JP5005830B1 - Rotor core, rotor and rotating electric machine - Google Patents

Abstract

To prevent demagnetization of a permanent magnet.
A rotor core according to an embodiment is arranged such that a distance between each other increases toward the outer peripheral side, and a pair of permanent magnets having the same magnetic pole direction with respect to the radial direction are respectively inserted. Provide holes. The magnet hole is a first hole portion formed along the shape of the permanent magnet, and when the permanent magnet is inserted into the first hole portion, the other permanent magnet among the corner portions of the permanent magnet. It is the shape which the 2nd hole part which covers the corner | angular part nearest to through a space | gap connected. Further, the second hole portion forms a bridge portion between the second hole portion and the other second hole portion.
[Selection] Figure 4

Description

  Embodiments disclosed herein relate to a rotor core, a rotor, and a rotating electrical machine.

  Conventionally, a permanent magnet type rotating electrical machine is known as a rotating electrical machine such as an electric motor or a generator. A permanent magnet type rotating electrical machine includes a rotor having a plurality of permanent magnets arranged side by side in the circumferential direction of the rotor core, and a rotor having a stator disposed opposite to the outer peripheral surface of the rotor via a gap. Electric.

  As this type of rotating electrical machine, in addition to an SPM (Surface Permanent Magnet) type rotating electrical machine in which a permanent magnet is disposed on the outer peripheral surface of the rotor core, an IPM in which the permanent magnet is embedded in the rotor core. There is an (Interior Permanent Magnet) type rotating electrical machine. The IPM type rotating electrical machine is widely used particularly in the fields of machine tools, electric vehicles, robots and the like.

JP 2005-039963 A

  However, there is room for further improvement in the conventional rotating electric machine in that it is difficult to cause demagnetization of the permanent magnet. Here, the demagnetization of the permanent magnet is a decrease in the residual magnetic flux of the permanent magnet. The demagnetization of the permanent magnet is caused, for example, by generation of a reverse magnetic field due to an armature reaction.

  Since the demagnetization of the permanent magnet can contribute to the performance degradation of the rotating electrical machine, it is desirable that the permanent magnet does not cause demagnetization in the rotating electrical machine.

  An object of one embodiment is to provide a rotor core, a rotor, and a rotating electrical machine that can reduce the demagnetization of a permanent magnet.

The rotor core according to one aspect of the embodiment is arranged so that a distance between each other increases toward the outer peripheral side, and a pair of permanent magnets into which a pair of permanent magnets having the same magnetic pole direction with respect to the radial direction are respectively inserted. Is provided. The magnet hole is a first hole portion formed along the shape of the permanent magnet, and when the permanent magnet is inserted into the first hole portion, the other permanent magnet among the corner portions of the permanent magnet. Is a shape in which a corner portion closest to is connected to a second hole portion that covers a gap to make it difficult for demagnetization due to a reverse magnetic field to occur . The second hole portion forms a bridge portion between the second hole portion and the other second hole portion.

  According to one aspect of the embodiment, demagnetization of the permanent magnet can be made difficult to occur.

FIG. 1 is a schematic view of the motor according to the first embodiment viewed from the axial direction of the shaft. FIG. 2 is a schematic diagram illustrating the configuration of the rotor core according to the first embodiment. FIG. 3 is an enlarged view around the magnet hole shown in FIG. FIG. 4 is an enlarged view around the second hole shown in FIG. FIG. 5A is a diagram illustrating another shape example of the second hole portion. FIG. 5B is a diagram illustrating another shape example of the second hole. FIG. 6 is a schematic view of the motor according to the second embodiment viewed from the axial direction of the shaft. FIG. 7 is a schematic diagram illustrating a configuration of a rotor core according to the second embodiment. FIG. 8 is an enlarged schematic view around the cavity. FIG. 9 is a schematic diagram showing the configuration of the magnet hole. FIG. 10A is an enlarged schematic view around the second hole. FIG. 10B is a schematic diagram illustrating the configuration of the second hole. FIG. 11A is a schematic diagram illustrating another configuration of the cavity. FIG. 11B is a schematic diagram illustrating another configuration of the cavity. FIG. 11C is a schematic diagram illustrating another configuration of the cavity. FIG. 11D is a schematic diagram illustrating another configuration of the cavity. FIG. 11E is a schematic diagram illustrating another configuration of the cavity. FIG. 11F is a schematic diagram illustrating another configuration of the rotor core. FIG. 12 is a schematic diagram illustrating another configuration of the second hole portion.

  Hereinafter, embodiments of a rotor core, a rotor, and a rotating electrical machine disclosed in the present application will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by embodiment shown below. For example, an example in which the rotating electrical machine disclosed in the present application is a motor will be described below, but the rotating electrical machine disclosed in the present application may be, for example, a generator.

(First embodiment)
First, the configuration of the motor according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic view of the motor according to the first embodiment viewed from the axial direction of the shaft. As shown in FIG. 1, the motor 1 according to the embodiment includes a rotor 10, a stator 20, and a shaft 30.

  The rotor 10 includes a rotor core 11 and a permanent magnet 12. The rotor core 11 is a cylindrical member (magnetic steel plate laminate) formed by laminating a large number of thin plate materials (electromagnetic steel plate forming bodies) such as electromagnetic steel plates, and a plurality of permanent magnets 12 are surrounded inside. Arranged along the direction. The rotor 10 is attached to a shaft 30 and rotates around the shaft 30 as a central axis.

  The stator 20 is a member that is disposed so as to face the outer peripheral surface of the rotor 10 via a gap. The stator 20 includes a stator core 21 and a stator winding 22.

  The stator core 21 is a substantially cylindrical member, and a large number of teeth 211 protruding radially inward are formed along the circumferential direction on the inner circumferential side. A space between the teeth 211 is referred to as a slot 212, and the stator winding 22 wound using an insulation-coated electric wire is accommodated in each slot 212. The stator winding 22 is wound by the distributed winding method, but may be wound by the concentrated winding method.

  When a current flows through the stator winding 22 of the stator 20, a rotating magnetic field is generated inside the stator 20. The rotor 10 is rotated by the interaction between the rotating magnetic field and the magnetic field generated by the permanent magnet 12 of the rotor 10, and the shaft 30 rotates as the rotor 10 rotates.

  In the motor 1 according to the first embodiment, the permanent magnet 12 constituting one pole is formed by two of the first magnet 12a and the second magnet 12b. The first magnet 12 a and the second magnet 12 b have the same magnetic pole direction with respect to the radial direction, and are arranged in a V shape in which the distance between the first magnet 12 a and the second magnet 12 b increases toward the outer peripheral side of the rotor core 11.

  For example, as shown in FIG. 1, when the first magnet 12a is arranged with the north pole facing the outer peripheral side, the second magnet 12b that forms a pair of the first magnet 12a also has the north pole arranged on the outer circumference. It is arranged toward the side.

  Adjacent permanent magnets 12 are arranged such that the magnetic poles are opposite to each other in the radial direction. For example, as shown in FIG. 1, the N poles of the first magnet 12 a and the second magnet 12 b are adjacent to the permanent magnet 12 with the N poles of the first magnet 12 a and the second magnet 12 b facing the outer peripheral side. The permanent magnet 12 is arranged so that the side faces the center of rotation.

  Here, in a conventional rotating electric machine, there is a possibility that demagnetization of a permanent magnet may occur due to a reverse magnetic field from a stator due to an armature reaction, for example. The demagnetization of the permanent magnet can contribute to the deterioration of the performance of the rotating electrical machine.

  Therefore, in the motor 1 according to the first embodiment, a predetermined gap is provided around a portion of the permanent magnet 12 where demagnetization is likely to occur. Specifically, portions (second holes 112b and 113b to be described later) where the permanent magnet 12 is not inserted are formed with respect to the magnet holes formed in the rotor core 11 in order to insert the permanent magnet 12. It was. Thereby, even if a reverse magnetic field from the stator 20 is generated, demagnetization of the permanent magnet 12 can be made difficult to occur.

  In the conventional rotating electric machine, there is a possibility that magnetic flux leakage occurs between the permanent magnets. For this reason, the motor 1 is aiming at the reduction | restoration of magnetic flux leakage by forming the cavity part 111 with respect to the area | region pinched | interposed by adjacent permanent magnets 12. FIG. This point will be described in the second embodiment.

  Next, the configuration of the rotor core 11 will be specifically described. FIG. 2 is a schematic diagram illustrating a configuration of the rotor core 11 according to the first embodiment.

  As shown in FIG. 2, the rotor core 11 is formed with a magnet hole portion 114 having a first magnet hole 112 and a second magnet hole 113 as a set side by side in the circumferential direction. Each magnet hole 114 is arranged so that the first magnet hole 112 and the second magnet hole 113 are line-symmetric with respect to a pole pitch line P provided at a 45-degree pole pitch angle.

  The first magnet hole 112 is a magnet hole into which the first magnet 12a (see FIG. 1) is inserted. The second magnet hole 113 is a magnet hole into which the second magnet 12b (see FIG. 1) is inserted. The 1st magnet hole 112 and the 2nd magnet hole 113 are arrange | positioned at the V shape where a mutual space expands toward an outer peripheral side.

  Here, an example in which eight sets of magnet hole portions 114 are formed in the rotor core 11 is shown, but the number of sets of magnet hole portions 114 formed in the rotor core 11 is eight sets. It is not limited.

  Next, the configuration of the magnet hole 114 will be specifically described with reference to FIG. FIG. 3 is an enlarged view around the magnet hole 114. FIG. 3 shows a state in which the first magnet 12a and the second magnet 12b are inserted into the first magnet hole 112 and the second magnet hole 113, respectively.

  As shown in FIG. 3, the first magnet hole 112 has a shape in which a first hole 112a, a second hole 112b, and a third hole 112c are connected. Similarly, the second magnet hole 113 has a shape in which the first hole 113a, the second hole 113b, and the third hole 113c are connected. The second magnet hole 113 is symmetrical with the first magnet hole 112. Therefore, only the shape of the first magnet hole 112 will be described below.

  The first hole 112a is a hole formed along the shape of the first magnet 12a. Specifically, since the first magnet 12a is a rectangular permanent magnet, the first hole 112a is also formed in a rectangular shape. The first magnet 12a is inserted into the first hole 112a.

  The second hole 112b is formed in the vicinity of the position where the first magnet 12a and the second magnet 12b are closest to each other. Specifically, the 2nd hole 112b is formed in the shape which covers the corner 120a nearest to the 2nd magnet 12b among the corners of the 1st magnet 12a.

  The corner 120a is a place where demagnetization is likely to occur in the first magnet 12a. Specifically, the reverse magnetic flux generated by the armature reaction or the like, that is, the magnetic flux flowing from the stator 20 toward the center of the rotor core 11 is generated in the region between the first magnet 12a and the second magnet 12b. There is a tendency to concentrate. For this reason, the corner 120a of the first magnet 12a closest to the second magnet 12b is susceptible to demagnetization.

  In particular, the space between the corner 120a of the first magnet 12a and the corner 120b of the second magnet 12b closest to the first magnet 12a is narrower than the other portions. Therefore, the magnetic flux that flows from the stator 20 toward the center of the rotor 10 is more likely to concentrate.

  On the other hand, the rotor core 11 according to the first embodiment is formed with a second hole portion 112b so as to cover the corner portion 120a of the first magnet 12a. As a result, a gap is formed between the corner 120 a of the first magnet 12 a and the rotor core 11. The air in the air gap has a lower magnetic permeability than a metal such as iron that forms the rotor core 11. Therefore, the second hole 112b covers the corner 120a through the gap, so that demagnetization of the corner 120a can be made difficult to occur.

  Next, a more specific configuration of the second hole 112b will be described with reference to FIG. FIG. 4 is an enlarged view around the second hole 112b shown in FIG.

  As shown in FIG. 4, the second hole portion 112 b is a first portion facing a part of the outer peripheral side surface 121 of the first magnet 12 a (see FIG. 3) and the second magnet 12 b (see FIG. 3). The magnet 12a (see FIG. 3) is formed to cover a part of the side surface 122. Note that the portion including each of the side surface 121 and the side surface 122 is the corner portion 120a of the first magnet 12a.

  Here, a region between the first magnet hole 112 and the second magnet hole 113 is referred to as a bridge portion. Magnetic flux generated by armature reaction or the like mainly passes through such a bridge portion.

  The corner 120a is disposed at a position away from the bridge 110. For this reason, compared with the case where the corner | angular part 120a is arrange | positioned in the position which contact | connects the bridge part 110, it becomes difficult to receive the influence of a demagnetization.

  The second hole 112b is formed in a shape in which the distance L1 between the outer peripheral side surface 60c and the side surface 121 located on the outer peripheral side of the first magnet 12a increases toward the bridge portion 110. The

  That is, as the shape of the second hole 112b is increased, the first magnet 12a becomes less susceptible to demagnetization, whereas the effective magnetic flux flowing from the first magnet 12a to the stator 20 is the first. The possibility of being obstructed by the second hole 112b is also increased. For this reason, by forming the second hole 112b so that the distance L1 increases as the distance from the corner 120a of the first magnet 12a increases, demagnetization of the corner 120a of the first magnet 12a is less likely to occur. However, the decrease in effective magnetic flux can be suppressed.

  In the first embodiment, since the corner 120a is disposed at a position away from the bridge 110, the corner 120a is demagnetized compared to the case where the corner 120a is not disposed at a position away from the bridge 110. Hard to do. For this reason, compared with the case where the corner | angular part 120a is not arrange | positioned in the position away from the bridge part 110, the distance L1 can be made small. As the distance L1 decreases, the effective magnetic flux is less likely to be inhibited by the second hole 112b. Therefore, according to the first embodiment, it is possible to further suppress the decrease in the effective magnetic flux.

  As shown in FIG. 4, the second holes 112b and 113b are formed such that the side surfaces 60a and 60b facing each other are parallel to each other.

  That is, the bridge portion 110 is a region having a relatively low strength in the rotor core 11. For this reason, by forming the side surfaces 60a and 60b in parallel, demagnetization of the corner portion 120a can be made difficult to occur while suppressing a decrease in strength of the bridge portion 110.

  Although FIG. 4 illustrates an example in which the opposing side surfaces 60a and 60b of the second hole portions 112b and 113b are formed in parallel, the side surfaces 60a and 60b do not necessarily have to be parallel.

  In the first embodiment, the second hole portions 112b and 113b are formed so that magnetic saturation occurs in the bridge portion 110 between the second hole portions 112b and 113b. When magnetic saturation occurs, no more magnetic flux flows through the bridge portion 110. That is, since the amount of magnetic flux flowing through the bridge portion 110 is limited, the leakage magnetic flux of the first magnet 12a can be reduced, and the decrease in effective magnetic flux can be suppressed.

  When the bridge portion 110 is saturated, the leakage magnetic flux of the first magnet 12a can be reduced and the decrease in effective magnetic flux can be suppressed, but the corner portion 120a tends to be demagnetized easily. On the contrary, if the bridge portion 110 is not saturated, the corner portion 120a tends not to be demagnetized, but the leakage flux of the first magnet 12a increases and the effective magnetic flux tends to decrease. In consideration of these, the width of the bridge unit 110 may be determined. In the first embodiment, the bridge unit 110 is saturated, but the present invention is not limited to this.

  In addition, what is necessary is just to narrow a width | variety, when making the bridge part 110 easy to saturate. Conversely, when it is difficult to saturate the bridge portion 110, the width may be increased.

  FIG. 5A shows another example of the shape of the second hole. For example, as shown in FIG. 5A, the opposing side surfaces 60a_1 and 60b_1 of the second holes 112b_1 and 113b_1 may be formed in a shape that moves away from the outer peripheral side.

  In order to prevent the demagnetization of the corner portion 120a from occurring more reliably, it is desirable to flow as much magnetic flux as possible through the bridge portion 110 by shortening the length of the bridge portion 110. This is because the magnetic flux that could not flow through the bridge portion 110 due to magnetic saturation can be prevented from demagnetizing the corner portion 120a by flowing through the second hole portion 112b or the like.

  Therefore, the length L2 from the apex a1 of the corner 120a to the end a3 of the second hole 112b on the side surface 122 of the first magnet 12a facing the second magnet 12b is the length of the side surface 122. It is desirable to be shorter than 1/2 of (the length from the vertex a1 to the vertex a2). In other words, the length L2 is desirably shorter than ½ of the length of the side surface in the short direction of the first magnet 12a.

  However, the length from the vertex a1 to the end a3 of the second hole 112b is not limited to this. FIG. 5B shows another example of the shape of the second hole.

  For example, as shown in FIG. 5B, the length L3 from the vertex a1 to the end a3_1 of the second hole 112b_2 is the length of the side surface 122 of the first magnet 12a (the length from the vertex a1 to the vertex a2). ) May be longer than 1/2. In other words, the length L3 may be longer than ½ of the length of the side surface in the short direction of the first magnet 12a. By doing in this way, since it becomes difficult for a magnetic flux to flow into the bridge part 110_1, the quantity of the leakage magnetic flux which goes around to the 1st magnet 12a through the bridge part 110_1 at the time of normal operation can be reduced.

  Returning to FIG. 3, the third hole 112c will be described. The third hole portion 112c is a hole portion in which the end portion of the first hole portion 112a is expanded toward the outer peripheral side. The third hole 112c is formed to reduce magnetic flux leakage by causing magnetic saturation with the outer periphery of the rotor core 11.

  By providing the third hole 112c, the interval between the first magnet hole 112 and the outer periphery of the rotor core 11 is narrowed. As a result, magnetic saturation is likely to occur in the region between the third hole 112c and the outer periphery of the rotor core 11, and magnetic flux does not easily pass through this region. Since the leakage magnetic flux passes through this region and flows to the south pole, the leakage of magnetic flux can be reduced by providing the third hole 112c.

  As described above, the rotor core according to the first embodiment is arranged so that the distance between the rotor cores increases toward the outer peripheral side, and a pair of permanent magnets having the same magnetic pole direction with respect to the radial direction are inserted. Provided with a pair of magnet holes.

  The magnet hole is a first hole portion formed along the shape of the permanent magnet, and when the permanent magnet is inserted into the first hole portion, the other permanent magnet among the corner portions of the permanent magnet. And a second hole that covers the corner closest to the surface via a predetermined gap. The second hole portion forms a bridge portion between the second hole portion and the second hole portion in the other magnet hole.

  Therefore, according to the rotor core according to the first embodiment, demagnetization of the permanent magnet can be made difficult to occur.

(Second Embodiment)
By the way, the shape of the magnet hole or the like formed in the rotor core is not limited to the shape illustrated in the first embodiment. Therefore, in the following, other shape examples of the rotor core will be described. FIG. 6 is a schematic view of the motor according to the second embodiment viewed from the axial direction of the shaft. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  As shown in FIG. 6, the motor 1_1 according to the second embodiment includes a rotor 10_1, a stator 20, and a shaft 30. The rotor 10_1 includes a rotor core 11_1 and a permanent magnet 12. In the rotor core 11_1, a cavity 111_1 is formed in a region sandwiched between adjacent permanent magnets 12.

  Similarly to the motor 1 according to the first embodiment, the motor 1_1 according to the second embodiment includes the first magnet 12a and the second magnet 12b that move toward each other toward the outer peripheral side of the rotor core 11_1. They are arranged in a V-shape with a wider interval.

  Here, an example in which the motor 1_1 includes the same permanent magnet 12 as the permanent magnet 12 according to the first embodiment is shown, but the motor 1_1 may include a permanent magnet different from the permanent magnet 12. Good. Here, an example in which the motor 1_1 includes the stator 20 and the shaft 30 that are the same as the stator 20 and the shaft 30 according to the first embodiment is shown. However, the motor 1_1 includes the stator 20 and the shaft 30. Different stators and shafts may be provided.

  Next, the configuration of the rotor core 11_1 according to the second embodiment will be described with reference to FIG. FIG. 7 is a schematic diagram illustrating a configuration of a rotor core 11_1 according to the second embodiment.

  As shown in FIG. 7, in the rotor core 11_1, magnet hole portions 114_1 each having a first magnet hole 112_1 and a second magnet hole 113_1 as a set are formed side by side in the circumferential direction. Each magnet hole 114_1 is arranged so that the first magnet hole 112_1 and the second magnet hole 113_1 are line-symmetric with respect to the pole pitch line P provided at a 45-degree pole pitch angle.

  The first magnet hole 112_1 is a magnet hole into which the first magnet 12a is inserted. The second magnet hole 113_1 is a magnet hole into which the second magnet 12b is inserted. The first magnet hole 112_1 and the second magnet hole 113_1 are arranged in a V shape in which the distance from each other increases toward the outer peripheral side.

  As shown in FIG. 7, the cavity 111_1 is formed with respect to the region R. The region R includes a first magnet hole 112_1 and a second magnet hole 113_1 that is adjacent to the first magnet hole 112_1 and into which the second magnet 12b having a reverse magnetic pole is inserted (that is, another magnet). The region sandwiched between the second magnet hole 113_1) provided in the hole 114_1.

  Specifically, the region R is a region surrounded by the virtual line L11, the virtual line L12, and the two magnet holes 112_1 and 113_1. The imaginary line L11 is an imaginary line that connects the points a11 and a12 located on the outermost side of the two magnet holes 112_1 and 113_1. The imaginary line L12 is an imaginary line that connects the points a13 and a14 located closest to the rotation center O of the two magnet holes 112_1 and 113_1.

  Here, a specific arrangement and shape of the cavity 111_1 will be described with reference to FIG. FIG. 8 is an enlarged schematic view around the cavity 111_1.

  In the description of FIG. 8, the second magnet hole 113_1 illustrated in FIG. 7, that is, the second magnet hole 113_1 adjacent to the first magnet hole 112_1 has a magnetic pole in the opposite direction. The second magnet hole 113_1 into which the magnet 12b is inserted is referred to as a “second magnet hole 113_1”.

  As shown in FIG. 8, the cavity 111_1 is formed in a region of the region R (see FIG. 7) where the first magnet hole 112_1 and the second magnet hole 113_1 are close to each other. This is because there is a high possibility that the magnetic flux passes through the above-described region when a leakage magnetic flux that circulates from the north pole to the south pole of the permanent magnet 12 is generated.

  Here, for example, assuming that a leakage magnetic flux is generated in the first magnet 12a inserted into the first magnet hole 112_1, the leakage magnetic flux reaching the S pole of the first magnet 12a is the first magnet hole 112_1. As the position is closer to the point a16, the number is larger, and as the position is farther from the point a16 along the side surface 65a of the first magnet hole 112_1, the number is smaller. The point a16 is one of the points where the first magnet hole 112_1 and the second magnet hole 113_1 are closest.

  On the other hand, the leakage magnetic flux reaching the point a14 (see FIG. 7) side from the point a18 in the first magnet hole 112_1 is very small, and hardly affects the performance of the motor 1_1. Point a18 is a point located at a distance of 1/3 from point a16 to point a14.

  Therefore, in the second embodiment, as shown in FIG. 8, the cavity 111_1 is formed in the region R1. The region R1 is located on the outer peripheral side of the virtual line L14 connecting the point a17 on the second magnet hole 113_1 and the point a18 on the first magnet hole 112_1, and on the second magnet hole 113_1. This is a region closer to the rotation center O than a virtual line L13 connecting the point a16 on one magnet hole 112_1. Here, a point a15 in the second magnet hole 113_1 is a point where the apex of the corner 120b of the second magnet 12b is located, and is also a point closest to the first magnet hole 112_1. Further, the point a17 is a point at a distance of 1/3 from the point a15 toward the point a13 (see FIG. 7). Thereby, magnetic flux leakage between the permanent magnets 12 can be effectively reduced.

  Although specifically described with reference to FIG. 9, a third hole 112c_1 is formed in the first magnet hole 112_1. The third hole portion 112c_1 is a hole portion that forms a gap with the first magnet 12a when the first magnet 12a is inserted.

  By providing the third hole 112c_1, the interval between the first magnet hole 112_1 and the outer periphery of the rotor core 11_1 is narrowed. As a result, magnetic saturation is likely to occur in the region between the third hole 112c_1 and the outer periphery of the rotor core 11_1, and the magnetic flux does not easily pass through this region. Since the leakage magnetic flux passes through this region and flows to the south pole, the leakage of magnetic flux can be reduced by providing the third hole 112c_1.

  The cavity 111_1 is arranged such that the minimum distance between the first magnet hole 112_1 and the first magnet hole 112_1 is the same as the minimum distance between the outer periphery of the rotor core 11_1. The same applies to the minimum distance between the cavity 111_1 and the second magnet hole 113_1.

  As described above, the interval between the cavity 111_1 and the magnet holes 112_1 and 113_1 is set to be approximately the same as the interval between the magnet holes 112_1 and 113_1 and the outer periphery of the rotor core 11_1. Thereby, since magnetic saturation easily occurs between the cavity 111_1 and the magnet holes 112_1 and 113_1, magnetic flux leakage can be further reduced.

  Further, in the cavity portion 111_1, the side surface 50a facing the first magnet hole 112_1 is formed in parallel to the side surface 65a of the first magnet hole 112_1 facing the cavity portion 111_1. Similarly, in the cavity portion 111_1, the side surface 50b facing the second magnet hole 113_1 is formed in parallel to the side surface 65b of the second magnet hole 113_1 facing the cavity portion 111_1. Although the side surface 50a and the side surface 65a are parallel and the side surface 50b and the side surface 65b are parallel, they are not limited to being parallel.

  That is, the side surfaces 50a and 50b in the cavity 111_1 and the side surfaces 65a and 65b in the magnet holes 112_1 and 113_1 are always arranged in contact with each other at the above-described minimum interval. As a result, the magnetic resistance between the cavity 111_1 and the magnet holes 112_1 and 113_1 is increased, so that magnetic saturation is more likely to occur. Therefore, magnetic flux leakage can be further reduced. In addition, all the side surfaces facing a magnet hole may be parallel, and only a part may be parallel in a cavity part.

  Next, the structure of the magnet hole 114_1 will be described with reference to FIG. FIG. 9 is a schematic diagram showing the configuration of the magnet hole 114_1.

  As shown in FIG. 9, the magnet hole portion 114_1 includes a first magnet hole 112_1 and a second magnet hole 113_1. The first magnet hole 112_1 has a shape in which the first hole 112a_1, the second hole 112b_3, and the third hole 112c_1 are connected. Similarly, the second magnet hole 113_1 also has a shape in which the first hole 113a_1, the second hole 113b_3, and the third hole 113c_1 are connected. Since the second magnet hole 113_1 is symmetrical with the first magnet hole 112_1, only the shape of the first magnet hole 112_1 will be described below.

  The first hole 112a_1 is a hole formed along the shape of the first magnet 12a. The first magnet 12a is inserted into the first hole 112a_1.

  The second hole 112b_3 and the third hole 112c_1 are holes that form a gap with the first magnet 12a when the first magnet 12a is inserted into the first hole 112a_1. Part.

  The third hole portion 112c_1 is a hole portion in which the end portion of the first hole portion 112a_1 is expanded toward the outer peripheral side. As described above, the third hole 112c_1 is formed to reduce magnetic flux leakage by causing magnetic saturation with the outer periphery of the rotor core 11_1.

  The second hole 112b_3 is formed in the vicinity of the position where the first hole 112a_1 in the first magnet hole 112_1 and the first hole 113a_1 in the second magnet hole 113_1 are closest to each other. The second hole 112b_3 is formed at a location where the first magnet 12a is susceptible to demagnetization.

  Hereinafter, a specific shape and arrangement of the second hole 112b_3 will be described with reference to FIGS. 10A and 10B. FIG. 10A is an enlarged schematic view around the second hole 112b_3. FIG. 10B is a schematic diagram showing the configuration of the second hole 112b_3.

  As shown in FIG. 10A, the second hole 112b_3 has a shape in which a part of the side surface 65e located on the outer peripheral side of the first hole 112a_1 is expanded toward the outer peripheral side.

  Here, the closer the first magnet 12a is to the position closest to the second magnet 12b on the outer peripheral side surface (the position corresponding to the point a20 of the first magnet hole 112_1), the more affected the demagnetization is. easy.

  Also, the larger the shape of the second hole 112b_3, the easier it is to prevent demagnetization, but the effective magnetic flux that flows from the first magnet 12a to the stator 20 can be hindered by the second hole 112b_3. Increases the nature. Therefore, the second hole 112b_3 is formed so that the thickness gradually increases from the point a19 farthest to the second magnet hole 113_1 to the point a20 closest to the second magnet hole 113_1.

  Specifically, as shown in FIG. 10B, the second hole 112b_3 has a shape in which the thickness distribution based on the side surface 65e of the first hole 112a_1 is closer to the second magnet hole 113_1. . That is, the second hole portion 112b_3 has a substantially triangular shape with a vertex located on the point a20 side with respect to the midpoint a21 between the points a19 and a20.

  Thus, by reducing the shape of the second hole 112b_3 so that the thickness distribution based on the side surface 65e of the first hole 112a_1 is closer to the other magnet hole 113_1, the effective magnetic flux can be reduced. While suppressing, demagnetization of the first magnet 12a can be made difficult to occur.

  In the example of FIG. 10A, the second hole 112b_3 has a maximum thickness T1 that is based on the side surface 65e of the first hole 112a_1 and is approximately 1 / th of the maximum thickness T2 in the first hole 112a_1. 2 is formed. Thereby, both generation | occurrence | production of the demagnetization in the 1st magnet 12a and the reduction | decrease of an effective magnetic flux can be prevented appropriately. It is more desirable that the maximum thickness T1 is in the range of about 1/4 to about 1/2 with respect to the maximum thickness T2.

  Further, the second hole 112b_3 of the first magnet hole 112_1 and the second hole 113b_3 of the second magnet hole 113_1 are formed such that the side surfaces 65c and 65d facing each other are parallel to each other.

  That is, the region where the first magnet hole 112_1 and the second magnet hole 113_1 are closest to each other is a region having relatively low strength in the rotor core 11_1. For this reason, the opposing side surfaces 65c and 65d of the second hole portions 112b_3 and 113b_3 are formed in parallel, so that the strength of the region where the first magnet hole 112_1 and the second magnet hole 113_1 are closest to each other is reduced. Can be suppressed as much as possible. Further, by forming the opposing side surfaces 65c and 65d of the second hole portions 112b_3 and 113b_3 in parallel with each other, the leakage magnetic flux flowing to the south pole through the region between the side surfaces 65c and 65d can be reduced. .

  As described above, the rotor core according to the second embodiment includes a plurality of magnet holes and a cavity. The plurality of magnet holes are formed side by side in the circumferential direction, and permanent magnets are inserted therein. And a cavity part is formed with respect to the area | region pinched | interposed by two magnet holes into which the permanent magnets which adjoin each other and the direction of a magnetic pole is reverse among each of several magnet holes are inserted. Therefore, the magnetic flux leakage of the permanent magnet can be reduced.

  In the rotor core according to the second embodiment, the magnet hole has a first hole formed along the shape of the permanent magnet, and the permanent magnet is inserted into the first hole. And a second hole that forms a gap with the permanent magnet. In the rotor core according to the second embodiment, the second hole is formed in the vicinity of the position where the first holes are closest to each other. Therefore, demagnetization of the permanent magnet can be made difficult to occur.

  By the way, the arrangement and shape of the cavity are not limited to the arrangement and shape of the cavity 111_1 described above. Therefore, hereinafter, other examples of the arrangement and shape of the cavity will be described. 11A to 11E are schematic views showing other configurations of the cavity, and FIG. 11F is a schematic view showing another configuration of the rotor core. In the following description, parts that are the same as those already described are given the same reference numerals as those already described, and redundant descriptions are omitted.

  For example, in the second embodiment, the minimum distance between the cavity 111_1 and the first magnet hole 112_1 is the same as the minimum distance between the first magnet hole 112_1 and the outer periphery of the rotor core 11_1. An example of the case has been described. However, the minimum distance between the cavity and the first magnet hole may be smaller than the minimum distance between the first magnet hole and the outer periphery of the rotor core.

  For example, as shown in FIG. 11A, the cavity 111_2 included in the rotor core 11_2 has a minimum interval T3 between the first magnet hole 112_1 and the outer periphery of the first magnet hole 112_1 and the rotor core 11_2. It is formed at about ½ of the minimum interval T4. In this way, by further reducing the minimum gap between the cavity 111_2 and the first magnet hole 112_1, the leakage magnetic flux becomes more difficult to pass through the region between the cavity 111_2 and the first magnet hole 112_1. Magnetic flux leakage can be further reduced.

  Further, the cavity may be extended from the region R1 shown in FIG. 8 toward the region surrounded by the points a11, a12, a15, and a16. For example, as illustrated in FIG. 11B, the rotor core 11_3 includes a cavity 111_3 in which the tip of the cavity 111_2 illustrated in FIG. 11A extends toward the outer peripheral side. Thus, magnetic flux leakage can be further reduced by forming a cavity in the region surrounded by the points a11, a12, a15, and a16.

  Note that the cavity 111_3 has a side surface 50c facing the third hole 112c_1 and a side surface where the minimum distance between the side surface 65g of the third hole 112c_1 facing the side surface 50c is opposed to the first hole 112a_1. 50a and the distance between the side surfaces 65a of the first hole 112a_1 facing the side surface 50a. Thereby, the magnetic resistance between the cavity 111_3 and the first magnet hole 112_1 can be further increased, and magnetic flux leakage can be further reduced.

  In the second embodiment, the cavity 111_1 has an outer periphery of the rotor core 11_1 that is more than the virtual line L14 connected by the point a17 on the second magnet hole 113_1 and the point a18 on the first magnet hole 112_1. The example in the case of forming in the side was demonstrated (refer FIG. 8). However, the hollow portion may be formed closer to the rotation center O than the virtual line L14.

  For example, as illustrated in FIG. 11C, the cavity 111_4 is formed in a region R2 on the outer peripheral side of the virtual line L15 and on the rotation center O side of the virtual line L13 in the region R. Here, the virtual line L15 is a virtual line that bisects the region R in the radial direction. That is, the distance T5 from the virtual line L11 to the virtual line L15 is half of the distance T6 from the virtual line L11 to the virtual line L12.

  Thus, the cavity may be formed in the region R2 on the outer peripheral side of the virtual line L15 that bisects the region R in the radial direction.

  In the second embodiment, the hollow portion has a substantially triangular shape, but the shape of the hollow portion is not limited to this. Specifically, the cavity has any shape as long as at least a part of the side surface facing the magnet holes 112_1 and 113_1 is parallel to the side surface of the magnet holes 112_1 and 113_1. Also good.

  For example, as shown in FIG. 11D, the cavity 111_5 may have a substantially boomerang shape in which the side surface on the rotation center O side is recessed toward the outer peripheral side. As shown in FIG. 11E, the cavity 111_6 is divided into two cavities 111_6a and 111_6b that are formed in parallel to the side surface of the first magnet hole 112_1 and the side surface of the second magnet hole 113_1. May be.

  Moreover, although each embodiment mentioned above demonstrated the example in case the permanent magnet 12 which comprises 1 pole was comprised with two of the 1st magnet 12a and the 2nd magnet 12b, the cavity part is One permanent magnet may be formed for a rotor constituting one pole.

  For example, as shown in FIG. 11F, the rotor core 11_4 is formed side by side in the circumferential direction, and includes six magnet holes 115 into which permanent magnets are inserted. Of these magnet holes 115, two magnet holes 115 adjacent to each other are inserted with permanent magnets whose magnetic poles are opposite to each other in the radial direction.

  The cavity 111_7 is formed in a region R3 sandwiched between the magnet holes 115. Specifically, the region R3 includes an imaginary line L16 connecting the points a22 and a23 located on the outermost peripheral side of the two adjacent magnet holes 115 and 115, and points a24 and a25 located on the most rotation center O side. This is an area formed by the connecting virtual line L17 and the two magnet holes 115, 115.

  As described above, even when the cavity 111_7 is formed with respect to the rotor core 11_4 of the rotor in which one permanent magnet constitutes one pole, similarly to the cavity according to each embodiment described above, Magnetic flux leakage can be reduced.

  Moreover, in each embodiment mentioned above, the example in the case of making it difficult to let a leakage magnetic flux pass with the air in a cavity part was demonstrated. However, the present invention is not limited to this, and the rotor or rotating electrical machine disclosed in the present application may be filled with a nonmagnetic member such as resin or aluminum in the cavity. Similarly, a nonmagnetic member such as resin or aluminum may be filled in the second hole or the third hole.

  Further, the shape of the second hole provided in the first magnet hole and the second magnet hole is not limited to the shape of the second hole according to the second embodiment. Therefore, another configuration example of the second hole portion will be described with reference to FIG. FIG. 12 is a schematic diagram illustrating another configuration of the second hole portion.

  For example, in 2nd Embodiment, in order to ensure the intensity | strength of the rotor core 11_1, the example in the case where the mutually opposing side surface 65c, 65d of 2nd hole part 112b_3, 113b_3 was formed in parallel was demonstrated. (See FIG. 10A). However, the opposing side surfaces of the second hole portion do not necessarily have to be parallel.

  For example, as shown in FIG. 12, the second hole portion 112b_4 and the second hole portion 113b_4 may be formed such that the side surfaces 65h and 65i facing each other move away toward the outer peripheral side of the rotor core. .

  Thus, if the minimum interval between the second hole portions is not less than the minimum interval between the first magnet hole and the second magnet hole, the first magnet hole and the second magnet hole It is possible to suppress as much as possible a decrease in the strength of the region closest to the magnet hole.

  Further effects and modifications can be easily derived by those skilled in the art. Thus, the broader aspects of the present invention are not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

DESCRIPTION OF SYMBOLS 1 Motor 10 Rotor 11 Rotor core 110 Bridge part 111 Cavity part 112 1st magnet hole 112a 1st hole part 112b 2nd hole part 112c 3rd hole part 113 2nd magnet hole 113a 1st hole Portion 113b Second hole 113c Third hole 114 Magnet hole 12 Permanent magnet 12a First magnet 12b Second magnet 120a 120b Corner 20 Stator 21 Stator core 211 Teeth 212 Slot 22 Stator winding 30 shaft

Claims (6)

A pair of magnet holes into which a pair of permanent magnets having the same direction of the magnetic pole with respect to the radial direction are respectively inserted are arranged so that the distance between them increases toward the outer peripheral side;
The magnet hole is
When the permanent magnet is inserted into the first hole formed along the shape of the permanent magnet and the first hole, the other permanent magnet among the corners of the permanent magnet Is a shape connected to a second hole portion that covers the corner portion closest to , through a gap for making it difficult to demagnetize due to a reverse magnetic field ,
The second hole is
A rotor core, wherein a bridge portion is formed between the second hole portion and the second hole portion in the other magnet hole. The second hole is
The rotor core according to claim 1, wherein the rotor core is formed in a size that causes magnetic saturation in the bridge portion. Both said second holes are
3. The rotor core according to claim 1, wherein the side surfaces facing each other are formed in a shape that is parallel or away from each other toward the outer peripheral side. The second hole is
4. The rotor core according to claim 1, wherein a distance between the permanent magnet and a side surface located on the outer peripheral side increases in a direction toward the bridge portion. The rotor core according to any one of claims 1 to 4,
And a permanent magnet inserted into the magnet hole provided in the rotor core. A rotor according to claim 5;
A rotating electric machine comprising: an outer peripheral surface of the rotor; and a stator arranged to face each other through a gap.

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