Terminal for superconducting wire, superconducting rotating machine having same, and method for manufacturing terminal

Abstract

Disclosed are a terminal for a superconducting wire, a superconducting rotating machine having the same, and a method for manufacturing the terminal, which can improve cooling efficiency and reduce the weight of the superconducting rotating machine. The terminal may include a frame having a hollow portion and having an open surface formed on at least one side thereof, and may include a superconductor filled in the hollow portion. An end of the superconducting wire may be coupled to at least the superconductor.

Description

Technical Field

[0001] The present invention relates to a terminal for a superconducting wire, a superconducting rotating machine having the terminal, and a method for manufacturing the terminal, which can improve cooling efficiency and reduce the weight of the superconducting rotating machine. Background Art

[0002] For example, in superconducting rotating machines (such as superconducting motors or superconducting generators), superconductors with near-zero resistance are used instead of copper wires as field coils. Field coils containing superconductors can be formed by winding superconducting wires into a racetrack or pancake shape.

[0003] The superconducting field coil can have a configuration in which a superconducting wire is wound multiple times around a bobbin, with terminals connected to the inner and outer ends of the wound superconducting wire. Furthermore, the superconducting field coil can be connected to a cooling system to reduce the temperature of the superconducting wire to a critical temperature. Typically, the terminals are formed into a wire or plate shape and made of a metal material such as copper.

[0004] When high currents are applied to superconducting field coils, terminals made of metal materials such as copper generate heat. This can lead to heat losses of approximately 91% at 20 Kelvin (K), increasing the cooling load on the cooling system. Furthermore, metal materials have a high specific gravity, which can increase the weight of the superconducting rotating machine. Summary of the Invention

[0005] Aspects of the present invention provide a terminal for a superconducting wire, a superconducting rotating machine having the terminal, and a method for manufacturing the terminal, each of which can improve cooling efficiency and reduce the weight of the superconducting rotating machine.

[0006] The terminal according to the present invention may include a frame having a hollow portion and an open surface formed on at least one side thereof. The terminal may also include a superconductor filled in the hollow portion. The end of the superconducting wire may be connected to at least the superconductor.

[0007] The superconductor can be formed by mixing a superconducting material and a binder to form a paste. The pasted superconducting material can then be filled into the hollow portion and the pasted superconducting material can be solidified.

[0008] The superconducting material may include rare earth barium copper oxide.

[0009] The superconducting material may include at least one rare earth metal of yttrium (Y), gadolinium (Gd), neodymium (Nd), samarium (Sm), or dysprosium (Dy).

[0010] The ends of the superconducting wire may be dipped into the paste, and the paste may then be cured and bonded.

[0011] The frame may be formed from a non-magnetic metal or alloy.

[0012] When the open surface faces upward, the opening may be formed on one side of the side wall toward the side of the frame.

[0013] Conductors may be added to the openings.

[0014] The conductor may be formed by filling an additional paste of a conductive metal material into the opening and curing the additional paste.

[0015] The surface roughness of the inner surface of the hollow portion may be in the range of an average roughness (Ra) of 0.5 to 1.0 micrometers (μm).

[0016] The depth of the hollow portion from the open surface may be in the range of 50 μm to 5 mm.

[0017] A superconducting rotating machine according to the present invention may include a rotor having a plurality of superconducting field coils arranged along a circumferential direction of a rotor core. The superconducting field coils may include a bobbin, a superconducting wire wound around the bobbin, and the above-described terminal connected to an end of the superconducting wire.

[0018] The superconducting field coil may further include at least an outer cover configured to cover the radially outer side.

[0019] A method for manufacturing a terminal may include preparing a frame having a hollow portion, preparing a paste containing a superconducting material, and filling the paste into the hollow portion and curing the paste to form a superconductor.

[0020] The paste may be formed by mixing rare earth barium copper oxide with a binder, wherein the weight ratio of the binder to the rare earth barium copper oxide may be 1:10.

[0021] The paste may have a viscosity in the range of 50,000 to 1,000,000 centipoise (cP) at a temperature of 25°C, a humidity of 65%, and atmospheric pressure.

[0022] The method for manufacturing the terminal may further include heat-treating the frame filled with the paste.

[0023] The method for manufacturing the terminal may further include adding a conductor to the opening formed in the side wall of the frame.

[0024] Adding the conductor may include filling an additional paste of a conductive metal material into the opening and curing the additional paste.

[0025] The method for manufacturing the terminal may include dipping an end portion of the superconducting wire into the paste before curing the paste.

[0026] According to an exemplary embodiment of the present invention, by forming at least a portion of the terminal with a superconductor, there is no electrical resistance. Therefore, when a large amount of current is applied, heat generation can be significantly reduced. This reduces the cooling load on the cooling system, thereby improving the cooling efficiency of the superconducting rotating machine.

[0027] Furthermore, according to the exemplary embodiments of the present invention, heat loss accompanying heat generation can be reduced, thereby achieving the effect of minimizing power consumed in the field coil.

[0028] Furthermore, according to the exemplary embodiment of the present invention, by using a superconductor having a low specific gravity and being much lighter than a metal material, it is possible to reduce the weight of not only the terminal but also the superconducting rotating machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other aspects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0030] Figure 1 is a perspective view showing a rotor to which a terminal according to the present invention is applied;

[0031] Figure 2 It shows Figure 1 An enlarged perspective view of one of the field coils of the central rotor:

[0032] Figure 3 is a perspective view showing a terminal according to the present invention;

[0033] Figure 4 is a flow chart illustrating a method for manufacturing a terminal according to the present invention; and

[0034] Figure 5 、 Figure 6A and Figure 6B is a perspective view showing a mobile device to which the superconducting rotating machine according to the present invention can be applied as a superconducting electric motor. DETAILED DESCRIPTION

[0035] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. When adding reference numerals to elements of each drawing, the same reference numerals may refer to the same elements even though the same elements may be shown in other drawings.

[0036] When a component, device, unit, element, etc. of the present invention is described as having a purpose or performing an operation, function, etc., the component, device, unit, element, etc. should be regarded as "configured to" satisfy the purpose or perform the operation or function.

[0037] Figure 1 is a perspective view showing a rotor to which a terminal according to the present invention is applied. Figure 2 It shows Figure 1 An enlarged perspective view of one of the field coils of the central rotor.

[0038] For example, a superconducting rotating machine (e.g., a superconducting motor or a superconducting generator) may include a rotor 10 and a stator (not shown). The superconducting rotating machine may be formed by surrounding a stator provided with an armature around the outside of a rotor provided with superconducting field coils 12. The superconducting rotating machine can generate rotational force (motor) or electricity (generator) together with the stator when the rotor rotates.

[0039] In this specification, an example is mainly shown and described in which the terminal 20 according to the present invention is applied to the superconducting field coil 12 of the rotor 10. However, the application of the present invention is not necessarily limited thereto, and the terminal 20 can also be applied to the stator when the stator armature coil uses a superconducting wire.

[0040] A rotor 10 of a superconducting rotating machine may include a rotor core 11 and a plurality of superconducting field coils 12 arranged along a circumferential direction of the rotor core.

[0041] The rotor core 11 can be coupled to an axially extending shaft (not shown) in or near its radial center. To this end, a hole for coupling the shaft can be formed in the radial center of the rotor core. However, the coupling method between the rotor core and the shaft is not necessarily limited to the above example. For example, the shaft can be fixedly coupled to the centers of both end surfaces of the rotor core without a hole.

[0042] A plurality of coupling portions (not shown) may be formed on the outer peripheral surface of rotor core 11 at predetermined intervals in the circumferential direction to mount and support superconducting field coils. The coupling portions may be integrally formed with the rotor core or may be separately manufactured and assembled to the rotor core.

[0043] For example, each coupling portion may be formed to protrude radially from the rotor core 11 and be fitted and coupled to the bobbin 13 of the superconducting field coil 12. However, the shape of the coupling portion is not necessarily limited thereto. The coupling portion may be provided in the form of a flat surface supporting the superconducting field coil or a groove accommodating a portion of the bobbin.

[0044] The superconducting field coil 12 may include a bobbin 13 , a superconducting wire 15 wound around the bobbin, and a terminal 30 connected to an end of the superconducting wire.

[0045] The bobbin 13 may be used as a support for winding the superconducting wire 15 and may form a magnetic flux path that carries magnetic flux. The bobbin 13 may have a shape such as a cylindrical shape, a square cylindrical shape, or an elliptical shape. Figure 2 In FIG, a spool 13 having an elliptical shape (ie a racetrack shape) is shown, wherein the straight portions are longer than the curved portions.

[0046] The superconducting wire 15 can be wound around the bobbin 13. Terminals 30 can be connected to both ends of the superconducting wire, such as the inner end and the outer end. The superconducting wire can be physically connected and / or electrically connected to a power source (not shown) via the terminals. Therefore, a large amount of current can be applied to the superconducting field coil.

[0047] For example, the superconducting wire 15 may be wound in a pancake shape having at least one layer around the bobbin 13. Depending on the device to which the superconducting rotating machine is applied, the superconducting wire may be wound on the bobbin in a single layer or in a plurality of uniform layers.

[0048] In a state in which superconducting field coil 12 is coupled to the coupling portion of rotor core 11 , the superconducting field coil and the coupling portion may form one magnetic pole. Figure 1 The rotor 10 shown has, for example, eight poles.

[0049] When a large amount of current is applied from a power source to superconducting wire 15, a magnetic field can be formed in superconducting field coil 12. In other words, a large amount of current can be supplied to the superconducting wire so that the superconducting field coil can become a superconducting magnet.

[0050] Optionally, the superconducting field coil 12 may include an outer cover 14 configured to cover the radially outer side to protect its components. The outer cover 14 may be coupled to the bobbin using, for example, bolts or other fasteners. Furthermore, the superconducting field coil may further include an inner cover 16 configured to cover the radially inner side and coupled to the bobbin 13.

[0051] In this manner, since the rotor 10 utilizes the superconducting phenomenon, the rotor 10 provided with the superconducting field coils 12 can be cooled to an extremely low temperature by a cooling system (not shown) and can be housed in a vacuum chamber to be insulated from the outside. Here, the vacuum chamber can be interposed between the rotor and the stator and can surround the rotor.

[0052] To reduce the temperature of the superconducting wire 15 to a critical temperature, the superconducting field coil 12 can be connected to a cooling system. The refrigerator of the cooling system can be separately provided outside the rotating machine, or can be installed in the rotor 10 and / or the vacuum chamber. In this case, the refrigerator can supply and recover liquid or gaseous refrigerant to the rotor and circulate the refrigerant. Since various cooling systems have been proposed for cooling superconducting rotating machines to cryogenic temperatures, a detailed description thereof is omitted in this specification.

[0053] Rotor 10 of the superconducting rotating machine configured as described above may be rotatably mounted by coupling a shaft to rotor core 11 and by supporting the shaft and the rotor with one or more bearings.

[0054] Figure 3is a perspective view showing a terminal according to the present invention.

[0055] The terminal 30 according to the present invention is configured such that at least a portion thereof is formed of a superconductor. To this end, the terminal according to the present invention may include a frame 31 and a superconductor 32.

[0056] The frame 31 may be formed in a box-like shape in which at least one side surface is open, and may include a hollow portion 33 and an open surface. Figure 3 An example is shown in which the frame has a substantially square or rectangular cross-sectional shape. However, the present invention is not necessarily limited thereto, and for example, the frame may have any polygonal or elliptical cross-sectional shape.

[0057] The frame 31 may be formed of at least one material having no magnetic properties, such as Hastelloy, austenitic stainless steel, or aluminum-magnesium (Al-Mg) alloy.

[0058] Optionally, when the open surface faces upward, an opening 34 may be formed on the side wall toward the side of the frame 31. In this case, the opening may form a connection portion for connecting the power line to the superconductor 32. Furthermore, when the open surface faces upward, a groove penetrating the side wall may be formed on the other side of the opening.

[0059] The superconductor 32 may be filled in the hollow portion 33 of the frame 31 and may be exposed to the outside through the open surface. The superconductor may be formed by mixing and pasting rare earth barium copper oxide (hereinafter referred to as REBCO) and a binder, then filling the pasted superconducting material into the hollow portion of the frame and solidifying the pasted superconducting material.

[0060] Here, REBCO may include at least one rare earth metal such as yttrium (Y), gadolinium (Gd), neodymium (Nd), samarium (Sm), dysprosium (Dy), or any combination thereof.

[0061] Examples of specific types of binders used for pasting REBCO are not limited. Various well-known polymer resins, organic solvents, inorganic solvents, aqueous solvents, etc. can be used as the binder.

[0062] More specifically, the binder may include, for example, one or more selected from polystyrene, o-xylene, methylene chloride, acrylic resin, butyl acetate, α-terpineol, carboxymethyl cellulose sodium salt, or epoxidized soybean oil.

[0063] A paste for forming a superconductor can be prepared by mixing REBCO with a binder. For example, the binder can be included in an amount of about 1 to 10 weight percent (wt%), and the weight ratio of the binder to REBCO can be about 1:10.

[0064] The prepared paste may have a viscosity ranging from about 50,000 to 1,000,000 cP at a temperature of 25° C., a humidity of 65%, and atmospheric pressure. In one example, the prepared paste may have a viscosity ranging from about 100,000 to 500,000 cP.

[0065] The surface roughness of the inner surface of the frame 31 to which the paste is attached (especially the hollow portion 33) may be in the range of Ra 0.5 to 1 μm. When the surface roughness of the frame is less than Ra 0.5 μm, the paste cannot be firmly attached to the frame. Conversely, when the surface roughness of the frame exceeds Ra 1 μm, the thickness of the paste attached to the frame becomes uneven, which may make it difficult to ensure uniform magnetic flux.

[0066] Furthermore, the depth of the hollow portion 33 within the frame 31, from the open surface of the paste-impregnated hollow portion, can be within a range of 50 μm to 5 mm. The adhesion between the paste and the frame depends on the particle size of the composition, the viscosity of the paste, and other factors. However, if the depth of the hollow portion is less than 50 μm, the paste may have difficulty flowing in, increasing the likelihood of empty spaces or pores within the hollow portion, thus potentially failing to ensure a secure attachment. On the other hand, if the depth of the hollow portion exceeds 5 mm, the superconductor 32 may become brittle as the thickness of the paste increases, potentially leading to the risk of the superconductor being easily damaged by external impact.

[0067] In this manner, the terminal 30 according to the present invention can include at least a portion of the superconductor 32 by using a paste formed of a superconducting material. Here, since the superconductor has reduced mechanical strength based on a substantially ceramic material, a frame 31 having a hollow portion 33 can be added to maintain the shape of the superconductor and to supplement its strength, so that the terminal can stably exhibit superconducting characteristics.

[0068] Superconductor 32 formed by solidifying the paste can have a critical current much lower than that of thin-film superconducting wires. However, due to the characteristics of the paste, superconductor 32 is not limited to shapes such as those manufactured from thin films, and the superconductor and terminal 30 provided with the superconductor can be formed into various shapes and manufactured to desired sizes.

[0069] Optionally, the terminal 30 according to the present invention may have a conductor 35 added to the opening 34 formed in the side wall of the frame 31. The conductor may be formed of a paste of a highly conductive metal material such as copper.

[0070] When connecting the power line to the terminal 30 through the opening 34 of the frame 31, the superconductor 32 formed by curing the paste may be cracked and its contact resistance may increase. To solve this problem, after the superconductor is cured and completed, the conductor 35 can be formed in the opening on one side of the frame side wall by filling the opening of the frame with metal paste and curing the metal paste.

[0071] With this configuration, the superconductor 32 and the conductor 35 can be physically and electrically connected, and electric power lines can be connected to the conductors, thereby enhancing the strength of the superconductor end and minimizing contact resistance.

[0072] The conductor 35 is not necessarily limited to being formed of paste, but any metal wire may be used as a conductor and joined by welding or the like.

[0073] On the other side of opening 34, the end of superconducting wire 15 of superconducting field coil 12 can pass through the side wall of frame 31 and be dipped into the paste that forms superconductor 32. To this end, a groove into which the superconducting wire can be inserted can be optionally formed on the other side of the opening. After the end of the superconducting wire is dipped in the paste, as the paste solidifies, the superconductor and the superconducting wire can achieve a physically fixed and electrically stable connection.

[0074] However, the connection between the superconducting wire 15 and the superconductor 32 is not necessarily limited thereto, and after the paste is solidified, the end portion of the superconducting wire may be bonded to the superconductor by welding or the like.

[0075] Figure 4 is a flowchart illustrating a method for manufacturing a terminal according to the present invention.

[0076] The method for manufacturing the terminal 30 according to the present invention may include: an operation (S10) of preparing a frame 31 having a hollow portion 33; an operation (S20) of preparing a paste containing a superconducting material; and an operation (S30) of forming the superconductor 32 by filling the paste into the hollow portion of the frame and curing the paste.

[0077] As described above, the frame 31 may be formed and made into a box-like shape in which at least one side is open using at least one material having no magnetic properties, such as Hastelloy, austenitic stainless steel, or Al—Mg alloy ( S10 ).

[0078] The paste may be formed and prepared by mixing the superconducting material with a binder ( S20 ).

[0079] REBCO may be used as the superconducting material, and REBCO may include at least one of rare earth metals such as yttrium (Y), gadolinium (Gd), neodymium (Nd), samarium (Sm), and dysprosium (Dy).

[0080] Furthermore, the binder may include one or more selected from, for example, polystyrene, o-xylene, methylene chloride, acrylic resin, butyl acetate, α-terpineol, carboxymethylcellulose sodium salt, and epoxidized soybean oil.

[0081] By mixing REBCO with a binder, a paste for forming the superconductor 32 may be prepared. For example, the binder may be included in an amount of about 1 to 10 wt %, and the weight ratio of the binder to REBCO may be about 1:10.

[0082] The prepared paste may have a viscosity ranging from about 50,000 to 1,000,000 cP at a temperature of 25° C., a humidity of 65%, and atmospheric pressure. In one example, the prepared paste may have a viscosity of about 100,000 to 500,000 centipoise (cP).

[0083] Next, superconductor 32 of terminal 30 may be formed by filling a paste containing a superconducting material into hollow portion 33 of frame 31 and curing the paste ( S30 ).

[0084] Optionally, the method for manufacturing a terminal according to the present invention may further include an operation of heat-treating the frame 31 filled with the paste.

[0085] By slowly heating the terminal 30 filled with the paste to evaporate the binder in the paste by thermal decomposition, the binder can be removed and the curing of the paste (i.e., superconductor 32) can be accelerated. Since the heat treatment temperature and time can be appropriately set according to the type of the binder, there is no particular limitation on the temperature and time in this specification.

[0086] Optionally, the method for manufacturing a terminal according to the present invention may further include an operation of adding a conductor 35 to the opening 34 formed on the side wall of the frame 31 .

[0087] For example, after forming superconductor 32, opening 34 of frame 31 is filled with another paste, namely a metal paste, and the metal paste is solidified. Thus, conductor 35 is formed in the opening on one side of the frame sidewall. However, the conductor is not necessarily limited to being formed from a paste, and any metal wire can be selected as the conductor and joined by welding or the like.

[0088] Finally, the method for manufacturing a terminal according to the present invention may include an operation of dipping the end of the superconducting wire 15 included in the superconducting field coil 12 into a paste. The end of the superconducting wire may pass through the side wall of the frame 31 and may be dipped into the paste that forms the superconductor 32. To this end, a groove may be formed on the other side of the opening 34 in the frame, but the present invention is not necessarily limited thereto.

[0089] As described above, according to the exemplary embodiments of the present invention, by forming at least a portion of the terminal with a superconductor, there is no electrical resistance. Therefore, when a large amount of current is applied, heat generation can be significantly reduced. This reduces the cooling load on the cooling system, thereby improving the cooling efficiency of the superconducting rotating machine.

[0090] Furthermore, according to the exemplary embodiments of the present invention, heat loss accompanying heat generation can be reduced, thereby achieving the effect of minimizing power consumed in the field coil.

[0091] Furthermore, according to the exemplary embodiment of the present invention, the weight of the terminal and the superconducting rotating machine can be reduced by using a superconductor having a low specific gravity and being much lighter than a metal material.

[0092] Meanwhile, a superconducting rotating machine provided with the terminal for a superconducting wire according to the present invention can be used as a superconducting motor. Hereinafter, an application example thereof is briefly described.

[0093] Figure 5 、 Figure 6A and Figure 6B 1 is a perspective view showing a mobile device or a vehicle to which the superconducting rotating machine according to the present invention can be applied as a superconducting electric motor.

[0094] Mobile devices V1 and V2 may include at least main bodies B1 and B2, drive devices W and P provided in main bodies B1 and B2, superconducting motors M1 and M2 connected to drive devices W and P, and batteries E1 and E2 configured to supply power to the superconducting motors. The superconducting motors M1 and M2 installed in mobile devices V1 and V2 may have the configuration of the above-described superconducting rotating machine.

[0095] refer to Figure 5 The mobile device V1 may be a vehicle that can move on the ground. The vehicle may include at least a body B1, wheels as a driving device W provided on the body B1, a superconducting motor M1 connected to the driving device W, and a battery E1 configured to supply power to the superconducting motor.

[0096] In addition, reference Figure 6A and Figure 6B The mobile device V2 may be an aerial mobile device that moves or flies in the air. The aerial mobile device may include at least a body B2, a propeller (e.g., a propeller) as a driving device P provided on the body B2, a superconducting motor M2 connected to the propeller, and a battery E2 configured to supply power to the superconducting motor.

[0097] Figure 6A The positions of the thrusters are shown when the aerial mobile device is turning during takeoff, landing, or hovering at a specific point. Figure 6BThe diagram shows the position of the propeller when the aerial mobile device is moving through the air, that is, when the aerial mobile device is operating or flying. In other words, the propeller, which serves as the driving device P of the aerial mobile device, can be provided with a structure in which the direction in which the propeller faces can be tilted. The superconducting motor M2 driving the propeller can also be tilted accordingly.

[0098] for Figure 6A In the hovering mode shown, the propellers of the main wings and / or tail are turned substantially perpendicular to the body B2. Figure 6B In the illustrated operating mode, the propellers of the main wings and / or tail wing can be rotated substantially parallel to the longitudinal axis of the main body B2. The pitch of the propellers of the main wings and / or tail wing can be synchronized according to the flight mode. Alternatively, within the same flight mode, the pitch of each propeller can be adjusted differently according to attitude control and flight conditions.

[0099] Meanwhile, although specific illustrations are omitted, the mobile device may be a device that moves in space, such as on land, underground, in the air, in space, at sea and / or underwater, depending on the space in which the mobile device is designed to move. The mobile device on the ground or underground may be provided in the form of, for example, a vehicle, a robot, etc. The mobile device in the air and space is an aerial mobile device, which may be provided in the form of, for example, a conventional fixed-wing or rotary-wing aircraft, a tilt-rotor aircraft, a vertical take-off and landing aircraft, an unmanned aerial vehicle, or a mobile device mounted on a drone, a rocket, or an artificial satellite. The mobile device at sea or underwater may be provided as, for example, a ship, a submarine, etc. The mobile device is not limited to a specific space, and may be a mobile body that can move in all of the above-mentioned spaces, that is, a mobile body that can move to multiple spaces, and may be, for example, an amphibious vehicle, an aircraft, etc.

[0100] The above description is merely illustrative of the technical concept of the present invention. A person skilled in the art may make various modifications and variations without departing from the basic features of the present invention.

[0101] Therefore, the exemplary embodiments disclosed in this specification and the accompanying drawings are not intended to limit the scope of the present invention, but are intended to illustrate the technical concept of the present invention. The scope of the technical concept of the present invention is not limited to these exemplary embodiments. The scope of protection of the present invention should be interpreted by the appended claims, and all technical concepts within the scope of equivalents should be interpreted as included within the scope of the present invention.

Claims

1. A terminal comprising: a frame having a hollow portion and having an open surface formed on at least one side of the frame; as well as a superconductor in the hollow portion, The end of the superconducting wire is at least connected to the superconductor.

2. The terminal according to claim 1, wherein The superconductor includes a superconducting material and a binder, is arranged in the hollow portion, and is solidified.

3. The terminal according to claim 2, wherein The superconducting material includes rare earth barium copper oxide.

4. The terminal according to claim 2, wherein The superconducting material includes at least one of the rare earth metals yttrium, gadolinium, neodymium, samarium, and dysprosium, or any combination thereof.

5. The terminal according to claim 2, wherein The end portion of the superconducting wire is dipped in the superconducting material, and the superconducting material is solidified and bonded. The terminal according to claim 1 , wherein: The frame is formed of a non-magnetic metal or alloy.

7. The terminal according to claim 1, wherein When the open surface faces upward, an opening is formed on one side of the side wall toward the side of the frame.

8. The terminal according to claim 7, wherein A conductor is disposed at the opening.

9. The terminal according to claim 8, wherein The conductor includes an additional paste of conductive metal material in the openings, the paste being cured.

10. The terminal according to claim 1, wherein The surface roughness of the inner surface of the hollow portion is within an average roughness range of 0.5 to 1.0 μm.

11. The terminal according to claim 1, wherein A depth of the hollow portion from the open surface is in a range of 50 μm to 5 mm.

12. A superconducting rotating machine comprising a rotor having a plurality of superconducting field coils arranged along a circumferential direction of a rotor core, the superconducting field coils comprising: spools; a superconducting wire wound on the spool; as well as a terminal connected to an end of the superconducting wire, the terminal comprising: a frame having a hollow portion and having an open surface formed on at least one side of the frame, and a superconductor filled in the hollow portion, The end portion of the superconducting wire is at least connected to the superconductor.

13. The superconducting rotating machine according to claim 12, wherein: The superconducting field coil further includes at least an outer cover configured to cover the radial outer side.

14. A method comprising: preparing a frame having a hollow portion; preparing a paste comprising a superconducting material; as well as The paste is filled into the hollow portion and cured to form a superconductor.

15. The method according to claim 14, wherein The paste is formed by mixing rare earth barium copper oxide with a binder in a weight ratio of 1:

10.

16. The method according to claim 14, wherein The paste has a viscosity ranging from 50,000 to 1,000,000 centipoise at a temperature of 25° C., a humidity of 65% and atmospheric pressure.

17. The method of claim 14, further comprising: The frame filled with the paste is heat treated.

18. The method of claim 14, further comprising: Conductors are added to the openings formed in the side walls of the frame.

19. The method according to claim 18, wherein Adding the conductor includes filling an additional paste of a conductive metal material into the opening and curing the additional paste.

20. The method of claim 14, comprising: Before curing the paste, the end of the superconducting wire is dipped in the paste.

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