JP2764546B2 - Superconducting bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting bearing device having increased rigidity so as to stably float without control.

[0002]

2. Description of the Related Art A high-temperature superconductor that reaches a superconducting state at the temperature of liquid nitrogen has a state in which the Meissner effect that completely eliminates the magnetic field from the superconductor depends on the magnitude of the external magnetic field, and a part of the magnetic field enters the superconductor. And the state where the pinning effect is mixed. In the former case, the same properties as those of a general superconductor cooled by liquid helium are exhibited, but in the latter case, a repulsive force by the superconductor portion and an attraction force by the pinning center portion are generated.

FIG. 4 shows a conventional superconducting bearing device, in which a high-temperature superconductor 1 is provided on a support side, and an annular permanent magnet 3 is arranged on a lower peripheral portion of a magnetic material 2 such as soft iron on a floating surface. ,
A columnar permanent magnet 4 is arranged at the center, the permanent magnet 3 at the periphery is arranged with NS polarity, and the permanent magnet 4 at the center is arranged with SN polarity opposite thereto. Therefore, the magnetic flux distribution of the permanent magnets 3 and 4 cannot enter the superconductor 1 due to the Meissner effect as shown in the magnetic flux diagram of FIG.
The permanent magnets 3, 4 and the magnetic body 2 float by receiving a repulsive force in the axial direction.

In a normal use state, the superconducting bearing device is used while being levitated as described above. At this time, a magnetic field of several thousand gauss is required to secure a necessary levitation force. Therefore, in a state where the permanent magnets 3 and 4 are levitated by the axial repulsive force, for example, when a force is applied in the lateral direction, the permanent magnets 3 and 4 return to the original position by the restoring force due to the pinning effect of the high-temperature superconductor 1. Since the permanent magnets 3 and 4 on the floating side receive the force, they are stably levitated.

This is because pseudo-permanent magnets having a small magnetomotive force having a polarity opposite to that of the permanent magnets 3 and 4 disposed opposite to the superconductor 1 are generated inside the superconductor 1. This is because a restoring force is generated. This is the same as the restoring force generating mechanism of the control type magnetic bearing in which the permanent magnets are arranged to face each other to control the attraction force to stably float.

[0006]

However, the most distinctive feature of the superconducting bearing device is that it floats stably without control, and it is essential to improve this stabilizing force in practical use. On the other hand, in the above-described conventional superconducting bearing device, if the magnetic material 2 floating above the superconductor 1 is largely displaced in a direction parallel to the surface facing the superconductor 1, the restoring force is not sufficient and the stability is lacking. There is a point.

An object of the present invention is to solve the above-mentioned problems,
It is an object of the present invention to provide a superconducting bearing device with improved restoring force against displacement.

[0008]

According to the present invention, there is provided a superconducting bearing device comprising a supporting superconductor and a magnetic body having a floating permanent magnet attached thereto. In the apparatus, a second permanent magnet is added to a side surface of the superconductor outside the first permanent magnet so that repulsive force is generated with the first permanent magnet,
When the first permanent magnet is relatively displaced in parallel with a surface facing the superconductor, a restoring force is generated by the repulsive force between the first permanent magnet and the second permanent magnet. And

[0009]

In the superconducting bearing device of the present invention having the above structure, the second permanent magnet is added to the side surface of the superconductor on the supporting side at a position outside the first permanent magnet attached to the magnetic material on the floating surface. Accordingly, when the magnetic body is relatively displaced in parallel with the surface facing the superconductor, the magnetic body is restored by the repulsive force of the first permanent magnet and the second permanent magnet.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a cross-sectional view of a thrust bearing according to a first embodiment. A disc-shaped magnetic member made of soft iron or the like floating above and having substantially the same diameter as a superconductor 10 is provided at a position facing a superconductor 10 on a support side. An annular permanent magnet 1 is provided around a surface of the magnetic body 11 facing the superconductor 10 side.
2 are provided, and a columnar permanent magnet 13 is provided at the center. At this time, the polarities of the permanent magnets 12 and 13 are arranged such that repulsive forces are generated. Further, an annular permanent magnet 16 is added to the side surface of the superconductor 10, and the permanent magnet 16 has an inner diameter larger than the outer diameter of the permanent magnet 12, and the polarities of the permanent magnets 16 are arranged so as to generate repulsive forces. .

The magnetic flux from the permanent magnets 12 and 13 is distributed in the same manner as in the conventional example, and the magnetic material 11 on the floating surface floats by the repulsive force due to the Meissner effect. At the same time, high-temperature superconductor 1
At 0, a restoring force is generated by the attractive force of the pseudo permanent magnet generated inside due to the pinning effect, and the levitation is stabilized.

In the present embodiment, a second permanent magnet 16 having a larger diameter than the floating permanent magnet 12 is added to the side surface of the superconductor 10 so that the permanent magnet 12 and the permanent magnet 16 exert a repulsive force. When the permanent magnets 12 on the floating side are largely displaced in one of the horizontal directions by arranging them so as to have the opposite polarities, the second permanent magnets 16 return the first permanent magnets 12 from the outside. The repulsive force acts as described above, so that the rigidity in the horizontal direction can be increased. In this way,
More stable and strong levitation can be realized.

FIG. 2 shows a second embodiment and is a sectional view of a radial bearing. A cylindrical or cylindrical superconductor 20 is arranged at the center, and annular permanent magnets 21 and 22 are arranged in opposite polarities so as to surround the periphery thereof.
An annular yoke 23 made of a magnetic material such as soft iron is provided on the upper side, a yoke 24 is provided between the permanent magnets 21 and 22, and a yoke 25 is provided below the permanent magnet 22. With these yokes, the magnetic flux of the permanent magnet is concentrated at the end of the yoke, thereby increasing the magnetic flux density. Permanent magnet 2
The outer diameters of the yokes 23, 24, 25 are the same, and the inner diameters of the yokes 23, 24, 25 are the same as those of the permanent magnet 21.
22 which is equal to or smaller than the inner diameter of the tube 22. Further, a columnar or annular second permanent magnet 26 is provided below the superconductor 20 with a reverse polarity so that a repulsive force acts on the permanent magnet 22.

Annular permanent magnet 2 surrounding superconductor 20
In the first and the second, a repulsive force acts in the radial direction and a restoring force acts in the axial direction, so that the surfaces 1 and 22 can stably float. The floating permanent magnets 21 and 22 may be magnetized in any of a radial direction and an axial direction. However, as shown in FIG. 2, annular permanent magnets 21 and 22 magnetized in the axial direction are used. By combining and laminating magnetic poles of opposite polarities, an axial restoring force is generated, and by further increasing the lamination of the permanent magnet and the yoke, a larger axial restoring force and a radial repulsive force are generated. .

The second permanent magnet 26 added to the superconductor 20 is for increasing the axial restoring force.
By arranging the second permanent magnet 26 magnetized in the axial direction with a polarity opposite to that of the permanent magnet 22, the yokes 23, 24, 25
Is shifted downward, an axial restoring force is increased by a repulsive force between the permanent magnets 22 and 26, so that axial displacement of the rotating body can be suppressed.

FIG. 3 is a graph of measured values obtained by measuring the relationship between the axial displacement d and the restoring force N in the second embodiment. The second permanent magnet 26 is not added to the superconductor 20 side. FIG. 9 is a graph of the actual measurement value A according to the conventional method and the actual measurement value B according to the improved method according to the present invention when the second permanent magnet 26 is added. The magnitude of the restoring force is about twice as large in the improved system as in the conventional system.

[0017]

As described above, in the superconducting bearing device according to the present invention, the second permanent magnet is added to the superconductor on the supporting side to repel the first permanent magnet on the floating surface from the outside. By applying a force, a restoring force can be improved in the event of a shift, and stable levitation can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a first embodiment.

FIG. 2 is a sectional view of a second embodiment.

FIG. 3 is a graph showing a restoring force and an axial displacement.

FIG. 4 is a sectional view of a conventional example.

[Explanation of symbols]

 10, 20 Superconductor 11 Magnetic body 12, 13, 16, 21, 22, 26 Permanent magnet 23, 24, 25 Yoke

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-272539 (JP, A) JP-A-5-180226 (JP, A) JP-A-5-60139 (JP, A) JP-A-4- 331815 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) F16C 32/04

Claims (2)

(57) [Claims] 1. A superconducting bearing device comprising a superconductor on a supporting side and a magnetic body to which a first permanent magnet on a floating surface is attached , wherein the superconducting member located outside the first permanent magnet is provided.
A repulsive force is generated on the side of the body with the first permanent magnet
A second permanent magnet is added to the first permanent magnet
The superconductor is not relatively positioned in parallel with the surface facing the superconductor.
In this case, the repulsive force is applied to the second permanent magnet.
A superconducting bearing device characterized in that more restoring force is generated . 2. The first and second permanent magnets are annular bodies.
The superconducting bearing device according to claim 1 .