JP2009106001A - Rotary electric machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary electric machine which can reduce an eddy current due to leakage flux and utilize reluctance torque sufficiently, while securing the durability of a permanent magnet. <P>SOLUTION: The rotary electric machine is equipped with a stator 130, which comprises a stator core 131 made annular and a coil 132 wound on the stator core 131, and a rotor 120, which comprises a rotor core 121 inserted into the stator core 131 and provided rotatably. The rotor core 121 comprises an eddy current suppressing region R1, where a slit 127 extending in the axial direction of the rotor 120 from one axial end is formed, an eddy current suppressing region R2, where a slit 125 extending in the axial direction of the rotor 120 from the other axial end is formed, and a torque generating region, which is positioned between the eddy current suppressing region R1 and the eddy current suppressing region R2 in which the first and second slits 125 are not formed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine, and more particularly to a rotating electrical machine in which eddy current generated in a rotor is reduced.

  Conventionally, various rotating electrical machines have been proposed in order to suppress leakage magnetic flux and to prevent magnetic flux leakage between magnets.

  For example, in a permanent magnet embedded synchronous motor described in Japanese Patent Application Laid-Open No. 2002-345189, a slit is formed in a portion of a pair of magnet pieces arranged in a V shape that is close to the outer periphery of the rotor. In this way, the generation of eddy currents is suppressed by forming slits in the portions where eddy currents tend to concentrate and increasing the resistance.

  In the permanent magnet rotor described in Japanese Patent Application Laid-Open No. 9-131209, a permanent magnet is inserted into a magnet insertion hole formed in a rotating iron core, and an annular core portion is disposed on the outer peripheral side of the magnet insertion hole. A plurality of slits are formed in the annular core member. Thus, since the slit is formed in the part which opposes a permanent magnet, it is suppressed that a leakage magnetic flux arises between adjacent permanent magnets.

  In the permanent magnet type rotating electrical machine described in Japanese Patent Application Laid-Open No. 2006-21823, noise is reduced and the efficiency of the rotating electrical machine is reduced by forming a plurality of slits on the outer peripheral side of the permanent magnet insertion hole of the rotor core. Is planned.

Furthermore, the permanent magnet electric motor described in Japanese Patent Application Laid-Open No. 2005-94968 includes a rotor core in which four or more slit holes are formed so as to be spaced apart along the permanent magnet hole.
JP 2002-345189 A Japanese Patent Laid-Open No. 9-131209 JP 2006-211183 A JP 2005-94968 A

  However, in the permanent magnet embedded synchronous motor described in Japanese Patent Application Laid-Open No. 2002-345189, since the slit is formed in the permanent magnet that is easy to apply, the permanent magnet is easily chipped, and there is a problem in durability of the permanent magnet. There is.

  Further, in the rotating electrical machines described in JP-A-9-131209, JP-A-2006-21118, and JP-A-2005-94968, slits formed on the outer peripheral side from the magnet housing holes are provided on both shafts of the rotor. Since it extends over the direction end, the reluctance torque cannot be fully utilized.

  The present invention has been made in view of the problems as described above, and its purpose is to reduce the eddy current due to leakage magnetic flux while ensuring the durability of the permanent magnet and to fully utilize the reluctance torque. It is providing the rotary electric machine which can do.

  A rotating electrical machine according to the present invention includes an annular stator core and a stator including a coil wound around the stator core, and a rotor including a rotor core that is inserted into the stator core and rotatably provided. The rotor core includes a first eddy current suppression region in which a first gap portion extending in the axial direction of the rotor is formed from one axial end portion, and a second extending in the axial direction of the rotor from the other axial end portion. A second eddy current suppression region in which an air gap is formed, a torque generation region in which the first and second air gaps are not formed and located between the first eddy current suppression region and the second eddy current suppression region; including.

  Preferably, the rotor includes a permanent magnet embedded in the rotor core and extending over both axial ends of the rotor core, and the first and second gap portions are radially outward of the rotor core with respect to the permanent magnet. Provided on the side.

  Preferably, the rotor is formed of a plurality of permanent magnets, includes a first permanent magnet group that defines an S magnetic pole on an outer peripheral surface of the rotor core, and a second permanent magnet group that defines an N magnetic pole, and includes a first gap portion. A plurality of second gap portions are formed, and are formed radially outward with respect to the first and second permanent magnet groups. And among the said 1st space | gap part, the depth of the axial direction of one 1st space | gap part located in the circumferential direction edge part side of the rotor core in the 1st permanent magnet group is the one 1st space | gap part. On the other hand, the first permanent magnet group is formed deeper than the axial depth of the other first gap portion located on the circumferential center portion side of the rotor core. Further, among the second gaps, the axial depth of one second gap located closest to the circumferential end of the rotor core in the second permanent magnet group is the same as that of the second gap. On the other hand, the second permanent magnet group is formed deeper than the axial depth of the other second gap portion located on the circumferential center portion side of the rotor core.

  Preferably, the length of the first gap portion and the second gap portion in the radial direction of the rotor core is longer than the circumferential length of the rotor core.

  Preferably, the rotor protrudes radially outward, extends across both axial end portions of the rotor, and has a plurality of rotor teeth portions formed at intervals in the circumferential direction of the rotor core, and the rotor teeth. And a recess defined between the parts. And the said 1st and 2nd space | gap part is formed in the part adjacent to a recessed part among rotor teeth. Preferably, the rotor includes a permanent magnet fitted in the recess.

  According to the rotating electrical machine according to the present invention, it is possible to reduce the generation of eddy currents due to leakage magnetic flux and sufficiently utilize the reluctance torque while ensuring the durability of the permanent magnet.

A rotating electrical machine according to the present embodiment will be described with reference to FIGS.
Note that in the embodiments described below, when referring to the number, amount, and the like, the scope of the present invention is not necessarily limited to the number, amount, and the like unless otherwise specified. In the following embodiments, each component is not necessarily essential to the present invention unless otherwise specified. In addition, when there are a plurality of embodiments below, it is planned from the beginning to appropriately combine the features of each embodiment unless otherwise specified.

(Embodiment 1)
The rotating electrical machine according to the first embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a side sectional view showing a schematic configuration of a rotating electrical machine 100 according to the first embodiment. 2 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is a cross-sectional view taken along line III-III in FIG.

  As shown in FIGS. 1 and 2, the rotating electrical machine 100 includes a rotating shaft 110 that is rotatably supported, a rotor 120 fixed to the rotating shaft 110, and an annular shape that is disposed around the rotor 120. The stator 130 is provided.

  The stator 130 includes an annular stator core 131 and a coil 132 wound around the stator core 131.

  In the stator core 131 of the rotating electrical machine 100 according to the first embodiment, a plurality of divided stator cores 142 are annularly arranged, and an annular fastening member 145 is shrink-fitted from the outer peripheral side of the annularly arranged divided stator cores 142 and press-fitted. Has been formed.

  Each divided stator core 142 is formed with a yoke portion 140 and a stator tooth 141 protruding from the yoke portion 140 inward in the radial direction of the stator core 131, and a coil 132 is wound around each stator tooth 141. ing. Coil 132 includes a U-phase coil, a V-phase coil, and a W-phase coil, and rotating electric machine 100 of the first embodiment is a three-phase AC motor. The split stator core 142 is configured by laminating a plurality of electromagnetic steel plates.

  The stator core 131 is not limited to the case where the stator core 131 is configured as described above, and the stator core 131 may be configured by stacking electromagnetic steel plates punched in an annular shape.

  The rotor 120 is fixed to a rotating shaft 110 that is rotatably supported and has a rotor core 121 formed in a cylindrical shape, and a plurality of permanent magnets 122 accommodated in magnet insertion holes 126 formed in the rotor core 121. The rotating electrical machine 100 is a so-called IMP motor.

  The magnet insertion hole 126 extends in the axial direction of the rotor core 121 and extends across both ends of the rotor core 121 in the axial direction.

  The permanent magnet 122 also extends over both axial ends of the rotor core 121 and is fixed in the magnet insertion hole 126 by a resin 124 filled in the magnet insertion hole 126.

  As shown in FIG. 2, a plurality of permanent magnets 122 are arranged along the outer peripheral edge of the rotor core 121, and two permanent magnets 122 are paired and arranged in a V shape.

  As shown in FIG. 1, the rotor core 121 includes an eddy current suppression region R1 in which a slit 127 extending from one axial end of the rotor core 121 toward the axial direction of the rotor core 121 is formed, and the other of the rotor core 121 An eddy current suppression region R3 in which a slit 125 extending in the axial direction of the rotor core 121 is formed from the axial end of the rotor, and a torque generation region R2 located between the eddy current suppression region R1 and the eddy current suppression region R3 Is stipulated.

  Here, the slit 125 extends to a portion located on the other end side of the rotor core 121 with respect to the torque generation region R2, and does not reach the torque generation region R2. Similarly, the slit 127 extends to a portion adjacent to one axial end of the rotor core 121 with respect to the torque generation region R2, and does not reach the torque generation region R2. That is, the slit 127 and the slit 125 are not formed in the torque generation region R2.

  For this reason, the electrical steel sheet in which the hole corresponding to the slits 125 and 127 and the hole corresponding to the magnet insertion hole 126 are formed in the portion of the rotor core 121 where the eddy current suppression region R1 and the eddy current suppression region R3 are located. Are laminated, and electromagnetic steel sheets in which holes corresponding to the magnet insertion holes 126 are formed are laminated in a portion where the torque generation region R2 is located. And as shown in FIG. 3, the electromagnetic steel plate in which the hole part corresponding to the slit 125 or the slit 127 is not formed is laminated | stacked in the part in which torque generation area | region R2 is located.

  4 is an enlarged perspective view of the slit 127 shown in FIG. 2 and its peripheral portion. In FIG. 4, in the process in which the rotating electrical machine 100 is driven, the magnetic flux density becomes the largest at a portion located on the radially outer side of the rotor core 121 with respect to the permanent magnet 122. Leakage magnetic flux is easily generated.

  Here, for example, as shown in FIG. 4, from a portion located on the radially outer side of the rotor core 121 with respect to the permanent magnet 122 to a portion located on the radially inner side of the rotor core 121 with respect to the permanent magnet 122. Assuming that the leakage magnetic flux MF is directed, an eddy current tends to flow in a portion located on the outer side with respect to the permanent magnet 122.

  On the other hand, in the rotating electrical machine 100 according to the first embodiment, when the eddy current flows because the slit 127 is formed in a portion located on the radially outer side with respect to the permanent magnet 122. The resistance of the eddy current is high, making it difficult for eddy currents to flow. That is, even when an eddy current flows in an eddy manner, the slit 127 is formed so as to cut the current path, so that the resistance of the current flow path of the eddy current is high.

  Thus, since it is possible to suppress the eddy current from flowing through the rotor core 121, it is possible to suppress the rotation of the rotor 120 or the occurrence of vibration due to the eddy current.

  Further, in the portion of the rotor core 121 that is located on the radially outer side of the rotor core 121 with respect to the permanent magnet 122, the magnetic flux in the portion that is particularly located at the axial end of the rotor core 121 when the rotating electrical machine 100 is driven. The density is high.

  For this reason, during the driving of the rotating electrical machine 100, the magnetic flux density in the eddy current suppression region R1 and the eddy current suppression region R3 is higher than the magnetic flux density in the torque generation region R2.

  On the other hand, in rotating electrical machine 100 according to the present embodiment, slits 125 and 127 are formed in eddy current suppression region R1 and torque generation region R2, respectively, and generation of eddy currents is suppressed. And in torque generation area | region R2 with a low magnetic flux density, the slit is not formed but the reluctance torque is ensured.

  As described above, in the rotating electrical machine 100 according to the first embodiment, a slit is formed in a portion with a high magnetic flux density, and a reluctance torque is secured without forming a slit in a portion with a low magnetic flux density. Thus, the rotation of the rotor 120 can be made smooth and torque can be secured.

  And as shown in FIG. 4, the permanent magnet 122 made into two pairs is arranged in V shape, and has prescribed | regulated one magnetic pole.

  In the example shown in FIG. 4, of the surfaces of the permanent magnets 122 </ b> A and 122 </ b> A, the portion located on the outer peripheral surface side of the rotor core 121 is an N magnetic pole, and the inner surface side portion of the rotor core 121 is an S magnetic pole. Has been. For this reason, N magnetic poles are defined by the permanent magnet group 160A including these two permanent magnets 122A in the portion located on the radially outer side of the permanent magnet group 160A in the outer peripheral surface of the rotor core 121.

  Furthermore, in the two permanent magnets 122B disposed in the circumferentially adjacent portion of the rotor core 121 with respect to the permanent magnet group 160A, the outer peripheral surface side surface of the rotor core 121 is an S magnetic pole. The surface on the inner peripheral surface side is an N magnetic pole.

  For this reason, by the permanent magnet group 160B including the two permanent magnets 122B, the S magnetic pole is defined on the portion of the surface of the rotor core 121 located on the radially outer side of the permanent magnet group 160B.

  As described above, a plurality of N magnetic poles and S magnetic poles are defined on the outer peripheral surface of the rotor core 121 so as to alternate.

  The slit 127 is provided for each permanent magnet group 160 (160A, 160B), and is formed on the radially outer side of the rotor core 121 with respect to each permanent magnet group 160.

  The slit 127 is composed of a plurality of slit portions 151 to 156, and the slit portions 151 to 156 are formed to be elongated in the radial direction of the rotor core 121. The length of the rotor core 121 in the radial direction is: The rotor core 121 is formed longer than the circumferential length. The slit portions 151 to 156 are formed at intervals in the circumferential direction of the rotor core 121.

  For this reason, for example, even when the leakage magnetic flux MF occurs, the flow of the eddy current generated on the radially outer side of the rotor core 121 with respect to the permanent magnet group 160 is substantially reduced by at least one of the slit portions 151 to 156. It is reliably blocked and the resistance when eddy current flows increases.

  Thereby, the amount of eddy current generated can be reduced, and the inhibition of rotation of the rotor 120 by this eddy current can be reduced. In addition, although the slit parts 151-156 are elongate toward the radial direction of the rotor core 121, it is not restricted to this, You may form in elongate in the circumferential direction.

  In the present embodiment, the case where the slit 127 is formed on the radially outer side of the rotor core 121 with respect to the permanent magnet group 160 as described above has been described. However, the present invention is not limited to this. On the other hand, a slit may be formed in a portion adjacent to the radially inner side of the rotor core 121.

  In this case, as described above, when leakage magnetic flux MF is generated, it is possible to suppress the generation of eddy current in the portion located on the radially inner side of rotor core 121 with respect to permanent magnet group 160. it can. That is, the slit 127 may be formed in a portion located around the permanent magnet group 160 in the eddy current suppression region R1.

  Further, in FIG. 4, a leakage magnetic flux MF that flows from the portion located on the radially outer side of the rotor core 121 with respect to the permanent magnet group 160 to the radially inner side of the rotor core 121 with respect to the permanent magnet group 160 is generated. However, the present invention is not limited to this.

  For example, even when a leakage magnetic flux is generated from a radially inner side of the rotor core 121 with respect to the permanent magnet group 160 to a portion located on the radially outer side of the rotor core 121 with respect to the permanent magnet group 160, the permanent magnet group It is possible to suppress the generation of eddy current in a portion located on the radially outer side with respect to 160.

  Here, in the portion of the rotor core 121 located on the radially outer side with respect to the permanent magnet group 160A, the magnetic flux density increases toward the circumferential end of the rotor core 121 in the permanent magnet group 160A. ing. For this reason, the leakage magnetic flux is likely to be generated toward the circumferential end of the permanent magnet group 160A.

  That is, in the portion located radially outward with respect to the permanent magnet group 160, a portion where leakage magnetic flux is likely to occur toward the circumferential end of the permanent magnet group 160 generates torque from the axial end of the rotor core 121. It extends to the vicinity of the region R2.

  On the other hand, each depth of each slit part 151-156 is formed so that the slit part 151-156 located in the circumferential direction edge part side of the rotor core 121 in the permanent magnet group 160A may become deep.

  For this reason, it is possible to suppress the occurrence of leakage magnetic flux from the axial end of the rotor core 121 to the vicinity of the torque generation region R2 at the circumferential end of the permanent magnet group 160 and in the vicinity thereof.

  And the slit 125 formed in the eddy current suppression area | region R3 is formed similarly to the said slit 127, and is provided with a some slit part, and the slit part located in the circumferential direction edge part side of the permanent magnet group 160 is the same. It is formed to be deep.

(Embodiment 2)
A rotating electrical machine according to the second embodiment will be described with reference to FIGS. 5 and 6 and FIG. 1 as appropriate. In FIG. 5, the same or corresponding components as those shown in FIGS. 1 to 4 may be assigned the same reference numerals and explanation thereof may be omitted.

  FIG. 5 is a partial cross-sectional view of the rotating electrical machine according to the second embodiment. As shown in FIG. 5, on the outer peripheral surface of the rotor core 121 of the rotating electrical machine according to the second embodiment, the rotor teeth 170 project outward in the radial direction and are spaced apart in the circumferential direction. A recess 171 formed between the rotor teeth 170 is formed.

  In the rotating electrical machine shown in FIG. 5, no permanent magnet is provided in the rotor core 121.

  In such a rotating electrical machine, a magnetic flux is generated by supplying electric power to the coil 132, and the generated magnetic flux flows from each stator tooth 141 to the rotor teeth 170 through an air gap. Then, the magnetic flux flows in the circumferential direction in the rotor core 121, and flows from the other rotor teeth 170 to the other stator teeth 141 through the air gap. Then, it flows in the yoke part 140 in the circumferential direction and flows back to the original stator teeth 141. And the rotor 120 rotates so that the flow path length of the magnetic flux which flows as mentioned above may become short. And the rotor 120 rotates because the coil 132 to excite sequentially moves.

  In such a rotating electrical machine, the magnetic flux density in the rotor teeth 170 increases when the rotor 120 rotates.

  In particular, the magnetic flux density is increased toward the end of the rotor teeth 170 in the circumferential direction, and the magnetic flux is likely to leak.

  On the other hand, in the rotating electrical machine according to the second embodiment, a slit 182 is formed in the circumferential end portion side of the rotor core 121 in the rotor teeth 170. For this reason, even if the magnetic flux leaks at the circumferential end portion side of the rotor teeth 170, as in the first embodiment, the eddy current generated in the rotor teeth 170 can be reduced, and the rotor rotates well. be able to.

  Furthermore, the slit 182 includes a plurality of slit portions 180 and 181 formed at intervals in the circumferential direction of the rotor core 121, and the slit portion located on the circumferential end side is closer to the axial depth of the rotor core 121. It is formed to be deep.

  In the rotating electrical machine according to the second embodiment, similarly, slits 182 are formed in the eddy current suppression region R1 and the eddy current suppression region R3, and the eddy current suppression region R1 and the eddy current suppression region R3 are separated from each other. The slit 182 is not formed in the torque generation region R2 positioned therebetween.

  Thereby, also in the present second embodiment, a large reluctance torque can be obtained in the torque generation region R2 as in the rotary electric machine 100 according to the first embodiment, and vibrations and the like generated in the rotor 120 are suppressed. be able to.

  FIG. 6 is a partial cross-sectional view showing a modification of the rotating electrical machine according to the second embodiment. As shown in FIG. 6, a permanent magnet 122 is fitted in the recess 171. Also in this case, similarly to the rotating electrical machine shown in FIG. 5, the slit 182 is formed in the rotor teeth 170 located in the eddy current suppression region R1 and the eddy current suppression region R3 shown in FIG. The eddy current can be reduced.

  In addition, by arranging the permanent magnet 122 in the recess 171, torque due to the magnetic flux from the permanent magnet 122 can be obtained, and the permanent magnet 122 rectifies the flow of magnetic flux from the stator teeth 141 to the rotor teeth 170. Can be obtained.

  Although the embodiment of the present invention has been described above, it should be considered that the embodiment disclosed this time is illustrative and not restrictive in all respects. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims. Furthermore, the above numerical values are examples, and are not limited to the above numerical values and ranges.

It is a sectional side view which shows schematic structure of the rotary electric machine which concerns on this Embodiment 1. FIG. It is sectional drawing in the II-II line of FIG. It is sectional drawing in the III-III line in FIG. FIG. 3 is an enlarged perspective view of the slit shown in FIG. 2 and its periphery. It is a partial cross section figure of the rotary electric machine which concerns on this Embodiment 2. FIG. It is a partial cross section figure which shows the modification of the rotary electric machine which concerns on this Embodiment 2. FIG.

Explanation of symbols

  100 rotating electric machine, 110 rotating shaft, 120 rotor, 121 rotor core, 122 permanent magnet, 124 resin, 125 slit, 126 magnet insertion hole, 131 stator core, 132 coil, 140 yoke portion, 141 stator teeth, 142 split stator core, 145 fastening member , R1, R3 Eddy current suppression region, R2 torque generation region, 151, 152, 153, 154, 155, 156 slit portion, 160 permanent magnet group.

Claims (6)

A stator including an annularly formed stator core and a coil wound around the stator core;
A rotor including a rotor core inserted into the stator core and rotatably provided;
The rotor core includes a first eddy current suppression region in which a first gap portion extending in the axial direction of the rotor is formed from one axial end portion;
A second eddy current suppression region in which a second gap extending in the axial direction of the rotor is formed from the other axial end;
A rotating electrical machine including a torque generation region that is located between the first eddy current suppression region and the second eddy current suppression region and in which the first and second gap portions are not formed. The rotor includes a permanent magnet embedded in the rotor core and extending across both axial ends of the rotor core;
2. The rotating electrical machine according to claim 1, wherein the first and second gap portions are provided on a radially outer side of the rotor core with respect to the permanent magnet. The rotor is formed of a plurality of the permanent magnets, and includes a first permanent magnet group that defines an S magnetic pole on an outer peripheral surface of the rotor core, and a second permanent magnet group that defines an N magnetic pole,
A plurality of the first gap portions and the second gap portions are respectively formed, and are respectively formed radially outward with respect to the first and second permanent magnet groups,
Of the first gaps, the depth in the axial direction of one of the first gaps located closest to the circumferential end of the rotor core in the first permanent magnet group is the one of the first gaps. With respect to the gap portion, the first permanent magnet group is formed deeper than the axial depth of the other first gap portion located on the circumferential center side of the rotor core,
Among the second gaps, the depth in the axial direction of one of the second gaps located closest to the circumferential end of the rotor core in the second permanent magnet group is the second of the second gaps. 3. The rotation according to claim 2, wherein the rotation is formed deeper than the gap in the axial direction of another second gap that is located on the circumferentially central side of the rotor core in the second permanent magnet group. Electric.   4. The rotation according to claim 1, wherein lengths of the rotor core in a radial direction of the first gap and the second gap are formed longer than a length in a circumferential direction of the rotor core. 5. Electric. The rotor protrudes radially outward, extends across both axial end portions of the rotor, and has a plurality of rotor teeth formed at intervals in the circumferential direction of the rotor core, and the rotor teeth Including a recess defined between,
2. The rotating electrical machine according to claim 1, wherein the first and second gap portions are formed in a portion of the rotor teeth adjacent to the concave portion.   The rotating electrical machine according to claim 5, wherein the rotor includes a permanent magnet fitted in the recess.

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