JPH0722232A - Supporting structure for superconducting electromagnet - Google Patents

Abstract

PURPOSE:To provide a highly rigid and mechanically excellent supporting structure for superconducting electromagnet which can absorb significant thermal shrinkage. CONSTITUTION:Arcuate surfaces for bearing compression load and tensile load, respectively, are provided at the securing part of a support 20 for supporting a radiation shield 4 and a superconducting coil 3 housed in a vacuum vessel 5. The load bearing surfaces are provided with a plurality of spherical seats 21, 22, 25 having an identical center of rotation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting electromagnet supporting structure in which a radiation shield and a superconducting coil are housed in a vacuum container (heat insulating container).

[0002]

2. Description of the Related Art FIG. 4 shows an example of a conventional superconducting electromagnet. The superconducting electromagnet 1 has a superconducting coil 2, and when the superconducting coil 2 is energized, a magnetic field is generated.
Since the superconducting coil 2 maintains the superconducting state, it needs to be kept at a cryogenic temperature at all times. Therefore, for example, the superconducting coil 2 is provided in the coil container 3, the radiation shield 4 is arranged outside the coil container 3, and they are finally housed in the vacuum container 5 to form the superconducting electromagnet 1.

Next, the coil container 3 and the radiation shield 4
Explain how is supported.

The radiation shield 4 is suspended from a vacuum container 5 by a suspension support 6a, and a shaft support 7 is provided.
Is pulled in the lateral direction. Since the shaft supports 7 are arranged on the left and right, the lateral movement of the radiation shield 4 is restricted. The weight of the radiation shield 4 is supported by the support 6b.

Similarly, the coil container 3 containing the superconducting coil 2 is suspended by the suspension support 6a and the shaft support 7, and is laterally stretched to restrain its movement.

[0006]

In the superconducting electromagnet 1 constructed as described above, in order to generate a magnetic field, to energize the superconducting coil 2, the superconducting coil 2 is cooled to an extremely low temperature and kept in the superconducting state. Must. At this time, the coil container 3 and the radiation shield 4 are also cooled to an extremely low temperature and contract respectively, so that the suspension support 6a, the support support 6b, and the shaft support 7 supporting them are stressed by the contraction. Will occur.

Generally, this stress tends to increase as the size of the superconducting magnet 1 increases. For example, the length of the coil container 3 is 8000 mm and the shaft support 7
If glass fiber reinforced plastic (FRP) is used as the material for the material and its length is 800 mm, stress of 100 Kgf / mm ² or more will be generated on the shaft support 7 when it is cooled to an extremely low temperature, and it will break. There is also.

For this reason, conventionally, as shown in FIG. 5, for example, a disc spring 8 is inserted into the shaft support 7 and the contraction of the disc spring 8 absorbs an excessive stress generated by cooling. Then, in FIG. 5, the shaft support 7
A screw rod 9 is fixed to the coil rod 3.
Is inserted into the fixed seat 3a fixed to the
And two nuts 10, 10 are screwed together.

That is, if the stress due to the thermal contraction of the coil container 3 is generated leftward in FIG. 5, the fixing seat 3a fixed to the coil container 3 also moves leftward. Here, since the shaft support 7 and the screw rod 9 are in a fixed state, the disc spring 8 contracts and absorbs thermal contraction.

However, when an electromagnetic force is applied to the coil container 3 in this state, the fixed seat 3a is difficult to move to the left, but easily moves to the right, so that it does not function as the shaft support 7. .

Further, since the coil container 3 contracts in the radial direction by cooling, bending stress is also applied to the shaft support 7 (since the coil container 3 contracts due to cooling, the same bending stress is applied to the suspension support 6a as well. Occurs). Therefore, conventionally, a structure having spherical seats 12 and 13 as shown in FIG. 6 is adopted so that the bending stress is not applied to the shaft support 7.

That is, in the support structure shown in FIG. 6, since the spherical seat 12 is fixed to the fixed seat 3a and the spherical seat 13 is screwed into the screw rod 9, when a bending stress is generated in the coil container 3. The spherical seat 12 is rotated with respect to the spherical seat 13 so that no bending stress is applied to the shaft support 7.

However, in the structure in which the spherical seats 12 and 13 are provided, only the leftward tensile load on the coil container 3 in FIG. 6 can be supported, and when the rightward compressive load is applied, the spherical container is fixed to the fixed seat 3a. The spherical seat 12 is moved and is useless. Therefore, if such a spherical seat support is adopted, the shaft supports 7 must inevitably be attached to both sides of the coil container 3, but as described above, a particularly large superconducting magnet causes a large shrinkage due to cooling, which results in a strong strength. It will not hold.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a mechanically excellent superconducting electromagnet supporting structure which can absorb a large heat shrinkage and has a large rigidity.

[0015]

In order to solve the above-mentioned problems, a support structure for a superconducting electromagnet according to the present invention is provided with a support for supporting a radiation shield and a superconducting coil housed in a vacuum container. Load supporting surfaces formed of arcuate surfaces for receiving a compressive load and a tensile load are respectively provided, and a plurality of spherical seats with the load supporting surfaces as the same rotation center are arranged.

[0016]

In the present invention having the above structure, the support supporting the radiation shield and the superconducting coil can receive a compressive load and a tensile load. Therefore, if the support is provided on only one side of the radiation shield and the superconducting coil, the support is supported. As a result, it is free from axial heat shrinkage due to cooling and does not generate excessive tensile stress in the support.

The bending stress generated by the thermal contraction of the superconducting coil in the radial direction can be easily supported from the center of rotation by disposing the spherical seat having the same center of rotation on the fixed portion of the support. It rotates to the same position, and excessive bending stress does not occur in the same manner as above.

Further, since no spring or the like is attached to the support, the support has a very high rigidity.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of a support structure for a superconducting electromagnet according to the present invention. It should be noted that the same or corresponding portions as those of the conventional configuration will be described using the same reference numerals as those in FIGS.

As shown in FIG. 1, a radiation container 4 and a coil container 3 having a superconducting coil are housed in a vacuum container 5. The radiation shield 4 is suspended by a plurality of suspension supports 6a (see FIG. 4; omitted in FIG. 1), and a load in the gravity direction is supported by a support support 6b (see FIG. 4: omitted in FIG. 1). The radiation shield 4 is axially supported by a plurality of shaft supports 7 (see FIG. 4; omitted in FIG. 1).

Like the radiation shield 4, the coil container 3 has a plurality of suspension supports 6a (see FIG. 4; omitted in FIG. 1),
The load in the gravity direction and the load in the axial direction are supported by the support 20 and the support 20, respectively. The support 20 has one end fixed to the coil container 3 and the other end fixed to the vacuum container 1.

FIG. 2 shows a fixed state of the coil container 3 and the support 20. As shown in FIG. 2, the fixed seat 3a is fixed to the coil container 3 by welding or bolting. The spherical seats 21 and 21 are fixed to both sides of the fixed seat 3a. At this time, the spherical surfaces (arc surfaces) of the two spherical seats 21 and 21 are concentric with the equivalent diameter φD about the rotation center P1.

On both sides of the spherical seat 21, a spherical seat 2 having an equivalent diameter that is substantially the same as or slightly larger than the equivalent diameter of the spherical seat 21 is provided.
2, 22 are arranged. The spherical seat 21, the spherical seat 22, and the fixed seat 3a are provided with holes through which the shaft 20a of the support 20 passes, and the shaft 20a is inserted through these holes.
The two nuts 23, 2 are attached to the threaded portion 20b formed at the tip of the
The support 20 is fixed by screwing 3 together.

FIG. 3 shows a fixed state of the vacuum container 5 and the support 20. As shown in FIG. 3, the spherical receiving seat 25 is fixed to the vacuum container 5 by welding, bolting or a screw machined in itself. A spherical surface having an equivalent radius R1 is machined on the spherical surface seat 25, while a spherical nut 26 (a spherical surface equivalent to the spherical surface) is machined on both ends of the support 10 so as to be concentric about P2. The radii R1 and R2) are screwed together.

A spherical pressing seat 27 is provided outside the spherical nut 26.
Is attached to the spherical nut 26 of the spherical pressing seat 27.
On the contact side of, a spherical surface having an equivalent radius that is substantially the same as or slightly smaller than the equivalent radius R2 is machined. Then, the spherical pressing seat 27 is attached to the spherical receiving seat 25 by a screw machined in itself.
It is fixed to.

Next, the operation of this embodiment will be described.

With the above-mentioned structure, the fixed seat 3a is formed even if the coil container 3 and the radiation shield 2 contract due to cooling.
Since the spherical seats 21 and 21 and the spherical seats 22 and 22 attached to both sides of the support 20 are the same spherical surface centering on the rotation center P1, the support 20 easily rotates about the rotation center P1 and the support 20 No excessive bending stress is applied to.

Similarly, on both sides of the spherical nut 26 attached to the support 20 on the side of the vacuum vessel 5, the rotation center P2 is provided.
Since the spherical surface is formed so that the equivalent radii R1 and R2 are concentric with respect to the center, the support 20 rotates around the rotation center P2.
Is easily rotated about the center of the support 20 and no excessive bending stress is generated in the support 20.

The load supporting surfaces are fixed seats 3a,
Since the spherical nuts 26 are located on both sides of the spherical nut 26, the support 20 configured as described above can receive both tensile load and compressive load.

As described above, according to this embodiment, since both the tensile load and the compressive load can be received, the support 20
Need only be provided on one side of the coil container 3, and as a result, there is almost no restraint against thermal contraction in the axial direction, and excessive tensile stress does not occur in the support 20.

The thermal shrinkage of the coil container 3 in the radial direction is
Since the shaft support rotates around the rotation centers P1 and P2 at the fixed positions of the support 20, no large bending stress is generated.

Furthermore, since the elements such as springs that reduce the rigidity of the shaft support are not used, the rigidity of the shaft support becomes very high.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in addition to the above-described embodiment, only the structures shown in FIGS. 2 and 3 are used for the vacuum container 1 side and the coil container 3 side, respectively. The same effect can be obtained even if is used on the coil container 3 side.

[0035]

As described above, according to the supporting structure of the superconducting electromagnet according to the present invention, the fixed portion of the support for supporting the radiation shield and the superconducting coil housed in the vacuum container is formed of an arc surface. By providing load supporting surfaces for receiving compressive load and tensile load respectively and arranging multiple spherical seats with these load supporting surfaces as the same center of rotation, large heat shrinkage is absorbed during cooling and excessive tension is applied to the support. No stress or bending stress is generated.

Further, since no spring or the like is used for the support, it is possible to obtain a mechanically excellent support having high rigidity.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a support structure for a superconducting electromagnet according to the present invention.

FIG. 2 is an enlarged cross-sectional view showing a fixed state of a coil container and a support in this embodiment.

FIG. 3 is an enlarged cross-sectional view showing a fixed state of a vacuum container and a support in this embodiment.

FIG. 4 is a sectional view showing a conventional superconducting electromagnet.

FIG. 5 is an enlarged view showing a state in which a support is fixed by using a spring in a conventional example.

FIG. 6 is an enlarged view showing a state in which a support is fixed using a spherical seat in a conventional example.

[Explanation of symbols]

 1 superconducting electromagnet 2 superconducting coil 3 coil container 3a fixed seat 4 radiation shield 5 vacuum container 6a hanging support 6b support support 7 axis support 20 support 21 spherical seat 22 spherical seat 23 nut 25 spherical receiving seat 26 spherical nut 27 spherical holding seat

Claims (1)

[Claims] 1. A load support surface for receiving a compressive load and a tensile load, each of which is formed of an arcuate surface, is provided on a fixed portion of a support that supports a radiation shield and a superconducting coil housed in a vacuum container. A support structure for a superconducting electromagnet, wherein a plurality of spherical seats having the same rotation center are arranged.