Rotors and rotating electric machines

Abstract

To provide a rotor and a rotary electric machine having a structure that can improve the inertial load that can be tolerated during the startup of the rotary electric machine.SOLUTION: A rotor 10 is rotatable around a central axis J. The rotor 10 includes a rotor core 20 and a plurality of flux barrier portion groups 130 that are provided on the rotor core and are arranged at circumferential spacing. Each of the plurality of flux barrier portion groups includes a plurality of flux barrier portions 30 arranged in a radially spaced arrangement. The rotor core has a convex portion 50 protruding inside the flux barrier portion from an edge of the flux barrier portion. In each of the plurality of flux barrier portion groups, two or more convex portions are provided on an edge 30e of at least one flux barrier portion.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a rotor and a rotating electric machine.

Background Art

[0002] A rotor of a rotating electric machine including a rotor core and holes provided in the rotor core is known. For example, the rotor of Patent Document 1 has a plurality of holes serving as flux barriers that are convex toward the radially outer side when viewed in the axial direction of the rotor, and a plurality of holes arranged at intervals on the outer side in the circumferential direction. A conductor is arranged inside the holes arranged on the outer side in the circumferential direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rotor of Patent Document 1, when starting the rotation of the rotor, if the direction of the magnetic flux generated by the stator and the direction in which the magnetic path extends between the flux barriers are not the same, the magnetic field generated by the stator may not be suitably used as a magnetic field for generating torque of the rotor. In this case, the inertial load of the rotor at the start of the rotating electric machine may exceed the maximum inertial load of the rotating electric machine that can be tolerated when the rotor is rotated up to the rated speed, and the rotational speed of the rotor may not be increased to the rated speed.

[0005] In view of the above circumstances, an object of the present invention is to provide a rotor and a rotating electric machine having a structure capable of improving the inertial load that can be tolerated at the start of the rotating electric machine.

Means for Solving the Problems

[0006] One embodiment of the rotor of the present invention is a rotor rotatable about a central axis, comprising a rotor core and a plurality of flux barrier groups provided on the rotor core and arranged at circumferential intervals. Each of the plurality of flux barrier groups includes a plurality of flux barrier portions arranged radially apart. The rotor core has protrusions projecting inward from the edges of the flux barrier portions, and in each of the plurality of flux barrier groups, at least one edge of the flux barrier portion is provided with two or more of these protrusions.

[0007] One embodiment of the rotating electric machine of the present invention comprises the rotor described above and a stator located radially outward from the rotor. [Effects of the Invention]

[0008] According to one aspect of the present invention, it is possible to provide a rotor and a rotating electric machine having a structure that can improve the allowable inertial load when the rotating electric machine is started up. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic cross-sectional view showing the rotating electric machine of this embodiment. [Figure 2] Figure 2 is a cross-sectional view showing the rotor and stator of this embodiment, and is a cross-sectional view taken along line II-II in Figure 1. [Figure 3] Figure 3 is a diagram illustrating the flow of magnetic flux in the rotor of this embodiment. [Figure 4A] Figure 4A is a cross-sectional view showing a modified example of the rotor of this embodiment. [Figure 4B] Figure 4B is a cross-sectional view showing another modified example of the rotor of this embodiment. [Figure 5A] Figure 5A is a diagram illustrating the flow of magnetic flux in the rotor shown in Figure 4B. [Figure 5B] Figure 5B is a diagram illustrating the flow of magnetic flux in the rotor when the magnetic field shown in Figure 5A rotates. [Figure 5C] Figure 5C is a diagram illustrating the flow of magnetic flux in the rotor when the magnetic field shown in Figure 5B rotates further. [Figure 6] Figure 6 is a cross-sectional view showing another modified example of the rotor of this embodiment. [Figure 7] Figure 7 is a cross-sectional view showing another modified example of the rotor of this embodiment. [Figure 8A] Figure 8A is a partially enlarged view of the rotor, showing another modified example of the rotor of this embodiment. [Figure 8B] Figure 8B is a partially enlarged view of the rotor, showing another modified example of the rotor of this embodiment. [Figure 8C] Figure 8C is a partially enlarged view of the rotor, showing another modified example of the rotor of this embodiment. [Modes for carrying out the invention]

[0010] The Z-axis direction, as shown in each figure, is the vertical direction, with the positive side being the "up" and the negative side being the "down". The central axis J, as shown in each figure, is a virtual line parallel to the Z-axis direction and extending in the vertical direction. In the following explanation, the axial direction of the central axis J, i.e., the direction parallel to the vertical direction, will simply be called the "axial direction", the radial direction centered on the central axis J will simply be called the "radial direction", and the circumferential direction centered on the central axis J will simply be called the "circumferential direction". When viewed from the upper side in the axial direction, the direction moving clockwise in the circumferential direction will be called the +θ side, and the direction moving counterclockwise will be called the -θ side.

[0011] Note that "up and down," "upper side," and "lower side" are merely terms used to describe the relative positions of the parts, and the actual relative positions may differ from those indicated by these terms.

[0012] The rotating electrical machine 1 of the present embodiment shown in FIG. 1 is an inner rotor type motor. As shown in FIG. 1, the rotating electrical machine 1 of the present embodiment includes a housing 2, a rotor 10, a stator 3, a bearing holder 4, and bearings 5a and 5b. The housing 2 houses the rotor 10, the stator 3, the bearing holder 4, and the bearings 5a and 5b inside. The bottom of the housing 2 holds the bearing 5b. The bearing holder 4 holds the bearing 5a. The bearings 5a and 5b are, for example, ball bearings.

[0013] The stator 3 is located radially outside the rotor 10. As shown in FIG. 1, the stator 3 has a stator core 3a, an insulator 3d, and a plurality of coils 3e. As shown in FIG. 2, the stator core 3a has a core back 3b and a plurality of teeth 3c. The core back 3b is annular with the central axis J as the center. The plurality of teeth 3c extend radially inward from the core back 3b. The plurality of teeth 3c are arranged at equal intervals along the circumferential direction over one turn. The plurality of coils 3e are attached to the stator core 3a via the insulator 3d.

[0014] The rotor 10 is rotatable about the central axis J. As shown in FIG. 2, the rotor 10 includes a shaft 11 and a rotor core 20. The shaft 11 is cylindrical and extends axially about the central axis J. As shown in FIG. 1, the shaft 11 is rotatably supported about the central axis J by the bearings 5a and 5b.

[0015] The rotor core 20 is a magnetic material. The material of the rotor core 20 is, for example, silicon steel having a higher magnetic permeability and a lower electrical conductivity than an alloy of iron and carbon. The rotor core 20 is fixed to the outer peripheral surface of the shaft 11. The rotor core 20 has a through-hole 20a penetrating the rotor core 20 in the axial direction. As shown in FIG. 2, the through-hole 20a is circular in shape centered on the central axis J when viewed in the axial direction. The shaft 11 is passed through the through-hole 20a. The shaft 11 is fixed in the through-hole 20a by, for example, press-fitting or the like. Although not shown, the rotor core 20 is, for example, composed of a plurality of electromagnetic steel sheets laminated in the axial direction.

[0016] The rotor core 20 has a plurality of flux barrier portions 30. In the present embodiment, each flux barrier portion 30 is constituted by a hole provided in the rotor core 20. The flux barrier portion 30, for example, penetrates the rotor core 20 in the axial direction. Each flux barrier portion 30 extends along a plane orthogonal to the axial direction and has a shape that protrudes radially outward when viewed in the axial direction. A plurality of sets including two or more flux barrier portions 30 are provided in the rotor core 20. A set of flux barrier portions 30 is also referred to as a flux barrier portion group 130. Each flux barrier portion group 130 includes a plurality of flux barrier portions 30.

[0017] The rotor 10 provided with the flux barrier portion 30 in this way serves as the rotor of a synchronous reluctance motor having a magnetic salient pole structure. More specifically, when viewed from the axial direction, the space between two adjacent sets of flux barrier portion groups 130 is a salient pole direction in which magnetic flux easily passes, and a direction in which magnetic flux hardly passes is provided at the central portion in the circumferential direction of one set of flux barrier portion groups 130. In the following description, the above-mentioned salient pole direction in which magnetic flux easily passes is referred to as the "d-axis direction", and the above-mentioned direction in which magnetic flux hardly passes is referred to as the "q-axis direction". Since the rotor 10 has magnetic anisotropy in the q-axis direction and the d-axis direction, a reluctance torque is generated when a magnetic field is generated by the stator 3, and the rotor 10 can be rotated. Furthermore, the d-axis direction is the radial direction passing through the circumferential center of the magnetic pole portion P of the rotor 10, and the q-axis direction is the radial direction passing through the circumferential center between adjacent magnetic pole portions P in the circumferential direction. The portion located between adjacent magnetic pole portions P in the circumferential direction will hereafter be called the magnetic pole intermediate portion M. The q-axis passes through the magnetic pole intermediate portion M. Thus, the rotor 10 is provided with a plurality of magnetic pole portions P arranged along the circumferential direction, and a plurality of magnetic pole intermediate portions M located between adjacent magnetic pole portions P in the circumferential direction. Each of the magnetic pole intermediate portions M has a flux barrier group 130.

[0018] In this embodiment, a conductor 40 is placed inside the flux barrier portion 30. The conductor 40 is filled inside all of the flux barrier portions 30. The material constituting the conductor 40 is a material with high electrical conductivity. Examples of materials constituting the conductor 40 include aluminum, copper, and alloys of aluminum and copper. The material constituting the conductor 40 is a metal that is not ferromagnetic so as not to affect the magnetic salient pole structure formed by the flux barrier portion 30. The conductor 40 within the flux barrier section 30 is made by heating the metal that will become the conductor 40 and pouring it into the flux barrier section 30.

[0019] When a conductor 40 is placed within the flux barrier section 30 of a synchronous reluctance motor, the conductor is placed in a rotating magnetic field. Therefore, when the magnetic field generated by the stator 3 rotates, an induced current flows through the conductor 40 due to electromagnetic induction, and the Lorentz force of the induced current makes it possible to generate rotational force in the rotor 10. In particular, since torque can be obtained due to the Lorentz force when starting the rotation of the stationary rotor 10, the allowable inertial load at the start of the rotating electric machine 1 can be improved. A synchronous reluctance motor with improved startup characteristics in this way is also called a DOL SynRM (Direct-On-Line Synchronous Reluctance Motor).

[0020] In the rotor 10 having a magnetic salient pole structure, since no conductor 40 is placed in the magnetic pole portion P, the amount of conductor 40 placed in the circumferential direction is not uniform. Also, as shown in Figure 3, if the direction in which the magnetic flux F generated by the stator 3 flows during startup does not coincide with the direction in which the magnetic path MP through which the magnetic flux flows in the rotor core 20 extends, the magnetic flux F may not pass through the rotor 10 properly, and the Lorentz force generated during startup may not be sufficiently obtained. The magnetic path MP refers to the region between multiple flux barrier portions 30 and the region near the flux barrier portions 30 within the rotor core 20.

[0021] Therefore, the inventors found that by arranging a protrusion 50 of the rotor core 20 that protrudes inward from the edge 30e of the flux barrier portion 30, the magnetic flux F generated by the stator 3 at startup can be suitably passed through the rotor 10 regardless of the direction in which the magnetic flux F flows. By arranging the protrusion 50, even if the direction in which the magnetic path MP extends and the direction in which the magnetic flux F generated by the stator 3 flows do not coincide, as shown in Figure 3, the magnetic flux F generated by the stator 3 can be suitably passed along the protrusion 50. As a result, a torque due to the Lorentz force can be obtained when the rotation of the stationary rotor 10 is started, and the allowable inertial load at startup of the rotor 10 can be improved.

[0022] The configuration of the flux barrier portion 30 and the protrusion portion 50 of the rotor 10 will be explained in more detail below with reference to Figures 2 and 3.

[0023] (Flux barrier section 30) As shown in Figure 2, the rotor 10 of this embodiment has two sets of flux barrier section groups 130, each comprising a first barrier section 31, a second barrier section 32, a third barrier section 33, a fourth barrier section 34, and a fifth barrier section 35. In this embodiment, five flux barrier units 30 are arranged in a group of flux barrier units 130. The number of flux barrier units 30 in a group of flux barrier units 130 is not limited to five; it is not particularly limited as long as there are two or more. The number of flux barrier units 30 may be appropriately changed depending on the size of the rotor 10. Hereafter, when referring to any of the first barrier section 31 to the fifth barrier section 35, it will also simply be called the flux barrier section 30.

[0024] The two sets of flux barrier groups 130 are arranged at equal intervals along the circumferential direction of the rotor 10. Furthermore, the two sets of flux barrier groups 130 face each other across a through-hole 20a. Each set of flux barrier components 130 has a similar configuration, except that they are arranged in a position rotated 180° in the circumferential direction. In the following description of each flux barrier component 30, we will describe a flux barrier component 30 included in one of the two sets of flux barrier components 130 as a representative.

[0025] Of the multiple flux barrier sections 30 included in the flux barrier section group 130, the first barrier section 31, the second barrier section 32, the third barrier section 33, the fourth barrier section 34, and the fifth barrier section 35 are arranged in this order from the radially outer to the radially inner. Each flux barrier section 30 is not in contact with the others and is located apart in the radial direction. Of the rotor core 20, the radially outer region of the first barrier section 31, the region between two radially adjacent flux barrier sections 30, and the radially inner region of the fifth barrier section 35 form a magnetic path MP through which magnetic flux flows.

[0026] The first barrier portion 31 to the fifth barrier portion 35 each extend in a direction intersecting the q-axis when viewed in the axial direction. In this embodiment, each of the first barrier portion 31 to the fifth barrier portion 35 has a line-symmetric shape with respect to the q-axis when viewed in the axial direction. In the following explanation, the direction in which the flux barrier portion 30 extends when viewed axially will be referred to as the "extension direction." The directions in which the first barrier portion 31, second barrier portion 32, third barrier portion 33, fourth barrier portion 34, and fifth barrier portion 35 extend when viewed axially will be referred to as the "first extension direction," "second extension direction," "third extension direction," "fourth extension direction," and "fifth extension direction," respectively.

[0027] Viewed axially, the flux barrier portion 30 located radially outward has a shorter extension dimension. That is, the extension dimension of the first barrier portion 31 is shorter than the extension dimension of the second barrier portion 32. The extension dimension of the second barrier portion 32 is shorter than the extension dimension of the third barrier portion 33. The extension dimension of the third barrier portion 33 is shorter than the extension dimension of the fourth barrier portion 34. The extension dimension of the fourth barrier portion 34 is shorter than the extension dimension of the fifth barrier portion 35.

[0028] Viewed in the axial direction, each flux barrier portion 30 is curved in a convex shape toward the radially outward direction. This allows multiple flux barrier portions 30 to be arranged while avoiding the area where the through hole 20a is located. Viewed in the axial direction, the central portion 30a of each of the first barrier portion 31 to the fifth barrier portion 35 in their respective extension directions has a shape that includes an arc that is convex radially outward. Among the arcs included in the central portion 30a of each flux barrier portion 30, the arc radius is smaller for flux barrier portions 30 located radially inward, and the arc radius is larger for flux barrier portions 30 located radially outward. Note that, viewed in the axial direction, one or more flux barrier portions 30 located radially outward may not include an arc in their central portion 30a and may extend linearly in a direction perpendicular to the q-axis.

[0029] The ends 30b on both sides of each flux barrier portion 30 in the extension direction are located on the radial outer edge of the rotor core 20. The radial positions of both ends 30b of the flux barrier portion 30 are equivalent.

[0030] Viewed in the axial direction, the width of the flux barrier portion 30 in the central portion 30a in the extension direction is smaller than the width of the flux barrier portion 30 at the end portion 30b. Furthermore, in the central portion 30a of multiple flux barrier portions 30, the width of the flux barrier portion 30 is narrower towards the radially inward side. Note that the width of the flux barrier portion 30 is the dimension in the direction perpendicular to the extension direction of each flux barrier portion 30 when viewed in the axial direction. By providing a narrow region of the flux barrier section 30 in this way, multiple flux barrier sections 30 can be arranged while ensuring a suitable width for the magnetic path MP. The widths of the first barrier section 31 to the fifth barrier section 35 may, for example, be uniform.

[0031] In this specification, "two parameters are the same" includes not only cases where two parameters are exactly the same, but also cases where two parameters are approximately the same. "Two parameters are approximately the same" includes, for example, cases where two parameters are slightly different within a tolerance range.

[0032] (Protrusion 50) The rotor core 20 has a protrusion 50 that extends inward from the edge 30e of the flux barrier portion 30. The edge portion 30e includes a first edge portion 30e1 on the radially outer side of the flux barrier portion 30 and a second edge portion 30e2 on the radially inner side. In this embodiment, the protrusion 50 is provided on the first edge portion 30e1 on the radially outer side of the flux barrier portion 30. This makes it easier for the magnetic flux F flowing from the radially outer side to pass through the protrusion 50. In each of the multiple flux barrier sections 130, at least one flux barrier section 30 has an edge 30e with two or more protrusions 50. In this embodiment, the second barrier section 32, the third barrier section 33, the fourth barrier section 34, and the fifth barrier section 35 each have a pair of protrusions 50.

[0033] The first barrier section 31, which is located on the outermost radial side, does not have a protrusion 50. This is because the effect of the protrusion 50 on controlling the magnetic flux F is weaker in the first barrier section 31, which is located closest to the stator 3, than in the protrusions 50 of the other flux barrier sections 30, and also because it may be possible to control the flow of magnetic flux F generated by the stator 3 even without providing a protrusion 50. Furthermore, the first barrier portion 31 may be provided with a protrusion 50.

[0034] The two protrusions 50 contained within one flux barrier portion 30 are arranged with a gap between them in the circumferential direction. The pairs of protrusions 50, respectively, located in the second barrier section 32, the third barrier section 33, the fourth barrier section 34, and the fifth barrier section 35, are positioned on either side of a virtual line IL that extends radially through the circumferential center of the flux barrier section 30 when viewed in the axial direction. This allows the magnetic flux F generated by the rotating magnetic field to pass through a position on either the +θ or -θ side of the virtual line IL when the rotor 10 is started, and one of the pairs of protrusions 50 can suitably direct the magnetic flux F in a direction that penetrates the width direction of the flux barrier section 30. The virtual line IL may be positioned to coincide with the q-axis.

[0035] The pair of protrusions 50 included in one flux barrier section 30 are arranged symmetrically with respect to the imaginary line IL when viewed in the axial direction. This allows for obtaining a torque of equivalent magnitude regardless of whether the rotor 10 is started to rotate in the +θ or -θ direction. Furthermore, it improves the allowable inertial load at startup, regardless of whether the rotor 10 is started to rotate in the +θ or -θ direction.

[0036] The distance between a pair of protrusions 50 located on the edge 30e of the flux barrier portion 30, which is located radially outward, is smaller. That is, the distance between a pair of protrusions 50 in the second barrier portion 32 is smaller than the distance between a pair of protrusions 50 in the third barrier portion 33. The distance between a pair of protrusions 50 in the third barrier portion 33 is smaller than the distance between a pair of protrusions 50 in the fourth barrier portion 34. The distance between a pair of protrusions 50 in the fourth barrier portion 34 is smaller than the distance between a pair of protrusions 50 in the fifth barrier portion 35. This allows for the optimal arrangement of multiple protrusions 50, making it easier for magnetic flux F to flow along the multiple protrusions 50. Furthermore, it allows magnetic flux F to pass through multiple flux barrier groups 130 while avoiding the through-hole 20a. Furthermore, it is preferable that the distance between a pair of protrusions 50 contained within one flux barrier portion 30 is 5 mm or more. This makes it possible to properly allow the molten conductor 40 to flow between the two protrusions 50 when placing the conductor 40 within the flux barrier portion 30.

[0037] When viewed in the axial direction, the dimensions of the protrusion 50 in the direction perpendicular to the direction in which it protrudes are uniform. That is, the protrusion 50 has a rectangular shape. Hereafter, the dimensions of the protrusion 50 in the direction perpendicular to the direction in which it protrudes will also be referred to as the width of the protrusion 50. It is preferable that the width of the protrusion 50 be such that it can guide the flow of magnetic flux F. The tip of the protrusion 50 is not in contact with the second edge 30e2. Also, the conductor 40 within one flux barrier portion 30 is not electrically separated by the protrusion 50. Furthermore, when viewed in the axial direction, it is preferable that the distance between the tip of the protrusion 50 and the second edge 30e2, which is opposite the first edge 30e1 on which the protrusion 50 is located, is 1.5 mm or more. This makes it possible to properly allow the molten conductor 40 to flow into the flux barrier portion 30 when the conductor 40 is placed inside the flux barrier portion 30.

[0038] As described above, the rotor of this embodiment is a rotor 10 rotatable about a central axis J, comprising a rotor core 20 and a plurality of flux barrier portion groups 130 provided on the rotor core 20 and arranged at intervals in the circumferential direction, each of the plurality of flux barrier portion groups 130 including a plurality of flux barrier portions 30 arranged side by side at intervals in the radial direction, the rotor core 20 has a convex portion 50 that protrudes inward from the edge portion 30e of the flux barrier portion 30, and in each of the plurality of flux barrier portion groups 130, at least one flux barrier portion 30 edge portion 30e is provided with two or more convex portions 50. In the rotor 10 of this embodiment, when the rotation of the stationary rotor 10 is started, the protrusion 50 allows the magnetic flux F generated from the stator 3 to flow suitably to the rotor 10, as shown in Figure 3. Thus, the rotor 10 of this embodiment has a structure that can improve the allowable inertial load when the rotating electric machine 1 is started. Because the magnetic field generated by the stator 3 can be suitably utilized, the inertial load of the rotor 10 when the rotating electric machine 1 is started can be prevented from exceeding the maximum allowable inertial load of the rotating electric machine 1 when the rotor 10 is rotated to the rated speed, and the rotational speed of the rotor 10 can be increased smoothly to the rated speed. Furthermore, in a steady state where the rotational speed of the rotor 10 is at the rated speed, the reluctance torque generated by the arrangement of the flux barrier group 130 allows the rotor 10 to rotate effectively.

[0039] Furthermore, the rotating electric machine 1 of this embodiment includes the rotor 10 described above and a stator 3 located radially outward from the rotor 10. As described above, the rotating electric machine 1 has a rotor 10 that can suitably pass the magnetic flux F of the rotating magnetic field, thus improving the allowable inertial load when the rotating electric machine 1 is started up.

[0040] The present invention is not limited to the embodiments described above, and other configurations can be adopted within the scope of the technical idea of ​​the present invention. For example, as shown in Figure 4A, the number of protrusions 50 arranged in one flux barrier section 30 may be two or more. In the example shown in Figure 4A, the first barrier section 31 has no protrusions 50, the second to fourth barrier sections 32 to 34 each have two protrusions 50, and the fifth barrier section 35 has four protrusions 50. The protrusions 50 of the fifth barrier section 35 in Figure 4A include a first protrusion 50a and a second protrusion 50b which is positioned closer to the end 30b than the first protrusion 50a in the extending direction of the fifth barrier section 35. In the example shown in Figure 4A, the multiple protrusions 50 of the second to fifth barrier sections 32 to 35 are arranged symmetrically with respect to the imaginary line IL.

[0041] Furthermore, each flux barrier section 30 may have four or six protrusions 50. In the rotor 10 shown in Figure 4B, six protrusions 50 are arranged in each of the second to fifth barrier sections 32 to 35. In the example shown in Figure 4B, the protrusions 50 of the second to fifth barrier sections 32 to 35 each include a first protrusion 50a, a second protrusion 50b, and a third protrusion 50c. In the second to fifth barrier sections 32 to 35 shown in Figure 4B, the first protrusion 50a, the second protrusion 50b, and the third protrusion 50c are arranged in this order from the central section 30a toward the end section 30b in the extension direction. In the example shown in Figure 4B, the multiple protrusions 50 of the second to fifth barrier sections 32 to 35 are arranged symmetrically with respect to the imaginary line IL.

[0042] The number of protrusions 50 may be appropriately changed considering the size of the rotor 10 and the shape of the flux barrier portion 30. For example, if no protrusions 50 are placed on the q-axis and multiple protrusions 50 are placed symmetrically with respect to the q-axis, the number of protrusions 50 placed on one flux barrier portion 30 may be an even number of two or more. However, it is preferable that the number of protrusions 50 arranged in each flux barrier section 30 be between two and four. This is because if the number of protrusions 50 is excessively large, it may affect the flow of magnetic flux F when the rotation of the rotor 10 reaches a steady state.

[0043] Figures 5A to 5C show the flow of magnetic flux F within the rotor 10 shown in Figure 4B when the magnetic field generated by the stator 3 begins to rotate in the direction of arrow A1. As shown in Figures 5A to 5C, the arrangement of multiple protrusions 50 allows the magnetic flux F to pass through the rotor 10 regardless of the angle at which the rotating magnetic field is positioned with respect to the central axis J. This makes it possible to obtain a suitable torque due to the Lorentz force when the stationary rotor 10 begins to rotate.

[0044] Furthermore, the spacing between a pair of protrusions 50 when only one flux barrier portion 30 is provided is not limited to the example shown in Figure 2. For example, the flux barrier portion 30 may be provided only with a pair of protrusions 50 positioned at the location of the first protrusion 50a shown in Figure 4B, or only with a pair of protrusions 50 positioned at the location of the second protrusion 50b, or only with a pair of protrusions 50 positioned at the location of the third protrusion 50c.

[0045] Furthermore, the number of magnetic poles P on the rotor 10 is not limited to 2 poles, but may be more than 2 poles. For example, the number of magnetic poles P on the rotor 10 may be 4 poles, 6 poles, or 8 poles. Figure 6 shows a rotor 10 with a four-pole structure. Four sets of flux barrier sections 130 are arranged at equal intervals along the circumferential direction of the rotor 10. Since magnetic pole sections P are provided between adjacent flux barrier sections 130 in the circumferential direction, the rotor 10 shown in Figure 6 has four magnetic pole sections P. In the rotor 10 shown in Figure 6, the shapes of the multiple flux barrier portions 30 are arc-shaped, convex radially inward when viewed in the axial direction. Thus, the shape of the flux barrier portion 30 may be an arc-shaped, convex radially inward when viewed in the axial direction, or it may be a bent line shape, convex radially inward when viewed in the axial direction. Furthermore, a group of flux barrier portions 130 may include both arc-shaped flux barrier portions 30 and bent line-shaped flux barrier portions 30.

[0046] Furthermore, the protrusions 50 may include protrusions 50 provided on the second edge 30e2 on the radially inner side of the flux barrier portion 30. This makes it easier for the magnetic flux F flowing from the radially inner side through the other flux barrier portion group 130 to pass through the protrusions 50. For example, as shown in Figure 7, the flux barrier portion 30 may have an outer protrusion 51 on the radially outer first edge 30e1 and an inner protrusion 52 on the radially inner second edge 30e2. The outer protrusion 51 and the inner protrusion 52 are positioned at different locations in the extending direction of the flux barrier portion 30. This makes it easier for the protrusions 50 to guide both the magnetic flux F flowing from the radially outer side and the magnetic flux F flowing from the radially inner side.

[0047] Furthermore, the outer protrusion 51 and the inner protrusion 52 may be positioned at the same location in the extension direction of the flux barrier portion 30. That is, within the flux barrier portion 30, the outer protrusion 51 and the inner protrusion 52 may be positioned opposite each other in a direction perpendicular to both the axial direction and the extension direction. In this case as well, both the magnetic flux F flowing from the radially outer side and the magnetic flux F flowing from the radially inner side can be more effectively guided by the protrusion 50. Here, for example, if the dimensions of the protrusion 50 in the direction in which it protrudes are designed to be long, the protrusion 50 may be prone to deformation during manufacturing. In such cases, by dividing one protrusion 50 into two parts, an outer protrusion 51 and an inner protrusion 52, it is possible to ensure the total protruding dimension of the protrusion 50 and obtain the effect of guiding the magnetic flux F, while preventing deformation of the protrusion 50 during the manufacturing process. Furthermore, as mentioned above, the distance between the tip of the outer protrusion 51 and the tip of the inner protrusion 52 is preferably 1.5 mm or more so that the conductive material 40 can be poured in.

[0048] Furthermore, the shape of the protrusion 50 is not limited to a rectangle. That is, the dimensions of the protrusion 50 in the direction perpendicular to the direction in which it protrudes when viewed in the axial direction do not have to be uniform. For example, as shown in Figure 8A, the protrusion 50 may be semi-elliptical when viewed in the axial direction, as shown in Figure 8B, the protrusion 50 may be triangular when viewed in the axial direction, and as shown in Figure 8C, the protrusion 50 may be trapezoidal when viewed in the axial direction. More specifically, in the rotor 10 shown in Figures 8A to 8C, when viewed in the axial direction, the dimensions of the protrusions 50 in the direction perpendicular to the direction in which the protrusions 50 protrude decrease as they move away from the edge 30e of the flux barrier portion 30. This makes it easier to suitably guide the magnetic flux F flowing through the protrusions 50 along the protrusions 50. Furthermore, in the rotor 10 shown in Figure 8B, the triangular tip of a protrusion 50 located in the radially outer flux barrier portion 30 points in the direction of another protrusion 50 located radially inward. This makes it easier to guide the magnetic flux F flowing through one protrusion 50 to another protrusion 50. Therefore, it becomes easier to suitably guide the magnetic flux F along multiple protrusions 50.

[0049] Furthermore, the shape of the protrusion 50 may be appropriately modified to take into account the inertial load during both startup and steady rotation. In addition, in order to suitably guide the magnetic flux F flowing through the protrusion 50 during startup in a direction that penetrates the width direction of the flux barrier portion 30, it is preferable that the dimensions of the protrusion 50 in the direction perpendicular to the direction in which the protrusion 50 protrudes, when viewed in the axial direction, do not increase as they move away from the edge 30e of the flux barrier portion 30.

[0050] Furthermore, the multiple protrusions 50 do not necessarily have to be positioned symmetrically with respect to the virtual line IL or the q-axis. Also, one flux barrier portion 30 may have an odd number of protrusions 50. By making the arrangement of the protrusions 50 asymmetrical in this way, the inertial load when the rotor 10 starts rotating in either the +θ side or the -θ side can be particularly improved.

[0051] Furthermore, the flux barrier portion 30 does not have to penetrate the rotor core 20 in the axial direction. The flux barrier portion 30 may open to the axial end face of the rotor core 20.

[0052] The flux barrier portion 30 is not particularly limited as long as it can suppress the flow of magnetic flux F. In the embodiment described above, the conductor 40 is placed inside the flux barrier portion 30, but the inside of the flux barrier portion 30 may be an empty space. Alternatively, the flux barrier portion 30 may be formed by embedding a non-magnetic material such as resin in the empty space. Even if the conductor 40 is not placed inside the flux barrier portion 30, the flow of magnetic flux F can be suitably guided by the protrusions 50.

[0053] The applications of the rotating electric machine to which the present invention is applied are not particularly limited. The rotating electric machine may be mounted on a vehicle, for example, or on equipment other than a vehicle. The configurations described herein can be combined as appropriate, within the bounds of what is not mutually contradictory. [Explanation of Symbols]

[0054] 1...Rotating electric machine, 3...Stator, 10...Rotor, 20...Rotor core, 30...Flux barrier section, 30e...Edge section, 30e1...First edge section, 30e2...Second edge section, 50...Convex section, 130...Flux barrier section group, IL...Imaginary line, J...Central axis

Claims

1. A rotor that can rotate around its central axis, Rotor core and The rotor core is provided with a plurality of flux barrier groups arranged at intervals in the circumferential direction, Equipped with, Each of the aforementioned plurality of flux barrier groups includes a plurality of flux barrier portions arranged in a line with a gap between them in the radial direction. The rotor core has a protrusion that extends inward from the edge of the flux barrier portion, In each of the plurality of flux barrier groups, the first barrier portion located on the outermost radial side is not provided with the protrusion. A rotor in which, in each of the plurality of flux barrier groups, two or more protrusions are provided on the edge of each flux barrier portion other than the first barrier portion.

2. A rotor that is rotatable about a central axis, Rotor core and The rotor core is provided with a plurality of flux barrier groups arranged at intervals in the circumferential direction, Equipped with, Each of the aforementioned plurality of flux barrier groups includes a plurality of flux barrier portions arranged in a line with a gap between them in the radial direction. The rotor core has a protrusion that extends inward from the edge of the flux barrier portion, In each of the plurality of flux barrier portions, at least one of the edges of the flux barrier portion is provided with two or more of the protrusions. A rotor in which, in one of the flux barrier portions, an outer protrusion provided on the first radially outer edge and an inner protrusion provided on the second radially inner edge are arranged at different positions in the extending direction of the flux barrier portion.

3. The two or more protrusions include a pair of protrusions arranged at intervals in the circumferential direction, The rotor according to claim 1 or 2, wherein the pair of protrusions are arranged, when viewed in the axial direction, on either side of a virtual line extending radially through the circumferential center of the flux barrier portion.

4. The rotor according to claim 3, wherein the pair of protrusions are arranged symmetrically with respect to the imaginary line when viewed in the axial direction.

5. In each of the plurality of flux barrier groups, the pair of protrusions is provided on the edges of two or more of the flux barrier portions. The rotor according to claim 3 or 4, wherein the circumferential spacing between the pair of protrusions is smaller for each pair of protrusions provided on the edge of the flux barrier portion located radially outward.

6. The rotor according to any one of claims 1 to 5, wherein the protrusion includes a protrusion provided on the first radially outer edge of the flux barrier portion.

7. The rotor according to any one of claims 1 to 6, wherein the protrusion includes a protrusion provided on the second edge of the radially inner side of the flux barrier portion.

8. The rotor according to any one of claims 1 to 7, wherein, when viewed in the axial direction, the dimensions of the protrusion in a direction perpendicular to the direction in which the protrusion is projected are uniform, or decrease as they move away from the edge of the flux barrier portion.

9. A rotor according to any one of claims 1 to 8, A stator located radially outward from the rotor, A rotating electric machine equipped with the following features.

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