WO2023199962A1

WO2023199962A1 - Rotor and rotor manufacturing method

Info

Publication number: WO2023199962A1
Application number: PCT/JP2023/014946
Authority: WO
Inventors: 一憲島田; 訓明松本; 崇平林
Original assignee: 株式会社デンソー
Priority date: 2022-04-13
Filing date: 2023-04-13
Publication date: 2023-10-19
Also published as: JP2023156759A

Abstract

A rotor (12) is provided with: a rotor base section (21); and a plurality of permanent magnets (22) that are disposed in a circumferential direction on a side surface (21a) of the rotor base section (21). The permanent magnets are formed by magnets in a Halbach array. Each of the permanent magnets includes: d-axis magnet sections (22dn, 22ds) that are in both circumferential side sections and that have the magnetic fluxes thereof oriented principally in a radial direction; and a q-axis magnet section (22q) that is in a circumferential center section and that has a magnetic flux thereof oriented principally in the circumferential direction. The d-axis magnet sections and the q-axis magnet section are formed integrally as a single magnet member. The plurality of permanent magnets are disposed so that d-axis magnet sections are arranged side-by-side in series, such sections being of the same polarity and being sections of circumferentially adjacent permanent magnets.

Description

Rotor and rotor manufacturing method

Cross-reference of related applications

This application is based on Japanese Application No. 2022-066301 filed on April 13, 2022, and the contents thereof are incorporated herein.

The present disclosure relates to a rotor having permanent magnets and a method for manufacturing the rotor.

A rotor of a motor is known in which a plurality of permanent magnets are arranged on the side surface of a rotor base as a magnetic pole part. The permanent magnet is, for example, a Halbach array magnet (see, for example, Patent Document 1). By using Halbach array magnets, motor performance can be expected to improve.

Japanese Patent Application Publication No. 2020-137387

A Halbach array magnet is a magnet formed by alternately arranging d-axis magnet portions whose magnetic flux is mainly oriented in the radial direction and q-axis magnet portions whose magnetic flux is mainly oriented in the circumferential direction. Due to the structure of such a magnet, it is difficult to magnetize the unmagnetized magnet material after attaching it to the rotor base. Therefore, in order to use Halbach array magnets in the rotor, it is necessary to magnetize each magnet material for the d-axis magnet section and the q-axis magnet section in advance, and then attach each magnetized magnet material to the rotor base. is common.

However, when attaching each magnetized magnet material for the d-axis magnet section and the q-axis magnet section to the rotor base, for example, the magnet material for the q-axis magnet section that is attached first is different from the magnet material for the d-axis magnet section that is attached later. An attractive force acts between the magnetic material and the magnetic material. In other words, during the installation work of the magnetic materials, the magnetic materials may come into contact with each other due to the action of mutual attraction. Therefore, there is a concern that the magnetic materials may be damaged if they come into strong contact with each other. In other words, it was necessary to perform careful and complicated installation work to prevent the magnetic materials from coming into strong contact with each other.

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 materials that constitute the Halbach array magnets.
In a first aspect of the present disclosure, the rotor includes a rotor base and a plurality of permanent magnets arranged along the circumferential direction on a side surface of the rotor base, and the permanent magnets are configured of Halbach array magnets. The permanent magnet includes a d-axis magnet portion in which the magnetic flux is mainly directed in the radial direction on both sides in the circumferential direction, and a q-axis magnet portion in the circumferential center portion in which the magnetic flux is mainly directed in the circumferential direction, The d-axis magnet section and the q-axis magnet section are integrally constituted as one magnet material, and the d-axis magnet sections of the same polarity of the circumferentially adjacent permanent magnets are arranged in succession. The plurality of permanent magnets are arranged as follows.

In a second aspect of the present disclosure, a method for manufacturing a rotor includes a rotor base and a plurality of permanent magnets disposed along a circumferential direction on a side surface of the rotor base, the permanent magnets being arranged in a Halbach array magnet. A method for manufacturing a rotor comprising: preparing the permanent magnet, the permanent magnet having a d-axis magnet portion on both sides in the circumferential direction, in which the magnetic flux is mainly oriented in the radial direction, and a d-axis magnet portion in the center in the circumferential direction. The part includes a q-axis magnet part whose magnetic flux is mainly directed in the circumferential direction, and the d-axis magnet part and the q-axis magnet part are integrally constituted as one magnet material, and the permanent magnet The permanent magnets are attached to the side surface of the rotor base every other time in the circumferential direction, and after the permanent magnets are attached, the following is done between the previously attached permanent magnets. The permanent magnet is inserted and attached from the radial direction, and the d-axis magnet portions of the same polarity of the permanent magnets adjacent in the circumferential direction are arranged in a continuous manner.

According to the above-mentioned rotor and rotor manufacturing method, the permanent magnets of the rotor include d-axis magnet portions on both sides in the circumferential direction in which the magnetic flux is mainly oriented in the radial direction, and q-axis magnet portions in the circumferential center portion in which the magnetic flux is mainly oriented in the circumferential direction. A structure in which the magnet part and the magnet part are integrally formed as one magnet material is used. The d-axis magnet portions of the same polarity of the permanent magnets that are adjacent to each other in the circumferential direction of the rotor are arranged in a continuous manner. In a rotor that uses Halbach array magnets, magnetized magnets are installed, but by having the individual permanent magnets configured and arranged as described above, there is no difference between the permanent magnets installed first and the permanent magnets installed later. The resulting magnetic force is not an attractive force but a repulsive force. In other words, since the installation utilizes the repulsive force between the first-installed permanent magnet and the second-installed permanent magnet, the occurrence of strong contact between the two due to the attractive force is suppressed, and this causes the permanent magnet to The occurrence of damage is suppressed. In other words, since strong contact due to attraction between the permanent magnets is less likely to occur during attachment, it is expected that the work of attaching the permanent magnets will become easier.

The above objects and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a configuration diagram of a motor having a rotor in one embodiment, FIG. 2 is a perspective view of the rotor in the same embodiment, FIG. 3 is a partially enlarged view of the rotor in the same embodiment, FIG. 4 is an explanatory diagram showing the manufacturing process of the rotor in the same embodiment.

An embodiment of a rotor and a method for manufacturing the rotor will be described below.
(Configuration of motor 10)
As shown in FIG. 1, the motor 10 of this embodiment includes a stator 11 and a rotor 12. The stator 11 has a substantially annular shape. The stator 11 has, for example, 24 coil magnetic pole portions (not shown) in the circumferential direction. A rotor 12 is rotatably arranged inside the stator 11. The stator 11 generates a rotating magnetic field for rotationally driving the rotor 12 based on energization of its own coil magnetic pole portion. The motor 10 of this embodiment is intended to be applied to a high-speed rotation motor with a maximum rotation speed of 12,000 [rpm] or more, as an example.

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

The rotor base 21 has a generally cylindrical shape as a whole. The rotor base 21 has a hollow structure in consideration of weight reduction and the like. An axial end portion of the rotor base portion 21 is integrally configured as an output shaft portion 21x. For example, twenty permanent magnets 22 are arranged in the circumferential direction on the outer surface 21a of the axially central portion of the rotor base 21. The outer surface 21a of the rotor base 21 of this embodiment has 20 flat surfaces corresponding to each permanent magnet 22 (see FIG. 3). The rotor 12 has 20 magnetic pole parts in the circumferential direction.

The permanent magnet 22 has a substantially rectangular 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 is a flat surface, and the flat surfaces are in contact with the outer surface 21a of the rotor base 21. The outer surface 22b of the permanent magnet 22, which is on the outer diameter side of the rotor 12, constitutes a uniform outer circumferential surface of the rotor 12 by all the permanent magnets 22 in the circumferential direction. 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 the inner surface 22a of the permanent magnet 22 into contact with the rotor base 21, the permanent magnet 22 has a gap at each side end surface 22c on both sides with respect to the permanent magnet 22 on both sides in the circumferential direction, or has a gap between only one side end surface 22c. It is in contact. In each figure, the permanent magnets 22 are drawn in contact with each other.

As shown in FIG. 3, the permanent magnet 22 is constructed of a Halbach array magnet in this embodiment. Specifically, the permanent magnet 22 is divided into three regions with different magnetization modes in the circumferential direction. Both sides of the permanent magnet 22 in the circumferential direction are d-axis magnet parts 22dn and 22ds in which the magnetic flux is mainly oriented in the radial direction. The circumferential central portion of the permanent magnet 22 is a q-axis magnet portion 22q in which the magnetic flux is mainly directed in the circumferential direction and directed toward the d-axis magnet portions 22dn and 22ds on both sides thereof. A more specific configuration of the permanent magnets 22 and a method for attaching them to the rotor base 21 will be described later.

As shown in FIG. 2, the anti-scattering member 23 is attached so as to revolve around the rotor 12 along the outer surface 22b of the 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 of CFRP material (not shown) is wound several times around the permanent magnet 22 of the rotor 12, and is wound in one layer or in multiple layers. Then, heat curing is performed to produce a cylindrical anti-scattering member 23 that fixes the permanent magnet 22 and prevents it from scattering.

(Specific configuration and mounting method of permanent magnet 22)
As shown in FIG. 3, in the permanent magnet 22 of this embodiment, the d-axis magnet parts 22dn, 22ds and the q-axis magnet part 22q are integrally constituted as one magnet material. The d-axis magnet portions 22dn and 22ds are provided on both sides of the permanent magnet 22 in the circumferential direction, and the q-axis magnet portion 22q is provided in the center portion in the circumferential direction. Further, in the d-axis magnet section 22dn on one side in the circumferential direction, an N pole appears on the outer surface 22b of the permanent magnet 22, and in the d-axis magnet section 22ds on the other side in the circumferential direction, an S pole appears on the outer surface 22b of the permanent magnet 22. It becomes. The arrangement of the permanent magnets 22 in the rotor 12 in the circumferential direction is such that the d-axis magnet portions 22dn and d-axis magnet portions 22ds of the same polarity of the permanent magnets 22 adjacent to each other in the circumferential direction are lined up consecutively. ing. That is, in this embodiment, the d-axis magnet parts 22dn and d-axis magnet parts 22ds of the same polarity of the adjacent permanent magnets 22 cooperate with each other to form the same-polarity magnet pole part.

Regarding the manner in which each permanent magnet 22 is attached to the outer surface 21a of the rotor base 21, in this embodiment, permanent magnets 22 are attached every other time around the entire circumference, and then the spaces between the previously attached permanent magnets 22 are filled. The remaining every other permanent magnet 22 is attached in this manner. Note that, after attaching the permanent magnets 22 with one space apart, the next permanent magnet 22 is attached repeatedly over the entire circumference of the rotor base 21 so as to fill the space between the permanent magnets 22. It may be. In any case, the permanent magnets 22 to be installed later are inserted between the previously installed permanent magnets 22 spaced one space apart from each other in the radial direction from the outside to the inside.

In consideration of such an attachment mode, the radially inner part 22e of each permanent magnet 22 has an inclined surface 22f at the corner of each d-axis magnet part 22dn, 22ds that is continuous with the inner surface 22a, and the radially inner part 22e has an inclined surface 22f. It is configured to have a tapered shape. That is, in the present embodiment, in which the permanent magnet 22 is attached so as to be inserted between the previously attached permanent magnets 22, the radially inner portion 22e, which is the insertion side tip of the permanent magnet 22, has a tapered shape. . Therefore, the permanent magnets 22 installed later are less likely to come into contact with the permanent magnets 22 on both sides in the circumferential direction that were installed earlier, and it is expected that the installation of the permanent magnets 22 will be made easier.

Moreover, since each permanent magnet 22 has a configuration in which it has d-axis magnet portions 22dn, 22ds on both sides and a q-axis magnet portion 22q in the center, the internal magnetic flux tends to be directed toward the center as it moves inward in the radial direction. In other words, the radially inner corner portion, which is omitted by providing the tapered inclined surface 22f on the radially inner portion 22e of the permanent magnet 22, is a portion where the internal magnetic flux is originally small, so it affects the performance of the permanent magnet 22. The impact is small enough. In this embodiment, further considering the flow of the internal magnetic flux of the permanent magnet 22, the d-axis magnet sections 22dn and 22ds are magnetized themselves so as to be inclined along the inclined surface 22f. That is, the d-axis centerline Ld is set to have a predetermined inclination angle θ1 with respect to the q-axis centerline Lq, which is also the circumferential centerline of the permanent magnet 22. In this embodiment using 20 permanent magnets 22, the inclination angle θ1 of the d-axis center line Ld is set to 30° to 40°, as an example. Coupled with the manner in which the magnetization of the d-axis magnet parts 22dn and 22ds is inclined, the influence on the performance of the permanent magnet 22 is sufficiently small, and the permanent magnet 22 of this embodiment has a rational configuration.

(Action of this embodiment)
The operation of this embodiment will be explained.
In manufacturing the rotor 12 of this embodiment, the permanent magnets 22 are configured as Halbach array magnets. Therefore, a plurality of permanent magnets 22 that have been magnetized in advance are attached.

First, every other permanent magnet 22 is attached to the outer surface 21a of the rotor base 21 over the entire circumference. The outer surface 21a of the rotor base 21 and the inner surface 22a of each permanent magnet 22 are flat surfaces in contact with each other. Next, the remaining every other permanent magnet 22 is inserted from the outside in the radial direction to the inside between the permanent magnets 22 installed previously in the circumferential direction. In this case, the d-axis magnet parts 22dn, 22ds on both sides of the permanent magnet 22 installed later to be inserted are arranged to have the same polarity as the d-axis magnet parts 22dn, 22ds of the permanent magnet 22 on both sides that are installed first. It is.

Therefore, as shown in FIG. 4, the later-attached permanent magnet 22 receives an equal repulsive force F1 from the first-attached permanent magnets 22 on both sides. As a result, the occurrence of a phenomenon in which the permanent magnet 22 attached first and the permanent magnet 22 attached later come into strong contact with each other due to the attractive force acting between them can be suppressed, which has been a concern in the past. In other words, the occurrence of damage due to strong contact between the permanent magnets 22 during attachment due to the attraction 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 work of attaching the permanent magnets 22 can be made relatively easy.

Furthermore, by providing the inclined surface 22f on the radially inner side 22e, which is the insertion side tip of each permanent magnet 22, to give it a tapered shape, it is possible to insert the later-attached permanent magnet 22 between the earlier-attached permanent magnets 22. It becomes easier. In other words, also in this case, it is expected that the work of attaching the permanent magnet 22 will be made easier.

Also, regarding the post-attached permanent magnet 22 that is attached in this way, 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 as flat surfaces. Therefore, the permanent magnets 22 are attached to the rotor base 21 in a state in which all the permanent magnets 22 around the entire circumference are prevented from rotating. Thereafter, the anti-scattering member 23 is attached to cover each permanent magnet 22, and each permanent magnet 22 is more securely fixed, thus completing the rotor 12.

(Effects of this embodiment)
The effects of this embodiment will be explained.
(1) The permanent magnets 22 of the rotor 12 have d-axis magnet parts 22dn, 22ds on both sides in the circumferential direction, where the magnetic flux mainly faces the radial direction, and a q-axis magnet part 22q, where the magnetic flux mainly faces the circumferential direction, on the center part in the circumferential direction. The d-axis magnet parts 22dn, 22ds and the q-axis magnet part 22q are integrally formed as one magnet material. The d-axis magnet portions 22dn and 22ds of the same polarity of the permanent magnets 22 adjacent to each other in the circumferential direction of the rotor 12 are arranged in a row. Here, in the rotor 12 of this embodiment which employs Halbach array magnets, magnetized magnet materials are attached. However, by having the individual permanent magnets 22 configured and arranged as described above, the magnetic force generated between the permanent magnet 22 attached first and the permanent magnet 22 attached later becomes a repulsive force F1 instead of an attractive force. In other words, since the repulsive force F1 is used between the first-attached permanent magnet 22 and the second-attached permanent magnet 22, the occurrence of strong contact between the two due to the attractive force is suppressed, and the The occurrence of damage to the permanent magnet 22 can be suppressed. In other words, since strong contact due to attraction between the permanent magnets 22 is less likely to occur during attachment, it can be expected that the work of attaching the permanent magnets 22 will be made easier.

(2) The permanent magnets 22 are arranged with their flat surfaces abutting 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 is possible to contribute to improving the fixing strength of the permanent magnets 22 in the rotational direction of the rotor 12.

(3) In the permanent magnet 22, the radially inner portion 22e, which is a portion facing the outer surface 21a of the rotor base 21, has a tapered shape. In other words, when the permanent magnets 22 to be attached later are inserted and attached to the permanent magnets 22 on both sides in the circumferential direction that were attached earlier, contact is less likely to occur, and it is fully expected that the attachment of the permanent magnets 22 will be made easier.

(4) In the permanent magnet 22, an inclined surface 22f is provided to make 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 a sufficiently small level.

(Example of change)
This embodiment can be modified and implemented as follows. This embodiment and the following modified examples can be implemented in combination with each other within a technically consistent range.

- The various numerical values described above are just examples, and may be changed as appropriate.
- Although the anti-scattering member 23 is provided so as to cover the entire permanent magnet 22, it may be configured so that a portion of the permanent magnet 22 is exposed. Moreover, the scattering prevention member 23 may be omitted.

- The shape of the permanent magnet 22 is just an example, and may be changed as appropriate. For example, the permanent magnet 22 does not need to be provided with the inclined surface 22f. Furthermore, 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.

- In addition, the configuration of the rotor 12 may be changed as appropriate.
- Although applied to an inner rotor type in which the rotor 12 is located radially inside the stator 11, it may also be applied to an outer rotor type in which the rotor 12 is located radially outside the stator 11.

- Although the present invention has been applied to a radial type in which the rotor 12 and the stator 11 face each other in the radial direction, it may also be applied to an axial type in which the rotor and the stator face each other in the axial direction.
- Although the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, various combinations and configurations, as well as other combinations and configurations that include only one, more, or fewer elements, are within the scope and scope of the present disclosure.

(Additional note)
The technical ideas that can be understood from the above embodiment and modification examples will be described.
(A) comprising a rotor base (21) and a plurality of permanent magnets (22) arranged along the circumferential direction on the side surface (21a) of the rotor base, the permanent magnets being constituted by Halbach array magnets; rotor (12),
A motor (10) comprising a stator (11) that generates a rotating magnetic field for rotationally driving the rotor,
The permanent magnets of the rotor include d-axis magnet portions (22dn, 22ds) in which magnetic flux mainly points in the radial direction on both sides in the circumferential direction, and q-axis magnet portions (22q) in which the magnetic flux mainly turns in the circumferential direction in the circumferential center portion. The d-axis magnet part and the d-axis magnet part are integrally constituted as one magnet material,
The plurality of permanent magnets are arranged such that the d-axis magnet portions of the same polarity of the permanent magnets that are adjacent to each other in the circumferential direction are consecutively arranged.
motor.

Claims

a rotor base (21);
A plurality of permanent magnets (22) arranged along the circumferential direction on the side surface (21a) of the rotor base,
The permanent magnet is a rotor (12) composed of a Halbach array magnet,
The permanent magnet includes a d-axis magnet part (22dn, 22ds) in which the magnetic flux is mainly directed in the radial direction on both sides in the circumferential direction, and a q-axis magnet part (22q) in which the magnetic flux is mainly directed in the circumferential direction in the circumferential center part. , the d-axis magnet section and the q-axis magnet section are integrally constituted as one magnet material,
The plurality of permanent magnets are arranged such that the d-axis magnet portions of the same polarity of the permanent magnets that are adjacent to each other in the circumferential direction are consecutively arranged.
Rotor.
The permanent magnets are arranged so that their flat surfaces are in contact with the side surface of the rotor base.
A rotor according to claim 1.
A portion (22e) of the permanent magnet facing the side surface of the rotor base has a tapered shape.
A rotor according to claim 1.
A portion (22e) of the permanent magnet facing the side surface of the rotor base has an inclined surface (22f) for forming a tapered shape;
The d-axis magnet section is magnetized at an angle along the inclined surface.
A rotor according to claim 1.
a rotor base (21);
A plurality of permanent magnets (22) arranged along the circumferential direction on the side surface (21a) of the rotor base,
A method for manufacturing a rotor (12) in which the permanent magnet is a Halbach array magnet,
Preparing the permanent magnet, the permanent magnet has a d-axis magnet part (22dn, 22ds) in which the magnetic flux is directed mainly in the radial direction on both sides in the circumferential direction, and a d-axis magnet part (22dn, 22ds) in which the magnetic flux is mainly directed in the circumferential direction in the center part in the circumferential direction. a q-axis magnet portion (22q) facing the magnet, and the d-axis magnet portion and the q-axis magnet portion are integrally constituted as one magnet material;
Attaching the permanent magnets to the side surface of the rotor base every other time in the circumferential direction over the entire circumference or a part of the circumferential direction;
After attaching the permanent magnets, the next permanent magnet is inserted and attached from the radial direction between the previously attached permanent magnets, and the d-axis magnet parts of the same polarity of the circumferentially adjacent permanent magnets are connected to each other. are arranged in a continuous manner,
Rotor manufacturing method.