JP5548986B2 - Vibration control mechanism in superconducting magnetic bearings and magnetic levitation equipment - Google Patents

Description

  The present invention relates to a vibration suppression control mechanism in a superconducting magnetic bearing / magnetic levitation device, and more particularly, a vibration suppression control that can be used for a superconducting magnetic bearing device such as a superconducting flywheel for power storage, a non-contact conveyance device, or the like. Regarding the mechanism.

  Since the magnetic bearing / magnetic levitation mechanism can support the object in a non-contact manner, there are advantages that there is no mechanical contact and no dust is generated, and that the rotational loss of the shaft is extremely small. Therefore, the magnetic bearing mechanism is used for flywheel power storage devices that need to prevent rotational loss, and the magnetic levitation mechanism is used for non-contact transfer devices in clean environments in the fields of semiconductor manufacturing, biotechnology, material manufacturing, etc. Has been.

When a normal conducting magnet (permanent magnet) is used to support the floating body or the rotating shaft, the vibration suppression control mechanism is performed by controlling the attractive force of the permanent magnet. However, since the positioning accuracy of the floating body and the rotating body is poor, there are problems in increasing the size of the apparatus and increasing the rotational speed.
On the other hand, Patent Document 1 and Patent Document 2 disclose superconducting magnetic bearings that reduce rotational loss and enable high-speed rotation by supporting the thrust direction and radial direction with a superconductor. Since a magnetic bearing using a superconductor has a high pinning effect due to magnetic flux, unlike conventional active magnetic bearings (permanent magnet magnetic bearings), stable floating in a magnetic field can be obtained without control. Therefore, it is possible to increase the size of the device, increase the rotational speed, and reduce the power consumption, which is difficult with conventional active magnetic bearings.

However, since the superconducting magnetic bearing and the levitation mechanism are not sufficiently controlled in the radial direction with respect to the external force, it is not possible to sufficiently suppress the swing of the rotating shaft that rotates at a high speed and the vibration of the levitation body when an external force is applied. . In particular, in the case of a flywheel battery using a superconducting magnetic bearing, the rotation axis tends to be inclined and the stability is poor, so that the swing is likely to occur. This swinging causes a serious problem that a so-called touchdown in which the rotating shaft comes into contact with the bearing portion or a rotation loss occurs when the swinging continues for a long time. Further, in the case of a non-contact conveyance device such as a linear motor car using a superconducting levitation mechanism, there is a problem that the ability to convey an object is significantly impaired if vibration due to an external force continues for a long time.
Here, as shown in FIG. 11, the whirling refers to a phenomenon in which the rotating body is shaken from the center axis of rotation due to the centrifugal force applied to the center of gravity of the rotating body. It tends to occur.

JP 2003-49836 A Japanese Patent Laid-Open No. 9-242755

  In order to solve the above problems, the present invention provides a vibration suppression control mechanism that can actively control the swing and vibration of a superconducting magnetic bearing / magnetic levitation device to reduce or suppress the swing and vibration. The purpose is to do.

In order to achieve this object, the present invention has the following configuration.
The invention according to claim 1 is a vibration suppression control mechanism that suppresses the whirling and vibration of a supported body composed of a floating body and / or a rotating body that are supported in a non-contact manner by a superconductor, and the displacement of the supported body A displacement sensor that detects the displacement, a drive unit that drives the superconductor, and a control unit that controls the drive of the drive unit. The displacement sensor is a displacement signal based on the detected displacement amount of the supported body. Is transmitted to the control means, and the control means controls the drive of the drive device based on the displacement signal, thereby suppressing swinging and vibration of the supported body, and the rotating body is a superconducting magnetic bearing. A rotating body of the device, wherein the superconducting magnetic bearing device includes a superconducting magnetic bearing including the superconductor, and a permanent magnet magnetic bearing, and the superconducting magnetic bearing and the permanent magnet magnetic bearing surround the rotating shaft. The permanent magnet magnetic bearing supports the upper end of the rotating shaft in the radial direction, the superconducting magnetic bearing supports the intermediate portion of the rotating shaft in the radial direction, and the driving means The present invention relates to a vibration damping control mechanism that drives the superconducting magnetic bearing and the permanent magnet magnetic bearing in radial directions opposite to each other .

  The invention according to claim 2 relates to the vibration damping control mechanism according to claim 1, wherein the control means includes a noise cut filter and a PID adjuster.

The invention according to claim 3 relates to the vibration damping control mechanism according to claim 1, wherein the levitated body is a levitated body of a superconducting magnetic levitation apparatus.

According to the first aspect of the present invention, there is provided a vibration suppression control mechanism for suppressing swinging and vibration of a supported body made up of a floating body and / or a rotating body supported in a non-contact manner by a superconductor. Displacement based on the displacement amount of the supported body detected by the displacement sensor, including a displacement sensor for detecting the displacement of the superconductor, a drive means for driving the superconductor, and a control means for controlling the drive of the drive means. Since the signal is transmitted to the control means, and the control means controls the driving of the driving device based on the displacement signal, the swinging and vibration of the supported body can be suppressed. Can be stably levitated, and in the case of a rotating body, high-speed rotation is possible and rotation loss can be reduced.
Further, since the rotating body is a rotating body of the superconducting magnetic bearing device, the rotating shaft is positioned in the vertical and horizontal directions, and the control of the swinging and vibration of the rotating shaft can be further ensured.
Further, the superconducting magnetic bearing device includes a superconducting magnetic bearing provided with the superconductor and a permanent magnet magnetic bearing, and the superconducting magnetic bearing and the permanent magnet magnetic bearing are formed in a ring shape so as to surround the rotating shaft. The permanent magnet magnetic bearing supports the upper end of the rotating shaft in the radial direction, the superconducting magnetic bearing supports the intermediate portion of the rotating shaft in the radial direction, and the driving means includes the superconducting magnetic bearing and the permanent magnet. The magnet magnetic bearing is driven in the radial direction opposite to each other. Accordingly, the permanent magnet magnetic bearing and the superconducting bearing generate a repulsive force with respect to the rotating shaft, and the restoring force of the rotating shaft is effectively generated, so that the swinging of the rotating shaft can be reliably suppressed.

  According to the invention which concerns on Claim 2, since the said control means has a noise cut filter and a PID adjuster, the rotation around a to-be-supported body and suppression of a vibration can be made still more reliable.

According to the invention of claim 3 , since the levitated body is a levitated body of a superconducting magnetic levitation device, the levitated body is positioned in the vertical and horizontal directions, and vibration control of the levitated body is further ensured. Can do.

It is the schematic sectional drawing which showed the superconducting magnetic bearing apparatus using the damping control mechanism which concerns on this invention. It is a schematic sectional drawing explaining the bearing of a radial direction and a thrust direction of the superconducting magnetic bearing apparatus using the vibration suppression control mechanism which concerns on this invention. It is a schematic sectional drawing explaining the pinning effect of the superconducting magnetic bearing device using the vibration suppression control mechanism according to the present invention. It is the schematic sectional drawing which showed the structure of the superconducting magnetic bearing apparatus using the damping control mechanism which concerns on this invention. It is the figure which showed the relationship between the displacement sensor, the control means, and drive means of the vibration suppression control mechanism based on this invention. It is a figure explaining the control method at the time of the whirling of the rotating shaft of the superconducting magnetic bearing using the vibration suppression control mechanism which concerns on this invention generate | occur | produced. It is the schematic which showed the structure of the test example regarding the vibration suppression control mechanism which concerns on this invention. It is the schematic which showed the vibration suppression control method of the test example regarding the vibration suppression control mechanism which concerns on this invention. It is the graph which showed the motion of the floating body and superconductor of the test example regarding the vibration suppression control mechanism which concerns on this invention. It is the graph which showed the test result of the test example regarding the vibration suppression control mechanism which concerns on this invention. It is a figure explaining the whirling which generate | occur | produces in the conventional magnetic bearing.

The present invention is a vibration suppression control mechanism in a superconducting magnetic bearing / magnetic levitation device that can be used in a superconducting magnetic bearing device such as a superconducting flywheel for power storage and a magnetic levitation device such as a linear motor.
The superconducting magnetic bearing device using the control mechanism according to the present invention will be described in detail below.

A superconducting magnetic bearing device will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view schematically showing the structure of a superconducting magnetic bearing device using a vibration suppression control mechanism according to an embodiment of the present invention, and FIG. 2 is a superconducting magnetic bearing using the vibration suppression control mechanism according to the present invention. FIG. 3 is a schematic cross-sectional view for explaining the contents of bearings in the radial direction and thrust direction of the device, and FIG. 3 shows the pinning effect when a superconductor is used in a superconducting magnetic bearing device using the vibration suppression control mechanism according to the present invention. FIG. 4 is a schematic cross-sectional view, FIG. 4 is a schematic cross-sectional view showing a configuration of a superconducting magnetic bearing device using the vibration suppression control mechanism according to the present invention, and FIG. 5 is a displacement of the vibration suppression control mechanism according to the present invention. FIG. 6 is a diagram illustrating a relationship between the control of the sensor, the control unit, and the drive unit, and FIG. 6 is a diagram illustrating an outline of the control method of the vibration suppression control mechanism according to the present invention when the rotation of the rotating shaft occurs. FIG. 7 shows a vibration suppression control mechanism according to the present invention. FIG. 8 is a schematic diagram illustrating a configuration of a vibration suppression mechanism of a test example relating to superconducting magnetic levitation, and FIG. 8 is a schematic diagram illustrating a vibration suppression control method of a test example relating to superconducting magnetic levitation of the vibration suppression control mechanism according to the present invention. FIG. 9 is a graph showing the movement of the levitation body and the superconductor in the test example regarding the superconducting magnetic levitation of the vibration suppression control mechanism according to the present invention, and FIG. 10 is the test of the test example regarding the vibration suppression control mechanism according to the present invention. It is the graph which showed the result.

  The magnetic bearing (1) shown in FIG. 1 is composed of radial magnetic bearing means for supporting the rotating shaft (2) in the radial direction (R) and thrust magnetic bearing means for supporting the rotating shaft (2) in the thrust direction (S). Has been. The radial magnetic bearing means includes a permanent magnet magnetic bearing (3) that supports the upper end of the rotating shaft (2) in the radial direction (R), and a superconducting magnet for positioning that supports the rotating shaft (2) in the radial direction (R). It is comprised with a bearing (4). The thrust magnetic bearing means is constituted by a levitation permanent magnet magnetic bearing (5) that supports the lower end of the rotating shaft (2) in the thrust direction (S). These magnetic bearing means stabilize the rotary shaft (2) in the radial direction (R) and the thrust direction (S). Since FIG. 1 is a cross-sectional view of a magnetic bearing device, the radial magnetic bearing means is shown in a square shape, but the actual radial magnetic bearing means is formed in a ring shape so as to surround the rotating shaft.

The rotating shaft (2) is arranged perpendicular to the ground (G) as shown in FIG. The permanent magnet magnetic bearing for levitation (5) attached to the lower end side in the direction of the rotating shaft (2) includes a permanent magnet (6a) provided at the lower end portion of the rotating shaft (2) and the rotating shaft (2). It consists of a permanent magnet (6a) arranged on the ground (G) opposite to the lower end and the axial direction, and the rotating shaft (2) floats in the thrust direction by the repulsive force. The permanent magnet magnetic bearing for positioning (3) mounted on the upper end side in the direction of the rotating shaft (2) includes a permanent magnet (6b) provided at the upper end portion of the rotating shaft, the upper end of the rotating shaft (2) and the radial direction. And a permanent magnet (6b) disposed opposite to the magnet.
As shown in FIG. 3, the superconducting magnetic bearing (4) is composed of a permanent magnet (6c) provided at an intermediate portion of the rotating shaft (2) and a superconductor (7) provided opposite to the permanent magnet (6). It is configured. The superconductor (7) can float stably with the rotating shaft (2) in the radial direction and the thrust direction due to the minus effect and the pinning effect.

  When the rotational axis (2) of the superconducting magnetic bearing (4) deviates from the central axis (2) in an equilibrium state, the magnetic lines of force are pinned, so that it tries to return to the original central axis with a restoring force. However, only with this passive restoring force control, when a whirling occurs, a so-called touchdown in which the rotating shaft (2) contacts the bearing portion occurs, or the vibration continues for a long time due to the whirling and rotation loss. May occur. Therefore, according to the present invention, the radial magnetic bearing means is actively controlled to actively control the swing of the rotary shaft (2), thereby quickly suppressing the vibration.

  As shown in FIG. 4, the magnetic bearing device to which the vibration damping control mechanism according to the present invention can be applied is a displacement sensor (8) for detecting the rotation (displacement) of the rotating shaft (2) in the radial direction. And radial magnetic bearing means for suppressing the swinging of the rotating shaft (2).

The displacement sensor (8) detects the displacement of the rotating shaft (2), and outputs a displacement signal proportional to the distance from the rotating shaft (2) to the control means described later.
The installation position of the displacement sensor (8) is in the vicinity of the radial magnetic bearing means and can be arranged so as to be located outside the outer periphery of the rotating shaft (2). The rotating shaft (2) includes a flywheel. In this case, the displacement sensor (8) may be disposed so as to face the upper and lower surfaces of the outer periphery of the flywheel (not shown). Thereby, the displacement sensor (8) can detect the displacement of the flywheel.

  The radial magnetic bearing means includes a permanent magnet magnetic bearing (3) and a superconducting magnetic bearing (4) for positioning, and a driving means (9) for driving the positioning magnetic bearings (3) and (4) in the radial direction, Control means (10) (see FIG. 5) for driving the drive means (9) based on the displacement signal of the rotating shaft (2) from the displacement sensor (8) is provided.

The driving means (9) drives the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) in the radial direction, and may drive them one-dimensionally (in one direction). It is preferable to drive the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) on the vertical plane in the radial direction with respect to the rotating shaft (2) using the driving means. Thereby, the whirling of a rotating shaft (2) can be suppressed effectively.
The method for controlling the rotating shaft (2) according to the present invention uses the repulsive force of the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) with respect to the swing of the rotating shaft (2). The restoring force of (2) is generated, and the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) are driven by the driving means (9) so that the rotating shaft (2) returns to the central axis.

  As shown in FIG. 5, the control means (10) includes a noise cut filter (11) and a PID adjuster (12). The noise cut filter (11) cuts a signal other than the displacement signal of the rotary shaft (2) from the displacement signal output from the displacement sensor (8). The PD adjuster (12) calculates the displacement signal of the rotating shaft (2) detected by the displacement sensor (8) to the displacement amount, and the permanent magnet magnetic bearing so that the displacement amount of the rotating shaft (2) becomes zero. The control values for driving (3) and the superconducting magnetic bearing (4) are calculated, and further, the control values of the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) are calculated to drive each of them. Output to means (9). Thereby, the drive means (9) drives the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) so that the displacement amount of the rotating shaft (2) becomes zero. Therefore, the rotating shaft (2) generates a restoring force due to the repulsive force with the magnetic bearing, returns to the central axis, and maintains high speed rotation.

FIG. 6 is a conceptual diagram showing a control method when a swing occurs on the rotating shaft (2), and the central axis (A) of the rotating shaft (2) is indicated by a broken line. For convenience of description of the drawings, the right side is the right direction and the left side is the left direction with respect to the drawing.
When the rotating shaft (2) is tilted to the right, the displacement sensor (8) detects the displacement of the rotating shaft and outputs a displacement signal to the control means (10). The control means (10) calculates a control value based on the displacement signal and outputs it to the drive means (9) for control. The drive means (9) drives the radial permanent magnet magnetic bearing (3) in the left direction and drives the superconducting magnetic bearing (4) in the right direction. Thereby, a repulsive force is generated between the rotating shaft (2), the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4), and the restoring force to the central shaft (A) is generated on the rotating shaft (2). Occur.

  As shown in FIG. 6, the permanent magnet magnetic bearing (3) and the superconducting magnetic bearing (4) are preferably driven and controlled so as to be opposite to each other in the radial direction. In particular, as the central axis (2) becomes longer, the permanent magnet magnetic bearing (3) for positioning the upper end of the central axis (2) and the superconducting magnetic bearing (4) for positioning the lower end are more opposite to the radial direction. By driving in the direction, the rotating shaft (2) can be effectively restored in the direction of the central axis, and swinging can be prevented.

  The superconducting magnetic bearing (4) can use a superconducting bulk body instead of the permanent magnet (6c) of the rotating shaft (2) provided to face the superconductor (7). Thereby, the superconducting magnetic bearing (4) can further enhance the pinning effect of the magnetic flux, and can further suppress the swing of the rotating shaft (2).

(Test example)
FIG. 7 shows a test apparatus for preventing vibration of the superconducting magnetic levitation apparatus.
As the permanent magnet (floating body) (13), a neodymium magnet having a diameter of 25 mm and a thickness of 10 mm was used. A superconductor having a diameter of 50 mm and a thickness of 10 mm is used. In the test examples, the type 2 superconductor (14), which is often used in the industrial field and provides relatively stable levitation, is used. The second type superconductor (14) is cooled with liquid nitrogen (15) and fixed to the slider (16). The slider (16) is controlled uniaxially by the motor (17), and the displacement (mm) of the displacement of the levitating body (13) and the slider is measured by the displacement sensor (18).

  The levitated body (13) is levitated on the second type superconductor (14) to give free vibration. Next, the vibration of the floating body (13) is detected by the displacement sensor (18), and the slider (16) is controlled in the direction opposite to that of the floating body (13). A digital controller is used to control the motor (17) (see FIG. 5).

  FIG. 8 is a diagram showing a control method of the levitated body (13) in which vibration has occurred. Referring to the drawing, when the levitated body (13) given free vibration moves to the right ( a) The second type superconductor (14) is moved in the left direction which is the opposite direction to the levitated body (13) (b). Then, a restoring force to the central axis of the levitated body (13) is generated (c) and tries to return to the original position (d). Next, when the levitated body (13) swings to the left (e), the second type superconductor (14) is moved to the right, which is the opposite direction to the levitated body (13) (f). Then, a restoring force to the central axis of the levitated body (13) is generated (g) and tries to return to the original position. By repeating this, the levitated body (13) returns to the original position (h).

FIG. 9 is a graph showing the movement of the levitated body (13) and the movement of the second type superconductor (14) fixed to the slider (16) when the second type superconductor (14) is moved and controlled. is there. The horizontal axis of the graph showing the movement of the levitated body (13) represents the elapsed time (second), the vertical axis represents the amplitude (mm), and the horizontal axis of the graph showing the movement of the slider (16) is the elapsed time (second). ), And the vertical axis represents the displacement (mm).
The broken line in the graph represents the movement of the levitated body (13) and the slider (16) at the same time. When the movement of the floating body (13) and the movement of the slider (16) are compared, it can be seen that the slider (16) holding the floating body (13) and the second type superconductor (14) is moving in the opposite direction. It is confirmed.

FIG. 10 shows the movement of the levitated body (13) when vibration control is performed using the second type superconductor (14) and (C), and the movement of the levitated body (13) when vibration control is not performed (N). ) In the graph. The horizontal axis of the graph showing the movement of the levitated body (13) represents elapsed time (seconds), and the vertical axis represents amplitude (mm).
When the vibration amplitude of the floating body is compared between when the vibration control is performed and when the vibration control is not performed, as shown in FIG. 10, when the vibration control is performed (C), the floating body (13) It was shown that the vibration of the slab was quickly suppressed.
In the superconducting magnetic levitation device, when the vibration generated by the external force is larger than the pinning effect of the superconductor, the levitation body continues to vibrate on the superconductor for a long time, causing a serious problem in non-contact conveyance.
Also in the case of a superconducting magnetic bearing, when the swing is greater than the pinning effect of the superconductor, problems such as so-called touchdown in which the rotating shaft contacts the bearing portion occur.
The vibration suppression effect shown in this test example has an effect of quickly suppressing a large vibration, and can solve the above problem.

  The vibration suppression control mechanism in the superconducting magnetic bearing / magnetic levitation apparatus according to the present invention can be suitably used for a superconducting levitation apparatus such as a large superconducting magnetic bearing apparatus such as a flywheel accumulator or a non-contact transfer apparatus.

DESCRIPTION OF SYMBOLS 1 ... Magnetic bearing 2 ... Rotary shaft 3 ... Permanent magnet magnetic bearing 4 ... Superconducting magnetic bearing 5 ... Floating permanent magnet magnetic bearing 6 ... Permanent magnet 7 ... Superconductor 8 ... Displacement sensor 9 ... Drive means 10 ... Control means 11 ... Noise cut filter 12 ... PID regulator 13 ... Floating body 14 ... -Type 2 superconductor 15 ... Liquid nitrogen 16 ... Slider 17 ... Motor 18 ... Displacement sensor

Claims (3)

A vibration suppression control mechanism for suppressing swinging and vibration of a supported body made of a floating body and / or a rotating body supported in a non-contact manner by a superconductor,
A displacement sensor for detecting the displacement of the supported body;
Driving means for driving the superconductor;
Control means for controlling the drive of the drive means,
The displacement sensor transmits a displacement signal based on the detected displacement amount of the supported body to the control means,
The control means controls the driving of the driving device based on the displacement signal, thereby suppressing the swinging and vibration of the supported body ,
The rotating body is a rotating body of a superconducting magnetic bearing device;
The superconducting magnetic bearing device comprises a superconducting magnetic bearing comprising the superconductor, and a permanent magnet magnetic bearing;
The superconducting magnetic bearing and the permanent magnet magnetic bearing are formed in a ring shape so as to surround the rotating shaft,
The permanent magnet magnetic bearing supports the upper end of the rotating shaft in a radial direction,
The superconducting magnetic bearing supports an intermediate portion of the rotating shaft in a radial direction,
The said drive means drives the said superconducting magnetic bearing and the said permanent magnet magnetic bearing to the mutually opposite radial direction, The damping control mechanism characterized by the above-mentioned.   2. The vibration suppression control mechanism according to claim 1, wherein the control means includes a noise cut filter and a PID adjuster.   The vibration suppression control mechanism according to claim 1 or 2, wherein the levitating body is a levitating body of a superconducting magnetic levitation apparatus.

Images