JPH062646A - Superconductive floating type turning gear - Google Patents

Abstract

PURPOSE:To make the surface flux density of a permanent magnet uniformizable as well as to secure the smooth rotation of a turntable, in a superconductive floating type turning gear that sets up a ringlike permanent magnet and an oxide superconductor rotatably in a relative manner. CONSTITUTION:Ringlike permanent magnets 1 consisting of Nd-Fe-B permanent magnets of six, twelve and eighteen divisions are embedded and set up in one side of a nonmagnetic material turntable 3 concentrically with a shaft 2 as the center, and each of ringlike metal soft magnetic materials 4 in the same form as the magnet is installed on each top of these ringlike permanent magnets 1. Since each surface flux density of these divided type permanent magnets installed on the turntable is uniformizable, the extent of resistance against rotation becomes lessened, and thus turning performance is improvable in this way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact superconducting levitation type rotating device for use in a flywheel or a magnetic bearing device for a power storage device utilizing the superconducting magnetic levitation force of an oxide superconductor, A superconducting levitation type in which a ring-shaped metallic soft magnetic material is fixed to the surface of the ring-shaped permanent magnet that faces the oxide superconductor to make the surface magnetic flux density generated by the ring-shaped permanent magnet uniform, enabling extremely smooth rotation of the rotating disk. Regarding a rotating device.

[0002]

2. Description of the Related Art Conventionally, a lot of research has been conducted on technology utilizing the physical characteristics of superconductors. In particular, recently, non-contact superconductivity utilizing superconducting levitation force by Meissner effect and pinning effect. The levitation type rotating device is theoretically capable of energy-free, low friction, high-speed rotation, and the like, and therefore its use for a magnetic bearing device, a large flywheel for a power storage device, and the like has been studied.

In particular, the discovery of oxide superconductors that operate at liquid nitrogen temperatures has made it possible to use liquid nitrogen as a cooling body, which is inexpensive and easy to handle, and a high-temperature superconducting bulk material having a strong superconducting levitation force. The development of was a major impetus for research using the levitation force for superconductors.

The electric power storage by the flywheel is one in which electric power is stored in rotational energy and is taken out and used as electric power when necessary. Larger superconducting flywheels allow more power storage, and such larger devices can be achieved by increasing the number of permanent magnets and superconductors.

Also in the magnetic bearing, in order to maintain stable rotation even when a large load is applied, and from the viewpoint of expansion of applications, it is required to increase their size. The following configurations are known as specific configurations of the bearing. 4 (Shikoku Electric Power Co., Inc., Shikoku Research Institute Co., Ltd., published in June 1991, Research Bulletin No. 57 (pages 52-61), written by Muneaki Shibayama and Ryoichi Takahata. This is explained with reference to “Basic characteristics of superconducting magnetic bearings and study of application to large flywheel bearings”), and a pair of discs 5 in which eight disc-shaped yttrium-based superconductors 6 are annularly embedded are provided as voids. The rotating discs 3 are formed so as to face each other, and the ring-shaped permanent magnets 1 are embedded on both surfaces in the space, and are arranged concentrically with the discs with a predetermined gap from the surface of each superconductor. The ring-shaped permanent magnet 1 is usually composed of a plurality of arc-shaped Nd-Fe-B-based permanent magnets,
It is embedded in the rotary disk 3 made of a non-magnetic material and integrated with the shaft 2. A drive motor 7 is installed above the shaft 2.

[0006]

In the above device,
When a rotating force is applied to the turntable 3 incorporating a permanent magnet by the drive motor 7, the non-contact state is maintained in principle due to the levitation force generated by the Meissner effect between the yttrium-based superconductor and the permanent magnet. It rotates semi-permanently. However, in reality, eccentricity occurs in the rotation of the disk due to the non-uniform magnetic force of each magnet, and the rotation eventually stops.

When the permanent magnet is disk-shaped and has a large diameter, the magnetic flux at the central portion becomes smaller than that at the outer peripheral portion, and the magnet itself cannot be used very efficiently.
Usually, it is used as a ring shape, and a plurality of ring magnets are arranged concentrically in order to obtain a required levitation force.

However, there is a limitation in manufacturing a large-sized ring-shaped permanent magnet as an integrated product, and a plurality of magnets having sizes within the manufacturable limit are bonded and arranged in a ring shape. Further, in order to make the magnetic force of the ring-shaped permanent magnet uniform, it is necessary to select and arrange a magnet having a similar magnetic force from a plurality of magnets, which is not efficient in terms of mass productivity. Moreover,
Since the magnets are adhered and integrated, it is inevitable that the magnetic flux density is low at the portion where the magnets and the magnets are circumferentially joined. The non-uniformity of the magnetic flux density causes a resistance against the rotation of the rotating disk, which causes the rotation to stop.

In view of the above-mentioned problems, the present invention is a superconducting levitation type rotating device in which a permanent magnet and an oxide superconductor are arranged so as to face each other, and the surface magnetic flux density of the permanent magnet can be made uniform and substantially non-contact. The object of the present invention is to provide a rotating device having a structure that enables permanent operation.

[0010]

DISCLOSURE OF THE INVENTION The present invention is a non-contact superconducting levitation type rotation in which at least one ring-shaped permanent magnet and an oxide superconductor which are opposed to each other with a gap are rotatably arranged. The superconducting levitation type rotating device is characterized in that a seamless ring-shaped metallic soft magnetic material penetrating in a facing direction is fixed to a surface of the ring-shaped permanent magnet facing the oxide superconductor.

In the present invention, since the superconductor used requires strong superconducting magnetic repulsion, YBa ₂ Cu is used.
₃ O _x, an oxide high-temperature superconductor such as _{Bi 2 Sr 2 Ca 2 Cu 3} O x is used. In particular, yttrium-based superconductors, which can provide strong repulsive force and stability against axis deviation, are suitable.

Conventional permanent magnets used in the present invention may be conventional cast magnets or ferrite magnets. However, the maximum energy required to generate a strong magnetic flux on the surface facing the superconductor and to downsize the device. High product Nd-Fe-B
A rare earth permanent magnet such as a system magnet is preferable. As described above, the permanent magnet needs to be composed of at least one ring-shaped permanent magnet, but the superconductor has a structure that achieves superconducting levitation by the good Meissner effect and pinning effect of these ring-shaped permanent magnets. Any configuration may be adopted, and for example, as shown in FIG. 3, a plurality of disc-shaped superconductors may be arranged in an annular shape so as to face the permanent magnets, and can be appropriately selected according to various characteristics required. . Further, when the outer diameter of the ring-shaped permanent magnet is small, a seamless integral type permanent magnet can be used, and when the outer diameter is large, a plurality of bow-shaped magnets are connected to form a ring-shaped permanent magnet having a required inner and outer diameter as in the embodiment. Can be assembled into a permanent magnet.

The permanent magnet and the superconductor are not limited to the structure in which the superconductor is arranged only on one magnetic pole facing surface of the permanent magnet.
Various configurations can be adopted, such as arranging at least one permanent magnet concentrically between a pair of superconductors. The magnetizing direction of the permanent magnet is the same as the facing direction of the superconductor in each case, but the magnetic poles (N, S) formed on each facing surface.
Is preferably selected according to the gap size (opposing distance) between the permanent magnet and the superconductor. That is, when the magnetic poles of the ring-shaped permanent magnets that are adjacent to each other in the radial direction have the same pole, even if the facing distance between the permanent magnet and the superconductor is relatively large, the magnetic flux generated from the permanent magnet is However, when the adjacent magnetic poles are different in polarity, if the distance is too large, some of the magnetic flux does not reach the superconductor, and thus does not act effectively on the superconductor. In consideration of these things, it is preferable to select the number, shape, arrangement, etc. of the permanent magnets.

The metal soft magnetic material adhered to the surface of the ring-shaped permanent magnet arranged on the rotating disk can be formed by punching from a single plate to form an integral ring having a required inner and outer diameters, and further having an outer diameter. If it is very large, it is formed into a ring shape by connecting arc-shaped members that divide the circumference into the required number, but the magnetic flux density generated when the seam penetrates in the direction facing the oxide superconductor of the permanent magnet is generated. In order to prevent the deterioration in the future, it is necessary to adopt a structure such as a wedge-shaped concave-convex fitting and overlapping inclined surfaces. Further, the thickness of the metal soft magnetic material is appropriately selected depending on the material described later and the dimensions of the permanent magnet. The metal soft magnetic material is preferably a material having a high saturation magnetic flux density, such as permendur, but it may be permalloy, pure iron, or a silicon steel plate. As for the method of joining the metal soft magnetic material and the permanent magnet, the metal soft magnetic material may simply be installed on the permanent magnet and fixed by the attractive force of the permanent magnet, but considering the use at high speed rotation, the adhesive It is desirable to firmly fix them by using such means as.

The rotary disk for supporting the above-mentioned permanent magnet is not limited to the disk-shaped structure shown in the embodiment,
Any form may be used as long as it can support one ring-shaped magnet or a plurality of ring-shaped magnets concentrically and does not impede relative rotation with the superconductor.
A non-magnetic material such as u is used.

Disclosure of the Invention According to the Drawings FIG. 1 and FIG. 2 show an example of a turntable for a superconducting levitation type rotating device according to the present invention. On one surface of the turntable 3a made of non-magnetic material, concentric 6-division, 12-division, and 18-division Nd-Fe- with the axis 2 as the center.
A ring-shaped permanent magnet 1 made of a B-system permanent magnet is embedded and arranged, and a ring-shaped metal soft magnetic material 4 having the same shape as the magnet is attached to the upper surface of each ring-shaped permanent magnet 1.

[0017]

In the superconducting levitation type rotating device according to the present invention, since the surface magnetic flux density of the split type permanent magnets provided on the rotating disk can be made uniform, the resistance against rotation can be reduced and the rotating performance can be improved. Further, by bonding the metal soft magnetic material to the surface of the facing surface of the permanent magnet, the magnetic flux density becomes larger than that of the permanent magnet alone, so that a stable levitation force can be obtained.

[0018]

Example: Outer diameter 220 mm, inner diameter 170 mm, height 20
The surface magnetic flux density of the 6-divided bonded product was measured with a ring-shaped Nd-Fe-B-based magnet of mm. As shown by the plot with a circle in FIG. 3, it can be seen that the magnetic flux density is significantly reduced at the bonded portion (seam). Therefore, by sticking a metallic soft magnetic material made of permendur having the same ring shape and a thickness of 2 mm to the permanent magnet, the magnetic flux density on the surface can be made uniform as shown by the plot of □ in FIG. It was

Further, the rotary disk 3 having the metal soft magnetic material 4 shown in FIG. 1 fixed to the surface of the ring-shaped permanent magnet 1 and arranged on both surfaces was used in the superconducting magnetic bearing device shown in FIG. When electric power is input to the drive motor of this device to operate it,
It was found that the rotation speed can be increased and the rotation performance is very good as compared with the case where the metal soft magnetic material is not fixed to the surface of the ring-shaped permanent magnet.

[0020]

The superconducting levitation type rotating device according to the present invention can make the surface magnetic flux density generated by the split type permanent magnet uniform, the resistance to the rotation becomes small, the eccentricity does not occur in the rotation of the disk, and the rotation performance is improved. Can be improved. Further, when a soft metal magnetic material is attached to the surface of the permanent magnet, the magnetic flux density becomes larger than that before attachment, and there is an advantage that a stable levitation force can be obtained. In addition, when the diameter of the rotary disk is increased, as in a flywheel for a power storage device, a multi-part permanent magnet is inevitably used, but the metal soft magnetic material of the present invention is attached to the surface of the permanent magnet. By setting
The surface magnetic flux density generated by the permanent magnet can be easily made uniform,
Even a rotating disc with a radius of several meters can be easily handled.

[Brief description of drawings]

FIG. 1 is a partially cutaway top view showing an example of a turntable used in a superconducting levitation type rotating device according to the present invention.

FIG. 2 is a vertical cross-sectional explanatory view in the diametrical direction in FIG.

FIG. 3 is a graph showing a relationship between a circumferential angle of a permanent magnet of a rotating disk and a magnetic flux density Bg on the surface of the permanent magnet.

FIG. 4 is a partially cutaway perspective view showing an example of a superconducting levitation type rotating device according to the present invention.

[Explanation of symbols]

 1 Ring-shaped permanent magnet 2 Axis 3, 3a Rotating disk 4 Metal soft magnetic material 5 Disk 6 Yttrium-based superconductor 7 Drive motor

Claims (1)

[Claims] 1. A non-contact superconducting levitation type rotating device in which at least one ring-shaped permanent magnet and a superconducting oxide which are opposed to each other with a gap formed therebetween are rotatably arranged relative to each other. 2. A superconducting levitation type rotating device, characterized in that a seamless ring-shaped metal soft magnetic material penetrating in the opposite direction is fixed to the surface of the oxide superconductor opposite to.