Rotating electric machine

Abstract

The present invention provides a rotating electric machine that ensures rotor strength while suppressing torque reduction. [Solution] The rotating electric machine 10 comprises a rotor 16 and a stator 14. The rotor 16 comprises a plurality of magnets 52 arranged in a Halbach arrangement along the circumferential direction of the rotor 16, and a magnet holder 38 that holds the plurality of magnets 52. The magnet holder 38 comprises a base 40 having a magnet holder surface 46 along the circumferential direction of the rotor 16, a plurality of rods 42 protruding from the base 40 along the radial direction of the rotor 16, and flanges 44 protruding from the protruding ends 48 of each rod 42 along the circumferential direction of the rotor 16. The magnets 52 are held between the base 40 and the flanges 44, and the magnetization directions of two adjacent magnets 52 with a rod 42 in between are either along the radial direction of the rotor 16 or both are along the circumferential direction of the rotor 16.

Description

[Technical Field]

[0001] The present disclosure relates to a rotating electrical machine. [Background Art]

[0002] Japanese Unexamined Patent Publication No. 2013-135506 discloses an inner-rotor type motor. A rotating portion (rotor) of the motor includes a rotor core, a plurality of magnets arranged in a circumferential direction, and a plurality of magnet holders that hold the magnets. [Prior Art Literature] [Patent Literature]

[0003] [Patent Literature 1] Japanese Unexamined Patent Publication No. 2013-135506 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] A high-performance rotating electrical machine is desired.

[0005] An object of the present disclosure is to solve the problem described above. [Means for Solving the Problem]

[0006] An aspect of the present disclosure is a rotating electrical machine including a rotor and a stator, wherein the rotor includes a plurality of magnets arranged in Halbach array along a circumferential direction of the rotor, and a magnet holding portion that holds the plurality of magnets. The magnet holding portion includes a base portion having a magnet holding surface along the circumferential direction of the rotor, a plurality of rod portions protruding from the base portion along a radial direction of the rotor, and a flange portion protruding along the circumferential direction of the rotor from a protruding end of each of the rod portions. The magnet is sandwiched between the base portion and the flange portion, and magnetization directions of two magnets adjacent to each other with the rod portion interposed therebetween both extend along the radial direction of the rotor, or both extend along the circumferential direction of the rotor. [Effect of the Invention]

[0007] According to this disclosure, a good rotating electric machine can be provided. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic longitudinal cross-sectional view of a rotating electric machine. [Figure 2] Figure 2 is a partially enlarged view of the section of line II-II in Figure 1. [Figure 3] Figure 3 is a partially enlarged view of a rotating electric machine according to the first embodiment. [Figure 4] Figure 4 is a partially enlarged view of a rotating electric machine according to the second embodiment. [Figure 5] Figure 5 is a partially enlarged view of the rotating electric machine relating to the first modified example. [Figure 6] Figure 6 is a partially enlarged view of the rotating electric machine relating to the second modified example. [Figure 7] Figure 7 is a partially enlarged view of the rotating electric machine relating to the third modified example. [Figure 8] Figure 8 is a partially enlarged view of the rotating electric machine relating to the fourth modified example. [Figure 9] Figure 9 is a schematic diagram of the magnet holder part relating to the fifth modified example. [Figure 10] Figure 10 is a cross-sectional view taken along line XX in Figure 9. [Modes for carrying out the invention]

[0009] The rotor of a rotating electric machine is equipped with multiple magnets. These magnets are arranged along the circumferential direction of the rotor and held by a retaining member such as a core. For example, the magnets may be fixed to the retaining member by adhesive, or they may be pressed radially by a reinforcing ring to secure them to the retaining member.

[0010] The first rotating electric machine, in which the magnets are fixed to the holding member by adhesive, is superior in terms of high torque. However, fixing with adhesive is inferior in fixing strength compared to mechanical fixing. Therefore, there is a concern that the rotor of the first rotating electric machine may be insufficient. It is preferable to fix the magnets to the holding member by a fixing means other than adhesive.

[0011] A second rotating electric machine, in which the magnet is pressed radially by a reinforcing ring and fixed to a holding member, possesses strength. However, when the reinforcing ring is interposed between the circumferential surface of the rotor and the circumferential surface of the stator, the distance between the rotor and the stator increases. Therefore, there is a concern that the torque of this second rotating electric machine will decrease. Rotating electric machines such as IPM (Interior Permanent Magnet) motors also face the same concerns as those with reinforcing rings.

[0012] A rotating electric machine having multiple magnets arranged in a Halbach configuration is superior in terms of high torque. The disclosure described below makes it possible to suppress torque reduction while ensuring rotor strength in a rotating electric machine having multiple magnets arranged in a Halbach configuration.

[0013] [1 Rotating Electric Machine] Figure 1 is a schematic longitudinal cross-sectional view of the rotating electric machine 10. The rotating electric machine 10 described below may be either an electric motor or a generator. The rotating electric machine 10 shown in Figure 1 is an outer rotor type, but the rotating electric machine 10 may also be an inner rotor type. In the following description, "radial direction" means the radial direction of a circle centered on the axis A of the rotating electric machine 10. Also, "circumferential direction" means the circumferential direction of a circle centered on the axis A of the rotating electric machine 10. In plan view, the clockwise direction centered on the axis of the rotating electric machine 10 is referred to as the C1 direction, and the counterclockwise direction is referred to as the C2 direction.

[0014] The rotating electric machine 10 comprises a housing member 12, a stator 14, and a rotor 16. The axes of the rotating electric machine 10, the housing member 12, the stator 14, and the rotor 16 all coincide. Hereinafter, each axis will be referred to as "axis A".

[0015] The housing member (12) comprises an inner housing (18) and a stator housing (20). The inner housing (18) and the stator housing (20) are connected to each other at one end side of the rotating electric machine (10). The inner housing (18) has a substantially cylindrical portion centered on an axis A. An inner circumferential surface of the inner housing (18) defines an inner circumferential surface of the rotating electric machine (10). That is, a hollow space penetrating along the axial direction is formed at the center of the rotating electric machine (10). An inner cylindrical portion (28) of a rotor (16) is attached to an outer periphery of the inner housing (18) via two bearings (36). The stator housing (20) has a substantially cylindrical portion centered on the axis A. The stator housing (20) is disposed radially outward of the inner housing (18). A stator (14) is attached to an outer periphery of the stator housing (20).

[0016] The stator (14) includes a stator core (22) and coils (24) for respective phases. The stator core (22) has a substantially cylindrical shape centered on the axis A. The stator core (22) has a plurality of teeth (26) protruding radially outward. The coil (24) is disposed between two adjacent teeth (26). An inner circumference of the stator core (22) is attached to the stator housing (20). The stator (14) is held by the stator housing (20).

[0017] The rotor 16 includes an inner cylinder portion 28, an outer cylinder portion 30, a connecting portion 32, and an external holding portion 34. The inner cylinder portion 28, the outer cylinder portion 30, the connecting portion 32, and the external holding portion 34 constitute a rotor shaft. Each of the inner cylinder portion 28 and the outer cylinder portion 30 has a substantially cylindrical shape centered on an axis A. The inner cylinder portion 28 is arranged radially inward of the outer cylinder portion 30. The outer cylinder portion 30 is arranged radially outward of the inner cylinder portion 28. The connecting portion 32 connects the inner cylinder portion 28 and the outer cylinder portion 30. The external holding portion 34 projects upward from the connecting portion 32. When the rotating electrical machine 10 is an electric motor, for example, a wheel, a propeller, or the like is connected to the external holding portion 34. When the rotating electrical machine 10 is a generator, for example, an internal combustion engine or the like is connected to the external holding portion 34. An inner housing 18 is attached to the inner circumference of the inner cylinder portion 28 via two bearings 36 arranged vertically. The inner cylinder portion 28 is held by the inner housing 18 via the two bearings 36.

[0018] Figure 2 is a partially enlarged view of a cross-section taken along line II-II in Figure 1. A magnet holding portion 38 is attached to the inner circumference of the outer cylinder portion 30. The magnet holding portion 38 is a rotor core (yoke). The magnet holding portion 38 holds a plurality of magnets 52. The magnet holding portion 38 includes a base portion 40, a plurality of rod portions 42, and a plurality of flange portions 44. The base portion 40, the plurality of rod portions 42, and the plurality of flange portions 44 are integrally formed of the same member. For example, the magnet holding portion 38 is formed by laminating plate materials taken out from a raw material by punching, wire cutting, or the like.

[0019] The base portion 40 has a magnet holding surface 46 on its inner circumference that is aligned with the circumferential direction of the rotor 16. The rod portion 42 protrudes from the base portion 40 along the radial direction of the rotor 16. The rod portion 42 protrudes from the base portion 40 toward the stator 14. Here, the rod portion 42 protrudes radially inward. Multiple rod portions 42 are arranged at equal intervals along the circumferential direction so as to surround the outer circumference of the stator 14. The flange portion 44 protrudes from the protruding end 48 of the rod portion 42 along the circumferential direction of the rotor 16. In other words, in a plan view, the flange portion 44 protrudes from the protruding end 48 of the rod portion 42 in both the C1 and C2 directions. In a plan view, the flange portion 44 has a substantially T-shape. Multiple flange portions 44 are arranged at equal intervals along the circumferential direction. Two adjacent flange portions 44 are spaced apart from each other.

[0020] The rotor 16 has a plurality of magnets 52 arranged along the circumferential direction. The plurality of magnets 52 are arranged together with a plurality of rod portions 42 to surround the outer circumference of the stator 14. Here, the plurality of magnets 52 are located radially inward of the base portion 40 and radially outward of the flange portion 44. The plurality of magnets 52 include magnets 52 adjacent to the rod portions 42 and magnets 52 not adjacent to the rod portions 42.

[0021] Multiple magnets 52, in this case four magnets 52, are located between adjacent first rods 42-1 and second rods 42-2. One of the four magnets 52 is adjacent to the first rod 42-1. Another of the four magnets 52 is adjacent to the second rod 42-2. Two of the four magnets 52 are not adjacent to either the first rod 42-1 or the second rod 42-2. Each of the four magnets 52 is in contact with the magnet holding surface 46 of the base 40. Each of the two magnets 52 closer to the first rod 42-1 is held between the base 40 and the first flange 44-1 formed on the first rod 42-1. Of the four magnets 52, the two magnets 52 closest to the second rod portion 42-2 are each held between the base portion 40 and the second flange portion 44-2 formed on the second rod portion 42-2. With this structure, the radial movement of all magnets 52 is restricted by the base portion 40 and the flange portion 44. In addition, the circumferential movement of all magnets 52 is restricted directly or indirectly by the rod portion 42. In this way, all magnets 52 are held by the magnet holder portion 38.

[0022] Two magnets 52 that are not adjacent to either the first rod portion 42-1 or the second rod portion 42-2 are provided with a contact portion 54 and a projection portion 56 located radially inward. The contact portion 54 is in contact with the flange portion 44. On the other hand, the projection portion 56 is not in contact with the flange portion 44. The projection portion 56 is located between the two flange portions 44, within a range that does not protrude radially inward beyond the two flange portions 44. A portion of the radially inward surface of the projection portion 56 and the radially inward surface of the flange portion 44 are arranged on approximately the same circle centered on axis A. With this structure, the volume of the magnets 52 is increased, and therefore the torque of the rotating electric machine 10 can be increased.

[0023] Multiple magnets 52 are arranged in a Halbach arrangement along the circumferential direction. Below, two embodiments (the first and second embodiments) in which the position of the rod portion 42 differs relative to the multiple magnets 52 arranged in a Halbach arrangement, and several modifications relating to each embodiment will be described.

[0024] [2 First Embodiment] Figure 3 is a partially enlarged view of a rotating electric machine 10 according to the first embodiment. In Figure 3, the arrows indicate the magnetization direction of the magnets 52. In this specification, a magnet 52 whose magnetization direction is aligned with the radial direction of the rotor 16 is referred to as a main magnet 52m. More specifically, a magnet 52 whose magnetization direction is offset by less than 45 degrees with respect to the radial direction of the rotor 16 is referred to as a main magnet 52m. A magnet 52 whose magnetization direction is aligned with the circumferential direction of the rotor 16 is referred to as a secondary magnet 52s. More specifically, a magnet 52 whose magnetization direction is offset by less than 45 degrees with respect to the tangential direction of the rotor 16 is referred to as a secondary magnet 52s. The circumferential width of the main magnet 52m is longer than the circumferential width of the secondary magnet 52s. The multiple magnets 52 attached to the rotor 16 are either main magnets 52m or secondary magnets 52s.

[0025] In the first embodiment, the magnetization directions of two adjacent magnets 52 flanking the shaft 42 are both aligned with the circumferential direction of the rotor 16. That is, each of the two adjacent magnets 52 flanking the shaft 42 is an auxiliary magnet 52s. The magnetization direction of the two auxiliary magnets 52s adjacent to the first shaft 42-1 is approximately in the C1 direction. The magnetization direction of the two auxiliary magnets 52s adjacent to the second shaft 42-2 is approximately in the C2 direction.

[0026] In the first embodiment, two magnets 52 having substantially the same magnetization direction are considered as a pair, and the magnets 52 of each pair are arranged in a Halbach array along the circumferential direction. A pair of auxiliary magnets 52s with a magnetization direction substantially in the C1 direction is adjacent to a pair of main magnets 52m with a magnetization direction substantially inward in the radial direction. A pair of main magnets 52m with a magnetization direction substantially inward in the radial direction is adjacent to a pair of auxiliary magnets 52s with a magnetization direction substantially in the C2 direction. A pair of auxiliary magnets 52s with a magnetization direction substantially in the C2 direction is adjacent to a pair of main magnets 52m with a magnetization direction substantially outward in the radial direction. A pair of main magnets 52m with a magnetization direction substantially outward in the radial direction is adjacent to a pair of auxiliary magnets 52s with a magnetization direction substantially in the C1 direction.

[0027] In a pair of auxiliary magnets 52s whose magnetization direction is approximately C1, a first rod portion 42-1 is positioned between one auxiliary magnet 52s and the other. Similarly, in a pair of auxiliary magnets 52s whose magnetization direction is approximately C2, a second rod portion 42-2 is positioned between one auxiliary magnet 52s and the other. All of the auxiliary magnets 52s among the multiple magnets 52 are adjacent to a rod portion 42 (either the first rod portion 42-1 or the second rod portion 42-2).

[0028] The performance of the rotating electric machine 10 varies depending on the magnetization direction of the magnets 52 adjacent to the shaft 42 and the materials used for the shaft 42 and the flange 44. When the two magnets 52 adjacent to the shaft 42 are auxiliary magnets 52s, it is preferable that the shaft 42 and the flange 44 be made of non-magnetic material. For example, the shaft 42 is made of stainless steel, which does not have magnetism.

[0029] When a secondary magnet 52s is adjacent to the shaft portion 42 and the flange portion 44 is made of a magnetic material, a short circuit of the circumferential magnetic flux occurs, leading to a decrease in the torque of the rotating electric machine 10. Therefore, when a secondary magnet 52s is adjacent to the shaft portion 42, the decrease in torque can be suppressed by making the flange portion 44 out of a non-magnetic material. When the materials of the shaft portion 42 and the flange portion 44 are non-magnetic, the magnetization direction that suppresses the decrease in torque more effectively than when the materials of the shaft portion 42 and the flange portion 44 are magnetic may be defined as "along the circumferential direction".

[0030] In experiments conducted by the present inventors, the torque of the rotating electric machine 10 equipped with a shaft 42 made of a non-magnetic material was higher than that of the rotating electric machine 10 equipped with a shaft 42 made of a magnetic material. However, although the torque will be lower, the shaft 42 may also be made of a magnetic material.

[0031] In a Halbach arrangement, magnets 52 with different magnetization directions are arranged alternately. In the first embodiment, a pair of auxiliary magnets 52s and a pair of main magnets 52m are arranged alternately. When the main magnets 52m are located in the same direction as the magnetization of the auxiliary magnets 52s, a moment due to the magnetization directions of the two magnets 52 acts at the adjacent points between the auxiliary magnets 52s and the main magnets 52m. Therefore, when the magnets 52 located on either side of the shaft 42 are auxiliary magnets 52s and main magnets 52m, a rotational force is generated in the shaft 42 due to the magnetization directions of the magnets 52. In order to resist this rotational force, the rigidity of the shaft 42 needs to be increased.

[0032] In contrast, in the first embodiment, since the magnetization directions of the two magnets 52 adjacent to the shaft 42 are the same, no rotational force is generated in the shaft 42 due to the magnetization direction of the magnets 52. Therefore, according to the first embodiment, the shaft 42 does not require high rigidity compared to the case where the magnetization directions of the two magnets 52 adjacent to the shaft 42 are different. As a result, the weight of the magnet holding portion 38 can be reduced.

[0033] According to the first embodiment, since all the magnets 52 are held between the base portion 40 and the flange portion 44, the strength of the rotor 16 can be ensured compared to fixing the magnets 52 with adhesive.

[0034] In the first embodiment, a portion of the main magnet 52m (protruding portion 56) is located between the two flange portions 44. Therefore, according to the first embodiment, the separation distance between the magnet 52 and the stator 14 can be shortened compared to rotating electric machines such as rotating electric machines equipped with reinforcing rings and IPM motors. According to the first embodiment, the reduction in torque can be suppressed compared to rotating electric machines such as rotating electric machines equipped with reinforcing rings and IPM motors.

[0035] According to the first embodiment, the increase in demagnetization rate can be suppressed compared to a rotating electric machine in which the magnet is fixed with adhesive.

[0036] [3 Second Embodiment] Figure 4 is a partially enlarged view of the rotating electric machine 10 according to the second embodiment. In the description of the second embodiment, the description of parts common to the first embodiment will be omitted. In Figure 4, the arrows indicate the magnetization direction of the magnet 52. In the second embodiment, the magnetization directions of two adjacent magnets 52 on either side of the shaft 42 are both along the radial direction of the rotor 16. That is, each of the two adjacent magnets 52 on either side of the shaft 42 is a main magnet 52m. The magnetization direction of the two main magnets 52m adjacent to the first shaft 42-1 is approximately radially inward. The magnetization direction of the two main magnets 52m adjacent to the second shaft 42-2 is approximately radially outward.

[0037] Similar to the first embodiment, in the second embodiment, two magnets 52 with substantially the same magnetization direction are arranged as a pair, and the magnets 52 of each pair are arranged in a Halbach arrangement along the circumferential direction. The arrangement order of the main magnets 52m in the second embodiment is the same as the order in the first embodiment.

[0038] In a pair of main magnets 52m whose magnetization direction is approximately radially inward, a first rod section 42-1 is positioned between one main magnet 52m and the other main magnet 52m. Similarly, in a pair of main magnets 52m whose magnetization direction is approximately radially outward, a second rod section 42-2 is positioned between one main magnet 52m and the other main magnet 52m. All of the main magnets 52m among the multiple magnets 52 are adjacent to a rod section 42 (either the first rod section 42-1 or the second rod section 42-2).

[0039] When the two magnets 52 adjacent to the shaft portion 42 are the main magnets 52m, it is preferable that the shaft portion 42 and the flange portion 44 are made of a magnetic material. For example, the shaft portion 42 is made of magnetic steel or electrical steel sheet.

[0040] In experiments conducted by the present inventors, the torque of the rotating electric machine 10 equipped with a rod portion 42 made of a magnetic material was higher than the torque of the rotating electric machine 10 equipped with a rod portion 42 made of a non-magnetic material. However, although the torque will be lower, the rod portion 42 may also be made of a non-magnetic material.

[0041] When the main magnet 52m is adjacent to the shaft 42 and the flange 44 is made of a magnetic material, the radial magnetic flux is concentrated in the shaft 42 and the flange 44 compared to when the flange 44 is made of a non-magnetic material. Therefore, when the main magnet 52m is adjacent to the shaft 42, forming the flange 44 of a magnetic material makes it possible to suppress the decrease in torque. When the material of the shaft 42 and the flange 44 is a magnetic material, the magnetization direction that can suppress the decrease in torque compared to when the material of the shaft 42 and the flange 44 is a non-magnetic material may be defined as "along the radial direction".

[0042] In the second embodiment, since the magnetization directions of the two magnets 52 adjacent to the shaft 42 are the same, no rotational force is generated in the shaft 42 due to the magnetization direction of the magnets 52, similar to the first embodiment. Therefore, according to the second embodiment, the shaft 42 does not require high rigidity compared to the case where the magnetization directions of the two magnets 52 adjacent to the shaft 42 are different. As a result, the weight of the magnet holding portion 38 can be reduced.

[0043] According to the second embodiment, since all the magnets 52 are held between the base portion 40 and the flange portion 44, the strength of the rotor 16 can be ensured compared to fixing the magnets 52 with adhesive.

[0044] In the second embodiment, a portion of the main magnet 52m (a portion of the protruding portion 56) is located between the two flange portions 44. Therefore, according to the second embodiment, the separation distance between the magnet 52 and the stator 14 can be shortened compared to rotating electric machines such as rotating electric machines equipped with reinforcing rings and IPM motors. According to the second embodiment, the reduction in torque can be suppressed compared to rotating electric machines such as rotating electric machines equipped with reinforcing rings and IPM motors.

[0045] [4. First variation] Figure 5 is a partially enlarged view of the rotating electric machine 10 relating to the first modified example. The projection 56 of the magnet 52 may have a shape that fills the space between the first flange portion 44-1 and the second flange portion 44-2. For example, the projection 56 may have a convex shape. The radially inner surface of the projection 56 and the radially inner surface of the flange portion 44 are arranged on approximately the same circle centered on axis A. That is, the distance from axis A to the radially inner surface of the projection 56 is approximately the same as the distance from axis A to the radially inner surface of the flange portion 44.

[0046] According to the first modification, the volume of the magnet 52 becomes larger, which allows the torque of the rotating electric machine 10 to be increased.

[0047] [5. Second variation] Figure 6 is a partially enlarged view of the rotating electric machine 10 relating to the second modified example. There may be a gap between the magnet 52 and the magnet holder 38. If there is a gap between the magnet 52 and the magnet holder 38, the four magnets 52 may move slightly. To suppress the movement of the magnets 52, the gap between each magnet 52 and the magnet holder 38 may be filled with resin 58. For example, the gap may be filled in advance by applying a generous amount of positioning adhesive (resin 58) to the magnet 52. Alternatively, the gap may be filled with resin 58 by vacuuming the resin 58 while the magnet holder 38 is holding multiple magnets 52.

[0048] According to the second modified example, since the movement of the magnet 52 is suppressed, the stress generated in the rod portion 42 due to the movement of the magnet 52 can be suppressed.

[0049] [6. Third variation] Figure 7 is a partially enlarged view of the rotating electric machine 10 according to the third modified example. In the magnet holding portion 38, the base end portion 50 of the rod portion 42 is located at the connection point between the base portion 40 and the rod portion 42. The magnetic flux passing around the base end portion 50 is relatively small. In other words, the portion of the magnet 52 located around the base end portion 50 does not contribute to the operation of the rotating electric machine 10. For this reason, as in the third modified example, the rod portion 42 (base end portion 50) may have a shape in which the width increases as it approaches the base portion 40.

[0050] According to the third modified example, the base portion 50 becomes thicker, which increases the strength of the shaft portion 42.

[0051] [7. Fourth variation] Figure 8 is a partially enlarged view of the rotating electric machine 10 according to the fourth modified example. In the first and second embodiments described above, four magnets 52 are located between the first shaft portion 42-1 and the second shaft portion 42-2. Furthermore, two magnets 52 that are not adjacent to the shaft portion 42 are located between the magnet 52 adjacent to the first shaft portion 42-1 and the magnet 52 adjacent to the second shaft portion 42-2. However, it is not limited to this, and as shown in Figure 8, one magnet 52 that is not adjacent to the shaft portion 42 may be located between the magnet 52 adjacent to the first shaft portion 42-1 and the magnet 52 adjacent to the second shaft portion 42-2. In this case, the one magnet 52 only needs to be in contact with at least one of the first flange portion 44-1 and the second flange portion 44-2.

[0052] [8. Fifth variation] Figure 9 is a schematic diagram of the magnet holder 38 according to the fifth modified example. The base 40 and the shaft 42 (and flange 44) provided in the magnet holder 38 may be formed from separate components. In this case, the shaft 42 is fixed to the base 40 by fitting.

[0053] Figure 10 is a cross-sectional view taken along line XX in Figure 9. In the fifth modified example, the shaft portion 42 may be divided along the circumferential direction. This facilitates the assembly of the shaft portion 42 to the base portion 40.

[0054] The following additional information is disclosed regarding the above embodiment.

[0055] (Note 1) The rotating electric machine (10) of the present disclosure is a rotating electric machine comprising a rotor (16) and a stator (14), wherein the rotor comprises a plurality of magnets (52) arranged in a Halbach arrangement along the circumferential direction of the rotor, and a magnet holder (38) that holds the plurality of magnets, wherein the magnet holder comprises a base (40) having a magnet holder surface (46) along the circumferential direction of the rotor, a plurality of rods (42) protruding from the base along the radial direction of the rotor, and flanges (44) protruding from each of the protruding ends (48) of the rods along the circumferential direction of the rotor, wherein the magnets are sandwiched between the base and the flanges, and the magnetization directions of two adjacent magnets with respect to the rods are both along the radial direction of the rotor or both along the circumferential direction of the rotor.

[0056] With the above configuration, all the magnets are held between the base and the flange, thus ensuring the strength of the rotor compared to fixing the magnets with adhesive.

[0057] According to the above configuration, the rod does not require high rigidity compared to the case where the magnetization directions of the magnets located on either side of the rod are different. As a result, for example, the weight of the magnet holding part can be reduced.

[0058] (Note 2) In the rotating electric machine described in Appendix 1, the plurality of magnets comprises a plurality of main magnets (52m) whose magnetization direction is along the radial direction of the rotor and a plurality of auxiliary magnets (52s) whose magnetization direction is along the circumferential direction of the rotor, and two adjacent magnets on either side of the shaft portion may be the auxiliary magnets.

[0059] (Note 3) In the rotating electric machine described in Appendix 2, the shaft portion and the flange portion may be formed of a non-magnetic material.

[0060] According to the above configuration, it is possible to achieve higher torque than with a rotating electric machine equipped with a rod made of magnetic material.

[0061] (Note 4) In the rotating electric machine described in Appendix 2 or 3, all of the auxiliary magnets among the plurality of magnets may be adjacent to the rod portion.

[0062] (Note 5) In the rotating electric machine described in Appendix 1, the plurality of magnets comprises a plurality of main magnets whose magnetization direction is along the radial direction of the rotor and a plurality of auxiliary magnets whose magnetization direction is along the circumferential direction of the rotor, and two adjacent magnets on either side of the shaft portion may be the main magnets.

[0063] (Note 6) In the rotating electric machine described in Appendix 5, the shaft portion and the flange portion may be made of a magnetic material.

[0064] According to the above configuration, it is possible to achieve higher torque than a rotating electric machine equipped with a rod made of a non-magnetic material.

[0065] (Note 7) In the rotating electric machine described in Appendix 5 or 6, all of the main magnets among the plurality of magnets may be adjacent to the rod portion.

[0066] (Note 8) In the rotating electric machine described in Appendix 1, the magnet located between the first rod portion (42-1) and the second rod portion (42-2) adjacent to the first rod portion, and not adjacent to the rod portion, may be provided with a projection (56) that protrudes in the area between the first flange portion (44-1), which is the flange portion protruding from the first rod portion, and the second flange portion (44-2), which is the flange portion protruding from the second rod portion.

[0067] With the above configuration, the volume of the magnet increases, which allows for a greater torque in the rotating electric machine.

[0068] (Note 9) In the rotating electric machine described in Appendix 1, resin (58) may be filled into the gap formed between each of the magnets and the magnet holder.

[0069] With the above configuration, the movement of the magnet is suppressed, and therefore the stress generated in the rod due to the movement of the magnet can be suppressed.

[0070] (Note 10) In the rotating electric machine described in Appendix 1, in a plan view, the base end portion (50) of the rod portion may become wider as it approaches the base.

[0071] With the above configuration, the base end becomes thicker, which increases the strength of the shaft.

[0072] (Note 11) In the rotating electric machine described in Appendix 1, the rotor may be located radially outward from the stator.

[0073] While this disclosure has been described in detail, it is not limited to the individual embodiments described above. These embodiments can be added, replaced, modified, partially deleted, etc., in any way that does not depart from the gist of this disclosure or from the intent of this disclosure derived from the claims and their equivalents. These embodiments can also be implemented in combination. For example, the order of operations and processes in the embodiments described above are given as examples only and are not limited thereto. The same applies when numerical values ​​or mathematical formulas are used in the description of the embodiments described above. [Explanation of Symbols]

[0074] 10... Rotating electric machine 14... Stator 16...Rotor 38...Magnet holder 40…base 42…shank 42-1…First neck section 42-2…Second neck section 44... Guard section 44-1... First guard section 44-2...Second flange 46...Magnet holding surface 48...Protruding end 50...Proximal end 52...Magnet 52m...Main magnet 52s…Sub-magnet 56…Protrusion 58… Resin

Claims

1. A rotating electric machine comprising a rotor and a stator, The rotor comprises a plurality of magnets arranged in a Halbach arrangement along the circumferential direction of the rotor, and a magnet holding portion for holding the plurality of magnets. The magnet holding portion comprises a base portion having a magnet holding surface aligned with the circumferential direction of the rotor, a plurality of rod portions protruding from the base portion along the radial direction of the rotor, and flange portions protruding from the protruding end of each rod portion along the circumferential direction of the rotor. The magnet is held between the base and the flange, A rotating electric machine in which the magnetization directions of two adjacent magnets, separated by the aforementioned rod, are both aligned with the radial direction of the rotor, or both aligned with the circumferential direction of the rotor.

2. In the rotating electric machine described in claim 1, The plurality of magnets comprises a plurality of main magnets whose magnetization direction is along the radial direction of the rotor, and a plurality of auxiliary magnets whose magnetization direction is along the circumferential direction of the rotor. The two magnets adjacent to each other, with the aforementioned rod in between, are the auxiliary magnets, in a rotating electric machine.

3. In the rotating electric machine according to claim 2, The shaft and flange are made of a non-magnetic material, forming a rotating electric machine.

4. In the rotating electric machine according to claim 2 or 3, A rotating electric machine in which all of the auxiliary magnets among the plurality of magnets are adjacent to the rod portion.

5. In the rotating electric machine described in claim 1, The plurality of magnets comprises a plurality of main magnets whose magnetization direction is along the radial direction of the rotor, and a plurality of auxiliary magnets whose magnetization direction is along the circumferential direction of the rotor. The two magnets adjacent to each other, with the aforementioned rod in between, are the main magnets of the rotating electric machine.

6. In the rotating electric machine according to claim 5, The shaft and flange are made of a magnetic material, forming a rotating electric machine.

7. In the rotating electric machine according to claim 5 or 6, A rotating electric machine in which all of the main magnets among the plurality of magnets are adjacent to the rod portion.

8. In the rotating electric machine described in claim 1, A rotating electric machine, wherein the magnet located between a first rod and a second rod adjacent to the first rod, and not adjacent to the rod, is provided with a projection that protrudes in the area between a first flange, which is a flange protruding from the first rod, and a second flange, which is a flange protruding from the second rod.

9. In the rotating electric machine described in claim 1, A rotating electric machine in which resin is filled into the gaps formed between each of the aforementioned magnets and the magnet holders.

10. In the rotating electric machine described in claim 1, In a plan view, the base end of the shaft portion widens as it approaches the base, in a rotating electric machine.

11. In the rotating electric machine described in claim 1, The rotor is located radially outward from the stator in a rotating electric machine.

Images