JP2006333656A - Rotor of rotary electric machine and rotary electric machine using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotor structure suitable for rotating a permanent magnet-embedded rotor for use in rotary electric machines, and a rotary electric machine using the rotor structure. <P>SOLUTION: A number of rectangular slots 12a equivalent to the number of poles are disposed in polygonal shape so that the rotating shaft of a rotor core is encircled with them, and permanent magnets 11 is embedded in the slots to obtain a rotor. The number of the rectangular slots equivalent to the number of poles are further divided into two, and the slots divided into two are disposed in substantially truncated chevron shape as viewed from the rotating shaft side. Bridges 17 that connect salient pole portions positioned outside the polygonal slots and the central portion positioned inside are formed between two slots. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a rotor structure of a rotating electrical machine in which a permanent magnet is attached to a rotor to form a field, and more particularly to a rotor structure suitable for high-speed rotation and a rotating electrical machine using the same.

  A permanent magnet field type rotating electrical machine in which a permanent magnet is embedded in a rotor to form a field is widely used as an electric motor and a generator. 8 and 9 show an example of a cross-sectional structure of a rotating electrical machine using a permanent magnet field system that is currently generally used.

  The rotating electrical machine 50 includes a stator 2 and a rotor 3. The stator 2 is formed in a substantially cylindrical shape, and a plurality of stator slots 6 having openings are formed at equal intervals on the inner peripheral surface side of the yoke 4. These stator slots 6 accommodate multiphase / multipolar stator coils 5. When the rotating electrical machine 50 is used as an electric motor, a multiphase alternating current having a specific phase relationship is supplied to the stator coil 5 to function as an armature.

  The rotor 3 is composed of a rotor core 9 formed in a cylindrical shape from laminated electromagnetic steel sheets, a rotating shaft 10 fitted in the center of the axis, and a permanent magnet 11 embedded in the rotor core 9. The rotor 2 is rotatably supported with a slight gap between the stator 2 and the inner peripheral surface. In the rotor core 9, a rectangular slot 12 penetrating in the axial direction is arranged in a substantially square shape so as to surround the rotary shaft 10, and a permanent magnet 11 is embedded in the slot 12. Outer portions of the four slots 12 arranged in a square shape in the rotor core 9 constitute salient pole portions 14.

  Such a rotor 3 having a conventional structure is frequently used as an electric motor for a washing machine, a refrigerator, or the like, or for a small generator. However, there are some problems in using this conventional rotor 3 for a rotating electric machine for high speed rotation. In the rotor 3 shown in FIG. 9, the salient pole part 14 exists in the outer side part of the slot 12 arrange | positioned at substantially square shape. The salient pole portion 14 has a structure in which the salient pole portion 14 is connected to the adjacent salient pole portion 14 by the remaining portion 15 provided at the top of the four slots 12 and also connected to the rotating shaft side portion of the rotor core 9.

  When the rotor 3 rotates, a centrifugal force generated from its own mass acts on the salient pole portion 14 in the outer diameter direction. A force against the centrifugal force acts on the remaining portion 15, and stress concentration occurs in the vicinity of the remaining portion 15 at this time. As a result, the salient pole part 14 swells to the outer diameter side, and the gap dimension between the stator 2 and the stator 2 may change, resulting in variations in characteristics. Further, if the remaining portion 15 is not strong enough to withstand this concentrated stress, it may break down. Since a strong centrifugal force works at high speed rotation, such stress concentration and change in the gap size are serious problems.

Patent Document 1 discloses a conventional technique in which a hole penetrating in the axial direction is formed in salient pole portion 14. The perforated hole has the effect of reducing the mass of the salient pole portion 14 and weakening the centrifugal force. However, the technique of this document is limited in its effect because it is not intended for high-speed rotation countermeasures.
JP-A-5-103453

  The present invention has been made to solve such problems of the prior art, and the problem is a permanent magnet embedded rotor for use in a rotating electrical machine, and a rotor structure particularly suitable for high-speed rotation. Is to provide.

  The invention according to claim 1 for solving the above-mentioned problem is that the rotary shaft (10) is fitted to the axial center of a cylindrical rotor core (9) made of laminated electromagnetic steel sheets, and the rotary shaft is surrounded in a polygonal shape. In the rotor (3a) of the rotating electrical machine (1) having the configuration in which the rectangular slots (12a) having the number of poles are arranged and the permanent magnets (11) are embedded therein, each rectangular slot having the number of poles is further divided into two. The two divided slots are arranged so as to form a substantially “C” shape when viewed from the rotating shaft side, and a polygonal outer salient pole portion (14) and an inner portion are arranged between the two slots. A bridge (17) is formed, and permanent magnets are embedded in each slot.

  According to a second aspect of the present invention, in the rotor of the rotating electric machine according to the first aspect, the rectangular slots are divided into three instead of being divided into two, and the three divided slots are arranged on the rotary shaft side. A bridge (17) connecting the outer salient pole part (14) of the polygonal shape and the inner part between each slot is arranged, and a permanent magnet is embedded in each slot. To do.

  According to a third aspect of the present invention, in the rotor of the rotating electric machine according to the first aspect, each rectangular slot is divided into four instead of being divided into two, and each of the four divided slots is viewed from the rotating shaft side. A bridge is formed between the slots to connect the outside salient poles of the polygonal slot and the inside, and permanent magnets are embedded in the slots.

  According to a fourth aspect of the present invention, in the rotor of the rotating electric machine according to any one of the first to third aspects, a plurality of holes (18) penetrating the salient pole portion (14) in the axial direction of the rotating shaft are provided. It is characterized in that it is provided.

  The invention according to claim 5 is a rotating electrical machine in which a stator is used as an armature and a rotor embedded with permanent magnets is used as a field, and the rotor is used as any one of claims 1 to 4. The rotor is used.

  In the rotor of the present invention, the two slots constituting each side are arranged in a substantially “C” shape or a mountain shape when viewed from the rotating shaft side. For this reason, the thickness of the salient pole portion is reduced, the mass is reduced from that of the conventional rotor, and the centrifugal force acting on the salient pole portion is reduced accordingly. Accordingly, there is an effect that the deformation of the salient pole portion is reduced and the risk of destruction is reduced. Further, the salient pole part and the central part of the rotor core are connected by a plurality of bridges in addition to the remaining four parts. For this reason, the concentrated stress generated in each remaining portion or bridge portion is greatly reduced. Therefore, this also has the effect of reducing the bulge of the salient pole portion toward the outer diameter and reducing the risk of destruction.

  Further, since the plurality of holes provided in the salient pole portion reduce the mass of the salient pole portion, the centrifugal force acting on the salient pole portion is further reduced by this. Therefore, the bulge of the salient pole part to the outer diameter side is further reduced, and the variation in electric characteristics is reduced, and the risk of destruction of the salient pole part is further reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 are diagrams according to a first embodiment in which the present invention is applied to a rotor having a four-pole structure. FIG. 1 is a cross-sectional configuration of a rotating electrical machine incorporating the rotor, and FIG. 2 is a rotor. The cross-sectional structure of is shown. In the figure, the same or corresponding parts as those in FIGS. 8 and 9 described in “Background Art” are denoted by the same reference numerals.

  The rotating electrical machine 1 includes a stator 2 and a rotor 3a. The stator 2 includes a yoke 4 and a stator coil 5 that are formed in a substantially cylindrical shape from laminated electromagnetic steel sheets. A plurality of stator slots 6 having openings are formed at equal intervals on the inner peripheral surface side of the yoke 4. These stator slots 6 accommodate multiphase / multipolar stator coils 5. Magnetic pole teeth 7 are formed between adjacent stator slots 6. When the rotating electrical machine 1 is used as an electric motor, a multiphase alternating current having a specific phase relationship is supplied to the stator coil 5 to function as an armature. On the contrary, when the rotating electrical machine 1 is used as a generator, an output current is taken out from the stator coil 5.

  The rotor 3 a includes a rotor core 9, a rotating shaft 10, and a permanent magnet 11. The rotor core 9 is formed in a columnar shape using laminated electromagnetic steel plates, and a rotating shaft 10 is fitted at the center of the shaft. The rotor 3a is rotatably supported with a slight gap between the rotor 3a and the inner peripheral surface of the stator 2. The rotor core 9 is provided with eight rectangular slots 12a penetrating in the axial direction. The eight slots 12a are arranged so as to surround the rotating shaft 10 so that each two of the eight slots 12a constitute one side of a substantially square.

  The two slots 12a constituting each side are arranged so as to form a substantially “C” shape when viewed from the rotating shaft 10 side. In other words, a narrow gap (bridge 17) is provided between the two slots 12a on each side, and the two slots 12a are symmetrical in a shape that is bent so that the central part of each side is slightly closer to the outer diameter side. Is arranged. A narrow gap (remaining part 15) is also provided between the two slots 12a constituting the substantially square top.

  A plate-like permanent magnet 11 is embedded in each slot 12a. The permanent magnets 11 embedded in the two slots 12a constituting each side have the same polarity in the radial direction, and the polarity in the radial direction is reversed in relation to the permanent magnets 11 on the adjacent sides. Is magnetized.

  An outer portion of the slot 12 a arranged in a substantially square shape in the rotor core 9 constitutes a salient pole portion 14. The salient pole portion 14 is magnetized by the permanent magnet 11 embedded in the slot 12a. The salient pole portion 14 is connected to the center side portion of the rotor core 9 by the bridge 17 and the remaining portion 15, and is also connected to and held at substantially square corner portions. The shapes of the bridge 17 and the remaining portion 15 are determined so that the mechanical strength is maintained and the magnetic path is electromagnetically saturated.

  With such a configuration, the rotor 3a of this embodiment forms a field pole having a four-pole configuration. When the rotor 3a rotates, centrifugal force acts on each part of the rotor 3a. Centrifugal force is proportional to the square of the speed and inversely proportional to the distance from the center of rotation. For this reason, a large centrifugal force acts on the salient pole part 14 located on the outer diameter side of the rotor 3a during high-speed rotation. The force against the centrifugal force acts on the connecting portion between the salient pole portion 14 and the central portion of the rotor core 9 and causes stress concentration in that portion. The concentrated stress causes deformation at the joints and causes the salient pole portions 14 to bulge to the outer diameter side. The swelling changes the size of the gap between the stator 2 and the rotor 3a to cause variation in electrical characteristics, and in some cases, the salient pole portion 14 is broken.

  In the case of the rotor 3a of the present embodiment, the two slots 12a constituting each side are arranged so as to form a substantially “C” shape when viewed from the rotating shaft 10 side. For this reason, the thickness of the salient pole portion 14 in the radial direction is reduced, the mass is smaller than that of the conventional rotor 3 shown in FIG. 8, and the centrifugal force acting on the salient pole portion 14 is reduced accordingly. Therefore, deformation of the salient pole portion 14 is reduced and the risk of destruction is reduced.

  In the case of the conventional configuration shown in FIGS. 8 and 9 described in “Background Art”, the salient pole portion 14 and the central portion of the rotor core 9 are connected by the remaining portions 15 at four locations. On the other hand, in the rotor 3a of the present embodiment, the salient pole portion 14 is connected to the central portion of the rotor core 9 by the four bridges 17 in addition to the four remaining portions 15. For this reason, the concentrated stress generated in each remaining portion 15 or bridge 17 portion is greatly reduced. This also has the effect of reducing the bulge of the salient pole portion 14 to the outer diameter side due to deformation, reducing the variation in electrical characteristics, and reducing the risk of destruction of the salient pole portion 14.

  FIG. 3 shows a cross-sectional configuration of a rotor 3b according to the second embodiment in which the present invention is applied to a rotor having a four-pole structure. The rotor 3b of this embodiment is different from the rotor 3a of FIG. 2 according to the first embodiment in that a plurality of holes 18 penetrating in the axial direction are additionally provided in the salient pole portion 14.

  The plurality of newly provided holes 18 reduce the mass of the salient pole portion 14. Thereby, the centrifugal force which acts on the salient pole part 14 further decreases. Therefore, the bulge of the salient pole part 14 to the outer diameter side due to the deformation is further reduced, and the variation in the electrical characteristics is reduced, and the risk of the destruction of the salient pole part 14 is further reduced.

  FIG. 4 shows a cross-sectional configuration of a rotor 3c according to a third embodiment in which the present invention is applied to a rotor having a four-pole structure. In the rotor 3 c of this embodiment, 12 rectangular slots 12 a penetrating in the axial direction are provided in the rotor core 9. The twelve slots 12b are arranged so as to surround the rotary shaft 10 so that each of the three slots 12b forms one side of a substantially square. A plate-like permanent magnet 11 is embedded in each slot 12b.

  The three slots 12b constituting each side are arranged so as to form a low angle when viewed from the rotating shaft 10 side. That is, the slot 12b located at the center of each side is provided near the outer periphery of the rotor 3c. A narrow bridge 17 is provided between the slots 12b.

  With such a configuration, the mass of the salient pole portion 14 in the rotor 3c of this embodiment is smaller than that in the prior art rotor 3 shown in FIG. 9, and the centrifugal force acting on the salient pole portion 14 is reduced. Further, the salient pole portion 14 is connected to the center side portion of the rotor core 9 by eight bridges 17 in addition to the four remaining portions 15. For this reason, the concentrated stress generated in each remaining portion 15 or bridge 17 portion is also greatly reduced. For this reason, the bulge of the salient pole part 14 to the outer diameter side due to the deformation is further reduced, the variation in the electrical characteristics is reduced, and the risk of the destruction of the salient pole part 14 is further reduced.

  FIG. 5 shows a cross-sectional configuration of a rotor 3d according to a fourth embodiment in which the present invention is applied to a four-pole rotor. The difference between the rotor 3d of this embodiment and the rotor 3c of FIG. 4 according to the third embodiment is that a plurality of holes 18 penetrating in the axial direction are additionally provided in the salient pole portion 14.

  The plurality of newly provided holes 18 reduce the mass of the salient pole portion 14. Thereby, the centrifugal force which acts on the salient pole part 14 further decreases. Therefore, the bulge of the salient pole portion 14 toward the outer diameter side is further reduced, and the variation in the electrical characteristics is reduced, and the risk of the destruction of the salient pole portion 14 is further reduced.

  FIG. 6 shows a cross-sectional configuration of a rotor 3e according to a fifth embodiment in which the present invention is applied to a four-pole rotor. In the rotor 3e of the present embodiment, 16 rectangular slots 12c penetrating in the axial direction are provided in the rotor core 9. The 16 slots 12c are arranged so as to surround the rotating shaft 10 so that each of the four slots 12c forms one side of a substantially square. A plate-like permanent magnet 11 is embedded in each slot 12c.

  The four slots 12c constituting each side are arranged so as to form a low angle when viewed from the rotating shaft 10 side. That is, the two slots 12c near the center of each side are provided near the outer periphery of the rotor 3e. A narrow bridge 17 is provided between the slots 12c.

  With such a configuration, the mass of the salient pole part 14 in the rotor 3e of this embodiment is smaller than that in the rotor 3 of the prior art shown in FIG. 9, and the centrifugal force acting on the salient pole part 14 is reduced. The salient pole portion 14 is connected to the central portion of the rotor core 9 by twelve bridges 17 in addition to the four remaining portions 15. For this reason, the concentrated stress generated in each remaining portion 15 or bridge 17 portion is also greatly reduced. For this reason, the bulge of the salient pole part 14 to the outer diameter side due to the deformation is further reduced, the variation in the electrical characteristics is reduced, and the risk of the destruction of the salient pole part 14 is further reduced.

  FIG. 7 shows a cross-sectional configuration of a rotor 3f according to a sixth embodiment in which the present invention is applied to a rotor having a four-pole structure. The rotor 3f of this embodiment is different from the rotor 3e of FIG. 6 according to the fifth embodiment in that a plurality of holes 18 penetrating in the axial direction are additionally provided in the salient pole portion 14.

  The plurality of newly provided holes 18 reduce the mass of the salient pole portion 14. Thereby, the centrifugal force which acts on the salient pole part 14 further decreases. Therefore, the bulge of the salient pole part 14 to the outer diameter side due to the deformation is further reduced, and the variation in the electrical characteristics is reduced, and the risk of the destruction of the salient pole part 14 is further reduced.

  In addition, although all the embodiments so far were examples when applied to a rotor having a four-pole structure, the present invention can also be applied to a rotor having multiple poles such as a six-pole and an eight-pole based on the same idea. In this case, the same effects as those of the above-described embodiments can be obtained.

It is a cross-sectional structure of the rotary electric machine 1 which concerns on 1st Embodiment. It is a cross-sectional structure of the rotor 3a which concerns on 1st Embodiment. It is a cross-sectional structure of the rotor 3b which concerns on 2nd Embodiment. It is a cross-sectional structure of the rotor 3c which concerns on 3rd Embodiment. It is a cross-sectional structure of the rotor 3d which concerns on 4th Embodiment. It is a cross-sectional structure of the rotor 3e which concerns on 5th Embodiment. It is a cross-sectional structure of the rotor 3f which concerns on 6th Embodiment. FIG. 2 is a view corresponding to FIG. FIG. 3 is a diagram corresponding to FIG.

Explanation of symbols

  In the drawings, 1 is a rotating electrical machine, 2 is a stator, 3 is 3a, 3b, 3c, 3d, 3e, 3f is a rotor, 6 is a stator slot, 9 is a rotor core, 10 is a rotating shaft, and 12 and 12a. 12b and 12c are slots, 11 is a permanent magnet, 14 is a salient pole part, 15 is a remaining part, 17 is a bridge, and 18 is a hole.

Claims (5)

A rotating shaft (10) is fitted to the axial center of a cylindrical rotor core (9) made of laminated electromagnetic steel plates, and a plurality of rectangular slots (12a) are arranged so as to surround the rotating shaft in a polygonal shape. In the rotor (3a) of the rotating electrical machine (1) configured to have the permanent magnet (11) embedded therein,
Each rectangular slot of the number of poles is further divided into two, and the two divided slots are arranged so as to form a substantially “C” shape when viewed from the rotating shaft side, and the polygonal shape is formed between the two slots. A rotor of a rotating electrical machine comprising a bridge (17) that connects the outer salient pole part (14) and the inner part of the magnet, and embedded with permanent magnets in each slot.   2. The rotor of the rotating electrical machine according to claim 1, wherein each rectangular slot is divided into three instead of being divided into two, and each of the three divided slots is arranged in a mountain shape when viewed from the rotating shaft side, so The rotor of the rotating electrical machine is characterized in that a bridge (17) connecting the outer salient pole part (14) and the inner part of the polygonal shape is formed in each slot, and a permanent magnet is embedded in each slot.   2. The rotor of the rotating electrical machine according to claim 1, wherein each rectangular slot is divided into four instead of being divided into two, and each of the four divided slots is arranged in a mountain shape when viewed from the rotating shaft side, and between the slots. The rotor of the rotating electrical machine is characterized in that a bridge (17) connecting the outer salient pole part (14) and the inner part of the polygonal shape is formed in each slot, and a permanent magnet is embedded in each slot.   The rotor of a rotating electrical machine according to any one of claims 1 to 3, wherein a plurality of holes (18) penetrating in the axial direction of the rotating shaft are provided in the salient pole portion. Child. A rotating electrical machine having a stator as an armature and a rotor embedded with permanent magnets as a field, wherein the rotor according to any one of claims 1 to 4 is used as the rotor. Rotating electric machine.

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