JP5472334B2 - Permanent magnet embedded rotor - Google Patents

Description

  The present invention relates to a permanent magnet embedded rotor configured by embedding a permanent magnet inside a substantially cylindrical rotor core.

  Conventionally, a permanent magnet embedded rotor has been used as a field element of a radial gap motor. 11 and 12 are cross-sectional views of a conventional permanent magnet embedded rotor 110 cut along a plane perpendicular to the rotation axis. As shown in FIGS. 11 and 12, the embedded permanent magnet rotor 110 has a substantially cylindrical rotor core 111 made of a high magnetic material such as iron, and a plurality of permanent magnets are provided inside the rotor core 111 along the circumferential direction. The magnet 113 is embedded.

  In such a permanent magnet embedded rotor 110, there are a direction in which the magnetic flux easily passes and a direction in which the magnetic flux does not easily pass in the radial direction, and this property is called magnetic saliency (or reverse saliency). When the embedded permanent magnet rotor 110 is operated, “magnet torque” is generated by the magnetic flux between the permanent magnet 113 and the stator, and “reluctance torque” is generated due to the saliency. For this reason, the permanent magnet embedded rotor 110 can obtain a high torque as a whole.

  Such a conventional permanent magnet embedded rotor is disclosed in Patent Document 1, for example.

JP 2003-111321 A

  In the permanent magnet embedded rotor 110, as shown in FIG. 11, a dm axis as a magnetic pole central axis related to magnet torque and a qm axis as a magnetic pole boundary axis related to magnet torque are defined. Further, in the same embedded permanent magnet rotor 110, as shown in FIG. 12, a dr axis as a magnetic pole central axis for reluctance torque and a qr axis as a magnetic pole boundary axis for reluctance torque are defined.

  When operating such a permanent magnet embedded rotor 110, it is operated while controlling the current phase so that the magnet torque and the reluctance torque can be obtained most efficiently as a whole. However, as shown in FIGS. 11 and 12, in the conventional permanent magnet embedded rotor 110, the dm-axis and the qr-axis normally coincide with each other, and the dr-axis and the qm-axis coincide with each other. For this reason, as shown in FIG. 13, when the current phase is advanced to increase the reluctance torque, the magnet torque decreases, and as a result, only the torque increase obtained by subtracting the decrease in magnet torque from the increase in reluctance torque can be obtained. could not.

  In this regard, Patent Document 1 discloses a configuration in which permanent magnets are unevenly distributed in the permanent magnet embedding holes of the rotor core. If the permanent magnets are unevenly distributed in this way, the phase relationship between the magnet torque and the reluctance torque is shifted, and there is a possibility that the magnet torque and the reluctance torque can be used efficiently. However, in the configuration of Patent Document 1, it is necessary to enlarge the gap portion in the permanent magnet embedding hole in order to make the permanent magnet unevenly distributed. For this reason, there has been a problem that the amount of permanent magnets embedded in the rotor core is reduced.

  The present invention has been made in view of such circumstances, and provides a permanent magnet embedded rotor that can efficiently use magnet torque and reluctance torque without reducing the amount of permanent magnet embedded. With the goal.

In order to solve the above-mentioned problem, the invention according to claim 1 is a permanent magnet embedded rotor (80), wherein a rotor core (81) having a substantially cylindrical shape having a plurality of permanent magnet embedding holes (82), and the rotor core ( 81) a plurality of permanent magnets (83) embedded in each of the plurality of permanent magnet embedding holes (82), and each of the plurality of permanent magnet embedding holes (82) is the permanent magnet An embedded portion (82a) for embedding (83), and a gap portion that is adjacent to the outer peripheral surface of the rotor core (81) at both circumferential ends of the embedded portion (82a) and does not embed the permanent magnet (83). (82b, 82c) and has, on the outer peripheral surface of the rotor core (81) in the magnetic pole boundary of the plurality of permanent magnets (83) are recesses (81c) are formed only in the rotational direction forward side The above End of the rotating direction forward side of the section is, from the end of the rotation direction forward side of the gap portion which faces the recess, characterized in that positioned in the rotational direction reverse side.
The invention according to claim 2 is the permanent magnet embedded rotor according to claim 1 (80), before Symbol recess while facing in the air gap portion in a radial direction, the rotational direction than the gap portion Extends to the reverse side.

  According to the first aspect of the present invention, the outer circumferential surface of the rotor core at the magnetic pole boundary portion of the plurality of permanent magnets is formed with a recess on the forward side in the rotational direction. For this reason, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole center axis (dr axis) for the reluctance torque are deviated, thereby reducing the magnet torque and the reluctance torque without reducing the amount of embedded permanent magnets. Can be used efficiently.

It is sectional drawing of the motor containing a rotor. It is sectional drawing of the rotor which concerns on 1st Embodiment. It is the graph which showed the waveform of the magnet torque and the reluctance torque in the rotor of this invention. It is sectional drawing of the rotor which concerns on 2nd Embodiment. It is sectional drawing of the rotor which concerns on 3rd Embodiment. It is sectional drawing of the rotor which concerns on 4th Embodiment. It is sectional drawing of the rotor which concerns on 5th Embodiment. It is sectional drawing of the rotor which concerns on 6th Embodiment. It is sectional drawing of the rotor which concerns on 7th Embodiment. It is sectional drawing of the rotor which concerns on 8th Embodiment. It is sectional drawing of the conventional permanent magnet embedded type rotor. It is sectional drawing of the conventional permanent magnet embedded type rotor. It is the graph which showed the waveform of the magnet torque and reluctance torque in the conventional rotor.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

<1. First Embodiment>
FIG. 1 is a cross-sectional view of a motor 1 including a rotor 10 according to a first embodiment of the present invention, cut along a plane perpendicular to a rotation axis. As shown in FIG. 1, the motor 1 includes a substantially cylindrical stator 90 and a substantially cylindrical rotor 10 disposed on the inner peripheral side of the stator 90. It has a function of generating a rotational force (torque) by the action of the magnetic flux between them.

  The stator 90 has a stator core 91 composed of a laminated steel plate or a dust core. A plurality of tooth portions 92 are formed to protrude from the inner peripheral surface of the stator core 91, and a coil 93 is wound around each tooth portion 92. On the other hand, the rotor 10 includes a rotor core 11 made of a high magnetic material such as iron, and a plurality of permanent magnets 13 embedded in the rotor core 11. The rotor 10 is fitted and fixed to a shaft 99 extending along the rotation axis, and rotates together with the shaft 99.

  FIG. 2 is an enlarged view of the rotor 10 of FIG. The rotor core 11 of the rotor 10 is formed with a plurality (six in this embodiment) of permanent magnet embedding holes 12 penetrating in the rotation axis direction. A permanent magnet 13 is embedded in each of the plurality of permanent magnet embedding holes 12. The plurality of permanent magnet embedding holes 12 and the plurality of permanent magnets 13 are arranged along the circumferential direction of the rotor core 11. The plurality of permanent magnets 13 are arranged so that the directions of the magnetic poles alternate along the circumferential direction (that is, the directions of the magnetic poles of adjacent permanent magnets 13 are opposite to each other). Yes.

  As shown in FIG. 2, each permanent magnet embedding hole 12 includes an embedding portion 12a for embedding the permanent magnet 13, and a flux barrier portion extending in the outer circumferential surface direction of the rotor core 11 at both ends in the circumferential direction of the embedding portion 12a. (Void part) 12b, 12c. The flux barrier portions 12 b and 12 c have a function of preventing the magnetic flux from being short-circuited by the permanent magnet 13 in the rotor core 11. The tip portions 12d and 12e of the flux barrier portions 12b and 12c are close to the outer peripheral surface of the rotor core 11, respectively. In this way, the plurality of permanent magnet embedding holes 12 are substantially U-shaped perforations opened in the direction of the outer peripheral surface of the rotor core 11 in a cross-sectional view.

  In the rotor 10 of the present embodiment, the shape of the flux barrier portion 12b on the forward side in the rotational direction (the direction of the arrow AR in FIG. 2) is different from the shape of the flux barrier portion 12c on the reverse side in the rotational direction. Specifically, each of the flux barrier portions 12b and 12c is set so that the circumferential width of the flux barrier portion 12c on the reverse side in the rotational direction is larger than the circumferential width of the flux barrier portion 12b on the forward side in the rotational direction. The width is specified.

  In such a motor 1, when a current is supplied to the coil 93 of the stator 90 to generate a magnetic pole in the tooth portion 92, magnet torque is generated between the magnetic pole of the tooth portion 92 and the magnetic pole of the permanent magnet 13 in the rotor 10. Occurs and the rotor 10 rotates. Further, since the rotor 10 has saliency, in addition to the magnet torque described above, a reluctance torque generated by the magnetic flux between the core portion 11a and the tooth portion 92 can be obtained.

  In the rotor 10 of the present embodiment, as described above, the circumferential width of the flux barrier portion 12c on the reverse side in the rotational direction is larger than the circumferential width of the flux barrier portion 12b on the forward side in the rotational direction. The width of each flux barrier portion 12b, 12c is defined. Therefore, as shown in FIG. 2, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque do not coincide with each other, and the dr axis rotates in the rotation direction with respect to the qm axis. It is in a state shifted by a minute angle Δθm to the reverse side. Further, when the number of pole pairs of the rotor 10 is Pn (3 in the present embodiment), the deviation of the minute angle Δθm is an electric angle deviation of Δθ = Pn · Δθm as a whole, and the reluctance torque generated in the rotor 10. Is shifted to the minus side by the electrical angle Δθ.

  That is, the torque T generated in the rotor 10 having the flux barrier portions 12b and 12c as in the present embodiment can be expressed by the following equation (Equation 1). In (Equation 1), φa represents the flux linkage, Ia represents the magnitude of the current vector, θ represents the current phase, Lq represents the q-axis inductance, and Ld represents the d-axis inductance. Further, the first term on the right side in (Equation 1) indicates the magnet torque Tm, and the second term indicates the reluctance torque Tr.

T = Pn · [φa · Ia · cos β + 0.5 · (Lq−Ld) · Ia ² · sin {2 · (β + Δθ)] (Equation 1)

  FIG. 3 is a graph showing the relationship between the current phase β, the magnet torque Tm, and the reluctance torque Tr in the rotor 10 having the flux barrier portions 12b and 12c as in the present embodiment. As shown in the graph of FIG. 3, the waveform of the reluctance torque Tr obtained in the rotor 10 is shifted to the minus side by the electrical angle Δθ as compared with the conventional waveform (broken line waveform in FIG. 3). It has become. For this reason, the maximum value of the total torque T including the magnet torque Tm and the reluctance torque Tr is higher than the conventional value. If the motor 1 is operated while controlling the current phase β, the torque T higher than the conventional value Can be obtained.

  Thus, in the rotor 10 of the present embodiment, each circumferential width of the flux barrier portion 12c on the reverse side in the rotational direction is larger than the circumferential width of the flux barrier portion 12b on the forward side in the rotational direction. The widths of the flux barrier portions 12b and 12c are defined. That is, the shape of the portion of the permanent magnet embedding hole 12 where the permanent magnet 13 is not embedded is adjusted, thereby realizing a state in which the dr axis is deviated from the qm axis. For this reason, the magnet torque Tm and the reluctance torque Tr can be efficiently used without reducing the amount of the permanent magnet 13 embedded. Alternatively, a torque equivalent to the conventional torque can be obtained with a relatively low current.

  In particular, in the rotor 10 of the present embodiment, the circumferential widths of the flux barrier portions 12b and 12c are substantially the same from the inner peripheral side to the outer peripheral side. For this reason, the short circuit of magnetic flux can be reliably prevented from the inner peripheral side to the outer peripheral side.

  Moreover, in the rotor 10 of this embodiment, the permanent magnet 13 is contained in the embedded portion 12a without protruding into the flux barrier portions 12b and 12c of the permanent magnet embedded hole 12. That is, the magnetic pole surface (the surface facing the radial direction) of the permanent magnet 13 is not exposed in the gaps of the flux barrier portions 12b and 12c. For this reason, an air gap does not occur in the magnetic pole direction of the permanent magnet 13, and the magnetic flux of the permanent magnet 13 can be used efficiently.

  In the rotor 10 of the present embodiment, the circumferential width of the core portion 11a sandwiched between adjacent flux barrier portions 12b and 12c is substantially the same from the inner peripheral side to the outer peripheral side. For this reason, the saturation characteristic of the core part 11a with respect to reluctance torque improves, and reluctance torque can be obtained more efficiently.

  The rotor 10 of this embodiment is suitable for low speed operation. For this reason, for example, if the motor of this embodiment is applied to the compressor for an air conditioner, high-efficiency and long-time operation can be realized particularly in a low-speed region with a large copper loss ratio.

<2. Second Embodiment>
FIG. 4 is a diagram showing a configuration of the rotor 20 according to the second embodiment of the present invention. The rotor 20 of the second embodiment is different from the first embodiment in the configuration of the flux barrier portions 22b and 22c of the permanent magnet embedding hole 22, and the configuration of the other parts is the same as that of the first embodiment. . For this reason, below, it demonstrates centering on the structure of the flux barrier parts 22b and 22c, and abbreviate | omits duplication description about another part. In addition, the configuration of the shaft 99 and the stator 90 connected to the rotor 20 of the present embodiment is also the same as that of the first embodiment described above, and thus a duplicate description is omitted.

  In the rotor 20 of the present embodiment, the shape of the flux barrier portion 22b on the forward side in the rotational direction (the direction of the arrow AR in FIG. 4) is different from the shape of the flux barrier portion 22c on the reverse side in the rotational direction. Specifically, the flux barrier portion 22b on the forward side in the rotational direction has a tapered shape (tapered shape) whose width becomes narrower toward the outer peripheral surface of the rotor core 21. Therefore, the width of the front end portion 22e of the flux barrier portion 22c on the reverse side in the rotational direction is larger than the width of the front end portion 22d of the flux barrier portion 22b on the forward side in the rotational direction.

  For this reason, in the rotor 20 of the present embodiment, as with the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, when the deviation of the electrical angle of the entire rotor 20 is Δθ, the torque T generated in the rotor 20 can be expressed by the above (Equation 1). Further, the waveform of the reluctance torque Tr obtained in the rotor 20 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 20 of this embodiment, the taper shape of the flux barrier portion 22b is realized by inclining (notching) the surface 22f on the rotation direction advance side of the flux barrier portion 22b on the rotation direction advance side toward the gap side. ing. For this reason, the width | variety of the core part 21a pinched | interposed between adjacent flux barrier parts 22b and 22c expands, and it becomes easy for magnetic flux to approach with respect to the core part 21a from the teeth part 92 of the stator 90. FIG. Thereby, the rotor 20 can obtain a higher reluctance torque. In addition, since the uniformity near the surface of the rotor core 21 is improved, the occurrence of cogging can be reduced.

  In the rotor 20 of the present embodiment, although the flux barrier portion 22b is tapered, the tip portion 22d is not completely converged and a predetermined width remains in the circumferential direction. For this reason, the function which prevents the short circuit of the magnetic flux of the flux barrier part 22b does not fall remarkably.

<3. Third Embodiment>
FIG. 5 is a view showing a configuration of the rotor 30 according to the third embodiment of the present invention. The rotor 30 of the third embodiment is different from the first embodiment in the configuration of the flux barrier portions 32b and 32c of the permanent magnet embedding hole 32, and the configuration of the other parts is the same as that of the first embodiment. . For this reason, below, it demonstrates centering on the structure of the flux barrier parts 32b and 32c, and abbreviate | omits duplication description about another part. In addition, the configuration of the shaft 99 and the stator 90 connected to the rotor 30 of the present embodiment is also the same as that of the first embodiment, and a duplicate description is omitted.

  In the rotor 30 of the present embodiment, the shape of the flux barrier portion 32b in the rotational direction (the direction of the arrow AR in FIG. 5) is different from the shape of the flux barrier portion 32c in the reverse direction of the rotational direction. Specifically, the flux barrier portion 32 b on the forward side in the rotational direction has a tapered shape (tapered shape) whose width decreases toward the outer peripheral surface of the rotor core 31. Therefore, the width of the tip 32e of the flux barrier 32c on the reverse side in the rotational direction is larger than the width of the tip 32d of the flux barrier 32b on the forward side in the rotational direction.

  For this reason, in the rotor 30 of the present embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque coincide with each other as in the rotor 10 of the first embodiment. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, when the deviation of the electrical angle of the entire rotor 30 is Δθ, the torque T generated in the rotor 30 can be expressed by the above (Equation 1). Further, the waveform of the reluctance torque Tr obtained in the rotor 30 of the present embodiment is shifted to the minus side by the electrical angle Δθ as in FIG. 3, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 30 of this embodiment, the taper shape of the flux barrier portion 32b is realized by inclining (notching) the surface 32g on the reverse side in the rotational direction of the flux barrier portion 32b on the forward side in the rotational direction. ing. For this reason, the circumferential width of the core portion 31a sandwiched between the adjacent flux barrier portions 32b and 32c is substantially the same from the inner peripheral side to the outer peripheral side. Thereby, the saturation characteristic of the core part 31a with respect to reluctance torque improves, and reluctance torque can be obtained more efficiently. Further, since the uniformity near the surface of the rotor core 31 is improved, the occurrence of cogging can be reduced.

  In the rotor 30 of the present embodiment, the flux barrier portion 32b is tapered, but the tip portion 32d is not completely converged, and a predetermined width remains in the circumferential direction. For this reason, the function which prevents the short circuit of the magnetic flux of the flux barrier part 32b does not fall remarkably.

<4. Fourth Embodiment>
FIG. 6 is a view showing a configuration of a rotor 40 according to the fourth embodiment of the present invention. In the rotor 40 of the fourth embodiment, the configuration of the flux barrier portions 42b and 42c of the permanent magnet embedding hole 42 is different from that of the first embodiment, and the configuration of the other parts is the same as that of the first embodiment. . For this reason, below, it demonstrates centering on the structure of the flux barrier parts 42b and 42c, and abbreviate | omits duplication description about another part. In addition, the configuration of the shaft 99 and the stator 90 connected to the rotor 40 of the present embodiment is also the same as that of the first embodiment, and therefore redundant description is omitted.

  In the rotor 40 of the present embodiment, the shape of the flux barrier portion 42b in the rotational direction (the direction of the arrow AR in FIG. 6) is different from the shape of the flux barrier portion 42c in the reverse direction of the rotational direction. Specifically, the flux barrier portion 42 b on the forward side in the rotational direction has a tapered shape (tapered shape) that decreases in width toward the outer peripheral surface of the rotor core 41. Therefore, the width of the tip end portion 42e of the flux barrier portion 42c on the reverse side in the rotational direction is larger than the width of the tip portion 32d of the flux barrier portion 42b on the forward side in the rotational direction.

  For this reason, in the rotor 40 of the present embodiment, as with the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, when the deviation of the electrical angle of the entire rotor 40 is Δθ, the torque T generated in the rotor 40 can be expressed by the above (Equation 1). In addition, the waveform of the reluctance torque Tr obtained in the rotor 40 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 40 of the present embodiment, the surface 42f on the rotational direction advance side and the surface 42g on the reverse direction in the rotational direction of the flux barrier portion 42b on the rotational direction advance side are both inclined (notched) toward the air gap side. The taper shape of the flux barrier portion 42b is realized. For this reason, the taper shape of the flux barrier part 42b can be formed at an optimum angle. Further, the width of the core portion 41a sandwiched between the adjacent flux barrier portions 42b and 42c is increased, and the magnetic flux easily enters the core portion 41a from the teeth portion 92 of the stator 90. Thereby, the rotor 40 can obtain a higher reluctance torque. Further, since the uniformity near the surface of the rotor core 41 is improved, the occurrence of cogging can be reduced.

<5. Fifth Embodiment>
FIG. 7 is a view showing a configuration of a rotor 50 according to the fifth embodiment of the present invention. The rotor 50 of the fifth embodiment is different from the first embodiment in the configuration of the flux barrier portions 52b and 52c of the permanent magnet embedding hole 52, and the configuration of the other parts is the same as that of the first embodiment. . For this reason, below, it demonstrates centering on the structure of the flux barrier parts 52b and 52c, and abbreviate | omits duplication description about another part. In addition, since the configuration of the shaft 99 and the stator 90 connected to the rotor 50 of the present embodiment is also the same as that of the first embodiment, a duplicate description is omitted.

  In the rotor 50 of the present embodiment, the shape of the flux barrier portion 52b on the forward side in the rotational direction (the direction of the arrow AR in FIG. 7) is different from the shape of the flux barrier portion 52c on the reverse side in the rotational direction. Specifically, the flux barrier portion 52b on the forward side in the rotational direction has a tapered shape (tapered shape) whose width decreases toward the outer peripheral surface of the rotor core 51, and the flux barrier portion 52c on the reverse side in the rotational direction The rotor core 51 has a substantially sector shape that increases in width toward the outer peripheral surface. Therefore, the width of the front end portion 52e of the flux barrier portion 52c on the reverse side in the rotational direction is larger than the width of the front end portion 52d of the flux barrier portion 52b on the forward side in the rotational direction.

  For this reason, in the rotor 50 of the present embodiment, as with the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, if the deviation of the electrical angle of the entire rotor 50 is Δθ, the torque T generated in the rotor 50 can be expressed by the above (Equation 1). Further, the waveform of the reluctance torque Tr obtained in the rotor 50 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 50 of the present embodiment, the width of the flux barrier portion 52b on the forward side in the rotational direction is narrowed toward the outer peripheral surface, and the width of the flux barrier portion 52c on the reverse side in the rotational direction is increased toward the outer peripheral surface. ing. For this reason, the deviation angle between the qm axis and the dr axis can be made larger.

  In the rotor 50 of the present embodiment, the circumferential width of the core portion 51a sandwiched between the adjacent flux barrier portions 52b and 52c is substantially the same from the inner peripheral side to the outer peripheral side. For this reason, the saturation characteristic of the core part 51a with respect to reluctance torque improves, and reluctance torque can be obtained more efficiently.

<6. Sixth Embodiment>
FIG. 8 is a view showing a configuration of a rotor 60 according to the sixth embodiment of the present invention. The rotor 60 of the sixth embodiment is a quadrupole machine and the configuration of the flux barrier portions 62b and 62c of the permanent magnet embedding hole 62 is different from that of the first embodiment, and the configuration of the other parts is the above. This is equivalent to the first embodiment. For this reason, below, it demonstrates centering on the structure of the flux barrier parts 62b and 62c, and abbreviate | omits duplication description about another part. In addition, since the configuration of the shaft 99 and the stator 90 connected to the rotor 60 of the present embodiment is also equivalent to that of the first embodiment described above, redundant description is omitted.

  In the rotor 60 of this embodiment, the shape of the flux barrier portion 62b on the forward side in the rotational direction (the direction of the arrow AR in FIG. 8) is different from the shape of the flux barrier portion 62c on the reverse side in the rotational direction. Specifically, the flux barrier portion 62 c on the reverse side in the rotational direction has a substantially sector shape that increases in width toward the outer peripheral surface of the rotor core 61. Therefore, the width of the front end 62e of the flux barrier 62c on the reverse side in the rotational direction is larger than the width of the front end 62d of the flux barrier 62b on the forward side in the rotational direction.

  For this reason, in the rotor 60 of the present embodiment, as in the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, if the deviation of the electrical angle of the entire rotor 60 is Δθ, the torque T generated in the rotor 60 can be expressed by the above (Equation 1). In addition, the waveform of the reluctance torque Tr obtained in the rotor 60 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 60 of the present embodiment, the substantially vertical fan shape of the flux barrier portion 62c is realized by inclining the surface 62h in the rotational direction forward side of the flux barrier portion 62c in the rotational direction backward to the permanent magnet 63 side. . For this reason, the circumferential width of the core portion 61a sandwiched between the adjacent flux barrier portions 62b and 62c is substantially the same from the inner peripheral side to the outer peripheral side. Thereby, the saturation characteristic of the core part 61a with respect to reluctance torque improves, and reluctance torque can be obtained more efficiently. Further, the circumferential width of the flux barrier portion 62b on the forward side in the rotational direction is substantially the same from the inner peripheral side to the outer peripheral side. For this reason, the minimum shape necessary for preventing a short circuit of the magnetic flux can be ensured.

<7. Seventh Embodiment>
FIG. 9 is a view showing a configuration of a rotor 70 according to the seventh embodiment of the present invention. The rotor 70 of the seventh embodiment is a quadrupole machine, and the configuration of the flux barrier portions 72b and 72c of the permanent magnet embedding hole 72 and the configuration of the auxiliary hole 74 are different from the first embodiment, The structure of other parts is the same as that of the first embodiment. For this reason, below, it demonstrates focusing on the structure of the flux barrier parts 72b and 72c and the auxiliary hole 74, and abbreviate | omits duplication description about another part. In addition, since the configurations of the shaft 99 and the stator 90 connected to the rotor 70 of the present embodiment are the same as those of the first embodiment, a duplicate description is omitted.

  In the rotor 70 of the present embodiment, the circumferential widths of the flux barrier portions 72b and 72c are substantially the same from the inner peripheral side to the outer peripheral side. An auxiliary hole 74 formed separately from the flux barrier portion 72c is provided in the vicinity of the flux barrier portion 72c on the reverse side in the rotation direction (the direction of the arrow AR in FIG. 9). The auxiliary hole 74 is formed as a through hole having a substantially fan-shaped cross section at a position that is on the more forward side in the rotational direction than the flux barrier portion 72 c and does not greatly enter the magnetic path of the permanent magnet 73.

  For this reason, in the rotor 70 of the present embodiment, as with the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, when the deviation of the electrical angle of the entire rotor 70 is Δθ, the torque T generated in the rotor 70 can be expressed by the above (Equation 1). Also, the waveform of the reluctance torque Tr obtained in the rotor 70 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3 described above, and if the current phase β is suitably controlled, Higher torque T can be obtained.

  In particular, in the rotor 70 of the present embodiment, the auxiliary hole 74 is formed on the forward side in the rotational direction with respect to the flux barrier portion 72c. For this reason, the circumferential width of the core portion 71a sandwiched between the adjacent flux barrier portions 72b and 72c is substantially the same from the inner peripheral side to the outer peripheral side. Thereby, the saturation characteristic of the core part 71a with respect to reluctance torque improves, and reluctance torque can be obtained more efficiently.

  Further, in the rotor 70 of the present embodiment, the flux barrier portion 62c itself is not enlarged as in the rotor 60 of the sixth embodiment, but an auxiliary hole 74 separate from the flux barrier portion 72c is provided. For this reason, a thin portion 71 b of the rotor core 71 is formed between the flux barrier portion 72 c and the auxiliary hole 74. As a result, the strength of the rotor core 71 is improved, and a minute magnetic flux path is formed between the flux barrier portion 72c and the auxiliary hole 74, thereby reducing the spatial harmonics of the magnetic flux.

<8. Eighth Embodiment>
FIG. 10 is a view showing a configuration of a rotor 80 according to the eighth embodiment of the present invention. The rotor 80 of the eighth embodiment is a quadrupole machine, and the configuration of the flux barrier portions 82b and 82c of the permanent magnet embedding hole 82 and the configuration of the recess 81c are different from those of the first embodiment described above. The configuration of this part is the same as that of the first embodiment. For this reason, below, it demonstrates centering around the structure of the flux barrier parts 82b and 82c, and the recessed part 81c, and abbreviate | omits duplication description about another part. In addition, since the configuration of the shaft 99 and the stator 90 connected to the rotor 80 of the present embodiment is also equivalent to that of the first embodiment described above, duplicate description is omitted.

  In the rotor 80 according to the present embodiment, the flux barrier portions 82 b and 82 c of the permanent magnet embedding hole 82 have a substantially fan shape whose width increases toward the outer peripheral surface of the rotor core 81. A plurality (four in this embodiment) of recesses 81 c are formed on the outer peripheral surface of the rotor 81. The recess 81 c is formed in a portion on the forward side in the rotational direction on the outer peripheral surface of the rotor core 81 at the magnetic pole boundary of the permanent magnet 83. In other words, the concave portion 81c is formed on the outer peripheral surface of the rotor core 81 including the outer peripheral portion of the flux barrier portion 82c on the reverse side in the rotational direction. As a result, the air gap between the outer peripheral surface of the rotor core 81 and the stator 90 partially increases in the recess 81c. In the rotor 80 of the present embodiment, the air gap on the forward side in the rotational direction is larger than the air gap on the backward side in the rotational direction at the outer peripheral portion of the core portion 81a, so that the magnetic pole central axis (dr Axis) is substantially deviated to the reverse side in the rotational direction with respect to the magnetic pole boundary axis (qm axis) with respect to the magnet torque.

  For this reason, in the rotor 80 of the present embodiment, as with the rotor 10 of the first embodiment, the magnetic pole boundary axis (qm axis) for the magnet torque and the magnetic pole central axis (dr axis) for the reluctance torque match. First, the dr axis is shifted from the qm axis by a small angle toward the reverse side in the rotational direction. Therefore, when the deviation of the electrical angle of the entire rotor 80 is Δθ, the torque T generated in the rotor 80 can be expressed by the above (Equation 1). Further, the waveform of the reluctance torque Tr obtained in the rotor 80 of the present embodiment is in a state shifted to the minus side by the electrical angle Δθ as in FIG. 3 described above, and if the current phase β is suitably controlled, Higher torque T can be obtained.

<9. Modification>
As mentioned above, although main embodiment of this invention was described, this invention is not limited to said example. For example, in the above first to fifth embodiments, a six-pole machine has been described, and in the sixth to eighth embodiments, a four-pole machine has been described, but the number of poles of the rotor of the present invention is limited to the above example. Is not to be done.

  In FIG. 1, a distributed winding type stator 90 is shown as an example of the stator 90, but the stator used together with the rotor of the present invention is not limited to the distributed winding type stator 90. For example, a concentrated winding type stator or other types of stators may be used.

1 Motor 10, 20, 30, 40, 50, 60, 70, 80 Rotor 11, 21, 31, 41, 51, 61, 71, 81 Rotor core 11a, 21a, 31a, 41a, 51a, 61a, 71a, 81a Core Portions 12, 22, 32, 42, 52, 62, 72, 82 Permanent magnet embedding holes 12a, 22a, 32a, 42a, 52a, 62a, 72a, 82a Buried portions 12b, 12c, 22b, 22c, 32b, 32c, 42b, 42c, 52b, 52c, 62b, 62c, 72b, 72c, 82b, 82c Flux barrier portion 12d, 12e, 22d, 22e, 32d, 32e, 42d, 42e, 52d, 52e, 62d, 62e Tip portion 13, 23 , 33, 43, 53, 63, 73, 83 Permanent magnet 74 Auxiliary hole 81c Recess 90 Stator 91 Teta Core 92 Teeth 93 Coil 99 Shaft

Claims (2)

In the permanent magnet embedded rotor (80),
A substantially cylindrical rotor core (81) having a plurality of permanent magnet embedding holes (82);
A plurality of permanent magnets (83) embedded in each of the plurality of permanent magnet embedding holes (82) of the rotor core (81);
With
Each of the plurality of permanent magnet embedding holes (82)
An embedded portion (82a) for embedding the permanent magnet (83);
Gap portions (82b, 82c) that are close to the outer peripheral surface of the rotor core (81) at both circumferential ends of the embedded portion (82a) and do not embed the permanent magnet (83);
Have
On the outer peripheral surface of the rotor core (81) at the magnetic pole boundary of the plurality of permanent magnets (83), a recess (81c) is formed only on the forward side in the rotational direction ,
The permanent magnet-embedded rotor (80) , wherein an end of the concave portion on the forward side in the rotational direction is positioned on the backward side in the rotational direction with respect to an end on the forward side in the rotational direction of the gap facing the concave portion . Before SL recess while facing in the air gap portion in a radial direction, extends in the direction of rotation reverse side of the gap portion, the permanent magnet embedded rotor according to claim 1 (80).

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