Magnet rotor and generator

Abstract

To provide a magnet rotor and a power generator, which can achieve miniaturization and weight-saving of a yoke and secure locking of a clutch mechanism.SOLUTION: A magnet rotor includes a yoke and a plurality of permanent magnets. In the yoke, a rotation axis is connected to a center of a bottom wall, and a clutch locking part for positioning a clutch mechanism is provided in an area radially outside a connection part of the bottom wall and the rotation axis. The plurality of permanent magnets are fixed to a peripheral wall of the yoke. The clutch locking part is composed of a plurality of cut-and-rise pieces which are cut and raised from the bottom wall of the yoke. The power generator includes the magnet rotor and a stator. The stator is arranged by facing the permanent magnet at an inner side of the yoke and a coil is wound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a magnet rotor and a generator. [Background technology]

[0002] Some vehicle engines have a generator directly connected to the rotating shaft. The generator used here has a magnet rotor connected to the rotating shaft of the engine, and a stator attached to the engine cover or the like so that it faces a permanent magnet fixed to the peripheral wall of the magnet stator. When the magnet rotor rotates together with the rotating shaft of the engine, the generator outputs generated electricity to a power storage device or on-board electrical equipment through a coil wound around the stator.

[0003] Another generator of this type has a magnet rotor equipped with a one-way clutch that can be connected to an engine starting motor via the one-way clutch. When starting the engine, the engine starting motor transmits torque to the engine's rotating shaft via the one-way clutch and the magnet rotor, starting the engine with that torque. Once the engine starts and the rotational speed of the rotating shaft increases, the one-way clutch interrupts the power transmission between the engine starting motor and the rotating shaft. In this generator, the clutch mechanism of the one-way clutch is positioned on the magnet rotor, and in this state, the clutch mechanism is fixed to the magnet rotor by bolting or the like.

[0004] In this type of generator, the magnet rotor has a cylindrical yoke with a bottom, the bottom wall of which is fixed to the end of the rotating shaft via a boss. The clutch mechanism is fitted and locked by a clutch locking portion (spigot portion) formed on the flange portion of the boss, and in this state is fixed to the bottom wall of the yoke by bolts or the like.

[0005] However, in the case of conventional magnet rotors, the flange and clutch locking portion are integrally formed with the boss that secures the yoke to the rotating shaft, which tends to increase the size of the boss and make the entire magnet rotor larger and heavier.

[0006] To address this issue, a magnet rotor has been proposed in which a clutch locking portion is integrally formed by stamping on the bottom wall of a cylindrical yoke with a bottom (see, for example, Patent Document 1).

[0007] The magnet rotor described in Patent Document 1 has a circular clutch locking portion formed by stamping into the bottom wall of a cylindrical yoke with a bottom, the circular clutch locking portion being recessed in a stepped shape axially inward of the yoke. In the clutch mechanism of the one-way clutch, the outer race is fitted and locked into the circular clutch locking portion, and in this state the outer race is fastened to the bottom wall of the yoke with bolts. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 4705639 Summary of the Invention [Problem to be solved by the invention]

[0009] However, in the magnet rotor described in Patent Document 1, the clutch locking portion is formed by stamping on the bottom wall of the yoke, so in order to ensure a sufficient locking margin (locking depth) of the clutch locking portion with respect to the outer circumferential surface of the clutch mechanism (outer race), the thickness of the bottom wall of the yoke must be made thicker than a certain level. This is undesirable from the perspective of making magnet rotors smaller and lighter, and further improvements are desired.

[0010] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a magnet rotor that can achieve both a small and lightweight yoke and a reliable engagement of the clutch mechanism. [Means for solving the problem]

[0011] In order to solve the above problems, the magnet rotor and generator according to the present invention employ the following configurations. That is, the magnet rotor of the present invention comprises a cylindrical yoke with a bottom, a rotating shaft connected to the center of the bottom wall, and a clutch engagement portion for positioning a clutch mechanism provided in a radially outer region of the connection portion of the bottom wall with the rotating shaft, and a plurality of permanent magnets fixed to the peripheral wall of the yoke, and the clutch engagement portion is characterized in that it is composed of a plurality of cut-out pieces cut and raised from the bottom wall of the yoke.

[0012] The generator according to the present invention is characterized in that it comprises the magnet rotor and a stator arranged inside the yoke facing the permanent magnet and around which a coil is wound. [Effects of the Invention]

[0013] In the magnet rotor according to the present invention, the clutch locking portion is formed by a plurality of cut-and-raised pieces cut and raised from the bottom wall of the yoke. Therefore, compared to when the clutch locking portion is formed by stamping out the bottom wall of the yoke, the clutch mechanism can be reliably locked by the plurality of cut-and-raised pieces without increasing the thickness of the bottom wall of the yoke. Therefore, when the magnet rotor according to the present invention is used, it is possible to achieve both a small and lightweight yoke and reliable engagement of the clutch mechanism. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 2 is a longitudinal cross-sectional view of the generator according to the embodiment. [Figure 2] FIG. 2 is a perspective view of a magnet rotor according to the embodiment. [Figure 3] FIG. 2 is a longitudinal sectional view of the magnet rotor according to the embodiment. [Figure 4] FIG. 3 is an enlarged perspective view of a portion IV of the magnet rotor of the embodiment shown in FIG. 2. [Figure 5] FIG. 3 is an enlarged front view of a portion IV of the magnet rotor of the embodiment shown in FIG. 2. [Figure 6] FIG. 6 is an enlarged front view corresponding to FIG. 5 of another embodiment 1. [Figure 7] FIG. 6 is an enlarged front view of another embodiment corresponding to FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments described below, the same components will be designated by common reference numerals and overlapping descriptions will be omitted.

[0016] FIG. 1 is a vertical cross-sectional view of a generator 1 according to this embodiment. The generator 1 is an outer rotor type AC generator and includes a magnet rotor 3 connected to the rotating shaft 2 of the engine, and a stator 4 arranged inside the magnet rotor 3 and fixed to the engine case (not shown) or the like.

[0017] The magnet rotor 3 includes a boss 10 into which the tip of the rotating shaft 2 is fitted, and a cylindrical yoke 11 with a bottom that is fixed to the boss 10. The boss 10 is fixed to the center of a bottom wall 15 of the yoke 11. A plurality of permanent magnets 12 are fixed to the inner circumferential surface of a peripheral wall 17 of the yoke 11. The permanent magnets 12 are magnetized so that their magnetic poles are arranged alternately in the circumferential direction. Protrusions (not shown) are formed by press working on the outer circumferential surface of the peripheral wall 17 of the yoke 11 to detect the rotational positions of the magnet rotor 3 and the rotating shaft 2. A clutch mechanism 30 of a one-way clutch is attached to the outer surface (the outer surface in the axial direction) of the bottom wall 15 of the yoke 11.

[0018] Fig. 2 is a perspective view of the magnet rotor 3 as seen from outside the bottom wall 15 of the yoke 11. Fig. 3 is a vertical cross-sectional view of the magnet rotor 3 with the permanent magnets 12 not shown. The boss 10 has a through hole 13 formed along its axis. The through hole 13 is a tapered hole whose inner diameter narrows toward the tip, following the shape of the tip of the rotating shaft 2. The base end of the boss 10 is provided with an annular flange portion 14 that extends radially outward. A fitting hole 24 into which the boss 10 is fitted is formed in the center of the bottom wall 15 of the yoke 11. The peripheral edge of the fitting hole 24 in the bottom wall 15 of the yoke 11 is recessed in an annular shape by the thickness of the flange portion 14 toward the axially inward side of the yoke 11. The flange portion 14 overlaps the recessed portion 23 around the peripheral edge of the fitting hole 24 in the bottom wall 15 from the axially outer side. In this state, the flange portion 14 is fixed to the inner peripheral edge of the bottom wall 15 of the yoke 11. As a result, the flange portion 14 of the boss 10 and the axially outer end faces of the bottom wall 15 of the yoke 11 are substantially flush with each other. The boss 10 and the tip of the rotary shaft 2 are fixed by a nut 16 so that they rotate together around the axis.

[0019] Additionally, in a region of the bottom wall 15 of the yoke 11 radially outward of the recessed portion 23, a plurality of bolt insertion holes 50 and an embossed portion 51 are formed concentrically about the center of the bottom wall 15. Bolts 32 for fastening and fixing a clutch mechanism 30 of a one-way clutch, which will be described later, are inserted into the plurality of bolt insertion holes 50. Furthermore, the protruding tip of the embossed portion 51 protrudes from the inner surface of the bottom wall 15 of the yoke 11 toward the inside of the yoke 11. A cover member (not shown) arranged inside the yoke 11 is engaged with the protruding portion of the embossed portion 51.

[0020] 1, a clutch mechanism 30 of a one-way clutch includes an annular outer race 31, an annular inner race 34 having a cylindrical portion 34a disposed radially inside the outer race 31, and rolling elements 33 interposed between the outer race 31 and the cylindrical portion 34a of the inner race 34. The rolling elements 33 function to transmit rotation in only one direction between the inner race 34 and the outer race 31 to a mating member, and to prevent transmission of rotation in the other direction. A detailed description of the structure of the clutch mechanism 30, which transmits only unidirectional rotation between the inner race 34 and the outer race 31 to the mating member, will be omitted here. The clutch mechanism 30 can employ various well-known structures.

[0021] The inner race 34 has a rotating plate 34b extending from one axial end of the cylindrical portion 34a (the end that is spaced apart from the bottom wall 15 of the yoke 11 when the clutch mechanism 30 is attached to the yoke 11) in a circular shape and projecting radially outward without contacting the outer race 31. A toothed surface 34c for transmitting rotation is formed on the outer peripheral surface of the rotating plate 34b. An output gear of a motor (not shown) for starting the engine can mesh with the toothed surface 34c of the rotating plate 34b. The inner race 34 is supported on the rotary shaft 2 via a bearing 35 at the inner periphery of the cylindrical portion 34a.

[0022] When one-way rotational torque is transmitted from the engine starting motor to the inner race 34 through the rotating plate 34b at the time of engine start-up, the clutch mechanism 30 transmits the torque to the yoke 11 through the rolling elements 33 and the outer race 31. This transmits the torque of the engine starting motor to the rotating shaft 2 of the engine, starting the engine. Furthermore, after the engine has started, as the rotational speed of the rotating shaft 2 increases, the clutch mechanism 30 interrupts the transmission of torque between the engine starting motor and the rotating shaft 2.

[0023] The stator 4 of the generator 1 also includes an annular stator core 40. The stator core 40 is formed by laminating annular magnetic plate materials in the axial direction. The inner diameter of the stator core 40 is set so as not to interfere with a nut 16 that is screwed onto the tip of the rotating shaft 2. The stator core 40 is provided with a plurality of teeth 40A extending radially outward and spaced equally apart in the circumferential direction. A coil 42 is wound around the outer periphery of each tooth 40A via an insulator 41. The coil 42 is electrically connected to a power storage device and on-board electrical equipment (not shown) via a power conversion circuit that converts AC and DC.

[0024] In generator 1, when yoke 11 rotates together with rotating shaft 2, multiple permanent magnets 12 fixed to peripheral wall 17 of yoke 11 move circumferentially across the outer periphery of multiple teeth 40A on stator 4. This generates AC power, which is output to the power storage device and on-board electrical equipment via coil 42 and a power conversion circuit.

[0025] 4 is an enlarged perspective view of the magnet rotor 3 at part IV in FIG. 2, and FIG. 5 is an enlarged front view of the magnet rotor 3 at part IV in FIG. A substantially triangular cutout 60 and a cut-up piece 61 formed by cutting out a portion of one side of the cutout 60 are provided in the bottom wall 15 of the yoke 11 in a region radially outward from the boss 10 (the portion connecting to the rotary shaft 2). A plurality of the cutouts 60 and a plurality of the cut-up pieces 61 (six in this embodiment) are arranged on concentric circles centered on the center of the bottom wall 15 of the yoke 11. The plurality of cut-up pieces 61 are arranged at equal intervals in the circumferential direction around the center of the bottom wall 15.

[0026] Each cutout 60 is formed in a generally triangular shape with one side 60a extending in a tangential direction of a circle centered at the center of the bottom wall 15 and the remaining two sides 60b, 60c extending from both ends of the side 60a toward the center of the bottom wall 15. The cut-and-raised piece 61 is cut and raised at a generally right angle toward the outside in the axial direction of the yoke 11 in a generally central region of the side 60a of the cutout 60. In this embodiment, the cut-and-raised piece 61 has a generally rectangular shape before being cut and raised and extending radially inward from the side 60a. The cutout 60 is formed to be sufficiently larger than the outline of the cut-and-raised piece 61 before being cut and raised. The width of the cutout 60 in the direction perpendicular to the radial direction gradually narrows toward the radially inner side of the bottom wall 15.

[0027] 2, each cut-and-raised piece 61 is disposed in a position on the bottom wall 15 of the yoke 11 radially outward from the positions where the bolt insertion holes 50 and the embossed portions 51 are formed. A portion of the cut-and-raised portion 60 corresponding to each cut-and-raised piece 61 is disposed between adjacent embossed portions 51 in the circumferential direction. In other words, a portion of each cut-and-raised portion 60 (a region extending radially inward of the bottom wall 15) extends to a position on the same circumference as the positions where the bolt insertion holes 50 and the embossed portions 51 are formed.

[0028] To be precise, the cut-and-raised pieces 61 are cut and raised in the axial direction at a position slightly radially inwardly spaced from one side 60a of the cut-and-raised portion 60. That is, the cut-and-raised pieces 61 include a short connection region 61a extending radially inwardly from one side 60a of the cut-and-raised portion 60, and a long support region 61b bending and extending axially outward from the tip of the connection region 61a. The outer race 31 of the clutch mechanism 30 can be fitted into the support region 61b of the multiple cut-and-raised pieces 61. Specifically, the outer peripheral surface of the outer race 31 of the clutch mechanism 30 is fitted into the radially inner surfaces of the support region 61b of the multiple cut-and-raised pieces 61. The plurality of cut-and-raised pieces 61 form clutch locking portions of the yoke 11. Furthermore, each notch 60 extends to a position radially outward beyond the outer circumferential surface of the clutch mechanism 30 (outer race 31).

[0029] As shown in FIG. 1, the outer race 31 of the clutch mechanism 30 is fastened to the bottom wall 15 of the yoke 11 by bolts 32 while fitted onto the plurality of cut-and-raised pieces 61. When the outer race 31 of the clutch mechanism 30 is attached to the bottom wall 15 of the yoke 11 in this manner, a portion of each notch 60 remains as communication openings 70a, 70b that communicate between the inside and outside of the yoke 11 in an area radially outward of the outer race 31. In the present embodiment, the communication openings 70a, 70b are formed on both circumferential sides of each cut-and-raised piece 61, as shown in FIGS. 4 and 5. The communication openings 70 allow heat from the inside of the yoke 11 to escape to the outside of the yoke when the magnet rotor 3 rotates.

[0030] <Effects of the embodiment> As described above, in the magnet rotor 3 of this embodiment, the clutch locking portion is formed by a plurality of cut-and-raised pieces 61 cut and raised from the bottom wall 15 of the yoke 11. Therefore, compared to when the clutch locking portion is formed by stamping from the bottom wall 15 of the yoke 11, the clutch mechanism 30 (outer race 31) can be securely locked by the plurality of cut-and-raised pieces 61 without increasing the thickness of the bottom wall 15 of the yoke 11. Therefore, when the magnet rotor 3 of this embodiment is used, it is possible to achieve both a small and lightweight yoke 11 and a reliable locking of the clutch mechanism 30.

[0031] Therefore, by adopting the magnet rotor 3 of this embodiment, it is possible to reduce the loss of motive energy, which makes it possible to contribute to Goal 7 of the Sustainable Development Goals (SDGs) led by the United Nations, which is to "Ensure access to affordable, reliable, sustainable and modern energy for all."

[0032] Furthermore, in the magnet rotor 3 of this embodiment, the tip end side of each cut-and-raised piece 61 is cut and raised from a radially inner region of the bottom wall 15 of the yoke 11 relative to the cut-and-raised base, so the clutch mechanism 30 can be locked by the cut-and-raised piece 61 at a more radially outer position of the bottom wall 15 without increasing the outer diameter of the bottom wall 15 of the yoke 11. Therefore, when this configuration is adopted, the clutch mechanism 30 (outer race 31), which has a large outer diameter, can be reliably supported without increasing the outer diameter of the bottom wall 15 of the yoke 11, which contributes to making the yoke 11 smaller and lighter.

[0033] Furthermore, in the magnet rotor 3 of this embodiment, the cutout portions 60 formed in the bottom wall 15 of the yoke 11 are shaped so that their circumferential width gradually narrows toward the radially inner side. This prevents the cut-and-raised pieces 61 from constricting the arrangement space for the bolt insertion holes 50 and embossed portions 51 that are arranged in a radially inner region of the bottom wall 15, and also enables the rigidity of the radially inner region of the bottom wall 15 to be maintained high.

[0034] Furthermore, in the magnet rotor 3 of this embodiment, the cutouts 60 extend to a position radially outward from the outer peripheral surface of the clutch mechanism 30 (outer race 31). Therefore, when the clutch mechanism 30 (outer race 31) is engaged with the plurality of cut-and-raised pieces 61, parts of the cutouts 60 function as communication openings 70a, 70b that connect the internal space of the yoke 11 to the outside. Therefore, when this configuration is adopted, heat inside the yoke 11 can be discharged to the outside through the communication openings 70a, 70b in the bottom wall 15 defined by the cutouts 60.

[0035] In particular, in this configuration, the cut-and-raised pieces 61 rotate together with the yoke 11 at positions circumferentially adjacent to the communication openings 70a, 70b of the bottom wall 15, so that when the yoke 11 rotates, the cut-and-raised pieces 61 actively fluctuate the air inside the yoke 11, and the heat inside the yoke 11 can be efficiently released to the outside along with that air.

[0036] Furthermore, in the magnet rotor 3 of this embodiment, each cut-and-raised piece 61 is disposed in a circumferential central region of the cut-and-raised portion 60. Therefore, when the clutch mechanism 30 is attached to the bottom wall 15 of the yoke 11 by the multiple cut-and-raised pieces 61, communication holes 70a, 70b are formed on both circumferential sides of the cut-and-raised pieces 61. Therefore, when the rotating shaft 2 is rotating at an increased speed or a decreased speed, heat inside the yoke 11 can be efficiently released to the outside through the communication holes 70a, 70b.

[0037] <Another embodiment 1> FIG. 6 is an enlarged cross-sectional view of the yoke 111 of the magnet rotor of this embodiment, corresponding to FIG. The yoke 111 of this embodiment has a basic configuration similar to that of the above-described embodiment, but differs from the above-described embodiment in the relative position of the cut-and-raised piece 61 with respect to the cut-and-raised portion 60. In the above-described embodiment, the cut-and-raised piece 61 was disposed in the circumferential center region of the radially outer side 60a of the cut-and-raised portion 60, but in this embodiment, the cut-and-raised piece 61 is provided protruding from a position offset to one side in the circumferential direction of the radially outer side 60a of the cut-and-raised portion 60. As in the above-described embodiment, the cut-and-raised piece 61 is raised in such a way that a position close to the radially outer side 60a of the cut-and-raised portion 60 serves as the cut-and-raised base, and the tip end of the cut-and-raised piece 61 extending radially inward is bent in the axial direction.

[0038] The magnet rotor of this embodiment has a basic configuration similar to that of the above-described embodiment, and therefore can achieve the same effects as those of the above-described embodiment. However, because the cut-and-raised piece 61 formed on the bottom wall 15 of the yoke 111 is positioned offset to one side in the circumferential direction of the notch 60, when the clutch mechanism is attached to the bottom wall 15 of the yoke 111, a communication opening 170 that opens wide on one side in the circumferential direction of the cut-and-raised piece 61 can be secured. Therefore, when this configuration is adopted, by taking into consideration the rotation direction of the yoke 111 and providing a communication port 170 with a large opening area on one circumferential side of the cut-and-raised piece 61, heat inside the yoke 111 can be efficiently released to the outside when the yoke 111 rotates.

[0039] <Another embodiment 2> FIG. 7 is an enlarged cross-sectional view of the yoke 211 of the magnet rotor of this embodiment, corresponding to FIG. In the yoke 211 of this embodiment, similar to the first embodiment, the cut-and-raised piece 261 is disposed at a position offset to one side in the circumferential direction of the cutout portion 60. However, the cut-and-raised piece 261 of this embodiment is cut and raised on one side 60b extending in the radial direction of the cutout portion 60.

[0040] Specifically, the connection region 261a of the cut-and-raised piece 261 extends circumferentially from a radially outer region of the side 60b, and the support region 261b is cut and raised in the axial direction at the tip of the connection region 261a. In this embodiment, the radially inner side surface of the cut-and-raised support region 261b abuts against the outer peripheral surface of the clutch mechanism 30 (outer race 31). In this embodiment as well, when the clutch mechanism 30 (outer race 31) is attached to the multiple cut-and-raised pieces 261, a communication port 270 is secured that opens widely on one circumferential side of the cut-and-raised piece 261.

[0041] The magnet rotor of this embodiment can achieve substantially the same effects as those of the other embodiment 1. However, in the magnet rotor of this embodiment, the cut-and-raised pieces 261 are cut and raised from the sides 60b extending in the radial direction of the cut-and-raised portions 60, so that it is possible to ensure a large area for the portions of the cut-and-raised pieces 261 that face the rotation direction of the yoke 11. Therefore, when the yoke 111 rotates, the cut-and-raised pieces 261 can more efficiently agitate the surrounding air. Therefore, when this configuration is adopted, the heat inside the yoke 111 can be released to the outside more efficiently when the yoke 111 rotates. Furthermore, in the magnet rotor of this embodiment, the curved ridge between the connection region 261a and the support region 261b of the cut-and-raised piece 261 extends along the radial direction of the bottom wall 15. Therefore, the clutch mechanism can be received in a direction where the cut-and-raised piece 261 has sufficiently high rigidity.

[0042] The present invention is not limited to the above-described embodiment, and various design modifications are possible without departing from the spirit of the present invention. For example, in each of the above embodiments, the notch 60 formed in the bottom wall 15 of the yoke 11 (111, 211) is formed in a substantially triangular shape that narrows toward the center of the bottom wall 15, but the shape of the notch 60 is not limited to this. The shape of the notch 60 may be a shape other than a triangle, such as a square. [Explanation of symbols]

[0043] 1...generator, 2...rotating shaft, 3...magnet rotor, 4...stator, 10...boss, 11...yoke, 12...permanent magnet, 13...through hole, 14...flange portion, 15...bottom wall, 16...nut, 17...circumferential wall, 23...recessed portion, 24...fitting hole, 30...clutch mechanism, 31...outer race, 32...bolt, 33...rolling element, 34...inner race, 34a...cylindrical portion, 34b...rotating plate, 34c ...tooth surface, 40...stator core, 40A...teeth, 41...insulator, 42...coil, 50...bolt insertion hole, 51...embossed portion, 60...cutout portion 60, 60a...one side, 60b, 60c...remaining sides, 61...cut-out piece (clutch locking portion), 61a, 261a...connection portion region, 61b, 261b...support portion region, 70a, 70b, 170, 270...communication port.

Claims

1. a cylindrical yoke having a bottom wall, a rotary shaft connected to the center of the bottom wall, and a clutch locking portion for positioning a clutch mechanism provided in a radially outer region of the connecting portion of the bottom wall with the rotary shaft; a plurality of permanent magnets fixed to the peripheral wall of the yoke; the bottom wall is provided with a plurality of bolt insertion holes, each of which is arranged concentrically around a center of the bottom wall and through which a bolt for fastening and fixing the clutch mechanism is inserted, and a notch portion formed extending from a position radially outward of the formation position of the bolt insertion hole to a position on the same circumference as the formation position of the bolt insertion hole, a magnet rotor characterized in that the clutch locking portion is composed of a plurality of cut-out pieces that are cut out from a position radially outward of the position where the bolt insertion hole is formed within the cut-out portion in the bottom wall of the yoke toward the axially outward side of the yoke.

2. 2. The magnet rotor according to claim 1, wherein the raised piece has a raised base portion positioned in a radially outer region of the bottom wall, and a tip portion side raised from a radially inner region of the bottom wall further than the raised base portion.

3. The bottom wall is provided with the notch portion that is larger than the outline of the cut-up piece before being cut and raised, 3. The magnet rotor according to claim 2, wherein the notch portion is formed in a shape in which the width in a direction perpendicular to the radial direction of the bottom wall gradually narrows toward the radially inner side of the bottom wall.

4. 4. The magnet rotor according to claim 3, wherein the notch extends to a position radially outward from an outer circumferential surface of the clutch mechanism.

5. 5. The magnet rotor according to claim 4, wherein the raised piece is disposed in a central region of the notch in the circumferential direction of the bottom wall.

6. 5. The magnet rotor according to claim 4, wherein the cut-and-raised piece is disposed at a position offset to one side in the circumferential direction of the bottom wall.

7. A generator comprising: the magnet rotor according to any one of claims 1 to 6; and a stator disposed inside the yoke facing the permanent magnets and around which a coil is wound.

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