Superconducting Motor

Abstract

To provide a superconducting motor capable of efficiently cooling superconducting coils at start-up.SOLUTION: A superconducting motor comprises: a stator 40 having a stator core 41 and a plurality of superconducting coils 42, and disposed so as to face a rotor 30 in a radial direction; a coil cooling container 50 in which the superconducting coils 42 are accommodated, and into which a cooling media for cooling the superconducting coils 42 flows; and a heat insulation container 10 in which the stator core 41 and the coil cooling container 50 are accommodated. The stator core 41 has an annular yoke part 41a, and a plurality of teeth 41b disposed spaced apart in a circumferential direction of the yoke part 41a, and protruding in the radial direction of the yoke part 41a. The coil cooling container 50 is formed so as to extend inward from an outer surface, and has a plurality of insertion paths 50b into which the teeth 41b are inserted. The superconductive coils 42 are wound on an outer circumferential side of the insertion paths 50b inside the coil cooling container 50.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a superconducting motor used as a power source for, for example, ships, trains, vehicles, aircraft, etc. [Background technology]

[0002] A conventional superconducting motor is known that includes a rotor that is supported for free rotation, a stator that has a stator core and a superconducting coil and is arranged radially opposite the rotor, and a coil cooling means that cools the superconducting coil (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5497625 Summary of the Invention [Problem to be solved by the invention]

[0004] The coil cooling means of the conventional superconducting motor cools the stator core by circulating the cooling medium discharged from the refrigerator through a thin tube formed to penetrate the stator core, and the cooled stator core cools the superconducting coil thermally connected to the stator core. Therefore, in the conventional superconducting motor, a large amount of cooling medium is consumed when cooling the superconducting coil to a superconducting state at start-up, and it may take a long time to reach a superconducting state.

[0005] An object of the present invention is to provide a superconducting motor capable of efficiently cooling a superconducting coil at start-up. [Means for solving the problem]

[0006] The superconducting motor of the present invention comprises a rotor that is supported for free rotation, a stator having a stator core and a plurality of superconducting coils and arranged radially opposite the rotor, a coil cooling vessel in which the superconducting coil is housed and into which a cooling medium for cooling the superconducting coil flows, and an insulated vessel in which the stator core and the coil cooling vessel are housed, the stator core having an annular yoke portion and a plurality of teeth portions arranged at intervals circumferentially of the yoke portion and protruding radially from the yoke portion, the coil cooling vessel being formed to extend inward from an outer surface and having a plurality of insertion passages through which the teeth portions are inserted, and the superconducting coil is wound around the outer periphery of the insertion passages inside the coil cooling vessel.

[0007] In addition, in the superconducting motor of the present invention, the stator is arranged radially outside the rotor, the insulated container is formed in a cylindrical shape surrounding the outer periphery of the rotor, and has an outer periphery side member located on the outer periphery side and an inner periphery side member located on the inner periphery side, and the inner periphery side member is formed of a material that is nonmagnetic and nonconductive.

[0008] In the superconducting motor according to the present invention, the coil cooling vessel is supported by the inner peripheral member.

[0009] In the superconducting motor according to the present invention, the teeth are disposed radially inside the yoke, and the tip portions are supported by the inner peripheral member.

[0010] In the superconducting motor according to the present invention, the teeth portion is separate from the yoke portion. Effect of the Invention

[0011] According to the present invention, by flowing a cooling medium into the coil cooling container, it is possible to cool only the superconducting coil without cooling the stator core, so that the superconducting coil can be efficiently cooled at start-up. [Brief description of the drawings]

[0012] [Figure 1] 1 is an overall perspective view of a superconducting motor according to an embodiment of the present invention; [Diagram 2] 1 is an exploded perspective view of a superconducting motor according to an embodiment of the present invention; [Diagram 3] 1 is a cross-sectional view of a superconducting motor according to an embodiment of the present invention. [Figure 4] 1A to 1C are diagrams illustrating a method of assembling a superconducting motor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Figures 1 to 4 show one embodiment of the present invention. Figure 1 is an overall perspective view of a superconducting motor, Figure 2 is an exploded perspective view of the superconducting motor, Figure 3 is a cross-sectional view of the superconducting motor, and Figure 4 is a diagram explaining a method of assembling the superconducting motor.

[0014] The superconducting motor 1 of this embodiment is used as a power source for ships, trains, vehicles, aircraft, and the like.

[0015] As shown in Figures 1 and 2, this superconducting motor 1 comprises an insulated container 10, a drive shaft 20 rotatably mounted relative to the insulated container 10, a rotor 30 fixed to the outer periphery of the drive shaft 20, a stator 40 mounted inside the insulated container 10 and facing the rotor 30 on the radially outer side of the rotor 30, and a coil cooling container 50 which houses a superconducting coil of the stator 40, which will be described later, and through which a cooling medium for cooling the superconducting coil circulates.

[0016] The heat-insulating container 10 has a cylindrical outer circumferential member 11 located on the outer circumferential side, a cylindrical inner circumferential member 12 located on the inner circumferential side, a first cover member 13 closing one axial end of the outer circumferential member 11 and the inner circumferential member 12, and a second cover member 14 closing the other axial end of the outer circumferential member 11 and the inner circumferential member 12. The inner circumferential member 12 has an inner cylindrical portion 12a extending between the first cover member 13 and the second cover member 14, and a fitting portion 12b provided on one end side of the inner cylindrical portion 12a and fitting to the inner circumferential surface of the outer circumferential member 11. The heat-insulating container 10 has a cylindrical sealed tubular space 10a surrounded by the outer circumferential member 11, the inner circumferential member 12, the first cover member 13, and the second cover member 14. The heat insulating container 10 creates a vacuum in the sealed cylindrical space 10a by evacuating the sealed cylindrical space 10a, thereby blocking heat transfer between the inside and outside of the sealed cylindrical space 10a. The inner peripheral member 12 is made of a nonmagnetic and nonconductive material. Examples of nonmagnetic and nonconductive materials include high-strength resin materials that can be used in a wide range of temperatures (especially low temperatures), such as fiber-reinforced plastics typified by GFRP, polyimide (PI), polyamide-imide (PAI), polybenzimidazole (PBI), polyether ether ketone (PEEK), and super engineering plastics such as fluororesin (PTFE), processed ceramics such as alumina, and glass materials.

[0017] The drive shaft 20 is arranged to extend axially on the inner side of the inner cylindrical portion 12a of the inner side member 12, and one end side is rotatably supported via a first bearing 21 in the radial center of the first cover member 13, and the other end side is rotatably supported via a second bearing 22 in the radial center of the second cover member 14.

[0018] The rotor 30 is provided on the outer periphery of the drive shaft 20 on the axial center side, and has an outer diameter slightly smaller than the inner diameter of the inner cylindrical portion 12a of the inner member 12. The rotor 30 has a rotor core 31 formed by laminating a plurality of electromagnetic steel plates in the axial direction of the drive shaft 20 and integrally forming the rotor core 31 by crimping, welding, or the like, and a plurality of permanent magnets 32, such as ferrite magnets, arranged circumferentially on the outer periphery of the rotor core 31.

[0019] The stator 40 has a stator core 41 housed in the sealed cylindrical space 10a of the heat-insulating container 10, and a plurality of superconducting coils 42 housed in a refrigerant flow space of the coil cooling container 50, which will be described later.

[0020] The stator core 41 is constructed by forming a plurality of laminated electromagnetic steel plates into one piece by caulking, welding, or the like. The stator core 41 has a yoke portion 41a formed in an annular shape, and a plurality of teeth portions 41b that are spaced apart in the circumferential direction of the annular shape of the yoke portion 41a and protrude toward the center of the annular shape. As shown in Figs. 3 and 4, the yoke portion 41a and the plurality of teeth portions 41b of the stator core 41 are separate bodies, and the yoke portion 41a is supported by the fitting portion 12b of the inner circumferential member 12, and the plurality of teeth portions 41b are supported by the outer periphery of the inner circumferential cylindrical portion 12a of the inner circumferential member 12 in a state where they are inserted into an insertion passage of the coil cooling vessel 50, which will be described later. When the superconducting motor 1 is assembled, the plurality of teeth portions 41b of the stator core 41 are assembled to the yoke portion 41a.

[0021] The plurality of superconducting coils 42 are each made of a wire made of a superconducting material such as bismuth (Bi2) or yttrium (Y), and are wound around the outer periphery of a coil frame 42a formed in an annular shape, as shown in FIG. 2. The plurality of superconducting coils 42 are disposed on the outer periphery of the teeth 41b through insertion passages, which will be described later, of the coil cooling vessel 50, as shown in FIG. 3. The superconducting motor 1 of this embodiment is configured with a concentrated winding stator 40 in which the superconducting coils 42 are wound around each of the plurality of teeth 41b of the stator core 41 in a concentrated manner. The electricity flowing through the plurality of superconducting coils 42 is supplied from a current introducing portion 42b provided in the second cover member 14.

[0022] 2 and 3, the coil cooling container 50 has a cylindrical external shape in which a cylindrical refrigerant flow space 50a extending along the circumferential direction of the sealed cylindrical space 10a of the thermally insulated container 10 is formed, and is supported by the inner peripheral member 12 of the thermally insulated container 10. In the coil cooling container 50, the refrigerant flow space 50a is disposed at intervals relative to each of the outer peripheral member 11, the inner peripheral member 12, the first cover member 13, and the second cover member 14, and heat transfer between the outside of the thermally insulated container 10 and the refrigerant flow space 50a is blocked.

[0023] The coil cooling container 50 has a plurality of insertion passages 50b, which are provided at approximately the center in the axial direction at intervals in the circumferential direction and extend inward from the outer surface, through which the plurality of teeth 41b of the stator core 41 are inserted. In this embodiment, the plurality of insertion passages 50b each penetrate the refrigerant flow space 50a to communicate between the outer circumferential side and the inner circumferential side of the coil cooling container 50. In the process of forming the refrigerant flow space 50a, the coil cooling container 50 is formed integrally with the plurality of superconducting coils 42 by placing the superconducting coils 42 on the outer circumferential side of each of the plurality of insertion passages 50b.

[0024] A refrigerant inlet pipe 51 for introducing the cooling medium is connected to the lower side of the outer circumferential surface of the coil cooling vessel 50, and a refrigerant outlet pipe 52 for discharging the cooling medium is connected to the upper side of the outer circumferential surface. A refrigerant inlet end 51a of the refrigerant inlet pipe 51 into which the cooling medium flows and a refrigerant outlet end 52a of the refrigerant outlet pipe 52 from which the cooling medium flows out are each disposed on the second cover member 14. Liquid nitrogen is used as the cooling medium that flows into the coil cooling vessel 50, and the superconducting coil 42 housed in the coil cooling vessel 50 is cooled by the liquid nitrogen, and the nitrogen vaporized by cooling the superconducting coil 42 flows out from the refrigerant outlet end 52a.

[0025] Here, a method for assembling the superconducting motor 1 will be described.

[0026] First, as shown in FIGS. 4(a) and 4(b), the yoke portion 41a of the stator core 41 is attached to the inner peripheral member 12 of the heat insulating container .

[0027] Next, as shown in Figures 4(c) and 4(d), the coil cooling container 50 housing the superconducting coil 42 and the multiple teeth 41b of the stator core 41 are assembled to the inner peripheral member 12 and the yoke portion 41a. When the inner peripheral cylindrical portion 12a of the inner peripheral member 12 is inserted into the inner peripheral side of the coil cooling container 50, the teeth 41b are inserted into the insertion passages 50b. As a result, the multiple teeth 41b are supported by the inner peripheral cylindrical portion 12a and inserted into the inner peripheral side of the yoke portion 41a, and the yoke portion 41a and the multiple teeth 41b are assembled together.

[0028] After the teeth 41b and the coil cooling container 50 are attached to the inner periphery member 12, the first cover member 13 is attached to one end of the inner periphery member 12 as shown in Fig. 4(e). After the first cover member 13 is attached to one end of the inner periphery member 12, the outer periphery member 11 is fitted into the fitting portion 12b of the inner periphery member 12 and attached to the first cover member 13 as shown in Fig. 4(f). After the outer periphery member 11 is attached, the drive shaft 20 and the rotor 30, which are assembled to each other, are inserted into the inner periphery of the inner cylindrical portion 12a of the inner periphery member 12, and one end of the drive shaft 20 is supported by the first cover member 13 via the first bearing 21 as shown in Fig. 4(g). Finally, as shown in FIG. 4(h), the other ends of the outer circumferential side member 11 and the inner circumferential side member 12 are closed by the second cover member 14, and the other end of the drive shaft 20 is supported by the second cover member 14 via the second bearing 22.

[0029] When the superconducting motor 1 configured as above is started, a cooling medium is flowed into the coil cooling vessel 50 to cool the superconducting coil 42 housed in the coil cooling vessel 50 and bring it into a superconducting state. This suppresses the occurrence of copper loss in the superconducting coil 42 during operation of the superconducting motor 1.

[0030] Only the superconducting coil 42 is accommodated in the coil cooling vessel 50 of the superconducting motor 1, and the stator core 41 is accommodated in the sealed cylindrical space 10a outside the coil cooling vessel 50. Therefore, the superconducting motor 1 of this embodiment consumes less cooling medium to bring the superconducting coil 42 into a superconducting state, and the superconducting coil 42 can be brought into a superconducting state in a short time. Furthermore, the superconducting motor 1 of this embodiment suppresses an increase in iron loss caused by the stator core 41 being cooled by the cooling medium during driving.

[0031] Moreover, in the superconducting motor 1 of this embodiment, the inner peripheral member 12 of the thermal insulation container 10 is formed of a nonmagnetic and nonconductive material. Therefore, the superconducting motor 1 of this embodiment can suppress an increase in eddy current loss caused by magnetic flux lines interlinking with a conductive material, without restricting the inflow of magnetic flux lines between the rotor 30 and the stator 40.

[0032] Furthermore, in the superconducting motor 1 of this embodiment, the inner peripheral member 12 of the heat insulating container 10 supports the plurality of teeth portions 41b and the coil cooling container 50. Therefore, in the superconducting motor 1 of this embodiment, the plurality of teeth portions 41b and the coil cooling container 50 do not come into direct contact with each other, and it is possible to suppress the transfer of heat therebetween, so that it is possible to intensively cool only the superconducting coil 42 accommodated in the coil cooling container 50.

[0033] Thus, the superconducting motor 1 of this embodiment includes a rotor 30 that is supported for free rotation, a stator 40 having a stator core 41 and a plurality of superconducting coils 42 and arranged radially opposite the rotor 30, a coil cooling container 50 that houses the superconducting coils 42 and into which a cooling medium flows to cool the superconducting coils 42, and an insulated container 10 that houses the stator core 41 and the coil cooling container 50, the stator core 41 having an annular yoke portion 41a and a plurality of teeth portions 41b that are arranged at intervals around the circumferential direction of the yoke portion 41a and protrude in the radial direction of the yoke portion 41a, the coil cooling container 50 being formed to extend inward from the outer surface and having a plurality of insertion passages 50b through which the teeth portions 41b are inserted, and the superconducting coils 42 are wound around the outer periphery of the insertion passages 50b inside the coil cooling container 50.

[0034] As a result, by flowing the cooling medium into the coil cooling container 50, it is possible to directly cool only the superconducting coil 42 without directly cooling the stator core 41, so that the superconducting coil 42 can be efficiently cooled at the time of starting. Specifically, it is possible to reduce the consumption of the cooling medium required to make the superconducting coil 42 superconductive, and to shorten the time required to make the superconducting coil 42 superconductive. Also, when the superconducting motor 1 is driven, it is possible to directly cool only the superconducting coil 42 without directly cooling the stator core 41, so that it is possible to reduce the consumption of the cooling medium. Furthermore, since the coil cooling container 50 only needs to be large enough to accommodate the superconducting coil 42, the required space is smaller than when a cooling container is formed to accommodate the stator core 41 and the superconducting coil 42, and it is possible to reduce the size and weight of the device.

[0035] It is also preferable that the stator 40 is arranged radially outside the rotor 30, the insulated container 10 is formed in a cylindrical shape surrounding the outer periphery of the rotor 30, and has an outer periphery side member 11 located on the outer periphery side and an inner periphery side member 12 located on the inner periphery side, and the inner periphery side member 12 is formed from a material that is nonmagnetic and nonconductive.

[0036] This makes it possible to suppress eddy current loss caused by the magnetic flux lines interlinking with the conductive material, without restricting the inflow of the magnetic flux lines between the rotor 30 and the stator 40.

[0037] Moreover, it is preferable that the coil cooling vessel 50 is supported by the inner peripheral member 12 .

[0038] This makes it possible to block the transfer of heat from the outer circumferential member 11 to the coil cooling vessel 50, thereby making it possible to more efficiently cool the superconducting coil 42 housed in the coil cooling vessel 50.

[0039] Moreover, it is preferable that the teeth portion 41b is disposed radially inside the yoke portion 41a, and that the tip portion is supported by the inner peripheral side member 12.

[0040] This makes it possible to reliably fix the stator 40 in the sealed cylindrical space 10a of the heat-insulating container 10 without requiring a dedicated fixing structure for fixing the stator 40 therein.

[0041] Moreover, it is preferable that teeth portion 41b is a separate body from yoke portion 41a.

[0042] As a result, by assembling the yoke portion 41a and the teeth portion 41b with the teeth portion 41b inserted into the insertion passage 50b of the coil cooling container 50, the stator core 41 and the superconducting coil 42 housed in the coil cooling container 50 can be easily assembled, thereby reducing the assembly labor.

[0043] In the above embodiment, the inner rotor type superconducting motor 1 is shown in which the rotor 30 having the permanent magnets 32 is arranged on the inner circumference side and the stator 40 having the superconducting coils 42 is arranged on the outer circumference side, but the present invention is not limited to this. For example, the present invention is also applicable to an outer rotor type superconducting motor in which a rotor having a permanent magnet is arranged on the outer circumference side and a stator having a superconducting coil is arranged on the inner circumference side.

[0044] In addition, in the above embodiment, liquid nitrogen is used as the cooling medium, but this is not limited to this. For example, liquid helium may be used as the cooling medium as long as it is capable of cooling the superconducting coil.

[0045] In the above embodiment, the sealed cylindrical space 10a is made into a vacuum state to form a vacuum insulation layer in the insulation container 10, but the present invention is not limited to this. For example, the outside of the coil cooling container may be covered with a heat insulating material as long as it is possible to block the transfer of heat between the outside and inside of the coil cooling container. [Explanation of symbols]

[0046] 1. Superconducting motor 10. Insulated containers 11 Outer periphery member 12 Inner peripheral part 30 rotors 40 Stator 41 Stator core 41a York 41b Teeth part 42 Superconducting coil 50 Coil Cooling Vessel 50b Insertion passage

Claims

1. A rotor supported for free rotation; a stator having a stator core and a plurality of superconducting coils and disposed radially opposite the rotor; a coil cooling vessel in which the superconducting coil is housed and into which a cooling medium for cooling the superconducting coil flows; a heat-insulating container in which the stator core and the coil cooling container are housed, the stator core has an annular yoke portion and a plurality of teeth portions arranged at intervals in a circumferential direction of the yoke portion and protruding in a radial direction of the yoke portion, the coil cooling container is formed to extend inward from an outer surface thereof and has a plurality of insertion passages through which the teeth portions are inserted; the superconducting coil is wound around an outer circumferential side of the insertion passage inside the coil cooling vessel, The stator is disposed radially outward of the rotor, the heat-insulating container is formed in a cylindrical shape surrounding an outer periphery side of the rotor, and includes an outer periphery side member located on the outer periphery side and an inner periphery side member located on the inner periphery side, The inner peripheral member is The magnetic flux is formed from a material that is non-magnetic and non-conductive. an inner circumferential cylindrical portion extending along a rotation axis of the rotor; a fitting portion provided on one end side of the inner cylindrical portion and fitted to an inner peripheral surface of the outer peripheral member, The coil cooling vessel comprises: the inner peripheral member is supported by a portion located between the inner peripheral cylindrical portion and the fitting portion, A spaced apart surface is disposed relative to the inner surface of the insulated container. Superconducting motor.

2. The teeth are disposed radially inside the yoke, and have their tips supported by the inner circumferential member.

2. The superconducting motor according to claim 1.

3. The teeth portion is separate from the yoke portion.

3. The superconducting motor according to claim 1 or 2.

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