Rotating electric machines

Abstract

A rotating electrical machine comprises: a stator having a stator core; and a rotor having a rotor core coaxially arranged with a gap between the stator core and a plurality of permanent magnet groups forming one magnetic pole, which are embedded in the rotor core and arranged at equal angular intervals in the circumferential direction; a magnetic barrier is formed between a group of circumferentially adjacent permanent magnets in the group of permanent magnets forming one magnetic pole; a pair of ribs are formed by a region of the rotor core between the adjacent group of permanent magnets and the magnetic barrier; a first slit is formed in a region of the rotor core on the radial side of the gap of the group of permanent magnets forming one magnetic pole, for biasing the magnetic flux generated from the group of permanent magnets forming one magnetic pole toward the rotation direction of the rotor; an end of the first slit on the magnetic barrier side is located between the extension lines of the pair of ribs.

Description

Technical Field

[0001] The present invention relates to a rotating electric machine, and more particularly to a rotating electric machine including a rotor having a permanent magnet. Background Art

[0002] For industrial rotating electrical machines and rotating electrical machines for electric vehicles and hybrid vehicles, permanent magnet rotating electrical machines are often used, which are advantageous for miniaturization and high output. In the case of a structure in which the permanent magnets in the permanent magnet rotating electrical machine are buried in the rotor core, two types of torque can be obtained: magnet torque generated by the magnet flux from the permanent magnets and reluctance torque generated by the reluctance flux formed by the reluctance of the rotor core. And the final torque of the rotating electrical machine becomes the combined torque of these two torques.

[0003] However, in the permanent magnet rotating electric machine configured in this way, the current phase angles at which the two torques obtain peak values ​​are different from each other. Therefore, the current phase angle at which the peak value of the combined torque of the two torques is obtained deviates from the current phase angle at which the peak values ​​of the two torques are obtained. As a result, the peak value of the combined torque of the two torques is smaller than the sum of the peak values ​​of the two torques.

[0004] In view of such a situation, a structure has been proposed in which a slit is provided in the rotor core for deviating the magnetic flux from the permanent magnet toward the stator in the rotation direction of the rotor (for example, Patent Document 1).

[0005] In Patent Document 1, the magnetic flux from the permanent magnet toward the stator passes through the slit and deviates toward the rotation direction of the rotor, and the current phase angle at which the magnet torque reaches its peak value changes. As a result, the difference between the current phase angle at which the magnet torque reaches its peak value and the current phase angle at which the reluctance torque reaches its peak value becomes smaller, and the peak value of the combined torque of the two increases.

[0006] Prior Art Literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 11-206046 Summary of the invention

[0009] Problems to be solved by the invention

[0010] In Patent Document 1, a slit for biasing the magnetic flux from the permanent magnet toward the stator toward the rotation direction of the rotor is formed in the core region on the outer diameter side of the permanent magnet of the rotor core. Therefore, during operation, due to the centrifugal force acting on the permanent magnet, there is a problem that the stress in the region of the rotor core between the permanent magnet and the slit becomes high.

[0011] Therefore, in order to alleviate the stress generated in the core area between the permanent magnet and the slit, it is necessary to increase the shape of the slit or expand the gap between the permanent magnet and the slit. However, when the shape of the slit is increased, the core area that generates the reluctance torque becomes narrower, and the reluctance torque becomes smaller. In addition, when the gap between the permanent magnet and the slit is increased, the current phase angle at which the magnet torque reaches the peak value cannot be changed to a current phase angle close to the current phase angle at which the reluctance torque reaches the peak value. As a result, in either case, the peak value of the synthetic torque will become smaller.

[0012] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to obtain a rotating electrical machine capable of reducing stress generated in a region of a rotor core and increasing a peak value of a combined torque of a magnet torque and a reluctance torque.

[0013] Solutions to Solve Problems

[0014] The rotating electric machine of the present invention comprises: a stator having a stator core and a stator coil; and a rotor having a rotor core arranged coaxially with the stator core with a gap therebetween, and a plurality of permanent magnet groups forming one magnetic pole which are embedded in the rotor core and arranged at equal angular intervals in the circumferential direction, wherein a magnetic barrier is formed between a group of permanent magnets adjacent to each other in the circumferential direction among the permanent magnet groups forming one magnetic pole, a pair of ribs are formed by a region of the rotor core between the adjacent group of permanent magnets and the magnetic barrier, a first slit is formed in a region of the rotor core on the radial side of the gap of the permanent magnet group forming one magnetic pole to bias the magnetic flux generated from the permanent magnet group forming one magnetic pole toward the rotation direction of the rotor, and an end of the first slit on the magnetic barrier side is located between the extension lines of the pair of ribs.

[0015] Effects of the Invention

[0016] According to the present invention, since the above-mentioned structure is obtained, it is possible to obtain a rotating electrical machine capable of reducing stress generated in the region of the rotor core and increasing the peak value of the combined torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a longitudinal sectional view showing the rotating electrical machine according to the first embodiment of the present invention.

[0018] Figure 2 It is shown Figure 1 Sectional view taken along the II-II direction.

[0019] Figure 3 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the rotor in the rotating electrical machine according to the first embodiment of the present invention.

[0020] Figure 4This is a diagram showing the distribution of air gap magnetic flux density caused by magnet magnetic flux corresponding to one electrical angle period in the non-energized state of the rotating electric machine according to the first embodiment of the present invention.

[0021] Figure 5 This is a diagram showing changes in torque with respect to a current phase angle under a condition where a current value is constant in the rotating electrical machine according to the first embodiment of the present invention.

[0022] Figure 6 It is an equivalent stress distribution diagram showing the stress analysis result in the rotor of the rotating electrical machine according to the first embodiment of the present invention.

[0023] Figure 7 3 is an equivalent stress distribution diagram showing the stress analysis result in the rotor of the comparative example.

[0024] Figure 8 This is a diagram showing changes in torque with respect to a current phase angle under a condition where a current value is constant in the rotating electrical machine according to the first embodiment of the present invention.

[0025] Fig. 9 This is a cross-sectional view of the main parts around one magnetic pole of a rotor showing a first modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0026] Fig.10 This is a cross-sectional view of the main parts around one magnetic pole of a rotor showing a second modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0027] Fig.11 This is a cross-sectional view of the main parts around one magnetic pole of a rotor showing a third modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0028] Fig.12 This is a cross-sectional view of the main parts around one magnetic pole of a rotor showing a fourth modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0029] Fig.13 This is a cross-sectional view of the main parts around one magnetic pole of the rotor showing a fifth modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0030] Fig.14 It is a cross-sectional view showing a rotating electrical machine according to Embodiment 2 of the present invention.

[0031] Fig.15 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the rotor in the rotating electrical machine according to the second embodiment of the present invention.

[0032] Fig.16It is a longitudinal sectional view showing a rotating electrical machine according to Embodiment 3 of the present invention.

[0033] Fig.17 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the first rotor in the rotating electrical machine according to the third embodiment of the present invention.

[0034] Fig.18 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the second rotor in the rotating electrical machine according to the third embodiment of the present invention.

[0035] Fig.19 It is a cross-sectional view showing a rotating electrical machine according to Embodiment 4 of the present invention.

[0036] Fig. 20 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of a rotor in a rotating electrical machine according to Embodiment 5 of the present invention.

[0037] Fig.21 It is a cross-sectional view showing a rotating electrical machine according to Embodiment 6 of the present invention. DETAILED DESCRIPTION

[0038] Implementation method 1.

[0039] Figure 1 is a longitudinal sectional view showing a rotating electrical machine according to Embodiment 1 of the present invention, Figure 2 yes Figure 1 The longitudinal sectional view is a sectional view showing a section including the axis of the rotation axis. Figure 2 In the figure, the frame and the coil end are omitted. In addition, in this specification, for convenience, the direction parallel to the axis of the rotating shaft is set as the axial direction, the direction perpendicular to the axis of the rotating shaft with the axis of the rotating shaft as the center is set as the radial direction, and the direction rotating with the rotating shaft as the center is set as the circumferential direction. In the figure, R is the rotation direction of the rotating shaft.

[0040] exist Figure 1 as well as Figure 2 In the embodiment, the rotary electric machine 1 includes: a cylindrical frame 2; a pair of end plates 3 mounted on both ends of the frame 2 in the axial direction and closing the openings on both sides of the frame 2 in the axial direction; and a rotary shaft 5 supported by bearings 4 mounted on the pair of end plates 3 and arranged to be rotatable in the frame 2. The rotary electric machine 1 also includes: a rotor 20 fixed to the rotary shaft 5 and arranged to be rotatable in the frame 2; and a stator 10 inserted and held in the frame 2 and coaxially arranged on the outer diameter side of the rotor 20. A gap G is formed between the rotor 20 and the stator 10.

[0041] The stator 10 includes a circular stator core 11 and a stator coil 12 mounted on the stator core 11. The stator core 11 includes a circular core back yoke 110 and a plurality of core teeth 111 protruding radially inward from the inner circumferential surface of the core back yoke 110, and is formed by, for example, laminating thin plates of electromagnetic steel sheets in the axial direction to form an integral body. There are 18 core teeth 111 arranged at equal angular intervals in the circumferential direction, and the area between adjacent core teeth 111 is a slot 112. The stator coil 12 is composed of a concentrated winding coil 120 formed by winding a conductive wire around each core tooth 111. Adjacent concentrated winding coils 120 are respectively accommodated in the slots 112.

[0042] The rotor 20 includes: a rotating shaft 5; a cylindrical rotor core 21 having a shaft insertion hole formed at the axial center; and 24 permanent magnets 22 embedded in the outer diameter side of the rotor core 21. The rotor core 21 is fixed to the rotating shaft 5 inserted into the shaft insertion hole. The rotor 20 is supported by bearings 4 at both ends of the rotating shaft 5 in the axial direction and is rotatable in the frame 2. The rotor core 21 is formed by, for example, laminating thin plates of electromagnetic steel sheets in the axial direction to form an integral body.

[0043] Here, refer to Figure 3 The structure around the magnetic poles of the rotor 20 will be described. Figure 3 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the rotor in the rotary electric machine according to Embodiment 1 of the present invention. The cross-sectional view refers to a cross-sectional view showing a cross section perpendicular to the axis of the rotating shaft.

[0044] On the outer diameter side of the rotor core 21, 12 pairs of magnet insertion holes 23 are formed in the circumferential direction at equal angular intervals, and the magnet insertion holes 23 penetrate the rotor core 21 in the axial direction. The pairs of magnet insertion holes 23 are arranged in a V-shape with the circumferential spacing gradually increasing toward the outer diameter side. The magnet insertion holes 23 are formed in a hole shape with a rectangular cross section. In addition, the ends of the inner diameter side of the magnet insertion holes 23 constituting the pair are separated from each other in the circumferential direction.

[0045] The permanent magnet 22 is configured as a prism with a rectangular cross section equal to the magnet insertion hole 23. The permanent magnet 22 is magnetized in a manner orthogonal to the plane formed by the long side of the rectangular cross section. Thus, the first surface of the permanent magnet 22 formed by the long side of the rectangular cross section becomes the N pole, and the second surface on the opposite side of the first surface becomes the S pole. The permanent magnet 22 is inserted and retained in a manner that the same polarity faces the outer diameter side in each pair of magnet insertion holes 23 and in a manner that different polarities face the outer diameter side in the pairs of adjacent magnet insertion holes 23. That is, a pair of permanent magnets 22 arranged in a V shape with a circumferential spacing gradually expanding toward the gap G side constitutes one magnetic pole. In addition, the pair of permanent magnets 22 constituting one magnetic pole is buried in the outer diameter side of the rotor core 21, and 12 pairs are arranged at equal angular intervals in the circumferential direction. Thus, 12 magnetic poles are formed on the rotor 20.

[0046] The first magnetic barrier 24 is formed by extending the surface of the magnet insertion hole 23 on the outer diameter side formed by the short side of the cross-sectional rectangle in the longitudinal direction of the long side of the cross-sectional rectangle. The second magnetic barrier 25, which is a magnet end magnetic barrier, is formed by extending the surface of the magnet insertion hole 23 on the inner diameter side formed by the short side of the cross-sectional rectangle in the longitudinal direction of the long side of the cross-sectional rectangle. The third magnetic barrier 26 is located between the second magnetic barriers 25 of the pair of magnet insertion holes 23. The first, second and third magnetic barriers 24, 25, 26 are respectively formed to penetrate the rotor core 21 in the axial direction.

[0047] Here, the second magnetic barrier 25 and a part of the third magnetic barrier 26 adjacent in the circumferential direction are located at the same radial distance from the axis of the rotating shaft 5. At this position, the core area between the second magnetic barrier 25 and the third magnetic barrier 26 becomes a rib 27. In addition, the core area between the first magnetic barrier 24 and the outer peripheral surface of the rotor core 21 becomes a bridge arm 28.

[0048] The first slit 29 is formed in the core region of the rotor core 21 located on the outer diameter side of the pair of permanent magnets 22 arranged in a V-shape. The first slit 29 extends in a straight band shape from the vicinity of the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the rotor core 21. The first slit 29 extends in a straight line inclined forward relative to the rotation direction R. The inner diameter side end of the first slit 29, that is, the end on the side of the third magnetic barrier 26, is located between the extension lines of the pair of ribs 27. The outer diameter side end of the first slit 29, that is, the end on the side of the gap G, is located near the outer peripheral surface of the rotor core 21. In addition, the first slit 29 can be formed to penetrate the rotor core 21 in the axial direction, or it can be formed to have a depth that ends halfway in the axial direction without penetrating in the axial direction. In addition, the minimum width portion of the first slit 29 is smaller than the circumferential width of the rib 27. As a result, the stress around the rib 27 can be reduced.

[0049] The first slit 29 is hollow. The magnetic permeability of air is lower than that of the rotor core 21. Therefore, the first slit 29 becomes a low magnetic permeability area in the core area on the outer diameter side of the pair of permanent magnets 22 arranged in a V shape. In addition, the first slit 29 may be filled with a resin, a heat dissipation material, etc. having a lower magnetic permeability than the rotor core 21. As a result, the strength of the rotor core 21 is improved. In addition, the cooling effect of the rotor core 21 and the permanent magnets 22 is improved.

[0050] In the rotating electric machine 1 thus constructed, the number of slots 112 of the stator 10 is 18, and the number of poles of the rotor 20 is 12. That is, the rotating electric machine 1 is an inner rotor type rotating electric machine with a pole-slot number of 2 to 3 (2:3) system. It is assumed that the rotating electric machine 1 is used for power operation. The so-called power operation refers to the operation of converting the electric energy supplied to the stator coil 12 into the kinetic energy of the rotor 20 rotation. At this time, the rotating electric machine 1 operates as a motor. The circumferential force acting on the rotor 20 by supplying electricity to the stator coil 12 is the same as the rotation direction R of the rotor 20. In addition, power operation is not the main purpose of the present invention, so its detailed description is omitted.

[0051] The first magnetic barrier 24 is formed so as to extend from the magnet insertion hole 23 to the outer diameter side in the longitudinal direction of the long side of the cross-sectional rectangular shape. The second magnetic barrier 25 is formed so as to extend from the magnet insertion hole 23 to the inner diameter side in the longitudinal direction of the long side of the cross-sectional rectangular shape. The third magnetic barrier 26 is formed between the second magnetic barriers 25. Therefore, the radial width of the bridge arm 28 between the first magnetic barrier 24 and the outer peripheral surface of the rotor core 21 is reduced. In addition, the circumferential width of the rib 27 between the second magnetic barrier 25 and the third magnetic barrier 26 is reduced. Thus, the flow of the magnet flux 31 flowing through the magnetic path closed in the rotor core 21, which returns from the permanent magnet 22 via the rib 27 and the bridge arm 28 to the permanent magnet 22, can be suppressed. As a result, the amount of the magnet flux 31 interlinked with the stator 10 via the gap G increases.

[0052] The first slit 29 extends linearly from the vicinity of the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the rotor core 21. The first slit 29 is inclined toward the front, i.e., the forward side, in the rotation direction R. The inner diameter side end of the first slit 29 is located near the third magnetic barrier 26. The outer diameter side end of the first slit 29 is located near the outer peripheral surface of the rotor core 21. Thus, the core region on the outer diameter side of the pair of permanent magnets 22 arranged in a V shape constituting one magnetic pole is separated by the first slit 29 into a core region 30A on the forward side of the rotation direction during power operation and a core region 30B on the reverse side of the rotation direction.

[0053] Next, the state of the magnetic flux that is the source of torque generation will be described.

[0054] The magnet flux 31 generated from the flux generating surface of the permanent magnet 22 located on the forward side in the rotation direction R flows from the rotor core 21 to the gap G. At this time, the direction in which the magnet flux 31 flows is restricted by the first slit 29 as a low permeability region, and the magnet flux 31 is biased toward the forward side in the rotation direction. Figure 3 As shown by the middle arrow, the core region 30A on the forward side in the rotation direction is deflected. As a result, the current phase angle at which the magnet torque becomes a positive peak value can be larger than the current phase angle when the first slit 29 is not provided.

[0055] The path of the reluctance flux 32 flowing from the stator core 11 to the rotor core 21 through the gap G is restricted by the first slit 29 as a low permeability region. Figure 3 As shown by the middle arrow, the current does not flow in the forward core region 30A in the rotation direction, but only flows in the backward core region 30B in the rotation direction. As a result, the current phase angle at which the reluctance torque becomes a positive peak can be made smaller than the current phase angle when the first slit 29 is not provided.

[0056] As a result, the interval between the current phase angles at which the magnet torque and the reluctance torque each become positive peaks becomes smaller. Therefore, the combined torque of the magnet torque and the reluctance torque during power running, that is, the total torque can be increased.

[0057] Next, in Figure 4 2 shows the results of analyzing the air gap magnetic flux density distribution formed by the magnet magnetic flux 31 for one period of electrical angle in the non-energized state by the finite element method. The one period of electrical angle refers to the amount of two magnetic poles. Figure 4 1 is a diagram showing the distribution of air gap magnetic flux density formed by magnet magnetic flux corresponding to one electrical angle cycle in the non-energized state of the rotary electric machine according to the first embodiment of the present invention. Figure 4 In FIG. 1 , the horizontal axis represents the circumferential position, and the vertical axis represents the air gap magnetic flux density. In addition, the dotted line represents the air gap magnetic flux density when the first slit 29 is not provided, and the solid line represents the air gap magnetic flux density when the first slit 29 is provided.

[0058] according to Figure 4 It is found that when the first slit 29 is provided, the air gap magnetic flux density in one magnetic pole during power operation is biased toward the forward side in the rotation direction of the rotor 20 compared to when the first slit 29 is not provided.

[0059] Next, in Figure 5 2 shows the results of analyzing the change in torque with respect to the current phase angle β under the condition of a constant current value using the finite element method. Figure 5 : is a diagram showing the change in torque with respect to the current phase angle under the condition that the current value is constant in the rotating electrical machine according to the first embodiment of the present invention. Figure 5 In FIG. 1 , the horizontal axis represents the current phase angle β, and the vertical axis represents the torque. The dotted line represents the torque when there is no first slit 29, and the solid line represents the torque when there is the first slit 29. The torque is the combined torque of the magnet torque and the reluctance torque.

[0060] according to Figure 5 It can be seen that the current phase angle β at which the positive peak value of the combined torque is obtained when the first slit 29 is present is smaller than the current phase angle β at which the positive peak value of the combined torque is obtained when the first slit 29 is not present. Figure 5It can be seen that the positive peak value of the combined torque in the case where the first slit 29 is present is larger than the positive peak value of the combined torque in the case where the first slit 29 is not present.

[0061] In the absence of the first slit 29, the magnet torque reaches a positive peak value when the current phase angle β is 0°, and the reluctance torque reaches a positive peak value when the current phase angle β is 45°. Figure 5 It can be inferred from the results that, by providing the first slit 29, the current phase angles β at which the magnet torque and the reluctance torque respectively obtain positive peaks are close to each other, and the combined torque is improved.

[0062] Thus, in the first embodiment, the first slit 29 as a low permeability region is provided in the core region on the outer diameter side of the permanent magnet 22 arranged in a V shape constituting one magnetic pole in a manner inclined toward the forward side of the rotation direction R. As a result, the current phase angles β at which the magnet torque and the reluctance torque respectively obtain positive peaks are close to each other. As a result, during power operation, the combined torque of the magnet torque and the reluctance torque is improved.

[0063] Here, stress generated in the rotor core during power operation will be described.

[0064] Figure 6 is an equivalent stress distribution diagram of a stress analysis result in a rotor of the rotating electrical machine according to the first embodiment of the present invention, Figure 7 It is an equivalent stress distribution diagram of the stress analysis result in the rotor of the comparative example.

[0065] In the rotor core 21 of the rotor 20, as shown in FIG. Figure 3 As shown in the figure, the third magnetic flux barrier 26 is formed between a group of permanent magnets 22 adjacent in the circumferential direction among the group of permanent magnets 22 constituting one magnetic pole. A pair of ribs 27 is formed by the region of the rotor core 21 between the adjacent group of permanent magnets 22 and the third magnetic flux barrier 26. The inner diameter side end of the first slit 29 is separated from the third magnetic flux barrier 26 and is located in the circumferential region between the extension lines of the pair of ribs 27.

[0066] In the rotor core 201 of the rotor 200 of the comparative example, as Figure 7 As shown, the inner diameter side end of the first slit 29 is separated from the third flux barrier 26 and is located on the rotation direction backward side of the extension line of the pair of ribs 27. The other configurations of the rotor core 201 are similar to those of the rotor core 21.

[0067] During power operation, the stress generated in the rotor core 201 of the comparative example is as follows: Figure 7 As shown in FIG. 1 , the stress generated in the rotor core 21 is 156 MPa. Figure 6 As shown, it is 78 MPa. Thus, it was confirmed that the stress generated in the rotor core 21 can be reduced by positioning the inner diameter side end of the first slit 29 in the circumferential region between the extension lines of the pair of ribs 27 .

[0068] This is because, in the rotor 200 of the comparative example, when the centrifugal force acts on the permanent magnet 22, the inner diameter side end of the first slit 29 is located in the direction of displacement of the rotor core 201. Furthermore, the minimum width portion of the first slit 29 is smaller than the circumferential width of the rib 27. Therefore, the stress generated at the inner diameter side end of the first slit 29 becomes larger. In the rotor 20, the inner diameter side end of the first slit 29 is located in a region sandwiched by the extension lines of the pair of ribs 27. Therefore, when the centrifugal force acts on the permanent magnet 22, the inner diameter side end of the first slit 29 is separated from the direction of displacement of the rotor core 21. Therefore, it can be inferred that the stress generated at the inner diameter side end of the first slit 29 is reduced.

[0069] Thus, in the rotor 20 according to the first embodiment, the inner diameter side end of the first slit 29 is located in the region sandwiched by the extension lines of the pair of ribs 27. Thus, the stress generated in the rotor core 21 is reduced. Furthermore, in the rotor 20, the first slit 29 is provided in the core region on the outer diameter side of the permanent magnet 22 arranged in a V shape constituting one magnetic pole so as to be inclined toward the forward side of the rotation direction R. Thus, during power operation, the combined torque of the magnet torque and the reluctance torque can be increased.

[0070] Next, in Figure 8 2 shows the result of analyzing the change of torque with respect to the current phase angle β under the condition of constant current value by the finite element method when the permanent magnet 22 is removed from the rotor 20 and the stator coil 12 is formed by concentrated winding coils or distributed winding coils. Figure 8 : is a diagram showing the change in torque with respect to the current phase angle under the condition that the current value is constant in the rotating electrical machine according to the first embodiment of the present invention. Figure 8 In FIG. 1 , the horizontal axis represents the current phase angle β, and the vertical axis represents the torque. The dotted line represents the torque when there is no first slit 29, and the solid line represents the torque when there is the first slit 29. The torque is the reluctance torque.

[0071] like Figure 8 As shown in FIG. 1 , in the case of the stator coil of the concentrated winding structure, the positive peak value of the reluctance torque becomes larger when the first slit 29 is provided than when the first slit 29 is not provided. On the other hand, in the case of the stator coil of the distributed winding structure, the positive peak value of the reluctance torque becomes smaller when the first slit 29 is provided than when the first slit 29 is not provided. Thus, it was confirmed that even for the concentrated winding structure that could not fully exert the reluctance torque in the past, the reluctance torque can be improved by providing the first slit 29 and changing the path of the reluctance magnetic flux.

[0072] In addition, if Figure 8As shown in FIG. 1 , regardless of the winding structure of the stator coil, the current phase angle β at which the positive peak value of the reluctance torque is obtained is reduced by providing the first slit 29. Therefore, regardless of the winding structure of the coil, the current phase angles β at which the magnet torque and the reluctance torque respectively obtain positive peak values ​​are close to each other by providing the first slit 29. As a result, during power operation, the combined torque of the magnet torque and the reluctance torque is increased.

[0073] Next, a modification example of the rotor will be described. Fig. 9 is a cross-sectional view of a main part around one magnetic pole of a rotor showing a first modified example in the rotating electrical machine according to the first embodiment of the present invention, Fig.10 is a cross-sectional view of a main part around one magnetic pole of a rotor showing a second modified example in the rotating electrical machine according to the first embodiment of the present invention, Fig.11 1 is a cross-sectional view of a main part around one magnetic pole of a rotor showing a third modified example of the rotating electrical machine according to the first embodiment of the present invention. Fig.12 1 is a cross-sectional view of a main part around one magnetic pole of a rotor showing a fourth modified example of the rotating electrical machine according to the first embodiment of the present invention. Fig.13 This is a cross-sectional view of the main parts around one magnetic pole of the rotor showing a fifth modified example in the rotating electrical machine according to the first embodiment of the present invention.

[0074] In the rotor 20A of the first modified example, as Fig. 9 As shown in the figure, the first slit 29 is formed in the rotor core 21A so as to open to the third magnetic barrier 26 and the gap G. The inner diameter side end of the first slit 29 is located in the circumferential region between the extension lines of the pair of ribs 27. The other structures of the rotor 20A are configured in the same manner as the rotor 20. Therefore, even if the rotor 20A is used, the same effect as that of the first embodiment can be obtained. In addition, when the rotor 20A is used, since the leakage flux on the gap G side of the first slit 29 is reduced, the torque can be further improved.

[0075] In the rotor 20B of the second modification, as Fig.10 As shown, the three magnet insertion holes 23 that hold the permanent magnets 22 that constitute one magnetic pole are arranged in a V-shape with their circumferential spacing gradually increasing toward the outer diameter side. That is, two magnet insertion holes 23 are arranged in a row inclined toward the forward side of the rotation direction. The remaining one magnet insertion hole 23 is inclined toward the backward side of the rotation direction. The first magnetic barrier 24 and the second magnetic barrier 25 are formed at both ends of the length direction of the long side of the cross-sectional rectangle of each magnet insertion hole 23. A rib 27 is formed between the magnet insertion holes 23 inclined toward the forward side of the rotation direction. A third magnetic barrier 26 is formed between the magnet insertion holes 23 with different inclination directions. A pair of ribs 27 are formed across the third magnetic barrier 26. The first slit 29 is formed in the rotor core 21B in a manner opening to the third magnetic barrier 26 and the gap G.

[0076] Therefore, even if the rotor 20B is used, the same effect as that of the case where the rotor 20A is used can be obtained. In addition, the number of permanent magnets 22 constituting one magnetic pole may be 4 or more. In this case, the permanent magnets 22 are arranged in a V-shape. The third magnetic barrier 26 is formed between the permanent magnets 22 constituting the valley of the V-shape.

[0077] In the rotor 20C of the third modification, as Fig.11 As shown in FIG. 1 , the first slit 29 is formed in the rotor core 21C so as to extend from the vicinity of the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the rotor core 21D. The first slit 29 is formed in an arc-shaped band shape convex toward the forward side of the rotation direction R. The other structures of the rotor 20C are configured in the same manner as the rotor 20. Therefore, even if the rotor 20C is used, the same effect as that of the first embodiment can be obtained.

[0078] In the rotor 20D of the fourth modification, as Fig.12 As shown in the figure, the second slit 33 in the form of a straight band is formed in the rotor core 21D on the forward side of the first slit 29 in the rotation direction so as to reach the vicinity of the outer peripheral surface of the rotor core 21D from the vicinity of the magnet insertion hole 23. The other configurations of the rotor 20D are configured in the same manner as the rotor 20. Therefore, even if the rotor 20D is used, the same effect as that of the first embodiment can be obtained. In addition, the second slit 33 is arranged on the outer diameter side of the permanent magnet 22 located on the forward side of the rotation direction R among the two permanent magnets 22 constituting one magnetic pole. Therefore, the inner diameter side end of the second slit 33 is away from the direction in which the rotor core 21D is displaced when the centrifugal force acts on the permanent magnet 22 located on the forward side of the rotation direction R. Therefore, the stress generated at the inner diameter side end of the second slit 33 does not increase. Furthermore, the second slit 33 as a low permeability region is provided in the core region 30A on the forward side of the rotation direction, tilted toward the forward side of the rotation direction. Therefore, the direction in which the magnet magnetic flux 31 flows is restricted by the second slit 33 as the low magnetic permeability region, and the magnet magnetic flux 31 is further biased toward the forward side in the rotation direction.

[0079] In the rotor 20E of the fifth modification, as Fig.13 As shown in the figure, two first slits 29a and 29b in the form of straight strips are arranged in a row on the rotor core 21E in a manner extending from the vicinity of the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the rotor core 21F. The other structures of the rotor 20E are the same as those of the rotor 20. Therefore, even if the rotor 20E is used, the same effect as that of the first embodiment can be obtained. In addition, in the fifth modification, the first slit is divided into two, but it can also be divided into three or more. In addition, in the rotor 20C of the third modification, the arc-shaped first slit 29 can also be divided into a plurality of first slits.

[0080] Thus, as described in the first embodiment and the first to fifth modified examples, if the inner diameter side end of the first slit 29 is located between the extension lines of the pair of ribs 27, the shape and arrangement of the first slit 29 and the number of permanent magnets 22 can be appropriately changed. As a result, magnetic saturation due to the magnet magnetic flux 31 does not occur, and high torque can be effectively obtained. In addition, if the inner diameter side end of the first slit 29 is located between the extension lines of the pair of ribs 27, one or more second slits 33 may be provided in the core region on the forward side of the rotation direction of the first slit 29.

[0081] Implementation method 2.

[0082] Fig.14 is a cross-sectional view showing a rotating electrical machine according to a second embodiment of the present invention. Fig.15 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the rotor in the rotating electrical machine according to the second embodiment of the present invention.

[0083] The rotating electrical machine 1 of the first embodiment is assumed to be used for power operation, while the rotating electrical machine 1A of the second embodiment is assumed to be used for regenerative operation. The so-called regenerative operation refers to an operation in which the kinetic energy given to the rotor 40 is converted into electrical energy and the electrical energy is taken out from the terminals of the stator coil 12. At this time, the rotating electrical machine 1A operates as a generator. In addition, since the regenerative operation is not the main purpose of the present invention, its detailed description is omitted.

[0084] exist Fig.14 as well as Fig.15 In the figure, the rotary electric machine 1A includes a stator 10 and a rotor 40, which is coaxially arranged on the inner diameter side of the stator 10 with a gap G provided between the stator 10. The rotor 40 includes a rotor core 41. Although not shown, the stator 10 and the rotor 40 are accommodated in a housing composed of a frame 2 and a pair of end plates 3.

[0085] The rotor core 41 is constructed in the same manner as the rotor core 21 except that the arrangement of the first slit 29 is different. Specifically, the first slit 29 extends in a straight band shape in the core region on the outer diameter side of the pair of permanent magnets 22 arranged in a V-shape, from the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the rotor core 41. The first slit 29 is inclined toward the rear, i.e., the reverse side, relative to the rotation direction R. The inner diameter side end of the first slit 29 is connected to the third magnetic barrier 26 and is located between the extension lines of the pair of ribs 27. The outer diameter side end of the first slit 29 is located near the outer peripheral surface of the rotor core 41.

[0086] The core region on the outer diameter side of the pair of permanent magnets 22 arranged in a V-shape constituting one magnetic pole is separated by the first slit 29 into a core region 30A on the forward rotation side and a core region 30B on the reverse rotation side during regeneration operation.

[0087] The rotor 40 receives kinetic energy from the outside to rotate. During regenerative operation, the direction of the circumferential force acting on the rotor 40 by energizing the stator coil 12 becomes opposite to the rotation direction R of the rotor 40. That is, during regenerative operation, the torque generated by the rotating electric machine 1A itself acts to cancel the torque from the outside.

[0088] Next, the state of the magnetic flux that is the source of torque generation is described. During regenerative operation, it is assumed that the magnetic flux 31 generated by the permanent magnet 22 located on the reverse side of the rotation direction is about to flow from the rotor core 41 to the gap G. At this time, the direction of the flow of the magnetic flux 31 is restricted by the first slit 29 as a low permeability region, and the magnetic flux 31 is biased toward the reverse side of the rotation direction. As a result, the magnetic flux 31 is Fig.15 As shown by the middle arrow, the magnet flux 31 is deflected in the core region 30B on the reverse side in the rotation direction. As a result, the current phase angle β that can make the magnet torque a negative peak is smaller than the current phase angle β in the case where there is no first slit 29. Therefore, the current phase angle β that can make the reluctance torque a negative peak is larger than the current phase angle β in the case where there is no first slit 29.

[0089] Furthermore, it is assumed that the reluctance flux 32 that is to flow from the stator core 11 to the rotor core 41 through the gap G is restricted in its path by the first slit 29 that is a low permeability region. Fig.15 As shown by the middle arrow, the current phase angle β at which the reluctance torque becomes a negative peak can be made larger than the current phase angle β when the first slit 29 is not present.

[0090] In the second embodiment, the current phase angle of the negative peak of the magnet torque and the current phase angle of the negative peak of the reluctance torque can be made close by providing the first slit 29. Therefore, the combined torque of the magnet torque and the reluctance torque of the rotary electric machine 1A during the regenerative operation can be improved.

[0091] Furthermore, since the inner diameter side end portion of the first slit 29 is located in the circumferential region between the extension lines of the pair of ribs 27 , stress generated at the inner diameter side end portion of the first slit 29 can be reduced.

[0092] In the second embodiment, as in the first embodiment, if the inner diameter side end of the first slit 29 is located between the extension lines of the pair of ribs 27, the shape and arrangement of the first slit 29 and the number of permanent magnets 22 can be changed as appropriate.

[0093] Implementation method 3.

[0094] Fig.16 is a longitudinal sectional view showing a rotating electrical machine according to a third embodiment of the present invention. Fig.17is a cross-sectional view of a main part showing the periphery of one magnetic pole of a first rotor in a rotating electrical machine according to a third embodiment of the present invention, Fig.18 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of the second rotor in the rotating electrical machine according to the third embodiment of the present invention.

[0095] exist Fig.16 In the embodiment, the rotary electric machine 1B includes: a frame 2; a pair of end plates 3 that seal the openings on both sides of the frame 2 in the axial direction; a rotary shaft 5 that is supported by bearings 4 mounted on the pair of end plates 3 and rotatably provided in the frame 2; a stator 10 that is accommodated and held in the frame 2; and a rotor 50 that is coaxially arranged on the inner diameter side of the stator 10 with a gap G provided between the stator 10. The rotor 50 includes a first rotor 50A and a second rotor 50B that are divided into two equal parts in the axial direction. The first rotor 50A and the second rotor 50B include a first split rotor core 51A and a second split rotor core 51B.

[0096] The first split rotor core 51A and the second split rotor core 51B are configured similarly except that the shapes and arrangements of the first slits 29A and 29B are different. The first split rotor core 51A and the second split rotor core 51B are configured similarly to the rotor core 21 of the first embodiment except that the shapes, arrangements, and axial lengths of the first slits are different.

[0097] The first slit 29A is as follows Fig.17 As shown in the figure, in the core region on the outer diameter side of the pair of permanent magnets 22 arranged in a V-shape, it extends linearly from the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the first split rotor core 51A. The first slit 29A is inclined forward, that is, toward the forward side, relative to the rotation direction R. The inner diameter side end of the first slit 29A is connected to the third magnetic barrier 26 and is located between the extension lines of the pair of ribs 27. The outer diameter side end of the first slit 29A is located near the outer peripheral surface of the first split rotor core 51A.

[0098] The first slit 29B is as follows Fig.18 As shown in the figure, in the core region on the outer diameter side of the pair of permanent magnets 22 arranged in a V-shape, it extends linearly from the third magnetic barrier 26 to the vicinity of the outer peripheral surface of the second split rotor core 51B. The first slit 29B is arranged on the rear side of the first slit 29A in the rotation direction, that is, on the reverse side. The first slit 29B is inclined toward the forward side of the rotation direction R. The inner diameter side end of the first slit 29B is connected to the third magnetic barrier 26 and is located between the extension lines of the pair of ribs 27. The outer diameter side end of the second slit 29B is located near the outer peripheral surface of the second split rotor core 51B.

[0099] In the third embodiment, the first slit 29A and the first slit 29B are provided in the core region on the outer diameter side of the permanent magnet 22 arranged in a V shape constituting one magnetic pole in a manner inclined toward the forward side of the rotation direction R. Therefore, in the third embodiment, the combined torque of the magnet torque and the reluctance torque is also improved during power operation. In addition, the inner diameter side ends of the first slit 29A and the first slit 29B are located in the region sandwiched by the extension lines of the pair of ribs 27. Therefore, in the third embodiment, the stress generated in the first split rotor core 51A and the second split rotor core 51B is also reduced.

[0100] By changing the shape and configuration of the first slit, the phase and amplitude of the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force change. In Embodiment 3, the first slit 29A and the first slit 29B have different shapes and configurations. Therefore, by appropriately combining the first slit 29A and the first slit 29B having different shapes and configurations, the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force can be eliminated. As a result, the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force can be reduced.

[0101] Furthermore, in the third embodiment described above, the rotor core is divided equally into two in the axial direction, but it may be divided unequally into two.

[0102] In addition, in the above-mentioned embodiment 3, the rotor core is divided into two in the axial direction, but the rotor core may be divided into three or more. In this case, in each of the divided rotor cores, as in the above-mentioned embodiment 1, if the inner diameter side end of the first slit is located between the extension lines of a pair of ribs, the shape and arrangement of the first slit and the number of permanent magnets may be appropriately changed. As a result, the types of combined first slits increase, and the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force can be further reduced.

[0103] In the third embodiment, the present invention is applied to a rotating electric machine used in power operation with the first slit inclined toward the forward side in the rotation direction. However, the present invention may be applied to a rotating electric machine used in regenerative operation with the first slit inclined toward the reverse side in the rotation direction.

[0104] Implementation method 4.

[0105] Fig.19 It is a cross-sectional view showing a rotating electrical machine according to Embodiment 4 of the present invention.

[0106] exist Fig.19 In the embodiment, the rotary electric machine 1C includes a stator 10 and a rotor 60, which is coaxially arranged on the inner diameter side of the stator 10 with a gap G provided between the stator 10 and the rotor 60. The rotor 60 includes a rotor core 61. Although not shown, the stator 10 and the rotor 60 are accommodated in a housing composed of a frame 2 and a pair of end plates 3.

[0107] In rotor core 61, first slits 29A and first slits 29B are alternately formed for each magnetic pole in core regions on the outer diameter side of a pair of permanent magnets 22 arranged in a V shape constituting one magnetic pole. The other configurations are similar to those of rotor 50 in the third embodiment.

[0108] In the fourth embodiment, the first slits 29A and the first slits 29B are alternately provided for each magnetic pole so as to be inclined toward the forward side of the rotation direction R. Therefore, in the fourth embodiment, the combined torque of the magnet torque and the reluctance torque is also improved during power operation. In addition, the inner diameter side ends of the first slits 29A and the first slits 29B are located in a region sandwiched by the extension lines of the pair of ribs 27. Therefore, in the fourth embodiment, the stress generated in the rotor core 61 is also reduced.

[0109] In Embodiment 4, the shapes and configurations of the first slits 29A and 29B alternately formed for each magnetic pole are different. That is, the first slits 29A and 29B having different shapes and configurations are dispersedly arranged in the circumferential direction. Therefore, in Embodiment 4, the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force can be eliminated by appropriately combining the first slits 29A and 29B having different shapes and configurations. As a result, the high-frequency components of the cogging torque, torque ripple, and electromagnetic excitation force can be reduced.

[0110] Furthermore, in the fourth embodiment, the two types of first slits are different in shape and arrangement, but the two types of first slits only need to be different in at least one of shape and arrangement.

[0111] In the fourth embodiment, the two types of first slits are alternately formed in the rotor core for each magnetic pole, but the two types of first slits may be alternately formed in the rotor core for each plurality of magnetic poles or for different numbers of magnetic poles.

[0112] Furthermore, in the fourth embodiment, two types of first slits are formed in the rotor core, but three or more types of first slits may be formed in the rotor core.

[0113] In the fourth embodiment, similarly to the first embodiment, if the outer diameter side end of the first slit is located between the extension lines of the pair of ribs, the shape and arrangement of the first slit and the number of permanent magnets can be changed as appropriate.

[0114] In the fourth embodiment described above, a single rotor core is used. However, similarly to the third embodiment described above, a rotor core divided in the axial direction may be used.

[0115] In the fourth embodiment, the present invention is applied to a rotating electric machine used in a power running operation in which the first slit is inclined toward the forward side in the rotation direction. However, the present invention may be applied to a rotating electric machine used in a regenerative running operation in which the first slit is inclined toward the backward side in the rotation direction.

[0116] Implementation method 5.

[0117] Fig. 20 This is a cross-sectional view of the main parts showing the periphery of one magnetic pole of a rotor in a rotating electrical machine according to Embodiment 5 of the present invention.

[0118] exist Fig. 20 In the rotor core 71 of the rotor 70, three magnet insertion holes 23 for holding permanent magnets 22 constituting one magnetic pole are arranged in a V-shape with their circumferential spacing gradually expanding toward the outer diameter side. That is, two magnet insertion holes 23 are arranged in a row inclined toward the forward side of the rotation direction. The remaining magnet insertion hole 23 is inclined toward the backward side of the rotation direction. The first magnetic barrier 24 and the second magnetic barrier 25 are formed at both ends of the length direction of the long side of the cross-sectional rectangle of each magnet insertion hole 23. A third magnetic barrier 26 is formed between adjacent magnet insertion holes 23. The ribs 27 are formed in pairs across each third magnetic barrier 26. The first slit 29 is formed in the rotor core 71 in a manner opening to each third magnetic barrier 26 and the gap G.

[0119] In addition, other structures are configured similarly to those of the above-mentioned first embodiment.

[0120] In the fifth embodiment, the third magnetic barriers 26 are respectively formed between the permanent magnets 22 of each group adjacent in the circumferential direction among the three permanent magnets 22 arranged in a V shape constituting one magnetic pole. Two slits 29 are formed in the region of the rotor core 71 on the outer diameter side of the three permanent magnets 22 arranged in a V shape constituting one magnetic pole. The two slits 29 extend linearly in a manner inclined toward the forward side of the rotation direction R. The inner diameter side end of one slit 29 is located between the extension lines of a pair of ribs 27 formed by circumferentially separating the third magnetic barriers 26 formed between one group of circumferentially adjacent permanent magnets 22. The inner diameter side end of the other slit 29 is located between the extension lines of a pair of ribs 27 formed by circumferentially separating the third magnetic barriers 26 formed between another group of circumferentially adjacent permanent magnets 22.

[0121] Therefore, in the fifth embodiment, the same effects as those of the first embodiment can be obtained.

[0122] In the fifth embodiment, one magnetic pole is formed by three permanent magnets 22. Therefore, when centrifugal force acts on the permanent magnets 22, the stress acting on the rotor core 71 is dispersed. As a result, the stress generated in the rotor core 71 is reduced compared to the case where there is one third magnetic barrier 26. In addition, since there are two first slits 29, a higher torque can be obtained compared to the case where there is one first slit 29.

[0123] In the fifth embodiment, as in the first and fourth embodiments, the shape and arrangement of the first slits and the number of permanent magnets can be changed as appropriate if the outer diameter side end of the first slit is located between the extension lines of a pair of ribs.

[0124] In the fifth embodiment described above, a single rotor core is used. However, similarly to the third embodiment described above, a rotor core divided in the axial direction may be used.

[0125] In the fifth embodiment, the present invention is applied to a rotating electric machine used in a power running operation in which the first slit is inclined toward the forward side in the rotation direction, but the present invention may also be applied to a rotating electric machine used in a regenerative running operation in which the first slit is inclined toward the backward side in the rotation direction.

[0126] Implementation method 6.

[0127] Fig.21 It is a cross-sectional view showing a rotating electrical machine according to Embodiment 6 of the present invention.

[0128] exist Fig.21 In the figure, the rotary electric machine 1D includes a stator 10A and a rotor 80 which is coaxially arranged on the outer diameter side of the stator 10A with a gap G provided between the rotor 80 and the stator 10A.

[0129] The stator 10A includes an annular stator core 11A and a stator coil 12A mounted on the stator core 11A. The stator core 11A includes an annular core back yoke 110A and a plurality of core teeth 111A protruding radially outward from the outer peripheral surface of the core back yoke 110A. There are 18 core teeth 111A arranged at equal angular intervals in the circumferential direction, and the area between adjacent core teeth 111A is a slot 112A. The stator coil 12A is composed of a concentrated winding coil 120A formed by winding a conductive wire around each core tooth 111A.

[0130] The rotor 80 includes a rotor core 81 and 24 permanent magnets 22 embedded in the inner diameter side of the rotor core 81. On the inner diameter side of the rotor core 81, 12 pairs of magnet insertion holes 23 are formed at equal angular intervals in the axial direction through the rotor core 81. The magnet insertion holes 23 are holes with a rectangular cross section. The pairs of magnet insertion holes 23 are arranged in a V-shape with the circumferential spacing gradually expanding toward the inner diameter side. The magnet insertion holes 23 are formed in a hole shape with a rectangular cross section. In addition, the ends of the outer diameter side of the magnet insertion holes 23 constituting the pair are separated from each other in the circumferential direction.

[0131] The permanent magnet 22 is configured as a prism with a rectangular cross section equal to the magnet insertion hole 23. The permanent magnet 22 is magnetized in a manner orthogonal to the plane formed by the long side of the rectangular cross section. Thus, the first surface of the permanent magnet 22 formed by the long side of the rectangular cross section becomes the N pole, and the second surface on the opposite side of the first surface becomes the S pole. The permanent magnet 22 is inserted and retained in a manner that the same polarity faces the inner diameter side in each pair of magnet insertion holes 23 and in a manner that different polarities face the inner diameter side in the pairs of adjacent magnet insertion holes 23. That is, a pair of permanent magnets 22 arranged in a V shape with a circumferential spacing gradually expanding toward the gap G side constitutes one magnetic pole. In addition, the pair of permanent magnets 22 constituting one magnetic pole is buried on the outer diameter side of the rotor core 21, and 12 pairs are arranged at equal angular intervals in the circumferential direction. Thus, 12 magnetic poles are formed on the rotor 20.

[0132] The first magnetic barrier 24 is formed by extending the inner diameter side surface of the magnet insertion hole 23 formed by the short side of the cross-sectional rectangle in the longitudinal direction of the long side of the cross-sectional rectangle of the magnet insertion hole 23. The second magnetic barrier 25 is formed by extending the outer diameter side surface of the magnet insertion hole 23 formed by the short side of the cross-sectional rectangle in the longitudinal direction of the long side of the cross-sectional rectangle of the magnet insertion hole 23. The third magnetic barrier 26 is formed at a position between the second magnetic barriers 25 of the pair of magnet insertion holes 23. The first, second and third magnetic barriers 24, 25, 26 are respectively formed so as to penetrate the rotor core 21 in the axial direction.

[0133] Here, the second magnetic barrier 25 and a part of the third magnetic barrier 26 adjacent in the circumferential direction are located at the same radial distance from the axis of the rotating shaft of the rotor. At this position, the core area between the second magnetic barrier 25 and the third magnetic barrier 26 becomes a rib 27. In addition, the core area between the first magnetic barrier 24 and the inner peripheral surface of the rotor core 21 becomes a bridge arm 28.

[0134] The first slit 29 is formed in a core region of the rotor core 81 located on the inner diameter side of the pair of permanent magnets 22 arranged in a V-shape, that is, on the gap G side. The first slit 29 extends in a straight band shape from the third magnetic barrier 26 to the vicinity of the inner peripheral surface of the rotor core 81. The first slit 29 extends in a straight line shape inclined forward with respect to the rotation direction R. The outer diameter side end of the first slit 29, that is, the end on the third magnetic barrier 26 side, is located between the extension lines of the pair of ribs 27. The inner diameter side end of the first slit 29, that is, the end on the gap G side, is located near the inner peripheral surface of the rotor core 81.

[0135] In the rotating electrical machine 1D thus configured, the number of slots 112A of the stator 10A is 18, and the number of poles of the rotor 80 is 12. That is, the rotating electrical machine 1D is an outer rotor type rotating electrical machine with a pole-slot number of 2 to 3. The rotating electrical machine 1D is assumed to be used for power running.

[0136] In the sixth embodiment, the first slit 29 is provided in a core region on the inner diameter side of the pair of permanent magnets 22 arranged in a V-shape so as to be inclined toward the advancing side of the rotation direction R. The inner diameter side end of the first slit 29 is located between the extension lines of the pair of ribs 27 formed so as to sandwich the third magnetic flux barrier 26. Therefore, in the sixth embodiment, the same effects as those of the first embodiment can be obtained.

[0137] In the sixth embodiment, similarly to the first, fourth and fifth embodiments, if the outer diameter side end of the first slit is located between the extension lines of a pair of ribs, the shape and arrangement of the first slit and the number of permanent magnets can be changed as appropriate.

[0138] In the sixth embodiment described above, a single rotor core is used. However, similarly to the third embodiment described above, a rotor core divided in the axial direction may be used.

[0139] In the sixth embodiment, the present invention is applied to a rotating electric machine used in a power running operation in which the first slit is inclined toward the forward side in the rotation direction. However, the present invention may be applied to a rotating electric machine used in a regenerative running operation in which the first slit is inclined toward the backward side in the rotation direction.

[0140] In the above-described embodiments, the stator core and the rotor core are formed of a laminated iron core formed by laminating electromagnetic steel sheets. However, the stator core and the rotor core may be formed of a block iron core formed by using a block of a magnetic body.

[0141] Furthermore, in each of the above-described embodiments, the stator coil is formed of a concentrated winding coil, but the stator coil may be formed of a distributed winding coil.

[0142] In addition, in the above-mentioned embodiments, a 12-pole 18-slot, 2-to-3 system rotary electric machine is described, but the number of poles and slots of the rotary electric machine is not limited to the 2-to-3 system, and may be an 8-to-9 system, a 10-to-12 system, etc. The 8-to-9 system and the 10-to-12 system have the effect of increasing the winding coefficient compared to the 2-to-3 system, and can achieve an increase in torque and suppression of torque pulsation.

[0143] In the above-mentioned embodiments, the second magnetic barrier is provided on the third magnetic barrier side of each of the magnet insertion holes located on both sides of the third magnetic barrier in the circumferential direction, but the second magnetic barrier only needs to be provided on the third magnetic barrier side of the magnet insertion hole located in the first direction in the circumferential direction of the third magnetic barrier.

[0144] The present invention has been described in detail with reference to the preferred embodiments. However, it is self-evident that a person skilled in the art can obtain various modifications based on the basic technical concept and teaching of the present invention.

[0145] Description of Reference Numerals

[0146] 10, 10A stator; 11, 11A stator core; 12, 12A stator coil; 20, 20A, 20B, 20C, 20D, 20E, 50, 60, 70, 80 rotor; 21, 21A, 21B, 21C, 21D, 21E, 61, 71, 81 rotor core; 22 permanent magnet; 29, 29a, 29b first slit; 29A first slit; 29B first slit; 33 second slit; 51A first split rotor core; 51B second split rotor core; 112, 112A slot; G gap.

Claims

1. A rotating electrical machine, wherein: The rotating electrical machine has: a stator having a stator core and a stator coil; and a rotor having a rotor core disposed coaxially with the stator core with a gap therebetween, and a plurality of permanent magnet groups, each constituting one magnetic pole, embedded in the rotor core and disposed at equal angular intervals in a circumferential direction, A magnetic barrier is formed between a group of permanent magnets adjacent to each other in the circumferential direction among the permanent magnet groups constituting one magnetic pole. A pair of ribs is formed by the region of the rotor core between the adjacent set of permanent magnets and the magnetic barriers. A first slit is formed in a region of the rotor core on the air gap side in a radial direction of the permanent magnet group constituting one magnetic pole so as to bias the magnetic flux generated from the permanent magnet group constituting one magnetic pole toward the rotation direction of the rotor. The end of the first slit on the magnetic barrier side is located between the extension lines of the pair of ribs. A minimum distance between an end of the first slit on the magnetic barrier side and the magnetic barrier is shorter than a minimum distance between an end of the first slit on the magnetic barrier side and each of the adjacent sets of permanent magnets.

2. The rotating electrical machine according to claim 1, wherein: The first slit is composed of a plurality of first slits having at least one of different shapes and arrangements. The plurality of first slits are arranged dispersedly in the circumferential direction.

3. A rotating electrical machine, wherein: The rotating electrical machine has: a stator having a stator core and a stator coil; and a rotor having a rotor core disposed coaxially with the stator core with a gap therebetween, and a plurality of permanent magnet groups, each constituting one magnetic pole, embedded in the rotor core and disposed at equal angular intervals in a circumferential direction, A magnetic barrier is formed between a group of permanent magnets adjacent to each other in the circumferential direction among the permanent magnet groups constituting one magnetic pole. A pair of ribs is formed by the region of the rotor core between the adjacent set of permanent magnets and the magnetic barriers. A first slit is formed in a region of the rotor core on the air gap side in a radial direction of the permanent magnet group constituting one magnetic pole so as to bias the magnetic flux generated from the permanent magnet group constituting one magnetic pole toward the rotation direction of the rotor. The end of the first slit on the magnetic barrier side is located between the extension lines of the pair of ribs. The rotor core includes a plurality of split rotor cores split in the axial direction. The shape and arrangement of the first slits are the same in the same split rotor core, and at least one of the shape and arrangement of the first slits is different for each split rotor core.

4. The rotating electrical machine according to any one of claims 1 to 3, wherein: An end portion of the first slit on the magnetic barrier side is located in a circumferential region between extension lines of the pair of ribs.

5. The rotating electrical machine according to any one of claims 1 to 3, wherein: An end portion of the first slit on the magnetic barrier side is located in a circumferential region of the rotor core between extension lines of the pair of ribs extending toward the gap side.

6. The rotating electrical machine according to any one of claims 1 to 3, wherein: An end portion of the first slit on the magnetic barrier side extends toward the magnetic barrier.

7. The rotating electrical machine according to any one of claims 1 to 3, wherein: An end portion of the first slit on the gap side is located outside a circumferential region between extension lines of the pair of ribs.

8. The rotating electrical machine according to any one of claims 1 to 3, wherein: The first slit is connected to the magnetic barrier.

9. The rotating electrical machine according to any one of claims 1 to 3, wherein: A magnet end flux barrier is formed between the adjacent set of permanent magnets and the pair of ribs.

10. The rotating electrical machine according to any one of claims 1 to 3, wherein: The permanent magnet group constituting one magnetic pole is arranged in a V-shape with the circumferential spacing gradually increasing toward the gap side. The magnetic barrier is formed in a valley portion of the permanent magnet group that is arranged in a V-shape and constitutes one magnetic pole.

11. The rotating electrical machine according to any one of claims 1 to 3, wherein: The stator coil is a concentrated winding coil.

12. The rotating electrical machine according to any one of claims 1 to 3, wherein: The first slit is inclined with respect to a direction of a force acting on the rotor in a circumferential direction when electricity is supplied to the stator coil.

13. The rotating electrical machine according to any one of claims 1 to 3, wherein: The permanent magnet group constituting one magnetic pole is composed of two permanent magnets.

14. The rotating electrical machine according to any one of claims 1 to 3, wherein: The second slit is a region of the rotor core on the air gap side in the radial direction of the permanent magnet group constituting one magnetic pole, and is formed on the advancing side in the rotation direction of the rotor with respect to the first slit.

15. The rotating electrical machine according to any one of claims 1 to 3, wherein: The minimum width portion of the first slit is smaller than the circumferential width of each of the pair of ribs.

16. The rotating electrical machine according to any one of claims 1 to 3, wherein: The ratio of the number of poles of the rotor to the number of slots of the stator is 2:3.

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