Stator and radial gap type transverse flux rotating electric machine

Abstract

To provide a new technology for a transverse flux type rotating electrical machine.SOLUTION: A stator 130 includes an annular phase magnetic circuit portion 132 corresponding to the individual phases arranged in the axial direction, and a plurality of inner magnetic cores 160 arranged dispersedly in a circular pattern. Each phase magnetic circuit portion 132 has a configuration in which a coil arranged on the inner periphery and an outer magnetic core 144 arranged on the outer periphery of the coil are sandwiched between two laminated cores in the axial direction. The plurality of inner magnetic cores 160 are arranged on the inner periphery of the coil so as to straddle the laminated cores of the phase magnetic circuit portions 132 for each phase in the axial direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a stator for a radial gap transverse flux type rotating electrical machine. [Background technology]

[0002] A transverse flux motor (TFM) is known as one type of rotating electric machine. The transverse flux motor is attracting attention as a rotating electric machine that is expected to contribute to miniaturization, weight reduction, and high efficiency. For example, Patent Document 1 and Patent Document 2 describe the technology of the transverse flux motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-129563 [Patent Document 2] Patent Publication No. 2021-192562 Summary of the Invention [Problem to be solved by the invention]

[0004] However, several problems have become apparent in the prior art related to transverse flux type rotating electrical machines.

[0005] (First Problem) For example, when attempting to create a highly flat, disk-shaped rotor by arranging a large number of long, thin permanent magnets and iron cores alternately in the circumferential direction, assembly involves first fixing the iron cores and then inserting the permanent magnets. However, because permanent magnets generate repulsive forces, the arrangement of the permanent magnets and iron cores is likely to become distorted during assembly, making assembly extremely difficult.

[0006] (Second issue) From the perspective of suppressing eddy current loss, it is preferable to use a powder magnetic core for the iron core. However, because powder magnetic cores have low mechanical strength, they are not suitable for use as structural components for rotors that must withstand strong magnetic and centrifugal forces. This requires the rotor to have separate non-magnetic and non-conductive structural components, and space to accommodate them. Furthermore, ceramics are one example of a non-magnetic and non-conductive material that can withstand high temperatures for long periods of time, but they are very expensive.

[0007] (Third issue) In the gap between the stator and rotor, the area of ​​the tips of the teeth of the iron core is the effective area of ​​the gap. It is desirable to make this effective gap area as large as possible.

[0008] The problem that the present invention aims to solve is to provide a new transverse flux type rotating electrical machine technology that addresses one or more of the above-mentioned problems. [Means for solving the problem]

[0009] A first invention for solving the above problems is a stator for a radial gap transverse flux rotating electric machine, comprising: an annular phase magnetic circuit section corresponding to each phase arranged in the axial direction; and a plurality of inner magnetic cores arranged in a circular pattern, wherein the phase magnetic circuit section has a configuration in which a coil arranged on the inner side and an outer magnetic core arranged on the outer side of the coil are sandwiched in the axial direction between two laminated cores, and the plurality of inner magnetic cores are arranged on the inner side of the coil so as to straddle the laminated cores of the phase magnetic circuit section for each phase in the axial direction.

[0010] A radial gap transverse flux rotating electric machine equipped with the stator of the first invention does not have the first problem. Furthermore, because the inner core is fixed to the stator, it does not require mechanical strength to withstand high rotation, and therefore does not have the second problem. Because the inner core can be positioned inside the stator, it is easy to increase the opposing area on the gap surface between the stator and rotor, which can be one way to solve the third problem.

[0011] A second invention is the stator described above, wherein each of the multiple inner magnetic cores is fixed to one of the laminated cores by a direct fixing method without using a non-magnetic member, and adjacent inner magnetic cores are fixed to different laminated cores by the direct fixing method.

[0012] A third invention is the stator described above, wherein the two laminated cores constituting one of the individual phase magnetic circuit units have different inner peripheral magnetic cores fixed by a direct fixing method without a non-magnetic member therebetween, and adjacent laminated cores in adjacent individual phase magnetic circuit units have the same inner peripheral magnetic core fixed by the direct fixing method.

[0013] A fourth aspect of the present invention is the stator described above, wherein the plurality of inner circumferential magnetic cores are arranged with adjacent inner circumferential magnetic cores spaced apart by a predetermined electrical angle.

[0014] A fifth aspect of the present invention is the stator described above, wherein the direct fixing method is a method in which the laminated core and the inner core are fixed together by a first fitting structure.

[0015] A sixth aspect of the present invention is the stator described above, wherein, among the laminated cores of the phase-specific magnetic circuit parts of the phases, the laminated cores located at both ends in the axial direction fix the inner magnetic core by an indirect fixing method via a non-magnetic member.

[0016] A seventh aspect of the present invention is the stator described above, wherein the indirect fixing method is a method in which the intervening non-magnetic member and the inner circumferential magnetic core are fixed by a second fitting structure, The laminated cores located at both ends and the intervening non-magnetic members constitute a stator that is fixed by a third fitting structure.

[0017] An eighth aspect of the present invention is the stator described above, wherein the laminated core has holes for fitting and holding the outer peripheral magnetic cores at arrangement positions of the outer peripheral magnetic cores.

[0018] A ninth aspect of the present invention is the stator described above, wherein the laminated core has a slit on the inner circumferential side of each of the holes.

[0019] A tenth aspect of the present invention is the stator described above, wherein the laminated core has a slit that cuts off the ring.

[0020] An eleventh aspect of the present invention is a radial gap transverse flux rotating electric machine equipped with the stator of the first aspect of the present invention. [Brief explanation of the drawings]

[0021] [Figure 1] 1A and 1B are diagrams for explaining a configuration example and an example of use of a radial gap transverse flux type rotating electric machine; [Figure 2] FIG. 2 is a perspective view showing an example of the configuration around the stator and rotor of the drive unit. [Figure 3] FIG. 1 is an exploded perspective view of one individual phase magnetic circuit section. [Figure 4] FIG. 10 is a perspective view of one individual phase magnetic circuit unit after assembly. [Figure 5] FIG. 10 is a perspective view for explaining the U-phase magnetic circuit portion, the V-phase magnetic circuit portion, and the W-phase magnetic circuit portion immediately before being connected. [Figure 6] A diagram showing the relative positions of the U-phase magnetic circuit, V-phase magnetic circuit, and W-phase magnetic circuit. [Figure 7] FIG. 10 is a diagram for explaining attachment of a spacer. [Figure 8] FIG. 4 is a perspective view of the stator with the inner core and wedges assembled. [Figure 9] An enlarged view of the inner periphery of the stator around the magnetic core. [Figure 10] Graph of simulation results. [Figure 11] Graph of simulation results. [Figure 12] Graph of simulation results. [Figure 13] 10A and 10B are diagrams showing modified examples of the first laminated core and the second laminated core. [Figure 14] FIG. 10 is a perspective view showing a modified example of the drive unit. [Figure 15] FIG. 2 is a perspective view showing an example of the configuration of a first-type magnetic circuit unit and a second-type magnetic circuit unit. [Figure 16] FIG. 10 is an exploded perspective view showing an example of the configuration of a stator according to a modified example. [Figure 17] FIG. 10 is a perspective view of a modified stator in an assembled state. DETAILED DESCRIPTION OF THE INVENTION

[0022] An example of an embodiment to which the present invention is applied will be described below, but it goes without saying that the form to which the present invention can be applied is not limited to the following embodiment.

[0023] 1 is a diagram for explaining a configuration example and an example of use of a radial gap transverse flux rotating electric machine (hereinafter referred to as an "RTF type rotating electric machine" where appropriate; RTF is an abbreviation for Radial Transverse Flux) according to this embodiment. Note that, to make the configuration easier to understand, the RTF type rotating electric machine in the drawing is partially cut away to reveal the internal structure.

[0024] The RTF type rotating electric machine 100 is a so-called "direct drive type traction motor" in which the rotating shaft (output shaft) is directly connected to the axle 3j of the wheel set 3 for a railway vehicle. Specifically, the RTF rotating electric machine 100 has a motor case 101 connected to a cross beam portion of a bogie frame 5 for a railway vehicle via a reaction force receiving portion 4. A motor control device (not shown) fixed to the body of the railway vehicle is connected to the RTF rotating electric machine 100 via a three-phase AC line 7, a sensor signal line 8, and a grounding line 9. A drive current is supplied from the motor control device to the RTF rotating electric machine 100 via the three-phase AC line 7, and a detection signal from a rotation sensor 10 is input to the motor control device via the sensor signal line 8. The grounding line 9 is brought into sliding contact with the axle 3j by a grounding device 12 provided on the RTF rotating electric machine 100, thereby achieving electrical grounding with the rail via the wheelset 3. In addition, a power line that supplies overhead power (or feed power via a power converter or the like configured according to the main circuit configuration) is connected to the motor control device.

[0025] In the wheel set 3, a motor case 101 is supported on an axle 3j by a bearing 102. In the main internal space of the motor case 101, rotors of three drive units 110 (110a, 110b, 110c) are fixed to the axle 3j. The number of drive units 110 included in the RTF type rotating electric machine 100 can be set as appropriate.

[0026] 2 is a perspective view showing an example of the configuration around the stator and rotor of the drive unit 110. One drive unit 110 has a rotor 112 and a stator .

[0027] The rotor 112 is a 12-pole embedded permanent magnet rotor, and can be manufactured and assembled in the same manner as conventional rotors.

[0028] Stator 130 has a plurality of phase-specific magnetic circuit portions 132 corresponding to each phase, arranged in the axial direction of rotation axis AX (the direction of the arrow of rotation axis AX). Specifically, the plurality of phase-specific magnetic circuit portions 132 include U-phase magnetic circuit portion 132u, V-phase magnetic circuit portion 132v, and W-phase magnetic circuit portion 132w. U-phase magnetic circuit portion 132u, V-phase magnetic circuit portion 132v, and W-phase magnetic circuit portion 132w basically have the same structure, are arranged coaxially in the direction of rotation axis AX and in close contact with each other, and are shifted circumferentially by a predetermined electrical angle, and are connected by inner circumferential magnetic core 160 and wedge 162 fitted to the inner circumferential side.

[0029] Eighteen inner circumferential magnetic cores 160 and eighteen wedges 162 are arranged alternately along the inner periphery. The inner circumferential magnetic cores 160 are fitted and fixed in recesses formed on the inner circumferential side surfaces of the phase-specific magnetic circuit parts 132 and spacers 170 (described in detail later).

[0030] Fig. 3 is a perspective exploded view of one of the phase magnetic circuit portions 132, specifically the U-phase magnetic circuit portion 132u. Fig. 4 is a perspective view of the assembled phase magnetic circuit portion 132 (U-phase magnetic circuit portion 132u). 3 and 4, one phase magnetic circuit unit 132 has two laminated cores (a first laminated core 141 and a second laminated core 142), 18 outer magnetic cores 144, and a coil 150 arranged on the inner circumferential side of the outer magnetic cores 144. The outer magnetic cores 144 and the coils 150 are sandwiched between the first laminated core 141 and the second laminated core 142 in the axial direction.

[0031] The first laminated core 141 and the second laminated core 142 are annular parts having the same shape.

[0032] For example, the first laminated core 141 and the second laminated core 142 can be integrated by punching and laminating non-oriented electromagnetic steel strips, which are used for stator cores in ordinary electric motors. The integration can be achieved by using adhesives, stud bolts, or the like.

[0033] In terms of shape, the first laminated core 141 and the second laminated core 142 each have 18 holes 143 set at equal intervals of 20 degrees in the circumferential direction. One outer core 144 is fitted into each hole 143 to fix and hold it in place.

[0034] Additionally, the first laminated core 141 and the second laminated core 142 have six teeth 146 set at equal intervals of 60 degrees in the circumferential direction. The teeth 146 extend from the inner circumference of the annulus toward the center and are used to fit the inner core 160 (described later). Both ends of the teeth 146 in the circumferential direction protrude inward. Therefore, when viewed from the axial direction, the inner end face of the teeth 146 forms a recess into which the inner core 160 is fitted.

[0035] When the relative positional relationship between the tooth portion 146 and the hole portion 143 is viewed in polar coordinates based on the rotation axis AX, one tooth portion 146 is provided for every three hole portions 143 in the same angular direction as the hole portion 143.

[0036] The first laminated core 141 and the second laminated core 142 are assembled with a relative angle around the rotation axis AX shifted by 20 degrees. Specifically, the outer core 144 is inserted into and fixed to the first laminated core 141, and the coil 150 is then arranged.

[0037] The coil 150 is made, for example, from a rectangular copper wire, wrapped in glass cloth, and impregnated with varnish. A space is provided between adjacent outer magnetic cores 144, and the lead wires 151 of the coil 150 are drawn out from the gaps between the adjacent outer magnetic cores 144.

[0038] Once the coil 150 is positioned, the second laminated core 142 is rotated 20 degrees clockwise relative to the first laminated core 141 when viewed from the positive direction of the rotation axis AX, and then the outer cores 144 are inserted and fixed into the holes 143 of the second laminated core 142. Note that the outer core 144 may be fixed to the holes 143 by fitting the outer core 144 into the laminated cores (first laminated core 141, second laminated core 142) in a bell-shaped manner and pressing it down from both sides with the two laminated cores. In this case, the outer core 144 can be formed into a stepped shape.

[0039] FIG. 5 is a perspective view for explaining the U-phase magnetic circuit portion 132u, the V-phase magnetic circuit portion 132v, and the W-phase magnetic circuit portion 132w immediately before being connected. The U-phase magnetic circuit portion 132u, the V-phase magnetic circuit portion 132v, and the W-phase magnetic circuit portion 132w are rotated by an electrical angle of 120 degrees around the rotation axis AX between adjacent phase magnetic circuit portions 132 in the axial direction, and are aligned coaxially with the rotation axis AX and closely packed together.

[0040] 6 is a diagram showing the relative positions of the U-phase magnetic circuit portion 132u, the V-phase magnetic circuit portion 132v, and the W-phase magnetic circuit portion 132w. The U-phase magnetic circuit portion 132u, the V-phase magnetic circuit portion 132v, and the W-phase magnetic circuit portion 132w are shown lined up vertically as viewed from the positive direction of the rotation axis AX (see FIG. 4; the front side of FIG. 6).

[0041] The V-phase magnetic circuit section 132v is positioned 120 electrical degrees and 20 mechanical degrees rotated clockwise relative to the U-phase magnetic circuit section 132u when viewed from the forward direction of the rotation axis AX. Therefore, the tooth portions 146 (146a) of the second laminated core 142 of the U-phase magnetic circuit section 132u and the tooth portions 146 (146b) of the first laminated core 141 of the V-phase magnetic circuit section 132v are in the same angular direction in polar coordinates based on the rotation axis AX, and are in close contact with each other on the front and back sides.

[0042] The W-phase magnetic circuit section 132w is positioned 120 electrical degrees and 20 mechanical degrees rotated clockwise relative to the V-phase magnetic circuit section 132v when viewed from the forward direction of the rotation axis AX. Therefore, the tooth portion 146 (146c) of the second laminated core 142 of the V-phase magnetic circuit section 132v and the tooth portion 146 (146d) of the first laminated core 141 of the W-phase magnetic circuit section 132w are in the same angular direction in polar coordinates based on the rotation axis AX, and are in close contact with each other on the front and back sides.

[0043] FIG. 7 is a diagram for explaining the attachment of the spacer 170. As shown in FIG. In the U-phase magnetic circuit portion 132u, a spacer 170 is fitted between each of the teeth 146 adjacent in the circumferential direction of the first laminated core 141. In the W-phase magnetic circuit portion 132w, a spacer 170 is fitted between each of the teeth 146 adjacent in the circumferential direction of the second laminated core 142. That is, a total of six spacers 170 (170a, 170b, ...) are attached to each of the U-phase magnetic circuit portion 132u and the W-phase magnetic circuit portion 132w. The spacers 170 may be fitted by cool fitting or by adhesive.

[0044] Spacer 170 is an arc-shaped body made of a non-magnetic material (e.g., stainless steel, aluminum, ceramic, etc.), and has two recesses 172 on the inner arc side surface for fitting inner circumferential magnetic core 160. Spacer 170 also has three protrusions 173 each having a screw hole 174.

[0045] When the spacer 170 is fitted into the phase-specific magnetic circuit portion 132 and viewed from the positive direction of the rotation axis AX, the recess 172 of the spacer 170 and the outer magnetic core 144 (see Figure 3) fitted into the hole portion 143 are aligned one-to-one on the inside and one-to-one on the outside in the same angular direction in polar coordinates based on the rotation axis AX.

[0046] Fig. 8 is a perspective view of one stator 130, showing the state in which the inner magnetic core 160 and the wedge 162 are assembled to the state shown in Fig. 7. Fig. 9 is a partially enlarged view of the periphery of the inner magnetic core 160 of a part of the stator 130 shown in Fig. 8, viewed from the positive direction of the rotation axis AX.

[0047] 8 and 9, the inner core 160 is a rod-shaped powder magnetic core having a polygonal cross section perpendicular to the axial direction that is flattened in the circumferential direction. The axial direction of the inner core 160 is the longitudinal direction, and its length spans the three closely-coupled U-phase magnetic circuit portions 132u, 132v, and 132w. The outward convex shape of the polygonal cross section of the inner core 160 is designed to fit into the inward concave shape of the tooth portion 146 and the inward concave shape of the recess 172 of the spacer 170.

[0048] Eighteen inner magnetic cores 160 are prepared. The inner magnetic cores 160 are fitted into the inner concave shapes of the tooth portions 146 and the inner concave shapes of the recesses 172 of the spacers 170 at equal intervals in the circumferential direction, with their longitudinal directions aligned with the axial direction. In other words, the multiple inner magnetic cores 160 are arranged with adjacent inner magnetic cores 160 spaced apart by a predetermined electrical angle (which is also a predetermined mechanical angle).

[0049] Wedge 162 is a rod-shaped non-magnetic material (e.g., non-magnetic stainless steel, aluminum, ceramic, glass-epoxy FRP, etc.) with a trapezoidal cross section perpendicular to the axial direction, with the outer periphery being the short side and the inner periphery being the long side. The axial direction is the longitudinal direction of wedge 162, and its length is long enough to span the U-phase magnetic circuit portion 132u, V-phase magnetic circuit portion 132v, and W-phase magnetic circuit portion 132w. Wedge 162 also has seat holes 163 at each of its longitudinal ends for screws 169 used to secure wedge 162.

[0050] The wedges 162 are fitted one by one from the inner circumferential side into the gaps between the circumferentially adjacent inner circumferential magnetic cores 160, and are screwed to the spacer 170 with screws 169. In this way, the inner circumferential magnetic cores 160 and the wedges 162 are fixed as an integrated cylindrical body.

[0051] Note that the spacers 170 may be added not only to the laminated cores at the ends in the axial direction but also to laminated cores in the middle in the axial direction, and may serve as seats for screwing the wedges 162. Specifically, a spacer 170 may be added that straddles the second laminated core 142 of the U-phase magnetic circuit portion 132u and the first laminated core 141 of the V-phase magnetic circuit portion 132v. Also, a spacer 170 may be added that straddles the second laminated core 142 of the V-phase magnetic circuit portion 132v and the first laminated core 141 of the W-phase magnetic circuit portion 132w.

[0052] Here, focusing on the fixed relationship between the inner magnetic core 160 and the phase magnetic circuit portion 132, as described above, when the tooth portion 146 is viewed from the axial direction, the inner surface of the tooth portion 146 forms a recess (see FIG. 3), which functions as a first fitting structure 191 that fits the inner magnetic core 160. Therefore, it can be said that one inner magnetic core 160 is fixed to two phase magnetic circuit portions 132 (more precisely, to one of the laminated cores (first laminated core 141, second laminated core 142) of the phase magnetic circuit portion 132) via the tooth portions 146 of those two phase magnetic circuit portions 132 by a direct fixing method using the first fitting structure 191 without interposing a non-magnetic member therebetween.

[0053] Furthermore, when focusing on one individual phase magnetic circuit unit 132, the two laminated cores (first laminated core 141, second laminated core 142) that make up that individual phase magnetic circuit unit are connected with a 20 degree offset in the clockwise direction as viewed from the positive direction of the rotation axis AX (see FIG. 4). Therefore, it can be said that the two laminated cores that make up one individual phase magnetic circuit unit 132 each have a different inner magnetic core 160 fixed thereto by a direct fixing method.

[0054] As described above, the three individual-phase magnetic circuit parts 132 are arranged coaxially, shifted by 20 degrees clockwise as viewed from the positive direction of the rotation axis AX (see FIG. 6). Therefore, it can be said that the adjacent inner circumferential magnetic cores 160 have different laminated cores fixed by the direct fixing method.

[0055] As described above, in the axially adjacent individual-phase magnetic circuit units 132, the tooth portion 146 of one second laminated core 142 and the direct fixing portion 146 of the other first laminated core 141 are in contact with each other in a front-to-back relationship in the direction of the rotation axis AX (see FIG. 6). In other words, they are in the same angular direction in polar coordinates based on the rotation axis AX. Therefore, it can be said that adjacent laminated cores in the axially adjacent individual-phase magnetic circuit units 132 are fixed to the same inner magnetic core 160 using a direct fixing method.

[0056] As described above, the spacer 170 fixes the inner core 160 in the recess 172. Therefore, it can be said that the inner core 160 is fixed by an indirect fixing method using the second fitting structure 192 via the spacer 170 to the laminated cores located at both ends in the axial direction of the individual phase magnetic circuit section 132 (the first laminated core 141 of the U-phase magnetic circuit section 132u and the second laminated core 142 of the W-phase magnetic circuit section 132w).

[0057] Furthermore, in the laminated cores located at both ends, the spacers 170 are fixed by the third fitting structures 193 formed by the recesses 147 formed between the teeth 146 adjacent to each other in the circumferential direction of the laminated cores.

[0058] When the stator 130 is assembled to the state shown in Figure 8, the U-phase magnetic circuit portion 132u, the V-phase magnetic circuit portion 132v, and the W-phase magnetic circuit portion 132w are integrally connected using the inner core 160 and the wedge 162 as a connecting structure. This is then impregnated with varnish, completing the assembly of the stator 130. The rotor 112 is inserted into the assembled stator 130, and the drive unit 110 is assembled.

[0059] 10, 11, and 12 are graphs showing the results of a magnetic field analysis simulation of the RTF rotating electric machine 100. Specifically, we performed a no-load magnetic field analysis simulation to check the voltage generated when rotating with no current and only permanent magnet magnetic flux, and a loaded magnetic field analysis simulation to pass three-phase AC current through the machine and make it function as an electric motor. The magnetic field analysis simulation was performed using a three-dimensional transient response analysis of electromagnetic field analysis software.

[0060] 10 and 11 are graphs showing the results of a magnetic field analysis simulation under no load. Figure 10 is a graph plotting the terminal voltage of each phase based on the connection point of the three-phase winding as the voltage generated in each winding. Figure 11 is a graph plotting the terminal voltage of each phase based on the average value of the voltage of each phase calculated from the results of Figure 10.

[0061] In Figure 10, the U and W phases are opposite in phase but have similar amplitudes, while the V phase has a waveform with a large amplitude at a phase intermediate between the U and W phases. Therefore, the voltage waveform is not three-phase symmetrical. On the other hand, the voltage waveform in Figure 11 is three-phase symmetrical. This is a characteristic of this magnetic circuit. In actual motors and generators, the connection points are often insulated, with a ground point on the power supply side. Therefore, the voltage is not determined based on the connection points. Therefore, it can be seen that there is no problem if the relative relationships of the three-phase terminals are three-phase symmetrical, as shown in Figure 11. From the results of this magnetic field analysis, it can be said that the RTF rotating electric machine 100 has a three-phase symmetrical magnetic circuit with respect to the voltage generated by the magnetic flux of the permanent magnets.

[0062] FIG. 12 is a graph showing the results of a magnetic field analysis simulation of average torque under load. The reluctance torque varies sinusoidally with a period twice that of the magnet torque, with the average torque peaking at current phase angles of 0 to 45 degrees and reaching zero at 90 degrees. In other words, this exhibits the torque characteristics of a typical interior permanent magnet synchronous machine. From these results, it can be said that the RTF rotating electric machine 100 has torque characteristics similar to those of a normal three-phase interior permanent magnet synchronous machine.

[0063] As described above, according to this embodiment, the following effects can be obtained. This solves the first problem, which is that when assembling a large number of permanent magnets and an iron core, the arrangement of the permanent magnets and the iron core is likely to become distorted during assembly due to the repulsive force of the permanent magnets, making assembly very difficult. That is, according to this embodiment, the permanent magnets are simply used in the embedded permanent magnet rotor 112, and the configuration of the rotor 112 is the same as that of a conventional rotor. The assembly of an embedded permanent magnet rotor is less problematic because the permanent magnets are embedded so that they are sucked into the iron core, which has pre-formed embedding holes.

[0064] Next, it is possible to solve the second problem caused by the mechanical strength of the powder magnetic core in the conventional structure using the powder magnetic core in the rotor. That is, in this embodiment, the powder magnetic cores (outer core 144, inner core 160) are fixed to the stator 130 and are not used in the rotor 112, so they do not need to withstand centrifugal force. Moreover, this structure fixes the inner core 160 to a strong laminated core formed from electromagnetic steel sheets with wedges 162 or the like. Essentially, only compressive stress is applied to the inner core 160. Because the powder magnetic core has high strength against compressive stress, problems caused by mechanical strength do not occur.

[0065] Furthermore, when used as a traction motor for a railway vehicle, it is desirable to use a rotor with salient poles in order to reduce inverter capacity, but this problem can be solved by using the rotor 112 of the embedded permanent magnet type in this embodiment, which makes it possible to utilize salient poles in the same way as in conventional permanent magnet synchronous machines.

[0066] Furthermore, this also provides a means for solving the third problem of ensuring the effective gap surface area. In other words, all gaps except for the gaps provided to prevent magnetic short-circuiting between the powder magnetic cores on the stator 130 side can be used as effective gap surfaces. This makes it possible to secure the effective gap surface area.

[0067] [Variations] Although an example of an embodiment to which the present invention is applied has been described, the forms to which the present invention can be applied are not limited to the above-described forms, and constituent elements can be added, omitted, or modified as appropriate.

[0068] (Variation 1) For example, in the laminated cores (first laminated core 141, second laminated core 142) of the above embodiment, the cores around the hole 143 that secures the outer core 144 are connected, but this is not limited to this. For example, as in the first laminated core 141B and second laminated core 142B shown in FIG. 13, individual slits 200 may be provided in each hole 143. Because an alternating magnetic field flows in the direction of the rotation axis AX in the outer core 144, an electromotive force is generated around it, and in-plane eddy currents may be generated in the laminated core. However, by providing the individual slits 200, it is possible to break the loop through which the in-plane eddy currents flow.

[0069] Similarly, the entire laminated core is one large loop, and since there is a possibility that in-plane eddy currents may flow, a full slit 202 may be provided to cut the loop that is made up of the entire laminated core.

[0070] (Variation 2) For example, as in a drive unit 110C shown in Fig. 14, three phase magnetic circuit parts 132 may be connected with stud bolts 204 to strengthen the connection in the axial direction. Specifically, holes may be drilled in the laminated core, and the three phase magnetic circuit parts 132 may be connected by passing stud bolts 204 through the holes in the axial direction. In the laminated core, the portion between the outer cores 144 does not play an important role as a magnetic circuit, so there is little or no disadvantage in passing stud bolts 204 through these portions.

[0071] When assembling the stator 130 into the motor case 101 (see FIG. 1), it is desirable to also extract the lead wires 151 of the coil 150 in the axial direction, so axial through holes for extracting the lead wires 151 may be added as appropriate.

[0072] (Variation 3) For example, the stator 130 of the above embodiment may be configured by combining a plurality of first-type magnetic circuit portions 300A and a plurality of second-type magnetic circuit portions 300B as shown in FIG. The first-type magnetic circuit portion 300A and the second-type magnetic circuit portion 300B have a flat circular ring portion 302 that is flat in the radial direction, an outer peripheral magnetic core portion 304, and an inner peripheral magnetic core portion 306, and are integrally molded as a powder magnetic core.

[0073] The flat annular portion 302 is a portion that corresponds to the first laminated core 141 in the above embodiment. The outer magnetic core portion 304 is a portion corresponding to the outer magnetic core 144 in the above embodiment, and is a portion that protrudes in the axial direction (the direction of the arrow of the rotation axis AX) from the flat annular portion 302. The protruding dimension from the flat annular portion 302 is half the axial distance between the first laminated core 141 and the second laminated core 142 in the above embodiment.

[0074] The inner circumferential magnetic core portion 306 is a portion corresponding to the inner circumferential magnetic core 160 in the above embodiment, and is a portion that protrudes from the flat annular portion 302 in the axial direction. However, the axial dimension of the inner magnetic core portion 306 differs between the first-type magnetic circuit portion 300A and the second-type magnetic circuit portion 300B. The dimension of the inner magnetic core portion 306 of the first-type magnetic circuit portion 300A is the axial thickness D of one phase magnetic circuit portion 132. The dimension of the inner magnetic core portion 306 of the second-type magnetic circuit portion 300B is the axial thickness 2D of two phase magnetic circuit portions 132.

[0075] Fig. 16 is an exploded perspective view showing an example of the configuration of a stator 130B in which a plurality of first-type magnetic circuit portions 300A and a plurality of second-type magnetic circuit portions 300B are combined together. Fig. 17 is a perspective view showing the stator 130B in an assembled state.

[0076] The first-type magnetic circuit portion 300A and the second-type magnetic circuit portion 300B have a forward orientation in which the inner circumferential magnetic core portion 306 faces the axial direction (the direction of the arrow of the rotation axis AX), and a reverse orientation in the opposite direction.

[0077] When assembling the stator 130B in order in the axial direction, first, the second-type magnetic circuit portion 300B is placed as the first part 300a in a forward orientation. Next, the type 1 magnetic circuit portion 300A of the second part 300b is brought closer to the first part 300a from the axial direction in a reverse position rotated 20 degrees mechanically in a predetermined direction, and the outer magnetic core portions 304 are brought into close contact with each other.

[0078] Next, type-2 magnetic circuit portion 300B of third part 300c is brought closer from the axial direction in a forward orientation that matches the same mechanical angle as second part 300b, and the flat end faces of flat annular portions 302 are brought into close contact with each other.

[0079] Next, the second-type magnetic circuit portion 300B of the fourth part 300d is brought into contact with the second part 300b and the third part 300c from the axial direction in a reverse orientation rotated 20 degrees mechanically in a predetermined direction. With the first part 300a as the reference, the fourth part 300d is rotated 40 degrees mechanically in the predetermined direction. The outer-circuit magnetic cores 304 are then butted against the third part 300c and brought into close contact.

[0080] Next, the first-type magnetic circuit portion 300A of the fifth part 300e is brought into contact with the fourth part 300d from the axial direction in a forward orientation that is aligned with the same mechanical angle as the fourth part 300d. With respect to the first part 300a as the reference, the fifth part 300e is rotated 40 degrees mechanically in the predetermined direction. Then, the flat end faces of the flat annular portions 302 are brought into close contact with each other.

[0081] Finally, the first-type magnetic circuit portion 300A of the sixth part 300f is brought closer to the fifth part 300e from the axial direction in a reverse orientation that matches the same mechanical angle as the first part 300a. With the first part 300a as the reference, the sixth part 300f is rotated 60 mechanical degrees in the specified direction. Then, the outer-circuit magnetic cores 304 are butted against the fifth part 300e and brought into close contact. [Explanation of symbols]

[0082] 100...RTF type rotating electric machine 110...Drive unit 112...Rotor 130...Stator 132...Phase-specific magnetic circuit section 132u...U-phase magnetic circuit section 132v...V phase magnetic circuit section 132w...W-phase magnetic circuit section 141...First laminated core 142...Second laminated core 143...hole 144...Outer magnetic core 146...tooth part 150...coil 160...Inner core 162...Wedge 170...Spacer 191...First fitting structure 192...Second fitting structure 193...Third fitting structure 200...Individual slits 202...Full slit 204...Stud bolt 300A...1-type magnetic circuit section 300B...Type 2 magnetic circuit section 302...Flat ring part 304...Outer magnetic core part 306...Inner magnetic core

Claims

1. A stator for a radial gap type transverse flux rotating electric machine, an annular phase magnetic circuit portion corresponding to each phase arranged in the axial direction; a plurality of inner circumferential magnetic cores dispersed in an annular shape; Equipped with The individual-phase magnetic circuit unit has a configuration in which a coil arranged on an inner circumferential side and an outer circumferential core arranged on an outer circumferential side of the coil are sandwiched between two laminated cores in the axial direction, the plurality of inner magnetic cores are arranged on the inner circumferential side of the coil so as to straddle the laminated core of the phase magnetic circuit portion of each phase in the axial direction. stator.

2. Each of the plurality of inner magnetic cores is fixed to one of the laminated cores by a direct fixing method without using a non-magnetic member, The adjacent inner cores have different laminated cores fixed by the direct fixing method. The stator of claim 1 .

3. The two laminated cores constituting one of the individual phase magnetic circuit units are fixed to the different inner circumferential magnetic cores by a direct fixing method without using a non-magnetic member, The adjacent laminated cores in the adjacent individual phase magnetic circuit portions have the same inner circumferential magnetic core fixed by the direct fixing method. The stator of claim 1 .

4. The plurality of inner magnetic cores are arranged such that adjacent inner magnetic cores are spaced apart by a predetermined electrical angle.

4. The stator according to claim 2 or 3.

5. The direct fixing method is a method in which the laminated core and the inner core are fixed together using a first fitting structure.

4. The stator according to claim 2 or 3.

6. Among the laminated cores of the phase-specific magnetic circuit units of each phase, the laminated cores located at both ends in the axial direction have the inner magnetic core fixed by an indirect fixing method via a non-magnetic member.

4. The stator according to claim 2 or 3.

7. The indirect fixing method is a method in which the intervening non-magnetic member and the inner circumferential magnetic core are fixed by a second fitting structure, The laminated cores located at both ends and the intervening non-magnetic members are fixed together by a third fitting structure. The stator according to claim 6.

8. The laminated core has a hole portion into which the outer magnetic core is fitted and held at a position where the outer magnetic core is arranged. The stator of claim 1 .

9. The laminated core has a slit on the inner circumferential side of each of the holes.

9. The stator of claim 8.

10. The laminated core has a slit that cuts through the ring. The stator of claim 1 .

11. A radial gap transverse flux type rotating electric machine comprising the stator according to claim 1.

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