JP7517138B2 - Rotor, rotating electric machine, vehicle - Google Patents

Description

The technology disclosed here relates to rotors, rotating electric machines, and vehicles.

Patent document 1 discloses a rotating electric machine having a stator and a rotor. The stator has an armature winding. The rotor has a rotor core, a fixed magnetic force magnet embedded in the rotor core, and variable magnetic force magnets arranged on both sides of the fixed magnetic force magnet. The magnetization state of the variable magnetic force magnet changes with the magnetic field formed by passing current through the armature winding.

JP 2013-51760 A

In the rotating electric machine of Patent Document 1, it is possible to provide an anisotropic magnetic member (e.g., an anisotropic electromagnetic steel sheet) whose easy magnetization direction faces the q-axis direction on the q-axis so that magnetic flux can easily flow in the q-axis direction. However, simply providing an anisotropic magnetic member on the q-axis may make it difficult for magnetic flux to flow in the variable magnetic force magnet.

The technology disclosed here has been developed in consideration of these points, and its purpose is to increase the magnetic flux flowing in the q-axis direction while suppressing the decrease in the magnetic flux passing through the variable magnet.

The technology disclosed herein relates to a rotor, which includes a rotor core, a plurality of magnetic pole parts arranged in the circumferential direction, and a plurality of anisotropic magnetic members arranged on the rotor core and disposed on the q-axis between the plurality of magnetic pole parts, each with its easy magnetization direction facing the q-axis direction. Each of the plurality of magnetic pole parts has a fixed magnet magnetized in the radial direction, and a first variable magnet and a second variable magnet disposed on one end side and the other end side of the fixed magnet in the circumferential direction, each capable of changing the magnetization state in the circumferential direction by a predetermined magnetic flux. The first variable magnet included in each of the plurality of magnetic pole parts is adjacent to the second variable magnet included in another magnetic pole part located on the one end side of the magnetic pole part in the circumferential direction, across the q-axis, and in each of the portions located on the q-axis between the plurality of magnetic pole parts of the rotor core, a non-forming region is provided between the first variable magnet and the second variable magnet adjacent to each other across the q-axis, where the anisotropic magnetic member is not formed.

In the above configuration, by providing an anisotropic magnetic member whose easy magnetization direction faces the q-axis direction, it is possible to increase the magnetic flux flowing in the q-axis direction. In addition, by providing a non-formed region (a region where no anisotropic magnetic member is formed) between the first variable magnet and the second variable magnet adjacent to each other across the q-axis, it is possible to prevent the flow of magnetic flux passing through the first variable magnet and the second variable magnet adjacent to each other across the q-axis from being obstructed by the anisotropic magnetic member. This makes it possible to prevent a decrease in the magnetic flux passing through each of the first variable magnet and the second variable magnet.

In addition, in the rotor, each of the multiple magnetic pole parts may have a first non-magnetic member arranged radially inward of the first variable magnet and a second non-magnetic member arranged radially inward of the second variable magnet, and the first non-magnetic member included in each of the multiple magnetic pole parts may be adjacent to the second non-magnetic member included in another magnetic pole part located on one end side of the magnetic pole part in the circumferential direction, with the anisotropic magnetic member sandwiched between them.

In the above configuration, by arranging the anisotropic magnetic member, the first non-magnetic member, and the second non-magnetic member radially inward of the first variable magnet and the second variable magnet, the flow of magnetic flux in the circumferential direction radially inward of the first variable magnet and the second variable magnet can be suppressed. This allows the flow of magnetic flux to be concentrated in the first variable magnet and the second variable magnet.

Furthermore, in the rotor, the first non-magnetic member may be a member for holding the first variable magnet, and the second non-magnetic member may be a member for holding the second variable magnet.

In the above configuration, by having the first non-magnetic member hold the first variable magnet, the number of parts can be reduced compared to when the member for holding the first variable magnet and the first non-magnetic member are separate members. Also, by having the second non-magnetic member hold the second variable magnet, the number of parts can be reduced compared to when the member for holding the second variable magnet and the second non-magnetic member are separate members.

In addition, in the rotor, the first non-magnetic member may have a first hollow portion, and the second non-magnetic member may have a second hollow portion.

In the above configuration, the weight of the first non-magnetic member can be reduced by providing a first hollow portion in the first non-magnetic member. Also, the weight of the second non-magnetic member can be reduced by providing a second hollow portion in the second non-magnetic member.

In addition, in the rotor, the non-forming region may be a region beginning at the radial outer end of the anisotropic magnetic member corresponding to the non-forming region and terminating at the outer peripheral edge of the rotor core, and the beginning of the non-forming region may be located within a range from a first position corresponding to the radial inner end of each of the first variable magnet and the second variable magnet adjacent to each other across the non-forming region to a second position corresponding to the radial center of each of the first variable magnet and the second variable magnet.

In the above configuration, by positioning the beginning of the non-forming region within the range from the first position to the second position, it is possible to appropriately ensure the amount of magnetic flux flowing in the q-axis direction and the amount of magnetic flux passing through the first variable magnet and the second variable magnet.

The technology disclosed herein also relates to a rotating electric machine, which includes the rotor and a stator that faces the rotor in the radial direction across an air gap.

The technology disclosed herein also relates to a vehicle, which includes the rotating electric machine and drive wheels to which the power of the rotating electric machine is transmitted.

The technology disclosed herein makes it possible to increase the magnetic flux flowing in the q-axis direction while suppressing the reduction in the magnetic flux passing through the first variable magnet and the second variable magnet.

1 is a cross-sectional view illustrating a configuration of a rotating electric machine according to an embodiment; 1 is a cross-sectional view illustrating a configuration of a main part of a rotating electric machine according to an embodiment; FIG. 11 is a schematic diagram for explaining the start end of a non-forming region. 1 is a schematic diagram illustrating a configuration of a vehicle including a rotating electric machine;

The following describes the embodiments in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are given the same reference numerals and their description will not be repeated.

(Embodiment)
1 illustrates a configuration of a rotating electric machine 1 according to an embodiment. The rotating electric machine 1 includes a rotor 10, a stator 20, and a shaft 30.

In the following description, the direction of the center of rotation Q of the rotor 10 is referred to as the "axial direction", the direction perpendicular to the axial direction is referred to as the "radial direction", and the direction along the direction of rotation of the rotor 10 is referred to as the "circumferential direction". The side farther from the center of rotation Q is referred to as the "radial outer side", and the side closer to the center of rotation Q is referred to as the "radial inner side". The shape of a cross section perpendicular to the axial direction is referred to as the "cross-sectional shape".

[Stator]
The stator 20 faces the rotor 10 in the radial direction across an air gap. The stator 20 includes a stator core 21 and a plurality of coils 22.

The stator core 21 has a back yoke 21a formed in an annular shape and a number of teeth 21b protruding radially inward from the back yoke 21a. For example, the stator core 21 is a laminated core in which a number of thin sheets of electromagnetic steel are stacked in the axial direction.

The multiple coils 22 are wound around the multiple teeth 21b. When current is applied to the multiple coils 22, magnetic flux is generated in the multiple coils 22. For example, the multiple coils 22 are three-phase coils.

In this example, the magnetic flux generated in the multiple coils 22 includes a rotational magnetic flux, which is a magnetic flux for rotating the rotor 10, and a variable magnetic flux (predetermined magnetic flux), which is a magnetic flux for changing the magnetization state of the first variable magnet 51 and the second variable magnet 52 described below.

For example, by supplying an AC current to the multiple coils 22, a rotating magnetic flux is generated in the multiple coils 22. This rotating magnetic flux rotates the rotor 10. Also, while the rotor 10 is rotating (or stopped), a predetermined current (e.g., a pulse current higher than the AC current that generates the rotating magnetic flux) is supplied to the multiple coils 22 for a predetermined period of time, thereby generating a variable magnetic flux in the multiple coils 22. This variable magnetic flux changes the magnetization state of the first variable magnet 51 and the second variable magnet 52, which will be described later.

[Rotor]
Next, the rotor 10 will be described with reference to Figures 1 and 2. The rotor 10 includes a rotor core 11, a plurality of magnetic pole portions 12, and a plurality of anisotropic magnetic members 15. The straight arrows in the figures illustrate the magnetization directions of the magnets.

[Rotor core]
The rotor core 11 is formed in a cylindrical shape. For example, the rotor core 11 is a laminated core in which a plurality of thin plates made of electromagnetic steel are laminated in the axial direction. A shaft hole S30 is provided in the center of the rotor core 11. A shaft 30 is inserted into and fixed in the shaft hole S30.

[Magnetic pole part]
The multiple magnetic pole portions 12 are provided on the rotor core 11 and are arranged in the circumferential direction. Each of the multiple magnetic pole portions 12 has a fixed magnet 40, a first variable magnet 51, a second variable magnet 52, a first auxiliary magnet 61, a second auxiliary magnet 62, a first non-magnetic member 71, and a second non-magnetic member 72.

<Fixed magnet>
The fixed magnets 40 are embedded in the rotor core 11. In this example, the fixed magnets 40 are housed in fixed magnet holes S40 provided in the rotor core 11. The fixed magnets 40 extend in a direction perpendicular to the radial direction (the tangential direction). Specifically, the fixed magnets 40 have a rectangular cross-sectional shape, and the longitudinal direction faces the tangential direction.

The fixed magnets 40 are magnetized in the radial direction. In this example, multiple fixed magnets 40 are magnetized so that fixed magnets 40 with north poles at their radially outer ends and fixed magnets 40 with south poles at their radially outer ends are arranged alternately in the circumferential direction.

The fixed magnet 40 is a permanent magnet that maintains its magnetization direction. Specifically, the magnetization state of the fixed magnet 40 does not substantially change even when a predetermined magnetic flux (in this example, the variable magnetic flux generated in the coil 22 of the stator 20) is applied. The fixed magnet 40 is a permanent magnet whose magnetization state is less likely to change than the first variable magnet 51 and the second variable magnet 52. For example, the coercive force of the fixed magnet 40 is higher than the coercive force of the first variable magnet 51 and the second variable magnet 52. Examples of the fixed magnet 40 include Nd-Fe-B magnets, Sm-Co magnets, metal magnets (e.g., Fe-Ni magnets), ferrite magnets, etc.

Variable magnet
The first variable magnet 51 included in each of the multiple magnetic pole portions 12 is adjacent to a second variable magnet 52 included in another magnetic pole portion 12 located at one circumferential end side (adjacent in the clockwise direction in the examples of FIGS. 1 and 2 ) of that magnetic pole portion 12, across the q axis. The q axis is an imaginary line that extends radially, passing between two magnetic pole portions 12 adjacent to each other in the circumferential direction.

In addition, in each of the multiple magnetic pole portions 12, the first variable magnet 51 and the second variable magnet 52 are symmetrical with respect to an imaginary line (d-axis) that passes through the center of the fixed magnet 40 in the circumferential direction and extends radially.

First variable magnet
The first variable magnet 51 is disposed on one circumferential end side of the fixed magnet 40. The first variable magnet 51 faces the fixed magnet 40 at a distance in the circumferential direction. The circumferential length between the first variable magnet 51 and the q axis is shorter than the circumferential length between the first variable magnet 51 and the fixed magnet 40.

The first variable magnet 51 is embedded in the rotor core 11. In this example, the first variable magnet 51 is housed in a first variable magnet hole S51 provided in the rotor core 11. The first variable magnet 51 also extends along the q axis (the q axis adjacent in the circumferential direction). Specifically, the first variable magnet 51 has a rectangular cross-sectional shape, and its longitudinal direction is parallel to the q axis.

<Second variable magnet>
The second variable magnet 52 is disposed on the other circumferential end side of the fixed magnet 40. The second variable magnet 52 faces the fixed magnet 40 at a distance in the circumferential direction. The circumferential length between the second variable magnet 52 and the q axis is shorter than the circumferential length between the second variable magnet 52 and the fixed magnet 40.

The second variable magnet 52 is embedded in the rotor core 11. In this example, the second variable magnet 52 is housed in a second variable magnet hole S52 provided in the rotor core 11. The second variable magnet 52 also extends along the q axis (the q axis adjacent in the circumferential direction). Specifically, the second variable magnet 52 has a rectangular cross-sectional shape, and its longitudinal direction is parallel to the q axis.

<Magnetic properties of variable magnets>
Each of the first variable magnet 51 and the second variable magnet 52 is a permanent magnet capable of changing the magnetization state. Specifically, each of the first variable magnet 51 and the second variable magnet 52 is capable of changing the magnetization state in the circumferential direction by a predetermined magnetic flux (in this example, the variable magnetic flux generated in the coil 22 of the stator 20). Each of the first variable magnet 51 and the second variable magnet 52 is a permanent magnet whose magnetization state is easier to change than the fixed magnet 40. For example, the coercive force of the first variable magnet 51 and the second variable magnet 52 is lower than the coercive force of the fixed magnet 40. Examples of the first variable magnet 51 and the second variable magnet 52 include Sm-Co magnets, Nd-Fe-B magnets, metal magnets (e.g., Fe-Ni magnets), ferrite magnets, and Al-Ni-Co magnets.

In this example, the easy magnetization direction of each of the first variable magnet 51 and the second variable magnet 52 is oriented in a direction perpendicular to the radial direction (tangential direction). The hard magnetization direction of the first variable magnet 51 is oriented in a direction perpendicular to the easy magnetization direction of the first variable magnet 51 (radial direction in this example). The hard magnetization direction of the second variable magnet 52 is oriented in a direction perpendicular to the easy magnetization direction of the second variable magnet 52 (radial direction in this example).

In this example, each of the first variable magnet 51 and the second variable magnet 52 can be switched between a first state in which the magnetization direction faces a first direction, a second state in which the magnetization direction faces a second direction, and a zero state in which the magnetic force is substantially zero. The first direction is a direction that increases the magnetic flux (effective magnetic flux) that links with the teeth 21b. The second direction is a direction that decreases the magnetic flux (effective magnetic flux) that links with the teeth 21b. For example, when the magnetization direction of the fixed magnet 40 is a direction toward the radial outward direction, the first direction is a direction from the first variable magnet 51 (or the second variable magnet 52) toward the fixed magnet 40, and the second direction is a direction from the fixed magnet 40 toward the first variable magnet 51 (or the second variable magnet 52).

<Auxiliary magnet>
In each of the multiple magnetic pole portions 12, the first auxiliary magnet 61 and the second auxiliary magnet 62 are symmetrical with respect to an imaginary line (d-axis) that passes through the circumferential center of the fixed magnet 40 and extends radially.

<First auxiliary magnet>
The first auxiliary magnet 61 is disposed between the fixed magnet 40 and the first variable magnet 51. The circumferential length between the first auxiliary magnet 61 and the fixed magnet 40 is shorter than the circumferential length between the first auxiliary magnet 61 and the first variable magnet 51.

The first auxiliary magnet 61 is embedded in the rotor core 11. In this example, the first auxiliary magnet 61 is housed in a first auxiliary magnet hole S61 provided in the rotor core 11. The first auxiliary magnet 61 also extends along one circumferential end of the fixed magnet 40. Specifically, the first auxiliary magnet 61 has a rectangular cross-sectional shape, with its short side facing the longitudinal direction of the fixed magnet 40.

The first auxiliary magnet 61 is magnetized in a direction that obstructs the flow of magnetic flux between the radially outer end of the fixed magnet 40 and the first variable magnet 51. Specifically, when the magnetization direction of the fixed magnet 40 is a direction toward the radially outward direction, the magnetization direction of the first auxiliary magnet 61 is a direction from the first variable magnet 51 toward the fixed magnet 40. When the magnetization direction of the fixed magnet 40 is a direction toward the radially inward direction, the magnetization direction of the first auxiliary magnet 61 is a direction from the fixed magnet 40 toward the first variable magnet 51.

<Second auxiliary magnet>
The second auxiliary magnet 62 is disposed between the fixed magnet 40 and the second variable magnet 52. The circumferential length between the second auxiliary magnet 62 and the fixed magnet 40 is shorter than the circumferential length between the second auxiliary magnet 62 and the second variable magnet 52.

The second auxiliary magnet 62 is embedded in the rotor core 11. In this example, the second auxiliary magnet 62 is housed in a second auxiliary magnet hole S62 provided in the rotor core 11. The second auxiliary magnet 62 also extends along the other circumferential end of the fixed magnet 40. Specifically, the second auxiliary magnet 62 has a rectangular cross-sectional shape, with its short side facing the longitudinal direction of the fixed magnet 40.

The second auxiliary magnet 62 is magnetized in a direction that obstructs the flow of magnetic flux between the radially outer end of the fixed magnet 40 and the second variable magnet 52. Specifically, when the magnetization direction of the fixed magnet 40 is a direction toward the radially outward direction, the magnetization direction of the second auxiliary magnet 62 is a direction from the second variable magnet 52 toward the fixed magnet 40. When the magnetization direction of the fixed magnet 40 is a direction toward the radially inward direction, the magnetization direction of the second auxiliary magnet 62 is a direction from the fixed magnet 40 toward the second variable magnet 52.

<Magnetic properties of auxiliary magnets>
Each of the first auxiliary magnet 61 and the second auxiliary magnet 62 is a permanent magnet that maintains its magnetization direction. Specifically, the magnetization state of each of the first auxiliary magnet 61 and the second auxiliary magnet 62 does not substantially change even when a predetermined magnetic flux (in this example, the variable magnetic flux generated in the coil 22 of the stator 20) is applied. The first auxiliary magnet 61 and the second auxiliary magnet 62 are permanent magnets whose magnetization state is less likely to change than the first variable magnet 51 and the second variable magnet 52. For example, the coercive force of the first auxiliary magnet 61 and the second auxiliary magnet 62 is higher than the coercive force of the first variable magnet 51 and the second variable magnet 52. Examples of the first auxiliary magnet 61 and the second auxiliary magnet 62 include Nd-Fe-B magnets, Sm-Co magnets, metal magnets (e.g., Fe-Ni magnets), ferrite magnets, and the like.

<Details of auxiliary magnet>
In this example, the radially outer ends of the first auxiliary magnet 61 and the second auxiliary magnet 62 are located radially outward from the radially outer end of the fixed magnet 40 .

In this example, the first auxiliary magnet 61 contacts one circumferential end of the fixed magnet 40. Specifically, the first auxiliary magnet hole S61 communicates with the fixed magnet hole S40. The first auxiliary magnet 61 is housed in the first auxiliary magnet hole S61 while in contact with the fixed magnet 40 housed in the fixed magnet hole S40.

In this example, the second auxiliary magnet 62 contacts the other circumferential end of the fixed magnet 40. Specifically, the second auxiliary magnet hole S62 communicates with the fixed magnet hole S40. The second auxiliary magnet 62 is housed in the second auxiliary magnet hole S62 while in contact with the fixed magnet 40 housed in the fixed magnet hole S40.

<Non-magnetic materials>
The first non-magnetic member 71 included in each of the multiple magnetic pole portions 12 is adjacent to a second non-magnetic member 72 included in another magnetic pole portion 12 located on one circumferential end side of the magnetic pole portion 12 (adjacent in the clockwise direction in the examples of Figures 1 and 2).

In each of the multiple magnetic pole portions 12, the first non-magnetic member 71 and the second non-magnetic member 72 are symmetrical about an imaginary line (d-axis) that passes through the center in the circumferential direction of the fixed magnet 40 and extends in the radial direction. For example, the first non-magnetic member 71 and the second non-magnetic member 72 are made of insulating resin.

<First non-magnetic member>
The first non-magnetic member 71 is disposed radially inward of the first auxiliary magnet 61 and the fixed magnet 40. The first non-magnetic member 71 faces the radially inner ends of the first auxiliary magnet 61 and the fixed magnet 40 with a gap therebetween.

The first non-magnetic member 71 is embedded in the rotor core 11. In this example, the first non-magnetic member 71 is accommodated in a first accommodation hole S71 provided in the rotor core 11. The first non-magnetic member 71 also extends along the q axis (the q axis adjacent in the circumferential direction). Specifically, the cross-sectional shape of the first non-magnetic member 71 is formed into a trapezoid. One oblique side of the first non-magnetic member 71 faces in a direction parallel to the q axis, and the other oblique side of the first non-magnetic member 71 faces in a direction parallel to the d axis.

In this example, the first non-magnetic member 71 is a member for holding the first variable magnet 51. Specifically, the first storage hole S71 is connected to the first variable magnet hole S51. The first non-magnetic member 71 has a protruding portion that protrudes toward the first variable magnet 51. The first non-magnetic member 71 is housed in the first storage hole S71 with the protruding portion pressing radially outward against the first variable magnet 51 housed in the first variable magnet hole S51.

In this example, the first non-magnetic member 71 also has a first hollow portion 71a. The first hollow portion 71a penetrates the first non-magnetic member 71 in the axial direction.

<Second non-magnetic member>
The second non-magnetic member 72 is disposed radially inward of the second auxiliary magnet 62 and the fixed magnet 40. The second non-magnetic member 72 faces the radially inner ends of the second auxiliary magnet 62 and the fixed magnet 40 with a gap therebetween.

The second non-magnetic member 72 is embedded in the rotor core 11. In this example, the second non-magnetic member 72 is accommodated in a second accommodation hole S72 provided in the rotor core 11. The second non-magnetic member 72 also extends along the q axis (the q axis adjacent in the circumferential direction). Specifically, the cross-sectional shape of the second non-magnetic member 72 is formed into a trapezoid. One oblique side of the second non-magnetic member 72 faces in a direction parallel to the q axis, and the other oblique side of the second non-magnetic member 72 faces in a direction parallel to the d axis.

In this example, the second non-magnetic member 72 is a member for holding the second variable magnet 52. Specifically, the second housing hole S72 is connected to the second variable magnet hole S52. The second non-magnetic member 72 has a protruding portion that protrudes toward the second variable magnet 52. The second non-magnetic member 72 is housed in the second housing hole S72 with the protruding portion pressing the second variable magnet 52 housed in the second variable magnet hole S52 radially outward.

In this example, the second non-magnetic member 72 also has a second hollow portion 72a. The second hollow portion 72a penetrates the second non-magnetic member 72 in the axial direction.

<Cutout>
A first cutout portion S55 is provided on the radial outer side of the first variable magnet 51. The first cutout portion S55 is provided on the outer circumferential surface of the rotor core 11 and extends in the axial direction. In this example, the first cutout portion S55 communicates with the first variable magnet hole S51.

A second cutout portion S56 is provided on the radially outer side of the second variable magnet 52. The second cutout portion S56 is provided on the outer peripheral surface of the rotor core 11 and extends in the axial direction. In this example, the second cutout portion S56 communicates with the second variable magnet hole S52.

<Vacancy>
A first gap S65 is provided radially outward of the first auxiliary magnet 61. The first gap S65 axially passes through the rotor core 11. In this example, the first gap S65 communicates with the first auxiliary magnet hole S61.

A second gap S66 is provided radially outward of the second auxiliary magnet 62. The second gap S66 penetrates the rotor core 11 in the axial direction. In this example, the second gap S66 communicates with the second auxiliary magnet hole S62.

[Anisotropic magnetic member]
The multiple anisotropic magnetic members 15 are provided on the rotor core 11 and are respectively arranged on the q axis between the multiple magnetic pole portions 12. The multiple anisotropic magnetic members 15 have the same configuration as each other. Examples of the anisotropic magnetic members 15 include grain-oriented electromagnetic steel sheets (also called anisotropic electromagnetic steel sheets) and amorphous magnetic materials utilizing induced magnetic anisotropy. Examples of amorphous magnetic materials utilizing induced magnetic anisotropy include Fe-Co-Si-B and Fe-Co-Si-B-Nb.

Each of the multiple anisotropic magnetic members 15 is embedded in the rotor core 11. In this example, the anisotropic magnetic members 15 are housed in housing holes S15 provided in the rotor core 11. The anisotropic magnetic members 15 extend in the radial direction and are symmetrical about the q axis. Specifically, the anisotropic magnetic members 15 are formed with a rectangular cross-sectional shape, and the longitudinal direction is oriented in the q axis direction.

In this example, the first non-magnetic member 71 included in each of the multiple magnetic pole parts 12 is adjacent to the second non-magnetic member 72 included in another magnetic pole part 12 located on one circumferential end side of that magnetic pole part 12, with the anisotropic magnetic member 15 sandwiched between them.

The magnetization easy direction of each of the multiple anisotropic magnetic members 15 is oriented in the q-axis direction. The magnetization hard direction of each of the multiple anisotropic magnetic members 15 is oriented in a direction perpendicular to the magnetization easy direction of that anisotropic magnetic member 15 (in this example, a direction perpendicular to the q-axis direction).

[Non-formation region]
In each of the portions located on the q-axis between the multiple magnetic pole portions 12 of the rotor core 11, a non-forming area 16 in which the anisotropic magnetic member 15 is not formed is provided in the portion between the first variable magnet 51 and the second variable magnet 52 adjacent to each other across the q-axis.

The non-forming region 16 is a region that begins at the radial outer end of the anisotropic magnetic member 15 corresponding to the non-forming region 16 and ends at the outer peripheral edge of the rotor core 11.

[Details of non-forming region]
Next, the non-forming region 16 will be described in detail with reference to FIG.

In FIG. 3, the first curve L1 shows the change in the power performance index. The second curve L2 shows the change in the variable performance index. The power performance index corresponds to the amount of magnetic flux linkage (the amount of magnetic flux linking with teeth 21b) and corresponds to the amount of magnetic flux flowing in the q-axis direction. The variable performance index corresponds to the amount of magnetic flux passing through the first variable magnet 51 and the second variable magnet 52 and corresponds to the amount of magnetic flux in the d-axis direction.

In addition, in FIG. 3, the start position P0 is a position that is located radially inward of the radial inner ends of the first variable magnet 51 and the second variable magnet 52 that are adjacent to each other across the non-forming region 16. The first position P1 is a position that corresponds to the radial inner ends of the first variable magnet 51 and the second variable magnet 52 that are adjacent to each other across the non-forming region 16. The second position P2 is a position that corresponds to the radial center of the first variable magnet 51 and the second variable magnet 52 that are adjacent to each other across the non-forming region 16. The end position P3 is a position that corresponds to the radial outer ends of the first variable magnet 51 and the second variable magnet 52 that are adjacent to each other across the non-forming region 16.

As shown in FIG. 3, the power performance index is relatively high when the start of the non-forming region 16 is in the range from the start position P0 to the second position P2, and gradually decreases as the start of the non-forming region 16 moves from the second position P2 to the end position P3. On the other hand, the variable performance index rises steeply as the start of the non-forming region 16 moves from the start position P0 to the first position P1, rises gently as the start of the non-forming region 16 moves from the first position P1 to the second position P2, and rises steeply as the start of the non-forming region 16 moves from the second position P2 to the end position P3. In this way, when the start of the non-forming region 16 is located in the range from the first position P1 to the second position P2, the power performance index and the variable performance index are well balanced.

In this example, the beginning of the non-forming region 16 is located within the range from the first position P1 to the second position P2. The first position P1 is a position corresponding to the radial inner end of each of the first variable magnet 51 and the second variable magnet 52 adjacent to each other across the non-forming region 16. The second position P2 is a position corresponding to the radial center of each of the first variable magnet 51 and the second variable magnet 52 adjacent to each other across the non-forming region 16.

[Effects of the embodiment]
As described above, in the rotor 10 of the embodiment, by providing the anisotropic magnetic member 15 on the q axis, whose easy magnetization direction faces the q axis direction, it is possible to increase the magnetic flux flowing in the q axis direction. In addition, by providing a non-formation region 16 (a region where the anisotropic magnetic member 15 is not formed) between the first variable magnet 51 and the second variable magnet 52 adjacent to each other across the q axis, it is possible to prevent the flow of magnetic flux passing through the first variable magnet 51 and the second variable magnet 52 adjacent to each other across the q axis from being obstructed by the anisotropic magnetic member 15. This makes it possible to prevent a decrease in the magnetic flux passing through each of the first variable magnet 51 and the second variable magnet 52.

In addition, in the rotor 10 of the embodiment, the anisotropic magnetic member 15, the first non-magnetic member 71, and the second non-magnetic member 72 are arranged radially inward of the first variable magnet 51 and the second variable magnet 52. With this configuration, the flow of magnetic flux in the circumferential direction can be suppressed radially inward of the first variable magnet 51 and the second variable magnet 52. This allows the flow of magnetic flux to be concentrated in the first variable magnet 51 and the second variable magnet 52.

In addition, in the rotor 10 of the embodiment, the beginning of the non-forming region 16 is located within the range from the first position P1 to the second position P2. With this configuration, it is possible to appropriately ensure the amount of magnetic flux flowing in the q-axis direction and the amount of magnetic flux passing through the first variable magnet 51 and the second variable magnet 52.

In addition, in the rotor 10 of the embodiment, the first non-magnetic member 71 holds the first variable magnet 51. With this configuration, the number of parts can be reduced compared to when the member for holding the first variable magnet 51 and the first non-magnetic member 71 are separate members. Furthermore, the second non-magnetic member 72 holds the second variable magnet 52. With this configuration, the number of parts can be reduced compared to when the member for holding the second variable magnet 52 and the second non-magnetic member 72 are separate members.

In addition, in the rotor 10 of the embodiment, the first non-magnetic member 71 has a first hollow portion 71a. With this configuration, the weight of the first non-magnetic member 71 can be reduced. Furthermore, the second non-magnetic member 72 has a second hollow portion 72a. With this configuration, the weight of the second non-magnetic member 72 can be reduced.

In addition, in the rotor 10 of the embodiment, by providing the first auxiliary magnet 61 and the second auxiliary magnet 62, it is possible to suppress short-circuiting of the magnetic flux between the radial outer end of the fixed magnet 40 and the first variable magnet 51 and the second variable magnet 52. This allows the magnetic flux of the fixed magnet 40, the first variable magnet 51, and the second variable magnet 52 to be effectively utilized.

(vehicle)
4 illustrates an example of the configuration of a vehicle including the rotating electric machine 1. In addition to the rotating electric machine 1, the vehicle includes a control device 2, drive wheels 3, a power transmission mechanism 4, and a battery 5.

The control device 2 controls the rotating electric machine 1. The control device 2 has a drive unit 2a and a control unit 2b. The drive unit 2a drives the rotating electric machine 1 by supplying power to the rotating electric machine 1. The control unit 2b controls the operation of the rotating electric machine 1 by controlling the drive unit 2a.

The power transmission mechanism 4 transmits the power of the rotating electric machine 1 to the drive wheels 3. In this way, the power of the rotating electric machine 1 is transmitted to the drive wheels 3. The battery 5 supplies power to the drive unit 2a and the control unit 2b.

Other Embodiments
In the above description, the rotating electric machine 1 is provided in a vehicle, but the present invention is not limited to this. For example, the rotating electric machine 1 may be provided in a refrigerator, a washing machine, a dryer, or the like.

The above embodiments may be combined as appropriate. The above embodiments are essentially preferred examples and are not intended to limit the scope of the technology disclosed herein, its applications, or its uses.

As explained above, the technology disclosed herein is useful for rotors, rotating electric machines, and vehicles.

Reference Signs List 1 Rotary electric machine 2 Control device 3 Drive wheel 10 Rotor 11 Rotor core 12 Magnetic pole portion 15 Anisotropic magnetic member 16 Non-forming region 20 Stator 30 Shaft 40 Fixed magnet 51 First variable magnet 52 Second variable magnet 61 First auxiliary magnet 62 Second auxiliary magnet 71 First non-magnetic member 72 Second non-magnetic member

Claims (7)

A rotor core;
A plurality of magnetic pole portions are provided on the rotor core and arranged in a circumferential direction;
a plurality of anisotropic magnetic members provided in the rotor core, each disposed on the q axis between the plurality of magnetic pole portions, each having an easy magnetization direction oriented in the q axis direction;
Each of the plurality of magnetic pole portions is
A fixed magnet that is magnetized in the radial direction;
a first variable magnet and a second variable magnet, which are disposed on one end side and the other end side of the fixed magnet in the circumferential direction, respectively, and each of which is capable of changing a magnetization state in the circumferential direction by a predetermined magnetic flux,
The first variable magnet included in each of the plurality of magnetic pole portions is adjacent to the second variable magnet included in another magnetic pole portion located on one end side of the magnetic pole portion in the circumferential direction, across the q axis,
A rotor characterized in that, in each portion located on the q-axis between the multiple magnetic pole portions of the rotor core, a non-forming area in which the anisotropic magnetic member is not formed is provided in the portion between the first variable magnet and the second variable magnet adjacent to each other across the q-axis. The rotor of claim 1,
Each of the plurality of magnetic pole portions is
a first non-magnetic member disposed radially inward of the first variable magnet;
a second non-magnetic member disposed radially inward of the second variable magnet,
A rotor characterized in that the first non-magnetic member included in each of the multiple magnetic pole portions is adjacent to the second non-magnetic member included in another magnetic pole portion located on one end side of the magnetic pole portion in the circumferential direction, with the anisotropic magnetic member sandwiched between them. The rotor of claim 2,
the first non-magnetic member is a member for holding the first variable magnet,
The rotor according to claim 1, wherein the second non-magnetic member is a member for holding the second variable magnet. In the rotor according to claim 2 or 3,
the first non-magnetic member has a first hollow portion,
The rotor according to claim 1, wherein the second non-magnetic member has a second hollow portion. In any one of claims 1 to 4,
the non-forming region is a region having a starting point at a radially outer end of the anisotropic magnetic member corresponding to the non-forming region and a terminal point at an outer circumferential edge of the rotor core,
A rotor characterized in that the starting end of the non-forming area is located within a range from a first position corresponding to the radial inner ends of each of the first variable magnet and the second variable magnet adjacent to each other across the non-forming area to a second position corresponding to the radial center of each of the first variable magnet and the second variable magnet. A rotor according to any one of claims 1 to 5;
a stator facing the rotor across an air gap in the radial direction. The rotating electric machine according to claim 6 ;
and drive wheels to which the power of the rotating electric machine is transmitted.

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