JP5621372B2 - Permanent magnet embedded rotor and rotating electric machine - Google Patents

Description

  In the present invention, a first permanent magnet extending in a direction orthogonal to the d-axis is embedded on the outer peripheral surface side of the rotor core, and a second permanent magnet is embedded so as to extend along the q-axis. The present invention relates to a permanent magnet embedded rotor in which a gap is formed in a rotor core away from a magnet on the q-axis side, and a rotary electric machine including the permanent magnet embedded rotor.

  An example of the rotating electrical machine is Patent Document 1. As shown in FIG. 4, the permanent magnet type reluctance type rotating electrical machine 90 of Patent Document 1 includes a stator 92 having a plurality of armature coils 91 and a rotor 93 inside the stator 92. Yes.

  The rotor 93 includes a cylindrical rotor core 94 and a plurality of magnetic poles. In the direction along each magnetic pole axis of the rotor core 94, rectangular first cavities 95 are formed at intervals of the magnetic pole width. The first cavity 95 is formed at a position where each magnetic pole is sandwiched from both sides. A first permanent magnet 96 is embedded in each of the first cavities 95. In the rotor core 94, a rectangular second cavity 97 is formed between the magnetic poles along the outer periphery of the rotor core 94. A second permanent magnet 98 is embedded in each of the second cavities 97.

  In the permanent magnet type reluctance type rotating electrical machine 90, the first permanent magnet 96 and the second permanent magnet 98 are provided in the rotor core 94, thereby increasing the reluctance torque, and the permanent magnet type reluctance type rotating electrical machine. The 90 torque is increased.

Japanese Patent No. 3597821

  By the way, in the permanent magnet type reluctance type rotating electrical machine 90 of Patent Document 1, since the second permanent magnet 98 is disposed on the surface of the rotor core 94, an alternating magnetic field linked to the second permanent magnet 98 is generated. In many cases, a large eddy current loss has occurred in the second permanent magnet 98. Due to this large eddy current loss, the temperature of the second permanent magnet 98 rises, the second permanent magnet 98 is demagnetized, and the torque of the permanent magnet type reluctance rotary electric machine 90 is lowered. Yes.

  Therefore, as a measure for reducing eddy current loss, a high coercive force magnet is used for the second permanent magnet 98, the thickness of the second permanent magnet 98 is increased, or the second permanent magnet 98 is divided into a plurality of parts. However, both are not preferable because the cost of the second permanent magnet 98 is increased.

  For this reason, in order to reduce the alternating magnetic field linked to the second permanent magnet 98, the second permanent magnet 98 is separated from the surface of the rotor core 94 as shown by a two-dot chain line in FIG. It is conceivable to move the embedded position of the permanent magnet 98 (the position where the second cavity 97 is formed) toward the inner peripheral surface of the rotor core 94. However, if the embedding position of the second permanent magnet 98 is moved toward the center of the rotor core 94, the second permanent magnet 98 and the first permanent magnet 96 approach each other, and the short-circuit magnetic flux increases. As a result, the magnetic flux across the stator 92 decreases, and the torque of the permanent magnet type reluctance rotating electrical machine 90 decreases.

  An object of the present invention is to provide an embedded permanent magnet rotor capable of reducing eddy current loss without reducing torque, and a rotating electrical machine including the embedded permanent magnet rotor.

In order to solve the above problems, the invention according to claim 1 is characterized in that the first permanent magnet is embedded in the direction perpendicular to the d axis near the outer peripheral surface of the rotor core inside the stator, and A second permanent magnet is embedded on both sides of the first permanent magnet so as to extend along the q-axis, and a permanent gap is formed in the rotor core away from both ends of the first permanent magnet toward the q-axis side. The present invention relates to a magnet embedded rotor. The gap has an outer peripheral side end located near the outermost peripheral surface of the rotor core and an inner peripheral side end located near the innermost peripheral surface of the rotor core, and the first permanent magnet is The magnetic pole surface of the first permanent magnet is positioned closer to the inner peripheral surface side of the rotor core than the outer peripheral end portion of the gap, and is positioned closer to the outer peripheral surface side of the rotor core than the inner peripheral side end portion of the gap. The gap is formed such that magnetic flux passes between the second permanent magnet and the gap .

  According to a sixth aspect of the present invention, the first permanent magnet is embedded near the outer peripheral surface of the stator and the rotor core inside the stator so as to extend in a direction orthogonal to the d-axis, and the first A second permanent magnet is embedded on both sides of the permanent magnet so as to extend along the q-axis, and a permanent magnet embedded in which a gap is formed in the rotor core away from both ends of the first permanent magnet toward the q-axis side. The present invention relates to a rotary electric machine including a built-in rotor. And the said permanent magnet embedded type | mold rotor is a permanent magnet embedded type | mold rotor as described in any one of Claims 1-5.

  According to this, by setting the arrangement position of the first permanent magnet in the rotor core, even if the first permanent magnet is arranged near the outer peripheral surface of the rotor core, the first permanent magnet may be too close to the outer peripheral surface. Thus, eddy current loss generated on the surface of the first permanent magnet can be suppressed. Further, in order to reduce the alternating magnetic field interlinked with the first permanent magnet, when the first permanent magnet is separated from the outer peripheral surface of the rotor core and the first permanent magnet is disposed on the inner peripheral surface side of the rotor core, the first permanent magnet is It is prevented that the two permanent magnets are too close to each other, and the magnetic flux from the first permanent magnet to the stator is prevented from decreasing. As a result, eddy current loss can be reduced without reducing the torque of the rotating electrical machine.

  The stator includes a plurality of teeth arranged on an inner periphery of an annular stator core, and a straight line extending along a radial direction of the stator core and passing through an intermediate point in the width direction of the teeth is a center of the teeth. When the pitch between the central axes of adjacent teeth is P, the embedded depth of the first permanent magnet from the outer peripheral surface of the rotor core to the magnetic pole surface along the d axis is 1 / The first permanent magnet may be arranged so as to satisfy 10P <embedding depth <2 / 3P.

  According to this, by setting the range of the embedding depth of the first permanent magnet, it is possible to suitably exhibit the effect that the eddy current loss can be reduced without reducing the torque of the rotating electrical machine. .

  The first permanent magnet has a flat plate shape extending in a direction perpendicular to the d-axis, and the length of the first permanent magnet in the long side direction is set to 1 to 3 times the pitch. It may be.

  According to this, by setting the length of the first permanent magnet in the long side direction, it is possible to prevent the magnetic flux from being reduced due to the first permanent magnet becoming too short, and the gap and the second permanent in the magnetic pole. The arrangement of the magnets can be suitably set.

The interval between the second permanent magnet and the gap may be set to 0.3 to 2 times the pitch.
According to this, by setting the interval, it is possible to suppress an increase in torque ripple while suppressing a decrease in torque of the rotating electrical machine.

  In addition, the second permanent magnet is arranged in a V shape extending from the inner peripheral surface side of the rotor core toward the outer peripheral surface side, or an arc shape recessed from the outer peripheral surface side of the rotor core toward the inner peripheral surface side. Also good.

  According to this, the magnetic flux passing through the q-axis can be increased, and the reluctance torque of the rotating electrical machine can be increased.

  According to the present invention, eddy current loss can be reduced without reducing torque.

The top view which shows the permanent magnet embedding type rotary electric machine of embodiment. The elements on larger scale which show the magnetic pole in a permanent magnet embedded rotor. The elements on larger scale which show another example of a 2nd permanent magnet. The top view which shows background art.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, an embedded permanent magnet type rotating electrical machine M includes an annular stator 10 and an embedded permanent magnet rotor 15 (hereinafter simply referred to as a rotor) that is rotatably provided in the stator 10. 15). The stator 10 includes an annular stator core 11, and the stator core 11 is configured by laminating a plurality of core plates made of a magnetic material (steel plate).

  A plurality of teeth 13 are formed on the inner periphery of the stator core 11. A slot 12 is formed between the teeth 13 adjacent in the circumferential direction of the stator core 11. The stator 10 includes a plurality of coils 30 incorporated in a plurality of slots 12. Here, as shown in FIG. 2, when the length of the teeth 13 along the direction orthogonal to the radial direction of the stator core 11 is the width of the teeth 13, it passes through an intermediate point of the width of the teeth 13, and A straight line extending in the radial direction of the stator core 11 is a center axis TL of the teeth 13. In such a case, the width between the central axes TL of the adjacent teeth 13 is set as the pitch P between the teeth 13. Since the pitch P gradually increases from the tip end of the tooth 13 toward the base end, in this embodiment, the pitch P is the width between the center axes TL at the tip of the teeth 13 and the width between the center axes TL is the largest. Set to a small value.

  Next, the rotor 15 will be described. As shown in FIG. 1, the rotor 15 includes an annular rotor core 16, and the rotor core 16 is configured by laminating a plurality of core plates 161 made of a magnetic material (steel plate). Further, a shaft hole 16a is provided in the center of the rotor core 16, and an output shaft (not shown) of the permanent magnet embedded type rotating electrical machine M is passed through and fixed to the shaft hole 16a.

  One first permanent magnet 17 and two second permanent magnets 18 are embedded in each virtual region W obtained by equally dividing the rotor core 16 in the circumferential direction (eight divided in this embodiment). Each of the first permanent magnet 17 and the second permanent magnet 18 has a flat plate shape, and a cross section orthogonal to the central axis C of the rotor core 16 is formed in a rectangular shape.

  In each virtual region W, the rotor core 16 is provided with one magnetic pole by a set of magnet groups of one first permanent magnet 17 and two second permanent magnets 18. In the present embodiment, the magnet group is arranged at eight locations along the circumferential direction of the rotor core 16, whereby the rotor 15 includes eight magnetic poles, and the plurality of magnetic poles are alternately different in the circumferential direction of the rotor core 16. It is provided to be a magnetic pole. The d-axis 26 shown in FIG. 1 represents the direction of the magnetic flux generated by each magnetic pole (the axis orthogonal to the long side direction of the first permanent magnet 17 and passing between the two second permanent magnets 18), q The shaft 27 represents an axis that is electrically and magnetically orthogonal to the d-axis 26 and extends in an arc shape.

  As shown in FIG. 2, in each virtual region W, a first embedded hole 19 is provided near the outer peripheral surface 16 b of the rotor core 16 in a direction parallel to the central axis C of the rotor core 16. The embedded hole 19 is formed in an elongated shape extending substantially along the circumferential direction of the rotor core 16. Specifically, the first embedded hole 19 is formed so that the d-axis is orthogonal to the long side of the first embedded hole 19. The first permanent magnet 17 is inserted into the first embedded hole 19.

  The first embedding hole 19 has an outer forming surface 19a closer to the outer peripheral surface 16b of the rotor core 16 among the forming surfaces on the long side, and the inner peripheral surface of the rotor core 16 facing the outer forming surface 19a. And an inner forming surface 19b closer to the inner surface. And in the 1st permanent magnet 17 inserted in the 1st embedding hole 19, it is an end surface near the outer peripheral surface 16b of the rotor core 16, and the surface facing the outer side formation surface 19a is the magnetic pole surface 17a. The surface that is the end surface closer to the inner peripheral surface of the rotor core 16 and faces the inner forming surface 19b is the anti-magnetic pole surface 17b. Furthermore, in the 1st permanent magnet 17, the end surface of both the short sides is the magnet end surface 17c.

  In each virtual region W, two rectangular embedded holes 20 having a rectangular shape are formed in the rotor core 16 such that the long sides extend from the inner peripheral surface side of the rotor core 16 toward the outer peripheral surface side, and It extends so as to extend in a direction parallel to the central axis C. In each virtual region W, the two second embedded holes 20 are arranged so as to be separated from each other as they go from the inner peripheral surface side of the rotor core 16 to the outer peripheral surface side, and are arranged in a V shape. In each virtual region W, the two second embedded holes 20 are formed with long sides extending so as to be parallel (along) with a part of the q-axis 27. A second permanent magnet 18 is fitted in each second embedded hole 20. Each of the second embedded holes 20 has a first formation surface 20a closer to the first embedded hole 19 among the formation surfaces on the long side, and the adjacent magnetic poles facing the first formation surface 20a. The second formation surface 20b closer to the second embedded hole 20 is provided.

  In each virtual region W, the two second permanent magnets 18 are arranged so that the same side (for example, the outer peripheral surface 16b side of the rotor core 16) has the same polarity. Moreover, the 2nd permanent magnet 18 arrange | positioned at the adjacent magnetic pole is arrange | positioned so that the outer peripheral surface 16b side of the rotor core 16 may become a different pole. For example, when a set of second permanent magnets 18 is arranged so that the outer peripheral surface 16b side of the rotor core 16 is an S pole, the set of second permanent magnets 18 arranged on the adjacent magnetic poles is the rotor core 16. The outer peripheral surface 16b side is arranged to be N pole. In the present embodiment, in order to allow the rotor 15 to rotate in both forward and reverse directions, the two second permanent magnets 18 are arranged in a line-symmetric position with respect to the d-axis 26.

  A first gap 21 is formed in the rotor core 16 so as to be continuous with both short sides of the first buried hole 19. In addition, the rotor core 16 is formed with a substantially fan-shaped second gap 22 that is separated from the first gap 21 toward the q-axis 27 side from the first permanent magnet 17. Each of the first gap 21 and the second gap 22 extends through the rotor core 16 so as to extend in a direction parallel to the central axis C. In the present embodiment, the first gap 21 and the second gap 22 constitute one gap portion 23.

  The first gap 21 is formed so as to gradually become narrower from the end surfaces of both short sides of the first permanent magnet 17 toward the q-axis 27 side from the first permanent magnet 17. The formation surface of the first gap 21 is continuous with the outer formation surface 19a of the first embedding hole 19 and extends toward the inner side of the rotor core 16, and from the magnet end surface 17c toward the inner side of the rotor core 16. The second forming surface 21b extends.

  The formation surface of the second gap 22 is formed from an outer peripheral side formation surface 22a extending in an arc shape along the outer peripheral surface 16b of the rotor core 16 and an end edge on the d-axis 26 side of both end edges of the outer peripheral side formation surface 22a. It is comprised from the d-axis side formation surface 22b extended, and the q-axis side formation surface 22c extended from the edge on the q-axis 27 side. The d-axis side forming surface 22b and the q-axis side forming surface 22c of the second gap 22 are formed so as to approach each other from the outer peripheral surface 16b side to the inner peripheral surface of the rotor core 16, and the d-axis side forming surface 22b and the q-axis are formed. An inner circumferential side end Y located near the innermost circumferential surface of the rotor core 16 is formed by the intersection of the side forming surfaces 22c. Further, in the present embodiment, the outer peripheral side forming surface 22 a of the second gap 22 constitutes an outer peripheral side end located near the outermost peripheral face of the rotor core 16 in the second gap 22.

  In the rotor core 16, a portion between the outer peripheral surface 16 b and the outer peripheral side forming surface 22 a of the second gap 22 is an outer peripheral side bridge 24, and a side surface of the outer peripheral side bridge 24 on the second gap 22 side is the second gap 22. The outer peripheral side forming surface 22a. The outer peripheral bridge 24 is formed so as to extend with a constant width along the circumferential direction of the rotor core 16.

  In the rotor core 16, a reinforcing bridge 25 is formed between the first gap 21 and the second gap 22. The side surface of the reinforcing bridge 25 on the first space 21 side is formed by the first forming surface 21 a of the first space 21, and the side surface of the reinforcing bridge 25 on the second space 22 side is the surface forming the d-axis side of the second space 22. 22b. The reinforcing bridge 25 extends with a constant width and is formed to have the same width as the outer peripheral bridge 24. The width of the outer bridge 24 and the reinforcing bridge 25 is preferably set to be twice or more the thickness of the core plate 161.

  The first permanent magnet 17 has a magnetic pole surface 17 a positioned on the inner peripheral surface side of the rotor core 16 with respect to the outer peripheral side forming surface 22 a (outer peripheral end portion) of the second air gap 22, and the inner peripheral end of the second air gap 22. It arrange | positions so that it may be located in the outer peripheral surface side of the rotor core 16 from the part Y. FIG. Here, the distance from the outer peripheral surface 16 b of the rotor core 16 to the magnetic pole surface 17 a along the d-axis 26 is defined as an embedding depth F of the first permanent magnet 17. In this case, the embedding depth F is preferably set to 1 / 10P <embedding depth F <2 / 3P, based on the pitch P between the teeth 13.

  When the embedding depth F is greater than 2 / 3P, the first permanent magnet 17 approaches the inner peripheral surface of the rotor core 16. At this time, since the two second permanent magnets 18 are arranged so as to narrow the distance between the two permanent magnets 18 toward the inner peripheral surface of the rotor core 16, when the first permanent magnet 17 approaches the inner peripheral surface of the rotor core 16, The magnet end surface 17c of the first permanent magnet 17 approaches the second permanent magnet 18, and the short-circuit magnetic flux with the second permanent magnet 18 increases, which is not preferable. On the other hand, when the embedding depth F is smaller than 1 / 10P, the first permanent magnet 17 approaches the outer peripheral surface 16b of the rotor core 16, and the alternating magnetic field linked to the first permanent magnet 17 increases, 1 The eddy current loss on the surface of the permanent magnet 17 increases, which is not preferable. Then, by setting the range of the embedding depth F of the first permanent magnet 17, the first permanent magnet 17 is disposed between the pair of second gaps 22.

  The length N of the first permanent magnet 17 in the long side direction is preferably set to 1 to 3 times the pitch P when the pitch P is used as a reference. If the length N of the first permanent magnet 17 is shorter than 1 times the pitch P, the first permanent magnet 17 is reduced in size and the magnetic force is lowered, and the magnetic flux generated from the first permanent magnet 17 is decreased, which is not preferable. On the other hand, when the length N of the first permanent magnet 17 is longer than three times the pitch P, the first permanent magnet 17 becomes too long, and the second gap 22 (gap part 23) and the second permanent magnet 18 in the magnetic poles. It becomes difficult to set the arrangement appropriately, which is not preferable.

  Further, in each magnetic pole, the distance H between each second gap 22 (gap 23) and the second permanent magnet 18 adjacent to the second gap 22 on the q-axis side (the q-axis side forming surface of the second gap 22). 22c and the distance between the long-side-side forming surface 20a of the second embedded hole 20) is preferably set to 0.3 to 2 times the pitch P with respect to the pitch P. If the distance H is shorter than 0.3 times the pitch P, the magnetic flux passing between the second permanent magnet 18 and the gap 23 (second gap 22) is reduced, which is not preferable because the torque is lowered. On the other hand, if the interval H is longer than twice the pitch P, the magnetic flux passing between the second permanent magnet 18 and the gap 23 (second gap 22) can be increased, but torque ripple is preferably increased. Absent.

Next, the operation of the permanent magnet embedded rotary electric machine M including the rotor 15 will be described.
When the coil 30 is energized, a rotating magnetic field is generated in the stator 10 and a rotating magnetic field acts on the rotor 15. Then, the rotor 15 is rotated by a magnetic attractive force and a repulsive force between the rotating magnetic field and the first permanent magnet 17 and the second permanent magnet 18. At this time, since the first permanent magnet 17 and the second permanent magnet 18 are provided on the rotor core 16, for example, as compared with the case where only the first permanent magnet 17 or the second permanent magnet 18 is provided on the rotor core 16. The reluctance torque is increased by the first and second permanent magnets 17 and 18, and the torque of the permanent magnet embedded rotary electric machine M is increased.

  In the rotor core 16, the embedding position of the first permanent magnet 17 in the rotor core 16 is such that the embedding depth F of the first permanent magnet 17 is in the range of 1 / 10P <embedding depth F <2 / 3P. Is set. For this reason, the 1st permanent magnet 17 is arrange | positioned in the position which is not too close to the outer peripheral surface 16b of the rotor core 16, and is not too close to the inner peripheral surface. Therefore, the eddy current loss generated on the surface of the first permanent magnet 17 can be suppressed, and the short-circuit magnetic flux between the first permanent magnet 17 and the second permanent magnet 18 is reduced.

According to the above embodiment, the following effects can be obtained.
(1) The first permanent magnet 17 is disposed on the rotor core 16 of the rotor 15 so as to be elongated toward the outer peripheral surface 16 b of the rotor core 16. Further, two second permanent magnets 18 are arranged on the rotor core 16 so as to sandwich the first permanent magnet 17. In the first permanent magnet 17, the magnetic pole surface 17 a on the outer peripheral surface 16 b side of the rotor core 16 is closer to the inner peripheral surface side of the rotor core 16 than the outer peripheral surface forming surface 22 a on the outer peripheral surface 16 b side of the rotor core 16. And embedded in the rotor core 16 so as to be positioned on the outer peripheral surface side of the rotor core 16 from the inner peripheral side end Y of the second gap 22. Thus, by setting the embedding position of the first permanent magnet 17, the first permanent magnet 17 is too close to the outer peripheral surface 16 b even if the first permanent magnet 17 is disposed closer to the outer peripheral surface 16 b of the rotor core 16. This can prevent the eddy current loss occurring on the surface of the first permanent magnet 17. Further, the first permanent magnet 17 is prevented from being too close to the inner peripheral surface of the rotor core 16, and the short-circuit magnetic flux between the first permanent magnet 17 and the second permanent magnet 18 is reduced.

  Therefore, the temperature rise of the first permanent magnet 17 due to eddy current loss can be suppressed to a small level, the demagnetization of the first permanent magnet 17 can be prevented, and the increase of the short-circuit magnetic flux can be prevented. The torque drop of the magnet-embedded rotating electrical machine M can be prevented. And since the eddy current loss of the 1st permanent magnet 17 can be suppressed, it is not necessary to adopt a magnet having a high coercive force for the first permanent magnet 17, to increase the thickness, or to divide it into a plurality of parts, thereby preventing torque reduction. Therefore, it is possible to avoid an increase in the cost of the first permanent magnet 17 for the purpose.

  (2) Since the range of the embedded depth F of the first permanent magnet 17 is set to 1 / 10P <embedded depth F <2 / 3P, the torque of the permanent magnet embedded rotary electric machine M is not reduced. The effect that eddy current loss can be reduced can be exhibited suitably.

  (3) The length N in the long side direction of the first permanent magnet 17 is preferably set to 1 to 3 times the pitch P when the pitch P between the teeth 13 is used as a reference. Setting the length N of the first permanent magnet 17 in this way prevents the magnetic flux from being reduced due to the first permanent magnet 17 becoming too short, and the second gap 22 and the second permanent magnet 18 in the magnetic pole. The arrangement can be set suitably.

  (4) The distance H between the second gap 22 and the adjacent second permanent magnet 18 is preferably set to 0.3 to 2 times the pitch P when the pitch P is used as a reference. By setting the interval H in this way, it is possible to suppress an increase in torque ripple while suppressing a decrease in torque of the permanent magnet embedded type rotary electric machine M.

  (5) In each magnetic pole, two second permanent magnets 18 are arranged in a V shape so as to sandwich one first permanent magnet 17. For this reason, in each magnetic pole, the magnetic flux passing through the q-axis 27 can be increased, and the reluctance torque can be increased.

  (6) The first permanent magnets 17 are provided with gaps 23 on the both magnet end surfaces 17 c side, and each gap 23 is disposed between the first permanent magnet 17 and the second permanent magnet 18. For this reason, the gap 23 can reduce the short-circuit magnetic flux from the first permanent magnet 17 to the second permanent magnet 18.

  (7) Since the width of the outer peripheral bridge 24 and the reinforcing bridge 25 is set to be twice or more that of the core plate 161, the strength at the time of punching the core plate 161 can be secured, and the outer peripheral side at the time of punching Deformation of the formation site of the bridge 24 and the reinforcing bridge 25 can be prevented.

In addition, you may change the said embodiment as follows.
As shown in FIG. 3, the second embedded hole 20 formed in the rotor core 16 is formed in an arc shape extending along the q axis 27 and recessed from the outer peripheral surface side of the rotor core 16 to the inner peripheral surface side. The second permanent magnet 18 fitted into the two embedded holes 20 may be formed by a single permanent magnet having an arc cross section.

  In the embodiment, the two second embedded holes 20 are formed in the rotor core 16 and the second permanent magnets 18 are inserted into the second embedded holes 20, but the second V-shape connected to the rotor core 16 is formed. Two embedded holes 20 may be formed, and one second permanent magnet 18 integrally formed in a V shape may be inserted into the second embedded hole 20, or the second permanent magnet 18 divided into a plurality of parts may be inserted. May be inserted.

In the embodiment, the second gap 22 is formed in a substantially fan shape, but the shape of the second gap 22 may be changed as appropriate.
In the embodiment, the first permanent magnet 17 and the two second permanent magnets 18 are arranged in line symmetry with respect to the d-axis 26 so that the embedded permanent magnet rotor 15 rotates in both forward and reverse directions. However, when the embedded permanent magnet rotor 15 is rotated only in one direction, the first permanent magnet 17 and the two second permanent magnets 18 are arranged so as to be axisymmetric with respect to the d-axis 26. May be.

  In the embodiment, the number of magnetic poles is eight, but may be changed.

  F: Embedded depth, H: Interval, M: Permanent magnet embedded rotary electric machine as rotating electric machine, N: Length, P ... Pitch, TL ... Center axis, Y ... Inner peripheral end, 10 ... Fixed , 11 ... stator core, 13 ... teeth, 15 ... embedded permanent magnet rotor (rotor), 16 ... rotor core, 16b ... outer peripheral surface, 17 ... first permanent magnet, 17a ... magnetic pole surface, 18 ... second permanent Magnet, 22 ... 2nd space | gap as a space | gap, 22a ... Outer peripheral side formation surface as an outer peripheral side edge part, 26 ... d-axis, 27 ... q-axis.

Claims (6)

A first permanent magnet is embedded near the outer peripheral surface of the rotor core inside the stator so as to extend in a direction orthogonal to the d-axis, and a second permanent magnet is extended on both sides of the first permanent magnet along the q-axis. In a permanent magnet embedded rotor in which a magnet is embedded, and further, a gap is formed in the rotor core apart from both ends of the first permanent magnet toward the q axis side.
The gap has an outer peripheral end located near the outermost peripheral surface of the rotor core, and an inner peripheral end located near the innermost peripheral surface of the rotor core,
In the first permanent magnet, the magnetic pole surface of the first permanent magnet is positioned closer to the inner peripheral surface side of the rotor core than the outer peripheral side end of the air gap, and the outer periphery of the rotor core from the inner peripheral side end of the air gap. It is arranged to be located on the surface side ,
The embedded permanent magnet rotor , wherein the gap is formed so that magnetic flux passes between the second permanent magnet and the gap . The stator includes a plurality of teeth arranged on the inner periphery of an annular stator core, and a straight line extending along the radial direction of the stator core and passing through an intermediate point in the width direction of the teeth is a central axis of the teeth. When the pitch between the central axes of adjacent teeth is P, the embedded depth of the first permanent magnet from the outer peripheral surface of the rotor core to the magnetic pole surface along the d axis is
1 / 10P <embedding depth <2 / 3P
The embedded permanent magnet rotor according to claim 1, wherein the first permanent magnet is disposed so as to satisfy the above.   The first permanent magnet has a flat plate shape elongated in a direction perpendicular to the d-axis, and the length of the first permanent magnet in the long side direction is set to 1 to 3 times the pitch. Item 3. The permanent magnet embedded rotor according to Item 2.   The embedded permanent magnet rotor according to claim 2 or 3, wherein an interval between the second permanent magnet and the gap is set to 0.3 to 2 times the pitch.   The said 2nd permanent magnet is arrange | positioned at the V shape extended toward the outer peripheral surface side from the inner peripheral surface side of the said rotor core, or the circular arc shape dented toward the inner peripheral surface side from the outer peripheral surface side of the rotor core. The embedded permanent magnet rotor according to any one of claims 1 to 4. A stator,
A first permanent magnet is embedded near the outer peripheral surface of the rotor core inside the stator so as to extend in a direction orthogonal to the d-axis, and a second so as to extend along the q-axis on both sides of the first permanent magnet. A rotating electric machine comprising: a permanent magnet embedded; and a permanent magnet embedded rotor in which a gap is formed in the rotor core at a distance from the both ends of the first permanent magnet toward the q-axis side,
The rotating electrical machine in which the permanent magnet embedded rotor is the permanent magnet embedded rotor according to any one of claims 1 to 5.

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