Rotating electrical machine

Abstract

Magnet slots (510, 520) have a structure in which V-shaped slots are disposed in multiple layers in a radial direction. Magnets (411, 421) on the anti-rotation side and magnets (412, 422) on the rotation side are respectively inserted into the magnet slots to constitute one pole, and the length W411 of a first-layer magnet on the anti-rotation side is shorter than the length W412 of the first-layer magnet on the rotation side. A line segment L3 connecting an intersection point P3 of extension lines of the long sides on the outer diameter side of the two first layer magnets and an intersection point P4 of the extension lines of the long sides on the inner diameter side is positioned closer to the anti-rotation side than d1. The shortest distance D12 between the two magnets on the rotation side is greater than the shortest distance D11 between the two magnets on the anti-rotation side, and a gap between the first layer magnet and a second layer magnet on the rotation side increases toward the inner diameter side.

Description

rotating electrical machines

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

[0002] Permanent magnet rotating electric machines, which are advantageous in terms of compact size and high output, are used for rotating electric machines for industrial equipment and electric vehicles. Among permanent magnet rotating electric machines, permanent magnet synchronous rotating electric machines, in which permanent magnets are embedded inside the rotor core, are widely used. These rotating electric machines employ a rotor with two or more layers of slots that open outward in a V-shape, with permanent magnets embedded in the slots. Rotating electric machines configured in this way can actively utilize reluctance torque in addition to magnet torque.

[0003] As a rotating electric machine having a rotor with permanent magnets embedded in multiple layers, one has been proposed in which the spacing between the layers of the permanent magnets at the ends on the rotating side is larger than the spacing between the layers of the permanent magnets in other parts in order to efficiently utilize magnetic torque and reluctance torque (see, for example, Patent Document 1). Another rotating electric machine has been proposed in which the shapes of the permanent magnets on the rotating side and the permanent magnets on the counter-rotating side are asymmetrical and a notch is provided on the outer circumferential surface of the rotor core on the counter-rotating side in order to improve the peak value of the combined torque of magnetic torque and reluctance torque (see, for example, Patent Document 2).

[0004] Japanese Patent Application Laid-Open No. 8-336246 International Publication No. 2020 / 194390

[0005] However, in conventional rotating electric machines in which the spacing between the layers of the permanent magnets at the ends of the rotation side is larger than the spacing between the layers of the permanent magnets in other parts, part of the magnetic flux of the second layer of permanent magnets on the counter-rotation side flows through the center into the first layer of permanent magnets on the rotation side, which causes the center of the magnetic pole to easily become magnetically saturated and reduces torque. Also, in conventional rotating electric machines in which the shapes of the permanent magnets on the rotation side and the counter-rotation side are asymmetrical and a notch is provided on the outer peripheral surface of the counter-rotation side rotor core, when the permanent magnets are embedded in multiple layers, the spacing between the layers of the permanent magnets on the counter-rotation side is larger than the spacing between the layers of the permanent magnets on the rotation side, which causes the problem of low peak torque due to the interaction between the magnetic flux due to the magnetomotive force of the permanent magnets and the magnetic flux due to the magnetomotive force of the armature.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine that can suppress torque reduction due to magnetic saturation in the center of the magnetic pole and improve peak torque.

[0007] The rotating electric machine of the present disclosure has a stator having a stator core and a stator coil, and a rotor arranged on the inner diameter side of the stator via a gap, and is a rotating electric machine in which the rotor is driven to rotate around a rotation axis by alternating current, the rotor has a rotor core and a plurality of magnets inserted into magnet slots provided in the rotor core, and in a cross section perpendicular to the rotation axis, the magnet slots have a structure in which V-shaped slots whose spacing increases toward the outer diameter side are arranged in multiple layers in the radial direction, and each of the multiple layers of magnet slots has a counter-rotation side magnet and a rotating side magnet inserted therein to form one pole, and the length along the magnet slot of the counter-rotation side magnet inserted in the magnet slot of the first layer is shorter than the length along the magnet slot of the rotating side magnet, and the counter-rotation side magnet inserted in the magnet slot of the first layer The line segment connecting the intersection of the line extending the outer diameter side edge of the magnet along the magnet slot with the line extending the outer diameter side edge of the rotating magnet along the magnet slot, and the intersection of the line extending the inner diameter side edge of the counter-rotation side magnet along the magnet slot with the line extending the inner diameter side edge of the rotating magnet along the magnet slot, is located on the counter-rotation side of the dimensional center line of one pole, and the shortest distance between the rotating side magnet inserted in the magnet slot of the first layer and the rotating side magnet inserted in the magnet slot of the second layer is greater than the shortest distance between the counter-rotation side magnet inserted in the magnet slot of the first layer and the counter-rotation side magnet inserted in the magnet slot of the second layer, and the gap between the rotating side magnet inserted in the magnet slot of the first layer and the rotating side magnet inserted in the magnet slot of the second layer increases toward the inner diameter side.

[0008] In the rotating electric machine of the present disclosure, the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the first layer is shorter than the length along the magnet slot of the rotation-side magnet, and the line segment connecting the intersection of the line extending the outer diameter side edge along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the first layer with the line extending the outer diameter side edge along the magnet slot of the rotation-side magnet, and the intersection of the line extending the inner diameter side edge along the magnet slot of the counter-rotation side magnet with the line extending the inner diameter side edge along the magnet slot of the rotation-side magnet, is longer than the dimensional center line of one pole. The shortest distance between the rotating magnets located on the counter-rotation side and inserted into the magnet slots of the first layer and the rotating magnets inserted into the magnet slots of the second layer is greater than the shortest distance between the counter-rotation magnets inserted into the magnet slots of the first layer and the counter-rotation magnets inserted into the magnet slots of the second layer, and the spacing between the rotating magnets inserted into the magnet slots of the first layer and the rotating magnets inserted into the magnet slots of the second layer is set to increase as you move toward the inner diameter, thereby suppressing torque reduction due to magnetic saturation in the center of the magnetic pole and improving peak torque.

[0009] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. FIG. 2 is a cross-sectional view of a rotor in the rotating electric machine according to the first embodiment. FIG. 3 is an enlarged cross-sectional view of a rotor in the rotating electric machine according to the first embodiment. FIG. 4 is a diagram showing magnetic flux vectors in the rotating electric machine according to the first embodiment. FIG. 5 is a diagram showing no-load phase voltage waveforms in the rotating electric machine according to the first embodiment. FIG. 6 is a diagram showing magnetic flux vectors in the rotating electric machine according to the first embodiment. FIG. 7 is a diagram showing magnetic flux vectors in the rotating electric machine according to the first embodiment. FIG. 8 is a diagram showing characteristics of a resultant torque in the rotating electric machine according to the first embodiment. FIG. 9 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a second embodiment. FIG. 10 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a third embodiment. FIG. 11 is a diagram showing magnetic flux vectors in the rotating electric machine according to the third embodiment. FIG. 12 is a diagram showing magnetic flux vectors in the rotating electric machine according to the third embodiment. FIG. 13 is a diagram showing magnetic flux vectors in the rotating electric machine according to the third embodiment. FIG. 14 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a fourth embodiment. FIG. 15 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a fifth embodiment. FIG. 16 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a sixth embodiment. FIG. 17 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a seventh embodiment. FIG. 18 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to an eighth embodiment. FIG. 19 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a ninth embodiment. Fig. 22 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 10. Fig. 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 11. Fig. 24 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 12. Fig. 25 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 13. Fig. 26 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 14. Fig. 27 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 15.

[0010] Hereinafter, a rotating electric machine according to an embodiment of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same reference numerals indicate the same or corresponding parts.

[0011] First Embodiment. FIG. 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. FIG. 1 is a cross-sectional view taken along a direction perpendicular to a rotation axis (described later). As shown in FIG. 1 , the rotating electric machine 1 according to this embodiment includes a circular stator 10 and a circular rotor 20 disposed on the inner diameter side of the stator 10 via a gap. A cylindrical rotating shaft 30 is fixed to the center of the rotor 20. The stator 10 and the rotor 20 are coaxially disposed with the rotating shaft 30 as a common axis. Bearings are disposed on both axial ends of the rotating shaft 30, and the rotor 20 is rotatably supported relative to the stator 10. As shown in FIG. 1 , the rotating electric machine according to the present disclosure will be described as rotating counterclockwise. The counterclockwise direction is referred to as the rotation side, and the clockwise direction is referred to as the counter-rotation side. In other words, the rotating electric machine according to the present disclosure is primarily driven to rotate counterclockwise about the rotation axis, but may also be driven to rotate clockwise depending on the application.

[0012] The direction parallel to the rotation axis 30 is referred to as the axial direction, the direction perpendicular to the rotation axis 30 as the radial direction, and the direction rotating around the rotation axis 30 as the circumferential direction. Furthermore, the inner diameter side is the direction approaching the rotation axis 30 in the radial direction, and the outer diameter side is the direction moving away from the rotation axis 30 in the radial direction.

[0013] The stator 10 is composed of an annular back core 11, teeth 12 extending radially inward from the back core 11, and stator coils 13 arranged in slots surrounded by adjacent teeth 12 and the back core 11. The back core 11 and teeth 12 together form the stator core. In the rotating electric machine 1 of this embodiment, 48 teeth 12 are arranged evenly in the circumferential direction, and a stator coil 13 is arranged in each of the 48 slots formed between the teeth 12.

[0014] Fig. 2 is a cross-sectional view of a rotor in a rotating electric machine according to this embodiment. Fig. 2 is a cross-sectional view taken along a direction perpendicular to a rotation axis 30. The rotor 20 of this embodiment is composed of an annular rotor core 21 and magnets. The rotation axis 30 is fixed to the center of the rotor core 21.

[0015] The rotor core 21 has a first-layer magnet slot 510 formed in a V-shape with the spacing increasing toward the outer diameter, and a second-layer magnet slot 520 formed on the inner diameter side of the first-layer magnet slot 510. The second-layer magnet slot 520 is also formed in a V-shape like the first-layer magnet slot 510. A first-layer magnet 411 is inserted in the slot on the counter-rotation side of the first-layer magnet slot 510, and a first-layer magnet 412 is inserted in the slot on the rotation side. A second-layer magnet 421 is inserted in the slot on the counter-rotation side of the second-layer magnet slot 520, and a second-layer magnet 422 is inserted in the slot on the rotation side. Hereinafter, the direction along the magnet slot is referred to as the long side of the magnet, and the direction perpendicular to the long side is referred to as the short side of the magnet. The first-layer magnets 411, 412 and the second-layer magnets 421, 422 are flat permanent magnets oriented parallel to their short sides and magnetized in the same direction. These four permanent magnets form one pole, and eight of these poles are arranged at equal intervals in the circumferential direction. As shown in Figure 2, the magnetization directions of adjacent poles are set to be opposite to each other in the radial direction.

[0016] The center of rotation of the rotor 20 is defined as point O. The point on the inner diameter side of pole 1 where the distance to the adjacent pole on the counter-rotation side is shortest is defined as point P1, and the point on the inner diameter side of pole 1 where the distance to the adjacent pole on the rotation side is shortest is defined as point P2. In the rotor 20 shown in FIG. 2 , the points where the distance between the second-layer magnets 421 and 422 is smallest are points P1 and P2, respectively. The line segment connecting point P1 and point O is defined as line segment L1, and the line segment connecting point P2 and point O is defined as line segment L2. Furthermore, the bisector of line segments L1 and L2 is defined as line q1. The line extending from line q1 toward the rotation side with point O as the center and an electrical angle of π is defined as line q2. One pole of the rotor 20 is the area enclosed by lines q1 and q2. The line extending from line q1 toward the rotation side with point O as the center and an electrical angle of π / 2 is defined as line d1. The straight line d1 is the dimensional center line of one pole of the rotor 20.

[0017] Figure 3 is an enlarged cross-sectional view of the rotor in the rotating electric machine according to this embodiment. Figure 3 is an enlarged cross-sectional view of one pole of the rotor 20. The length of the first layer magnet 411 on the counter-rotation side along the magnet slot 510 is designated as W411, and the length of the first layer magnet 412 on the rotation side along the magnet slot 510 is designated as W412. In the rotating electric machine of this embodiment, W411 is shorter than W412.

[0018] Point P3 is the point where a line extending from the long side of the outer diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the outer diameter of first-layer magnet 412 on the rotation side, and point P4 is the point where a line extending from the long side of the inner diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the inner diameter of first-layer magnet 412 on the rotation side. The line segment connecting points P3 and P4 is line segment L3. In the rotating electric machine of this embodiment, line segment L3 is located on the counter-rotation side of line d1.

[0019] The shortest distance between the first-layer magnet 411 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side is D11, and the shortest distance between the first-layer magnet 412 on the rotation side and the second-layer magnet 422 on the rotation side is D12. Furthermore, the shortest circumferential distance on the counter-rotation side between the first-layer magnet slot 510 and the second-layer magnet slot 520 is D21, and the shortest circumferential distance on the rotation side between the first-layer magnet slot 510 and the second-layer magnet slot 520 is D22. In the rotating electric machine of this embodiment, at least one of the conditions that D12 is greater than D11 and D22 is greater than D21 is satisfied. Satisfying at least one of these two conditions means that the distance between the first-layer magnet 411 on the rotation side and the second-layer magnet 422 on the rotation side is greater than the distance between the first-layer magnet 411 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side. In the following description of this embodiment, it is assumed that D12 is greater than D11.

[0020] Furthermore, the gap between the first layer magnet 411 and the second layer magnet 421 on the counter-rotation side increases toward the inner diameter, and the gap between the first layer magnet 411 and the second layer magnet 422 on the rotation side also increases toward the inner diameter. In other words, the angle formed by the V-shaped first layer magnet slot 510 is larger than the angle formed by the V-shaped second layer magnet slot 520.

[0021] In a rotating electric machine configured in this manner, the magnetic path on the counter-rotation side, where the magnetomotive force of the magnet and the armature magnetomotive force weaken each other, is narrow, while the magnetic path on the rotation side, where the magnetomotive force of the magnet and the armature magnetomotive force strengthen each other, is wide, and these magnetic paths become wider toward the inner diameter side. Therefore, this rotating electric machine can suppress torque reduction due to magnetic saturation in the center of the magnetic poles and improve peak torque. The reason for this is explained below.

[0022] Figure 4 is a diagram showing magnetic flux vectors in a rotating electric machine according to this embodiment. Figure 4 shows magnetic flux vectors under no-load conditions analyzed using the finite element method. Magnetic flux generated on the outer diameter side from first-layer magnet 411 on the counter-rotation side flows into teeth 12 without changing direction in region A1 between first-layer magnet 411 and the gap. Magnetic flux generated on the outer diameter side from first-layer magnet 412 on the rotation side also flows into teeth 12 without changing direction in region A2 between first-layer magnet 412 and the gap.

[0023] Some of the magnetic flux generated from the second-layer magnet 421 on the counter-rotation side toward the outer diameter side flows into region B1 sandwiched between the first-layer magnet 411 and the second-layer magnet 421, while the other portion flows into region B3 across line d1 sandwiched between the first-layer magnet 412 and the second-layer magnet 422 on the rotation side. This is because the length W411 of the long side of the first-layer magnet 411 on the counter-rotation side is shorter than the length W412 of the long side of the first-layer magnet 412 on the rotation side, and because D12 is greater than D11. In region B1, the magnetic path of the rotor core 21 sandwiched between the first-layer magnet 411 and the second-layer magnet 421, which have low permeance, is narrow, so the magnetic flux flows in a direction along the long side of the first-layer magnet 411. The magnetic flux then flows from there into the first-layer magnet 411 and the opposing teeth 12. Magnetic flux flows into the second-layer magnet 421 on the counter-rotation side from the rotor core 21 that constitutes the adjacent pole on the counter-rotation side, via region D1 on the inner diameter side of the second-layer magnet 421, in the direction of line q1. On the other hand, the magnetic flux vector passing through region C1 near the surface of the rotor core 21 and close to line q1 is small.

[0024] Part of the magnetic flux generated on the outer diameter side from the second-layer magnet 422 on the rotation side flows into region B2 sandwiched between the first-layer magnet 412 and the second-layer magnet 422, and the other part flows into region B3. In region B2, because the magnetic path of the rotor core 21 sandwiched between the first-layer magnet 412 and the second-layer magnet 422, which have low permeance, is wide, the magnetic flux changes direction in an arc and flows into the first-layer magnet 412 and the opposing teeth 12. Magnetic flux flows into the second-layer magnet 422 on the rotation side from the direction of line q2, via region D2 on the inner diameter side of the second-layer magnet 422 from the rotor core 21 constituting the adjacent pole on the rotation side. On the other hand, the magnetic flux vector passing through region C2 near line q2 near the surface of the rotor core 21 is small. Magnetic flux generated by both second-layer magnets 421 and 422 flows into region B3, and the magnetic flux that passes through region B3 flows into first-layer magnet 412 on the rotating side and region B2.

[0025] FIG. 5 is a diagram showing the no-load phase voltage waveform of the rotating electric machine according to this embodiment. FIG. 5 shows the no-load phase voltage waveform analyzed using the finite element method. In FIG. 5, the horizontal axis represents the rotor position in electrical angle, and the vertical axis represents the relative value of the no-load phase voltage. The no-load phase voltage waveform has two asymmetric peaks with low voltage on the lagging side relative to the pole center when the rotor position is approximately 120 and 300 electrical degrees. This is because, as shown in FIG. 4, on the lagging side relative to the pole center, the region B1 of the rotor core 21 sandwiched between the first-layer magnet 411 and the second-layer magnet 421 on the counter-rotation side is narrow, causing strong magnetic saturation. However, on the leading side relative to the pole center, the regions B2 and B3 of the rotor core 21 sandwiched between the first-layer magnet 412 and the second-layer magnet 422 on the rotation side are wide, making magnetic saturation unlikely to occur.

[0026] Fig. 6 is a diagram showing magnetic flux vectors in a rotating electric machine according to this embodiment, which is obtained by analyzing, by the finite element method, the conditions under which an armature magnetomotive force of a current phase that maximizes the resultant torque is applied to the stator coil, while no magnetomotive force is applied to the rotor magnet.

[0027] The magnetic flux generated in the stator coil 13 flows from the teeth 12 into the opposing regions A1, B1, and C1 of the rotor core 21. The magnetic flux that flows into region A1 passes through regions A2 and B2 and returns to the teeth 12. At this time, the direction of the magnetic flux in region A1 shown in Fig. 6 is opposite to the direction of the magnetic flux in region A1 shown in Fig. 4, and the directions cancel each other out. The direction of the magnetic flux in region A2 shown in Fig. 6 intersects with the direction of the magnetic flux in region A2 shown in Fig. 4.

[0028] The magnetic flux that has flowed into region B1 passes through regions B3 and B2 and returns to tooth 12. At this time, the direction of the magnetic flux in region B1 shown in Fig. 6 is opposite to the direction of the magnetic flux in region B1 shown in Fig. 4, and the directions of the magnetic flux cancel each other out. The direction of the magnetic flux in regions B2 and B3 shown in Fig. 6 is the same as the direction of the magnetic flux in regions B2 and B3 shown in Fig. 4, and the directions of the magnetic flux reinforce each other.

[0029] The magnetic flux that flows into region C1 passes through regions D1, D2, and C2 and returns to tooth 12. While the magnetic flux vectors in regions C1 and C2 shown in Fig. 4 are small, the magnetic flux vectors in regions C1 and C2 shown in Fig. 6 are in opposite directions, and regions C1 and C2 are effectively used as magnetic paths. The direction of the magnetic flux in regions D1 and D2 shown in Fig. 6 intersects with the direction of the magnetic flux in regions D1 and D2 shown in Fig. 4.

[0030] Fig. 7 is a diagram showing magnetic flux vectors in the rotary electric machine according to this embodiment, which are obtained when the conditions under which the combined torque of the rotary electric machine is maximized are analyzed using the finite element method.

[0031] In regions A1 and B1, as described above, the direction of the magnetic flux due to the magnetomotive force and the direction of the magnetic flux due to the armature magnetomotive force are opposite to each other, so the amount of magnetic flux is small. On the other hand, in regions A2, B2, and B3, the direction of the magnetic flux due to the magnetomotive force and the direction of the magnetic flux due to the armature magnetomotive force are the same, so the amount of magnetic flux is large.

[0032] FIG. 8 is a diagram showing the characteristics of the resultant torque in the rotating electric machine according to this embodiment. FIG. 8 shows the results of an analysis using the finite element method of the change in resultant torque with respect to the current phase angle under the condition that the current value is constant in the rotating electric machine according to this embodiment. In FIG. 8, the horizontal axis represents the current phase angle, and the vertical axis represents the relative value of the resultant torque. The resultant torque is a torque obtained by combining the magnet torque and the reluctance torque. In FIG. 8, the solid line represents the resultant torque of the rotating electric machine according to this embodiment, and the dashed line represents the resultant torque of the rotating electric machine according to the comparative example. Here, the comparative rotating electric machine is a rotating electric machine having a rotor in which the shape of the first layer magnet slot 510 and the shape of the first layer magnets 411, 421 are symmetrical with respect to the line d1 in the rotor of the rotating electric machine shown in FIG. 3.

[0033] 8, the current phase angle at which the combined torque of the rotating electric machine of this embodiment reaches its peak is smaller than the current phase angle at which the combined torque of the rotating electric machine of the comparative example reaches its peak. Also, the peak value of the combined torque of the rotating electric machine of this embodiment is greater than the peak value of the combined torque of the rotating electric machine of the comparative example.

[0034] In the rotating electric machine of the comparative example, in which the shape of the magnet slots and the shape of the first-layer magnets are symmetrical with respect to the line d1, the magnet torque reaches a positive peak value when the current phase angle is 0 degrees. However, when the current phase angle is 0 degrees, the positional relationship between the stator and rotor is such that the magnetic resistance from the q-axis is minimum, so the reluctance torque is zero (the d-axis current is zero). On the other hand, when the current phase angle is 90 degrees, the positional relationship between the stator and rotor is such that the magnetic resistance from the d-axis is minimum, so the reluctance torque is zero (the q-axis current is zero). Here, if the arrangement of the rotor magnets can be made asymmetric and the current phase angle at which the magnetic resistance is maximum or minimum can be shifted from the current phase angle of 0 degrees or 90 degrees defined in the rotating electric machine of the comparative example, the peak position of the reluctance torque can be changed. In the rotating electric machine of this embodiment, in which the shape of the first layer magnet slots and the shape of the first layer magnets are arranged on the counter-rotation side of line d1, a reluctance torque equal to or greater than that of the rotating electric machine of the comparative example is generated when the current phase angle is 0 degrees, and a negative reluctance torque is generated when the current phase angle is 90 degrees, so it is possible to make the reluctance torque lead the current phase angle. As a result, in the rotating electric machine of this embodiment, it is estimated that the current phase angle when the magnet torque reaches its positive peak value and the current phase angle when the reluctance torque reaches its positive peak value are closer together, making the positive peak value of the resultant torque larger.

[0035] As described above, in the rotating electric machine 1 of this embodiment, the first-layer magnets are arranged asymmetrically toward the counter-rotation side, the length W411 of the long side of the counter-rotation-side first-layer magnet 411 is shorter than the length W412 of the long side of the rotating-side first-layer magnet 412, D12, which relates to the width of region B2 where the magnetomotive force of the magnet and the armature magnetomotive force reinforce each other, is made larger than D11, which relates to the width of region B1 where the magnetomotive force of the magnet and the armature magnetomotive force weaken each other, and the spacing between the rotating-side first-layer magnet 412 and the rotating-side second-layer magnet 422 is increased toward the inner diameter so that the width of region B3 where the magnetomotive force of the magnet and the armature magnetomotive force reinforce each other is larger than the width of region B2. As a result, the rotating electric machine of this embodiment can suppress torque reduction due to magnetic saturation in the center of the magnetic poles and improve peak torque.

[0036] In the rotating electric machine of this embodiment, the magnet slots formed in a V shape are connected between the magnet slot on the counter-rotation side and the magnet slot on the rotation side, but the magnet slot on the counter-rotation side and the magnet slot on the rotation side may also be separated on the inner diameter side.

[0037] Embodiment 2 Fig. 9 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 2. Fig. 9 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the structure of the rotor shown in Fig. 9.

[0038] The rotor of this embodiment has three layers of magnet slots. As shown in FIG. 9 , the rotor core 21 of this embodiment has first-layer magnet slots 510 formed in a V-shape with the spacing increasing toward the outer diameter, second-layer magnet slots 520 formed on the inner diameter side of the first-layer magnet slots 510, and third-layer magnet slots 530 formed on the inner diameter side of the second-layer magnet slots 520. The second-layer magnet slots 520 and third-layer magnet slots 530 are also formed in a V-shape like the first-layer magnet slots 510. A first-layer magnet 411 is inserted in the slot on the counter-rotation side of the first-layer magnet slot 510, and a first-layer magnet 412 is inserted in the slot on the rotation side. Furthermore, a second-layer magnet 421 is inserted in the slot on the counter-rotation side of the second-layer magnet slot 520, and a second-layer magnet 422 is inserted in the slot on the rotation side. Furthermore, third-layer magnet 431 is inserted into the slot on the counter-rotation side of third-layer magnet slot 530, and third-layer magnet 432 is inserted into the slot on the rotation side. First-layer magnets 411, 412, second-layer magnets 421, 422, and third-layer magnets 431, 432 are flat permanent magnets oriented parallel to their short sides and magnetized in the same direction. These six permanent magnets form one pole, and eight of these poles are arranged at equal intervals around the circumference. The magnetization directions of adjacent poles are set to be opposite to each other in the radial direction.

[0039] The center of rotation of the rotor 20 is defined as point O. The point on the inner diameter side of pole 1 where the distance to the adjacent pole on the counter-rotation side is shortest is defined as point P1, and the point on the inner diameter side of pole 1 where the distance to the adjacent pole on the rotation side is shortest is defined as point P2. In the rotor shown in FIG. 9 , the points where the distance between the third-layer magnets 431 and 432 is smallest are points P1 and P2, respectively. The line segment connecting point P1 and point O is defined as line segment L1, and the line segment connecting point P2 and point O is defined as line segment L2. Furthermore, the bisector of line segments L1 and L2 is defined as line q1. The line extending from line q1 toward the rotation side with point O as the center and an electrical angle of π is defined as line q2. One pole of the rotor 20 is the area enclosed by lines q1 and q2. The line extending from line q1 toward the rotation side with point O as the center and an electrical angle of π / 2 is defined as line d1. The straight line d1 is the dimensional center line of one pole of the rotor 20.

[0040] Point P3 is the point where a line extending from the long side of the outer diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the outer diameter of first-layer magnet 412 on the rotation side, and point P4 is the point where a line extending from the long side of the inner diameter of first-layer magnet 411 on the rotation side intersects with a line extending from the long side of the inner diameter of first-layer magnet 412 on the counter-rotation side. The line segment connecting points P3 and P4 is line segment L3. In the rotating electric machine of this embodiment, line segment L3 is located on the counter-rotation side of line d1.

[0041] Furthermore, the length of the long side of the first layer magnet 411 on the rotation side is W411, and the length of the long side of the first layer magnet 412 on the counter-rotation side is W412. In the rotating electric machine of this embodiment, W411 is shorter than W412.

[0042] Furthermore, the shortest distance between the first-layer magnet 411 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side is defined as D11, and the shortest distance between the first-layer magnet 412 on the rotation side and the second-layer magnet 422 on the rotation side is defined as D12. Furthermore, the shortest circumferential distance on the counter-rotation side between the first-layer magnet slot 510 and the second-layer magnet slot 520 is defined as D21, and the shortest circumferential distance on the rotation side between the first-layer magnet slot 510 and the second-layer magnet slot 520 is defined as D22. In the rotating electric machine of this embodiment, at least one of the conditions that D12 is greater than D11 and D22 is greater than D21 is satisfied. Satisfying at least one of these two conditions means that the distance between the first-layer magnet 411 on the rotation side and the second-layer magnet 422 on the rotation side is greater than the distance between the first-layer magnet 411 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side. In the following description of this embodiment, it is assumed that D12 is greater than D11.

[0043] Furthermore, the gap between the first-layer magnet 411 and the second-layer magnet 421 on the counter-rotation side increases toward the inner diameter, and the gap between the first-layer magnet 411 and the second-layer magnet 422 on the rotation side also increases toward the inner diameter. That is, the angle formed by the V-shaped first-layer magnet slot 510 is larger than the angle formed by the V-shaped second-layer magnet slot 520. The angle formed by the V-shaped third-layer magnet slot 530 is the same as the angle formed by the V-shaped second-layer magnet slot 520. In other words, the angle formed by the V-shaped first-layer magnet slot is larger than the angles formed by the V-shaped magnet slots of the other layers.

[0044] In a rotating electric machine configured in this manner, as in embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length W411 of the long side of the counter-rotation-side first-layer magnet 411 is shorter than the length W412 of the long side of the rotation-side first-layer magnet 412, D12, which relates to the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other, is made larger than D11, which relates to the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the distance between the rotation-side first-layer magnet 412 and the rotation-side second-layer magnet 422, which is the region where the magnetomotive force and the armature magnetomotive force reinforce each other, is made larger toward the inner diameter. As a result, the rotating electric machine of this embodiment can suppress torque reduction due to magnetic saturation in the center of the magnetic poles and improve peak torque.

[0045] Embodiment 3 Fig. 10 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 3. Fig. 10 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the structure of the rotor shown in Fig. 10.

[0046] 10 , in the rotor of this embodiment, the first layer magnet slots 510, which are formed in a V-shape with the spacing increasing toward the outer diameter, are composed of first layer counter-rotation side magnet slots 511 and rotation side magnet slots 512. A center bridge 110, which is part of the rotor core 21, is provided between the counter-rotation side magnet slots 511 and the rotation side magnet slots 512. Furthermore, the second layer magnet slots 520, which are formed in a V-shape with the spacing increasing toward the outer diameter, are composed of second layer counter-rotation side magnet slots 521 and rotation side magnet slots 522. A center bridge 120, which is part of the rotor core 21, is provided between the counter-rotation side magnet slots 521 and the rotation side magnet slots 522.

[0047] Furthermore, in the rotor of this embodiment, in order to keep the stress generated by centrifugal force during rotation below an allowable value, peripheral bridges 111 and 112, which are part of the rotor core 21, are provided on the outer peripheries of the anti-rotation side magnet slots 511 and the rotation side magnet slots 512 of the first layer, respectively, and peripheral bridges 121 and 122, which are part of the rotor core 21, are provided on the outer peripheries of the anti-rotation side magnet slots 521 and the rotation side magnet slots 522 of the second layer, respectively.

[0048] The configuration of the rotating electric machine of this embodiment is the same as that of Embodiment 1, except for the shape of the magnet slots. That is, in the rotating electric machine of this embodiment, the first-layer magnets are also arranged asymmetrically, closer to the counter-rotation side, the length of the long side of the counter-rotation-side first-layer magnet 411 is shorter than the length of the long side of the rotation-side first-layer magnet 412, D12, which relates to the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other, is made larger than D11, which relates to the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the distance between the rotation-side first-layer magnet 412 and the rotation-side second-layer magnet 422, which are regions where the magnetomotive force and the armature magnetomotive force reinforce each other, is made larger toward the inner diameter. As a result, the rotating electric machine of this embodiment can suppress torque reduction due to magnetic saturation in the center of the magnetic poles and improve peak torque.

[0049] In addition, in this rotating electric machine, the rotor is provided with an outer bridge and a central bridge, which can reduce stress concentration on the outer bridge due to centrifugal force during rotation, thereby increasing the allowable rotation speed.

[0050] FIG. 11 is a diagram showing magnetic flux vectors in a rotating electric machine according to this embodiment. FIG. 11 shows magnetic flux vectors under no-load conditions analyzed using the finite element method. A portion of the magnetic flux generated on the outer diameter side from the first-layer magnet 411 on the counter-rotation side flows into region A4 of the center bridge 110. A portion of the magnetic flux generated on the outer diameter side from the first-layer magnet 412 on the rotation side also flows into region A4 of the center bridge 110. A portion of the magnetic flux generated on the outer diameter side from the second-layer magnet 421 on the counter-rotation side flows into region B4 of the center bridge 120. A portion of the magnetic flux generated on the outer diameter side from the second-layer magnet 422 on the rotation side also flows into region B4 of the center bridge 120. As a result, the magnetic flux flowing through regions A1, A2, B1, B2, and B3 is reduced compared to FIG. 4 shown in embodiment 1.

[0051] Fig. 12 is a diagram showing magnetic flux vectors in a rotating electric machine according to this embodiment, which is obtained by analyzing, by the finite element method, the conditions under which an armature magnetomotive force of a current phase that maximizes the resultant torque is applied to the stator coils, while no magnetomotive force is applied to the rotor magnet.

[0052] The magnetic flux generated in the stator coil 13 flows from the teeth 12 into regions A1, A4, B1, and C1 of the opposing rotor core 21. A portion of the magnetic flux that has flowed into regions A1 and A4 passes through regions B4, D2, and C2 and returns to the teeth 12. As a result, the magnetic flux flowing in regions A2, B2, and B3 is reduced compared to that shown in FIG. 6 of the first embodiment.

[0053] Fig. 13 is a diagram showing magnetic flux vectors in the rotary electric machine according to this embodiment, which are obtained when the conditions under which the combined torque of the rotary electric machine is maximized are analyzed by the finite element method.

[0054] A portion of the magnetic flux that flows into region A1 flows into region A4, and some of this flux forms a loop as leakage flux via adjacent magnets. Furthermore, a portion of the magnetic flux that passes through region C1, region D1, and second-layer magnet 421 on the counter-rotation side flows into region B4, and some of this flux forms a loop as leakage flux via adjacent magnets. As a result, the magnetic flux flowing into regions A2, B1, B2, and B3 is reduced compared to Figure 7 shown in embodiment 1.

[0055] Although the leakage flux described above does not contribute to torque, the magnetic flux further increases in the central portion of the rotor where regions A4 and B4 are located. This increased magnetic flux increases the magnetic flux density in the central portion of the rotor, and when combined with the effective magnetic flux, magnetic saturation occurs, resulting in a decrease in effective magnetic flux and a decrease in torque. The location of regions A4 and B4 makes it easier for magnetic saturation to occur in the central portion of the rotor, so it is also effective in the rotating electric machine of this embodiment to increase the gap between the first layer magnet 412 and the second layer magnet 422 on the rotating side as one moves toward the inner diameter.

[0056] Embodiment 4. Figure 14 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 4. Figure 14 is an enlarged cross-sectional view of the outer periphery of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 14. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0057] 14, the counter-rotation side outer bridge 111 is located between the outermost surface 510a on the counter-rotation side of the first layer magnet slot 510 and the opposing outer surface 21a of the rotor core 21. The rotation side outer bridge 112 is located between the outermost surface 510b on the rotation side of the first layer magnet slot 510 and the opposing outer surface 21a of the rotor core 21.

[0058] In the rotating electric machine of this embodiment, the radial width D111 of the counter-rotation side peripheral bridge 111 is set smaller than the radial width D112 of the rotation side peripheral bridge 112. Because the length of the long side of the counter-rotation side first layer magnet 411 is shorter than the length of the long side of the rotation side first layer magnet 412, the mass of the counter-rotation side first layer magnet 411 is smaller than the mass of the rotation side first layer magnet 412. Therefore, the stress applied to the peripheral bridge 111 by centrifugal force during rotation is smaller than the stress applied to the peripheral bridge 112. In the rotating electric machine of this embodiment, by making the radial width D111 of the counter-rotation side peripheral bridge 111 smaller than the radial width D112 of the rotation side peripheral bridge 112, leakage flux from the peripheral bridge can be reduced.

[0059] Fifth Embodiment Figure 15 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the fifth embodiment. Figure 15 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 15. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0060] As shown in Figure 15, in the rotating electric machine of this embodiment, the thickness D411 of the short side of the first layer magnet 411 on the counter-rotation side is set to be larger than the thickness D412 of the short side of the first layer magnet 412 on the rotation side.

[0061] Increasing the amount of magnet is an effective way to increase torque, but increasing the amount of magnet reduces the area of ​​low magnetic resistance and increases the magnetomotive force, causing magnetic saturation and hindering torque increase. Therefore, making the thickness D411 of the short side of the first layer magnet 411 on the counter-rotation side, where the magnetomotive force and the armature magnetomotive force weaken each other, larger than the thickness D412 of the short side of the first layer magnet 412 on the rotation side, where the magnetomotive force and the armature magnetomotive force strengthen each other, can alleviate the inhibition of torque increase due to magnetic saturation. Therefore, in a rotating electric machine configured in this manner, the effect of weakening the magnet magnetic flux by the armature magnetic flux can be more effectively utilized. Note that a similar effect can be achieved by making the first layer magnets 411 and 412 the same thickness and using a magnetic material for the counter-rotation side first layer magnet 411 with a higher residual magnetic flux density than the magnetic material for the rotation side first layer magnet 412.

[0062] Sixth Embodiment Figure 16 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the sixth embodiment. Figure 16 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to the present embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 16. That is, in the rotating electric machine according to the present embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0063] As shown in Figure 16, in the rotating electric machine of this embodiment, the thickness D421 of the short side of the second layer magnet 421 on the counter-rotation side is set to be larger than the thickness D422 of the short side of the second layer magnet 422 on the rotation side.

[0064] Increasing the amount of magnet is an effective way to increase torque, but increasing the amount of magnet reduces the area of ​​low magnetic resistance and increases the magnetomotive force, causing magnetic saturation and hindering torque increase. Therefore, by making the thickness D421 of the short side of the second-layer magnet 421 on the counter-rotation side, where the magnetomotive force and the armature magnetomotive force weaken each other, larger than the thickness D422 of the short side of the second-layer magnet 422 on the rotation side, where the magnetomotive force and the armature magnetomotive force strengthen each other, the inhibition of torque increase due to magnetic saturation can be alleviated. Therefore, in a rotating electric machine configured in this manner, the effect of weakening the magnet magnetic flux by the armature magnetic flux can be more effectively utilized. Note that a similar effect can be achieved by making the second-layer magnets 421 and 422 the same thickness and using a magnetic material for the counter-rotation side second-layer magnet 421 with a higher residual magnetic flux density than the magnetic material for the rotation side second-layer magnet 422.

[0065] Seventh Embodiment Figure 17 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the seventh embodiment. Figure 17 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 17. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0066] 17, in the rotating electric machine of this embodiment, the first layer magnet 412 on the rotating side is composed of two divided magnets 412a and 412b. The shapes of the divided magnets 412a and 412b are the same as the shape of the first layer magnet 411 on the counter-rotation side.

[0067] In a rotating electric machine configured in this way, magnets of the same shape can be used as the first-layer magnets, allowing for efficient magnet manufacturing. Furthermore, compared to using magnets of different shapes as the first-layer magnets, the complexity of distinguishing between magnets and the risk of handling errors can be reduced. Furthermore, by configuring the first-layer magnet on the rotating side from two separate magnets, the eddy current path is lengthened and magnetic resistance is increased, reducing losses generated in the first-layer magnet on the rotating side.

[0068] Eighth Embodiment Figure 18 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the eighth embodiment. Figure 18 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 18. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0069] As shown in Figure 18, in the rotating electric machine of this embodiment, the first layer magnet 411 on the counter-rotation side is composed of two divided magnets 411a and 411b, and the first layer magnet 412 on the rotation side is composed of three divided magnets 412a, 412b, and 412c. The divided magnets 411a, 411b, 412a, 412b, and 412c all have the same shape. Note that the counter-rotation side first layer magnet 411 and the rotation side first layer magnet 412 may be composed of four or more divided magnets with the same shape, in addition to the configuration shown in Figure 18. In this case, the number of divided magnets constituting the counter-rotation side first layer magnet 411 should be less than the number of divided magnets constituting the rotation side first layer magnet 412.

[0070] In a rotating electric machine configured in this way, multiple magnets of the same shape can be used as the first-layer magnets, allowing for efficient magnet manufacturing. Furthermore, compared to using magnets of different shapes as the first-layer magnets, the complexity of distinguishing between magnets and the risk of handling errors can be reduced. Furthermore, by configuring the first-layer magnets from multiple divided magnets, the eddy current paths become longer and the magnetic resistance increases, reducing losses generated in the first-layer magnets.

[0071] Ninth Embodiment Figure 19 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the ninth embodiment. Figure 19 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 19. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0072] 19, in the rotating electric machine of this embodiment, the second layer magnet 421 on the counter-rotation side is composed of two divided magnets 421a and 421b. The shapes of the divided magnets 421a and 421b are the same as the shape of the second layer magnet 422 on the rotation side.

[0073] In a rotating electric machine configured in this way, magnets of the same shape can be used as the second-layer magnets, allowing for efficient magnet manufacturing. Furthermore, compared to using magnets of different shapes as the second-layer magnets, the complexity of distinguishing between magnets and the risk of handling errors can be reduced. Furthermore, by configuring the second-layer magnet on the counter-rotation side from two separate magnets, the eddy current path is lengthened and magnetic resistance is increased, thereby reducing losses generated in the second-layer magnet on the counter-rotation side.

[0074] Tenth Embodiment Figure 20 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a tenth embodiment. Figure 20 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 20. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0075] 20, in the rotating electric machine of this embodiment, the first layer magnet 412 on the rotating side is composed of two divided magnets 412a and 412b. The second layer magnet 421 on the counter-rotation side is composed of four divided magnets 421a, 421b, 421c, and 421d. The second layer magnet 422 on the rotating side is composed of four divided magnets 422a, 422b, 422c, and 422d.

[0076] In the rotating electric machine of this embodiment, two or more of the divided magnets among the first layer magnet 411 on the counter-rotation side, the divided magnets 412a and 412b of the first layer magnet on the rotation side, and the divided magnets 421a, 421b, 421c, 421d, 422a, 422b, 422c, and 422d of the second layer magnet are set to have the same shape. The shapes of the magnets that are different are set to be easily distinguishable. In the example shown in Figure 20, all of the magnets except for divided magnet 412b are set to have the same shape.

[0077] The first-layer magnet 411 and the divided magnets 412a, 421a, 421b, 421c, 421d, 422a, 422b, 422c, and 422d all have the same shape. The first-layer magnet 412 and the second-layer magnets 421 and 422 on the rotating side may be composed of five or more divided magnets with the same shape, in addition to the configuration shown in FIG.

[0078] In a rotating electric machine configured in this way, multiple magnets with the same shape can be used as the first-layer magnets and second-layer magnets, allowing for efficient magnet manufacturing. Furthermore, because magnets with different shapes are easily distinguishable, the complexity of distinguishing between magnets and the risk of handling errors can be reduced. Furthermore, by configuring the first-layer magnets and second-layer magnets from multiple divided magnets, the eddy current paths are lengthened and the magnetic resistance is increased, reducing losses generated in the first-layer magnets and second-layer magnets.

[0079] Eleventh Embodiment Figure 21 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to the eleventh embodiment. Figure 21 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in the first embodiment, except for the rotor structure shown in Figure 21. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to the first embodiment, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0080] 21 , the rotating electric machine of this embodiment has first-layer magnet slots 510 formed in a V-shape with the spacing increasing toward the outer diameter, second-layer magnet slots 520 formed on the inner diameter side of the first-layer magnet slots 510, and third-layer magnet slots 530 formed on the inner diameter side of the second-layer magnet slots 520. The third-layer magnet slots 530 have a bent slot on the counter-rotation side. A third-layer magnet 431 is inserted in the slot on the counter-rotation side of the third-layer magnet slot 530, and a third-layer magnet 432 is inserted in the slot on the rotation side.

[0081] In the rotating electric machine of this embodiment, the first-layer magnet 412 on the rotation side is composed of two divided magnets 412a and 412b. The second-layer magnet 421 on the counter-rotation side is composed of three divided magnets 421a, 421b, and 421c. The second-layer magnet 422 on the rotation side is composed of two divided magnets 422a and 422b. The third-layer magnet 431 on the counter-rotation side is composed of seven divided magnets 431a, 431b, 431c, 431d, 431e, 431f, and 431g. The third-layer magnet 432 on the rotation side is composed of four divided magnets 432a, 432b, 432c, and 432d. Note that the first-layer magnet, second-layer magnet, and third-layer magnet may be composed of five or more divided magnets in addition to those shown in FIG. 21 . In this case, the number of divided magnets constituting the magnet on the counter-rotation side may be configured to be different from the number of divided magnets constituting the magnet on the rotation side.

[0082] In the rotating electric machine of this embodiment, two or more of the magnets among the first layer magnet 411 on the counter-rotation side, the divided magnets 412a and 412b of the first layer magnet on the rotation side, the divided magnets 421a, 421b, 421c, 422a, and 422b of the second layer magnet, and the divided magnets 431a, 431b, 431c, 431d, 431e, 431f, 431g, 432a, 432b, 432c, and 432d of the third layer magnet are set to have the same shape. The shapes of the magnets that are different are set to be easily distinguishable.

[0083] In a rotating electric machine configured in this way, multiple magnets with the same shape can be used as the first-, second-, and third-layer magnets, allowing for efficient magnet manufacturing. Furthermore, because magnets with different shapes are easily distinguishable, the complexity of distinguishing between magnets and the risk of handling errors can be reduced. Furthermore, by configuring the first-, second-, and third-layer magnets from multiple divided magnets, the eddy current paths are lengthened and the magnetic resistance is increased, reducing losses generated in the first-, second-, and third-layer magnets.

[0084] Embodiment 12. Figure 22 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 12. Figure 22 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 22. That is, in the rotating electric machine of this embodiment, as in the rotating electric machine of embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0085] As shown in Figure 22, the length of the long side of the second-layer magnet 421 on the counter-rotation side is designated as W421, and the length of the long side of the second-layer magnet 422 on the rotation side is designated as W422. In the rotating electric machine of this embodiment, W422 is shorter than W421. Furthermore, the shortest distance between the first-layer magnet 411 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side is designated as D11, and the shortest distance between the first-layer magnet 412 on the rotation side and the second-layer magnet 422 on the rotation side is designated as D12. In the rotating electric machine of this embodiment, D12 is greater than D11. Furthermore, the distance between the first-layer magnet 412 on the rotation side and the second-layer magnet 422 on the rotation side increases as one moves toward the inner diameter side.

[0086] Increasing the amount of magnets is one effective way to increase torque, but increasing the amount of magnets reduces the area of ​​low magnetic resistance and increases the magnetomotive force, causing magnetic saturation and hindering torque increase. Therefore, to increase the amount of magnets on the counter-rotation side, where the magnetomotive force and armature magnetomotive force weaken each other, compared to the amount of magnets on the rotation side, where the magnetomotive force and armature magnetomotive force strengthen each other, shortening the length W422 of the long side of the second-layer magnet 422 on the rotation side compared to the length W421 of the long side of the second-layer magnet 421 on the counter-rotation side can alleviate the inhibition of torque increase due to magnetic saturation. Therefore, in a rotating electric machine configured in this way, the effect of the armature magnetic flux weakening the magnet magnetic flux can be more effectively utilized.

[0087] Embodiment 13. Figure 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 13. Figure 23 is an enlarged cross-sectional view of the outer periphery of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 23. That is, in the rotating electric machine of this embodiment, as in the rotating electric machine of embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0088] As shown in FIG. 23 , the counter-rotation side perimeter bridge 121 is located between the outermost peripheral surface 520a of the second-layer magnet slot 520 on the counter-rotation side and the opposing outer peripheral surface 21a of the rotor core 21. The rotation side perimeter bridge 122 is located between the outermost peripheral surface 520b of the second-layer magnet slot 520 on the rotation side and the opposing outer peripheral surface 21a of the rotor core 21. In the rotating electric machine of this embodiment, the long side of the counter-rotation side second-layer magnet 421 is longer than the long side of the rotation side second-layer magnet 422, so the mass of the counter-rotation side second-layer magnet 421 is heavier than the mass of the rotation side second-layer magnet 422. Therefore, the stress applied to the perimeter bridge 122 by centrifugal force during rotation is smaller than the stress applied to the perimeter bridge 121. In the rotating electric machine of this embodiment, the radial width D122 of the rotation side perimeter bridge 122 is set smaller than the radial width D121 of the counter-rotation side perimeter bridge 121.

[0089] In a rotating electric machine configured in this manner, the radial width D121 of the outer bridge 121 on the counter-rotating side is set smaller than the radial width D122 of the outer bridge 122 on the rotating side, thereby reducing the leakage magnetic flux of the outer bridge.

[0090] Embodiment 14. Figure 24 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 14. Figure 24 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 24. That is, in the rotating electric machine of this embodiment, as in the rotating electric machine of embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0091] 24 , in the rotating electric machine of this embodiment, the thickness D411 of the short side of the first-layer magnet 411 on the counter-rotation side is set to be greater than the thickness D412 of the short side of the first-layer magnet 412 on the rotation side. Furthermore, the length W422 of the long side of the second-layer magnet 422 on the rotation side is set to be shorter than the length W421 of the long side of the second-layer magnet 421 on the counter-rotation side. Furthermore, the shortest distance D11 between the first-layer magnet 411 and the second-layer magnet 421 on the counter-rotation side is set to be shorter than the shortest distance D12 between the first-layer magnet 412 and the second-layer magnet 422 on the rotation side.

[0092] Increasing the amount of magnets is an effective way to increase torque, but increasing the amount of magnets reduces the area of ​​low magnetic resistance and increases the magnetomotive force, causing magnetic saturation and hindering torque increase. Therefore, by making the thickness D411 of the short side of the first-layer magnet 411 on the counter-rotation side, where the magnetomotive force and the armature magnetomotive force weaken each other, larger than the thickness D412 of the short side of the first-layer magnet 412 on the rotation side, where the magnetomotive force and the armature magnetomotive force strengthen each other, and by making the length W422 of the long side of the second-layer magnet 422 on the rotation side shorter than the length W421 of the long side of the second-layer magnet 421 on the counter-rotation side, the inhibition of torque increase due to magnetic saturation can be alleviated. Therefore, in a rotating electric machine configured in this way, the effect of the armature magnetic flux weakening the magnet magnetic flux can be more effectively utilized. Furthermore, the same effect can be obtained by making the thickness of the first layer magnets 411 and 412 the same and using a magnetic material for the first layer magnet 411 on the counter-rotation side that has a higher residual magnetic flux density than the magnetic material for the first layer magnet 412 on the rotation side.

[0093] Fifteenth Embodiment Figure 25 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a fifteenth embodiment. Figure 25 is an enlarged cross-sectional view of one pole of the rotor. The configuration of the rotating electric machine according to this embodiment is the same as the configuration of the rotating electric machine described in embodiment 1, except for the rotor structure shown in Figure 25. That is, in the rotating electric machine according to this embodiment, as in the rotating electric machine according to embodiment 1, the first-layer magnets are arranged asymmetrically and closer to the counter-rotation side, the length of the long sides of the first-layer magnets on the counter-rotation side is shorter than the length of the long sides of the first-layer magnets on the rotation side, the width of the region where the magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnetomotive force and the armature magnetomotive force weaken each other, and further, the gap between the first-layer magnets on the rotation side and the second-layer magnets on the rotation side is larger toward the inner diameter.

[0094] 25 , in the rotating electric machine of this embodiment, the thickness D421 of the short side of the counter-rotation side second-layer magnet 421 is set to be larger than the thickness D422 of the short side of the rotation-side second-layer magnet 422. Furthermore, the length W422 of the long side of the rotation-side second-layer magnet 422 is set to be shorter than the length W421 of the long side of the counter-rotation side second-layer magnet 421. Furthermore, the shortest distance D11 between the counter-rotation side first-layer magnet 411 and the counter-rotation side second-layer magnet 421 is set to be smaller than the shortest distance D12 between the rotation-side first-layer magnet 412 and the rotation-side second-layer magnet 422.

[0095] Increasing the amount of magnets is an effective way to increase torque, but increasing the amount of magnets reduces the area of ​​low magnetic reluctance and increases the magnetomotive force, which causes magnetic saturation and inhibits torque increase. Therefore, to increase the amount of magnets on the counter-rotation side, where the magnetomotive force and the armature magnetomotive force weaken each other, compared to the amount of magnets on the rotation side, where the magnetomotive force and the armature magnetomotive force strengthen each other, by making the thickness D421 of the short sides of the counter-rotation side second-layer magnets 421 greater than the thickness D422 of the short sides of the rotation side second-layer magnets 422 and by making the length W422 of the long sides of the rotation side second-layer magnets 422 shorter than the length W421 of the long sides of the counter-rotation side second-layer magnets 421, this can alleviate the inhibition of torque increase due to magnetic saturation. Therefore, in a rotating electric machine configured in this way, the effect of the armature magnetic flux weakening the magnet magnetic flux can be more effectively utilized. Furthermore, the same effect can be obtained by making the thickness of the second layer magnets 421, 422 the same and using a magnetic material for the second layer magnet 421 on the counter-rotation side that has a higher residual magnetic flux density than the magnetic material for the second layer magnet 422 on the rotation side.

[0096] Various aspects of the present disclosure are summarized below as appendices. (Appendix 1) A rotating electric machine having a stator having a stator core and a stator coil, and a rotor disposed on the inner diameter side of the stator via a gap, wherein the rotor is driven to rotate in one direction around a rotation axis by alternating current, wherein the rotor has a rotor core and a plurality of magnets inserted into magnet slots provided in the rotor core, and in a cross section perpendicular to the rotation axis, the magnet slots have a structure in which V-shaped slots whose spacing increases toward the outer diameter side are arranged in multiple layers in the radial direction, and a counter-rotation side magnet and a rotation side magnet are inserted into each of the multiple layered magnet slots to form one pole, and the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the first layer is shorter than the length along the magnet slot of the rotation side magnet, a line segment connecting the intersection of a line extending the outer diameter side edge of the counter-rotation side magnet inserted into the magnet slot of the first layer and a line extending the outer diameter side edge of the rotation-side magnet along the magnet slot, and the intersection of a line extending the inner diameter side edge of the counter-rotation side magnet along the magnet slot and a line extending the inner diameter side edge of the rotation-side magnet along the magnet slot, is located on the counter-rotation side of the dimensional center line of one pole; the shortest distance between the rotation-side magnet inserted into the magnet slot of the first layer and the rotation-side magnet inserted into the magnet slot of the second layer is greater than the shortest distance between the counter-rotation side magnet inserted into the magnet slot of the first layer and the counter-rotation side magnet inserted into the magnet slot of the second layer; and the interval between the rotation-side magnet inserted into the magnet slot of the first layer and the rotation-side magnet inserted into the magnet slot of the second layer increases toward the inner diameter side. (Appendix 2) A rotating electric motor as described in Appendix 1, characterized in that the shortest distance between the outermost surface of the magnet slot on the counter-rotation side of the first layer and the outer surface of the rotor core is smaller than the shortest distance between the outermost surface of the magnet slot on the rotation side of the first layer and the outer surface of the rotor core.(Supplementary Note 3) The rotating electric machine according to Supplementary Note 1 or 2, characterized in that the length along the magnet slot of the counter-rotation-side magnet inserted into at least one of the magnet slots arranged in multiple layers is different from the length along the magnet slot of the rotation-side magnet, and at least one of the counter-rotation-side magnet and the rotation-side magnet is composed of a plurality of divided magnets, and at least two of the plurality of divided magnets have the same shape. (Supplementary Note 4) The rotating electric machine according to any one of Supplementary Note 1 to 3, characterized in that the length along the magnet slot of the rotation-side magnet inserted into the magnet slot of the second layer is shorter than the length along the magnet slot of the counter-rotation-side magnet. (Supplementary Note 5) The rotating electric machine according to any one of Supplementary Note 1 to 4, characterized in that the shortest distance between the outermost peripheral surface of the counter-rotation side of the magnet slot of the second layer and the outer peripheral surface of the rotor core is greater than the shortest distance between the outermost peripheral surface of the rotation-side of the magnet slot of the second layer and the outer peripheral surface of the rotor core. (Supplementary Note 6) The rotating electric machine according to any one of Supplementary Notes 1 to 5, characterized in that the thickness of the counter-rotation side magnet inserted into at least one of the magnet slots arranged in multiple layers is greater than the thickness of the rotation side magnet. (Supplementary Note 7) The rotating electric machine according to any one of Supplementary Notes 1 to 6, characterized in that the magnet slots formed in a V shape with the spacing increasing toward the outer diameter side are composed of a counter-rotation side magnet slot and a rotation side magnet slot, and a central bridge that is part of the rotor core is provided between the counter-rotation side magnet slot and the rotation side magnet slot.

[0097] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are contemplated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0098] 1 Rotating electric machine, 10 Stator, 11 Back core, 12 Teeth, 13 Stator coil, 20 Rotor, 21 Rotor core, 30 Rotating shaft, 411, 412 First layer magnet, 421, 422 Second layer magnet, 431, 432 Third layer magnet, 510, 520, 530 Magnet slot, 511, 521 Counter-rotation side magnet slot, 512, 522 Rotation side magnet slot.

Claims

1. A rotating electric machine comprising a stator having a stator core and a stator coil, and a rotor disposed on the inner diameter side of the stator via a gap, wherein the rotor is driven to rotate about a rotation axis by alternating current, wherein the rotor comprises a rotor core and a plurality of magnets inserted into magnet slots provided in the rotor core, and in a cross section perpendicular to the rotation axis, the magnet slots have a structure in which V-shaped slots whose spacing increases toward the outer diameter side are arranged in multiple layers in the radial direction, and each of the multiple layers of magnet slots has a counter-rotation side magnet and a rotating side magnet inserted therein to form one pole, and the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the first layer is shorter than the length along the magnet slot of the rotating side magnet, a line segment connecting an intersection point between a straight line extending the outer diameter side edge of the counter-rotation side magnet inserted into the magnet slot of the first layer and a straight line extending the outer diameter side edge of the rotation-side magnet along the magnet slot, and an intersection point between a straight line extending the inner diameter side edge of the counter-rotation side magnet along the magnet slot and a straight line extending the inner diameter side edge of the rotation-side magnet along the magnet slot, is located on the counter-rotation side of the dimensional center line of one pole; the shortest distance between the rotation-side magnet inserted into the magnet slot of the first layer and the rotation-side magnet inserted into the magnet slot of the second layer is greater than the shortest distance between the counter-rotation side magnet inserted into the magnet slot of the first layer and the counter-rotation side magnet inserted into the magnet slot of the second layer; and the distance between the rotation-side magnet inserted into the magnet slot of the first layer and the rotation-side magnet inserted into the magnet slot of the second layer increases toward the inner diameter side.

2. A rotating electric motor as described in claim 1, characterized in that the shortest distance between the outermost surface of the anti-rotation side of the magnet slot in the first layer and the outer peripheral surface of the rotor core is smaller than the shortest distance between the outermost surface of the rotation side of the magnet slot in the first layer and the outer peripheral surface of the rotor core.

3. A rotating electric motor as described in claim 1 or 2, characterized in that the length along the magnet slot of the counter-rotation side magnet inserted into at least one of the magnet slots arranged in multiple layers is different from the length along the magnet slot of the rotating side magnet, at least one of the counter-rotation side magnet and the rotating side magnet is composed of a plurality of split magnets, and at least two or more of the multiple split magnets have the same shape.

4. A rotating electric motor as described in any one of claims 1 to 3, characterized in that the length along the magnet slot of the rotating side magnet inserted into the magnet slot of the second layer is shorter than the length along the magnet slot of the counter-rotating side magnet.

5. A rotating electric motor as described in any one of claims 1 to 4, characterized in that the shortest distance between the outermost surface of the anti-rotation side of the magnet slot in the second layer and the outer peripheral surface of the rotor core is greater than the shortest distance between the outermost surface of the rotation side of the magnet slot in the second layer and the outer peripheral surface of the rotor core.

6. A rotating electric motor as claimed in any one of claims 1 to 5, characterized in that the thickness of the magnet on the counter-rotation side inserted into at least one of the magnet slots arranged in multiple layers is greater than the thickness of the magnet on the rotation side.

7. A rotating electric motor as claimed in any one of claims 1 to 6, characterized in that the magnet slots formed in a V-shape with the spacing increasing towards the outer diameter side are composed of a counter-rotation side magnet slot and a rotation side magnet slot, and a central bridge which is part of the rotor core is provided between the counter-rotation side magnet slot and the rotation side magnet slot.

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