Rotor and rotating electric motor using the rotor

Abstract

The rotor core (21) is provided. When the magnetic pole center of the rotor core (21) is set as the d-axis and the axis in the direction orthogonal to the d-axis is set as the q-axis, the rotor core (21) has a bypass barrier (23) in a non-magnetic region on the q-axis, a first magnet (221) in a region of the rotor core (21) closer to the d-axis than the q-axis, and a second magnet (222) in a region of the rotor core (21) that is radially inner than the first magnet (221). The second magnet (222) is in a region of the rotor core (21) that is closer to the q-axis than the first magnet (221). The end point of the second magnet (222) that is closest to the q-axis is located in the rotor core (21) at a position radially inner than the radially innermost surface of the bypass barrier (23).

Description

Technical Field

[0001] This disclosure relates to rotors and rotating electric machines having permanent magnets. Background Technology

[0002] In a rotor with a structure in which permanent magnets are embedded in the rotor core, in order to reduce the main magnetic flux under no-load conditions, if the rotor core is formed in such a way that it has a closed magnetic circuit with leakage flux, the efficiency of the permanent magnet rotary motor is improved. In contrast, the output decreases due to the reduction of the main magnetic flux caused by the magnetic circuit with leakage flux.

[0003] In view of the above situation, a variable flux rotary motor is proposed, which controls the leakage flux leaking to the adjacent permanent magnet by means of the q-axis current, thereby controlling the flux of the permanent magnet linked with the coil wound on the stator (for example, Patent Document 1).

[0004] In this patent document 1, the rotor has at least one permanent magnet forming a d-axis magnetic circuit, and has a magnetic flux bypass path that serves as a path for leakage from the at least one permanent magnet disposed on the rotor to the pole of an adjacent permanent magnet. The magnetic flux inflow and magnetic flux outflow portions of the magnetic flux bypass path are disposed near the air gap between the rotor and the stator.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2014 / 003730 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in structures where the flux inflow and outflow portions of the flux bypass are located near the air gap between the rotor and stator, it is necessary to generate both flux linked to the stator and flux short-circuited inside the rotor within a limited area on the rotor surface. Furthermore, in order to generate both flux linked to the stator and flux short-circuited inside the rotor within a limited area, the flux amounts of both types are in a trade-off relationship, resulting in a problem where the variable flux of the magnet decreases as the maximum torque increases.

[0010] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a rotor that can increase the variable flux of a magnet and a rotary motor using the rotor.

[0011] Solution for solving the problem

[0012] The rotor and rotary electric machine using the rotor disclosed herein are characterized in that, when the magnetic pole center of the rotor core is set as the d-axis and the axis in the direction electrically orthogonal to the d-axis is set as the q-axis, the rotor core has: a bypass barrier of a non-magnetic region disposed on the q-axis; a first magnet disposed in a region of the rotor core closer to the d-axis than the q-axis; and a second magnet, at least a portion of which is disposed in a region of the rotor core radially inner than the first magnet. The second magnet is disposed in a region of the rotor core closer to the q-axis than the first magnet, and the endpoint of the second magnet closest to the q-axis is located in the rotor core at a position radially inner than the radially innermost surface of the bypass barrier. A flux bypass portion is provided between the second magnet and the bypass barrier in the radial direction, which serves as a path for the magnetic flux generated by the stator.

[0013] Invention Effects

[0014] According to the rotor disclosed herein and the rotating motor using the rotor, the variability of the magnetic flux of the magnet can be increased. Attached Figure Description

[0015] Figure 1 This is a longitudinal sectional view of a rotary electric motor having the rotor of Embodiment 1 of this disclosure.

[0016] Figure 2 It is a rotary electric motor having the rotor of Embodiment 1 of this disclosure. Figure 1 Sectional view from direction II.

[0017] Figure 3 This is a cross-sectional view of the main part of the rotor of Embodiment 1 of this disclosure.

[0018] Figure 4 This is a graph showing the magnetic field analysis results of the rotor of Embodiment 1 of this disclosure when it is unloaded.

[0019] Figure 5 This is a graph showing the magnetic field analysis results of the rotor of Embodiment 1 of this disclosure under load.

[0020] Figure 6 This is a diagram showing the magnetic field analysis of a modified rotor of Embodiment 1 of this disclosure under no-load conditions.

[0021] Figure 7 This is a diagram showing the magnetic field analysis under load of a modified rotor according to Embodiment 1 of this disclosure.

[0022] Figure 8 This is a graph showing the relationship between the rotor current and Φd in Embodiment 1 of this disclosure.

[0023] Figure 9 This is a cross-sectional view of the main part of the rotor of Embodiment 1 of this disclosure.

[0024] Figure 10 This is a cross-sectional view of the main part of the rotor of Embodiment 2 of this disclosure.

[0025] Figure 11 This is a cross-sectional view of the main part of the rotor of Embodiment 3 of this disclosure.

[0026] Figure 12 It is a rotary electric motor having the rotor of Embodiment 4 of this disclosure. Figure 1 Sectional view from direction II. Detailed Implementation

[0027] Hereinafter, embodiments will be described with reference to the accompanying drawings. It should be noted that the drawings are schematic representations, and structural details have been omitted or simplified for ease of explanation. Furthermore, the relative sizes and positions of structures shown in different drawings may not be accurately depicted and can be appropriately modified. In the following description, the same reference numerals are used to illustrate the same constituent elements, and their names and functions are also the same. Therefore, detailed descriptions of them are sometimes omitted to avoid repetition.

[0028] Implementation Method 1

[0029] Figure 1 This is a longitudinal sectional view of a rotary electric motor having the rotor of Embodiment 1 of the present disclosure. Figure 2 yes Figure 1 The second-direction sectional view. It should be noted that the longitudinal sectional view is a sectional view showing the section including the axis of rotation. Moreover, for simplicity, the direction parallel to the axis of rotation is defined as the axial direction, the direction centered on and orthogonal to the axis of rotation is defined as the radial direction, and the direction of rotation centered on the axis of rotation is defined as the circumferential direction.

[0030] like Figure 1 As shown, the rotary electric motor 100 includes: a generally cylindrical frame 13; a pair of brackets 14 mounted at both ends of the frame 13 along its axial direction, closing the openings on both sides of the frame 13 along its axial direction; and a rotating shaft 16 rotatably disposed within the frame 13, supported by bearings 15 mounted on the pair of brackets 14. The rotary electric motor 100 also includes: a rotor 20 fixed to the rotating shaft 16 and rotatably disposed within the frame 13; and a stator 10 inserted into and held within the frame 13, and coaxially disposed on the outer diameter side of the rotor 20. A gap G is formed between the rotor 20 and the stator 10. Since the frame 13, brackets 14, bearings 15, and rotating shaft 16 are known technologies, further detailed descriptions of each structure are omitted.

[0031] like Figure 2As shown, the stator 10 includes an annular stator core 11 and a stator coil 12 assembled on the stator core 11. The stator core 11 has an annular core back 18 and a plurality of teeth 19 protruding radially inward from the inner circumference of the core back 18, for example, formed by axially stacking and integrally integrating thin sheets of electromagnetic steel. 48 teeth 19 are arranged circumferentially at equal angular intervals. The circumferential width of the innermost diameter of each tooth 19 is defined as the circumferential width T. The stator coil 12 is composed of a distributed winding coil, which is formed by conductor wires inserted between the teeth 19 and spanning multiple teeth 19. By employing a distributed winding, reluctance torque can be easily and effectively utilized.

[0032] The rotor 20 includes: a rotating shaft 16, a cylindrical rotor core 21 with a shaft insertion hole formed at the axial center, a plurality of permanent magnets 22 (hereinafter referred to as magnets 22) embedded inside the rotor core 21, and bypass barriers 23 in the non-magnetic region. The arrows shown on the magnets 22 in the figure indicate orientation. The rotor core 21 is fixed to the rotating shaft 16, which is inserted into the shaft insertion hole. The rotor core 21 is constructed, for example, by integrally stacking and layering thin sheets of electromagnetic steel along the axial direction. The permanent magnets 22 can be, for example, neodymium magnets with high residual magnetic flux density.

[0033] Regarding the structure of rotor 20, using Figure 3 Further explanation is needed. Figure 3 This is a transverse sectional view of the main part of the rotor according to Embodiment 1 of this disclosure. It should be noted that a transverse sectional view is a sectional view showing a section orthogonal to the axis of rotation. Regarding... Figure 3 The parts not shown in the diagram form the same structure as the parts shown in the diagram, continuously along the circumference.

[0034] The magnets 22 disposed on the rotor 20 are each formed into a rectangle, and a flux barrier 25 (described later) is provided on the short side of each rectangle of the magnet 22. Furthermore, the magnets 22 are either the first magnet 221 or the second magnet 222 (described later). They are magnetized along a direction from one long side of the rectangle to the other long side, that is, parallel to the short side. It should be noted that, to avoid cluttering the drawings, the reference numerals for the magnets 22 are omitted, and only a portion is shown.

[0035] As shown by the arrows in the figure, a portion of the magnets 22 magnetized and arranged towards the stator 10 form an N-pole, which becomes the path through which the magnetic flux of the magnets 22 links with the stator 10. Furthermore, as shown by the arrows in the figure, a portion of the magnets 22 magnetized from the stator 10 towards the rotation axis 16 forms an S-pole, which becomes the path from the stator 10 towards the rotor 20. Here, the center of the N-pole is defined as the d-axis, and the direction located between the N and S poles, i.e., between the poles and electrically orthogonal to the d-axis, is defined as the q-axis. Through this magnetization and arrangement, the magnetic path generated by each magnet 22 can be formed in the shortest possible quantity, thus effectively increasing the magnetic flux linking with the stator 10. Therefore, the amount of magnets 22 arranged in the rotor 20 required to achieve the desired output of the rotary motor 100 can be formed with minimal quantity.

[0036] One magnetic pole of the rotor core 21 is composed of a first magnet 221 and two second magnets 222 from a plurality of magnets 22. The first magnet 221 is arranged circumferentially across the d-axis of the rotor core 21, and the second magnets 222 are arranged in a region of the rotor core 21 closer to the q-axis than the first magnet 221. With this structure, magnets 22 primarily intended for magnetic flux output to the stator 10 and magnets 22 primarily intended for magnetic flux output to the rotor 20 can be separated and combined to form a single magnetic pole. When the three magnets 22 constituting this single magnetic pole are arranged as a magnet group, the plurality of magnet groups are arranged circumferentially and at equal intervals within the rotor core 21. Furthermore, the d-axis, the center of the N-pole, serves as an axis that circumferentially divides the first magnet 221 equally. Moreover, the q-axis passes through the rotor core 21 circumferentially, dividing adjacent magnet groups equally.

[0037] Two second magnets 222 in the magnet group constituting a magnetic pole are separated circumferentially, sandwiching the first magnet 221, and are arranged in an arc shape as a whole. This arc is formed with a concave portion relative to the rotation axis 16 of the rotor 20. That is, the first magnet 221 of the three magnets 22 constituting a magnetic pole is disposed in a region of the rotor core 21 that is radially outer than the other second magnets 222. In the N pole, the flux output surface of the first magnet 221 is closer to the radial outer surface of the rotor core 21 than the flux output surfaces of each of the second magnets 222. In the S pole, the flux input surface of the first magnet 221 is closer to the radial outer surface of the rotor core 21 than the flux input surface of each of the second magnets 222.

[0038] The second magnet 222 is configured such that at least a portion of it is located in a region of the rotor core 21 that is radially inner than the first magnet 221. More specifically, it is configured such that the endpoint of the second magnet 222 closest to the q-axis is located radially inner than the radially innermost surface of the bypass barrier 23 described later. Furthermore, the second magnet 222 is configured such that the end of its circumferential ends closest to the q-axis is closer to the axis than the end furthest from the q-axis, and the end furthest from the q-axis is closer to the radially outer surface of the rotor core 21 than the other end. That is, the flux output surface of the second magnet 222 is inclined, and the inclination of the flux output surface of the second magnet 222 in the N-pole direction is inclined towards the q-axis. This inclination facilitates the linking of the flux of the second magnet 222 in a predetermined direction. This inclination is determined to link the flux flowing from the flux output surface of the second magnet 222 to other second magnets 222 adjacent to it across the q-axis. The same configuration is also found in each of the magnets 22 that constitute the S pole, with the second magnets 222, which are opposite poles separated by the q axis, arranged in an inclined manner that is linearly symmetrical with respect to the q axis.

[0039] Each magnet 22 has a magnetic flux barrier 25 at both circumferential ends. The magnetic flux barrier 25 penetrates the rotor core 21 axially and is a non-magnetic region with gaps. The magnetic flux barriers 25 at both ends of the first magnet 221 and the magnetic flux barriers 25 at both ends of the second magnet 222 are adjacent to each other across the rotor core 21. The rotor core 21 between adjacent first magnets 221 and second magnets 222 of the same pole is designated as a bypass section 24b.

[0040] A bypass barrier 23 is formed on the q-axis of the rotor core 21. The bypass barrier 23 extends axially through the rotor core 21 and is a non-magnetic region of voids. The bypass barrier 23 is disposed within the region of the rotor core 21 bounded by the radially outer surfaces of two adjacent second magnets 222 separated by the q-axis and the outermost radial surface of the rotor. The rotor core 21 between the second magnets 222 and the bypass barrier 23 radially forms a path through which the magnetic flux of one of the second magnets 222 (separated by the q-axis) passes through the other second magnet 222 and short-circuits within the rotor core. This path is designated as a bypass section 24a. The rotor core 21 radially inner than the bypass barrier 23 and circumferentially between adjacent second magnets 222 (separated by the q-axis) forms a path for the magnetic flux generated by the stator 10. This path is designated as the q-axis magnetic circuit section.

[0041] Next, the relationship between the magnets 22, the bypass barrier 23, and the magnetic flux barrier 25 will be explained. For example... Figure 3As shown, distance A is defined as the distance between the outermost radial surface of the rotor core 21 and the corner of the second magnet 222 closest to the q-axis, when they are connected parallel to the q-axis. Distance B is defined as the maximum distance from the outermost radial surface of the rotor core 21 to the bypass barrier 23 when the innermost radial surface of the bypass barrier 23 and the outermost radial surface of the rotor core 21 are connected parallel to the q-axis. Here, distance B is defined as the distance connecting the intersection of the outermost radial surface of the rotor core 21 with the q-axis and the intersection of the innermost radial surface of the bypass barrier 23 with the q-axis. In this case, the bypass barrier 23 and the second magnet 222 are arranged in the rotor core 21 such that distance A > distance B.

[0042] Furthermore, the shortest distance between the rotor cores 21 circumferentially separated by the flux barriers 25 positioned on adjacent second magnets 222 across the q-axis is defined as the shortest distance C. The minimum distance between the bypass barrier 23 and the rotor cores 21 radially between the bypass barrier 23 and the second magnet 222, or between the bypass barrier 23 and the rotor cores 21 radially between the bypass barrier 23 and the flux barriers 25 located at the circumferential end of the second magnet 222, is defined as the minimum distance D. In this case, the flux barriers 25, the second magnet 222, and the bypass barrier 23 are respectively arranged on the rotor cores 21 in such a way that the shortest distance C ≥ the minimum distance D × 2. Moreover, the bypass barrier 23 is arranged such that the minimum distance D is larger than the radial width of the rotor core 21 radially outside the bypass barrier 23.

[0043] Furthermore, the minimum distance from the intersection of the outermost radial surface of the first magnet 221 and the d-axis to the outermost radial surface of the rotor core 21 of the rotor 20 is defined as distance E, and the minimum distance from the outermost radial end point of the first magnet to the outermost radial surface of the rotor core 21 of the rotor 20 is defined as distance F. In this case, the first magnet 221 is arranged in the rotor core 21 such that distance E > distance F.

[0044] Furthermore, the circumferential width of the second magnet 222 is set to circumferential width H. At this time, the relationship that circumferential width H ≥ shortest distance C × 2 is satisfied. In addition, when the circumferential width of the outermost diameter of the bypass barrier 23 is set to circumferential width P, the relationship with the circumferential width T of the innermost diameter of the tooth 19 is satisfied that circumferential width P ≥ circumferential width T.

[0045] Here, use Figures 4-7 This will illustrate the effect of setting the structure as described above. Figure 4 It means Figure 3 A diagram of the magnetic flux density vector in the analysis of the magnetic field under no-load conditions for the rotor shape shown. Figure 5 It means Figure 3 A diagram of the magnetic flux density vector in the magnetic field analysis of a rotor with the shape shown under load. Figure 6 It means to make Figure 4 The diagram shows the magnetic flux density vector in the analysis of the magnetic field when the rotor shape changes from its shortest distance C to its shape under no-load conditions. Figure 7 It means to make Figure 4 The diagram shows the magnetic flux density vector in the analytical magnetic field under load, representing the change in the shortest distance C of the rotor shape. Figures 4-7 In this design, the range of the rotor core 21 including the minimum distance D described above is defined as the main part a. Furthermore, the range of the q-axis magnetic circuit portion of the rotor core 21 between the second magnets 222 (which are adjacent to each other on the q-axis) and separated by the shortest distance C described above is defined as the main part b. And, the range of the rotor core 21 between the second magnets 222 and the first magnet 221 (which are of the same pole) including the bypass portion 24b is defined as the main part c.

[0046] The magnetic flux density within rotor 20 under no-load conditions is as follows Figure 4 As shown, the magnetic flux density of the main part a increases. Furthermore, the magnetic flux density of the main part b decreases. Also, a large amount of magnetic flux flowing from the first magnet 221 passes through the main part c. In other words, a large amount of magnetic flux flowing from the second magnet 222, which is adjacent to it across the q-axis, passes through the bypass portion 24a of the rotor core 21 and links to the adjacent second magnet 222, short-circuiting within the rotor core 21. A portion of the magnetic flux from the first magnet 221 short-circuits through the bypass portion 24b between it and the second magnet 222.

[0047] When under load, such as Figure 5 As shown, the magnetic flux density of main part a and main part b is of the same magnitude. Furthermore, it is known that when current flows through the stator coil 12 of the stator 10, the magnetic flux generated by the stator 10 links with both main parts b and a of the rotor core 21. Similarly, the magnetic flux generated by the stator 10 also links with main part c.

[0048] That is, as explained above, especially with the bypass barrier 23 and the second magnet 222 arranged in the rotor core 21 in a manner that satisfies the relationship that distance A > distance B, a path for magnetic flux can be ensured in the rotor core 21 between the bypass barrier 23 and the second magnet 222 in the radial direction. Furthermore, the magnetic flux of the second magnet 222 under no-load conditions can be short-circuited within the rotor core 21 at a point on the rotor core 21 that is radially inward of the bypass barrier 23. Moreover, by separating the first magnet 221 and the second magnet 222 within the same pole, the rotor core 21, which forms the path for magnetic flux, can ensure a path for magnetic flux, and a portion of the magnetic flux of the first magnet 221 under no-load conditions can be short-circuited within the rotor core 21. Therefore, under no-load conditions, by increasing the magnetic flux short-circuited within the rotor core 21, the main magnetic flux is reduced, and the efficiency of the rotary motor 100 can be improved.

[0049] Furthermore, the saturation magnetic flux density is approximately 2T when an electromagnetic steel plate is used in the rotor core 21, and approximately 1T when a neodymium magnet is used in the second magnet 222. Therefore, in order to short-circuit the magnetic flux of the second magnet 222 by the minimum distance D before reaching the saturation magnetic flux density, the circumferential width H must satisfy the relationship that the shortest distance C × 2. Moreover, by satisfying the relationship that the circumferential width H ≥ the shortest distance C × 2, the magnetic flux short-circuited in the main part a of the rotor core 21 can be increased to the maximum extent. Thus, under no-load conditions, by increasing the short-circuited magnetic flux within the rotor core 21, the main magnetic flux is reduced, and the efficiency of the rotating motor 100 can be improved.

[0050] Furthermore, by arranging the rotor core 21 with a bypass portion 24a radially between the bypass barrier 23 and the second magnet 222, the bypass portion 24a, which serves as a short-circuit path for the magnetic flux of the second magnet 222 under no-load conditions, can become a path for the magnetic flux generated primarily by the stator 10 under load. Moreover, it is possible to simultaneously increase both the amount of short-circuit magnetic flux generated within the rotor 20 and the amount of magnetic flux linked to the stator 10. Furthermore, as... Figure 5 As shown in the main part d, the magnetic flux linked with the stator 10 can be increased by satisfying the relationship that the circumferential width P ≥ circumferential width T.

[0051] Next, we will explain how to make the shortest distance C greater than the above. Figure 4 The magnetic flux density within rotor 20 when the shortest distance C is narrowest is shown. Under no-load conditions, as... Figure 6 As shown, the magnetic flux density of the main part a increases. This is because, compared with... Figure 4 Similarly, in this structure, a large amount of magnetic flux flowing from the second magnet 222, which is adjacent to it across the q-axis, passes through the bypass portion 24a of the rotor core 21 and through the adjacent second magnet 222 with opposite poles, thus short-circuiting within the rotor core 21. This is because a portion of the magnetic flux from the first magnet 221 passes through the rotor core 21 between it and the second magnet 222, causing a short circuit. That is, if the relationship A > B is satisfied, the magnetic flux short-circuiting within the rotor core 21 can be increased, reducing the influence of the shortest distance C on the magnetic flux of the second magnet 222 under no-load conditions.

[0052] On the other hand, the magnetic flux density within the rotor 20 under load is as follows: Figure 7 As shown, the magnetic flux density of main part a is lower than that of main part b. This is related to the orientation of the magnetic flux of the second magnet 222 and the magnetic flux generated by the stator 10. This will be explained in detail below.

[0053] The magnetic flux density under load is determined by the superposition of the magnetic flux generated by the stator 10 and the magnetic flux generated within the rotor 20. In main section a, the orientation of the magnetic flux of the second magnet 222 is reversed compared to the orientation of the magnetic flux generated by the stator 10; in main section b, the magnetic flux density tends towards saturation from a state of 0. For example, if the orientation of the magnetic flux generated by the second magnet 222 is defined as the -direction, the phenomenon in main section a changes from magnetic saturation in the -direction to magnetic saturation in the +direction. On the other hand, the phenomenon in main section b changes from a state of 0 magnetic flux to magnetic saturation in the +direction. Therefore, in such a state... Figure 7 When the shortest distance C and the minimum distance D are of the same degree, the main part b is more prone to magnetic saturation than the main part a. When the main part b becomes magnetically saturated, it links with the main part a, and the magnetic flux toward the stator 10 decreases. The same applies when the shortest distance C is smaller than the minimum distance D.

[0054] Therefore, under load, in order to more effectively and flexibly utilize the rotor core 21 of the main part a as a magnetic flux path, it is necessary to design a structure where the shortest distance C is greater than the minimum distance D. By designing a structure where the shortest distance C is greater than the minimum distance D, the linkage suppression of magnetic flux to the main part a caused by the magnetic saturation of the main part b can be avoided, and the rotor core 21 near the main part a can be used more effectively and flexibly under load.

[0055] use Figure 8 This further illustrates the relationship between the shortest distance C and the minimum distance D. Figure 8 This diagram illustrates the result of separating the magnetic flux linked with stator 10 when current flows through it into the d-axis and q-axis directions, resulting in Φd. The solid line in the diagram represents Φd in a structure that satisfies the relationship that the shortest distance C ≥ the minimum distance D × 2 (C ≥ 2D), while the dashed line represents Φd in a structure that satisfies the relationship that the minimum distance D × 2 > the shortest distance C (2D > C).

[0056] Φd is equivalent to the magnetic flux from each magnet 22 disposed on the rotor 20 linked with the magnetic flux of the stator 10. It can be seen that when current flows, the increase in Φd is greater in structures that satisfy the relationship C≥2D. The increase in Φd refers to the increase in magnetic flux of the magnet 22.

[0057] As explained above, the magnetic flux passing through the main part b is determined by the superposition of the magnetic flux from the stator 10 and the magnetic flux from the magnet 22, and this superposition forms Φd. Therefore, the bypass barrier 23 is formed at a position radially outer of the rotor core 21 than the magnetic flux generating surface of the second magnet 222, and their arrangement satisfies the aforementioned distance A > distance B relationship, thus creating a structure that generates the superposition of magnetic flux under load. Therefore, Φd can be increased. Furthermore, by arranging the magnetic flux barrier 25, the second magnet 222, and the bypass barrier 23 in the rotor core 21 in a manner that satisfies the relationship C ≥ 2D, the superposition of magnetic flux in the main parts a and b can be increased, thus further increasing Φd. As a result, the maximum torque can be improved.

[0058] In addition, it is known that Figure 4 The main part c and Figure 5 The magnetic flux density of the main part c is reversed. This produces the same phenomenon as the main part a, where the magnetic flux generated from the stator 10 by utilizing the structure in which the first magnet 221 and the second magnet 222 are separately configured within the same pole can increase Φd.

[0059] As described above, Embodiment 1 of this disclosure includes a bypass barrier 23 and a second magnet 222 disposed radially inward of the bypass barrier 23. A bypass portion 24a, serving as a path for magnetic flux, is provided in the rotor core 21 radially between the bypass barrier 23 and the second magnet 222. With this structure, under no-load conditions, the magnetic flux of the second magnet 222 can be short-circuited more extensively within the rotor core 21 at a location radially inward of the bypass barrier 23. Furthermore, under load conditions, it can serve as a path for magnetic flux from the stator 10. Therefore, by simultaneously increasing the amount of short-circuit magnetic flux generated within the rotor 20 and increasing the amount of magnetic flux linked to the stator 10 when current is applied, the variability of the magnetic flux can be increased.

[0060] Furthermore, the rotor core 21 is configured such that the minimum distance D is increased in radial width compared to the radially outer side of the bypass barrier 23. This structure allows for further magnetic flux linkage of the second magnet 222 at a radially inner side compared to the bypass barrier 23, enabling more magnetic flux short-circuiting within the rotor 20. The endpoint of the second magnet closest to the q-axis is located in the region of the rotor core 21 where the magnetic flux flows into and out of the bypass portion 24a, which is located radially inner than the radially inner surface of the bypass barrier 23. This structure allows for more magnetic flux linkage at the rotor core 21 at a radially inner side compared to the bypass barrier 23. Moreover, the variable Φd under load can be further increased. The magnetic flux input / output surfaces of the second magnet 222 are inclined relative to the q-axis. This structure facilitates magnetic flux linkage within the rotor core 21 between adjacent second magnets 222. Furthermore, second magnets 222 with opposite poles are arranged adjacent to each other across the q-axis. With this structure, since the second magnet 222 on one side moves towards the second magnet 222 on the other side, the magnetic flux can be further short-circuited within the rotor 20 via the bypass section 24a.

[0061] Furthermore, each magnetic pole is composed of multiple magnets 22. This structure allows for the separation of a first magnet 221, which primarily generates magnetic flux linking with the stator 10, and a second magnet 222, which primarily generates magnetic flux short-circuiting within the rotor core 21. The rotor core 21 between the multiple magnets 22 can be configured as a magnetic flux path. Moreover, even with rectangular magnets 22, a more optimized configuration is easily achieved, reducing magnet machining and improving manufacturability. Regarding the configuration of the first magnet 221, compared to the second magnet 222, it is positioned across the d-axis in the radially outer region of the rotor core 21. This structure allows a large amount of magnetic flux from the first magnet 221 to link towards the stator 10 when energized. Furthermore, by satisfying the relationship that circumferential width P ≥ circumferential width T, the amount of magnetic flux linking with the stator 10 can be increased.

[0062] Furthermore, the circumferential width H is satisfied, which satisfies the relationship that the shortest distance C×2. This allows the magnetic flux short-circuited within the rotor core 21 to be increased to its maximum. Consequently, under no-load conditions, by increasing the magnetic flux short-circuited within the rotor core 21, the main magnetic flux is reduced, thereby improving the efficiency of the rotating electric machine 100.

[0063] Furthermore, the first magnet 221 on the d-axis is positioned such that distance E > distance F. With this structure, the rotor core 21 on the gap G side generates reluctance torque through the magnetic flux based on the stator 10. Therefore, by separating the first magnet 221 from the second magnet 222, the increase in Φd can be increased, and the reluctance torque can be increased.

[0064] It should be noted that the above description illustrates the structure of the first magnet 221 arranged across the d-axis. However, the first magnet 221 constituting one magnetic pole can be composed of multiple magnets, and the number of magnets 22 can be appropriately varied. For example, it can be as follows: Figure 9 The configuration shown is linearly symmetrical about the d-axis. This configuration also increases the amount of Φd, and further increases the main magnetic flux linked to the stator 10.

[0065] Furthermore, while each magnet 22 is rectangular, it can also be integrally formed into an arc shape or have each magnet follow an arc-like shape. In this case, it is possible to increase the main magnetic flux linked to the stator 10 and improve efficiency by reducing the higher harmonics of the magnetic flux generated by the rotor 20.

[0066] In addition, it is explained that each magnet 22 is magnetized parallel to the short side, but it is not necessarily limited to being parallel to the short side. It can be appropriately changed to be parallel to the long side or not parallel.

[0067] Furthermore, the structure of providing magnetic flux barriers 25 at the circumferential ends of each magnet has been described, but it is not necessarily required, as long as the rotor cores 21 between the magnets 22 are arranged in a manner that satisfies the relationships described above. In this case, it is also possible to increase the magnetic flux that short-circuits within the rotor cores 21, thereby increasing the variable Φd, and to increase the main magnetic flux generated from the first magnet 221 that links with the stator 10.

[0068] Furthermore, the bypass barrier 23 and the magnetic flux barrier 25 are set as non-magnetic regions of the gap, but as long as the permeability is lower than that of the rotor core 21, non-magnetic materials can be embedded in them. In this case, the magnetic properties can also be degraded by residual stress, thereby reducing the permeability.

[0069] Implementation method 2.

[0070] The rotor of Embodiment 2 will be described below using the accompanying drawings.

[0071] Figure 10 This is a cross-sectional view of the main part of the rotor 20 in Embodiment 2. In the figure, the second magnet 222 is disposed on the q-axis of the rotor core 21, which is radially inward of the bypass barrier 23 disposed on the q-axis. In the N-pole, the second magnet 222 is magnetized such that its magnetic flux is directed towards the stator 10, as indicated by the arrow. Since the second magnet 222 is disposed on the q-axis, the magnetization direction is opposite in the S-pole. Other structures are the same as in Embodiment 1.

[0072] This structure also achieves the same effect as embodiment 1. Since the second magnet 222 is positioned along the q-axis, the radial distance between it and the bypass barrier 23 can be increased. This reduces the number of magnets, thus increasing the variability of Φd and lowering costs.

[0073] As described above, the rotor according to Embodiment 2, similar to Embodiment 1, achieves the effect of increasing the variability of the magnetic flux by simultaneously increasing the short-circuit magnetic flux generated inside the rotor 20 and increasing the magnetic flux of the magnet linked with the stator 10 when current is applied. Furthermore, it can increase the reluctance torque.

[0074] Implementation method 3.

[0075] The rotor of Embodiment 3 will be described below using the accompanying drawings.

[0076] Figure 11 This is a cross-sectional view of the main part of the rotor 20 in Embodiment 3. In the figure, the second magnet 222 is arranged at an angle such that its radially inner end near the d-axis is closer to the axis than its radially inner end near the q-axis. Furthermore, the second magnets 222 within the same pole are arranged linearly symmetrically with respect to the d-axis. The second magnets 222 are magnetized such that their magnetic flux is directed towards the stator 10. That is, each magnet 22 within one pole is configured as two layers. Other structures are the same as in Embodiment 1 or Embodiment 2.

[0077] This structure also has the same effect as embodiment 1. By configuring each magnet 22 in one magnetic pole as two layers, the magnetic circuit linking the magnetic flux generated from the stator 10 with the rotor 20 can be increased, thereby increasing the reluctance torque.

[0078] As described above, the rotor according to Embodiment 3, similar to Embodiment 1 or Embodiment 2, achieves the effect of increasing the variable value of the magnetic flux by simultaneously increasing the short-circuit magnetic flux generated inside the rotor 20 and increasing the magnetic flux of the magnet linked with the stator 10 when current is applied. Furthermore, it can increase the reluctance torque.

[0079] Implementation method 4.

[0080] The stator and rotor of Embodiment 4 will be described below using the accompanying drawings.

[0081] Figure 12 This is implementation method 4. Figure 1The stator 10 is shown in section II. The stator 10 includes an annular stator core 11 and a stator coil 12 mounted on the stator core 11. The stator core 11 has an annular core back 18 and a plurality of teeth 19 protruding radially inward from the inner circumference of the core back 18. For example, it is constructed by axially stacking and integrally forming thin sheets of electromagnetic steel. Twelve teeth 19 are arranged circumferentially at equal angular intervals. The circumferential width of the innermost diameter of each tooth 19 is defined as T. The stator coil 12 is composed of a concentrated winding coil formed by winding conductor wire around the teeth 19. Other structures are the same as in embodiments 1-3.

[0082] In the figure, when the circumferential width of the outermost diameter of the bypass barrier 23 is set as the circumferential width P, the relationship between it and the circumferential width T of the innermost diameter of the tooth 19 is such that the circumferential width P ≥ the circumferential width T.

[0083] This structure also achieves the same effects as embodiment 1. Moreover, by employing concentrated windings, the coil end length can be shortened, thereby reducing copper losses and shortening the overall length of the motor.

[0084] It should be noted that although the structure of teeth 19 arranged in 12 equal angles is described, it does not necessarily have to be 12 and can be changed appropriately.

[0085] As described above, the rotor according to Embodiment 4, similar to Embodiments 1 to 3, achieves the effect of increasing the variability of the magnetic flux by simultaneously increasing the short-circuit magnetic flux generated inside the rotor 20 and increasing the magnetic flux of the magnet linked with the stator 10 when current is applied. Furthermore, it enables a reduction in copper losses and a shortening of the overall length of the motor.

[0086] This application describes various exemplary embodiments and examples, but the various features, forms and functions described in one or more embodiments are not limited to the application of a specific embodiment, and can be applied to the embodiment alone or in various combinations.

[0087] Therefore, numerous variations not illustrated are conceivable within the scope of the technology disclosed in this application. These include variations on at least one constituent element, additions, omissions, and extraction of at least one constituent element combined with constituent elements of other embodiments.

[0088] Explanation of reference numerals in the attached figures

[0089] 10 Stator, 12 Stator Coil, 13 Frame, 14 Bracket, 15 Bearing, 16 Rotating Shaft, 18 Back of Core, 19 Tooth, 20 Rotor, 21 Rotor Core, 22 Magnet, 23 Bypass Barrier, 24a & 24b Bypass Section, 25 Flux Barrier, 221 First Magnet, 222 Second Magnet

Claims

1. A rotor characterized by comprising: the rotor has a rotor core, when the pole center of the rotor core is set as a d-axis, and the axis of the direction orthogonal to the d-axis is set as a q-axis, the rotor core has a bypass barrier of a non-magnetic region provided on the q-axis, and has a radially innermost surface as a radially innermost surface; a first magnet provided in a region of the rotor core closer to the d-axis than the q-axis; and a second magnet provided at least in a region of the rotor core radially inside the first magnet, the second magnet is provided in a region of the rotor core closer to the q-axis than the first magnet, the second magnet has a magnetic flux barrier at least at one end in the circumferential direction, the end of the second magnet closest to the q-axis is located radially inside the radially innermost surface of the bypass barrier within the rotor core, a magnetic flux bypass portion having a path of magnetic flux generated by a stator between the second magnet and the bypass barrier in the radial direction, one surface of the magnetic flux barrier faces the radially innermost surface of the bypass barrier in the radial direction.

2. The rotor according to claim 1, characterized by comprising: the rotor core has: a plurality of the second magnets provided adjacent across the q-axis; the magnetic flux bypass portion is a path of magnetic flux generated by the stator and a path of magnetic flux of the second magnet that passes through the second magnet on one side and the second magnet on the other side and short-circuits inside the rotor core; and a q-axis magnetic circuit portion that is the rotor core radially inside the bypass barrier and is the rotor core between the circumferential directions of the adjacent plurality of the second magnets, the shortest distance C of the q-axis magnetic circuit portion orthogonal to the q-axis is greater than the minimum distance D of the magnetic flux bypass portion.

3. The rotor according to claim 2, characterized by comprising: the second magnet has a magnetic flux barrier at both ends in the circumferential direction, the shortest distance C of the q-axis magnetic circuit portion is the width of the rotor core between the magnetic flux barriers adjacent across the q-axis, the minimum distance D of the magnetic flux bypass portion is the width between the bypass barrier and the second magnet or between the bypass barrier and the magnetic flux barrier.

4. The rotor according to claim 2, characterized by comprising: the shortest distance C of the q-axis magnetic circuit portion and the minimum distance D of the magnetic flux bypass portion satisfy the relationship C ≥ D × 2.

5. The rotor according to claim 1, characterized by comprising: the second magnet is located on the d-axis side of a straight line connecting the d-axis side end of the bypass barrier and the axis center.

6. The rotor according to claim 1, characterized by comprising: the second magnet is inclinedly arranged with the end closer to the q-axis side of both ends in the circumferential direction closer to the axis center than the end away from the q-axis side, and the end away from the q-axis side closer to the radially outer surface of the rotor core than the other end.

7. The rotor according to claim 1, characterized by comprising: The second magnet is disposed on the q-axis of the rotor core at a radially inner side than a radially innermost surface of the bypass barrier.

8. The rotor according to claim 1, wherein The rotor core has a plurality of the second magnets disposed adjacent across the d-axis, The plurality of the second magnets have an inclination in a manner that an end portion closer to a radially inner side of the d-axis than an end portion closer to a radially inner side of the q-axis is closer to an axis center in the circumferential end portion, and are disposed in line symmetry with respect to the d-axis.

9. The rotor according to claim 1, wherein The first magnet is disposed on the d-axis, When a smallest distance from an intersection of a radially outermost surface of the first magnet and the d-axis to an outer circumferential surface of the rotor core is set as a distance E, and a smallest distance from an end point of the radially outermost surface of the first magnet to the outer circumferential surface of the rotor core is set as a distance F, A relationship of E > F is satisfied.

10. The rotor according to claim 1, wherein The rotor core has a magnet group including the first magnet and the second magnet constituting one magnetic pole, The magnet group is disposed separately in the circumferential direction on the rotor core.

11. The rotor according to claim 1, wherein When a width of the second magnet is set as H, and a shortest distance C of a q-axis magnetic path portion of the rotor core between the circumferential directions of the second magnet, which is orthogonal to the q-axis, is set as a shortest distance, A relationship of H ≥ C x 2 is satisfied.

12. The rotor according to any one of claims 1 to 11, wherein An end point of the second magnet closest to the q-axis is located at a radially inner side than a radially innermost surface of the bypass barrier within the rotor core, and a magnetic flux input / output surface of the second magnet has an inclination with respect to the q-axis, A distance A when a radially outermost surface of a radially outermost side of the rotor core and a corner portion of the second magnet closest to the q-axis are connected in parallel with the q-axis is set as a distance A, A distance B when a radially innermost surface of an innermost diameter side of the bypass barrier and a radially outermost surface of the rotor core are connected in parallel with the q-axis, a maximum distance of the radially outer surface of the rotor core to the bypass barrier is set as a distance B, The distance A is larger than the distance B.

13. A rotary electric machine characterized by comprising: having: The rotor according to any one of claims 1 to 12; and A stator disposed with a gap in a radially outer side of the rotor.

14. The rotary electric machine according to claim 13, wherein The stator has a stator core and a stator coil, The stator core has a core back portion in a circular ring shape and a plurality of teeth protruding from the core back portion to a radially inner side, When a circumferential width of an innermost diameter portion of the teeth is set as T, and a circumferential width of an outermost diameter portion of the bypass barrier of a non-magnetic region disposed on the q-axis is set as P, A relationship of P ≥ T is satisfied.

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