JPH0694030A - Superconductive bearing device - Google Patents

Abstract

PURPOSE:To prevent the ordinary conduction of a superconductor with the high speed rotation of a rotation body made available, by stably supporting the rotation body in a contactless condition with the deviation of the rotation body lessened. CONSTITUTION:This superconductive bearing device is provided with an annular permanent magnet part 2, concentrically provided on a rotating body 1, and an annular superconductor part 3, arranged on a fixed part 4 so as to be faced to the end surface of the permanent magnet part 2 at an interval in a rotation axis direction. Position sensors X1 and X2, for detecting the position in the radial direction of the rotation body 1, are provided on the fixed part 4. A piezoelectric element 13X, capable of adjusting the position of the superconductor part 3 by moving the superconductor part 3 in the radial direction of the rotation body 1, is provided between the fixed part 4 and the superconductor part 3. A control apparatus is provided, which is driving the piezoelectric element 13X based on the output of the position sensors X1 and X2.

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, a gyroscope, or an electric power storage device for converting surplus electric power into kinetic energy of a flywheel for storage. The present invention relates to a superconducting bearing device.

[0002]

2. Description of the Related Art In recent years, a superconducting bearing device has been developed which can support a rotating body in a non-contact state with a fixed portion.

As a superconducting bearing device of this type, an annular permanent magnet portion concentrically provided on a rotating body and an end face in the rotating shaft center direction of the permanent magnet portion are spaced from each other in the rotating shaft direction of the rotating body. And the annular superconductor portion arranged to face each other, the permanent magnet portion is fixedly and concentrically provided on the rotating body, and an annular groove is formed on the surface facing the superconductor portion. It is considered that the disk includes a circular disk and a ring-shaped permanent magnet that is fitted in the groove and is concentric with the center of rotation of the rotating body.

In this superconducting bearing device, during operation, first, the center of the annular superconductor portion arranged in the rotating body and the fixed portion are aligned with each other, and further, the rotating body and the fixed portion are axially separated from each other. By cooling the body and holding it in the superconducting state, the magnetic flux generated from the permanent magnet part is allowed to enter the inside of the superconductor to be restrained, and as a result, the so-called pinning force causes the rotating body to move axially with respect to the fixed part. And it is designed to be supported in a non-contact state in the radial direction. Then, the rotating body is rotated by, for example, a high frequency electric motor arranged around the rotating body.

However, it is unavoidable that the surface magnetic flux density of the surface of the annular permanent magnet facing the superconductor portion varies in the circumferential direction, and the center of the magnetic field in consideration of this variation deviates from the center of the annular permanent magnet. . Therefore,
In the conventional superconducting bearing device, the center of the rotating body and the center of the annular superconductor part are displaced from the center of the magnetic field of the permanent magnet, and as a result, radial runout occurs in the rotating body and the rotating body is not rotated. There is a problem that it cannot be stably supported in the contact state. Moreover, there is a problem that the rotating body cannot be rotated at a high speed because the rotating body cannot be stably supported in a non-contact state.

Therefore, as a bearing device that solves such a problem, the present applicant has previously opposed the annular permanent magnet portion provided concentrically and fixedly to the rotating body, and the permanent magnet portion. Superconducting bearing part composed of an annular superconducting part arranged in the fixed part, and an electromagnet provided at a position axially separated from the superconducting bearing part and controlling two radial positions of the rotating body orthogonal to each other. And a device provided with a magnetic bearing part using the above (Japanese Patent Application No. 3-1965).
48). In this device, when a runout occurs in the rotating body, the runout is corrected by controlling the radial position of the rotating body by the magnetic bearing portion.

However, in this device, an unreasonable force is applied to the superconductor portion, which may cause the superconductor in the superconductor portion to become a normal conductor and damage the rotating body and parts around it.

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

[0009]

A superconducting bearing device according to the present invention has an annular permanent magnet portion concentrically provided on a rotating body and a space in the direction of the rotation axis from the end face of the permanent magnet portion. A superconducting bearing device that includes a ring-shaped superconductor portion that is disposed in the fixed portion so as to face each other, and that can support the rotating body in a non-contact state with respect to the fixed portion. A position sensor that detects the radial position of the rotating body, and is provided between the fixed part and the superconductor part, and moves the superconductor part in the radial direction of the rotating body to adjust the position of the superconductor part. Means and a control device for driving the position adjusting means based on the output of the position sensor.

[0010]

According to the present invention, after the operation is started, when the radial deflection of the rotating body occurs, the position sensor detects the radial displacement of the rotating body, and the control is performed based on the output signal of the position sensor. The position adjusting means is driven by the device to vibrate the superconductor portion in the radial direction of the rotating body to adjust its position, and the magnetic field center of the magnetic flux penetrating the superconductor portion is made to coincide with the center of the shape of the rotating body. To be Therefore, the runout of the rotating body is reduced.

[0011]

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

FIG. 1 schematically shows the overall structure of a superconducting bearing device to which the present invention is applied, and FIG. 2 shows the structure of a part relating to control of means for moving the superconducting portion in the radial direction of the rotating body to adjust the position. Indicates.

In FIG. 1, the superconducting bearing device comprises a vertical shaft-shaped rotating body (1). Although illustration is omitted, the rotating body (1) is rotated at a high speed by a high-frequency driving electric motor including a rotor mounted on the rotating body (1) and a stator mounted on a fixed part and arranged around the rotor. It is designed to be used. The rotor (1) has a horizontal disk-shaped permanent magnet part.
(2) are provided concentrically, and the annular superconductor part (3) is arranged so as to face the upper end surface of the permanent magnet part (2) with a gap in the direction of the rotation axis of the rotating body (1). It is located on the fixed part (4).

The permanent magnet part (2) is provided with a horizontal disk (5) fixedly provided on the rotating body (1) and made of, for example, copper or non-magnetic stainless steel. An annular groove (5a) is formed on the upper surface of the disc (5) concentrically with the rotating body (1).
An annular permanent magnet (6) is fitted and retained in the groove (5a). The permanent magnet (6) is provided so that the magnetic flux distribution around the rotation axis of the rotating body (1) does not change due to rotation.

The superconductor part (3) is made of, for example, copper or non-magnetic stainless steel, and is horizontally slidably arranged on the inwardly projecting annular wall part (4a) of the fixing part (4). ) Is provided. Peripheral wall (4b) of fixed part (4) and peripheral edge of annular body (7)
There is a gap between and. In addition, a hole (7a) is formed at the center of the annular body (7) so as to vertically pass therethrough, and the rotating body (1) is passed through the through hole (7a) with a gap. An annular hollow part (8) is formed in the annular body (7), and a plurality of disc-shaped superconductors (9) are arranged in the annular hollow part (8) at equal intervals in the circumferential direction and close to each other. . In the annular body (7),
The cooling fluid supply pipe (11) and the discharge pipe (12) are arranged so as to communicate with the annular hollow portion (8) inside thereof. The cooling fluid supply pipe (11) and the cooling fluid supply pipe (12) can move the peripheral wall (4b) of the fixed part (4) in the lengthwise direction and in the horizontal plane in a direction orthogonal to the lengthwise direction. It penetrates so that it can be connected to a cooling device or the like via a temperature control unit (not shown). Then, the cooling fluid is circulated through the cooling fluid supply pipe (11), the annular hollow portion (8) and the cooling fluid discharge pipe (12) by the cooling device, and the hollow portion
The superconductor (9) is cooled by the cooling fluid filled in (8).

The disk-shaped superconductor (9) is a type II superconductor, and is a yttrium-based high-temperature superconductor such as YBa ₂ C.
u ₃ O _x consisting bulk inside normal conductor particles _(Y 2 Ba
₁ Cu ₁ ) is uniformly mixed and has the property of internally confining the magnetic flux generated from the permanent magnet (6) in the environment where the type 2 superconducting state appears. Then, the superconductor (9) is located at a separated position where the magnetic flux of the permanent magnet (6) penetrates by a predetermined amount, and the distribution of the magnetic flux entering the permanent magnet (6) does not change due to the rotation of the rotating body (1). ) Is arranged so as to face.

Assuming two axes extending in the radial direction of the rotating body (1) which are orthogonal to each other to be the X axis and the Y axis, the superconducting bearing device is placed at a position above the superconducting portion (3) and rotated. A displacement detector (X) for detecting displacement of the body (1) in the X-axis direction is provided. Displacement detector (X) is fixed
Two position sensors (X1) (X1) are provided in (4) so as to sandwich the rotating body (1) from both sides in the X-axis direction and detect the position of the rotating body (1) in this direction in the X-axis direction. X2). Also, on the X-axis, the outer peripheral surface of the annular body (7) and the fixed portion (4)
A piezoelectric element (13X) for moving the superconductor portion (3) in the X-axis direction to adjust its position is arranged between the piezoelectric element (13X) and the peripheral wall. Although not shown in FIG. 1, the superconducting bearing device is a displacement detection device that detects displacement of the rotating body (1) in the Y-axis direction at the same height as the displacement detection device (X) in the X-axis direction. Equipped with device (Y). The displacement detector (Y) has a fixed part (4).
In addition, two position sensors are provided so as to sandwich the rotating body (1) from both sides in the Y-axis direction and detect the position of the rotating body (1) in this portion in the Y-axis direction. Further, on the Y axis, between the outer peripheral surface of the annular body (7) and the peripheral wall of the fixed portion (4), the piezoelectric element (3) which moves the superconductor portion (3) in the Y axis direction to adjust its position is provided. 13Y) is located.

FIG. 2 shows the configuration of only the part relating to the control of the piezoelectric elements (13X) (13Y). In FIG. 2, the control device (14) for the piezoelectric elements (13X) and (13Y) controls the X-axis based on the output signals of the X-axis displacement detector (X) and the Y-axis displacement detector (Y). PID control circuit (15X) and Y axis P
The ID control circuit (15Y) controls the piezoelectric elements (13X) (13Y) via the voltage amplifiers (16X) (16Y). The X-axis direction displacement detection device (X) detects the displacement of the rotating body (1) in the X-axis direction and outputs a signal proportional to this, and the Y-axis direction displacement detection device (Y) detects the displacement of the rotating body (1). The displacement in the Y-axis direction is detected and a signal proportional to this is output. X-axis and Y-axis PID control circuits (15X) (15Y) are for each displacement detection device (X) (Y)
Is processed and a corresponding control signal is output.

When operating the superconducting bearing device,
(1) is moved up with respect to the fixed part (4) to position the rotating body (1) relative to the fixed part (4). This allows
Axial and radial relative positioning of the permanent magnet part (2) and the superconductor part (3) is performed. Then, each superconductor
(9) is cooled by a cooling fluid circulated in the annular hollow portion (8), and is maintained in a second-type superconducting state. Then, most of the magnetic flux generated from the permanent magnet part (2) of the rotating body (1) enters the inside of the superconductor (9) and is restricted (pinning phenomenon). Here, since the superconductor (9) has the normal conductor particles uniformly mixed therein,
(9) The distribution of the magnetic flux penetrating inside becomes constant, and the so-called pinning force causes the permanent magnet part (2) to move against the superconductor (9).
At the same time, the rotating body (1) is restrained. Therefore, the rotating body
In (1), it will be supported in the axial direction and the radial direction in a stable floating state. At this time, the magnetic flux that has entered the superconductor (9) does not become a resistance that prevents rotation.

Then, the rotating body (1) is rotated by the high frequency electric motor. Then, the superconductor part of the permanent magnet (6)
Due to the fact that the surface magnetic flux density of the surface facing (3) varies in the circumferential direction and the material of each superconductor (9) varies, the rotating body (1) has a radial Deflection of direction occurs. When the rotor (1) is shaken, the displacement detectors (X) and (Y) detect the radial displacement of the rotor (1), and the controller (14) controls the displacement detectors (X). Based on the output signal of (Y), PID control circuit for X-axis (15
The piezoelectric elements (13X) and (13Y) are driven through the voltage amplifiers (16X) and (16Y) by the X) and Y-axis PID control circuit (15Y).
As a result, the superconductor part (3) is vibrated in the radial direction of the rotor (1), and the magnetic field center of the magnetic flux penetrating the superconductor part (3) coincides with the center of the shape of the rotor (1). To be Therefore, the deflection of the rotating body (1) is reduced.

In the above embodiment, the position adjusting means of the superconductor portion (3) is composed of the piezoelectric elements (13X) and (13Y), but the position adjusting means is not limited to this and can be appropriately changed.

[0022]

As described above, according to the superconducting bearing device of the present invention, the runout of the rotating body can be reduced.
Therefore, the rotating body can be stably supported in a non-contact state, and as a result, the rotating body can rotate at high speed. Moreover, unlike the case where the position of the rotating body is adjusted, an unreasonable force does not act on the superconductor, and the superconductor can be prevented from becoming a normal conductor.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of a superconducting bearing device showing an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a portion related to control of a piezoelectric element.

[Explanation of symbols]

 1 Rotating body 2 Annular permanent magnet section 3 Annular superconductor section 4 Fixed section 13X, 13Y Piezoelectric element (position adjusting means) X1, X2 Position sensor

Claims (1)

[Claims] 1. A ring-shaped permanent magnet portion concentrically provided on a rotating body, and a ring-shaped permanent magnet portion arranged on a fixed portion so as to face an end surface of the permanent magnet portion with a gap in a rotation axis direction. A superconducting bearing device which is capable of supporting the rotating body in a non-contact state with respect to the fixed portion, and which is provided in the fixed portion and detects the radial position of the rotating body. Based on the output of the position sensor, a means provided between the fixed part and the superconductor part and capable of adjusting the position of the superconductor part by moving the superconductor part in the radial direction of the rotating body. A superconducting bearing device, comprising: a control device that drives a position adjusting means.