JPH05240246A - Method for assembling superconductive bearing device - Google Patents

Abstract

PURPOSE:To improve rigidity and load capacity, prevent the shaft deflection of a rotating body and stably support the rotating body in non-contact state. CONSTITUTION:A superconductor 17 is preliminarily cooled and held in superconductive state. A vertical shaft-like rotating body 2 and the superconductor 17 are arranged in such a manner that a ring permanent magnet part 9 provided concentrically and firmly to the vertical shaft-like rotating body 2 in this state is opposed to the superconductor 17 with a vertical space.

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 which is applied to, for example, a fluid machine or a machine tool which requires high-speed rotation, or an electric power storage device for converting surplus electric power into kinetic energy of a flywheel and storing it. Assembling method

[0002]

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

As a superconducting bearing device of this type, the applicant of the present invention has, for example, an annular permanent magnet portion concentrically and fixedly provided on a rotating body, and an axis of rotation of the rotating body with respect to an end face of the permanent magnet portion. We have developed one that has annular superconductors that are arranged so as to face each other at intervals in the direction.

[0004] This superconducting bearing device is designed to operate after the rotating body provided with the permanent magnet portion and the annular superconductor are arranged at predetermined positions, and then the superconductor is cooled to be kept in the superconducting state.

However, when the superconducting bearing device is operated as described above, there is a problem that rigidity and load capacity in the direction of the rotation axis are insufficient. In addition, there is a problem in that the rigidity of the rotating body causes axial deviation of the rotating body, which makes it impossible to stably support the rotating body in a non-contact state.

The reason why such a problem occurs is considered as follows. That is, the magnetic field strength H of the permanent magnet
And the magnetic flux density B decreases in inverse proportion to the distance to the permanent magnet as the distance increases. When the distance between the superconductor and the permanent magnet is Z, the apparent magnetic susceptibility generated by the superconductor is M, the magnetic field strength of the permanent magnet is H, and the magnetic flux density of the permanent magnet is B, the superconductor and the permanent magnet are The magnetic repulsive force between the magnet and the magnet is a value proportional to the product of the magnetic susceptibility M and the gradient dH / dZ of the magnetic field strength or the product of the magnetic susceptibility M and the gradient dB / dZ of the magnetic flux density. Is the magnetic susceptibility M and d ² B / d
Although proportional to the product of Z ² , when operated as described above, the gradient dH / dZ of the magnetic field strength of the annular permanent magnet or the gradient dB / dZ of the magnetic flux density does not become sufficiently large, and therefore the load It is considered that the capacity and rigidity are insufficient.

An object of the present invention is to provide a method of assembling a superconducting bearing device which solves the above problems.

[0008]

A method of assembling a superconducting bearing device according to the present invention includes an annular permanent magnet portion concentrically and fixedly provided on a rotating body, and an interval between the permanent magnet portion and the permanent magnet portion. A method for assembling a superconducting bearing device comprising a superconductor arranged so as to face each other, wherein the superconductor is cooled in advance and held in a superconducting state, and in this state, the permanent magnet portion and the superconductor are The rotating body and the superconductor are arranged so as to face each other with a space.

[0009]

When the rotating body and the superconductor are arranged such that the superconductor is cooled and held in the superconducting state in advance and the permanent magnet portion and the superconductor are opposed to each other with a gap in this state. Is compressed between the permanent magnet portion and the superconductor, and the gradient of magnetic flux density dB / dz increases and d ² B / dZ ² increases. Therefore, load capacity and rigidity are improved.

[0010]

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

FIG. 1 schematically shows the structure of a superconducting bearing device.

The superconducting bearing device comprises a housing (1) arranged vertically and a vertical shaft-shaped rotating body (2) supported in a non-contact state at the center of the housing (1).

A high-frequency motor (3) for rotating the rotating body (2) at a high speed is provided above the housing (1) to support the rotating body (2) in the housing (1) in a non-contact state. A superconducting bearing (4) is provided.

The housing (1) has a cylindrical shape, and a hollow portion (6) for circulating the coolant (C) is formed on the entire peripheral wall of the housing (1). Although not shown, the housing
A refrigerator is connected to the hollow portion (6) of (1) through a temperature control unit.

The electric motor (3) comprises a rotor (7) attached to the rotating body (2) and a stator arranged around the rotor (7).
It consists of (8) and.

The superconducting bearing (4) is constructed as follows. A horizontal disk-shaped permanent magnet portion (9) is concentrically provided on the rotating body (2) at the upper and lower central portions in the housing (1). The permanent magnet part (9) includes a horizontal disc (10) fixedly provided on the rotating body (2) and made of, for example, copper. An annular groove (11) is formed concentrically with the rotating body (2) on each of the upper and lower surfaces of the disc (10).
An annular permanent magnet (12) is fitted and fixed in each of (1). The permanent magnet (12) is provided so that the magnetic flux distribution around the rotation axis of the rotating body (2) does not change due to rotation.

Horizontal annular superconductor parts (13) and (14) are arranged at the upper and lower ends of the housing (1). Both superconductor parts (13) and (14) are made of, for example, copper perforated horizontal discs (15) and (16) and perforated discs (15) (16) holes (15a) (16).
On the surface facing the permanent magnet part (9) of the annular part around a),
It is composed of a plurality of disc-shaped superconductors (17) embedded in the circumferential direction so as to be close to each other. And in the holes (15a) (16a) the rotating body
(2) is passed through with a gap. Screws (1) are attached to the outer peripheral surfaces of the disks (15) (16) of the upper and lower superconductors (13) (14), respectively.
5b) and (16b) are formed, and these screws (15b) and (16b) are attached to the upper and lower ends of the inner peripheral surface of the housing (1).
It is mounted on the housing (1) by screwing it onto a) (1b). All the disc-shaped superconductors (17) of both superconductor parts (13) and (14) have the same volume.

The superconductor (17) is composed of a yttrium-based high-temperature superconductor, for example, a YBa ₂ Cu ₃ O _x substrate in which normal conductive particles (Y ₂ Ba ₁ Cu ₁ ) are uniformly mixed. It has the property of restraining the magnetic flux penetrating from the permanent magnet section (9). Then, the superconductor (1
7) is arranged at a separated position where the magnetic flux of the permanent magnet portion 9 invades 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 2.

2 to 5 show step by step a method of assembling the superconducting bearing device.

First, the housing (1) is assembled into a stand (20).
Then, cool the housing (1) by circulating a coolant (C) such as liquid nitrogen in the hollow part (6) (see Fig. 2). On the other hand, the annular superconductor parts (13) and (14) are immersed in a coolant such as liquid nitrogen to be cooled, and the superconductor (17) is kept in a superconducting state. Then, after the lower annular superconductor part (14) is screwed into the housing (1) (see Fig. 3), the rotating body (2) provided with the permanent magnet part (9) is placed in the housing (1). Through, and the screw (2a) formed at the lower end thereof is screwed into the screw hole (21) formed in the assembly stand (20) (see FIG. 4). After that, the upper annular superconductor part (13) is
Screw it into (1) (see Fig. 5).

At this time, most of the magnetic flux generated from the permanent magnet portion (9) of the rotating body (2) is compressed between the superconductor portion (13) and (14), and a part thereof is superconductor. It will enter the inside of (17) and be restrained (pinning phenomenon). Here, since the superconductor (17) has the normal conductor particles uniformly mixed therein, the distribution of the magnetic flux penetrating into the inside of the superconductor (17) becomes constant, and therefore, as if the superconductor (17) The permanent magnet part of the rotating body (2) is attached to the erected virtual pin.
(9) seems to be penetrated, and the rotating body (2) is restrained together with the permanent magnet part (9) with respect to the superconductor (17). Therefore, the rotating body (2) is very stably levitated,
It will be supported in the axial and radial directions.

Finally, the rotor (7) of the high-frequency electric motor (3) is attached to the screw (2b) formed on the upper end of the rotating body (2), and the stator (8) is arranged around the rotor (7), and further assembled. Remove the stand (20). In this way, the superconducting bearing device is assembled to support the rotating body (2) in a non-contact state, and the high frequency motor (3) rotates the rotating body (2) at a high speed to start the operation.

Since the magnetic flux generated from the permanent magnet portion (9) is compressed between the permanent magnet portion (13) and the superconductor portion (14), the magnetic flux density gradients dB / dZ and d ² B / dZ ² are Magnet part (9)
Also, the size becomes larger than that in the case where the superconductor (17) is cooled after the superconductor parts (13) and (14) are arranged to be in the superconducting state. Therefore, the magnetic repulsive force between the permanent magnet part (9) and the superconductor (17) becomes large. Moreover, the permanent magnet part (9) and the superconductor (1
A large magnetic attraction force acts between them and 7) only by slightly increasing in the direction of the axis of rotation from the distance where the magnetic repulsive force and the pinning force are balanced. On the contrary, when the distance is slightly smaller than the balance distance, a large magnetic repulsive force acts between them. Therefore, load capacity and rigidity are improved.

In this embodiment, as the superconductor, a type 1 superconductor, that is, a superconductor which completely blocks the penetration of magnetic flux may be used. In this case, the rotating body (2) is supported in the axial direction in a non-contact state by utilizing the perfect diamagnetic phenomenon of the superconductor. In this case, in order to support the rotating body (2) in the radial direction, it is preferable to provide a superconducting bearing at an appropriate position.

[0025]

[Specific Experimental Example] This experimental example was carried out using the apparatus shown in FIG.

The disk (10) of the permanent magnet part (9) is made of copper, and the annular permanent magnet (12) has an outer diameter of 90 mm, an inner diameter of 68 mm, an axial length of 12 mm, and a surface magnetic flux. An annular rare earth magnet of 4000 gauss was used, and a superconductor (17) having a diameter of 28 mm and a thickness of 12 mm was used.

Then, the apparatus was assembled as described above. Then, using a tensile compression tester,
(9) and the superconductor parts (13) and (14) were relatively moved closer to or apart from each other by 0.5 mm, and the load required for them was measured.
The result is shown in FIG. The rigidity was 8 kgf / mm.

For comparison, after arranging the permanent magnet part and the superconductor part, the superconductor part is cooled to be in a superconducting state,
In the same manner as above, the permanent magnet portion and the superconductor portion were relatively moved toward or away from each other by 0.5 mm, and the load required for them was measured. The result is shown in FIG. 7. The rigidity at this time was 4 kgf / mm.

[0029]

According to the method of assembling the superconducting device of the present invention, as described above, the gradient dB / dZ of the magnetic flux density becomes large and the d ² B / dZ ² becomes large. Therefore, the load capacity and the rigidity are improved, the shaft deviation of the rotating body can be prevented, and the rotating body can be stably supported in a non-contact state.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a main part of a superconducting bearing device.

FIG. 2 is a vertical cross-sectional view showing a state in which a housing is attached to an assembly stand.

FIG. 3 is a vertical cross-sectional view showing a state in which a lower superconductor portion is attached inside a housing.

FIG. 4 is a vertical cross-sectional view showing a state in which a rotating body is passed through a housing.

FIG. 5 is a vertical cross-sectional view showing a state in which an upper superconductor portion is attached inside a housing.

FIG. 6 is a graph showing a result of an experiment conducted by the assembling method of the present invention.

FIG. 7 is a graph showing a result of an experiment conducted by a conventional assembling method.

[Explanation of symbols]

 2 Rotating body 9 Permanent magnet part 17 Superconductor

Claims (1)

[Claims] 1. A superconductor comprising an annular permanent magnet portion concentrically and fixedly provided on a rotating body, and a superconductor arranged so as to face the permanent magnet portion with a gap. A method of assembling a bearing device, wherein the superconductor is cooled in advance and kept in a superconducting state, and in this state, the rotating body and the superconductor are arranged so that the permanent magnet section and the superconductor face each other with a gap. A method for assembling a superconducting bearing device, characterized by arranging.