JP2005287093A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine capable of utilizing the opposite end faces of a rotor effectively in the direction of the rotary shaft by suppressing magnetic saturation. <P>SOLUTION: The rotary electric machine comprises a stator consisting of axial sections 31 and 32 and a radial section 33. The axial section 31 has cores 311-314 and coils 321-324 and the axial section 32 has cores 312-315 and coils 322-325. The radial section 33 has cores 332-337 and coils 352-357. The cores 311-313 at the axial section 31 are arranged in correspondence with the cores 332, 334 and 336, and the cores 313-315 at the axial section 32 are arranged in correspondence with the cores 333, 335 and 337. Width W2 of the cores 311-315 in the circumferential direction DR2 is equal to two times of the width W1 of the cores 332-337 in the circumferential direction DR2. Number of turns of the coils 321-325 and 352-357 is equal. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotating electrical machine that can effectively use both end faces of a rotor in the direction of a rotating shaft magnetically.

  The rotating electrical machine includes a stator and a rotor. The rotor has a substantially cylindrical shape and is provided to be rotatable with respect to the stator.

  In many rotating electrical machines, the stator is disposed to face the outer peripheral surface of the rotor. The rotor includes a magnet magnetized in the radial direction. The stator generates magnetic flux in the radial direction of the rotor and applies a magnetic field to the magnet of the rotor. Thus, in many rotating electrical machines, the rotor rotates due to the magnetic interaction between the stator and the rotor in the radial direction of the rotor.

  On the other hand, there is also known a rotating electrical machine in which a stator is disposed on an end face side in the rotation axis direction of a rotor (Patent Document 1). In this type of rotating electrical machine, the rotor includes a magnet magnetized in the direction of the rotation axis. The stator generates a magnetic flux in the direction of the rotation axis of the rotor and applies a magnetic field to the magnet of the rotor. Thus, in the rotating electrical machine in which the stator is disposed on the end face side in the rotation axis direction of the rotor, the rotor rotates due to the magnetic interaction between the stator and the rotor in the rotation axis direction of the rotor.

Therefore, in order to produce a rotating electrical machine capable of outputting a high torque, a stator is disposed not only on the outer peripheral surface side of the rotor but also on both end surface sides of the rotor in the rotation axis direction, and the rotor radial direction and rotation axis direction The rotor needs to be rotated by the magnetic interaction between the stator and the rotor.
JP-A-10-271784

  However, the stator disposed on the rotor end surface side in the rotation axis direction is disposed along the rotor radial direction, and includes a core whose inner peripheral side is thinner than the outer peripheral side, so that it faces the outer peripheral surface of the rotor. Therefore, there is a problem that magnetic saturation is likely to occur compared to the stator arranged in this manner. As a result, there is a problem that torque decreases in a high output region.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide a rotating electrical machine that can effectively use both end faces of the rotor in the rotation axis direction while suppressing magnetic saturation. is there.

  According to this invention, the rotating electrical machine includes a rotor and a stator. The rotor has a first rotor magnetic pole portion magnetized in the radial direction and a second rotor magnetic pole portion magnetized in the rotation axis direction. The stator is provided corresponding to the first rotor magnetic pole part, provided corresponding to the first stator magnetic pole part generating the magnetic flux in the radial direction, and the second rotor magnetic pole part, and the rotating shaft. And a second stator magnetic pole portion that generates magnetic flux in the direction. The rotor rotates freely with respect to the stator by receiving magnetic fluxes from the first and second stator magnetic pole portions at the first and second rotor magnetic pole portions, respectively. The first stator magnetic pole portions are provided corresponding to the plurality of first cores arranged in the circumferential direction of the rotor and the plurality of first cores, and each of them is wound around the corresponding first core. It consists of a plurality of first coils. The second stator magnetic pole portions are provided corresponding to the plurality of second cores arranged in the circumferential direction of the rotor and the plurality of second cores, and each of them is wound around the corresponding second core. It consists of a plurality of second coils. The second core has a cross-sectional area equal to or larger than the cross-sectional area of the first core in the plane direction perpendicular to the rotation axis direction in the plane direction perpendicular to the radial direction of the rotor. The minimum width of the first core in the circumferential direction of the rotor is W1, the number of turns of the first coil is N1, the minimum width of the second core in the circumferential direction of the rotor is W2, and the number of turns of the second coil Is N2, W2 / N2> W1 / N1 holds.

  Preferably, the plurality of coils of any one of the plurality of first coils and the plurality of second coils are coil ends of the other plurality of coils of the plurality of first coils and the plurality of second coils. Placed inside.

  Preferably, N1> N2 holds.

  Preferably, the first and second coils are wound integrally.

  Preferably, the first coil is wound separately from the second coil.

  Preferably, the total number of the plurality of first cores is larger than the total number of the plurality of second cores.

  Preferably, the rotor has a substantially cylindrical shape. The plurality of first cores are arranged in the circumferential direction of the rotor so as to face the cylindrical outer peripheral surface. The plurality of second cores includes a plurality of first axial cores arranged in the circumferential direction of the rotor so as to face one end face of the cylindrical shape in the rotation axis direction of the rotor, and a cylindrical shape in the rotation axis direction of the rotor. It consists of several 2nd axial cores arrange | positioned in the circumferential direction of a rotor facing the other end surface. The plurality of second coils are provided corresponding to the plurality of first axial cores, each of the plurality of first axial coils wound around the corresponding first axial core, and the plurality of second coils. It comprises a plurality of second axial coils provided corresponding to the axial cores, each wound around a corresponding second axial core. The plurality of first axial cores are arranged at positions shifted in the circumferential direction of the rotor with respect to the plurality of second axial cores.

  Preferably, the first and second axial coils are wound in a direction in which the winding direction of the first coil is reversed.

  Preferably, the first and second axial coils are wound integrally with the first coil.

  In the rotating electrical machine according to the present invention, magnetic interaction occurs between the rotor and the stator in both the radial direction and the rotational axis direction of the rotor, and the rotor rotates freely with respect to the stator. That is, the rotational torque of the rotor is generated in both the radial direction and the rotational axis direction of the rotor. A value W2 / N2 obtained by dividing the circumferential width of the second core by the number of coil turns in the second stator magnetic pole portion disposed opposite to the end surface of the rotor in the rotation axis direction is calculated on the outer circumferential surface of the rotor. It is larger than the value W1 / N1 obtained by dividing the circumferential width of the first core by the number of coil turns in the first stator magnetic pole portions arranged to face each other. As a result, the second stator magnetic pole portion generates more magnetic flux in the direction of the rotation axis than when W1 = W2 and N1 = N2.

  Therefore, according to the present invention, magnetic saturation can be suppressed and both end faces of the rotor in the rotation axis direction can be effectively used.

  Embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
1 is an exploded view of a rotating electrical machine according to Embodiment 1 of the present invention. Referring to FIG. 1, rotating electric machine 100 according to the first embodiment includes a shaft 10, a rotor 20, a stator 30, a case 40, and covers 50 and 60.

  The rotor 20 is fixed to the shaft 10. The rotor 20 includes axial portions 21 and 22 and a radial portion 23. The axial part 21 consists of magnets 21A to 21H, the axial part 22 consists of magnets 22A to 22H, and the radial part 23 consists of magnets 23A to 23H. In FIG. 1, the magnets 22C to 22F and 23C to 23G are not shown.

  The eight magnets 21A to 21H are arranged along the circumferential direction DR2 on one end face of the rotor 20 in the rotation axis direction DR1. The eight magnets 22A to 22H are arranged along the circumferential direction DR2 on the other end face of the rotor 20 in the rotation axis direction DR1. Further, the eight magnets 23 </ b> A to 23 </ b> H are arranged on the outer peripheral surface of the rotor 20 along the circumferential direction DR <b> 2.

  The magnets 21A to 21H and 22A to 22H are magnetized in the rotation axis direction DR1, and the magnets 23A to 23H are magnetized in the radial direction DR3 of the rotor 20.

  The stator 30 includes axial portions 31 and 32 and a radial portion 33. The axial portions 31 and 32 generate magnetic flux in the rotation axis direction DR1, and the radial portion 33 generates magnetic flux in the radial direction DR3.

  The shaft 10, the rotor 20, and the stator 30 are inserted into the case 40, and the covers 50 and 60 are attached to both ends of the case 40 from the rotation axis direction DR1.

  FIG. 2 is a cross-sectional view of rotating electric machine 100 taken along line II-II shown in FIG. Referring to FIG. 2, axial portion 21 is disposed on one end surface of rotor 20 in rotation axis direction DR1, and axial portion 22 is disposed on the other end surface of rotor 20 in rotation axis direction DR1. . A radial portion 23 is disposed on the outer peripheral surface of the rotor 20 in the radial direction DR3.

  The axial part 31 is fixed to the cover 50, and the axial part 32 is fixed to the cover 60. The axial portion 31 of the stator 30 is disposed to face the axial portion 21 of the rotor 20, and the axial portion 32 of the stator 30 is disposed to face the axial portion 22 of the rotor 20. Further, the radial portion 33 of the stator 30 is disposed to face the radial portion 23 of the rotor 20.

  FIG. 3 is a perspective view of the axial portion 31 of the stator 30 shown in FIG. The axial part 31 includes a bracket 310, cores 311 to 316, and coils 321 to 326. The bracket 310 has holes 310 </ b> A to 310 </ b> F through which terminals of a coil of the radial portion 33 described later pass. The cores 311 to 316 are fixed to the bracket 310. The cores 311 to 316 are arranged in the circumferential direction DR2, and the coils 321 to 326 are wound around the cores 311 to 316, respectively. Then, the terminal 320 is taken out from the coils 321 to 326 in the rotation axis direction DR1.

  Note that the axial portion 32 of the stator 30 shown in FIG. 1 has the same structure as the axial portion 31.

  FIG. 4 is a perspective view of the radial portion 33 of the stator 30 shown in FIG. Referring to FIG. 4, radial portion 33 includes a steel plate 330, cores 331 to 342, and coils 351 to 362. Note that the cores 336 to 342 are not shown in FIG.

  The steel plate 330 has a structure in which a plurality of electromagnetic steel plates are laminated in the rotation axis direction DR1. The cores 331 to 342 are fixed to the inner peripheral surface of the steel plate 330 along the circumferential direction DR2. The coils 351 to 362 are wound around the cores 331 to 342, respectively.

  The terminals of the coils 352, 354, 356, 358, 360, 362 are taken out to one side in the rotation axis direction DR1, and the terminals of the coils 351, 353, 355, 357, 359, 361 are the other side in the rotation axis direction DR1. Is taken out. The terminals of the coils 352, 354, 356, 358, 360, and 362 pass through the holes 310A to 310F of the axial portion 31 and are connected to the bus bar, and the coils 351, 353, 355, 357, 359, and 361 are connected. The terminal is connected to the bus bar through the holes 310A to 310F of the axial part 32, for example.

  As described above, in the rotating electrical machine 100, the axial portions 31 and 32 of the stator 30 include the six cores 311 to 316 and the six coils 321 to 326, and the radial portion 33 of the stator 30 includes twelve radial portions 33. Cores 331 to 342 and twelve coils 351 to 362. Further, the axial portions 21 and 22 of the rotor 20 are each composed of eight magnets 21A to 21H and 22A to 22H, and the radial portion 23 of the rotor 20 is composed of eight magnets 23A to 23H.

  FIG. 5 is a perspective view of the rotating electrical machine 100. Referring to FIG. 5, radial portion 33 of stator 30 is arranged in contact with inner peripheral surface 40 </ b> A of case 40. The rotor 20 is disposed on the inner peripheral side of the radial portion 33 of the stator 30, and the shaft 10 is disposed at the center of the rotor 20. The axial portion 31 of the stator 30 is housed in the case 40 from one side in the rotation axis direction DR1. In this case, the terminal 340 taken out from the six coils of the radial portion 33 of the stator 30 in the rotation axis direction DR1 passes through the hole 310A of the axial portion 31 and the like.

  FIG. 6 is another perspective view of the rotating electrical machine 100. Referring to FIG. 6, bus bar 70 is arranged on axial portion 31 of stator 30 housed in case 40, and terminal 320 of axial portion 31 and terminal 340 of radial portion 33 are connected to bus bar 70.

  Terminal 80 includes a U-phase terminal, a V-phase terminal, and a W-phase terminal, and bus bar 70 is connected to the U-phase terminal, the V-phase terminal, and the W-phase terminal. As a result, the terminal 80 supplies current to the coils of the axial portion 31 and the six coils of the radial portion 33. The terminal 90 supplies current to the coil of the axial portion 32 of the stator 30 and the remaining six coils of the radial portion 33. The cover 50 is provided on the axial portion 31 side of the stator 30.

  FIG. 7 is a development view of a part of the axial portions 31 and 32 and the radial portion 33 of the stator 30 shown in FIG. Referring to FIG. 7, in axial portion 31 of stator 30, cores 311 to 314 constitute a U-phase core, a W-phase core, a V-phase core, and a U-phase core, respectively. 325 constitutes a W-phase core, a V-phase core, a U-phase core, and a W-phase core, respectively. Further, in radial portion 33 of stator 30, cores 332 to 334 constitute a U-phase core, a V-phase core, and a W-phase core, respectively, and cores 335 to 337 respectively constitute a U-phase core, a V-phase core, and a W-phase core. Constitute.

  The core 332 of the radial portion 33 is provided corresponding to the core 311 of the axial portion 31, the core 333 of the radial portion 33 is provided corresponding to the core 313 of the axial portion 32, and the core 334 of the radial portion 33 is It is provided corresponding to the core 312 of the axial part 31. The core 335 of the radial portion 33 is provided corresponding to the core 314 of the axial portion 32, the core 336 of the radial portion 33 is provided corresponding to the core 313 of the axial portion 31, and the core 337 of the radial portion 33. Are provided corresponding to the core 315 of the axial portion 32.

  Each of the cores 332 to 337 of the radial portion 33 has a width W1 in the circumferential direction DR2, and each of the cores 311 to 315 of the axial portions 31 and 32 has a width W2 in the circumferential direction DR2. The width W2 is equal to a width obtained by doubling the width W1.

  The cores 311, 312, and 313 of the axial portion 31 are arranged such that the centers in the circumferential direction DR 2 coincide with the centers in the circumferential direction DR 2 of the corresponding cores 332, 334, and 336 of the radial portion 33, respectively. The cores 313, 314, and 315 are arranged such that the centers in the circumferential direction DR2 coincide with the centers in the circumferential direction DR2 of the corresponding cores 333, 335, and 337 of the radial portion 33, respectively.

  The coil 352 is connected to the coil 321 of the axial portion 31, and the coils 321 and 352 are integrally wound around the cores 311 and 332. In this case, the coils 321 and 352 are wound in the shape of figure 8 in the direction indicated by the arrow.

  The coil 353 is connected to the coil 323 of the axial portion 32, and the coils 323 and 353 are integrally wound around the cores 313 and 333. In this case, the coils 323 and 353 are wound in the shape of figure 8 in the direction indicated by the arrow.

  Further, the coil 354 is connected to the coil 322 of the axial portion 31, and the coils 322 and 354 are integrally wound around the cores 312 and 334. In this case, the coils 322 and 354 are wound in a figure 8 shape in the direction indicated by the arrow.

  Further, the coil 355 is connected to the coil 324 of the axial portion 32, and the coils 324 and 355 are integrally wound around the cores 314 and 335. In this case, the coils 324 and 355 are wound in the shape of figure 8 in the direction indicated by the arrow.

  Further, the coil 356 is connected to the coil 323 of the axial portion 31, and the coils 323 and 356 are integrally wound around the cores 313 and 336. In this case, the coils 323 and 356 are wound in a figure 8 shape in the direction indicated by the arrow.

  Further, the coil 357 is connected to the coil 325 of the axial portion 32, and the coils 325 and 357 are integrally wound around the cores 315 and 337. In this case, the coils 325 and 357 are wound in an 8-shape in the direction indicated by the arrow.

  The coils 321 and 352 are U-phase coils, one end of which is connected to the U-phase terminal UT of the bus bar 70 disposed on the axial part 31 side, and the other end is connected to the neutral point N of the bus bar 70. Coils 322 and 354 are W-phase coils, and one end thereof is connected to W-phase terminal WT of bus bar 70 and the other end is connected to neutral point N of bus bar 70. Further, coils 323 and 356 are V-phase coils, and one end thereof is connected to V-phase terminal VT of bus bar 70 and the other end is connected to a neutral point of bus bar 70.

  On the other hand, on the axial part 32 side, the coils 323 and 353 are connected to the V-phase terminal VT of the bus bar 71 arranged on the axial part 32 side as the V-phase coil, and the other end is connected to the neutral point N. Is done. Coils 324 and 355 are U-phase coils, and one end thereof is connected to U-phase terminal UT of bus bar 71 and the other end is connected to neutral point N of bus bar 71. Further, coils 325 and 357 are W-phase coils, and one end thereof is connected to W-phase terminal WT of bus bar 71 and the other end is connected to neutral point N of bus bar 71.

  As described above, the coils 352 to 357 of the radial portion 33 are alternately connected to the coils 321 to 324 of the axial portion 31 and the coils 322 to 325 of the axial portion 32. The number of turns N1 of the coils 352 to 357 in the radial part 33 is the same as the number of turns N2 of the coils 321 to 325 in the axial parts 31 and 32.

  In the axial parts 31, 32, each phase changes in the circumferential direction DR2 in the order of W phase → V phase → U phase, and in the radial part 33, each phase changes in the circumferential direction DR2 from U phase → V phase → W. Change in order of phase. That is, in the axial portions 31 and 32, each phase changes opposite to the radial portion 33. Therefore, the coils 321 to 325 wound around the cores 311 to 315 of the axial portions 31 and 32 are wound in a direction opposite to the winding direction of the coils 352 to 357 wound around the cores 332 to 337 of the radial portion 33. Turned. For this reason, when winding a coil integrally between the axial parts 31 and 32 and the radial part 33, as above-mentioned, the coils 321, 352; 323, 353; 322, 354; 324, 355; 356; 325 and 357 are each wound into an 8-shape. As a result, in the axial parts 31 and 32 and the radial part 33, a rotating magnetic field can be generated in the order of U phase → V phase → W phase.

  Further, as described above, the cores 311 to 315 of the axial portions 31 and 32 have the width W2 in the circumferential direction DR2 that is twice the width W1 of the cores 332 to 337 of the radial portion 33 in the circumferential direction DR2, and the radial portion Since the coils 352 to 357 of 33 are alternately connected to the coils 321 to 324 of the axial part 31 and the coils 322 to 325 of the axial part 32, the U-phase cores (cores 311 and 314) and V in the axial part 31 are connected. The phase core (core 313) and the W phase core (core 312) are circumferential with respect to the U phase core (core 314), the V phase core (core 313), and the W phase core (cores 312 and 315) in the axial portion 32. It is arranged at a position shifted to DR2.

  When a current flows through the coils 351 to 362, the radial portion 33 of the stator 30 generates a magnetic field in the radial direction DR3 and applies the generated magnetic field to the magnets 23A to 23H of the rotor 20. Further, the axial portions 31 and 32 of the stator 30 generate a magnetic field in the rotation axis direction DR1 when a current flows through the coils 321 to 326, and the generated magnetic fields are applied to the magnets 21A to 21H and 22A to 22H of the rotor 20, respectively. Effect.

  Then, as described above, the magnets 23A to 23H are magnetized in the radial direction DR3, and the magnets 21A to 21H and 22A to 22H are magnetized in the rotation axis direction DR1, so that the magnets 23A to 23H and the magnet 21A are magnetized. -21H and 22A-22H interact with the magnetic field from the radial part 33 and the axial parts 31 and 32 of the stator 30, respectively. As a result, the rotor 20 rotates around the rotation axis.

  In this case, the rotor 20 has a magnetic interaction between the radial portion 33 of the stator 30 existing in the radial direction DR3 and the magnets 23A to 23H of the rotor 20, and the axial portions 31, 32 of the stator 30 existing in the rotation axis direction DR1. And the magnetic interaction with the magnets 21A to 21H and 22A to 22H of the rotor 20 rotate around the rotation axis. Therefore, the rotating electrical machine 100 can have a higher torque density than when the rotor 20 rotates only by the magnetic interaction between the radial portion 33 of the stator 30 and the magnets 23A to 23H of the rotor 20 that exist in the radial direction DR3. In addition, since torque is generated at both ends of the rotor 20 in the rotational axis direction DR1, there is no wasted space and the space utilization efficiency can be increased. Furthermore, there is little magnetic flux leaking in the rotational axis direction DR1 on the end surface of the rotor 20 in the rotational axis direction DR1 and in the radial direction DR3 on the outer peripheral surface of the rotor 20, and torque can be generated efficiently.

  FIG. 8 is a perspective view showing some cores of the axial portions 31 and 32 and the radial portion 33 shown in FIG. In FIG. 8, cores 311 and 312 are shown as cores of the axial part 31, a core 313 is shown as a core of the axial part 32, and a core 333 is shown as a core of the radial part 33.

  Referring to FIG. 8, the core 333 of the radial portion 33 has a width W1 in the circumferential direction DR2 at the innermost circumferential end 333A in the radial direction DR3. The core 333 has a width wider than the width W1 in the circumferential direction DR2 at the outermost peripheral end 333B. That is, the core 333 has a substantially fan-shaped planar shape in the radial direction DR3. The core 333 has a length L1 in the radial direction DR3. Therefore, the width W1 is the minimum width of the core 333 in the circumferential direction DR2.

  The cores 311 and 312 of the axial portion 31 and the core 313 of the axial portion 32 have a width W2 in the circumferential direction DR2 at the innermost circumferential ends 311A, 312A, and 313A in the radial direction DR3. The cores 311, 312, and 313 have a width wider than the width W2 in the circumferential direction DR2 at the outermost peripheral ends 311B, 312B, and 313B. That is, the cores 311, 312, and 313 have a substantially fan-shaped planar shape in the radial direction DR3. The cores 311, 312, and 313 have a length L2 in the radial direction DR3. Therefore, the width W2 is the minimum width in the circumferential direction DR2 of the cores 311, 312, and 313.

  The length L2 of the cores 311, 312, and 313 of the axial parts 31 and 32 is the same width as the width W1 in the circumferential direction DR2 of the core 333 of the radial part 33, and the radial direction DR3 when the cores of the axial parts 31 and 32 are manufactured. Is the same length. Further, in the core 333 of the radial portion 33, the cross-sectional area of the plane 333C perpendicular to the rotation axis direction DR1 is S1, and in the core 311 of the axial portions 31 and 32, the cross-sectional area of the end surface 311D perpendicular to the radial direction DR3 is S2. S2> S1.

  Therefore, the cores 311, 312, and 313 correspond to cores obtained by expanding the core 370 having the same width as the width W <b> 1 in the circumferential direction DR <b> 2 of the core 333 of the radial portion 33 in the circumferential direction DR <b> 2.

  The coil 321 is wound around the core 311 so as to surround the end faces 311C, 311D, 311E, and 311F of the core 311. The coils 322 and 323 are also wound around the cores 312 and 313 in the same manner as the coil 321. The coil 353 is wound around the core 333 so as to surround the end faces 333D, 333E, 333F, and 333G.

  As described above, since the number of turns N1 of the coil 353 is the same as the number of turns N2 of the coils 321, 322, and 323, the following equation is established.

W2 / N2> W1 / N1 (1)
That is, the value W2 / N2 obtained by dividing the minimum width W2 in the circumferential direction DR2 of the cores 311, 312 and 313 of the axial portions 31 and 32 by the number of turns N2 of the coils 321, 322 and 323 is the circumferential direction of the core 333 of the radial portion 33 It is larger than the value W1 / N1 obtained by dividing the minimum width W1 of DR2 by the number of turns N1 of the coil 353.

  When a current flows through the coils 321, 322, and 323, the cores 311, 312, and 313 generate magnetic flux in the rotation axis direction DR1, and are less likely to cause magnetic saturation than when having a width W1 in the circumferential direction DR2. That is, the cores 311, 312, and 313 have a width W2 in the circumferential direction DR2 corresponding to twice the width W1 at the innermost peripheral ends 311A, 312A, and 313A, and the same length L2 as the core 370 in the radial direction DR3. Therefore, the cross-sectional area of the plane perpendicular to the rotation axis direction DR1 in the cores 311, 312, and 313 is larger than that of the core 370. Then, the cores 311, 312, and 313 can generate more magnetic flux than the core 370, and it is difficult for magnetic saturation to occur. As a result, the stator 30 is less likely to cause magnetic saturation than in the case where the cores of the axial portions 31 and 32 have the same width as the core of the radial portion 33 in the circumferential direction DR2, and the rotating electrical machine 100 is more resistant to the high power region. A large torque can be output.

  In the first embodiment, the width W2 (minimum value) in the circumferential direction DR2 of the cores 311 to 316 of the axial portions 31 and 32, the number of turns N2 of the coils 321 to 326 of the axial portions 31 and 32, and the core 331 of the radial portion 33. The above formula (1) is established between the width W1 (minimum value) in the circumferential direction DR2 of ˜342 and the number of turns N1 of the coils 351 to 362 of the radial portion 33, and the cores 311 to 316 of the axial portions 31 and 32 The cross-sectional area S2 perpendicular to the radial direction DR3 is larger than the cross-sectional area S1 perpendicular to the rotation axis direction DR1 of the cores 331 to 342 of the radial portion 33.

  Due to this feature, the axial portions 31 and 32 are less likely to cause magnetic saturation than when including the core 370 having the same width as the cores 331 to 342 of the radial portion 33 in the circumferential direction DR2. As a result, the rotating electrical machine 100 can output higher torque in the high output region.

  In the above description, it has been described that the number of turns N1 of the coils 351 to 362 of the radial portion 33 is the same as the number of turns N2 of the coils 321 to 326 of the axial portions 31 and 32. However, the present invention is not limited to this. The number of turns N1 of the coils 351 to 362 of the part 33 may be larger than the number of turns N2 of the coils 321 to 326 of the axial parts 31 and 32. Thereby, W2 / N2 becomes larger than W1 / N1 as compared with the case where N1 = N2, and the magnetic saturation in the axial portions 31 and 32 is less likely to occur.

  In this case, after the coil is integrally wound around the cores 311 to 316 of the axial part 31 or 32 and the cores 331 to 342 of the radial part 33 in an 8-shape, only the cores 331 to 342 of the radial part 33 are further wound. N1> N2 may be established by winding a coil, and N1> N2 is established by separately winding coils around the cores 311 to 316 of the axial portions 31 and 32 and the cores 331 to 342 of the radial portion 33. You may make it do.

  One of the coils 321 to 326 of the axial parts 31 and 32 and the coils 351 to 362 of the radial part 33 is any of the coils 321 to 326 of the axial parts 31 and 32 and the coils 351 to 360 of the radial part 33. It is arranged inside the coil end of the other coil.

  Thus, the other coil can be arranged in the dead space inside the coil end, and the torque can be increased without increasing the size of the rotating electrical machine.

  Furthermore, the cores 311 to 316, 331 to 342 and the core of the rotor 20 may be formed of a dust core.

  The magnets 21A to 21H and the magnets 22A to 22H constitute a “second rotor magnetic pole portion” magnetized in the rotational axis direction DR1, and the magnets 23A to 23H are “first” magnetized in the radial direction DR3. 1 rotor magnetic pole part ".

  In addition, the axial portions 31 and 32 are provided corresponding to the first rotor magnetic pole portion and constitute a “second stator magnetic pole portion” that generates a magnetic flux in the rotation axis direction DR1. A “first stator magnetic pole portion” is provided corresponding to the first rotor magnetic pole portion and generates a magnetic flux in the radial direction DR3.

  Furthermore, the cores 311 to 316 of the axial part 31 constitute “a plurality of first axial cores”, and the coils 321 to 326 of the axial part 31 constitute “a plurality of first axial coils”.

  Further, the cores 311 to 316 of the axial portion 32 constitute “a plurality of second axial cores”, and the coils 321 to 326 of the axial portion 32 constitute “a plurality of second axial coils”.

[Embodiment 2]
FIG. 9 is a perspective view of a stator and a rotor of the rotating electrical machine according to the second embodiment. Referring to FIG. 9, rotating electric machine 200 according to Embodiment 2 includes a stator 110 and a rotor 120.

  The stator 110 has a hollow and substantially cylindrical shape and is made of an iron material. Stator 110 includes a core 111 and a coil 112. The core 111 is substantially U-shaped and is integrally formed. A plurality of cores 111 are provided at predetermined intervals along the inner wall of the stator 110.

  The core 111 has a radial part 111A and axial parts 111B and 111C. The radial portion 111A is disposed in the rotational axis direction DR1 of the rotor 120, and the axial portions 111B and 111C are disposed in the radial direction DR3 of the rotor 120. On the paper surface of FIG. 9, the axial portion 111 </ b> B is provided at the upper portion of the stator 110, and the axial portion 111 </ b> C is provided at the lower portion of the stator 110.

  The coil 112 is wound along the core 111 in the rotation axis direction DR1 and the radial direction DR3. Therefore, the coil 112 is also substantially U-shaped and has a radial portion 112A and axial portions 112B and 112C. Since the coil 112 wound around the core 111 is in contact with the inner wall of the stator 110, the cooling performance of the coil 112 can be improved. That is, since the coil 112 is covered with the iron material which comprises the stator 110, the cooling property of the coil 112 can be improved.

  Rotor 120 includes a rotor shaft 121, a rotor core 122, and a magnet 123. The rotor core 122 has a substantially cylindrical shape and has a structure in which a plurality of electromagnetic steel plates are laminated in the rotation axis direction DR1 of the rotor 120. The rotor core 122 is fixed to the rotor shaft 121. The magnet 123 has a substantially U-shape and is fixed to the rotor core 122 so as to sandwich the rotor core 122. A plurality of magnets 123 are arranged at a predetermined interval in the circumferential direction DR2 of the rotor 120.

  The magnet 123 has a radial part 123A and axial parts 123B and 123C. Then, the radial portion 123A protrudes in the radial direction DR3 from the cylindrical surface 122A of the rotor core 122. Further, the axial portions 123B and 123C protrude in the rotation axis direction DR1 from the cylindrical end surfaces 122B and 122C of the rotor core 122.

  That is, the radial portion 123A is a magnet disposed on the cylindrical surface 122A of the rotor 120, and the axial portions 123B and 123C are disposed on the cylindrical end surfaces 122B and 122C existing at both ends of the rotor 120 in the rotation axis direction DR1. Magnet. The radial portion 123A is magnetized in the radial direction DR3, and the axial portions 123B and 123C are magnetized in the rotational axis direction DR1.

  The rotor 120 is disposed in the hollow portion of the stator 110. In this case, the radial portion 111A of the core 111 and the radial portion 112A of the coil 112 are opposed to the radial portion 123A of the magnet 123, and the axial portion 111B of the core 111 and the axial portion 112B of the coil 112 are opposed to the axial portion 123B of the magnet 123. The axial portion 111 </ b> C of the core 111 and the axial portion 112 </ b> C of the coil 112 are opposed to the axial portion 123 </ b> C of the magnet 123.

  That is, the radial part 111A of the core 111 and the radial part 112A of the coil 112 are provided corresponding to the radial part 123A of the magnet 123, and the axial part 111B of the core 111 and the axial part 112B of the coil 112 are the axial part of the magnet 123. The axial portion 111 </ b> C of the core 111 and the axial portion 112 </ b> C of the coil 112 are provided corresponding to the axial portion 123 </ b> C of the magnet 123. As described above, the radial portion 123A of the magnet 123 is disposed on the cylindrical surface 122A of the rotor core 122, and the axial portions 123B and 123C of the magnet 123 are disposed on the cylindrical end surfaces 122B and 122C of the rotor core 122, respectively. Therefore, the radial portion 111A of the core 111 and the radial portion 112A of the coil 112 are provided to face the cylindrical surface 122A of the rotor core 122, and the axial portion 111B of the core 111 and the axial portion 112B of the coil 112 are the cylinder of the rotor core 122. The axial portion 111 </ b> C of the core 111 and the axial portion 112 </ b> C of the coil 112 are provided to face the cylindrical end surface 122 </ b> C of the rotor core 122.

  FIG. 10 is a perspective view of the coil 112 and the rotor 120 shown in FIG. Referring to FIG. 10, radial portion 123 </ b> A and axial portions 123 </ b> B and 123 </ b> C of magnet 123 can rotate in the circumferential direction DR <b> 2 inside coil 112 having a substantially U-shape.

  11 is a cross-sectional view of stator 110 and rotor 120 of rotating electric machine 200 shown in FIG. Referring to FIG. 11, magnet 123 is fixed to rotor core 122 from radial direction DR <b> 3 of rotor 120 so as to sandwich rotor core 122.

  The bearings 3 to 6 are provided between the stator 110 and the rotor shaft 121 of the rotor 120. And the rotor shaft 121 is supported by the bearings 3-6. As a result, the rotor 120 is rotatably supported with respect to the stator 110.

  Stator 110 includes a radial portion 110A, axial portions 110B and 110C, and coupling portions 110D and 110E. The radial portion 110 </ b> A is disposed in the rotation axis direction DR <b> 1 of the rotor 120. The axial portions 110B and 110C are disposed in the radial direction DR3 of the rotor 120. The radial portion 110A faces the radial portion 123A of the magnet 123, and the axial portions 110B and 110C face the axial portions 123B and 123C of the magnet 123, respectively.

  The radial part 110A includes the radial part 111A of the core 111 and the radial part 112A of the coil 112, and the axial parts 110B and 110C include the axial parts 111B and 111C of the core 111 and the axial parts 112B and 112C of the coil 112, respectively. Including. Therefore, when a current flows through the coil 112, the radial portion 110A generates a magnetic field in the radial direction DR3 and applies the generated magnetic field to the radial portion 123A of the magnet 123. Further, when current flows through the coil 112, the axial portions 110B and 110C generate a magnetic field in the rotation axis direction DR1, and apply the generated magnetic field to the axial portions 123B and 123C of the magnet 123, respectively.

  Then, as described above, since the radial portion 123A of the magnet 123 is magnetized in the radial direction DR3 and the axial portions 123B and 123C are magnetized in the rotation axis direction DR1, the radial portion 123A and the axial portion 123B, 123C interacts with the magnetic fields from the radial portion 110A and the axial portions 110B and 110C of the stator 110, respectively. As a result, the rotor 120 rotates around the rotation axis AX.

  In this case, the rotor 120 has a magnetic interaction between the radial portion 110A of the stator 110 existing in the radial direction DR3 and the radial portion of the rotor 120 (= the radial portion 123A of the magnet 123), and the stator existing in the rotation axis direction DR1. It rotates around the rotation axis AX by the magnetic interaction between the 110 axial portions 110B and 110C and the axial portion of the rotor 120 (= the axial portions 123B and 123C of the magnet 123). Therefore, the rotating electrical machine 200 is more than the case where the rotor 120 rotates only by the magnetic interaction between the radial portion 110A of the stator 110 existing in the radial direction DR3 and the radial portion of the rotor 120 (= radial portion 123A of the magnet 123). Torque density can be increased. In addition, since torque is generated at both ends of the rotor 120 in the rotational axis direction DR1, there is no wasted space and space utilization efficiency can be increased. Furthermore, there is little magnetic flux leaking in the rotational axis direction DR1 on the cylindrical surface 122A and in the radial direction DR3 on the cylindrical end surfaces 122B and 122C, and torque can be generated efficiently.

  12 is a perspective view of the core 111 shown in FIG. Referring to FIG. 12, radial portion 111A has a width W3 in circumferential direction DR2 at the innermost circumferential end in radial direction DR3 and a width W4 in radial direction DR3. Further, the axial portion 111B contacts the radial portion 111A at the innermost peripheral end of the radial portion 111A in the radial direction DR3, and has a width W3 in the circumferential direction DR2 and a width in the rotational axis direction DR1. W4. The axial portion 111C has the same widths W3 and W4 as the axial portion 111B.

  Accordingly, the cross-sectional area S3 of the radial portion 111A perpendicular to the rotation axis direction DR1 is the same as the cross-sectional area S4 of the axial portions 111B and 111C perpendicular to the radial direction DR3. That is, the axial portions 111B and 111C of the core 111 have the same cross-sectional area S4 in the radial direction DR3 as the cross-sectional area S3 of the radial portion 111A perpendicular to the rotation axis direction DR1.

  FIG. 13 is a perspective view of the coil 112 shown in FIG. Referring to FIG. 13, coil 112 includes coils 1121 and 1122. The coil 1121 is integrally wound in a substantially U shape from the rotational axis direction DR1 of the rotor 120 to the radial direction DR3. The coil 1121 includes a radial part 1121A and axial parts 1121B and 1121C. Further, the coil 1122 is wound in the rotation axis direction DR1 of the rotor 120.

  The radial portion 112A of the coil 112 includes a radial portion 1121A and a coil 1122 of the coil 1121, the axial portion 112B of the coil 112 includes an axial portion 1121B of the coil 1121, and the axial portion 112C of the coil 112 includes the axial portion of the coil 1121. Part 1121C.

  As described above, the radial portion 112A of the coil 112 includes the radial portion 1121A of the coil 1121 that is integrally wound in the rotation axis direction DR1 and the radial direction DR3 and the coil 1122 that is wound in the rotation axis direction DR1. The radial part 112A of the coil 112 (= the radial part 1121A and the coil 1122 of the coil 1121) has more turns than the axial part 112B (= the axial part 1121B of the coil 1121) and 112C (= the axial part 1121C of the coil 1121). There are many. That is, when the number of turns of the radial portion 112A of the coil 112 is N3 and the number of turns of the axial portions 112B and 112C of the coil 112 is N4, N3> N4 is established.

  As described above, the coil 112 includes the coil 1121 integrally wound in a substantially U-shape in the rotation axis direction DR1 and the radial direction DR3, and the coil 1122 wound in the rotation axis direction DR1. The number of turns N3 of the portion 112A is larger than the number of turns N4 of the axial portions 112B and 112C.

  FIG. 14 is another perspective view of the coil 112 shown in FIG. Referring to FIG. 14, coil 112 includes coils 1123 to 1125. The coil 1123 is wound in the rotation axis direction DR1 of the rotor 120. The coils 1124 and 1125 are wound in the radial direction DR3 of the rotor 120. The number of turns N5 of the coil 1123 is larger than the number of turns N6 of the coils 1124 and 1125.

  The coil 1123 constitutes the radial part 112A of the coil 112, the coil 1124 constitutes the axial part 112B of the coil 112, and the coil 1125 constitutes the axial part 112C of the coil 112.

  Therefore, even when the coil 112 is composed of the coils 1123 to 1125, the number N5 of turns of the radial portion 112A (= coil 1123) of the coil 112 is equal to that of the axial portions 112B (= coil 1124) and 112C (= coil 1125) of the coil 112. More than the number of turns N6.

  Thus, in the second embodiment, the radial portion 111A of the core 111 and the axial portions 111B and 111C have the same width W3 in the circumferential direction DR2, and the number of turns N5 of the radial portion 112A of the coil 112 is the axial portion 112B. , 112C, more than the number of turns N6.

  As a result, the following equation is established.

W3 / N6> W3 / N5 (2)
That is, the value W3 / N6 obtained by dividing the width W3 of the axial portions 111B and 111C of the core 111 by the number of turns N6 of the axial portions 112B and 112C of the coil 112 is the width of the radial portion 111A of the radial portion 111A of the core 111. W3 is larger than the value W3 / N5 obtained by dividing the number of turns N5 of the radial portions 112B and 112C of the coil 112.

  As a result, in the axial portions 111B and 111C of the core 111, magnetic saturation is less likely to occur than when the radial portions 112A and the axial portions 112B and 112C of the coil 112 have the same number of turns.

  The radial portion 123A of the magnet 123 constitutes a “first rotor magnetic pole portion” magnetized in the radial direction, and the axial portions 123B and 123C of the magnet 123 are “second” magnetized in the rotation axis direction. Of the rotor magnetic pole part ”.

  Further, the radial portion 111A of the core 111 and the radial portion 112A of the coil 112 are provided corresponding to the first rotor magnetic pole portion and constitute a “first stator magnetic pole portion” that generates a magnetic flux in the radial direction. .

  Furthermore, the axial portions 111B and 111C of the core 111 and the axial portions 112B and 112C of the coil 112 are provided corresponding to the second rotor magnetic pole portion and generate a magnetic flux in the direction of the rotation axis. Part ".

  Further, the plurality of axial portions 111B, 111B,... Of the plurality of cores 111, 111,... Constitute “a plurality of first axial cores”.

  Further, the plurality of axial portions 112B, 112B,... Of the plurality of coils 112, 112,... Constitute “a plurality of first axial coils”.

  Further, the plurality of axial portions 111C, 111C,... Of the plurality of cores 111, 111,... Constitute “a plurality of second axial cores”.

  Further, the plurality of axial portions 112C, 112C,... Of the plurality of coils 112, 112,... Constitute “a plurality of second axial coils”.

  In the first embodiment described above, the value W2 // is obtained by dividing the width W2 (minimum value) in the circumferential direction DR2 of the cores 311 to 316 of the axial portions 31 and 32 by the number of turns N2 of the coils 321 to 326 of the axial portions 31 and 32. N2 is larger than a value W1 / N1 obtained by dividing the width W1 (minimum value) in the circumferential direction DR2 of the cores 331 to 342 of the radial part 33 by the number of turns N1 of the coils 352 to 362 of the radial part 33, and the axial part 31 , 32, the cross-sectional area S2 perpendicular to the radial direction DR3 of the cores 311 to 316 is larger than the cross-sectional area S1 perpendicular to the rotational axis direction DR1 of the cores 331 to 342 of the radial portion 33.

  In the second embodiment, the value W3 / N6 obtained by dividing the circumferential width DR2 of the axial portions 111B and 111C of the core 111 by the number of turns N6 of the axial portions 112B and 112C of the coil 112 is the radial portion of the core 111. The cross-sectional area D4 that is larger than the value W3 / N5 obtained by dividing the width W3 of 111A in the circumferential direction DR2 by the number of turns N5 of the radial portion 112A of the coil 112 and perpendicular to the radial direction DR3 of the axial portions 111B and 111C of the core 111 The radial section 111A of the core 111 has the same cross-sectional area D3 perpendicular to the rotational axis direction DR1.

  Therefore, in the present invention, the cross-sectional area perpendicular to the radial direction of the core in the axial part of the stator is set to be equal to or larger than the cross-sectional area perpendicular to the rotational axis direction of the core in the radial part of the stator, and A value obtained by dividing the width in the direction DR2 by the number of turns in the axial portion of the coil is set to be larger than the value obtained by dividing the width in the circumferential direction DR2 of the core in the radial portion by the number of turns in the radial portion of the coil.

  As a result, the axial portion of the stator receives more magnetic flux than the case where the width in the circumferential direction DR2 is the same as the width in the circumferential direction DR2 of the radial portion and the number of turns of the coil is the same as that in the radial portion. Can be generated and magnetic saturation is less likely to occur. As a result, the rotating electrical machine can output higher torque in the high output region.

  Further, in the second embodiment, one of the radial portion 112A and the axial portions 112B and 112C of the coil 112 is the coil end of the other portion of the radial portion 112A and the axial portions 112B and 112C of the coil 112. Placed inside.

  Thus, the other coil can be arranged in the dead space inside the coil end, and the torque can be increased without increasing the size of the rotating electrical machine.

  Furthermore, the core 111 and the rotor core 122 may be formed of a dust core.

  The rotating electrical machines 100 and 200 function as, for example, an electric motor that drives the driving wheels of the vehicle, or a generator that generates electric power by the rotational power of the driving wheels.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and is intended to include meanings equivalent to the scope of claims for patent and all modifications within the scope.

  The present invention is applied to a rotating electrical machine that can effectively use both end faces of a rotor in a rotation axis direction while suppressing a magnetic direction.

It is an exploded view of the rotary electric machine by Embodiment 1 of this invention. It is sectional drawing of the rotary electric machine between the lines II-II shown in FIG. It is a perspective view of the axial part of the stator shown in FIG. It is a perspective view of the radial part of the stator shown in FIG. It is a perspective view of a rotary electric machine. It is another perspective view of a rotary electric machine. FIG. 2 is a development view of a part of an axial part and a radial part of the stator shown in FIG. 1. It is a perspective view which shows a part of core of the axial part and radial part which are shown in FIG. 6 is a perspective view of a stator and a rotor of a rotating electrical machine according to Embodiment 2. FIG. FIG. 10 is a perspective view of the coil and the rotor shown in FIG. 9. FIG. 10 is a cross-sectional view of a stator and a rotor of the rotating electrical machine shown in FIG. 9. FIG. 10 is a perspective view of the core shown in FIG. 9. FIG. 10 is a perspective view of the coil shown in FIG. 9. FIG. 10 is another perspective view of the coil shown in FIG. 9.

Explanation of symbols

  3-6 bearing, 10 shaft, 20, 120 rotor, 21, 22, 31, 32, 110B, 110C, 111B, 111C, 112B, 112C, 123B, 123C, 1121B, 1121C Axial part, 23, 33, 110A, 111A , 112A, 123A, 1121A Radial part, 21A-21H, 22A-22H, 23A-23H, 123 magnet, 30, 110 stator, 40 case, 40A inner peripheral surface, 50, 60 cover, 70, 71 bus bar, 80, 90 , 320, 340 terminal, 100, 200 rotating electrical machine, 110D, 110E coupling part, 111, 311 to 316, 331 to 342, 370 core, 112, 321-326, 351 to 362, 1121 to 1125 coil, 121 rotor shaft, 122 b Tacore, 122A cylindrical surface, 122B, 122C cylindrical end surface, 310 bracket, 310A-310F hole, 311A, 312A, 313A, 333A innermost peripheral end, 311B, 312B, 313B, 333B outermost peripheral end, 311C, 311D, 311E, 311F , 333D, 333E, 333F, 333G end face, 333C plane.

Claims (9)

A rotor having a first rotor magnetic pole portion magnetized in the radial direction and a second rotor magnetic pole portion magnetized in the rotation axis direction;
A first stator magnetic pole portion provided corresponding to the first rotor magnetic pole portion and generating a magnetic flux in the radial direction; and provided corresponding to the second rotor magnetic pole portion; and A stator having a second stator magnetic pole portion for generating magnetic flux in the axial direction,
The rotor freely rotates with respect to the stator by receiving magnetic fluxes from the first and second stator magnetic pole portions at the first and second rotor magnetic pole portions, respectively.
The first stator magnetic pole portion is
A plurality of first cores arranged in a circumferential direction of the rotor;
A plurality of first coils provided corresponding to the plurality of first cores, each of which is wound around the corresponding first core;
The second stator magnetic pole portion is
A plurality of second cores arranged in a circumferential direction of the rotor;
A plurality of second coils provided corresponding to the plurality of second cores, each wound around the corresponding second core;
The second core has a cross-sectional area equal to or larger than the cross-sectional area of the first core in the plane direction perpendicular to the rotation axis direction in the plane direction perpendicular to the radial direction of the rotor,
The minimum width of the first core in the circumferential direction of the rotor is W1, the number of turns of the first coil is N1, the minimum width of the second core in the circumferential direction of the rotor is W2, and the second When the number of turns of the coil is N2,
A rotating electrical machine that satisfies W2 / N2> W1 / N1.   The plurality of coils of any one of the plurality of first coils and the plurality of second coils are coils of the other plurality of coils of the plurality of first coils and the plurality of second coils. The rotating electrical machine according to claim 1, wherein the rotating electrical machine is disposed inside the end.   The rotating electrical machine according to claim 1, wherein N1> N2 is established.   The rotating electrical machine according to claim 3, wherein the first and second coils are integrally wound.   The rotating electrical machine according to claim 3, wherein the first coil is wound separately from the second coil.   The rotating electrical machine according to claim 1, wherein a total number of the plurality of first cores is larger than a total number of the plurality of second cores. The rotor has a substantially cylindrical shape,
The plurality of first cores are arranged in a circumferential direction of the rotor so as to face the cylindrical outer peripheral surface,
The plurality of second cores includes:
A plurality of first axial cores arranged in the circumferential direction of the rotor so as to face one end surface of the cylindrical shape in the rotation axis direction of the rotor;
A plurality of second axial cores arranged in the circumferential direction of the rotor facing the other end surface of the cylindrical shape in the rotation axis direction of the rotor;
The plurality of second coils include:
A plurality of first axial coils provided corresponding to the plurality of first axial cores, each wound around a corresponding first axial core;
A plurality of second axial coils provided corresponding to the plurality of second axial cores, each wound around a corresponding second axial core;
The rotating electrical machine according to claim 6, wherein the plurality of first axial cores are arranged at positions shifted in a circumferential direction of the rotor with respect to the plurality of second axial cores.   The rotating electrical machine according to claim 7, wherein the first and second axial coils are wound in a direction in which a winding direction of the first coil is reversed.   The rotating electrical machine according to claim 8, wherein the first and second axial coils are wound integrally with the first coil.

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