JPH10103285A - Turbo-molecular pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce kinds of power units to a turbo-molecular pump body having various characteristics. SOLUTION: In a turbo-molecular pump having a turbomolecular pump body 2 and a power unit 3 capable of transmitting/receiving a power and a signal to or from the turbo-molecular pump body 2, memory means ROM2f for storing a characteristic parameter of the turbo-molecular pump body 2 and transmission means (communication control circuit 2e) for transmitting the characteristic parameter to the turbomolecular pump body side are provided to the power unit 3 and receiving means (communication control circuit 3e) for receiving the characteristic parameter from the transmission means and control means 3b, 3c for controlling the turbomolecular pump body using the characteristic parameter are provided to the turbo-molecular pump body 2. A condition of performing a control of the turbo-molecular pump body 2 is set by the characteristic parameter from the power unit 3 side and the power units are used in common to thereby reduce the kind.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a vacuum pump for obtaining a high vacuum or an ultra-high vacuum, and more particularly to a turbo-molecular pump.

[0002]

2. Description of the Related Art In general, turbo molecular pumps are provided with various models having different rotation speeds of a motor of a turbo molecular pump body, voltages and currents applied to the motors, and the like. And
In order to drive the motors of the turbo molecular pump main bodies of each model, a dedicated power supply device for supplying and controlling electric power corresponding to each characteristic and condition is required.

In the case of a magnetic levitation type turbo molecular pump, since the mass and the center of gravity of the rotor blades are different for each model, a dedicated magnetic levitation control circuit corresponding to each control characteristic is required on the power supply side. And

FIG. 3 is a schematic block diagram for explaining the configuration of a conventional turbo-molecular pump. In FIG. 3, the turbo molecular pump 10 includes a turbo molecular pump main body 20 and a power supply device 30, and the two devices 20 and 30 are connected by a power line and a signal line 40. Turbo molecular pump body 2
0 is provided with a motor 20a for driving the rotor blades, and a temperature sensor 20b for detecting the temperature of the motor. Further, when the rotor is magnetically levitated, an electromagnet 20 for a magnetic bearing is provided.
d, and a position sensor 20c for detecting a rotor position. The power supply device 30 includes an inverter power circuit 30a for supplying drive power to the motor 20a, and an inverter drive circuit 3
0a, and a magnetic bearing operation circuit 30 for supplying electric power to the electromagnet 20d of the magnetic bearing.
and a magnetic bearing control circuit 30c for controlling the magnetic bearing operation circuit 30d. A power line 40 for transmitting electric power from the power supply device 30 to the turbo molecular pump body 20 is provided between the turbo molecular pump body 20 and the power supply device 30.
a, 40d and signal lines 40b, 40c for transmitting sensor signals from the turbo molecular pump main body 20 to the power supply 30.

The power supply 30 includes a ROM 30e storing various operating conditions for optimal operation of the motor according to the type of the turbo molecular pump, and an optimal magnetic levitation control according to the mass and the position of the center of gravity of the rotor blades. And a ROM 30f which stores control conditions for the control, and inputs each condition to the inverter control circuit 30b and the magnetic bearing control circuit 30c to set the condition.

[0006]

In the conventional turbo-molecular pump, the combination of the turbo-molecular pump body and the power supply is determined for each model. There is a problem that only the number of types is required and the power supply device requires many types. The necessity of these various types of power supply devices causes a waste in managing the inventory and supply of the power supply devices.

In the case where a new model is formed by changing the design of the motor and rotor blades of the turbo molecular pump body, a power supply unit having motor operating conditions and magnetic levitation control conditions in accordance with the design change is required. There is a problem that it is newly required. Usually, in order to respond to the failure of the turbo molecular pump, it is necessary to keep the stock of the turbo molecular pump main body and the power supply unit, and also retain the old model power supply unit with the model change of the turbo molecular pump main unit. It is necessary to increase the number of types of power supply devices that need to be maintained.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional turbo-molecular pump and to reduce the number of types of power supply units for the turbo-molecular pump having various characteristics.

[0009]

SUMMARY OF THE INVENTION The present invention provides a turbo-molecular pump body having a rotor blade, a motor for driving the rotor blade, and a bearing for rotatingly supporting the rotor blade, and power and signal transmission between the turbo-molecular pump body. In a turbo molecular pump including a power supply device capable of giving and receiving, a storage means for storing characteristic parameters of the turbo molecular pump main body in the power supply apparatus, and a transmission means for transmitting the characteristic parameters to the turbo molecular pump main body side are provided; The turbo molecular pump main body is provided with a receiving means for receiving the characteristic parameter from the transmitting means, and a control means for controlling the turbo molecular pump main body using the received characteristic parameter.

The characteristic parameter is a value representing the operation and control characteristics of the turbo-molecular pump main body, and differs depending on the model of the turbo-molecular pump and the turbo-molecular pump main body. The storage means included in the power supply device stores unique characteristic parameters of the turbo-molecular pump main body driven by using the power supply device. This characteristic parameter is transmitted from the transmission unit on the power supply device side to the reception unit on the turbo molecular pump main body side,
It is set in the control means of the turbo molecular pump main body. The control means of the turbo molecular pump main body performs control using the characteristic parameters.

With this configuration, various conditions for controlling the turbo molecular pump main body can be set by characteristic parameters sent from the power supply device. Therefore, the power supply device can correspond to the turbo molecular pump main body having various characteristics by changing only the characteristic parameter stored in the storage means. It is possible to reduce the number of types of the power supply devices by performing commonization without making the power supply devices.

In the first embodiment of the present invention, the characteristic parameters are set as optimum operating conditions of the turbo-molecular pump, and the number of rotations of the motor, applied voltage, applied current, voltage / frequency characteristics, slip, feedback control are set. The differential constant, proportional constant and integral constant of are stored in the storage means. By setting the values of the operating conditions stored in the storage means of the power supply device according to the model of the turbo-molecular pump and the unique characteristics of the turbo-molecular pump main body, the drive of various turbo-molecular pump main bodies by the common power supply device , Control can be performed.

In a second embodiment of the present invention, characteristic parameters are used as control conditions for a magnetic bearing control circuit of a turbo-molecular pump. The gain, differential constant, proportional constant, integral constant of feedback control, and filter circuit The constant is stored in the storage means. By setting the value of the control condition to be stored in the storage means of the power supply device according to the model of the turbo-molecular pump and the inherent characteristics of the turbo-molecular pump main body, the magnetic bearing of the various turbo-molecular pump main bodies can be controlled by the common power supply device. Control can be performed.

According to a third embodiment of the present invention, the characteristic parameter is set to both the operating condition of the turbo-molecular pump and the control condition of the magnetic bearing control circuit. By making the conditions and control conditions correspond to the model of the turbo-molecular pump and the inherent characteristics of the turbo-molecular pump main body, it is possible to drive and control various turbo-molecular pump main bodies and control magnetic bearings with a common power supply device.

According to a fourth embodiment of the present invention, the characteristic parameter is an abnormal value for identifying an abnormality of the turbo-molecular pump, and the abnormal value of the operating condition and the abnormal value of the control condition are determined by the model of the turbo-molecular pump. And the characteristic of the turbo-molecular pump main body, it is possible to detect abnormality of various turbo-molecular pump main bodies by a common power supply device.

[0016]

Embodiments of the present invention will be described below in detail with reference to the drawings. A configuration example of an embodiment of the present invention will be described with reference to a schematic block diagram illustrating an embodiment of the turbo-molecular pump of the present invention in FIG. The turbo-molecular pump 1 of the present invention has substantially the same configuration as that of FIG. 3, and has a storage means for storing characteristic parameters of the turbo-molecular pump main body such as operating conditions and control conditions on the turbo-molecular pump main body side. The difference lies in the configuration in which characteristic parameters are set in the power supply device using a communication control circuit provided in the pump body and the power supply device.

In FIG. 1, a turbo molecular pump main body 2 and a power supply device 3 are provided, and both devices 2 and 3 are connected by a power line and a signal line 4. The turbo molecular pump main body 2 includes a motor 2a for driving the rotor blades, and a temperature sensor 2b for detecting the temperature of the motor. When the rotor is magnetically levitated, an electromagnet 2d for a magnetic bearing and a rotor position are set. And a position sensor 2c for detecting.
Inverter power circuit 3 for supplying drive power to motor 2a
a, an inverter control circuit 3b for controlling the inverter drive circuit 3a, a magnetic bearing operation circuit 3d for supplying power to the electromagnet 2d of the magnetic bearing, and a magnetic bearing control circuit 3c for controlling the magnetic bearing operation circuit 3d. I have.

Then, between the turbo molecular pump main body 2 and the power supply 3,
The power lines 4a and 4d for transmitting electric power to the power supply device 3 and the signal lines 4b and 4c for transmitting a sensor signal from the turbo molecular pump main body 2 to the power supply device 3 are electrically connected to each other.

The turbo molecular pump main body 2 includes a ROM 2f for storing characteristic parameters of the turbo molecular pump,
A communication control circuit 2e for transmitting data stored in the ROM 2f to the power supply device 3 through a signal line 4e;
The power supply device 3 is provided with a communication control circuit 3e that receives data sent from the turbo-molecular pump main body 2 and sets conditions for operating conditions and control conditions in the inverter control circuit 3b and the magnetic bearing control circuit 3c.

The characteristic parameters stored in the ROM 2f are:
Various operating conditions for optimal operation of the motor according to the model of the turbo molecular pump, control conditions for optimal magnetic levitation control according to the mass of the rotor blades and the position of the center of gravity, or abnormalities that detect abnormal conditions It can be a value. The operating conditions, control conditions, and abnormal values differ depending on the model of the turbo-molecular pump and the individual turbo-molecular pump main bodies, and are characteristic parameters provided in each turbo-molecular pump main body. The characteristics of the turbo molecular pump model
The characteristic can be obtained from the characteristic data known for each model, and the characteristic peculiar to the turbo molecular pump main body can be obtained by measuring the characteristic characteristic of the turbo molecular pump main body in advance. The abnormal value can be obtained from the model data or the unique data.

The operating conditions are conditions for optimal operation of the pump, and include, for example, the number of rotations of the motor, applied voltage, applied current, voltage / frequency characteristics, slip, differential constant of feedback control, proportional constant, and integral constant. The control condition is a control condition of the magnetic bearing control circuit of the turbo molecular pump, and may be a gain, a differential constant, a proportional constant, an integral constant, and a filter circuit constant of the feedback control. Further, the abnormal value can be a determination value for determining a normal state and an abnormal state, for example, with respect to the number of rotations of the motor, voltage, current, temperature, rotor position, and the like.

Next, the operation of the power supply of the present invention will be described with reference to the flowchart of FIG. When power is turned on in the power supply device 3, the inverter control circuit 3b
The CPU inside initializes storage data such as operating parameters, control conditions, and characteristic parameters such as abnormal values (step S1), and confirms connection with the turbo molecular pump main body 2 through the communication control circuit 3e (step S2). ).

When the connection between the power supply device 3 and the turbo molecular pump main body 2 is confirmed, the communication control circuit 3e on the power supply device 3 side
Requests the data transfer to the communication control circuit 2e of the turbo molecular pump main body 2 side. Upon receiving the data transfer request, the communication control circuit 2e of the turbo molecular pump main body 2
Is transferred to the communication control circuit 3e of the power supply 3 via the signal line 4e (step S3).

The CPU of the inverter control circuit 3b writes the read characteristic parameters into the storage means in the inverter control circuit 3b, and sets operating conditions and abnormal values (step S4). Further, the CPU sets parameters such as a gain of feedback control, a differential constant, a proportional constant, an integral constant, and a constant of a filter circuit for a digital signal processor (DSP) in the magnetic bearing control circuit 3e (step S5). By setting the parameters for each control circuit in steps S4 and S5, the preparation for driving the turbo molecular pump is completed, and the power supply device 3 is in a state of waiting for the input of a start signal.

The CPU of the power supply device 3 receives the input of the start signal, operates the inverter power circuit 3a and the magnetic bearing power circuit 3d by the control signals generated by the inverter control circuit 3b and the magnetic bearing control circuit 3c, and generates the generated operating power. To the motor 2a and the electromagnet 2d through the power lines 4a and 4d to drive the turbo molecular pump main body 2 (step S6).

In driving the turbo molecular pump main body 2, the magnetic bearing control circuit 3c receives a detection signal from the position sensor 2c through the signal line 4c, generates an exciting current, sends the exciting current to the electromagnet 2d through the power line 4d, and drives the rotor. Rotationally supported by magnetic levitation. Further, the detection signal from the position sensor 2c is compared with an abnormal value, and an abnormal signal is generated if necessary (step S7). The inverter control circuit 3b receives a detection signal from the temperature sensor 2b through a signal line 4b, generates an operation signal, and
a to the motor 2a to drive the motor 2a for driving the rotor blades. Further, a detection signal from the temperature sensor 2b is compared with an abnormal value, and an abnormal signal is generated if necessary (step S8).

According to the embodiment of the turbo-molecular pump of the present invention, even if there are individual differences in the sensitivity and center value of the position sensor of the magnetic bearing, individual differences in the motor characteristics and the inertia of the rotor, the individual differences are used. By storing the characteristic parameters in the ROM of the turbo molecular pump main body, the magnetic bearing control circuit of the power supply device can control the rotor and the shaft to appropriate positions. Therefore, the magnetic bearing can be operated normally without extremely increasing the mechanical accuracy of the pump body.

According to the embodiment of the turbo-molecular pump of the present invention, the turbo-molecular pump can be operated only by connecting the main body of the turbo-molecular pump and the power supply, and the power supply can be used for general purpose without adjustment. Further, since the characteristic parameters stored in the ROM of the turbo molecular pump main body are fixed at the time of manufacturing the turbo molecular pump main body, it is not necessary to rewrite the data thereafter.

The motor used for the turbo-molecular pump of the present invention is not limited to the induction motor, but may be a DC brushless motor. In a DC brushless motor, the voltage and the rotational speed are normally in a proportional relationship, and if an overvoltage is supplied to the motor, it causes an overspeed. According to the turbo-molecular pump of the present invention, the proportional constant between the voltage and the rotational speed is stored in the ROM even when there is an individual difference in the proportional constant between the voltage and the rotational speed depending on the magnetization state of the built-in permanent magnet. This allows the inverter control circuit 3b to set the detection applied to the motor to an optimum value and prevent overspeed due to overvoltage.

[0030]

As described above, according to the present invention,
The number of types of power supply devices can be reduced for turbo molecular pump bodies having various characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram illustrating an embodiment of a turbo-molecular pump according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the power supply device of the present invention.

FIG. 3 is a schematic block diagram illustrating a configuration of a conventional turbo-molecular pump.

[Explanation of symbols]

1. Turbo molecular pump 2. Turbo molecular pump body 2.
a ... motor, 2b ... temperature sensor, 2c ... position sensor, 2
d: electromagnet, 2e, 3e: communication control circuit, 2f: RO
M, 3 ... power supply device, 3a ... inverter power circuit, 3b ...
Inverter control circuit, 3c ... magnetic bearing control circuit, 3d ...
Magnetic bearing power circuit, 4a, 4d ... power line, 4b, 4c,
4e: Signal line.

Claims (1)

[Claims] 1. A turbo-molecular pump main body including a rotor blade, a motor for driving the rotor blade, and a bearing for rotatably supporting the rotor blade, and a power supply device capable of transmitting and receiving power and signals between the turbo-molecular pump main body. Wherein the power supply device includes storage means for storing characteristic parameters of the turbo-molecular pump main body, and transmission means for transmitting the characteristic parameters to the turbo-molecular pump main body side, wherein the turbo-molecular pump main body includes: Comprises a receiving means for receiving characteristic parameters from a transmitting means, and a control means for controlling the turbo molecular pump body using the characteristic parameters.