Rotor and method for manufacturing the rotor

Abstract

To provide a rotor that can be easily mounted while preventing damage to a magnet material comprising a Halbach array magnet and to provide a manufacturing method for the same.SOLUTION: A permanent magnet 22 of a rotor 12 is integrally configured of d-axial magnet portions 22dn, 22ds on both sides of the circumferential direction and a q-axis magnet portion 22q at a central part of the circumferential direction as one magnetic material. The permanent magnet has a configuration in which the d-axis magnet portions 22dn, 22ds of the same poles of the permanent magnets 22 adjacent to each other in the circumferential direction of the rotor 12 are arranged in such a way that they are continuously lined up with each other. In the rotor 12 that employs Halbach array magnets, magnetized magnet materials are to be attached. By configuring and arranging individual permanent magnets 22 as described above, permanent magnets 22 to be attached after first permanent magnets 22 are attached using repulsive force rather than attractive force.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a rotor having a permanent magnet and a method for manufacturing the rotor.

Background Art

[0002] In a motor rotor, there is known a configuration in which a plurality of permanent magnets are arranged on the side surface of a rotor base as magnetic pole portions. The permanent magnet is configured by, for example, a Halbach array magnet (see, for example, Patent Document 1). By using a Halbach array magnet, an improvement in the performance of the motor can be expected.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A Halbach array magnet is a magnet in which a d-axis magnet portion mainly having magnetic flux in the radial direction and a q-axis magnet portion mainly having magnetic flux in the circumferential direction are alternately arranged in the circumferential direction. Due to the configuration of such a magnet, it is difficult to magnetize the magnet after attaching an unmagnetized magnetic material to the rotor base. Therefore, in order to use a Halbach array magnet for the rotor, it is common to adopt a method in which each magnetic material to be a d-axis magnet portion and a q-axis magnet portion is magnetized in advance, and each magnetized magnetic material is attached to the rotor base.

[0005] However, when attaching each magnet material that has been magnetized as the d-axis magnet portion and the q-axis magnet portion to the rotor base, for example, an attractive force acts between the magnet material of the q-axis magnet portion attached first and the magnet material of the d-axis magnet portion to be attached later. That is, during the attachment operation of each magnet material, the magnet materials can come into contact with each other under the action of the mutual attractive force. Therefore, there has been a concern that the magnet material may be damaged when the magnetic materials come into strong contact with each other. In other words, it has been necessary to perform a careful and complicated attachment operation so that the magnet materials do not come into strong contact with each other.

[0006] An object of the present disclosure is to provide a rotor and a method for manufacturing the rotor that can be easily attached while preventing damage to the magnet material constituting the Halbach array magnet.

Means for Solving the Problems

[0007] The rotor for solving the above problems includes a rotor base (21) and a plurality of permanent magnets (22) arranged in the circumferential direction on the side surface (21a) of the rotor base. The permanent magnet is a rotor (12) constituted by a Halbach array magnet. The permanent magnet is integrally formed as one magnet material with a d-axis magnet portion (22dn, 22ds) in which magnetic flux mainly faces the radial direction on both circumferential sides and a q-axis magnet portion (22q) in which magnetic flux mainly faces the circumferential direction in the central portion in the circumferential direction. The d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction are arranged so as to be continuously aligned.

[0008] A method for manufacturing a rotor that solves the above problems includes a rotor base (21) and a plurality of permanent magnets (22) arranged in the circumferential direction on the side surface (21a) of the rotor base. The permanent magnet is a method for manufacturing a rotor (12) composed of a Halbach array magnet. The permanent magnet uses a structure in which a d-axis magnet portion (22dn, 22ds) mainly having a magnetic flux in the radial direction on both circumferential sides and a q-axis magnet portion (22q) mainly having a magnetic flux in the circumferential direction in the central portion of the circumferential direction are integrally formed as one magnetic material. After attaching the permanent magnet to the side surface of the rotor base at every other position in the circumferential direction over the entire circumference or a part of the circumferential direction, the next permanent magnet is inserted and attached from the radial direction between the previously attached permanent magnets, so that the d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction are arranged continuously side by side.

[0009] According to the above rotor and the method for manufacturing the rotor, the permanent magnet of the rotor uses a structure in which a d-axis magnet portion mainly having a magnetic flux in the radial direction on both circumferential sides and a q-axis magnet portion mainly having a magnetic flux in the circumferential direction in the central portion of the circumferential direction are integrally formed as one magnetic material. And it is arranged such that the d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction of the rotor are arranged continuously side by side. In a rotor adopting a Halbach array magnet, it is the attachment of a magnetized magnetic material. By configuring and arranging each permanent magnet as described above, the magnetic force generated between the previously attached permanent magnet and the later attached permanent magnet becomes a repulsive force rather than an attractive force. That is, since it is an attachment using the repulsive force between the previously attached permanent magnet and the later attached permanent magnet, the occurrence of the event that they strongly contact each other due to the attractive force between the two is suppressed, and the occurrence of damage to the permanent magnet due to this is suppressed. In other words, since strong contact due to the attraction between the permanent magnets during attachment is less likely to occur, the ease of the permanent magnet attachment work can be expected.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0011] Hereinafter, an embodiment of a rotor and a method for manufacturing the rotor will be described. (Configuration of Motor 10) As shown in FIG. 1, the motor 10 of the present embodiment includes a stator 11 and a rotor 12. The stator 11 is configured in a substantially annular shape. The stator 11 has, for example, 24-pole coil magnetic pole portions (not shown) in the circumferential direction. Inside the stator 11, the rotor 12 is rotatably arranged. The stator 11 generates a rotating magnetic field for driving the rotation of the rotor 12 based on the energization of its coil magnetic pole portions. The motor 10 of the present embodiment is assumed to be applied to a high-speed rotation specification motor with a maximum operating speed of 12,000 [rpm] or more as an example.

[0012] (Configuration of Rotor 12) As shown in FIGS. 1 and 2, the rotor 12 of the present embodiment includes a rotor base 21, a permanent magnet 22, and a scattering prevention member 23.

[0013] The rotor base 21 is configured in a substantially cylindrical shape as a whole. The rotor base 21 has a hollow structure in consideration of weight reduction and the like. The axial end portion of the rotor base 21 is integrally configured as an output shaft portion 21x. On the outer surface 21a of the central portion in the axial direction of the rotor base 21, for example, 20 permanent magnets 22 are arranged in the circumferential direction. The outer surface 21a of the rotor base 21 of the present embodiment has 20 flat surfaces corresponding to each permanent magnet 22 (see FIG. 3). The rotor 12 has a magnetic pole portion with 20 poles in the circumferential direction.

[0014] The permanent magnet 22 has a substantially square shape. The inner surface 22a of the permanent magnet 22 on the inner diameter side of the rotor 12 is in contact with the outer surface 21a of the rotor base 21. The inner surface 22a of the permanent magnet 22 forms a flat surface, and the flat surfaces of the inner surface 22a of the permanent magnet 22 and the outer surface 21a of the rotor base 21 are in contact with each other. The outer surface 22b of the permanent magnet 22 on the outer diameter side of the rotor 12 constitutes a uniform outer peripheral surface of the rotor 12 by all the permanent magnets 22 in the circumferential direction. The side end surfaces 22c on both sides of the permanent magnet 22 in the circumferential direction of the rotor 12 form flat surfaces along the radial direction of the rotor 12. In order to bring its own inner surface 22a into contact with the rotor base 21, the permanent magnet 22 has gaps at the side end surfaces 22c on both sides with respect to the permanent magnets 22 on both sides in the circumferential direction, or is in contact only with the side end surface 22c on one side. In each figure, the permanent magnets 22 are depicted as being in contact with each other.

[0015] As shown in FIG. 3, in this embodiment, the permanent magnet 22 is composed of a Halbach array magnet. Specifically, the permanent magnet 22 is divided into three parts with different magnetization modes in the circumferential direction. The both side parts in the circumferential direction of the permanent magnet 22 are mainly d-axis magnet parts 22dn, 22ds in which the magnetic flux is directed in the radial direction. The central part in the circumferential direction of the permanent magnet 22 is mainly a q-axis magnet part 22q in which the magnetic flux is directed in the circumferential direction and is directed to the d-axis magnet parts 22dn, 22ds on both sides of itself. The more specific configuration of the permanent magnet 22 and the mounting method to the rotor base 21 will be described later.

[0016] As shown in FIG. 2, the scattering prevention member 23 is mounted in a manner that circulates around the rotor 12 along the outer surface 22b of a plurality of permanent magnets 22 in the circumferential direction. The scattering prevention member 23 is provided, for example, in a cylindrical shape so as to completely cover the permanent magnet 22. For example, a carbon fiber reinforced resin material (referred to as CFRP material) is used for the scattering prevention member 23. A ribbon-shaped material (not shown) of the CFRP material is wound around the permanent magnet 22 of the rotor 12 for several turns, and is wound in one layer or multiple layers. Then, heat curing is performed to produce a cylindrical scattering prevention member 23 for fixing the permanent magnet 22 and preventing scattering.

[0017] (Specific Configuration and Mounting Method of Permanent Magnet 22) As shown in FIG. 3, in the permanent magnet 22 of the present embodiment, the d-axis magnet portions 22dn and 22ds and the q-axis magnet portion 22q are integrally formed as a single magnetic material. The d-axis magnet portions 22dn and 22ds are provided on both circumferential sides of the permanent magnet 22, and the q-axis magnet portion 22q is provided at the circumferential center portion. Further, the N pole appears on the outer surface 22b of the permanent magnet 22 for the d-axis magnet portion 22dn on one circumferential side, and the S pole appears on the outer surface 22b of the permanent magnet 22 for the d-axis magnet portion 22ds on the other circumferential side. As the circumferential arrangement mode of each permanent magnet 22 in the rotor 12, the d-axis magnet portions 22dn of the same poles and the d-axis magnet portions 22ds of the same poles of the adjacent permanent magnets 22 are arranged continuously in the circumferential direction. That is, in the present embodiment, the d-axis magnet portions 22dn of the same poles and the d-axis magnet portions 22ds of the same poles of the adjacent permanent magnets 22 cooperate with each other to form a magnet pole portion of the same pole.

[0018] Regarding the mounting mode of each permanent magnet 22 with respect to the outer surface 21a of the rotor base 21, in the present embodiment, after mounting one permanent magnet 22 at intervals over the entire circumference, the remaining permanent magnets 22 are mounted so as to fill the spaces between the previously mounted permanent magnets 22. Note that it may also be an aspect in which, after mounting the permanent magnets 22 at intervals of one, the next permanent magnet 22 is continuously mounted so as to fill the spaces between the permanent magnets 22 over the entire circumference of the rotor base 21. In any case, the permanent magnet 22 to be mounted later has a mounting mode in which it is inserted from the radially outer side to the inner side between the previously mounted permanent magnets 22 spaced apart by one.

[0019] In consideration of such a mounting mode and the like, the radially inner portion 22e of each permanent magnet 22 is configured such that the corners of the d-axis magnet portions 22dn and 22ds continuous with the inner surface 22a are inclined surfaces 22f, respectively, and the shape becomes tapered toward the radially inner side. That is, in the present embodiment, which adopts a mode of mounting the permanent magnets 22 so as to be inserted between the previously mounted permanent magnets 22, the radially inner portion 22e, which is the tip portion on the insertion side of the permanent magnet 22, has a tapered shape. Therefore, it becomes difficult for the later-mounted permanent magnet 22 to come into contact with the previously mounted permanent magnets 22 on both circumferential sides, and it is expected that the mounting of the permanent magnet 22 will be facilitated.

[0020] In addition, each permanent magnet 22 has d-axis magnet portions 22dn and 22ds on both sides and a q-axis magnet portion 22q in the center. Therefore, the internal magnetic flux tends to be directed toward the center more on the radially inner side. That is, since the radially inner corner portion that is omitted by providing the inclined surface 22f with the radially inner portion 22e of the permanent magnet 22 having a tapered shape is a portion where the internal magnetic flux is originally small, the influence on the performance of the permanent magnet 22 is sufficiently small. In the present embodiment, further considering the flow of the internal magnetic flux of the permanent magnet 22, the magnetization of the d-axis magnet portions 22dn and 22ds themselves is an inclined magnetization along the inclined surface 22f. That is, the d-axis center line Ld is set to have a predetermined inclination angle θ1 with respect to the q-axis center line Lq, which is also the circumferential center line of the permanent magnet 22. The inclination angle θ1 of the d-axis center line Ld is set to 30° to 40° as an example in the present embodiment using 20 permanent magnets 22. Coupled with the aspect in which the magnetization of the d-axis magnet portions 22dn and 22ds is inclined, the influence on the performance of the permanent magnet 22 is sufficiently small, and the permanent magnet 22 of the present embodiment has a reasonable configuration.

[0021] (Operation of the present embodiment) The operation of the present embodiment will be described. In manufacturing the rotor 12 of the present embodiment, the permanent magnet 22 is configured as a Halbach array magnet. Therefore, a plurality of pre-magnetized permanent magnets 22 are attached.

[0022] First, the permanent magnets 22 are attached to the outer surface 21a of the rotor base 21 at intervals of one around the entire circumference. The outer surface 21a of the rotor base 21 and the inner surface 22a of each permanent magnet 22 are in contact with each other as flat surfaces. Next, the remaining permanent magnets 22 are inserted from the radially outer side toward the inner side between the permanently attached permanent magnets 22 arranged at intervals of one in the circumferential direction. In this case, the d-axis magnet portions 22dn and 22ds on both sides of the subsequently attached permanent magnet 22 and the d-axis magnet portions 22dn and 22ds of the permanently attached permanent magnets 22 on both sides are arranged such that the same poles face each other.

[0023] Therefore, as shown in FIG. 4, the later-attached permanent magnet 22 receives an equal repulsive force F1 from the permanent magnets 22 on both sides of the earlier-attached ones. As a result, the occurrence of the phenomenon in which the earlier-attached permanent magnet 22 and the later-attached permanent magnet 22 strongly contact each other due to the attractive force acting between the two, which has been a concern in the past, is suppressed. That is, the occurrence of damage due to strong contact between the permanent magnets 22 during attachment due to the action of the attractive force of the permanent magnets 22 is suppressed. In other words, since strong contact due to attraction between the permanent magnets 22 does not occur, the attachment work of the permanent magnets 22 can be made relatively easy.

[0024] Also, by providing an inclined surface 22f on the radially inner portion 22e, which is the insertion-side tip of each permanent magnet 22, to form a tapered shape, the insertion of the later-attached permanent magnet 22 between the earlier-attached permanent magnets 22 becomes easy. That is, also in this regard, the attachment work of the permanent magnets 22 can be expected to be facilitated.

[0025] And for the later-attached permanent magnet 22 attached in this way, the contact between its inner surface 22a and the outer surface 21a of the rotor base 21 is between flat surfaces. Therefore, all the permanent magnets 22 are attached to the rotor base 21 in a state where they are prevented from rotating. After that, a scattering prevention member 23 is attached so as to cover each permanent magnet 22, and each permanent magnet 22 is more securely fixed, completing the rotor 12.

[0026] (Effects of this Embodiment) The effects of this embodiment will be described. (1) In the permanent magnet 22 of the rotor 12, a d-axis magnet portion 22dn, 22ds in which magnetic flux mainly faces the radial direction on both side portions in the circumferential direction and a q-axis magnet portion 22q in which magnetic flux mainly faces the circumferential direction in the central portion in the circumferential direction are integrally formed as one magnetic material. And, the d-axis magnet portions 22dn, 22ds of the same poles of the permanent magnets 22 adjacent to each other in the circumferential direction of the rotor 12 are arranged so as to be continuously aligned. Here, in the rotor 12 such as the present embodiment that employs a Halbach array magnet, it is the attachment of the magnetized magnetic material. However, by configuring and arranging each permanent magnet 22 as described above, the magnetic force generated between the previously attached permanent magnet 22 and the subsequently attached permanent magnet 22 is a repulsive force F1 rather than an attractive force. That is, since the attachment uses the repulsive force F1 between the previously attached permanent magnet 22 and the subsequently attached permanent magnet 22, the occurrence of the phenomenon that they strongly contact each other due to the attractive force is suppressed, and the occurrence of damage to the permanent magnet 22 can be suppressed thereby. In other words, since strong contact due to attraction between the permanent magnets 22 during attachment is less likely to occur, the facilitation of the attachment operation of the permanent magnet 22 can be fully expected.

[0027] (2) The permanent magnets 22 are arranged in contact with each other with flat surfaces against the outer surface 21a of the rotor base 21. That is, since the permanent magnets 22 are attached to the rotor base 21 in a state where they are prevented from rotating, it can contribute to the improvement of the fixing strength of the permanent magnets 22 in the rotational direction of the rotor 12.

[0028] (3) In the permanent magnet 22, the radially inner portion 22e, which is the portion facing the outer surface 21a of the rotor base 21, has a tapered shape. That is, when attaching the subsequently attached permanent magnet 22 by inserting it with respect to the permanent magnets 22 on both sides in the circumferential direction that have been attached previously, contact is less likely to occur, and the facilitation of the attachment of the permanent magnet 22 can be fully expected.

[0029] (4) In the permanent magnet 22, an inclined surface 22f is provided for making the radially inner portion 22e tapered. Since the d-axis magnet portions 22dn and 22ds of the permanent magnet 22 where the inclined surface 22f is located are magnetized in an inclined manner along the inclined surface 22f, the influence on the performance of the permanent magnet 22 can be suppressed to be sufficiently small.

[0030] (Modified Example) This embodiment can be implemented with the following modifications. This embodiment and the following modified examples can be implemented in combination with each other within a technically non - conflicting range.

[0031] · The above - described various numerical values are examples and can be changed as appropriate. · Although the scattering prevention member 23 is provided to cover the entire permanent magnet 22, a mode in which a part of the permanent magnet 22 is exposed may also be acceptable. Also, the scattering prevention member 23 may be omitted.

[0032] · The shape of the permanent magnet 22 is an example and can be changed as appropriate. For example, the inclined surface 22f may not be provided on the permanent magnet 22. Also, the inner surface 22a of the permanent magnet 22 may be a circumferential surface. In this case, the shape of the outer surface 21a of the rotor base 21 is also changed accordingly.

[0033] · In addition, the configuration of the rotor 12 can be changed as appropriate. · Although the rotor 12 is applied to the inner - rotor type where the rotor 12 is located radially inside the stator 11, it may also be applied to the outer - rotor type where the rotor 12 is located radially outside the stator 11.

[0034] · Although the rotor 12 and the stator 11 are applied to the radial type where they face each other in the radial direction, they may also be applied to the axial type where the rotor and the stator face each other in the axial direction. (Supplementary Note) The technical idea grasped from the above - described embodiment and modified examples will be described.

[0035] (A) A rotor (12) comprising a rotor base (21) and a plurality of permanent magnets (22) arranged in the circumferential direction on the side surface (21a) of the rotor base, the permanent magnets being formed of Halbach array magnets, and a stator (11) that generates a rotating magnetic field for rotationally driving the rotor, a motor (10) comprising: the permanent magnets of the rotor are integrally formed as a single magnetic material including d-axis magnet portions (22dn, 22ds) in which magnetic flux mainly faces in the radial direction at both circumferential sides and a q-axis magnet portion (22q) in which magnetic flux mainly faces in the circumferential direction at the circumferential center, the d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction are arranged so as to be continuously aligned, motor.

Explanation of reference numerals

[0036] 12 Rotor, 21 Rotor base, 21a Outer surface (side surface), 22 Permanent magnet, 22dn, 22ds d-axis magnet portion, 22q q-axis magnet portion

Claims

1. A rotor base (21), A plurality of permanent magnets (22) arranged in the circumferential direction on the side surface (21a) of the rotor base, Comprising, The permanent magnet is a rotor (12) composed of Halbach array magnets, The permanent magnet is integrally formed as one magnetic material with a d-axis magnet portion (22dn, 22ds) in which magnetic flux mainly faces the radial direction on both circumferential sides and a q-axis magnet portion (22q) in which magnetic flux mainly faces the circumferential direction in the central portion in the circumferential direction, The d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction are arranged so as to be continuously aligned, The circumferential side end surface (22c) of the permanent magnet forms a flat surface along the radial direction of the rotor, The portion (22e) of the permanent magnet facing the side surface of the rotor base has an inclined surface (22f) for tapering, The inclined surface is formed so as to be continuous with the side end surface (22c) and the radial inner surface (22a) of the permanent magnet, respectively, In the permanent magnet, the inclined surface continuous with the side end surface and its radially inner side is inclined with respect to the side end surface along the radial direction of the rotor, Rotor.

2. The permanent magnets are arranged in contact with each other with flat surfaces against the side surface of the rotor base, The rotor according to claim 1.

3. In the permanent magnets adjacent to each other in the circumferential direction, the inclined surfaces adjacent to each other in the circumferential direction have a gap between the inclined surfaces without contacting each other, The rotor according to claim 1.

4. The d-axis magnet portion is magnetized with an inclination along the inclined surface, The rotor according to claim 1.

5. A rotor base (21), A plurality of permanent magnets (22) arranged in the circumferential direction on the side surface (21a) of the rotor base, Comprising, The permanent magnet is a method for manufacturing a rotor (12) composed of Halbach array magnets, The permanent magnet uses one in which a d-axis magnet portion (22dn, 22ds) in which magnetic flux mainly faces the radial direction on both circumferential sides and a q-axis magnet portion (22q) in which magnetic flux mainly faces the circumferential direction in the central portion in the circumferential direction are integrally formed as one magnetic material, After attaching the permanent magnets to the side surface of the rotor base at every other position in the circumferential direction over the entire circumference or a part of the circumferential direction, the next permanent magnet is inserted and attached from the radial direction between the previously attached permanent magnets so that the d-axis magnet portions of the same poles of the permanent magnets adjacent in the circumferential direction are arranged continuously side by side. Method for manufacturing a rotor.

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