Rotor structure and method for manufacturing rotor structure

Abstract

The present invention provides a rotor structure and a method for manufacturing the rotor structure that suppress magnetic flux leakage and achieve an excellent torque-boosting effect. The rotor structure includes: a plurality of rotor cores; a plurality of magnets, each disposed through a plurality of magnet insertion holes formed axially through the rotor cores; and a shaft, which extends through a center hole of the rotor cores and is integrally formed with the rotor cores. The rotor core includes: a first rotor core, formed so that the diameter of the center hole is substantially equal to the outer diameter of the shaft; and a second rotor core, formed so that at least a portion of the center hole has a larger diameter than the outer diameter of the shaft, and coaxially sandwiched between the two first rotor cores. The magnet inclusion is interposed in the gap between the inner periphery of the second rotor core and the outer periphery of the shaft.

Description

Technical Field

[0001] The present invention relates to a rotor structure and a method for manufacturing the rotor structure. Background Art

[0002] For example, Figure 13 、 Figure 14 as well as Figure 15 As shown, the rotor (rotor structure) of an electric rotating machine such as an electric motor for an automobile or an electric appliance is constructed by integrating multiple rotor cores 1 along an axis O1, with a shaft 2 passing through a center hole (shaft hole) 1a of each rotor core 1. In addition, an IPM rotor core (embedded magnet rotor core) or an SPM rotor core (surface magnet rotor core) is commonly used as the rotor core 1.

[0003] For example, the IPM rotor core 1 is constructed to include: a laminated iron core 3 formed by stacking multiple core components (thin plate-shaped components) formed by punching electromagnetic steel plates, a permanent magnet 4 inserted into and accommodated in a magnet insertion hole 3c formed from one end 3a to the other end 3b in the axis O1 direction of the laminated iron core 3, and a resin material 5 injected into the magnet insertion hole 3c to bury and fix the permanent magnet 4 (for example, refer to patent document 1).

[0004] The laminated core 3 is provided with a center hole (shaft hole) 3 d formed to penetrate from one end 3 a to the other end 3 b on the axis O1 and to fit the shaft 2 therein by shrink fitting or press fitting.

[0005] On the other hand, Figure 14 As shown, the IPM rotor core 1 has the following structure: a pair of permanent magnets 4 (4a, 4b) adjacent to each other from the axis O1 side are arranged in a deep V shape in such a manner that the circumferential spacing gradually increases as they go radially outward, and multiple groups of pairs of permanent magnets 4 in a deep V shape are regularly arranged in the circumferential direction.

[0006] Alternatively, there is a configuration in which a plurality of permanent magnets 4 are radially arranged so as to extend in a radial direction centered on the axis O1.

[0007] By using the rotor core 1 in which the permanent magnets 4 are arranged radially in a deep V shape in this manner, a rotor having excellent torque performance can be realized.

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 3-036945 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] However, in the conventional IPM rotor core 1 in which the permanent magnets 4 are arranged radially in a deep V shape, there is a problem that a magnetic flux leakage S occurs between adjacent permanent magnets 4 (4a, 4b) located on the inner circumference side (the shaft 2 side) radially inward of the center of the axis O1. This magnetic flux leakage S deteriorates the torque improvement effect (see FIG. Figure 14 ).

[0011] Therefore, there is a strong demand for a method and apparatus that suppresses magnetic flux leakage at this location and exhibits an excellent torque improvement effect.

[0012] Solutions for solving problems

[0013] A technical solution of the rotor structure disclosed in the present invention is a rotor structure, which includes: a plurality of rotor cores; a plurality of magnets, which are respectively arranged to pass through a plurality of magnet insertion holes, and the plurality of magnet insertion holes are formed by axially penetrating the rotor core; and a shaft, which passes through the center hole of the rotor core and is integrally provided with the rotor core, as the rotor core, which includes: a first rotor core, which is formed so that the diameter of the center hole is approximately the same as the outer diameter of the shaft; and a second rotor core, which is formed so that at least a part of the diameter of the center hole is larger than the outer diameter of the shaft, and is configured to be coaxially sandwiched between the two first rotor cores with the first rotor core, and a magnet inclusion is sandwiched in the gap between the inner peripheral edge of the second rotor core and the outer peripheral surface of the shaft.

[0014] For the above-mentioned rotor structure, it can also be that, in the rotor core, a pair of magnets adjacent to each other in the circumferential direction with the axis as the center are arranged in a roughly V-shaped manner with the radial inner side of the axis as the center forming a valley, and a plurality of pairs of roughly V-shaped magnets are regularly arranged in the circumferential direction, and the magnet contains matter that is at least sandwiched between the valley of the pair of magnets in the roughly V-shaped shape and the shaft in the radial direction.

[0015] For the above-mentioned rotor structure, it can also be that, in the rotor core, the multiple magnets extend along the radial direction centered on the axis, and are radially arranged at predetermined intervals in the circumferential direction centered on the axis, and the magnet content is at least sandwiched between a pair of magnets adjacent to each other in the circumferential direction and the shaft in the radial direction.

[0016] In the above rotor structure, the magnetic inclusions may be arranged in a ring shape throughout the entire circumference of the axis.

[0017] In the above rotor structure, the magnet-containing material may be a bonded magnet formed by mixing a powdered or granular magnet with a resin material or a rubber material.

[0018] A technical solution of the manufacturing method of the rotor structure disclosed in the present invention is a method for manufacturing the rotor structure of the above-mentioned technical solution, wherein the first rotor core is provided with an injection hole extending from one axial end to the other end thereof, and after the first rotor core and the second rotor core are installed on the shaft, the magnet content is injected from the injection hole to fill the gap.

[0019] Effects of the Invention

[0020] In the above-mentioned technical solution, magnetic inclusions are interposed between the shaft and adjacent magnets of the second rotor core, where magnetic flux leakage is most likely to occur, thereby suppressing magnetic flux leakage. This enables a rotor structure that exhibits superior torque performance (torque boosting effect) compared to conventional rotors.

[0021] Furthermore, by interposing magnet inclusions between the shaft and adjacent magnets of the second rotor core at the portion where magnetic flux leakage is most likely to occur, the amount of magnets can be increased, thereby achieving a rotor structure that exhibits even better torque performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a cross-sectional view showing a rotor (rotor structure) according to one embodiment.

[0023] Figure 2 yes Figure 1 The X1-X1 line view is a diagram showing the rotor (rotor structure) and the first rotor core (IPM type rotor core) of one embodiment.

[0024] Figure 3 yes Figure 1 The X2-X2 line view is a diagram showing the rotor (rotor structure) and the second rotor core (IPM type rotor core) of one embodiment.

[0025] Figure 4 This is a perspective view showing a first rotor core (IPM type rotor core) according to one embodiment.

[0026] Figure 5 This is a perspective view showing a second rotor core (IPM type rotor core) according to one embodiment.

[0027] Figure 6 It is a cross-sectional view showing the rotor (rotor structure).

[0028] Figure 7 yes Figure 6 X1-X1 line view.

[0029] Figure 8 yes Figure 6 X2-X2 line view.

[0030] Figure 9 It is a diagram showing a modified example of the rotor (rotor structure) and the first rotor core (IPM type rotor core) according to one embodiment.

[0031] Figure 10 It is a diagram showing a modified example of the rotor (rotor structure) and the second rotor core (IPM type rotor core) according to one embodiment.

[0032] Figure 11 It is a perspective view showing a modified example of the first rotor core (IPM type rotor core) according to one embodiment.

[0033] Figure 12 It is a perspective view showing a modified example of the second rotor core (IPM type rotor core) according to one embodiment.

[0034] Figure 13 It is a cross-sectional view showing a conventional rotor (rotor structure).

[0035] Figure 14 yes Figure 13 X1-X1 line view.

[0036] Figure 15 It is a perspective view showing a conventional rotor core (IPM type rotor core).

[0037] Description of Reference Numerals

[0038] 2. Shaft; 3. Laminated iron core; 3c. Magnet insertion hole; 3d. Center hole (shaft hole); 4. Permanent magnet; 5. Resin material; 10. First rotor core; 10a. Center hole (shaft hole); 11. Second rotor core; 11a. Center hole (shaft hole); 12. Magnet contents; A. Rotor (rotor structure); H. Gap; O1. Axis line; S. Magnetic flux leakage. DETAILED DESCRIPTION

[0039] Below, refer to Figures 1 to 12 A rotor structure and a method for manufacturing the rotor structure according to an embodiment of the present invention will be described.

[0040] For example, the rotor (rotor structure) A of this embodiment is a rotor of an electric rotating machine such as an electric motor of an automobile or an electric appliance. Figure 1 、 Figure 2 、 Figure 3 As shown, the structure is such that the shaft 2 is passed through the center holes (shaft holes) 10 a and 11 a of the rotor cores 10 and 11 to integrate the shaft 2 with the plurality of IPM type rotor cores 10 and 11 in the axis O1 direction.

[0041] For example, Figure 2 and Figure 4 、 Figure 3 and Figure 5As shown, the IPM rotor core 10, 11 of this embodiment is constructed to include: a laminated iron core 3 formed by stacking multiple core components (thin plate-shaped components) formed by punching electromagnetic steel plates, a permanent magnet 4 inserted into and accommodated in a magnet insertion hole 3c formed by passing through from one end 3a to the other end 3b in the axis O1 direction of the laminated iron core 3, and a resin material 5 injected into the magnet insertion hole 3c to bury and fix the permanent magnet 4.

[0042] The laminated core 3 is provided with a center hole (shaft hole) 3 d for inserting a shaft, which is formed to penetrate from one end 3 a to the other end 3 b on the axis O1 .

[0043] like Figure 2 、 Figure 3 As shown, the IPM rotor core 10, 11 of this embodiment is constructed as follows: a pair of permanent magnets 4 (4a, 4b) adjacent to each other from the axis O1 side are arranged in a deep V shape in such a manner that the circumferential spacing gradually increases as they go radially outward, and a plurality of groups of pairs of permanent magnets 4 (4a, 4b) in a deep V shape are regularly arranged in the circumferential direction.

[0044] Furthermore, if Figure 1 、 Figure 2 、 Figure 3 As shown, the rotor A of this embodiment uses two types of rotor cores, namely a first rotor core (IPM type rotor core) 10 for conventional shaft mounting and a second rotor core (IPM type rotor core) 11 for preventing magnetic flux leakage. The first rotor core 10 is formed so that the inner diameter of its center hole 10a is roughly the same as the outer diameter of the shaft 2, so that the shaft 2 passes through the center hole 10a and is mounted as a whole with the shaft 2 by heat fitting and pressing at a predetermined position of the shaft 2. The second rotor core 11 is formed so that the inner diameter of its center hole 11a is larger than the outer diameter of the shaft 2.

[0045] Specifically, the second rotor core 11 is sandwiched between the two first rotor cores 10. For example, by engaging pins and pinholes provided on each rotor core 10, 11, the second rotor core 11 is aligned coaxially with the axis O1 of the adjacent first rotor core 10, and the two rotor cores are assembled into one piece. Thus, the second rotor core 11, sandwiched between the two first rotor cores 10, is supported by the two first rotor cores 10, with the inner periphery of the second rotor core 11a spaced apart from the outer diameter of the shaft 2, leaving a gap H between the inner periphery and the shaft 2.

[0046] The magnetic inclusions 12 are provided in the gap H between the inner periphery of the second rotor core 11 and the shaft 2 so as to fill the gap H. That is, the rotor A of this embodiment is configured such that the magnetic inclusions 12 are interposed between the second rotor core 11 and the shaft 2 .

[0047] The magnetic inclusion 12, such as a bonded magnet formed by mixing and dispersing a powdered (or granular) magnet in a resin or rubber material, is injected into and fills the gap H between the inner periphery of the second rotor core 11 and the shaft 2. The magnetic inclusion 12 solidifies / hardens to a desired level of flexibility, elasticity, and stretchability, and is then sandwiched between the second rotor core 11 and the shaft 2. The first and second rotor cores 10, 11 have essentially the same structure, except for the diameters of their center holes 10a and 11a.

[0048] As a method for injecting and filling the gap H between the inner peripheral edge of the second rotor core 11 and the shaft 2 with a magnet-containing material 12 obtained by mixing and dispersing a powdered (or granular) magnet in a resin material or a rubber material (in the manufacturing method of the rotor structure of this embodiment), for example, Figure 1 As shown, an injection hole 10b is pre-set, extending from one end of the first rotor core 10 to the other end. After the first rotor core 10 and the second rotor core 11 are assembled in predetermined positions with the shaft 2 inserted through the center holes 10a and 11a, the uncured magnetic inclusion 12 is injected and filled into the gap H between the inner periphery of the second rotor core 11 and the shaft 2 through the injection hole 10b of the first rotor core 10. After a predetermined period of time, the magnetic inclusion 12 filled in the injection hole 10b and the gap H between the second rotor core 11 and the shaft 2 achieves a predetermined softness, elasticity, and stretchability, and solidifies / hardens. This allows the magnetic inclusion 12 to be appropriately filled and sandwiched in the gap H between the second rotor core 11 and the shaft 2, resulting in the rotor A of this embodiment including the magnetic inclusion 12.

[0049] Here, in the rotor A of this embodiment, even if the second rotor core 11 is not firmly connected to the shaft 2, the first rotor core 10 is firmly connected to the shaft 2 by shrink fitting or press fitting, and the second rotor core 11 is integrally provided between adjacent first rotor cores 10. In addition, the gap H between the second rotor core 11 and the shaft 2 is filled with magnetic inclusions 12. Thus, it is possible to ensure (improve) the rotor inertia and ensure (improve) the rigidity of the rotor A itself. In addition, by evenly arranging a plurality of first rotor cores 10 in the direction of the axis O1, it is possible to more reliably seek to ensure (improve) the rotor inertia and ensure (improve) the rigidity of the rotor A itself.

[0050] In addition, for example, the adjacent first rotor core 10 and second rotor core 11 can be set as one group, and the first rotor core 10 of each group can be hot-fitted and press-fitted and installed on the shaft 2. After the second rotor core 11 is installed on the first rotor core 10, the magnetic inclusion 12 is filled into the gap H between the second rotor core 11 and the shaft 2, and multiple groups of first rotor cores 10 and second rotor cores 11 are installed in sequence in the same way as above to form rotor A.

[0051] Alternatively, the magnetic inclusion 12 may be a hardened material such as an Nd magnet. However, in this case, when heated, the Nd magnet contracts while the shaft 2, made of iron or the like, expands, potentially causing damage such as cracks in the magnetic inclusion 12. Therefore, it is preferable that the magnetic inclusion 12 have a solidified / hardened strength that is unlikely to crack during use of the rotor A. In other words, it is preferable that the magnetic inclusion 12 have flexibility, elasticity, and elasticity that are unlikely to crack during use of the rotor A. In this regard, a bonded magnet is preferably used.

[0052] Alternatively, a magnet-containing material 12 may be used as a molded product formed by mixing and dispersing a powdered magnet in a resin material or the like and then hardening (solidifying) the mixture. When the shaft 2 is passed through the center holes 10a and 11a of the first rotor core 10 and the second rotor core 11, the magnet-containing material 12 may be sandwiched in the gap H between the second rotor core 11 and the shaft 2, thereby manufacturing and constituting the rotor A.

[0053] Furthermore, for the rotor A of this embodiment constituted by the above-mentioned structure, by sandwiching a magnetic inclusion 12 between the radially inner portion of the adjacent permanent magnets 4 of the second rotor core 10 where magnetic flux leakage occurs (the valley portion of a pair of permanent magnets 4 (4a, 4b) in a deep V shape) and the shaft 2, the magnetic flux of the permanent magnet 4 at the magnetic inclusion 12 can be suppressed from leaking from the valley portion of the pair of permanent magnets 4 (4a, 4b) to the side of the shaft 2 (magnetic flux leakage S).

[0054] On the other hand, Figures 6 to 8 As shown, even when the magnetic inclusion 12 is not provided in the gap H between the second rotor core 11 and the shaft 2 and the gap H between the second rotor core 11 and the shaft 2 is used as a space, the magnetic flux leakage S can be suppressed.

[0055] However, as in the rotor A of this embodiment, when the magnetic inclusion 12 is sandwiched in the gap H between the second rotor core 11 and the shaft 2, not only can the magnetic flux leakage S be suppressed, but the magnetic force of the magnetic inclusion 12 can also be utilized, that is, the magnets of the magnetic inclusion 12 also contribute to the torque, thereby achieving a torque increase of the rotor A.

[0056] Furthermore, by interposing the magnetic inclusions 12 in the gap H between the second rotor core 11 and the shaft 2 , the rotor inertia can be increased, thereby increasing the rigidity of the rotor A itself. Therefore, the control performance of an electric rotating machine such as a motor having the rotor A of this embodiment can be improved.

[0057] Furthermore, by alternately arranging the first rotor core 10 and the second rotor core 11 in the direction of the axis O1, and in particular, by evenly arranging the first rotor core 10 in the direction of the axis O1, it is possible to obtain an excellent torque enhancement effect caused by the provision of the magnetic inclusion 12 while ensuring the desired bonding strength of the rotor cores 10 and 11 relative to the shaft 2.

[0058] Therefore, for the rotor structure A (and the manufacturing method of the rotor structure) of this embodiment, by sandwiching the magnetic inclusion 12 between the adjacent pair of permanent magnets 4 (4a, 4b) of the shaft 2 and the second rotor core 11 in the part where magnetic flux leakage S is most likely to occur, a rotor A with better torque performance (torque boosting effect) than before can be achieved.

[0059] As mentioned above, one embodiment of the rotor structure and the method for manufacturing the rotor structure of the present invention has been described. However, the present invention is not limited to the above embodiment, and appropriate changes can be made without departing from the scope of the present invention.

[0060] For example, in this embodiment, the first rotor core 10 and the second rotor core 11 are arranged alternately in the direction of the axis O1. However, if the second rotor core 11 is arranged between the two first rotor cores 10, for example, the two first rotor cores 10 in other parts can be assembled adjacent to each other, thereby eliminating the need for the first rotor core 10 and the second rotor core 11. Figure 1 The rotor A is constructed as shown.

[0061] In addition, in this embodiment, multiple sets of deep V-shaped pairs of permanent magnets 4 (4a, 4b) are regularly arranged in the circumferential direction to form the rotor cores 10, 11 and the rotor structure A, but it can also be as follows Figures 9 to 12 As shown, the rotor cores 10 and 11 and the rotor structure A are constituted by a plurality of permanent magnets 4 extending in a radial direction centered on the axis O1 and arranged radially.

[0062] Furthermore, for the rotor structure A having rotor cores 10 and 11 in which such permanent magnets 4 are radially arranged, when magnet inclusions 12 are provided, as in the present embodiment, the magnetic flux leakage S between circumferentially adjacent permanent magnets 4 can be more effectively suppressed, and a more excellent torque enhancement effect can be obtained.

[0063] Furthermore, in this embodiment, the gap H is formed annularly along the entire circumference centered on the axis O1, and the magnetic inclusion 12 is provided annularly. However, the gap H may be provided locally, such as between the valley portion of a pair of deep V-shaped permanent magnets 4 (4a, 4b) and the shaft 2, where magnetic flux leakage S is likely to occur, or between the axially adjacent portions of a pair of radially arranged adjacent permanent magnets 4. The magnetic inclusion 12 may be provided in the gap H provided locally along the circumference of the axis O1. Even in this case, the same effects as those of this embodiment can be achieved.

Claims

1. A rotor structure comprising: a plurality of rotor cores; A plurality of magnets are respectively provided through a plurality of magnet insertion holes, the plurality of magnet insertion holes being formed through the rotor core along the axis direction; and a shaft is provided through the center hole of the rotor core and is integrally provided with the rotor core, characterized in that: In the rotor core, a pair of magnets adjacent to each other in the circumferential direction around the axis are arranged so that the radially inner sides thereof form a valley portion in a substantially V-shape around the axis. The rotor core includes: a first rotor core formed so that the diameter of the center hole is substantially equal to the outer diameter of the shaft; and a second rotor core formed so that at least a portion of the center hole has a diameter larger than the outer diameter of the shaft and arranged coaxially with the first rotor core so as to be sandwiched between the two first rotor cores. A magnetic inclusion is interposed in a ring shape in a gap between the inner peripheral edge of the second rotor core and the outer peripheral surface of the shaft over the entire circumference centered on the axis.

2. The rotor structure according to claim 1, characterized in that: The pair of magnets are regularly arranged in a plurality in the circumferential direction. The magnetic inclusion is provided at least between the substantially V-shaped valley portion and the shaft in the radial direction.

3. The rotor structure according to claim 1 or 2, characterized in that: The magnet-containing material is a bonded magnet formed by mixing powdered or granular magnets with a resin material or a rubber material.

4. A method for manufacturing a rotor structure, which is a method for manufacturing the rotor structure according to any one of claims 1 to 3, characterized in that: The first rotor core is provided with an injection hole extending from one end to the other end thereof in the direction of the axis. After the first rotor core and the second rotor core are mounted on the shaft, the magnet content is injected from the injection hole to fill the gap.

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