivity value is smaller compared to magnetically isotropic materials. This reduces hysteresis loss and improves permeability, which is preferable.

[0060] In a plane parallel to the flattened plane of the flattened magnetic metal particles of the magnetic wedge, the larger the ratio of the coercivity difference depending on the direction, the more preferable it is, preferably 1% or more. More preferably, the ratio of the coercivity difference is 10% or more, even more preferably 50% or more, and even more preferably 100% or more. The ratio of the coercivity difference referred to here is defined as (Hc(max)-Hc(min)) / Hc(min)×100(%), using the maximum coercivity Hc(max) and the minimum coercivity Hc(min) within the flattened plane.

[0061] Furthermore, coercivity can be easily evaluated using a vibrating sample magnetometer (VSM). If the coercivity is low, it can be measured even below 0.1 Oe by using a low-field unit. The measurement is performed by changing the direction of the magnetic wedge within the aforementioned plane (a plane parallel to the flattened plane of the flattened magnetic metal particle) with respect to the direction of the measurement magnetic field.

[0062] When calculating coercivity, the difference between the magnetic fields at two points where the horizontal axis intersects (magnetic fields H1 and H2 where magnetization is zero) can be divided by 2 (i.e., coercivity can be calculated as |H2-H1| / 2).

[0063] The magnetic wedge of this embodiment comprises a first portion including a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, and a second portion provided in contact with the first portion and including a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers. With the above configuration, it has been found that the magnetic wedge of this embodiment can improve magnetic properties and mechanical strength. This is thought to be due to the multiple second flattened magnetic metal particles that have entered between the multiple fibers while maintaining the orientation tendency of the multiple first flattened magnetic metal particles. As a result, in a rotating electric machine, magnetism is imparted to the magnetic wedge up to near the air gap surface between the rotor and stator, making it possible to significantly reduce harmonic losses occurring on the opposing core surface through the air gap. Furthermore, in the magnetic wedge of this embodiment, the number of flattened magnetic metal particles located near the surface of the magnetic wedge is reduced, so the surface electrical resistance of the magnetic wedge can be increased. As a result, in a rotating electric machine, the path of the short-circuit current from the core teeth through the magnetic wedge is blocked, making it possible to prevent malfunctions.

[0064] As described above, this embodiment makes it possible to provide a magnetic wedge with excellent properties.

[0065] (Second Embodiment) The rotating electric machine of this embodiment is equipped with the magnetic wedge of the first embodiment. Therefore, descriptions that overlap with the first embodiment are omitted. In this specification, the term "rotating electric machine" refers to a concept that includes electric motors, generators, and motor-generators that perform both motor and generator functions as needed.

[0066] Figure 15 shows an example of a radial gap motor according to this embodiment. A radial gap motor has a rotor and a stator that is positioned opposite the rotor with a predetermined radial gap. In Figure 15, the rotor is positioned inside the stator, but it may also be positioned outside. The rotor has a rotor core and a shaft and is supported so that it can rotate. The stator, on the other hand, has a stator core, field coils inserted into slots in the stator core, and magnetic wedges held in wedge grooves in the slot openings. Figure 15 shows an example of the arrangement of magnetic wedges according to the first embodiment, but is not limited to this. In the case of a radial gap rotating electric machine, since the stator is positioned opposite the rotor with a predetermined radial gap, the "gap surface" is a surface parallel to the cylindrical surface centered on the rotor's axis of rotation. Therefore, the radial direction is perpendicular to the gap surface, and the axial direction and rotational direction are parallel to the gap surface. Figure 15 shows the magnetic wedge 100, the rotating electric machine 200, the rotor 210, the stator 220, the coil 230, the air gap surface 240, and the iron core teeth 250.

[0067] By arranging the magnetic wedge of the first embodiment, it becomes possible to reduce harmonic losses occurring on the rotor surface while suppressing leakage flux. Furthermore, since the magnetic flux passing through the air gap increases, the torque of the radial gap type motor is increased. High efficiency can be achieved through either or both of the above loss reduction effect and torque increase effect.

[0068] Furthermore, radial gap motors can be any of the following: those with a conductor in the rotor (induction motor), those with a permanent magnet (permanent magnet motor), or those with a magnetic material (reluctance motor).

[0069] Figure 16 shows an example of an axial gap motor according to this embodiment. The axial gap motor has a rotor and a stator that is positioned opposite the rotor with a predetermined 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 in the slot openings. By arranging the magnetic wedges in this embodiment, it is possible to reduce harmonic losses occurring on the rotor surface while suppressing the increase in leakage flux. In addition, the torque of the axial gap motor is increased because the magnetic flux passing through the gap increases. As a result, high efficiency can be achieved. In Figure 16, the rotor is positioned between two stators, but it may also be positioned on one side or both sides of a single stator. In the case of an axial gap rotating electric machine, since the stators are positioned opposite the rotor with a predetermined gap in the axial direction, the "gap surface" is a surface perpendicular to the rotor's rotation axis. Therefore, the axial direction is perpendicular to the air gap surface, and the rotational and radial directions are parallel to the air gap surface. Figure 16 shows the magnetic wedge 100, rotating electric machine 200, rotor 210, coil 230, air gap surface 240, iron core teeth 250, stator 270, and shaft 280.

[0070] Figure 17 is a schematic diagram showing an example of a generator according to this embodiment. The generator typically has a rotor in which excitation coils are housed in slots in the rotor core (in addition, a rotor using permanent magnets as an excitation source may be used), and a stator in which armature coils are housed in slots in the stator core. By rotating the rotor and passing an excitation current through the excitation coils, power is generated in the armature coils. The rotor comprises a rotor core, field coils inserted into slots in the rotor core, and magnetic wedges held in wedge grooves in the slot openings, and is supported by bearings so that it can rotate. By arranging the magnetic wedges in this embodiment, it is possible to reduce harmonic losses occurring on the surface of the stator while suppressing the increase in leakage flux. Furthermore, since the magnetic flux passing through the air gap and linking with the armature coils increases, the generated voltage induced in the armature coils increases. As a result, high efficiency can be achieved. In Figure 17, the magnetic wedge is positioned in the slot opening of the rotor core, but it may also be positioned in the slot opening of the stator core. Also, although the figure shows a wound-type generator with an excitation coil on the rotor, it may also be a permanent magnet type generator with a permanent magnet on the rotor. In this case, the magnetic wedge is positioned in the slot opening of the stator core. Figure 17 shows the magnetic wedge 100, the rotating electric machine 200, the rotor 210, the stator core 222, the excitation coil 232, the armature coil 234, the air gap surface 240, and the core teeth 250.

[0071] Since a linear motor is a radial gap type motor unfolded into a flat plate structure, the magnetic wedge of the present invention can also be applied to a linear motor. That is, the stator comprises a stator core and field coils inserted into slots in the stator core, and a magnetic wedge may be provided at the slot opening. Figure 18 is a schematic diagram showing an example of a linear motor of this embodiment. In a linear motor, the direction of travel of the movable element, the direction perpendicular to the direction of travel of the movable element, and the direction perpendicular to the stator correspond to the rotational direction, axial direction, and radial direction of the radial gap type motor, respectively. By arranging the magnetic wedge of this embodiment, it is possible to reduce harmonic losses occurring on the surface of the movable element while suppressing the increase in leakage flux. In addition, the thrust of the linear motor is improved because the magnetic flux passing through the air gap increases. As a result, high efficiency can be achieved. Figure 18 shows the magnetic wedge 100, stator 220, coil 230, air gap surface 240, core teeth 250, and movable element 290.

[0072] As described above, the rotating electric machine of this embodiment can suppress the increase in leakage flux due to the use of magnetic wedges and effectively mitigate the pulsation of the magnetic flux distribution on the surface of the iron core, thereby achieving high efficiency. The slot shape of the rotating electric machine of this embodiment may be a semi-closed slot, but it is preferably an open slot. This is preferable because it can significantly reduce harmonic losses.

[0073] 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 blowers; energy systems such as thermal power generators, hydroelectric power generators, wind power generators, nuclear power generators, and geothermal power generators; and home appliances such as washing machines, thereby improving the efficiency of the system. In particular, for large-capacity industrial machines, open slots are generally used for the slot shape, so it is preferable to provide the magnetic wedge of the first embodiment. Also, for main motors for railways, type-wound coils are used due to the need to withstand high voltage and vibration, and open slots are adopted for the slot shape, so it is preferable to provide the magnetic wedge of the first embodiment.

[0074] In railways, losses in rotating electric machinery account for approximately half of the power consumption during train operation, so reducing losses in rotating electric machinery has a significant effect on improving efficiency. Furthermore, in electric vehicles and hybrid cars, using the magnetic wedge of the first embodiment can improve the efficiency of the main motor, thereby extending the driving range.

[0075] In the field of power generation, significant improvements are expected for hydroelectric generators, particularly variable-speed pumped-storage generators. Significant improvements are also expected for wind turbines.

[0076] (Examples) Examples 1 to 14 are described in more detail below, in comparison with Comparative Examples 1 to 3.

[0077] (Example 1) First, a ribbon of Fe-Co-B-Si (Fe:Co:B:Si = 52:23:19:6 (at%), Fe:Co = 70:30 (at%), with the total amount of added elements B+Si being 25 at% relative to the total amount of Fe+Co+B+Si) was prepared using a single-roll quenching apparatus. Next, the obtained ribbon was heat-treated at 300°C in an H2 atmosphere. Then, the heat-treated ribbon was crushed in a mixer apparatus to obtain flattened magnetic metal particles. Through classification and sorting, the flattened magnetic metal particles were found to have an average thickness of 15 μm, an average length of the flattened surface of 250 μm, an average ratio A of the average length within the flattened surface to the thickness of 17, and the flattened surface had an angular contour shape with a ratio a / b of 1.2 or more for the maximum length to the minimum length. Next, a glass fiber mat (basis weight 300) and flat magnetic metal particles were placed in the mold coated with a release agent, and then a liquid resin containing organic peroxides was dripped onto them. After that, another glass fiber mat was added, and the mold was left to stand for a while with the upper mold attached. Next, the mold containing the flat magnetic metal particles, glass fiber mat, and liquid resin was attached to a hot press machine and molded into the shape of a magnetic wedge. During molding, a pressure of 2 MPa was applied and released at atmospheric pressure multiple times, and then a constant pressure of 2 MPa was maintained until the magnetic wedge was removed from the mold.

[0078] (Example 2) This example is almost identical to Example 1, except that a fiberglass mat (weight 100) was used instead of a fiberglass mat (weight 300).

[0079] (Example 3) This example is almost identical to Example 1, except that a fiberglass mat (weight 600) was used instead of a fiberglass mat (weight 300).

[0080] (Example 4) This example is almost identical to Example 1, except that instead of using a fiberglass mat (weight 300), a combination of fiberglass cloth (weight 100) and fiberglass mat (weight 230) was used.

[0081] (Example 5) This example is almost identical to Example 1, except that a fiberglass cloth (weight 300) was used instead of a fiberglass mat (weight 300).

[0082] (Example 6) The procedure is almost identical to Example 5, except that the fiberglass cloth (weight 300) was lightly loosened before being placed in the mold.

[0083] (Example 7) This example is almost identical to Example 1, except that a bundle of glass fibers with an average fiber length of 0.1 mm was used instead of a glass fiber mat (basis weight 300).

[0084] (Example 8) This example is almost identical to Example 1, except that a bundle of glass fibers with an average fiber length of 100 mm was used instead of a glass fiber mat (basis weight 300).

[0085] (Example 9) This example is almost identical to Example 1, except that aramid fiber cloth was used instead of glass fiber mat (weight 300).

[0086] (Example 10) This method is almost identical to Example 1, except that a mixture of powdered resin and flat magnetic metal particles was placed into the mold and the molding pressure was set to 8 MPa.

[0087] (Example 11) This example is almost identical to Example 1, except that multiple flattened magnetic metal particles were used in which the ratio a / b of the minimum to maximum length of the flattened surface was 1.0 or more and less than 1.2, achieved by adjusting the grinding conditions using a mixer and classifying and sorting the flattened magnetic metal particles.

[0088] (Example 12) This example is almost identical to Example 1, except that multiple flattened magnetic particles were used, with an average length of the flattened surface being 75 μm and an average ratio of the average length within the flattened surface to the thickness being 5, achieved by adjusting the grinding conditions using a mixer and classifying and sorting the flattened magnetic metal particles.

[0089] (Example 13) The procedure is almost identical to Example 1, except that a constant pressure of 2 MPa was continuously applied during molding.

[0090] (Example 14) This example is almost identical to Example 1, except that a glass fiber mat (basis weight 300) was not placed inside the mold, and a surface coating layer was applied to the surface of the magnetic wedge as a post-processing step after molding, using flat magnetic metal particles, liquid resin, and a bundle of glass fibers with an average fiber length of 0.1 mm.

[0091] (Comparative Example 1) First, a ribbon of Fe-Co-B-Si (Fe:Co:B:Si = 52:23:19:6 (at%), Fe:Co = 70:30 (at%), with the total amount of added elements B+Si being 25 at% relative to the total amount of Fe+Co+B+Si) was prepared using a single-roll quenching device. Next, the obtained ribbon was heat-treated at 300°C in an H2 atmosphere. Then, the heat-treated ribbon was crushed in a mixer device to obtain flattened magnetic metal particles. The flattened magnetic metal particles were classified and sorted to confirm that they had an average thickness of 15 μm, an average length of the flattened surface of 250 μm, an average ratio A of the average length within the flattened surface to the thickness of 20, and that the flattened surface had an angular contour shape with a ratio a / b of 1.2 or more for the maximum length to the minimum length. Next, the flattened magnetic metal particles were placed in a mold coated with a release agent, and a liquid resin containing organic peroxides was dropped onto them. Afterward, the mold was left undisturbed for a while with the upper mold attached. Next, the mold containing the flattened magnetic metal particles and liquid resin was attached to a hot press machine and molded into the shape of a magnetic wedge. During molding, a constant pressure of 2 MPa was continuously applied until the magnetic wedge was removed from the mold.

[0092] (Comparative Example 2) The procedure is almost identical to Comparative Example 1, except that when the flat magnetic metal particles were introduced into the mold, a bundle of glass fibers with an average fiber length of 0.1 mm was mixed in.

[0093] (Comparative Example 3) The post-processing after molding was almost the same as in Comparative Example 1, except that a fibrous portion was created on the surface of the magnetic wedge using liquid resin and a glass fiber mat (based on the amount of resin used).

[0094] Table 1 shows the arrangement of fibers, the number of second flattened magnetic metal particles, and the orientation angle of the second flattened magnetic metal particles relative to the first flattened magnetic metal particles in the magnetic wedge of this embodiment, along with Comparative Examples 1 to 3. The number of second flattened magnetic metal particles is counted separately in the region near the boundary with the first part and in the region away from the boundary. The two regions are divided into two equal parts based on a cross-sectional photograph of the second part.

[0095] Table 2 shows the strength, permeability, surface electrical resistance, and degree of efficiency improvement as a rotating electric machine of the magnetic wedge of this embodiment, along with Comparative Examples 1 to 3.

[0096] (1) Strength: A commercially available composite magnetic material in which spherical magnetic metal particles are dispersed ectographically was used as a comparative sample. The magnetic metal particles in this comparative sample mainly consist of Fe. The bending strength of the example, comparative example, and comparative sample was measured at 25°C and is shown as a ratio to the bending strength of the comparative sample at 25°C (= bending strength of the evaluation sample at 25°C / bending strength of the comparative sample at 25°C).

[0097] (2) Permeability: The amplitude permeability at 0.3T·100Hz is measured in a plane perpendicular to the thickness direction of the magnetic wedge. The permeability of the examples and comparative examples is shown as a ratio based on the permeability of Comparative Example 1. When measuring the amplitude permeability, the magnitude of the magnetic flux density is given by dividing the voltage integral value induced in the coil wrapped around the magnetic wedge by the cross-sectional area of ​​the magnetic wedge.

[0098] (3) Surface electrical resistance: Using a tester, measure the electrical resistance at 20 points on the surface of the magnetic wedge (distance between test pins: 10 mm), and calculate the percentage of points with a measurement value exceeding 50 MΩ. The surface electrical resistance of the examples and comparative examples is shown as a ratio based on the percentage of Comparative Example 1.

[0099] (4) Degree of efficiency improvement as a rotating electric machine: Using electromagnetic field simulations based on a standard radial gap motor, the efficiency improvement when using magnetic wedges in the examples and comparative examples is calculated, with the efficiency when using non-magnetic wedges as the baseline. The degree of efficiency improvement in the examples and comparative examples is shown as a ratio based on the degree of efficiency improvement of Comparative Example 1.

[0100] [Table 1]

[0101] [Table 2]

[0102] Table 2 shows that Examples 1-4, 6, and 10-12 possess excellent properties in terms of strength and surface electrical resistance, and their effect in improving the efficiency of the rotating electric machine is equivalent to that of Comparative Example 1. On the other hand, Example 5 shows significantly higher strength than Comparative Examples 1 and 2, although its effect in improving the efficiency of the rotating electric machine is reduced. Furthermore, while Examples 9 and 13 do not achieve the same high strength as Example 5, they are still sufficiently strong compared to Comparative Example 3, which had a second section added as a post-processing step after molding. Furthermore, Examples 7 and 8 exhibit higher strength compared to Comparative Example 2 while having the same effect on improving the efficiency of the rotating electric machine. In addition, compared to Example 14, Examples 7 and 8 have a reduced number of flattened magnetic metal particles located near the surface of the magnetic wedge (a region away from the boundary with the first part), resulting in higher surface electrical resistance. Moreover, because the second flattened magnetic metal particles are oriented along the first flattened magnetic metal particles, the magnetic flux flows smoothly through the magnetic wedge, resulting in a high effect on improving the efficiency of the rotating electric machine. As in Example 14, if magnetic particles are present throughout the fibrous portion, the low surface electrical resistance makes it easier to electrically short-circuit the multiple electromagnetic steel sheets forming the core when using a power switch. Therefore, as in Examples 1-13, it is preferable that the number density of the multiple second flattened magnetic metal particles within the second portion is higher in the region closer to the first portion than in the region further away from the first portion, as can be seen from Table 2.

[0103] While several embodiments and examples of the present invention have been described, these embodiments and examples are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents.

[0104] Furthermore, the above embodiments can be summarized in the following technical proposal. (Technical proposal 1) A first portion comprising a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, A second portion provided in contact with the first portion, comprising a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers, A magnetic wedge equipped with [a specific feature]. (Technical proposal 2) The second flattened magnetic metal particle is oriented along the first flattened magnetic metal particle located in the vicinity of the second portion. A magnetic wedge as described in Technical Proposal 1. (Technical proposal 3) The number density of the plurality of second flattened magnetic metal particles within the second portion is higher in the region closer to the first portion than in the region further away from the first portion. A magnetic wedge as described in Technical Proposal 1 or Technical Proposal 2. (Technical proposal 4) The number density of the plurality of second flattened magnetic metal particles in the second portion is lower than the number density of the plurality of first flattened magnetic metal particles in the first portion. A magnetic wedge as described in any one of Technical Proposals 1 to 3. (Technical proposal 5) A flat surface is provided on the surface of the magnetic wedge, and the weight of the plurality of fibers is such that in a plane parallel to the flat surface, 100 cm 2The amount is between 1g and 6g per person. A magnetic wedge as described in any one of Technical Proposals 1 to 4. (Technical proposal 6) The thickness of the second portion is 5 μm or more and 2 mm or less. A magnetic wedge as described in any one of Technical Proposals 1 to 5. (Technical proposal 7) At least a portion of the surface of the first or second flattened magnetic metal particle is covered with a coating layer with a thickness of 0.1 nm to 1 μm that contains at least one element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). A magnetic wedge as described in any one of Technical Proposals 1 to 6. (Technical proposal 8) The first flattened magnetic metal particle and the second flattened magnetic metal particle have a difference in coercivity depending on the direction, respectively, within the flattened plane of the first flattened magnetic metal particle and within the flattened plane of the second flattened magnetic metal particle, as described in any one of Technical Proposals 1 to 7. (Technical proposal 9) A magnetic wedge according to any one of Technical Proposals 1 to 8, wherein a plane is provided on the surface of the magnetic wedge, and within the plane, there is a difference in coercivity depending on the direction. (Technical proposal 10) A rotating electric machine equipped with a magnetic wedge as described in any one of Technical Proposals 1 to 9. [Explanation of Symbols]

[0105] 6: flat surface 9: Covering layer 10: Flat magnetic metal particles 10a: First flattened magnetic metal particle 10b: Second flattened magnetic metal particle 12: 1st part 14:Second part 16: Resin 16a: First resin 16b: Second resin 18: Fibers 20: Intervening phase 22 :Void 30: Mold 32: Heater 100:Magnetic wedge 200: Rotating Electric Machine 210: Rotor 220: Stator 222: Stator core 230: Coil 232: Excitation coil 234: Armature coil 240 :Void surface 250: Iron Core Teeth 260: Iron Core Slot 270: Stator 280: Axis 290: Mover

Claims

1. A first portion comprising a plurality of first flattened magnetic metal particles and a first resin provided between the plurality of first flattened magnetic metal particles, A second portion provided in contact with the first portion, comprising a plurality of fibers, a plurality of second flattened magnetic metal particles provided between the plurality of fibers, and a second resin provided between the plurality of fibers, A magnetic wedge equipped with [a specific feature].

2. The second flattened magnetic metal particle is oriented along the first flattened magnetic metal particle located in the vicinity of the second portion. The magnetic wedge according to claim 1.

3. The number density of the plurality of second flattened magnetic metal particles within the second portion is higher in the region closer to the first portion than in the region further away from the first portion. The magnetic wedge according to claim 1.

4. The number density of the plurality of second flattened magnetic metal particles in the second portion is lower than the number density of the plurality of first flattened magnetic metal particles in the first portion. The magnetic wedge according to claim 1.

5. A flat surface is provided on the surface of the magnetic wedge, and the weight of the plurality of fibers is such that in a plane parallel to the flat surface, 100 cm ２ The amount is between 1g and 6g per unit. The magnetic wedge according to claim 1.

6. The thickness of the second portion is 5 μm or more and 2 mm or less. The magnetic wedge according to claim 1.

7. At least a portion of the surface of the first or second flattened magnetic metal particle is covered with a coating layer with a thickness of 0.1 nm to 1 μm that contains at least one element selected from the group consisting of oxygen (O), carbon (C), nitrogen (N), and fluorine (F). The magnetic wedge according to claim 1.

8. The magnetic wedge according to claim 1, wherein the first flattened magnetic metal particle and the second flattened magnetic metal particle have a difference in coercivity depending on the direction within the flattened plane of the first flattened magnetic metal particle and within the flattened plane of the second flattened magnetic metal particle, respectively.

9. The magnetic wedge according to claim 1, wherein a plane is provided on the surface of the magnetic wedge, and within the plane, there is a difference in coercivity depending on the direction.

10. A rotating electric machine comprising a magnetic wedge as described in claim 1.

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