JP2003049836A - Superconductive magnetic bearing device and superconductive flywheel device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce rotational loss and improve reliability after assembling a flywheel device by supporting thrust and radial directions with a superconductive body. SOLUTION: High temperature superconductive bulk bodies 18, 19 are installed on a heat conduction plate 15, the heat conduction plate 15 and a refrigerating machine 16 are installed on a second casing 2 kept in a vacuum, a deflectable conductor 17 is accommodated in the second casing 2, and the second casing 2 is detachably installed at a casing 1. The high temperature superconductive bulk bodies 18, 19, the refrigerating machine 16 and the like are integrated and modulated by the second casing 2, and the thrust and radial directions are supported by a superconductive magnetic bearing 33 to reduce the rotational loss. Thus, reliability after assembling the flywheel device can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnetic bearing device and a flywheel device, and is suitable for use in, for example, a flywheel for power storage.

[0002]

2. Description of the Related Art A superconducting magnetic bearing device is constructed so as to support a rotating shaft in a non-contact manner by magnetic levitation using a permanent magnet and a superconductor, and has a rotational loss such as viscous resistance as compared with a bearing through an oil film. There is no problem. For this reason, various bearing devices such as flywheels for electric power storage have been conventionally applied.

[0003]

Since the superconducting magnetic bearing device needs to be used at a low temperature, a superconductor or the like is placed in a vacuum atmosphere and is used in a vacuum-insulated state. . Further, since the supporting force is not as strong as that of mechanical bearings, the supporting force of the rotating shaft is secured by variously devising the size and the like. Therefore, the conventional superconducting magnetic bearing device has a room for various improvements including rotation loss and maintainability.

The present invention has been made in view of the above circumstances, and is a superconducting magnetic bearing device which suppresses rotation loss, is excellent in maintainability, and is capable of independent function inspection, and a fly using the superconducting magnetic bearing device. It is an object to provide a wheel device.

[0005]

The structure of a superconducting magnetic bearing device of the present invention for achieving the above object is provided with a rotary shaft which is driven and rotated in a casing held in a vacuum, and a thrust collar is provided on the rotary shaft. Fix it, attach the thrust permanent magnet to the thrust collar, attach the thrust superconductor arranged with a gap to the thrust permanent magnet to the heat conduction plate, and connect the heat conduction plate to the refrigerator via the flexible conductor. ,
The heat conducting plate and the refrigerator are attached to the second casing which is held in vacuum, the flexible conductor is accommodated in the second casing, and the second casing is detachably attached to the casing.

The thrust superconductor is a high-temperature superconducting bulk body.

Further, the structure of the superconducting magnetic bearing device of the present invention for achieving the above-mentioned object comprises a rotating shaft which is driven and rotated in a casing which is held in a vacuum, and a thrust collar is fixed to the rotating shaft, Attach a thrust permanent magnet to the collar, attach a ring-shaped radial permanent magnet to the rotating shaft, attach the thrust superconductor that is placed with a gap to the thrust permanent magnet to the heat conduction plate, and attach it to the radial permanent magnet. The radial superconductor arranged with a gap between them is attached to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, and the heat conduction plate and the refrigerator are attached to the second casing held in vacuum. It is characterized in that the flexible conductor is accommodated in the second casing while being attached, and the second casing is detachably attached to the casing.

Further, the structure of the superconducting magnetic bearing device of the present invention for achieving the above object is such that a rotating shaft which is driven and rotated is provided in a casing which is held in a vacuum, and a thrust collar is fixed to the rotating shaft. Attach a thrust permanent magnet to the collar, attach a ring-shaped radial permanent magnet to the rotating shaft, attach the thrust superconductor that is placed with a gap to the thrust permanent magnet to the heat conduction plate, and attach it to the radial permanent magnet. The radial superconductor arranged with a gap therebetween is attached to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, and the heat conduction plate is supported on the casing side.

The thrust superconductor and the radial superconductor are high-temperature superconducting bulk bodies.

A flywheel device of the present invention for achieving the above object is a superconducting magnetic bearing device according to any one of claims 1 to 5, and a flywheel fixed to a rotating shaft of the superconducting magnetic bearing device. It is characterized by having.

[0011]

FIG. 1 shows a cross section of a flywheel device to which a superconducting magnetic bearing device according to a first embodiment of the present invention is applied.

As shown in FIG. 1, a second casing 2 is attached to the lower surface of a casing 1 whose lower side is open, and the upper end of a rotary shaft 3 is rotatably supported by an upper radial bearing 31 on the casing 1. The lower end of the rotary shaft 3 is rotatably supported on the second casing 2 by a lower radial bearing 32. The rotary shaft 3 is composed of an upper shaft 5, an intermediate shaft 6 and a lower shaft 7. Lower flange of upper shaft 5
A support disk 8 is sandwiched between 5a and an upper flange 6a of the intermediate shaft 6 and fixed by bolts or the like, and a flywheel ring 9 is fixed to the outer circumference of the support disk 8.

A thrust collar 10 is sandwiched between a lower flange 6b of the intermediate shaft 6 and an upper flange 7a of the lower shaft 7 and fixed by a bolt or the like. The lower surface of the thrust collar 10 has a ring-shaped inner peripheral permanent magnet. 11 and a ring-shaped outer peripheral permanent magnet 12 are provided with an intermediate ring 13 interposed. The inner circumferential permanent magnet 11 and the outer circumferential permanent magnet 12 are, for example, Nd-based (neodymium-based) magnets or Pr-based (praseodymium-based) magnets.

The upper surface of the second casing 2 is formed of, for example, a heat conduction plate 15 made of copper, and the refrigerator 16 is attached to the lower surface of the second casing 2. The heat conduction plate 15 and the refrigerator 16 are, for example, They are connected by a flexible conductor 17 made of copper. The flexible conductor 17 is accommodated inside the second casing 2.

A high temperature superconducting bulk body 18, which is a thrust superconductor, is bonded to the surface of the heat conducting plate 15 facing the inner and outer peripheral permanent magnets 11 and 12. Opposing surface of the upper surface of the second casing 2 (upper surface of the high temperature superconducting bulk body 18)
Is covered with the thrust sealing plate 40 so that the second casing 2 is sealed. High temperature superconducting bulk body 18
For example, a Y-based (yttrium-based) superconducting substance or a Gd-based (gadolinium-based) superconducting substance is applied. Rotating shaft 3
Are rotatably supported by being supported in the thrust direction by a superconducting magnetic bearing 33 composed of an inner peripheral permanent magnet 11, an outer peripheral permanent magnet 12 and a high temperature superconducting bulk body 18.

A generator / motor 22 having an upper shaft 5 serving as a rotor is provided above the casing 1, and the generator / motor 22 is charged and discharged to rotate energy of a rotary shaft 3 provided with a flywheel ring 9. It is designed to input and output.

A vacuum exhaust port 23 for making the inside of the casing 1 into a vacuum state is provided in the upper part of the casing 1, and by making the inside of the casing 1 into a vacuum state through the vacuum exhaust port 23, wind damage of the rotating shaft 3 is prevented. Reduced and superconducting magnetic bearing 3
Vacuum insulation of 3 is performed.

On the other hand, a second vacuum exhaust port 24 is provided on a side portion of the second casing 2, and an auxiliary vacuum exhaust port 25 is provided at a portion of the casing 1 corresponding to the second vacuum exhaust port 24. The second vacuum exhaust port 24 is connected to the auxiliary vacuum exhaust port 25, and the second vacuum exhaust port 24 and the auxiliary vacuum exhaust port 25 are connected.
By making the inside of the second casing 2 into a vacuum state via the, the vacuum insulation of the superconducting magnetic bearing 21 and the flexible conductor 17 is performed. Second vacuum exhaust port 24 and auxiliary vacuum exhaust port 25
Is connected through a manhole (not shown) or a work hole (not shown) provided in the casing 1.

It is also possible to open the second vacuum exhaust port 24 into the casing 1 and simultaneously perform vacuum exhaust of the casing 1 and the second casing 2 from the vacuum exhaust port 23.

In the flywheel device to which the above-mentioned superconducting magnetic bearing device is applied, the superconducting magnetic bearing 33, the refrigerator 16, the flexible conductor 17, a part of the rotating shaft 3 and the like are externally mounted on the second casing 2 side. After performing various performance tests and confirmation of airtightness, the remaining rotary shaft 3 and the casing 1 are attached from above, and the flywheel device is assembled. Then, a magnetic repulsive force is generated between the high temperature superconducting bulk body 18 of the superconducting magnetic bearing 33 and the inner circumferential permanent magnet 11, and the weight of the rotating shaft 3 provided with the flywheel ring 9 is supported by levitation to support the thrust direction. To support.

Since the inside of the casing 1 is in a vacuum state, the windage loss of the rotating shaft 3 is reduced, and the rotating loss is reduced because the rotating shaft 3 is supported in the thrust direction by the superconducting magnetic bearing 33. The rotation efficiency is kept high. Further, since the high-temperature superconducting bulk body 18 is directly cooled by the heat conduction plate 15 by the refrigerator 16 via the flexible conductor 17 that is vacuum-insulated in the second casing 2,
The cooling structure is compact and the refrigeration loss can be reduced. Further, since the cooling devices such as the refrigerator 16 and the flexible conductor 17 are arranged adjacent to the superconducting magnetic bearing 33, the heat entering the cooling path can be minimized.

Since the superconducting magnetic bearing 33, the refrigerator 16 and the flexible conductor 17 are integrated into a module by the second casing 2, the bearing portion, the refrigerator portion and the connecting portion are assembled on the second casing 2 side. The second casing 2 can be assembled to the casing 1 after the attachment work of the heat insulating material or the like is performed independently. Therefore, the work of attaching the device of the refrigerator unit can be performed easily and with high quality, and the assembling work can be facilitated and the accuracy can be improved. Moreover, since it is not necessary to perform these operations under the flywheel, it is possible to minimize difficult operations.

Furthermore, since the superconducting magnetic bearing 33, the refrigerator 16 and the flexible conductor 17 are integrated into a module by the second casing 2, the second casing 2 can be evacuated by itself, and the flywheel device can be used. The airtightness check, cooling test, and thrust bearing performance test with vibration and load applied before assembly are possible in the atmosphere. Therefore, the reliability after assembling the flywheel device is improved, and it is possible to prevent the disassembling / reassembling work due to misalignment after the flywheel device is assembled once, and the assembling / maintenance work can be prevented. It can be shortened.

A second embodiment of the present invention will be described with reference to FIG. FIG. 2 shows a cross section of a flywheel device to which a superconducting magnetic bearing device according to a second embodiment of the present invention is applied. The same members as those shown in FIG. 1 are designated by the same reference numerals.

As shown in FIG. 2, a second casing 2 is attached to the lower surface of a casing 1 whose lower side is open, and the upper and lower ends of a rotating shaft 3 are rotatably supported by auxiliary ball bearings 4 on the casing 1. It is supported. The rotating shaft 3
It is rotatably supported by being supported in a thrust direction and a radial direction by a superconducting magnetic bearing 21. The rotary shaft 3 is composed of an upper shaft 5, an intermediate shaft 6 and a lower shaft 7. A support disk 8 is sandwiched between the lower flange 5a of the upper shaft 5 and the upper flange 6a of the intermediate shaft 6 and fixed by bolts or the like, and a flywheel ring 9 is fixed to the outer periphery of the support disk 8.

A thrust collar 10 is sandwiched between a lower flange 6b of the intermediate shaft 6 and an upper flange 7a of the lower shaft 7 and fixed by bolts or the like. The lower surface of the thrust collar 10 has a ring-shaped inner peripheral permanent magnet. 11 and a ring-shaped outer peripheral permanent magnet 12 are provided with an intermediate ring 13 interposed. Further, four sets of permanent magnet rings 14 are provided on the outer periphery of the lower shaft 7 in the axial direction. The inner peripheral permanent magnet 11, the outer peripheral permanent magnet 12, and the permanent magnet ring 14 are, for example, Nd-based (neodymium-based) magnets or Pr-based (praseodymium-based) magnets.

The upper surface of the second casing 2 and the portion facing the lower shaft 7 are formed by, for example, a heat conduction plate 15 made of copper, and a refrigerator 16 is attached to the lower surface of the second casing 2 and the heat conduction plate 15 is attached. The refrigerator 16 and the refrigerator 16 are connected by a flexible conductor 17 made of copper, for example. And the flexible conductor 1
7 is accommodated inside the second casing 2.

A high temperature superconducting bulk body 18, which is a thrust superconductor, is joined to the surface of the heat conducting plate 15 facing the inner and outer peripheral permanent magnets 11 and 12, and the heat conducting plate 15 faces the permanent magnet ring 14. A high temperature superconducting bulk body 19 which is a radial superconductor is joined to the surface. The upper surface of the second casing 2 and the surface facing the lower shaft 7 (the upper surfaces of the high-temperature superconducting bulk bodies 18 and 19) are covered with the sealing plate 41 so that the second casing 2 is sealed. For the high-temperature superconducting bulk body 18 and the high-temperature superconducting bulk body 19, for example, a Y-based (yttrium-based) superconducting substance or a Ga-based (gadolinium-based) superconducting substance is applied.

A generator / motor 22 having an upper shaft 5 serving as a rotor is provided above the casing 1, and the generator / motor 22 is charged / discharged to rotate energy of a rotary shaft 3 provided with a flywheel ring 9. It is designed to input and output.

A vacuum exhaust port 23 for vacuuming the inside of the casing 1 is provided on the upper part of the casing 1, and the inside of the casing 1 is vacuumized via the vacuum exhaust port 23 to prevent wind damage of the rotary shaft 3. Reduced and superconducting magnetic bearing 2
Vacuum insulation of 1 is performed.

On the other hand, a second vacuum exhaust port 24 is provided on the side portion of the second casing 2, and an auxiliary vacuum exhaust port 25 is provided on the portion of the casing 1 corresponding to the second vacuum exhaust port 24. The second vacuum exhaust port 24 is connected to the auxiliary vacuum exhaust port 25, and the second vacuum exhaust port 24 and the auxiliary vacuum exhaust port 25 are connected.
By making the inside of the second casing 2 into a vacuum state via the, the vacuum insulation of the superconducting magnetic bearing 21 and the flexible conductor 17 is performed. Second vacuum exhaust port 24 and auxiliary vacuum exhaust port 25
Is connected through a manhole (not shown) or a work hole (not shown) provided in the casing 1.

As in the case of the first embodiment, it is possible to open the second vacuum exhaust port 24 into the casing 1 and simultaneously perform vacuum exhaust of the casing 1 and the second casing 2 from the vacuum exhaust port 23. is there.

In the flywheel device to which the above-mentioned superconducting magnetic bearing device is applied, the superconducting magnetic bearing 21, the refrigerator 16, the flexible conductor 17, a part of the rotary shaft 3 and the like are externally mounted on the second casing 2 side. After performing various performance tests and confirmation of airtightness, the remaining rotary shaft 3 and the casing 1 are attached from above, and the flywheel device is assembled. Then, a magnetic repulsive force is generated between the high temperature superconducting bulk body 18 of the superconducting magnetic bearing 21 and the inner peripheral permanent magnet 11 and the outer peripheral permanent magnet 12 to levitate the weight of the rotary shaft 3 provided with the flywheel ring 9 by levitation. It supports and supports in the thrust direction, and supports the moment of the rotating shaft 3 in the radial direction.

Since the inside of the casing 1 is in a vacuum state, the windage loss of the rotary shaft 3 is reduced, and since the rotary shaft 3 is supported by the superconducting magnetic bearing 21 in the thrust direction and the radial direction, the rotation loss is reduced. It is greatly reduced, and the rotation efficiency is kept extremely high. Further, the high-temperature superconducting bulk body 18 and the high-temperature superconducting bulk body 19 are integrally cooled by direct cooling by the heat conduction plate 15 by the refrigerator 16 via the flexible conductor 17 vacuum-insulated in the second casing 2. Therefore, the cooling structure is compact and the refrigeration loss can be reduced. Further, since the cooling device such as the refrigerator 16 and the flexible conductor 17 is arranged adjacent to the superconducting magnetic bearing 21, the heat entering the cooling path can be minimized.

Since the superconducting magnetic bearing 21, the refrigerator 16 and the flexible conductor 17 are integrated into a module by the second casing 2, the bearing portion, the refrigerator portion and the connecting portion are assembled on the second casing 2 side. The second casing 2 can be assembled to the casing 1 after the attachment work of the heat insulating material or the like is performed independently. Therefore, the work of attaching the device of the refrigerator unit can be performed easily and with high quality, and the assembling work can be facilitated and the accuracy can be improved. Moreover, since it is not necessary to perform these operations under the flywheel, it is possible to minimize difficult operations.

Further, since the superconducting magnetic bearing 21, the refrigerator 16 and the flexible conductor 17 are integrated into a module by the second casing 2, the second casing 2 can be evacuated by itself, and the flywheel device can be used. Airtightness check and cooling test before assembly, and thrust and radial bearing performance test with vibration and load added are possible in air atmosphere. For this reason, the reliability after assembling the flywheel device is improved, and it is possible to prevent the disassembling / reassembling work due to misalignment after the flywheel device is assembled once, and the assembling / maintenance work can be prevented. It can be shortened.

The inside of the second casing 2 and the inside of the casing 1 shown in FIG. 2 may be configured to be open, and the superconducting magnetic bearing 21 may be vacuum-insulated by vacuum exhaust from the vacuum exhaust port 23. And in this case also, the rotary shaft 3
Is supported by the superconducting magnetic bearing 21 in the thrust direction and the radial direction, the rotation loss is reduced, and the rotation efficiency is kept extremely high.

[0038]

The structure of the superconducting magnetic bearing device of the present invention is as follows.
A thrust that is equipped with a rotating shaft that is driven and rotated in a casing that is held in a vacuum, a thrust collar is fixed to the rotating shaft, and a thrust permanent magnet is attached to the thrust collar. The superconductor is attached to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, the heat conduction plate and the refrigerator are attached to the second casing that is held in vacuum, and the flexible conductor is accommodated in the second casing. Since the second casing is detachably attached to the casing, the thrust superconductor, the refrigerator, and the like can be integrated into a module by the second casing.

Therefore, the windage loss of the rotating shaft is reduced, and the rotating shaft is supported in the thrust direction by the thrust superconductor, so that the rotating loss is reduced and the rotating efficiency is kept high. Further, since the refrigerator and the cooling device such as the flexible conductor are arranged adjacent to the thrust superconductor, the heat entering the cooling path can be minimized.

Further, the second casing can be assembled to the casing after the bearing part, the refrigerator part, the connecting part and the like are assembled and the heat insulating material is attached independently on the second casing side. It is possible to easily and high-quality mount the equipment, and to facilitate the assembling work and improve the accuracy.

Furthermore, the second casing can be evacuated independently, and the airtightness check, cooling test, and thrust bearing performance test with vibration and load applied can be performed in the atmosphere, and reliability is improved. It will be possible to shorten the assembly and maintenance work.

Further, the structure of the superconducting magnetic bearing device of the present invention comprises a rotating shaft which is driven and rotated in a casing which is held in a vacuum, a thrust collar is fixed to the rotating shaft, and a thrust permanent magnet is attached to the thrust collar. Along with it, a ring-shaped radial permanent magnet is attached to the rotating shaft, and a thrust superconductor is placed with a gap between it and the thrust permanent magnet. The radial superconductor is attached to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, the heat conduction plate and the refrigerator are attached to the second casing that is held in vacuum, and the flexure is applied to the second casing. Since the conductor is accommodated and the second casing is detachably attached to the casing, the thrust superconductor and the radial It can be integrated module of the conductor or the refrigerator or the like.

Therefore, the windage loss of the rotary shaft is reduced, and the rotary shaft is supported in the thrust direction and the radial direction by the thrust superconductor and the radial superconductor, so that the rotation loss is greatly reduced and the rotation efficiency is extremely high. Maintained in a state. Further, since the cooling device such as the refrigerator and the flexible conductor is arranged adjacent to the thrust superconductor and the radial superconductor, the heat entering the cooling path can be minimized.

Further, the second casing can be assembled to the casing after the bearing part, the refrigerator part, the connecting part and the like are assembled and the heat insulating material is attached on the second casing side. It is possible to easily and high-quality mount the equipment, and to facilitate the assembling work and improve the accuracy.

Furthermore, the second casing can be evacuated independently, and the airtightness check, cooling test, thrust and radial bearing performance test with vibration and load applied can be performed in the atmosphere. The reliability is improved and the assembly and maintenance work can be shortened.

Further, the structure of the superconducting magnetic bearing device of the present invention is provided with a rotating shaft which is driven and rotated in a casing held in vacuum, the thrust collar is fixed to the rotating shaft, and the thrust permanent magnet is attached to the thrust collar. Along with it, a ring-shaped radial permanent magnet is attached to the rotating shaft, and a thrust superconductor is placed with a gap between it and the thrust permanent magnet. Since the radial superconductor is attached to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, and the heat conduction plate is supported on the casing side, the thrust superconductor and the radial superconductor are used to thrust the rotating shaft. Can be supported in both the radial direction and the radial direction, and rigidity can be imparted to the inclination of the rotating shaft.

Therefore, the windage loss of the rotary shaft is reduced, the rotation loss is significantly reduced, and the rotation efficiency is maintained in a very high state. Further, since the cooling device such as the refrigerator and the flexible conductor is arranged adjacent to the thrust superconductor and the radial superconductor, the heat entering the cooling path can be minimized.

The flywheel device of the present invention is defined in claim 1.
Since the superconducting magnetic bearing device according to any one of claims 5 to 5 and the flywheel fixed to the rotating shaft of the superconducting magnetic bearing device are provided, the superconducting magnetic bearing device is useful for power storage and the like having a flywheel.

[Brief description of drawings]

FIG. 1 is a sectional view of a flywheel device to which a superconducting magnetic bearing device according to a first embodiment of the present invention is applied.

FIG. 2 is a sectional view of a flywheel device to which a superconducting magnetic bearing device according to a second embodiment of the present invention is applied.

[Explanation of symbols]

1 casing 2 Second casing 3 rotation axes 4 auxiliary ball bearings 5 Upper shaft 6 Middle axis 7 Lower shaft 8 support discs 9 flywheel ring 10 Thrust color 11 Inner circumference permanent magnet 12 Peripheral permanent magnet 13 Middle ring 14 Permanent magnet ring 15 heat conduction plate 16 refrigerator 17 Flexible conductor 18,19 High temperature superconducting bulk 21,33 Superconducting magnetic bearing 22 Power generator / motor 23 Vacuum exhaust port 24 Second vacuum exhaust port 25 Auxiliary vacuum exhaust port 31 Upper radial bearing 32 Lower radial bearing 41 Sealing plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kiyoshi Furumura             20 Kitakanzan, Otakamachi, Midori-ku, Nagoya-shi, Aichi             No. 1 Chubu Electric Power Co., Inc.             Inside the technical laboratory (72) Inventor Naoji Kashima             20 Kitakanzan, Otakamachi, Midori-ku, Nagoya-shi, Aichi             No. 1 Chubu Electric Power Co., Inc.             Inside the technical laboratory (72) Inventor Masaharu Minami             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Yu Kawashima             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Works, Mitsubishi Heavy Industries, Ltd. F term (reference) 3J102 AA01 BA03 CA21 DA02 DA03                       DA06 FA30                 5H607 BB25 DD09 GG03 GG23

Claims (6)

[Claims] 1. A rotary shaft, which is driven and rotated in a casing held in a vacuum, has a thrust collar fixed to the rotary shaft, a thrust permanent magnet is attached to the thrust collar, and a gap is interposed between the thrust permanent magnet. The thrust superconductor arranged as a unit to the heat conduction plate, the heat conduction plate is connected to the refrigerator via the flexible conductor, the heat conduction plate and the refrigerator are attached to the second casing that is held in vacuum, and the second casing is also attached. A superconducting magnetic bearing device, wherein a flexible conductor is accommodated and a second casing is detachably attached to the casing. 2. The superconducting magnetic bearing device according to claim 1, wherein the thrust superconductor is a high-temperature superconducting bulk body. 3. A casing, which is held in a vacuum, is provided with a rotating shaft that is driven to rotate, a thrust collar is fixed to the rotating shaft, a thrust permanent magnet is attached to the thrust collar, and a ring-shaped radial permanent magnet is attached to the rotating shaft. Attach the thrust superconductor that is placed with a gap to the thrust permanent magnet to the heat conduction plate, and attach the radial superconductor that is placed with a gap to the radial permanent magnet to the heat conduction plate. Connecting the heat conducting plate to the refrigerator via a flexible conductor, attaching the heat conducting plate and the refrigerator to a second casing held in vacuum, and accommodating the flexible conductor in the second casing, and placing the second casing in the casing. A superconducting magnetic bearing device that is detachably attached. 4. A rotary shaft that is driven and rotated in a casing that is held in a vacuum, a thrust collar is fixed to the rotary shaft, a thrust permanent magnet is attached to the thrust collar, and a ring-shaped radial permanent magnet is attached to the rotary shaft. Attach the thrust superconductor that is placed with a gap to the thrust permanent magnet to the heat conduction plate, and attach the radial superconductor that is placed with a gap to the radial permanent magnet to the heat conduction plate. The superconducting magnetic bearing device is characterized in that the heat conducting plate is connected to the refrigerator via a flexible conductor, and the heat conducting plate is supported on the casing side. 5. The superconducting magnetic bearing device according to claim 3 or 4, wherein the thrust superconductor and the radial superconductor are high-temperature superconducting bulk bodies. 6. A flywheel device, comprising: the superconducting magnetic bearing device according to claim 1; and a flywheel fixed to a rotation shaft of the superconducting magnetic bearing device.