Rotor for rotary electric machine

[0029] Embodiments of the rotor for a rotating electrical machine will be described with reference to the drawings. In addition, in the following description, with respect to "axial direction L", "radial direction R", and "circumferential direction C", the axial center A (refer to figure 1 ) as the benchmark. The axis A is an imaginary axis around which the rotor 2 rotates. In addition, if figure 2 As shown, one side of the circumferential direction C is referred to as the "first circumferential side C1", and the other side of the circumferential direction C (the side opposite to the first circumferential side C1) is referred to as the "second circumferential side C2" ". In this specification, terms about dimensions, arrangement directions, arrangement positions, and the like are used as concepts including states including differences due to errors (errors of an allowable level in manufacturing).

[0030] like figure 1 As shown, the rotor 2 is a rotor for the rotating electrical machine, and is used together with the stator 3 for the rotating electrical machine 1 . exist figure 1 In the illustrated example, the rotating electrical machine 1 is housed in the casing 4 , the stator core 10 , which is the core of the stator 3 , is fixed to the casing 4 (here, the inner surface of the casing 4 ), and the rotor 2 is supported relative to the casing 4 . rotate. Specifically, the rotating electrical machine 1 includes a rotor shaft 6 rotatably supported relative to the casing 4 via a bearing 5 , and the rotor core 15 , which is the core of the rotor 2 , and the rotor shaft 6 are coupled to rotate integrally.

[0031] The rotor core 15 is arranged to face the stator core 10 in the radial direction R. As shown in FIG. Specifically, the rotor 2 is a rotor for an inner rotor type rotating electrical machine, and the rotor core 15 is arranged inward in the radial direction R than the stator core 10 , and is arranged at a position overlapping the stator core 10 when viewed in the radial direction R. The rotary electric machine 1 is a rotary excitation type rotary electric machine, and the coil 13 is wound around the stator core 10 . Then, by the magnetic field generated from the stator 3, the rotor 2, which is an excitation, rotates. In this specification, a "rotating electric machine" is used as a concept including a motor (electric motor), a generator (generator), and a motor/generator that functions as both a motor and a generator as needed.

[0032] like figure 2 As shown, the rotor 2 includes a rotor core 15 and a permanent magnet 60 arranged (embedded) in the rotor core 15 . That is, the rotor 2 is a rotor for a rotary electric machine (for example, a synchronous motor) having an embedded magnet structure. The rotor core 15 is formed, for example, by laminating a plurality of annular magnetic plates (eg, electromagnetic steel sheets) in the axial direction L, or by press-molding a powder of a magnetic material, that is, a powdered powder material. formed as the main constituent element. The rotor core 15 has a plurality of hole portions 20 extending in the axial direction L at each magnetic pole P. As shown in FIG. The hole portions 20 are respectively formed so as to penetrate the rotor core 15 in the axial direction L. As shown in FIG. In the present embodiment, the hole portions 20 are formed to extend in parallel with the axial direction L, respectively. In addition, in the present embodiment, various cross-sectional shapes orthogonal to the axial direction L of the hole portion 20 are formed uniformly (uniformly) along the axial direction L. As shown in FIG. Further, a plurality of magnetic poles P are formed in the rotor core 15 in the circumferential direction C, and the magnetic poles P adjacent in the circumferential direction C have opposite polarities. figure 2 A region in the rotor core 15 where one magnetic pole P is formed is shown.

[0033] The plurality of hole portions 20 provided in one magnetic pole P include a first hole portion 21 arranged on the first side C1 in the circumferential direction with respect to the magnetic pole center line 90 and a second hole portion 21 arranged on the second side in the circumferential direction with respect to the magnetic pole center line 90 The second hole portion 22 of C2. Here, the magnetic pole center line 90 is a line extending in the radial direction R through the center of the magnetic pole P in the circumferential direction C. As shown in FIG. Specifically, the magnetic pole center line 90 is a straight line (imaginary line) extending parallel to the radial direction R through the center of the circumferential direction C of the magnetic pole P in the cross section of the rotor core 15 orthogonal to the axial direction L. In the present embodiment, among the plurality of hole portions 20 provided in one magnetic pole P, the third hole portion 23 (specifically, the third hole portion 23 in the circumferential direction C including the magnetic pole center line 90 is further included) The third hole portion 23 ) whose center position coincides with the center in the circumferential direction C of the magnetic pole P.

[0034] The rotor core 15 includes a plurality of hole portions 20 including magnet insertion holes in which the permanent magnets 60 are arranged in each of the plurality of magnetic poles P. As shown in FIG. In the present embodiment, all of the first hole portion 21 , the second hole portion 22 and the third hole portion 23 are magnet insertion holes. In the present embodiment, a flat permanent magnet is used as the permanent magnet 60 . That is, with respect to the permanent magnet 60, the cross-sectional shape orthogonal to the axial direction L is uniformly formed along the axial direction L, and the cross-sectional shape is rectangular. Furthermore, the permanent magnet 60 has a flat-shaped magnetic pole face F (refer to image 3 ). The magnetic pole surface F is an outer surface orthogonal to the magnetization direction (magnetization direction), and is a surface through which the magnetic flux of the permanent magnet 60 enters and exits. In the present embodiment, of the outer peripheral surfaces of the permanent magnet 60 (four surfaces forming the outer edge of the cross section orthogonal to the axial direction L), the two surfaces forming the long sides of the rectangle are the magnetic pole surfaces F. In this way, in the present embodiment, the plurality of hole portions 20 provided in the respective magnetic poles P include the first hole portion 21 and the second hole portion 22 in which the permanent magnets 60 having the planar magnetic pole faces F are respectively arranged.

[0035] The magnet insertion hole serves as a magnet arrangement region for arranging the permanent magnet 60 in a part or all of the region in the cross section perpendicular to the axial direction L. As shown in FIG. In the present embodiment, in the cross section perpendicular to the axial direction L, only a partial region of the magnet insertion hole is the magnet arrangement region, and the magnet arrangement regions of the magnet insertion hole are located on both sides in the direction along the magnetic pole face F with respect to the magnet arrangement region. The magnetic resistance part 20a which functions as a magnetic resistance (magnetic flux barrier) with respect to the magnetic flux which flows inside the rotor core 15 is formed in the side part. The magnetoresistive portion 20a becomes a void (air layer) or is filled with a filler (eg, resin or the like) having a lower magnetic permeability than the rotor core 15 (eg, a magnetic body plate such as an electromagnetic steel sheet).

[0036] like figure 2 As shown, the plurality of holes 20 of the plurality of magnetic poles P are arranged so as to form a first surrounding hole group 31 surrounding the magnetic pole center point 91 which is the intersection of the magnetic pole center line 90 and the outer peripheral surface 15 a of the rotor core 15 . That is, the rotor core 15 includes the plurality of hole portions 20 that form the first surrounding hole portion group 31 in the plurality of magnetic poles P, respectively. The plurality of hole portions 20 forming the first surrounding hole portion group 31 include a first hole portion 21 and a second hole portion 22, and in this embodiment, further include a third hole portion 23. Specifically, the first surrounding hole group 31 is formed by one first hole 21 , one second hole 22 and one third hole 23 . In the present embodiment, the first surrounding hole group 31 corresponds to the "surrounding hole group".

[0037] In the present embodiment, the rotor core 15 includes a plurality of holes 20 forming the second surrounding hole group 32 in each of the plurality of magnetic poles P in addition to the plurality of holes 20 forming the first surrounding hole group 31 . In the present embodiment, the rotor core 15 further includes a plurality of hole portions 20 in each of the plurality of magnetic poles P that form the third surrounding hole portion group 33 . The second surrounding hole group 32 is a hole group surrounding the magnetic pole center point 91 on the side closer to the magnetic pole center point 91 than the first surrounding hole group 31 . The flow of the q-axis magnetic flux is formed between the first surrounding hole group 31 and the second surrounding hole group 32 . The third surrounding hole group 33 is a hole group surrounding the magnetic pole center point 91 on the side closer to the magnetic pole center point 91 than the second surrounding hole group 32 . The flow of the q-axis magnetic flux is formed between the second surrounding hole group 32 and the third surrounding hole group 33 . The plurality of hole portions 20 forming the second surrounding hole portion group 32 include the first hole portion 21 and the second hole portion 22, and in this embodiment, the third hole portion 23 is also included. Specifically, the second surrounding hole portion group 32 is formed by one first hole portion 21 , one second hole portion 22 and one third hole portion 23 . In addition, the plurality of hole portions 20 forming the third surrounding hole portion group 33 include the first hole portion 21 and the second hole portion 22, and the third hole portion 23 is not included in this embodiment. Specifically, the third surrounding hole portion group 33 is formed by one first hole portion 21 and one second hole portion 22 .

[0038] Here, when focusing on the paired first hole portion 21 and the second hole portion 22, as figure 2 As shown, the first hole portion 21 and the second hole portion 22 are arranged at two positions in the circumferential direction C with respect to the magnetic pole center line 90 so that the separation distance in the circumferential direction C from each other becomes longer toward the outer side in the radial direction R. side separated. Here, "a pair of the first hole portion 21 and the second hole portion 22" means that they belong to the same surrounding hole portion group (in the present embodiment, the first surrounding hole portion group 31, the second surrounding hole portion group 32 and the The third surrounds the first hole portion 21 and the second hole portion 22 of any one of the hole portion groups 33). When the plurality of first hole portions 21 and the plurality of second hole portions 22 are included in the plurality of hole portions 20 forming one surrounding hole portion group, the first hole portion 21 and the second hole portion 22 belong to the same surrounding hole portion group. Among the two hole portions 22, the first hole portion 21 and the second hole portion 22 arranged at the same position in the radial direction R are referred to as "paired first hole portion 21 and second hole portion 22". As described above, in the present embodiment, since the permanent magnet 60 is a flat permanent magnet, both the first hole portion 21 and the second hole portion 22 are formed such that, in a cross-section perpendicular to the axial direction L, along the The flat magnetic pole face F of the permanent magnet 60 extends linearly. In addition, in the present embodiment, the cross-sectional shape of the portion of the rotor core 15 that constitutes one magnetic pole P perpendicular to the axial direction L is a shape that is symmetric about the magnetic pole center line 90 as the axis of symmetry. That is, the paired first hole portion 21 and the second hole portion 22 have shapes that are symmetrical to each other with the magnetic pole center line 90 as the axis of symmetry in a cross section orthogonal to the axial direction L. As shown in FIG. Therefore, in the present embodiment, the paired first hole portion 21 and the second hole portion 22 are arranged in a V in which the interval between the paired first hole portions 21 and the second hole portions 22 in a cross section orthogonal to the axial direction L becomes wider toward the outer side of the radial direction R. font.

[0039] The rotor core 15 includes a plurality of first bridge portions 41 formed between the two hole portions 20 adjacent to each other in the circumferential direction C. As shown in FIG. The first bridge portion 41 is formed between the plurality of hole portions 20 forming the first surrounding hole portion group 31 . That is, the rotor core 15 includes a plurality of first bridge portions 41 formed between the plurality of hole portions 20 forming the first surrounding hole portion group 31 . like figure 2 As shown, in this embodiment, the first hole portion 21 and the third hole portion 21 are adjacent to each other in the circumferential direction C (in other words, adjacent in the arrangement direction of the plurality of hole portions 20 forming the first surrounding hole portion group 31 , the same applies hereinafter). A first bridge portion 41 is formed between the hole portions 23 , and a first bridge portion 41 is formed between the second hole portion 22 and the third hole portion 23 adjacent in the circumferential direction C. As shown in FIG. In the present embodiment, the magnetoresistive portions 20a of each of the two hole portions 20 forming the first surrounding hole portion group 31 are arranged adjacent to each other in the circumferential direction C, and between the two magnetoresistive portions 20a adjacent in the circumferential direction C are formed The first bridge portion 41 . In addition, among the plurality of hole portions 20 forming the first surrounding hole portion group 31, two hole portions 20 (the first hole portion in the present embodiment) are arranged at both end portions (both ends in the above-mentioned arrangement direction). 21 and the second hole portion 22), respectively, and an outer peripheral side bridge portion is formed between the outer peripheral surface 15a of the rotor core 15. In the present embodiment, the first bridge portion 41 corresponds to a “bridge portion”.

[0040] In the present embodiment, the rotor core 15 includes a plurality of second bridge portions 42 formed between the plurality of hole portions 20 forming the second surrounding hole portion group 32 . In the present embodiment, the first hole portion 21 and the third hole portion 23 are adjacent in the circumferential direction C (in other words, adjacent in the arrangement direction of the plurality of hole portions 20 forming the second surrounding hole portion group 32 , the same applies hereinafter) The second bridge portion 42 is formed therebetween, and the second bridge portion 42 is formed between the second hole portion 22 and the third hole portion 23 adjacent in the circumferential direction C. As shown in FIG. In the present embodiment, the magnetoresistive portions 20a of each of the two hole portions 20 forming the second surrounding hole portion group 32 are arranged adjacent to each other in the circumferential direction C, and between the two magnetoresistive portions 20a adjacent in the circumferential direction C are formed. The second bridge portion 42 . In addition, among the plurality of hole portions 20 forming the second surrounding hole portion group 32, two hole portions 20 (first hole portions in the present embodiment) are arranged at both end portions (both ends in the above-mentioned arrangement direction). 21 and the second hole portion 22), respectively, and an outer peripheral side bridge portion is formed between the outer peripheral surface 15a of the rotor core 15.

[0041]In addition, in the present embodiment, the rotor core 15 includes the third bridge portion 43 formed between the plurality of hole portions 20 forming the third surrounding hole portion group 33 . In the present embodiment, the rotor core 15 includes only one third bridge portion 43 , and this third bridge portion 43 is formed in the plurality of hole portions 20 that are adjacent in the circumferential direction C (in other words, in the plurality of hole portions 20 forming the third surrounding hole portion group 33 ). are adjacent to each other in the arrangement direction, hereinafter the same) between the first hole portion 21 and the second hole portion 22 . In the present embodiment, the magnetoresistive portions 20a of each of the two hole portions 20 forming the third surrounding hole portion group 33 are arranged adjacent to each other in the circumferential direction C, and between the two magnetoresistive portions 20a adjacent in the circumferential direction C are formed The third bridge portion 43 . In addition, among the plurality of hole portions 20 forming the third surrounding hole portion group 33, two hole portions 20 (the first hole portion in the present embodiment) are arranged at both end portions (both ends in the above-mentioned arrangement direction). 21 and the second hole portion 22), respectively, and an outer peripheral side bridge portion is formed between the outer peripheral surface 15a of the rotor core 15.

[0042] like figure 1 As shown, among the plurality of first bridge portions 41 , the first offset bridge portion 51 located at a position offset in the circumferential direction C with respect to the magnetic pole center line 90 is included. Specifically, the first bridge portion 41 formed between the first hole portion 21 and the third hole portion 23 is a first offset bridge located at a position offset to the first side C1 in the circumferential direction with respect to the magnetic pole center line 90 part 51, the first bridge part 41 formed between the second hole part 22 and the third hole part 23 is a first offset bridge part located at a position offset to the second side C2 in the circumferential direction with respect to the magnetic pole center line 90 51. In the present embodiment, the first offset bridge portion 51 corresponds to the “offset bridge portion”.

[0043] In the present embodiment, among the plurality of second bridge portions 42 , the second offset bridge portion 52 located at a position offset in the circumferential direction C with respect to the magnetic pole center line 90 is included. Specifically, the second bridge portion 42 formed between the first hole portion 21 and the third hole portion 23 is a second offset bridge located at a position offset to the first side C1 in the circumferential direction with respect to the magnetic pole center line 90 part 52, the second bridge part 42 formed between the second hole part 22 and the third hole part 23 is a second offset bridge part located at a position offset to the second side C2 in the circumferential direction with respect to the magnetic pole center line 90 52.

[0044] However, since the output torque of the rotary electric machine 1 generally increases with the magnetic flux (leakage magnetic flux) passing through each bridge portion (in the present embodiment, the first bridge portion 41 , the second bridge portion 42 and the third bridge portion 43 ) Therefore, it is preferable to suppress the width of each bridge portion as small as possible within a range in which the strength of the rotor core 15 against centrifugal force can be appropriately secured. Here, the width of the bridge portion refers to the width of the cross section orthogonal to the axial direction L in the direction orthogonal to the extending direction of the bridge portion (substantially the width in the circumferential direction C or orthogonal to the magnetic pole center line 90 ). width in the direction). In this regard, in the rotor 2 of the present disclosure, by having the structure described below, the strength of the rotor core 15 against centrifugal force can be appropriately ensured, and the offset bridge portion (in the present embodiment, the first offset can be realized) The width of the bridge portion 51 and the second offset bridge portion 52) is reduced.

[0045] like figure 2 As shown, the portion surrounded by the first surrounding hole portion group 31 in the rotor core 15 is referred to as the first target portion 81 . In addition, although the outer edge on the outer side in the radial direction R of the first object portion 81 is formed along the outer peripheral surface 15a of the rotor core 15, for ease of understanding, the figure 2 Among them, the outer edge on the outer side in the radial direction R of the first object portion 81 is shown on the outer side in the radial direction R than the outer peripheral surface 15a. In addition, the outer edges on both sides in the circumferential direction C of the first target portion 81 and the inner outer edges in the radial direction R are formed along the arrangement area of ​​the plurality of holes 20 forming the first surrounding hole group 31 . That is, the outer edge of the first side C1 in the circumferential direction of the first target portion 81 is formed along the arrangement region of the first hole portion 21 belonging to the first surrounding hole portion group 31 in the extending direction of the first hole portion 21 . (here radial R) extension. In addition, the outer edge of the inner side in the radial direction R of the first target portion 81 is formed along the arrangement region of the third hole portion 23 belonging to the first surrounding hole portion group 31, in the extending direction of the third hole portion 23 ( Here, the direction perpendicular to the magnetic pole center line 90) extends. In addition, the outer edge of the second side C2 in the circumferential direction of the first target portion 81 is formed along the arrangement region of the second hole portion 22 belonging to the first surrounding hole portion group 31 in the extending direction of the second hole portion 22 (here radial R) extension. Furthermore, in figure 2 In the description, the first target portion 81 is set to include the plurality of holes 20 forming the first surrounding hole group 31, and this case is shown as an example, but the first target portion 81 may be set to not include the formation of the first target portion 81. The first surrounds the plurality of hole portions 20 of the hole portion group 31 . In this embodiment, the first object part 81 corresponds to the "object part".

[0046] When the rotor 2 is rotated, the first bias bridge portion 51 supports the above-described first object portion 81 against centrifugal force. Furthermore, considering a simplified model, since centrifugal force acts on the first center of gravity G1, which is the center of gravity of the first object portion 81, when the rotor 2 rotates, a tensile load on the side of the first center of gravity G1 acts on the first offset Bridge portion 51 . Further, the first center of gravity G1 is the center of gravity (center of mass) of the first object portion 81 , and is the center of gravity in a state where the permanent magnets 60 are arranged in the holes 20 used as magnet insertion holes, respectively. As described above, the tensile load to the first gravity center G1 side acts on the first offset bridge portion 51, and in view of this point, as figure 2 As shown, the extending direction of the first offset bridge portion 51 in the cross-section perpendicular to the axial direction L, that is, the first extending direction D1, is set as the radial direction (starting from the first offset bridge portion 51 ). The direction in which the outer side of R is close to the magnetic pole center line 90 is inclined with respect to the magnetic pole center line 90 . like figure 2 As shown, since the first center of gravity G1 is located on the outer side in the radial direction R with respect to the first offset bridge portion 51 and on the magnetic pole center side in the circumferential direction C, by making the first extending direction D1 the above-mentioned direction, the first Compared with the case where the extending direction D1 is parallel to the magnetic pole center line 90 , the first extending direction D1 can be made closer to the direction in which the above-mentioned tensile load acts, and the generation of the first offset bridge portion 51 when the rotor 2 is rotated can be reduced. bending stress. Furthermore, in figure 2 Among the pair of first offset bridges 51 arranged to be spaced apart on both sides in the circumferential direction with respect to the magnetic pole center line 90 , the first extension direction D1 is shown for only one of the first offset bridges 51 , but The respective first extending directions D1 of the pair of first offset bridge portions 51 are mutually symmetrical directions with respect to the magnetic pole center line 90 as the axis of symmetry.

[0047] In this embodiment, in order to further reduce the bending stress generated in the first offset bridge portion 51 when the rotor 2 rotates, as figure 2 As shown, the first extending direction D1 (starting from the first offset bridge portion 51 ) is along the direction toward the first center of gravity G1. By setting the first extending direction D1 in such a manner that the first extending direction D1 is aligned with the direction in which the tensile load acts, the bending stress generated in the first offset bridge portion 51 when the rotor 2 is rotated can be further reduced. In addition, the bending stress generated in the first offset bridge portion 51 is reduced, and the concentration of stress on the first offset bridge portion 51 when the rotor 2 is rotated can be reduced accordingly. As a result, the rotor core 15 against centrifugal force can be ensured. strength, and the width of the first offset bridge portion 51 can be suppressed to be small. In addition, the "direction toward the first center of gravity G1" includes not only the case where the first center of gravity G1 is located exactly on the extension line of the direction, but also includes the first center of gravity G1 extending from the extension line within the range considered to be toward the first center of gravity G1 The concept of the situation on the offset. The same applies to the "direction toward the second center of gravity G2" described later. In other words, the first center of gravity G1 and the second center of gravity G2 can be regarded as regions having some extent of expansion.

[0048] In the present embodiment, the extending direction of the second offset bridge portion 52 in the cross section perpendicular to the axial direction L, that is, the second extending direction D2 is configured such that (from the second offset bridge portion 52 ) along the The direction toward the center of gravity of the second object portion 82 , that is, the second center of gravity G2 . Here, as figure 2 As shown, the second object portion 82 is a portion surrounded by the second surrounding hole group 32 in the rotor core 15 . The second target portion 82 is set to be the same as the first target portion 81 except for the point where the first surrounding hole portion group 31 is replaced by the second surrounding hole portion group 32 , and detailed descriptions thereof are omitted. Furthermore, when the rotor 2 rotates, the second offset bridge portion 52 supports the second object portion 82 against the centrifugal force. Therefore, when the rotor 2 rotates, a tensile load on the side of the second center of gravity G2 is considered by a simplified model. Acts on the second offset bridge portion 52 . In this regard, in the present embodiment, as described above, since the second extending direction D2 (starting from the second offset bridge portion 52 ) is along the direction toward the second center of gravity G2, the second extending direction D2 is The direction in which the above-mentioned tensile load acts is the same, and the bending stress generated in the second offset bridge portion 52 when the rotor 2 is rotated can be reduced. In addition, the bending stress generated in the second offset bridge portion 52 is reduced, and the concentration of stress on the second offset bridge portion 52 when the rotor 2 is rotated can be alleviated accordingly. As a result, the rotor core 15 against centrifugal force can be ensured. strength, and the width of the second offset bridge portion 52 can be suppressed to be small. Furthermore, in figure 2 Among the pair of second offset bridge portions 52 arranged to be spaced apart on both sides in the circumferential direction with respect to the magnetic pole center line 90, the second extension direction D2 is shown for only one second offset bridge portion 52, but The respective second extending directions D2 of the pair of second offset bridge portions 52 are mutually symmetrical directions with respect to the magnetic pole center line 90 as the axis of symmetry.

[0049] image 3 It is an analytical diagram showing the stress distribution in the first offset bridge portion 51 when the rotor 2 rotates. exist image 3 , the stress distribution is represented by contour lines. That is, the dotted lines are respectively the contour lines connecting the points of equal magnitude of stress, the contour line represented by "H1" is the first contour line H1 with the largest stress, and the contour line represented by "H2" is the second stress line Large second contour H2. exist image 3 In order to easily grasp the stress distribution, hatching is applied to the region where the stress is the largest (region surrounded by the first contour line H1 ). on the other hand, Figure 5 is directed at Figure 4 The rotor 2 of the illustrated comparative example shows an analytical view of the stress distribution in the first offset bridge portion 51 when the rotor 2 rotates. also, Figure 4 and Figure 5 The illustrated comparative example is not an example of the rotor for a rotating electrical machine of the present disclosure, and is marked with the figure 2 and image 3 the same reference numerals. like Figure 4 As shown, in this comparative example, the extension direction of the first offset bridge portion 51 in the cross section orthogonal to the axial direction L, that is, the first extension direction D1, and the second offset in the cross section orthogonal to the axial direction L The extending direction of the bridge portion 52 , that is, the second extending direction D2 is a direction parallel to the magnetic pole center line 90 . For the shape of the first contour line H1 and the second contour line H2, compare image 3 and Figure 5 It can be seen that in the rotor 2 ( image 3 ), and the rotor 2 ( Figure 5 ), the concentration of stress in the first offset bridge portion 51 is alleviated.

[0050] As described above, in the present embodiment, the extending direction of the first offset bridge portion 51 in the cross section perpendicular to the axial direction L, that is, the first extending direction D1 is configured so as to extend from the first offset bridge portion 51 along the towards the first center of gravity G1 (refer to figure 2 ). That is, in a cross section orthogonal to the axial direction L, the first offset bridge portion 51 is formed to face the center of gravity on the magnetic pole center line 90 corresponding to the magnetic pole P on which the first offset bridge portion 51 is formed. Here, "the center of gravity corresponding to the magnetic pole P on which the first offset bridge portion 51 is formed" means that the portion of the rotor core 15 constituting the magnetic pole P is supported by the first offset bridge portion 51 (which can be regarded as a support). ) the center of gravity of the support object part. In the present embodiment, since the supporting target portion of the first offset bridge portion 51 is the first target portion 81 , the center of gravity of the first target portion 81 , ie, the first center of gravity G1 , is the same as the first target portion G1 where the first offset bridge portion 51 is formed. The center of gravity corresponding to the magnetic pole P. That is, in the cross section orthogonal to the axial direction L, the first offset bridge portion 51 is formed to face the first center of gravity G1 on the magnetic pole center line 90 .

[0051] In addition, in the present embodiment, the extending direction of the second offset bridge portion 52 in the cross-section perpendicular to the axial direction L, that is, the second extending direction D2 is configured so as to extend from the second offset bridge portion 52 toward the second offset bridge portion 52 . The direction of the center of gravity G2 (refer to figure 2). That is, in a cross section orthogonal to the axial direction L, the second offset bridge portion 52 is formed to face the center of gravity on the magnetic pole center line 90 corresponding to the magnetic pole P on which the second offset bridge portion 52 is formed. Here, "the center of gravity corresponding to the magnetic pole P on which the second offset bridge portion 52 is formed" means that the portion of the rotor core 15 constituting the magnetic pole P is supported by the second offset bridge portion 52 (which can be regarded as a support ) the center of gravity of the support object part. In the present embodiment, since the supporting target portion of the second offset bridge portion 52 is the second target portion 82 , the center of gravity of the second target portion 82 , ie, the second center of gravity G2 , is the same as the second target portion 52 . The center of gravity corresponding to the magnetic pole P. That is, in the cross section orthogonal to the axial direction L, the second offset bridge portion 52 is formed to face the second center of gravity G2 on the magnetic pole center line 90 .

[0052] In the present embodiment, the first offset bridge portion 51 and the second offset bridge portion 52 are formed in the specific portion 70 where the interval between the two hole portions 20 is the narrowest in the cross section perpendicular to the axial direction L. As shown in FIG. The interval between the two hole portions 20 can be, for example, the interval in the circumferential direction C or the interval in the magnetic pole orthogonal direction B described later. like Image 6 As shown, the first offset bridge portion 51 is formed at a specific portion 70 where the interval between the first hole portion 21 and the third hole portion 23 belonging to the first surrounding hole portion group 31 is the narrowest. Furthermore, in Image 6 , although only a specific part formed between the first hole part 21 and the third hole part 23 belonging to the first surrounding hole part group 31 is denoted by the reference numeral "70", the specific part 70 exists along the circumference Between the two hole portions 20 of the two hole portions 20 adjacent to C. For example, the second offset bridge portion 52 is formed at the specific portion 70 where the interval between the first hole portion 21 and the third hole portion 23 belonging to the second surrounding hole portion group 32 is the narrowest.

[0053] Furthermore, in the present embodiment, in the cross section orthogonal to the axial direction L, the first offset bridge portion 51 is formed in the region sandwiched by the third straight line T3 and the fourth straight line T4, and the first offset bridge is The entirety of the two hole portions 20 sandwiched by the portion 51 from both sides in the circumferential direction C is configured to be disposed outside the region sandwiched by the third straight line T3 and the fourth straight line T4, thereby forming the first offset bridge portion 51 In a cross-section perpendicular to the axial direction L, it faces the first center of gravity G1 on the magnetic pole center line 90 . In addition, in the cross section perpendicular to the axial direction L, the second offset bridge portion 52 is formed in the region sandwiched by the third straight line T3 and the fourth straight line T4, and the second offset bridge portion 52 is extended from the circumferential direction C to the second offset bridge portion 52. The entirety of the two holes 20 sandwiched between the two sides is configured to be disposed outside the region sandwiched by the third straight line T3 and the fourth straight line T4, whereby the second offset bridge portion 52 is formed so as to be in the axial direction of the In the cross section orthogonal to L, it faces the second center of gravity G2 on the magnetic pole center line 90 . Here, the third straight line T3 is a straight line passing through the end of the first side C1 in the circumferential direction of the specific portion 70 and the center of gravity on the magnetic pole center line 90 in a cross section orthogonal to the axial direction L, and the fourth straight line T4 is a straight line passing through the A straight line passing through the end of the second side C2 in the circumferential direction of the specific portion 70 and the center of gravity on the magnetic pole center line 90 in a cross section orthogonal to the axial direction L. Further, the center of gravity on the magnetic pole center line 90 is the first center of gravity G1 for the first offset bridge portion 51 and the second center of gravity G2 for the second offset bridge portion 52 .

[0054] Specifically, the first offset bridge portion 51 formed between the first hole portion 21 and the third hole portion 23 belonging to the first surrounding hole portion group 31 is described as follows. Image 6 As shown, the third straight line T3 is a straight line passing through the end of the first side C1 in the circumferential direction of the specific portion 70 and the first center of gravity G1, and the fourth straight line T4 is the end portion of the second side C2 in the circumferential direction of the specific portion 70. A straight line passing through the first center of gravity G1. Furthermore, the first offset bridge portion 51 is formed in a region sandwiched by the third straight line T3 and the fourth straight line T4. In addition, the entirety of the two hole portions 20 (here, the entirety of the first hole portion 21 and the entirety of the third hole portion 23 ) sandwiched by the first offset bridge portion 51 from both sides in the circumferential direction C is arranged on the third The outer side of the area sandwiched by the straight line T3 and the fourth straight line T4. Accordingly, the first offset bridge portion 51 is formed so as to face the first center of gravity G1 on the magnetic pole center line 90 in a cross section orthogonal to the axial direction L. As shown in FIG. On the other hand, in Figure 7 The structure of the comparative example shown (and Figure 4 In the same structure), at least a part of at least one of the two hole portions 20 sandwiching the first offset bridge portion 51 from both sides in the circumferential direction C (in the Figure 7 A portion of the first hole portion 21 and a portion of the third hole portion 23) are arranged inside the region sandwiched by the third straight line T3 and the fourth straight line T4. Therefore, in the structure of this comparative example, the first offset bridge portion 51 is not formed so as to face the first center of gravity G1 on the magnetic pole center line 90 in a cross section orthogonal to the axial direction L.

[0055] In addition, here, the interval between the third straight line T3 and the fourth straight line T4 is set so that the interval between the third straight line T3 and the fourth straight line T4 becomes narrower toward the center of gravity on the magnetic pole center line 90 (here, toward the first center of gravity G1 or the second center of gravity G2 ). The three straight lines T3 and the fourth straight line T4 have been described by taking this case as an example, but the third straight line T3 and the fourth straight line T4 may be set so that the interval between the third straight line T3 and the fourth straight line T4 is constant (that is, so as to be parallel to each other). Three straight lines T3 and fourth straight lines T4. That is, the first center of gravity G1 can also be regarded as a region with a certain degree of expansion, and the third straight line T3 passing through the end portion of the first side C1 in the circumferential direction of the specific portion 70 and the first center of gravity G1, and A fourth straight line T4 passing through the end of the second side C2 in the circumferential direction of the specific portion 70 and the first center of gravity G1.

[0056] Finally, the definition of the extending direction of the bridge portion in the cross section orthogonal to the axial direction L will be described. Except for the point that the combination of the two hole portions 20 forming the bridge portion is different, the extending direction of each bridge portion can be defined in the same way, so here, refer to image 3 The first extending direction D1, which is the extending direction of the first offset bridge portion 51 in the cross section orthogonal to the axial direction L, will be described. In addition, hereinafter, the two hole portions 20 forming the first offset bridge portion 51 are simply referred to as the two hole portions 20 .

[0057] like image 3 As shown, the portion forming the first offset bridge portion 51 among the respective outer edges of the two hole portions 20 (here, the first hole portion 21 and the third hole portion 23 ) is used as the bridge forming edge portion 20b. The direction perpendicular to the magnetic pole center line 90 in the cross section perpendicular to the axial direction L can be referred to as the magnetic pole orthogonal direction B. The region sandwiched on both sides (in the region between the two hole portions 20, the region where a line parallel to the perpendicular direction B of the magnetic poles intersects the outer edges of the two hole portions 20) is defined as a bridge formation region, and the Among the outer edges of each of the two hole portions 20, a portion that defines the bridge formation region is referred to as a bridge formation edge portion 20b. From the viewpoint of alleviating stress concentration, the shape of the bridge forming edge portion 20b in the cross section perpendicular to the axial direction L is preferably a shape with a constant curvature and a shape (arc shape) with the center of curvature located inside the hole portion 20, or It is a shape in which the curvature continuously changes and the center of curvature of each part is located inside the hole portion 20 . In the present embodiment, the shape of the bridge forming edge portion 20b in the cross section orthogonal to the axial direction L is the latter shape. In addition, in the present embodiment, the bridge forming edge portion 20b is constituted by a part of the outer edge of the magnetoresistive portion 20a.

[0058] like image 3 As shown, in the cross section perpendicular to the axial direction L, the bridge forming edge 20b of the one hole 20 and the bridge forming edge 20b of the other hole 20 of the two holes 20 are shared in the two holes. The tangent lines are taken as the first straight line T1 and the second straight line T2, respectively. Here, the common inner tangent line is a tangent line common to the two bridge forming edge portions 20b, and is a tangent line on which the two bridge forming edge portions 20b are located on opposite sides of the tangent line. In the present embodiment, based on the first straight line T1 and the second straight line T2 defined as described above, the first extending direction D1 is set to bisect the angle formed by the first straight line T1 and the second straight line T2 And the direction of the line segment that does not intersect the two hole portions 20 .

[0059] In addition, the first extending direction D1 can also be defined by other methods different from those described above. For example, in a cross section orthogonal to the axial direction L, a straight line (in A straight line passing through a plurality of center positions, or an approximate curve determined based on a plurality of center positions) is set as the first extending direction D1. In this case, the plurality of positions can include both end portions in the direction parallel to the magnetic pole centerline 90 in the bridge formation region, and a central portion in the direction parallel to the magnetic pole centerline 90 in the bridge formation region. In addition, in the cross section orthogonal to the axial direction L, the direction in which the distance between the two parallel tangent lines that are in contact with the two bridge-forming edge portions 20b, respectively, is the largest (the extending direction of the tangent lines) as the first an extension direction D1.

[0060] [Other Embodiments]

[0061] Next, another embodiment of the rotor for a rotating electrical machine will be described.

[0062] (1) In the above-described embodiment, the configuration in which the second extending direction D2 (from the second offset bridge portion 52 ) follows the direction toward the second center of gravity G2 has been described as an example. However, it is not limited to such a structure, and a structure in which the second extending direction D2 does not follow the direction toward the second center of gravity G2 may be employed. Even in this case, it is preferable to set the second extending direction D2 relative to the magnetic pole center line 90 so as to approach the magnetic pole center line 90 toward the outer side of the radial direction R (from the second offset bridge portion 52 ). inclined direction. At this time, a straight line extending in the second extending direction D2 from the second offset bridge portion 52 intersects the magnetic pole center line 90 at a position different from the second center of gravity G2. For example, the second extending direction D2 (starting from the second offset bridge portion 52 ) can be configured to follow the direction toward the first center of gravity G1 .

[0063] (2) In the above-described embodiment, a configuration in which the first extending direction D1 (from the first offset bridge portion 51 ) follows the direction toward the first center of gravity G1 has been described as an example. However, it is not limited to this configuration, and the first extending direction D1 may be relative to the magnetic pole center so as to approach the magnetic pole center line 90 toward the outer side of the radial direction R (from the first offset bridge portion 51 ). A structure in which the line 90 is inclined in a direction that does not follow the direction toward the first center of gravity G1. At this time, a straight line extending in the first extending direction D1 from the first offset bridge portion 51 intersects the magnetic pole center line 90 at a position different from the first center of gravity G1. For example, the first extension direction D1 (starting from the first offset bridge portion 51 ) can be configured to follow the direction toward the second center of gravity G2.

[0064] (3) In the above-described embodiment, the rotor core 15 includes the second surrounding hole group 32 and the third surrounding hole group 33 in addition to the first surrounding hole group 31 , and this configuration has been described as an example. . However, it is not limited to this structure, and for example, the rotor core 15 may have only the first surrounding hole group 31 and the second surrounding hole group 32, and the rotor core 15 may include only the first surrounding hole group 31 and the second surrounding hole group 32. A structure in which the third group of holes surrounds 33 , or a structure in which the rotor core 15 includes only the first group of holes for surrounds 31 . Further, in addition to the first surrounding hole group 31 , the rotor core 15 may be provided with at least a fourth surrounding hole group surrounding the magnetic pole center point 91 on the side farther from the magnetic pole center point 91 than the first surrounding hole group 31 . structure.

[0065] (4) In the above-described embodiment, among the plurality of hole portions 20 forming the first surrounding hole portion group 31, each of the first hole portion 21 and the second hole portion 22 is included, and when the second surrounding hole portion group is formed Among the plurality of hole portions 20 of 32 , each of the first hole portion 21 and the second hole portion 22 is included, and this structure is described as an example. However, it is not limited to such a structure, and a structure in which a plurality of first hole portions 21 and a plurality of second hole portions 22 are included in the plurality of hole portions 20 forming the first surrounding hole portion group 31 may be adopted. A structure in which the plurality of hole portions 20 surrounding the hole portion group 32 includes a plurality of first hole portions 21 and a plurality of second hole portions 22 . At this time, the first offset bridge portion 51 or the second offset bridge is formed between the two first hole portions 21 adjacent in the circumferential direction C and between the two second hole portions 22 adjacent in the circumferential direction C Section 52.

[0066](5) In the above-described embodiment, the third hole 23 is included in the plurality of holes 20 forming the first surrounding hole group 31 , and the plurality of holes 20 forming the second surrounding hole group 32 , including the third hole portion 23 , and this structure is described as an example. However, it is not limited to this structure, and a structure in which the third hole portion 23 is not included in the plurality of hole portions 20 forming the first surrounding hole portion group 31 (for example, only the plurality of first hole portions 21 and the plurality of A structure in which there are two second holes 22), a structure in which the third hole 23 is not included in the plurality of holes 20 forming the second surrounding hole group 32 (for example, only a plurality of first holes 21 and a plurality of The structure of the two hole portion 22).

[0067] (6) In the above-described embodiment, the first hole portion 21 , the second hole portion 22 and the third hole portion 23 are all magnet insertion holes, and this configuration has been described as an example. However, it is not limited to such a configuration, and for example, a configuration in which the permanent magnet 60 is not arranged in the third hole portion 23 can be adopted. For example, the entire third hole portion 23 can be a structure in which a void (air layer) is formed, or a structure in which a non-magnetic filler (eg, resin, etc.) is filled in the entire third hole portion 23 .

[0068] (7) In the above-described embodiment, the plurality of hole portions 20 provided in the respective magnetic poles P include the first hole portion 21 and the second hole portion 22 in which the permanent magnets 60 having the planar magnetic pole faces F are arranged, respectively. , and the structure is described as an example. However, it is not limited to such a configuration, and a configuration in which permanent magnets having curved magnetic pole faces are arranged in the first hole portion 21 and the second hole portion 22 may be employed.

[0069] (8) In addition, unless a conflict arises, the configuration disclosed in each of the above-mentioned embodiments can be applied in combination with the configuration disclosed in other embodiments (including combinations of the embodiments described as other embodiments). . As for other structures, all the embodiments disclosed in this specification are merely illustrative. Therefore, various changes can be appropriately made without departing from the gist of the present disclosure.

[0070] [Outline of the above-mentioned embodiment]

[0071] Hereinafter, the rotor for a rotating electrical machine described above will be briefly described.

[0072] A rotor (2) for a rotating electrical machine, comprising a rotor core (15) and permanent magnets (60) arranged in the rotor core (15), wherein the rotor core (15) includes a plurality of magnetic poles (P), respectively. The plurality of holes (20) include a first hole (21) and a second hole (22) in which the permanent magnet (60) having a planar magnetic pole face (F) is disposed, respectively. ), the above-mentioned first hole portion (21) and the above-mentioned second hole portion (22) are in such a way that the separation distance in the circumferential direction (C) of each other becomes longer toward the outer side in the radial direction (R), relative to the passage through the above-mentioned The magnetic pole center lines (90) extending in the circumferential direction (C) of the magnetic poles (P) along the radial direction (R) are arranged to be separated on both sides of the circumferential direction (C), and the rotor core (15) is provided with A plurality of bridges (41) formed between two adjacent holes (20) in the circumferential direction (C), among the plurality of bridges (41), are included relative to the magnetic pole center line (90). ) an offset bridge portion (51) located at a position offset in the circumferential direction (C), and the extension direction (D1) of the offset bridge portion (51) in a cross-section orthogonal to the axial direction (L) follows the It is inclined with respect to the magnetic pole center line (90) so as to approach the magnetic pole center line (90) toward the outer side in the radial direction (R).

[0073] According to this structure, the extension direction ( D1 ) of the offset bridge portion ( 51 ) in the cross-section perpendicular to the axial direction (L) is so as to approach the magnetic pole center line ( 90 ) as it goes to the outer side in the radial direction (R). Compared with the case where the extending direction (D1) is parallel to the magnetic pole center line (90), the stress can be alleviated when the rotor (2) rotates. Concentration of the bridge section (51). As a result, the strength of the rotor core (15) against centrifugal force can be appropriately ensured, and the width of the offset bridge portion (51) can be reduced.

[0074] In addition, when the rotor (2) rotates, the offset bridge portion (51) supports the radially outer portion of the rotor core (15) in the magnetic pole (P) provided with the offset bridge (51) against centrifugal force (hereinafter in the referred to in this paragraph as the "support object portion"). Furthermore, considering a simplified model, since centrifugal force acts on the center of gravity of the object, when the rotor (2) rotates, a tensile load on the center of gravity side of the supporting object acts on the offset bridge (51). Since the cross-sectional shape of the portion constituting one magnetic pole in the rotor core (15) perpendicular to the axial direction (L) is symmetrical or nearly symmetrical with the magnetic pole center line (90) as the axis of symmetry, the center of gravity of the supporting target portion Generally, the offset bridge portion (51) is located on the outer side in the radial direction (R) and on the magnetic pole center side in the circumferential direction (C). In this regard, according to the above configuration, the extension direction ( D1 ) of the offset bridge portion ( 51 ) in the cross-section perpendicular to the axial direction (L) becomes closer to the magnetic pole center line as it goes outward in the radial direction (R). (90), the extension direction (D1) of the offset bridge (51) can be made closer to the tensile load than when the extension direction (D1) is parallel to the magnetic pole center line (90). The direction of action reduces the bending stress generated in the offset bridge portion (51) when the rotor (2) rotates. In addition, the bending stress generated in the offset bridge portion (51) is reduced, and accordingly the concentration of stress on the offset bridge portion (51) when the rotor (2) rotates can be alleviated. As a result, the rotor against centrifugal force can be secured. The strength of the core (15) and the width of the offset bridge portion (51) can be suppressed to be small.

[0075] As described above, according to the above configuration, it is possible to realize the rotor ( 2 ) for a rotating electrical machine that can appropriately secure the strength of the rotor core ( 15 ) against centrifugal force and reduce the width of the offset bridge portion ( 51 ).

[0076] In addition, according to the above configuration, since the permanent magnet (60) having the planar magnetic pole face (F) can be used as the permanent magnet (60) arranged in the first hole (21) and the second hole (22), Therefore, compared with the case of using a permanent magnet having a curved magnetic pole face, there is an advantage that the cost can be kept low and the required residual magnetic flux density can be easily secured. In addition, since the first hole portion (21) and the second hole portion (22) are arranged so that the separation distance in the circumferential direction (C) from each other becomes longer toward the outer side in the radial direction (R), it also has the advantage of being able to use magnetic resistance torque.

[0077] Here, it is preferable that the plurality of holes (20) of each of the plurality of magnetic poles (P) are arranged so as to form a magnetic pole center point that surrounds the intersection of the magnetic pole center line (90) and the outer peripheral surface (15a) of the rotor core (15). In the surrounding hole group (31) of (91), the extension direction (D1) of the offset bridge (51) in the cross section orthogonal to the axial direction (L) is along the direction defined by the surrounding hole group (31). ) in the direction of the center of gravity (G1) of the object part (81) enclosed by it.

[0078] According to this structure, since the extending direction ( D1 ) of the offset bridge portion ( 51 ) can be aligned with the direction of the tensile load acting on the offset bridge portion ( 51 ) when the rotor ( 2 ) rotates, it can be further reduced. The bending stress generated on the offset bridge portion (51) when the rotor (2) rotates, thereby further relaxing the concentration of stress on the offset bridge portion (51) when the rotor (2) rotates.

[0079] A rotor (2) for a rotating electrical machine, comprising a rotor core (15) and permanent magnets (60) arranged in the rotor core (15), wherein the rotor core (15) includes a plurality of magnetic poles (P) including A plurality of hole portions (20) of magnet insertion holes (21, 22) in which the permanent magnets (60) are arranged, and a plurality of the hole portions (20) of each of the plurality of the magnetic poles (P) are arranged so as to surround and pass the magnetic poles. (P) The center in the circumferential direction (C) of the magnetic pole center line (90) extending in the radial direction (R) and the intersection point of the outer peripheral surface (15a) of the rotor core (15), that is, the surrounding hole of the magnetic pole center point (91) A portion group (31), wherein the rotor core (15) includes a plurality of bridge portions (41) formed between the two hole portions (20) adjacent in the circumferential direction (C), and the plurality of bridge portions ( 41), including an offset bridge portion (51) located at a position offset in the circumferential direction (C) with respect to the magnetic pole center line (90), and the offset bridge portion (51) is in the axial direction (L). ) in the cross section orthogonal to the extending direction ( D1 ) along the direction toward the center of gravity ( G1 ) of the target portion ( 81 ) surrounded by the surrounding hole group ( 31 ).

[0080] According to this structure, since the extension direction ( D1 ) of the offset bridge portion ( 51 ) in the cross section orthogonal to the axial direction ( L ) is along the direction toward the target portion ( 81 ) surrounded by the surrounding hole portion group ( 31 ) The direction of the center of gravity (G1), so compared with the case where the extending direction (D1) is parallel to the magnetic pole center line (90), the stress on the offset bridge portion (51) when the rotor (2) rotates can be alleviated. concentrated. As a result, the strength of the rotor core (15) against centrifugal force can be appropriately ensured, and the width of the offset bridge portion (51) can be reduced.

[0081] In addition, when the rotor (2) rotates, the offset bridge portion (51) supports the target portion (81) surrounded by the surrounding hole portion group (31) against centrifugal force. Furthermore, considering a simplified model, since centrifugal force acts on the center of gravity of the object, when the rotor (2) rotates, a tensile load on the center of gravity (G1) side of the object portion (81) acts on the offset bridge portion ( 51). In this regard, according to the above-mentioned structure, since the extension direction (D1) of the offset bridge portion (51) in the cross section orthogonal to the axial direction (L) is along the direction toward the center of gravity (G1) of the target portion (81), Therefore, making the extension direction (D1) of the offset bridge (51) coincide with the direction in which the tensile load acts as described above, it is possible to reduce the bending stress generated on the offset bridge (51) when the rotor (2) rotates. Furthermore, the bending stress generated in the offset bridge portion (51) is reduced, and accordingly the concentration of stress on the offset bridge portion (51) when the rotor (2) is rotated can be alleviated, and as a result, the rotor core (15) can be secured. ) against centrifugal force, and the width of the offset bridge (51) can be suppressed to be small.

[0082] As described above, according to the above configuration, a rotor (2) for a rotating electrical machine can be realized, in which the strength of the rotor core (15) against centrifugal force can be appropriately secured, and the width of the offset bridge portion (51) can be reduced.

[0083] In addition, according to the above configuration, since the plurality of holes (20) are arranged to form the surrounding hole group (31) surrounding the magnetic pole center point (91), there is also an advantage that the reluctance torque can be utilized.

[0084] As described above, it is preferable that the extension direction (D1) of the offset bridge portion (51) in the cross-section perpendicular to the axial direction (L) is along the direction toward the center of gravity (G1) of the target portion (81). In the structure of the rotor core (15), each of the plurality of the magnetic poles (P) is provided with a plurality of the magnetic pole center points (91) formed on the side closer to the magnetic pole center point (91) than the surrounding hole group (31). ) of the second surrounding hole group (32) of the plurality of holes (20), and the rotor core (15) is provided with a plurality of the plurality of holes (20) forming the second surrounding hole group (32). 20) The second bridge portion (42) formed between the plurality of second bridge portions (42) includes a position offset in the circumferential direction (C) with respect to the magnetic pole center line (90) The second offset bridge portion (52), the extension direction (D2) of the second offset bridge portion (52) in the cross section orthogonal to the axial direction (L) is along the direction surrounded by the second hole portion. The direction of the center of gravity (G2) of the second object portion (82) enclosed by the cluster (32).

[0085]According to this structure, since the extending direction (D2) of the second offset bridge portion (52) in the cross-section perpendicular to the axial direction (L) is directed toward the second portion surrounded by the second surrounding hole portion group (32) The direction of the center of gravity (G2) of the target portion (82), so compared with the case where the extending direction (D2) is parallel to the magnetic pole center line (90), the stress can be alleviated when the rotor (2) rotates in the second Concentration of the offset bridge (52). As a result, the strength of the rotor core (15) against centrifugal force can be appropriately ensured, and the width of the second offset bridge portion (52) can be reduced in addition to the width of the first offset bridge portion (51). .

[0086] In addition, when the rotor (2) rotates, the second offset bridge portion (52) supports the second object portion (82) surrounded by the second surrounding hole portion group (32) against centrifugal force. Furthermore, considering a simplified model, since centrifugal force acts on the center of gravity of the object, when the rotor (2) rotates, a tensile load on the side of the center of gravity (G2) of the second object portion (82) acts on the second bias The bridge part (52) is installed. In this regard, according to the above-mentioned structure, since the extending direction ( D2 ) of the second offset bridge portion ( 52 ) in the cross-section orthogonal to the axial direction (L) is along the center of gravity ( G2 ) toward the second object portion ( 82 ) ) direction, so the extending direction (D2) of the second offset bridge portion (52) can be aligned with the direction in which the above-mentioned tensile load acts, reducing the amount of friction in the second offset bridge portion (52) when the rotor (2) rotates. The resulting bending stress. In addition, the bending stress generated in the second offset bridge portion (52) is reduced, and accordingly, the stress concentration on the second offset bridge portion (52) when the rotor (2) is rotated can be alleviated. As a result, it is possible to ensure The strength of the rotor core (15) against centrifugal force, and the width of the second offset bridge portion (52) can be suppressed to be small.

[0087] In the rotor (2) for a rotating electrical machine of each of the above-mentioned structures, it is preferable that a portion forming the offset bridge portion (51) among the outer edges of each of the two hole portions (20) is used as a bridge forming edge portion (20b). In a cross section perpendicular to the axial direction (L), the bridges on one side of the two hole portions (20) are formed as edge portions (20b) and the bridges on the other side are formed as two of the edge portions (20b). The common inscribed lines are respectively a first straight line (T1) and a second straight line (T2), and the extension direction (D1) of the offset bridge portion (51) in the cross-section perpendicular to the axial direction (L) is along the The direction of the line segment that bisects the angle contained by the first straight line (T1) and the second straight line (T2) and does not intersect the two holes (20).

[0088] According to this structure, the extending direction ( D1 ) of the offset bridge portion ( 51 ) can be appropriately set.

[0089] A rotor (2) for a rotating electrical machine, comprising a rotor core (15) and permanent magnets (60) arranged in the rotor core (15), wherein the rotor core (15) includes a plurality of magnetic poles (P), respectively. The plurality of holes (20) include a first hole (21) and a second hole (22) in which the permanent magnet (60) having a planar magnetic pole face (F) is disposed, respectively. ), the above-mentioned first hole portion (21) and the above-mentioned second hole portion (22) are in such a way that the separation distance in the circumferential direction (C) of each other becomes longer toward the outer side in the radial direction (R), relative to the passage through the above-mentioned The magnetic pole center lines (90) extending in the circumferential direction (C) of the magnetic poles (P) along the radial direction (R) are arranged to be separated on both sides of the circumferential direction (C), and the rotor core (15) has a plurality of One bridge portion (41) formed between two of the above-mentioned hole portions (20) adjacent to the above-mentioned circumferential direction (C), among the plurality of the above-mentioned bridge portions (41), the number of the bridge portions (41) relative to the above-mentioned magnetic pole center line (90) is included. ) The offset bridge portion (51) located at a position offset in the circumferential direction (C), in a cross section orthogonal to the axial direction (L), the offset bridge portion (51) is formed so as to face the magnetic pole center The center of gravity (G1) on the line (90) corresponding to the above-mentioned magnetic pole (P) on which the offset bridge portion (51) is formed.

[0090] According to this structure, in the cross section orthogonal to the axial direction (L), the offset bridge portion (51) is formed so as to face the magnetic pole ( P) corresponds to the center of gravity (G1), so compared with the case where the offset bridge (51) is not formed to face the center of gravity (G1), it is possible to reduce the friction in the offset bridge (51) when the rotor (2) rotates Stress concentration. As a result, the strength of the rotor core (15) against centrifugal force can be appropriately ensured, and the width of the offset bridge portion (51) can be reduced.

[0091] In addition, when the rotor (2) rotates, the offset bridge portion (51) supports the radially outer portion of the rotor core (15) in the magnetic pole (P) provided with the offset bridge (51) against centrifugal force. Furthermore, considering a simplified model, since centrifugal force acts on the center of gravity of the object, when the rotor (2) rotates, the center of gravity (G1) on the magnetic pole center line (90) corresponding to each magnetic pole (P) is oriented toward the side of the center of gravity (G1). A tensile load acts on the offset bridge (51). In this regard, according to the above-mentioned configuration, in the cross section orthogonal to the axial direction (L), the offset bridge portion (51) is formed so as to face the center of gravity ( G1), the direction of the offset bridge portion (51) can be aligned with the direction in which the above-mentioned tensile load acts to reduce the bending stress generated on the offset bridge portion (51) when the rotor (2) rotates. In addition, the bending stress generated in the offset bridge portion (51) is reduced, and accordingly the concentration of stress on the offset bridge portion (51) when the rotor (2) rotates can be alleviated. As a result, the rotor against centrifugal force can be secured. The strength of the core (15) and the width of the offset bridge portion (51) can be suppressed to be small.

[0092] As described above, according to the above configuration, it is possible to realize the rotor (2) for a rotating electrical machine which can appropriately ensure the strength of the rotor core (15) against centrifugal force and can reduce the width of the offset bridge portion (51).

[0093] In addition, according to the above configuration, since the permanent magnet (60) having the planar magnetic pole face (F) can be used as the permanent magnet (60) arranged in the first hole (21) and the second hole (22), Therefore, compared with the case of using a permanent magnet having a curved magnetic pole face, there is an advantage that the cost can be kept low and the required residual magnetic flux density can be easily secured. In addition, since the first hole portion (21) and the second hole portion (22) are arranged so that the separation distance in the circumferential direction (C) from each other becomes longer toward the outer side in the radial direction (R), it also has the advantage of being able to use magnetic resistance torque.

[0094] Here, it is preferable that the offset bridge portion (51) is formed at a specific portion (70) where the interval between the two hole portions (20) is the narrowest in a cross section perpendicular to the axial direction (L).

[0095] According to this configuration, since the interval between the two hole portions (20) is narrow, as described above, the specific portion (70) where the strength is likely to be low can be formed to relieve the concentration of stress when the rotor (2) rotates. Set the bridge part (51). Therefore, when the rotor (2) rotates, the concentration of stress in the specific portion (70) can be alleviated, and as a result, the strength required for the specific portion (70) can be easily secured.

[0096] Preferably, in the structure in which the offset bridge portion (51) is formed at the specific portion (70) as described above, the circumferential direction passing through the specific portion (70) in a cross section orthogonal to the axial direction (L) is preferably The straight line between the end of one side (C1) of (C) and the center of gravity (G1) is a third straight line (T3), which will pass through the other side (C2) of the circumferential direction (C) of the specific portion (70). The straight line between the end of the center of gravity (G1) and the center of gravity (G1) is the fourth straight line (T4). The above-mentioned offset bridge portion (51) is formed in the clamping region, and the entirety of the two hole portions (20) sandwiching the above-mentioned offset bridge portion (51) from both sides of the above-mentioned circumferential direction (C) is arranged in the above-mentioned No. The outer side of the area sandwiched by the three straight lines (T3) and the above-mentioned fourth straight line (T4).

[0097] According to this configuration, the offset bridge portion (51) can be formed from the specific portion (70) toward the center of gravity (G1) in a cross-section perpendicular to the axial direction (L). Therefore, when the rotor (2) rotates, the concentration of stress in the specific portion (70) can be further alleviated.

[0098] The rotor for a rotating electrical machine of the present disclosure may exhibit at least one of the aforementioned effects.