JP7524823B2 - Rotor - Google Patents

Description

The present invention relates to a rotor.

Conventionally, in surface magnet rotors in which magnets are arranged on the outer surface of the rotor core, a cylindrical magnet cover and a plate-like plate are installed to prevent the magnets from scattering. The magnet cover is press-fitted onto the outside of the rotor core, and the plates are arranged on both axial sides of the rotor core and held by the magnet cover. In the rotor disclosed in Patent Document 1, the axial movement of the plate is restricted by the crimped portions on both ends of the magnet cover.

JP 2018-33241 A

The plate is pressed into the shaft to restrict relative rotation. However, if the plate becomes misaligned when forming the crimped portion of the magnet cover, the hole in which the plate fits onto the shaft will deform, reducing the restrictive force of the plate, which may cause the plate to move in the direction of rotation when the rotor rotates, resulting in abnormal noise.

The present invention was made in consideration of the above points, and its purpose is to provide a rotor that suppresses the generation of abnormal noise.

The rotor of the present invention comprises a shaft (20), a rotor core (30) fixed to the shaft, a plurality of magnets (40) arranged on the radially outer surface of the rotor core, a cylindrical magnet cover (50) covering the plurality of magnets, and plates (60) arranged on both axial sides of the rotor core. The plates are held by crimped portions (51) at the ends of the magnet cover. One of the plate and the rotor core has a rotation restriction portion (71, 72, 712, 722, 713, 714, 715, 716, 717, 727, 718) that contacts the other of the plate and the rotor core in the rotational direction.

As a result, even if the plate becomes misaligned when forming the crimped portion of the magnet cover, causing the plate's fitting hole for the shaft to deform and reducing the plate's binding force, the rotation restriction portion restricts the relative rotation of the plate. This prevents the plate from moving in the rotational direction when the rotor rotates, and suppresses the generation of abnormal noise.

FIG. 2 is a longitudinal sectional view of the rotor according to the first embodiment. 2 is a view of the rotor of FIG. 1 as seen from the direction of arrow II. Cross-sectional view taken along line III-III in Figure 2. FIG. 4 is a diagram showing a disk member that serves as the base of the plate. FIG. 7 is a cross-sectional view of a rotor according to a second embodiment, which corresponds to FIG. 3 of the first embodiment. FIG. 11 is a view of a rotor according to a third embodiment as viewed from the axial direction, and corresponds to FIG. 2 of the first embodiment. FIG. 11 is a diagram showing a rotor according to a fourth embodiment as viewed from the axial direction, and corresponds to FIG. 2 showing the first embodiment. FIG. 13 is a cross-sectional view of a rotor according to a fifth embodiment, which corresponds to FIG. 3 of the first embodiment. FIG. 13 is a cross-sectional view of a rotor according to a sixth embodiment, which corresponds to FIG. 3 of the first embodiment. FIG. 13 is a cross-sectional view of a rotor according to a seventh embodiment, which corresponds to FIG. 3 of the first embodiment. FIG. 13 is a cross-sectional view of a rotor according to an eighth embodiment, which corresponds to FIG. 3 of the first embodiment. FIG. 13 is a diagram showing a disk member according to a ninth embodiment, and corresponds to FIG. 4 of the first embodiment.

Below, several embodiments of the rotor will be described with reference to the drawings. Configurations that are substantially the same between the embodiments will be given the same reference numerals and will not be described.

[First embodiment]
1 and 2 , the rotor 10 of the first embodiment is provided as a rotor of the motor 1, and is rotatably provided inside the stator 5. The rotor 10 includes a shaft 20, a rotor core 30, a plurality of magnets 40, a magnet cover 50, and a pair of plates 60.

The shaft 20 is provided so as to be rotatable about the rotation axis O. The rotor core 30 is formed in a cylindrical shape and is fixed to the shaft 20 so as to be rotatable together with it. In the first embodiment, the shaft 20 has a knurled portion 21 in the middle of its longitudinal direction, and the rotor core 30 is fixed to the shaft 20 by being pressed into the knurled portion 21.

In FIG. 1, the rotor core 30 is shown as a single member to avoid complicating the description, but in reality the rotor core 30 is a laminate of multiple plates. The rotor core 30 is made by stacking and integrating multiple rotor core sheets in the axial direction, the rotor core sheets being formed, for example, by punching electromagnetic steel plate material using a press process.

Hereinafter, the direction parallel to the rotation axis O will be referred to as the axial direction. The direction perpendicular to the rotation axis O will be referred to as the radial direction. The direction around the rotation axis O will be referred to as the rotational direction or circumferential direction.

The magnets 40 are arranged at equal intervals in the circumferential direction on the radially outer surface of the rotor core 30. The magnet cover 50 is a cylindrical member that covers the magnets 40 collectively and is made of a non-magnetic material. The plates 60 are arranged at both axial ends of the magnet cover 50, on both axial sides of the rotor core 30. The plate 60 has an inner part 62 located on the radially inner side and abutting the rotor core 30 in the axial direction, and an outer part 63 that extends radially outward while bending from the inner part 62 to move away from the magnet 40. The magnet cover 50 has a crimped part 51 formed at both axial ends thereof, which is crimped with the outer edge of the plate 60 as a fulcrum, and the plate 60 is held by the crimped part 51. The axial movement of the plate 60 is restricted by the crimped part 51. The crimped part 51 is formed by crimping.

The plate 60, like the rotor core 30, is designed to engage with the knurled portion 21 to restrict relative rotation. A fitting hole 64 that fits into the knurled portion 21 is formed in the center of the plate 60. However, in the past, when forming the crimped portion 51 of the magnet cover 50, if a radial force acts on the plate 60 and the plate 60 becomes misaligned, the fitting hole 64 deforms and the restraining force of the plate 60 decreases, causing the plate 60 to move in the rotational direction when the rotor 10 rotates, resulting in the generation of abnormal noise.

In response to the above problem, in the first embodiment, the rotor 10 is provided with claws 71, 72 as "rotation restriction parts" as shown in Figures 2 and 3. The claws 71, 72 are provided on the plate 60 and contact the rotor core 30 in the rotation direction to restrict the relative rotation of the plate 60. In other words, the claws 71, 72 function as rotation stoppers.

The plate 60 has a disk-shaped main body 61 and claws 71, 72 that are integral with each other. In other words, the main body 61 and the claws 71, 72 are made of the same material. The main body 61 has an inner part 62 and an outer part 63. The inner part 62 has through holes 65 at two locations in the circumferential direction. Each through hole 65 is arranged point-symmetrically with respect to the rotation axis O. The claws 71, 72 are formed on the edge of the through hole 65.

The rotor core 30 has multiple gap holes 31 that open in the axial direction. The claws 71 and 72 are protrusions that protrude from the edge of the through hole 65 into the gap hole 31. The claws 71 are formed on one circumferential edge of the through hole 65 and regulate the relative rotation of the plate 60 in one circumferential direction. The claws 72 are formed on the other circumferential edge of the through hole 65 and regulate the relative rotation of the plate 60 in the other circumferential direction. The multiple claws 71 and 72 are arranged point-symmetrically with respect to the rotation axis O.

The plate 60 is made from a disk member 80 as shown in FIG. 4. The disk member 80 is formed, for example, by punching out by press processing, and has a main body 61 and plate-like protrusions 81, 82 that will later become the claws 71, 72. The plate-like protrusions 81, 82 are protrusions that protrude in one and the other circumferential directions from the edge of the through hole 65, and are integrated with the main body 61. After the disk member 80 is pressed into the shaft 20, its axial movement is restricted by the crimping portion 51, which is formed by crimping the axial end of the magnet cover 50 with the outer edge of the disk member 80 as a fulcrum. The plate-like protrusions 81, 82 are bent until they abut the inner wall surface of the gap hole 31 as shown in FIG. 2 and FIG. 3, to become the claws 71, 72.

(effect)
As described above, in the first embodiment, the rotor 10 includes the plate 60 held by the crimped portion 51 at the end of the magnet cover 50. The plate 60 has the claws 71, 72 as rotation restricting portions that come into contact with the rotor core 30 in the rotational direction. As a result, even if the plate 60 is misaligned when forming the crimped portion 51 of the magnet cover 50, and the fitting hole 64 of the plate 60 to the shaft 20 is deformed and the binding force of the plate 60 is reduced, the claws 71, 72 restrict the relative rotation of the plate 60. Therefore, the plate 60 is prevented from moving in the rotational direction when the rotor 10 rotates, and the generation of abnormal noise can be suppressed.

In the first embodiment, the rotor core 30 has a gap hole 31 that opens in the axial direction. The claw portions 71 and 72 are formed from protrusions that protrude from the main body portion 61 of the plate 60 into the gap hole 31. This allows the claw portions 71 and 72 to come into contact with the rotor core 30 and prevent rotation, thereby restricting the relative rotation of the plate 60.

In the first embodiment, the claws 71, 72 are curved portions formed by bending the plate-shaped protrusions 81, 82 integral with the main body 61 until they abut the inner wall surface of the gap hole 31. By bending a part of the disk member 80 that forms the base of the plate 60 to form the claws 71, 72, no additional parts are required. For example, there is no need to assemble additional parts to the plate to provide protrusions. Therefore, there is no need to change the parts configuration from the conventional form.

In the first embodiment, multiple claws 71, 72 are provided. The multiple claws 71, 72 are arranged point-symmetrically with respect to the rotation axis O. This prevents rotational imbalance of the rotor 10.

[Second embodiment]
In the second embodiment, claws 712, 722 are provided as a "rotation restriction portion" as shown in Fig. 5. The claws 712, 722 are bent by 90° or more. This ensures that the claws 712, 722 always come into contact with the inner wall surface of the gap hole 31 even if the edge of the through hole 65 and the edge of the gap hole 31 are designed to have a positional relationship that does not match, or even if a misalignment occurs between the edge of the through hole 65 and the edge of the gap hole 31 during assembly.

[Third embodiment]
In the third embodiment, as shown in Fig. 6, a claw portion 713 is provided as a "rotation restricting portion". The claw portion 713 is a protrusion that protrudes from the radially inner side of the edge of the through hole 65 into the gap hole 31. Both circumferential sides of the claw portion 713 contact the inner wall surface of the gap hole 31 to restrict the relative rotation of the plate 60.

[Fourth embodiment]
7, a claw portion 714 is provided as a "rotation restricting portion". The claw portion 714 is a protrusion that protrudes from the radially outer side of the edge of the through hole 65 into the gap hole 31. Both circumferential sides of the claw portion 714 contact the inner wall surface of the gap hole 31 to restrict the relative rotation of the plate 60.

[Fifth embodiment]
In the fifth embodiment, as shown in Fig. 8, a protrusion 715 is provided as a "rotation restricting portion". The protrusion 715 is formed so as to protrude into the gap hole 31, and is formed, for example, by pressing a part of the disk member 80 press-fitted into the shaft 20 toward the rotor core 30. Both circumferential sides of the protrusion 715 come into contact with the inner wall surface of the gap hole 31, restricting the relative rotation of the plate 60.

Sixth Embodiment
In the sixth embodiment, as shown in Fig. 9, a protrusion 716 is provided as a "rotation restricting portion". The protrusion 716 protrudes from the rotor core 30 into a rotation restricting hole 756 of the plate 60. Both circumferential sides of the protrusion 716 contact the inner wall surfaces of the rotation restricting hole 756 to restrict the relative rotation of the plate 60. In this manner, a rotation restricting portion may be provided on the rotor core 30.

[Seventh embodiment]
10 , claw members 707, 757 are provided as "rotation restricting portions". The claw members 707, 757 are separate members from the plate 60. The claw member 707 has a claw portion 717 that protrudes into the gap hole 31, and the claw member 757 has a claw portion 727 that protrudes into the gap hole 31. In this manner, the claw portions 717, 727 as rotation restricting portions may be formed as separate members from the plate 60.

[Eighth embodiment]
11 , a protruding member 708 is provided as a “rotation restricting portion”. The protruding member 708 is a separate member from the plate 60, and has a protrusion 718 protruding into the gap hole 31. In this manner, the rotation restricting portion may be formed of a separate member from the plate 60.

[Ninth embodiment]
12 , the plate-like projections 81, 82 of the disk member 80 may be bent to form the claw portions 71, 72 in a separate state before being assembled to the shaft 20, and then the plate 60 may be assembled to the shaft 20. Even so, the claw portions 71, 72 may come into contact with the rotor core 30 in the rotational direction, thereby restricting the relative rotation of the plate 60.

[Tenth embodiment]
In the tenth embodiment, as shown in Fig. 12, the plate-like projections 81, 82 of the disk member 80 are bent to form the claws 71, 72 in a separate state before being assembled to the shaft 20, and then the plate 60 is assembled to the shaft 20, and then the claws 71, 72 are further bent as shown in Fig. 5 to abut against the inner wall surface of the gap hole 31. As a result, even if the edge of the through hole 65 and the edge of the gap hole 31 are designed to have a positional relationship that does not coincide with each other, or even if a misalignment occurs in the positional relationship between the edge of the through hole 65 and the edge of the gap hole 31 during assembly, the claws 71, 72 can always abut against the inner wall surface of the gap hole 31. Furthermore, when bending the plate-like projections 81, 82 after assembly to the shaft 20, it is possible to avoid a situation in which the plate-like projections 81, 82 interfere with the rotor core 30 and cannot be bent.

[Other embodiments]
In other embodiments, the number of claws may be 3 or less, or 5 or more. Also, instead of forming a through hole, a U-shaped slit may be formed in the disk member, and the portion inside the slit may be bent to form the claw.
In other embodiments, the rotor is not limited to being applied to a motor and may be applied to a generator.

The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention.

10 rotor, 20 shaft, 30 rotor core, 40 magnet, 50 magnet cover, 51 crimping portion, 60 plate, 71, 72, 712, 722, 713, 714, 715, 716, 717, 727, 718 rotation restriction portion.

Claims (4)

A shaft (20);
A rotor core (30) fixed to the shaft;
A plurality of magnets (40) arranged on a radially outer surface of the rotor core;
A cylindrical magnet cover (50) that covers the plurality of magnets;
Plates (60) are arranged on both sides of the rotor core in the axial direction and are held by crimped portions (51) at the ends of the magnet cover;
Equipped with
A rotor, wherein one of the plate and the rotor core has a rotation restricting portion (71, 72, 712, 722, 713, 714, 715, 716, 717, 727, 718) that contacts the other of the plate and the rotor core in a rotational direction. The rotor core has a gap hole (31) that is open in the axial direction,
2. The rotor according to claim 1, wherein the rotation restricting portion is formed of a protrusion protruding from a main body portion (61) of the plate into the gap hole. The rotor according to claim 2, wherein the protrusion is a curved portion in which a plate-shaped protrusion integral with the main body is bent until it abuts against the inner wall surface of the gap hole. The protrusions are provided in plurality,
The rotor according to claim 2 or 3, wherein the plurality of protrusions are arranged point-symmetrically with respect to a rotation axis (O) of the shaft.

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