JPH11210673A - Magnetic levitation rotating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic levitation rotating device which can store memories on the hysteresis of operations and unusual break outs together with their times in details, can keep the contents of the memories even if a power source for control is cut out, can recognize the hysteresis of operations and unusual break outs in details, and can diagnose failures and something wrong with ease. SOLUTION: This magnetic levitation rotating device is equipped with a machinery main body 1 having both a magnetic bearing 5 supporting a rotor 4 in a non-contact state and an electric motor 7 rotating the rotor 4, and with a controller 2 controlling the aforesaid machinery main body. The controller is equipped with a DSP(digital signal processor) controlling both the magnetic bearing 6 and the electric motor 7, a processing program in the DSP 14, a flush memory 16 storing control parameters, and a real time clock 15. The DSP 14 stores the hysteresis of the operation of the device and unusual breakouts together with times in the flush memory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic levitation rotating apparatus in which a rotating body is supported by a magnetic bearing in a non-contact manner and is rotated by an electric motor, such as a turbo molecular pump using a magnetic bearing used in a semiconductor manufacturing apparatus and the like. And a magnetic levitation rotating device.

Hereinafter, a turbo molecular pump will be described as an example of a magnetic levitation rotating device.

[0003]

2. Description of the Related Art As a turbo-molecular pump, a machine body (pump body) in which a rotating body (rotor) constituting the pump is non-contactly supported by a control type magnetic bearing and rotated by an electric motor, and a controller for controlling the same. What is provided is known.

In such a conventional magnetic levitation rotating apparatus, control of a magnetic bearing by a controller is performed by an analog PI.
D control is mainly used, and there is no device that stores the operation history of the apparatus or the history of occurrence of an abnormality due to a failure or the like.

In this type of magnetic levitation rotating apparatus, it is sometimes necessary to know the operation history of driving of a magnetic bearing, driving of a motor, etc. in order to grasp and manage the state of use of the apparatus. Conventionally, an hour meter is provided in the controller to display the operation time of the magnetic bearing and the operation time of the motor.

Therefore, it is necessary to provide two hour meters separately in the controller. In addition, the hour meter can only know the cumulative operating time of the magnetic bearing or the motor, but cannot know the details of the history of these operations.

Some conventional magnetic levitation rotating apparatuses of this type display and store the contents of an abnormality caused by a failure or the like in the apparatus. In many cases, the contents disappeared, and even when the memory remained, it was only the contents of the abnormality that occurred last.

For this reason, it has been difficult to diagnose the true failure or the content of the abnormality from the content of the generated abnormality.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to be able to store the operation history of an apparatus and the history of occurrence of an abnormality in detail together with the time, so that the stored contents disappear even when the controller is turned off. Therefore, it is an object of the present invention to provide a magnetic levitation rotating device that can know the operation history of the device and the history of occurrence of abnormality in detail, and can easily diagnose a failure or abnormality.

[0010]

SUMMARY OF THE INVENTION A magnetic levitation rotating apparatus according to the present invention comprises a machine body having a magnetic bearing for supporting a rotating body in a non-contact manner and an electric motor for rotating the rotating body; A magnetic levitation rotating device comprising: a controller that controls the magnetic bearing and the electric motor; a digital processing unit that controls the magnetic bearing and the electric motor; and a nonvolatile memory that stores a processing program and control parameters in the digital processing unit. And a real time clock, wherein the digital processing means includes a history storage means for storing, in the nonvolatile memory, a history of operation of the apparatus and a history of occurrence of an abnormality together with a time based on an output of the real time clock. It is characterized by having.

As the digital processing means, for example, M
A PU (microprocessor), a digital signal processor or the like is used. In this specification, a digital signal processor (Digital Signal Processor)
The term “dedicated hardware” refers to dedicated hardware that inputs a digital signal, outputs a digital signal, is software-programmable, and is capable of high-speed real-time processing. Hereinafter, this is abbreviated as DSP.

As the nonvolatile memory, for example, an appropriate memory such as a flash memory and an EPROM is used.

For example, every time the start and stop of the magnetic bearing and the start and stop of the motor are performed, the contents thereof are stored in the nonvolatile memory together with the time at that time as the operation history. In addition, the output signal of the displacement sensor for detecting the displacement of the rotating body due to the failure of the machine body or the controller, the output signal of the rotation speed sensor for detecting the rotating speed of the rotating body, the operation value of the control signal in the controller In the case where an abnormality occurs, the content of the abnormality is stored in the nonvolatile memory together with the time at that time as a history of occurrence of the abnormality. Such a history of operation and a history of occurrence of an abnormality are stored in the non-volatile memory, and thus do not disappear even when the power of the controller is turned off. Therefore, the operation history of the apparatus can be known in detail at any time at any time. In addition, since the history of a plurality of past abnormalities can be known together with the time of occurrence, it is possible to diagnose the cause of a true failure or abnormality based on these, and the diagnosis is easy. further,
It is not necessary to provide an hour meter or the like as in the related art, and the cost and size of the controller can be reduced.

For example, the nonvolatile memory is connected to a computer, and the computer includes display means for reading and displaying the history stored in the nonvolatile memory.

As the computer, for example, a personal computer (personal computer) is used. The computer is connected to the non-volatile memory via, for example, a cable, a communication line, or the like.

In this case, the history can be displayed on the computer side and can be viewed.

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

FIG. 1 shows a configuration in which the magnetic levitation rotating apparatus according to the present invention is applied to a turbo molecular pump.

The turbo-molecular pump includes a machine body (1) constituting a pump body and a controller (2) constituting a pump control section, and a personal computer (3) is connected to the controller (2).
Is connected.

The machine body (1) includes a rotating body (rotor) (4) constituting a pump, a displacement detector (5), and a control type magnetic bearing.
(6), built-in type electric motor (7) and speed sensor
(8) is provided.

The controller (2) includes a displacement calculation circuit (9),
Magnetic bearing drive circuit (10), inverter (11), DSP board
(12) and a serial communication board (13)
The board (12) has a DSP (1
4), real-time clock (15), non-volatile flash memory (16), AD converter (17) and DA converter (18)
Is provided. The controller (2) and the personal computer (3) are set apart from each other, and the flash memory (16) and the personal computer (3) are connected via a communication board (13) and a cable (19). Although not shown, the controller (2) is provided with a power-on switch, a power-off switch, a motor start switch, a motor stop switch, and the like.

The magnetic bearing (6) is provided with an axial control shaft (axial control shaft) at one location in the axial direction of the rotating body (4) by magnetic attraction of a plurality of electromagnets (not shown).
In the axial direction of the rotating body (4), and respectively support the rotating body (4) in two radial control axes (radial control axes) orthogonal to each other. Things. Although not shown, the displacement detector (5) includes a plurality of displacement sensors for detecting the displacement of the rotating body (4). The displacement calculation circuit (9) is
(5) Based on the output signals of the plurality of displacement sensors,
In addition to calculating the displacement in the axial control axis direction of (4), calculating the displacements in the two radial control axis directions at two locations in the axial direction of the rotating body (4), the displacement signals corresponding to these displacements are calculated by AD. Output to the DSP (14) via the converter (17). The DSP (14) calculates a control current value for each electromagnet of the magnetic bearing (6) based on the displacement signal input from the AD converter (17), and converts the corresponding control current signal into a DA signal.
Output to the magnetic bearing drive circuit (10) via the converter (18).
The magnetic bearing drive circuit (10) includes a plurality of power amplifiers and the like corresponding to the electromagnets of the magnetic bearing (6), and supports the magnetic bearing (6) based on a control current signal output from the DA (18). An exciting current is supplied to the electromagnet to be driven. This allows the rotating body
(4) is supported in a non-contact manner at a predetermined target position.

The motor (7) rotates the rotating body (4) which is supported in a non-contact manner by the magnetic bearing (6). The rotation speed sensor (8) is for detecting the rotation speed of the rotating body (4). For example, the DSP (14) outputs a fixed number (for example, one) of pulse signals per rotation of the rotating body (4). ). DS
P (14) is calculated from the pulse signal of the rotation speed sensor (8) by the rotating body (4).
, And outputs a rotation speed command signal for controlling the rotation of the motor (7) to the inverter (11) based on the calculated rotation speed. Then, the inverter (11) controls the rotation of the motor (7) based on the rotation speed command signal from the DSP (14).

The real time clock (15) measures the actual time by always counting a constant clock pulse. While the power of the controller (2) is not turned on, the real-time clock (15) is operated by a backup battery (not shown).

The flash memory (16) stores a processing program for the DSP (14). Although not shown, the flash memory (16) has a magnetic bearing (6).
A control parameter table storing the control parameters of
An operation history storage table for storing the operation history of the apparatus, an abnormality history storage table for storing the history of occurrence of abnormality, and the like are provided.

While the power of the controller (2) is not turned on, the rotating body (4) is mechanically supported by a touch-down bearing (not shown) and is stopped. controller
When the power-on switch of (2) is operated and the power is turned on, the magnetic bearing (6) is driven as described above, and the rotating body is turned on.
(4) is separated from the touchdown bearing and supported in a non-contact manner at the target position. Thereafter, when the motor start switch is operated, as described above, the motor (7) is driven, and the rotating body (4)
Is rotated, and the operation of the device is continued. When the motor stop switch is operated during operation of the device, the DSP (14)
Outputs a rotation stop command to the inverter (11).
(7) stops, and the rotating body (4) stops. And the rotating body
When the power cutoff switch of the controller (2) is operated after the stop of (4), the stop command from the DSP (14)
The power supply from the magnetic bearing drive circuit (10) to the electromagnet of the magnetic bearing (6) stops, and the rotating body (4) is no longer supported by the magnetic bearing (6). Power is shut off.

While the power is turned on, the controller (2) grasps the operation status of the device such as the magnetic bearing (6) and the motor (7), and uses it as a history of the operation of the device in the flash memory (16). In the operation history table.

That is, when the power-on switch of the controller (2) is operated, the time at that time is read from the real time clock (15), and the time and the start of the operation of the magnetic bearing (6) are recorded in the operation history. Store in a storage table. Similarly, when the motor drive switch is operated, the time at that time and the start of the operation of the motor (7) are stored.When the motor stop switch is operated, the time at that time and the motor (7) are stored.
The fact that the operation of (7) has been stopped is stored. When the power cutoff switch is operated, the time at that time and the magnetic bearing
The fact that the operation of (6) has been stopped is stored, and then the power is shut off.

While the power is turned on, the controller (2) outputs a displacement signal, which is an output signal of the AD converter (17), an output signal of the rotation speed sensor (8), a calculation result of a control current value, and the like. Are constantly monitored, and when these abnormalities are detected, the abnormalities are stored in the abnormality history storage table of the flash memory (16) as the history of the occurrence of the abnormality of the apparatus.

That is, when an abnormality in a certain portion of the apparatus is detected, the time at that time is read from the real time clock (15), and the time and the contents of the abnormality are stored in the abnormality history storage table.

The history of the operation of the apparatus and the history of occurrence of abnormalities are stored in the flash memory (16), which is a non-volatile memory, so that they do not disappear even when the power of the controller (2) is cut off.

The personal computer (3) reads the contents of the operation history storage table of the flash memory (16) and the contents of the abnormality history storage table as necessary, and stores them in a hard disk or the like as an external memory. The operation history, the abnormality occurrence history, or the combination of both are displayed on the display (20).

FIG. 2 shows an example in which the operation history is displayed on the display (20) in the order of the occurrence time.

In FIG. 2, the left column indicates the date of occurrence, and the center column indicates the time of occurrence. The column on the right shows the contents of the driving history.
“n” indicates the start of operation of the magnetic bearing (6), and “start” indicates the motor.
The start of the operation of (7), "stop" indicates the stop of the operation of the motor (7), and "power off" indicates the stop of the operation of the magnetic bearing (6).

The history of occurrence of an abnormality in the apparatus can be displayed in the same manner.

If necessary, a personal computer (3)
The control parameters of the magnetic bearing (6) stored in the control parameter table of the flash memory (16) can be rewritten. However, the controller (2)
May not be connected to a computer such as a personal computer.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a turbo-molecular pump showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an example of display contents on a display of a personal computer;

[Explanation of symbols]

 (1) Machine body (2) Controller (3) Personal computer (4) Rotating body (6) Magnetic bearing (7) Electric motor (14) Digital signal processor (15) Real-time clock (16) Flash memory (20) display

Claims (2)

[Claims] A machine body having a magnetic bearing for supporting the rotating body in a non-contact manner and an electric motor for rotating the rotating body;
A magnetic levitation rotating device including a controller that controls the machine body, wherein the controller stores a digital processing unit that controls the magnetic bearing and the electric motor, and a processing program and control parameters in the digital processing unit. Comprising a non-volatile memory and a real-time clock,
Magnetic levitation, wherein the digital processing means includes history storage means for storing the operation history of the apparatus and the history of occurrence of an abnormality in the nonvolatile memory together with the time based on the output of the real-time clock. Rotating device. 2. The magnetic apparatus according to claim 1, wherein said non-volatile memory is connected to a computer, and said computer includes display means for reading and displaying said history stored in said non-volatile memory. Floating rotating device.