Rotor of rotating electrical machine

Abstract

A rotor of a rotating electrical machine provided with a rotor core having magnets and a plurality of magnet holes into which the magnets are inserted, the plurality of magnet holes including a first magnet hole formed in a V shape and a second magnet hole provided on the outer peripheral side of the first magnet hole, the magnets include a main magnet inserted into the first magnet hole, and an auxiliary magnet inserted into the second magnet hole and disposed at a position facing a side surface on a magnetic pole boundary side of the main magnet, and a bridge is provided between the first magnet hole and the second magnet hole.

Description

Technical Field

[0001] The present invention relates to a rotor of a rotating electric machine. Background Art

[0002] Patent Document 1 listed below discloses a structure of a rotor for a rotating electrical machine in which trapezoidal auxiliary magnets having different magnetization directions are arranged on the side surfaces of magnets arranged in a V-shape for the purpose of suppressing demagnetization. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2019-30206 Summary of the Invention Problems to be solved by the invention

[0004] Increasing the maximum torque in the configuration described in Patent Document 1 increases torque ripple. Therefore, an object of the present invention is to provide a rotor for a rotating electrical machine that achieves a trade-off between increasing the maximum torque and reducing the torque ripple. Technical means to solve the problem

[0005] A rotor of a rotating electric machine having a rotor core, the rotor core having magnets and a plurality of magnet holes into which the magnets are respectively inserted, the plurality of magnet holes including a first magnet hole formed in a V-shape and a second magnet hole arranged on the outer peripheral side of the first magnet hole, the magnets including: a main magnet inserted into the first magnet hole; and an auxiliary magnet inserted into the second magnet hole and arranged at a position opposite to the side surface on the magnetic pole boundary side of the main magnet, and a bridge is provided between the first magnet hole and the second magnet hole. Effects of the Invention

[0006] According to the present invention, it is possible to provide a rotor for a rotating electrical machine that achieves both an increase in maximum torque and a reduction in torque ripple. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a cross-sectional view of a rotor of a rotating electrical machine according to one embodiment of the present invention. Figure 2 This indicates the structure of the magnet holes that form the magnetic poles. Figure 1 A magnified view of . Figure 3 This is a modified example. DETAILED DESCRIPTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description and drawings are examples for illustrating the present invention and have been appropriately omitted or simplified for clarity. The present invention may also be implemented in various other ways. Unless otherwise specified, each component may be singular or plural.

[0009] To facilitate understanding of the invention, the positions, sizes, shapes, and ranges of the components shown in the drawings may not necessarily represent their actual positions, sizes, shapes, and ranges. Therefore, the present invention is not necessarily limited to the positions, sizes, shapes, and ranges disclosed in the drawings.

[0010] (One embodiment and overall structure) ( Figure 1 ) The rotating electrical machine includes a stator core 1 and a rotor core 2. A plurality of magnets 3 are arranged on the rotor core 2 to form a plurality of magnetic poles, which are arranged adjacent to each other in the circumferential direction.

[0011] ( Figure 2 ) The rotor core 2 has multiple magnet holes. These include a V-shaped first magnet hole 8 and a trapezoidal second magnet hole 9 located further outward from the first magnet hole 8. The main magnet 3 is inserted into the first magnet hole 8. The auxiliary magnet 5 is inserted into the second magnet hole 9. The main magnet 3 and the auxiliary magnet 5 are inserted into the first magnet hole 8 and the second magnet hole 9, respectively, to form magnetic poles.

[0012] The main magnet 3 has a pair of side surfaces extending parallel to the magnetization direction 10, with the outer peripheral side surfaces serving as the magnetic pole boundary side surfaces 3a. The auxiliary magnet 5 is positioned within the second magnet hole 9, facing the magnetic pole boundary side surfaces 3a of the main magnet 3. A bridge 11 is provided between the first magnet hole 8 and the second magnet hole 9 to support the main magnet 3. The main magnet 3 and the auxiliary magnet 5 are, for example, rectangular in shape.

[0013] The second magnet hole 9 has a first side 6 with the bridge 11 as its wall surface, and a second side 7 with the outer circumference 4 of the rotor core 2 as its wall surface. The first side 6 is formed parallel to the magnetic pole boundary side 8a of the first magnet hole 8. Furthermore, when a centerline is drawn through the center of the second side 7, the second side 7 is parallel to a tangent to the outer circumference 4 of the rotor core 2 perpendicular to the centerline. Alternatively, the first side 6 may be formed substantially parallel to the magnetic pole boundary side 8a of the first magnet hole 8.

[0014] A magnetic path, serving as a passage for magnetic flux, is provided between the outer circle 4 and the second side 7. The presence of bridge 11 in the rotor core 2 improves the strength between the first and second magnet holes 8 and 9, thereby narrowing the width of the magnetic path between the outer circle 4 and the second side 7 compared to conventional configurations. This increases the magnetic flux density in the magnetic path, reducing leakage flux. While torque increases compared to conventional configurations, the maximum stress can be suppressed to the same level as in conventional configurations.

[0015] On the other hand, the adjacent magnetic poles (refer to Figure 1 ) is configured with a significantly wider magnetic circuit 2a than before. This arrangement reduces the magnetic flux density and, consequently, the torque. According to the present invention, since the torque-reducing component is greater than the torque-increasing component described above, the torque peak in the torque pulsation can be suppressed to a smaller value than before, thereby reducing torque pulsation. Thus, it is possible to achieve both an increase in maximum torque and a reduction in torque pulsation.

[0016] The auxiliary magnet 5 has a magnetization direction 5a that is different from the magnetization direction 10 of the main magnet 3. The magnetization direction 5a of the auxiliary magnet 5 is circumferential and parallel to a tangent to the outer circumference 4 of the rotor core 2, which tangent is perpendicular to the centerline of the second side 7. The auxiliary magnet 5 is arranged in the second magnet hole 9 closer to the second side 7 than to the first side 6.

[0017] In this way, by arranging the auxiliary magnet 5 having a magnetization direction different from that of the main magnet 3 near the outer circle 4, the width of the magnetic path or the magnetic path 2a between the outer circle 4 and the second side 7 can be adjusted, or the angle of the magnetization direction 10 can be changed to change the flow of magnetic flux, thereby adjusting the level of magnetic flux density at each rotational position of the rotor, thereby reducing torque pulsation.

[0018] Furthermore, according to the configuration of the present invention, a rotor of a rotating electric machine can be provided, which has an arrangement structure of main magnets 3 and auxiliary magnets 5 that can increase maximum torque while reducing torque pulsation, and has a flux barrier shape that alleviates the stress of centrifugal force with respect to the rotational strength of the rotor core 2.

[0019] (Variation) ( Figure 3 ) The auxiliary magnet 5 has a trapezoidal shape corresponding to the second magnet hole 9, resulting in a larger magnet volume than in the aforementioned embodiment. In this modified example, the volume of the auxiliary magnet 5 is increased, while the volume of the main magnet 3 is reduced, resulting in a total magnet volume comparable to that of the aforementioned embodiment. Furthermore, the magnetization direction 5a of the auxiliary magnet 5 is tangential to the outer circumference 4 of the rotor core 2, perpendicular to the centerline of the aforementioned second side 7.

[0020] The reason for adjusting the magnet volume distribution in this way is that, since the volume of the auxiliary magnet 5 is larger than in the above-mentioned embodiment, more magnetic flux flows through the magnetic path between the outer circle 4 and the second side 7, increasing the magnetic flux density and thus increasing the torque. This increases the torque at the rotation angle where the torque is minimum.

[0021] On the other hand, by increasing the volume of the auxiliary magnet 5 and correspondingly reducing the volume of the main magnet 3, the magnetic flux flowing from the main magnet 3 toward the outer circumference 4 decreases, lowering the magnetic flux density and thus reducing torque. Furthermore, since the stress on the bridge 11 is reduced, there is a margin for structural strength, allowing the bridge 11 to be correspondingly thinner compared to the aforementioned embodiment. This keeps the maximum stress to the same level as in the conventional configuration, while reducing leakage flux and thereby increasing torque. This structural combination allows for the adjustment of magnetic flux density at various rotational positions, increasing torque while reducing torque ripple.

[0022] According to the embodiment of the present invention described above, the following effects are achieved.

[0023] (1) A rotor for a rotating electric machine, comprising a rotor core 2 having magnets and a plurality of magnet holes into which the magnets are inserted, the plurality of magnet holes including a first magnet hole 8 formed in a V-shape and a second magnet hole 9 disposed on the outer peripheral side of the first magnet hole 8. The magnets include a main magnet 3 inserted into the first magnet hole 8 and an auxiliary magnet 5 inserted into the second magnet hole 9 and disposed at a position opposite to the side surface of the main magnet 3 on the magnetic pole boundary side. A bridge 11 is provided between the first magnet hole 8 and the second magnet hole 9. Thus, a rotor for a rotating electric machine can be provided that achieves both an increase in maximum torque and a reduction in torque ripple.

[0024] (2) The second magnet hole 9 has a first side 6 with a bridge 11 as a wall surface. The first side 6 is formed parallel to the side 8a on the magnetic pole boundary side of the first magnet hole 8. This allows the bridge 11 supporting the main magnet 3 to be provided at the same time as the second magnet hole 9 is formed.

[0025] (3) The second magnet hole 9 has a second side 7 with the outer circumference 4 of the rotor core 2 as a wall surface. The second side 7 is parallel to a tangent to the outer circumference 4 of the rotor core 2, and the tangent is perpendicular to the center line of the second side 7. Thus, a magnetic path between the outer circumference 4 and the second side 7 can be defined.

[0026] (4) The second magnet hole 9 has a trapezoidal shape, thereby defining the bridge 11 that supports the main magnet 3 .

[0027] (5) The auxiliary magnet 5 has a trapezoidal shape, and its magnetization direction 5a is different from the magnetization direction 10 of the main magnet 3 and is circumferential. This allows the magnetic flux density to be adjusted at each rotational position, reducing torque ripple.

[0028] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications and other configurations can be combined without departing from the gist thereof. Furthermore, the present invention is not limited to the configuration having all the configurations described in the above-described embodiments, and also includes a configuration in which a portion of the configuration is deleted. Explanation of symbols

[0029] 1 stator core 2 Rotor core 3 Main magnet 3a Side view of the magnetic pole boundary 4 outer circle 5 Auxiliary magnet 5a Magnetization direction of auxiliary magnet 6 First side 7 Second side 8 First magnet hole 8a Edge on the magnetic pole boundary side 9 Second magnet hole 10 Magnetization direction 11 bridges.

Claims

1. A rotor of a rotating electric machine comprising a rotor core, the rotor core having magnets and a plurality of magnet holes into which the magnets are inserted, wherein: The plurality of magnet holes include: a first magnet hole formed in a V-shape; as well as The second magnet hole is provided on the outer peripheral side of the first magnet hole. The magnet includes: a main magnet inserted into the first magnet hole; and an auxiliary magnet inserted into the second magnet hole and arranged at a position facing the side surface on the magnetic pole boundary side of the main magnet, A bridge is provided between the first magnet hole and the second magnet hole.

2. The rotor of the rotating electrical machine according to claim 1, wherein The second magnet hole has a first side with the bridge as a wall surface, The first side is formed parallel to a side of the first magnet hole on the magnetic pole boundary side.

3. The rotor of the rotating electrical machine according to claim 1, wherein The second magnet hole has a second side having the outer peripheral surface of the rotor core as a wall surface. The second side is parallel to a tangent line of the outer peripheral surface of the rotor core, and the tangent line is perpendicular to a center line of the second side.

4. The rotor of a rotating electrical machine according to claim 1, wherein The second magnet hole is trapezoidal in shape.

5. The rotor of the rotating electrical machine according to claim 4, wherein: The auxiliary magnet has the trapezoidal shape, The magnetization direction of the auxiliary magnet is different from the magnetization direction of the main magnet and is a circumferential direction.

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