JP2000145775A - Controller for magnetic bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a collective management by a computer by use of a communication line. SOLUTION: The detection signals of each sensor 8, 9, 10 and 13 of a magnetic bearing spindle 1 are transmitted from an I/O interface 33 to a CPU 41 through A/D converters 21-24, the CPU 41 calculates the current values to be carried to magnetic bearings and a motor on the basis of the output of each sensor, the respective values are transmitted to D/A converters 25-28 and converted to analog signals to drive a thrust bearing 4, and radial magnetic bearings 5, 6 and a motor 7 by each drive circuit 29-31. The outputted current and the detection output of each sensor are stored in a RAM 43, and the CPU 41 transfers the data stored in the RAM 43 to an external computer 54 to monitor the operating state of the magnetic bearing spindle 1 in a remote place by the computer 54.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a magnetic bearing device, and more particularly to a magnetic bearing device which is used for a vacuum pump for obtaining a high vacuum and magnetically mounts a rotating shaft of a turbo molecular pump spindle. It relates to a control device.

[0002]

2. Description of the Related Art A magnetic bearing device for a spindle for a turbo-molecular pump has two radial magnetic bearings and one thrust bearing, and also has two radial position sensors and one thrust position sensor. . The radial magnetic bearing performs a radial bearing above and below the rotating shaft in a non-contact manner, and the thrust magnetic bearing performs a thrust bearing near the center of the rotating shaft in a non-contact manner.

Further, the magnetic bearing device is provided with sensors for detecting the radial position and the thrust position of the rotating shaft, and each magnetic bearing is controlled by a control device based on the output of each sensor.

[0004]

The above-described magnetic bearing device has many mechanical parts, and therefore requires periodic maintenance. Such inspection and maintenance is generally performed by a technician of a manufacturer that manufactures the magnetic bearing device. In semiconductor factories and the like, a large number of vacuum pumps are used, and the number of magnetic bearing devices becomes considerable. Moreover,
The installation locations are scattered, which places a heavy burden on manufacturers and users to perform maintenance and inspection of these magnetic bearing devices.

On the other hand, recently, with the liberalization of communications, the usage fee for communication lines has become lower. If the magnetic bearing devices can be managed collectively using the communication lines, the maintenance cost will be reduced. I can expect that.

[0006] Therefore, a main object of the present invention is to provide a control device for a magnetic bearing device which can be collectively managed by a computer using a communication line.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a magnetic bearing device having a position sensor for detecting the position of a rotating body and a magnetic bearing for magnetically supporting the rotating body in a non-contact manner. To control magnetic bearing based on
A control means including U, an information processing means installed at a position remote from the control means, and a communication means for transmitting information between the information processing means and the control means.

According to the invention of claim 2, the CPU of the control means of claim 1 is included in a one-chip microcomputer having a built-in RAM and ROM.

[0009]

FIG. 1 is a block diagram of a configuration and a control device of a magnetic bearing device according to an embodiment of the present invention.

In FIG. 1, a magnetic bearing spindle 1 comprises:
A rotating shaft 3 is provided in the case 2, and is rotated by a thrust magnetic bearing 4 provided substantially at the center of the rotating shaft 3 and radial magnetic bearings 5 and 6 provided above and below the thrust magnetic bearing 4. The shaft 3 is supported in the thrust direction and the radial direction in a non-contact manner, and is rotationally driven by a driving motor 7.

The radial position of the rotating shaft 3 is detected by the radial position sensors 8 and 9, the thrust position is detected by the thrust position sensor 10, and the rotation speed is detected by the rotation speed sensor 13. Further, protective ball bearings 11 and 12 for bearing the rotating shaft 3 when the radial magnetic bearings 5 and 6 are abnormal are arranged above and below the rotating shaft 3.

The detection outputs of the sensors 8, 9, 10, and 13 are converted into digital signals by A / D converters 21, 22, 23, and 24, and the I / O interface 33
Is given to the CPU 41 via the. CPU 41 is ROM
It is built in the one-chip microcomputer 40 together with the RAM 42 and the RAM 43. The CPU 41 sequentially reads the detection output of each sensor and stores it in the RAM 43 based on a program stored in the ROM 42 in advance, and outputs a drive signal for driving the magnetic bearings 4, 5, 6, and the motor 7. These drive signals are supplied to the D / A converters 25, 26, 27 and 28 via the I / O interface 33.
And converted to an analog signal. Each analog signal is applied to bearing drive circuits 29, 30 and 31 and a motor drive circuit 32 to drive the thrust magnetic bearing 4, the radial magnetic bearings 8, 9 and the motor 7.

Further, a modem 51 is connected to the CPU 41, and the modem 51 is connected to a remote modem 53 via a communication line 52, and the modem 53 is connected to a computer 54. The CPU 41 communicates with the remote computer 54 via the modem 51, the communication line 52, and the modem 53.
Exchanges data with the

Next, a specific operation of the embodiment of the present invention will be described. First, the CPU 41 calculates a current value for magnetically levitating the rotating shaft 3 based on the detection outputs of the radial position detection sensors 8 and 9 and the thrust position detection sensor 10, and outputs a current command signal. At this time, CP
U41 stores each current value and sensor output value in the RAM 43. The output current command signal is supplied to the D / A converters 25 to 2
7, and is converted into an analog signal.
The corresponding bearing is driven by .about.31.

When the rotation speed sensor 13 detects the rotation speed of the rotating shaft 3, the CPU 41 calculates a current value to be supplied to the motor 7 so that the rotation speed matches the set rotation speed. Output the value. At this time, the CPU 4
1 causes the RAM 43 to store the current command value and the rotation speed. The output current command value is converted into an analog signal by the D / A converter 28, and the motor 7 is driven by the motor drive circuit 32.

As described above, the data stored in the RAM 43 is sent by the CPU 41 to the computer 54 via the modem 51, the communication line 52 and the modem 53 as necessary. Therefore, if the computer 54 is arranged at the manufacturer of the magnetic bearing spindle 1, the operation status of the magnetic bearing spindle 1 can be constantly monitored.

Note that the CPU 41 does not always monitor the output of each sensor, but monitors the output of a timer at regular intervals, and stores the time in the RAM 43.

In the above embodiment, the CPU 41 and the computer 54 are connected one-to-one.
Without being limited to this, a plurality of magnetic bearing spindles may be monitored by one computer 54. In that case, a modem may be installed in each control device corresponding to each magnetic bearing spindle 1, and each modem may be connected to the modem 53 of the computer 54 via a communication line.

[0019]

As described above, according to the present invention, the control means including the CPU for controlling the magnetic bearing based on the signal from the position sensor of the magnetic bearing device is provided, and between the control means and the information processing means. Is connected by communication means, and the operating status of the magnetic bearing device can be monitored on the information processing means side.
It becomes possible to monitor the magnetic bearing device at a remote location. Moreover, by using the control means including the CPU, the number of components can be reduced, a compact controller can be configured, the software program can be easily changed, and communication can be easily performed.

[Brief description of the drawings]

FIG. 1 is a block diagram of a configuration and a control device of a magnetic bearing device according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic bearing spindle 2 Case 3 Rotating shaft 4 Thrust bearing 5,6 Radial magnetic bearing 7 Motor 8,9 Radial position sensor 10 Thrust position sensor 11,12 Protective ball bearing 13 Rotation speed sensor 21-24 A / D converter 25 -28 D / A converter 29-31 Bearing drive circuit 32 Motor drive circuit 33 I / O interface 40 1-chip microcomputer 41 CPU 42 ROM 43 RAM 51,53 Modem 52 Communication line 54 Computer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H022 AA01 BA06 CA12 CA16 CA20 DA16 3J102 AA01 BA03 BA19 CA20 DA02 DA03 DA09 DB05 DB10 DB11 DB37 GA06 5H607 AA14 BB01 BB09 BB14 BB26 CC07 DD18 EE26 FF06 GG01 GG21 HH01 H09

Claims (2)

[Claims] 1. A position sensor for detecting a position of a rotating body,
A magnetic bearing device having a magnetic bearing that magnetically supports the rotating body in a non-contact manner; a control unit including a CPU that controls the magnetic bearing based on a signal from the position sensor; A control device for a magnetic bearing device, comprising: an information processing unit installed at a position; and a communication unit for transmitting information between the information processing unit and the control unit. 2. The CPU of the control means is a RAM and a ROM.
The control device for a magnetic bearing device according to claim 1, wherein the control device is included in a one-chip microcomputer having a built-in microcomputer.