Rotating electric machines

Abstract

The magnet slots (510, 520) have a structure in which V-shaped slots are arranged in multiple layers radially, and a counter-rotation side magnet (411, 421) and a rotating side magnet (412, 422) are inserted into each magnet slot to form one pole, the length W411 of the first layer magnet on the counter-rotation side is shorter than the length W412 of the first layer magnet on the rotating side, the line segment L3 connecting the intersection P3 of the extension lines of the long sides on the outer diameter side of the two first layer magnets and the intersection P4 of the extension lines of the long sides on the inner diameter side is located on the counter-rotation side of d1, the shortest distance D12 between the two magnets on the rotating side is greater than the shortest distance D11 between the two magnets on the counter-rotation side, and the distance between the first layer magnet and the second layer magnet on the rotating side increases as you move toward the inner diameter side.

Description

[Technical Field]

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

[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 inside the rotor core that open outward in a V-shape, with permanent magnets embedded in the slots. In rotating electric machines configured in this way, reluctance torque can be actively utilized in addition to magnet torque.

[0003] As a rotating electric machine having a rotor in which permanent magnets are embedded in multiple layers, one has been proposed in which the spacing between the layers of the permanent magnets at the ends located on the rotating side is made larger than the spacing between the layers of the permanent magnets in other parts in order to efficiently utilize magnet 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 located on the rotating side and the permanent magnets located 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 magnet torque and reluctance torque (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-336246 [Patent Document 2] International Publication No. 2020 / 194390 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional rotating electric machines in which the spacing between the layers of the permanent magnets at the ends of the rotating 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 rotating side, which causes the center of the magnetic pole to easily become magnetically saturated and reduces torque. Furthermore, in conventional rotating electric machines in which the shapes of the permanent magnets on the rotating side and the counter-rotation side are asymmetrical and a notch is provided on the outer circumferential 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 rotating side, which causes a 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. [Means for solving the problem]

[0007] The rotating electric machine of the present disclosure is a rotating electric machine that 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 driven to rotate around a rotation axis by alternating current, and 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 of the rotating magnet with the line extending the outer diameter side edge of the magnet along the magnet slot of the rotating side, and the intersection of the line extending the inner diameter side edge of the magnet along the magnet slot of the counter-rotation side with the line extending the inner diameter side edge of the magnet along the magnet slot of the rotating side, 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 as you go towards the inner diameter side. The length of the magnets on the rotating side inserted into the magnet slots on the second layer along the magnet slots is shorter than the length of the magnets on the counter-rotating side along the magnet slots. . [Effects of the Invention]

[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, 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 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 is set to increase toward the inner diameter side. The length of the magnets on the rotating side inserted into the magnet slots on the second layer along the magnet slots is shorter than the length of the magnets on the counter-rotating side along the magnet slots. Therefore, it is possible to suppress torque reduction due to magnetic saturation in the center of the magnetic pole and improve peak torque. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Figure 2] 2 is a cross-sectional view of a rotor in the rotary electric machine according to the first embodiment. FIG. [Figure 3] 2 is an enlarged cross-sectional view of a rotor in the rotary electric machine according to the first embodiment. FIG. [Figure 4] 3 is a diagram showing magnetic flux vectors in the rotary electric machine according to the first embodiment. FIG. [Figure 5] 4 is a diagram showing a no-load phase voltage waveform in the rotary electric machine according to the first embodiment. FIG. [Figure 6] 3 is a diagram showing magnetic flux vectors in the rotary electric machine according to the first embodiment. FIG. [Figure 7] 3 is a diagram showing magnetic flux vectors in the rotary electric machine according to the first embodiment. FIG. [Figure 8]5 is a diagram showing the characteristics of a combined torque in the rotary electric machine according to the first embodiment. FIG. [Figure 9] FIG. 10 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a second embodiment. [Figure 10] FIG. 11 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a third embodiment. [Figure 11] FIG. 10 is a diagram showing magnetic flux vectors in a rotary electric machine according to a third embodiment. [Figure 12] FIG. 10 is a diagram showing magnetic flux vectors in a rotary electric machine according to a third embodiment. [Figure 13] FIG. 10 is a diagram showing magnetic flux vectors in a rotary electric machine according to a third embodiment. [Figure 14] FIG. 10 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a fourth embodiment. [Figure 15] FIG. 11 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a fifth embodiment. [Figure 16] FIG. 13 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a sixth embodiment. [Figure 17] FIG. 13 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a seventh embodiment. [Figure 18] FIG. 13 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to an eighth embodiment. [Figure 19] FIG. 20 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a ninth embodiment. [Figure 20] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a tenth embodiment. [Figure 21] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to an eleventh embodiment. [Figure 22] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a twelfth embodiment [Figure 23] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a thirteenth embodiment [Figure 24] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a fourteenth embodiment. [Figure 25] FIG. 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to a fifteenth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[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] Embodiment 1 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 the present embodiment includes a ring-shaped stator 10 and a ring-shaped 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 specification of 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 specification of the present disclosure is primarily driven to rotate counterclockwise around 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 called the axial direction, the direction perpendicular to the rotation axis 30 is called the radial direction, and the direction rotating around the rotation axis 30 is called 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 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 in a direction perpendicular to a rotating shaft 30. Rotor 20 of this embodiment is composed of an annular rotor core 21 and magnets. Rotating shaft 30 is fixed to the center of 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 will be referred to as the long side of the magnet, and the direction perpendicular to the long side will be 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 around the circumference. 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 rotor 20. The length of first layer magnet 411 on the counter-rotation side along magnet slot 510 is designated as W411, and the length of first layer magnet 412 on the rotation side along magnet slot 510 is designated as W412. In the rotating electric machine of this embodiment, W411 is shorter than W412.

[0018] The point where a line extending the long side of the outer diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending the long side of the outer diameter of first-layer magnet 412 on the rotation side is designated as point P3, and the point where a line extending the long side of the inner diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending the long side of the inner diameter of first-layer magnet 412 on the rotation side is designated as point P4. The line segment connecting points P3 and P4 is designated as 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 counter-rotation side first-layer magnet 411 and the counter-rotation side second-layer magnet 421 is defined as D11, and the shortest distance between the rotation-side first-layer magnet 412 and the rotation-side second-layer magnet 422 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 rotation-side first-layer magnet 411 and the rotation-side second-layer magnet 422 is greater than the distance between the counter-rotation side first-layer magnet 411 and the counter-rotation side second-layer magnet 421. 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 flows into region B1 sandwiched between the first-layer magnet 411 and the second-layer magnet 421, while the other 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 the 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, 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, so 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 that constitutes 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 shows the no-load phase voltage waveform of the rotating electric machine according to this embodiment. It illustrates 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 the voltage on the lagging side relative to the pole center at rotor positions of approximately 120 and 300 electrical degrees being low. 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 tooth 12 into the opposing regions A1, B1, and C1 of the rotor core 21. The magnetic flux that has flowed into region A1 passes through regions A2 and B2 and returns to the tooth 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 two directions 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 two directions 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 by the finite element method.

[0031] As mentioned above, in regions A1 and B1, the direction of the magnetic flux due to the magnet 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 magnet 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 is the current phase angle, and the vertical axis is 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 shapes 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 minimized, 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 minimized, 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 angles at which the magnetic resistance is maximized or minimized can be shifted from the current phase angles 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 , 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 first-layer magnet slot 510, and third-layer magnet slots 530 formed on the inner diameter side of second-layer magnet slot 520. Like first-layer magnet slot 510, second-layer magnet slot 520 and third-layer magnet slot 530 are also formed in a V-shape. First-layer magnet 411 is inserted in the slot on the counter-rotation side of first-layer magnet slot 510, and first-layer magnet 412 is inserted in the slot on the rotation side. Furthermore, second-layer magnet 421 is inserted in the slot on the counter-rotation side of second-layer magnet slot 520, and 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 is defined as line q2, which extends at an electrical angle of π from line q1 toward the rotation side. 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 is defined as line d1, which extends at an electrical angle of π / 2 from line q1 toward the rotation side with point O as the center 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 first layer magnet 411 on the rotation side is taken as W411, and the length of the long side of first layer magnet 412 on the counter-rotation side is taken as 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 larger than D11 and D22 is larger 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 larger 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 second-layer magnet 421 on the counter-rotation side increases toward the inner diameter, and the gap between the first-layer magnet 411 and 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, with the length W411 of the long side of counter-rotation-side first-layer magnet 411 being shorter than the length W412 of the long side of rotation-side first-layer magnet 412, D12, which relates to the width of the region where the magnetomotive force and armature magnetomotive force reinforce each other, being larger than D11, which relates to the width of the region where the magnetomotive force and 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 armature magnetomotive force reinforce each other, increasing 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] As shown in Figure 10, in the rotor of this embodiment, first layer magnet slots 510, which are formed in a V-shape with the spacing increasing toward the outer diameter, are made up of first layer counter-rotation side magnet slots 511 and rotation side magnet slots 512. A center bridge 110, which is part of rotor core 21, is provided between counter-rotation side magnet slots 511 and rotation side magnet slots 512. Furthermore, second layer magnet slots 520, which are formed in a V-shape with the spacing increasing toward the outer diameter, are made up of second layer counter-rotation side magnet slots 521 and rotation side magnet slots 522. A center bridge 120, which is part of rotor core 21, is provided between counter-rotation side magnet slots 521 and 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 periphery of the counter-rotation side magnet slot 511 and the rotation side magnet slot 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 periphery of the counter-rotation side magnet slot 521 and the rotation side magnet slot 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 counter-rotation-side first-layer magnet 411 is shorter than the length of the long side of 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 increased 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 reduces 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 the first embodiment.

[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 coil, 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 the opposing regions A1, A4, B1, and C1 of the 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 through 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 that shown in FIG. 7 for 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. Because the locations of regions A4 and B4 make it easier for magnetic saturation to occur in the central portion of the rotor, it is also effective in the rotating electric machine of this embodiment to increase the gap between first-layer magnet 412 and second-layer magnet 422 on the rotating side as one moves toward the inner diameter.

[0056] Embodiment 4 FIG. 14 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 4. FIG. 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 FIG. 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 wider 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 wider 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 outer bridge 111 is set smaller than the radial width D112 of the rotation side outer 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 outer bridge 111 by centrifugal force during rotation is smaller than the stress applied to the outer bridge 112. In the rotating electric machine of this embodiment, by making the radial width D111 of the counter-rotation side outer bridge 111 smaller than the radial width D112 of the rotation side outer bridge 112, leakage magnetic flux from the outer bridge can be reduced.

[0059] Embodiment 5 FIG. 15 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 5. FIG. 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 embodiment 1, except for the rotor structure shown in FIG. 15. 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 wider 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 wider toward the inner diameter.

[0060] As shown in FIG. 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 reluctance 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 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 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 way, 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] Embodiment 6 FIG. 16 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 6. FIG. 16 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 FIG. 16. 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 wider 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 wider toward the inner diameter.

[0063] As shown in FIG. 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 reluctance 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 way, 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] Embodiment 7 FIG. 17 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 7. FIG. 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 embodiment 1, except for the rotor structure shown in FIG. 17. 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 wider 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 wider toward the inner diameter.

[0066] 17, in the rotating electric machine of this embodiment, first layer magnet 412 on the rotating side is composed of two divided magnets 412a and 412b. The shapes of divided magnets 412a and 412b are the same as the shape of 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] Embodiment 8 FIG. 18 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 8. FIG. 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 embodiment 1, except for the rotor structure shown in FIG. 18. 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 magnet magnetomotive force and the armature magnetomotive force reinforce each other is larger than the width of the region where the magnet 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 increases toward the inner diameter.

[0069] As shown in FIG. 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 first-layer magnet 411 on the counter-rotation side and the first-layer magnet 412 on the rotation side may be composed of four or more divided magnets with the same shape, in addition to the configuration shown in FIG. 18. In this case, the number of divided magnets constituting the first-layer magnet 411 on the counter-rotation side should be less than the number of divided magnets constituting the first-layer magnet 412 on the rotation side.

[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] Embodiment 9 FIG. 19 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 9. FIG. 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 embodiment 1, except for the rotor structure shown in FIG. 19. 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 wider 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 wider toward the inner diameter.

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

[0074] Embodiment 10 FIG. 20 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 10. FIG. 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 FIG. 20. 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 wider 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 wider toward the inner diameter.

[0075] 20, in the rotating electric machine of this embodiment, first-layer magnet 412 on the rotation side is composed of two divided magnets 412a and 412b. Second-layer magnet 421 on the counter-rotation side is composed of four divided magnets 421a, 421b, 421c, and 421d. Second-layer magnet 422 on the rotation 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] First-layer magnet 411 and divided magnets 412a, 421a, 421b, 421c, 421d, 422a, 422b, 422c, and 422d all have the same shape. Note that first-layer magnet 412 and second-layer magnets 421, 422 on the rotating side may be made up 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 the magnets are shaped in a way that makes them easy to distinguish between different magnet shapes, 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] Embodiment 11 FIG. 21 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 11. FIG. 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 embodiment 1, except for the rotor structure shown in FIG. 21. 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 wider 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 wider 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 first-layer magnet slots 510, and third-layer magnet slots 530 formed on the inner diameter side of second-layer magnet slots 520. The slots on the counter-rotation side of third-layer magnet slots 530 are bent. Third-layer magnets 431 are inserted in the slots on the counter-rotation side of third-layer magnet slots 530, and third-layer magnets 432 are inserted in the slots 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. 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, of 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, two or more magnets 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 the magnets are shaped in a way that makes them easy to distinguish, 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 FIG. 22 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 12. FIG. 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 FIG. 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 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 side.

[0085] As shown in FIG. 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 toward the inner diameter.

[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 reluctance 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 long side length W422 of the second-layer magnet 422 on the rotation side compared to the long side length W421 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 FIG. 23 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 13. FIG. 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 FIG. 23. 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 wider 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 wider toward the inner diameter.

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

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

[0090] Embodiment 14 FIG. 24 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 14. FIG. 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 FIG. 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 wider 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 wider 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 larger 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 smaller 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 reluctance and increases the magnetomotive force, which causes magnetic saturation and inhibits torque increase. Therefore, by making the short side thickness D411 of the first-layer magnet 411 on the counter-rotation side, where the magnetomotive force and armature magnetomotive force weaken each other, larger than the short side thickness D412 of the first-layer magnet 412 on the rotation side, where the magnetomotive force and armature magnetomotive force strengthen each other, and by making the long side length W422 of the second-layer magnet 422 on the rotation side shorter than the long side length W421 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. The same effect can be achieved 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] Embodiment 15 FIG. 25 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 15. FIG. 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 FIG. 25. 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 wider 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 wider toward the inner diameter.

[0094] 25, 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. In addition, 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 on the counter-rotation side and the second-layer magnet 421 on the counter-rotation side is set to be smaller than the shortest distance D12 between the first-layer magnet 412 on the rotation side and the second-layer magnet 422 on the rotation side.

[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 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, by making the short side thickness D421 of the counter-rotation side second-layer magnet 421 larger than the short side thickness D422 of the rotation side second-layer magnet 422 and shortening the long side length W422 of the rotation side second-layer magnet 422. This can mitigate the inhibition of torque increase due to magnetic saturation. Therefore, a rotating electric machine configured in this way can more effectively utilize the effect of the armature magnetic flux weakening the magnet magnetic flux. Furthermore, the same effect can be achieved 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 comprising: a stator having a stator core and a stator coil; and a rotor disposed on an inner diameter side of the stator via a gap, wherein the rotor is driven to rotate in one direction around a rotation axis by an alternating current, The rotor has a rotor core and a plurality of magnets inserted into magnet slots provided in the rotor core, 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 magnet on the counter-rotation side and a magnet on the rotation side are inserted into each of the multiple-layered magnet slots to form one pole, the length of the counter-rotation side magnet inserted into the magnet slot of the first layer along the magnet slot is shorter than the length of the rotation side magnet along the magnet slot, 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 an 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, A rotating electric machine characterized in that the gap between the rotating magnet inserted in the magnet slot of the first layer and the rotating magnet inserted in the magnet slot of the second layer increases toward the inner diameter. (Appendix 2) A rotating electric machine 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. (Appendix 3) A rotating electric motor as described in Appendix 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. (Appendix 4) A rotating electric machine as described in any one of appendixes 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. (Appendix 5) A rotating electric machine according to any one of appendices 1 to 4, characterized in that the shortest distance between the outermost surface of the magnet slot on the counter-rotation side of the second layer and the outer surface of the rotor core is greater than the shortest distance between the outermost surface of the magnet slot on the rotation side of the second layer and the outer surface of the rotor core. (Appendix 6) A rotating electric machine as described in any one of appendices 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. (Appendix 7) A rotating electric machine as described in any one of appendices 1 to 6, characterized in that the magnet slots, which are formed in a V-shape with the spacing increasing toward the outer diameter side, are composed of anti-rotation side magnet slots and rotation side magnet slots, and a central bridge, which is part of the rotor core, is provided between the anti-rotation side magnet slots and the rotation side magnet slots.

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

[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 including a stator having a stator core and a stator coil, and a rotor disposed on an inner diameter side of the stator via a gap, wherein the rotor is driven to rotate about a rotation axis by an alternating current, The rotor has a rotor core and a plurality of magnets inserted into magnet slots provided in the rotor core, 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 magnet on the counter-rotation side and a magnet on the rotation side are inserted into each of the multiple-layered magnet slots to form one pole, the length of the counter-rotation side magnet inserted into the magnet slot of the first layer along the magnet slot is shorter than the length of the rotation side magnet along the magnet slot, 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 an 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, the gap between the rotation-side magnet inserted in the magnet slot of the first layer and the rotation-side magnet inserted in the magnet slot of the second layer increases toward the inner diameter side, A rotating electric machine 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.

2. A rotating electric motor according to claim 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.

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, and 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 claim 1 or 2, characterized in that the shortest distance between the outermost surface of the magnet slot on the counter-rotation side of the second layer and the outer surface of the rotor core is greater than the shortest distance between the outermost surface of the magnet slot on the rotation side of the second layer and the outer surface of the rotor core.

5. 3. A rotating electric machine according to claim 1, wherein 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.

6. A rotating electric motor as described in claim 1 or 2, characterized in that the magnet slots, which are 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, 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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