JP2006304562A - Rotor structure of axial gap rotating electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide the rotor structure of an axial gap rotating electric machine in which the holding strength of a rotor to a permanent magnet can be enhanced and generation torque as a rotating electric machine can be prevented from decreasing. <P>SOLUTION: A plurality of substantially sectoral columnar permanent magnets 11 are inserted into a plurality of substantially sectoral holes 13 formed in the circumferential direction of a disc-like member 12. A holding member 14 is bonded axially from the outside to the disc-like member 12 located between the adjacent permanent magnets 11. A pair of shaft securing portions 15 are bonded to the inner circumferential side of the permanent magnet 11 in the disc-like member 12, and a pair of outer rings 16 are bonded to the outer circumferential side of the permanent magnet 11 in the disc-like member 12. The outer ring 16 is constituted by bonding an inner circumferential side 16a composed of a nonmagnetic body and an outer circumferential side 16b composed of a high strength member to each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotor structure of an axial gap type rotating electrical machine in which a stator and a rotor are arranged to face each other along a rotation axis.

  A rotating electrical machine having a permanent magnet on a rotor is used in many automobiles or industrial machines for reasons such as low loss, high efficiency, and high output. In particular, since the axial gap type rotating electrical machine in which the stator and the disk-shaped rotor are arranged so as to face each other along the rotation axis can reduce the thickness in the rotation axis direction, Patent Document 1 and Patent Document As described in FIG. 2, it is more frequently used when there is a layout restriction.

In the rotor structure of the axial gap type rotating electrical machine described in Patent Document 1, in fixing the permanent magnet to the rotor, the resin adhesive on the back side of the permanent magnet is devoured to hold the permanent magnet in the radial direction and the circumferential direction. In the rotor structure of the axial gap type rotating electrical machine described in Patent Document 2, the strength is increased, and a plurality of holes are formed in a disk-like member made of a non-magnetic material in the axial direction so that the divided permanent magnet is axially The holding strength in the radial direction and the circumferential direction with respect to the permanent magnet is increased.
JP 2004-80898 A JP-A-6-38418

  However, in the axial gap type rotating electrical machine described in Patent Document 1, when a large force is applied in the radial direction by centrifugal force to the permanent magnet of the rotor, the radial force is supported only by the resin adhesive. In the axial gap type rotating electrical machine described in Patent Document 2, a plurality of round cylindrical magnets are arranged to form a rotor by resin molding in order to reduce inertia and increase rotation of the rotor. However, since the magnets are discretely arranged in the rotor, the leakage magnetic flux is increased, and it is difficult to secure the amount of magnets, which makes it difficult to secure the necessary torque. In addition, since the permanent magnet is held by the resin, there is a problem that it is difficult to increase the rotation speed. In order to solve such problems, it is conceivable to provide an outer ring on the outer peripheral side of the permanent magnet to hold the permanent magnet in the radial direction. However, depending on this alone, leakage may occur on the outer peripheral side of the permanent magnet. A new problem arises that the magnetic flux increases and the torque generated by the rotating electrical machine decreases.

  The object of the present invention is to solve the above-described problems, and the purpose is to increase the radial holding strength of the rotor with respect to the permanent magnet and to reduce the generated torque as the rotating electrical machine. It is an object of the present invention to provide a rotor structure for an axial gap type rotating electrical machine that can prevent the above.

  In the rotor structure of the axial gap type rotating electrical machine according to the present invention, the plurality of permanent magnets are inserted through a plurality of holes arranged in the circumferential direction of the disk-shaped member, and the disks located between the adjacent permanent magnets. A plurality of pairs of holding members are joined to the cylindrical member from the outside in the axial direction, and a pair of shaft fixing portions are joined to the inner peripheral side of the permanent magnet of the disk-like member from the outside in the axial direction. A pair of outer rings are joined to the outer peripheral side of the permanent magnet of the plate-like member from the outside in the axial direction, and the outer ring is provided with an inner peripheral side portion made of a nonmagnetic material, and an outer peripheral side portion made of a high-strength member. Are characterized by being joined to each other.

  According to this, while providing the outer ring which hold | maintains the said permanent magnet to radial direction, the said outer ring joins the inner peripheral side part which consists of nonmagnetic materials, and the outer peripheral side part which consists of a high strength member mutually. By configuring the permanent magnet in the radial direction by the outer peripheral side portion made of the high strength member of the outer ring, and configuring the inner peripheral side portion of the outer ring from a nonmagnetic material, the outer circumference of the permanent magnet It is possible to prevent the leakage magnetic flux from being generated on the side and the generated torque as the rotating electrical machine from being reduced.

  Further, when the outer ring is a simple double ring without joining the outer peripheral part made of a high-strength member and the inner peripheral part made of a nonmagnetic material, the outer peripheral part and the inner peripheral part are When the longitudinal elastic modulus is the same and the density is the same, the outer peripheral portion suppresses deformation due to the centrifugal force of the inner peripheral portion due to the larger deformation amount of the outer peripheral portion. And the material strength of the inner peripheral part made of a non-magnetic material typified by austenitic stainless steel is smaller than that of the outer peripheral part made of a high-strength member. End up. Therefore, by joining the inner peripheral side portion and the outer peripheral side portion, the outer peripheral side portion can suppress deformation due to the centrifugal force of the inner peripheral side portion, so that such breakage can be prevented.

  Furthermore, as compared with the case where the outer ring is formed as an annular shape by compressing and heating different kinds of powder composed of a high-strength member and a non-magnetic material, the outer ring is divided into an inner peripheral portion and an outer peripheral portion as in the present invention. Since the tensile strength of the outer peripheral portion made of the high-strength member can be made equal to the tensile strength of the high-strength member itself, the holding strength of the outer ring is increased, Rotational strength can be increased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing an embodiment of a general axial gap type rotating electrical machine.
In this axial gap type rotating electrical machine, a stator 3 formed by winding a coil 2 around a core 1 and a rotor 4 are arranged to face each other along a rotation axis. The rotor 4 includes a plurality of permanent magnets 5. Are arranged at equal intervals in the circumferential direction, and a shaft 6 is provided on the inner circumferential side thereof. The shaft 6 is rotatably supported by a case 8 via a bearing 7. Further, a cooling path 9 is provided in the case 8 to circulate a cooling liquid for absorbing and cooling heat generated by the loss of the stator 3. Furthermore, an encoder 10 for detecting the rotation amount and position of the rotor 4 is provided at the end of the rotating shaft 6.

  In the axial gap type rotating electrical machine shown in FIG. 1, when the coil 2 is excited by an inverter (not shown), a rotating magnetic field is formed in the circumferential direction of the stator 3, and a plurality of permanent magnets 5 having different polarities alternately are embedded in the circumferential direction. The disk-shaped rotor 4 is attracted and repelled by the rotating magnetic field generated by the stator 3 to generate magnet torque, and also generates reluctance torque due to the presence of the magnetic material constituting the rotor 4, which is used as power. The rotor 4 rotates at a synchronous speed with the rotating magnetic field.

FIG. 2 is a schematic diagram showing in detail the rotor structure of the axial gap type rotating electrical machine according to the present invention. FIG. 2 (a) shows a state before assembly, and FIG. 2 (b) shows a state after assembly.
In the rotor structure of this axial gap type rotating electrical machine, a plurality of substantially sector-shaped columnar permanent magnets 11 are inserted through a plurality of substantially sector-shaped holes 13 arranged side by side in the circumferential direction of the disk-shaped member 12, and the permanent magnets 11. A taper shape or a step shape, here a taper shape 11a, is provided at the circumferential end on the gap side, and a taper fitted into the disk-like member 12 positioned between the adjacent permanent magnets 11 in the taper shape or the step shape. A plurality of pairs of holding members 14 having a shape or step shape, here a tapered shape 14a, are provided by being joined from the outside in the axial direction, and a pair of shaft fixing portions 15 on the inner peripheral side of the permanent magnet 11 of the disk-like member 12. Are joined from the outside in the axial direction, and a pair of outer rings 16 are joined from the outside in the axial direction to the outer peripheral side of the permanent magnet 11 of the disk-shaped member 12, and the outer ring 16 is made nonmagnetic. And the inner peripheral portion 16a of the additional level, are formed by joining to each other and an outer peripheral portion 16b made of high-strength member. (Equivalent to claim 1)
In addition, a hole for fitting a shaft (not shown) is provided on the inner peripheral side of the disk-shaped member 12 and the pair of shaft fixing portions 15, and is configured by stacking electromagnetic steel plates or integrated with a soft magnetic dust material. Molded and configured.

  According to this, while providing the outer ring 16 which hold | maintains the said permanent magnet 11 in radial direction, the said outer ring 16 is the inner peripheral side part 16a which consists of a nonmagnetic body, and the outer peripheral side part 16b which consists of a high intensity | strength member. Are joined to each other, whereby the permanent magnet is held in the radial direction by the outer peripheral side portion 16b made of a high-strength member of the outer ring 16, and the inner peripheral side portion 16a of the outer ring 16 is made of a non-magnetic material. By comprising, it can prevent that the leakage magnetic flux generate | occur | produces in the outer peripheral side of the permanent magnet 11, and the generated torque as a rotary electric machine falls.

  Further, when the outer ring 16 is a simple double ring without joining the outer peripheral side portion 16b made of a high-strength member and the inner peripheral side portion 16a made of a nonmagnetic material, the outer peripheral side portion 16b and the inner circumference When the side portion 16a has the same longitudinal elastic modulus and the same density, the deformation of the inner peripheral side portion 16a due to the centrifugal force is caused by the larger deformation amount of the outer peripheral side portion 16a. Since the outer peripheral side portion 16b cannot be suppressed and the material strength of the inner peripheral side portion 16a made of a nonmagnetic material typified by austenitic stainless steel is smaller than the outer peripheral side portion 16b made of a high strength member, The inner peripheral side portion 16a is broken by centrifugal force. Therefore, by joining the inner peripheral side portion 16a and the outer peripheral side portion 16b, the outer peripheral side portion 16b can suppress deformation due to the centrifugal force of the inner peripheral side portion 16a. Can do.

  Furthermore, as compared with the case where the outer ring 16 is formed as an annular shape by compressing and heating different kinds of powders composed of a high-strength member and a non-magnetic material, the outer ring 16 and the inner peripheral side portion 16a are formed as in the present invention. By being configured separately from the outer peripheral side portion 16b, the tensile strength of the outer peripheral side portion 16b made of a high strength member can be made equal to the tensile strength of the high strength member itself. And the rotational strength of the rotor can be increased.

Here, the inner peripheral side portion 16a and the outer peripheral side portion 16b forming the outer ring 16 are joined by a hot isostatic pressing method. (Equivalent to claim 2)
According to this, the inner peripheral side portion 16a and the outer peripheral side portion 16b melt into each other at the joint portion between the inner peripheral side portion 16a and the outer peripheral side portion 16b to form a mixed region of the nonmagnetic material and the high strength member. It is possible to prevent the leakage magnetic flux from being generated on the outer peripheral side of the permanent magnet 11 more effectively.

  Here, the taper shape or step shape 11a and the taper shape or step shape 14a fitted to the taper shape or the step shape 14a cover the permanent magnet 11 with the holding member 14 covering the circumferential end of the gap surface of the permanent magnet 11 from the outside in the axial direction. As long as the holding force in the axial direction is applied, the shape is not limited to the taper shape or the step shape, and other forms are also possible. Thereby, the permanent magnet 11 can be firmly held in the axial direction by the holding member 14, and the axial holding strength of the rotor 4 with respect to the permanent magnet 11 can be increased.

  FIG. 3 is a schematic view showing a permanent magnet having a rotor structure of an axial gap type rotating electrical machine according to the present invention. 3A shows a view of the permanent magnet as viewed from the gap side of the rotor, FIG. 3B shows a view of the permanent magnet as viewed from the circumferential direction of the rotor, and FIG. It is a figure which shows the AA cross section in a).

As shown in FIG. 3A, the permanent magnet 11 is formed in a substantially fan shape when viewed from the gap side of the rotor, and the circumferential end on the outer peripheral side of the hole 13 of the disk-shaped member 12 described above. Corresponding to the shape of the portion having an R shape for securing the strength, the circumferential end on the outer peripheral side is chamfered into a C shape. Further, the permanent magnet 11 is configured by laminating thin plate-like permanent magnets in the radial direction and bonding them with a resin or the like.
Furthermore, as shown to Fig.3 (a), the taper shape 11a is provided in the circumferential direction both ends by the side of a gap.

  Therefore, when the permanent magnet 11 is viewed from the circumferential direction, as shown in FIG. 3B, tapered shapes 11a are formed on both sides thereof, and the shape in the cross section AA perpendicular to the radial direction shown in FIG. , Make a rectangle with chamfered corners.

  FIG. 4 is a schematic view showing a holding member of a rotor structure of an axial gap type rotating electrical machine according to the present invention. 4A shows a view of the holding member as seen from the radial direction of the rotor, FIG. 4B shows a view of the holding member as seen from the gap side of the rotor, and FIG. 4C shows the holding member as the rotor. FIG. 4D is a perspective view showing the gap side of the holding member as seen from the inner circumference side.

As shown in FIG. 4, the holding member 14 is formed with a tapered shape 14 a that fits to the tapered shape 11 a of the permanent magnet 11 described above at the opposite circumferential end when viewed from the gap side. The holding strength in the axial direction of the permanent magnet 11 can be increased by the holding member 14 by fitting the tapered shape 14a to the tapered shape 11a described above.
Further, an additional tapered shape 14b described later is provided on the inner peripheral end of the holding member 14 on the gap side.

Here, the holding member 14 is configured by laminating electromagnetic steel plates.
According to this, eddy current loss generated inside the holding member 14 can be reduced with a simple configuration, and the holding member 14 is made of a magnetic material, and the holding member 14 having a low magnetic resistance and a high magnetic resistance are used. Due to the fact that the permanent magnets are alternately provided in the circumferential direction, reluctance torque can be obtained.

Alternatively, the holding member 14 can be made of a soft magnetic powder material.
This also makes it possible to reduce the eddy current loss generated inside the holding member 14 with a simple configuration, and to use the holding member 14 as a magnetic body, to make the holding member 14 with a low magnetic resistance, and to make a permanent with a high magnetic resistance. Reluctance torque can be obtained due to the magnets being alternately provided in the circumferential direction. In addition, as compared with the case where the holding member 14 is configured by a laminated core in which electromagnetic steel plates are laminated, the degree of freedom of shape of the holding member 14 can be increased and the manufacturing cost can be suppressed.

FIG. 5 is a schematic view showing a disk-shaped member of the rotor structure of the axial gap type rotating electric machine according to the present invention as seen from the direction of the central axis of the rotor.
As shown in FIG. 5, the disk-shaped member 12 is provided with a plurality of fan-shaped holes in the circumferential direction, which is the same number as the plurality of fan-shaped permanent magnets described above. By providing holes at equal intervals in the circumferential direction as described above, the portion located between the holes increases the radial strength of the disk-shaped member. As a result, the radial holding strength of the disk-shaped member 12 with respect to the permanent magnet 11 can be increased.

FIG. 6 is a schematic diagram showing the outer ring of the rotor structure of the axial gap type rotating electrical machine according to the present invention as seen from the direction of the central axis of the rotor.
As shown in FIG. 6, the outer ring 16 is formed in an annular shape, and as described above, the outer circumferential surface of the outer ring 16 is a disk-shaped member so as to be joined to the outer circumferential side of the permanent magnet of the disk-shaped member (not shown). An annular groove that encloses the outer peripheral side of the disk-shaped member is formed on the inner peripheral surface thereof.

FIG. 7 is a schematic cross-sectional view showing the rotor structure of the axial gap type rotating electrical machine according to the present invention in a cross section including the central axis.
As described above, a plurality of substantially sector-shaped columnar permanent magnets 11 are inserted through a plurality of substantially sector-shaped holes 13 arranged side by side in the circumferential direction of the disk-shaped member 12, and the circumferential direction of the permanent magnet 11 on the gap side. A tapered shape or stepped shape, here a tapered shape 11a, is provided, and a tapered shape 14a (or a stepped shape) is fitted to the disk-shaped member 12 positioned between the adjacent permanent magnets 11 (or the stepped shape). Alternatively, a plurality of pairs of holding members 14 having a step shape) are joined from the outside in the axial direction, and a pair of shaft fixing portions 15 are joined from the outside in the axial direction to the inner peripheral side of the permanent magnet 11 of the disk-like member 12. A pair of outer rings 16 are joined to the outer peripheral side of the permanent magnet 11 of the disk-shaped member 12 from the outside in the axial direction. In addition, the shaft 6 is fitted to the inner peripheral side of the disk-shaped member 12 and the pair of shaft fixing portions 15 via a key.

Furthermore, an additional tapered shape 14b (or an additional step shape) is provided on at least one of the inner peripheral side end and the outer peripheral side end on the gap side of the holding member 14, here the inner peripheral side end, and the shaft fixing portion and the outer ring, The shaft fixing portion 15 is provided with an additional taper shape 15b (or additional step shape) that fits into the additional taper shape (or additional step shape).
In addition, what is called an additional taper shape or an additional step shape here is for distinguishing from the taper shape or step shape provided in a holding member and a permanent magnet, respectively.

  According to this, the additional taper shape 14b of the holding member 14 is covered with the additional taper shape 15b of the shaft fixing portion 15 from the outside in the axial direction, so that the holding strength in the axial direction of the holding member 14 can be increased. Further, the holding strength in the axial direction of the permanent magnet 11 by the holding member 14 can also be increased. This effect is the same whether the additional taper shape is provided at the outer peripheral end or both the inner peripheral end and the outer peripheral end.

Here, the joint diameter Φ1 between the inner peripheral side portion 16a and the outer peripheral side portion 16b is made larger than the outer diameter Φ2 of the disk-shaped member 12. (Equivalent to claim 3)
According to this, it is possible to prevent the magnetic flux from leaking to the outer peripheral side portion 16 b of the outer ring 16 via the disk-like member 12 on the outer peripheral side of the permanent magnet 11.

Furthermore, the maximum diameter Φ3 of the hole through which the permanent magnet 11 of the disk-shaped member 12 is inserted is made larger than the inner diameter Φ4 of the outer ring 16. (Equivalent to claim 4)
According to this, since the centrifugal force acting on the permanent magnet 11 when the rotor rotates can be supported by the outer ring 16 without being supported by the disk-shaped member 12 which is disadvantageous in terms of rotational strength, the rotational strength of the rotor can be increased. It is possible to increase the rotation speed further.

FIG. 8 is a schematic view showing the rotor structure of the axial gap type rotating electrical machine according to the present invention as seen from the central axis direction.
As described above, a plurality of substantially sector-shaped columnar permanent magnets 11 are inserted through a plurality of substantially sector-shaped holes 13 arranged side by side in the circumferential direction of the disk-shaped member 12, and the circumferential direction of the permanent magnet 11 on the gap side. A taper shape or a step shape, here a taper shape 11a, is provided at the end, and a plurality of pairs of holding members having a taper shape 14a fitted to the taper shape 11a on the disk-like member 12 positioned between the adjacent permanent magnets 11 The member 14 is joined and provided from the outside in the axial direction, and a pair of shaft fixing portions 15 are joined to the inner periphery side of the permanent magnet 11 of the disk-like member 12 by bolting from the outside in the axial direction. A pair of outer rings 16 are provided on the outer peripheral side of the permanent magnet 11 of the shaped member 12 by bonding with an adhesive from the outside in the axial direction.

  In addition, the shaft 6 is fitted to the inner peripheral side of the disk-shaped member 12 and the pair of shaft fixing portions 15 via a key. A gap formed between the substantially fan-shaped hole 13 and the permanent magnet 11 is filled with resin or the like.

  Further, an additional tapered shape 14b is provided on at least one of the inner peripheral side end and the outer peripheral side end on the gap side of the holding member 14, here the inner peripheral end, and the shaft fixing part and the outer ring, here the shaft fixing part 15 are provided. An additional taper shape 15b fitted to the additional taper shape 14b is provided.

For this reason, as shown in FIG. 8, the circumferential end of the permanent magnet 11 and the circumferential end of the holding member 14 overlap in the circumferential direction by the width of the tapered shape 11a. Thereby, the holding strength in the axial direction of the permanent magnet 11 can be increased.
Further, as shown in FIG. 8, the inner peripheral end of the holding member 14 overlaps the outer peripheral end of the shaft fixing portion 15 in the radial direction by the width of the additional tapered shape 14b. Thereby, the holding strength in the axial direction of the holding member 14 by the shaft fixing portion 15 can be increased, and consequently the holding strength in the axial direction of the holding member 15 with respect to the permanent magnet 11 can be increased.

In addition, this invention is not limited only to the said embodiment, Many deformation | transformation or a change is possible.
For example, FIG. 1 shows, as an example, an axial gap type rotating electric machine in the form of one rotor and two stators, but the rotor structure according to the present invention is also applied to an axial gap type rotating electric machine in the form of one rotor and two stators. Is possible.

  INDUSTRIAL APPLICABILITY The present invention is suitable for use in a rotor of an axial gap type rotating electrical machine, and a large force acts in the radial direction by centrifugal force on the permanent magnet of the rotor. The holding strength in the direction can be increased, and the rotation limit can be increased.

It is a schematic cross section which shows the structure of a general axial gap type rotary electric machine. It is a mimetic diagram showing one embodiment of a rotor structure of an axial gap type rotating electrical machine concerning the present invention. It is a schematic diagram which shows one Embodiment of the permanent magnet of the rotor structure of the axial gap type rotary electric machine which concerns on this invention. It is a schematic diagram which shows one Embodiment of the holding member of the rotor structure of the axial gap type rotary electric machine which concerns on this invention. It is a schematic diagram which shows one Embodiment of the disk-shaped member of the rotor structure of the axial gap type rotary electric machine which concerns on this invention. It is a schematic diagram which shows one Embodiment of the outer ring | wheel of the rotor structure of the axial gap type rotary electric machine which concerns on this invention. It is a schematic cross section which shows the rotor structure of the axial gap type rotary electric machine which concerns on this invention in the cross section containing a central axis. It is a schematic diagram which shows the rotor structure of the axial gap type rotary electric machine which concerns on this invention seeing from the center axis line direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Core 2 Coil 3 Stator 4 Rotor 5 Permanent magnet 6 Shaft 7 Bearing 8 Case 9 Cooling path 10 Encoder 11 Permanent magnet 11a Taper shape 12 Disk-shaped member 13 Hole 14 Holding member 14a Taper shape 14b Additional taper shape 15 Shaft fixing part 15b Additional taper shape 16 outer ring

Claims (4)

  A plurality of permanent magnets are inserted through a plurality of holes arranged in the circumferential direction of the disk-shaped member, and a plurality of pairs of holding members are inserted into the disk-shaped member located between adjacent permanent magnets from the outside in the axial direction. A pair of shaft fixing portions are provided on the inner circumferential side of the disk-shaped member from the outer side in the axial direction, and a pair of outer parts are disposed on the outer circumferential side of the disk-shaped member. Axial characterized in that a ring is joined from the outside in the axial direction, and the outer ring is constructed by joining an inner peripheral side portion made of a non-magnetic material and an outer peripheral side portion made of a high strength member to each other. Gap-type rotating electrical machine rotor structure.   The rotor structure of an axial gap type rotating electrical machine according to claim 1, wherein the inner peripheral side portion and the outer peripheral side portion forming the outer ring are joined by a hot isostatic pressing method.   The rotor of an axial gap type rotating electrical machine according to claim 1 or 2, wherein a joint diameter between the inner peripheral side portion and the outer peripheral side portion is larger than an outer diameter of the disk-shaped member. Construction.   The stator of an axial gap type rotating electrical machine according to any one of claims 1 to 3, wherein a maximum diameter of a hole through which the permanent magnet of the disk-shaped member is inserted is larger than an inner diameter of the outer ring. Construction.

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