Superconducting motor

Abstract

To provide a superconducting motor capable of lowering a degree of vacuum in vacuum insulation space more than high vacuum without reducing heat insulation property.SOLUTION: A superconducting motor has a rotor 30 rotatably supported, a stator 40 with a plurality of superconducting coils 42, a coil cooling container 50 in which the superconducting coils 42 are accommodated and a cooling medium cooling the superconducting coils 42 is circulated, a vacuum insulation container 10 in which a vacuum insulation space 10a is formed and the coil cooling container 50 is accommodated in the vacuum insulation space 10a, and a heat insulating material 60 provided on an outer surface side of the coil cooling container 50 in the vacuum insulation space 10a.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] A known conventional superconducting motor includes a rotor that is supported for free rotation, a stator having a plurality of superconducting coils, a coil cooling vessel that houses the superconducting coils and through which a cooling medium for cooling the superconducting coils flows, and a vacuum insulation vessel that has a vacuum insulation space formed therein and houses the coil cooling vessel in the vacuum insulation space (see, for example, Patent Document 1).

[0003] Conventional superconducting motors house a coil cooling vessel in a vacuum insulated space to prevent heat from entering the coil cooling vessel and efficiently cool the superconducting coil with a cooling medium. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-124886 Summary of the Invention [Problem to be solved by the invention]

[0005] In conventional superconducting motors, the pressure in the vacuum insulation space is kept at 10 -3 It is necessary to create a high vacuum state of less than 100 Pa. For this reason, conventional superconducting motors require the use of high-strength materials for the vacuum insulation container and a high-output pump to evacuate the vacuum insulation space, which can increase manufacturing costs.

[0006] An object of the present invention is to provide a superconducting motor in which the degree of vacuum in the vacuum insulation space can be made lower than a high vacuum without deteriorating the insulation performance. [Means for solving the problem]

[0007] The superconducting motor of the present invention comprises a rotor that is supported for free rotation, a stator having a plurality of superconducting coils, a coil cooling vessel that houses the superconducting coils and through which a cooling medium for cooling the superconducting coils circulates, a vacuum insulated vessel that has a vacuum insulated space formed therein and in which the coil cooling vessel is housed, and an insulating material that is arranged on the outer surface side of the coil cooling vessel in the vacuum insulated space of the vacuum insulated vessel.

[0008] In the superconducting motor according to the present invention, the vacuum insulating container has a portion made of a resin member.

[0009] In addition, in the superconducting motor according to the present invention, the pressure in the vacuum insulation space is 10 -2 Pa or more 10 3 The temperature is kept below Pa.

[0010] In the superconducting motor according to the present invention, the stator has a stator core that enhances the magnetic force generated by the superconducting coil. [Effects of the Invention]

[0011] According to the present invention, the insulating material prevents heat from entering the coil cooling container, allowing the vacuum insulated space to be lower than a high vacuum without compromising thermal insulation performance. This allows for greater flexibility in the materials used to form the vacuum insulated container and reduces manufacturing costs. The vacuum insulated space can be evacuated in a much shorter time than conventional methods using low-power pumps and other equipment, thereby reducing operating costs. The presence of insulating material in the vacuum insulated space reduces vibration noise and shock loads, and also provides cushioning and shatter prevention against refrigerant leakage from the cooling container due to malfunction or damage, or rupture of the vacuum container due to refrigerant vaporization and expansion. Furthermore, by making the vacuum container out of resin, it is possible to significantly reduce its weight compared to conventional metal vacuum containers. Furthermore, because the inner peripheral member separately supports the stator core and the coil cooling container, the cold air from the coil cooling container is less likely to be transmitted to the stator core or the outer container, maintaining high thermal insulation performance. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall perspective view of a superconducting motor according to an embodiment of the present invention; [Figure 2] 1 is an exploded perspective view of a superconducting motor according to an embodiment of the present invention. [Figure 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. [Figure 5] FIG. 10 is a cross-sectional view of a superconducting motor according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[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, for example.

[0015] As shown in Figures 1 and 2, this superconducting motor 1 comprises a vacuum insulated container 10, a drive shaft 20 rotatably mounted relative to the vacuum insulated container 10, a rotor 30 fixed to the outer periphery of the drive shaft 20, a stator 40 mounted inside the vacuum insulated container 10 and facing the rotor 30 radially outward, a coil cooling container 50 that houses a superconducting coil of the stator 40 (described later) and through which a cooling medium for cooling the superconducting coil circulates, and an insulating material 60 arranged between the inner surface of the vacuum insulated container 10 and the outer surface of the coil cooling container 50.

[0016] The vacuum insulated container 10 has a cylindrical outer peripheral member 11 located on the outer periphery, a cylindrical inner peripheral member 12 located on the inner periphery, a first lid member 13 that closes one axial end of the outer peripheral member 11 and the inner peripheral member 12, and a second lid member 14 that closes the other axial end of the outer peripheral member 11 and the inner peripheral member 12.

[0017] The inner peripheral side member 12 has an inner peripheral cylindrical portion 12a extending between the first cover member 13 and the second cover member 14, and an engaging cylindrical portion 12b provided at one axial end of the inner peripheral cylindrical portion 12a, having larger outer dimensions than the inner peripheral cylindrical portion 12a, and engaging with the inner peripheral surface at one end of the outer peripheral side member 11.

[0018] The vacuum insulated container 10 has a cylindrical vacuum insulated space 10a surrounded by an outer peripheral member 11, an inner peripheral member 12, a first lid member 13, and a second lid member 14. The vacuum insulated container 10 blocks heat transfer between the inside and outside of the vacuum insulated space 10a by using a pump to create a vacuum in the vacuum insulated space 10a.

[0019] Here, the vacuum insulation space 10a has a pressure of 10 -2 Pa or more 10 3 The pressure is maintained at or below Pa.

[0020] The outer peripheral member 11, the inner peripheral member 12, the first cover member 13, and the second cover member 14 are formed of a resin material, for example, except for portions such as a first bearing and a second bearing (described later) that rotatably support the drive shaft 20. Examples of resin materials include polyolefin resin, polyamide resin, polyetheramide resin, polyimide resin, polyamideimide resin, polyurethane resin, urea resin, polyester resin, liquid crystal polyester resin, polyacetal resin, polycarbonate resin, polyphenylene ether (including modified polyphenylene ether) resin, polysulfone resin, polyethersulfone resin, polyphenylene sulfide resin, polyetheretherketone (including modified polyetheretherketone) resin, polyetherketone resin, polyaryletherketone resin, polyarylate resin, fluorine-based resin, polyphenylene oxide resin, polylactic acid, phenolic resin, melamine resin, epoxy resin, phenoxy resin, silicone resin, the modified resins described above, and resins containing fillers such as fiber-reinforced plastics. As the resin material, polyimide resin, polyamideimide resin, polybenzimidazole resin, polyetheretherketone resin, and fluororesin are more preferable, as they are usable over a wide range of temperatures and have high strength and dimensional accuracy.

[0021] 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 at the radial center of the first cover member 13, and the other end side is rotatably supported via a second bearing 22 at the radial center of the second cover member 14.

[0022] 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 periphery 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 them by caulking, 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.

[0023] The stator 40 has a stator core 41 housed in the vacuum insulation space 10a of the vacuum insulation 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.

[0024] The stator core 41 is formed by integrally forming a plurality of laminated electromagnetic steel plates 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 41b that protrude toward the center of the annular shape at intervals in the circumferential direction of the annular shape of the yoke portion 41a. As shown in Figures 3 and 4, the yoke portion 41a of the stator core 41 is supported by the fitting cylindrical portion 12b of the inner peripheral side member 12, and the tips of the plurality of teeth 41b are located near the outer peripheral surface side of the coil cooling vessel 50.

[0025] Each of the multiple superconducting coils 42 is made of wire made of, for example, a bismuth (Bi2)-based or yttrium (Y)-based superconducting material, and is wound around the outer periphery of a ring-shaped coil frame 42a, as shown in FIG. 2. As shown in FIG. 3, each of the multiple superconducting coils 42 is wound around a ring shape centered on an extension of the extension direction of the teeth 41b of the stator core 41. 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 multiple teeth 41b of the stator core 41 in a concentrated manner. Furthermore, electricity flowing through the multiple superconducting coils 42 is supplied from a current introducing portion 42b provided in the second cover member 14, as shown in FIGS. 1 and 2.

[0026] 2 and 3, the coil cooling container 50 has a cylindrical external shape in which a cylindrical refrigerant flow space 50a extending circumferentially of the vacuum insulation space 10a of the vacuum insulation container 10 is formed, and is supported by a flange portion 12a1 extending radially outward from one end of the inner cylindrical portion 12a of the inner peripheral member 12. 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 cylindrical portion 12a of the inner peripheral member 12, the first cover member 13, and the second cover member 14, and heat transfer between the outside of the vacuum insulation container 10 and the refrigerant flow space 50a is blocked.

[0027] In addition, the refrigerant flow space 50a accommodates a plurality of superconducting coils 42 spaced apart around the circumference of the cylindrical body, and the tip ends of the plurality of tooth portions 41b of the stator core 41 are located near the central portion of the annular coil frame 42a of each superconducting coil 42.

[0028] A refrigerant inlet pipe 51 for introducing a cooling medium is connected to the lower side of the outer peripheral 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 peripheral surface. A refrigerant inlet end 51a of the refrigerant inlet pipe 51, through which the cooling medium flows, and a refrigerant outlet end 52a of the refrigerant outlet pipe 52, through which the cooling medium flows, are each disposed on the second lid 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. The nitrogen vaporized by cooling the superconducting coil 42 flows out from the refrigerant outlet end 52a.

[0029] The thermal insulator 60 is disposed on the outer surface side of the coil cooling container 50 in the vacuum insulation space 10a of the vacuum insulation container 10, and is disposed mainly on the outer periphery side of the coil cooling container 50. The thermal insulator 60 includes a cylindrical first thermal insulator 61 disposed in the space surrounded by the first cover member 13, the fitting cylindrical portion 12b of the inner periphery side member 12, and the coil cooling container 50 in the vacuum insulation space 10a, a cylindrical second thermal insulator 62 disposed in the space between the inner periphery surface of the outer periphery side member 11 and the outer periphery surface of the stator core 41, and a cylindrical third thermal insulator 63 disposed in the space surrounded by the outer periphery side member 11, the second cover member 14, and the coil cooling container 50. The third thermal insulator 63 is divided into two parts, forming a pair of semi-cylindrical parts 63a, which are assembled so as to sandwich from the outside the coil cooling container 50 to which the refrigerant inlet pipe 51 and the refrigerant outlet pipe 52 are connected.

[0030] Examples of the insulating material 60 that can be used include fiber-based insulating materials such as glass wool, rock wool, and cellulose fiber, which are fiber materials; foam-based insulating materials such as expanded polystyrene beads, expanded polystyrene, urethane foam, and phenol foam, which are resin materials; and particulate-based insulating materials such as silica aerogel, fumed silica, and perlite, which are porous particulate materials. Particulate-based insulating materials, which have a small change in thermal conductivity even under vacuum pressure, are particularly preferred as the insulating material 60.

[0031] Here, a method for assembling the superconducting motor 1 will be described.

[0032] First, as shown in Figures 4(a) and 4(b), a first insulating material 61 is assembled to the inner side of the mating cylindrical portion 12b of the inner side member 12 of the vacuum insulated container 10, and then the stator core 41 is assembled to the mating cylindrical portion 12b, and the coil cooling container 50 is assembled to the flange portion 12a1 of the inner cylindrical portion 12a of the inner side member 12, and a second insulating material 62 is assembled to the outer side of the stator core 41.

[0033] Next, as shown in FIGS. 4(c) and 4(d), a third heat insulating material 63 consisting of a pair of semi-cylindrical parts 63a is attached to the outer periphery of the coil cooling vessel 50.

[0034] After assembling the third insulating material 63 on the outer periphery of the coil cooling vessel 50, as shown in Fig. 4(e), the first cover member 13 is assembled to one end of the inner periphery side member 12. After assembling the first cover member 13 to one end of the inner periphery side member 12, as shown in Fig. 4(f), the outer periphery side member 11 is fitted into the fitting cylindrical portion 12b of the inner periphery side member 12 and assembled to the first cover member 13.

[0035] After assembling the outer peripheral side member 11, as shown in FIG. 4(g), the drive shaft 20 and rotor 30 that are assembled together are inserted into the inner peripheral side of the inner cylindrical portion 12a of the inner peripheral side member 12, one end of the drive shaft 20 is supported by the first cover member 13 via the first bearing 21, and the other ends of the outer peripheral side member 11 and the inner peripheral side member 12 are closed by the second cover member 14.

[0036] Finally, as shown in FIG. 4(h), the other end of the drive shaft 20 is supported by the second cover member 14 via the second bearing 22.

[0037] 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. As a result, the occurrence of copper loss in the superconducting coil 42 during operation of the superconducting motor 1 is suppressed.

[0038] The coil cooling vessel 50 of the superconducting motor 1 accommodates only the superconducting coil 42, and the stator core 41 is accommodated in the vacuum insulation space 10a outside the coil cooling vessel 50. Therefore, the superconducting motor 1 of this embodiment consumes a small amount of 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 operation.

[0039] Furthermore, in the superconducting motor 1 of this embodiment, the inner peripheral member 12 of the vacuum insulating container 10 is formed of a non-magnetic and non-conductive material. Therefore, the superconducting motor 1 of this embodiment can suppress an increase in eddy current loss caused by magnetic flux lines interlinking with conductive materials without restricting the flow of magnetic flux lines between the rotor 30 and the stator 40.

[0040] Furthermore, in the superconducting motor 1 of this embodiment, the inner peripheral member 12 of the vacuum insulating container 10 separately supports the stator core 41 and the coil cooling container 50. Therefore, in the superconducting motor 1 of this embodiment, the plurality of teeth 41b and the coil cooling container 50 do not come into direct contact with each other, and heat transfer between them can be suppressed, so that the superconducting coil 42 housed in the coil cooling container 50 can be cooled intensively by the cooling medium.

[0041] Furthermore, in the superconducting motor 1 of this embodiment, the multiple teeth 41b of the stator core 41 do not penetrate the inner periphery of the annular shape of the superconducting coil 42 housed in the coil cooling container 50, and the tips of the teeth 41b are located near the outer periphery of the coil cooling container 50. Therefore, the shape of the coil cooling container 50 in the superconducting motor 1 of this embodiment is simple. Furthermore, the superconducting motor 1 of this embodiment can reduce the amount of heat released from the teeth 41b and transferred to the coil cooling container 50, making it possible to reduce the amount of cooling medium used.

[0042] In addition, in the superconducting motor 1 of this embodiment, the coil cooling container 50 is placed in the vacuum insulation space 10a of the vacuum insulation container 10, and an insulating material 60 is placed on the outer surface side of the coil cooling container 50 in the vacuum insulation space 10a, thereby suppressing the penetration of heat from the outside of the vacuum insulation container 10 to the inside of the coil cooling container 50.

[0043] As described above, the superconducting motor 1 of this embodiment includes a rotor 30 that is supported for free rotation, a stator 40 having a plurality of superconducting coils 42, a coil cooling container 50 that houses the superconducting coils 42 and through which a cooling medium for cooling the superconducting coils 42 flows, a vacuum insulation container 10 that has a vacuum insulation space 10a formed therein and in which the coil cooling container 50 is housed, and an insulating material 60 that is arranged on the outer surface side of the coil cooling container 50 in the vacuum insulation space 10a.

[0044] As a result, the insulating material 60 prevents heat from entering the coil cooling container 50, so the degree of vacuum in the vacuum insulation space 10a can be made lower than a high vacuum without reducing the insulating performance.This increases the freedom in the materials used to form the vacuum insulation container 10, and also makes it possible to evacuate the vacuum insulation space 10a using equipment such as a low-output pump, thereby reducing manufacturing costs.

[0045] Furthermore, it is preferable that the vacuum insulating container 10 has a portion made of a resin member.

[0046] This makes it possible to reduce the weight of the vacuum insulated container 10, thereby reducing the weight of the superconducting motor 1, thereby improving the operating efficiency of equipment driven by the superconducting motor 1 as a power source.

[0047] The vacuum insulation space 10a has a pressure of 10 -2 Pa or more 10 3 It is preferable that the temperature is kept at or below 1000 Pa.

[0048] This makes it possible to evacuate the vacuum insulation space 10a using a low-output pump, compared to when the vacuum insulation space 10a is made highly vacuum, while maintaining the insulating performance of the vacuum insulation.

[0049] Furthermore, the stator 40 preferably has a stator core 41 that enhances the magnetic force generated by the superconducting coil 42 .

[0050] This makes it possible to generate a large torque, and the superconducting motor 1 can be used in equipment that requires a large torque.

[0051] 5 is a cross-sectional view of a superconducting motor showing another embodiment of the present invention, in which the same components as those in the previous embodiment are denoted by the same reference numerals.

[0052] The superconducting motor 1 of this embodiment is a so-called coreless motor in which the stator 40 does not have the stator core 41 in the above embodiment.

[0053] In addition, instead of the first insulating material 61 and the second insulating material 62 in the above embodiment, the insulating material 60 consists of a cylindrical fourth insulating material 64 arranged in the space surrounded by the outer peripheral side member 11, the first cover member 13, the fitting cylindrical portion 12b of the inner peripheral side member 12 and the coil cooling container 50 at one end side of the vacuum insulating space 10a, and a third insulating material 63 similar to the above embodiment.

[0054] In the superconducting motor 1 configured as above, the superconducting coil 42 is in a superconducting state, and copper loss in the superconducting coil 42 is suppressed during operation, as in the previous embodiment.

[0055] Furthermore, in the superconducting motor 1 of this embodiment, as in the previous embodiment, the coil cooling container 50 is disposed in the vacuum insulation space 10a of the vacuum insulation container 10, and an insulating material 60 is disposed on the outer surface side of the coil cooling container 50 in the vacuum insulation space 10a, thereby suppressing the penetration of heat from the outside of the vacuum insulation container 10 to the inside of the coil cooling container 50.

[0056] As described above, according to the superconducting motor 1 of this embodiment, as in the previous embodiment, the heat insulating material 60 suppresses the penetration of heat into the coil cooling vessel 50, so that the degree of vacuum in the vacuum insulation space 10a can be made lower than a high vacuum without reducing the insulation performance. This increases the freedom in the material for forming the vacuum insulation vessel 10, and also makes it possible to evacuate the vacuum insulation space 10a using equipment such as a low-output pump, thereby enabling reductions in manufacturing costs.

[0057] In the above embodiment, an inner rotor type superconducting motor 1 is shown in which the rotor 30 having the permanent magnets 32 is arranged on the inner periphery side and the stator 40 having the superconducting coils 42 is arranged on the outer periphery side, but the present invention is not limited to this. For example, the present invention can also be applied to an outer rotor type superconducting motor in which a rotor having permanent magnets is arranged on the outer periphery side and a stator having superconducting coils is arranged on the inner periphery side.

[0058] In addition, in the above embodiment, liquid nitrogen is used as the cooling medium, but this is not limited to this, and for example, liquid helium may be used as the cooling medium as long as it is capable of cooling the superconducting coil.

[0059] In the above embodiment, the insulating material 60 is disposed on the outer peripheral surface side of the coil cooling container 50 in the vacuum insulation space 10a of the vacuum insulation container 10, but this is not limited to this. The insulating material may be disposed on the cylindrical inner peripheral surface side of the coil cooling container 50 as long as it is disposed on the outer peripheral surface side of the coil cooling container 50 in the vacuum insulation container 10. [Explanation of symbols]

[0060] 1. Superconducting motor 10 Vacuum insulated container 10a Vacuum insulated space 30 rotors 40 Stator 41 Stator core 42 Superconducting coil 50 Coil Cooling Vessel 60 Insulation

Claims

1. a rotor that is rotatably supported; a stator having a plurality of superconducting coils; a coil cooling vessel in which the superconducting coil is housed and through which a cooling medium for cooling the superconducting coil flows; a vacuum insulation container having a vacuum insulation space formed therein and accommodating the coil cooling container in the vacuum insulation space; a heat insulating material disposed on the outer surface side of the coil cooling container in the vacuum insulation space; Superconducting motor.

2. The vacuum insulated container has a portion made of a resin member.

2. The superconducting motor according to claim 1.

3. The vacuum insulation space has a pressure of 10 －２ Pa or more 10 ３ Pa or less 2. The superconducting motor according to claim 1.

4. The stator has a stator core that enhances the magnetic force generated by the superconducting coil.

4. The superconducting motor according to claim 1.

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