Magnetizing device

Abstract

A magnetizing device (60) comprises a coil (61), a rope (63) (restraining member), and a molded resin body. The coil (61) is wound around a center line (C1) and generates a magnetic field for magnetization upon energization. The rope (63) is a non-magnetic material that extends annularly around the winding center line (C1) of the coil (61), and restrains the coil (61) from the outer peripheral side of the winding. The molded resin body molds the coil (61) together with the rope (63). The material of the rope (63) is stronger than the material of the molded resin body.

Description

Magnetizing device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2024-147382 filed in Japan on August 29, 2024, and the contents of the original application are incorporated by reference in their entirety.

[0002] The disclosure in this specification relates to a magnetizing device.

[0003] Patent Document 1 discloses a magnetizing device that concentrates a magnetic field on a magnetic body to be magnetized, thereby magnetizing the body. This magnetizing device includes a coil and a core. The coil is wound around the core. The core functions as a yoke that concentrates the magnetic field generated when current is passed through the coil. The magnetic body is magnetized by placing it on the path of the magnetic field.

[0004] A hoop force acts on this type of coil when electricity is applied. Hoop force is a force that acts on the coil in a direction that expands the diameter of the windings. In particular, the greater the power supplied to the coil to strongly magnetize it, the greater the hoop force. A large hoop force can cause damage to the coil, such as deformation or breakage.

[0005] Therefore, in the magnetizing device, a convex portion is formed on the resin body that molds the coil, and a concave portion is formed on the core pressing portion that determines the position of the core. When the coil tries to expand in diameter due to the hoop force, the convex portion engages with the concave portion, thereby suppressing the expansion of the coil in diameter.

[0006] Japanese Patent Application Laid-Open No. 2018-64417

[0007] However, as the required magnetization capacity increases, the hoop force also increases along with the increase in the power supplied to the coil, which in turn increases the force acting on the convex and concave portions, necessitating the enlargement of the resin body and core pressing portion to withstand this force.

[0008] One disclosed object is to provide a magnetizing device that can suppress coil damage caused by hoop force while suppressing an increase in the size of the device.

[0009] In order to achieve the above object, a magnetizing device according to one aspect of the present disclosure includes: a coil wound around a center line and generating a magnetic field for magnetization when current is applied; a restraining member made of a non-magnetic material extending annularly around the center line and restraining the coil from the outer periphery of the winding; and a molded resin body that molds the coil together with the restraining member, wherein the material of the restraining member is stronger than the material of the molded resin body.

[0010] According to the magnetizing device disclosed herein, the coil is constrained from the outer periphery of the winding by a constraining member that is stronger than the molded resin body, which makes it possible to prevent the device from becoming too large and to prevent coil damage due to hoop force.

[0011] The reference numbers in parentheses above merely indicate an example of the correspondence with specific configurations in the embodiments described below, and do not in any way limit the technical scope.

[0012] 1 is a cross-sectional view of a rotating machine equipped with a magnet to be magnetized in the first embodiment. FIG. 2 is a front view of the rotor shown in FIG. 1 as seen from the axial direction. FIG. 3 is a perspective view schematically showing the magnetizing device according to the first embodiment and the magnet to be magnetized. FIG. 4 is an enlarged view of FIG. 3. FIG. 5 is a perspective view partially showing the magnetizing device according to the first embodiment. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5. FIG. 7 is a cross-sectional view schematically showing the positional relationship between the magnetizing device according to the first embodiment and a rotating machine equipped with a magnet to be magnetized. FIG. 8 is a schematic view showing the magnetization procedure in the magnetizing device according to the first embodiment. FIG. 9 is a diagram schematically showing the positional relationship between the Halbach array of the magnet to be magnetized and the coil of the magnetizing device in the first embodiment. FIG. 10 is a cross-sectional view of the magnetizing device according to the second embodiment as seen from the direction of the rotation center line. FIG. 11 is a perspective view showing a part of a yoke according to the second embodiment, illustrating the positional relationship between the rotation center line of the rotor and the winding center line of the coil.

[0013] Hereinafter, several embodiments for carrying out the present disclosure will be described with reference to the drawings. In addition to the combination of parts specifically indicated as being combinable in each embodiment, it is also possible to combine parts of embodiments even if not specifically indicated, provided that there is no particular problem with the combination.

[0014] First Embodiment A magnetizing device according to this embodiment magnetizes a magnet included in a rotating machine 10 shown in FIG. 1 . The rotating machine 10 functions as a power source for rotating a propeller of an aircraft and is mounted on the aircraft. The aircraft in question is a vertical take-off and landing (eVTOL) aircraft. The propeller in question may be a propeller that generates flight thrust during vertical take-off and landing or hovering, or may be a propeller that generates flight thrust during horizontal cruising.

[0015] 1 is a motor that is rotationally driven by a supply of three-phase AC power. The rotating machine 10 includes a housing 20, a stator 30, a rotor 40, a rotating shaft 50, and a bearing 50B.

[0016] The housing 20 is a metal enclosure that houses the stator 30 and the rotor 40. A pair of bearings 50B are attached to the housing 20. The bearings 50B hold the rotating shaft 50 in the housing 20 in a rotatable state.

[0017] The stator 30 has a stator core 31 and windings 32. The stator core 31 is configured by stacking multiple electromagnetic steel plates in the direction of the rotation axis. The direction of the rotation axis refers to the direction along the rotation center line C of the rotation axis 50. The windings 32 are wound around the stator core 31. The windings 32 are configured by star-connecting or delta-connecting U-phase coils, V-phase coils, and W-phase coils. The on / off of current to each phase is controlled by a control device (not shown). The magnetic field generated by the current flowing through the windings 32 is emitted to the outside of the stator 30 through the stator core 31. The emitted magnetic field rotates when the current to each phase coil is switched on and off. In this way, the stator 30 generates a rotating magnetic field.

[0018] The stator 30 is formed in a cylindrical shape surrounding the rotating shaft 50. The outer peripheral surface of the stator 30 and the inner peripheral surface of the housing 20 are tightly attached with resin 33. Metallic heat dissipation fins 21 are attached to the outer peripheral surface of the housing 20. The heat dissipation fins 21 are plate-shaped and extend in the rotational axis direction and the rotational diameter direction. The heat dissipation fins 21 are provided in at least the range of the rotational axis direction where the windings 32 are provided. A plurality of heat dissipation fins 21 are arranged in the circumferential direction. An air-cooling fan (not shown) is disposed at one axial end of the rotating machine 10. This air-cooling fan causes cooling air to flow in the rotational axis direction along the outer peripheral surface of the housing 20. This cooling air exchanges heat with the heat dissipation fins 21.

[0019] The windings 32 generate heat when current is applied. This heat raises the temperature of the stator 30, and ultimately the rotor 40 and the rotating shaft 50. Such a rise in temperature of the rotating machine 10 leads to a decrease in rotational output. In particular, an increase in the electrical resistance of the windings 32 leads to a decrease in rotational output. Therefore, in this embodiment, the resin 33 is used to tightly attach the windings 32 to the housing 20, thereby transferring heat from the windings 32 to the stator 30 and dissipating the heat from the stator 30 through the heat dissipation fins 21. This suppresses a rise in temperature of the rotating machine 10.

[0020] The rotor 40 is disposed so as to provide an axial gap with respect to the stator 30. In this embodiment, the rotors 40 are disposed on both sides of the stator 30 in the direction of the rotation axis. The rotor 40 has a plurality of magnets 41 and a rotor main body 42.

[0021] As shown in FIG. 2 , the magnets 41 are arranged in a ring shape at equal intervals in the circumferential direction of rotation. The multiple magnets 41 are magnetized in a Halbach array. The surfaces of the magnets 41 that face the stator 30 are exposed from the rotor main body 42. The axial gap described above is formed between the exposed surfaces of the magnets 41 and the stator core 31. The multiple stator cores 31 are arranged in a ring shape around the rotation center line C in the same manner as the magnets 41. The multiple stator cores 31 are disposed opposite the multiple magnets 41 arranged in a ring shape. The stator core 31 concentrates the magnetic field generated when current is passed through the windings 32.

[0022] The rotor body 42 has a disk shape and holds the magnet 41. A shaft hole 42a, through which the rotating shaft 50 is inserted, is formed in the center of the rotor body 42. An air gap 42g, as shown in FIG. 1, is formed between the inner circumferential surface of the shaft hole 42a and the outer circumferential surface of the rotating shaft 50 that faces the inner circumferential surface of the shaft hole 42a. A plurality of through holes 42b, through which bolts BT are inserted, are formed in the rotor body 42 around the shaft hole 42a. The plurality of through holes 42b are formed at equal intervals in the circumferential direction.

[0023] The rotating shaft 50 is made of metal and has a shaft main body 51 and a fastening portion 52. A portion of the shaft main body 51 is inserted into the shaft hole 42a. A portion of the shaft main body 51 is supported by a bearing 50B. The fastening portion 52 extends radially from the shaft main body 51 and faces the rotor main body 42. The fastening portion 52 has a plurality of threaded holes formed therein for fastening with bolts BT. By fastening with the bolts in this manner, the rotating shaft 50 is connected to the two rotors 40 and rotates integrally with the rotors 40.

[0024] 3, the magnetization device 60 includes a coil 61, a yoke 62, a rope 63 (restraining member), and a molded resin body 64. The multiple yokes 62 are arranged in a ring shape at equal intervals. The yokes 62 are arranged in a ring shape similar to the stator core 31. The multiple yokes 62 are arranged in a positional relationship facing the multiple magnets 41 included in the rotating machine 10. It can also be said that the multiple yokes 62 are arranged in a ring shape around a center line corresponding to the rotation center line C.

[0025] The multiple yokes 62 do not have to be arranged in a ring shape, but may be arranged on an arc around the center line. The number of yokes 62 arranged is preferably three or more. The multiple yokes 62 arranged are preferably arranged in a direction perpendicular to the center line C1.

[0026] A coil 61 is wound around each yoke 62. The coil 61 is wound around a center line C1 parallel to the center line. The coil 61 generates a magnetic field for magnetization when current is applied. The yoke 62 is made of metal and concentrates the magnetic field generated by the coil 61. A coil coating (not shown) is formed on the surface of the coil 61. Specific examples of the coil coating include polyimide and polyamide. The coil coating is preferably 100 μm or less. The wire of the coil 61 according to this embodiment has a rectangular cross section (see FIG. 6), but may also have a circular cross section (see FIG. 7).

[0027] As shown in Fig. 4, a rope 63 is wound around each yoke 62 from above the coil 61. Note that the rope 63 is not shown in Fig. 3. The rope 63 is wound around the center line C1. The rope 63 restrains the coil 61 from the outer periphery of the wound coil.

[0028] When current is applied to the coil 61, a hoop force acts on the coil 61. The hoop force is a force acting on the coil in a direction that increases (expands) the diameter of the coil windings, as shown by the arrow in FIG. 4. If the coil 61 expands in diameter due to the hoop force, damage to the coil 61, such as plastic deformation or breakage, may occur. The rope 63 surrounds and restrains the coil 61 against this hoop force. As a result, the restraint of the rope 63 suppresses the expansion of the diameter of the coil 61.

[0029] The rope 63 is made of a resin containing a fiber material, which improves the tensile strength of the rope 63. Specific examples of the fiber material include carbon fiber, aramid fiber, and glass fiber. The rope 63 is made of a non-magnetic material that is electrically insulating. The rope 63 has a cross-sectional area that is sufficiently smaller than the cross-sectional area of ​​the coil 61, and is wound around the coil 61, entering the gaps between the coils 61. The number of turns of the rope 63 is greater than the number of turns of the coil 61.

[0030] The material of rope 63 is stronger than the material of molded resin body 64. For example, test pieces for a tensile test are made from each of the material of rope 63 and the material of molded resin body 64. The tensile strengths obtained in the tensile test using these test pieces are that of rope 63 is stronger than that of molded resin body 64.

[0031] In short, the hoop force is countered by surrounding the magnetizing coil 61 with a non-magnetic, high-resistance, high-tensile-strength rope 63 (e.g., CFRP). CFRP stands for Carbon Fiber Reinforced Plastic. CFRP is a high-strength, lightweight composite material made by combining carbon fiber and resin (e.g., epoxy resin). Note that before winding the rope 63 around the coil 61, the coil 61 may be temporarily fixed with an impregnating material.

[0032] As shown in Figures 5 and 6, molded resin body 64 is a resin that molds coil 61 and yoke 62 together with rope 63. Note that illustration of molded resin body 64 is omitted in Figures 3 and 4. Molded resin body 64 seals the entire coil 61 together with rope 63. However, the electrically connected portion of coil 61 is exposed from molded resin body 64. Before being molded with molded resin body 64, rope 63 wound around yoke 62 may be temporarily fixed by being molded with a resin different from molded resin body 64.

[0033] The molded resin body 64 functions to hold the plurality of yokes 62, thereby integrating the plurality of yokes 62 and fixing the relative positions of the yokes 62. Furthermore, the molded resin body 64 functions to integrate the yokes 62 and the ropes 63, and also to protect the ropes 63 from the outside.

[0034] As shown in Figure 7, the magnetization device 60 includes a heat insulator 65 (buffer material). The heat insulator 65 is attached to the yoke 62 or the molded resin body 64. The heat insulator 65 is disposed between the magnet 41 to be magnetized and the yoke 62. The heat insulator 65 prevents the heat of the heated magnet 41 from being transferred to the magnetization device 60. In this embodiment, the heat insulator 65 is attached to the magnetization device 60, but it may also be attached to the magnet 41.

[0035] Here, during magnetization, in addition to the hoop force, an attractive force is generated between the magnetizer 60 and the magnet 41. If this attractive force causes direct contact between the magnet 41 and the magnetizer 60, it could lead to damage to the magnet 41 or the magnetizer 60. The heat insulating material 65 prevents such contact. In other words, the heat insulating material 65 also functions as a buffer material. It is desirable that the material for the heat insulating material 65 is one that has excellent insulating and cushioning properties. A specific example of the material for the heat insulating material 65 is fluororubber. Note that the heat insulating material 65 is not shown in Figures 3 to 5. Furthermore, in Figure 7, the coil 61, which has a rectangular cross section, is schematically represented as having a circular cross section.

[0036] As shown in FIG. 8 , the magnetization device 60 includes a heater 70 and an arm 80. The heater 70 and the arm 80 are not shown in FIGS. 3 to 7 . The arm 80 can detachably mount the magnet 41 to be magnetized. In this embodiment, the magnet 41 is attached to the arm 80 while being attached to the rotor main body 42. That is, the arm 80 holds the magnet 41 together with the rotor 40. The arm 80 can move while holding the magnet 41. For example, as shown by the arrows in FIG. 8 , the arm 80 can move to a position facing the heater 70 and a position facing the yoke 62. Furthermore, the arm 80 can rotate the rotor 40 about the rotation center line C, thereby adjusting the rotational position of the rotor 40.

[0037] The heater 70 heats the magnet 41 to be magnetized. Some high-power magnets, such as samarium-cobalt magnets, are easier to magnetize when heated. Therefore, before magnetization (magnetization process) is performed by energizing the coil 61, the heater 70 heats the magnet 41 (heating process). In other words, the arm 80 moves to a position opposite the heater 70, performs the heating process there, and then moves to a position opposite the yoke 62 to perform the magnetization process.

[0038] As shown in Figure 9, in the magnetization process, the arm 80 rotates the rotor 40 so that two magnets 41 face three yokes 62. Thereafter, the three yokes 62 simultaneously magnetize the two magnets 41 facing the yokes 62. Note that the number of magnets 41 to be simultaneously magnetized is not limited to two, and may be three or more. However, the number of yokes 62 used when simultaneously magnetizing is an odd number, and the number of magnets 41 to be simultaneously magnetized is one less than the number of yokes 62.

[0039] The dotted arrows in Figure 9 indicate the direction of the magnetic field B concentrated in the yoke 62. As shown in the figure, the directions of the magnetic fields B generated from adjacent yokes 62 are opposite to each other. For example, the direction of current flow is set to be opposite between the coil 61N wound around the yoke 62N located in the center of the three yokes 62 and the coil 61S wound around the yokes 62S at both ends. As a result, the directions of the adjacent magnetic fields B are set to be opposite to each other.

[0040] In the example of Fig. 9, magnetic field B emitted from yoke 62N passes through the center of two-pole magnets 41N and 41S, and then passes through both ends of magnets 41N and 41S in opposite directions. As a result, magnets 41N and 41S are magnetized so that the magnetization direction rotates from the center to both ends inside, as shown by the solid arrows in Fig. 9. In other words, north-pole magnet 41N and south-pole magnet 41S are magnetized simultaneously so as to form a Halbach array.

[0041] <Operation and Effect> As described above, according to the present embodiment, the magnetizing device 60 includes the rope 63 (restraining member) and the molded resin body 64. The rope 63 is a non-magnetic material that extends in an annular shape around the winding center line C1 of the coil 61 and restrains the coil 61 from the outer periphery of the winding. The molded resin body 64 molds the coil 61 together with the rope 63. The material of the rope 63 is stronger than the material of the molded resin body 64. As a result, the coil 61 is restrained from the outer periphery of the winding by the rope 63, which is stronger than the molded resin body 64. Therefore, with a simple configuration in which the coil 61 is simply surrounded by the rope 63 from the outer periphery, damage to the coil due to hoop force can be suppressed.

[0042] Furthermore, in this embodiment, the wire of the coil 61 has a rectangular cross section. The rope 63 is in contact with the rectangular surface of the wire on the outer circumferential surface of the coil 61. The coil 61 having a rectangular cross section can improve the space factor and the output of the magnetizing device. In this case, the hoop force is increased, and therefore the above-mentioned effect of providing the restraining member is preferably exerted.

[0043] Furthermore, in this embodiment, at least three yokes 62 are arranged in a direction perpendicular to the center line C1. The odd number of yokes 62N, 62S simultaneously magnetize the magnets 41N, 41S, which is one less than the number of yokes 62. This allows magnetization to be performed more efficiently than when the magnets 41 are magnetized one by one, improving the manufacturing efficiency of the rotor 40.

[0044] Furthermore, in this embodiment, the magnetic fields concentrated in adjacent yokes 62 are oriented in opposite directions. In addition, the multiple magnets 41 are magnetized to form a Halbach array. Therefore, by passing current through the coil 61 once, the multiple magnets 41 can be simultaneously magnetized in a Halbach array. This allows for efficient production of Halbach array magnets 41.

[0045] Furthermore, in this embodiment, the magnetizing device 60 includes a heater 70 that heats the magnet 41. Therefore, when a high-power magnet that is easier to magnetize when heated, such as a samarium-cobalt magnet, is to be magnetized, the magnetization efficiency can be improved.

[0046] Furthermore, in this embodiment, the magnetizing device 60 includes a heat insulating material 65 located between the magnet 41 and the coil 61. This prevents heat from being transferred from the magnet 41 heated by the heater 70 to the coil 61. This prevents an increase in electrical resistance due to a rise in temperature of the coil 61, improving magnetization efficiency. Furthermore, the provision of the heat insulating material 65 also prevents thermal damage to the coating of the coil 61.

[0047] Furthermore, in this embodiment, a buffer material is provided between the magnet 41 and the coil 61. Therefore, even if the distance between the magnet 41 and the magnetizing device 60 is made sufficiently small, the risk of the magnet 41 and the magnetizing device 60 coming into contact and being damaged can be reduced. In other words, by providing the buffer material, the distance between the magnet 41 and the magnetizing device 60 can be made shorter. Therefore, the magnetic field can more easily reach the magnet 41, improving magnetization efficiency. Moreover, since the heat insulating material 65 also serves as a buffer material, the number of parts can be reduced.

[0048] Furthermore, in this embodiment, the magnets 41 included in the rotor 40 of the axial gap motor (rotating machine 10) are to be magnetized. The multiple coils 61 are arranged in a ring shape and are oriented so that their center lines C1 are parallel to one another. Therefore, the multiple magnets 41 can be magnetized by the magnetizing device 60 while they are still attached to the rotor 40.

[0049] Furthermore, in this embodiment, the restraining member is made of a resin containing a fiber material. For example, when a fiber-reinforced plastic such as CFRP is used for the rope 63, the fiber-reinforced plastic has excellent electrical insulation and strength. This makes it easy to arrange multiple coils 61 in close proximity. Another advantage of fiber-reinforced plastic is that it is less likely to generate induced current, which can cause power loss.

[0050] Furthermore, in this embodiment, the restraining member is in the form of a rope that is wound around the center line C1 from the outer periphery of the coil 61. Therefore, a restraining member with a small size and simple structure can be realized.

[0051] Second Embodiment The magnetization device 60 according to the first embodiment magnetizes the magnet 41 included in the rotor 40 of an axial gap motor. In contrast, in this embodiment, as shown in Fig. 10, the magnetization target is the magnet 41R included in the rotor of a radial gap motor. Note that the solid arrows in the figure indicate the magnetization direction, and the magnet 41R is magnetized to form a Halbach array.

[0052] The yoke 62 according to this embodiment is also referred to as teeth. At least three teeth are arranged side by side in the circumferential direction of the rotation center line C. The teeth extend in the radial direction of the rotor 40 toward the rotation center line C. The multiple teeth are provided at equal intervals in the circumferential direction. The multiple teeth are connected by an annular portion 62a. The annular portion 62a is shaped to extend in an annular shape around the rotation center line C. Note that the annular portion 62a may be arc-shaped.

[0053] A coil 61 is wound around each tooth. In other words, the direction in which the teeth extend (the rotor radial direction) coincides with the winding center line C1 of the coil 61. Slots 62c are formed between adjacent teeth. A portion of the coil 61 wound around the tooth is disposed in the slot 62c. The multiple slots 62c are disposed at equal intervals in the circumferential direction of the rotation center line C.

[0054] The coils 61 wound around the slots 62c are arranged in an annular shape around the rotation center line C. If the annular portion 62a is arc-shaped, the wound coils 61 will be arranged in an arc-like shape rather than in an annular shape. As shown in Figures 10 and 11, the multiple coils 61 are arranged in a direction such that their center lines C1 pass through the rotation center line C.

[0055] The rope 63 (restraint member) is a non-magnetic material that extends in a ring shape around the center line C1 and restrains the coil 61 from the outer periphery of the wound coil 61. In other words, the rope 63 is also wound around the teeth in the same manner as the coil 61, and a portion of the rope 63 is disposed in the slot 62c.

[0056] In this embodiment, similarly to the first embodiment, the rope 63 and the coil 61 are molded in a molded resin body 64. However, the molded resin body 64 is not shown in FIG.

[0057] The coil 61 and the rope 63 may be manufactured by the following procedure. First, the coil 61 is wound around a mock tooth that is separate from the yoke 62 (teeth) of the magnetizing device 60. Next, the rope 63 is wound around the coil 61 wound around the mock tooth. After that, the coil 61 and the rope 63 are removed from the mock tooth and fitted into the teeth of the magnetizing device 60. After that, the yoke 62, the annular portion 62a, the coil 61, and the rope 63 are molded with resin to form the molded resin body 64.

[0058] In the first embodiment, similarly to this embodiment, the magnetizing device 60 may be manufactured by winding the coil 61 and the rope 63 around a simulated yoke, and then fitting the annular coil 61 and the rope 63 into the yoke 62 provided in the magnetizing device 60.

[0059] In this embodiment, as in the first embodiment, the material of the rope 63 is stronger than the material of the molded resin body 64. Therefore, with a simple configuration in which the coil 61 is simply surrounded by the rope 63 from the outer periphery, damage to the coil due to the hoop force can be suppressed.

[0060] (Other Embodiments) While the present disclosure has been described with reference to examples, it is understood that the present disclosure is not limited to those examples or structures. The present disclosure also encompasses various modifications and modifications within the scope of equivalents. In addition, although various combinations and forms are shown in the present disclosure, other combinations and forms including only one element, more than one element, or less than one element are also within the scope and spirit of the present disclosure.

[0061] In the first embodiment, the restraining member is not limited to the rope 63, and may be, for example, a molded resin that contains the coil 61 therein, or an impregnated resin that is impregnated between the wires of the coil 61. However, these resins are required to have a portion that extends annularly around the center line C1 and to have the function of restraining the coil 61 from the outer periphery of the winding. Furthermore, in the first embodiment, a resin containing a fiber material (e.g., CFRP) is used for the rope 63, but a resin that does not contain a fiber material may also be used for the rope 63.

[0062] In the first embodiment, the plurality of magnets 41 are magnetized simultaneously, but the magnets 41 may be magnetized one by one. Furthermore, the magnets 41 to be magnetized are not limited to the Halbach array, and are not limited to the rotor 40 of the axial gap motor.

[0063] In the first embodiment, the heat insulating material 65 also serves as a cushioning material. However, the magnetizing device 60 may be provided with a cushioning material in addition to the heat insulating material 65 .

[0064] The rotating machine 10 according to each of the above embodiments is a double axial gap motor in which two rotors 40 are provided for one stator 30. In contrast, the rotating machine 10 may have a structure in which one rotor 40 is provided for one stator 30, or a structure in which one rotor 40 is provided for two stators 30.

[0065] The rotating machine 10 is not limited to being used for propelling a flying object, but may also be used as a running power source mounted on a vehicle, or as a stationary motor, generator, etc. The object to be magnetized by the magnetizing device 60 may be a magnet used in a sensor that detects a rotation angle or a sensor that detects a position.

[0066] The magnetizing device 60 according to the first embodiment has a structure in which the coil 61 is wound around the yoke 62, but the yoke 62 may be eliminated and an air-core coil may be used.

[0067] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0068] (Technical Idea 1) A magnetization device comprising: a coil (61) wound around a center line (C1) and generating a magnetic field for magnetization when current is applied; a restraining member (63) made of a non-magnetic material extending in a ring shape around the center line and restraining the coil from the outer periphery of the winding; and a molded resin body (64) that molds the coil together with the restraining member, wherein the material of the restraining member is stronger than the material of the molded resin body.

[0069] (Technical Concept 2) The magnetizing device according to Technical Concept 1, wherein the wire of the coil has a rectangular cross section, and the restraining member is an outer peripheral surface of the coil and is in contact with the rectangular surface of the wire.

[0070] (Technical Concept 3) The magnetizing device according to Technical Concept 1 or 2, further comprising a yoke (62) around which the coil is wound, and at least three of the yokes are arranged side by side in a direction perpendicular to the center line.

[0071] (Technical Concept 4) The magnetizing device according to Technical Concept 3, wherein an odd number of the yokes are used to simultaneously magnetize magnets (41) whose number is one less than the number of the yokes.

[0072] (Technical Concept 5) The magnetizing device according to Technical Concept 4, wherein the directions of the magnetic fields concentrated in the adjacent yokes are opposite to each other.

[0073] (Technical Concept 6) The magnetizing device according to Technical Concept 4 or 5, wherein the magnets are magnetized so as to form a Halbach array.

[0074] (Technical Concept 7) A magnetizing device according to any one of Technical Concepts 1 to 6, comprising a heater (70) for heating the magnet (41) to be magnetized.

[0075] (Technical Concept 8) The magnetizing device according to Technical Concept 7, further comprising a heat insulating material (65) positioned between the magnet (41) to be magnetized and the coil.

[0076] (Technical Concept 9) The magnetizing device according to any one of Technical Concepts 1 to 8, further comprising a buffer material positioned between the magnet (41) to be magnetized and the coil.

[0077] (Technical Idea 10) A magnetization device according to any one of Technical Ideas 1 to 9, wherein a magnet (41) included in a rotor (40) of an axial gap motor (10) is to be magnetized, and the plurality of coils are arranged in a circular or arc shape, and are oriented so that the center lines of each coil are parallel to one another.

[0078] (Technical Idea 11) A magnetization device according to any one of Technical Ideas 1 to 9, wherein a magnet (41R) included in a rotor of a radial gap motor is to be magnetized, and the plurality of coils are arranged in a circular ring or arc shape, and the center line of each coil is arranged in a direction passing through the rotation center line (C) of the rotor.

[0079] (Technical Concept 12) The magnetizing device according to any one of Technical Concepts 1 to 11, wherein the restraining member is made of a resin containing a fibrous material.

[0080] (Technical Concept 13) The magnetizing device according to any one of Technical Concepts 1 to 12, wherein the restraining member has a rope shape that is wound around the center line from the outer periphery of the coil.

Claims

1. A magnetization device comprising: a coil (61) wound around a center line (C1) that generates a magnetic field for magnetization when current is applied; a restraining member (63) made of non-magnetic material that extends in an annular shape around the center line and restrains the coil from the outer periphery of the winding; and a molded resin body (64) that molds the coil together with the restraining member, wherein the material of the restraining member is stronger than the material of the molded resin body.

2. The magnetizing device according to claim 1, wherein the wire of the coil has a rectangular cross section, and the restraining member is on the outer circumferential surface of the coil and is in contact with the rectangular surface of the wire.

3. The magnetizing device according to claim 1 or 2, comprising a yoke (62) around which the coil is wound, and at least three of the yokes are arranged side by side in a direction perpendicular to the center line.

4. The magnetizing device according to claim 3, wherein an odd number of said yokes simultaneously magnetize magnets (41) whose number is one less than the number of said yokes.

5. The magnetizing device according to claim 4, wherein the directions of the magnetic fields concentrated by the adjacent yokes are opposite to each other.

6. The magnetizing device according to claim 5, wherein the magnets are magnetized so as to form a Halbach array.

7. The magnetizing device according to claim 1 or 2, further comprising a heater (70) for heating the magnet (41) to be magnetized.

8. The magnetizing device according to claim 7, further comprising a heat insulating material (65) positioned between the magnet (41) to be magnetized and the coil.

9. The magnetizing device according to claim 8, further comprising a buffer material positioned between the magnet (41) to be magnetized and the coil.

10. A magnetization device as described in claim 1 or 2, wherein the magnet (41) included in the rotor (40) of an axial gap motor (10) is the target of magnetization, and the multiple coils are arranged in a circular or arc shape, and are oriented so that the center lines of each are parallel to each other.

11. A magnetizing device as described in claim 1 or 2, wherein the magnet (41R) included in the rotor of a radial gap motor is to be magnetized, and the multiple coils are arranged in a circular or arc shape, and each center line is arranged in a direction that passes through the rotation center line (C) of the rotor.

12. The magnetizing device according to claim 1 or 2, wherein the restraining member is made of a resin containing a fiber material.

13. A magnetization device according to claim 1 or 2, wherein the restraining member is in the form of a rope wound around the center line from the outer periphery of the coil.

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