Rotary electric machine

Abstract

To provide a rotary electric machine capable of enhancing the mechanical strength of a rotor while suppressing leakage of magnetic flux.SOLUTION: A rotary electric machine includes a stator and a rotor 11. A magnetic pole 18 of the rotor includes a magnet hole 19, a permanent magnet 13A, a first gap part 21, a second gap part 22, and a rib 23. The magnet hole extends circumferentially across a magnet pole center line along a radial direction of the rotor, and is formed in an almost arc shape in an axial view so that both ends in an extension direction are close to an outer circumferential edge of the rotor. The permanent magnet is inserted and disposed in the magnet hole. The first gap part is formed between both ends of the magnet hole in the extension direction and the permanent magnet. The second gap part extends to be separated from the magnet hole on an extension of both ends of the magnet hole in the extension direction. The rib is disposed between the first gap part and the second gap part, and connects an outer region and an inner region of the first gap part and the second gap part in the radial direction.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine in which a rotor is rotatably disposed radially inside an annular stator. [Background technology]

[0002] 2. Description of the Related Art A known rotating electric machine has a rotor rotatably disposed radially inside an annular stator, with a plurality of permanent magnets provided inside the rotor (see, for example, Patent Document 1).

[0003] The rotating electric machine described in Patent Document 1 has a rotor with multiple magnetic poles spaced apart in the circumferential direction. Each magnetic pole has a substantially arc-shaped (L-shaped) magnet hole provided symmetrically on either side of a magnetic pole center line (d-axis) along the radial direction, and a permanent magnet is inserted into each magnet hole. The left and right magnet holes are formed so as to form a substantially U-shape that opens outward in the radial direction.

[0004] The permanent magnets housed in each magnet hole generate magnetic torque (attractive and repulsive forces) between them and the magnetic poles caused by the winding current on the stator side. Furthermore, areas in each magnet hole where no permanent magnets exist function as flux barriers that regulate the flow of magnetic flux. The vicinity of the outer periphery of the rotor close to the outer ends of the pair of roughly U-shaped magnet holes functions as a salient pole on the rotor side, providing a path for the flow of the rotating magnetic flux of the stator. The rotor rotates under the magnetic torque and reluctance torque of the permanent magnets.

[0005] A center rib is disposed between the ends of the pair of magnet holes on the magnetic pole center line side so as to extend along the magnetic pole center line. The center rib connects the radial outer region and inner region of the magnet holes, which are separated by the magnet holes, and maintains the mechanical strength of the outer peripheral edge of the rotor. Since a large centrifugal force acts on the outer peripheral edge of the rotor when the rotor rotates, the center rib prevents the outer peripheral edge of the rotor from being deformed by this centrifugal force. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2020-137139 A Summary of the Invention [Problem to be solved by the invention]

[0007] The rotating electric machine described in Patent Document 1 has a center rib disposed between the left and right magnet holes, which allows the mechanical strength of the rotor to be kept high. However, since the center rib is disposed in the vicinity of the magnetic pole center line (d-axis) where the magnet magnetic flux and the rotating magnetic flux of the stator are concentrated, the center rib becomes a short-circuit path for the magnet magnetic flux and the rotating magnetic flux, which increases leakage magnetic flux. For this reason, the magnetic force of the magnet cannot be efficiently utilized in the rotating electric machine, which causes the permanent magnets to be mounted to be large.

[0008] Therefore, the present invention aims to provide a rotating electric machine that can increase the mechanical strength of the rotor while suppressing leakage of magnetic flux, which in turn contributes to reducing the size and weight of the permanent magnets mounted therein and to improving energy efficiency. [Means for solving the problem]

[0009] A rotating electric machine according to one aspect of the present invention includes an annular stator (e.g., stator 10 in the embodiment), and a rotor (e.g., rotor 11 in the embodiment) that is rotatably arranged radially inside the stator and has a plurality of magnetic poles (e.g., magnetic pole 18 in the embodiment) spaced apart in the circumferential direction, and the magnetic poles of the rotor extend circumferentially across a magnetic pole center line (e.g., magnetic pole center line op in the embodiment) along the radial direction of the rotor, and both ends in the extending direction are close to the outer circumferential edge portion of the rotor. A magnet hole (e.g., magnet hole 19 in the embodiment) formed in a substantially arc-shaped shape in the axial direction so as to be in contact with the magnet hole, a permanent magnet (e.g., permanent magnet 13A in the embodiment) inserted into the magnet hole, a first gap (e.g., first gap 21 in the embodiment) formed between the permanent magnet and both ends of the magnet hole in the extension direction, a second gap (e.g., second gap 22 in the embodiment) extending away from the magnet hole on the extension of both ends of the magnet hole in the extension direction, and a gap between the first gap and the second gap. and a rib (e.g., rib 23 in the embodiment) arranged on the outer periphery of the first gap portion and the second gap portion, connecting the outer region and the inner region in the radial direction of the first gap portion and the second gap portion, an opening angle between a normal line (e.g., normal line nm in the embodiment) passing through an outer end portion of the permanent magnet on a side away from the magnetic pole center line and the magnetic pole center line is θMag, an opening angle between a normal line (e.g., normal line nr in the embodiment) passing through an outer end portion of the first gap portion on a side away from the magnetic pole center line and the magnetic pole center line is θRib, The opening angle θRib is set so as to satisfy the following formulas (1) and (2), where θ1 is the opening angle between a normal line (e.g., normal line ns in the embodiment) passing through the outer end portion away from the magnetic pole center line and the magnetic pole center line, and θ2 is the opening angle between a normal line (e.g., normal line ni in the embodiment) passing through an intermediate position between the outer end portion of the permanent magnet on the side away from the magnetic pole center line and the outer end portion of the second gap on the side away from the magnetic pole center line. θ2=(θ1+θMag) / 2 … (1) θRib<θ2 …(2)

[0010] In the above configuration, the magnets are arranged to straddle the magnetic pole center line, and the ribs connecting the radial outer and inner regions of the gaps (first and second gaps) are arranged on one end side and the other end side in the extension direction of the magnet hole. Therefore, in the vicinity of the magnetic pole center line where the magnetic flux of the magnet and the rotating magnetic flux of the stator tend to concentrate, magnetic flux leakage due to the wraparound of the magnetic flux and the rotating magnetic flux is unlikely to occur. In addition, when a tensile load is input in a direction substantially along the magnetic pole center line, tension acts on the ribs on both sides in the extension direction of the magnet hole, suppressing deformation of the outer periphery of the rotor. In particular, since the opening angle θRib of the ribs satisfies the above formulas (1) and (2), bending stress is unlikely to occur in the ribs when a tensile load acts in a direction substantially along the magnetic pole center line. Therefore, the mechanical strength of the rotor can be maintained high.

[0011] The first gap portion may have a first flange portion (e.g., first flange portion 24 in the embodiment) thicker than the permanent magnet at its end facing the rib, and the second gap portion may have a second flange portion (e.g., second flange portion 25 in the embodiment) thicker than the permanent magnet at its end facing the rib.

[0012] In this case, the length of the rib can be increased by using the first and second flanges that are thicker than the permanent magnet. This increases the magnetic path resistance of the magnetic flux flowing through the rib, making it possible to further suppress the magnetic flux and rotating magnetic flux from flowing through the rib. Therefore, when this configuration is adopted, it becomes possible to more effectively utilize the magnetic force of the permanent magnet, making it possible to further reduce the size and weight of the permanent magnet.

[0013] It is desirable that the first flange portion and the second flange portion have substantially the same length of extension toward the inside in the radial direction of the rotor.

[0014] When one of the first and second flanges extends radially inward longer than the other, the flange with the longer extension is more likely to obstruct the flow of rotating magnetic flux. However, in the case of this configuration, the first and second flanges extend radially inward by approximately the same length, so these flanges are less likely to obstruct the flow of rotating magnetic flux. Therefore, when this configuration is adopted, it is possible to more effectively utilize the magnetic force of the permanent magnet.

[0015] The first and second flanges may extend radially inward and outward, respectively, of the rotor.

[0016] In this case, the extension length (protrusion length) per radially inner and outer side of the first and second flanges is suppressed, while the length of the rib between the first and second flanges is made sufficient, thereby making it possible to set a sufficiently large magnetic flux resistance of the magnetic flux attempting to flow through the rib.

[0017] The second gap may include a third flange portion at an outer end portion away from the magnetic pole center line, the third flange portion being thicker than the permanent magnet.

[0018] In this case, the length of the magnetic flux path between the outer end of the second gap and the outer circumferential surface of the rotor is increased, and as a result, the magnetic path resistance of the magnetic flux flowing through the magnetic flux path is increased. This suppresses the magnetic flux from wandering around the outer end of the second gap. Therefore, when this configuration is adopted, it becomes possible to more effectively utilize the magnetic force of the permanent magnet, and it becomes possible to further reduce the size and weight of the permanent magnet.

[0019] The magnetic pole components including the magnet holes, the permanent magnets, the first gaps, the second gaps, and the ribs may be arranged in a plurality of layers in the radial direction.

[0020] In this case, the same function as described above can be obtained by the magnetic pole components of each layer, and in addition, a larger rotational torque can be obtained by the magnetic pole components of multiple layers. Effect of the Invention

[0021] In the rotating electric machine according to the present invention, the magnet holes are arranged so as to straddle the magnetic pole center line, and ribs connecting the radially outer and inner regions of the first and second gaps are arranged on one and the other end sides in the extending direction of the magnet holes. This makes it possible to suppress the magnetic flux and rotating magnetic flux from wandering around the area near the magnetic pole center line, and the left and right ribs can increase the mechanical strength of the rotor. Therefore, when the rotating electric machine according to the present invention is used, the permanent magnets to be mounted can be made smaller and lighter. [Brief description of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view perpendicular to the axial direction of a rotating electric machine according to a first embodiment. [Diagram 2] 2 is a cross-sectional view perpendicular to the axial direction of the rotor according to the first embodiment. FIG. [Diagram 3] FIG. 3 is a cross-sectional view of the rotor according to the first embodiment, also showing the flow of magnetic flux within the rotor. [Figure 4] 5A to 5C are schematic cross-sectional views of a rotor showing the deformation behavior of the rotor when the position of a rib is changed. [Diagram 5] An enlarged view of part V in Figure 1. [Figure 6] 6 is a graph showing a torque change rate of a rotating electric machine when the thicknesses of the ends of the first gap and the second gap are changed. [Figure 7] 6 is a graph showing a torque change rate of a rotating electric machine when the shape of the end of the second gap is changed. [Figure 8] 13 is a schematic cross-sectional view of a rotor in which the extension length of the second flange portion is longer than the extension length of the first flange portion. FIG. [Figure 9] An enlarged view of part IX in Figure 1. [Figure 10] 6 is a graph showing a torque change rate of a rotating electric machine when the shape of the outer end of the second gap is changed. [Figure 11] FIG. 11 is an enlarged cross-sectional view showing a portion of a rotor according to a second embodiment. [Figure 12] 6 is a graph showing a torque change rate of a rotating electric machine when the shapes of the ends of the first gap and the second gap are changed. [Figure 13]FIG. 11 is a cross-sectional view perpendicular to the axial direction of a rotor according to a third embodiment. [Figure 14] FIG. 11 is a cross-sectional view perpendicular to the axial direction of a rotor according to a fourth embodiment. [Figure 15] FIG. 13 is a cross-sectional view perpendicular to the axial direction of a rotor according to a fifth embodiment. [Figure 16] FIG. 13 is a cross-sectional view perpendicular to the axial direction of a rotor according to a sixth embodiment. [Figure 17] FIG. 13 is an enlarged cross-sectional view of a portion of a rotor according to a seventh embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In each embodiment described below, the same reference numerals are used to designate common parts, and some overlapping descriptions will be omitted.

[0024] First Embodiment FIG. 1 is a diagram showing a cross section perpendicular to the axial direction of a rotating electric machine 1 according to this embodiment. The rotating electric machine 1 of this embodiment can be used, for example, as a drive source for a vehicle. The rotating electric machine 1 includes an annular stator 10 and a rotor 11 rotatably disposed radially inside the stator 10. The rotating electric machine 1 of this embodiment is a magnet synchronous rotating electric machine in which a plurality of permanent magnets 13A, 13B are embedded inside a rotor core 12 of the rotor 11.

[0025] The stator 10 includes an annular stator core 16 having a plurality of teeth 15 formed on its inner periphery, and coils 17 wound around each of the teeth 15 of the stator core 16. The coils 17 are U-phase, V-phase, and W-phase coils, and are connected to a drive circuit (not shown). When a three-phase AC current is applied from the drive circuit, the coils 17 wound around each of the teeth 15 generate a rotating magnetic field on the inner periphery of the stator 10.

[0026] FIG. 2 is a cross-sectional view perpendicular to the axial direction of the rotor 11. As shown in FIG. 1 and 2, rotor 11 is formed into a thick cylindrical shape overall, with a rotating shaft (not shown) fixed to its axial center. Rotor 11 and the rotating shaft are arranged coaxially with the inner peripheral surface of stator 10 on the radial inside (inner peripheral side) of stator 10. A small gap is secured between the inner peripheral surface of stator 10 and the outer peripheral surface of rotor 11. In the description of this embodiment, the direction in which the axis of the rotor 11 and the rotating shaft faces is referred to as the "axial direction," the radial direction perpendicular to the axial direction and centered on the axis is referred to as the "radial direction," and the circumferential direction centered on the axis is referred to as the "circumferential direction."

[0027] The rotor 11 includes a rotor core 12 made of a magnetic material such as laminated steel plates, and multiple pairs of permanent magnets 13A, 13B embedded inside the rotor core 12. The two permanent magnets 13A, 13B arranged at a distance on the inside and outside in the radial direction form a pair, and multiple sets of the paired permanent magnets 13A, 13B are arranged at a distance on the circumferential area of ​​the rotor core 12. The paired permanent magnets 13A, 13B are embedded in the rotor core 12 so that the magnetic poles face the same side in the radial direction. In addition, the pair of permanent magnets 13A, 13B adjacent in the circumferential direction have opposite poles facing radially outward. Multiple magnetic poles 18 having paired permanent magnets 13A, 13B are arranged at equal intervals on the circumferential area of ​​the rotor 11.

[0028] Each magnetic pole 18 of the rotor 11 includes a first magnetic pole component 18F disposed radially inside and a second magnetic pole component 18S disposed radially outside. That is, each magnetic pole 18 is composed of inner and outer two-layer magnetic pole components (the first magnetic pole component 18F and the second magnetic pole component 18S).

[0029] The first magnetic pole component 18F includes a magnet hole 19, a permanent magnet 13A, a first gap 21, a second gap 22, and a rib 23.

[0030] The magnet hole 19 extends circumferentially across the magnetic pole center line op (d-axis) that runs along the radial direction of the rotor 11. The magnet hole 19 is a hole that penetrates the rotor core 12 in the axial direction. The shape of the magnet hole 19 as viewed in the axial direction is an arc shape with the arc center oa being an arbitrary point radially outward from the outer circumferential surface of the rotor 11 on the magnetic pole center line op. Both ends of the magnet hole 19 in the extension direction are curved radially outward.

[0031] The permanent magnet 13A is formed in an arc shape when viewed in the axial direction, and is inserted and disposed in the magnet hole 19 so as to straddle the magnetic pole center line op. The permanent magnet 13A is disposed in the central region of the magnet hole 19 in the extension direction. The arc shape of the permanent magnet 13A is an arc shape with the same radius as the magnet hole 19 and centered on the same arc center oa as the magnet hole 19. The permanent magnet 13A is fixed to the inner circumferential surface of the magnet hole 19 by press-fitting or adhesive. The length of the permanent magnet 13A in the extension direction is set to be sufficiently shorter than the length of the magnet hole 19 in the extension direction.

[0032] The first gap 21 is a gap formed between each end of the magnet hole 19 on both sides in the extension direction and each end face of the permanent magnet 13A, and is provided so as to face both end faces in the extension direction of the permanent magnet 13A. The second gap 22 is a gap extending away from the magnet hole 19 on the extension of both ends of the magnet hole 19 in the extension direction, and has an arc shape with the same radius as the first gap 21 and centered on the same arc center oa. The second gap 22 is formed by an arc-shaped hole penetrating the rotor core 12 in the axial direction. The first gap 21 and the second gap 22 function as flux barriers that regulate the flow of magnetic flux on the outside of the extension direction of the permanent magnet 13A. 3 is a cross-sectional view of rotor 11 similar to FIG. 2, which also shows the flow of magnetic flux within rotor 11. As shown in the drawing, the flow of magnetic flux within rotor 11 is regulated by a first gap 21 and a second gap 22.

[0033] The ribs 23 are disposed between the first gap 21 and the second gap 22 on the left and right sides of the permanent magnet 13A. Each of the left and right ribs 23 extends substantially along a normal line centered on the arc center oa. Each rib 23 connects the radial outer region and inner region of the first gap 21 and the second gap 22, thereby suppressing a decrease in the mechanical strength of the rotor core 12 due to these gaps 21, 22.

[0034] The left and right ribs 23 have opening angles θRib with respect to the magnetic pole center line op set so as to satisfy the following expressions (1) and (2). θ2=(θ1+θMag) / 2 … (1) θRib<θ2 …(2)

[0035] The opening angles θMag, θRib, θ1, and θ2 (see FIG. 2) in the formulas (1) and (2) are defined as follows: [Opening angle θMag] The opening angle between a normal nm (e.g., a normal centered on an arbitrary point near the arc center oa) passing through the outer end of the permanent magnet 13A away from the magnetic pole center line op and the magnetic pole center line op. Hereinafter, this opening angle θMag will be referred to as the "opening angle θMag of the permanent magnets." [Opening angle θRib] The opening angle between a normal nr (e.g., a normal centered on any point near the arc center oa) passing through the outer end of the first gap portion 21 away from the magnetic pole center line op and the magnetic pole center line op. Hereinafter, this opening angle θRib will be referred to as "the opening angle θRib of the rib 23." [Opening angle θ1] The opening angle between a normal ns (e.g., a normal centered on any point near the arc center oa) passing through the outer end of the second gap portion 22 away from the magnetic pole center line op and the magnetic pole center line op. Hereinafter, this opening angle θ1 will be referred to as "the opening angle θ1 of the second gap portion 22." [Opening angle θ2] The opening angle between the magnetic pole center line op and a normal line ni (for example, a normal line centered at an arbitrary point near the arc center oa) passing through a midpoint between the outer end of the permanent magnet 13A on the side away from the magnetic pole center line op and the outer end of the second gap portion 22 on the side away from the magnetic pole center line op. Hereinafter, this opening angle θ2 will be referred to as "the opening angle θ2 at the intermediate position of the gap region."

[0036] FIG. 4 is a schematic cross-sectional view of the rotor 11 showing, in (a), (b), and (c), the difference in deformation behavior of the rotor 11 when the position of the rib 23 (opening angle θRib) is changed. In (a), the position of the rib 23 is set so that the opening angle θRib of the rib 23 is smaller than the opening angle θ2 at the middle position of the gap region. In (b), the position of the rib 23 is set so that the opening angle θRib of the rib 23 is the same as the opening angle θ2 at the middle position of the gap region. In (c), the position of the rib 23 is set so that the opening angle θRib of the rib 23 is larger than the opening angle θ2 at the middle position of the gap region. The left half of each of (a), (b), and (c) shows the state of the rotor 11 before it is deformed, and the right half of each of the figures shows the deformation behavior of the rotor 11 when a tensile load is applied along the magnetic pole center line op to the outer circumferential surface of the rotor 11. In the right half of each of (a), (b), and (c), dots are added to the areas where the stress becomes higher than a specified value.

[0037] As shown in Figures 4(a) and (b), when the opening angle θRib of the ribs 23 is equal to or smaller than the opening angle θ2 at the middle position of the gap region, the left and right ribs 23 can absorb the tensile load approximately along the magnetic pole center line op as tension along the extension direction, thereby efficiently suppressing deformation of the rotor 11. On the other hand, as shown in (c) of Figure 4, when the opening angle θRib of the rib 23 is larger than the opening angle θ2 at the middle position of the gap region, when a tensile load acting on the rotor 11 approximately along the magnetic pole center line op, bending stress is generated in each rib 23, making it difficult to efficiently suppress deformation of the rotor 11. Therefore, by setting the opening angle θRib of the rib 23 to be equal to or smaller than the opening angle θ2 at the middle position of the gap region so as to satisfy the above equations (1) and (2), deformation of the rotor 11 can be efficiently suppressed.

[0038] In addition, in the rotating electric machine 1 of this embodiment, the magnet hole 19 is disposed so as to straddle the magnetic pole center line op, and the ribs 23 connecting the radial outer region and inner region of the first gap portion 21 and the second gap portion 22 are disposed on one end side and the other end side in the extension direction of the magnet hole 19. For this reason, as shown in Fig. 3, in the vicinity of the magnetic pole center line op where the magnetic flux of the permanent magnet 13A and the rotating magnetic flux of the stator 10 tend to concentrate, magnetic flux leakage due to the magnetic flux or the rotating magnetic flux flowing around is less likely to occur.

[0039] FIG. 5 is an enlarged view of part V in FIG. 5, the first gaps 21 on the left and right sides of the magnet hole 19 are provided with first flanges 24 that are thicker than the permanent magnet 13A at the ends facing the ribs 23. In the case of this embodiment, the first flanges 24 have extension regions 24a that extend radially inward substantially along the normal line nr with respect to the general portion of the first gap 21 (portion other than the first flanges 24). The first flanges 24 are thicker than the permanent magnet 13A by the length of the extension regions 24a.

[0040] Further, the left and right second gaps 22 are provided with second flanges 25 that are thicker than the permanent magnets 13A at the ends facing the ribs 23. In the present embodiment, the second flanges 25 have extension regions 25a that extend radially inwardly approximately along the normal line nr with respect to the general portion (portion other than the second flanges 25) of the second gaps 22. The second flanges 25 are thicker than the permanent magnets 13A by the length of the extension regions 25a. Therefore, the length of the rib 23 formed between the first gap 21 and the second gap 22 is longer than the thickness of the permanent magnet 13A by the extension regions 24a, 25a of the flanges 24, 25. Since the rib 23 is formed of a part of the rotor core 12 made of a magnetic material, some of the magnet magnetic flux and rotating magnetic flux flowing through the rotor core 12 may leak along the extension direction of the rib 23. However, since the rib 23 is set to a sufficient length in this way, the magnetic path resistance when the magnetic flux flows is large. Therefore, leakage of the magnetic flux through the rib 23 can be suppressed as much as possible.

[0041] FIG. 6 is a graph showing the torque change rate of the rotating electrical machine 1 when the thickness of the ends (the ends facing the ribs 23) of the first gap 21 and the second gap 22 is changed. As shown in the figure, when the torque change rate is 0 when the thickness of the ends of the first and second gaps 21 and 22 is the same as the thickness of the permanent magnet 13A, when the thickness of the ends of the first and second gaps 21 and 22 is made thinner than the thickness of the permanent magnet 13A, the torque change rate increases in the negative direction approximately in proportion to the decrease in thickness. Also, when the thickness of the ends of the first and second gaps 21 and 22 is made thicker than the thickness of the permanent magnet 13A, the torque change rate increases in the positive direction approximately in proportion to the increase in thickness. Therefore, as is clear from this figure, by providing first and second flange portions 24 and 25 of sufficient thickness at each end of the first and second gap portions 21 and 22, respectively, the rotational torque of the rotating electric machine 1 can be increased.

[0042] FIG. 7 is a graph showing the rate of change in torque of the rotating electrical machine 1 when the shape of the end portion (the end portion facing the rib 23) of the second gap portion 22 is changed. As shown in the figure, a first flange 24 is provided at the end of the first gap 21, and no flange is provided at the end of the second gap 22. If the extension length of the second flange 25 provided at the end of the second gap 22 is gradually increased from this state, the positive torque change rate of the rotating motor 1 will be maximized when the extension lengths of the first flange 24 and the second flange 25 become the same.

[0043] FIG. 8 is a schematic cross-sectional view of rotor 11 in which the extension length of second flange portion 25 is longer than the extension length of first flange portion 24. As shown in FIG. 8, if the length of the extension region 25a of the second flange 25 is made longer than the length of the extension region 24a of the first flange 24, the flow of the rotating magnetic flux flowing from the outer peripheral edge of the rotor core 12 along the extension direction of the second gap 22 is obstructed by the extension region 25a of the second flange 25. As a result, the rotating magnetic flux cannot be fully utilized to increase the rotational torque of the rotating electric machine 1. Therefore, by making the extension lengths of the extension regions 24a, 25a of the first flange 24 and the second flange 25 the same, the rotational torque of the rotating electric machine 1 can be further increased.

[0044] FIG. 9 is an enlarged view of part IX in FIG. As shown in Figure 9, the magnetic flux and the rotating magnetic flux may try to flow around the area between the outer end of the second gap 22 in the extension direction (the end away from the magnetic pole center line op) and the outer peripheral surface of the rotor core 12.

[0045] FIG. 10 is a graph showing the torque change rate of the rotating electric machine 1 when the shape of the outer end portion (the end portion on the side away from the magnetic pole center line op) of the second gap portion 22 is changed. As shown in FIG. 10, when the thickness of the outer end of the second gap 22 is increased, the torque change rate of the rotating electric machine 1 increases in a positive direction. In other words, it is desirable to provide a third flange 40 that is thicker than the permanent magnet 13A at the outer end of the second gap 22 on the side away from the magnetic pole center line op. This can increase the torque change rate of the rotating electric machine 1 in a positive direction. This is because increasing the thickness of the outer end of the second gap 22 (providing the third flange 40 at the outer end) increases the length of the region between the outer end of the second gap 22 and the outer circumferential surface of the rotor core 12, and as a result, the magnetic path resistance of the magnetic flux flowing through the region increases. Therefore, by providing the third flange 40 that is thicker than the permanent magnet 13A at the outer end of the second gap 22, the rotational torque of the rotating electric machine 1 can be increased.

[0046] The second magnetic pole component 18S shown in FIG. 1 includes a magnet hole 26, a permanent magnet 13B, and a gap 27. The magnet hole 26 of the second magnetic pole component 18S is a hole that penetrates the rotor core 12 in the axial direction and extends circumferentially across the magnetic pole center line op. The shape of the magnet hole 26 as viewed in the axial direction is an arc shape with the arc center being an arbitrary point radially outward from the outer circumferential surface of the rotor 11 on the magnetic pole center line op. The magnet hole 26 has both ends in the extension direction curved radially outward, similar to the magnet hole 19 of the first magnetic pole component 18F.

[0047] Permanent magnet 13B is formed in an arc shape when viewed in the axial direction, and is inserted and disposed in magnet hole 26 so as to straddle magnetic pole center line op. Permanent magnet 13B is disposed in the central region in the extension direction of magnet hole 26. Permanent magnet 13B is fixed to the inner circumferential surface of magnet hole 26 by press-fitting or adhesive.

[0048] The length of permanent magnet 13B in the extension direction is set to be sufficiently short compared to the length of magnet hole 26 in the extension direction. Gaps 27 are provided between both ends of permanent magnet 13B housed and arranged in magnet hole 26 in the extension direction and both ends of magnet hole 26 in the extension direction. Gaps 27 arranged on both sides of permanent magnet 13B function as flux barriers to regulate the flow of magnet magnetic flux and rotating magnetic flux.

[0049] As described above, in the rotating electric machine 1 of this embodiment, the magnet hole 19 of the first magnetic pole constituent part 18F is arranged so as to straddle the magnetic pole center line op, and the rib 23 connecting the radial outer region and the radial inner region of the first gap part 21 and the second gap part 22 is arranged on one end side and the other end side in the extension direction of the magnet hole 19. Therefore, in the vicinity of the magnetic pole center line op where the magnetic flux and the rotating magnetic flux are likely to concentrate, magnetic flux leakage due to the magnetic flux and the rotating magnetic flux going around is unlikely to occur. Since the opening angle θRib of the rib 23 is formed so as to satisfy the above formulas (1) and (2), bending stress is unlikely to occur in the rib 23 when a tensile load acts in a direction substantially along the magnetic pole center line op. Therefore, the mechanical strength of the rotor 11 can be maintained high. Therefore, when the rotating electric machine 1 of this embodiment is used, it is possible to suppress the magnetic flux and the rotating magnetic flux from flowing around the magnetic pole center line op, and to increase the mechanical strength of the rotor 11 by the left and right ribs 23. Therefore, when the rotating electric machine 1 of this embodiment is used, it is possible to reduce the size and weight of the permanent magnet 13A to be mounted, which contributes to energy efficiency.

[0050] In addition, in the rotating electric machine 1 of this embodiment, a first flange 24 thicker than the permanent magnet 13A is provided at the end of the first gap 21 facing the rib 23, and a second flange 25 thicker than the permanent magnet 13A is provided at the end of the second gap 22 facing the rib 23. This makes it possible to sufficiently lengthen the length of the rib 23 in the extension direction formed between the first gap 21 and the second gap 22, thereby increasing the magnetic path resistance of the magnetic flux attempting to flow through the rib 23. This makes it possible to further suppress the magnetic flux of the magnet and the rotating magnetic flux from detouring through the rib 23. Therefore, when the rotating electric machine 1 of this embodiment is adopted, it becomes possible to more effectively utilize the magnetic force of the permanent magnet 13A, and it becomes possible to further reduce the size and weight of the permanent magnet 13A.

[0051] In addition, in the rotating electric machine 1 of this embodiment, the radially inward extension lengths of the first flange 24 and the second flange 25 are set to be approximately the same. Therefore, one of the flanges with a longer extension length does not interfere with the flow of the rotating magnetic flux. Therefore, when the rotating electric machine 1 of this configuration is adopted, it is possible to more effectively utilize the magnetic force of the permanent magnet 13A.

[0052] Furthermore, in the rotating electric machine 1 of this embodiment, a third flange 40 that is thicker than the permanent magnet 13A is provided at the outer end of the second gap 22 on the side away from the magnetic pole center line op. Therefore, the length of the magnetic flux path between the outer end of the second gap 22 and the outer circumferential surface of the rotor core 12 (rotor 11) is increased, and the magnetic path resistance of the magnetic flux flowing through the magnetic flux path is increased. As a result, the magnetic flux is prevented from wandering around the outer end of the second gap 22. Therefore, when this configuration is adopted, it is possible to more effectively utilize the magnetic force of the permanent magnet 13A, and it is possible to further reduce the size and weight of the permanent magnet 13A.

[0053] <Second embodiment> FIG. 11 is a cross-sectional view similar to FIG. 5, showing an enlarged portion of the rotor 11 of this embodiment. The basic configuration of the rotating electric machine of this embodiment is almost the same as that of the first embodiment. However, while in the first embodiment, the first flange 24 of the first gap 21 and the second flange 25 of the second gap 22 extend only radially inward, the first flange 124 and the second flange 125 of this embodiment extend not only radially inward but also radially outward. In this embodiment, the radially inward extension length and the radially outward extension length of the first flange 124 and the second flange 125 are almost the same length.

[0054] FIG. 12 is a graph showing the torque change rate of a rotating electrical machine when the shapes of the ends (the ends facing the ribs 23) of the first gap 21 and the second gap 22 are changed. As shown in the figure, when the thickness of the ends of the first gap 21 and the second gap 22 is made thinner than the thickness of the permanent magnet 13A, the torque change rate increases in the negative direction approximately in proportion to the decrease in thickness, and when the thickness of the ends of the first gap 21 and the second gap 22 is made thicker than the thickness of the permanent magnet 13A, the torque change rate increases in the positive direction approximately in proportion to the increase in thickness. Furthermore, when the first flange 124 and the second flange 125 formed at each end of the first gap 21 and the second gap 22 are extended to both the radially inner and outer sides, the extension length of the rib 23 can be increased while suppressing an increase in the extension length per side.

[0055] The rotating electric machine of this embodiment has the same basic configuration as that of the first embodiment, and therefore can obtain the same basic effects as those of the first embodiment described above. In addition, in the rotating electric machine of this embodiment, since the first flange portion 124 and the second flange portion 125 extend on both the radially inner and outer sides, the extension length per side required to obtain the same magnetic flux leakage prevention effect can be shortened compared to when the first flange portion 124 and the second flange portion 125 extend only on one side, the radially inner or outer side.

[0056] <Third embodiment> FIG. 13 is a diagram showing a cross section perpendicular to the axial direction of the rotor 211 of this embodiment. In the rotating electric machine of this embodiment, the configuration of the first magnetic pole constituent portion 18F of each magnetic pole 18 is similar to that of the first embodiment, but the configuration of the second magnetic pole constituent portion 218S of each magnetic pole 18 is different from that of the first embodiment. The second magnetic pole constituent portion 218S of this embodiment has a configuration substantially similar to that of the first magnetic pole constituent portion 18F.

[0057] The second magnetic pole constituent portion 218S is disposed radially outwardly of and spaced apart from the first magnetic pole constituent portion 18F, and includes a magnet hole 30, a permanent magnet 13B, a first gap portion 31, a second gap portion 32, and a rib 33.

[0058] The magnet hole 30 extends so as to straddle the magnetic pole center line op (d-axis) in the circumferential direction. The magnet hole 30 is a hole that penetrates the rotor core 12 in the axial direction. The shape of the magnet hole 30 as viewed in the axial direction is an arc shape with the arc center at an arbitrary point radially outward from the outer circumferential surface of the rotor 211 on the magnetic pole center line op. Both ends of the magnet hole 30 in the extension direction are curved radially outward.

[0059] Permanent magnet 13B is formed in an arc shape when viewed in the axial direction, and is inserted and disposed in magnet hole 30 so as to straddle magnetic pole center line op. Permanent magnet 13B is disposed in the central region in the extension direction of magnet hole 30. Permanent magnet 13B is fixed to the inner circumferential surface of magnet hole 30 by press-fitting or adhesive.

[0060] The first gap 31 is a gap formed between each end of the magnet hole 30 on both sides in the extension direction and each end face of the permanent magnet 13B, and is provided so as to face both end faces in the extension direction of the permanent magnet 13B. The second gap 32 is a gap extending away from the magnet hole 30 on the extension of both ends of the magnet hole 30 in the extension direction. The second gap 32 is formed in an arc shape with the same radius as the first gap 31 and centered at the same arc center. The first gap 31 and the second gap 32 function as flux barriers that regulate the flow of magnetic flux on the outside of the extension direction of the permanent magnet 13B.

[0061] The ribs 33 are disposed between the first gap 31 and the second gap 32 on the left and right sides of the permanent magnet 13B. Each of the left and right ribs 33 extends approximately along a normal line centered on the arc center of the magnet hole 30 and the second gap 32. Each of the ribs 33 connects the radial outer region and the radial inner region of the first gap 31 and the second gap 32.

[0062] The opening angle θRib of the rib 23 with respect to the magnetic pole center line op is set so as to satisfy the formulas (1) and (2) described in the description of the first embodiment. However, in application of formulas (1) and (2) to the second magnetic pole configuration 218S, the definitions of the opening angles θMag, θRib, θ1, and θ2 are to be read as follows. [Opening angle θMag] The opening angle between the normal line passing through the outer end of the permanent magnet 13B away from the magnetic pole center line op and the magnetic pole center line op. [Opening angle θRib] The opening angle between the normal line passing through the outer end of the first gap 31 away from the magnetic pole center line op and the magnetic pole center line op. [Opening angle θ1] The opening angle between the normal line passing through the outer end of the second gap 32 away from the magnetic pole center line op and the magnetic pole center line op. [Opening angle θ2] The opening angle between the normal line passing through the midpoint between the outer end of the permanent magnet 13B on the side away from the magnetic pole center line op and the outer end of the second gap portion 32 on the side away from the magnetic pole center line op, and the magnetic pole center line op.

[0063] As described above, the rotating electric machine of this embodiment includes the first magnetic pole component 18F having the same configuration as in the first embodiment, and therefore can obtain the same basic effects as in the first embodiment described above. In addition, in the rotating electric machine of this embodiment, the second magnetic pole constituent portion 218S, which has approximately the same configuration as the first magnetic pole constituent portion 18F, is arranged radially outside each first magnetic pole constituent portion 18F, so that a greater rotational torque can be obtained by multiple magnetic poles (magnetic pole constituent portions) arranged radially.

[0064] <Fourth embodiment> FIG. 14 is a diagram showing a cross section perpendicular to the axial direction of the rotor 311 of this embodiment. The rotating electric machine of this embodiment includes a first magnetic pole component 18F similar to that of the first embodiment, but does not include the second magnetic pole component 18S of the first embodiment or the second magnetic pole component 218S of the third embodiment.

[0065] Although the rotating electric machine of this embodiment does not include the second magnetic pole constituent portions 18S, 218S, it does include the first magnetic pole constituent portion 18F, and therefore can obtain the same basic effects as those of the first embodiment described above.

[0066] <Fifth embodiment> FIG. 15 is a diagram showing a cross section perpendicular to the axial direction of rotor 411 of this embodiment. The basic configuration of the rotating electric machine of this embodiment is similar to that of the third embodiment shown in Fig. 13. That is, a first magnetic pole component 18F and a second magnetic pole component 218S having similar configurations are arranged in two layers in the radial direction of the rotor 411. 13, permanent magnets 13A and 13B each having a substantially arc-shaped shape when viewed in the axial direction are housed in the magnet hole 19 of the first magnetic pole component 18F and the magnet hole 30 of the second magnetic pole component 218S. In contrast, in the rotating electric machine of this embodiment, permanent magnets 413A and 413B each having a substantially rectangular shape when viewed in the axial direction are housed in the magnet hole 19 of the first magnetic pole component 18F and the magnet hole 30 of the second magnetic pole component 218S.

[0067] A pair of permanent magnets 413A, 413B is housed and arranged in each of the magnet holes 19, 30, and the permanent magnets 413A, 413B of each pair are arranged closely to each other with no gap between them.

[0068] The rotating electric machine of this embodiment has a basic configuration substantially similar to that of the third embodiment, and therefore can obtain the same basic effects as those of the third embodiment described above. In addition, in the rotating electric machine of this embodiment, the permanent magnets 413A, 413B housed and arranged in each magnet hole 19, 30 are configured from a pair of divided pieces that are substantially rectangular when viewed in the axial direction, so that the shape of each permanent magnet 413A, 413B can be simplified and the manufacture of the permanent magnets 413A, 413B can be facilitated. In particular, when all the permanent magnets 413A, 413B are set to the same shape and size as in this embodiment, productivity is improved and it is possible to reduce product costs.

[0069] Sixth Embodiment FIG. 16 is a diagram showing a cross section perpendicular to the axial direction of rotor 511 of this embodiment. The rotating electric machine of this embodiment has a configuration similar to that of the fifth embodiment, but differs from that of the fifth embodiment in that the permanent magnet 513A housed in the magnet hole 19 of the first magnetic pole component 18F is composed of three divided pieces each having an approximately rectangular shape when viewed in the axial direction. Three permanent magnets 513A of the same shape and size are used. The three divided pieces of the permanent magnet 513A are arranged such that the central one straddles the magnetic pole center line op.

[0070] The rotating electric machine of this embodiment can obtain the same effects as the fifth embodiment, and in addition, the central permanent magnet 513A (central divided piece) housed and arranged in the magnet hole 19 is arranged straddling the magnetic pole center line op, and the three permanent magnets 513A are housed in the magnet hole 19 so as to form a smooth arc. This makes it possible to more effectively utilize the magnet magnetic flux and rotating magnetic flux without loss.

[0071] Seventh embodiment FIG. 17 is an enlarged cross-sectional view of a portion of the rotor 611 of this embodiment. The rotating electric machine of this embodiment differs from the other embodiments described above in the shape of the magnet hole 619 including the first gap portion 621 and the shape of the second gap portion 622 arranged outside the first gap portion 621 in the extension direction.

[0072] The magnet hole 619 extends across the magnetic pole center line op in the circumferential direction, and is generally V-shaped when viewed in the axial direction, opening radially outward. The magnet hole 619 has inclined hole components 619a, 619b of a constant width that extend left and right with the magnetic pole center line op as the center, inclining radially outward. Each hole component 619a, 619b accommodates and disposes a permanent magnet 413A that is generally rectangular when viewed in the axial direction. A gap is provided between the end of each hole component 619a, 619b in the extending direction and the permanent magnet 413A, and the gap is defined as a first gap portion 621. To be precise, magnet hole 619 in this embodiment is generally V-shaped when viewed in the axial direction, but it can also be said to be generally arc-shaped with both ends in the extension direction approaching the outer circumferential edge of rotor 611.

[0073] The second gap 622 extends linearly on the extension of the end of each hole forming portion 619a, 619b in the extension direction at the same angle as the inclination angle of each hole forming portion 619a, 619b. The second gap 622 is provided at a predetermined distance from the adjacent first gap 621. A rib 23 is provided between the first gap 621 and the second gap 622.

[0074] The rotating motor of this embodiment differs from the other embodiments described above in the shape of the magnet hole 619 including the first gap portion 621 and the shape of the second gap portion 622, but the basic configuration itself remains unchanged, so that the same basic effects as those of the other embodiments described above can be obtained.

[0075] The present invention is not limited to the above-described embodiment, and various design modifications are possible without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0076] 1...Rotary electric machine 10…Stator 11,211,311,411,511,611…Rotor 13A,13B,413A,413B,513A...Permanent magnet 18...Magnetic pole 19,30,619…Magnetic hole 21,31,621...first cavity 22,32,622…Second cavity 23,33…Ribs 24,124…First flange 25,125…Second flange 40…Third flange nm,nr,ns,ni…normal op…Magnetic pole center line

Claims

1. An annular stator; a rotor that is rotatably disposed radially inside the stator and has a plurality of magnetic poles spaced apart from one another in a circumferential direction; The magnetic poles of the rotor are a magnet hole extending across a magnetic pole center line along a radial direction of the rotor in a circumferential direction and formed in a substantially arc-shaped shape when viewed in the axial direction such that both ends in the extending direction are close to an outer peripheral edge portion of the rotor; A permanent magnet is inserted into the magnet hole; a first gap portion formed between the permanent magnet and each end portion of the magnet hole in the extending direction; a second gap portion extending along extensions of both ends of the magnet hole in a direction in which the magnet hole extends and spaced apart from the magnet hole; a rib disposed between the first gap and the second gap and connecting an outer region and an inner region in a radial direction of the first gap and the second gap, The opening angle between the normal line passing through the outer end of the permanent magnet on the side away from the magnetic pole center line and the magnetic pole center line is θMag, an opening angle between a normal line passing through an outer end portion of the first gap portion away from the magnetic pole center line and the magnetic pole center line is defined as θRib; an opening angle between a normal line passing through an outer end portion of the second gap portion away from the magnetic pole center line and the magnetic pole center line is defined as θ1; When an opening angle between a normal line passing through a middle position between an outer end of the permanent magnet on a side away from the magnetic pole center line and an outer end of the second gap on a side away from the magnetic pole center line and the magnetic pole center line is defined as θ2, A rotating electric machine, characterized in that the opening angle θRib is set so as to satisfy the following expressions (1) and (2). θ2=(θ1+θMag) / 2…(1) θRib<θ2 ... (2)

2. The first gap portion includes a first flange portion at an end portion facing the rib, the first flange portion being thicker than the permanent magnet, 2. The rotating electric machine according to claim 1, wherein the second gap portion is provided with a second flange portion, the second flange portion being thicker than the permanent magnet, at an end portion facing the rib.

3. 3. The rotating electric machine according to claim 2, wherein the first flange portion and the second flange portion have substantially the same length of extension toward the inside in the radial direction of the rotor.

4. 3. The rotating electric machine according to claim 2, wherein the first flange portion and the second flange portion extend radially inward and outward, respectively, of the rotor.

5. 2 . The rotating electric machine according to claim 1 , wherein the second gap portion has a third flange portion at an outer end portion away from the magnetic pole center line, the third flange portion being thicker than the permanent magnet.

6. 2. The rotating electric machine according to claim 1, wherein the magnetic pole components, including the magnet hole, the permanent magnet, the first gap, the second gap, and the rib, are arranged in multiple layers in the radial direction.

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