Magnetic pole piece rotor and magnetic gear rotating machine

Abstract

This magnetic pole piece rotor comprises a plurality of magnetic pole pieces arranged at intervals in the circumferential direction and a plurality of non-magnetic bodies arranged alternately with the plurality of magnetic pole pieces in the circumferential direction. The plurality of magnetic pole pieces and the plurality of non-magnetic bodies each include an adjacent magnetic pole piece and an adjacent non-magnetic body adjacent to each other. The magnetic pole piece rotor further comprises a buffer material including a buffer body part sandwiched between the adjacent magnetic pole piece and the adjacent non-magnetic body. A material forming the adjacent non-magnetic body includes a plastic material, and the Young's modulus of the buffer material is smaller than the Young's modulus of the plastic material.

Description

Pole piece rotor and magnetic gear rotating machine

[0001] This application claims priority to Japanese Patent Application No. 2023-200640, filed on November 28, 2023, with the Japan Patent Office, the contents of which are incorporated herein by reference.

[0002] A pole piece rotor incorporated in a magnetic gear rotating machine is known. The pole piece rotor includes a plurality of pole pieces and a plurality of non-magnetic bodies arranged alternately in the circumferential direction (see, for example, Patent Document 1).

[0003] International Publication No. 2022 / 118598

[0004] In general, non-magnetic materials tend to be more susceptible to thermal deformation than magnetic pole pieces. The above-mentioned patent document employs a configuration in which two magnetic pole pieces sandwich one non-magnetic material in the circumferential direction, and the thermal deformation of the non-magnetic material is limited by each of the two magnetic pole pieces. Therefore, when a temperature change occurs in the magnetic pole piece rotor, a large thermal strain occurs in the non-magnetic material, which may result in damage to the non-magnetic material.

[0005] An object of the present disclosure is to provide a pole piece rotor and a magnetic gear rotating machine that can suppress damage to non-magnetic materials even when temperature changes occur.

[0006] A pole piece rotor according to at least one embodiment of the present disclosure comprises: a plurality of pole pieces arranged at intervals in the circumferential direction; and a plurality of non-magnetic bodies arranged alternately with the plurality of pole pieces in the circumferential direction, wherein the plurality of pole pieces and the plurality of non-magnetic bodies each comprise adjacent pole pieces and adjacent non-magnetic bodies that are adjacent to each other; the pole piece rotor further comprises a buffer material including a buffer main body portion sandwiched between the adjacent pole pieces and the adjacent non-magnetic bodies; the material forming the adjacent non-magnetic bodies includes a plastic material; and the Young's modulus of the buffer material is smaller than the Young's modulus of the plastic material.

[0007] A magnetic gear rotating machine according to at least one embodiment of the present disclosure includes: the above-described pole piece rotor; a magnet rotor positioned radially inward relative to the plurality of pole pieces and the plurality of non-magnetic bodies; and a stator positioned radially outward relative to the plurality of pole pieces and the plurality of non-magnetic bodies.

[0008] According to the present disclosure, it is possible to provide a pole piece rotor and a magnetic gear rotating machine that can suppress damage to non-magnetic materials even when temperature changes occur.

[0009] FIG. 1 is a schematic diagram of a magnetic gear rotating machine according to one embodiment; FIG. 2 is a schematic diagram of the internal structure of a magnetic gear rotating machine according to one embodiment; FIG. 3 is a schematic diagram of a pole piece rotor according to a first embodiment; FIG. 4 is a schematic diagram of a pole piece rotor according to a second embodiment; FIG. 5 is a schematic diagram of a pole piece rotor according to a third embodiment; FIG. 6 is a schematic diagram of a pole piece rotor according to a fourth embodiment; FIG. 7 is a schematic diagram of a pole piece rotor according to a fifth embodiment; FIG. 8 is a schematic diagram of a cushioning material and adjacent non-magnetic bodies according to a fifth embodiment; FIG. 9 is a schematic diagram showing a cushioning material according to a modified example; FIG. 10 is a schematic diagram showing adjacent non-magnetic bodies according to a modified example.

[0010] Several embodiments of the present disclosure will be described below with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of components described as embodiments or shown in the drawings are not intended to limit the scope of the present disclosure and are merely illustrative examples. For example, expressions expressing relative or absolute arrangements, such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial," not only strictly express such arrangements, but also express relative displacements with a tolerance or angle or distance to the extent that the same function is achieved. For example, expressions expressing the equality of things, such as "same," "equal," and "homogeneous," not only express strict equality, but also express tolerance or differences to the extent that the same function is achieved. For example, expressions expressing shapes such as a square or cylindrical shape not only express shapes such as a square or cylindrical shape in the strict geometric sense, but also express shapes including concave and convex portions, chamfered portions, etc., to the extent that the same effect is achieved. On the other hand, the expressions "comprise," "include," or "have" one component are not exclusive expressions that exclude the existence of other components. Note that similar components may be assigned the same reference numerals and descriptions thereof may be omitted.

[0011] 1 is a schematic diagram of a magnetic gear rotating machine 1 according to one embodiment of the present disclosure. In the following description, the "axial direction" refers to the axial direction of the axis S of the magnetic gear rotating machine 1, the "circumferential direction" refers to the circumferential direction based on the axis S, and the "radial direction" refers to the radial direction based on the axis S. Furthermore, the "radially outer side" refers to the side away from the axis S, and the "radially inner side" refers to the side approaching the axis S.

[0012] The magnetic gear rotating machine 1 is connected to an external device 9 via a rotating shaft 18. The axis of the rotating shaft 18 substantially coincides with the axis S described above. In Fig. 1, the rotating shaft 18 is depicted as a single solid shaft member for the sake of simplicity of illustration, but the present disclosure is not limited to this. The rotating shaft 18 may be realized by a plurality of shaft members, and the plurality of shaft members may include a cylindrical shaft member.

[0013] The magnetic gear rotating machine 1 includes a magnet rotor 10 connected to a rotating shaft 18 via a bearing B1. The magnet rotor 10 has a rotor core 15 configured to rotate relative to the rotating shaft 18 and a plurality of magnets 19 supported by the rotor core 15. The plurality of magnets 19 are arranged circumferentially on the rotor core 15. Each magnet 19 extends axially. The magnet rotor 10 illustrated in FIG. 1 employs a surface permanent magnet (SPM) configuration in which the plurality of magnets 19 are provided on the surface of the rotor core 15, but the present disclosure is not limited thereto. For example, an interior permanent magnet (IPM) configuration in which the plurality of magnets 19 are embedded in the rotor core 15 may also be employed (see FIG. 2).

[0014] The magnetic gear rotating machine 1 further includes a pole piece rotor 30 configured to rotate integrally with the rotating shaft 18. The pole piece rotor 30 includes a ring unit 33 disposed radially outward of the magnet rotor 10, a first connecting portion 31 connecting one axial end of the ring unit 33 to the rotating shaft 18, and a second connecting portion 32 connecting the other axial end of the ring unit 33 to the rotating shaft 18. Details of the ring unit 33 will be described later.

[0015] The magnetic gear rotating machine 1 further includes a stator 20 disposed radially outward of the ring unit 33. The stator 20 has a stator core 22 extending in the circumferential direction, a plurality of stator coils 27 disposed in the stator core 22, and a plurality of stator magnets 29 attached to the inner circumferential surface of the stator core 22. The stator coil 27 is electrically connected to the electric system 16. The plurality of stator magnets 29 are disposed in the circumferential direction (see FIG. 2).

[0016] Several methods can be used to attach the stator magnets 29 to the stator core 22. As a first method, each stator magnet 29 may be attached to the inner circumferential surface of the stator core 22 with an adhesive. As a second method, each stator magnet 29 may be attached to two fingers (or two protrusions) that protrude radially inward from the inner circumferential surface of the stator core 22. Alternatively, an attachment method that combines the first and second methods may be used.

[0017] 2 illustrates an example of the ring unit 33 of the pole piece rotor 30. The ring unit 33 faces the magnet rotor 10 in the radial direction with an inner air gap G1 therebetween, and faces the stator 20 in the radial direction with an outer air gap G2 therebetween.

[0018] The ring unit 33 includes a plurality of magnetic pole pieces 35 and a plurality of non-magnetic bodies 36 arranged alternately in the circumferential direction, and each of the magnetic pole pieces 35 and each of the non-magnetic bodies 36 extends in the axial direction. Each of the magnetic pole pieces 35 is realized by a plurality of electromagnetic steel plates stacked in the axial direction, one or more powder magnetic cores extending in the axial direction, or a combination thereof. Furthermore, at least one of the plurality of magnetic pole pieces 35 may be formed with a magnetic pole piece hole 56 that is open in the axial direction. The magnetic pole piece hole 56 may function as a ventilation passage through which cooling air can pass, or as an insertion hole into which a support shaft that supports the magnetic pole piece 35 is inserted.

[0019] The material forming the non-magnetic body 36 includes a plastic material. For example, the non-magnetic body 36 is formed from fiber reinforced plastics (FRP). In this case, the non-magnetic body 36 has a structure in which a plurality of prepregs 89 are laminated. The lamination direction of the prepregs 89 may be the radial direction (see FIG. 3A ) or the circumferential direction (not shown). Note that the non-magnetic body 36 preferably has not only non-magnetic properties but also non-conductive properties.

[0020] The ring unit 33 may further include an inner cover 339 and an outer cover 332 that radially sandwich the plurality of magnetic pole pieces 35 and the plurality of non-magnetic bodies 36. The inner cover 339 and the outer cover 332 are cylindrical members formed of a non-magnetic material such as FRP. However, the present disclosure is not limited to this, and the inner cover 339 and the outer cover 332 may not be provided. In this case, each magnetic pole piece 35 and each non-magnetic body 36 are both exposed to the inner air gap G1 and the outer air gap G2, respectively.

[0021] Returning to FIG. 1 , the magnetic gear rotating machine 1 according to one embodiment is a magnetic gear generator configured to generate electricity by inputting power from an external device 9, which may be, for example, a prime mover. Its operating principle is as follows: When the external device 9 drives the rotating shaft 18, the pole piece rotor 30 rotates. The relative positions of the multiple pole pieces 35 with respect to the multiple magnets 19 and the multiple stator magnets 29 change, modulating the magnetic flux between the magnet rotor 10 and the stator 20. When the magnet 19 receives a magnetic force from the modulated magnetic field and the magnet rotor 10 rotates, a current is generated in the stator coil 27 by electromagnetic induction, and power is supplied from the stator coil 27 to the electrical system 16.

[0022] A magnetic gear rotating machine 1 according to another embodiment is a magnetic gear motor configured to output power to an external device 9 by receiving power from an electrical system 16. The operating principle is as follows: The magnet rotor 10 rotates due to a rotating magnetic field generated by controlling the current flowing through the stator coil 27. The relative positions of the plurality of pole pieces 35 with respect to the plurality of magnets 19 and the plurality of stator magnets 29 change, modulating the magnetic flux between the magnet rotor 10 and the stator 20. The pole pieces 35 receive magnetic force from the modulated magnetic field, causing the pole piece rotor 30 to rotate, and power is output from the rotating shaft 18 to the external device 9. In this case, the external device 9 may be, for example, an electric vehicle, and the power output from the rotating shaft 18 may be transmitted to the drive shaft of the electric vehicle.

[0023] 1 illustrates a structure in which the rotating shaft 18 rotates together with the pole piece rotor 30, but the present disclosure is not limited to this. For example, a structure in which the rotating shaft 18 rotates together with the magnet rotor 10 may be employed. In this case, the pole piece rotor 30 is connected to the rotating shaft 18 via a bearing. Furthermore, the pole piece rotor 30 may be configured to rotate together with a shaft member separate from the rotating shaft 18. If the separate shaft member is connected to a device separate from the external device 9, the magnetic gear rotating machine 1 can also transmit power output from the separate shaft member to that device.

[0024] <Pole piece rotors 30A-30E (30)> Figures 3A-3E illustrate pole piece rotors 30A-30E (30) according to several embodiments. Prior to describing each embodiment in detail, a configuration common to these embodiments will be described. In the following description, any two adjacent pole pieces 35 and non-magnetic bodies 36 alternately arranged in the circumferential direction may be referred to as an "adjacent pole piece 37" and an "adjacent non-magnetic body 38." An adjacent non-magnetic body 38 is located between two adjacent pole pieces 35 spaced apart in the circumferential direction.

[0025] The pole piece rotors 30A-30E (30) are equipped with buffer materials 50. The buffer materials 50 include buffer main bodies 53 sandwiched between adjacent pole pieces 37 and adjacent non-magnetic bodies 38. The buffer materials 50 extend in the axial direction. The buffer materials 50 are interposed between the adjacent pole pieces 37 and adjacent non-magnetic bodies 38 over the entire axial length of each of the adjacent pole pieces 37 and adjacent non-magnetic bodies 38. The buffer materials 50 may be formed from a thermoplastic resin such as polyetherimide (PEI), polyamide (PA), or polypropylene (PP), or may be formed from a thermoplastic elastomer or synthetic rubber. As mentioned above, the material forming the adjacent non-magnetic bodies 38 (non-magnetic bodies 36) includes a plastic material, but the plastic material and the material forming the buffer materials 50 are different from each other.

[0026] The Young's modulus of the buffer material 50 is smaller than the Young's modulus of the plastic material of the adjacent non-magnetic bodies 38. This relationship in Young's modulus holds true in both the circumferential and radial directions. More specifically, the Young's modulus of the buffer material 50 in the circumferential direction is smaller than the Young's modulus of the plastic material of the adjacent non-magnetic bodies 38 in the circumferential direction, and the Young's modulus of the buffer material 50 in the radial direction is smaller than the Young's modulus of the plastic material of the adjacent non-magnetic bodies 38 in the radial direction.

[0027] With the above configuration, the buffer material 50 is more easily deformed than the adjacent non-magnetic material 38. Therefore, when a temperature change occurs in the pole piece rotor 30, the adjacent non-magnetic material 38 can thermally deform while deforming the buffer material 50, thereby reducing the thermal stress generated in the adjacent non-magnetic material 38. This realizes a pole piece rotor 30 that can suppress damage to the non-magnetic material 36 even when a temperature change occurs.

[0028] To give a more specific example, if the pole piece rotor 30 includes a thermoplastic adhesive (e.g., the first adhesive layer 71 shown in FIG. 3A ) interposed between the buffer material 50 and the adjacent non-magnetic material 38, a manufacturing process is required in which the ring unit 33 is heated using equipment such as an autoclave. When the heated ring unit 33 is cooled, if the thermal contraction of the adjacent non-magnetic material 38 is hindered by the adjacent pole piece 37, the thermal strain in the adjacent non-magnetic material 38 increases, potentially causing damage to the adjacent non-magnetic material 38. In this regard, with the above-described configuration, at least a portion of the buffer material 50 deforms together with the adjacent non-magnetic material 38, reducing the thermal strain of the adjacent non-magnetic material 38. This reduces damage to the adjacent non-magnetic material 38.

[0029] To give another specific example, when the magnetic gear rotating machine 1 is in operation, the temperature of the ring unit 33 rises due to eddy currents generated in the adjacent pole pieces 37. If the thermal expansion of the adjacent non-magnetic material 38 caused by the temperature rise is inhibited by the adjacent pole pieces 37, the thermal strain in the adjacent non-magnetic material 38 increases, and there is a possibility that the adjacent non-magnetic material 38 may be damaged. In this regard, with the above-described configuration, the deformation of the buffer material 50 reduces the thermal strain in the adjacent non-magnetic material 38, thereby suppressing damage to the adjacent non-magnetic material 38.

[0030] The Young's modulus of the plastic material of the adjacent non-magnetic body 38 is smaller than the Young's modulus of the adjacent pole piece 37. This relationship in Young's modulus holds true in both the circumferential and radial directions.

[0031] The configuration of each of the pole piece rotors 30A to 30E (30) will be described in detail below.

[0032] <Pole piece rotor 30A according to the first embodiment> Figure 3A shows a schematic diagram of the pole piece rotor 30A (30) according to the first embodiment. The adjacent non-magnetic bodies 38A (38) of the pole piece rotor 30A (30) include a pair of non-magnetic divisions 39A (39) spaced apart in the radial direction and an intermediate portion 42 connecting the circumferential ends of each non-magnetic division 39A. The intermediate portion 42 is shorter in the circumferential direction than the non-magnetic division 39A, and a non-magnetic hole 57 is formed on the opposite side of the intermediate portion 42 from the adjacent pole piece 37A (37). In other words, the pair of non-magnetic divisions 39A are radially spaced apart by the non-magnetic hole 57 when viewed in the axial direction.

[0033] According to the above configuration, the non-magnetic hole 57 can be used as a ventilation passage through which cooling air passes. This reduces the temperature rise in the adjacent non-magnetic body 38 and suppresses thermal deformation of the adjacent non-magnetic body 38A. The adjacent non-magnetic body 38A does not need to include the intermediate portion 42. In this case, the non-magnetic hole 57 is formed over the entire circumferential length of the adjacent non-magnetic body 38A. Furthermore, instead of functioning as a ventilation passage, the non-magnetic hole 57 may function as an insertion hole into which a rod member supporting the adjacent non-magnetic body 38A is inserted. If the rod member is cylindrical, the cylindrical hole formed inside the rod member can function as a ventilation passage.

[0034] Continuing with the description of the pole piece rotor 30A, the adjacent non-magnetic body 38A is formed of a plurality of prepregs 89 stacked in the radial direction. More specifically, the prepregs 89 have a plurality of first prepregs 81 that form each of the non-magnetic divided portions 39A and a plurality of second prepregs 82 that form the intermediate portion 42.

[0035] The buffer material 50A (50) of the pole piece rotor 30A includes a buffer main body 53A (53). The buffer main body 53A is plate-shaped and has a thickness in the circumferential direction. The buffer main body 53A abuts against the adjacent non-magnetic body 38A over the entire radial length of the adjacent non-magnetic body 38A. More specifically, the buffer main body 53A has a pair of first abutment surfaces 51A (51) that abut against the pair of non-magnetic divided portions 39A, respectively, and an intermediate abutment surface 59 that abuts against the intermediate portion 42.

[0036] According to the above configuration, the buffer material 50A can contact each of the pair of non-magnetic divided portions 39A, allowing thermal deformation of each non-magnetic divided portion 39A. This prevents damage to each non-magnetic divided portion 39A. Note that the adjacent non-magnetic body 38A does not need to include the intermediate portion 42. Even in this case, the above technical advantages can be obtained.

[0037] Continuing with the description of the pole piece rotor 30A, the pole piece rotor 30A includes a first adhesive layer 71 interposed between the adjacent non-magnetic body 38A and the buffer main body portion 53A. The first abutment surface 51A and the intermediate abutment surface 59 abut against the non-magnetic divided portion 39A and the intermediate portion 42, respectively, via the first adhesive layer 71.

[0038] The pole piece rotor 30A further includes a second adhesive layer 72, a third adhesive layer 73, and a fourth adhesive layer (not shown). The second adhesive layer 72 is interposed between the buffer body portion 53A and the adjacent pole piece 37A. The second adhesive layer 72 is interposed between the buffer body portion 53A and the adjacent pole piece 37A over the entire radial length of each of the buffer body portion 53A and the adjacent pole piece 37A. The third adhesive layer 73 is disposed on the outer peripheral surface of the inner cover 339, and the fourth adhesive layer is disposed on the inner peripheral surface of the outer cover 332. As a result, the inner cover 339 and the outer cover 332 are adhered to the adjacent pole piece 37A and the adjacent non-magnetic material 38A, respectively.

[0039] The pole piece rotor 30A includes the first adhesive layer 71, which deforms when the adjacent non-magnetic body 38A thermally deforms, thereby suppressing thermal distortion of the adjacent non-magnetic body 38A. This prevents damage to the adjacent non-magnetic body 38A even when temperature changes occur. The above technical advantages can be achieved even if the adjacent pole piece 37A does not include the second adhesive layer 72, the third adhesive layer 73, and the fourth adhesive layer.

[0040] The first adhesive layer 71, the second adhesive layer 72, the third adhesive layer 73, and the fourth adhesive layer are also provided in the pole piece rotors 30B to 30E described below. However, for ease of viewing, these adhesive layers are omitted from Figures 3B to 3E. These adhesive layers are not essential components of the present disclosure.

[0041] The linear expansion coefficient of the buffer material 50A (50) illustrated in FIG. 3A is greater than that of the adjacent pole piece 37A (37) and less than that of the plastic material forming the adjacent non-magnetic body 38A. For example, if a structure in which prepregs 89 are stacked in the radial direction is employed, the adjacent non-magnetic body 38A is prone to deformation in the radial direction. Therefore, it is preferable that the above-described linear expansion coefficient relationship hold at least in the radial direction. That is, the linear expansion coefficient of the buffer material 50A in the radial direction is greater than that of the adjacent pole piece 37A and less than that of the plastic material forming the adjacent non-magnetic body 38A. On the other hand, if a structure in which prepregs 89 are stacked in the circumferential direction is employed (not shown), the adjacent non-magnetic body 38A is prone to deformation at least in the circumferential direction. Therefore, it is preferable that the above-described linear expansion coefficient relationship hold at least in the circumferential direction.

[0042] With the above configuration, when a temperature change occurs in the pole piece rotor 30A, the buffer material 50A is more susceptible to thermal deformation than the adjacent pole piece 37A, but less susceptible to thermal deformation than the adjacent non-magnetic body 38A. This allows the buffer material 50A to deform appropriately to accommodate the thermal deformation of the adjacent non-magnetic body 38A, and prevents high thermal stress from occurring in the adjacent non-magnetic body 38A.

[0043] <Pole piece rotor 30B according to the second embodiment> Figure 3B shows a schematic diagram of a pole piece rotor 30B (30) according to the second embodiment. Among the components according to the second embodiment, descriptions of components similar to those illustrated in Figure 3A may be omitted or simplified.

[0044] The buffer material 50B (50) of the pole piece rotor 30B (30) includes a buffer main body portion 53B (53). The buffer main body portion 53B has a pair of first abutment surfaces 51B (51) that respectively abut against a pair of non-magnetic divided portions 39B (39) of the adjacent non-magnetic body 38B (38). The first abutment surfaces 51B are inclined relative to the radial direction. The angle (acute angle) at which the first abutment surfaces 51B are inclined relative to the radial direction is, for example, greater than or equal to 30° and less than or equal to 45°.

[0045] With the first contact surface 51B inclined with respect to the radial direction, the buffer main body 53B can deform in response to thermal deformation of the non-magnetic divided portion 39B, regardless of whether the non-magnetic divided portion 39B is thermally deformed in the circumferential direction or the radial direction, thereby preventing damage to each of the non-magnetic divided portions 39B.

[0046] An example of the direction in which the first abutment surfaces 51B are inclined will be described. In the example of FIG. 3B , the center of the adjacent non-magnetic body 38B (38) as viewed in the axial direction is defined as the non-magnetic center Cr. The non-magnetic center Cr is the center of the adjacent non-magnetic body 38B (38) in both the circumferential and radial directions. Each of the pair of first abutment surfaces 51B is inclined so that the further it moves toward the non-magnetic center Cr in the radial direction, the more it moves toward the non-magnetic center Cr in the circumferential direction.

[0047] According to the above configuration, the circumferential length of the nonmagnetic divided portion 39B increases as it moves away from the nonmagnetic center Cr in the radial direction, and therefore the amount of thermal deformation of the nonmagnetic divided portion 39B in the circumferential direction increases. Even in this case, the buffer material 50B can deform in response to the thermal deformation of the nonmagnetic divided portion 39B, thereby preventing damage to each nonmagnetic divided portion 39B.

[0048] As described above, the pole piece rotor 30B may further include adhesive layers such as a first adhesive layer 71 (see FIG. 3A) and a second adhesive layer 72 (see FIG. 3A). The first adhesive layer 71 is interposed between the first abutment surface 51B and the nonmagnetic dividing portion 39B, and the second adhesive layer 72 is interposed between the buffer main body portion 53B and the adjacent pole piece 37.

[0049] <Pole piece rotor 30C according to the third embodiment> Figure 3C shows a schematic diagram of a pole piece rotor 30C (30) according to the third embodiment. Among the components according to the third embodiment, descriptions of components similar to those illustrated in Figures 3A and 3B may be omitted or simplified.

[0050] The buffer material 50C (50) of the pole piece rotor 30C (30) includes a buffer main body portion 53C (53). The buffer main body portion 53C is located between the adjacent non-magnetic body 38C (38) and the adjacent pole piece 37. The adjacent non-magnetic body 38C includes a pair of non-magnetic dividing portions 39C (39), but does not include the intermediate portion 42 (see FIG. 3A).

[0051] The buffer material 50C (50) includes a buffer hole 60C (60), which is an opening extending in the axial direction in the buffer main body 53C. The buffer hole 60C penetrates the buffer main body 53C in the axial direction. With the above configuration, the rigidity of the buffer main body 53C is reduced, making the buffer main body 53C more susceptible to deformation. This further reduces thermal strain in the nonmagnetic divided portion 39C, further suppressing damage to the nonmagnetic divided portion 39C. Furthermore, because the buffer hole 60C penetrates the buffer main body 53C, the manufacturing process for forming the buffer hole 60C in the buffer material 50C can be simplified.

[0052] Continuing with the description of the pole piece rotor 30C, the buffer main body portion 53C has a pair of first abutment surfaces 51C (51) that respectively abut the pair of nonmagnetic divided portions 39C. Each of the first abutment surfaces 51C has a first end 111 on the nonmagnetic center Cr side when viewed in the axial direction.

[0053] The buffer hole portion 60C has a first recess 61 that recesses in the circumferential direction from the first end 111 side toward the adjacent pole piece 37 side. As an example, the first recess 61 is configured so that its radial dimension (dimension La) increases as it moves away from the first end 111 in the circumferential direction. However, the present disclosure is not limited to this, and the first recess 61 may be formed so that, for example, its radial dimension is the same regardless of its circumferential position. In this case, the first recess 61 is rectangular when viewed in the axial direction.

[0054] Because the buffer hole 60C has the first recess 61, the buffer main body 53C is particularly susceptible to deformation on the nonmagnetic center Cr side. For example, the first end 111, which is the portion of the buffer main body 53C located on the nonmagnetic center Cr side, is susceptible to radial deformation. This reduces thermal strain in the portion of the nonmagnetic divided portion 39C on the nonmagnetic center Cr side, thereby preventing damage to the nonmagnetic divided portion 39C. As a more specific example, the portion of the nonmagnetic divided portion 39C surrounded by the two-dot chain line M1 can thermally deform in the circumferential or radial direction while pushing aside the first end 111, thereby reducing thermal strain in that portion.

[0055] Furthermore, by configuring the first recess 61 so that the radial dimension (dimension La) increases as the distance from the first end 111 increases in the circumferential direction, the first recess 61 can be enlarged, further reducing the rigidity of the buffer main body 53C and thus further reducing the thermal strain of the non-magnetic divided portion 39C.

[0056] <Pole piece rotor 30D according to the fourth embodiment> Figure 3D is a schematic diagram of a pole piece rotor 30D (30) according to the fourth embodiment. Among the components according to the fourth embodiment, descriptions of components similar to those illustrated in Figures 3A to 3C may be omitted or simplified.

[0057] The adjacent non-magnetic body 38D (38) of the pole piece rotor 30D (30) does not have a non-magnetic hole 57 (see FIG. 3A), and a solid structure is adopted in which prepreg 89 is laminated over the entire radial length of the adjacent non-magnetic body 38D. However, the fourth embodiment is not limited to this, and the adjacent non-magnetic body 38D may have a pair of non-magnetic divided portions 39A (see FIG. 3A) arranged on either side of the non-magnetic hole 57.

[0058] The pole piece rotor 30D (30) includes a buffer material 50D (50), which includes a buffer main body portion 53D (53). The buffer main body portion 53D has a second abutment surface 52 that abuts against an adjacent pole piece 37D (37). The buffer hole portion 60D (60) includes a second recess 62 formed in the second abutment surface 52. The second recess 62 axially penetrates the buffer main body portion 53D.

[0059] Additionally, the adjacent pole piece 37D (37) of the pole piece rotor 30D includes a pole piece end face 101 that abuts against the second abutment surface 52, and a pole piece recess 102 formed in the pole piece end face 101. In this example, the space Sp defined by the pole piece recess 102 and the space S2 defined by the second recess 62 are in communication with each other.

[0060] The technical advantage of including the second recess 62 in the buffer hole 60D is explained below. Generally, the adjacent pole piece 37D is less susceptible to thermal deformation than the adjacent non-magnetic body 38D, and can exert a thermal deformation prevention effect on the adjacent non-magnetic body 38D. In this regard, according to the above-described configuration, the provision of the second recess 62 reduces the radial contact area between the buffer main body 53D and the adjacent pole piece 37D, thereby suppressing the effect of preventing thermal deformation on the adjacent non-magnetic body 38D. Therefore, thermal distortion of the adjacent non-magnetic body 38D can be reduced. The adjacent pole piece 37D does not necessarily need to include the pole piece recess 102. Even in this case, the above-described technical advantage can be obtained.

[0061] 3D is configured such that the radial dimension (dimension Lb) increases as the second recess 62 approaches the adjacent pole piece 37D in the circumferential direction. This configuration further reduces the radial contact range between the buffer main body 53D and the adjacent pole piece 37D.

[0062] <Pole piece rotor 30E according to the fifth embodiment> Fig. 3E is a schematic diagram of a pole piece rotor 30E (30) according to the fifth embodiment. Among the components according to the fifth embodiment, descriptions of components similar to those illustrated in Figs. 3A to 3D may be omitted or simplified.

[0063] The buffer material 50E (50) according to the fifth embodiment includes a buffer main body portion 53E (53) and an intervening portion 54. The intervening portion 54 extends from the buffer main body portion 53E along the circumferential direction on the side opposite the adjacent pole piece 37. The intervening portion 54 and the buffer main body portion 53E are integrally formed from the same material. The intervening portion 54 is radially sandwiched between a pair of nonmagnetic divided portions 39E (39) of the adjacent nonmagnetic body 38E (38). The adjacent nonmagnetic body 38E does not have a nonmagnetic hole 57 (see FIG. 3A ).

[0064] According to the above configuration, the pair of non-magnetic divided portions 39E can be joined via the intervening portion 54. Furthermore, the deformation of the intervening portion 54 can reduce thermal strain of the non-magnetic divided portions 39E, thereby suppressing damage to the non-magnetic divided portions 39E.

[0065] 3E includes a first non-magnetic contact surface 391 that contacts the first contact surface 51E (51) of the buffer main body 53E and a second non-magnetic contact surface 392 that contacts the interposition portion 54, and a non-magnetic connecting surface 395, which is a portion where the first non-magnetic contact surface 391 and the second non-magnetic contact surface 392 are connected, is an R-surface. Note that the non-magnetic connecting surface 395 may also be a C-surface (not shown).

[0066] According to the above configuration, the corners of the nonmagnetic dividing portion 39E are curved or rounded, which can prevent thermal stress from concentrating on the nonmagnetic dividing portion 39E. Furthermore, the layer of adhesive between the nonmagnetic connecting surface 395 and the buffer material 50E can be made thicker than the first adhesive layer 71 (see FIG. 4) and the fifth adhesive layer 75 (see FIG. 4), which will be described later, making it possible to avoid concentration of thermal stress.

[0067] 4 is a schematic diagram showing a more specific configuration of a buffer material 50E and an adjacent non-magnetic body 38E according to the fifth embodiment, in which the non-magnetic connecting surface 395 (see FIG. 3E) is not shown.

[0068] The buffer material 50E has a substantially symmetrical shape in the circumferential direction. More specifically, the buffer material 50E includes a pair of buffer main body portions 53E arranged side by side in the circumferential direction with the interposition portion 54 interposed therebetween. The first adhesive layer 71 described above is disposed between the buffer main body portion 53E and the nonmagnetic divided portion 39E, and the fifth adhesive layer 75 is disposed between the interposition portion 54 and the nonmagnetic divided portion 39E. The first adhesive layer 71 and the fifth adhesive layer 75 are integrally formed thermoplastic adhesives, and the buffer material 50E and the adjacent nonmagnetic body 38E are integrally formed. The first adhesive layer 71 and the fifth adhesive layer 75 may be rubber-based adhesives or elastomer sheets.

[0069] <Other Modifications> Fig. 5 is a schematic diagram showing a cushioning material 50 according to a modification. The cushioning hole 60 of the cushioning material 50 illustrated in the figure is a hollow portion extending in the axial direction inside the cushioning main body portion 53. If the cushioning material 50 is a resin molded product, it is possible to form such a hollow portion. This configuration may be applied to the cushioning hole portions 60C and 60D illustrated in Figs. 3C and 3D.

[0070] 6 is a schematic diagram showing the adjacent non-magnetic body 38. The adjacent non-magnetic body 38 may be formed of a single resin member instead of an FRP structure. In this case, the adjacent non-magnetic body 38 does not include a plurality of laminated prepregs 89. Furthermore, the buffer material 50 may be disposed on only one circumferential side of the adjacent non-magnetic body 38. Even in this case, it is possible to obtain the technical advantage of reducing thermal strain in the adjacent non-magnetic body 38.

[0071] <Summary> The contents described in the above-described embodiments can be understood, for example, as follows.

[0072] 1) A pole piece rotor (30) according to at least one embodiment of the present disclosure is a pole piece rotor comprising: a plurality of pole pieces (35) arranged at intervals in the circumferential direction; and a plurality of non-magnetic bodies (36) arranged alternately with the plurality of pole pieces in the circumferential direction, wherein the plurality of pole pieces and the plurality of non-magnetic bodies each include adjacent pole pieces (37) and adjacent non-magnetic bodies (38) that are adjacent to each other, and the pole piece rotor further comprises a buffer material (50) including a buffer main body portion (53) sandwiched between the adjacent pole pieces and the adjacent non-magnetic bodies, and the material forming the adjacent non-magnetic bodies includes a plastic material, and the Young's modulus of the buffer material is smaller than the Young's modulus of the plastic material.

[0073] According to the configuration of 1) above, the buffer material is more easily deformed than the plastic material of the adjacent non-magnetic body. When a temperature change occurs in the pole piece rotor, the adjacent non-magnetic body can thermally deform while deforming the buffer material, thereby reducing the thermal stress generated in the adjacent non-magnetic body. This results in a pole piece rotor that can suppress damage to the non-magnetic body even when a temperature change occurs.

[0074] 2) In some embodiments, in the pole piece rotor described in 1) above, the adjacent non-magnetic bodies include a pair of non-magnetic divided portions (39) arranged at a radial interval, and the buffer main body portion has a pair of first abutment surfaces (51) that abut against the pair of non-magnetic divided portions, respectively.

[0075] According to the configuration of 2), the cushioning material can contact each of the pair of non-magnetic divided portions, allowing each non-magnetic divided portion to deform due to heat, thereby preventing damage to each non-magnetic divided portion.

[0076] 3) In some embodiments, in the pole piece rotor according to 2) above, the pair of first abutment surfaces are each inclined with respect to the radial direction.

[0077] According to the configuration of 3), even if the non-magnetic divided portions are thermally deformed in either the circumferential or radial direction, the buffer main body can deform in response to the thermal deformation, thereby preventing damage to each of the non-magnetic divided portions.

[0078] 4) In some embodiments, in a pole piece rotor as described in 2) or 3) above, the center of the adjacent non-magnetic body when viewed in the axial direction is defined as a non-magnetic center (Cr), and each of the pair of first abutment surfaces is inclined so as to move toward the non-magnetic center in the circumferential direction as it moves toward the non-magnetic center in the radial direction.

[0079] According to the configuration of 4) above, the circumferential length of each non-magnetic divided portion is increased, which increases the amount of thermal deformation of the non-magnetic divided portion in the circumferential direction. Even in this case, the buffer material can deform in accordance with the thermal deformation of the non-magnetic divided portion, thereby preventing damage to each non-magnetic divided portion.

[0080] 5) In some embodiments, the pole piece rotor is as described in 3) or 4) above, wherein the buffer material includes a buffer hole portion (60) which is an opening or hollow portion extending axially in the buffer main body portion.

[0081] According to the configuration of 5), the rigidity of the buffer main body is reduced, making the buffer main body more susceptible to deformation, thereby further reducing thermal strain in the non-magnetic divided portion and further suppressing damage to the non-magnetic divided portion.

[0082] 6) In some embodiments, in the pole piece rotor described in 5) above, the pair of first abutment surfaces each have a first end (111) on the non-magnetic center (Cr) side, which is the center of the adjacent non-magnetic body, when viewed in the axial direction, and the buffer hole portion has a first recess (61) recessed in the circumferential direction from the first end side toward the adjacent pole piece side.

[0083] According to the configuration of 6), the buffer main body is particularly susceptible to deformation at the non-magnetic center side, which reduces thermal strain at the non-magnetic center side of the non-magnetic divided portion and suppresses damage to the non-magnetic divided portion.

[0084] 7) In some embodiments, in the pole piece rotor according to 6) above, the first recess is configured so that the radial dimension thereof increases as it becomes farther from the first end in the circumferential direction.

[0085] According to the above configuration 7), the first recess can be enlarged, further reducing the rigidity of the buffer main body, thereby further reducing the thermal strain in the non-magnetic divided portion.

[0086] 8) In some embodiments, a pole piece rotor as described in any of 2) to 7) above, wherein the buffer body portion has a second abutment surface (52) that abuts against the adjacent pole piece, the buffer material includes a buffer hole portion (60) that is an opening or hollow portion extending axially in the buffer body portion, and the buffer hole portion includes a second recess (62) formed in the second abutment surface.

[0087] Generally, adjacent magnetic pole pieces are less susceptible to thermal deformation than adjacent non-magnetic materials, and can exert a thermal deformation-preventing effect on the adjacent non-magnetic materials. In this regard, according to the configuration of 8) above, the provision of the second recess reduces the radial contact area between the buffer main body and the adjacent magnetic pole piece, thereby suppressing the effect of preventing thermal deformation on the adjacent non-magnetic materials. Therefore, thermal distortion of the adjacent non-magnetic materials can be reduced.

[0088] 9) In some embodiments, in the pole piece rotor according to 8) above, the second recess is configured so that the radial dimension thereof increases as it approaches the adjacent pole piece in the circumferential direction.

[0089] According to the above configuration 9), the contact area between the buffer main body and the adjacent pole piece in the radial direction can be further reduced.

[0090] 10) In some embodiments, the pole piece rotor according to any one of 5) to 9) above, wherein the buffer hole portion penetrates the buffer main body portion in the axial direction.

[0091] According to the above configuration 10), the manufacturing process for forming the buffer holes in the buffer material can be simplified.

[0092] 11) In some embodiments, in a pole piece rotor described in any one of 2) to 10) above, the buffer material includes an intervening portion (54) that extends from the buffer main body portion along the circumferential direction to the opposite side from the adjacent pole piece side and is sandwiched between the pair of non-magnetic dividing portions.

[0093] According to the configuration of 11), the pair of non-magnetic divided parts can be joined via the intervening part. Furthermore, the deformation of the intervening part can reduce thermal strain in the non-magnetic divided parts, thereby suppressing damage to the non-magnetic divided parts.

[0094] 12) In some embodiments, in the pole piece rotor described in 11) above, each of the non-magnetic divided portions includes a first non-magnetic abutment surface (391) that abuts against the first abutment surface, and a second non-magnetic abutment surface (392) that abuts against the intervening portion, and a non-magnetic connecting surface (395) that is the portion where the first non-magnetic abutment surface and the second non-magnetic abutment surface are connected is a C surface or an R surface.

[0095] According to the configuration of 12) above, the corners of the non-magnetic divided portion are curved or rounded, so that concentration of thermal stress on the corners of the non-magnetic divided portion can be suppressed.

[0096] 13) In some embodiments, the pole piece rotor described in any one of 1) to 10) above further comprises an adhesive layer (first adhesive layer 71) interposed between the adjacent non-magnetic body and the buffer material.

[0097] According to the configuration of 13), when the adjacent non-magnetic material is thermally deformed, the adhesive layer is deformed, so that the thermal strain of the adjacent non-magnetic material can be suppressed, thereby suppressing damage to the adjacent non-magnetic material even when temperature changes occur.

[0098] 14) In some embodiments, the pole piece rotor is described in any one of 2) to 10) above, wherein the pair of non-magnetic divided portions are arranged in the radial direction with a gap (non-magnetic hole 57) between them when viewed in the axial direction.

[0099] According to the configuration of 14) above, the gap between the pair of non-magnetic divided parts can be used as a ventilation passage, thereby suppressing thermal deformation of the non-magnetic divided parts.

[0100] 15) In some embodiments, a pole piece rotor as described in any one of 1) to 14) above, wherein the linear expansion coefficient of the buffer material is greater than the linear expansion coefficient of the adjacent pole piece and less than the linear expansion coefficient of the plastic material.

[0101] According to the configuration of 15) above, when a temperature change occurs in the pole piece rotor, the buffer material is more susceptible to thermal deformation than the adjacent pole pieces, but less susceptible to thermal deformation than the adjacent non-magnetic material. This allows the buffer material to deform appropriately to accommodate the thermal deformation of the adjacent non-magnetic material, and prevents high thermal stress from occurring in the adjacent non-magnetic material.

[0102] 16) A magnetic gear rotating machine (1) according to at least one embodiment of the present disclosure comprises: a pole piece rotor (30) according to any one of 1) to 15) above; a magnet rotor (10) positioned radially inward relative to the plurality of pole pieces and the plurality of non-magnetic bodies; and a stator (20) positioned radially outward relative to the plurality of pole pieces and the plurality of non-magnetic bodies.

[0103] The configuration 16) above provides the same technical advantages as the configuration 1).

[0104] 1: Magnetic gear rotating machine 9: External device 10: Magnet rotor 15: Rotor core 16: Electrical system 18: Rotating shaft 19: Magnet 20: Stator 22: Stator core 27: Stator coil 29: Stator magnet 30: Pole piece rotor 31: First connecting portion 32: Second connecting portion 33: Ring unit 35: Pole piece 36: Non-magnetic body 37: Adjacent pole piece 38: Adjacent non-magnetic body 39: Non-magnetic dividing portion 42: Intermediate portion 50: Cushioning material 51: First contact surface 52: Second contact surface 53: Cushioning main body portion 54: Interposition portion 56: Pole piece hole 57: Non-magnetic hole 59: Intermediate contact surface 60: Cushioning hole portion 61: First recess 62: Second recess 71: First adhesive layer (adhesive layer) 72: Second adhesive layer 73: Third adhesive layer 75: Fifth adhesive layer 81: First prepreg 82: Second prepreg 89: Prepreg 101: Pole piece end face 102: Pole piece recess 111: First end 332: Outer cover 339: Inner cover 391: First non-magnetic abutment surface 392: Second non-magnetic abutment surface 395: Non-magnetic connecting surface B1: Bearing Cr: Non-magnetic center G1: Inner air gap G2: Outer air gap La, Lb: Dimensions M1: Two-dot chain line S: Axis line Sp, S2: Space

Claims

1. A pole piece rotor comprising: a plurality of pole pieces spaced apart in the circumferential direction; and a plurality of non-magnetic bodies arranged alternately with the plurality of pole pieces in the circumferential direction, wherein the plurality of pole pieces and the plurality of non-magnetic bodies each include adjacent pole pieces and adjacent non-magnetic bodies that are adjacent to each other, the pole piece rotor further comprising a buffer material including a buffer main body portion sandwiched between the adjacent pole pieces and the adjacent non-magnetic bodies, wherein the material forming the adjacent non-magnetic bodies includes a plastic material, and the Young's modulus of the buffer material is smaller than the Young's modulus of the plastic material.

2. A pole piece rotor as set forth in claim 1, wherein the adjacent non-magnetic bodies include a pair of non-magnetic divided parts spaced apart from each other in the radial direction, and the buffer main body part has a pair of first abutment surfaces that respectively abut against the pair of non-magnetic divided parts.

3. The pole piece rotor according to claim 2, wherein each of the pair of first abutment surfaces is inclined with respect to the radial direction.

4. A pole piece rotor as described in claim 2 or 3, wherein the center of the adjacent non-magnetic body when viewed in the axial direction is defined as the non-magnetic center, and each of the pair of first abutment surfaces is inclined so as to approach the non-magnetic center in the circumferential direction as it approaches the non-magnetic center in the radial direction.

5. The pole piece rotor according to claim 3, wherein the buffer material includes a buffer hole portion which is an opening or hollow portion extending axially in the buffer body portion.

6. A pole piece rotor as described in claim 5, wherein each of the pair of first abutment surfaces has a first end on the non-magnetic center side which is the center of the adjacent non-magnetic body when viewed in the axial direction, and the buffer hole portion has a first recess that is recessed from the first end side toward the adjacent pole piece side in the circumferential direction.

7. The pole piece rotor according to claim 6, wherein the first recess is configured so that the radial dimension thereof increases as it moves away from the first end in the circumferential direction.

8. A pole piece rotor as described in claim 2 or 3, wherein the buffer body portion has a second abutment surface that abuts against the adjacent pole piece, the buffer material includes a buffer hole portion which is an opening or hollow portion extending axially in the buffer body portion, and the buffer hole portion includes a second recess formed in the second abutment surface.

9. The pole piece rotor according to claim 8, wherein the second recess is configured such that the radial dimension thereof becomes longer as it approaches the adjacent pole piece in the circumferential direction.

10. The pole piece rotor according to claim 5, wherein the buffer hole portion penetrates the buffer body portion in the axial direction.

11. A pole piece rotor as described in claim 2 or 3, wherein the buffer material includes an intervening portion extending from the buffer main body portion along the circumferential direction to the opposite side to the adjacent pole piece and sandwiched between the pair of non-magnetic divided portions.

12. A pole piece rotor as described in claim 11, wherein each of the non-magnetic divided portions includes a first non-magnetic abutment surface that abuts against the first abutment surface and a second non-magnetic abutment surface that abuts against the intermediate portion, and a non-magnetic connecting surface that is a portion where the first non-magnetic abutment surface and the second non-magnetic abutment surface are connected is a C surface or an R surface.

13. A pole piece rotor according to any one of claims 1 to 3, further comprising an adhesive layer interposed between the adjacent non-magnetic body and the cushioning material.

14. A pole piece rotor according to claim 2 or 3, wherein the pair of non-magnetic divided portions are arranged in the radial direction with a gap therebetween when viewed in the axial direction.

15. A pole piece rotor according to any one of claims 1 to 3, wherein the linear expansion coefficient of the buffer material is greater than the linear expansion coefficient of the adjacent pole pieces and less than the linear expansion coefficient of the plastic material.

16. A magnetic gear rotating machine comprising: a pole piece rotor according to any one of claims 1 to 3; a magnet rotor positioned radially inward relative to said plurality of pole pieces and said plurality of non-magnetic bodies; and a stator positioned radially outward relative to said plurality of pole pieces and said plurality of non-magnetic bodies.

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