JP2011097783A - Rotor of rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor of an embedded magnet type rotary electric machine having a multilayered permanent magnet, which improves output by forming flux barriers into a proper shape. <P>SOLUTION: Each pole includes surface-side flux barriers and center-side flux barriers formed with a gap in a radial direction. Each flux barrier includes: magnet embedding parts 42, 52 in which a surface-side permanent magnet 3A and a center-side permanent magnet 3B are embedded respectively; and side barrier parts 43, 44, 53, 54 located on both sides in a rotating direction of the magnet embedding parts. The surface-side permanent magnet and the center-side permanent magnet are parallel to each other in the direction orthogonal to the radial direction. The shortest distance between the side barrier part of the surface-side flux barrier and the side barrier part of the center-side flux barrier is larger than that between the surface-side permanent magnet and the center-side permanent magnet. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a rotor having a flux barrier forming a permanent magnet synchronous rotating electric machine.

  The torque of the embedded magnet synchronous motor (IPMSM) that forms the flux barrier is the sum of the magnet torque and the reluctance torque. The reluctance torque is proportional to the difference between the q-axis inductance and the d-axis inductance. It is known that it is proportional to the stator interlinkage magnetic flux by the embedded permanent magnet (see, for example, Non-Patent Document 1). This Non-Patent Document 1 further discloses that the permanent magnets are multilayered. The d-axis inductance due to the multi-layered permanent magnet hardly changes and the q-axis inductance and the armature interlinkage magnetic flux of the permanent magnet are greatly increased. It is described that the rate of increase in the armature flux linkage of the magnet becomes very small and tends to saturate.

  As a rotor of an embedded magnet type rotating electrical machine, the barriers on both sides in the circumferential direction of the magnet housing hole are deeper than the tangential line passing through the side end that is the deepest point of the side surface on both sides in the circumferential direction of the magnet housing hole. There is also known one in which an output at the time of high-speed rotation is improved by providing a flange (see Patent Document 1). In Patent Document 1, the problem is to improve the output by digging the barrier on the side of the magnet deeper than the magnet, but it is not disclosed that the permanent magnet is multilayered, and the multilayered permanent is not disclosed. Improvement in output in a structure having a magnet is not a problem.

  Furthermore, a plurality of permanent magnets having a predetermined thickness are mounted inside the rotor, and are extended to the vicinity of the surface of the rotor so as to be continuous with the circumferential end of each permanent magnet, and larger than the thickness of the permanent magnet. There is also known a technique for achieving high efficiency by reducing both iron loss and copper loss by having a non-magnetic portion having a circumferential length (see Patent Document 2). Note that Patent Document 2 discloses a rotor in which an auxiliary permanent magnet having an arcuate cross section is further provided outside the permanent magnet having an arcuate cross section. However, the flux barrier is not considered for this auxiliary permanent magnet, and substantially the same idea as that having a single layer permanent magnet is applied. The output improvement in the structure which has is not made into the subject.

Japanese Patent Laying-Open No. 2005-341655 (paragraph number [0007-0009], FIG. 1) JP 2002-44888 (paragraph numbers [0011, 0107-0110], FIG. 1, FIG. 19)

Takeda Yoji et al., “Design and Control of Embedded Magnet Synchronous Motor”, Ohmsha, pp. 9-13, 89-94

  In view of the above circumstances, an object of the present invention is to improve the output of a rotor of an embedded magnet type rotating electrical machine having multilayered permanent magnets by making the shape of a flux barrier appropriate.

In order to achieve the above object, a rotor of a rotating electrical machine having a permanent magnet multilayer structure according to the present invention comprises a surface side flux barrier and a center side flux barrier formed at intervals in the radial direction of the rotation axis. The surface-side flux barrier and the center-side flux barrier are each composed of a magnet-embedded portion for embedding a permanent magnet and side barrier portions located on both sides in the rotational direction of the magnet-embedded portion, The magnet embedded so that the surface side permanent magnet embedded in the magnet embedded portion of the side flux barrier and the center side permanent magnet embedded in the magnet embedded portion of the center side flux barrier are parallel to each other in a direction perpendicular to the radial direction Part is formed and the surface side permanent than the shortest distance between the side barrier part of the surface side flux barrier and the side barrier part of the center side flux barrier. Towards the distance between the stone and the center-side permanent magnet is configured to be larger.
In the present application, the “rotary electric machine” is used as a concept including a motor (electric motor), a generator (generator), and a motor / generator that functions as both a motor and a generator as necessary.

  The important point of view in the configuration of the present invention described above is that it is sufficient to pass the so-called q-axis magnetic flux between the side barrier portions, whereas the q-axis magnetic flux is between the permanent magnets, that is, between the magnet embedded portions. In addition, it is necessary to pass a magnetic flux from the permanent magnet, and magnetic saturation occurs if a sufficient magnetic flux path is not secured. According to the configuration of the present invention in consideration of this viewpoint, a sufficient width can be ensured with respect to the region for the magnetic flux path created between the surface side permanent magnet and the center side permanent magnet. Thus, magnetic saturation caused by crossing of the magnetic flux from the stator winding and the magnetic flux generated from the magnet is suppressed. As a result, the difference between the q-axis inductance: Lq and the d-axis inductance: Ld: (Lq−Ld) can be optimized and the maximum torque can be improved.

  In such a rotor of the rotating electric machine, the radial length of the boundary region of the side flux barrier in the center side flux barrier with respect to the magnet embedded portion is larger than the thickness in the radial direction of the center side permanent magnet. It is preferable that the surface side edge of the boundary region of the barrier portion is located on the radial surface side of the surface side edge of the center permanent magnet. With this configuration, the distance between the surface-side permanent magnet and the center-side permanent magnet can be increased, and d-axis inductance: Ld can be reduced. Therefore, the difference: (Lq−Ld) is also increased, and the maximum Torque can be improved. Further, by increasing the radial length of the side barrier portion, the magnet leakage flux is reduced and the magnet torque is improved.

  In the structure of the rotor of the rotating electrical machine described above, the boundary region of the side flux barrier with respect to the magnet embedded portion in the center side flux barrier has a larger radial cross sectional area than a radial cross sectional area of the central permanent magnet. It is also suitable to have a portion. The size and shape that the radial cross-sectional area of the boundary region of the flux barrier extending from the permanent magnet to the rotor surface with respect to the magnet buried portion of the side barrier portion is larger than the radial cross-sectional area of the permanent magnet is the surface side permanent magnet. And the possibility of increasing the width of the magnetic flux path between the center permanent magnet and the center side permanent magnet. Further, by reducing the d-axis inductance Ld, the difference between the axis inductance Lq and the d-axis inductance Ld: (Lq−Ld) can be increased.

  With respect to the q-axis magnetic flux path that passes between the surface-side permanent magnet and the center-side permanent magnet, it is separated from the permanent magnet with a step located on the center side from the magnetic flux path area between the surface-side permanent magnet and the center-side permanent magnet. It is conceivable to adjust the difference (Lq−Ld) between the q-axis inductance: Lq and the d-axis inductance: Ld by creating a going magnetic flux path region. In order to achieve this, in one preferred embodiment of the present invention, the boundary region of the side barrier portion with respect to the magnet embedded portion rises from the circumferential end of the magnet embedded portion to the surface side in the radial direction. It is comprised so that it may have a part. As a result of such a configuration, a flux barrier other than the magnetic flux path that is the path of the two magnetic fluxes of the q-axis magnetic flux and the magnet magnetic flux becomes a flux barrier, which inhibits the d-axis magnetic flux and reduces the d-axis inductance: Ld.

  Since the rotor according to the present invention employs a configuration in which a flux barrier is formed of a plurality of layers, there may be a problem in strength. In order to solve such a problem, in one of the preferred embodiments of the present invention, a radial bridge that connects the walls facing the radial direction of the boundary peripheral wall forming the side barrier portion is a side barrier. Provided in the department.

  As the embedded permanent magnet, it is preferable to use a neodymium magnet having a strong magnetic force. In this case, considering the moldability of the neodymium magnet and the fact that the flux barrier is formed by punching, the permanent magnet has the same shape. In addition, the cross section with respect to the axial direction is preferably rectangular. However, in the present invention, the neodymium magnet is not limited as the embedded permanent magnet, and other magnet materials can be used. Further, when the side barrier portions positioned on both sides of the magnet embedded portion with the magnet embedded portion interposed therebetween are configured to be symmetrical with respect to the radial line, the flux barrier is particularly formed by punching. This is convenient, and since the magnetic flux lines are also symmetric, it is convenient for motor control.

  Considering that the q-axis magnetic flux path flowing between the surface-side permanent magnet and the center-side permanent magnet shifts to the stator teeth on the rotor surface, in order to ensure a smooth flow of the q-axis magnetic flux path, The shortest length between the side barrier portion of the surface side flux barrier and the side barrier portion of the center side flux barrier is longer than the circumferential length of one tooth of the stator of the corresponding rotating electrical machine, preferably A configuration in which the shortest length is about one pitch is preferable.

It is a perspective view including the tomographic illustration part of the rotary electric machine which uses the rotor which concerns on this invention as a component. It is a top view of a rotary electric machine. It is an enlarged plan view showing a part of the rotating electrical machine. It is explanatory drawing which has shown the relationship between the space | interval of a two-layer permanent magnet, (Lq-Ld), and maximum torque with a diagram. It is a magnetic flux diagram which shows the magnetic flux produced at the time of rotor rotation rotation, (a) shows magnet magnetic flux, (b) is a magnetic flux diagram which shows winding magnetic flux, (c) is magnet magnetic flux and winding magnetic flux. Is a combination.

  A rotor 2 of a rotating electrical machine 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the rotating electrical machine 1 is configured as a synchronous motor (IPMSM) having a rotation axis X and having an embedded magnet structure, and includes a rotor 2 and a stator 6. Hereinafter, unless otherwise specified, the terms “axial direction”, “radial direction”, and “circumferential direction” refer to the “axial direction”, “radial direction”, and “circumferential direction” of the axis X. A plurality of permanent magnets 3 are embedded in the rotor 2, and a stator coil 61 is attached to the stator 6. The stator 6 is fixed to the inner surface of a case (not shown). The stator 6 has a stator coil 61 and a stator core 62. The stator core 62 has a plurality of teeth 64 formed at regular intervals in the circumferential direction on the inner peripheral surface side, and a groove-like slot 63 is created between the teeth 64. The stator coil 61 is wound in the plurality of slots 63. In the present embodiment, the stator core 62 is configured by laminating a plurality of electromagnetic steel plates, and is formed in a substantially cylindrical shape.

  The rotor 2 includes a substantially cylindrical rotor core 4 and end plates 4 a attached to both ends of the rotor core 4 in the axial direction. Although not shown, the rotor 2 includes a rotor shaft fixed so as to rotate integrally with the rotor core 4, and the rotor shaft is supported by the case so as to be rotatable around the rotation axis X. The rotor core 4 is substantially formed by stacking a large number of core forming punching plates (hereinafter simply referred to as “rotor plates”) 4 formed in a substantially annular plate shape from a thin electromagnetic steel sheet or the like by punching or the like in the axial direction. It is configured in a cylindrical shape.

  As shown in FIGS. 2 and 3, the rotor plate 40 constituting the rotor 2 is divided into a plurality of sectors (sections) having the same shape and form in the circumferential direction, and in this embodiment, eight sectors. Can be considered. Therefore, only the configuration of one sector will be described here. In this sector, a surface-side flux barrier 41 and a center-side flux barrier 51 are formed that are spaced apart in the radial direction of the rotation axis X. The surface-side flux barrier 41 is located in the vicinity of the outer peripheral surface of the rotor 2, and the center-side flux barrier 51 is in the vicinity of the outer peripheral surface of the rotor 2. ). The surface-side flux barrier 41 includes a surface-side magnet embedded portion 42 in which the surface-side permanent magnet 3A having a rectangular cross section is embedded, and a surface-side side barrier connected to both sides of the surface-side magnet embedded portion 42 along the rotation direction. It consists of parts. Of these two surface side barrier portions, the one located on the front side of the surface side magnet buried portion 42 in the counterclockwise direction of rotation in FIG. The one located on the rear side in the direction is referred to as a surface side second side barrier portion 44. However, when it is not necessary to distinguish the surface side second barrier portion 44, the name of the surface side side barrier portion is simply used. Similarly, the center-side flux barrier 51 includes a center-side magnet embedded portion 52 in which the center-side permanent magnet 3B having a rectangular cross section is embedded, and a surface side side barrier portion connected to both sides of the center-side magnet embedded portion 52. Become. Of these two central side barrier portions, the one located on the front side of the central magnet buried portion 52 in the counterclockwise direction of rotation in FIG. The side located on the rear side in the direction is referred to as the center-side second side barrier portion 54, but when it is not necessary to distinguish between them, the name of the center-side side barrier portion is simply used.

  Since the surface-side permanent magnet 3A is embedded in the surface-side magnet embedded portion 42 and the center-side permanent magnet 3B is embedded in the center-side magnet embedded portion 52 with substantially no gap, the surface-side magnet embedded portion 42 and the surface-side permanent magnet are embedded. The shape and size of the magnet 3A and the shape and size of the center-side magnet buried portion 52 and the center-side permanent magnet 3B are substantially the same, and both the cross-sectional shape with respect to the axial direction (the cross-sectional shape perpendicular to the axial direction) is the same. It is a rectangle. Further, the surface-side permanent magnet 3A and the center-side permanent magnet 3B have the same cross-sectional shape. The surface-side permanent magnet 3A and the center-side permanent magnet 3B are formed so as to extend in parallel to each other in a direction orthogonal to the radial direction when viewed from the rotation axis X direction. Accordingly, the surface side magnet buried portion 42 and the center side magnet buried portion 52 are also formed to extend in parallel with each other.

  In this embodiment, the surface-side permanent magnet 3A and the center-side permanent magnet 3B arranged in two layers in the radial direction are magnetized in the radial direction of the rotor 2, and thus the permanent magnet set 3 arranged in two layers in this way. However, the polarity with respect to the stator 6 is alternately reversed along the circumferential direction of the rotor 2. That is, the polarity of each permanent magnet set is set so that N poles and S poles appear alternately along the circumferential direction of the rotor 2 when viewed from the outside in the radial direction of the rotor 2. That is, the surface side flux barrier 41 and the center side flux barrier 51 are provided corresponding to each pole of the permanent magnet set 3.

  In this embodiment, as can be understood from FIG. 3, the lengths of the surface-side permanent magnet 3 </ b> A and the center-side permanent magnet 3 </ b> B are about two pitches of the teeth 64 of the stator core 62 as viewed from the axial center X direction. . Further, the front side first side barrier portion 43 and the front side second side barrier portion 44 of the front side flux barrier 41 extend so that the tips thereof face the slots 63 of the stator core 62, and The distance is about 3 pitches of the teeth 64. On the other hand, the center-side first side barrier portion 53 and the center-side second barrier portion 54 of the center-side flux barrier 51 also extend so that their tips face the slots 63 of the stator core 62. The distance is about 5 pitches of the teeth 64. Therefore, the distance between both ends of the q-axis magnetic flux path created between the surface side flux barrier 41 and the center side flux barrier 51 is about 4 pitches. As a result, the center-side flux barrier 51 as a whole is arranged substantially along a curved line that protrudes toward the rotation axis X side (in the radial direction). The surface-side flux barrier 41 is not as clear as the center-side flux barrier 51, but has a tendency to substantially follow a curved line that is convex toward the rotation axis X side.

  The q-axis magnetic flux path passing between the surface side flux barrier 41 and the center side flux barrier 51 is an intermediate magnetic flux path located in a region sandwiched between the surface side magnet buried part 42 and the center side magnet buried part 52 and its It consists of side magnetic flux paths located on both sides in the rotational direction (circumferential direction). In this embodiment, the surface side first side barrier portion 43 and the surface side second side barrier portion 44 have a shape that is symmetrical with respect to the radial line with the surface side magnet buried portion 42 interposed therebetween, The center-side first side barrier part 53 and the center-side second side barrier part 54 have a shape that is symmetrical with respect to the radial line with the center-side magnet embedded part 52 interposed therebetween.

  Further, the rotor 2 is characterized by the surface side first side barrier portion 43 or the surface side second side barrier portion 44 of the surface side flux barrier 41 and the center side first side of the center side flux barrier 51. The distance between the surface side permanent magnet 3A and the center side permanent magnet 3B: D1 is larger than the distance D2 between the side barrier portion 53 or the center side second side barrier portion 54.

  Further, as is apparent from FIG. 3, the radial direction of the boundary region S with respect to the center side magnet buried portion 52 of the center side first side barrier portion 53 or the center side second side barrier portion 54 in the center side flux barrier 51. In this embodiment, the length is set larger than the radial thickness of the central permanent magnet 3B. The boundary region S described here is a region where the center side magnet barrier portion 52 in the center side flux barrier 51 transitions from the center side first side barrier portion 53 or the center side second side barrier portion 54. 3, the length from the side of the center-side permanent magnet 3 </ b> B to the surface of the rotor 2 in the center-side first side barrier portion 53 or the center-side second side barrier portion 54. It can be defined as having about one third of the length of the central permanent magnet side. Further, the surface side edge of the boundary region S of the center-side first side barrier portion 53 or the center-side second side barrier portion 54 is arranged on the radial surface side (radial direction side) from the surface-side edge of the center-side permanent magnet 3B. It is arranged to be located on the outside. In terms of the radial cross-sectional area, the boundary region of the center side flux barrier 51 with respect to the center side magnet buried portion 52 of the center side first side barrier portion 53 or the center side second side barrier portion 54 is the center side permanent magnet. It has a portion where the radial cross-sectional area is larger than the radial cross-sectional area of 3B. As apparent from the enlarged illustration of FIG. 3, the center-side magnet burying portion 52 of the center-side first side barrier portion 53 or the center-side second side barrier portion 54 is obtained from the above-described dimensions and shape of the center-side flux barrier 51. The boundary region S with respect to includes a rising portion S1 rising from the circumferential end of the center side magnet buried portion 52 to the surface side in the radial direction. The rising portion S1 is formed so as to rise substantially perpendicularly to the surface side edge of the central permanent magnet 3B. The rotor radial direction surface side end portion of the rising portion S1 is connected to a surface substantially orthogonal to the rotor radial direction. The rising height in the radial direction of the rising portion S1 is equal to or greater than the thickness of the central permanent magnet 3B. Further, a falling portion S2 is formed on the rotation axis X side of the rising portion S1. The rising portion S1 and the falling portion S2 are provided on both sides of the center side magnet buried portion 52, and projections 57, 58 are formed on the boundary surface between each falling portion S2 and the center side magnet buried portion 52, It is used for fixing the position of the center side permanent magnet 3B. Similarly, projections for fixing the position of the surface-side permanent magnet 3A are also provided on the boundary surfaces of the surface-side magnet buried portion 42 with the surface-side first and second side barrier portions 43 and 44 on both sides thereof. .

  Further, the shortest distance between the surface side first side barrier part 43 of the surface side flux barrier 41 and the center side first side barrier part 53 of the center side flux barrier 51, and the surface side of the surface side flux barrier 41 The shortest distance between the two side barrier portions 44 and the center side second side barrier portion 54 of the center side flux barrier 51 is substantially the same as or longer than the circumferential length of one tooth 64 of the stator 6. It has become. That is, in the rotor 2, the side magnetic flux path that is the q-axis magnetic flux path area excluding the intermediate magnetic flux path that is the q-axis magnetic flux path area between the surface-side permanent magnet 3A and the center-side permanent magnet 3B of the q-axis magnetic flux path. The narrowest width is substantially the same as or longer than the circumferential length of one tooth 64. Thereby, the q-axis magnetic flux from the tooth 64 can appropriately pass through the q-axis magnetic flux path.

  Due to the shape and dimensions of the surface side flux barrier 41 and the center side flux barrier 51 described above, the q-axis magnetic flux path secures a sufficient cross-sectional area as a path for the magnetic flux from each tooth 64, The magnetic flux path has a larger cross-sectional area than the side magnetic flux path. In other words, the cross-sectional area of the intermediate magnetic flux path is ensured to be larger than the cross-sectional area for passing the magnetic flux from each tooth 64. Thereby, in this region, magnetic saturation caused by the crossing of the q-axis magnetic flux and the magnetic flux from the permanent magnet 3 is suppressed. As a result, the q-axis inductance: Lq is higher than the d-axis inductance: Ld, and the difference between the q-axis inductance: Lq and the d-axis inductance: Ld is increased. As a result, since the motor torque is improved, it is possible to reduce the number of permanent magnets or increase the torque with the same amount of permanent magnets while securing the same torque as compared with the conventional case.

  Since the cross section of the center side first side barrier portion 53 and the center side second side barrier portion 54 has a size that cannot be ignored in terms of strength, in this embodiment, the respective side barriers The radial bridges 55 and 56 are respectively connected to the center side first side barrier part 53 and the center side second side barrier part 54 so as to connect the walls facing the radial direction of the boundary peripheral wall forming the parts 53 and 54. Is provided. The radial bridges 55 and 56 in the rotor plate 4 are formed as remaining portions after the center-side first side barrier portion 53 and the center-side second side barrier portion 54 are formed by stamping or the like. Therefore, it has the same thickness as the rotor plate 4. Since the bridges 55 and 56 are provided in the central side barrier portions 53 and 54 that are large in the radial direction in this way, the length of the bridges 55 and 56 is lengthened, and the magnetic flux path from the permanent magnet 3 is lengthened. Leakage magnetic flux can be reduced.

As described above, the rotating electrical machine 1 having a configuration as a permanent magnet synchronous motor (PMSM) is provided with the flux barriers 41 and 51 serving as magnetic flux barriers, and thus has magnetic saliency along the circumferential direction. As a result, the reluctance changes according to the rotational position of the rotor 2 to generate a reluctance torque. Magnet torque is generated by the stator 6 and the permanent magnet 3 of the rotor 2. Therefore, the motor torque of the rotating electrical machine 1 is the sum of the magnet torque and the reluctance torque. According to Non-Patent Document 1 described above, motor torque: T is represented by the following equation.
[Formula 1]
T = Pn..PHI.a.iq + Pn (Ld-Lq) id.iq
here,
Pn: Number of pole pairs Φa: Effective value of stator interlinkage magnetic flux by permanent magnet multiplied by route 3 iq: q-axis current component id: d-axis current component Ld: d-axis inductance Lq: q-axis inductance When the magnitude of the current vector: Ia and the phase: β are used, the following expression is obtained.
[Formula 2]
T = Pn {Φa · Ia · cos β + ½ (Lq−Ld) · Ia ² · sin 2β}
In the above two motor torque equations, the first term represents the magnet torque, and the second term represents the reluctance torque generated by the saliency.

  As can be understood from Equation 2, a large motor torque can be produced by appropriately determining the shape dimensions of the barrier fluxes 41 and 51 so that (Lq−Ld) becomes large. For example, in the rotor structure described above in the present embodiment, when only the radial position of the center side magnet burying portion 52 that is the second layer is changed, that is, only the radial position of the center side permanent magnet 3B is changed as a result. As a result, the maximum torque that can be obtained also changes. Hereinafter, this will be described with reference to FIG. FIG. 4 shows experimentally shown changes in maximum torque at three different radial positions of the central permanent magnet 3B, and changes in the difference between the q-axis inductance and the d-axis inductance (Lq−Ld) at each position. It is shown together. One of the three radial positions is the same as that of the embodiment described with reference to FIGS. 1 to 3, and the distance D1 between the surface-side permanent magnet 3A and the center-side permanent magnet 3B is the first side. The shortest distance between the side barrier portions 43 and 44 or the second side barrier portions 53 and 54: D2, that is, about 1.5 times the minimum width of the above-described side magnetic flux path. The other is a positional relationship in which the distance: D1 is approximately equal to the shortest distance: D2, and the other is a positional relationship in which the distance: D1 is approximately 2.3 times the shortest distance: D2.

  From the experimental results shown in FIG. 4, the distance between the surface side permanent magnet 3A and the center side permanent magnet 3B: D1 and the shortest distance between the first side barrier portions 43 and 44 or the second side barrier portions 53 and 54. It can be understood that (Lq−Ld) is increased and the maximum torque is increased by making the distance: D1 larger than the shortest distance: D2 compared to the form in which the distance: D2 is equal. In particular, the torque performance is optimized by making the distance D1 about twice the shortest distance D2.

  The reason for the above phenomenon will be described with reference to FIG. FIG. 5A is a magnetic flux diagram showing the magnet magnetic flux during driving rotation, FIG. 5B is a magnetic flux diagram showing the winding magnetic flux during driving rotation, and FIG. It is a magnetic flux diagram which combined magnet magnetic flux and winding magnetic flux. When torque is generated, both the magnet magnetic flux and the winding magnetic flux pass through the rotor 2, and in particular, the magnetic flux and the winding magnetic flux are generated in the region between the surface side permanent magnet 3A and the center side permanent magnet 3B. Intersect. For this reason, magnetic saturation is likely to occur in an intermediate magnetic flux path that is a region between the surface-side permanent magnet 3A and the center-side permanent magnet 3B. Therefore, by making the distance: D1 larger than the shortest distance: D2, that is, by lowering the central permanent magnet 3B, which is the permanent magnet 3 in the second layer, between the surface permanent magnet 3A and the central permanent magnet 3B. The magnetic path cross-sectional area of the intermediate magnetic flux path is sufficient. Thereby, the possibility of magnetic saturation due to the intersection of the magnet magnetic flux and the winding magnetic flux can be suppressed, and as a result, a decrease in the q-axis inductance: Lq can be prevented.

[Another embodiment]
(1) In the above embodiment, the flux barrier and the permanent magnet 3 are arranged in two layers, but in the present invention, it is only limited to a plurality of layers, and it is arranged in multiple layers other than two. Configurations that are made are not excluded.
(2) In the above embodiment, the permanent magnet 3 and the magnet buried portions 42 and 52 of the flux barrier extend in the direction perpendicular to the radial direction, that is, in the tangential direction of the rotor 2. You may arrange | position so that it may extend in the direction which inclines with respect to.
(3) In the embodiment described above, the radial bridges 55 and 56 that bridge the opening space of the side barrier portion 53 in the radial direction are the center side first side barrier portion 53 and the center side second side barrier portion 54. One is provided for each, but a plurality may be provided.

  The rotating electrical machine having the rotor structure according to the present invention can be applied not only to a vehicle mounted rotating electrical machine such as an electric vehicle and a hybrid vehicle but also to a rotating electrical machine used for various purposes.

2: Rotor 3: Permanent magnet 3A: Surface side permanent magnet 3B: Center side permanent magnet 4: Rotor core 40: Rotor plate 41: Surface side flux barrier 42: Surface side magnet buried portion (magnet buried portion)
43: Surface side first side barrier part (surface side side barrier part)
44: Front side second side barrier part (front side side barrier part)
51: Center-side flux barrier 52: Center-side magnet buried portion (magnet buried portion)
53: Center side first side barrier part (center side side barrier part)
54: Center side second side barrier section (center side side barrier section)
55: radial bridge 56: radial bridge 57: protrusion 58: protrusion 6: stator 61: stator coil 62: stator core 63: slot 64: teeth

Claims (8)

Each surface has a surface side flux barrier and a center side flux barrier formed at intervals in the radial direction of the rotation axis, and each of the surface side flux barrier and the center side flux barrier has a permanent magnet embedded therein. The surface-side permanent magnet embedded in the magnet-embedded portion of the surface-side flux barrier and the magnet-embedded portion of the center-side flux barrier The magnet embedded portion is formed so that the central permanent magnet embedded in the portion is parallel to each other in the direction orthogonal to the radial direction,
Rotation in which the distance between the surface side permanent magnet and the center side permanent magnet is larger than the shortest distance between the side barrier part of the surface side flux barrier and the side barrier part of the center side flux barrier. Electric rotor.   The radial length of the boundary region with respect to the magnet buried portion of the side barrier portion in the central flux barrier is larger than the radial thickness of the central permanent magnet, and the surface side of the boundary region of the side barrier portion 2. The rotor of a rotating electrical machine according to claim 1, wherein the edge is positioned on a radial surface side with respect to a surface side edge of the central permanent magnet.   The boundary region with respect to the magnet buried portion of the side barrier portion in the center-side flux barrier has a portion having a radial cross-sectional area larger than a radial cross-sectional area of the center-side permanent magnet. The rotor of the described rotating electrical machine.   The rotating electrical machine according to any one of claims 1 to 3, wherein a boundary region of the side barrier portion with respect to the magnet embedded portion has a rising portion that rises from the circumferential end of the magnet embedded portion to the surface side in the radial direction. Rotor.   The rotating electrical machine according to any one of claims 1 to 4, wherein a radial bridge that connects walls facing each other in a radial direction of a boundary peripheral wall forming the side barrier portion is provided in the side barrier portion. Rotor.   The rotor for a rotating electrical machine according to any one of claims 1 to 5, wherein a cross section of the center-side permanent magnet and the surface-side permanent magnet with respect to the axial direction is rectangular and has the same shape.   The rotating electrical machine according to any one of claims 1 to 6, wherein the side barrier portions positioned on both sides of the magnet embedded portion with the magnet embedded portion interposed therebetween have shapes that are symmetrical with respect to a radial line. Rotor. The shortest distance between the side barrier portion of the surface side flux barrier and the side barrier portion of the center side flux barrier is longer than the circumferential length of one tooth of the stator of the corresponding rotating electric machine. The rotor of the rotating electrical machine according to any one of 7.

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