Magnetic circuit structure of a rotating machine rotor

Abstract

This invention provides a magnetic circuit structure that can increase the torque of a rotating machine without narrowing the region between the outer diameter arc magnet and the inner diameter arc magnet. [Solution] The magnetic pole section 10 comprises outer diameter arc magnet sections 11a, 11b arranged to be convex inward in the radial direction of the rotor core, and inner diameter arc magnets 12a to 12d located radially inside the outer diameter arc magnets 11a, 11b and arranged to be convex inward in the radial direction. Both arc magnets 11a, 11b, 12a to 12d are arranged in pairs symmetrically across the radial central axis of the magnetic pole section 10. The inner circumferential surfaces 20, 21 of the outer diameter arc magnets 11a, 11b are not concentric, and the positions of the centers P1, Q1 of circles P, Q are different. The inner circumferential surfaces 22a, 22b of the inner diameter arc magnets 12a, 12 and the inner circumferential surfaces 23a, 23b of the inner diameter magnets 12c, 12d are also not concentric, and the positions of the centers S1, R1 of circles S, R are different.

Description

Technical Field

[0001] The present invention relates to a magnetic circuit of a rotary machine rotor mounted on an electric vehicle or the like, and particularly to an arrangement structure of magnets of the rotary machine rotor.

Background Art

[0002] Electric vehicles such as hybrid vehicles, battery-driven vehicles, and fuel cell vehicles are equipped with rotary machines used as electric motors or generators. With the spread of these electric vehicles, an improvement in the output performance of the mounted rotary machines is required.

[0003] Therefore, a magnetic circuit structure of a rotary machine rotor shown in Patent Document 1 has been proposed. Describing based on FIG. 2(a), an outer diameter side arc magnet 5 and an inner diameter side arc magnet 6 are provided in a magnetic pole portion 2 of a rotor 1.

[0004] The outer diameter side arc magnet 5 is arranged in a magnet insertion hole 3 formed on the outer diameter side of the rotor 1, while the inner diameter side arc magnet 6 is arranged in a magnet insertion hole 4 formed on the inner diameter side of the rotor 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Patent Document 1 improves torque by using arc magnets 5 and 6 in the magnetic pole portion 2, and further suppresses demagnetization by making the coercive force of the inner diameter side arc magnet 6 higher than that of the outer diameter side arc magnet 5.

[0007] However, if the width of the outer diameter arc magnet 5 is increased to increase torque, the region A between the ends 5a and 6a of both arc magnets 5 and 6 becomes narrower, as shown in Figure 2(b). When this region A narrows, the magnetic flux may saturate, potentially reducing the torque increase due to the increased magnet width.

[0008] This invention was made to solve the problems of the conventional invention, and aims to provide a magnetic circuit structure that can increase the torque of a rotating machine without narrowing the region between the outer diameter arc magnet and the inner diameter arc magnet. [Means for solving the problem]

[0009] This invention relates to a rotor core of a rotating machine rotor that is formed to be substantially annular, The rotor core has magnetic pole portions formed at regular intervals in the circumferential direction, Equipped with, The aforementioned magnetic pole portion is The outer diameter side magnet group consists of outer diameter side arc magnets arranged to be convex radially inward of the rotor core, An inner diameter side magnet group consisting of an inner diameter side arc magnet located inside the outer diameter side magnet group in the radial direction and arranged to be convex in the radial direction, Equipped with, The outer diameter magnet group is configured by arranging outer diameter arc magnets symmetrically across the radial central axis of the magnetic pole portion. The inner diameter magnet group is configured by symmetrically arranging inner diameter arc magnets across the central axis. The inner surfaces of each of the symmetrically arranged arc magnets are not concentric circles, A key feature is that the center position of the circle corresponding to each of the aforementioned inner surfaces is shifted.

[0010] (2) The centers of the circles along the inner circumferential surfaces of each outer diameter arc magnet and each inner diameter arc magnet are Each is arranged symmetrically across the aforementioned central axis, Let L1 be the distance of each of the outer diameter arc magnets from the central axis. Let L2 be the distance of each of the inner diameter arc magnets from the central axis. It is preferable that "L1 > L2" holds.

[0011] (3) The outer diameter side magnet group is configured by arranging the outer diameter side arc magnets one by one across the central axis. The inner diameter side magnet group may be configured by arranging a pair of the inner diameter side arc magnets in series across the central axis.

[0012] (4) Let the angle between the straight lines when the inner peripheral edges of the respective outer diameter side arc magnets are connected by straight lines be θ1. Let the angle between the straight lines when the outermost inner peripheral edges of the inner diameter side arc magnet groups arranged in series are connected by straight lines be θ2. It is preferable that "θ1 > θ2" holds.

[0013] (5) Moreover, it is more preferable that "θ2 < 90°", and it is further preferable that the respective arc magnets are formed in similar shapes of the same size.

Advantages of the Invention

[0014] According to the present invention, it becomes possible to increase the torque of the rotating machine without narrowing the region between the inner diameter side arc magnet and the outer diameter side arc magnet.

Brief Description of the Drawings

[0015] [Figure 1] Partial enlarged view of a rotating machine rotor showing the magnetic circuit shape of an embodiment. [Figure 2] (a) is a partial view of the magnetic circuit shape of Patent Document 1, and (b) is a state diagram of the increased magnet width of (a).

Modes for Carrying Out the Invention

[0016] Hereinafter, the magnetic circuit structure of a rotating machine rotor according to an embodiment of the present invention will be described. This magnetic circuit structure is applied to a rotating machine mounted on an electric vehicle such as a hybrid vehicle, a battery-driven vehicle, or a fuel cell vehicle and used as an electric motor or a generator.

[0017] This rotating machine includes a rotor shaft rotatably supported in a housing via bearings, a rotor (rotating element) fixed to the outer periphery of the rotor shaft, and a stator (stator element) disposed opposite to the rotor and fixed to the inner periphery of the housing. The rotor includes a substantially annular rotor core.

[0018] The rotor core has a rotor shaft hole at the center of the annular shape, and is formed by laminating a plurality of substantially annular electromagnetic steel sheets of the same shape in the axial direction. Here, the rotor core has a plurality of magnetic pole portions at predetermined intervals in the circumferential direction. The magnetic circuit structure is provided in this magnetic pole portion.

Embodiment

[0019] An embodiment of the magnetic circuit structure will be described based on FIG. 1. In FIG. 1, reference numeral 10 indicates a magnetic pole portion of the rotor core, and the d-axis indicates a central axis connecting the rotor shaft hole and the center of the magnetic pole portion 10.

[0020] The magnetic circuit structure of the magnetic pole portion 10 is mainly composed of a double arc magnet layer. That is, in FIG. 1, reference numeral 11 indicates an outer diameter side magnet group disposed on the outer side (outer diameter side) in the radial direction of the magnetic pole portion 10, and reference numeral 12 indicates an inner diameter side magnet group disposed on the inner side (inner diameter side) in the radial direction of the outer diameter side magnet group 11.

[0021] Here, the outer diameter side magnet group 11 includes outer diameter side arc magnets 11a and 11b symmetrically disposed across the d-axis. On the other hand, the inner diameter side magnet group 12 includes inner diameter side arc magnets 12a and 12b disposed on one side across the d-axis and inner diameter side arc magnets 12c and 12d disposed on the other side.

[0022] ​​​

[0023] In this case, the inner diameter arc magnets 12a, 12b, 12c, and 12d are arranged in series within the magnet insertion holes 16a and 16b, but they do not need to be in contact with each other, or conversely, they may be bonded together, as long as they are provided in series within the magnet insertion holes 16a and 16b.

[0024] Specifically, each of the arc magnets 11a, 11b, 12a-12d has an arc shape that is convex on the inner diameter side, and is formed in a similar shape of the same size, with the same shape in the longitudinal cross-section in the axial direction. In this embodiment, cost reduction is achieved by unifying the shape and size of the arc magnets 11a, 11b, 12a-12d.

[0025] Furthermore, each of the arc magnets 11a, 11b, 12a to 12d is formed with approximately the same curvature as the magnet insertion holes 15a, 15b, 16a, and 16b, and its inner and outer surfaces are curved. The outer diameter arc magnets 11a, 11b and the inner diameter arc magnets 12a to 12d are in the following positional relationship.

[0026] Not concentric circles The inner surfaces 20 and 21 of the outer diameter arc magnets 11a and 11b are not concentric. That is, the circle P along the inner surface 20 is centered at P1, while the circle Q along the inner surface 21 is centered at Q1, and the center positions of P and Q are different. As a result, the outer edges a3 and b3 of the outer diameter arc magnets 11a and 11b tend to move away from the inner edges c1 and d1 of the inner diameter arc magnets 12a and 12c.

[0027] Similarly, the inner surfaces 22a and 22b of the inner diameter arc magnets 12a and 12b, and the inner surfaces 23a and 23b of the inner diameter arc magnets 12c and 12d are not concentric. That is, the circle R along the inner surfaces 22a and 22b is centered at R1, while the circle S along the inner surfaces 23a and 23b is centered at S1, and the center positions of R and S are different. As a result, the inner edges c1 and d1 of the inner diameter arc magnets 12a and 12c tend to move away from the outer edges a3 and b3 of the outer diameter arc magnets 13a and 13b.

[0028] As a result, it becomes possible to secure the length of the region A between the ends (outer peripheral edges a3, b3) of the outer diameter side arc magnets 11a, 11b and the ends (inner peripheral edges c1, d1) of the inner diameter side arc magnets 12a, 12b.

[0029] When the width of the outer diameter side arc magnets 11a, 11b is increased in this way, the region A is not narrowed as in the prior art, and it becomes possible to prevent the reduction of the torque increase due to the increase in the magnet width. In this regard, the torque of the rotating machine can be increased by increasing the magnet width.

[0030] ≪L1>L2≫ In FIG. 1, L1 indicates the distance from the d-axis to the centers P1, Q1, and L2 indicates the distance from the d-axis to the centers S1, R1. Here, the positional relationship of "L1 > L2" is established. The details of this point will be described below.

[0031] (1) That is, when the centers P1, Q1 approach the d-axis, that is, when L1 becomes smaller, the outer peripheral edges a3, b3 of the outer diameter side arc magnets 11a, 11b tend to approach the inner peripheral edges c1, d1 of the inner diameter side arc magnets 12a, 12c.

[0032] Also, when the centers R1, S1 move away from the d-axis, that is, when L2 becomes larger, the inner peripheral edges c1, d1 of the inner diameter side arc magnets 12a, 12c tend to approach the outer peripheral edges a3, b3 of the outer diameter side arc magnets 11a, 11b.

[0033] Therefore, in the case of the positional relationship of "L1 < L2", the region A becomes narrow, the magnetic flux saturates as in the prior art, and there is a possibility that the increase in torque due to the increase in the magnet width is reduced.

[0034] (2) On the other hand, when the centers P1, Q1 move away from the d-axis, that is, when L1 becomes larger, the outer peripheral edges a3, b3 of the outer diameter side arc magnets 11a, 11b tend to move away from the inner peripheral edges c1, d1 of the inner diameter side arc magnets 12a, 12c.

[0035] Furthermore, when the centers R1 and S1 approach the d-axis, that is, when L2 becomes smaller, the inner edges c1 and d1 of the inner diameter arc magnets 12a and 12c tend to move away from the outer edges a3 and b3 of the outer diameter arc magnets 11a and 11b.

[0036] Therefore, when the positional relationship "L1 > L2" holds true, a wider area A can be secured, and in this respect as well, the reduction in torque increase due to the increase in magnet width can be prevented.

[0037] ≪θ1>θ2≫ (1) θ1 in Figure 1 is A straight line E1 connecting the inner circumferential edges a1 and a2 of the outer diameter arc magnet 11a, The straight line E2 connecting the inner circumferential edges b1 and b2 of the outer diameter arc magnet 11b, This shows the angle between them.

[0038] (2) The same θ2 is, A straight line F1 connecting the inner circumference edges c1 and c2 (the inner circumference edges furthest apart) of the inner diameter arc magnets 12a and 12b, The straight line F2 connecting the inner circumference edges d1 and d2 (the inner circumference edges furthest apart) of the inner diameter arc magnets 12c and 12d, This shows the angle between them.

[0039] When θ1 increases, the outer edges a4 and b4 of the outer diameter arc magnets 11a and 11b move toward the outer diameter. Conversely, when θ2 decreases, the inner edges c2 and d2 of the inner diameter arc magnets 12b and 12d move toward the inner diameter. Therefore, if the positional relationship "θ1 > θ2" is met, it becomes easier to secure the radial length of the region between the outer edges a4 and b4 and the inner edges c2 and d2, i.e., region B.

[0040] This makes it possible to suppress the magnetic flux density between the outer diameter arc magnets 11a and 11b and the inner diameter arc magnets 12b and 12d near the d-axis, thereby increasing the torque.

[0041] ≪θ²<90°≫ If "θ2 > 90°" is true, the inner circumferential edges c2 and d2 will face the outer diameter side, which may shorten the length of region B. Therefore, setting "θ < 90°" is preferable for increasing torque.

[0042] It should be noted that the present invention is not limited to the embodiments described above, and can be implemented with modifications within the scope of each claim. For example, the number of outer diameter magnets 11 and inner diameter magnets 12 is not limited to the number in the embodiment (outer diameter arc magnets 11a, 11b = 2, inner diameter arc magnets 12a to 12d = 4), and the number may be appropriately changed according to the specifications. [Explanation of Symbols]

[0043] 10...Magnetic pole part 11...Outer diameter side magnet group 11a, 11b... Outer diameter side arc magnet section 12…Inner diameter side magnet group 12a, 12b... Inner diameter arc magnet 15a, 15b, 16a, 16b…Magnet insertion holes 21,22,22a,22b,23a,23b…Inner peripheral surface a1, a2, b1, b2, c1, c2, d1, d2... inner circumference edge d axis…center axis L1, L2... Distance from the d-axis E1,E2,F1,F2…straight line P, Q, R, S... yen P1,Q1,S1,R1…center θ1…Angle between E1 and E2 θ2…Angle between F1 and F2

Claims

1. The rotor core of a rotating machine rotor, which is formed in a roughly circular shape, The rotor core has magnetic pole portions formed at regular intervals in the circumferential direction, Equipped with, The aforementioned magnetic pole portion is The outer diameter side magnet group consists of outer diameter side arc magnets arranged to be convex radially inward of the rotor core, An inner diameter side magnet group consisting of an inner diameter side arc magnet located inside the outer diameter side magnet group in the radial direction and arranged to be convex in the radial direction, Equipped with, The outer diameter magnet group is configured by arranging outer diameter arc magnets symmetrically across the radial central axis of the magnetic pole portion. The inner diameter magnet group is configured by symmetrically arranging inner diameter arc magnets across the central axis. The inner surfaces of each of the symmetrically arranged arc magnets are not concentric circles, The center position of the circle corresponding to each of the aforementioned inner surfaces is shifted. A magnetic circuit structure for a rotating machine rotor characterized by the following features.

2. The centers of the circles along the inner circumferential surfaces of each outer diameter arc magnet and each inner diameter arc magnet are, Each is arranged symmetrically across the aforementioned central axis, Let L1 be the distance of each of the outer diameter arc magnets from the central axis. Let L2 be the distance of each of the inner diameter arc magnets from the central axis. The magnetic circuit structure of a rotating machine rotor according to claim 1, characterized in that "L1 > L2" holds true.

3. The group of outer diameter magnets is configured by arranging the outer diameter arc magnets one by one across the central axis. The group of inner diameter magnets is configured by arranging a pair of the inner diameter arc magnets in series across the central axis. The magnetic circuit structure of a rotating machine rotor according to claim 1.

4. Let θ1 be the angle between the straight lines that connect the inner edges of each of the outer diameter arc magnets. Let θ2 be the angle between the straight lines connecting the furthest inner edges of the series-arranged inner diameter arc magnets. The magnetic circuit structure of a rotating machine rotor according to claim 3, characterized in that "θ1 > θ2" holds true.

5. The magnetic circuit structure of a rotating machine rotor according to claim 4, characterized in that "θ² < 90°".

6. Each of the aforementioned arc magnets is formed to be similar in shape and of the same size. A magnetic circuit structure for a rotating machine rotor according to any one of claims 1 to 5.

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