JP7799562B2 - Magnet rotor and generator - Google Patents

Description

The present invention relates to a magnet rotor and a generator.

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

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.

The magnet rotor of this type of generator 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 engaged 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 other fastening means.

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.

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

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, recessed in a stepped shape axially inward of the yoke. In the clutch mechanism of the one-way clutch, the outer race is engaged 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.

Patent No. 4705639

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. Therefore, in order to ensure sufficient locking margin (locking depth) of the clutch locking portion with respect to the outer peripheral 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.

The present invention therefore aims to provide a magnet rotor that can achieve both a small, lightweight yoke and secure engagement of the clutch mechanism.

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.

The generator according to the present invention is characterized by comprising the magnet rotor and a stator disposed inside the yoke facing the permanent magnet and wound with a coil.

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.

FIG. 2 is a longitudinal cross-sectional view of the generator according to the embodiment. FIG. 2 is a perspective view of a magnet rotor according to the embodiment. FIG. 2 is a longitudinal cross-sectional view of the magnet rotor according to the embodiment. FIG. 4 is an enlarged perspective view of a portion IV of the magnet rotor of the embodiment shown in FIG. 2 . FIG. 4 is an enlarged front view of a portion IV of the magnet rotor of the embodiment shown in FIG. 2 . FIG. 6 is an enlarged front view corresponding to FIG. 5 of another embodiment 1. FIG. 10 is an enlarged front view of another embodiment corresponding to FIG. 5 .

Embodiments of the present invention will be described below with reference to the drawings. Note that in each embodiment described below, identical components will be designated by common reference numerals, and duplicate descriptions will be omitted.

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 an engine case (not shown) or the like.

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 one-way clutch mechanism 30 is attached to the outer surface (the outer surface in the axial direction) of the bottom wall 15 of the yoke 11 .

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 omitted.
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, and the peripheral portion 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 direction of the yoke 11. The flange portion 14 overlaps the recessed portion 23 on 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.

In addition, in the area of the bottom wall 15 of the yoke 11 radially outward of the recessed portion 23, multiple bolt insertion holes 50 and embossed portions 51 are formed concentrically around the center of the bottom wall 15. Bolts 32 are inserted into the multiple bolt insertion holes 50 to fasten and secure the clutch mechanism 30 of the one-way clutch, which will be described later. 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) that is placed inside the yoke 11 engages with the protruding portion of the embossed portion 51.

1, a clutch mechanism 30 of the 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 one-way 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.

The inner race 34 has a rotating plate 34b extending from one axial end of the cylindrical portion 34a (the end that is spaced 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 rotation transmitting toothed surface 34c 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 has an inner circumferential side of a cylindrical portion 34 a supported by the rotary shaft 2 via a bearing 35 .

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

The stator 4 of the generator 1 also includes an annular stator core 40. The stator core 40 is constructed 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 the nut 16 that is threaded onto the tip of the rotating shaft 2. The stator core 40 has a plurality of teeth 40A extending radially outward and spaced equally apart circumferentially. 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.

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

4 is an enlarged perspective view of the magnet rotor 3 at the portion IV in FIG. 2, and FIG. 5 is an enlarged front view of the magnet rotor 3 at the portion 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 connection portion with the rotating 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.

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, 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.

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

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).

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 with bolts 32 while fitted into the multiple 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 cutout 60 remains as communication ports 70a, 70b that connect the inside and outside of the yoke 11 in the radially outer region of the outer race 31. In this embodiment, the communication ports 70a, 70b are formed on both circumferential sides of each cut-and-raised piece 61, as shown in FIGS. 4 and 5. The communication ports 70 allow heat from the inside of the yoke 11 to escape to the outside of the yoke when the magnet rotor 3 rotates.

<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 out 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 employed, it is possible to achieve both a small and lightweight yoke 11 and a reliable engagement of the clutch mechanism 30 .

Therefore, by adopting the magnet rotor 3 of this embodiment, it is possible to reduce power energy loss. This will therefore make it possible to contribute to Goal 7 of the United Nations-led Sustainable Development Goals (SDGs), which is to "Ensure access to affordable, reliable, sustainable and modern energy for all."

In addition, in the magnet rotor 3 of this embodiment, the tip end side of each raised piece 61 is raised from a radially inner region of the bottom wall 15 of the yoke 11 relative to the raised base, so the clutch mechanism 30 can be engaged by the 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 more compact and lightweight.

In addition, in the magnet rotor 3 of this embodiment, the cutouts 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 bolt insertion holes 50 and embossed portions 51, which are located in the radially inner region of the bottom wall 15 than the cut-and-raised pieces 61, from taking up space, and also enables the rigidity of the radially inner region of the bottom wall 15 to be maintained at a high level.

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 multiple cut-and-raised pieces 61, portions of the cutouts 60 function as communication ports 70a, 70b that connect the internal space of the yoke 11 to the outside. Therefore, when this configuration is adopted, heat within the yoke 11 can be released to the outside through the communication ports 70a, 70b in the bottom wall 15 defined by the cutouts 60.

In particular, with this configuration, the raised pieces 61 rotate with the yoke 11 at positions circumferentially adjacent to the communication openings 70a and 70b in the bottom wall 15. As the yoke 11 rotates, the raised pieces 61 actively move the air within the yoke 11, allowing the heat within the yoke 11 to be efficiently released to the outside along with that air.

In addition, in the magnet rotor 3 of this embodiment, each cut-and-raised piece 61 is positioned in the circumferential center 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. As a result, when the rotating shaft 2 is rotating at an increased or decreased speed, heat inside the yoke 11 can be efficiently released to the outside through the communication holes 70a, 70b.

<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 protrudes 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.

The magnet rotor of this embodiment has a basic configuration similar to that of the above embodiment, and therefore can achieve the same effects as the above 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 port 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 within the yoke 111 can be efficiently released to the outside when the yoke 111 rotates.

<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 notched 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 notched portion 60.

Specifically, the connection region 261a of the cut-and-raised piece 261 extends circumferentially from the 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 wide on one circumferential side of the cut-and-raised piece 261.

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 a large area can be secured 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 stir 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 261 a and the support region 261 b 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 of the cut-and-raised piece 261 where the rigidity is sufficiently high.

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.

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... Peripheral 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...notch portion 60, 60a...one side, 60b, 60c...remaining side, 61...raised piece (clutch locking portion), 61a, 261a...connection portion region, 61b, 261b...support portion region, 70a, 70b, 170, 270...communication port.

Claims (7)

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 . A magnet rotor as described in claim 1, characterized in that the raised piece has a raised base located in the radially outer region of the bottom wall and a tip end side cut and raised from a radially inner region of the bottom wall beyond the raised base. 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. A magnet rotor as described in claim 3, characterized in that the notch extends to a position radially outward from the outer circumferential surface of the clutch mechanism. A magnet rotor as described in claim 4, characterized in that the raised piece is positioned in the central region of the cutout portion in the circumferential direction of the bottom wall. A magnet rotor as described in claim 4, characterized in that the raised piece is positioned offset to one side in the circumferential direction of the bottom wall. A generator comprising the magnet rotor described in any one of claims 1 to 6, and a stator disposed inside the yoke facing the permanent magnet and wound with a coil.