WO2024080143A1 - Core unit and rotor - Google Patents

Abstract

This core unit comprises at least one core and a pipe. The at least one core is formed with a powder magnetic core hole penetrated in a first direction. The pipe extends in the first direction. Further, the pipe is inserted into the powder magnetic core hole. The core unit is thereby obtained that can maintain the shape of a powder magnetic core and improve the cooling performance of the core.

Description

Core unit and rotor

The present disclosure relates to a core unit and a rotor.
This application claims priority based on Japanese Patent Application No. 2022-163885 filed with the Japan Patent Office on October 12, 2022, the contents of which are incorporated herein by reference.

　Conventionally, iron core units that include a powder magnetic core are known. For example, Patent Document 1 discloses a stator core made of a powder magnetic core as an example of an iron core unit (see Figure 2 of the same document).

JP 2008-271713 A

If, for example, tensile stress occurs in the powder magnetic core of the above-mentioned iron core unit, the powder magnetic core may be damaged, making it difficult to maintain the shape of the iron core unit. In addition, the temperature of the iron core unit may rise due to, for example, iron loss.

The objective of this disclosure is to provide an iron core unit and a rotor that can maintain the shape of the powder magnetic core while improving the cooling performance of the iron core.

At least one embodiment of the present disclosure provides a core unit comprising:
An iron core including at least one powder core having a powder core hole penetrating in a first direction;
A pipe extending in the first direction and inserted into the powder core hole;
Equipped with.

A rotor according to an embodiment of the present disclosure includes:
a ring unit including the plurality of iron core units and a plurality of non-magnetic bodies arranged alternately with the plurality of iron core units in a circumferential direction that is a direction perpendicular to the first direction;
a pair of flanges respectively connected to both ends of the ring unit in the first direction, the pair of flanges being configured to be connected to a rotation shaft extending in the first direction;
Equipped with
At least one flange hole is formed in each of the flanges, the flange hole communicating with an inner space of the pipe of each of the plurality of core units.

This disclosure provides an iron core unit and rotor that can maintain the shape of the powder magnetic core while improving the cooling performance of the iron core.

FIG. 2 is a schematic diagram of an iron core unit according to one embodiment. FIG. 2 is a schematic diagram illustrating an iron core according to an embodiment. FIG. 13 is a schematic diagram showing an iron core according to another embodiment. 1 is a schematic diagram showing a joint structure between an iron core and a pipe according to an embodiment; FIG. 2 is a schematic diagram showing a detailed structure of a pipe according to an embodiment. 13 is a schematic diagram showing a joint structure between an iron core and a pipe according to another embodiment. FIG. FIG. 1 is a schematic diagram showing a pipe according to an embodiment (first example). FIG. 2 is a schematic diagram showing a pipe according to an embodiment (second example). FIG. 13 is a schematic diagram showing a pipe according to an embodiment (third example). FIG. 2 is a schematic diagram of a rotor according to an embodiment. 3 is a schematic diagram showing a part of a configuration of a ring unit according to one embodiment. FIG. FIG. 1 is a schematic diagram of a magnetic geared electric machine according to an embodiment.

Hereinafter, some embodiments of the present disclosure will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present disclosure.
For example, expressions expressing relative or absolute configuration, such as "in a certain direction,""along a certain direction,""parallel,""orthogonal,""center,""concentric," or "coaxial," not only express such a configuration strictly, but also express a state in which there is a relative displacement with a tolerance or an angle or distance to the extent that the same function is obtained.
For example, expressions indicating that things are in an equal state, such as "identical,""equal," and "homogeneous," not only indicate a state of strict equality, but also indicate a state in which there is a tolerance or a difference to the extent that the same function is obtained.
For example, expressions describing shapes such as a rectangular shape or a cylindrical shape do not only refer to rectangular shapes, cylindrical shapes, etc. in the strict geometric sense, but also refer to shapes that include uneven portions, chamfered portions, etc., to the extent that the same effect is obtained.
On the other hand, the expressions "comprise", "include", or "have" a certain element are not exclusive expressions excluding the presence of other elements.
In addition, the same components are denoted by the same reference numerals and the description thereof may be omitted.

1. Overview of the core unit 10
1 is a schematic exploded perspective view of an iron core unit 10 according to an embodiment of the present disclosure. The iron core unit 10, which may be incorporated into an armature, includes an iron core 60 extending in a first direction.
When the iron core unit 10 is incorporated into a stator, which is an example of an armature, an armature coil may be wound around the iron core 60. When the iron core unit 10 is incorporated into a rotor 30 (see FIG. 7 ), which is an example of an armature, an armature coil does not have to be wound around the iron core 60. The first direction may be any direction, and may be the vertical direction, the horizontal direction, or a direction intersecting the vertical direction and the horizontal direction.

An insertion hole 68 is formed in the center of the iron core 60. The insertion hole 68 illustrated in FIG. 1 is a through hole penetrating in the first direction, but the present disclosure is not limited to this, and the insertion hole 68 may be closed on one side in the first direction and open only on the other side (details will be described later). The iron core unit 10 further includes a pipe 80 extending in the first direction, and the pipe 80 is inserted into the insertion hole 68 of the iron core 60. The fit between the pipe 80 and the insertion hole 68 may be an interference fit, an intermediate fit, or a clearance fit. Regardless of the fit used, an adhesive 9 (see FIG. 3) may be interposed between the inner circumferential surface that defines the insertion hole 68 and the pipe 80. The pipe 80 (see FIG. 1) inserted into the insertion hole 68 supports the iron core 60.

In the example of FIG. 1, the insertion hole 68 is circular when viewed in the first direction, and the pipe 80 is cylindrical, but the present disclosure is not limited to this. In other embodiments, the insertion hole 68 may be rectangular when viewed in the first direction, in which case the pipe 80 is formed in a square tube shape. The following explanation will mainly focus on an example in which the pipe 80 is inserted into a single circular insertion hole 68.

In the example of FIG. 1, a single insertion hole 68 is formed, but the present disclosure is not limited to this. In other embodiments, two insertion holes 68 may be arranged at a distance from each other in a direction perpendicular to the first direction (not shown). In this case, both of the two insertion holes 68 may be through holes that penetrate in the first direction. Alternatively, the two insertion holes 68 may be arranged at a distance from each other in the first direction. In any embodiment, two pipes 80 may be inserted into two insertion holes 68, respectively.

2. Details of the structure of the iron core 60
2A and 2B are schematic diagrams showing cores 60A, 60B (60) according to some embodiments of the present disclosure. The cores 60A, 60B (60) include at least one powder magnetic core 70. The core 60A illustrated in Fig. 2A includes a plurality of powder magnetic cores 70 stacked continuously in a first direction. The core 60B illustrated in Fig. 2B includes a steel plate laminate 79 including a plurality of steel plates 77 stacked continuously in the first direction, and a pair of powder magnetic cores 70 arranged on either side of the steel plate laminate 79 in the first direction.

In the center of each powder core 70 illustrated in Figures 2A and 2B, a powder core hole 75 is formed which penetrates in the first direction. The powder core hole 75 is a component of the insertion hole 68. In the example of Figure 2A, the insertion hole 68A (68) formed by the multiple powder core holes 75 is a through hole which penetrates in the first direction. In the example of Figure 2B, a steel plate hole 78 is formed in the center of each steel plate 77, and the insertion hole 68 is formed by the multiple steel plate holes 78 and two powder core holes 75. In the example of Figure 2B, the insertion hole 68 is also a through hole which penetrates in the first direction.

According to the above configuration, the dust core hole 75 into which the pipe 80 is inserted is formed in the dust core 70, so that the air flowing through the inner space of the pipe 80 can cool the iron core 60. This makes it possible to suppress a rise in temperature of the iron core 60 due to, for example, the generation of eddy currents. In addition, the dust core 70 may be damaged if tensile stress occurs in, for example, the first direction. In this regard, according to the above configuration, since the pipe 80 is inserted into the dust core hole 75, even if the dust core 70 is damaged, the flake-shaped dust core 70 can be prevented from falling off the iron core 60. This realizes an iron core unit 10 that can maintain the shape of the dust core 70 and improves the cooling performance of the iron core 60.

The temperature rise of the iron core 60 is not limited to the generation of eddy currents. For example, in an embodiment in which an armature coil is wound around the iron core 60, heat generated by current flow in the armature coil may be transferred to the iron core 60, causing the temperature of the iron core 60 to rise. Even in this embodiment, air flows through the inner space of the pipe 80 inserted into the powder core hole 75, and the cooling performance of the iron core 60 can be expected to be improved. Furthermore, the insertion hole 68 is not limited to being a through hole penetrating in the first direction. More specifically, the steel plate 77 in FIG. 2B does not need to have a steel plate hole 78 formed therein. In this case, two insertion holes 68 are formed by two powder cores 70 arranged on both sides of the steel plate laminate 79. In other words, the two insertion holes 68 are arranged with a gap between them in the first direction. Both of the two insertion holes 68 are blocked by the steel plate laminate 79 (that is, one side of each insertion hole 68 in the first direction is blocked by the steel plate laminate 79). In this embodiment, two pipes 80 are inserted into two powder core holes 75, respectively. Even in this case, air can flow through the inner space of the pipes 80, so the cooling performance of the iron core 60 can be expected to be improved. In addition, it is also possible to prevent the flake-shaped powder core 70 from falling off the iron core 60.

Although not a required configuration of the present disclosure, in the example of Figures 2A and 2B, a single pipe 80 that is longer in the first direction than the iron cores 60A, 60B (60) is inserted from one end of the iron core 60 to the other end. With the above configuration, the pipe 80 is inserted so as to penetrate the iron core 60, so that the pipe 80 can support the iron core 60 more firmly, improving the mechanical strength of the iron core unit 10.

Also, in the example of FIG. 2A, as described above, the iron core 60A (60) includes a plurality of powder cores 70 stacked continuously in the first direction, and a single pipe 80 is inserted into each of the powder core holes 75. Also, in the example of FIG. 2B, the iron core 60B (60) includes two powder cores 70 stacked in the first direction with a steel plate laminate 79 sandwiched therebetween, and a single pipe 80 is inserted into each of the powder core holes 75. According to the above configuration, the iron core 60 includes a plurality of powder cores 70, thereby realizing miniaturization of each powder core 70 forming the iron core 60. This makes it possible to simplify the work of inserting each powder core 70 into the pipe 80 in the assembly process of the iron core 60. Furthermore, by realizing miniaturization of the powder core 70, the molding pressure required for the molding machine responsible for the molding process of the powder core 70 can be reduced, and the manufacturing of the powder core 70 can be facilitated.
As described above, the steel plate holes 78 may not be formed in the steel plate 77 in Fig. 2B, and two pipes 80 may be inserted into each of the two powder cores 70 arranged at both ends of the iron core 60. In this case, each pipe 80 is shorter than the iron core 60 in the first direction. In this embodiment, too, the iron core 60 includes multiple powder cores 70, so that each powder core 70 can be made smaller. Therefore, the above-mentioned advantages can be obtained.

The pipe 80 according to one embodiment of the present disclosure is preferably formed of a non-magnetic material, and more preferably formed of a non-magnetic metal material. Examples of non-magnetic metal materials include aluminum, austenitic stainless steel, and copper. According to the above configuration, the pipe 80 is formed of a non-magnetic material, which can suppress the occurrence of hysteresis loss associated with magnetization of the pipe 80 and maintain the magnetic flux modulation function of the iron core 60. Furthermore, the pipe 80 is formed of a non-magnetic metal material, which can improve the thermal conductivity of the pipe 80 and improve the thermal conductivity from the powder magnetic core 70 to the pipe 80. The pipe 80 may be formed of a non-metallic non-magnetic material such as a resin material. Even in this case, the above-mentioned advantages of suppressing the occurrence of hysteresis loss associated with magnetization of the pipe 80 and maintaining the magnetic flux modulation function of the iron core 60 can be obtained.

In the example of FIG. 2B, the powder core 70 forming the end of one side of the iron core 60 in the first direction is the one-side powder core 71, and the powder core 70 forming the end on the other side is the other-side powder core 72. The one-side powder core 71 is disposed on one side of the steel plate laminate 79 in the first direction, and the other-side powder core 72 is disposed on the other side of the steel plate laminate 79 in the first direction. According to the above configuration, the provision of the one-side powder core 71 can suppress leakage flux that tends to occur at the end on one side of the iron core 60, and can suppress the generation of eddy currents in the iron core 60. Therefore, the temperature rise of the iron core 60 can be suppressed. Furthermore, the provision of the other-side powder core 72 can suppress the temperature rise of the iron core 60 for the same reason. At least one powder core 70 may be further disposed between the one-side powder core 71 and the steel plate laminate 79. Similarly, at least one powder core 70 may be further disposed between the other powder core 72 and the steel sheet laminate 79. The above advantages can be obtained in any of the embodiments.

Furthermore, the thickness of the pipe 80 according to one embodiment of the present disclosure is 10% or less of the minimum inner diameter of the powder core hole 75. With the above configuration, the pipe 80 can be made thinner, which promotes heat exchange between the air flowing through the inner space of the pipe 80 and the powder core 70, and is expected to improve the cooling performance of the iron core unit 10.

<3. Insulator 110>
Returning to FIG. 1, the iron core unit 10 according to an embodiment of the present disclosure further includes an insulator 110 arranged so as to be stacked on the end of the iron core 60 in the first direction. The insulator 110 forms the end of the iron core unit 10 in the first direction. The insulator 110 illustrated in FIG. 1 is a plate having a thickness in the first direction. As an example, the material forming the insulator 110 is a fiber reinforced composite material (FRP; Fiber Reinforced Plastics), more specifically, a glass fiber reinforced plastic (GFRP; Glass Fiber Reinforced Plastics). As another example of the material forming the insulator 110, a resin material or a ceramic material may be adopted. In addition, in the example of FIG. 1, the insulators 110 are arranged on both sides of the iron core 60 in the first direction. An insulator hole 115 is formed in the center of each insulator 110, penetrating in the first direction, and each insulator hole 115 faces the insertion hole 68 of the iron core 60 in the first direction. The pipe 80 according to an embodiment of the present disclosure is inserted not only into the insertion hole 68 but also into the insulator hole 115. More specifically, as an example, the end of the pipe 80 in the first direction is accommodated in the insulator hole 115. In other words, the pipe 80 does not protrude from the insulator hole 115 to the opposite side to the iron core unit 10. The fit between the pipe 80 and the insulator hole 115 may be any of an interference fit, an intermediate fit, and a clearance fit.

According to the above configuration, the pipe 80 is inserted into the insulator hole 115 of the insulators 110 arranged so as to be stacked at the end of the iron core 60, thereby making it difficult for the pipe 80 to come out of the powder core hole 75. This improves the mechanical strength of the iron core unit 10. Furthermore, the provision of the insulators 110 can suppress leakage flux that tends to occur at the end of the iron core 60 in the first direction, and can suppress the generation of eddy currents in the iron core 60. This can also suppress a rise in temperature of the iron core 60.
Furthermore, even if the powder magnetic core 70 becomes damaged, the insulators 110 piled up on the end of the iron core 60 can function to prevent the flake-shaped powder magnetic core 70 from falling off the iron core 60.

Also, one end 87 of the pipe 80 on one side in the first direction may be located on the opposite side (i.e., the other side) of the end 111 of the insulator 110 on the one side (see Figs. 3 and 5). In an embodiment in which the core unit 10 is incorporated into a rotor 30 (see Fig. 7) described below, the insulator 110 is sandwiched between an end ring 31, which is a component of the rotor 30, and the above-mentioned iron core 60. In this regard, by positioning one end 87 of the pipe 80 on the other side of the end 111 of the insulator 110, contact between the one end 87 housed in the insulator hole 115 and the end ring 31, which may be made of metal, is avoided. This makes it possible to avoid unintended electrical conduction between the iron core 60 and the end ring 31.
However, the present disclosure does not exclude an embodiment in which the one end 87 of the pipe 80 and the end 111 of the insulator 110 are at the same position as each other in the first direction (see FIG. 4 ). In addition, the present disclosure does not exclude an embodiment in which the one end 87 of the pipe 80 is located on one side of the end 111 of the insulator 110 (not shown).

<4. Joint structure between iron core 60A (60) and pipe 80>
3 is a schematic cross-sectional view showing a joint structure between an iron core 60A (60) according to an embodiment of the present disclosure and a pipe 80. In the iron core 60A shown in the figure, the insulators 110 are stacked in a first direction.

The powder core 70 has a powder core inner surface 76 that defines the powder core hole 75, the insulator 110 has an insulator inner surface 116 that defines the insulator hole 115, and the pipe 80 has a pipe outer surface 89. The pipe 80 illustrated in FIG. 3 is inserted into the powder core hole 75 and the insulator hole 115. The pipe outer surface 89 has a portion that overlaps with the powder core inner surface 76 in the axial direction and a portion that overlaps with the insulator inner surface 116 in the axial direction. The axial direction of the pipe 80 coincides with the first direction.

In the example of FIG. 3, adhesive 9 is interposed between the powder core inner surface 76 and the pipe outer surface 89. In the example of the same figure, adhesive 9 is present over substantially the entire length of the iron core 60A in one direction, and more specifically, adhesive 9 is interposed between the powder core inner surface 76 of all powder cores 70 constituting the iron core 60A and the pipe outer surface 89. However, the present disclosure is not limited to adhesive 9 being interposed only between the pipe outer surface 89 and powder core inner surface 76. As illustrated in the same figure, adhesive 9 may be interposed between the insulator inner surface 116 and the pipe outer surface 89. In addition, adhesive 9 is preferably insulating, and more preferably insulating and non-magnetic.

According to the above configuration, the adhesive 9 is interposed between the pipe outer peripheral surface 89 and the powder core inner peripheral surface 76, so that it is possible to prevent the flake-shaped powder core 70 caused by chipping from falling off the iron core 60. In addition, the pipe outer peripheral surface 89 and the powder core inner peripheral surface 76 can be closely attached via the adhesive 9, so that the thermal conductivity from the powder core 70 to the pipe 80 can be further improved.
The core unit 10 does not have to include the insulator 110. The adhesive 9 may be disposed on the core 60B (FIG. 2B) instead of the core 60A. More specifically, the adhesive 9 may be disposed between the inner circumferential surface that forms the insertion hole 68B (i.e., the powder core inner circumferential surface 76 and the steel plate inner circumferential surface 176 described below) and the pipe outer circumferential surface 89. The above advantages can be obtained in this embodiment as well.

Figure 4 is a schematic diagram showing the detailed structure of pipe 80A (80), which is an example of pipe 80. Pipe 80A in the figure is inserted into insertion hole 68A of iron core 60A. Pipe outer surface 89A (89) of pipe 80A has at least one of outer peripheral surface concave portion 181 or outer peripheral surface convex portion 183. In the figure, both outer peripheral surface concave portion 181 and outer peripheral surface convex portion 183 are provided, and as a more detailed example, multiple outer peripheral surface concave portions 181 are provided at intervals in the first direction, and multiple outer peripheral surface convex portions 183 are provided at intervals in the first direction. Outer peripheral surface concave portion 181 or outer peripheral surface convex portion 183 are formed by performing machining such as blasting, knurling, or groove engraving on pipe outer peripheral surface 89A. At least one of the outer peripheral surface recess 181 and the outer peripheral surface protrusion 183 may be formed over the entire pipe outer peripheral surface 89, or may be formed only in a portion of the pipe outer peripheral surface 89A that overlaps with the powder core inner peripheral surface 76 in the axial direction. Also, only one of the outer peripheral surface recess 181 and the outer peripheral surface protrusion 183 may be provided on the pipe outer peripheral surface 89A. Furthermore, the outer peripheral surface protrusion 183 may be a separate member from the pipe outer peripheral surface 89. According to the above configuration, by providing at least one of the outer peripheral surface recess 181 and the outer peripheral surface protrusion 183, the amount of adhesive 9 interposed between the pipe outer peripheral surface 89A (89) and the powder core inner peripheral surface 76 is increased. This further suppresses the piece-shaped powder core 70 caused by the defect from falling off the iron core 60A (60).

Although not a required component of the present disclosure, the pipe 80A (80) may further include a pipe inner surface 86 and at least one of an inner surface convex portion 861 or an inner surface concave portion 863 provided on the pipe inner surface 86. In the example of FIG. 4, both the inner surface convex portion 861 and the inner surface concave portion 863 are provided. The inner surface convex portion 861 is, for example, a fin separate from the pipe inner surface 86, and extends over the entire circumferential length of the pipe 80A. The multiple inner surface convex portions 861 are arranged at intervals along the axial direction. The inner surface concave portion 863 is a groove provided on the pipe inner surface 86, and extends over the entire circumferential length of the pipe 80A. The multiple inner surface concave portions 863 are arranged at intervals along the axial direction. The inner circumferential surface protrusion 861 is preferably provided at a portion of the pipe inner circumferential surface 86 that overlaps with the insertion hole 68A of the core 60A in the axial direction, and the inner circumferential surface recess 863 is also provided in the same manner. Note that only one of the inner circumferential surface protrusion 861 or the inner circumferential surface recess 863 may be provided on the pipe inner circumferential surface 86. Also, the inner circumferential surface protrusion 861 or the inner circumferential surface recess 863 may be provided at a portion of the pipe inner circumferential surface 86 that overlaps with the insulator inner circumferential surface 116 in the axial direction (in the example of FIG. 4, the inner circumferential surface recess 863 is provided at that portion of the pipe inner circumferential surface 86). The pipe 80 on which at least one of the inner circumferential surface protrusion 861 or the inner circumferential surface recess 863 is provided is, for example, a rifled pipe.

The above configuration promotes heat exchange between the pipe inner surface 86 and the air, improving the cooling performance of the iron core 60A (60). Note that the present disclosure is not limited to the pipe 80A being inserted into the insertion hole 68A of the iron core 60A. The pipe 80A may also be inserted into the insertion hole 68B of the iron core 60B (see FIG. 2B). In this case, the inner surface convex portion 861 and the inner surface concave portion 863 may be arranged to axially overlap with the inner surfaces (the powder core inner surface 76 and the steel plate inner surface 176 described below) that form the insertion hole 68B.

<5. Joint structure between iron core 60B (60) and pipe 80>
5 is a schematic cross-sectional view showing a joint structure between an iron core 60B (60) and a pipe 80 according to another embodiment of the present disclosure. In the iron core 60B shown in the figure, the insulators 110 are stacked in the first direction. As described above, the iron core 60B includes a steel plate stack 79 including a plurality of steel plates 77. Each steel plate 77 has a steel plate inner peripheral surface 176 that defines a steel plate hole 78 that penetrates in the first direction.

The pipe 80 is inserted into the insertion hole 68B (68) and the insulator hole 115. The pipe outer surface 89 of the pipe 80 illustrated in FIG. 5 has a portion that overlaps with the powder core inner surface 76 in the axial direction, a portion that overlaps with the steel plate inner surface 176 in the axial direction, and a portion that overlaps with the insulator inner surface 116 in the axial direction.

In this example, an insulating member 120 is further disposed at least between the pipe outer surface 89 and the steel plate inner surface 176. The insulating member 120 illustrated in the figure is disposed between the pipe outer surface 89 and the steel plate inner surface 176, between the pipe outer surface 89 and the powder core inner surface 76, and between the pipe outer surface 89 and the insulator inner surface 116. The insulating member 120 may be formed by insulating coating the pipe outer surface 89, or may be a member formed from a resin material, a ceramic material, or a rubber material.

Generally, a steel plate 77 having a steel plate inner surface 176 is obtained by performing a punching process on a steel plate material (not shown) having an insulating coating formed on its outer surface. Therefore, no insulating coating is formed on the steel plate inner surface 176. Therefore, if an eddy current occurs in any of the stacked steel plates 77, the current may flow to the other steel plates 77 via the steel plate inner surface 176. In other words, the current may flow in the first direction through the steel plate stack 79. In this regard, according to the above configuration, the insulator 110 is disposed between the pipe outer surface 89 and the steel plate inner surface 176, so that the current generated in any of the steel plates 77 can be prevented from flowing in the first direction through the steel plate stack 79.

6. Slit 85 of Pipe 80
6A to 6C are schematic diagrams showing pipes 81, 82, and 83 (80) as an example of a pipe 80. The pipes 81 to 83 illustrated in Fig. 6A to 6C include peripheral walls 84A, 84B, and 84C (84) and slits 85A, 85B, and 85C (85) that penetrate the peripheral wall 84 in the radial direction of the pipe 80. The slits 85A, 85B, and 85C extend along a first direction. More specifically, the slits 85A and 85B extend linearly along the first direction, and the slit 85C extends spirally along the first direction.

Also, as illustrated in Figures 6A and 6C, the slits 85A, 85C (85) may be formed from one end to the other end of the pipes 81, 83 (80) in the first direction. That is, the slits 85A, 85C are open to one side and the other side in the first direction. Also, as illustrated in Figure 6B, the slit 85B (85) is open to one side in the first direction, while the other side of the slit 85B is not open. In this case, the other end of the slit 85B in the first direction is located on one side of the other end of the pipe 82 (80). Also, although detailed illustration is omitted, both ends of the slit 85 in the first direction may not be open in the first direction. That is, both ends of the slit 85 in the first direction may be located toward the center of the pipe 80 in the first direction with respect to both ends of the pipe 80 in the first direction. It is also preferable that the number of slits 85 formed in the pipe 80 is one, which simplifies the structure of the pipe 80.

With the above configuration, since the slits 85 are provided, during the manufacturing process of the iron core unit 10, the pipe 80 can be inserted into the insertion hole 68 in a state where it is compressed toward the axis. After the insertion is completed, the compressed pipe 80 expands away from the axis, and at least a portion of the peripheral wall 84 of the pipe 80 presses against the inner circumferential surface that constitutes the insertion hole 68 (more specifically, as an example, the powder core inner circumferential surface 76). This improves the thermal conductivity from the powder core 70 to the pipe 80, further improving the cooling performance of the iron core unit 10.

7. Examples of rotor 30 incorporating core unit 10
7 and 8, a rotor 30 incorporating the core unit 10 is illustrated. The rotor 30 is configured to rotate in a circumferential direction that is a direction perpendicular to the first direction, and is connected to a rotating shaft 5 that constitutes, for example, a magnetic geared electric machine 1 (see FIG. 9) (the configuration of the magnetic geared electric machine 1 will be outlined later). The first direction coincides with the axial direction of the rotor 30, and the rotating shaft 5 extends in the first direction. In the following description, the radial direction based on the axis of the rotor 30 may be simply referred to as the "radial direction".

FIG. 7 is a schematic diagram of a rotor 30 according to one embodiment. The rotor 30 includes a ring unit 50 extending in the circumferential direction. The ring unit 50 includes a plurality of iron core units 10 and a plurality of non-magnetic bodies 52. The plurality of iron core units 10 and the plurality of non-magnetic bodies 52 are arranged alternately in the circumferential direction, and each iron core unit 10 is sandwiched between a pair of non-magnetic bodies 52 located on both sides in the circumferential direction. In the example shown in the figure, a pair of end rings 31 are provided as components of the rotor 30 at both ends of the ring unit 50 in the first direction. The end rings 31 are plate-shaped, extending in the circumferential direction and having a thickness in the first direction.

The rotor 30 further includes a pair of flanges 41 that are respectively connected to both ends of the ring unit 50 in the first direction, and each flange 41 is configured to be connected to the rotating shaft 5. A detailed example of the configuration of the flanges 41 is as follows. The flange 41 includes a ring portion 42 extending in the circumferential direction, a plurality of extension portions 47 extending radially inward from the ring portion 42, and a shaft connecting portion 48 that connects to the inner end of the extension portion 47. The ring portion 42 in this example is a plate having a thickness in the first direction and is connected to the end of the ring unit 50 via the end ring 31 (i.e., the flange 41 is indirectly connected to the end of the ring unit 50). The shaft connecting portion 48 is cylindrical along the first direction, and the inner surface of the shaft connecting portion 48 is connected to the rotating shaft 5 (see FIG. 9).

Furthermore, at least one flange hole 43 is formed in the ring portion 42 of the flange 41, which communicates in a first direction with the inner space of each pipe 80 (see Figures 2A and 2B) of the core unit 10. In the example of Figure 7, the flange hole 43 faces in the first direction with a plurality of end ring holes (not shown) formed in the end ring 31, and the plurality of end ring holes each face in the first direction with the insulator holes 115 (see Figure 1) of the plurality of core units 10. This allows the flange hole 43 to communicate with the inner space of the pipe 80, allowing air to flow through the inner space of the pipe 80 as the rotor 30 rotates.

To explain a more detailed configuration example, at least one flange hole 43 is a plurality of flange holes 43 arranged at intervals in the circumferential direction, and each of the plurality of flange holes 43 faces a plurality of end ring holes in the first direction. However, the present disclosure is not limited to the above configuration. The ring portion 42 according to another embodiment may be a frame-shaped (in other words, hollow) ring extending in the circumferential direction instead of a plate-shaped ring extending in the circumferential direction. In this case, a single open hole formed inside the frame corresponds to the flange hole 43. Therefore, the number of flange holes 43 is one. In addition, the rotor 30 does not need to have a pair of end rings 31. In this case, the ring portion 42 may be directly connected to the end of the ring unit 50. And when one end 87 of the pipe 80 is located on the other side in the first direction than the end 111 of the insulator 110 (see Figures 3 and 5), contact between the one end 87 of the pipe 80 and the ring portion 42, which may be made of metal, is avoided, and unintended conduction between the iron core 60 and the ring unit 50 can be avoided.

FIG. 8 is a schematic diagram showing a portion of the configuration of a ring unit 50 according to one embodiment of the present disclosure. In this figure, the circumferential direction is illustrated as coinciding with the left-right direction of the page. The non-magnetic body 52 is formed of the FRP already described. The FRP may be, for example, glass fiber reinforced plastic (GFRP; Glass Fiber Reinforced Plastics) or carbon fiber reinforced plastic (CFRP; Carbon Fiber Reinforced Plastics).

Furthermore, the ring unit 50 includes a flexible member 150 interposed between the iron core 60 and the non-magnetic body 52. The flexible member 150 has a smaller Young's modulus than the iron core 60 and is a member that is elastically deformable in the first direction. The flexible member 150 is formed of, for example, rubber, resin, or elastomer. The flexible member 150 is preferably in the form of a sheet. In the example shown in the figure, the flexible member 150 is interposed between the iron core 60 and the non-magnetic body 52 over the entire length of the iron core 60 in the first direction.

According to the above configuration, since the non-magnetic body 52 is a fiber-reinforced composite material, the insulation of the non-magnetic body 52 is ensured, and the rotor 30 is made lighter and more rigid. On the other hand, the linear expansion coefficient of the non-magnetic body 52 formed by FRP is smaller than that of the powder core 70. For this reason, when the temperature of the rotor 30, which has a configuration in which the powder core 70 and the non-magnetic body 52 are in direct contact with each other, rises, the non-magnetic body 52 extends in the first direction more than the powder core 70. As a result, tensile stress caused by the expansion of the non-magnetic body 52 is generated in the powder core 70 as thermal stress, and the powder core 70, which has a relatively weak mechanical strength, may be damaged. In other words, the powder core 70 may be damaged. In this regard, according to the above configuration, the flexible member 150 has a portion that contacts the non-magnetic body 52 and a portion that contacts the iron core 60, and it is possible to make the amount of extension in the first direction of both portions different. In other words, the flexible member 150 can reduce the thermal stress generated in the powder core 70. This allows the rotor 30 to suppress damage to the powder core 70.

The flexible member 150 according to one embodiment is formed from a thermoplastic elastomer. With the above configuration, the elastomer has an adhesive function, so there is no need to prepare a separate adhesive material for joining the iron core 60, the non-magnetic body 52, and the flexible member 150. This simplifies the configuration of the rotor 30.

3, flexible members 151, 152 made of the same material as flexible member 150 are arranged on the radial outer and inner surfaces of iron core unit 10, respectively. Flexible members 150-152 in this example are integrally formed elastomer sheet materials, and are arranged to wrap iron core unit 10. Furthermore, rotor 30 in the same figure further includes outer cover 55A that covers ring unit 50 from the radial outside, and inner cover 55B that covers ring unit 50 from the radial inside. In this example, outer cover 55A and inner cover 55B are prepreg materials made of a fiber base material such as CFRP impregnated with thermosetting resin. Outer cover 55A and inner cover 55B are bonded to ring unit 50 by being in close contact with flexible members 151, 152 via adhesive layer 59. The outer cover 55A and the inner cover 55B are provided over the entire circumferential length of the ring unit 50, thereby reinforcing the ring unit 50.

8. Examples of rotor 30 incorporating core unit 10
FIG. 9 is a schematic diagram of the magnetic geared electric machine 1 including a rotor 30. The magnetic geared electric machine 1 includes a rotating shaft 5 extending in a first direction, and the rotor 30 includes a pair of flanges 41 as described above. Each flange 41 is directly connected to the rotating shaft 5. The magnetic geared electric machine 1 further includes a magnet rotor 15 supported by the rotating shaft 5 between the pair of flanges 41 via a bearing. The magnet rotor 15 includes a plurality of rotor magnets 19 arranged in a circumferential direction on the inner side of the iron core unit 10. The magnetic geared electric machine 1 also includes a stator 20 fixed radially outward of the iron core unit 10. The stator 20 includes a plurality of stator magnets 29 arranged in a circumferential direction, a stator yoke 25 supporting the plurality of stator magnets 29, and a coil 27 wound around the stator yoke 25 as an armature coil. The coil 27 is electrically connected to the power system 6. In the magnetic geared electric machine 1 having the above-described structure, the core unit 10 functions as a pole piece unit, and the rotor 30 functions as a pole piece rotor.

The rotating shaft 5 is connected to an external rotating device 7. The magnetic geared electric machine 1 is, for example, a magnetic geared motor that receives power from a power system 6 to drive the external rotating device 7. The operating principle of the magnetic geared electric machine 1 as a magnetic geared motor is as follows. The magnet rotor 15 rotates due to a rotating magnetic field generated by energizing the coil 27. The relative positional relationship of the multiple iron core units 10 to the multiple rotor magnets 19 and multiple stator magnets 29 changes, modulating the magnetic flux between the magnet rotor 15 and the stator 20, and the rotor 30 rotates together with the rotating shaft 5. Torque is transmitted from the rotating shaft 5 to the external rotating device 7, allowing the external rotating device 7 to be driven.

The magnetic geared electric machine 1 may be a magnetic geared generator instead of a magnetic geared motor. In this case, a configuration in which the external rotating device 7 drives the rotating shaft 5 may be adopted. When the rotor 30 rotates together with the rotating shaft 5, the relative positions of the multiple iron core units 10 to the multiple rotor magnets 19 and the multiple stator magnets 29 change, causing the magnet rotor 15 to rotate. Electromagnetic induction occurs as the rotor 30 and magnet rotor 15 rotate, generating a current in the coil 27, and power is supplied to the power system 6.

The rotor 30 including the iron core unit 10 can improve cooling performance for the reasons already described. Furthermore, as the magnetic geared electric machine 1 operates, at least one of centrifugal force, vibration, and electromagnetic force acts on the iron core unit 10, which may cause damage to the powder magnetic core 70. Even in this case, the rotor 30 can prevent the powder magnetic core 70 from falling off the iron core unit 10 for the reasons already described.

＜9. Other＞
The present disclosure is not limited to the core unit 10 being incorporated into the rotor 30. The core unit 10 may be incorporated into the stator 20 of the above-described magnetic geared electric machine 1. Alternatively, the core unit 10 may be incorporated into a stator (not shown) that constitutes an axial gap motor.

<10. Summary>
The contents described in the above-mentioned embodiments can be understood, for example, as follows.

1) At least one embodiment of the iron core unit (10) according to the present disclosure includes:
An iron core (60) including at least one powder core (70) having a powder core hole (75) penetrating in a first direction;
A pipe (80) extending in the first direction and inserted into the powder core hole;
Equipped with.

In the configuration of 1) above, a powder core hole into which a pipe is inserted is formed in the powder core, allowing air flowing through the inner space of the pipe to cool the iron core. This makes it possible to suppress a rise in temperature of the iron core due to, for example, the generation of eddy currents or the passage of current through the armature coil. In addition, for example, the generation of tensile stress in the first direction may cause the powder core to break. In this regard, in the configuration of 1) above, because the pipe is inserted into the powder core hole, even if the powder core breaks, it is possible to suppress the flake-shaped powder core from falling off the iron core. This realizes an iron core unit that can maintain the shape of the powder core while improving the cooling performance of the iron core.

2) In some embodiments, the core unit according to 1) above,
The pipe is
A peripheral wall (84);
A slit (85) that penetrates the peripheral wall in a radial direction and extends along the first direction;
including.

In the configuration of 2) above, since a slit is provided, the pipe can be inserted into the insertion hole in a compressed state toward the axis during the manufacturing process of the iron core unit. After insertion is complete, the compressed pipe expands away from the axis, and at least a portion of the pipe's peripheral wall presses against the inner peripheral surface of the powder core. This improves thermal conductivity from the powder core to the pipe, further improving the cooling performance of the iron core unit.

3) In some embodiments, the core unit according to 1) or 2) above,
The apparatus further includes an adhesive (9) interposed between an outer circumferential pipe surface (89) of the pipe and an inner circumferential powder core surface (76) of the powder core that defines the powder core hole.

In the configuration of 3) above, adhesive is interposed between the outer circumferential surface of the pipe and the inner circumferential surface of the powder core, so that the flakes of the powder core caused by the chipping can be prevented from falling off the iron core. In addition, the outer circumferential surface of the pipe and the inner circumferential surface of the powder core can be tightly attached via adhesive, so that the thermal conductivity from the powder core to the pipe can be further improved.

4) In some embodiments, the core unit according to 3) above,
The outer circumferential surface of the pipe has at least one of an outer circumferential surface recess (181) or an outer circumferential surface protrusion (183).

The configuration of 4) above increases the amount of adhesive present between the outer circumferential surface of the pipe and the inner circumferential surface of the powder core, further preventing the chipped powder core from falling off the iron core.

5) In some embodiments, the core unit according to any one of 1) to 4) above,
The insulator (110) is arranged to be stacked on an end of the iron core in the first direction, and the insulator has an insulator hole (115) penetrating therethrough in the first direction,
The pipe is inserted into the insulator hole.

In the configuration of 5) above, the pipe is inserted into the insulator hole of the insulators arranged in a stacked manner at the end of the iron core, making it difficult for the pipe to come out of the powder core hole. This improves the mechanical strength of the iron core unit. Furthermore, the provision of the insulator can suppress leakage flux, which has a high tendency to occur at the end of the iron core in the first direction, and can suppress the generation of eddy currents in the iron core. This can also suppress the temperature rise of the iron core.

6) In some embodiments, the core unit according to 5) above,
An end (87) of the pipe on one side in the first direction is located on the opposite side to the one side relative to an end (111) of the insulator on the one side.

The configuration of 6) above prevents one end of the pipe from coming into contact with a component (e.g., end ring 31) of another unit (e.g., rotor 30) to which the iron core unit is attached. This makes it possible to prevent unintended electrical conduction between the component and the iron core.

7) In some embodiments, the core unit according to any one of 1) to 6) above,
The iron core includes a plurality of the powder magnetic cores stacked in the first direction,
The pipe is inserted into the powder core hole of each of the powder cores.

In the configuration of 7) above, the iron core includes multiple powder magnetic cores, which allows each powder magnetic core forming the iron core to be made smaller. This simplifies the work of inserting each powder magnetic core into a pipe during the iron core assembly process. Furthermore, by realizing smaller powder magnetic cores, the molding pressure of the molding machine used in the powder magnetic core molding process can be reduced, making it easier to manufacture powder magnetic cores.

8) In some embodiments, the core unit according to any one of 1) to 7) above,
The iron core is
A steel plate stack (79) having a plurality of steel plates (77) stacked in the first direction;
The powder core is disposed on one side of the steel plate laminate in the first direction, and the powder core forms an end portion on the one side of the iron core.
Further includes:

In the configuration of 8) above, the end of the iron core in the first direction is formed by a one-sided powder magnetic core, which suppresses leakage flux that tends to occur at one end of the iron core, and suppresses the generation of eddy currents in the iron core. This suppresses the temperature rise of the iron core.

9) In some embodiments, the core unit according to any one of 1) to 8) above,
The pipe is longer than the iron core in the first direction, and is inserted from one end of the iron core to the other end of the iron core in the first direction.

In the configuration of 9) above, the pipe is inserted so as to penetrate the iron core, so that the pipe can support the iron core more firmly, improving the mechanical strength of the iron core unit.

10) In some embodiments, the core unit according to any one of 1) to 9) above,
The pipe is made of a non-magnetic material.

The configuration of 10) above makes it possible to suppress the occurrence of hysteresis loss associated with magnetization of the pipe, while also maintaining the magnetic flux modulation function of the iron core.

11) In some embodiments, the core unit according to 10) above,
The pipe is made of a non-magnetic metallic material.

The configuration of 11) above improves the thermal conductivity of the pipe, further improving the thermal conductivity from the powder magnetic core to the pipe.

12) In some embodiments, the core unit according to any one of 1) to 11) above,
The iron core is
A plurality of steel plates (77) stacked in the first direction include a plurality of steel plates each having a steel plate hole (78) penetrating therethrough in the first direction,
The core unit further includes an insulating member (120) interposed between an outer circumferential pipe surface (89) of the pipe and an inner circumferential steel plate surface (176) of the steel plate that defines the steel plate hole.

Generally, since no insulating coating is formed on the inner circumferential surface of the steel plates, if eddy currents are generated in any of the steel plates, the currents may flow in the first direction through the steel plate stack via the inner circumferential surface of the steel plates. In this regard, according to the configuration of 12) above, an insulating member is disposed between the outer circumferential surface of the pipe and the inner circumferential surface of the steel plates, so that the currents generated in any of the steel plates can be prevented from flowing in the first direction through the steel plate stack.

13) In some embodiments, the core unit according to any one of 1) to 12) above,
The pipe is
A pipe inner peripheral surface (86);
At least one of an inner circumferential surface convex portion (861) or an inner circumferential surface concave portion (863) provided on the inner circumferential surface of the pipe;
It further comprises:

The configuration of 13) above promotes heat exchange between the inner surface of the pipe and the air, improving the cooling performance of the iron core.

14) The rotor (30) according to at least one embodiment of the present disclosure comprises:
a ring unit (50) including a plurality of iron core units (10) according to any one of 1) to 12) above, and a plurality of non-magnetic bodies (52) arranged alternately with the plurality of iron core units in a circumferential direction that is a direction perpendicular to the first direction;
A pair of flanges (34) respectively connected to both ends of the ring unit in the first direction, the pair of flanges being configured to be connected to a rotation shaft extending in the first direction;
Equipped with
At least one flange hole (43) is formed in each of the flanges, the flange hole (43) communicating with an inner space of the pipe (80) of each of the plurality of core units.

The configuration of 14) above allows for the same reason as 1) above to achieve a rotor that can maintain the shape of the powder magnetic core and has improved cooling performance for the iron core.

15) In some embodiments, the rotor (30) described in 14) above,
each of the non-magnetic bodies is formed of a fiber reinforced composite material;
The ring unit further includes a flexible member (150) interposed between the iron core and the non-magnetic body.

According to the configuration of 15) above, the non-magnetic body is a fiber-reinforced composite material, so that the insulation of the non-magnetic body is ensured, and the rotor is made lighter and more rigid. On the other hand, the linear expansion coefficient of the non-magnetic body formed from the fiber-reinforced composite material is smaller than that of the powder core. For this reason, when the temperature of a rotor having a configuration in which the powder core and the non-magnetic body are in direct contact with each other rises, the non-magnetic body extends in the first direction more than the powder core. As a result, tensile stress caused by the expansion of the non-magnetic body is generated in the powder core as thermal stress, and the powder core, which has a relatively weak mechanical strength, may be damaged. In other words, the powder core may be damaged. In this regard, according to the configuration of 15) above, the flexible member has a portion that contacts the non-magnetic body and a portion that contacts the iron core, and it is possible to make the amount of extension in the first direction of both portions different. In other words, the flexible member can reduce the thermal stress generated in the powder core. This allows the rotor to suppress damage to the powder core.

16) In some embodiments, the rotor according to 15) above,
The flexible member is formed from an elastomer.

In the configuration of 16) above, the elastomer has an adhesive function, so there is no need to prepare a separate adhesive material for joining the iron core, the non-magnetic material, and the flexible member. This simplifies the rotor configuration.

5: Rotating shaft 9: Adhesive 10: Core unit 30: Rotor 41: Flange 43: Flange hole 50: Ring unit 52: Non-magnetic material 60: Core 70: Powder core 71: One side powder core 75: Powder core hole 76: Powder core inner peripheral surface 77: Steel plate 78: Steel plate hole 79: Steel plate laminate 80 (80A, 81 to 83): Pipe 84: Peripheral wall 85: Slit 86: Pipe inner peripheral surface 87: One end 89: Pipe outer peripheral surface 110: Insulator 111: End 115: Insulator hole 120: Insulating member 150: Flexible member 176: Steel plate inner peripheral surface 181: Outer peripheral surface recess 183: Outer peripheral surface convex portion 861: Inner peripheral surface convex portion 863: Inner peripheral surface concave portion

Claims (16)

1. An iron core including at least one powder core having a powder core hole penetrating in a first direction;
   A pipe extending in the first direction and inserted into the powder core hole;
   An iron core unit comprising:
2. The pipe is
   The surrounding wall and
   a slit penetrating the peripheral wall in a radial direction and extending along the first direction;
   including,
   The core unit according to claim 1 .
3. The pipe further includes an adhesive interposed between an outer peripheral surface of the pipe and an inner peripheral surface of the powder core that defines the powder core hole,
   The core unit according to claim 1 or 2.
4. The pipe outer circumferential surface has at least one of an outer circumferential surface concave portion and an outer circumferential surface convex portion.
   The core unit according to claim 3 .
5. an insulator disposed so as to be stacked on an end portion of the iron core in the first direction, the insulator having an insulator hole penetrating therethrough in the first direction;
   The pipe is inserted into the insulator hole.
   The core unit according to claim 1 or 2.
6. One end of the pipe on one side in the first direction is located on the opposite side to the one side relative to an end of the insulator on the one side.
   The core unit according to claim 5 .
7. The iron core includes a plurality of the powder magnetic cores stacked in the first direction,
   The pipe is inserted into the powder core hole of each of the powder cores.
   The core unit according to claim 1 or 2.
8. The iron core is
   A steel plate stack having a plurality of steel plates stacked in the first direction;
   The powder core is disposed on one side of the steel plate laminate in the first direction, and the powder core forms an end portion on the one side of the iron core;
   Further comprising:
   The core unit according to claim 1 or 2.
9. the pipe is longer than the iron core in the first direction and is inserted from one end of the iron core to the other end of the iron core in the first direction.
   The core unit according to claim 1 or 2.
10. The pipe is made of a non-magnetic material.
    The core unit according to claim 1 or 2.
11. The pipe is made of a non-magnetic metal material.
    The core unit according to claim 10.
12. The iron core is
    A plurality of steel plates are stacked in the first direction, each of the steel plates having a steel plate hole penetrating therethrough in the first direction,
    The core unit further includes an insulating member interposed between an outer circumferential surface of the pipe and an inner circumferential surface of the steel plate that defines the steel plate hole.
    The core unit according to claim 1 or 2.
13. The pipe is
    An inner peripheral surface of the pipe;
    At least one of an inner circumferential surface convex portion and an inner circumferential surface concave portion provided on the inner circumferential surface of the pipe;
    Further comprising:
    The core unit according to claim 1 or 2.
14. a ring unit including a plurality of the core units according to claim 1 or 2 and a plurality of non-magnetic bodies arranged alternately with the plurality of core units in a circumferential direction that is a direction perpendicular to the first direction;
    a pair of flanges respectively connected to both ends of the ring unit in the first direction, the pair of flanges being configured to be connected to a rotation shaft extending in the first direction;
    Equipped with
    At least one flange hole is formed in each of the flanges, the flange hole communicating with an inner space of the pipe of each of the plurality of core units.
    Rotor.
15. each of the non-magnetic bodies is formed of a fiber reinforced composite material;
    The ring unit further includes a flexible member interposed between the iron core and the non-magnetic body.
    A rotor as claimed in claim 14.
16. The flexible member is formed of an elastomer.
    A rotor as claimed in claim 15.
    
    

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