Interior magnet rotor and rotating electric machine

Abstract

To provide an interior magnet rotor that is more effective in improving the torque of a rotating electrical machine than a conventional rotor.SOLUTION: In an interior magnet rotor with multiple magnetic poles formed around the circumferential direction of the core, each of the magnetic poles includes a first layer of magnets arranged in a V-shaped pattern with increasing spacing toward the outer periphery of the rotor, and a second layer of magnets arranged in a pattern that surrounds the first layer of magnets from the inner periphery of the rotor. The first layer of magnets are arranged in a pattern where the valley of the V is offset circumferentially with respect to the circumferential center of the magnetic poles at mechanical angle and the center of the arrangement of the second layer of magnets.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to an embedded magnet rotor and a rotating electrical machine.

Background Art

[0002] Conventionally, in order to achieve high torque density and high output density of a rotating electrical machine, an embedded magnet rotor in which a plurality of magnets are arranged in a V shape for one pole is known. Regarding this type of embedded magnet rotor, Patent Document 1 proposes a configuration in which the magnets are arranged asymmetrically with respect to the center in the rotational direction of the poles in order to increase the salient pole ratio and improve the torque. In addition, in the configuration of Patent Document 1, the apexes of the magnets arranged in a V shape are arranged on the center line of the pole pitch.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] For example, when a plurality of magnets are symmetrically arranged in a V shape for one pole in an embedded magnet rotor, magnetic saturation occurs on the advancing side in the rotational direction during load, resulting in a decrease in torque. In the embedded magnet rotor of Patent Document 1, the torque can be improved compared to the case where the magnets are symmetrically arranged, but the torque improvement effect is still limited.

[0005] The present invention has been made in view of the above situation, and an object thereof is to provide an embedded magnet rotor having a higher torque improvement effect for a rotating electrical machine than in the prior art.

Means for Solving the Problems

[0006] One aspect is an embedded magnet type rotor in which a plurality of magnetic poles are formed in the circumferential direction of the iron core. Each magnetic pole includes a first layer of magnets arranged in a V-shaped pattern that spreads apart toward the outer peripheral side of the rotor, and a second layer of magnets arranged in a pattern that surrounds the first layer of magnets from the inner peripheral side of the rotor. The first layer of magnets is arranged in a pattern in which the position of the V-shaped valley is shifted in the circumferential direction with respect to the circumferential center of the magnetic pole at the mechanical angle and the arrangement center of the second layer of magnets.

[0007] The embedded magnet type rotor may be applied to a motor, and the first layer of magnets may be such that the position of the V-shaped valley is shifted to the side of retardation in the forward rotation direction of the motor with respect to the circumferential center of the magnetic pole at the mechanical angle.

[0008] Also, the first layer of magnets may be arranged asymmetrically with the V-shaped valley as the center, and the magnets on the retardation side in the forward rotation direction of the first layer may have a shape with a shorter major axis length than the magnets on the advance side in the forward rotation direction of the first layer.

[0009] Also, the first layer of magnets and the second layer of magnets may have the same minor axis length, and the major axis length of the second layer of magnets may be the same as the major axis length of any of the first layer of magnets or a length obtained by combining the major axis lengths of the first layer of magnets.

[0010] Also, the second layer of magnets may be arranged symmetrically with respect to the circumferential center of the magnetic pole at the mechanical angle, and the first layer of magnets may be such that the position of the V-shaped valley is shifted in the circumferential direction with respect to the arrangement center of the second layer of magnets.

[0011] Also, the second layer of magnets may be arranged asymmetrically with respect to the circumferential center of the magnetic pole at the mechanical angle, and the magnets on the advance side in the forward rotation direction of the second layer may form a pattern that opens wider to the outer peripheral side than the magnets on the retardation side in the forward rotation direction of the second layer.

[0012] Also, a flux barrier extending toward the inside of the first layer may be formed at each outer peripheral side end of the first layer of magnets. Furthermore, the flux barrier on the advance side in the forward rotation direction and the flux barrier on the retardation side in the forward rotation direction may have different shapes.

[0013] Further, the embedded magnet type rotor may have a groove extending in the axial direction on the outer periphery of the iron core. Furthermore, the groove may be formed asymmetrically with respect to the circumferential center of the magnetic pole in mechanical angle. Another aspect of the rotating electrical machine includes a stator and the above-described embedded magnet type rotor.

Advantages of the Invention

[0014] According to one aspect, it is possible to provide an embedded magnet type rotor having a higher torque improvement effect of the rotating electrical machine than the conventional one.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0016] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the embodiments, for easy understanding, structures and elements other than the main part of the present invention will be described in a simplified or omitted manner. Also, in the drawings, the same elements are denoted by the same reference numerals. Note that the shapes, dimensions, etc. of the elements shown in the drawings are schematically shown and do not indicate actual shapes, dimensions, etc.

[0017] <First Embodiment> FIG. 1 is a cross-sectional view showing a cross-section in a direction orthogonal to the rotation axis Ax in the rotating electrical machine according to the first embodiment. In the following description, the direction parallel to the extension direction of the rotation axis Ax is referred to as the axial direction, the circumferential direction centered on the rotation axis Ax is simply referred to as the circumferential direction, and the radial direction centered on the rotation axis Ax is simply referred to as the radial direction.

[0018] The rotating electrical machine 1 shown in FIG. 1 is an inner rotor type motor for an electric vehicle, and includes a rotor 2 which is an example of an embedded magnet type rotor, and a cylindrical stator 3 disposed on the outer periphery of the rotor 2. In FIG. 1, the extension direction of the rotation axis Ax of the rotating electrical machine 1 is the direction perpendicular to the paper surface. Also, the rotating electrical machine 1 has a forward rotation direction as the counterclockwise direction.

[0019] The stator 3 is disposed on the outer periphery of the rotor 2 with an air gap therebetween. In the rotating electrical machine 1, by sequentially switching the magnetic field of the stator 3 by controlling the current of the coil, the rotor 2 rotates about the rotation axis Ax due to the attractive force or repulsive force with the magnetic field of the rotor 2.

[0020] The stator 3 houses the rotor 2 in a central space portion centered on the rotation axis Ax. On the inner peripheral side of the stator 3, a plurality of teeth 3a protruding radially inward toward the rotation axis Ax are provided at equal intervals in the circumferential direction. Slots 3b are formed between adjacent teeth 3a. Coils (not shown) are mounted in the slots 3b of the stator 3 along the outer periphery of the rotor 2.

[0021] The rotor 2 has a core 4, a shaft 5, and permanent magnets 6 and 7. The core 4 of the rotor 2 is, for example, a cylindrical member formed by axially laminating punched silicon steel sheets. An insulating layer is interposed between the individual silicon steel sheets constituting the core 4, and the individual silicon steel sheets are in an insulated state from each other. And, a shaft 5 is fitted along the rotation axis Ax in the axial center portion of the core 4. In the rotating electrical machine 1, the shaft 5 is rotatably supported by bearings (not shown).

[0022] The rotor 2 of the first embodiment is an 8-pole rotor, and a plurality of permanent magnets 6 are arranged in a predetermined array in the core 4 of the rotor 2 so that eight magnetic poles are formed at equal intervals along the circumferential direction. In the rotor 2, the permanent magnets 6 are arranged so that adjacent magnetic poles in the circumferential direction have opposite polarities.

[0023] FIG. 2 is a diagram showing a configuration example of the rotor 2 for one magnetic pole in the first embodiment. One magnetic pole of the core 4 has a structure in which permanent magnets 6 and 7 are arranged in two layers on the outer peripheral side and the axial center side. Hereinafter, the arrangement of the permanent magnet 6 facing the outer peripheral side in one magnetic pole is also referred to as the first layer, and the arrangement of the permanent magnet 7 located closer to the axial center side than the first layer is also referred to as the second layer.

[0024] The first layer is composed of two first magnet holes 11a and 11b and two permanent magnets 6a and 6b respectively fitted into the first magnet holes 11a and 11b.

[0025] The first magnet holes 11a and 11b include an advancing-side first magnet hole 11a located on the advancing side in the forward rotation direction of the rotating electrical machine 1 and a retarding-side first magnet hole 11b located on the retarding side in the forward rotation direction of the rotating electrical machine 1. The advancing-side first magnet hole 11a and the retarding-side first magnet hole 11b are each formed to axially penetrate the core 4 from one end face in the axial direction of the core 4 to the other end face in the axial direction.

[0026] The advancing-side first magnet hole 11a and the retarding-side first magnet hole 11b are arranged in a V-shaped pattern in which a V-shaped valley is located on the axial center side of the rotor 2 and the interval between the magnet holes widens from the axial center side to the outer peripheral side of the rotor 2. That is, the advancing-side first magnet hole 11a is formed with the outer peripheral side inclined toward the advancing side in the forward rotation direction, and the retarding-side first magnet hole 11b is formed with the outer peripheral side inclined toward the retarding side in the forward rotation direction. Also, the inclination angle of the advancing-side first magnet hole 11a with respect to the V-shaped valley Cv is set larger than the inclination angle of the retarding-side first magnet hole 11b.

[0027] The minor-axis lengths (dimensions in the minor-axis direction in a cross-section orthogonal to the axial direction) of the leading-side first magnet holes 11a and the trailing-side first magnet holes 11b are the same, but the major-axis length (dimension in the major-axis direction in a cross-section orthogonal to the axial direction) of the leading-side first magnet holes 11a is formed to be longer than the major-axis length of the trailing-side first magnet holes 11b. Therefore, the shapes of the two first magnet holes 11a and 11b are asymmetric in the circumferential direction of the rotor 2.

[0028] Also, the V-shaped valley Cv formed by the leading-side first magnet holes 11a and the trailing-side first magnet holes 11b is shifted to the trailing side in the forward rotation direction from the circumferential center C of the magnetic poles in mechanical angle.

[0029] Long plate-shaped permanent magnets 6a and 6b along the axial direction of the iron core 4 are inserted into the leading-side first magnet holes 11a and the trailing-side first magnet holes 11b, respectively. In the first layer, the magnetic pole faces facing the outer peripheral sides of the permanent magnets 6a and 6b all have the same magnetic polarity (S pole or N pole).

[0030] As a result, in one magnetic pole, the permanent magnets 6a and 6b are arranged in a V-shaped pattern in the first layer on the outer peripheral side of the iron core 4. Also, the permanent magnets 6a and 6b in the first layer are arranged such that the V-shaped valley Cv is shifted to the trailing side in the forward rotation direction from the circumferential center C of the magnetic poles in mechanical angle, and are arranged asymmetrically with the V-shaped valley Cv as the center.

[0031] Also, the dimensions of the permanent magnets 6a and 6b in a cross-section orthogonal to the axial direction correspond to the dimensions of the first magnet holes 11a and 11b into which they are respectively inserted. That is, the minor-axis lengths of the permanent magnets 6a and 6b are the same, but the major-axis length of the permanent magnet 6b inserted into the trailing-side first magnet hole 11b is shorter than the major-axis length of the permanent magnet 6a inserted into the leading-side first magnet hole 11a. Note that a gap 13 may be formed between each end of the first magnet holes 11a and 11b and the permanent magnets 6a and 6b, respectively.

[0032] The second layer is composed of three second magnet holes 12a, 12b, 12c and three permanent magnets 7a, 7b, 7c respectively inserted into the second magnet holes 12a, 12b, 12c.

[0033] The second magnet holes 12a, 12b, and 12c include a forward-side second magnet hole 12a located on the forward side in the normal rotation direction of the rotating electric machine 1, a backward-side second magnet hole 12b located on the backward side in the normal rotation direction of the rotating electric machine 1, and an intermediate second magnet hole 12c. The forward-side second magnet hole 12a, the backward-side second magnet hole 12b, and the intermediate second magnet hole 12c are each formed to axially penetrate the iron core 4 from one end face in the axial direction of the iron core 4 to the other end face in the axial direction.

[0034] The forward-side second magnet hole 12a, the backward-side second magnet hole 12b, and the intermediate second magnet hole 12c form a semi-annular shape that protrudes toward the axial center side of the rotor 2, and are arranged in a pattern that surrounds the first-layer permanent magnets 6a and 6b from the inner peripheral side of the rotor 2. As shown in FIG. 2, the intermediate second magnet hole 12c is formed closer to the axial center side than the first magnet holes 11a and 11b. The intermediate second magnet hole 12c has a major axis direction that intersects the radial direction of the rotor 2 and extends across the circumferential center C of the magnetic poles at the mechanical angle.

[0035] The forward-side second magnet hole 12a is arranged on the forward side in the normal rotation direction of the intermediate second magnet hole 12c, and the end on the axial center side faces the end on the forward side in the normal rotation direction of the intermediate second magnet hole 12c. The outer peripheral side of the forward-side second magnet hole 12a is inclined toward the forward side in the normal rotation direction, and is located on the forward side in the normal rotation direction than the forward-side first magnet hole 11a.

[0036] Also, the backward-side second magnet hole 12b is arranged on the backward side in the normal rotation direction of the intermediate second magnet hole 12c, and the end on the axial center side faces the end on the backward side in the normal rotation direction of the intermediate second magnet hole 12c. The outer peripheral side of the backward-side second magnet hole 12b is inclined toward the backward side in the normal rotation direction, and is located on the backward side in the normal rotation direction than the backward-side first magnet hole 11b.

[0037] In the first embodiment, the advancing-side second magnet holes 12a, the retarding-side second magnet holes 12b, and the intermediate second magnet holes 12c are symmetrically arranged with reference to the circumferential center C of the magnetic poles in mechanical angle. The minor-axis lengths of the advancing-side second magnet holes 12a, the retarding-side second magnet holes 12b, and the intermediate second magnet holes 12c are all the same. Further, the major-axis lengths of the advancing-side second magnet holes 12a, the retarding-side second magnet holes 12b, and the intermediate second magnet holes 12c are appropriately set according to the major-axis lengths of the permanent magnets 7a, 7b, 7c to be accommodated, respectively.

[0038] In the advancing-side second magnet holes 12a, the retarding-side second magnet holes 12b, and the intermediate second magnet holes 12c, long plate-shaped permanent magnets 7a, 7b, 7c along the axial direction of the iron core 4 are inserted respectively. In the second layer, the magnetic pole surfaces facing the outer peripheral sides of the permanent magnets 7a, 7b, 7c all have the same magnetic polarity as the permanent magnets 6a, 6b in the first layer.

[0039] Thereby, in one magnetic pole, the permanent magnets 7a, 7b, 7c are arranged in a semi-circular shape in the second layer of the iron core 4. Further, the permanent magnets 7a, 7b, 7c in the second layer are symmetrically arranged with reference to the circumferential center C of the magnetic poles in mechanical angle. Note that a gap portion 13 may be formed between the permanent magnets 7a, 7b, 7c at each end of the advancing-side second magnet holes 12a, the retarding-side second magnet holes 12b, and the intermediate second magnet holes 12c.

[0040] Here, it is preferable that the minor axis lengths of the permanent magnets 7a, 7b, and 7c in the second layer are the same as the minor axis lengths of the permanent magnets 6a and 6b in the first layer, and the major axis lengths (L3, L4, L5) of the permanent magnets 7a, 7b, and 7c in the second layer are preferably the lengths obtained by combining the permanent magnets 6a and 6b in the first layer. For example, the major axis lengths (L3, L4, L5) of the permanent magnets 7a, 7b, and 7c in the second layer may be the same as the major axis lengths (L1, L2) of any of the permanent magnets 6a and 6b in the first layer, or may be the dimensions obtained by combining a plurality of the permanent magnets 6a and 6b in the first layer (for example, L1 + L2, L1 × 2, L2 × 2, etc.). When combining a plurality of the permanent magnets 6a and 6b in the first layer as the permanent magnets 7a, 7b, and 7c in the second layer, different dimensions L1 and L2 may be combined as described above. Also, the major axis lengths L3 and L4 of the permanent magnets 7a and 7b may be different from the major axis length L5 of the permanent magnet 7c in the intermediate second magnet hole 12c.

[0041] With the above configuration, the dimensions of the permanent magnets in the first layer and the second layer can be made common, and the manufacturing cost of the rotor 2 can be significantly reduced. Note that FIG. 2 shows an example in which the major axis lengths L3, L4, and L5 of the permanent magnets 7a, 7b, and 7c in the second layer are the same as the major axis length L1 of the permanent magnet 6a in the advancing-side first magnet hole 11a.

[0042] As described above, in the rotor 2 of the first embodiment, the permanent magnets 7a, 7b, and 7c in the second layer are symmetrically arranged with respect to the circumferential center C of the magnetic poles at the mechanical angle, while the permanent magnets 6a and 6b in the first layer are arranged such that the V-shaped valley Cv is shifted to the reverse-direction lag side from the circumferential center C of the magnetic poles at the mechanical angle. As a result, magnetic saturation on the advancing side in the forward rotation direction during load is alleviated, and magnetic saturation is likely to occur on the lag side in the forward rotation direction. Therefore, the magnetic saturation on the advancing side and the lag side within one magnetic pole approaches uniformity, and the torque of the rotating electrical machine 1 can be significantly improved.

[0043] In the first embodiment, the major axis length L2 of the permanent magnet 6b on the lag side of the first layer is shorter than the major axis length L1 of the permanent magnet 6a on the advance side of the first layer, and the permanent magnets 6a and 6b of the first layer are arranged asymmetrically in the circumferential direction of the rotor 2. Thereby, while maintaining the total magnetic amount of the first layer, the radial distance between the V-shaped valley Cv of the first layer and the second layer, and as shown in FIG. 1, the circumferential interval S between the first layer and the second layer on the forward rotation side can be widened, and the torque of the rotating electrical machine 1 can be more easily improved.

[0044] <Second Embodiment> FIG. 3 is a diagram showing a configuration example of the rotor 2 for one magnetic pole in the second embodiment. In the description of each of the following embodiments, the same reference numerals are given to the elements common to the first embodiment, and the overlapping description is omitted as appropriate.

[0045] The rotor 2 of the second embodiment is a modification of the first embodiment, and is a configuration example in which flux barriers 14a and 14b are formed on the outer peripheral sides of the advance-side first magnet hole 11a and the lag-side first magnet hole 11b of the first layer, respectively.

[0046] The flux barrier 14a of the advance-side first magnet hole 11a extends from the gap portion 13 on the outer peripheral side of the advance-side first magnet hole 11a to the inside of the first layer in the reverse rotation direction lag side. Further, the flux barrier 14b of the lag-side first magnet hole 11b extends from the gap portion 13 on the outer peripheral side of the lag-side first magnet hole 11b to the inside of the first layer in the reverse rotation direction advance side. These flux barriers 14a and 14b are holes (spaces) that communicate with the first magnet holes 11a and 11b and penetrate the iron core 4 in the axial direction, and have a very small magnetic permeability compared to the iron core 4, making it difficult for magnetic flux to pass through, so they function as magnetic blocking portions.

[0047] In the second embodiment, by forming the flux barriers 14a and 14b between the permanent magnets 6a and 6b of the first layer, the harmonic components included in the waveform of the magnetic flux density are suppressed. As a result, the distribution of the magnetic flux density generated on the outer peripheral surface of the rotor 2 by the permanent magnets 6a and 6b changes, and the magnetic flux density distribution approaches a sine wave. As a result, the torque ripple and the electromagnetic exciting force of the rotor 2 are effectively reduced, and the noise and vibration of the rotating electrical machine 1 can be suppressed.

[0048] In addition, the flux barriers 14a and 14b of the second embodiment have different shapes on the forward rotation advancing side and the lagging side. In the example of FIG. 3, the flux barrier 14b on the lagging side in the forward rotation direction extends along the circumferential direction, and the tip is formed to bend slightly toward the axial center side. On the other hand, the flux barrier 14a on the forward rotation advancing side bends toward the axial center on the magnet side closer to the front compared to the flux barrier 14b on the lagging side in the forward rotation direction, and increases the length of the bent tip side portion. With such a configuration, the effect of suppressing torque ripple can be further improved.

[0049] FIG. 4 is a graph of the analysis result showing the change in torque waveform due to the flux barrier. The horizontal axis of FIG. 4 is the electrical angle ([deg.]), and the vertical axis of FIG. 4 is the torque ([p.u.]). Also, the broken line in FIG. 4 shows the torque waveform of the rotor of the first embodiment without a flux barrier as Example 1. The two-dot chain line in FIG. 4 shows the torque waveform when a flux barrier with a symmetric shape is provided in the first layer of the rotor of the first embodiment as Example 2. The solid line in FIG. 4 shows the torque waveform of a rotor having the same shape as the second embodiment shown in FIG. 3 (when an asymmetric shape flux barrier is provided) as Example 3.

[0050] Comparing with the torque waveform of Example 1 in FIG. 4, it can be seen that the harmonic components of the torque waveforms of both Example 2 and Example 3 having a flux barrier are suppressed and the amplitude is reduced. Also, comparing the torque waveforms of Example 2 and Example 3 in FIG. 4, it can be seen that the torque waveform of Example 3 in which the flux barrier is formed in an asymmetric shape has a lower harmonic amplitude and the torque ripple is more suppressed.

[0051] <Third Embodiment> FIG. 5 is a diagram showing a configuration example of the rotor 2 for one pole in the third embodiment. The rotor 2 of the third embodiment is a modification of the first embodiment, and is a configuration example in which grooves (15a to 15f) extending in the axial direction are formed on the outer peripheral portion of the rotor 2.

[0052] In FIG. 5, the grooves 15a to 15f of the rotor 2 are provided at two positions (15c, 15d) between the V-shapes of the first layer, at each position (15b, 15e) between the first layer and the second layer on the advancing side and the delaying side, and at each position (15a, 15f) between the second layer of the second layer and the second layer of the adjacent magnetic pole on the advancing side and the delaying side, respectively. By forming the grooves 15a to 15f in the rotor 2, it becomes possible to reduce the torque ripple and the electromagnetic excitation force of the rotor 2.

[0053] Here, the positions of the grooves 15a to 15f of the rotor 2 are not limited to the example of FIG. 5. For example, one or more of the grooves in FIG. 5 may not be provided. Further, the positions of the grooves formed in the rotor 2 may be formed asymmetrically with reference to the circumferential center C of the magnetic poles in mechanical angle.

[0054] Also, the grooves 15a to 15f of the rotor 2 in FIG. 5 are formed such that the depths of the grooves 15d to 15f on the delaying side in the forward rotation direction are deeper than the depths of the grooves 15a to 15c on the advancing side in the forward rotation direction. As shown in FIG. 5, by relatively increasing the groove depth on the delaying side in the forward rotation direction, the reduction effect of the torque ripple and the electromagnetic excitation force of the rotor 2 can be made greater. Note that the same effect as above may be obtained by not forming a groove on the advancing side in the forward rotation direction of the rotor 2 and forming a groove on the delaying side in the forward rotation direction of the rotor 2.

[0055] FIG. 6 is a graph of the analysis results showing the change in the torque waveform due to the formation of grooves in the rotor. The horizontal axis of FIG. 6 is the electrical angle ([deg.]), and the vertical axis of FIG. 6 is the torque ([p.u.]). The broken line in FIG. 6 shows the torque waveform of the rotor of the first embodiment without grooves on the outer periphery of the rotor as Example 4. The two-dot chain line in FIG. 6 shows the torque waveform when grooves are formed on the outer periphery of the rotor of the first embodiment as Example 5. The positions of the grooves in the fifth embodiment are the same as the positions of the grooves of the rotor of the third embodiment, but the depths of the grooves are all uniform. The solid line in FIG. 6 shows the torque waveform of the rotor having the same shape as the third embodiment shown in FIG. 5 (when the groove depth on the delaying side in the forward rotation direction is increased) as Example 6.

[0056] In FIG. 6, when compared with the torque waveform of Example 4, it can be seen that the harmonic components of the torque waveforms of both Examples 5 and 6 are suppressed and the amplitudes are smaller. Further, when comparing the torque waveforms of Examples 5 and 6 in FIG. 6, it can be seen that the torque waveform of Example 6 with the groove depth on the forward rotation direction delay side increased has a lower harmonic amplitude and more suppressed torque ripple.

[0057] <Fourth Embodiment> FIG. 7 is a diagram showing a configuration example of the rotor 2 for one pole in the fourth embodiment. The rotor 2 of the fourth embodiment is a modification of the first embodiment, and is a configuration example in which the permanent magnets 7a, 7b, and 7c in the second layer are arranged asymmetrically with respect to the circumferential center C of the magnetic poles in mechanical angle.

[0058] In the rotor 2 of the fourth embodiment, the outer peripheral side of the advancing side second magnet hole 12a and the permanent magnet 7a in the second layer is greatly inclined toward the advancing side in the forward rotation direction compared to the first embodiment. That is, the second layer forms a pattern in which the permanent magnet 7a opens wider on the outer peripheral side than the permanent magnet 7b. Thereby, it is possible to secure a larger interval S1 between the advancing sides in the forward rotation direction of the first layer and the second layer compared to the first embodiment.

[0059] In the case of increasing the interval between the advancing sides in the forward rotation direction of the first layer and the second layer in the rotor 2, the arrangement of the first layer and the second layer may be as follows. For example, in the magnetic poles, the first layer may be symmetrically arranged with respect to the circumferential center C of the magnetic poles in mechanical angle, and the outer peripheral sides of the advancing side second magnet hole 12a and the permanent magnet 7a in the second layer may be greatly inclined toward the advancing side in the forward rotation direction, and the second layer may be arranged asymmetrically with respect to the circumferential center C of the magnetic poles.

[0060] The present invention is not limited to the above embodiments, and various improvements and design changes may be made without departing from the spirit of the present invention.

[0061] For example, in the present invention, the configurations of the above-described first to fourth embodiments may be arbitrarily combined. Further, when the embedded magnet type rotor of the present invention is applied to a motor, the use of the motor is not limited to electric vehicles.

[0062] In the above embodiment, the case where the rotating electrical machine 1 is a motor has been described. However, the embedded magnet type rotor of the present invention may be applied to the rotor of a generator. When the embedded magnet type rotor of the present invention is applied to a generator, the relationship between the forward rotation direction and the reverse rotation direction is reversed. That is, in the case of a generator, the permanent magnets of the first layer or the second layer may be arranged so as to be shifted toward the forward rotation direction side from the circumferential center C of the magnetic poles in the mechanical angle, and the interval between the first layer and the second layer on the reverse rotation direction side of each magnetic pole may be increased.

[0063] In the above embodiment, the configuration example of an 8-pole rotor has been described. However, the number of poles of the rotor 2 is not limited to the above embodiment. Further, in the above embodiment, an example in which the counterclockwise direction of the rotating electrical machine 1 is the forward rotation direction has been described. However, the clockwise direction of the rotating electrical machine 1 may be the forward rotation direction. When the clockwise direction is the forward rotation direction, the pattern of the magnetic poles of the rotor 2 has a shape in which the left and right are reversed from the above embodiment.

[0064] In the above embodiment, an example in which permanent magnets having a rectangular cross section are used for the first layer and the second layer has been described. However, permanent magnets having an arc cross section may be applied.

[0065] In addition, the embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims are included.

Explanation of Reference Numerals

[0066] 1... Rotating electrical machine, 2... Rotor, 3... Stator, 4... Core, 5... Shaft, 6, 6a, 6b... Permanent magnets of the first layer, 7, 7a, 7b, 7c... Permanent magnets of the second layer, 11a... Advance side first magnet hole, 11b... Retard side first magnet hole, 12a... Advance side second magnet hole, 12b... Retard side second magnet hole, 12c... Intermediate second magnet hole, 13... Air gap, 14a, 14b... Flux barrier, 15a - 15f... Grooves

Claims

1. An embedded magnet type rotor having a plurality of magnetic poles formed in the circumferential direction of the iron core, wherein each of the magnetic poles comprises a first layer of magnets arranged in a V-shaped pattern that widens in the direction of the outer periphery of the rotor, and a second layer of magnets arranged in a pattern that surrounds the first layer of magnets from the inner periphery side of the rotor, and the first layer of magnets is arranged in a pattern in which the position of the valley of the V-shape is shifted in the circumferential direction with respect to the circumferential center of the magnetic pole in mechanical angle and the arrangement center of the second layer of magnets Embedded magnet type rotor.

2. The embedded magnet type rotor is applied to a motor, and the position of the valley of the V-shape of the first layer of magnets is shifted to the side of retardation in the forward rotation direction of the motor with respect to the circumferential center of the magnetic pole in mechanical angle The embedded magnet type rotor according to claim 1.

3. The first layer of magnets is arranged asymmetrically about the valley of the V-shape, and the magnets on the retardation side in the forward rotation direction of the first layer have a shape with a shorter major axis length than the magnets on the advance side in the forward rotation direction of the first layer The embedded magnet type rotor according to claim 2.

4. The first layer of magnets and the second layer of magnets have the same minor axis length, respectively, and the major axis length of the second layer of magnets is the same as the major axis length of any one of the magnets in the first layer or the length obtained by combining the major axis lengths of the magnets in the first layer The embedded magnet type rotor according to claim 3.

5. The second layer of magnets is arranged symmetrically with respect to the circumferential center of the magnetic pole in mechanical angle, and the position of the valley of the V-shape of the first layer of magnets is shifted in the circumferential direction with respect to the arrangement center of the second layer of magnets The embedded magnet type rotor according to claim 2.

6. The second layer of magnets is arranged asymmetrically with respect to the circumferential center of the magnetic pole in mechanical angle, and the magnets on the advance side in the forward rotation direction of the second layer form a pattern that opens wider to the outer periphery side than the magnets on the retardation side in the forward rotation direction of the second layer The embedded magnet type rotor according to claim 2.

7. At the outer peripheral end of each magnet in the first layer, a flux barrier extending toward the inside of the first layer is formed respectively, and the flux barrier on the advance side in the forward rotation direction and the flux barrier on the retardation side in the forward rotation direction have different shapes The embedded magnet type rotor according to claim 2.

8. The outer periphery of the iron core has a groove extending in the axial direction, and the groove is formed asymmetrically with respect to the circumferential center of the magnetic pole in mechanical angle The embedded magnet type rotor according to claim 2.

9. A stator, and the embedded magnet type rotor according to any one of claims 1 to 8 A rotating electrical machine comprising.

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