JP2020036518A - Variable magnetic flux dynamo-electric machine - Google Patents

Abstract

To provide a technology capable of improving magnetic flux characteristics of permanent magnets constituting one magnetic pole, without increasing the cost of manufacture.SOLUTION: A variable magnetic flux dynamo-electric machine has a stator (1) generating a revolving magnetic field, and a rotor (2) placed via an air gap (9) of a prescribed width or the stator (1). The rotor (2) of the variable magnetic flux dynamo-electric machine has a rotor core (12), multiple flux barriers (5) provided in the hoop direction in the rotor core (12), and magnet fitting holes (30) placed between the multiple flux barriers (5) and fitted with permanent magnets (3). In the magnet fitting holes (30), the depth from the outer peripheral surface of the rotor core (12) in the hoop direction center on the outer peripheral side is set shallower than the depth from the outer peripheral surface of the rotor core (12) at the hoop direction end on the outer peripheral side, and multiple permanent magnets (permanent magnet pieces) of different magnetic characteristics are fitted side by side in the hoop direction to constitute one magnetic pole.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a variable magnetic flux type rotating electric machine.

  2. Description of the Related Art Conventionally, in a rotor of an interior permanent magnet synchronous motor, a technique has been known in which the shape of a permanent magnet constituting one magnetic pole is formed into a circular arc shape that is convex toward the outer peripheral side to improve magnetic flux characteristics (see Patent Document 1). ).

JP 2017-225277 A

  However, in the patent document, since one magnetic pole is composed of one (integral type) permanent magnet in principle, the magnetic flux characteristics contributing to an improvement in output and torque are further reduced due to restrictions on the manufacturable size of the arc-shaped magnet. There is a problem that it is difficult to improve. Further, there is also a problem that the manufacturing cost of the integrally formed arc-shaped magnet increases as compared with, for example, a permanent magnet on a flat plate.

  An object of the present invention is to provide a technique capable of improving the magnetic flux characteristics of a permanent magnet constituting one magnetic pole without increasing the manufacturing cost.

  A variable magnetic flux type rotating electric machine according to the present invention is a variable magnetic flux type rotating electric machine having a stator for generating a rotating magnetic field, and a rotor arranged via an air gap having a predetermined width with the stator. A rotor provided in the variable magnetic flux type rotating electric machine includes a rotor core, a plurality of flux barriers provided in the rotor core in a circumferential direction, and a magnet disposed between the plurality of flux barriers and fitted with a permanent magnet. And a fitting hole. The magnet fitting hole is set so that the depth from the outer circumferential surface of the rotor core at the circumferential center on the outer circumferential side is smaller than the depth from the outer circumferential surface of the rotor core at the circumferential end on the outer circumferential side, A plurality of permanent magnets having different magnetic properties are fitted side by side in the circumferential direction to form one magnetic pole.

  According to the present invention, since one magnetic pole is constituted by a plurality of permanent magnets having different magnetic characteristics, the magnetic flux characteristics of the permanent magnet constituting one magnetic pole can be further improved without being restricted by a manufacturable size. In addition, by forming one magnetic pole with a plurality of permanent magnets, it is not necessary to manufacture an integrated permanent magnet that matches the shape of the magnet fitting hole, so that an increase in manufacturing cost can be suppressed.

FIG. 1 is a cross-sectional view perpendicular to the axial direction of the variable magnetic flux type rotating electric machine according to the first embodiment. FIG. 2 is a diagram for explaining characteristics of the variable magnetic flux leakage motor. FIG. 3 is an enlarged view of FIG. 1 around the q axis shown in FIG. FIG. 4 is a characteristic diagram illustrating a relationship between a current flowing through a stator winding and a torque of the variable magnetic flux type rotating electric machine according to the first embodiment. FIG. 5 is a characteristic diagram showing a relationship between a current flowing through a stator winding of the variable magnetic flux type rotating electric machine of the first embodiment and a torque constant. FIG. 6 is a diagram illustrating a relationship between the rotation speed and the torque of the rotating electric machine. FIG. 7 is a diagram illustrating the configuration of the permanent magnet according to the first embodiment. FIG. 8 is a diagram illustrating a leakage magnetic flux variable width according to the configuration of the permanent magnet of the first embodiment. FIG. 9 is a diagram illustrating another example of the configuration of the permanent magnet of the first embodiment. FIG. 10 is a diagram illustrating a leakage magnetic flux variable width according to another example of the configuration of the permanent magnet of the first embodiment. FIG. 11 is a diagram illustrating the configuration of the permanent magnet according to the second embodiment. FIG. 12 is a diagram illustrating another example of the configuration of the permanent magnet according to the second embodiment. FIG. 13 is a diagram illustrating another example of the configuration of the permanent magnet according to the second embodiment in which the residual magnetic flux density is considered. FIG. 14 is a view for explaining a permanent magnet composed of an even number of permanent magnet pieces according to the third embodiment. FIG. 15 is a diagram illustrating a spatial magnetomotive force waveform accompanying rotation of the rotor according to the third embodiment. FIG. 16 is a diagram illustrating an FFT result of a spatial magnetomotive force waveform according to the third embodiment. FIG. 17 is a diagram illustrating a permanent magnet including an odd number of permanent magnet pieces according to the third embodiment. FIG. 18 is a diagram illustrating another example of the spatial magnetomotive force waveform associated with the rotation of the rotor according to the third embodiment. FIG. 19 is a diagram illustrating an FFT result of another example of the spatial magnetomotive force waveform according to the third embodiment. FIG. 20 is a diagram illustrating another example of the permanent magnet including an even number of permanent magnet pieces according to the third embodiment. FIG. 21 is a diagram illustrating another example of the permanent magnet including an odd number of permanent magnet pieces according to the third embodiment. FIG. 22 is a diagram illustrating a permanent magnet composed of an odd number of permanent magnet pieces according to the fourth embodiment. FIG. 23 is a diagram illustrating a permanent magnet composed of an even number of permanent magnet pieces according to the fourth embodiment. FIG. 24 is a diagram illustrating a permanent magnet composed of an odd number of permanent magnet pieces according to the fifth embodiment. FIG. 25 is a diagram illustrating a permanent magnet composed of an even number of permanent magnet pieces according to the fifth embodiment. FIG. 26 is a diagram for explaining a method of forming a trapezoidal permanent magnet piece. FIG. 27 is a diagram illustrating a conventional method for manufacturing a permanent magnet.

[First Embodiment]
FIG. 1 is a cross-sectional view perpendicular to the axial direction of the variable magnetic flux type rotating electric machine 100 according to the first embodiment, showing a quarter of the entire configuration. In the remaining three quarters of the overall configuration, the partial configuration shown in FIG. 1 is continuously repeated. The variable magnetic flux type rotating electric machine 100 according to the present embodiment is arranged so as to form an annular stator 1, form a concentric circle with the stator 1, and have an air gap 9 between the stator 1 and the stator 1. It comprises a rotor 2 and a plurality of permanent magnets 3 fitted to the rotor 2, and constitutes a motor or a generator.

  The stator 1 includes a ring-shaped stator core 11, a plurality of teeth 8 protruding from the stator core 11 toward the inner peripheral side, and slots that are spaces between adjacent teeth 8. A stator winding 10 is wound around the teeth 8. The stator core 11 is formed of, for example, an electromagnetic steel plate that is a soft magnetic material.

  The rotor 2 has a rotor core 12. The rotor core 12 is formed in a cylindrical shape by a so-called laminated steel plate structure in which a number of electromagnetic steel plates formed by punching a metal steel plate having a high magnetic permeability into an annular shape are laminated in the axial direction. ing. Further, in the vicinity of a peripheral portion of the rotor core 12 facing the stator 1, a plurality of permanent magnets 3 are arranged at regular intervals in the circumferential direction, and the permanent magnets adjacent to each other have different polarities. It is provided so that it becomes. As inferred from the partial configuration shown in FIG. 1, the rotor core 12 according to the variable magnetic flux type rotating electric machine 100 of the present embodiment has the permanent magnets 3 forming one magnetic pole along the circumferential direction. It has an eight-pole structure.

  Although details will be described later, in the variable magnetic flux type rotating electric machine 100 to which the present invention is applied, the permanent magnet 3 forming one magnetic pole is configured by a combination of a plurality of permanent magnets (for example, permanent magnets 3a and 3b).

  The rotor 2 has a flux barrier (magnetic barrier) 4 which is a space formed by punching out an electromagnetic steel sheet forming the rotor core 12 between magnetic poles formed by the adjacent permanent magnets 3. , 5. The magnetic barriers 4 and 5 have a higher magnetic resistance than the electromagnetic steel sheet. Therefore, the magnetic barriers 4 and 5 act as magnetic flux barriers for the magnetic flux in the magnetic circuit formed by the permanent magnet 3 on the rotor 2. As shown in the figure, the magnetic barrier 4 (first magnetic barrier) has a substantially triangular shape having a smaller width on the rotation center side than on the outer circumference of the rotor 2 at a position near the outer circumference of the rotor core 12. Formed. The magnetic barrier 5 (second magnetic barrier) is located between the center between adjacent magnetic poles and the circumferential end of the permanent magnet 3 and in a region closer to the rotation center than the magnetic barrier 4. A gap (magnet fitting hole 30) in which the permanent magnet 3 is fitted extends from the circumferential end of the permanent magnet 3 toward the center between adjacent magnetic poles.

  However, the shapes of the magnetic barriers 4 and 5 are not limited to the shapes shown in the drawings as long as the technical effects described below are exerted. Further, the rotor 2 has the magnetic barriers 4 and 5 formed as shown in the figure, so that the magnetic flux emitted from the permanent magnet 3 forming one magnetic pole is formed by the adjacent permanent magnet 3. A leakage magnetic flux path 6 is formed as a path for leakage to the magnetic pole side. In other words, the leakage flux path 6 is provided between the magnetic barrier 4 and the magnetic barrier 5, and has a rotor circumferential end of one permanent magnet 3 and a circumferential end of another adjacent permanent magnet 3. And a V-shaped path that connects. Further, the rotor 2 is provided with a bridge portion 7 formed at a central portion between adjacent magnetic poles and connecting the leakage flux path 6 and a region of the magnetic barrier 5 on the inner circumferential side of the rotor.

  The permanent magnet 3 is fixed to the rotor core 12 by being fitted into a gap (magnet fitting hole 30) formed in a corresponding portion of the rotor core 12. Here, in the present embodiment, the geometric center of the permanent magnet 3 is defined as a d-axis, and a position electrically orthogonal to the d-axis is defined as a q-axis. Since the variable magnetic flux type rotating electric machine 100 of the present embodiment has an 8-pole structure, a position at a mechanical angle of 22.5 degrees from the d axis is defined as the q axis. Since the q axis and the center between the adjacent magnetic poles coincide with each other, it can be said that the magnetic barrier 4 and the bridge portion 7 are formed on the q axis.

  The magnet fitting hole 30 is a space formed by stamping out an electromagnetic steel plate forming the rotor core 12, and the rotor core 12 is fitted with the permanent magnet 3 as described above. Are holes for fixing the permanent magnet 3 to the laminated rotor 2. The magnet fitting hole 30 of the present embodiment is arranged on the d axis of the rotor core 12 and between the magnetic barriers 5 provided symmetrically with respect to the d axis.

  The above is the basic configuration of the variable magnetic flux type rotating electric machine 100 of the first embodiment. Here, before a detailed description of the present embodiment, a basic principle of a variable magnetic flux type rotating electric machine which is an object of the present invention will be described.

  The variable magnetic flux type rotating electric machine to which the present invention is directed is characterized in that a rotating magnetic field generated by applying a load current (stator current) to the stator winding reduces the magnetic flux generated from the permanent magnet provided in the rotor. The magnetic path of the portion (leakage magnetic flux) can be changed. With this feature, the rotating electric machine can passively change the stator flux linkage by controlling the stator current, so that the magnetic force of the permanent magnet provided in the rotor can be apparently changed by current control. it can. From such characteristics, the variable magnetic flux type rotating electric machine to which the present invention is applied is also called a variable leakage magnetic flux motor.

  FIG. 2 is a configuration diagram showing a part of the variable magnetic flux leakage motor, and is a diagram for explaining an outline of the operation of the variable magnetic flux leakage motor. However, since the shape and arrangement of each component of the variable magnetic flux leakage motor shown in FIG. 2 are general ones shown for explaining the outline of the operation, detailed portions excluding the basic configuration are the same as those of the present invention. different.

  The variable magnetic flux leakage motor shown in FIG. 2 includes a stator 101 and a rotor 102 arranged with an air gap formed between the stator 101 and the stator 101. The rotor 102 is disposed between the permanent magnet 103, the magnetic barriers 104 and 105, and the magnetic barriers 104 and 105 from the magnetic pole side of one permanent magnet 103 to the magnetic pole side of another adjacent permanent magnet 103. And a leakage flux path 106 connected via the The direction indicated by the arrow on the left side of the drawing indicates the rotation direction of the rotor 102.

  The magnetic path direction 15 shown in FIG. 2 indicates the direction in which the leakage magnetic flux flows when current is not supplied to the stator winding provided in the stator 101. As shown in FIG. 2, in the rotor, a part of the magnetic flux from the permanent magnet 103 leaks to the adjacent different pole side through the leakage flux path 106.

  Therefore, the amount of magnetic flux of the main magnetic flux component from the permanent magnet 103 to the stator 101 side, that is, the stator linkage flux is relatively reduced, so that the magnetic force of the permanent magnet 103 is apparently weak. Thereby, iron loss generated by the stator interlinkage magnetic flux can be reduced. This effect is particularly effective in improving the efficiency of the rotating electric machine in a low load and high speed region.

  On the other hand, the magnetic path direction 20 indicates the direction in which the magnetic flux flows when current is supplied to the stator winding. When the stator current flows, the magnetic flux emitted from the permanent magnet 103 is drawn toward the stator in the rotation direction of the rotor 102 as indicated by the magnetic path direction 20. Therefore, when no current is supplied to the stator winding, the magnetic flux leaking as a leakage magnetic flux in the rotor 102 can be efficiently converted into a stator linkage magnetic flux. Thereby, the rotating electric machine can output a high torque equivalent to a state where the magnetic flux emitted from the permanent magnet 103 is not leaking.

  As described above, by providing the leakage flux path between the magnetic poles formed in the rotor and controlling the stator current to change the leakage flux in the rotor, the characteristic that the stator linkage flux changes passively (leakage flux). A rotating electric machine having magnetic flux characteristics is called a variable magnetic flux type rotating electric machine (variable leakage magnetic flux motor).

  The above is the basic principle of the variable magnetic flux type rotating electric machine to which the present invention is applied. Hereinafter, details of the shape and arrangement of each component included in the variable magnetic flux type rotating electric machine 100 according to the first embodiment of the present invention will be described with reference to the drawings and the like.

  FIG. 3 is a configuration diagram viewed from a cross section perpendicular to the axial direction of the variable magnetic flux type rotating electric machine 100 according to the first embodiment, and is an enlarged view around the q axis shown in FIG. With reference to FIG. 3, the configuration of the variable magnetic flux type rotating electric machine of the present embodiment and characteristics obtained from the configuration will be described.

  As described above, the magnetic barrier 5 has a gap in which the permanent magnet 3 is buried extending from the circumferential end of the permanent magnet 3 toward the q-axis side in a region closer to the rotation center than the magnetic barrier 4. It is configured to be. Since the magnetic resistance of the leakage flux path 6 formed on the rotor core 12 is smaller than the magnetic resistance of the magnetic barrier 5 which is a space part of the rotor core 12, the magnetic flux emitted from the permanent magnet 3 is 3 is leaked to the opposite pole side of another adjacent permanent magnet 3 via the leakage magnetic flux path 6.

  As described above, the magnetic flux inflow / outflow portion 14 of the leakage magnetic flux path 6 is arranged near the air gap 9. This makes it easier to control the magnetic flux flowing through the leakage flux path 6 by controlling the current flowing through the stator winding.

  In addition, the variable magnetic flux type rotating electric machine 100 according to the present embodiment has a leakage current flowing through the leakage magnetic flux path 6 when the current I flowing through the stator winding 10 is small, such as under no load or low load. Since the magnetic flux is generated, the back electromotive force generated by the magnet magnetic flux from the permanent magnet 3 is reduced, and the torque Tr generated in the rotor 2 is reduced. On the other hand, when the current I flowing through the stator winding is increased in order to rotate the rotating electric machine at high speed, the leakage magnetic flux is reduced, and the main magnetic flux component linked to the stator side relatively increases. Can be higher. That is, the current I and the torque Tr of the variable magnetic flux type rotating electric machine according to the present embodiment increase as the current I increases, as shown by the dotted line in FIG.

  In other words, the variable magnetic flux type rotating electric machine 100 according to the present embodiment is configured such that when the torque Tr is represented by Tr = KT × I by the torque constant KT and the current I, the torque constant KT is a function KT of the current I. = Kt (I), and in a region equal to or lower than the magnetic saturation point of the core material of the stator core 11, a relationship of “d (Kt (I)) / dI ≧ 0” is provided.

  Therefore, when a current is applied to the stator 1, the linkage between the magnet magnetic flux and the stator winding (the stator linkage flux) increases, and the torque constant increases. For this reason, in the low torque region, the stator linkage flux is reduced, so that the iron loss is reduced, and the induced voltage is also reduced, so that the variable speed range is expanded. Since the magnetic circuit of the rotor 2 is formed substantially symmetrically with respect to the center of the magnetic pole of the permanent magnet 3, substantially the same characteristics can be obtained regardless of the rotation direction of the rotor 2.

  Further, the above-mentioned relationship of “d (Kt (I)) / dI ≧ 0” indicates that the amount of leakage of the magnet magnetic flux to the different pole in the no-load state in the magnet magnetic flux distribution in the rotor 2 indicates that the stator 1 This indicates that the current is applied to the stator winding 10 and the maximum torque constant KT_max is set to be larger than the minimum torque constant KT_min by 10% or more. That is, as shown by the curve shown by the dotted line in FIG. 5, when there is no load in which the current I is not supplied to the stator winding 10, the torque constant KT is set to the minimum value KT_min, and when the current I becomes large, the torque constant KT becomes the maximum value. KT_max is set. Then, the maximum torque constant KT_max is set to be larger than the minimum torque constant KT_min by 10% or more. With this setting, the magnet flux can be controlled by the normal current control for the stator 1 without using an additional structure or a special control method.

  Further, due to the arrangement of the magnetic barriers 4 and 5 on the rotor core 12 and the permanent magnets 3, the q-axis magnetic resistance is set smaller than the d-axis magnetic resistance. More specifically, by adjusting the relative amounts of the circumferential width of the magnetic poles formed by the permanent magnets 3 constituting one magnetic pole and the rotor circumferential width and the radial width of the magnetic barriers 4 and 5, The q-axis magnetic resistance is set smaller than the d-axis magnetic resistance. Therefore, the rotor 2 of the present embodiment has a reverse saliency in which the inductance Ld in the d-axis direction and the inductance Lq in the q-axis direction have a relationship of Ld <Lq. In the rotor circumferential direction, the ratio occupied by the width of the permanent magnet 3 between the adjacent q axes is increased, or the rotor circumferential width or the radial width of the magnetic barriers 4 and 5 is further reduced. Thus, the salient pole ratio related to the reverse saliency increases.

  The side surface of the permanent magnet 3 included in the rotor 2 of the present embodiment on the stator 1 side (the outer peripheral side of the rotor 2), in other words, the side surface of the magnet fitting hole 30 of the present embodiment on the stator 1 side is a rotor. It has an arc shape convex toward the outer peripheral side. The embedding depth Hd from the outer peripheral surface of the rotor 2 at the center of the magnetic pole of the permanent magnet 3, in other words, at the center in the circumferential direction of the magnet fitting hole 30 (portion on the d-axis) is equal to the magnet fitting hole 30. Is shallower than the burial depth He from the outer peripheral surface of the rotor 2 at the circumferential end. That is, the magnet fitting holes 30 formed in the rotor 2 in the present embodiment have a band shape and an arc shape, and are arranged so as to satisfy the relationship of Hd <He. By configuring the magnet fitting holes 30 in this manner, the magnetic path of the q-axis magnetic flux formed on the rotor core 12 is narrowed.

  Then, since the permanent magnet 3 has a higher magnetic resistance than the rotor core 12, the magnetic resistance with respect to the q-axis magnetic flux increases, and the q-axis inductance Lq decreases. As a result, the induced voltage (back electromotive force) is reduced, so that the power factor (the ratio of the active power to the apparent power) can be improved. As a result, the output (the product of the rotation speed and the torque) with respect to the input power can be further improved particularly in the maximum output region (see FIG. 6B) as compared with the conventional flat permanent magnet. Note that the shape of the magnet fitting hole 30 of the present embodiment on the inner peripheral side is such that the distance connecting the circumferential end (point A) on the inner peripheral side and the rotation center of the rotor core 12 is equal to the inner peripheral side. It is set to be shorter than the distance connecting the center of the direction (point B) and the rotation center of the rotor core 12.

  Further, since the position of the permanent magnet 3 near the center of the magnetic pole approaches the stator 1 side, the magnet torque can be increased in the maximum torque region (see FIG. 6A) as compared with the conventional flat permanent magnet.

  Further, as a further effect, since the side surface of the permanent magnet 3 on the rotor outer peripheral side has an arc shape, the magnetomotive force space distribution accompanying the rotation of the rotor 2 is sinusoidal (sine wave) as compared with the conventional flat plate shape. , The harmonic component of the magnetic flux density in the stator 1 is suppressed, and iron loss can be reduced.

  However, the conventional permanent magnet fitted in the magnet fitting hole 30 as described above is manufactured as follows. That is, the conventional permanent magnet fitted in the magnet fitting hole 30 is formed by being cut out from a cylindrical permanent magnet 330 as shown in FIG. More specifically, the conventional permanent magnet is formed by dividing a cylindrical permanent magnet 330 manufactured by, for example, hot rolling in the longitudinal direction so as to match the size of the magnet fitting hole 30 ( For example, it is divided along the dotted line shown). The conventional permanent magnet manufactured in this manner is limited in size or shape that can be manufactured in manufacturing an arc-shaped (cylindrical) permanent magnet. There is a problem that it is difficult to further increase the torque. In addition, the conventional permanent magnet needs to match the shape of the magnet fitting hole 30 and needs to be manufactured for each shape of the rotor core 12, so that there is also a problem that the manufacturing cost increases.

  Therefore, in order to solve the above-described conventional problem, the permanent magnet 3 forming one magnetic pole in the variable magnetic flux type rotating electric machine 100 to which the present invention is applied is composed of a plurality of permanent magnets having different magnetic characteristics (for example, permanent magnets). It is configured by combining the magnets 3a, 3b). Hereinafter, details of the permanent magnet 3 of the present embodiment will be described with reference to FIGS.

  FIG. 7 is a diagram illustrating the permanent magnet 3 of the present embodiment. FIG. 7 is a configuration diagram of the variable magnetic flux type rotating electric machine 100 of the present embodiment viewed from a plane perpendicular to the axial direction, and is enlarged around a portion corresponding to the d-axis shown in FIG. FIG.

  As illustrated, the permanent magnet 3 of the present embodiment is configured by a combination of one permanent magnet 3a and three permanent magnets 3b (hereinafter, the permanent magnets 3a and 3b are collectively referred to as "permanent magnet pieces"). Name). Further, the apex angles of the triangles drawn on the permanent magnets 3a and 3b in the figure indicate the magnetization direction (magnetic field orientation direction) of the permanent magnet, but as shown, the permanent magnet 3a of the present embodiment has: The other permanent magnets 3b are different in the magnetic field orientation direction (hereinafter, simply referred to as "orientation direction").

  More specifically, among the permanent magnet pieces constituting the permanent magnet 3 of the present embodiment, at least one of the permanent magnet pieces located at the circumferential end, in other words, the permanent magnet pieces adjacent to the leakage flux path 6. The orientation direction of a certain permanent magnet 3a is different from the orientation direction of a permanent magnet 3b which is another permanent magnet piece. Specifically, while the orientation direction of the permanent magnet 3b is a direction (radial direction) substantially coinciding with the radial direction of the rotor core 12, the orientation direction of the permanent magnet 3a is relative to the radial direction. The magnet fitting hole 30 is inclined at a predetermined angle toward the adjacent circumferential end (the q-axis side or the leakage flux path 6 side).

  More specifically, referring to FIG. 7, the permanent magnet 3 a is configured such that a leakage magnetic flux adjacent to a line C obtained by drawing the circumferential center (magnet center) of the permanent magnet 3 a in the radial direction from the rotation center of the rotor 2. It is oriented at a predetermined angle α toward the road 6 (see line D). Further, the residual magnetic flux density B'r of the permanent magnet 3a of the present embodiment is set to be equal to or larger than the residual magnetic flux density Br of the permanent magnet 3b (B'r≥Br). The effect obtained by the permanent magnet 3 of this embodiment having such a configuration will be described with reference to FIG.

  FIG. 8 is a diagram illustrating a variable leakage magnetic flux width of the variable magnetic flux type rotating electric machine 100 of the present embodiment. The horizontal axis shows the current [A] supplied to the stator 1, and the vertical axis shows the flux linkage [%] at no load. The solid line in the figure shows the interlinkage magnetic flux of the conventional permanent magnet which is of the integral type and has the same orientation direction and residual magnetic flux density. The dotted line in the figure indicates the linkage flux of the permanent magnet 3 of the present embodiment. The double-headed arrow in the figure indicates the leakage magnetic flux variable width [%] of each of the conventional and this embodiment. Leakage flux variable width [%] is calculated by subtracting the minimum value of the linkage flux under no load (see the solid line) divided by the maximum value of the linkage flux under the no load (see the dotted line) from 1. (Variable width of leakage flux [%] = 1−minimum value of linkage flux at no load / maximum value of linkage flux at no load).

  As shown, according to the configuration of the permanent magnet 3 of the present embodiment, the amount of leakage magnetic flux passing through the leakage flux path 6 can be increased at a low load, and the linkage flux linked to the stator at a high load. Since the amount can be changed, the maximum value of the variable range of the leakage magnetic flux can be improved from 21.7 [%] of the related art to 24.8 [%]. That is, the permanent magnet 3 of the present embodiment changes the orientation direction of the permanent magnet 3a close to the leakage flux path 6 and sets the residual magnetic flux density Br to a value larger than the residual magnetic flux density B'r of the other permanent magnet pieces. By setting the value, the leakage magnetic flux characteristics can be improved. As a result, it is possible to further improve the efficiency (power factor) of the rotating electric machine particularly in a low-load and high-speed region. Can be improved. The above-mentioned predetermined angle α is appropriately set from the viewpoint of increasing the variable leakage magnetic flux width and improving the above-described leakage magnetic flux characteristics.

  Note that the permanent magnet 3 of the present embodiment may be configured as shown in FIG.

  FIG. 9 is a diagram illustrating another example of the permanent magnet 3 of the present embodiment. As illustrated, the permanent magnet 3 of the present embodiment may be configured by a combination of two permanent magnets 3a and two permanent magnets 3b. That is, of the permanent magnet pieces constituting the permanent magnet 3, the permanent magnet pieces located at the circumferential end, in other words, the two permanent magnet pieces which are the permanent magnet pieces adjacent to the leakage flux path 6 are both permanent magnet pieces. 3a. These permanent magnets 3a are oriented in a direction inclined by a predetermined angle α toward the adjacent leakage magnetic flux path 6 with respect to a line C in which the circumferential center of the permanent magnet 3a is drawn in the radial direction from the rotation center of the rotor 2 in the radial direction. (See line D). Further, the residual magnetic flux density B'r of the two permanent magnets 3a is set to be equal to or larger than the residual magnetic flux density Br of the permanent magnet 3b (B'r≥Br). The effect obtained by the permanent magnet 3 of this embodiment having such a configuration will be described with reference to FIG.

  FIG. 10 is a view showing the leakage magnetic flux variable width of the variable magnetic flux type rotating electric machine 100 of the present embodiment, similarly to FIG. FIG. 10 shows the variable leakage magnetic flux width of the permanent magnet 3 including two permanent magnets 3a and two permanent magnets 3b. As shown in the figure, according to the configuration of the permanent magnet 3 according to the present embodiment, it is possible to increase the amount of leakage magnetic flux passing through two adjacent leakage flux paths 6 at a low load and to link the stator to the stator at a high load. Since the amount of interlinkage magnetic flux intersecting can be changed, the maximum value of the leakage magnetic flux variable width can be improved from 21.7 [%] of the related art to 31.9 [%]. That is, the permanent magnet 3 according to the present example changes the orientation direction of the two permanent magnets 3a close to the leakage flux path 6, and makes the residual magnetic flux density Br equal to or higher than the residual magnetic flux density B'r of the other permanent magnet pieces. By setting the size to, the leakage magnetic flux characteristics can be further improved.

  As described above, the variable magnetic flux type rotating electric machine 100 according to the first embodiment has the variable magnetic flux including the stator 1 that generates a rotating magnetic field, and the rotor 2 that is arranged via the stator 1 and the air gap 9 having a predetermined width. Type rotating electric machine. The rotor 2 included in the variable magnetic flux type rotating electric machine 100 includes a rotor core 12, a plurality of flux barriers 5 provided in the circumferential direction in the rotor core 12, and a plurality of permanent magnets 3 disposed between the plurality of flux barriers 5. And a magnet fitting hole 30 into which is fitted. The magnet fitting hole 30 has a depth (Hd) from the outer circumferential surface of the rotor core 12 at the center in the circumferential direction on the outer circumferential side, and a depth (Hd) from the outer circumferential surface of the rotor core 12 at the circumferential end on the outer circumferential side. He) is set shallower than He, and a plurality of permanent magnets 3a and 3b having different magnetic properties are fitted side by side in the circumferential direction to form one magnetic pole. Since one magnetic pole is constituted by a plurality of permanent magnets having different magnetic characteristics, the magnetic flux characteristics (leakage magnetic flux characteristics) of the permanent magnets constituting one magnetic pole can be further improved without being restricted by the manufacturable size. In addition, by configuring one magnetic pole with a plurality of permanent magnets, an increase in manufacturing cost can be suppressed.

  Further, according to the variable magnetic flux type rotating electric machine 100 of the first embodiment, the magnetic characteristics are at least one of the magnetic field orientation direction, the residual magnetic flux density, and the coercive force (the magnetic field orientation direction and the residual magnetic flux density).

  That is, according to the variable magnetic flux type rotating electric machine 100 of the first embodiment, of the plurality of permanent magnets (permanent magnet pieces) constituting one magnetic pole, at least one of the permanent magnets disposed at the circumferential end of the magnet fitting hole 30 is provided. The magnetic field orientation direction of the two permanent magnets (permanent magnets 3a) is set to a direction inclined by a predetermined angle α to the adjacent circumferential end of the magnet fitting hole 30 with respect to the radial direction at the magnet center of the permanent magnets 3a. Is done. Further, the residual magnetic flux density B′r of at least one permanent magnet (permanent magnet 3a) is larger than the residual magnetic flux density Br of another permanent magnet (permanent magnet 3b). Thereby, the orientation direction of the permanent magnet 3a close to the leakage magnetic flux path 6 is changed, and the residual magnetic flux density B'r is set to be equal to or larger than the residual magnetic flux density Br of the other permanent magnet pieces. The magnetic flux characteristics can be improved. As a result, it is possible to further improve the efficiency (power factor) of the rotating electric machine particularly in a low-load and high-speed region. Can be improved.

[Second embodiment]
Hereinafter, the variable magnetic flux type rotating electric machine 200 according to the second embodiment will be described. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the variable magnetic flux type rotating electric machine 200 of the present embodiment, the permanent magnet 3 forming one magnetic pole is configured by a combination of a plurality of permanent magnets having different magnetic properties (for example, the permanent magnets 3c and 3d).

  FIG. 11 is a diagram illustrating the permanent magnet 3 of the present embodiment. FIG. 11 is a configuration diagram of the variable magnetic flux type rotating electric machine 200 of the present embodiment viewed from a plane perpendicular to the axial direction, and is enlarged around a portion corresponding to the d-axis shown in FIG. FIG.

  As illustrated, the permanent magnet 3 of the present embodiment is configured by a combination of three permanent magnets 3c and one permanent magnet 3d (hereinafter, the permanent magnets 3c and 3d are collectively referred to as "permanent magnet pieces"). Name). The magnitude of the coercive force differs between the permanent magnet 3c and the permanent magnet 3d. Note that the coercive force is an index indicating the stability of magnetization with respect to magnetic field fluctuation. The smaller the value, the more easily the residual magnetic flux density changes due to the magnetomotive force generated by the current flowing through the stator winding 10.

  Here, in the variable magnetic flux type rotating electric machine (variable leakage magnetic flux motor) to which the present invention is applied, the largest permanent magnet 3d is positioned at the rearmost position with respect to the rotation direction of the rotor 2 (the direction of the arrow in the figure). It is designed to act on a magnetic field. Therefore, in the present embodiment, the coercive force H'c of the permanent magnet 3d is set to be equal to or larger than the coercive force Hc of the permanent magnet 3c (H'c ≧ Hc). As a result, the coercive force of the permanent magnet 3d located rearmost in the rotation direction of the rotor 2 becomes larger than that of the other permanent magnet pieces. The magnetic resistance can be improved.

  Further, the permanent magnet 3 of the present embodiment may be configured as shown in FIG.

  FIG. 12 is a diagram illustrating another example of the permanent magnet 3 of the present embodiment. As illustrated, the permanent magnet 3 of the present embodiment may be configured by a combination of two permanent magnets 3c, one permanent magnet 3d, and one permanent magnet 3e. In this case, the coercive force H ″ c of the permanent magnet 3e located rearmost in the rotation direction of the rotor 2 is larger than the coercive force H′c of the permanent magnet 3d and the coercive force Hc of the permanent magnet 3c. Is set. That is, the permanent magnet piece in the present example is configured such that the coercive force is larger toward the rear and smaller toward the front with respect to the rotation direction of the rotor 2 (H ″ c ≧ H′c). ≧ Hc). Accordingly, the coercive force of the permanent magnet 3d located rearmost in the rotation direction of the rotor 2 is set to be larger, and as a result, the coercive force of the entire permanent magnet 3 is set to be larger. Can be improved in thermal demagnetization resistance.

  Further, the permanent magnet 3 of the present embodiment may be configured as shown in FIG. 13 in consideration of the residual magnetic flux density.

  FIG. 13 is a diagram illustrating another example of the permanent magnet 3 of the present embodiment. As illustrated, the permanent magnet 3 of the present embodiment may be configured by combining permanent magnet pieces including at least two types of orientation directions as described in the first embodiment. The permanent magnet 3 in this example is configured by a combination of one permanent magnet 3f, two permanent magnets 3g, and one permanent magnet 3h.

  First, the orientation direction of the permanent magnet 3f which is at least one of the permanent magnet pieces adjacent to the leakage flux path 6 is different from the orientation direction of the other permanent magnet pieces. Specifically, while the orientation direction of the permanent magnets 3g and 3e is a direction (radial direction) substantially coinciding with the radial direction of the rotor core 12, the orientation direction of the permanent magnet 3f is the radial direction ( (Refer to line C) to the adjacent leakage flux path 6 side at a predetermined angle α (see line D).

  The relationship between the residual magnetic flux density Br′r and the coercive force Hc of the permanent magnet 3f, the residual magnetic flux density Br and the coercive force Hc of the permanent magnet 3g, and the residual magnetic flux density Br and the coercive force H′c of the permanent magnet 3h are as follows. , B′r ≧ Br, and H′c ≧ Hc. That is, the permanent magnet 3 in this example is a permanent magnet piece adjacent to the leakage flux path 6, and the residual magnetic flux density B'r of the permanent magnet 3f having a different orientation direction from the other permanent magnet pieces is maximized. Be composed. Further, the permanent magnet 3 in the present example is configured such that the coercive force of the permanent magnet 3h located at the rearmost portion with respect to the rotation direction of the rotor 2 is maximized.

  Thereby, as described in the first embodiment with reference to FIG. 8, the variable leakage magnetic flux width can be improved as compared with the related art to reduce the loss, and the thermal demagnetization of the permanent magnet 3 h constituting the permanent magnet 3 can be reduced. Resistance can be improved.

  As described above, according to the variable magnetic flux type rotating electric machine 200 of the second embodiment, of the plurality of permanent magnets (permanent magnet pieces) constituting one magnetic pole, the magnet fitting hole 30 is located rearmost in the rotation direction of the rotor 2. The coercive force of the located permanent magnet (3d, 3e, 3h) is greater than the coercive force of the other permanent magnets. As a result, the coercive force of the permanent magnet 3d located rearmost in the rotation direction of the rotor 2 becomes larger than that of the other permanent magnet pieces. The magnetic resistance can be improved.

[Third embodiment]
Hereinafter, the variable magnetic flux type rotating electric machine 300 according to the third embodiment will be described. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the variable magnetic flux type rotating electric machine 300 of the present embodiment, the permanent magnet 3 forming one magnetic pole is configured by a combination of an even number of permanent magnets having different characteristics (for example, permanent magnets 3i and 3j).

  FIG. 14 is a diagram illustrating the permanent magnet 3 of the present embodiment. FIG. 14 is a configuration diagram of the variable magnetic flux type rotating electric machine 300 of the present embodiment viewed from a plane perpendicular to the axial direction, and is enlarged around a portion corresponding to the d-axis shown in FIG. FIG.

  As illustrated, the permanent magnet 3 of the present embodiment is configured by a combination of an even number of permanent magnet pieces including two permanent magnets 3i and two permanent magnets 3j. The permanent magnet 3i and the permanent magnet 3j have different residual magnetic flux densities, and the residual magnetic flux density Br of the permanent magnet 3i is set to be smaller than the residual magnetic flux density B'r of the permanent magnet 3j. Then, the permanent magnet 3j having a larger residual magnetic flux density is arranged at the center in the circumferential direction, that is, a position near the d-axis, and the permanent magnet 3i having a smaller residual magnetic flux density is arranged at the circumferential end, that is, a position near the q-axis. You. Effects obtained by the permanent magnet 3 of this embodiment having such a configuration will be described with reference to FIGS.

  FIG. 15 is a diagram illustrating a spatial magnetomotive force waveform accompanying rotation of the rotor 2 of the present embodiment. The horizontal axis represents time, and the vertical axis represents stator linkage flux. A dotted line indicates a spatial magnetomotive force waveform at one magnetic pole when the residual magnetic flux density of the permanent magnet 3 is set to be constant (conventional), and a solid line indicates the permanent magnet 3 of the present embodiment, which is located at the center. 3 shows a spatial magnetomotive force waveform at one magnetic pole when the residual magnetic flux density of the magnetic pole piece is set larger than that of the other permanent magnet pieces.

  As shown in the figure, it can be seen that the stator linkage flux in the spatial magnetomotive force waveform of the present embodiment is larger in both the positive direction and the negative direction than in the related art. FIG. 16 shows the results of Fourier transform (FFT) of these spatial magnetomotive force waveforms.

  FIG. 16 is a diagram showing an FFT result of a spatial magnetomotive force waveform. The horizontal axis indicates the order of the spatial magnetomotive force waveform, and the vertical axis indicates the stator linkage flux density. A white bar indicates a conventional FFT result, and a colored bar indicates the FFT result of the present embodiment. As shown in the figure, the harmonic component of the spatial magnetomotive force due to the configuration of the permanent magnet 3 of the present embodiment hardly increases compared to the related art. That is, according to the configuration of the permanent magnet 3 of the present embodiment, the fundamental wave component can be increased without increasing the harmonic component of the spatial magnetomotive force. As a result, torque can be improved without increasing loss (iron loss) due to harmonic components.

  Note that the permanent magnet 3 of the present embodiment may be configured as shown in FIG.

  FIG. 17 is a diagram illustrating another example of the permanent magnet 3 of the present embodiment. As illustrated, the permanent magnet 3 of the present embodiment may be configured by a combination of an odd number of permanent magnet pieces including two permanent magnets 3i, two permanent magnets 3j, and one permanent magnet 3k. Also in this example, the magnitude of the residual magnetic flux density differs between the permanent magnet 3i, the permanent magnet 3j, and the permanent magnet 3k. Specifically, the residual magnetic flux density B ″ r of the permanent magnet 3k located at the center in the circumferential direction, that is, on the d-axis, is set to be the highest, and the residual magnetic flux density becomes higher at the circumferential end, that is, at the q-axis side. It is set so that the magnetic flux density becomes small. That is, the residual magnetic flux density B ″ r of the permanent magnet 3k, the residual magnetic flux density B′r of the permanent magnet 3j, and the residual magnetic flux density Br of the permanent magnet 3i are set so that B ″ r ≧ B′r ≧ Br holds. Is set. Effects obtained by the permanent magnet 3 of this embodiment having such a configuration will be described with reference to FIGS.

  FIG. 18 is a diagram for explaining a spatial magnetomotive force waveform accompanying rotation of the rotor 2 of the present example, similarly to FIG. FIG. 19 is a diagram showing the FFT result of the spatial magnetomotive force waveform of the present example as in FIG. From FIG. 18, it can be seen that the stator linkage flux in the spatial magnetomotive force waveform of this example is also larger in the positive and negative directions than in the conventional case. Also, from FIG. 19, it can be seen that the harmonic component of the spatial magnetomotive force due to the configuration of the permanent magnet 3 of this example has hardly increased compared to the related art. That is, even with the configuration of the permanent magnet 3 of the present example configured by combining an odd number of permanent magnet pieces, the fundamental component can be increased without increasing the harmonic component of the spatial magnetomotive force.

  Further, the permanent magnet 3 of the present embodiment may be configured as shown in FIG.

  FIG. 20 is a diagram illustrating the permanent magnet 3 of the present embodiment. In this example, the permanent magnet 3 constituting one magnetic pole is configured by a combination of an even number of permanent magnets (for example, permanent magnets 31, 3 m, and 3 n) having different characteristics.

  As shown in the figure, the permanent magnet 3 according to the present example is configured by a combination of one permanent magnet 31, two permanent magnets 3m, and one permanent magnet 3n.

  The relationship between the residual magnetic flux density Br and the coercive force Hc of the permanent magnet 3l, the residual magnetic flux density B'r and the coercive force Hc of the permanent magnet 3m, and the residual magnetic flux density Br and the coercive force H'c of the permanent magnet 3n is represented by B It is configured such that 'r ≧ Br and H′c ≧ Hc are satisfied.

  That is, also in this example, the permanent magnet 3m having a larger residual magnetic flux density is disposed at the center in the circumferential direction, that is, a position close to the d-axis, and the permanent magnets 3l and 3n having the smaller residual magnetic flux density are located at the circumferential ends, that is, q. It is located close to the axis. With this configuration of the permanent magnet 3 of the present example, the spatial magnetomotive force can be reduced in the same manner as described above using the spatial magnetomotive force waveform shown in FIG. 15 and the FFT result shown in FIG. Since the fundamental wave component can be increased without increasing the harmonic component, the torque can be improved without increasing the loss (iron loss) due to the harmonic component.

  Furthermore, since the holding force H'c of the permanent magnet 3n located at the rearmost position with respect to the rotation direction of the rotor 2 is set to be the largest, the largest demagnetizing field among the permanent magnet pieces constituting the permanent magnet 3 Can act to improve the thermal demagnetization resistance of the permanent magnet 3n.

  Furthermore, the permanent magnet 3 of the present embodiment may be configured as shown in FIG.

  FIG. 21 is a diagram illustrating the permanent magnet 3 of the present embodiment. In this example, the permanent magnet 3 constituting one magnetic pole is configured by a combination of an odd number of permanent magnets having different characteristics (for example, permanent magnets 31, 3 m, 3 n, and 3 o).

  As shown in the figure, the permanent magnet 3 according to the present example is configured by a combination of one permanent magnet 31, two permanent magnets 3m, one permanent magnet 3n, and one permanent magnet 3o.

  The residual magnetic flux density Br and the coercive force Hc of the permanent magnet 3l, the residual magnetic flux density B'r and the coercive force Hc of the permanent magnet 3m, the residual magnetic flux density Br and the coercive force H'c of the permanent magnet 3n, and the The relationship between the residual magnetic flux density B ″ r and the coercive force Hc is configured such that B ″ r ≧ B′r ≧ Br and H′c ≧ Hc.

  That is, also in this example, the permanent magnets 3o having a larger residual magnetic flux density are arranged at the center in the circumferential direction, that is, on the d-axis, and the permanent magnets 3l and 3n having the smallest residual magnetic flux density are located at the circumferential ends, that is, at the q-axis. It is located closest. That is, also in the permanent magnet piece constituting the permanent magnet 3 of the present example, the residual magnetic flux density B ″ r of the permanent magnet 3o located on the d-axis is set to be the highest, and the circumferential end, ie, q It is configured such that a permanent magnet piece having a smaller residual magnetic flux density is disposed closer to the shaft side. Even when the permanent magnet 3 of this example is configured in this manner, the spatial magnetomotive force shown in FIG. 18 and the FFT result shown in FIG. Since the fundamental wave component can be increased without increasing the harmonic component, the torque can be improved without increasing the loss (iron loss) due to the harmonic component.

  Furthermore, since the holding force H'c of the permanent magnet 3n located at the rearmost position with respect to the rotation direction of the rotor 2 is set to be the largest, the largest demagnetizing field among the permanent magnet pieces constituting the permanent magnet 3 Can act to improve the thermal demagnetization resistance of the permanent magnet 3n.

  As described above, according to the variable magnetic flux type rotating electric machine 300 of the third embodiment, the residual magnetic flux densities of the plurality of permanent magnets (permanent magnet pieces) constituting one magnetic pole are arranged at the circumferential center of the magnet fitting hole 30. The permanent magnets (3j, 3k, 3m, 3o) are the highest, and are lower as the permanent magnets are located closer to the circumferential end. As a result, the fundamental wave component can be increased without substantially increasing the harmonic component of the spatial magnetomotive force, so that the torque can be improved without increasing the loss (iron loss) due to the harmonic component.

[Fourth embodiment]
Hereinafter, a variable magnetic flux type rotating electric machine 400 according to the fourth embodiment will be described. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The permanent magnet 3 constituting one magnetic pole in the variable magnetic flux type rotating electric machine 400 of the present embodiment has a difference in characteristics as described in the above embodiment, and is viewed from a plane perpendicular to the axial direction of the rotor 2. It is configured by combining a plurality of permanent magnets 3p having a rectangular shape. Since the permanent magnet pieces constituting the permanent magnet 3 according to the present embodiment are characterized by their shapes, differences in the characteristics (at least one of the orientation direction, the residual magnetic flux density, and the coercive force) described in the above embodiment are provided. Regardless of this, it is referred to as the permanent magnet 3p.

  FIG. 22 is a diagram illustrating the permanent magnet 3 including five (odd number) permanent magnets 3p. FIG. 23 is a diagram illustrating the permanent magnet 3 including four (even number) permanent magnets 3p. As shown in these figures, the permanent magnet 3 of the present embodiment is configured by combining rectangular permanent magnets 3p, and the envelope of the side (line) of the permanent magnet 3p on the outer side (outer peripheral side) in the rotor radial direction. The wires are arranged so as to show a substantially arc shape that is convex toward the outer peripheral side.

  As described above, by forming the substantially arc-shaped permanent magnet 3 by combining the rectangular permanent magnet pieces, it is not necessary to manufacture an arc-shaped or cylindrical permanent magnet, so that the manufacturing cost of the permanent magnet is reduced. be able to. In the magnet fitting holes 30 in both figures, a wedge-shaped portion formed between the permanent magnets 3p is a space formed on the rotor core 12. The space may function as a flux barrier or may be filled with an elastic material having a desired magnetic permeability.

  As described above, according to the variable magnetic flux type rotating electric machine 400 of the fourth embodiment, the permanent magnet 3p is configured such that the shape of the surface perpendicular to the axial direction of the rotor 2 is rectangular. Thereby, the substantially arc-shaped permanent magnet 3 can be configured by combining the rectangular permanent magnet 3p, so that it is not necessary to manufacture an arc-shaped or cylindrical permanent magnet, and the manufacturing cost of the permanent magnet is reduced. be able to.

[Fifth Embodiment]
Hereinafter, the variable magnetic flux type rotating electric machine 500 of the fifth embodiment will be described. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The permanent magnet 3 constituting one magnetic pole in the variable magnetic flux type rotating electric machine 500 of the present embodiment has a difference in characteristics as described in the above embodiment, and is viewed from a plane perpendicular to the axial direction of the rotor 2. It is configured by combining a plurality of trapezoidal permanent magnets 3q. Since the permanent magnet pieces constituting the permanent magnet 3 according to the present embodiment are characterized by their shapes, differences in the characteristics (at least one of the orientation direction, the residual magnetic flux density, and the coercive force) described in the above embodiment are provided. Regardless of this, it is referred to as a permanent magnet 3q.

  FIG. 24 is a diagram illustrating a permanent magnet 3 including five (odd number) permanent magnets 3q. FIG. 25 is a diagram illustrating the permanent magnet 3 including four (even number) permanent magnets 3q. As shown in these figures, the permanent magnet 3 of the present embodiment has a pseudo circular arc by combining a trapezoidal permanent magnet 3q whose side on the outer side (outer side) in the rotor radial direction is longer than the side on the inner side. It is configured to form a shape.

  As described above, since the permanent magnet 3 is formed by combining trapezoidal permanent magnet pieces, there is no limit on the size or shape imposed when manufacturing an arc-shaped or cylindrical permanent magnet. The output and torque of the variable magnetic flux type rotating electric machine 500 can be improved by increasing the thickness of the magnet 3 in the rotor radial direction.

  In addition, in the case of the trapezoidal permanent magnet 3q, one magnetic pole can be formed without generating a space between the adjacent permanent magnets 3q, so that the space magnetomotive force waveform is made closer to a sine wave shape to reduce loss. Can be done. A method of forming such a trapezoidal permanent magnet 3q will be described with reference to FIG.

  FIG. 26 is a diagram illustrating a method of forming the trapezoidal permanent magnet 3q. FIG. 26A is a diagram illustrating a method of forming an odd number of permanent magnets 3q in the magnet fitting hole 30. FIG. 26B is a diagram illustrating an even number of permanent magnets in the magnet fitting hole 30. It is a figure showing the method of forming magnet 3q.

  The left side of FIG. 26 (a) shows the magnet fitting hole 30 having an ideal arc-shaped curve, and the right side shows the magnet fitting hole of the present embodiment when an odd number of permanent magnets 3q are applied. 30 is shown. Similarly, FIG. 26B shows a magnet fitting hole 30 having an ideal arc-shaped curve on the left side, and a magnet according to the present embodiment when an even number of permanent magnets 3q are applied on the right side. The fitting hole 30 is shown. A plurality of permanent magnets 3q that are fitted into the magnet fitting holes 30 of the present embodiment to form the permanent magnet 3 have an equilateral trapezoidal shape, and have a length (longer side) on the outer peripheral side (longer side) thereof. Is X, and the internal angle formed by the long side and the leg is θ, X and θ are calculated by the following equation (1).

  However, the variables in the above equation (1) are set as follows with reference to FIG. That is, n indicates the number of permanent magnets 3q fitted in the magnet fitting holes 30 corresponding to one magnetic pole. φ is a point p formed by a line formed by extending the outer leg of each of the two permanent magnets 3q located at both ends in the circumferential direction to the inner diameter side (the lower side in the figure) and the magnet fitting shown in the left side of the figure. The figure shows the angle of the central angle of the sector formed by the outer peripheral side (arc-shaped curve) of the mounting hole 30. r indicates the length of the radius of the sector.

  In this way, by formulating the shape of the permanent magnet 3q, it is possible to easily manufacture a pseudo arc-shaped magnet formed by using a plurality of permanent magnets 3q having the same trapezoidal shape. Accordingly, it is not necessary to manufacture an arc-shaped or cylindrical permanent magnet, and a substantially arc-shaped permanent magnet 3 can be formed using trapezoidal-shaped permanent magnet pieces, so that the manufacturing cost of the permanent magnet 3 is reduced. can do.

  As described above, according to the variable magnetic flux type rotating electric machine 500 of the fifth embodiment, the shape of the surface of the permanent magnet 3q perpendicular to the axial direction of the rotor 2 has a trapezoidal shape whose long side is the outer side of the rotor 2. It is configured to be. Thus, the substantially arc-shaped permanent magnet 3 can be formed by using the trapezoidal permanent magnet pieces, so that the manufacturing cost of the permanent magnet 3 can be reduced.

  Further, according to the variable magnetic flux type rotating electric machine 500 of the fifth embodiment, the shape of the permanent magnet 3q can be set using the above equation (1). Thereby, since the shape of the permanent magnet 3q can be formulated, a pseudo arc-shaped magnet formed by using a plurality of permanent magnets 3q having the same trapezoidal shape can be easily manufactured.

  As described above, the embodiments of the present invention and the modifications thereof have been described. However, the above embodiments and the modifications are only a part of the application examples of the present invention, and the technical scope of the present invention is not limited to the above embodiments. The purpose is not limited to a specific configuration. Further, the above-described embodiment and its modified examples can be appropriately combined.

  In the above description, the inequality sign “≧” with an equal sign is used to specify the magnitude of the coercive force and the residual magnetic flux density of the permanent magnet piece. This is based on the premise that the permanent magnet pieces constituting the permanent magnet 3 include at least two kinds of different magnetic characteristics.

DESCRIPTION OF SYMBOLS 1 ... Stator 2 ... Rotor 3a, 3b, 3c, 3d, 3e, 3f, 3g, 3h, 3i, 3j, 3k, 3l, 3m, 3n, 3o, 3p, 3q ... Permanent magnet 5 ... Flux barrier 12 ... Rotor core 30: magnet fitting hole

Claims (8)

A stator that generates a rotating magnetic field, and a variable magnetic flux type rotating electric machine including a stator and a rotor arranged via an air gap having a predetermined width,
The rotor,
A rotor core,
A plurality of flux barriers provided in the circumferential direction in the rotor core,
A magnet fitting hole in which a permanent magnet is fitted, disposed between the plurality of flux barriers,
In the magnet fitting hole, the depth from the outer circumferential surface of the rotor core at the circumferential center on the outer circumferential side is set to be smaller than the depth from the outer circumferential surface of the rotor core at the circumferential end on the outer circumferential side. A plurality of permanent magnets having different magnetic properties are fitted side by side in the circumferential direction to form one magnetic pole,
A variable magnetic flux type rotating electric machine characterized by the above-mentioned. The magnetic characteristics are at least one of a magnetic field orientation direction, a residual magnetic flux density, and a coercive force.
The variable magnetic flux type rotating electric machine according to claim 1, wherein: Among the plurality of permanent magnets constituting the one magnetic pole, the magnetic field orientation direction of at least one of the permanent magnets disposed at the circumferential end of the magnet fitting hole is in a radial direction at the center of the permanent magnet. On the other hand, it is set in a direction inclined by a predetermined angle α to the adjacent circumferential end portion side of the magnet fitting hole,
The residual magnetic flux density of the at least one permanent magnet is larger than the residual magnetic flux densities of the other permanent magnets,
The variable magnetic flux type rotating electric machine according to claim 1 or 2, wherein: Among the plurality of permanent magnets constituting the one magnetic pole, the coercive force of the permanent magnet located rearmost in the rotation direction of the rotor in the magnet fitting hole is larger than the coercive force of the other permanent magnets. large,
The variable magnetic flux type rotating electric machine according to any one of claims 1 to 3, wherein: The residual magnetic flux densities of the plurality of permanent magnets constituting the one magnetic pole are highest in the permanent magnet disposed in the circumferential center of the magnet fitting hole, and the permanent magnet disposed in the circumferential end portion side. As low as
The variable magnetic flux type rotating electric machine according to any one of claims 1 to 4, wherein: The permanent magnet is configured such that the shape of a surface perpendicular to the axial direction of the rotor is a rectangular shape,
The variable magnetic flux type rotating electric machine according to any one of claims 1 to 5, wherein: The permanent magnet is configured such that a shape of a surface perpendicular to an axial direction of the rotor has a trapezoidal shape with a long side on an outer peripheral side of the rotor.
The variable magnetic flux type rotating electric machine according to claim 6, wherein: The number of the plurality of permanent magnets fitted in the magnet fitting hole is n, the length of the long side of the trapezoidal shape of the permanent magnet is X, the internal angle between the long side and the leg is θ, The center angle of the sector formed by the arc-shaped curve connecting the circumferential ends of the magnet fitting hole on the outer diameter side and the intersection point when the two legs at the circumferential end extend to the inner diameter side. φ and the radius of the sector is r,
The X and the θ are set so as to satisfy the following equation (1).

The variable magnetic flux type rotating electric machine according to claim 7, characterized in that:

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