JP6848135B1 - Rotor - Google Patents

Abstract

The rotor core of the rotor of the present embodiment has a first hole into which the first permanent magnet is inserted, a second hole into which the second permanent magnet is inserted, and a hole located between the first hole and the second hole. Each of the first permanent magnet and the second permanent magnet has a first point closest to the d-axis and a second point on the innermost peripheral side of the rotor core, and the holes intersect the d-axis. However, the distance between the inner wall of the hole and the d-axis increases monotonically as it approaches the inner circumference of the rotor core in the section between the straight line connecting the first points and the straight line connecting the second points, and becomes empty. The innermost point of the rotor core on the inner wall of the hole is located on the inner peripheral side of the inner wall of the first hole on the inner peripheral side of the innermost point of the rotor core. The point farthest from the magnet side is located on the d-axis side of the innermost peripheral side of the rotor core in the portion of the inner wall of the first hole on the d-axis side of the first point.

Description

Embodiments of the present invention relate to rotors.

A rotary electric machine is known which includes a cylindrical stator and a rotor rotatably supported inside the stator, and rotates the rotor by a rotating magnetic field generated by the stator. Further, regarding a rotary electric machine, a technique of forming a hole in a rotor core is also known in order to reduce the weight of the rotor or suppress leakage flux. Further, a technique of filling the pores with a non-magnetic filler is also known.

Japanese Unexamined Patent Publication No. 2018-85819

An object of the present embodiment is to provide a rotor capable of reducing magnetic flux leakage and suppressing a decrease in strength.

The rotor of this embodiment is
A substantially cylindrical rotor core and a first permanent magnet and a second permanent magnet forming magnetic poles in the rotor core are provided, and the rotor core has a first hole into which the first permanent magnet is inserted and the second permanent magnet. A second hole into which a magnet is inserted, a hole located between the first hole and the second hole, a first core portion on the outer peripheral side of the first hole and the second hole, and the above. A first bridge connecting the first core portion and the second core portion on the inner peripheral side of the first hole and the second hole, and the first core portion and the second core portion between the first hole and the hole. And a second bridge connecting the first core portion and the second core portion between the second hole and the hole, in the circumferential direction of the central axis of the rotor core and the magnetic pole. Assuming that the axis passing through the center is the d-axis, each of the first permanent magnet and the second permanent magnet has a first point closest to the d-axis and a second point on the innermost peripheral side of the rotor core. The hole intersects the d-axis, and the distance between the inner wall of the hole and the d-axis is a straight line connecting the first points and a straight line connecting the second points. In the section between and, the number increases monotonically as it approaches the inner circumference of the rotor core, and the point on the innermost circumference side of the rotor core among the inner walls of the holes is the inner wall of the first hole of the rotor core. The point located on the inner peripheral side of the innermost peripheral side and farthest from the d-axis to the first permanent magnet side of the inner wall of the hole is the first of the inner walls of the first hole. It is located on the d-axis side of the innermost peripheral side of the rotor core in the portion on the d-axis side of the point.

FIG. 1 is a cross-sectional view of the rotary electric machine 1 of the present embodiment. FIG. 2 is a cross-sectional view taken along the line AB of the rotor 3 applicable to the rotary electric machine 1 shown in FIG. FIG. 3 is an enlarged cross-sectional view of the rotor core 32 for one magnetic pole of the rotor 3 shown in FIG. FIG. 4 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG. FIG. 5 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG. FIG. 6 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG. FIG. 7 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG. FIG. 8 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.

Hereinafter, the present embodiment will be described with reference to the drawings. It should be noted that the disclosure is merely an example, and those skilled in the art can easily conceive of appropriate changes while maintaining the gist of the invention are naturally included in the scope of the present invention. Further, in order to clarify the description, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is merely an example, and the present invention is provided. It does not limit the interpretation. Further, in the present specification and each figure, components exhibiting the same or similar functions as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and duplicate detailed description may be omitted as appropriate. ..

FIG. 1 is a cross-sectional view of the rotary electric machine 1 of the present embodiment.
The rotary electric machine 1 of the present embodiment is configured as an embedded permanent magnet type (IPM: Interior Permanent Magnet) rotary electric machine, and is suitably applied to a drive motor or a generator in, for example, a hybrid electric vehicle (HEV) or an electric vehicle (EV). Will be done. The rotary electric machine 1 includes a substantially cylindrical stator 2, a substantially cylindrical rotor 3 in which a permanent magnet is embedded, a housing 10 accommodating the stator 2 and the rotor 3, and a cover 11 fixed to the housing 10. I have.

The stator 2 includes a cylindrical stator core 21 and a winding 22 mounted on the stator core 21. The stator core 21 is configured as a laminated body in which a large number of magnetic materials, for example, annular electromagnetic steel sheets, are laminated concentrically. The housing 10 has a substantially cylindrical inner peripheral surface 10A. The stator core 21 is fixed to the inner peripheral surface 10A. The structure of the stator 2 is not particularly limited, and a general structure can be widely adopted.

The rotor 3 is located inside the stator 2 and is arranged with a slight gap (air gap) between the rotor 3 and the stator 2. The rotor 3 includes a shaft 31, a substantially cylindrical rotor core 32, and a permanent magnet (not shown in FIG. 1). The shaft 31 and the rotor core 32 are configured to be rotatable about the central axis C.

Bearings 41 and 42 are attached to the shaft 31. The bearings 41 and 42 are fixed by the housing 10 and the cover 11. The shaft 31 is rotatably supported by the housing 10 and the cover 11 around the central axis C via bearings 41 and 42. The illustrated example simply shows an example of a bearing structure that supports the shaft 31, and a detailed description of the structure will be omitted.

The rotor core 32 is configured as a laminated body in which a large number of magnetic materials, for example, a large number of annular electromagnetic steel plates such as silicon steel are laminated concentrically. The outer peripheral surface 32S of the rotor core 32 faces the inner peripheral surface 2S of the stator 2 with a slight gap. The rotor core 32 has a hole 32H formed coaxially with the central axis C at the center thereof. The hole 32H penetrates the rotor core 32 in the axial direction. The shaft 31 is press-fitted into the hole 32H and extends coaxially with the rotor core 32.

In the present specification, the axial direction corresponds to the direction in which the shaft 31 or the central axis C shown in FIG. 1 extends. Further, the radial direction described later corresponds to a direction in which a straight line connecting the central axis C and the outer peripheral surface 32S of the rotor core 32 extends in a cross section orthogonal to the central axis C, and the circumferential direction is a rotor in the cross section. It corresponds to the direction along the circumference of 3.

FIG. 2 is a cross-sectional view of the rotary electric machine 1 shown in FIG. 1 along the line AB of the rotor 3.
In this embodiment, the rotor 3 has a plurality of magnetic poles, for example, eight magnetic poles. In the rotor core 32, the axis extending in the radial direction of the rotor core 32 through the boundary between the magnetic poles adjacent to each other in the circumferential direction and the central axis C is called the q-axis, and the axis electrically separated from the q-axis by 90 ° in the circumferential direction. That is, the axis passing through the center of one magnetic pole in the circumferential direction and the central axis C is referred to as the d-axis. Here, the direction in which the interlinkage magnetic flux formed by the stator is likely to flow is referred to as the q-axis. The d-axis and the q-axis are provided alternately in the circumferential direction of the rotor core 32 and in a predetermined phase. One magnetic pole portion of the rotor core 32 refers to a region between two q-axis adjacent to each other in the circumferential direction (a circumferential angle region of 1/8 circumference).

The rotor 3 includes a shaft 31, a rotor core 32, and a plurality of permanent magnets M. A plurality of permanent magnets M, for example, two permanent magnets M, are inserted into the rotor core 32 for each magnetic pole. At each magnetic pole, the two permanent magnets M are arranged line-symmetrically with respect to the d-axis. These permanent magnets M are fixed to the rotor core 32 with, for example, an adhesive.

The permanent magnet M is formed, for example, in the shape of an elongated flat plate having a rectangular cross section, and has a length substantially equal to the axial length of the rotor core 32. That is, each permanent magnet M is embedded over almost the entire length of the rotor core 32. The permanent magnet M may be configured by combining magnets divided into a plurality of magnets in the axial direction. Each permanent magnet M has a pair of long sides and a pair of short sides in the cross section. The shape of the cross section of the permanent magnet M is not limited to a rectangular shape (rectangular shape), and may be a parallelogram. Each permanent magnet M is magnetized in a direction perpendicular to the long side. The two permanent magnets M located on both sides of the d-axis in the circumferential direction, that is, the two permanent magnets M constituting one magnetic pole are arranged so that the magnetization directions are the same. Further, the two permanent magnets M located on both sides in the circumferential direction with the q-axis in between are arranged so that the magnetization directions are opposite to each other.

The rotor core 32 has a plurality of holes H. The plurality of holes H each penetrate the rotor core 32 in the axial direction. The permanent magnet M is inserted into the hole H. Such a hole H may be referred to as a magnet holding hole, a magnet insertion hole, or the like. Focusing on one magnetic pole, the holes H are formed on both sides in the circumferential direction with the d-axis in between. These two holes H are arranged so that the distance in the circumferential direction gradually increases from the central axis C toward the outer peripheral surface 32S of the rotor core 32 in the cross section.

FIG. 3 is an enlarged cross-sectional view of the rotor core 32 for one magnetic pole of the rotor 3 shown in FIG.
In the example shown in FIG. 3, the permanent magnet located on the left side of the d-axis is shown as the first permanent magnet M1, the hole is shown as the first hole H1, and the permanent magnet located on the right side of the d-axis is the first permanent magnet. The two permanent magnets are M2, and the holes are shown as the second holes H2. The first permanent magnet M1 is inserted into the first hole H1. The second permanent magnet M2 is inserted into the second hole H2. Each of the first permanent magnet M1 and the second permanent magnet M2 has a short side facing the d-axis, and the distance between the d-axis and the short side gradually increases from the outer circumference to the inner circumference of the rotor core 32. It is arranged like this.

In addition to the first hole H1 and the second hole H2, the rotor core 32 has a hole A, a first core portion C1, a second core portion C2, a first bridge BR1, and a second bridge BR2. are doing. The first core portion C1 corresponds to a portion of the rotor core 32 on the outer peripheral side of the first hole H1 and the second hole H2. Alternatively, the first core portion C1 corresponds to a fan-shaped portion surrounded by the outer peripheral surface 32S of the rotor core 32 and the first hole H1 and the second hole H2. The second core portion C2 corresponds to a portion of the rotor core 32 on the inner peripheral side of the first hole H1 and the second hole H2. The inner wall of the first hole H1 described below corresponds to the inner wall extending in the axial direction of the rotor core 32 forming the first hole H1, and the inner wall of the second hole H2 corresponds to the axial direction of the rotor core 32 forming the second hole H2. The inner wall of the hole A corresponds to the inner wall extending in the axial direction of the rotor core 32 forming the hole A.

The first hole H1 has a rectangular magnet holding region H11 corresponding to the cross-sectional shape of the first permanent magnet M1, a void region H12 extending from the magnet holding region H11 toward the first bridge BR1, and a magnet holding region H11. It has a gap region H13 extending from the outer peripheral surface 32S toward the outer peripheral surface 32S. The second core portion C2 has a pair of holding protrusions C22 and C23 protruding from the edge C21 facing the long side of the first permanent magnet M1 toward the first core portion C1 at both ends in the longitudinal direction of the magnet holding region H11. ing. The holding protrusion C22 faces the gap region H12, and the holding protrusion C23 faces the gap region H13. The first core portion C1 has a holding protrusion C13 protruding from an edge C11 facing the long side of the first permanent magnet M1 toward the second core portion C2. The holding protrusion C13 faces the holding protrusion C23. The magnet holding region H11 is formed between the edge C11 and the edge C21. The edges C11 and C21 are substantially parallel to each other and are inclined with respect to the d-axis, respectively. The void regions H12 and H13 in the first hole H1 function as a flux barrier that suppresses magnetic flux leakage from both ends in the longitudinal direction of the first permanent magnet M1 to the rotor core 32, and also contributes to weight reduction of the rotor core 32.

The second hole H2 has a rectangular magnet holding region H21 corresponding to the cross-sectional shape of the second permanent magnet M2, a void region H22 extending from the magnet holding region H21 toward the second bridge BR2, and a magnet holding region H21. It has a gap region H23 extending from the outer peripheral surface 32S toward the outer peripheral surface 32S. The second core portion C2 has a pair of holding protrusions C25 and C26 protruding from the edge C24 facing the long side of the second permanent magnet M2 toward the first core portion C1 at both ends in the longitudinal direction of the magnet holding region H21. ing. The holding protrusion C25 faces the gap region H22, and the holding protrusion C26 faces the gap region H23. The first core portion C1 has a holding protrusion C16 protruding from an edge C14 facing the long side of the second permanent magnet M2 toward the second core portion C2. The holding protrusion C16 faces the holding protrusion C26. The magnet holding region H21 is formed between the edge C14 and the edge C24. The edges C14 and C24 are substantially parallel to each other and are inclined with respect to the d-axis, respectively. The void regions H22 and H23 in the second hole H2 function as a flux barrier that suppresses magnetic flux leakage from both ends in the longitudinal direction of the second permanent magnet M2 to the rotor core 32, and also contributes to weight reduction of the rotor core 32.

The first bridge BR1 is located between the first hole H1 and the hole A, and connects the first core portion C1 and the second core portion C2. The first bridge BR1 does not overlap with the d-axis, is located on the side of the first permanent magnet M1 with respect to the d-axis, and extends in the radial direction. The second bridge BR2 is located between the second hole H2 and the hole A, and connects the first core portion C1 and the second core portion C2. The second bridge BR2 does not overlap with the d-axis, is located on the second permanent magnet M2 side with respect to the d-axis, and extends in the radial direction. The outer walls of the first bridge BR1 and the second bridge BR2 close to the d-axis form a part of the inner wall of the hole A.

The hole A is located between the first hole H1 and the second hole H2. The hole A penetrates the rotor core 32 in the axial direction. The holes A are formed so as to intersect the d-axis. The inner wall of the hole A is formed line-symmetrically with respect to the d-axis. Regarding the shape of the hole A, the width of the hole A orthogonal to the d-axis is gradually expanded from the outer circumference to the inner circumference of the rotor core 32.

The first permanent magnet M1 has a first point F1 closest to the d-axis and a second point G1 on the innermost peripheral side of the rotor core 32. The second permanent magnet M2 has a first point F2 closest to the d-axis and a second point G2 on the innermost peripheral side of the rotor core 32.

Here, the straight line connecting the first point F1 of the first permanent magnet M1 and the first point F2 of the second permanent magnet M2 is defined as a straight line LF, and the second point G1 of the first permanent magnet and the second permanent magnet M2 The straight line connected to the second point G2 is defined as a straight line LG. The distance between the inner wall of the hole A and the d-axis increases monotonically as it approaches the inner circumference of the rotor core 32 in the section between the straight line LF and the straight line LG. That is, of the inner wall of the hole A, the distance W1 between the portion of the inner wall on the first permanent magnet M1 side of the d-axis and the d-axis, and the distance between the portion of the inner wall of the second permanent magnet M2 side of the d-axis and the d-axis. W2 increases monotonically as it approaches the inner circumference of the rotor core 32 in the section between the straight line LF and the straight line LG. Of the inner wall of the hole A, the portion of the first permanent magnet M1 side of the d-axis and the portion of the second permanent magnet M2 side of the d-axis are line-symmetrical with respect to the d-axis. In the section between the straight line LF and the straight line LG, the inner wall of the hole A may include a section in which the distance from the d-axis does not change, that is, a straight line section parallel to the d-axis.

Here, "monotonically increasing" means that the inner wall of the hole A locally protrudes toward the d-axis or is locally recessed with respect to the d-axis in the section between the straight line LF and the straight line LG. It means that you are not slack. If the distance between the inner wall and the d-axis is not monotonically increased, for example, if a part of the inner wall protrudes toward the d-axis, stress may be concentrated on this portion, resulting in a decrease in strength. On the other hand, according to one configuration example of the present embodiment in which the distance between the inner wall and the d-axis monotonically increases, the stress is relaxed and the decrease in strength is suppressed.

The inner wall of the hole A may be formed in a curved shape, may be formed in a straight line, or may partially include a curved portion or a straight portion.

The point B on the innermost peripheral side of the rotor core 32 on the inner wall of the hole A is located on the inner peripheral side of the innermost peripheral point C1 on the inner wall of the first hole H1. Further, the point B is located on the inner peripheral side of the inner wall of the second hole H2 with respect to the point C2 on the innermost peripheral side. That is, when the straight line connecting the points C1 and C2 is defined as the straight line LC, the point B is located on the inner peripheral side of the straight line LC. Further, the hole A intersects the straight line LC and extends to the inner peripheral side of the straight line LC. In the illustrated example, the inner wall of the hole A includes a portion parallel to the straight line LC, and the point B is located at this portion. Although the point B is located on the d-axis, it may be located at a position deviated from the d-axis.

Of the inner wall of the hole A, the point farthest from the d-axis, that is, the point farthest from the d-axis to the first permanent magnet M1 side in the portion closer to the first permanent magnet M1 than the d-axis is referred to as point E1. To do. If the portion of the inner wall of the first hole H1 on the d-axis side of the first point F1, that is, the straight line passing through the first point F1 and parallel to the d-axis is defined as the straight line LF1, the straight line LF1 of the first hole H1 is larger than the straight line LF1. In the portion on the d-axis side, the point on the innermost peripheral side of the rotor core 32 is defined as the point D1. The point E1 is located on the d-axis side of the point D1. That is, when a straight line passing through the point D1 and parallel to the d-axis is defined as a straight line LD1, the point E1 is located between the d-axis and the straight line LD1.

Of the inner wall of the hole A, the point farthest from the d-axis, that is, the point farthest from the d-axis to the second permanent magnet M2 side in the portion closer to the second permanent magnet M2 than the d-axis is referred to as point E2. To do. If the portion of the inner wall of the second hole H2 on the d-axis side of the first point F2, that is, the straight line passing through the first point F2 and parallel to the d-axis is the straight line LF2, the straight line LF2 of the first hole H1 is larger than the straight line LF2. In the portion on the d-axis side, the point on the innermost peripheral side of the rotor core 32 is defined as the point D2. The point E2 is located on the d-axis side of the point D2. That is, when the straight line passing through the point D2 and parallel to the d-axis is defined as the straight line LD2, the point E2 is located between the d-axis and the straight line LD2.

Further, the points E1 and E2 are located between the straight line LD1 and the straight line LD2. That is, the hole A is formed between the straight line LD1 and the straight line LD2, and does not intersect with either the straight line LD1 or the straight line LD2. Further, both the point E1 and the point E2 are located on the inner peripheral side of the straight line LG. In the illustrated example, the points E1 and E2 are both located on the inner peripheral side of the straight line LC. That is, the width of the hole A orthogonal to the d-axis is maximum on the inner peripheral side of the straight line LG or on the inner peripheral side of the straight line LC.

The outer peripheral surface 32S has a first notch N1 communicating with the first hole H1 and a second notch N2 communicating with the second hole H2. That is, each of the first hole H1 and the second hole H2 extends toward the outer peripheral surface 32S and is opened or opened on the outer periphery of the rotor core 32. In short, in the rotor core 32, no bridge is formed between the outer peripheral surface 32S and the first hole H1 and between the outer peripheral surface 32S and the second hole H2. Each of the first notch N1 and the second notch N2 penetrates the rotor core 32 in the axial direction. Since such a first notch N1 and a second notch N2 are formed, magnetic flux leakage is suppressed. On the other hand, by forming the first notch N1 and the second notch N2, the first core portion C1 is connected to the second core portion C2 by the first bridge BR1 and the second bridge BR2. Therefore, a bridge is provided between the outer peripheral surface 32S and the first hole H1 and between the outer peripheral surface 32S and the second hole H2 (a configuration in which the first notch and the second notch are not formed). In the configuration of the present embodiment, the support strength of the first core portion C1 is low, and stress tends to be concentrated on the first bridge BR1 and the second bridge BR2.

According to one configuration example of the present embodiment, since the pore A is formed between the first hole H1 and the second hole H2, it orbits through the rotor core 32 in the magnetic flux of the same permanent magnet M. Leakage flux is reduced. Further, the hole A is expanded toward the inner peripheral side of the rotor core 32, and is expanded in a direction orthogonal to the d-axis between the holding protrusion C22 and the holding protrusion C25. Therefore, the weight of the rotor core 32 is reduced. Then, the stress generated by the centrifugal force and torque applied to the rotor 32 is suppressed, and the first core portion C1 can be stably supported by the first bridge BR1 and the second bridge BR2.

Next, another configuration example of this embodiment will be described. In each of the following configuration examples, the rotor core 32 for one magnetic pole will be described with reference to an enlarged cross-sectional view. In the other configuration examples described below, the same reference numerals are given to the same parts as the above-mentioned configuration examples to omit or simplify the detailed description, and parts different from the above-mentioned configuration examples are used. I will explain in detail mainly.

FIG. 4 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.
The configuration example shown in FIG. 4 is different from the configuration example shown in FIG. 3 in that the rotor core 32 further has a first hole O1 and a second hole O2. The first hole O1 and the second hole O2 are located on the outer peripheral side of the rotor core 32 with respect to the hole A. Further, the first hole O1 is located on the outer peripheral side of the first bridge BR1, and the second hole O2 is located on the outer peripheral side of the second bridge BR2. These first hole O1 and second hole O2 penetrate the rotor core 32 in the axial direction. Further, the first hole O1 and the second hole O2 are formed in a substantially triangular shape in which the length in the circumferential direction gradually shortens from the outer circumference to the inner circumference of the rotor core 32.

When a straight line parallel to the d-axis passing through the point K1 closest to the d-axis of the inner wall of the first hole H1 is defined as a straight line LK1, the first hole O1 intersects the straight line LK1 and intersects the d-axis. do not do. The first bridge BR1 is branched into a bridge BR11 and a bridge BR12 on the outer peripheral side of the rotor core 32. The bridge BR11 is formed between the void region H12 of the first hole H1 and the first hole O1. The bridge BR12 is formed between the hole A and the first hole O1.

When a straight line parallel to the d-axis passing through the point K2 closest to the d-axis of the inner wall of the second hole H2 is defined as a straight line LK2, the second hole O2 intersects the straight line LK2 and intersects the d-axis. do not do. The second bridge BR2 is branched into a bridge BR21 and a bridge BR22 on the outer peripheral side of the rotor core 32. The bridge BR21 is formed between the gap region H22 of the second hole H2 and the second hole O2. The bridge BR22 is formed between the hole A and the second hole O2.

A straight line LP is a straight line connecting the midpoint P1 on the long side facing the first core portion C1 of the first permanent magnet M1 and the midpoint P2 on the long side facing the first core portion C1 of the second permanent magnet M2. Then, at least a part of the first hole O1 and at least a part of the second hole O2 are located on the inner peripheral side of the rotor core 32 with respect to the straight line LP. In the illustrated example, the first hole O1 and the second hole O2 both intersect the straight line LP, but the entire first hole O1 and the entire second hole O2 are inside the straight line LP. It may be located on the circumferential side.

According to such a configuration example, the first hole O1 is formed on the outer peripheral side of the first bridge BR1, and the second hole O2 is formed on the outer peripheral side of the second bridge BR2, whereby the rotor core 32 is further formed. Is lighter. Further, the stress generated by the centrifugal force and torque applied to the rotor 32 is suppressed.

FIG. 5 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.
The configuration example shown in FIG. 5 differs from the configuration example shown in FIG. 3 in that the rotor core 32 further has a first hole O1, a second hole O2, and a third hole O3. There is. The first hole O1, the second hole O2, and the third hole O3 are located on the outer peripheral side of the rotor core 32 with respect to the hole A. The third hole O3 is located between the first hole O1 and the second hole O2. Further, the first hole O1 is located on the outer peripheral side of the first bridge BR1, the second hole O2 is located on the outer peripheral side of the second bridge BR2, and the third hole O3 is located on the outer peripheral side of the hole A. are doing. The third hole O3 intersects the d-axis, but the first hole O1 and the second hole O2 do not intersect the d-axis. These first hole O1, second hole O2, and third hole O3 penetrate the rotor core 32 in the axial direction. The third pore O3 is formed in a substantially triangular shape in which the length in the circumferential direction gradually shortens from the outer circumference to the inner circumference of the rotor core 32.

The first bridge BR1 is branched into a bridge BR11 and a bridge BR12 on the outer peripheral side of the rotor core 32. The bridge BR11 is formed between the first hole H1 and the first hole O1. The bridge BR12 is formed between the hole A and the first hole O1. The second bridge BR2 is branched into a bridge BR21 and a bridge BR22 on the outer peripheral side of the rotor core 32. The bridge BR21 is formed between the second hole H2 and the second hole O2. The bridge BR22 is formed between the hole A and the second hole O2. The third bridge BR3 between the hole A and the third hole O3 connects the bridge BR12 and the bridge BR22. The third bridge BR3 is branched into a bridge BR31 and a bridge BR32 on the outer peripheral side of the rotor core 32. The bridge BR31 is formed between the first hole O1 and the third hole O3. The bridge BR32 is formed between the second hole O2 and the third hole O3.

According to such a configuration example, the rotor core 32 is further reduced in weight due to the formation of the third hole O3 in addition to the first hole O1 and the second hole O2, and the centrifugal force applied to the rotor 32 is applied. And the stress generated by torque is suppressed.

FIG. 6 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.
The configuration example shown in FIG. 6 is different from the configuration example shown in FIG. 3 in that the hole A is expanded to the outer peripheral side of the rotor core 32. Of the inner wall of the hole A, the point R on the outermost peripheral side of the rotor core 32 is located on the outer peripheral side of the straight line LF. That is, the hole A intersects the straight line LF and extends to the outer peripheral side of the straight line LF. Although the point R is located on the d-axis, it may be located at a position deviated from the d-axis.

According to such a configuration example, the rotor core 32 is further reduced in weight by expanding the pore A to the outer peripheral side, and the same effect as that of the above configuration example can be obtained.

FIG. 7 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.
The configuration example shown in FIG. 7 is different from the configuration example shown in FIG. 4 in that the first hole O1 and the second hole O2 are round holes. Although the first hole O1 and the second hole O2 shown in the figure intersect with the straight line LP, they may be entirely located on the inner peripheral side of the straight line LP.

Even in such a configuration example, the same effect as the above configuration example can be obtained.

FIG. 8 is a cross-sectional view showing another configuration example of the rotor 3 applicable to the rotary electric machine 1 shown in FIG.
The configuration example shown in FIG. 8 is different from the configuration example shown in FIG. 3 in that the inner wall of the hole A has portions S1 and S2 parallel to the d-axis on the inner peripheral side of the straight line LG. ing. The portion S1 is located closer to the first permanent magnet M1 than the d-axis, and the portion S2 is located closer to the second permanent magnet M2 than the d-axis. The point E1 of the inner wall of the hole A located at the point E1 farthest from the d-axis toward the first permanent magnet M1 is located in the portion S1. The point E2 of the inner wall of the hole A, which is the farthest point from the d-axis toward the second permanent magnet M2, is located at the portion S2.

Even in such a configuration example, the same effect as the above configuration example can be obtained.

As described above, according to the present embodiment, it is possible to provide a rotor capable of reducing magnetic flux leakage and suppressing a decrease in strength.

It should be noted that the present invention is not limited to the above-described embodiment as it is, and at the implementation stage, the constituent elements can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. In addition, components across different embodiments may be combined as appropriate.
For example, the number of magnetic poles, dimensions, shape, etc. of the rotor 3 are not limited to the above-described embodiment, and can be variously changed according to the design. The number of permanent magnets M installed at each magnetic pole of the rotor 3 is not limited to two, and can be increased as needed.

1 ... Rotating electric machine 2 ... Stator 3 ... Rotor C ... Central shaft 31 ... Shaft 32 ... Rotor core 32S ... Outer peripheral surface C1 ... 1st core part C2 ... 2nd core part BR1 ... 1st bridge BR2 ... 2nd bridge H1 ... 1st Hole H2 ... 2nd hole A ... Hole O1 ... 1st hole O2 ... 2nd hole O3 ... 3rd hole M1 ... 1st permanent magnet M2 ... 2nd permanent magnet N1 ... 1st notch N2 ... 2nd notch

Claims (4)

A substantially cylindrical rotor core and a first permanent magnet and a second permanent magnet forming magnetic poles in the rotor core are provided.
The rotor core includes a first hole into which the first permanent magnet is inserted, a second hole into which the second permanent magnet is inserted, and a hole located between the first hole and the second hole. , The first core portion on the outer peripheral side of the first hole and the second hole, the second core portion on the inner peripheral side of the first hole and the second hole, and the first hole and the hole. The first bridge that connects the first core portion and the second core portion, and the first core portion and the second core portion are connected between the second hole and the hole. Has a second bridge and
Assuming that the axis passing through the central axis of the rotor core and the center in the circumferential direction of the magnetic pole is the d-axis,
Each of the first permanent magnet and the second permanent magnet has a first point closest to the d-axis and a second point on the innermost peripheral side of the rotor core.
The vacancies intersect the d-axis and
The distance between the inner wall of the hole and the d-axis is monotonous as it approaches the inner circumference of the rotor core in the section between the straight line connecting the first points and the straight line connecting the second points. Increased to
The innermost point of the rotor core in the inner wall of the hole is located on the innermost side of the inner wall of the first hole with respect to the innermost point of the rotor core.
The point of the inner wall of the hole that is farthest from the d-axis toward the first permanent magnet is the innermost point of the rotor core in the portion of the inner wall of the first hole that is closer to the d-axis than the first point. A rotor located on the d-axis side from a point on the circumferential side. The rotor core further has a first hole and a second hole located on the outer peripheral side of the rotor core with respect to the hole.
The first hole passes through a point of the inner wall of the first hole closest to the d-axis, intersects a straight line parallel to the d-axis, and does not intersect the d-axis.
The second hole passes through a point of the inner wall of the second hole closest to the d-axis, intersects a straight line parallel to the d-axis, and does not intersect the d-axis.
At least a part of the first hole and at least a part of the second hole are the midpoint of the long side facing the first core portion of the first permanent magnet and the second permanent magnet. The rotor according to claim 1, which is located on the inner peripheral side of a straight line connecting the midpoints of the long sides facing the first core portion. The rotor core further has a third hole located between the first hole and the second hole.
The rotor according to claim 2, wherein the third hole intersects the d-axis. The method according to any one of claims 1 to 3, wherein the outer peripheral surface of the rotor core has a first notch communicating with the first hole and a second notch communicating with the second hole. Rotor.

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