Rotor for rotary electric machine

Abstract

A rotor for a rotary electric machine includes a rotor core, a first permanent magnet in a first magnet hole in a convex shape protruding radially inward on one side in a circumferential direction with respect to a d-axis, and a second permanent magnet in a second magnet hole in a radial inward direction with respect to one side in a circumferential direction with respect to the d-axis. The second magnet hole has a convex shape that protrudes inward in the radial direction of the iron core on one side in the circumferential direction with respect to the d-axis, and a portion of at least one of the first magnet hole and the second magnet hole that extends toward both sides in the circumferential direction with respect to the d-axis across the d-axis or through the d-axis has a convex shape that protrudes outward in the radial direction of the iron core when viewed in the axial direction. A curved portion is provided in a convex shape that protrudes inward in the radial direction of the iron core when viewed in the axial direction.

Description

Technical Field

[0001] The present disclosure relates to a rotor for a rotating electrical machine. Background Art

[0002] A two-layer configuration structure is known in which a plurality of permanent magnets are arranged in two layers in a rotor core.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2022-107370. Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] However, in the case of this two-layer configuration structure (similarly for a multi-layer configuration structure of three or more layers), in order to cope with an increase in centrifugal force accompanying high-speed rotation of the rotating electrical machine, the magnet holes are sometimes formed (or arranged) in a W shape centered on the d-axis when viewed axially. However, from the viewpoint of further optimizing the magnetic circuit and further reducing the centrifugal force, there is room for improvement in the details of the W-shaped configuration.

[0008] Therefore, in one aspect, an object of the present disclosure is to further optimize the magnetic circuit and further reduce the centrifugal force in a multi-layer configuration structure in which the magnet holes are W-shaped when viewed axially.

[0009] Means for Solving the Problems

[0010] In one aspect, there is provided a rotor for a rotating electrical machine, including: a rotor core having a first magnet hole formed symmetrically about the d-axis when viewed axially and a second magnet hole formed symmetrically about the d-axis when viewed axially, the second magnet hole including two or more hole portions in a circumferentially continuous state;

[0011] a first permanent magnet disposed in the first magnet hole; and

[0012] a second permanent magnet disposed in the second magnet hole,

[0013] The rotor core includes: a first portion located radially outside the first magnet hole and forming an outer peripheral surface of the rotor core; a second portion passing between the first magnet hole and the second magnet hole and extending to the outer peripheral surface of the rotor core on both circumferential sides; and a third portion passing through a position radially inside the second magnet hole and extending to the outer peripheral surface of the rotor core on both circumferential sides,

[0014] The first magnet hole has a convex shape that protrudes radially inward of the rotor core on one side in the circumferential direction with respect to the d-axis.

[0015] The second magnet hole has a convex shape that protrudes radially inward of the rotor core on one side in the circumferential direction with respect to the d-axis.

[0016] In at least one of the first magnet hole and the second magnet hole, a hole portion that extends to both sides in the circumferential direction with respect to the d-axis while sandwiching the d-axis or passing through the d-axis has a convex shape that protrudes radially outward of the rotor core when viewed axially, and the convex shape that protrudes radially inward of the rotor core when viewed axially has a bent portion.

[0017] Advantages of the Invention

[0018] In one aspect, according to the present disclosure, in a multi-layer configuration structure in which the magnet holes have a W-shaped cross-section when viewed axially, further optimization of the magnetic circuit and further reduction of the centrifugal force can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view schematically showing a cross-sectional structure of a motor according to an embodiment.

[0020] Figure 2 is a cross-sectional view of the rotor.

[0021] Figure 3 is Figure 2 an enlarged view of a part related to one magnetic pole shown.

[0022] Figure 4 is Figure 3 a further enlarged view of a part (one side in the circumferential direction with respect to the d-axis) of.

[0023] Figure 5A is a diagram showing the structure of a comparative example.

[0024] Figure 5B is a diagram showing the structure of another comparative example.

[0025] Figure 6 is by comparing with Figure 5A a part of a diagram for explaining the effects of this embodiment by comparison with a comparative example of.

[0026] Figure 7 is a top view showing a part of the rotor core according to Embodiment 2.

[0027] Figure 8 is a top view showing a part of the rotor core according to Embodiment 3.

[0028] Figure 9It is a top view showing a part of the rotor core related to Embodiment 4.

[0029] Figure 10 It is a top view showing a part of the rotor core related to Embodiment 5. Detailed implementation manners

[0030] Hereinafter, each embodiment will be described in detail with reference to the drawings. It should be noted that the dimensional ratios of the drawings are only examples and are not limited thereto. In addition, for the sake of convenience of explanation, the shapes in the drawings may sometimes be locally exaggerated.

[0031] Figure 1 It is a cross-sectional view schematically showing the cross-sectional structure of the motor 1 related to one embodiment. Figure 2 It is a cross-sectional view of the rotor 30 (a cross-sectional view based on a plane perpendicular to the axial direction). In addition, in Figure 2 etc., for the sake of easy observation, sometimes only a part of the parts having the same attribute existing in plural numbers are labeled with reference signs.

[0032] In Figure 1 the rotation shaft 12 of the motor 1 is illustrated. In the following description, the axial direction refers to the direction in which the rotation shaft (rotation center) 12 of the motor 1 extends, and the radial direction refers to the radial direction centered on the rotation shaft 12. Therefore, the outer side in the radial direction refers to the side away from the rotation shaft 12, and the inner side in the radial direction refers to the side toward the rotation shaft 12. In addition, the circumferential direction corresponds to the rotation direction around the rotation shaft 12.

[0033] The motor 1 can be, for example, a motor for vehicle drive used in a hybrid vehicle or an electric vehicle. However, the motor 1 can also be used for any other purpose.

[0034] The motor 1 is an inner rotor type, and the stator 21 is provided around the outer side in the radial direction of the rotor 30. The outer side in the radial direction of the stator 21 is fixed to the motor housing 10. The stator 21 has, for example, a stator core 211 formed of a laminated steel sheet of an annular magnetic body, and a plurality of slots (not shown) for winding the coil 212 are formed on the inner side in the radial direction of the stator core 211.

[0035] The rotor 30 is disposed on the inner side in the radial direction of the stator 21.

[0036] The rotor 30 includes a rotor core 32, a rotor shaft 34, end plates 35A and 35B, and permanent magnets 61 and 62.

[0037] The rotor core 32 is fixed to the surface on the outer side in the radial direction of the rotor shaft 34 and rotates integrally with the rotor shaft 34. The rotor core 32 has a shaft hole 320 (refer to Figure 2) A rotor shaft 34 is fitted in the shaft hole 320. The rotor core 32 can be fixed to the rotor shaft 34 by shrink fitting, press fitting, or a similar method. For example, the rotor core 32 can also be coupled to the rotor shaft 34 by key coupling or spline coupling. The rotor shaft 34 is rotatably supported by the motor housing 10 via bearings 14a and 14b. In addition, the rotor shaft 34 defines the rotation axis 12 of the motor 1.

[0038] The rotor core 32 is formed, for example, by stacking steel plates of a circular ring-shaped magnetic material. Permanent magnets 61 and 62 are embedded inside the rotor core 32 (see Figure 2 ). That is, the rotor core 32 has magnet holes 321 and 322 that penetrate in the axial direction (see Figure 2 ), and the 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 can also be formed by a powder compact obtained by compressing and solidifying magnetic powder.

[0039] When viewed axially, the rotor core 32 has a circular ring shape, and the outer peripheral surface 328 of the rotor core 32 includes a portion having a fixed outer diameter. In addition, in a modified example, the circular shape of the outer shape of the rotor core 32 does not need to be a perfect circle, and for example, it can also be a circular shape having a cut (such as a welding groove, etc.) in a part.

[0040] As Figure 2 shown, when viewed axially, the rotor core 32 has a rotationally symmetric shape centered on the rotation axis 12. In the example shown in Figure 2 , the rotor core 32 is in a state where the permanent magnets 61 and 62 of each group overlap every time it rotates 45 degrees around the rotation axis 12.

[0041] The plurality of permanent magnets 61 and 62 can be sintered magnets or can be formed of a material for bonded magnets (hereinafter, also simply referred to as "bonded magnet material") in which magnetic powder and a binder material are mixed. In the present embodiment, as an example, as Figure 2 shown, when viewed axially, the plurality of permanent magnets 61 and 62 are respectively arranged in pairs. In this case, a common magnetic pole is formed between the paired permanent magnets 61 and between the paired permanent magnets 62. In addition, the plurality of permanent magnets 61 and 62 are arranged such that the S pole and the N pole alternate in the circumferential direction. In addition, in the present embodiment, the number of magnetic poles is 8, but the number of magnetic poles is arbitrary.

[0042] In addition, in Figure 1 , a motor 1 having a specific structure is shown, but the structure of the motor 1 is not limited to this specific structure. For example, in Figure 1 , the rotor shaft 34 is hollow, but it can also be solid.

[0043] Next, with reference to Figure 3 the following figures, the rotor core 32 and the permanent magnets 61 and 62 will be described in more detail. Hereinafter, the structure related to one magnetic pole will be described, but the structures related to the other magnetic poles may be the same.

[0044] Figure 3 is Figure 2 an enlarged view of a part related to one magnetic pole shown. The structure related to one magnetic pole is substantially symmetric about the d-axis (expressed in English as "d-axis" in Figure 3 ). Hereinafter, the side far from the d-axis means the side away from the d-axis, and the side close to the d-axis means the side approaching the d-axis. In addition, both sides in the circumferential direction of the d-axis mean both sides in the circumferential direction sandwiching the d-axis, and mean both sides in the circumferential direction with the d-axis as the center. In addition, one side in the circumferential direction with respect to the d-axis means any one of both sides in the circumferential direction of the d-axis.

[0045] In the rotor core 32, a magnet hole 321 (hereinafter referred to as "first magnet hole 321") and a magnet hole 322 (hereinafter referred to as "second magnet hole 322") are formed. The first magnet hole 321 includes two or more hole portions continuously in the circumferential direction symmetrically about the d-axis when viewed axially, and the second magnet hole 322 includes two or more hole portions continuously in the circumferential direction symmetrically about the d-axis when viewed axially. The first magnet hole 321 includes two or more hole portions continuously in the circumferential direction at a position radially outside the second magnet hole 322 via a second portion 3212 described later. It should be noted that the "continuous state" means a continuous manner via various bridges described later.

[0046] The first magnet hole 321 includes a hole portion on the d-axis and two hole portions located in pairs on both sides in the circumferential direction of the d-axis. However, in a modified example, the hole portion on the d-axis of the first magnet hole 321 may also be separated on both sides in the circumferential direction of the d-axis. Alternatively, the first magnet hole 321 may not form a hole portion on the d-axis and may only include hole portions on both sides in the circumferential direction of the d-axis (refer to Figure 9 ). Alternatively, the first magnet hole 321 may be formed by a collection of a plurality of small hole portions. In this case, the shape of the first magnet hole 321 corresponds to the shape (arrangement) of the collection of a plurality of small hole portions as a whole. A permanent magnet 61 is provided in each hole portion of the first magnet hole 321. At this time, the permanent magnet 61 can be arranged in the first magnet hole 321 without a gap, but a gap (magnetic flux barrier) can also be provided at both ends in the long side direction of the permanent magnet 61 between the first magnet hole 321 and the permanent magnet 61. In addition, this gap can be a cavity or can be filled with resin or the like. In addition, a plurality of permanent magnets 61 can also be arranged in one hole portion of the first magnet hole 321.

[0047] The second magnet hole 322 is provided at a position more radially inward than the first magnet hole 321. That is, the second magnet hole 322 is provided in a state facing the first magnet hole 321 from the radially inner side.

[0048] In the present embodiment, the second magnet hole 322 includes a total of four hole portions formed in pairs of two on both sides in the circumferential direction of the d-axis. That is, two hole portions are formed on one side of the d-axis in the circumferential direction of the second magnet hole 322, and two hole portions are formed on the other side of the d-axis in the circumferential direction. Thus, in the present embodiment, a total of four hole portions form the second magnet hole 322 for one magnetic pole. However, in a modified example, similar to the first magnet hole 321, the second magnet hole 322 may also be composed of a hole portion on the d-axis and two hole portions located on both sides in the circumferential direction of the d-axis. Alternatively, the second magnet hole 322 may also be formed by a collection of more small hole portions. In any case, the shape of the second magnet hole 322 corresponds to the shape (configuration) of the whole as a collection of a plurality of hole portions. Permanent magnets 62 are provided in each hole portion of the second magnet hole 322. At this time, the permanent magnets 62 can be arranged in the second magnet hole 322 without a gap, but a gap can also be provided at both ends in the long side direction of the permanent magnet 62 between the second magnet hole 322 and the permanent magnet 62. In addition, this gap can be a cavity or can be filled with resin or the like. Further, a plurality of permanent magnets 62 may also be arranged in one hole portion of the second magnet hole 322.

[0049] By having such first magnet holes 321 and second magnet holes 322, the rotor core 32 has three portions 3211, 3212, 3213 (hereinafter, also referred to as the first portion 3211, the second portion 3212, and the third portion 3213) connected only via bridges in the radial direction.

[0050] Specifically, the first portion 3211 extends more radially outward than the first magnet hole 321. The first portion 3211 forms a part of the outer peripheral surface 328 of the rotor core 32.

[0051] The second portion 3212 extends through between the second magnet hole 322 and the first magnet hole 321 and both sides in the circumferential direction to the outer peripheral surface 328 of the rotor core 32. The second portion 3212 forms a part of the outer peripheral surface 328 of the rotor core 32 on both sides in the circumferential direction of the first portion 3211. The second portion 3212 forms a magnetic path for the q-axis magnetic flux. Specifically, the q-axis magnetic flux flows from one end of the second portion 3212 toward the other end through between the second magnet hole 322 and the first magnet hole 321.

[0052] The third part 3213 passes through a position radially more inward than the second magnet hole 322 and extends to the outer peripheral surface 328 of the rotor core 32 on both circumferential sides. The third part 3213 forms a part of the outer peripheral surface 328 of the rotor core 32 on both circumferential sides of the second part 3212.

[0053] In addition, in the present embodiment, the mass of the third part 3213 can be 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.

[0054] Further, by having such three parts 3211, 3212, and 3213, the rotor core 32 has a plurality of bridges 41, 42, 43, 44, and 45 connecting the three parts 3211, 3212, and 3213.

[0055] The bridge 41 (hereinafter referred to as "first bridge 41") supports the first part 3211 on the second part 3212 on the radially outer side. That is, the first bridge 41 connects the second part 3212 and the first part 3211 and extends in the circumferential direction. The first bridge 41 is provided in pairs on both circumferential sides of the first part 3211.

[0056] The bridge 42 (hereinafter referred to as "second bridge 42") supports the second part 3212 on the third part 3213 on the radially outer side. That is, the second bridge 42 connects the third part 3213 and the second part 3212 and extends in the circumferential direction. The second bridge 42 is provided in pairs on both circumferential sides of the second part 3212.

[0057] The bridge 43 supports the first part 3211 on the second part 3212 at a position radially more inward than the first bridge 41. In Figure 3 the example shown, the bridge 43 is arranged in pairs on both circumferential sides of the d-axis.

[0058] The bridge 44 (hereinafter referred to as "center bridge 44") supports the second part 3212 on the third part 3213 on the d-axis.

[0059] The bridge 45 (hereinafter referred to as "intermediate bridge 45") supports the second part 3212 on the third part 3213 at a position radially more outward than the center bridge 44 and radially more inward than the second bridge 42.

[0060] Next, with reference to Figure 4 the following figures, further characteristic structures of the present embodiment will be described. Figure 4 is Figure 3 a further enlarged view of a part (one side in the circumferential direction with respect to the d-axis) and is a figure showing lines for explaining the shape characteristics. Figure 5A is a figure showing the structure of the rotor core 32' of the comparative example, Figure 5BIt is a diagram showing the structure of the rotor core 32” of another comparative example. Figure 6 It is a diagram that is part of explaining the effects of the present embodiment through comparison with a comparative example of Figure 5A . In Figure 4 and Figure 5A , the flow of the q-axis magnetic flux in each is schematically indicated by arrows M5 and M5'.

[0061] In the following description, unless otherwise specified, various configurations and forms refer to the configurations and forms when viewed along the axial direction.

[0062] In the present embodiment, the second magnet hole 322 has a W-shaped form centered on the d-axis. Specifically, the portion of the second magnet hole 322 closer to the d-axis side has a convex form that protrudes radially outward centered on the d-axis, and has a convex form that protrudes radially inward on one side in the circumferential direction of the d-axis. In the present embodiment, the portion closer to the d-axis side corresponds to the hole portions 322-1 on both circumferential sides provided with the center bridge 44 interposed therebetween. On one side in the circumferential direction of the d-axis, the portion having a convex form that protrudes radially inward corresponds to the hole portions 322-1 and 322-2 on both circumferential sides provided with one intermediate bridge 45 interposed therebetween.

[0063] In addition, when the portion of the second magnet hole 322 closer to the d-axis side has a convex form that protrudes radially outward centered on the d-axis, as Figure 4 shown, the angle α formed by the shape center line LN4 of the portion closer to the d-axis side and the d-axis is an acute angle on the radially inner side. In addition, as Figure 4 shown, when the portion of the second magnet hole 322 closer to the d-axis side has an arc form, the shape center line LN4 can be the tangential direction of the d-axis side end of the arc. In addition, when the portion on one side in the circumferential direction of the d-axis has a convex form that protrudes radially inward, as Figure 4 shown, on one side in the circumferential direction of the d-axis, the shape center line LN5 of the second magnet hole 322 as a whole has a convex form that protrudes radially inward.

[0064] Moreover, in the present embodiment, as Figure 4 shown, the convex form that protrudes radially inward has a bent portion (refer to R41, R42) having a center of curvature on the d-axis side (radially outer side). When the convex form that protrudes radially inward has a bent portion, on one side in the circumferential direction of the d-axis, the shape center line LN5 of the second magnet hole 322 as a whole has a bent portion having a center of curvature on the d-axis side (radially outer side). In addition, in Figure 4In the example shown, the second magnet hole 322 sandwiches the intermediate bridge 45 and has bent portions on both sides (refer to R41, R42), but it may also have a bent portion on only one side (R41 or R42). Additionally, the second magnet hole 322 does not need to be entirely a bent portion. For example, only the portion close to the intermediate bridge 45 may be set as the bent portion. Further, the radius of curvature of the bent portion may be constant or may vary within one bent portion.

[0065] Among them, in Figure 5A the comparative example shown, the second magnet hole 322' into which the permanent magnet 62' is inserted, similar to this embodiment, the hole portions 322'-1, 322'-2 are in a W-shaped form centered on the d-axis. However, different from this embodiment, the convex-shaped second magnet hole 322' does not have a bent portion. That is, the second magnet hole 322' is in a linear form. Additionally, in Figure 5B another comparative example shown, the hole portions 322''-1, 322''-2 of the second magnet hole 322'' into which the permanent magnet 62'' is inserted are not in a W-shaped form centered on the d-axis, but in a V-shaped form centered on the d-axis.

[0066] However, in Figure 5B the case of another comparative example shown, as Figure 5B schematically shown, since it does not have a convex-shaped form that protrudes radially outward centered on the d-axis, the magnetic path width L50 near the d-axis side is significantly larger than the magnetic path width L61 far from the d-axis side. In this case, the mass of the second part 3212'' becomes larger, and stress concentration in each bridge (especially the bridges 42'', 44'', 45'' between the second part 3212'' and the third part 3213) caused by centrifugal force tends to become significant.

[0067] Regarding this point, according to this embodiment ( Figure 5A the comparative example shown is the same), since the second magnet hole 322 is in a W-shaped form centered on the d-axis, the required magnetic path width L61 can be ensured, and the mass of the second part 3212 can be effectively reduced. Thereby, the stress in each bridge (especially the bridges 42, 44, 45 between the second part 3212 and the third part 3213) caused by centrifugal force can be effectively reduced.

[0068] On the other hand, in Figure 5A the comparative example shown, as Figure 6As shown by the comparison, since the second magnet hole 322’ has a linear shape, a portion that is significantly larger than the magnetic path width L50 (the portion of the magnetic path width L60’) is generated. Specifically, in the second portion 3212’, in the central portion of the side portion with respect to the d-axis (a convex shape protruding radially inward) in the W-shaped form of the second magnet hole 322’, a relatively large magnetic path width L60’ is generated. If such a relatively large magnetic path width L60’ is generated, correspondingly, the mass of the second portion 3212’ increases, and stress concentration in each bridge (especially the bridges 42’, 44’, 45’ between the second portion 3212’ and the third portion 3213) caused by centrifugal force is likely to become significant.

[0069] In contrast, according to this embodiment, as described above, the second magnet hole 322 has a bent portion (refer to R41, R42), so as Figure 6 shown, it is possible to eliminate or reduce the above-mentioned adverse conditions generated in the Figure 5A comparative example shown. Specifically, according to this embodiment, in the second portion 3212, it is possible to make the magnetic path width L60 generated in the central portion of the side portion with respect to the d-axis (a convex shape protruding radially inward) in the W-shaped form of the second magnet hole 322 significantly smaller than the magnetic path width L60’ of the comparative example. For example, according to this embodiment, it is possible to make the magnetic path width L60 substantially the same as the magnetic path width L61. As a result, according to this embodiment, it is possible to ensure the required magnetic path width (for example, a magnetic path width of L61 or more) within the entire range of the second portion 3212, and it is possible to effectively reduce the stress in each bridge 42, 44, 45 caused by centrifugal force.

[0070] In addition, according to this embodiment, since the first magnet hole 321 also has a W-shaped form, based on the same principle, it is possible to effectively reduce the stress in each bridge 41, 43 caused by centrifugal force. Furthermore, if the first magnet hole 321 has a W-shaped form, it is possible to reduce the mass of the first portion 3211, but on the other hand, the mass of the portion corresponding to the second portion 3212 is likely to increase. For example, in the Figure 5B another comparative example shown, since the first magnet hole 321” has a W-shaped form, the width (radial width) of the second portion 3212” on the d-axis correspondingly increases, and the mass of the second portion 3212” is likely to increase.

[0071] In response to this, according to this embodiment, since the second magnet hole 322 and the first magnet hole 321 together have a W-shaped form, it is possible to effectively reduce the mass of each of the first portion 3211 and the second portion 3212.

[0072] In addition, in the present embodiment, when the permanent magnets 61 and 62 are formed of a bonded magnet material, the permanent magnets 61 and 62 can also be filled in the first magnet hole 321 and the second magnet hole 322 without gaps respectively. In this case, since the amounts (volumes) occupied by the permanent magnets 61 and 62 in the first magnet hole 321 and the second magnet hole 322 are maximized respectively, the torque characteristics of the motor 1 can be improved. In addition, in this structure, the permanent magnets 61 and 62 respectively have a bent shape corresponding to the bent portions of the first magnet hole 321 and the second magnet hole 322. However, in a modified example, even when the permanent magnets 61 and 62 are formed of a bonded magnet material, a flux barrier (gap) can be set. In addition, either one of the permanent magnets 61 and 62 may be formed of a bonded magnet material. In addition, only a part of the permanent magnet 61 and / or a part of the permanent magnet 62 may be formed of a bonded magnet material.

[0073] Next, referring to Figure 7 the following figures, several other embodiments will be described. Hereinafter, the above-described embodiments such as Figure 2 and Figure 3 will be referred to as "Embodiment 1", and the differences from Embodiment 1 will be mainly described. Hereinafter, in other embodiments, for the constituent elements that can be the same as those in the above-described Embodiment 1, the same reference numerals may be used and the description may be omitted.

[0074] Figure 7 is a top view showing a part of the rotor core 32A of Embodiment 2. Figure 7 The part of the rotor core 32A shown is the same part as the part of the rotor core 32 of Figure 3 Embodiment 1 shown. The same applies to the Figures 8 - 10 referred to later.

[0075] The difference between the rotor core 32A of Embodiment 2 and the rotor core 32 of Embodiment 1 is that the first magnet hole 321 and the permanent magnet 61 are replaced with the first magnet hole 321A and the permanent magnet 61A.

[0076] The first magnet hole 321A of Embodiment 2 has the following differences from the first magnet hole 321 of Embodiment 1. The first magnet hole 321A has a W-shaped form similar to the first magnet hole 321 of Embodiment 1, but different from the first magnet hole 321 of Embodiment 1, the convex form protruding radially inward has a bent portion (refer to R71). In Figure 7In the example shown, among the three parts of the hole part 321A-2 on the d-axis of the first magnet hole 321A and the hole parts 321A-2 arranged separately on both sides of the d-axis, the hole part 321A-2 has a bent part having a center of curvature on the d-axis side (refer to R71). Further, in this case, the shape center line LN7 of the first magnet hole 321A as a whole also has the same bent part at the position corresponding to the bridge 43A.

[0077] In this case, the radius of curvature of the bent part (refer to R71) of the hole part 321A-2 can be smaller than the radius of curvature of the bent part (refer to R41, R42) of the second magnet hole 322. Thereby, the magnetic path width between the first magnet hole 321A and the second magnet hole 322 (that is, the magnetic path width L61A at the second part 3212A) can be made substantially constant as a whole.

[0078] The permanent magnet 61A of the second embodiment may have a bent shape corresponding to the shape of the first magnet hole 321A. The permanent magnet 61A may also be formed of a bonded magnet material. Further, in Figure 7 the example shown, the permanent magnet 61A is formed of a bonded magnet material and is filled in the first magnet hole 321A without a gap, but a magnetic flux barrier (gap) may also be set.

[0079] According to the second embodiment like this, the same effect as that of the first embodiment described above can also be obtained. That is, the magnetic path width L60A generated at the central part of the one-side part (the convex shape protruding radially inward) with respect to the d-axis in the W-shaped form of the second magnet hole 322 can be made significantly smaller than Figure 5A the magnetic path width L60' of the comparative example shown. As a result, according to the present embodiment, the required magnetic path width (for example, the magnetic path width equal to or more than the magnetic path width L61A) can be ensured in the entire second part 3212A, and the stress in each of the bridges 42, 44, 45 caused by the centrifugal force can be effectively reduced. Further, similarly, the mass of the first part 3211A can be reduced, and the stress in each of the bridges 41A, 43A caused by the centrifugal force can be effectively reduced.

[0080] Further, according to the second embodiment, the hole part 321A-1 on the d-axis of the first magnet hole 321A has a bent part having a center of curvature radially inward (refer to R72). Thereby, compared with the case where this bent part is linear, the required magnetic path width (for example, the magnetic path width equal to or more than the magnetic path width L61A) can be ensured, and the magnetic path width on the d-axis (refer to the magnetic path width L62A) can be reduced. Thereby, the mass of the second part 3212A can be reduced, and the stress in each of the bridges 42, 44, 45 caused by the centrifugal force can be more effectively reduced. Further, such an effect is the same for the first embodiment described above.

[0081] Figure 8 It is a top view showing a part of the rotor core 32B of Embodiment 3.

[0082] The difference between the rotor core 32B of Embodiment 3 and the rotor core 32 of Embodiment 1 is that the first magnet holes 321 and the permanent magnets 61 are replaced with the second magnet holes 321B and the permanent magnets 61B. Additionally, the difference between the rotor core 32B of Embodiment 3 and the rotor core 32 of Embodiment 1 is that the first magnet holes 322 and the permanent magnets 62 are replaced with the second magnet holes 322B and the permanent magnets 62B.

[0083] The first magnet holes 321B and the permanent magnets 61B of Embodiment 3 can be the same as the first magnet holes 321A and the permanent magnets 61A of Embodiment 2 described with reference to Figure 7 above.

[0084] The second magnet holes 322B of Embodiment 3 have the following differences with respect to the second magnet holes 322 of Embodiment 1. The difference between the second magnet holes 322B and the second magnet holes 322 of Embodiment 1 is that the part corresponding to the middle bridge 45 is connected and the overall shape is the same. Therefore, the second magnet holes 322B have the same bending part (refer to R43).

[0085] The permanent magnets 62B of Embodiment 3 can have a bending shape corresponding to the shape of the second magnet holes 322B. The permanent magnets 62B can also be formed of a bonded magnet material. In addition, in Figure 8 the example shown, the permanent magnets 62B are formed of a bonded magnet material and are filled in the second magnet holes 322B without gaps, but a flux barrier (gap) can also be set.

[0086] In addition, in Embodiment 3, the magnetic path widths L60B, L61B, and L62B can also be substantially the same as the magnetic path widths L60A, L61A, and L62A of Embodiment 2 shown in Figure 7 above.

[0087] According to such Embodiment 3, the same effects as those of Embodiment 1 and Embodiment 2 described above can also be obtained. That is, according to this embodiment, the required magnetic path width (for example, a magnetic path width of L61B or more) can be ensured throughout the second part 3212B, and the stress in each of the bridges 41B and 44B caused by centrifugal force can be effectively reduced. Additionally, similarly, the mass of the first part 3211B can be reduced, and the stress in each of the bridges 41B and 43B caused by centrifugal force can be effectively reduced.

[0088] Figure 9 It is a top view showing a part of the rotor core 32C of Embodiment 4.

[0089] The difference between the rotor core 32C of Example 4 and the rotor core 32 of Example 1 is that the first magnet holes 321 and the permanent magnets 61 are replaced by the second magnet holes 321C and the permanent magnets 61C. Additionally, the difference between the rotor core 32C of Example 4 and the rotor core 32 of Example 1 is that the second magnet holes 322 and the permanent magnets 62 are replaced by the second magnet holes 322C and the permanent magnets 62C.

[0090] The first magnet hole 321C of Example 4 has the following differences compared to the first magnet hole 321 of Example 1. The difference between the first magnet hole 321C and the first magnet hole 321 of Example 1 is that two are separately arranged on both sides of the d-axis, and the overall shape is the same. Therefore, the first magnet hole 321C has the same bending portion (refer to R73).

[0091] The permanent magnet 61C of Example 4 can have a bending shape corresponding to the shape of the first magnet hole 321C. The permanent magnet 61C can also be formed of a bonded magnet material. In addition, in Figure 9 the example shown, the permanent magnet 61C is formed of a bonded magnet material and fills the first magnet hole 321C without a gap, but a flux barrier (gap) can also be set.

[0092] The second magnet hole 322C of Example 4 can be the same as the second magnet hole 322B of Example 3 referred to in Figure 8 the above.

[0093] The permanent magnet 62C of Example 4 can have a bending shape corresponding to the shape of the second magnet hole 322C. The permanent magnet 62C can also be formed of a bonded magnet material. In addition, in Figure 9 the example shown, the permanent magnet 62C is formed of a bonded magnet material and fills the second magnet hole 322C without a gap, but a flux barrier (gap) can also be set.

[0094] In addition, in Example 4, the magnetic path widths L60C, L61C, L62C can also be substantially the same as the magnetic path widths L60, L61, L62 of Example 1 above (refer to Figure 6 ).

[0095] According to such Example 4, the same effects as those of the above Example 1 and Example 2 can also be obtained. That is, according to this embodiment, the required magnetic path width (for example, a magnetic path width of L61C or more) can be ensured throughout the second portion 3212C, and the stress in each of the bridges 42C, 44C caused by centrifugal force can be effectively reduced. Additionally, similarly, the mass of the first portion 3211C can be reduced, and the stress in each of the bridges 41C, 43C caused by centrifugal force can be effectively reduced.

[0096] Figure 10 It is a top view showing a part of the rotor core 32D of Embodiment 5. The difference between the rotor core 32D of Embodiment 5 and the rotor core 32 of Embodiment 1 is that the second magnet holes 322 and the permanent magnets 62 are replaced with the second magnet holes 322D and the permanent magnets 62D. The second magnet holes 322D and the permanent magnets 62D are the same as the second magnet holes 322B and the permanent magnets 62B of Embodiment 3 described with reference to Figure 8 above.

[0097] According to such Embodiment 5, the same effects as those of Embodiment 1 described above can also be obtained.

[0098] As described above, each embodiment has been described in detail, but it is not limited to a specific embodiment, and various changes and modifications can be made within the scope described in the claims. In addition, all or a plurality of the constituent elements of the above embodiments can be combined.

[0099] For example, in the above Embodiment 1 (the same applies to other embodiments), the convex shape of the second magnet hole 322 protruding radially inward has a bent portion, but it is not limited thereto. It is also possible that only the convex shape of the first magnet hole 321 protruding radially inward has a bent portion. In addition, in the above Embodiment 1 (the same applies to other embodiments), the first magnet hole 321 includes two or more hole portions in a circumferentially continuous state symmetrically about the d-axis when viewed in the axial direction, but the first magnet hole 321 may also be formed of a single hole portion.

[0100] Explanation of reference numerals

[0101] 30 Rotor (rotor for rotating electrical machine), 32, 32A - D Rotor cores, 328 Outer peripheral surface, 3211, 3211A - C First parts, 3212, 3212A - C Second parts, 3213 Third part, 321, 321A - C First magnet holes, 322, 322A - D Second magnet holes, 61, 61A - C Permanent magnets (first permanent magnets), 62, 62A - D Permanent magnets (second permanent magnets), R41, R42 Bent portions.

Claims

1. A rotor for a rotating electrical machine, wherein, comprising: a rotor core having a first magnet hole formed symmetrically about the d-axis when viewed axially, and a second magnet hole formed symmetrically about the d-axis when viewed axially, the second magnet hole including two or more hole portions in a circumferentially continuous state; a first permanent magnet disposed in the first magnet hole; and a second permanent magnet disposed in the second magnet hole, the rotor core including: a first portion located radially outside the first magnet hole and forming an outer peripheral surface of the rotor core; a second portion passing between the first magnet hole and the second magnet hole and extending to the outer peripheral surface of the rotor core on both circumferential sides; and a third portion passing through a position radially inside the second magnet hole and extending to the outer peripheral surface of the rotor core on both circumferential sides, the first magnet hole being convex in a shape protruding radially inward of the rotor core on one circumferential side with respect to the d-axis, the second magnet hole being convex in a shape protruding radially inward of the rotor core on one circumferential side with respect to the d-axis, in at least one of the first magnet hole and the second magnet hole, a hole portion extending to both circumferential sides with respect to the d-axis while sandwiching the d-axis or passing through the d-axis is convex in a shape protruding radially outward of the rotor core when viewed axially, and the convex shape protruding radially inward of the rotor core when viewed axially has a bent portion.

2. The rotor for a rotating electrical machine according to claim 1, wherein, at least one of them includes the second magnet hole, and the second permanent magnet has a bent shape corresponding to the bent portion.

3. The rotor for a rotating electrical machine according to claim 2, wherein, at least one of them further includes the first magnet hole, and the first permanent magnet has a bent shape corresponding to the bent portion.

4. The rotor for a rotating electrical machine according to claim 3, wherein, the radius of curvature of the bent shape of the second magnet hole is larger than the radius of curvature of the bent shape of the first magnet hole.

5. The rotor for a rotating electrical machine according to claim 1, wherein, the second permanent magnet is formed of a bonded magnet material.

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