JPH1162964A - Magnetic bearing device using second class superconductor - Google Patents

Abstract

(57) Abstract: The present invention provides a first magnetic repulsive force acting between a second type superconductor 1 and a first permanent magnet 3 and a first magnetic repulsive force acting between the first permanent magnet 3 and the second permanent magnet 2. It is an object of the present invention to provide a magnetic bearing device capable of obtaining a levitation force in which a second magnetic repulsion force acting therebetween is obtained. SOLUTION: The magnetic bearing device according to the present invention comprises (A)
A plurality of second-class superconductors 1 arranged circumferentially in a coolant container 4 below a disk 5 attached perpendicular to the rotation axis 6; (C) Apart from the second type superconductor 1, the first permanent magnet 3 and the same magnetic pole face the disk 5 separately from the second type superconductor 1. The ring-shaped second permanent magnet 2 attached as described above is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superconducting magnetic bearing device for a power storage flywheel system.

[0002]

[Prior art]

(Explanation of Terms) (1) The “second-class superconductor” refers to a substance in which a superconducting state and a normal conducting state coexist at a high temperature and a high magnetic field. (2) “Pinning” is a general term for a mechanism that prevents the movement of a deformable (elastic) object, that is, a mechanism that causes friction. In particular, type 2 superconductors and charge density waves (CDW)
Attention has been paid to the state.

In the type 2 superconductor, the interaction between the pinned center and the magnetic flux lines is classified into the following three cases depending on the type of energy involved. (A) when the condensed energy of the superconducting material changes locally, (b) when the elastic energy of the strain field of the pinning center changes by the magnetic flux lines, and (c) the magnetic energy of the magnetic flux lines changes. (3) "Pinning force" refers to a kind of static frictional force acting on the magnetic flux line system due to the pinning center. (4) The “bearing portion” refers to a portion of the bearing device that exhibits performance as a bearing, that is, the portion of the coolant container 4 and the portion of the disk 5 in the bearing device of FIG. (Prior Art) FIG. 3 shows a conventional superconducting magnetic bearing device.

FIG. 3 is an axial sectional view of a superconducting magnetic bearing device that supports the rotating shaft 6 by utilizing a levitation force generated by a “pinning force” of the second type superconductor 1.
1b is a second type superconductor, 2a and 2b are second permanent magnets, 4
Reference numerals a and 4b denote coolant containers such as liquid nitrogen for fixing the type 2 superconductor, 5 denotes a disk attached to the rotating shaft 6, 7 denotes a pipe for flowing the coolant to the coolant container 4, and 8 denotes a magnetic bearing device. It is a built-in housing.

The device shown in FIG. 3 is a superconducting magnetic bearing device using a magnetic levitation mechanism based on the "pinning force" of the second type superconductor 1 at a temperature higher than the temperature of liquid nitrogen. Is a container (4) in a housing that circulates a coolant such as liquid nitrogen by a permanent magnet (2a, 2b) attached to a disk 5 attached to a rotating shaft and a circulatory system (7a, 7b).
a, 4b), and levitates using the magnetic force generated by the “pinning force” generated between the second-type superconductor (1a, lb) stored in the superconductor.

[0006]

However, the prior art has the following problems. (1) FIG. 4 shows a magnetic force per unit area (hereinafter, referred to as a first magnetic repulsion) acting between the second type superconductor (1a, 1b) and the second permanent magnet (2a, 2b). And a second permanent magnet (2) instead of the second type superconductor (1a, 1b).
a, 2b) and the first permanent magnet (3a, 3
b) the magnetic force per unit area that acts when (b) is provided
(Referred to as second magnetic repulsion).

As shown in FIG. 4, the first magnetic repulsive force is:
It shows a steep rise with respect to the gap as compared with the second magnetic repulsion. Therefore, the first magnetic repulsive force can obtain only a small levitation force as compared with the second magnetic repulsive force in the same gap larger than zero. An object of the present invention is to provide a device that can solve these problems.

[0008]

[Means for Solving the Problems]

(First Means) The magnetic bearing device according to the present invention is characterized in that (A)
A plurality of second-class superconductors 1 arranged circumferentially in a coolant container 4 below a disk 5 attached perpendicular to the rotation axis 6; (C) a ring-shaped second permanent magnet 2 attached to the disk 5 so that the same magnetic pole faces the first permanent magnet 3. It is characterized by being arranged. (Second Means) The magnetic bearing device according to the present invention is characterized in that (A)
The superconductor 1 includes a second-type superconductor 1, a first permanent magnet 3, a second permanent magnet 2, a coolant container 4, a disk 5 mounted so as to be orthogonal to the rotating shaft 6, and a housing 8, (B) The second type superconductor 1 is stored in a container 4 in a housing 8 in which a coolant is circulated by a pipe 7, and (C) the second permanent magnet 2 is attached to a disk 5, D) First permanent magnet 3
The housing 8 has the same magnetic pole as the second permanent magnet 2.
(E) The rotating shaft 6 includes a ring-shaped second permanent magnet 2 attached to a disk 5 and a second type superconductor (1a) stored in the container 4 in the housing 8. , 1
b), ie, the first magnetic repulsive force, and the first permanent magnet (3a, 3) attached to the bearing portion so as to have the same magnetic pole as the second permanent magnet (2a, 2b).
b), the second magnetic repulsive force acting between the first and second surfaces b) causes the surface to fly. (Third Means) In a magnetic bearing device according to the present invention, in the second means, the installation position of the first permanent magnet 3 attached to the bearing portion is changed to the second permanent magnet based on the magnetic field distribution of the second permanent magnet 2. It is characterized in that an adjustment mechanism is provided which is shifted from the position of the magnet 2 so that the radial repulsion is adjusted to zero and the radial rigidity can be increased. (Fourth Means) The magnetic bearing device according to the second aspect of the present invention is the magnetic bearing apparatus according to the second means, wherein the weight of the rotating shaft 6 and the magnetic repulsion force are balanced by the second position at the gap between the disk 5 and the bearing portion.
The first magnetic repulsion acting between the second permanent magnet 2 and the second type superconductor 1 is larger than the second magnetic repulsion acting between the permanent magnet 2 and the first permanent magnet 3. The upper surface of the first permanent magnet 3 attached to the bearing portion is disposed below the upper surface of the second type superconductor 1.

Therefore, the operation is as follows. The first magnetic repulsion acting between the second type superconductor 1 and the first permanent magnet 3 and the second magnetic repulsion acting between the second permanent magnet 2 and the first permanent magnet 3 are combined. Magnetic repulsion can be obtained.

However, if the magnetic repulsion between the permanent magnets becomes large, the magnet becomes unstable in the radial direction.
The magnetic repulsive force acting between the second type superconductor 1 and the second permanent magnet 2 is balanced to enhance the radial stability by the radial holding force acting between the second type superconductor 1 and the second permanent magnet 2.

Further, by making the gap between the second permanent magnet 2 and the first permanent magnet 3 larger than the gap between the second permanent magnet 1 and the second permanent magnet 2, The first magnetic repulsion acting between the first and second permanent magnets 3 is the first
The second magnetic repulsive force acting between the permanent magnet 3 and the second permanent magnet 2 can be made larger.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) FIGS. 1, 2, and 5 show a first embodiment of the present invention. FIG. 1 is an axial sectional view of a superconducting magnetic bearing device according to a first embodiment, wherein 1a and 1b are second-class superconductors, 2a and 2b are second permanent magnets, and 3a to 3d. Is a first permanent magnet installed below the second type superconductor, 4a to 4d are coolant containers such as liquid nitrogen for fixing the second type superconductor, 5 is a disk attached to the rotating shaft 6, and 7 is A tube for flowing the coolant to the coolant container 4 and a housing 8 incorporating a magnetic bearing device are shown.

FIG. 2 is a top view of the superconducting magnetic bearing device according to the first embodiment, in which la to 1i are second-class superconductors 2a and 2b circumferentially arranged in the bearing portion. Denotes a ring-shaped second permanent magnet mounted on a disk, and 3a to 3s denote first permanent magnets mounted circumferentially on a bearing portion.

As shown in FIG. 2, the second type superconductor (1a
1i) are ring-shaped second permanent magnets (2a and 2b)
Are arranged at equal intervals on the circumference of the middle of the diameter. Also,
The first permanent magnets (3a to 3s) are of the second type superconductor (1a
1i) and the second permanent magnets (2a, 2b) overlap with each other.

As shown in FIGS. 1 and 2, (a) the rotating shaft 6 is attached to the disk 5, and (b) the second permanent magnets (2a, 2b) are also attached to the disk 5. . (C) The second type superconductors (1a to 1i) are circulatory (7)
a, 7b) are stored in containers (4a, 4b) in the housing 8 for circulating a coolant such as liquid nitrogen. (D) The first permanent magnets (3a to 3p) are attached to the bearing portion so as to have the same magnetic pole as the second permanent magnets (2a, 2b). (E) The rotating shaft 6 includes the second permanent magnets (2a, 2b) attached to the disc 5 and the containers (4a, 4) in the housing 8.
b) The "pinning force" generated between the second type superconductors (1a, 1b) stored in the second superconductor (1a, 1b), that is, the first magnetic repulsive force and the same magnetic pole as the second permanent magnets (2a, 2b). And the first magnetic magnet (3a, 3b) attached to the bearing portion.

FIG. 5 is a diagram showing that dynamic stiffness can be reduced by setting different gaps in the first embodiment. "Dynamic stiffness" is not the static spring constant of the bearing (repulsive force per unit length generated when pressed slowly), but the rebound per unit length generated when it is dynamically changed. Say power.

[0017]

Since the present invention is configured as described above, it has the following effects. (1) In the first embodiment, in addition to the second type superconductor 1 in the bearing portion, the first permanent magnet 3 is circumferentially arranged,
By disposing the ring-shaped second permanent magnet 2 attached to the rotating shaft so that the first permanent magnet 3 and the same magnetic pole face each other,
The second type superconductor (1a-1d) and the second permanent magnet (2a,
A levitation force is obtained by combining the first magnetic repulsion acting between 2b) and the second magnetic repulsion acting between the second permanent magnets (2a, 2b) and the first permanent magnets (3a to 3d). I can do it. (2) Further, the center of (3a, 3d) of the first permanent magnet is located radially outward from the second permanent magnet 2a, and the center of (3b, 3c) of the first permanent magnet is located closer to the second permanent magnet 2b. By being installed inside in the radial direction, rigidity in the radial direction can be increased even when the rotating shaft is displaced in the radial direction. (3) At this time, the first magnetic repulsive force per unit area acting in the axial direction between the second type superconductor 1 and the second permanent magnet 2 and the first magnetic repulsion force between the first permanent magnet 3 and the second permanent magnet 2 FIG. 4 shows the second magnetic repulsion per unit area acting in the axial direction.

As shown in FIG. 4, a first magnetic repulsion (a magnetic repulsion acting between the second type superconductor 1 and the second permanent magnet 2) and a second magnetic repulsion (the second 1st permanent magnet 3 and 2nd
The magnitude of the magnetic repulsion acting between the permanent magnets 2 increases in inverse proportion to the size of the gap, but in the same gap, the second magnetic repulsion (the first permanent magnet 3 and the second permanent magnet 3) The magnetic repulsion acting between the two becomes unstable, so that it becomes unstable.

The second permanent magnet 2 is installed by an adjusting mechanism so that the magnetic field generated by the first permanent magnet 3 and the radial repulsion generated by the second permanent magnet 2 are balanced. A magnetic bearing device capable of stable magnetic levitation can be provided by a radial holding force acting between the magnetic bearing and the second type superconductor 1. (4) Further, by providing a gap between the first permanent magnet 3 and the second permanent magnet 2 slightly larger than the gap between the second permanent magnet 2 and the second type superconductor 1, the weight of the rotating shaft is balanced. The first magnetic repulsion (magnetic repulsion acting between the second permanent magnet 2 and the second type superconductor 1) at the position of the gap where the levitation force is obtained
Is larger than the second magnetic repulsion (the magnetic repulsion acting between the first permanent magnet 3 and the second permanent magnet 2), so that a stable magnetic bearing device can be obtained. (5) In the case of a magnetic bearing, the vibration of the rotating system generates an AC magnetic field, and the magnetic repulsive force is attenuated by the flow of the magnetic flux.
In FIG. 4, by setting the offset of the gap between the first permanent magnet 3 and the second permanent magnet 2 in advance,
As shown in FIG. 5, rigidity can be reduced and energy loss can be suppressed.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a superconducting magnetic bearing device according to a first embodiment of the present invention.

FIG. 2 is a top view of the superconducting magnetic bearing device according to the first embodiment of the present invention.

FIG. 3 is an axial sectional view of a conventional superconducting magnetic bearing device.

FIG. 4 is a diagram showing a difference between a magnetic repulsion acting between a permanent magnet and a magnetic repulsion acting between a permanent magnet and a second type superconductor.

FIG. 5 is a diagram showing that dynamic rigidity can be reduced by setting different gaps in the first embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 2nd type superconductor 2 ... 2nd permanent magnet 3 ... 1st permanent magnet 4 ... Coolant container 5 ... Disk 6 ... Rotating shaft 7 ... Tube 8 ... Housing

Continued on the front page (72) Inventor Masaharu Minami 2-1-1 Shinama, Arai-machi, Takasago City, Hyogo Prefecture Inside the Takasago Research Laboratory, Mitsubishi Heavy Industries, Ltd. (72) Inventor Seiichi Kawanami 2-1-1, Araimachi Shinama, Takasago-shi, Hyogo Prefecture Inside Mitsubishi Heavy Industries, Ltd. Takasago Research Laboratory (72) Inventor Hiroshi Kawashima 2-1-1, Shinhama, Arai-machi, Takasago City, Hyogo Prefecture Inside Takasago Machinery Works, Mitsubishi Heavy Industries, Ltd.

Claims (4)

[Claims] (A) A plurality of second type super-circularly arranged in a coolant container (4) below a disk (5) mounted to be orthogonal to a rotation axis (6). Conductor (1) and (B)
A first permanent magnet (3) mounted in the disk (5) so as to be arranged circumferentially; and (C) the same magnetic pole as the first permanent magnet (3) faces the disk (5). A magnetic bearing device comprising a ring-shaped second permanent magnet (2) mounted so as to be mounted. 2. A type 2 superconductor (1), a first permanent magnet (3), a second permanent magnet (2), a coolant container (4), and a rotating shaft (6). And (B) the second type superconductor (1) is provided with a housing (8) through which a coolant is circulated by a pipe (7). ) Is stored in the container (4)
(C) The second permanent magnet (2) is attached to a disk (5), and (D) the first permanent magnet (3) has a housing (2) having the same magnetic pole as the second permanent magnet (2). (E) The rotating shaft (6) is attached to the second permanent magnet (2) attached to the disk (5) and the container (4) in the housing (8). Type 2 superconductor (1
a, 1b) between the "pinning force"
And the first permanent magnet (3) attached to the bearing portion so as to have the same magnetic pole as the second permanent magnet (2a, 2b).
a, the magnetic bearing device floats by a second magnetic repulsive force acting between the magnetic bearing device and the magnetic bearing device. 3. The installation position of the first permanent magnet (3) attached to the bearing portion is shifted from the position of the second permanent magnet (2) based on the magnetic field distribution of the second permanent magnet (2), and 3. The magnetic bearing device according to claim 2, further comprising an adjusting mechanism that adjusts the repulsive force of the first member to zero and increases the radial rigidity. 4. The position of the first permanent magnet (3) and the second permanent magnet (2) at the gap between the disk (5) and the bearing portion where the weight of the rotating shaft (6) and the magnetic repulsive force are to be balanced. The second permanent magnet (2) and the second
The upper surface of the first permanent magnet (3) attached to the bearing portion is mounted on the second superconductor (1) so that the first magnetic repulsion acting between the superconductor and the first superconductor (1) is larger. 3. The magnetic bearing device according to claim 2, wherein the magnetic bearing device is disposed below the upper surface of the magnetic bearing.