JP2605200B2 - Superconducting bearing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to, for example, a fluid machine or a machine tool requiring high speed rotation, an electric power storage device for converting surplus electric power into kinetic energy of a flywheel and storing it, or a gyroscope. To a superconducting bearing device to be used.

[0002]

2. Description of the Related Art In recent years, a superconducting device capable of supporting a rotating body in a non-contact state has been developed as a bearing device capable of rotating the rotating body at high speed and high rigidity.

As this type of superconducting bearing device, for example, one annular permanent magnet portion which is provided concentrically on a rotating body and whose opposite axial ends have polarities opposite to each other, and an end face of this permanent magnet are provided. And an annular superconductor disposed so as to face each other at an interval in the direction of the axis of rotation of the rotating body.

[0004]

However, since this type of bearing has a lower rigidity than conventional bearings, a superconductor having a strong pinning force has been developed (Murakami et al., I.
CMC90 Topical Conference
1990). Efforts have been made to optimize the dimensions of the magnets and the method of arranging the combination of magnets with different polarities, and the rigidity is 0.2 kgf / mm · c.
It has been reached in m ^2. (Shibayama et al., Shikoku Electric Power Research Bulletin No. 58, 1991). The use of a strong magnet having a high residual magnetic flux density is expected to increase about four times in the future, but there is still a problem that the practical level of rigidity of 1 kgf / mm · cm ² is insufficient by 20 to 30%.

[0005] The reason why this problem occurs is considered as follows. That is, the rigidity of the bearing is proportional to the gradient dB / dz of the magnetic flux density generated by the permanent magnet. Due to the periodic arrangement of the polarity of the magnets, the strength of the magnetic field on the side in contact with the superconductor is strengthened and contributes to the increase in rigidity, but the magnetoresistance is added due to the atmosphere on the side not in contact with the superconductor It has not been fully effective.

[0006]

SUMMARY OF THE INVENTION The present invention provides a superconducting bearing device capable of improving load capacity and rigidity, preventing shaft runout of a rotating body, and stably supporting the rotating body in a non-contact state. With the goal.

According to a first aspect of the present invention, there is provided a superconducting bearing device comprising: a disk-shaped permanent magnet portion extending in a direction perpendicular to a rotation axis of a rotating body; and a disk-shaped end surface of the permanent magnet portion. A superconducting bearing device comprising: an yttrium-based high-temperature superconductor disposed so as to face each other at an interval, wherein the permanent magnet portion is formed of a ferromagnetic material fixed to the rotating body. And a plurality of annular permanent magnets disposed concentrically with the rotation axis on a surface of the disk portion facing the superconductor and spaced apart from each other, and a permanent magnet adjacent to the disk portion. And a non-magnetic material disposed so as to be interposed between the magnets. Each of the plurality of permanent magnets has magnets of opposite polarities at the superconductor-side end and the disc-side end. Further, the ends of the adjacent permanent magnets on the superconductor side have opposite polarities. And characterized in that it is tinged with care.

According to a second aspect of the present invention, there is provided a superconducting bearing device, comprising: a disk-shaped permanent magnet portion extending in a direction perpendicular to a rotation axis of a rotating body; It is arranged so as to face each other at intervals in the radius of rotation of the body
A superconducting bearing device comprising an yttrium-based high-temperature superconductor, wherein the permanent magnet portion is fixed to the rotating body, and a disc portion made of a ferromagnetic material; and a side portion of the disc portion to the superconductor. A plurality of annular permanent magnets disposed so as to face each other and having an interval in the rotational axis direction, and a non-magnetic body interposed between adjacent annular permanent magnets,
Both ends in the rotational radius direction of the rotating body of each permanent magnet bear magnets of opposite polarities, and the same sides of adjacent permanent magnets bear magnets of opposite polarities.

[0009]

In any of the first and second aspects of the invention, the permanent magnet and the superconductor are held in a state where they face each other at a predetermined interval, and the rotating body is supported in a non-contact state. According to the superconducting bearing device according to the first aspect of the invention, the magnetic flux emitted from the positive electrode of one magnet is added to the magnetic flux emitted from the positive electrode of the other magnet toward the negative electrode side of the same magnet after reversing, And the gradient of magnetic flux density dB / dz increases. Further, since the space not in contact with the superconductor is occupied by the ferromagnetic material, the magnetic resistance is small, and the magnetic flux density in the space in contact with the superconductor can be kept high. For this reason, rigidity and loading force are improved.

Further, according to the superconducting bearing device of the second invention, the magnetic flux generated from the positive electrode of one magnet is reversed, and then the magnetic flux directed toward the negative electrode of the same magnet and generated from the positive electrode of the other magnet is reversed. Is added to As a result, the magnetic flux is strengthened, and the magnetic flux density gradient dB / dz increases.
Further, since the space not in contact with the superconductor is occupied by the ferromagnetic material, the magnetic resistance is small, and the magnetic flux density in the space in contact with the superconductor can be kept high. For this reason, rigidity and loading force are improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A superconducting bearing device according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a main portion of a superconducting bearing device designed as a first embodiment and having a loading force of about 200 kgf.

The superconducting bearing device has a vertical shaft-like rotating body 1.
It has. The rotating body 1 includes a horizontal disk-shaped permanent magnet 2
Are provided concentrically, and the annular superconductor section 3 is provided below the lower end surface of the permanent magnet section 2 so as to face the permanent magnet section 2 at an interval in the rotation axis direction of the rotating body 1. Are arranged.

The permanent magnet section 2 has a horizontal disk section 4 made of a ferromagnetic material, for example, steel, provided in a state fixed to the rotating body 1. As shown in FIG. 2, a plurality of seven annular partition walls 5 a to 5 g made of a nonmagnetic material, for example, duralumin, are formed on the disk portion 4 concentrically with the rotating body 1. Annular permanent magnets 6a to 6f are fitted and fixed between the partition walls 5a to 5g, respectively. All of the permanent magnets have magnets of opposite polarities at upper and lower ends, and the same vertical end of adjacent permanent magnets has magnetism of opposite polarities. For example, the upper end of the innermost permanent magnet 6a has an N pole and the lower end has S pole magnetism. The upper end of the second permanent magnet 6b from the inside has an S pole and the lower end has N pole magnetism. Takes on. The magnetic flux distribution around the rotation axis is not changed by the rotation.

The superconductor portion 3 has a perforated horizontal disk portion 7 made of, for example, copper and an annular portion around the hole 7a of the perforated disk portion 7 facing the permanent magnets 6a to 6f and in the circumferential direction. Disc-shaped superconductors 8 buried adjacent to each other
Consisting of

The superconductor 8 is made of an yttrium-based high-temperature superconductor, for example, one in which normal conductive particles (Y ₂ Ba ₁ Cu ₁ ) are uniformly mixed in a substrate made of YBa ₂ Cu ₃ O _x , It has the property of restricting the intrusion of the magnetic flux emitted from the magnet 2. The superconductor 8 is arranged at a separated position where the magnetic flux of the permanent magnet portion 2 enters by a predetermined amount and at a position where the distribution of the invading magnetic flux does not change due to the rotation of the rotating body.

A cooling case 11 cooled by a temperature control unit 10 and a refrigerator 9 is fixed in a housing (not shown) of the superconducting bearing device.
1, a superconductor section 3 is fixed.

When operating the superconducting bearing device, the superconductor 8 is cooled by an appropriate refrigerant circulated in the cooling case 11 and is kept in a superconducting state. For this reason,
Most of the magnetic flux emitted from the permanent magnet portion 2 of the rotating body 1 enters the superconductor 8 and is restrained (pinning phenomenon). Here, since the superconductor 8 has the normal conductor particles uniformly mixed therein, the distribution of the magnetic flux penetrating into the superconductor 8 becomes constant. Therefore, the permanent magnet 2 of the rotating body 1 is as if penetrated by the virtual pin erected on the superconductor 8, and the rotating body 1 is restrained by the superconductor 8 together with the permanent magnet portion 2. Therefore, the rotating body 1 is supported in the axial direction and the radial direction while being extremely stably levitated.

Permanent magnets 6a-6 adjacent to the permanent magnet portion 2
Since the magnetic flux of f is strengthened by the magnetic flux being emitted from the adjacent magnets and being reversed, the gradient dB / dz of the magnetic flux density is larger than that in the case where a single permanent magnet is provided in the permanent magnet portion. Become. Therefore, the magnetic repulsion between the permanent magnet portion 2 and the superconductor 8 increases.

Moreover, the upper sides of the six permanent magnets adjacent to each other are connected by steel having a high magnetic permeability, so that the magnetic resistance of the magnetic circuit is reduced. The magnetic flux density in the lower space in contact with the superconductor becomes larger and the gradient of the magnetic flux density becomes larger than when the upper and lower spaces are occupied by air and a nonmagnetic material. This increases the stiffness.

(Specific Experimental Example) This experimental example was carried out using the apparatus shown in FIG. 3 in which a part of the large thrust bearing shown in FIG. 1 was extracted and simulated for experiments.

The permanent magnet section 12 simulating a part of the rotor side
A plate formed of steel was used as the flat plate 14. Bar-shaped rare earth magnets having a width of 20 mm, a thickness of 15 mm, and a length of 160 mm were used as the bar-shaped magnets 16a to 16f that simulate a part of the ring magnet. Each bar magnet was a combination of different poles in which the same vertical end of an adjacent bar magnet had opposite polarities. The partition has a height of 15 mm, a width of 8 mm and a length of 160
A duralumin square bar of mm was used. Also, the superconductor 18
As a result, seven simulated discs having a diameter of 108 mm and a thickness of 12 mm were formed by accumulating seven pieces each having a diameter of 36 mm and a thickness of 12 mm, and buried in a copper disc 17.

The permanent magnet section 12 and the superconductor section 13
After superposition, the superconductor 18 was cooled and maintained in a superconducting state. At this time, the distance Z between the permanent magnet section 12 and the superconductor section 13 was 2 mm. Then, the permanent magnet part 12 and the superconductor part 1 were measured using a tensile compression tester.
3 was relatively approached or separated, and the required weight was measured. FIG. 4 shows the results. When the distance Z is 1.
The rigidity in the range of 3 to 2.7 mm is 6.4 kgf /
mm.

For comparison, when the flat plate 4 was changed from steel to duralumin, the permanent magnet portion and the superconductor portion were relatively moved closer to or away from each other, and the required load was measured. The result is shown in FIG. The distance Z is 1.3
The stiffness in the range of ２2.7 mm was 4.7 kg / mm.

As described above, the distribution of the magnetic flux density was measured in order to examine the causal relationship between the effect of the arrangement of the magnets and the material of the partition walls on the rigidity. The magnetic flux density under the arrangement and material of FIG. 3 of the present invention was as shown in FIG. 6 on the perpendicular line to the center of the magnet. The magnetic flux density distribution when the conventional flat plate and the partition are all made of duralumin is shown by a broken line in the figure.

In the range of Z = 2 to 14 mm occupied by the superconductor, the magnetic flux density B and its gradient dB / dz are about 1.2 times, which tends to increase the rigidity (1.36 times). I do.

FIG. 7 schematically shows a main part of the superconducting bearing device according to the second embodiment.

In this case, the permanent magnet portion 32 has a disk portion 34 made of a ferromagnetic material, for example, steel. A plurality of, for example, three annular partition walls 35a to 35c are formed on the outer peripheral surface of the disk portion 34 at intervals in the vertical direction, and are formed of a non-magnetic material, for example, duralumin. To 36b are fitted and fixed. Each of the permanent magnets 36a, 36b has magnets of opposite polarities on both sides in the radial direction, and the adjacent permanent magnets 36a, 36b
On the same side in the radial direction are magnetized with opposite polarities.
For example, the outer periphery of the upper permanent magnet 36a has N pole and the inner periphery has S pole magnetism, and the outer periphery of the lower permanent magnet 36b has S pole and the inner periphery has N pole magnetism. ing. The magnetic flux distribution around the rotation axis is not changed by the rotation.

A superconductor 33 is disposed at a position facing the outer peripheral surface of the permanent magnet portion 32 at an interval in the radial direction of the rotating body 31. The superconductor 33 may be a complete ring or a part of the ring.

Also in this case, as described in the first embodiment, first, the magnetic fluxes of the adjacent permanent magnets 36a and 36b on the outer peripheral portion of the permanent magnet portion 32 are emitted from the adjacent magnets and are being reversed. Second, since the inner space not in contact with the superconductor is occupied by a ferromagnetic material, the gradient of the magnetic flux density dB / dz in the outer space in contact with the superconductor is reduced by the permanent magnet. It is larger than when a single permanent magnet is provided in the portion or when a non-magnetic material is used as a partition. Therefore, the magnetic repulsion between the permanent magnet portion 32 and the superconductor 33 increases.

Moreover, the nature of the loading force due to this magnetic force is as follows:
The distance between the permanent magnet portion 32 and the superconductor 33 is slightly increased in the direction of the axis of rotation due to the distance between the magnetic repulsion force and the pinning force, and a large magnetic attraction force is generated therebetween. Conversely, if the distance is slightly smaller than the hanging distance, a large magnetic repulsion is generated between the two. Therefore, according to the configuration of the above embodiment, the load capacity and rigidity of the superconducting bearing device are improved.

[0032]

According to the superconducting bearing device according to the first and second aspects of the present invention, the ferromagnetic disk portion is arranged on the opposite surface of the superconductor, having the above-described configuration. In each of the plurality of permanent magnets, the end on the superconductor side and the end on the disk portion side are magnetized with polarities opposite to each other, and the ends on the superconductor side of adjacent permanent magnets are opposite to each other. Since the magnet has polar magnetism, the gradient dB / dz of the magnetic flux density is increased, the load capacity and rigidity are improved, and the rotating body is prevented from being displaced during rotation, so that the rotating body is in a non-contact state. And can be stably supported.

[Brief description of the drawings]

FIG. 1 is a schematic view of a main part of a superconducting bearing device according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged view showing an arrangement state of permanent magnets in the superconducting bearing device shown in FIG.

FIG. 3 is a schematic diagram of a main part of a partial model in which a part of a superconductor bearing is extracted for a rigidity test.

FIG. 4 is a graph showing the results of an experiment performed using a partial model according to the first embodiment.

FIG. 5 is a graph showing the results of an experiment performed for comparison.

FIG. 6 is a graph showing a result of an auxiliary experiment performed for investigating an effect of the present invention.

FIG. 7 is a schematic view of a main part of a superconducting bearing device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotating body 2 Permanent magnet part 3 Superconductor part 4 Ferromagnetic disk part 5a-5g Nonmagnetic partition wall 6a-6f Annular permanent magnet 14 Ferromagnetic flat plate 15a-15f Square rod-shaped permanent magnet 34 Strong Disk portion of magnetic material 36a-36b Annular permanent magnet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Koji Koyama 1420 Yashima Nishimachi, Takamatsu City, Kagawa Prefecture (72) Inventor Fumihiko Ishikawa 2867-4 Kitamachi, Takamatsu City, Kagawa Prefecture (72) Inventor Hiromasa Higasa Takamatsu, Kagawa Prefecture 2911-5 Kitamachi (56) References Japanese Utility Model 1-104430 (JP, U) Japanese Utility Model 1-100924 (JP, U) Japanese Utility Model 61-49125 (JP, U) Japanese Utility Model 59-144221 (JP, U)

Claims (2)

(57) [Claims] 1. A disk-shaped permanent magnet portion extending in a direction perpendicular to a rotation axis of a rotating body, and a disk-shaped end surface of the permanent magnet portion is disposed so as to face with a space therebetween. Done it
A superconducting bearing device comprising a lithium-based high-temperature superconductor, wherein the permanent magnet portion has a disk portion made of a ferromagnetic material fixed to the rotating body, and a surface of the disk portion facing the superconductor. And a plurality of annular permanent magnets disposed concentrically with the rotation axis and separated from each other, and a non-magnetic material disposed so as to be interposed between adjacent permanent magnets in the disk portion. Each of the plurality of permanent magnets has an end on the superconductor side and an end on the disc side having magnets having polarities opposite to each other,
Further, the superconducting bearing device is characterized in that ends of the adjacent permanent magnets on the superconductor side are magnetized with polarities opposite to each other. 2. A disk-shaped permanent magnet portion extending in a direction orthogonal to the rotation axis of the rotating body, and spaced apart from the outer peripheral surface of the permanent magnet portion in the rotating radius direction of the rotating body. A superconducting bearing device comprising: an yttrium-based high-temperature superconductor arranged to face each other, wherein the permanent magnet portion is fixed to the rotating body and is made of a ferromagnetic disk. A plurality of annular permanent magnets arranged on the side surface so as to face the superconductor, and having an interval in the rotation axis direction, and a non-magnetic material interposed between adjacent annular permanent magnets. A superconducting bearing device in which both ends in the rotational radius direction of the rotating body of each permanent magnet bear magnets of opposite polarities and the same sides of adjacent permanent magnets bear magnets of opposite polarities.