Magnetic pole piece module, magnetic geared rotating machine, and method for manufacturing a magnetic pole piece module

Abstract

This invention provides a magnetic pole piece module that improves the positional accuracy of the magnetic pole pieces. [Solution] A pole piece module having a plurality of pole pieces 21 arranged in an annular pattern with spacing between them, and a molded resin 22 filled between the pole pieces, wherein the pole pieces are made by laminating a plurality of electromagnetic steel sheets rolled in one direction, the rolling direction of adjacent pole pieces in the same layer is the same, and at least one of the inner diameter side surface and the outer diameter side surface of the pole piece is a machined surface.

Description

Technical Field

[0001] The present disclosure relates to a pole piece module, a magnetic geared rotary machine, and a method for manufacturing a pole piece module.

Background Art

[0002] In recent years, a flux modulation type magnetic gear device (magnetic gear) that realizes a high torque density has been developed. And a magnetic geared rotary machine in which a magnetic gear device and a wound stator are integrated has been developed. In this magnetic geared rotary machine, a high-speed side rotor is rotated by a stator coil disposed inside, and the magnetic flux of a magnet disposed on the high-speed side rotor is modulated by a pole piece to rotate a low-speed side rotor. As a result, the low-speed side rotor can obtain torque increased by the speed ratio (reduction ratio) of the high-speed side rotor. Therefore, in a magnetic geared rotary machine, a high torque density can be realized.

[0003] The low-speed side rotor is composed of a pole piece module including a plurality of pole pieces arranged at equal intervals in an annular shape. The inner diameter side and the outer diameter side of this pole piece module face the high-speed side rotor and the stator through gaps, respectively. If the positional accuracy of the pole pieces in the radial direction and the circumferential direction is low, it is necessary to increase the gap. When the gap increases, there arises a problem that the torque transmission efficiency decreases.

[0004] In a conventional pole piece module with improved positional accuracy of pole pieces, there is disclosed one in which a pole piece is disposed between a cylindrical outer peripheral cover member and an inner peripheral cover member to determine the positions of the pole piece in the radial direction and the circumferential direction (see, for example, Patent Document 1). Further, in another pole piece module, there is disclosed one including a cylindrical frame having gaps at equal intervals, and inserting a pole piece into the gaps of this frame to determine the positions of the pole piece in the radial direction and the circumferential direction (see, for example, Patent Document 2).

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] International Publication No. 2021 / 149772 [Patent Document 2] International Publication No. 2022 / 118598 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] In conventional pole piece modules, multiple individually manufactured poles are inserted into a regulating component that restricts the position of the pole pieces to create the module. The positional accuracy of the pole pieces in a pole piece module manufactured in this way is affected by the processing errors of each pole piece and the regulating component, as well as the assembly errors that occur when inserting the pole pieces into the regulating component. As a result, conventional pole piece modules suffer from the problem of low positional accuracy of the pole pieces.

[0007] This disclosure was made to solve the above-mentioned problems and aims to provide a pole piece module that improves the positional accuracy of the pole pieces. [Means for solving the problem]

[0008] The pole piece module of the present disclosure is a pole piece module having a plurality of pole pieces arranged with annular spacing and a molded resin filled between the plurality of pole pieces, wherein the pole pieces are made by laminating a plurality of electromagnetic steel sheets rolled in one direction, the rolling direction of adjacent pole pieces in the same layer is the same, and at least one of the inner diameter side surface and the outer diameter side surface of the pole piece is a machined surface. [Effects of the Invention]

[0009] The pole piece module of this disclosure is constructed by laminating a plurality of electromagnetic steel sheets in which the pole pieces are rolled in one direction, and the rolling direction of adjacent pole pieces in the same layer is the same direction, and at least one of the inner diameter side surface and the outer diameter side surface of the pole piece is a machined surface, thereby improving the positional accuracy of the pole pieces. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view of a magnetic geared rotating machine according to Embodiment 1. [Figure 2] This is a cross-sectional view of a magnetic geared rotating machine according to Embodiment 1. [Figure 3] This is a perspective view of the magnetic pole piece module according to Embodiment 1. [Figure 4] This is a cross-sectional view of a magnetic pole module according to Embodiment 1. [Figure 5] This is a cross-sectional view of a magnetic pole module according to Embodiment 1. [Figure 6] This is a perspective view of the magnetic pole piece according to Embodiment 1. [Figure 7] This is a flowchart of the manufacturing method for a magnetic pole piece module according to Embodiment 1. [Figure 8] This is a plan view of the magnetic pole piece connecting plate according to Embodiment 1. [Figure 9] This is a perspective view of the pole piece connector according to Embodiment 1. [Figure 10] This is a cross-sectional view of a mold for manufacturing a magnetic pole module according to Embodiment 1. [Figure 11] This is a diagram illustrating the manufacturing method of a magnetic pole piece module according to Embodiment 1. [Figure 12] This is a cross-sectional view of the pole piece connector according to Embodiment 1. [Figure 13] This is a cross-sectional view of the pole piece connector according to Embodiment 1. [Figure 14] This is an enlarged cross-sectional view of a magnetic pole piece module according to Embodiment 1. [Figure 15] This is a perspective view of the pole piece connector according to Embodiment 2. [Figure 16] This is a perspective view of the pole piece connector according to Embodiment 3. [Figure 17] This is a diagram illustrating the manufacturing method of a magnetic pole piece module according to Embodiment 4. [Figure 18] This is a perspective view of the pole piece connector according to Embodiment 5. [Figure 19] Cross-sectional view showing an enlarged magnet pole piece connector according to Embodiment 6. [Figure 20] Flowchart showing a method for manufacturing a magnet pole piece module according to Embodiment 7.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, a magnet pole piece module and a magnetic gear drive rotating machine according to embodiments for carrying out the present disclosure will be described in detail with reference to the drawings. In each figure, the same reference numerals denote the same or corresponding parts. In the following description, the magnetic gear drive rotating machine will be described as a magnetic speed reducer. However, the same applies even if the magnetic gear drive rotating machine is a magnetic speed increaser or a magnetic gear drive rotating electric machine.

[0012] Embodiment 1. FIG. 1 is a cross-sectional view of a magnetic gear drive rotating machine according to Embodiment 1. FIG. 1 is a cross-sectional view of a plane orthogonal to the inner rotor shaft. The magnetic gear drive rotating machine 10 of the present embodiment has an inner rotor 1, a magnet pole piece module 2, and an outer rotor 3. The inner rotor 1 has an inner rotor shaft 11 serving as a rotation axis, an inner rotor core 12 fixed to the outer diameter side of the inner rotor shaft 11, and a plurality of inner rotor magnets 13 arranged at equal intervals on the outer peripheral surface of the inner rotor core 12. Hereinafter, the direction parallel to the inner rotor shaft 11 will be referred to as the axial direction, the direction orthogonal to the inner rotor shaft 11 will be referred to as the radial direction, and the direction of rotation around the inner rotor shaft 11 will be referred to as the circumferential direction. Also, in the radial direction, the direction away from the inner rotor shaft 11 will be referred to as the outer diameter side, and the opposite direction will be referred to as the inner diameter side.

[0013] The pole piece module 2 has a plurality of pole pieces 21 arranged in an annular shape with spacing between them, and a molded resin 22 for fixing the plurality of pole pieces 21. The outer rotor 3 has a cylindrical outer rotor core 31 and a plurality of outer rotor magnets 32 arranged at equal intervals on the inner circumferential surface of the outer rotor core 31. In this embodiment, the magnetic geared rotating machine 10 has the inner rotor 1, pole piece module 2, and outer rotor 3 arranged in order from the inner diameter side with gaps between them. The inner rotor 1, pole piece module 2, and outer rotor 3 are also arranged coaxially with the inner rotor shaft 11 as the central axis.

[0014] The inner rotor core 12, the magnetic pole pieces 21, and the outer rotor core 31 are constructed by laminating, for example, electromagnetic steel sheets, which are magnetic materials, in the axial direction. The inner rotor magnet 13 and the outer rotor magnet 32 ​​are permanent magnets.

[0015] Figure 2 is a cross-sectional view of a magnetic geared rotating machine according to this embodiment. Figure 2 is a cross-sectional view of the position indicated by AA in Figure 1. The pole piece module 2 is fixed at both ends in the axial direction with a non-magnetic member 23 such as resin or aluminum. This non-magnetic member 23 is fixed to the outer frame (not shown) of the outer rotor 3. The multiple pole pieces 21 of the pole piece module 2 transmit magnetic flux from the inner rotor 1 to the outer rotor 3, or from the outer rotor 3 to the inner rotor 1. In this embodiment, the pole pieces 21 are constructed by laminating electromagnetic steel sheets in the axial direction. The method of fixing the laminated electromagnetic steel sheets may be crimping, bonding, or welding, or a combination thereof.

[0016] The inner rotor shaft 11 and the inner rotor core 12 are integrally formed. The inner rotor shaft 11 extends outward from one end in the axial direction. The inner rotor 1 is positioned on the inner diameter side of the non-magnetic member 23 via a bearing 41. The outer rotor shaft 33 is integrally formed with the outer rotor core 31 at the other end in the axial direction of the outer rotor core 31. The rotation center of the inner rotor shaft 11 and the rotation center of the outer rotor shaft 33 are the same. The outer rotor 3 is positioned on the outer diameter side of the non-magnetic member 23 via a bearing 42.

[0017] Let Nh be the number of pole pairs of the inner rotor magnets 13 of the inner rotor 1, Np be the number of poles of the pole pieces of the pole piece module 2, and Nl be the number of pole pairs of the outer rotor magnets 32 of the outer rotor 3. In the magnetic geared rotating machine of this embodiment, the relationship Np = Nl + Nh holds. In this case, if the reduction ratio is Gr, then Gr = Nl / Nh. The rotational speed of the inner rotor 1 is multiplied by 1 / Gr and transmitted to the outer rotor 3, and the torque of the inner rotor 1 is multiplied by Gr and transmitted to the outer rotor 3. In the magnetic geared rotating machine of this embodiment, for example, if Nh = 4, Np = 30, and Nl = 26, then Gr = 6.5. The formula for the reduction ratio also holds if Np = Nl - Nh.

[0018] In the magnetic geared rotary machine of this embodiment, the magnetic pole module 2 is fixed and does not rotate. The inner rotor 1 and the outer rotor 3 rotate in the same direction, and rotational force is transmitted from the inner rotor 1 to the outer rotor 3. When the magnetic pole module 2 is fixed, the transmitted torque decreases compared to when it is not fixed, i.e., when the outer rotor 3 is fixed and the magnetic pole module 2 rotates. However, since the magnetic pole module 2 is fixed, no centrifugal force is applied to the magnetic pole module 2, so no countermeasures against centrifugal force are required. For example, it is not necessary to provide restricting parts to counteract centrifugal force on the outer or inner surface of the magnetic pole 21. Therefore, the inner rotor 1 and the outer rotor 3 can be positioned with the smallest possible gap width between them, which improves the magnetic flux density and thus improves the transmitted torque.

[0019] Although the magnetic geared rotating machine in this embodiment shown in Figures 1 and 2 is a cylindrical rotating type device, it may also be a disc rotating type, a flat plate linear type, or a cylindrical linear type device.

[0020] Next, the pole piece module of the magnetic geared rotating machine of this embodiment will be described in detail. Figure 3 is a perspective view of the pole piece module according to this embodiment. As shown in Figure 3, in the axial central part of the pole piece module 2 of this embodiment, the pole pieces 21 and molded resin 22 are arranged alternately in the circumferential direction.

[0021] Figure 4 is a cross-sectional view of the pole piece module according to this embodiment. Figure 4 is a cross-sectional view of the pole piece module on a plane parallel to the axial direction at the position indicated by AA in Figure 1. Figure 5 is a cross-sectional view of a plane perpendicular to the axial direction at the position indicated by BB in Figure 4. To reiterate, in the axial central part of the pole piece module 2 of this embodiment, the pole pieces 21 and molded resin 22 are arranged alternately in the circumferential direction. The inner diameter side surface and the outer diameter side surface of the pole piece 21 may or may not be in contact with the molded resin 22.

[0022] Figure 6 is a perspective view of a pole piece according to this embodiment. Figure 6 shows only the pole pieces of a pole piece module. The number of pole pieces 21 in the pole piece module of this embodiment is 30. As shown in Figure 6, the circumferential width of each pole piece is smallest at the radial center and increases from the center toward the inner and outer diameters. The pole piece module of this embodiment consists of the pole pieces shown in Figure 6 and molded resin integrated with the pole pieces.

[0023] Next, a method for manufacturing a pole piece module according to this embodiment will be described. Figure 7 is a flowchart of the method for manufacturing a pole piece module according to this embodiment. In step S01, a pole piece connecting plate is manufactured by punching out an electromagnetic steel sheet that has been rolled in one direction. Figure 8 is a plan view of the pole piece connecting plate according to this embodiment. As shown in Figure 8, the pole piece connecting plate 200 is composed of a plurality of pole pieces 21a arranged in an annular shape with spacing between them, and a pole piece connecting portion 21b that connects the plurality of pole pieces 21a on the inner diameter side.

[0024] Next, in step S02, the pole piece connecting plates 200 are stacked. Next, in step S03, the stacked pole piece connecting plates 200 are fixed to manufacture a pole piece assembly. The stacked pole piece connecting plates 200 may be fixed by crimping, bonding, or welding, or a combination thereof. Figure 9 is a perspective view of a pole piece assembly according to this embodiment. As shown in Figure 9, the pole piece assembly 210 is made up of stacked pole piece connecting plates 200, and the portion where the pole pieces 21a of the pole piece connecting plates 200 are stacked becomes the pole piece 21 of the pole piece assembly 210. The pole pieces 21 are connected on the inner diameter side by a pole piece connecting portion 21b.

[0025] Next, in step S04, the pole piece connector 210 is placed into the mold. Figure 10 is a cross-sectional view of the mold for manufacturing a pole piece module according to this embodiment. As shown in Figure 10, the mold in this embodiment consists of a disc-shaped base plate 51, a cylindrical core 52, and a cylindrical outer frame 53. A space is formed between the core 52 and the outer frame 53 for arranging the pole piece connector and filling with molding resin. Figure 11 is a diagram illustrating the method for manufacturing a pole piece module according to this embodiment. First, the core 52 is placed on the upper surface of the base plate 51. Then, the outer frame 53 is placed on the upper surface of the base plate 51. Next, the pole piece connector 210 is placed between the core 52 and the outer frame 53. At this time, the radial position of the pole piece connector 210 is determined by aligning the outer circumferential surface of the pole piece connector 210 with the inner circumferential surface of the outer frame 53. Furthermore, the axial position of the pole piece connector 210 is determined by bringing the lower surface of the pole piece connector 210 into contact with the stepped portion 52a formed on the outer circumference of the core 52. In this manufacturing method, there is no need to specifically determine the circumferential position of the pole piece connector 210. Since the pole pieces are fixed in a connected state at the pole piece connector, the positional relationship of the pole pieces is already determined. Figure 11 also shows the mold resin 22 injected into the mold in the next step S05.

[0026] Next, in step S05, the mold resin, which has been vacuum-degassed and heated and melted in advance, is poured into the mold. At this time, the entire mold is heated, and the mold resin 22 is poured into the space between the core 52 and the outer frame 53. As shown in Figure 11, after the mold resin 22 has filled almost to the top of the core 52, the entire mold is vacuum-heated again to degas the mold resin 22.

[0027] Next, in step S06, the entire mold is cooled to harden the mold resin. Next, in step S07, the pole piece assembly integrated with the mold resin is removed from the mold. Figure 12 is a cross-sectional view of the pole piece assembly according to this embodiment. Figure 12 is a cross-sectional view of the central part of the pole piece assembly when it has been removed from the mold, in a direction perpendicular to the axial direction. Figure 13 is a cross-sectional view of the pole piece assembly according to this embodiment in the axial direction. As shown in Figures 12 and 13, the mold resin 22 is arranged between adjacent pole pieces 21 of the pole piece assembly 210 removed from the mold, at both axial ends of the pole piece assembly 210, and on the inner diameter side of the pole piece assembly 21b.

[0028] Finally, in step S08, the inner diameter side of the pole piece connector 210 removed from the mold is machined to remove the unnecessary molded resin 22 and pole piece connector 21b on the inner circumference to manufacture a pole piece module. The pole piece module manufactured in this way has the structure shown in Figures 3 to 5. In the pole piece module of this embodiment, the inner diameter side surface of the pole piece 21 is the machined surface. In the pole piece module of this embodiment, since molded resin is filled between a plurality of pole pieces arranged with annular spacing, the pole pieces remain firmly fixed even if the pole piece connector is removed. Furthermore, as shown in Figure 4, molded resin 22 is arranged around the entire circumference at both axial ends of the pole piece 21, so the pole pieces are fixed even more firmly. Note that the inner diameter side of the molded resin 22 at both axial ends may or may not be removed, similar to the portion of the pole piece 21.

[0029] In magnetic pole piece modules manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by their fixed positions at the magnetic pole piece connectors. Therefore, their positions do not shift during assembly. As a result, the positional accuracy of the magnetic pole pieces is improved. Furthermore, since there is no need to provide regulating parts on the outer or inner diameter side of the magnetic pole pieces to restrict their position, the gap between the magnetic pole pieces and the inner and outer rotors can be reduced. As a result, the torque transmission efficiency can be improved.

[0030] Figure 14 is an enlarged cross-sectional view of the pole piece module according to this embodiment. Figure 14 is an enlarged cross-sectional view of the central part of the pole piece module perpendicular to the axial direction shown in Figure 5. In Figure 14, the arrows indicate the rolling direction of one layer of the pole piece 21. In the pole piece module of this embodiment, pole pieces are formed by stacking pole piece connecting plates that have been rolled in one direction, so the rolling directions of adjacent pole pieces in the same layer are in the same direction and are almost parallel.

[0031] In this embodiment, the pole piece module may be constructed by integrally molding the molded resin constituting the pole piece module with the non-magnetic member shown in Figure 2. Furthermore, when removing the pole piece connecting portion together with the molded resin, the shape of the pole piece module may be adjusted by machining not only the inner diameter side but also the outer diameter side of the pole piece.

[0032] In the manufacturing method of the pole piece module of this embodiment, molded resin is formed on the inner circumference side of the pole piece connecting portion, but the molded resin on the inner circumference side of the pole piece connecting portion is not necessarily required. It is sufficient if the molded resin is filled between a plurality of pole pieces arranged with spacing in an annular shape. In this case, in step S08 of the manufacturing method of the pole piece module shown in Figure 7, only the pole piece connecting portion is removed.

[0033] In the magnetic geared rotating machine of this embodiment, the outer rotor core and inner rotor core are made of soft magnetic materials such as electromagnetic steel sheets, compacted iron cores, amorphous metals, and Permendur. However, if there are no specification issues, these materials may be ferromagnetic materials such as carbon steel S45C and SS400. When electromagnetic steel sheets are used for the outer rotor core, magnetic pole pieces, and inner rotor core, multiple thin sheets of electromagnetic steel are laminated together to prevent eddy currents caused by changes in magnetic flux.

[0034] As shown in Figure 6, the shape of the pole pieces in the pole piece module according to this embodiment is such that the circumferential width is smallest at the radial center and increases from the center toward the inner and outer diameters. The shape of the pole pieces is not limited to this shape. For example, the pole piece may have a shape in which the radial center is concave in an arc shape, or a shape in which the radial center is convex. Also, the cross-section perpendicular to the axial direction of the pole piece may be Z-shaped or trapezoidal. Furthermore, the shapes of the pole pieces arranged in the circumferential direction do not all need to be the same, and pole pieces of different shapes may be arranged in the circumferential direction.

[0035] Embodiment 2. In the manufacturing method of the pole piece module of Embodiment 1, a pole piece assembly is used in which the inner diameter side of the pole pieces is connected by a pole piece connecting portion. In the manufacturing method of the pole piece module of Embodiment 2, a pole piece assembly is used in which the outer diameter side of the pole pieces is connected by a pole piece connecting portion.

[0036] The method for manufacturing the pole piece module in this embodiment is the same as the method for manufacturing the pole piece module in Embodiment 1. In the method for manufacturing the pole piece module in this embodiment, the structure of the pole piece connector differs from that of the method for manufacturing the pole piece module in Embodiment 1. Therefore, in this embodiment, the structure of the pole piece connector will be described mainly.

[0037] Figure 15 is a perspective view of a pole piece connector according to this embodiment. As shown in Figure 15, the pole piece connector plate 200 is composed of a plurality of pole pieces 21a arranged in an annular shape with spacing between them, and a pole piece connector portion 21b that connects the plurality of pole pieces 21a on the outer diameter side. The pole piece connector body 210 is formed by stacking the pole piece connector plates 200, and the portion of the pole piece connector plate 200 where the pole pieces 21a are stacked becomes the pole piece 21 of the pole piece connector body 210. The pole pieces 21 are connected on the outer diameter side by the pole piece connector portion 21b.

[0038] In this embodiment, the pole piece module is manufactured by machining the outer diameter side of the pole piece connector 210 removed from the mold in step S08 of the flowchart for the manufacturing method of the pole piece module shown in Figure 7 of Embodiment 1, thereby removing the unnecessary mold resin 22 and pole piece connector 21b on the outer circumference. The pole piece module manufactured in this way has the structure shown in Figures 3 to 5 of Embodiment 1. In the pole piece module of this embodiment, the outer diameter side surface of the pole piece 21 becomes the machined surface.

[0039] In a magnetic pole piece module manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by fixing them at the magnetic pole piece connecting portion, similar to Embodiment 1. Therefore, their positions do not shift when assembling the magnetic pole piece module. As a result, the positional accuracy of the magnetic pole pieces is improved.

[0040] In addition, in the manufacturing method of the pole piece module of this embodiment, when removing the pole piece connecting portion together with the molded resin, the shape of the pole piece module may be adjusted by cutting not only the outer diameter side of the pole piece but also the inner diameter side.

[0041] Embodiment 3. In the manufacturing method of the pole piece module of Embodiment 1, a pole piece assembly is used in which the inner diameter side of the pole pieces is connected by a pole piece connecting portion. In the manufacturing method of the pole piece module of Embodiment 3, a pole piece assembly is used in which the inner diameter side and outer diameter side of the pole pieces are connected by a pole piece connecting portion.

[0042] The method for manufacturing the pole piece module in this embodiment is the same as the method for manufacturing the pole piece module in Embodiment 1. In the method for manufacturing the pole piece module in this embodiment, the structure of the pole piece connector differs from that of the method for manufacturing the pole piece module in Embodiment 1. Therefore, in this embodiment, the structure of the pole piece connector will be described mainly.

[0043] Figure 16 is a perspective view of a pole piece connector according to this embodiment. As shown in Figure 16, the pole piece connector plate 200 is composed of a plurality of pole pieces 21a arranged in an annular shape with spacing between them, and pole piece connectors 21b that connect the plurality of pole pieces 21a on the inner and outer circumferential sides. The pole piece connector 210 is formed by stacking the pole piece connector plates 200, and the portion of the pole piece connector plate 200 where the pole pieces 21a are stacked becomes the pole piece 21 of the pole piece connector 210. The pole pieces 21 are connected by the pole piece connectors 21b on the inner and outer circumferential sides.

[0044] In this embodiment, the pole piece module is manufactured by machining both the inner and outer diameter sides of the pole piece connector 210 removed from the mold in step S08 of the flowchart for the manufacturing method of the pole piece module shown in Figure 7 of Embodiment 1, thereby removing the unnecessary mold resin 22 on the inner and outer circumferences and the pole piece connector 21b on the inner and outer circumferences. The pole piece module manufactured in this way has the structure shown in Figures 3 to 5 of Embodiment 1. In the pole piece module of this embodiment, both the inner and outer diameter surfaces of the pole piece 21 are machined surfaces.

[0045] In a magnetic pole piece module manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by fixing them at the magnetic pole piece connecting portion, similar to Embodiment 1. Therefore, their positions do not shift when assembling the magnetic pole piece module. As a result, the positional accuracy of the magnetic pole pieces is improved.

[0046] Embodiment 4. In the manufacturing method of the pole piece module of Embodiment 1, the rolling direction of the pole piece connecting plates is not particularly considered when stacking the pole piece connecting plates. In the manufacturing method of the pole piece module of Embodiment 4, the rolling direction of the pole piece connecting plates is considered when stacking them.

[0047] Generally, when rolled electrical steel sheets are punched out, variations in thickness occur depending on the punching position. Therefore, when magnetic pole piece connecting plates obtained by punching out rolled electrical steel sheets are laminated with the rolling direction aligned, the variation in thickness in the lamination direction of the magnetic pole pieces increases by multiplying the thickness variation by the number of laminated sheets.

[0048] Figure 17 is a diagram illustrating the manufacturing method of the pole piece module according to this embodiment. Figure 17 shows two representative pole piece connecting plates 200 when multiple pole piece connecting plates are stacked, and the two arrows indicate the rolling direction of each pole piece connecting plate 200. In the manufacturing method of the pole piece module according to this embodiment, in step S02 of the flowchart for the manufacturing method of the pole piece module shown in Figure 7 of Embodiment 1, the multiple pole piece connecting plates 200 are stacked with their rolling directions offset, as shown in Figure 17. The rest of the manufacturing method of the pole piece module is the same as the manufacturing method of the pole piece module according to Embodiment 1.

[0049] In a magnetic pole piece module manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by fixing them at the magnetic pole piece connecting portion, similar to Embodiment 1. Therefore, their positions do not shift when assembling the magnetic pole piece module. As a result, the positional accuracy of the magnetic pole pieces is improved.

[0050] Furthermore, in the manufacturing method of the pole piece module of this embodiment, when stacking multiple pole piece connecting plates, the rolling directions of the pole piece connecting plates are offset, so that variations in the thickness of the pole piece connecting plates caused by the punching process can be dispersed. As a result, variations in the thickness of the pole pieces in the stacking direction can be suppressed.

[0051] Embodiment 5. In the manufacturing method of the pole piece module of Embodiment 1, when stacking the pole piece connecting plates, the pole piece connecting plates are also stacked with the circumferential positions of the pole pieces aligned. In the manufacturing method of the pole piece module of Embodiment 5, when stacking the pole piece connecting plates, the pole pieces are stacked with their circumferential positions offset.

[0052] Figure 18 is a perspective view of the pole piece connector according to this embodiment. In the manufacturing method of the pole piece module of this embodiment, in step S02 of the flowchart for manufacturing the pole piece module shown in Figure 7 of Embodiment 1, as shown in Figure 18, the pole piece connector 210 is formed by stacking pole piece connecting plates 200 that are offset in one direction in the circumferential direction. The portion of the pole piece connecting plate 200 to which the pole pieces 21a are stacked becomes the pole piece 21 of the pole piece connector 210. In other words, in the manufacturing method of the pole piece module of this embodiment, the pole piece 21 is skewed in the axial direction. The rest of the manufacturing method of the pole piece module is the same as the manufacturing method of the pole piece module of Embodiment 1.

[0053] In a magnetic pole piece module manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by fixing them at the magnetic pole piece connecting portion, similar to Embodiment 1. Therefore, their positions do not shift when assembling the magnetic pole piece module. As a result, the positional accuracy of the magnetic pole pieces is improved.

[0054] Furthermore, in the magnetic pole module manufactured by the manufacturing method of this embodiment, the magnetic poles are skewed in the axial direction. Therefore, in a magnetic geared rotating machine equipped with this magnetic pole module, the cogging torque and torque ripple are improved.

[0055] In the manufacturing method of the pole piece module of this embodiment, the pole piece connecting plates are stacked with a offset in one direction in the circumferential direction, but the pole piece connecting plates may be stacked alternately every few plates, with some having the same circumferential direction and others having a offset.

[0056] Furthermore, in the method for manufacturing the pole piece module of this embodiment, the pole piece connecting portion of the pole piece connector connects the pole pieces on the inner diameter side of the pole pieces, but the pole piece connecting portion may also connect the pole pieces on the outer diameter side of the pole pieces, or it may connect the pole pieces on both the inner and outer diameter sides.

[0057] Embodiment 6. In the manufacturing method of the pole piece module of Embodiment 1, the inner diameter side of the pole piece connector removed from the mold is machined to remove unnecessary mold resin and pole piece connectors from the inner circumference, thereby manufacturing the pole piece module. At this time, in order to ensure that the pole piece connectors are removed, some pole pieces may be removed beyond the pole piece connectors to the inner circumference of the pole piece. In Embodiment 1, the circumferential width of the pole piece is smallest at the radial center and increases from the center toward the inner and outer diameters. Therefore, pole pieces that are removed beyond the pole piece connectors to the inner circumference will have a smaller circumferential width. This can lead to variations in the width of the inner diameter of the pole pieces, which may cause unstable torque transmission in a magnetic geared rotating machine equipped with this pole piece module. The manufacturing method of the pole piece module of Embodiment 6 is a manufacturing method that minimizes variations in the width of the inner diameter of the pole pieces, even if some pole pieces are removed to the inner circumference.

[0058] Figure 19 is an enlarged cross-sectional view of the pole piece connector according to this embodiment. Figure 19 is an enlarged view of a portion of one pole piece 21 of the pole piece connector. As shown in Figure 19, the pole piece 21 of the pole piece connector in this embodiment is connected to the pole piece connector portion 21b on the inner circumference side of the pole piece 21. The sides 21c on both sides of the position where the pole piece 21 is connected to the pole piece connector portion 21b are parallel to each other. In other words, in the pole piece connector according to this embodiment, the sides on both sides in the circumferential direction of the position where the pole piece is connected to the pole piece connector portion are parallel to each other.

[0059] In the pole piece connector configured in this way, the pole piece connector portion 21b on the inner diameter side of the pole piece 21 is removed up to the position on the outer circumference side of the pole piece connector portion 21b shown by the dashed line in Figure 19. However, in order to reliably remove the pole piece connector portion, there is a possibility that some pole pieces may be removed beyond this dashed line position to the inner circumference side of the pole piece. In the manufacturing method of the pole piece module of this embodiment, since the circumferential sides of both pole pieces at the position connected to the pole piece connector portion are parallel to each other, even if some pole pieces are removed up to the inner circumference side of the pole piece, the variation in the width on the inner diameter side of the pole piece is reduced. As a result, the transmitted torque is stable in a magnetic geared rotating machine equipped with this pole piece module.

[0060] In this embodiment, the method for manufacturing a pole piece module was described using a pole piece assembly equipped with a pole piece connecting portion that connects multiple pole pieces on the inner diameter side. However, the pole piece assembly may also be equipped with a pole piece connecting portion that connects multiple pole pieces on the outer diameter side, or with a pole piece connecting portion that connects multiple pole pieces on both the inner and outer diameter sides. In other words, in this embodiment, the pole piece assembly only needs to have sides on both sides in the circumferential direction of the position where the pole piece is connected to the pole piece connecting portion that are parallel to each other.

[0061] Embodiment 7. In the manufacturing methods of pole piece modules in Embodiments 1 to 6, pole piece connecting plates made of electromagnetic steel sheets were stacked to produce a pole piece assembly. The manufacturing method of pole piece modules in Embodiment 7 produces the pole piece assembly by a different method.

[0062] Figure 20 is a flowchart of the manufacturing method for a magnetic pole piece module according to this embodiment. In step S11, a magnetic pole piece assembly is manufactured by cutting from a block of magnetic material. Examples of magnetic materials include iron and nickel. Methods for cutting include wire cutting and machining. The cut magnetic pole piece assembly comprises a plurality of magnetic pole pieces arranged at intervals in an annular shape, and a magnetic pole piece connecting portion that connects the plurality of magnetic pole pieces on the inner diameter side.

[0063] Next, in step S12, the pole piece assembly is placed into the mold. The mold used in step S12 is the same as the mold used in the manufacturing method of the pole piece module in Embodiment 1, so its description is omitted.

[0064] Next, in step S13, the mold resin, which has been vacuum-degassed and heated and melted in advance, is injected into the mold. Next, in step S14, the entire mold is cooled to harden the mold resin. Next, in step S15, the pole piece assembly, which is integrated with the mold resin, is removed from the mold. Finally, in step S16, the inner diameter side of the pole piece assembly removed from the mold is machined to remove the unnecessary mold resin and pole piece assembly on the inner circumference to manufacture a pole piece module. The pole piece module manufactured in this way has the structure shown in Figures 3 to 5 of Embodiment 1.

[0065] In a magnetic pole piece module manufactured using this method, the circumferential, radial, and axial positions of the magnetic pole pieces are determined by fixing them at the magnetic pole piece connecting portion, similar to Embodiment 1. Therefore, their positions do not shift when assembling the magnetic pole piece module. As a result, the positional accuracy of the magnetic pole pieces is improved.

[0066] In the method for manufacturing the pole piece module of this embodiment, in step S11, the pole piece connector is manufactured by cutting it from a block of magnetic material, but the pole piece connector may be manufactured by another method. For example, the pole piece connector may be manufactured by compression molding of magnetic material powder such as iron powder. Even when the pole piece connector is manufactured by compression molding, the circumferential position, radial position, and axial position of the pole piece are determined by being fixed at the pole piece connector, so their positions will not shift when assembling the pole piece module. As a result, the positional accuracy of the pole piece is improved.

[0067] Furthermore, although the method for manufacturing a pole piece module of this embodiment was described using a pole piece assembly equipped with a pole piece connecting portion that connects multiple pole pieces on the inner diameter side, it may also be a pole piece assembly equipped with a pole piece connecting portion that connects multiple pole pieces on the outer diameter side, or a pole piece assembly equipped with a pole piece connecting portion that connects multiple pole pieces on both the inner and outer diameter sides.

[0068] The various aspects of this disclosure are summarized below as an appendix. (Note 1) A pole piece module having a plurality of pole pieces arranged in an annular shape with spacing between them, and a molded resin filled between the plurality of pole pieces, The pole piece module is characterized in that the pole piece is composed of multiple electromagnetic steel sheets rolled in one direction and laminated, the rolling direction of adjacent pole pieces in the same layer is the same, and at least one of the inner diameter side surface and the outer diameter side surface of the pole piece is a machined surface. (Note 2) A magnetic geared rotating machine having an inner rotor, an intermediate cylindrical section, and an outer rotor arranged coaxially with a gap between them, The inner rotor has a cylindrical inner rotor core and a plurality of inner rotor magnets arranged at equal intervals on the outer circumferential surface of the inner rotor core. The outer rotor has a cylindrical outer rotor core and a plurality of outer rotor magnets arranged at equal intervals on the inner circumferential surface of the outer rotor core. A magnetic geared rotating machine characterized in that the intermediate cylindrical portion is composed of the magnetic pole piece module described in Appendix 1. (Note 3) A process for manufacturing a pole piece assembly having a plurality of pole pieces arranged in an annular shape with spacing between them, and a pole piece connecting portion that connects the plurality of pole pieces on at least one side of the inner diameter and outer diameter of the plurality of pole pieces, A step of filling the spaces between the multiple magnetic pole pieces with molten molded resin, The process of curing the aforementioned mold resin, A method for manufacturing a pole piece module, characterized by having a step of removing the pole piece connecting portion. (Note 4) The method for manufacturing a pole piece module according to Appendix 3, characterized in that, at the position where it is connected to the pole piece connecting portion, both circumferential sides of the pole piece are parallel to each other. (Note 5) The process for manufacturing the aforementioned pole piece connector is as follows: A process of manufacturing a plurality of pole piece connecting plates having the pole pieces and pole piece connecting portions by punching out an electromagnetic steel sheet that has been rolled in one direction, A lamination step of stacking multiple magnetic pole piece connecting plates, A method for manufacturing a pole piece module according to appendix 3 or 4, characterized by comprising the step of fixing together a plurality of stacked pole piece connecting plates. (Note 6) The method for manufacturing a pole piece module according to Appendix 5, characterized in that the lamination step involves laminating a plurality of pole piece connecting plates with a circumferential offset. (Note 7) The method for manufacturing a pole piece module according to Appendix 5 or 6, characterized in that the lamination step involves laminating a plurality of pole piece connecting plates with their rolling directions offset from each other.

[0069] While this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but are applicable to the embodiments individually or in various combinations. Accordingly, countless variations not illustrated are conceivable within the scope of the art disclosed in this specification. These include, for example, modifying, adding or omitting at least one component, or even extracting at least one component and combining it with components of other embodiments. [Explanation of Symbols]

[0070] 1 Inner rotor, 2 Pole piece module, 3 Outer rotor, 11 Inner rotor shaft, 12 Inner rotor core, 13 Inner rotor magnet, 21, 21a Pole piece, 21b Pole piece connector, 21c Side, 22 Molded resin, 23 Non-magnetic member, 31 Outer rotor core, 32 Outer rotor magnet, 33 Outer rotor shaft, 41, 42 Bearings, 51 Bottom plate, 52 Core, 53 Outer frame, 200 Pole piece connecting plate, 210 Pole piece connector.

Claims

1. A pole piece module having a plurality of pole pieces arranged in an annular shape with spacing between them, and a molded resin filled between the plurality of pole pieces, The pole piece module is characterized in that the pole piece is composed of multiple electromagnetic steel sheets rolled in one direction and laminated, the rolling direction of adjacent pole pieces in the same layer is the same, and at least one of the inner diameter side surface and the outer diameter side surface of the pole piece is a machined surface.

2. A magnetic geared rotating machine having an inner rotor, an intermediate cylindrical section, and an outer rotor arranged coaxially with a gap between them, The inner rotor has a cylindrical inner rotor core and a plurality of inner rotor magnets arranged at equal intervals on the outer circumferential surface of the inner rotor core. The outer rotor has a cylindrical outer rotor core and a plurality of outer rotor magnets arranged at equal intervals on the inner circumferential surface of the outer rotor core. A magnetic geared rotating machine characterized in that the intermediate cylindrical portion is composed of the magnetic pole piece module described in claim 1.

3. A process for manufacturing a pole piece assembly having a plurality of pole pieces arranged in an annular shape with spacing between them, and a pole piece connecting portion that connects the plurality of pole pieces on at least one side of the inner diameter and outer diameter of the plurality of pole pieces, A step of filling the spaces between the multiple magnetic pole pieces with molten molded resin, The process of curing the aforementioned mold resin, A method for manufacturing a pole piece module, characterized by having a step of removing the pole piece connecting portion.

4. The method for manufacturing a pole piece module according to claim 3, characterized in that, at the position where it is connected to the pole piece connecting portion, both circumferential sides of the pole piece are parallel to each other.

5. The process for manufacturing the aforementioned pole piece connector is as follows: A process of manufacturing a plurality of pole piece connecting plates having the pole pieces and pole piece connecting portions by punching out an electromagnetic steel sheet that has been rolled in one direction, A lamination step of stacking multiple magnetic pole piece connecting plates, A method for manufacturing a magnetic pole piece module according to claim 3 or 4, comprising the step of fixing together a plurality of stacked magnetic pole piece connecting plates.

6. The method for manufacturing a pole piece module according to claim 5, characterized in that the lamination step involves laminating a plurality of pole piece connecting plates with a circumferential offset.

7. The method for manufacturing a pole piece module according to claim 5, characterized in that the lamination step involves laminating a plurality of pole piece connecting plates with their rolling directions offset from each other.

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