JPH05149337A - Magnetic bearing device - Google Patents

Abstract

PURPOSE:To improve the mass productivity at manufacture of equipment, which has a magnetic bearing, and simplify the after service, getting off with the replacement or the repair of either faulty side at the time of fault of the magnetic bearing controller or the structure having a rotor. CONSTITUTION:Some (a center position offset adjuster 8, a position feedback gain adjuster 9, and a filter 10) of the control elements of a magnetic bearing controller 1 are installed outside the magnetic bearing controller 1, which dissolves the factors limiting the compatibility between the magnetic bearing controller 1 and the structure for example, a casing) 2 having a rotor, so the magnetic bearing device and the structure 2 having a rotor come to be produced individually, and the mass productivity in manufacture of equipment having the magnetic bearing improves. Moreover, at fault of the magnetic controller 1 or the structure 2 having a rotor, it gets off with the replacement of the repair of either faulty side, and the after service of the equipment having the magnetic bearing is simplified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bearing device applied to a floating object such as a turbo molecular pump, a compressor, a turbine, a high speed rotating body such as a spindle for machine tools.

[0002]

2. Description of the Related Art As means for floating and holding a high-speed rotating body,
There is a magnetic bearing using an electromagnet. A conventional example will be described with reference to FIG. 5. Reference numeral 4 denotes a rotating body, 5a and 5b denote a pair of magnetic bearings (journal bearings) that rotatably support the rotating body 4, and 6a and 6b denote floating positions of the rotating body 4. It is a position sensor for detecting.

The floating position of the rotating body 4 is determined by the position sensors 6a, 6
b, and the value of the current flowing through the electromagnets (not shown) provided in the magnetic bearings 5a and 5b is determined based on the detection signal obtained at that time, and the magnitude of the magnetic force generated in the electromagnets is controlled to cause rotation. The floating position of the body 4 is set.
FIG. 6 is a block diagram of the magnetic bearing control device. In FIG. 6, 1 is a magnetic bearing control device, 2 is a structure having a rotating body (for example, a casing), 3 is a portion that limits compatibility, 7 is a position sensor, and 8 is a center position (offset).
An adjuster, 9 is a position feedback gain adjuster, 10 is a filter, 11 is a control circuit, and 12 is an electromagnet.

The center position (offset) adjuster 8 is
The mechanical deviation of the levitation holding center of the rotating body due to an assembly error when the position sensor 7 is installed is electrically corrected and adjusted, and the adjustment value is different for each device having a magnetic bearing. The position feedback gain adjuster 9 converts the output voltage value of the position sensor 7 into the amount of displacement of the rotating body 4 from the floating center, and includes a function of correcting different sensitivities of the position sensor 7 for each point. There is.

The filter 10 has a high-frequency hunting (rotating body bending mohd natural vibration) which is generated in the high frequency region of the magnetic bearing with high gain and low damping capability due to phase delay.
The center frequency of the filter 10 is set to the natural frequency of the rotating body 4, so that the set value of the center frequency of the filter 10 is different for each device having a magnetic bearing.

The control circuit 11 is generally arranged so as to ensure position control with respect to the deviation amount of the rotor 4 from the floating center and to secure a gain and phase designed to attenuate oscillation of the rigid body mode eigenvalue of the rotor 4. It is composed of a proportional element, an integral element, and a derivative element (PID element). Normally, the center position (offset) adjuster 8, the position feedback gain adjuster 9, the filter 10, and the control circuit 11 are incorporated in the magnetic bearing control device 1, and the position sensor 7 and the electromagnet 12 are the rotating bodies. It is incorporated in the structure 2, 2.

[0007]

[Problems to be Solved by the Invention]

(1) In general, a device having a magnetic bearing includes a structure having a rotating body and a magnetic bearing control device for controlling the levitation of the rotating body.
It consists of two units. Of course, the magnetic bearing control device also includes an inverter for rotating the rotating body at a high speed. The two units are connected by a magnetic bearing control cable and a motor drive cable. (2) The magnetic bearing control device has a portion that is adjusted or set according to the individuality of the structure having the rotating body. For example, the output voltage value of the center position (offset) adjuster 8 and the position sensor 7 for correcting the mechanical deviation of the floating center of the rotating body due to the assembly error when the position sensor 7 is installed is used as the deviation amount from the floating center of the rotating body. The position feedback gain controller 9 for conversion and the filter 10 for attenuating the oscillation of the bending primary eigenvalue of the rotating body correspond to this.

These adjustment values and set values are different for each structure having the rotating body, and the structure having the magnetic bearing control device and the rotating body is a one-to-one combination. (-) The magnetic bearing control device and the structure having the rotating body,
Since this is a one-to-one combination, if the combination is changed, the magnetic bearing control loses its proper function and stable rotation cannot be guaranteed. (4) The inability to change this one-to-one combination, that is, the incompatibility between the magnetic bearing control device and the structure having the rotating body significantly reduces the mass productivity of the device having the magnetic bearing. In addition, it is not preferable in terms of after-sales service management and troubleshooting.

The present invention has been proposed in view of the above problems, and an object of the present invention is to improve mass productivity in manufacturing a device having a magnetic bearing. Further, in the case of failure of the magnetic bearing control device or the structure having the rotating body, it is only necessary to replace or repair the failed one, and to provide a magnetic bearing device capable of simplifying after-service of equipment having a magnetic bearing. It is in.

[0010]

In order to achieve the above object, the present invention controls the magnetic force by feeding back a detection signal from a position sensor for detecting the floating position of a floating holding object, and controls the magnetic force. By means of a structure having a magnetic bearing for holding the levitated object and a center position adjustment and a position feedback gain adjustment with respect to the detection signal from the position sensor, the natural frequency of the levitated object was tuned. In a magnetic bearing device including a magnetic bearing control device configured to feed back after passing through a filter, a part of control elements in the magnetic bearing control device is installed outside the magnetic bearing control device.

[0011]

As described above, in the magnetic bearing device of the present invention, a part of the control elements in the magnetic bearing control device is installed outside the magnetic bearing control device, and the magnetic bearing control device and the structure having the rotating body are provided. The factor that limits the compatibility between devices will be eliminated, and the structure (for example, casing) having the magnetic bearing device and the rotating body will be produced separately, and at the time of manufacturing the device having the magnetic bearing. Mass productivity is improved. Further, when the magnetic bearing control device or the structure having the rotating body fails, replacement or repair of the failed one is sufficient, and the after-service of the device having the magnetic bearing is simplified.

[0012]

【Example】

(First Embodiment) Next, a magnetic bearing device of the present invention will be described with reference to a first embodiment shown in FIGS. 1, 1 is a magnetic bearing control device, 2 is a structure having a rotating body (for example, a casing), 3 is a portion that limits compatibility, 7 is a position sensor,
8 is a center position (offset) adjuster, 9 is a position feedback gain adjuster, 10 is a filter, 11 is a control circuit, and 12 is an electromagnet. The above-mentioned FIG. The block diagram when incorporated in the structure (for example, casing) 2 which has a rotating body is shown.

FIG. 2 shows an application example in which the magnetic bearing device is applied to a turbo molecular pump. The output of the position sensor 7 includes a center position (offset) adjuster (a center position adjuster that corrects the axial center position deviation of the rotating body 4 due to the installation of the position sensor 7) 8 and the output value of the position sensor 7 itself varies Is adjusted by a feedback gain adjuster 9 that corrects, and is passed through a filter 10 that is tuned to the natural frequency of the rotating body 4. Then, the magnetic force of the electromagnet 12 is controlled by the control circuit 11 by PID and phase compensation. Then, the rotating body 4 is levitated and held by the same magnetic force.

Due to the characteristics of the turbo molecular pump body,
The part 3 that limits the compatibility that is adjusted or adjusted, ie
The central position (offset) adjuster 8, the feedback gain adjuster 9, and the filter 10 are integrated into a turbo molecular pump body as one unit. (Second Embodiment) Next, a magnetic bearing device of the present invention will be described with reference to a first embodiment shown in FIGS. In FIG. 3, 1 is a magnetic bearing control device, 2 is a structure having a rotating body (for example, a casing), 3 is a portion that limits compatibility, 7 is a position sensor,
8 is a center position (offset) adjuster, 9 is a position feedback gain adjuster, 10 is a filter, 11 is a control circuit, and 12 is an electromagnet. The above-mentioned FIG. The block diagram when the magnetic bearing control device 1 is separated as one unit and is installed outside the structure (for example, casing) 2 having a rotating body is shown.

FIG. 4 shows an application example in which the magnetic bearing device is applied to a turbo molecular pump. The operation is similar to that of the turbo molecular pump shown in FIG.

[0016]

As described above, in the magnetic bearing device of the present invention, a part of the control elements in the magnetic bearing control device is installed outside the magnetic bearing control device, and a structure having the magnetic bearing control device and the rotating body is provided. The factor that limits the compatibility between the magnetic bearing device and the magnetic bearing device and the structure having the rotating body (for example, the casing) can be separately produced, and the device having the magnetic bearing can be manufactured. Mass productivity can be improved.

Further, when the magnetic bearing control device or the structure having the rotating body is out of order, either one of the two can be replaced or repaired, and the after-service of the device having the magnetic bearing can be simplified.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a magnetic bearing device of the present invention.

FIG. 2 is a vertical cross-sectional side view in which the magnetic bearing device is applied to a turbo molecular pump.

FIG. 3 is a block diagram showing a second embodiment of the magnetic bearing device of the present invention.

FIG. 4 is a vertical sectional side view in which the magnetic bearing device is applied to a turbo molecular pump.

FIG. 5 is a side view showing a conventional magnetic bearing device.

FIG. 6 is a block diagram of the magnetic bearing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic bearing control device 2 Structure (for example, casing) having a rotating body 3 Part that limits compatibility 4 Rotating body 7 Position sensor 8 Center position (offset) adjuster 9 Position feedback gain adjuster 10 Filter 11 Control circuit 12 Electromagnet

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[Procedure amendment]

[Submission date] December 4, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction content]

The filter 10 has a high frequency hunting (rotating body bending mode natural vibration) which is generated in the high frequency region of the magnetic bearing with a high gain and a low damping capability due to a phase delay.
The center frequency of the filter 10 is set to the natural frequency of the rotating body 4, so that the set value of the center frequency of the filter 10 is different for each device having a magnetic bearing.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

The control circuit 11 is generally arranged so as to ensure position control with respect to the deviation amount of the rotor 4 from the floating center and to secure a gain and phase designed to attenuate oscillation of the rigid body mode eigenvalue of the rotor 4. It is composed of a proportional element, an integral element, and a derivative element (PID element). Normally, the center position (offset) adjuster 8, the position feedback gain adjuster 9, the filter 10, and the control circuit 11 are incorporated in the magnetic bearing control device 1, and the position sensor 7 and the electromagnet 12 are the rotating bodies. It is incorporated in the structure 2.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

These adjustment values and set values are different for each structure having the rotating body, and the structure having the magnetic bearing control device and the rotating body is a one-to-one combination. (3) The magnetic bearing control device and the structure having the rotating body are
Since this is a one-to-one combination, if the combination is changed, the magnetic bearing control loses its proper function and stable rotation cannot be guaranteed. (4) The inability to change this one-to-one combination, that is, the incompatibility between the magnetic bearing control device and the structure having the rotating body significantly reduces the mass productivity of the device having the magnetic bearing. In addition, it is not preferable in terms of after-sales service management and troubleshooting.

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

[Figure 4]

Claims (1)

[Claims] 1. A structure having a magnetic bearing that holds a floating object by controlling the magnetic force by feeding back a detection signal from a position sensor that detects the floating position of the floating object, and A magnetic bearing control device configured to perform center position adjustment and position feedback gain adjustment with respect to a detection signal from a position sensor, pass through a filter tuned to the natural frequency of the floating object, and then perform feedback. A magnetic bearing device comprising: a magnetic bearing device, wherein a part of control elements in the magnetic bearing control device is installed outside the magnetic bearing control device.