JP2000097236A - Magnetic bearing system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic bearing system capable of monitoring a plural number of magnetic bearing main bodies in the lump from a remote place. SOLUTION: A plural number of magnetic bearing spindles 21, 22...2n are respectively connected to their corresponding controllers 31, 32...3n, each of the controllers 31, 32...3n is perfomed a daisy chain connection by a communication cable 40 and it is connected to a computer 44 from a communication port of the controller 3n to a modem 41 through a public telephone line 42 and a modem 43. Each of the controllers 31, 32...3n memorizes a state of the corresponding magnetic bearing spindle in a memory by monitoring it, delivers monitor information memorized in the memory to the computer 44 when a discrimination signal is transmitted from the computer 44 and the discrimination signal concides with its own discrimination signal and controls the corresponding magnetic bearing spindle by discriminating the discrimination signal when a control command is transmitted to it from the computer 44.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic bearing system, for example, a magnetic bearing system used in a vacuum pump for obtaining a high vacuum and supporting a rotary shaft of a spindle rod for a turbo molecular pump with a magnetic bearing. About.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a configuration of a conventional magnetic bearing spindle. In FIG. 3, a magnetic bearing spindle 1 for a turbo molecular pump has a rotating shaft 3 provided in a case 2, and a thrust magnetic bearing 4 provided substantially at the center of the rotating shaft 3 and a thrust magnetic bearing 4. The radial magnetic bearings 5 and 6 provided above and below support the rotating shaft 3 in the thrust and radial directions in a non-contact manner, and are rotationally driven by a driving motor 7.

The radial position of the rotating shaft 3 is detected by radial position sensors 8 and 9, and the thrust position is detected by a thrust position sensor 10. Protective ball bearings 11, 12 for bearing the rotary shaft 3 when the radial magnetic bearings 5, 6 are abnormal are arranged above and below the rotary shaft 3. The detection output of each of the sensors 8, 9, 10 is given to a controller 50 provided externally,
Controls the magnetic bearings 4, 5, and 6 according to a command from the external system controller 60, and drives the motor 7 to rotate the rotating shaft 3 of the magnetic bearing spindle 1.

[0004]

The above-described magnetic bearing spindle 1 is used for various purposes by many users, but requires regular maintenance.
To this end, conventionally, a technician of the manufacturer of the manufacturer goes to a place where the magnetic bearing spindle is installed, determines the operating condition and whether there is a failure, and adjusts the controller 50. Such an operation had to be performed for each remote magnetic bearing spindle, which required a lot of time and effort.

SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide a magnetic bearing system capable of monitoring a plurality of magnetic bearing bodies collectively from a remote place.

[0006]

The invention according to claim 1 is
A magnetic bearing system for monitoring a plurality of magnetic bearing bodies having a position sensor for detecting the position of the rotating body and a magnetic bearing for magnetically contacting the rotating body in a non-contact manner with a monitoring device collectively. Provided corresponding to the magnetic bearing body,
In addition to controlling the magnetic bearing based on the signal from the position sensor, a plurality of devices that transmit and receive information to and from the monitoring device in response to the identification signal sent from the monitoring device matching its own identification signal. The control means includes a communication line that serially connects the plurality of control means and connects the control means on one end and the control means on the other end with the monitoring device.

In the invention according to claim 2, the monitoring device of claim 1 sends a control command signal together with the identification signal, and each control means responds to the discrimination of its own identification signal.
Then, the corresponding magnetic bearing main body is controlled based on the control command signal sent.

According to the third aspect of the invention, each control means of the first aspect sends the monitoring information of the corresponding magnetic bearing body to the monitoring device via the communication line together with the identification signal.

[0009]

FIG. 1 is a block diagram of one embodiment of the present invention. In FIG. 1, a plurality of magnetic bearing spindles 21, 22,... 2n as shown in FIG. 3 are provided, and controllers 31, 32... 3n are provided corresponding to the respective magnetic bearing spindles 21, 22,. Each is connected by a control cable. Each controller 3
1, 32... 3n respectively have identification numbers ID1, ID1,
2... IDn are determined.

Each controller 31, 32,... 3n is provided with a communication port P1 for transmission and a communication port P2 for reception, which are the same serial port for connecting a communication cable 40. Connected (Digi chain). That is, the transmission port P4 of the modem 41 is connected to the reception communication port P2 of the controller 3n at one end of the plurality of controllers 31, 32,. The trust port P1 is connected to the receiving port P3 of the modem 41. Modem 4
1 is connected to a modem 43 via a public telephone line 42,
The modem 43 is connected to a computer 44. The computer 44 is installed in, for example, a manufacturer of a magnetic bearing spindle, and the like.
.., 2n are collectively monitored.

FIG. 2 is a diagram showing the configuration of the controller. As shown in FIG. 2A, the controller 31 has a built-in CPU 311 for controlling the magnetic bearing spindle 21 and performing communication, and has an identification number ID1.
Are stored in a memory in the CPU 311. Further, as shown in FIG. 2B, the control C
The PU 312 and the communication CPU 313 may be provided separately.

Next, a specific operation of the embodiment of the present invention will be described. Each controller 31, 32 ... 3n
Controls the corresponding magnetic bearing spindle based on the detection signals from the position detection sensors of the corresponding magnetic bearing spindles 21, 22,... 2n. Magnetic bearing spindles 21, 22, ...
During the operation of 2n, the operation status of each controller 31, 32,... 3n is monitored. That is, values such as the rotation speed of the magnetic bearing, the detection output of each sensor, and the current flowing through each magnetic bearing are determined by the CPU in the controllers 31, 32,.
Is stored in the memory.

On the computer 44 side, it is possible to send a packet containing a control command such as a control parameter and a setting of a motor rotational speed to the controllers 31, 32,... 3n together with an identification signal. These control commands are included in the packet together with the identification signal and the modem 4
3 to the receiving port P2 of the controller 3n via the public telephone line 42 and the modem 41. The controller 3n compares the identification signal of the transmitted packet with its own identification signal IDn, and if they match, takes in the control command and controls the corresponding magnetic bearing spindle 2n according to the control command. If the identification signal is different from its own identification signal IDn, the controller 3n sends the identification signal and the control command packet to the next controller via the transmission communication port P1.

The next-stage controller operates in the same manner.
If the identification signals match, the packet is fetched. If not, the packet is sent to the next controller. If the identification number of any of the controllers does not match its own identification number, the packet is sent back to the modem 4 from the transmission communication port P1 of the controller 31.

When the computer 44 wants to know the operation status of each of the magnetic bearing spindles 21, 22,...
3. The data is sent to the controller 3n via the public telephone line 42 and the modem 41. The controller 3n compares the received identification signal with its own identification signal IDn, and if they match, fetches the inquiry command and sends back the monitoring information stored in the memory of the CPU to the computer 44. If the identification signal does not match its own identification signal IDn, the other communication port P1 sends the identification signal and the inquiry command to the next-stage controller as they are.

Therefore, according to the above embodiment, 1
A plurality of magnetic bearing spindles 21, 22... 2n can be monitored collectively from a remote location by one computer 44. Moreover, since each controller is connected by a daisy chain, only one modem and one public communication line are required, and the number of modems and communication lines can be reduced as compared with a case where each controller is monitored in parallel. .

In addition, when there is no controller having the corresponding identification number, the packet returns to the modem 41, so that it can be easily determined that there is no corresponding controller.

Note that if there is a controller that is not powered on, there is a risk that packets will stop at that controller. When the power is not on, the transmission port P2 and the reception port P1 are connected. A relay or the like may be provided so that

It should be noted that the embodiments disclosed this time are illustrative in all aspects and are not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0020]

As described above, according to the present invention, the identification signal is serially sent from the monitoring device to the control means provided corresponding to each of the plurality of magnetic bearing bodies.
Since the control means that matches the identification signal transmits and receives information to and from the monitoring device, a plurality of magnetic bearing bodies can be monitored collectively at a remote location, and the status of each magnetic bearing body can be monitored. And the necessary control can be performed remotely.

[Brief description of the drawings]

FIG. 1 is a block diagram of one embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a controller shown in FIG.

FIG. 3 is a diagram showing a configuration of a conventional magnetic bearing spindle.

[Explanation of symbols]

 21, 22 ... 2n Magnetic bearing spindle 31, 32 ... 3n Controller 40 Communication cable 41, 43 Modem 42 Public telephone line 44 Computer 311, 312, 313 CPU

Claims (3)

[Claims] 1. A position sensor for detecting a position of a rotating body,
A magnetic bearing system that collectively monitors a plurality of magnetic bearing bodies having a magnetic bearing that supports the rotating body in a magnetically non-contact manner with a monitoring device, provided corresponding to each magnetic bearing body, Controlling the magnetic bearing based on the signal from the position sensor, and transmitting and receiving information to and from the monitoring device in response to the identification signal sent from the monitoring device matching its own identification signal. A magnetic bearing system comprising: a plurality of control means for performing the control; and a communication line for serially connecting the plurality of control means and connecting the control means on one end and the control means on the other end to the monitoring device. 2. The monitoring device sends a control command signal together with an identification signal, and each control means sends a control command signal subsequently sent in response to determining the identification signal of the corresponding magnetic bearing main body. The magnetic bearing system according to claim 1, wherein a corresponding magnetic bearing main body is controlled on the basis of: 3. The magnetic bearing system according to claim 1, wherein each control unit sends monitoring information of a corresponding magnetic bearing main body to the monitoring device via the communication line together with an identification signal. .