Rotating electric machine

Abstract

Provided is a rotating electric machine comprising: a stator 1 having a slot 9 and a winding 10; and a rotor 2 having a permanent magnet 3 and a rotor core 12, the rotor being disposed with an air gap 13 between the rotor and the stator 1. The permanent magnet 3 comprises: a main magnet 31 that is arranged at a magnetic pole center and that has a magnetic pole oriented in a radial direction of the rotor 2; and an auxiliary magnet 32 that is adjacent to the main magnet 31 and that has a magnetic pole oriented in a circumferential direction. The main magnet 31 and the auxiliary magnet 32 are alternately arranged on an outer peripheral side of the rotor core 12 according to a Halbach array. In a radial direction cross section of the rotor 2, the main magnet 31 is formed in a trapezoidal shape in which the length of one side facing the stator 1 is shorter than the length of the other side located on the side opposite the stator 1. The rotor core 12 has, on the stator 1-side surface thereof, a groove-shaped main magnet fixation part 21 that is formed so as to correspond to the cross-sectional shape of the main magnet 31, and the main magnet 31 is fitted into and fixed to the main magnet fixation part 21.

Description

Rotating electric machines

[0001] The present invention relates to a rotating electric machine.

[0002] JP2022-161445A discloses a rotating electric machine having an outer rotor in which permanent magnets consisting of main magnets and auxiliary magnets are arranged in a Halbach array.

[0003] The rotating electric machine described in the above document has a configuration in which the main magnets and auxiliary magnets are fixed to the surface of the rotor with adhesive, etc. In such a configuration, the permanent magnets are held in place by the adhesive, which limits how much holding strength can be increased, and there is a problem in that durability cannot be sufficiently improved.

[0004] The present invention has been made in view of the above problems, and has an object to provide a rotating electric machine that can improve durability by increasing the holding strength of the permanent magnets.

[0005] According to one aspect of the present invention, there is provided a rotating electric machine including a stator having slots and windings, and a rotor having permanent magnets and a rotor core, with an air gap between the stator and the rotor. The permanent magnets include main magnets arranged at the magnetic pole center and with their magnetic poles oriented in the radial direction of the rotor, and auxiliary magnets adjacent to the main magnets and with their magnetic poles oriented in the circumferential direction, the main magnets and auxiliary magnets being alternately arranged on the outer periphery of the rotor core in a Halbach array. In a radial cross section of the rotor, the main magnets are formed in a trapezoidal shape, with one side facing the stator being shorter than the other side on the opposite side from the stator. The rotor core has groove-shaped main magnet fixing portions formed on its surface facing the stator to correspond to the cross-sectional shape of the main magnets, and the main magnets are fitted and fixed into the main magnet fixing portions.

[0006] FIG. 1 is a cross-sectional view of a rotating electric machine according to an embodiment of the present invention. FIG. 2 is an enlarged view of a main portion of a rotating electric machine according to the present invention. FIG. 3 is a cross-sectional view of a rotating electric machine according to a modified example of the present invention. FIG. 4 is a cross-sectional view of a rotating electric machine according to another modified example of the present invention. FIG. 5 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention. FIG. 6 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention. FIG. 7 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention. FIG. 8 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention. FIG. 9 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention. FIG. 10 is a cross-sectional view of a rotating electric machine according to yet another modified example of the present invention.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0008] 1 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to an embodiment of the present invention, showing a part of the overall configuration. The remaining parts of the overall configuration are successive repetitions of the partial configuration shown in FIG.

[0009] The rotating electric machine 100 of this embodiment includes a ring-shaped stator 1, a rotor 2 that is concentric with the stator 1 and is arranged on the outer periphery of the stator 1 with an air gap 13 between it and the rotor 2, and permanent magnets 3 that are arranged on the inner periphery of the rotor 2 and face the air gap 13. The permanent magnets 3 are made up of main magnets 31 and auxiliary magnets 32. The main magnets 31 and auxiliary magnets 32 are arranged alternately in the circumferential direction in a Halbach array.

[0010] The rotating electric machine 100 of this embodiment is mounted on an electric vehicle and functions as an electric motor that drives the wheels. It also functions as a generator that generates electricity (regenerative) by receiving rotation of the wheels. Note that the rotating electric machine 100 may also be used as a drive device for devices other than automobiles, such as various electrical appliances or industrial machines.

[0011] The stator 1 is composed of a ring-shaped stator core 11 and stator windings 10 wound in slots 9 formed in the stator core 11. The stator core 11 is formed with a plurality of teeth 8 protruding toward the outer periphery (toward the rotor 2) and slots 9 which are spaces between adjacent teeth 8. The stator core 11 is composed of laminated electromagnetic steel sheets.

[0012] The rotor 2 has a rotor core 12. The rotor core 12 is formed by laminating electromagnetic steel sheets. A main magnet 31 and an auxiliary magnet 32 ​​are fixed to the inner peripheral surface (the surface facing the stator 1) of the rotor core 12. The rotor 2 is connected to a rotor shaft via a connecting portion (not shown).

[0013] In the rotor 2 of this embodiment, the main magnets 31 and the auxiliary magnets 32 are arranged alternately in the circumferential direction along the inner circumferential surface of the rotor core 12 in a Halbach array. The main magnets 31 are arranged so that their magnetic poles are in the radial direction of the rotor 2, and the magnetic poles of adjacent main magnets 31 are opposite to each other. The auxiliary magnets 32 are arranged so that their magnetic poles are in the circumferential direction of the rotor 2, i.e., so that their magnetic poles are perpendicular to those of the main magnets 31. With this configuration, the magnetic flux of the main magnet 31, which is the magnetic pole center, is deflected toward the stator 1 by the auxiliary magnets 32, increasing the magnetic flux linking with the stator 1, thereby improving the torque efficiency of the rotating electric machine 100.

[0014] The rotor 2 has magnetic poles formed by two circumferentially adjacent main magnets 31 and an auxiliary magnet 32 ​​between them, and in Fig. 1, four magnetic poles are formed by four main magnets 31. The opposing stator 1 has three teeth 8 and three slots 9 arranged thereon, with two magnetic poles facing each tooth 8.

[0015] In this way, the rotating electric machine 100 is configured so that two magnetic poles face each other for one slot 9. The relationship between these holds: S = R ± P, where S is the number of slots, R is the number of pole pairs of the permanent magnet 3, and P is the number of pole pairs of the stator winding 10 of the stator 1. In this embodiment, by configuring the rotating electric machine 100 in this way, modulated flux linkage is generated in the stator 1 when the rotor 2 rotates, and a magnetic field is generated in the stator 1 in synchronization with the modulated flux linkage. As a result, an advance in the electrical angle is generated by the magnetic field of the stator 1, and this effect is applied to the magnetic flux of the rotor 2, thereby increasing the torque of the rotating electric machine 100.

[0016] Next, the fixing of the permanent magnets 3 in the rotor 2 configured as above will be described.

[0017] 2, the main magnet 31 is formed so that its cross-sectional shape along the radial direction is a trapezoid with long sides in the circumferential direction, and the length of one side (top side) 31d facing the stator 1 is shorter than the length of the other side (bottom side) 31a on the side opposite the stator 1. The auxiliary magnet 32 ​​is disposed between the main magnets 31, and its cross-sectional shape along the radial direction is formed into a rectangular shape with a long side in the circumferential direction that is shorter than that of the main magnet 31.

[0018] The main magnet 31 is fitted and fixed in a main magnet fixing portion 21 formed on the inner circumferential surface of the rotor core 12. The main magnet fixing portion 21 is configured in a groove shape that opens toward the inner circumferential surface of the rotor core 12, and its radial cross section is configured as a trapezoidal groove corresponding to the shape of the main magnet 31. The main magnet fixing portion 21 has circumferential side portions 21b, 21c formed as a tapered slope that increases in diameter toward the outer periphery of the rotor core 12, and this slope is configured to correspond to the side shape of the main magnet 31. When the main magnet 31 is fitted in the main magnet fixing portion 21, the side surfaces 31b, 31c of the main magnet 31 abut and are supported by the side portions 21b, 21c of the main magnet fixing portion 21, so that the main magnet 31 is firmly fixed to the rotor core 12 without shifting in the radial direction. This increases the holding strength of the main magnet 31 and makes it possible to improve the durability of the rotor 2.

[0019] Furthermore, because the main magnets 31 are fitted and fixed in the groove-shaped main magnet fixing portions 21, the main magnets 31 can be arranged so that they are exposed on the surface of the rotor 2, and can be brought as close as possible to the surface of the stator 1 (the surface facing the tips of the teeth 8). In other words, the distance of the air gap 13 can be reduced. This increases the efficiency with which the magnetic flux of the rotor 2 acts on the stator 1, thereby improving the torque efficiency of the rotating electric machine 100.

[0020] The auxiliary magnets 32 are fixed to the rotor core 12 by being inserted into auxiliary magnet fixing portions 22 serving as magnet fixing holes (through holes) formed by penetrating the rotor core 12 in the axial direction. The auxiliary magnet fixing portions 22 are formed in the rotor core 12 between adjacent main magnet fixing portions 21. This allows the auxiliary magnets 32 to be firmly fixed to the rotor core 12.

[0021] Note that the shapes of the main magnet 31 and the main magnet fixing portion 21 may vary due to manufacturing tolerances. If the inclination of the side portions 21 b, 21 c of the main magnet fixing portion 21 and the inclination of the side surfaces 31 b, 31 c of the main magnet 31 deviate from the design values ​​due to these tolerances, the main magnet 31 may protrude more than necessary from the surface of the rotor 2.

[0022] To prevent this, it is desirable to form the main magnet fixing portion 21 so that the angle θ1 formed between the bottom 21a of the main magnet fixing portion 21 and the side portions 21b, 21c at both ends in the circumferential direction is more acute than the angle θ2 formed between the other side (bottom side) 31a of the main magnet 31 and the side surfaces 31b, 31c at both ends in the circumferential direction, i.e., so that θ1 < θ2. As an example, θ1 is formed to be 80 degrees and θ2 is formed to be 85 degrees.

[0023] By configuring it in this manner, even if the tolerance between the main magnet 31 and the main magnet fixing portion 21 becomes large to a certain extent, the protrusion of the main magnet 31 can be suppressed, and the distance of the air gap 13 can be reduced to a necessary and sufficient extent.

[0024] As described above, the rotating electric machine 100 of this embodiment includes a stator 1 having slots 9 and stator windings 10, and a rotor 2 having permanent magnets 3 and a rotor core 12 and arranged with an air gap 13 between it and the stator 1. The permanent magnets 3 include main magnets 31 arranged at the magnetic pole center with their magnetic poles oriented in the radial direction of the rotor 2, and auxiliary magnets 32 adjacent to the main magnets 31 with their magnetic poles oriented in the circumferential direction, with the main magnets 31 and auxiliary magnets 32 arranged alternately on the surface side of the rotor core 12 in a Halbach array. In a radial cross section of the rotor 2, the main magnets 31 are formed in a trapezoidal shape with one side 31d facing the stator 1 being shorter than the other side 31a located opposite the stator 1. The rotor core 12 has, on its surface facing the stator 1, main magnet fixing portions 21 formed to correspond to the cross-sectional shape of the main magnets 31, and the main magnets 31 are fitted into the main magnet fixing portions 21.

[0025] In this configuration, by forming the main magnet 31 into a trapezoidal shape and fixing it to the main magnet fixing portion 21, the main magnet 31 is firmly fixed to the rotor core 12, increasing the holding strength of the main magnet 31 and making it possible to increase the durability of the rotor 2. Furthermore, because the main magnet 31 can be arranged so that it is exposed on the surface of the rotor 2, the main magnet 31 can be brought as close as possible to the surface of the stator 1 (the surface facing the tips of the teeth 8).

[0026] In the rotating electric machine 100 of this embodiment, the rotor 2 is an outer rotor disposed on the outer diameter side of the stator 1 .

[0027] Next, a modification of this embodiment will be described.

[0028] FIG. 3 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to a modified example of this embodiment, showing a part of the overall configuration.

[0029] The configuration shown in FIG. 3 differs in that the auxiliary magnets 32 are fixed to the inner peripheral surface of the rotor core 12 and are arranged so as to be exposed on the surface of the rotor 2 .

[0030] The auxiliary magnet 32 ​​is located between adjacent main magnets 31, and the surface on the side opposite to the stator 1 abuts against the auxiliary magnet fixing portion 22 of the rotor core 12 and is fixed with an adhesive.

[0031] The main magnets 31 are fitted and fixed in groove-shaped main magnet fixing portions 21 formed in the rotor core 12. In the configuration shown in Fig. 3, the groove depth of the main magnet fixing portions 21 is shorter in the radial direction than in the configuration shown in Fig. 1.

[0032] In this modified example, the auxiliary magnets 32 can be arranged so that they are exposed on the surface of the rotor 2, thereby increasing the effect of deflecting the magnetic flux of the main magnets 31 toward the stator 1 by the auxiliary magnets 32.

[0033] FIG. 4 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to another modified example of this embodiment, showing a part of the overall configuration.

[0034] The configuration shown in FIG. 4 differs in that both circumferential side surfaces of the auxiliary magnet 32 ​​abut against both circumferential side surfaces of the main magnet 31 .

[0035] In a radial cross section of the rotor 2, the auxiliary magnet 32 ​​is formed in a trapezoidal shape in which the length of one side facing the stator 1 is longer than the length of the other side located opposite the stator 1. Both side surfaces of this trapezoidal shape are formed so as to be inclined along both side surfaces of the main magnet 31.

[0036] The main magnet 31 is fitted and fixed in the groove-shaped main magnet fixing portion 21. In the configuration shown in Fig. 4, the radial groove depth of the main magnet fixing portion 21 is configured to be short in the radial direction, similar to the configuration shown in Fig. 3. Both side surfaces of the main magnet 31 are fitted into the main magnet fixing portion 21 near the other side (bottom side) located opposite the stator 1, and the portion closer to the stator 1 than that is not in contact with the rotor core 12.

[0037] The auxiliary magnets 32 are arranged between the main magnets 31 and 31 , and are configured so that both side surfaces of the main magnets 31 that do not contact the rotor core 12 abut against both side surfaces of the auxiliary magnets 32 .

[0038] In this modified example, the main magnet 31 and the auxiliary magnet 32 ​​can be arranged without any gaps, thereby further enhancing the effect of deflecting the magnetic flux of the main magnet 31 toward the stator 1 by the auxiliary magnet 32.

[0039] FIG. 5 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to yet another modified example of the present embodiment, showing a part of the overall configuration.

[0040] The configuration shown in FIG. 5 is similar to that shown in FIG. 4, but differs in that the auxiliary magnet 32 ​​has an anchor portion 34 that protrudes radially outward from the rotor 2.

[0041] 4 , the auxiliary magnet 32 ​​is formed in a trapezoidal shape in a radial cross section of the rotor 2, with one side facing the stator 1 being longer than the other side located opposite the stator 1. As with the configuration described in FIG. 4 , the auxiliary magnet 32 ​​is disposed so that both side surfaces thereof abut against both side surfaces of the main magnet 31.

[0042] Furthermore, the auxiliary magnet 32 ​​has an anchor portion 34 that protrudes radially outward from the other side of the rotor 2 opposite the stator 1. The anchor portion 34 has a tapered shape that increases in diameter as it moves away from the stator 1. In other words, the anchor portion 34 is formed so that its width increases toward its tip. The rotor core 12 has a groove-shaped anchor groove 44 that is recessed from the auxiliary magnet 32 ​​on the side opposite the stator 1.

[0043] By fitting the anchor portions 34 of the auxiliary magnets 32 into the anchor grooves 44 of the rotor core 12, the anchor portions 34 are supported by the inclined surfaces of the anchor grooves 44, and the auxiliary magnets 32 are firmly fixed to the rotor core 12. This increases the holding strength of the auxiliary magnets 32 while arranging the auxiliary magnets 32 so that they are exposed on the surface of the rotor 2.

[0044] FIG. 6 is a cross-sectional view perpendicular to the axial direction of the rotating electrical machine 100 according to yet another modification of this embodiment, showing a part of the overall configuration.

[0045] The configuration shown in FIG. 6 differs in that the auxiliary magnets 32 are configured such that both side surfaces thereof do not contact the main magnets 31 but only contact the inside of the auxiliary magnet fixing portions 22 formed on the rotor core 12 .

[0046] As shown in Fig. 6, main magnet fixing portions 21 that fix the main magnets 31 and auxiliary magnet fixing portions 22 that fix the auxiliary magnets 32 are formed on the inner circumferential surface of the rotor core 12. The main magnet fixing portions 21 are configured in a groove shape that opens toward the inner circumferential surface of the rotor core 12, and their radial cross sections are configured as trapezoidal grooves that correspond to the shape of the main magnets 31. The auxiliary magnet fixing portions 22 are similarly configured in a groove shape that opens toward the inner circumferential surface of the rotor core 12, and their radial cross sections are configured as trapezoidal grooves that correspond to the shape of the auxiliary magnets 32 and that face in the opposite direction to the main magnet fixing portions 21.

[0047] A wall-like portion 211 is formed between the main magnet fixing portion 21 and the auxiliary magnet fixing portion 22, protruding toward the stator 1 so as to separate them. One circumferential side of the wall-like portion 211 is inclined to fit along the side of the main magnet 31, and the other side is inclined to fit along the side of the auxiliary magnet 32. These one and other side surfaces are parallel to each other.

[0048] The auxiliary magnets 32 are fitted into the auxiliary magnet fixing portions 22 formed in grooves on the inner circumferential side of the rotor core 12 and fixed therein with adhesive or the like.

[0049] In this modified example, the auxiliary magnet 32 ​​is configured to be fixed to the groove-shaped auxiliary magnet fixing portion 22, so that the auxiliary magnet 32 ​​can be positioned so that it is exposed on the surface of the rotor 2, while increasing the holding strength of the auxiliary magnet 32.

[0050] Fig. 7 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to yet another modification of the present embodiment, showing part of the overall configuration. Fig. 8 is an enlarged view of part A in Fig. 7.

[0051] The configuration shown in Figure 7 is similar to that shown in Figure 6, but differs in that the rotor core 12 is configured to have claw portions 45 on the inner surface side of the auxiliary magnets 32 that hold the auxiliary magnets 32 in the radial direction.

[0052] As described with reference to FIG. 6 , the rotor core 12 is formed with the main magnet fixing portions 21 for fixing the main magnets 31 and the auxiliary magnet fixing portions 22 for fixing the auxiliary magnets 32 .

[0053] 8, a pair of claws 45 (45a, 45b) that protrude circumferentially from both ends of the auxiliary magnet 32 ​​and hold the auxiliary magnet 32 ​​radially are formed on the surface side of the auxiliary magnet fixing portion 22. The claws 45a and 45b are spaced apart, and the auxiliary magnet 32 ​​is exposed to the stator 1 side between the claws 45a and 45b.

[0054] In this modified example, the auxiliary magnet fixing portion 22 has a claw portion 45 extending from the circumferential direction toward the circumferential center of the auxiliary magnet 32, so that the auxiliary magnet 32 ​​is held by the claw portion 45 of the auxiliary magnet fixing portion 22, and the auxiliary magnet 32 ​​is positioned so that it is exposed on the surface of the rotor 2, thereby further increasing the holding strength of the auxiliary magnet 32.

[0055] 8 , the auxiliary magnet 32 ​​is configured to be radially spaced away from the air gap 13 by the claws 45 compared to the main magnet 31. This configuration can prevent the magnetic flux of the auxiliary magnet 32 ​​from acting on the stator 1 and causing iron loss in the stator 1. By reducing iron loss in the stator 1, it is possible to improve the torque efficiency of the rotating electric machine 100.

[0056] FIG. 9 shows yet another modification of this embodiment, and is an enlarged view of a portion corresponding to part A in FIG.

[0057] 9 , the auxiliary magnets 32 are fixed to the rotor core 12 by being inserted into auxiliary magnet fixing portions 22 formed to penetrate the rotor core 12 in the axial direction. The outer peripheral side of the auxiliary magnet fixing portions 22 on the stator 1 side (the surface facing the tips of the teeth 8) is configured with curved portions 46 that curve in an arc from both ends of the auxiliary magnets 32 to the center toward the opposite side from the stator 1.

[0058] In this modification, in the auxiliary magnet fixing portion 22 of the rotor core 12, a curved portion 46 that is a part of the rotor core 12 interposed between the auxiliary magnet 32 ​​and the air gap 13 is formed so as to curve toward the center of the auxiliary magnet 32. With this configuration, the cross-sectional area of ​​the rotor core 12 that exists between the auxiliary magnet 32 ​​and the air gap 13 becomes smaller as the curved portion 46 approaches the center. This suppresses the magnetic flux of the auxiliary magnet 32 ​​from acting on the rotor core 12 and causing iron loss, while further increasing the holding strength of the auxiliary magnet 32 ​​compared to the configurations shown in Figures 7 and 8 described above.

[0059] FIG. 10 is a cross-sectional view perpendicular to the axial direction of a rotating electrical machine 100 according to yet another modification of this embodiment.

[0060] The configuration shown in FIG. 10 is an inner rotor type rotating electrical machine 100 in which the rotor 2 is disposed on the outer periphery of the stator 1 .

[0061] 10, the rotating electric machine 100 includes a ring-shaped stator 1 and a rotor 2 that is concentric with the stator 1 and is arranged on the inner periphery of the stator 1 with an air gap 13 between it and the rotor 2. The inner periphery of the rotor 2 includes a shaft hole 14 to which a rotor shaft 15 is fixed.

[0062] 1, the main magnet 31 has a cross-sectional shape along its radial direction that is trapezoidal, with long sides in the circumferential direction, and the length of one side facing the stator 1 being shorter than the length of the other side located on the opposite side from the stator 1. The main magnet 31 is fixed to a main magnet fixing portion 21 formed to correspond to the shape of the main magnet 31 on the outer peripheral surface side of the rotor core 12.

[0063] The auxiliary magnets 32 are disposed between the main magnets 31, and have a rectangular cross section along the radial direction. The auxiliary magnets 32 are fixed to the rotor core 12 by being inserted into auxiliary magnet fixing portions 22 formed to penetrate the rotor core 12.

[0064] 10 , the rotor 2 is configured as an inner rotor that is placed inside the stator 1. Even in this configuration, the main magnets 31 are supported on the inclined surfaces of the main magnet fixing portions 21, so the main magnets 31 are firmly fixed to the rotor core 12. This increases the holding strength of the main magnets 31, making it possible to increase the durability of the rotor 2.

[0065] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0066] Furthermore, although the main magnet 31 in this embodiment is rectangular in shape, the upper surface facing the stator 1 may be formed in an arc shape to correspond to the shape of the outer peripheral surface of the stator 1 (the tip surfaces of the teeth 8).

[0067] Moreover, the configurations of the main magnets 31 and auxiliary magnets 32 described with reference to FIGS. 3 to 9 can also be applied to an inner rotor type rotating electric machine 100 as shown in FIG.

Claims

1. A rotating electric machine comprising: a stator having slots and windings; and a rotor having permanent magnets and a rotor core, with an air gap between it and the stator; wherein the permanent magnets comprise main magnets arranged at the magnetic pole center with their magnetic poles oriented in the radial direction of the rotor, and auxiliary magnets adjacent to the main magnets with their magnetic poles oriented in the circumferential direction, the main magnets and the auxiliary magnets being arranged alternately on the outer periphery of the rotor core in a Halbach array; wherein the main magnets are formed in a trapezoidal shape in a radial cross section of the rotor, with one side facing the stator having a shorter length than the other side located opposite the stator; and wherein the rotor core has, on its surface facing the stator, groove-shaped main magnet fixing portions formed to correspond to the cross-sectional shape of the main magnets; and wherein the main magnets are fitted into and fixed in the main magnet fixing portions.

2. A rotating electric machine according to claim 1, wherein the auxiliary magnets are formed in a trapezoidal shape in which the length of one side facing the stator is longer than the length of the other side located opposite the stator in a radial cross section of the rotor.

3. A rotating electric machine according to claim 2, wherein the main magnet is arranged so as to protrude from the main magnet fixing portion towards the stator, and the side of the auxiliary magnet abuts against the side of the main magnet protruding from the main magnet fixing portion.

4. A rotating electric machine according to claim 1, wherein the auxiliary magnet has an anchor portion that protrudes radially from the surface opposite to the surface facing the stator, the anchor portion being formed so that its width increases toward its tip, and the rotor core has an anchor groove into which the anchor portion is fitted.

5. A rotating electric machine according to claim 1, wherein the rotor core has, on the surface facing the stator, a groove-shaped auxiliary magnet fixing portion formed to correspond to the cross-sectional shape of the auxiliary magnet.

6. A rotating electric machine according to claim 5, wherein the auxiliary magnet is fitted into and fixed to the auxiliary magnet fixing portion, and one side of the auxiliary magnet facing the stator is exposed to the air gap.

7. A rotating electric machine according to claim 5, wherein the auxiliary magnet fixing portion has a claw portion extending from the circumferential direction toward the center of the auxiliary magnet in the circumferential direction.

8. A rotating electric machine according to claim 1, wherein the rotor core has auxiliary magnet fixing portions formed as through holes, and the auxiliary magnets are embedded and fixed in the auxiliary magnet fixing portions.

9. A rotating electric machine according to claim 7, wherein the surface of the auxiliary magnet fixing portion facing the stator is curved in an arc shape toward the auxiliary magnet.

10. A rotating electric machine according to claim 1, wherein the angle formed between the bottom of the main magnet fixing part and the side edges at both ends in the circumferential direction is more acute than the angle formed between the other side of the main magnet and the side edges at both ends in the circumferential direction.

11. A rotating electric machine according to claim 1, wherein, when the number of slots in the stator is S, the number of magnet pole pairs in the rotor is R, and the number of pole pairs in the stator is P, S = R ± P.

12. A rotating electric machine according to any one of claims 1 to 11, wherein the rotor is configured as an outer rotor disposed on the outer diameter side of the stator.

Images