Rotor of rotary electric machine

Abstract

A rotor of a rotary electric machine in which the outer peripheral surface of a rotor and the inner peripheral surface of a stator are coaxially disposed comprises a plurality of sub-rotors stacked in the axial direction of the rotary electric machine. Each of the sub-rotors included among the plurality of sub-rotors is provided with a sub-rotor core, a cylindrical cylinder portion that covers the circumferential-direction side surface of the sub-rotor core, and a flange portion that covers at least part of the axial-direction end surface of the sub-rotor core.

Description

Rotor of a rotating electric machine

[0001] The present invention relates to a rotor for a rotating electric machine.

[0002] With growing global awareness of protecting the global environment, the automotive industry is shifting from traditional internal combustion engines to electric motors, which do not emit greenhouse gases during operation. Electric drive systems, essential for vehicle electrification, include a power converter, an electric motor, and a reduction gear to extract driving force from the power supplied by the battery. In electric vehicles, the driving range is determined by battery capacity, making it an important performance indicator. Therefore, miniaturization of drive systems other than the battery is required to balance securing interior space and increasing the battery capacity. In particular, miniaturization of motors, whose main components are metal, is also required from the perspective of weight reduction. Because it is difficult to suppress output while maintaining driving force, the mainstream approach is to combine a reduction gear with a high reduction ratio to increase the motor's rotation speed, thereby suppressing motor torque and reducing the motor's size. Patent document 1 discloses a rotor for a rotating electric machine that includes a rotating shaft, a rotor core made of a magnetic material fixed to the rotating shaft, a plurality of magnets arranged on the outer surface of the rotor core, plate-shaped end plates made of a non-magnetic material that cover the axial end faces of the rotor core on which the magnets are arranged, and a cylindrical magnet cover made of a non-magnetic material that covers the outer surface of the rotor core on which the magnets are arranged, wherein the axial end of the magnet cover covers the outer surface of the end plate and is folded back toward the axis center around the entire circumference on the side of the end plate opposite the rotor core.

[0003] Japanese Patent Application Publication No. 2014-050244

[0004] In the invention described in Patent Document 1, there is room for improvement in suppressing radial deformation of the member covering the side surface of the rotor core.

[0005] The rotor of a rotating electric machine according to a first aspect of the present invention is a rotor of a rotating electric machine in which the outer peripheral surface of the rotor and the inner peripheral surface of the stator are arranged coaxially, and the rotor is provided with a plurality of sub-rotors stacked in the axial direction of the rotating electric machine, and each of the sub-rotors included in the plurality of sub-rotors comprises a sub-rotor core, a cylindrical portion covering the circumferential side surface of the sub-rotor core, and a flange portion covering at least a portion of the axial end surface of the sub-rotor core.

[0006] According to the present invention, it is possible to suppress radial deformation of the member covering the side surface of the rotor core.

[0007] FIG. 1 shows the structure of the sub-rotor. FIG. 2 shows the rotor. FIG. 3 shows the names of the parts of the sub-rotor. FIG. 4 shows the measurement results of the radial displacement. FIG. 5 shows the rotor in the second embodiment. FIG. 6 shows the shape of the sleeve in the third embodiment. FIG. 7 shows the shape of the sleeve in the fourth embodiment. FIG. 8 shows the shape of the sleeve in the fifth embodiment. FIG. 9 shows the sub-rotor in the fifth embodiment.

[0008] First Embodiment A rotor for a rotating electrical machine according to a first embodiment will now be described with reference to FIGS.

[0009] FIG. 1 is a diagram showing the structure of a first sub-rotor 101 that constitutes a rotor 203. The rotor 203 constitutes a rotating electric machine 1 and is composed of multiple sub-rotors 100. In this embodiment, each sub-rotor 100 has the same shape, but here, one of the sub-rotors 100 will be referred to as the first sub-rotor 101 to explain the configuration. The rotating electric machine 1 is, for example, a motor or a generator. The rotor 203 has a rotating shaft 104 extending left and right in the figure. In other words, the axial direction of the rotating electric machine 1 is the left and right direction in FIG. 1.

[0010] The first sub-rotor 101 includes a sub-rotor core 111 formed by stacking discs, a rotating shaft 114 that supports the rotation of the first sub-rotor 101, and a first sleeve 102 that is arranged on the outer periphery of the sub-rotor core 111. The discs that make up the sub-rotor core 111 are preferably made of a magnetic material. The first sleeve 102 is preferably made of a non-magnetic material, but the material is not particularly limited. The first sleeve 102 includes a first cylindrical portion 112 that is arranged along the outer periphery of the first sub-rotor 101, and a first flange portion 113 that is provided parallel to one axial end face of the sub-rotor core 111. It can also be said that the first cylindrical portion 112 covers the circumferential side surface of the sub-rotor core 111. The first flange portion 113 covers at least a portion of the axial end face of the sub-rotor core 111.

[0011] FIG. 2 is a diagram showing a rotor 203. The rotor 203 is formed by stacking the first sub-rotors 101 shown in FIG. 1 in the axial direction. The rotating shaft 204 may be shared by the first sub-rotors 101 stacked in the axial direction. If the rotating shaft 204 cannot be shared by multiple first sub-rotors 101, all of the first sub-rotors 101 may be arranged on the same axis. In the axial direction of the rotor 203, i.e., the left-right direction in FIG. 2, multiple first flange portions 113 of the first sleeve 102 provided on the first sub-rotor 101 are arranged in the axial direction. The multiple first flange portions 113 support the first cylindrical portion 112 of the first sleeve 102 in the inner diameter direction, which has the effect of suppressing the amount of deformation in the radial direction.

[0012] 3 is a diagram showing the names of parts of the first sub-rotor 101. The diameter of the first sleeve 102 is called the sleeve diameter D, the axial length of the first sleeve 102 is called the sleeve axial length L, and the thickness of the first sleeve 102 is called the sleeve thickness t. The inventors of the present application created first sub-rotors 101 with various sleeve diameters D, sleeve axial lengths L, and sleeve thicknesses t, and found a suitable relationship.

[0013] FIG. 4 shows the measurement results of the radial displacement s using an actually fabricated first sub-rotor 101. The inventors of the present application fabricated first sub-rotors 101 with various sleeve diameters D, sleeve axial lengths L, and sleeve thicknesses t. Then, the radial displacement s of each first sub-rotor 101 was measured. Note that in FIG. 4, a correlation line 80 showing the correlation between dimensions and radial displacement s is shown by a dashed line. Also in FIG. 4, the same plot is used for cases where the sleeve thickness t is constant. The correlation line 80 is expressed by the following equation 1:

[0014] s / (t / L) －３ = A x exp(B x D ２ / (t / L)) ... (Formula 1)

[0015] In Equation 1, A and B represent constants, and x is a multiplication symbol. The left side of Equation 1 represents an operation of dividing the radial displacement s by the value obtained by dividing the sleeve thickness t by the sleeve axial length L. Hereinafter, the left side of Equation 1 will also be referred to as the first physical quantity. The multiplier of the natural logarithm on the right side of Equation 1 will be referred to as the second physical quantity. This second physical quantity is the value obtained by dividing the cross-sectional area of ​​the first sub-rotor 101 by the value indicating the ratio between the sleeve thickness t and the sleeve axial length L. As such, the measurement results shown in FIG. 4 indicate that the first physical quantity and the second physical quantity have an exponential relationship. By using Equation 1, the sleeve axial length L that can effectively suppress the radial displacement s can be calculated using the sleeve diameter D and sleeve thickness t.

[0016] The first embodiment described above provides the following advantageous effects. (1) The rotor 203 of the rotating electric machine 1 includes a plurality of first sub-rotors 101 stacked in the axial direction of the rotating electric machine 1, i.e., the left-right direction in FIG. 1-3 . Each of the first sub-rotors 101 includes a sub-rotor core 111, a cylindrical first cylindrical portion 112 that covers the circumferential side surface of the sub-rotor core 111, and a first flange portion 113 that covers at least a portion of the axial end surface of the sub-rotor core 111. This makes it possible to suppress radial deformation of the first cylindrical portion 112, which is a member that covers the side surface of the sub-rotor core 111.

[0017] - Second embodiment - A rotor for a rotating electric machine according to a second embodiment will be described with reference to Figure 5. In the following description, the same components as those in the first embodiment will be assigned the same reference numerals, and differences will be mainly described. Points that are not specifically described are the same as those in the first embodiment. This embodiment differs from the first embodiment mainly in that the end of the sleeve is not open.

[0018] Fig. 5 is a diagram showing a rotor 203A according to the second embodiment, corresponding to Fig. 2 for the first embodiment. The rotor 203A includes a plurality of first sub-rotors 101 and one second sub-rotor 501. The configuration of the first sub-rotor 101 is the same as that of the first embodiment, so a description thereof will be omitted. The second sub-rotor 501 includes a sub-rotor core 111, a rotating shaft 114, a first sleeve 102, and a second sleeve 502. For convenience of illustration, the sub-rotor core 111 and the rotating shaft 114 are omitted from Fig. 5.

[0019] As described above, the first sleeve 102 includes the first cylindrical portion 112 and the first flange portion 113. The second sleeve 502 includes a cylindrical second cylindrical portion 512 that covers the circumferential side surface of the sub rotor core 111, and a second flange portion 513 that covers at least a portion of the axial end surface of the sub rotor core 111. The first sleeve 102 and the second sleeve 502 are opposite in orientation in the axial direction. In other words, the first sleeve 102 and the second sleeve 502 have in common the fact that they are arranged coaxially with the rotor 203A, but their orientations are opposite.

[0020] In the example shown in FIG. 5 , the first sleeve 102 is disposed on the right side of the figure, and the second sleeve 502 is disposed on the left side of the figure. The first flange portion 113 of the first sleeve 102 contacts the right end of the sub rotor core 111, and the second flange portion 513 of the second sleeve 502 contacts the left end of the sub rotor core 111. The inner diameter of the second cylindrical portion 512 is equal to or greater than the outer diameter of the first cylindrical portion 112. However, the two may have the same dimensions, or the outer diameter of the first cylindrical portion 112 may be slightly larger than the inner diameter of the second cylindrical portion 512 and inserted by shrink fitting or the like. At least the ends of the first cylindrical portion 112 and the second cylindrical portion 512 overlap each other in the radial direction.

[0021] The second embodiment described above provides the following advantageous effects. (2) The second sub-rotor 501, which is at least one sub-rotor included in the multiple sub-rotors 100 that make up the rotor 203A, includes a first sleeve 102 and a second sleeve 502 that cover the sub-rotor core 111. The first sleeve 102 includes a first cylindrical portion 112 and a first flange portion 113 that covers the end on the right side in the figure. The second sleeve 502 includes a second cylindrical portion 512 and a second flange portion 513 that covers the end on the left side in the figure. The inner diameter of the second cylindrical portion 512 is equal to or greater than the outer diameter of the first cylindrical portion 112. The end of the second cylindrical portion 512 radially overlaps the end of the second cylindrical portion 512. Therefore, by overlapping the first cylindrical portion 112 and the second cylindrical portion 512, deformation of the end on the left side in the figure, where the first flange portion 113 is not located, can be suppressed by the second flange portion 513.

[0022] (First Modification of the Second Embodiment) In the second embodiment described above, the second sleeve 502 has a larger diameter than the first sleeve 102. However, the size relationship between the first sleeve 102 and the second sleeve 502 may be reversed. That is, the inner diameter of the first cylindrical portion 112 may be equal to or greater than the outer diameter of the second cylindrical portion 512.

[0023] This modification provides the following advantageous effects: (3) The inner diameter of the first cylindrical portion 112 of the first sub-rotor 101 is in a fit-fit relationship with the outer diameter of the cylindrical portion of the second sub-rotor 501. Therefore, even if the size relationship is reversed, the same advantageous effects as those of the second embodiment can be obtained.

[0024] (Second Modification of the Second Embodiment) The positions of the first sleeve 102 and the second sleeve 502 may be interchanged. Also, the positions of the first sub-rotor 101 and the second sub-rotor 501 may be interchanged.

[0025] -Third embodiment- A rotor for a rotating electric machine according to a third embodiment will be described with reference to Fig. 6. In the following description, the same components as those in the first embodiment are designated by the same reference numerals, and differences will be mainly described. Points that are not specifically described are the same as those in the first embodiment. In this embodiment, the main difference from the first embodiment is the shape of the sleeve.

[0026] In the third embodiment, a third sub-rotor 601 is provided instead of the first sub-rotor 101. The third sub-rotor 601 includes a sub-rotor core 111, a rotating shaft 114, and a third sleeve 602.

[0027] Fig. 6 is a diagram showing a rotor 203B according to the third embodiment. The rotor 203B includes a plurality of third sub-rotors 601. Each third sub-rotor 601 includes a sub-rotor core 111, a rotating shaft 114, and a third sleeve 602. For convenience of illustration, the sub-rotor cores 111 and the rotating shafts 114 are omitted from Fig. 6.

[0028] The third sleeve 602 includes a cylindrical third cylindrical portion 612 that covers the circumferential side surface of the sub rotor core 111, a third flange portion 613 that covers at least a portion of the axial end face of the sub rotor core 111, and a first protrusion 614 that is provided at a corner that connects the third cylindrical portion 612 and the third flange portion 613. The first protrusion 614 protrudes from the third flange portion 613 on the opposite side of the axial direction from the third cylindrical portion 612, i.e., to the right side in the figure.

[0029] The presence of the first protrusion 614 allows the radius, or radius, of the connection between the third cylindrical portion 612 and the third flange portion 613 to be increased. This has the following effects. First, stress concentration at the connection between the third cylindrical portion 612 and the third flange portion 613 can be reduced. Furthermore, as described below, it also has the effect of suppressing deformation of the third sleeve 602. That is, the first protrusion 614 receives a force in the circumferential direction due to rotational centrifugal force during rotation, and thus pulls the third flange portion 613 radially together with the third sleeve 602. This tensile force reduces axial bending stress and increases radial tensile stress in the stress generated in the third sleeve 602. As described above, the higher rigidity against tension than bending suppresses deformation of the third sleeve 602.

[0030] The third embodiment described above provides the following advantageous effects. (4) The third sub-rotor 601 includes a first protruding portion 614 that is provided at a corner portion connecting the third cylindrical portion 612 and the third flange portion 613 and that protrudes beyond the third flange portion 613 in the axial direction of the rotating electric machine, i.e., the left-right direction in FIG. 6 , opposite the third cylindrical portion 612. This reduces stress concentration at the connection portion between the third cylindrical portion 612 and the third flange portion 613. Furthermore, this also provides the effect of suppressing deformation of the third sleeve 602.

[0031] Fourth Embodiment A rotor for a rotating electric machine according to a fourth embodiment will be described with reference to Fig. 7. In the following description, the same components as those in the third embodiment are designated by the same reference numerals, and differences will be mainly described. Points that are not specifically described are the same as those in the third embodiment. This embodiment differs from the third embodiment mainly in the shape of the protrusions.

[0032] FIG. 7 is a diagram showing a rotor 203C according to the fourth embodiment. The rotor 203C includes a plurality of fourth sub-rotors 701. Each fourth sub-rotor 701 includes a sub-rotor core 111, a rotating shaft 114, and a fourth sleeve 702. For convenience of illustration, the sub-rotor core 111 and the rotating shaft 114 are omitted from FIG. 7 . The fourth sleeve 702 includes a fourth cylindrical portion 712, a fourth flange portion 713, and a second protruding portion 714, similar to the third sleeve 602 according to the third embodiment. The second protruding portion 714 according to the present embodiment differs from the third embodiment in that it is located on the outer periphery of the fourth cylindrical portion 712 relative to the outer diameter of the fourth cylindrical portion 712.

[0033] When the fourth sleeves 702 are lined up in the axial direction, the fourth cylindrical portion 712 and the second protruding portion 714 of adjacent fourth sleeves 702 overlap in the radial direction. Focusing on one fourth sleeve 702, the farther the fourth cylindrical portion 712 is positioned axially away from the connection portion with the fourth flange portion 713, the smaller the supporting effect of the fourth flange portion 713 becomes, and the greater the amount of radial deformation. In this embodiment, by covering the fourth cylindrical portion 712 from the outer periphery with the second protruding portion 714 of the adjacent fourth sleeve 702, the effect of suppressing deformation of the fourth cylindrical portion 712 is obtained.

[0034] According to the fourth embodiment described above, the following advantageous effects can be obtained: (5) The fourth flange portion 713 is radially larger than the fourth cylindrical portion 712. Therefore, deformation of the fourth cylindrical portion 712 is suppressed.

[0035] Fifth Embodiment A rotor for a rotating electric machine according to a fifth embodiment will be described with reference to Fig. 8. In the following description, the same components as those in the first embodiment will be assigned the same reference numerals, and differences will be mainly described. Points that are not specifically described are the same as those in the first embodiment. This embodiment differs from the first embodiment mainly in that the sub-rotors are fitted together.

[0036] Fig. 8 is a diagram showing a rotor 203D according to the fifth embodiment. The rotor 203D includes a plurality of fifth sub-rotors 801. Each fifth sub-rotor 801 includes a sub-rotor core 111, a rotating shaft 114, and a fifth sleeve 802. For convenience of illustration, the sub-rotor cores 111 and the rotating shafts 114 are omitted from Fig. 8.

[0037] The fifth sleeve 802, like the first sleeve 102 in the first embodiment, includes a fifth cylindrical portion 812 and a fifth flange portion 813. The fifth sleeve 802 also includes an annular protrusion 860, similar to the second protrusion 714 in the fourth embodiment, at the tip of the fifth cylindrical portion 812, on the end opposite the fifth flange portion 813, i.e., on the left side in the figure. The fifth flange portion 813 includes a groove portion 870 that is a groove that fits into the annular protrusion 860. It is desirable that the protrusion height of the annular protrusion 860 and the groove depth of the groove portion 870 are the same. The fifth sleeve 802 in this embodiment has the effect of suppressing deformation of the opening of the fifth cylindrical portion 812. Furthermore, because the groove portion 870 and the tip of the fifth sleeve 802 are mechanically fastened together, the fifth sub-rotor 801 is effectively fixed in the axial direction.

[0038] According to the fifth embodiment described above, the following advantageous effects can be obtained. (6) The fifth cylindrical portion 812 has an annular protrusion 860, which is an annular protrusion, on the end opposite the fifth flange portion 813. The fifth flange portion 813 has a groove portion 870, which is a groove into which the annular protrusion 860 provided on the other fifth sub-rotor 801 is inserted. Therefore, deformation of the opening of the fifth cylindrical portion 812 can be suppressed, and the fifth sub-rotor 801 can be fixed in the axial direction.

[0039] Sixth Embodiment A rotor for a rotating electric machine according to a sixth embodiment will be described with reference to Fig. 9. In the following description, the same components as those in the first embodiment will be assigned the same reference numerals, and differences will be mainly described. Points that are not specifically described are the same as those in the first embodiment. This embodiment differs from the first embodiment mainly in that sleeves of different shapes are combined.

[0040] FIG. 9 is a diagram showing a rotor 203E according to the sixth embodiment. The rotor 203E includes multiple sixth sub-rotors 901. However, for convenience of drawing, only one sixth sub-rotor 901 is shown in FIG. 9 . The sixth sub-rotor 901 includes a sub-rotor core 111, a rotating shaft 114, and a sixth sleeve 902. For convenience of drawing, the sub-rotor core 111 and the rotating shaft 114 are omitted from FIG. 9 . The sixth sleeve 902 is composed of a first part 902-1, a second part 902-2, and a third part 902-3. The first part 902-1 includes a one-end cylindrical portion 912A and a one-end flange portion 913A. The second part 902-2 includes a central cylindrical portion 912B. The third part 902-3 includes a second-end cylindrical portion 912C and a second-end flange portion 913C. In this embodiment, the left end of the sub rotor core 111 (not shown) is referred to as "one end", and the right end of the sub rotor core 111 is referred to as "the other end".

[0041] The one-end cylindrical portion 912A covers at least the circumferential side surface of one axial end of the sub rotor core 111. The central cylindrical portion 912B covers at least the circumferential side surface of the sub rotor core 111 at approximately the center in the axial direction. The other-end cylindrical portion 912C covers at least the circumferential side surface of the other end of the sub rotor core 111, which is opposite to the one axial end. The one-end flange portion 913A covers at least a portion of the end face at one end of the sub rotor core 111. The other-end flange portion 913C covers at least a portion of the end face at the other end of the sub rotor core 111. The diameter of the central cylindrical portion 912B is smaller than the one-end cylindrical portion 912A and the other-end cylindrical portion 912C. At least one end of the central cylindrical portion 912B radially overlaps with the one-end cylindrical portion 912A, and at least the other end of the central cylindrical portion 912B radially overlaps with the other-end cylindrical portion 912C. The first part 902-1 and the third part 902-3 may be formed to have the same shape and may be inverted to be used as the other part.

[0042] According to the sixth embodiment described above, the following advantageous effects can be obtained. (7) The sixth cylindrical portion 912 includes a one-end cylindrical portion 912A, a central cylindrical portion 912B, and an other-end cylindrical portion 912C. The sixth flange portion 913 includes a one-end flange portion 913A and an other-end flange portion 913C. The one-end cylindrical portion 912A covers at least the circumferential side surface of one axial end of the sub rotor core 111. The central cylindrical portion 912B covers at least the circumferential side surface of the sub rotor core 111 at approximately the center in the axial direction. The other-end cylindrical portion 912C covers at least the circumferential side surface of the other end of the sub rotor core 111, which is opposite to the one axial end. The one-end flange portion 913A covers at least a portion of the end face at one end of the sub rotor core 111. The other-end flange portion 913C covers at least a portion of the end face at the other end of the sub rotor core 111. This suppresses radial deformation of the end of the sixth sleeve 902. In addition, since the sixth sleeve 902 is not divided in the axial direction, it has the effect of preventing rotor parts from scattering radially in the event of breakage.

[0043] The above-described embodiments and modifications may be combined with each other. For example, sub-rotors in different embodiments may be combined with each other. Although various embodiments and modifications have been described above, the present invention is not limited to these. Other aspects that can be considered within the technical scope of the present invention are also included within the scope of the present invention.

[0044] 100: Sub-rotor 101: First sub-rotor 102: First sleeve 111: Sub-rotor core 112: First cylindrical portion 113: First flange portion 203-203E: Rotor 614: First protrusion 714: Second protrusion 860: Annular projection 870: Groove portion 912: Sixth cylindrical portion 912A: One end cylindrical portion 912B: Central cylindrical portion 912C: Other end cylindrical portion 913: Sixth flange portion 913A: One end flange portion 913C: Other end flange portion

Claims

1. A rotor for a rotating electric machine in which the outer peripheral surface of the rotor and the inner peripheral surface of the stator are arranged coaxially, and which comprises a plurality of sub-rotors stacked in the axial direction of the rotating electric machine, each of the sub-rotors comprising a sub-rotor core, a cylindrical portion covering the circumferential side surface of the sub-rotor core, and a flange portion covering at least a portion of the axial end face of the sub-rotor core.

2. A rotor for a rotating electric machine as described in claim 1, wherein a second sub-rotor, which is at least one sub-rotor included in the plurality of sub-rotors, comprises a first sleeve and a second sleeve covering the sub-rotor core, the first sleeve comprising a first cylindrical portion which is the first of the cylindrical portions, and a first flange portion which covers at least a portion of an end face at one end of the sub-rotor core, the second sleeve comprising a second cylindrical portion which is the second of the cylindrical portions, and a second flange portion which covers at least a portion of an end face at the other end opposite to the one end of the sub-rotor core, the inner diameter of the second cylindrical portion being equal to or greater than the outer diameter of the first cylindrical portion, and the end of the first cylindrical portion radially overlaps the end of the second cylindrical portion.

3. A rotor for a rotating electric machine as described in claim 1, wherein a second sub-rotor, which is at least one sub-rotor included in the plurality of sub-rotors, comprises a first sleeve and a second sleeve covering the sub-rotor core, the first sleeve comprising a first cylindrical portion which is the first of the cylindrical portions, and a first flange portion which covers at least a portion of an end face at one end of the sub-rotor core, the second sleeve comprising a second cylindrical portion which is the second of the cylindrical portions, and a second flange portion which covers at least a portion of an end face at the other end opposite to the one end of the sub-rotor core, and the inner diameter of the second cylindrical portion is in a fitting relationship with the outer diameter of the first cylindrical portion.

4. A rotor for a rotating electric machine as described in claim 1, wherein at least one of the sub-rotors included in the plurality of sub-rotors is provided at a corner portion connecting the cylindrical portion and the flange portion, and further comprises a protrusion that protrudes beyond the flange portion in the axial direction of the rotating electric machine in the opposite direction to the cylindrical portion.

5. A rotor for a rotating electric machine according to claim 4, wherein the flange portion is radially larger than the cylindrical portion.

6. A rotor for a rotating electric machine as described in claim 1, wherein the cylindrical portion has an annular protrusion at the end opposite to the flange portion, and the flange portion has a groove portion into which the annular protrusion provided on another sub-rotor is inserted.

7. A rotor for a rotating electric machine according to claim 1, wherein the cylindrical portion includes a one-end cylindrical portion, a central cylindrical portion, and an other-end cylindrical portion, the flange portion includes a one-end flange portion and an other-end flange portion, the one-end cylindrical portion covers at least the circumferential side surface of one axial end of the sub-rotor core, the central cylindrical portion covers at least the circumferential side surface of the sub-rotor core at approximately the center in the axial direction, the other-end cylindrical portion covers at least the circumferential side surface of the other axial end of the sub-rotor core that is on the opposite side to the one end, the one-end flange portion covers at least a part of the end face at the one end of the sub-rotor core, the other-end flange portion covers at least a part of the end face at the other end of the sub-rotor core, the one-end cylindrical portion and the one-end flange portion are formed integrally, the other-end cylindrical portion and the other-end flange portion are formed integrally, an end of the central cylindrical portion close to the one-end cylindrical portion radially overlaps the one-end cylindrical portion, a rotor for a rotating electric machine, wherein an end of the central cylindrical portion close to the other end cylindrical portion radially overlaps with the other end cylindrical portion;

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