Rotor for a rotating electric machine

Abstract

A rotor for a rotating electric machine includes a rotor core (32) having first magnet holes (321) and second magnet holes (322) formed on each of a plurality of magnetic poles; a plurality of permanent magnets (61, 62) disposed in the first magnet holes and the second magnet holes, forming the plurality of magnetic poles; a first portion (3211) extending radially outward from the first magnet holes; a second portion (3212) extending between the first magnet holes and the second magnet holes and to an outer circumferential surface of the rotor core; a third portion (3213) extending radially inward from the second magnet holes and to the outer circumferential surface of the rotor core; a first bridge portion (41) connecting the second portion and the first portion and forming a portion of the outer circumferential surface of the rotor core; and a second bridge portion (42) connecting the third portion and the second portion and forming a portion of the outer circumferential surface of the rotor core, the first bridge portion being disposed radially inward from the second bridge portion.

Description

Technical Field

[0001] This invention relates to rotors for rotary electric machines. Background Technology

[0002] There is a known technology that has a rotor core with radially inner and radially outer magnet holes formed relative to each magnetic pole, which enlarges the q-axis magnetic circuit inlet and outlet portions between the radially inner and radially outer magnet holes.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2012-161226

[0004] However, in many cases, the rotor core, with its radially inner and radially outer magnetic holes forming relative to the magnetic poles, forms bridging sections connecting the various parts separated by these magnetic holes. These bridging sections cause problems such as magnetic flux leakage (and consequently, a reduction in torque). Therefore, from the viewpoint of reducing these problems, it is preferable to reduce the width of the bridging section. However, reducing the width of the bridging section can lead to stress problems. Summary of the Invention

[0005] Therefore, the object of the present invention is to reduce the stress at the bridging portion in a rotor for a rotating electric motor in which the rotor core has radially inner and radially outer magnet holes.

[0006] According to one aspect of the present invention, a rotor for a rotary electric motor is provided, which is a rotor for a rotary electric motor having a plurality of magnetic poles along the circumferential direction, comprising:

[0007] The rotor core has radially outer first magnet holes and radially inner second magnet holes formed relative to each magnetic pole; and

[0008] Multiple permanent magnets are disposed in the first magnet hole and the second magnet hole to form the multiple magnetic poles.

[0009] The rotor core includes: a first portion radially outward of the first magnet hole; a second portion extending circumferentially to the outer peripheral surface of the rotor core through the space between the first magnet hole and the second magnet hole; a third portion extending radially inward of the second magnet hole and circumferentially to the outer peripheral surface of the rotor core; a first bridging portion connecting the second portion and the first portion and forming a portion of the outer peripheral surface of the rotor core; and a second bridging portion connecting the third portion and the second portion and forming a portion of the outer peripheral surface of the rotor core.

[0010] The first bridging portion is located radially inward than the second bridging portion.

[0011] According to the present invention, in a rotor for a rotating electric motor in which the rotor core has radially inner magnet holes and radially outer magnet holes, the stress at the bridging portion can be reduced. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view that briefly illustrates the cross-sectional structure of a motor according to one embodiment.

[0013] Figure 2 It is a sectional view of the rotor (a sectional view of a plane perpendicular to the axial direction).

[0014] Figure 3 This is an enlarged cross-sectional view of a portion of the rotor in this embodiment.

[0015] Figure 4 This is an explanatory diagram of the rotor for the comparative example.

[0016] Figure 5A This is an explanatory diagram illustrating the stress reduction principle of this embodiment.

[0017] Figure 5B This is an illustration of the forces generated in the rotor of the comparative example, used as a comparison.

[0018] Figure 6 It is an enlarged cross-sectional view of a portion of the rotor of the first modified example.

[0019] Figure 7 It is an enlarged cross-sectional view of a portion of the rotor of the second variant. Detailed Implementation

[0020] The embodiments will now be described in detail with reference to the accompanying drawings.

[0021] Figure 1 This is a cross-sectional view that briefly illustrates the cross-sectional structure of a motor 1 (an example of a rotary electric machine) according to an embodiment. Figure 2 This is a sectional view of rotor 30 (a sectional view of a plane perpendicular to the axial direction). Furthermore, in Figure 2 In order to facilitate observation, for parts with the same attribute that have multiple instances, sometimes only a portion is labeled with a reference symbol.

[0022] exist Figure 1 The diagram shows the rotating shaft 12 of the motor 1. In the following description, axial direction refers to the direction in which the rotating shaft (center of rotation) 12 of the motor 1 extends, and radial direction refers to the radial direction centered on the rotating shaft 12. Therefore, radial outer side refers to the side away from the rotating shaft 12, and radial inner side refers to the side facing the rotating shaft 12. In addition, circumferential direction corresponds to the direction of rotation about the rotating shaft 12.

[0023] Motor 1 can be, for example, a vehicle drive motor used in hybrid vehicles or electric vehicles. However, motor 1 can also be a motor used for any other purpose.

[0024] Motor 1 is an internal rotor type, with stator 21 arranged radially outside rotor 30. The radially outside stator 21 is fixed to motor housing 10. Stator 21 has a stator core 211, for example, made of stacked steel plates of annular magnetic material, and a plurality of slots (not shown) on the radially inside stator core 211 are formed with coils 22 wound around it.

[0025] The rotor 30 is arranged on the radial inner side of the stator 21.

[0026] The rotor 30 includes: a rotor core 32; a rotor shaft 34; end plates 35A and 35B; and permanent magnets 61 and 62.

[0027] The rotor core 32 is fixed to the radially outer surface of the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor core 32 has a shaft hole 320 (see reference). Figure 2 The rotor shaft 34 is fitted into the shaft hole 320. The rotor core 32 can be fixed to the rotor shaft 34 by heat fitting, pressing, or similar methods. For example, the rotor core 32 can also be connected to the rotor shaft 34 by key or spline connection. The rotor shaft 34 is supported by the motor housing 10 via bearings 14a and 14b to enable rotation. Furthermore, the rotor shaft 34 constitutes the rotating shaft 12 of the motor 1.

[0028] The rotor core 32 is formed, for example, from a stack of steel plates containing annular magnetic materials. Permanent magnets 61 and 62 (see reference) are embedded inside the rotor core 32. Figure 2 That is, the rotor core 32 has axially penetrating magnet holes 321 and 322 (see reference). Figure 2 Permanent magnets 61 and 62 are inserted and fixed in the magnet holes 321 and 322. In addition, in a modified example, the rotor core 32 may also be formed from a compressed powder body in which magnetic powder is compressed and solidified.

[0029] The rotor core 32 is designed as a circle with a first radius r1, and the outer peripheral surface of the rotor core 32 includes a portion with the first radius r1 (the outer peripheral portion 328B, portion 328C, etc., described later). In this embodiment, the outer peripheral surface of the rotor core 32 has the first radius r1 except for the recess 70 described later. Furthermore, in a modified example, the circular shape of the rotor core 32 does not need to be a perfect circle; for example, it can also be a circle partially based on a cut.

[0030] like Figure 2 As shown, the rotor core 32, viewed axially, has a rotationally symmetrical shape about the rotation axis 12. Figure 2In the example shown, the rotor core 32 is in the form of overlapping permanent magnets 61 and 62 in each group when the rotating shaft 12 is rotated 45 degrees.

[0031] Multiple permanent magnets 61, 62 can be formed of neodymium or the like. In this embodiment, as an example, such as... Figure 2 As shown, when viewed axially, the multiple permanent magnets 61 and 62 are arranged in pairs in a generally V-shape (a generally V-shape with radially outward opening). In this case, shared magnetic poles are formed between pairs of permanent magnets 61 and between pairs of permanent magnets 62. Furthermore, the multiple permanent magnets 61 and 62 are arranged such that S poles and N poles alternate in the circumferential direction. Although the number of magnetic poles is eight in this embodiment, the actual number of magnetic poles is arbitrary.

[0032] In addition, Figure 1 The diagram shows a motor 1 with a specific construction, but the construction of motor 1 is not limited to the specific construction described above. For example, in... Figure 1 In the rotor shaft 34, although it is hollow, it can also be solid. Furthermore, in... Figure 1 In this configuration, end plates 35A and 35B have an outer diameter that is approximately the same as the outer diameter of the rotor core 32 and an inner diameter that is approximately the same as the inner diameter of the rotor core 32, but are not limited thereto. For example, end plates 35A and 35B may also have an outer diameter that is significantly smaller than the outer diameter of the rotor core 32.

[0033] Next, refer to Figure 3 The following diagrams will illustrate the rotor core 32 and the permanent magnets 61 and 62 in more detail. Although the structure of one magnetic pole will be described below, the structure of the other magnetic poles will be described in the same way.

[0034] Figure 3 yes Figure 2 The image shows a magnified view of a portion of a magnetic pole. The structure of a magnetic pole is essentially relative to the d-axis (in...). Figure 3 In Chinese, symmetry is indicated by the "d-axis". Below, the circumferential outer side refers to the side furthest from the d-axis.

[0035] A magnetic hole 321 (hereinafter referred to as "first magnetic hole 321") is formed on the radially outer side of the rotor core 32, and a magnetic hole 322 (hereinafter referred to as "second magnetic hole 322") is formed on the radially inner side.

[0036] The two first magnet holes 321 are arranged in a generally V-shape (a generally V-shape that opens radially outwards). However, in a modified example, the two first magnet holes 321 may also be arranged in a straight line, or only one first magnet hole 321 may be formed in a straight line (a straight line perpendicular to the d-axis). A permanent magnet 61 is disposed in each of the first magnet holes 321. Furthermore, a gap may be provided between the first magnet holes 321 and the permanent magnets 61 at both ends along the long side of the permanent magnet 61. This gap may be an empty space or filled with resin or the like.

[0037] The second magnet hole 322 is located radially inward than the first magnet hole 321. The two second magnet holes 322 are arranged in a pair to form a generally V-shape (a generally V-shape that opens radially outward). Furthermore, the circumferential extension of the pair of second magnet holes 322 is wider than the circumferential extension of the pair of first magnet holes 321. A permanent magnet 62 is provided in each of the second magnet holes 322. In addition, a gap may be provided between the second magnet hole 322 and the permanent magnet 62 at both ends in the long side direction of the permanent magnet 62. Furthermore, this gap may be an empty cavity or filled with resin or the like.

[0038] The rotor core 32 has three portions 3211, 3212, and 3213 (hereinafter also referred to as the first portion 3211, the second portion 3212, and the third portion 3213) that are connected radially only via bridging portions, through a first magnet hole 321 and a second magnet hole 322.

[0039] Specifically, the first portion 3211 extends radially outward beyond the first magnet hole 321. The first portion 3211 forms a portion 328A of the outer peripheral surface 328 of the rotor core 32.

[0040] The second portion 3212 extends circumferentially to the outer peripheral surface 328 of the rotor core 32, passing between the second magnet hole 322 and the first magnet hole 321. The second portion 3212 forms a portion 328B (hereinafter also referred to as "the outer peripheral surface 328B of the second portion 3212") of the outer peripheral surface 328 of the rotor core 32 on both circumferential sides of the first portion 3211. The second portion 3212 forms a magnetic circuit for the q-axis magnetic flux. Specifically, the q-axis magnetic flux flows from one end (one side of the outer peripheral surface 328B) of the second portion 3212 toward the other end (the other side of the outer peripheral surface 328B) and passes between the second magnet hole 322 and the first magnet hole 321.

[0041] The third portion 3213 extends radially inward and circumferentially to both sides of the outer peripheral surface 328 of the rotor core 32, which is closer to the second magnet hole 322. The third portion 3213 forms a portion 328C of the outer peripheral surface 328 of the rotor core 32 on both sides of the second portion 3212.

[0042] Furthermore, in this embodiment, the mass of the third part 3213 is significantly greater than the mass of the second part 3212, and the mass of the second part 3212 is significantly greater than the mass of the first part 3211.

[0043] In addition, the rotor core 32 has three parts 3211, 3212, and 3213, and thus has multiple bridging parts 41, 42, 43, and 44 connecting the three parts 3211, 3212, and 3213.

[0044] The bridging portion 41 (hereinafter referred to as "first bridging portion 41") supports the first portion 3211 radially outward relative to the second portion 3212. That is, the first bridging portion 41 connects the second portion 3212 and the first portion 3211 and extends circumferentially. The first bridging portions 41 are provided in pairs on both circumferential sides (circumferentially outward) of the first portion 3211.

[0045] The first bridging portion 41 extends between the outer peripheral surface 328 of the rotor core 32 and the first magnet hole 321. In this embodiment, as... Figure 3 As shown, the first bridging portion 41 extends radially inward beyond the outermost diameter position (the position of the first radius r1) of the rotor core 32. Specifically, the rotor core 32 has a radially inward recess 70 on its outer peripheral surface 328, and the first bridging portion 41 is located between this recess 70 and the first magnet hole 321. That is, the outer peripheral surface 328 of the rotor core 32 has a recess 70, which has a second radius r2 smaller than the first radius r1, and the outer peripheral surfaces of the first bridging portion 41 and the second radius r2 form part of the peripheral wall surface of the first magnet hole 321. The technical significance of such a configuration of the first bridging portion 41 will be described later. Furthermore, the second radius r2 of the recess 70 does not need to be constant, depending on... Figure 3 It can be seen that it can also be minimized near the center of the circumference and continuously vary along the circumference from the first radius r1.

[0046] The first bridging portion 41 extends circumferentially with its two ends wider than its central portion. That is, the width of the first bridging portion 41 increases at the connection position P1 with the first portion 3211 and at the connection position P2 with the second portion 3212. As a result, stress concentration that may occur at the two ends of the first bridging portion 41 can be reduced or eliminated.

[0047] Furthermore, when the width of the first bridging portion 41 widens at both ends in the circumferential direction, it is difficult to uniquely determine the boundary (connection position P1) between the first bridging portion 41 and the first portion 3211, and the boundary (connection position P2) between the first bridging portion 41 and the second portion 3212. In this specification, when the width of the first bridging portion 41 is taken as the dimension in the direction perpendicular to the extension direction of the first bridging portion 41, the positions where the width of the first bridging portion 41 is increased by more than 10% compared to the width of the central portion are designated as connection positions P1 and P2.

[0048] Furthermore, the first bridging portion 41 can also extend circumferentially with its center position in the width direction located on concentric circles, but as... Figure 3 As shown, it can also extend circumferentially in a different manner. Figure 3 In the example shown, the first bridging portion 41 extends circumferentially in a manner that gradually moves radially inward from the center position in the width direction toward the circumferentially outward.

[0049] The bridging portion 42 (hereinafter referred to as "second bridging portion 42") supports the second portion 3212 radially outward relative to the third portion 3213. That is, the second bridging portion 42 connects the third portion 3213 and the second portion 3212 and extends circumferentially. The second bridging portions 42 are provided in pairs on both circumferential sides (circumferentially outward) of the second portion 3212.

[0050] The second bridging portion 42 extends between the outer peripheral surface 328 of the rotor core 32 and the second magnet hole 322. In this embodiment, the second bridging portion 42 extends circumferentially outward from the first bridging portion 41. That is, the first bridging portion 41 is disposed radially inward from the second bridging portion 42. Here, the radial positional relationship of each bridging portion, such as the first bridging portion 41 and the second bridging portion 42, can be determined based on the radial positional relationship between their center positions, such as the center of gravity or centroid. For example, the radial positional relationship between the first bridging portion 41 and the second bridging portion 42 can be determined based on the relationship between the radius of the center positions between the connecting positions P1 and P2, and the radius of the center positions between the connecting positions P3 and P4, which will be described later.

[0051] The second bridging portion 42 forms a part of the outer peripheral surface 328 of the rotor core 32. Unlike the first bridging portion 41, the outer peripheral surface 328 formed by the second bridging portion 42 of the rotor core 32 does not have a recess like the recess 70. That is, the second bridging portion 42 forms the outermost diameter position (the position of the first radius r1) of the rotor core 32. Furthermore, in a modified example, the second bridging portion 42 may also be formed between the recess 70 and the second magnet hole 322. However, in this case, the recess is formed as a radially shallower recess than the recess 70. That is, the outermost diameter position of the second bridging portion 42 is radially outward than the outermost diameter position of the first bridging portion 41.

[0052] In addition, Figure 3 In the example shown, the width of the second bridging portion 42 is approximately constant, extending circumferentially with its center position in the width direction located on concentric circles, but it is not limited to this. Furthermore, in Figure 3 In the example shown, the second bridging portion 42 extends circumferentially with its two ends wider than its central portion. Specifically, the second bridging portion 42 widens at the connection point P3 with the second portion 3212 and at the connection point P4 with the third portion 3213. This reduces or eliminates stress concentrations that may occur at the two ends of the second bridging portion 42. Furthermore, in this embodiment, the radially outer side surface of the second bridging portion 42 is formed by an outer peripheral surface 328 without recesses, so the second bridging portion 42 widens in such a way that only the radially inner side surface (the wall surface of the second magnet hole 322) moves radially inward.

[0053] The bridging portion 43 (hereinafter referred to as "first central bridging portion 43") supports the first portion 3211 on the d-axis relative to the second portion 3212.

[0054] The bridging portion 44 (hereinafter referred to as "second center bridging portion 44") supports the second portion 3212 on the d-axis relative to the third portion 3213. Furthermore, the width of the second center bridging portion 44 may be wider than the width of the first center bridging portion 43.

[0055] Next, refer to Figure 4 , Figure 5A as well as Figure 5B The effects of the rotor 30 in this embodiment will be explained.

[0056] Figure 4 This is an explanatory diagram of the rotor 30′ of the comparative example, which is... Figure 3 Comparative sectional views. Figure 5A This is an explanatory diagram of the forces generated in the rotor 30 of this embodiment, and an explanatory diagram of the stress reduction principle. Figure 5B This is an explanatory diagram showing the forces generated in the rotor 30′ of the comparative example, used as a comparison.

[0057] The rotor 30′ of the comparative example differs from the rotor 30 of this embodiment in that the rotor core 32 is replaced by the rotor core 32′.

[0058] The difference between the rotor core 32' in the comparative example and the rotor core 32 of this embodiment is that the first magnet hole 321 is replaced by a first magnet hole 321', and the first bridging portion 41 is replaced by a first bridging portion 41'. In the case of the comparative example, the first bridging portion 41' is different from the first bridging portion 41 of this embodiment, such as... Figure 4 As shown, it extends to the outermost diameter position of the rotor core 32.

[0059] However, when rotor 30 (and rotor 30′) rotates, a radially outward force, i.e., centrifugal force (refer to arrow R0), acts on rotor 30. If such a centrifugal force is generated, the first bridging portion 41 and the first central bridging portion 43 overcome the centrifugal force corresponding to the mass of the first portion 3211 and the permanent magnet 61, supporting the first portion 3211 relative to the second portion 3212. Furthermore, the second bridging portion 42 and the second central bridging portion 44 overcome the centrifugal force corresponding to the mass of the first portion 3211, the permanent magnet 61, the second portion 3212, and the permanent magnet 62, supporting the second portion 3212 relative to the third portion 3213. Moreover, the greater the mass, the greater the centrifugal force; therefore, the centrifugal force acting on the second bridging portion 42 and the second central bridging portion 44 is greater than the centrifugal force acting on the first bridging portion 41 and the first central bridging portion 43. Therefore, relatively large stresses tend to be generated at and near the two ends of the second bridging portion 42 (connection positions P3, P4).

[0060] Regarding this point, according to this embodiment, as described above, since the first bridging portion 41 is located radially inward from the outermost diameter position of the rotor core 32, the stress on the second bridging portion 42 (e.g., the stress that may be generated at or near the two ends of the second bridging portion 42) can be reduced when centrifugal force is generated.

[0061] Specifically, in the case of the comparative example, such as Figure 5B As illustrated, if the first portion 3211 and the permanent magnet 61 are subjected to centrifugal force radially outward, a force F1 pulling along the d-axis is generated at the end of the second portion 3212 of the first bridging portion 41'. This force F1 acts at the same outermost diameter position as the second bridging portion 42, thus similarly exerting a force F2 pulling along the d-axis on the second bridging portion 42. Consequently, the second bridging portion 42 deforms in a bending manner due to the force F1, easily leading to stress concentration.

[0062] In contrast, according to this embodiment, as Figure 5AAs schematically shown, if the first portion 3211 and the permanent magnet 61 are subjected to centrifugal force radially outward, a force F3 pulling inward along the d-axis is generated at the end of the second portion 3212 of the first bridging portion 41. However, unlike the first bridging portion 41' in the comparative example, the end of the second portion 3212 of the first bridging portion 41 is located radially inward beyond the outermost diameter position, so the force F3 becomes a component of the force pulling radially inward more than the second bridging portion 42. Due to this change in the orientation of the force F3 (from the change in the orientation of the force F1), the orientation of the force F4 acting on the second bridging portion 42 changes from the orientation of the force F2 in the comparative example. Specifically, in the comparative example... Figure 5B It can be seen that the radial component (radial outward component) along the force F4 is reduced. As a result, the second bridging portion 42 is less prone to bending deformation. That is, the bending of the second bridging portion 42 is mitigated. Consequently, when centrifugal force is generated, the stress on the second bridging portion 42 (e.g., the stress that may be generated at or near the two ends of the second bridging portion 42) can be reduced.

[0063] Thus, according to this embodiment, as described above, the first bridging portion 41 extends radially inward beyond the outermost diameter position of the rotor core 32, thereby mitigating the bending of the second bridging portion 42 when centrifugal force is generated. As a result, the stress on the second bridging portion 42 can be reduced when centrifugal force is generated.

[0064] In addition, according to Figure 5A It can be seen that the end of the second part 3212 side of the first bridging part 41 (refer to) Figure 3 Although the connection position P2 is located radially inward than the outermost diameter position of the rotor core 32, it helps to reduce the stress on the second bridging portion 42. More essentially, the end of the second portion 3212 side of the first bridging portion 41 (refer to...) Figure 3 The connection position P2) is located at the end of the second portion 3212 of the second bridging portion 42 (refer to...). Figure 3 The connection position P3) is radially inward, which helps reduce the stress on the second bridging portion 42. Therefore, when the above positional relationship is achieved, even with... Figure 3 Even with slightly different specific constructions, the same effect can be achieved. For example, although not shown, the end portion 3211 on the first part of the first bridging portion 41 (see reference) Figure 3 The connection position P1 can also be located in a position greater than... Figure 3 It can be located on the radially outer side, for example, at the outermost diameter position.

[0065] Next, refer to Figure 6 as well as Figure 7Various modifications to this embodiment will be described. Furthermore, in the following descriptions of these modifications, sometimes structures that are substantially the same as those in the above embodiment (e.g., structural members that differ only slightly in shape, orientation, or position) are used. Figure 6 as well as Figure 7 The same reference symbols are marked in the text and the explanation is omitted.

[0066] Figure 6 It is an enlarged cross-sectional view of a portion of the rotor 30A of the first modified example. Figure 6 With the previous Figure 3 Similarly, although the structure of one magnetic pole is shown, the structures of the other magnetic poles can also be the same. Furthermore, the rotor 30A of the first modified example is the same as the rotor 30 of the above embodiment, and the structure of one magnetic pole is also symmetrical with respect to the d-axis.

[0067] The rotor 30A of the first variant differs from the rotor 30 of the above embodiment in that the rotor core 32 is replaced by the rotor core 32A, and the two permanent magnets 61 are replaced by a single permanent magnet 61A.

[0068] The rotor core 32A differs from the rotor 30 in that the two first magnet holes 321 are replaced by a single first magnet hole 321A, and an axially penetrating hole 323 is provided. Furthermore, while the rotor core 32A replaces the two first magnet holes 321 with a single first magnet hole 321A, it lacks a first central bridging portion 43.

[0069] The first magnet hole 321A extends in a straight line in the circumferential tangential direction (the direction perpendicular to the d-axis). In this case, the first magnet hole 321A also cooperates with the recess 70 to form the first portion 3211. A permanent magnet 61A is provided in the first magnet hole 321A. The permanent magnet 61A also extends in the circumferential tangential direction. Furthermore, in this case, the permanent magnet 61A is not V-shaped.

[0070] A hole 323 is disposed between a pair of second magnet holes 322. In this case, the second portion 3212 extends circumferentially to the outer peripheral surface 328 of the rotor core 32 through the space between the hole 323 and the first magnet hole 321A, and between the second magnet hole 322 and the first magnet hole 321A. Furthermore, due to the presence of the hole 323, two second central bridging portions 44A are formed on both circumferential sides of the hole 323 (see reference). Figure 6 Parts 441 and 442).

[0071] According to this first modification, a first bridging portion 41 is provided radially inward from the outermost diameter position of the rotor core 32, thereby achieving the same effect as in the above embodiment. Furthermore, in this first modification, the various modifications described in the above embodiments can also be applied.

[0072] Figure 7 This is an enlarged cross-sectional view of a portion of the rotor 30B of the second variant. Figure 7 With the previous Figure 3 Similarly, although the structure of one magnetic pole is shown, the structures of the other magnetic poles can also be the same. Furthermore, the rotor 30B of the second variation is the same as the rotor 30 of the above embodiment, and the structure of one magnetic pole is also symmetrical with respect to the d-axis.

[0073] The rotor core 32B differs from the rotor 30 in that the two first magnet holes 321 are replaced by a single first magnet hole 321B, the two second magnet holes 322 are replaced by a single second magnet hole 322B, and a hole 324 is provided. Furthermore, while the rotor core 32B replaces the two first magnet holes 321 with a single first magnet hole 321B, it lacks a first central bridging portion 43.

[0074] The first magnet hole 321B is the same as the first magnet hole 321A in the first modified example described above, extending in a circumferential tangential direction. In this case, the first magnet hole 321B also cooperates with the recess 70 to form the first portion 3211. A permanent magnet 61B is provided in the first magnet hole 321B. The permanent magnet 61B also extends in a circumferential tangential direction. Furthermore, in this case, the permanent magnet 61B is not V-shaped.

[0075] The second magnet hole 322B extends along the circumferential tangential direction. Furthermore, the second magnet hole 322B is positioned radially inward compared to the first magnet hole 321B, as is the case in the above embodiment and the first modified example.

[0076] A permanent magnet 62B is provided in the second magnet hole 322B. Furthermore, in this case, the permanent magnet 62B is not V-shaped.

[0077] Holes 324 are provided in pairs on both circumferential sides of the second magnet hole 322B. In this case, the second portion 3212 extends circumferentially to the outer circumferential surface 328 of the rotor core 32 through the spaces between each hole 324 and the first magnet hole 321B, and between the second magnet hole 322B and the first magnet hole 321B. Furthermore, since the holes 324 are provided on both circumferential sides of the second magnet hole 322B, second central bridging portions 44B are formed on both circumferential sides of the second magnet hole 322B (see reference). Figure 7 Parts 441B and 442B).

[0078] According to this second modification, a first bridging portion 41 is provided radially inward at a position greater than the outermost diameter of the rotor core 32, thereby achieving the same effect as in the above embodiment. Furthermore, in this second modification, various modifications of the above embodiment can also be applied.

[0079] While the embodiments have been described in detail above, they are not limited to specific embodiments. Various modifications and alterations can be made within the scope of the technical solutions described. In addition, all or more structural components of the above embodiments can be combined.

[0080] Explanation of reference numerals in the attached figures

[0081] 1…Motor (rotary motor), 30, 30A, 30B…Rotor, 32, 32A, 32B…Rotor core, 321, 321A, 321B…First magnet hole, 322, 322B…Second magnet hole, 61, 61A, 61B, 62B, 62, 62B…Permanent magnet, 3211…First part, 3212…Second part, 3213…Third part, 328…Outer peripheral surface, 41…First bridging part, 42…Second bridging part.

Claims

1. A rotor for a rotating electric motor, comprising having multiple magnetic poles along the circumferential direction, and comprising: The rotor core has radially outer first magnet holes and radially inner second magnet holes formed relative to each magnetic pole; and Multiple permanent magnets are disposed in the first magnet hole and the second magnet hole to form the multiple magnetic poles. The rotor core includes: a first portion radially outward of the first magnet hole; a second portion extending circumferentially to the outer peripheral surface of the rotor core through the space between the first magnet hole and the second magnet hole; a third portion extending circumferentially to the outer peripheral surface of the rotor core through the radially inward of the second magnet hole; a first bridging portion connecting the second portion and the first portion and forming a portion of the outer peripheral surface of the rotor core; a second bridging portion connecting the third portion and the second portion and forming a portion of the outer peripheral surface of the rotor core; a first central bridging portion supporting the first portion radially relative to the second portion of the rotor core; and a second central bridging portion supporting the second portion radially relative to the third portion of the rotor core. The first bridging portion is located radially inward than the second bridging portion, and the width of the second central bridging portion is wider than the width of the first central bridging portion.

2. The rotor for a rotary electric machine according to claim 1, wherein, The rotor core is designed as a circle with a first radius, and the outer circumferential surface of the rotor core includes a portion having the first radius. The second bridging portion forms part of the outer circumferential surface of the first radius of the rotor core.

3. The rotor for a rotary electric motor according to claim 2, wherein, The outer circumferential surface of the aforementioned rotor core also includes a recess having a second radius smaller than the first radius. The first bridging portion is located between the recess and the first magnet hole.

4. The rotor for a rotating electric motor according to any one of claims 1 to 3, wherein, The aforementioned first bridging portion is arranged in pairs on both sides of the aforementioned first part, with each of the aforementioned plurality of magnetic poles as a unit. The aforementioned second bridging portion is arranged in pairs on both sides of the aforementioned second part, with each of the aforementioned plurality of magnetic poles as a unit.

5. The rotor for a rotating electric machine according to any one of claims 1 to 3, wherein, The aforementioned second magnet holes, taking each of the aforementioned plurality of magnetic poles as a unit, are arranged in pairs symmetrically with respect to a straight line parallel to the radial direction and passing through the rotation axis of the rotary motor, forming a V-shape that opens radially outward. The aforementioned first magnet hole, with each of the aforementioned plurality of magnetic poles as a unit, is arranged in pairs symmetrically with respect to the aforementioned straight line in a radially outward V-shape.

6. The rotor for a rotating electric motor according to claim 4, wherein, The aforementioned second magnet holes, taking each of the aforementioned plurality of magnetic poles as a unit, are arranged in pairs symmetrically with respect to a straight line parallel to the radial direction and passing through the rotation axis of the rotary motor, forming a V-shape that opens radially outward. The aforementioned first magnet hole, with each of the aforementioned plurality of magnetic poles as a unit, is arranged in pairs symmetrically with respect to the aforementioned straight line in a radially outward V-shape.

Images