Rotating electric machines

Abstract

The magnet slots (510, 520) have a structure in which V-shaped slots are arranged in multiple layers, and a magnet (411, 421) on the counter-rotation side and a magnet (412, 422) on the rotation side are inserted into each magnet slot to form one pole, and the line segment L3 connecting the intersection point P3 of the extension lines of the long sides on the outer diameter sides of the two first-layer magnets and the intersection point P4 of the extension lines of the long sides on the inner diameter sides is located on the counter-rotation side of d1, and the angle between d1 and the line L4 connecting point P5 on the outer diameter side of the first-layer magnet on the counter-rotation side and point O is θ 11 The angle between the line L5 connecting point P6 on the outer diameter side of the first layer magnet on the rotating side and point O and d1 is θ 12 When this is done, θ 11 is θ 12 is greater than 0 degrees and less than 30 degrees.

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 widely used in rotating electric machines for industrial equipment and electric vehicles. Among permanent magnet rotating electric machines, permanent magnet synchronous rotating electric machines, in which permanent magnets are embedded inside the rotor core, are widely used. These rotating electric machines employ a rotor with two or more layers of slots that open outward in a V-shape, with permanent magnets embedded in the slots. 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 with permanent magnets embedded in multiple layers, a rotating electric machine has been proposed in which the spacing between the layers of the permanent magnets at the ends located on the rotational direction 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). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-336246 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 magnets located in the direction of rotation is larger than the spacing between the layers of the permanent magnets in other parts, some of the magnetic flux from the second layer of permanent magnets located in the counter-rotational direction flows into the first layer of permanent magnets located in the direction of rotation, which causes the centers of the magnetic poles to easily become magnetically saturated and reduces torque.In addition, this conventional rotating electric machine has the problem of increased torque ripple due to harmonic components in the rotor magnetic flux waveform.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a rotating electric machine that can suppress magnetic saturation, improve torque, and reduce torque ripple. [Means for solving the problem]

[0007] The rotating electric machine of the present disclosure has a stator having a stator core and stator coils, and a rotor disposed on the inner diameter side of the stator via a gap, and is driven to rotate about a rotation axis by three-phase alternating current, and 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 each of the multiple magnet slots has a counter-rotation side magnet and a rotation side magnet inserted therein to form one pole, and the intersection of a line extending the outer diameter side edge of the counter-rotation side magnet inserted in 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 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 counter-rotation side magnet along the magnet slot The line segment connecting the intersection point with the line extending the inner diameter side edge is located on the counter-rotation side of the dimensional center line of one pole, and the angle formed by the line connecting the rotation center point and the end point furthest from the dimensional center line on the outer diameter side of the counter-rotation side magnet inserted into the magnet slot of the first layer, and the dimensional center line is defined as the counter-rotation side pole arc angle of the first layer, and the angle formed by the line connecting the rotation center point and the end point furthest from the dimensional center line on the outer diameter side of the rotation side magnet inserted into the magnet slot of the first layer, and the dimensional center line is defined as the rotation side pole arc angle of the first layer, the counter-rotation side pole arc angle of the first layer is larger than the rotation side pole arc angle of the first layer by an angle greater than 0 degrees and less than 30 degrees 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 second layer with the line extending the outer diameter side edge along the magnet slot of the rotating 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 rotating side magnet, is located on the rotation side of the dimensional center line of one pole, and the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the second layer is longer than the length along the magnet slot of the rotating side magnet. . [Effects of the Invention]

[0008] In the rotating electric machine of the present disclosure, 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, and the angle formed by the line connecting the end point farthest from the dimensional center line on the outer diameter side of the counter-rotation side magnet inserted into the magnet slot of the first layer and the center point of rotation and the dimensional center line is defined as the counter-rotation side pole arc angle of the first layer, and the angle formed by the line connecting the end point farthest from the dimensional center line on the outer diameter side of the rotation-side magnet inserted into the magnet slot of the first layer and the center point of rotation and the dimensional center line is defined as the rotation-side pole arc angle of the first layer, the counter-rotation side pole arc angle of the first layer is larger than the rotation-side pole arc angle of the first layer by an angle greater than 0 degrees and less than 30 degrees 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 second layer with the line extending the outer diameter side edge along the magnet slot of the rotating 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 rotating side magnet, is located on the rotation side of the dimensional center line of one pole, and the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the second layer is longer than the length along the magnet slot of the rotating side magnet. Therefore, it is possible to suppress magnetic saturation, improve torque, and reduce torque ripple. [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] 3 is a diagram showing magnetic flux vectors 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] 4 is a diagram showing the relationship between the counter-rotation side pole arc angle of the first layer and torque in the rotary electric machine according to the first embodiment. FIG. [Figure 8]3 is a diagram showing a rectangular wave model of the magnetic flux waveform of the rotor in the rotary electric machine according to the first embodiment. FIG. [Figure 9] 5 is a diagram showing the magnitudes of the 11th and 13th spatial harmonics of the magnetomotive force of the rotor in the rotary electric machine according to the first embodiment. FIG. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a second embodiment. [Figure 11] FIG. 11 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a third embodiment. [Figure 12] FIG. 10 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a fourth embodiment. [Figure 13] FIG. 11 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a fifth embodiment. [Figure 14] FIG. 13 is an enlarged cross-sectional view of a rotor in a rotary electric machine according to a sixth 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] FIG. 3 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to this embodiment. FIG. 3 is an enlarged cross-sectional view of one pole of rotor 20. 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. Point P4 is the point where a line extending from the long side of the inner diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the inner diameter of first-layer magnet 412 on the rotation side. Furthermore, line segment L3 is the line segment connecting points P3 and P4. In the rotating electric machine of this embodiment, line segment L3 is located on the counter-rotation side of line d1.

[0018] In the rotating electric machine of this embodiment, point P5 is the end furthest from line d1 on the outer diameter side of first layer magnet 411 on the counter-rotation side, and line L4 is the line connecting point P5 and point O. The angle between line L4 and line d1 is the counter-rotation side pole arc angle θ of the first layer. 11 Also, point P6 is the end point farthest from line d1 on the outer diameter side of the first layer magnet 412 on the rotation side, and the line connecting point P6 and point O is L5. The angle between line L5 and line d1 is the first layer rotation side pole arc angle θ 12 In the rotating electric machine of this embodiment, the counter-rotation side pole arc angle θ of the first layer is 11 is the pole arc angle θ of the first layer 12 is greater than 0 degrees and less than 30 degrees.

[0019] As shown in FIG. 3, the polar arc angle θ1 of the first layer across the straight line d1 is defined by the following formula (1). θ1=θ 11 +θ 12 ····(1) Furthermore, point P7 is the end furthest from line d1 on the outer diameter side of second-layer magnet 421 on the counter-rotation side, and line L6 is the line connecting point P7 and point O. Furthermore, point P8 is the end furthest from line d1 on the outer diameter side of second-layer magnet 422 on the rotation side, and line L7 is the line connecting point P8 and point O. The angle between line L6 and line L7 is defined as the second-layer polar arc angle θ2.

[0020] 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 narrowed, and the magnetic path on the rotation side, where the magnetomotive force of the magnet and the armature magnetomotive force strengthen each other, is widened. As a result, this rotating electric machine can suppress magnetic saturation, improve torque, and reduce torque ripple. The reason for this is explained below.

[0021] First, the reason why the rotating electrical machine of this embodiment can suppress magnetic saturation and improve torque will be described. 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.

[0022] The magnetic flux generated from the second-layer magnet 421 on the counter-rotation side toward the outer diameter is divided into magnetic flux that flows into area B1 sandwiched between the first-layer magnet 411 and second-layer magnet 421 on the counter-rotation side, and magnetic flux that flows into the first-layer magnet 412 on the rotation side. The magnetic flux that flows into area B1 is divided into magnetic flux that flows directly into the teeth 12 corresponding to area B1 and magnetic flux that flows into the teeth 12 via the first-layer magnet 411. Because the first-layer magnets are asymmetrically arranged toward the counter-rotation side, the magnetic flux generated from the second-layer magnet 421 on the counter-rotation side includes magnetic flux that flows into the first-layer magnet 411 on the counter-rotation side and magnetic flux that flows into the first-layer magnet 412 on the rotation side. 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 area 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 the region C1 near the surface of the rotor core 21, which is close to the straight line q1, is small.

[0023] Part of the magnetic flux generated from the second-layer magnet 422 on the rotation side toward the outer diameter side flows into region B2 on the outer diameter side sandwiched between the first-layer magnet 412 and the second-layer magnet 422, and the other part flows into the first-layer magnet 412 on the rotation side. The magnetic flux that flows into region B2 flows directly into the teeth 12 corresponding to region B2. The magnetic flux that flows into the first-layer magnet 412 flows into the teeth 12 via region A2. Because the arrangement of the first-layer magnets is asymmetric and shifted toward the counter-rotation side, the magnetic flux generated from the second-layer magnet 422 on the rotation side flows into the first-layer magnet 412 on the rotation side, but does not flow into the first-layer magnet 411 on the counter-rotation side. Magnetic flux flows into the second-layer magnet 422 on the rotation side from the rotor core 21 that constitutes the adjacent pole on the rotation side, via region D2 on the inner diameter side of the second-layer magnet 422, in the direction of line q2. On the other hand, the magnetic flux vector passing through the region C2 near the surface of the rotor core 21, which is close to the straight line q2, is small.

[0024] Fig. 5 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.

[0025] The magnetic flux generated in the stator coil 13 flows from the teeth 12 into the opposing regions A1, B1, and C1 of the rotor core 21. The magnetic flux that has flowed into region A1 passes through region A2 and returns to the teeth 12. At this time, the direction of the magnetic flux in region A1 shown in FIG. 5 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. 5 intersects with the direction of the magnetic flux in region A2 shown in FIG. 4.

[0026] The magnetic flux that has flowed into region B1 passes through region B2 and returns to tooth 12. At this time, the direction of the magnetic flux in region B1 shown in Fig. 5 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 region B2 shown in Fig. 5 is the same as the direction of the magnetic flux in region B2 shown in Fig. 4, and the two directions reinforce each other.

[0027] 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. 5 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. 5 intersects with the direction of the magnetic flux in regions D1 and D2 shown in Fig. 4.

[0028] Fig. 6 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.

[0029] 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 and B2, 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 almost the same, so the amount of magnetic flux is large.

[0030] In this way, in the rotating electric machine 1 of this embodiment, the arrangement of the first layer magnets is asymmetrical and closer to the counter-rotation side, and the counter-rotation side pole arc angle θ 11 The first layer's rotation side pole arc angle θ 12 As a result, the rotating electrical machine of this embodiment can suppress magnetic saturation and improve torque.

[0031] Next, the reason why the rotating electrical machine of this embodiment can reduce torque ripple will be explained. 7 is a diagram showing the relationship between the counter-rotation side pole arc angle of the first layer and torque in the rotating electric machine according to this embodiment. In FIG. 7, the horizontal axis represents the counter-rotation side pole arc angle θ of the first layer. 11 The vertical axis represents the electrical angle, and the vertical axis represents the relative torque. In addition, in Figure 7, the solid line represents the pole arc angle θ 12 is the torque when the electrical angle is 31.3 degrees, and the dashed line is the pole arc angle θ of the rotating side of the first layer 12is the torque when the electrical angle is 30.0 degrees, and the dashed line is the pole arc angle θ of the rotating side of the first layer 12 is the torque when the electrical angle is 27.6 degrees, and the dotted line is the pole arc angle θ of the rotating side of the first layer 12 is the torque when the electrical angle is 24.5 degrees.

[0032] FIG. 8 is a diagram showing a rectangular wave model of the rotor magnetomotive force waveform generated in the gap of a rotating electric machine according to this embodiment. In FIG. 8, the horizontal axis represents the electrical angle indicating the rotor's rotational position, and the vertical axis represents the magnetomotive force. The horizontal axis also represents time. In a rotating electric machine with two layers of magnet slots, there is magnetic flux that passes through the first and second layer magnets and flows into the gap, and magnetic flux that passes through the second layer magnet and flows into the gap. Therefore, the magnetomotive force is modeled as a waveform with two peaks. Specifically, as shown in FIG. 8, the magnetomotive force waveform is modeled as a combination of a rectangular wave with a height A1 and a width of the first-layer pole arc angle θ1 and a rectangular wave with a height A2 and a width of the second-layer pole arc angle θ2. θ1 and θ2 in FIG. 8 correspond to the electrical angle equivalents of the first-layer pole arc angle and the second-layer pole arc angle, respectively.

[0033] The rotating electric machine 1 according to this embodiment is an 8-pole, 48-slot rotating electric machine. It is known that torque ripple of a 6f-order component in electrical angle occurs due to space harmonics superimposed on the magnetomotive force waveform for each pole per phase and time harmonics contained in the phase current. Torque ripple generated in a rotating electric machine driven by three-phase AC current occurs when m±n=6f, where m is a natural number, for the space harmonic n in the magnetomotive force waveform for each pole per phase and the time harmonic m contained in the phase current. The 12th-order torque ripple occurs due to a combination of the 11th and 13th order space harmonics in the magnetomotive force waveform relative to the fundamental wave (m=1) of the phase current. Therefore, reducing the 11th and 13th order space harmonics in the magnetomotive force waveform of the rotor shown in FIG. 8 is effective in reducing torque ripple.

[0034] 9 is a diagram showing the magnitudes of the 11th and 13th spatial harmonics of the magnetomotive force waveform of the rotor in the rotating electric machine according to this embodiment. In FIG. 9, the horizontal axis represents the counter-rotation side pole arc angle θ of the first layer. 11and the first layer rotation side pole arc angle θ 12 The difference α between the two is shown on the vertical axis, and the magnitude of the 11th and 13th spatial harmonics when the rotor magnetomotive force waveform is Fourier expanded. The pole arc angle θ1 of the first layer and the pole arc angle θ2 of the second layer are constant. The pole arc angle θ of the counter-rotation side of the first layer is 11 and the first layer rotation side pole arc angle θ 12 The difference α between and is given by the following equation (2): α=θ 11 -θ 12 ····(2)

[0035] From Figure 9, it can be seen that the range of -30 degrees < α < 0 degrees or 0 degrees < α < 30 degrees is necessary to reduce the 12th-order torque ripple. However, in the range of -30 degrees < α < 0 degrees, the first layer rotation side pole arc angle θ 12 is the polar arc angle θ of the first layer on the opposite side of rotation 11 This narrows the magnetic path on the rotating side, which is the region where the magnetomotive force of the magnet and the armature magnetomotive force reinforce each other. Therefore, in this range, there is a possibility that torque will decrease due to the influence of magnetic saturation. In the rotating electric machine of this embodiment, the counter-rotation side pole arc angle θ of the first layer 11 is the pole arc angle θ of the first layer 12 The rotational speed is greater than 0 degrees and less than 30 degrees. The rotating electric machine configured in this manner can reduce torque ripple.

[0036] As explained so far, in the rotating electric machine of this embodiment, 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 rotating-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 rotating-side magnet, is located on the counter-rotation side of the dimensional center line of one pole, and When the angle between the dimensional centerline and the line connecting the point at the end farthest from the dimensional centerline on the outer diameter side of the magnet and the center of rotation is defined as the counter-rotation-side pole arc angle of the first layer, and the angle between the dimensional centerline and the line connecting the point at the end farthest from the dimensional centerline on the outer diameter side of the rotation-side magnet inserted into the magnet slot of the first layer and the center of rotation is defined as the counter-rotation-side pole arc angle of the first layer, which is greater than 0 degrees and less than 30 degrees than the rotation-side pole arc angle of the first layer, and therefore magnetic saturation can be suppressed, improving torque and reducing torque ripple.

[0037] In the rotating electric machine of this embodiment, the first-layer magnet slots 510 and the second-layer magnet slots 520 are formed in a V-shape with the spacing increasing toward the outer diameter, but they may also be U-shaped. However, it is preferable that the spacing between the first-layer magnets 412 on the rotation side and the second-layer magnets 422 on the rotation side increases toward the inner diameter. In other words, it is preferable that the angle formed by the V-shaped first-layer magnet slots 510 is larger than the angle formed by the V-shaped second-layer magnet slots 520. In a rotating electric machine configured in this manner, the magnetic path on the rotation side, which is the region where the magnet magnetomotive force and the armature magnetomotive force reinforce each other, becomes even wider.

[0038] Embodiment 2 Fig. 10 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 2. Fig. 10 is an enlarged cross-sectional view of one pole of rotor 20. 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.

[0039] As shown in Figure 10, point P3 is the point where a line extending from the long side of the outer diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the outer diameter of first-layer magnet 412 on the rotation side, and point P4 is the point where a line extending from the long side of the inner diameter of first-layer magnet 411 on the counter-rotation side intersects with a line extending from the long side of the inner diameter of first-layer magnet 412 on the rotation side. The line segment connecting points P3 and P4 is line segment L3. In the rotating electric machine of this embodiment, line segment L3 is located on the counter-rotation side of line d1. In this case, line segment L3 and line d1 do not have to be parallel to each other.

[0040] Furthermore, as shown in FIG. 10, in the rotating electric machine of this embodiment, when the length of the long side of the first layer magnet 411 on the counter-rotation side is W411 and the length of the long side of the first layer magnet 412 on the rotation side is W412, W411 is shorter than W412.

[0041] In the rotating electric machine of this embodiment, similarly to the first embodiment, the counter-rotation side pole arc angle θ 11 The first layer's rotation side pole arc angle θ 12 Since the angle is set to be greater than 0 degrees and less than 30 degrees, it is possible to suppress magnetic saturation, improve torque, and reduce torque ripple.

[0042] Furthermore, in the rotating electric machine of this embodiment, the length W411 of the long side of the first layer magnet 411 on the counter-rotation side is set shorter than the length W412 of the long side of the first layer magnet 412 on the rotation side, thereby suppressing a decrease in the magnetomotive force of the first layer magnet.

[0043] Embodiment 3 Fig. 11 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 3. Fig. 11 is an enlarged cross-sectional view of one pole of rotor 20. 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. 11.

[0044] 11, point P9 is the point where a line extending from the long side of the outer diameter of second-layer magnet 421 on the counter-rotation side intersects with a line extending from the long side of the outer diameter of second-layer magnet 422 on the rotation side, and point P10 is the point where a line extending from the long side of the inner diameter of second-layer magnet 421 on the counter-rotation side intersects with a line extending from the long side of the inner diameter of second-layer magnet 422 on the rotation side. The line segment connecting points P9 and P10 is line segment L8. In the rotating electric machine of this embodiment, line segment L8 is located closer to the rotation side than line d1.

[0045] Also, as shown in Figure 11, in the rotating electric machine of this embodiment, when the length of the long side of the second layer magnet 421 on the counter-rotation side is W421 and the length of the long side of the second layer magnet 422 on the rotation side is W422, W421 is longer than W422.

[0046] Furthermore, in the rotating electric machine of this embodiment, similarly to the first embodiment, the counter-rotation side pole arc angle θ 11 The first layer's rotation side pole arc angle θ 12 Since the angle is set to be greater than 0 degrees and less than 30 degrees, it is possible to suppress magnetic saturation, improve torque, and reduce torque ripple.

[0047] In a rotating electric machine configured in this manner, by positioning line segment L8 on the rotation side of straight line d1, the distance between first layer magnet 412 and second layer magnet 422 on the rotation side can be increased.

[0048] Furthermore, in the rotating electric machine of this embodiment, the length W421 of the long side of the second layer magnet 421 on the counter-rotation side is set longer than the length W422 of the long side of the second layer magnet 422 on the rotation side, thereby suppressing a decrease in the magnetomotive force of the second layer magnet.

[0049] Embodiment 4 Fig. 12 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 4. Fig. 12 is an enlarged cross-sectional view of one pole of rotor 20. The configuration of the rotating electric machine according to this embodiment is similar to the configuration of the rotating electric machine described in embodiment 1, except that the second layer magnet is made up of a plurality of divided magnets.

[0050] 12, 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. Also, second-layer magnet 422 on the rotation side is composed of two divided magnets 422a and 422b. The four divided magnets 421a, 421b, 422a, and 422b have the same shape.

[0051] 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 magnets from two separate magnets, the eddy current path becomes longer and the magnetic resistance increases, reducing losses generated in the second-layer magnets.

[0052] In the rotating electric machine of this embodiment, the second layer magnet is composed of two divided magnets, but it may be composed of three or more divided magnets, and the first layer magnet may be composed of two or more divided magnets.

[0053] Embodiment 5. Fig. 13 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 5. Fig. 13 is an enlarged cross-sectional view of one pole of rotor 20. The structure of the rotating electric machine according to this embodiment is similar to the structure of the rotating electric machine described in embodiment 4, except that the split magnets are arranged at intervals in the second layer magnet made up of split magnets.

[0054] 13, in the rotating electric machine of this embodiment, bent portions are provided in the counter-rotation side slots and rotation side slots of the V-shaped second-layer magnet slots 520. Two divided magnets 421a and 421b of the counter-rotation side second-layer magnet 421 are spaced apart with a bent portion between them. Similarly, two divided magnets 422a and 422b of the rotation-side second-layer magnet 422 are spaced apart with a bent portion between them.

[0055] 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 magnets from two separate magnets, the eddy current path becomes longer and the magnetic resistance increases, reducing losses generated in the second-layer magnets.

[0056] Furthermore, in a rotating electric machine configured in this manner, the second-layer magnet slots have bent portions, so the amount of magnet in the second-layer magnet can be increased while maintaining a constant second-layer pole arc angle θ2. Note that in the rotating electric machine of this embodiment, the second-layer magnet is configured with two divided magnets spaced apart, but it may also be configured with three or more divided magnets. Also, the first-layer magnet may be configured with two or more divided magnets spaced apart.

[0057] Embodiment 6 Fig. 14 is an enlarged cross-sectional view of a rotor in a rotating electric machine according to embodiment 6. Fig. 14 is an enlarged cross-sectional view of one pole of rotor 20. 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. 14.

[0058] As shown in FIG. 14 , in the rotor of this embodiment, the first layer magnet slots 510, which are formed in a V-shape with the spacing increasing toward the outer diameter, are composed of the first layer counter-rotation side magnet slots 511 and rotation side magnet slots 512. A center bridge 110, which is part of the rotor core 21, is provided between the counter-rotation side magnet slots 511 and rotation side magnet slots 512. The second layer magnet slots 520, which are formed in a V-shape with the spacing increasing toward the outer diameter, are composed of the second layer counter-rotation side magnet slots 521 and rotation side magnet slots 522. A center bridge 120, which is part of the rotor core 21, is provided between the counter-rotation side magnet slots 521 and rotation side magnet slots 522. The sections between the first layer magnet slots 510 and second layer magnet slots 520 and the outer circumferential surface of the rotor core 21 are referred to as outer circumferential bridges.

[0059] The rotating electric machine of this embodiment has the same structure as the rotating electric machine of embodiment 1, except that it includes center bridges 110 and 120. Therefore, like embodiment 1, the rotating electric machine of this embodiment can suppress magnetic saturation, improve torque, and reduce torque ripple. Furthermore, since the rotor core is provided with a center bridge, stress concentration on the peripheral bridge due to centrifugal force during rotation can be alleviated, thereby increasing the allowable rotation speed.

[0060] 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 a three-phase 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, 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, a rotating electric machine characterized in that, when the angle formed by the line connecting the center of rotation and the end point furthest from the dimensional center line on the outer diameter side of the counter-rotation-side magnet inserted into the magnet slot of the first layer is defined as the counter-rotation-side pole arc angle of the first layer, and the angle formed by the line connecting the center of rotation and the end point furthest from the dimensional center line on the outer diameter side of the rotation-side magnet inserted into the magnet slot of the first layer, and the angle formed by the line connecting the center of rotation and the end point furthest from the dimensional center line on the outer diameter side of the rotation-side magnet inserted into the magnet slot of the first layer, the counter-rotation-side pole arc angle of the first layer is greater than 0 degrees and less than 30 degrees than the rotation-side pole arc angle of the first layer. (Appendix 2) A rotating electric machine as described in Appendix 1, characterized in that 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. (Appendix 3) 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 second 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 rotation side of the dimensional center line of one pole, The rotating electric machine described in Appendix 1 or 2, characterized in that the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the second layer is longer than the length along the magnet slot of the rotation side magnet. (Appendix 4) A rotating electric motor as described in any one of appendices 1 to 3, characterized in that at least one of the counter-rotation side magnets and the rotating side magnets inserted into the magnet slots arranged in multiple layers is composed of a plurality of split magnets, and at least two or more of the multiple split magnets have the same shape. (Appendix 5) 5. The rotating electric machine according to claim 4, wherein the plurality of divided magnets are arranged at intervals. (Appendix 6) A rotating electric machine as described in any one of appendices 1 to 5, 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. (Appendix 7) A rotating electric machine according to any one of appendices 1 to 6, characterized in that the gap between the rotating-side magnet inserted in the magnet slot of the first layer and the rotating-side magnet inserted in the magnet slot of the second layer increases toward the inner diameter side.

[0061] 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]

[0062] 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, 510, 520 magnet slot, 511, 521 counter-rotation side magnet slot, 512, 522 rotation side magnet slot.

Claims

1. A rotating electric machine comprising: a stator having a stator core and a stator coil; and a rotor disposed on an inner diameter side of the stator via a gap, wherein the rotor is driven to rotate about a rotation axis by a three-phase 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, 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, when the angle formed by the line connecting the end point of the counter-rotation side magnet inserted into the magnet slot of the first layer farthest from the dimensional center line on the outer diameter side and the rotation center point and the dimensional center line is defined as the counter-rotation side pole arc angle of the first layer, and the angle formed by the line connecting the end point of the counter-rotation side magnet inserted into the magnet slot of the first layer farthest from the dimensional center line on the outer diameter side and the rotation center point and the dimensional center line is defined as the rotation side pole arc angle of the first layer, the counter-rotation side pole arc angle of the first layer is larger than the rotation side pole arc angle of the first layer by an angle greater than 0 degrees and less than 30 degrees, 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 second 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 rotation side of the dimensional center line of one pole, A rotating electric machine characterized in that the length along the magnet slot of the counter-rotation side magnet inserted into the magnet slot of the second layer is longer than the length along the magnet slot of the rotation side magnet.

2. 2. The rotating electric machine according to claim 1, wherein 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.

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

4. 4. The rotating electric machine according to claim 3, wherein the plurality of divided magnets are arranged at intervals.

5. 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.

6. 3. A rotating electric motor according to claim 1, wherein the distance 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 side.

Images