JP2004100624A - Vacuum pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vacuum pump system capable of preventing a beat and low-frequency vibration by matching the RPM and phase of a rotary member of respective vacuum pumps with each other even when a plurality of vacuum pumps are arranged. <P>SOLUTION: A rotation synchronous signal 501 is outputted from a controller 400A on the master side through its output switch 402. The rotation synchronous signal 501 is taken in to a controller 400B on the slave side through an input switch 403. A phase comparison is performed between the rotation synchronous signal 501 and a detection signal of a rotation detection sensor 124A inside a synchronous signal comparison circuit 405. On a gate signal generating circuit 246, a motor drive circuit 222 is controlled and the revolutionary speed of a rotor shaft 113 is changed according to the result of the comparison in the synchronous signal comparison circuit 405. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vacuum pump system, and in particular, even when a plurality of vacuum pumps are provided, prevents a beat or a low-frequency vibration by matching the rotation speed and the phase of a rotating body of each vacuum pump. It relates to a vacuum pump system.
[0002]
[Prior art]
With the recent development of electronics, demand for semiconductors such as memories and integrated circuits has been rapidly increasing.
These semiconductors are manufactured by doping impurities into a very high purity semiconductor substrate to give electrical properties, or by forming a fine circuit on the semiconductor substrate by etching.
[0003]
These operations need to be performed in a high vacuum chamber in order to avoid the influence of dust and the like in the air. A vacuum pump is generally used for exhausting the chamber, but a turbo-molecular pump, which is one of the vacuum pumps, is frequently used in terms of particularly low residual gas and easy maintenance.
[0004]
Also, in a semiconductor manufacturing process, there are many steps of applying various process gases to a semiconductor substrate, and a turbo molecular pump not only evacuates the chamber but also exhausts these process gases from the chamber. Is also used.
Further, vacuum pumps are also used in equipment such as electron microscopes to prevent the refraction of an electron beam due to the presence of dust and the like, and to bring the environment in a chamber containing an electron microscope and the like to a high vacuum state. ing.
[0005]
As described above, vacuum pumps are widely used in various fields. Recently, however, larger semiconductor wafers have been planned for manufacturing semiconductors, and larger electron microscopes have been used in fields such as electron microscopes. There are many opportunities for equipment to be installed or for additional equipment.
[0006]
In such a case, a plurality of vacuum pumps may be used. FIG. 7 shows a simplified configuration diagram of this pump system.
In FIG. 7, a plurality of vacuum pumps, for example, turbo molecular pumps 100A, 100B, 100C, 100D are connected to a chamber 300 of a suction target device to be suctioned and decompressed.
[0007]
In addition, a valve such as an opening / closing valve and a damper for vibration absorption are actually provided between the turbo molecular pumps 100A, 100B, 100C, and 100D and the chamber 300 of the suction target device that is depressurized by the turbo molecular pumps 100A, 100B, 100C, and 100D. Are omitted for simplicity.
[0008]
The turbo molecular pumps 100A, 100B, 100C, and 100D are controlled by control devices 200A, 200B, 200C, and 200D, respectively. FIG. 8 shows a longitudinal sectional view of the turbo-molecular pump.
[0009]
8, the turbo molecular pump 100 has a cylindrical outer cylinder 127 having an intake port 101 formed at the upper end. Inside the outer cylinder 127, there is provided a rotating body 103 in which a plurality of rotating blades 102a, 102b, 102c...
A rotor shaft 113 is attached to the center of the rotating body 103, and the rotor shaft 113 is levitated in the air and position-controlled by, for example, a so-called five-axis control magnetic bearing.
[0010]
The upper radial electromagnet 104 has four electromagnets arranged in pairs on the X axis and the Y axis. An upper radial sensor 107 including four electromagnets is provided in proximity to and corresponding to the upper radial electromagnet 104. The upper radial sensor 107 is configured to detect a radial displacement of the rotor shaft 113 and send it to the control device 200.
The control device 200 controls the excitation of the upper radial electromagnet 104 via a compensation circuit (not shown) having a PID adjustment function based on the displacement signal detected by the upper radial sensor 107, and controls the upper radial direction of the rotor shaft 113. Adjust the position.
[0011]
The rotor shaft 113 is formed of a material having high magnetic permeability (such as iron) and is attracted by the magnetic force of the upper radial electromagnet 104. Such adjustment is performed independently in the X-axis direction and the Y-axis direction.
Further, the lower radial electromagnet 105 and the lower radial sensor 108 are arranged similarly to the upper radial electromagnet 104 and the upper radial sensor 107, and the lower radial position of the rotor shaft 113 is changed to the upper radial position. It is adjusted in the same way.
[0012]
Further, the axial electromagnets 106A and 106B are arranged vertically above and below a disk-shaped metal disk 111 provided below the rotor shaft 113. The metal disk 111 is made of a high magnetic permeability material such as iron. An axial sensor 109 is provided to detect an axial displacement of the rotor shaft 113, and an axial displacement signal is sent to the control device 200.
[0013]
The excitation of the axial electromagnets 106A and 106B is controlled via a compensation circuit (not shown) having a PID adjustment function of the control device 200 based on the axial displacement signal. The axial electromagnet 106A attracts the metal disk 111 upward by magnetic force, and the axial electromagnet 106B attracts the metal disk 111 downward.
As described above, the control device 200 appropriately adjusts the magnetic force exerted on the metal disk 111 by the axial electromagnets 106A and 106B, magnetically levitates the rotor shaft 113 in the axial direction, and holds the rotor shaft 113 in a space without contact. ing.
[0014]
The motor 121 is a so-called three-phase brushless motor. FIG. 9 shows a circuit configuration diagram of the motor and the motor control circuit.
9, two permanent magnets (N-pole, S-pole) are mounted around the rotor shaft 113 on the rotor side of the motor 121.
[0015]
The motor 121 is provided with three rotation detection sensors 124A, 124B, 124C on the stator side, and these rotation detection sensors 124A, 124B, 124C are arranged so as to surround the periphery of the rotor shaft 113. Have been. The rotation detection sensors 124A, 124B, 124C are arranged at an interval of about 120 ° from each other.
[0016]
The rotation detection sensors 124A, 124B, and 124C are, for example, semiconductor Hall sensors and the like. The rotation number and phase of the rotor shaft 113 are detected by detecting the magnetic flux density of the permanent magnet on the rotor side of the motor 121. It is designed to detect.
[0017]
The motor 121 has three-phase motor windings 126U, 126V, 126W on the stator side. These motor windings 126U, 126V, 126W are also arranged so as to surround the rotor shaft 113 (in the figure, the rotor side of the motor 121 is shown separately for convenience).
The motor windings 126U, 126V, 126W are connected to a motor drive circuit 222 provided in the control device 200.
[0018]
The motor drive circuit 222 includes a DC power supply 238 and six transistors 226, 228, 230, 232, 234, 236 forming a three-phase bridge. A predetermined gate signal is input to the base terminal of each of the transistors 226, 228, 230, 232, 234, and 236, and the AC signal supplied to the motor windings 126U, 126V, and 126W is pulse-width-controlled by the gate signal. Control (PWM control).
[0019]
On the other hand, the detection signal detected by the rotation detection sensor 124A is input to a rotation speed detection circuit 240 provided in the control device 200, and the detection signals detected by the rotation detection sensors 124A, 124B, and 124C are gated. The signal is input to the signal generation circuit 246.
[0020]
The rotation speed detection circuit 240 detects the rotation speed of the rotor shaft 113 based on the detection signal detected by the rotation detection sensor 124A, and outputs the detected rotation speed to the comparator 242.
[0021]
Further, the comparator 242 is configured to receive a predetermined reference rotation speed preset in the reference value setting circuit 244. The comparator 242 compares the predetermined reference rotation speed with the rotation speed of the rotor shaft 113 detected by the rotation speed detection circuit 240, and outputs the comparison result to the gate signal generation circuit 246. I have. Note that the reference value setting circuit 244 is configured by, for example, a crystal oscillator.
[0022]
The gate signal generation circuit 246 receives the comparison result of the comparator 242 and, when the rotation speed of the rotor shaft 113 is equal to or higher than the reference rotation speed, compares it with the detection signals of the rotation detection sensors 124A, 124B and 124C, and The gate signals of the transistors 226, 228, 230, 232, 234, 236 are controlled so that the 113 rotates at a low speed. On the other hand, when the rotation speed of the rotor shaft 113 is lower than the reference rotation speed, the gate signal is controlled so that the rotor shaft 113 rotates at high speed.
In this manner, the motor 121 is controlled, and controls the rotation of the rotor shaft 113.
[0023]
On the other hand, rotor blades 102a, 102b, 102c,... Are formed on the rotor shaft 113, and a plurality of fixed blades 123a are spaced apart from the rotor blades 102a, 102b, 102c,. , 123b, 123c,... Each of the rotor blades 102a, 102b, 102c,... Is formed to be inclined at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113 in order to transfer the molecules of the exhaust gas downward by collision.
[0024]
Similarly, the fixed blade 123 is also formed to be inclined by a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and is arranged alternately with the step of the rotary blade 102 toward the inside of the outer cylinder 127. ing.
One end of the fixed wing 123 is supported by being inserted between a plurality of stacked fixed wing spacers 125a, 125b, 125c,.
[0025]
The fixed wing spacer 125 is a ring-shaped member and is made of, for example, a metal such as aluminum, iron, stainless steel, or copper, or a metal such as an alloy containing these metals as components.
[0026]
An outer cylinder 127 is fixed to the outer periphery of the fixed blade spacer 125 with a slight gap therebetween. A base portion 129 is provided at the bottom of the outer cylinder 127, and a threaded spacer 131 is provided between a lower portion of the fixed wing spacer 125 and the base portion 129. An exhaust port 133 is formed below the threaded spacer 131 in the base portion 129 and communicates with the outside.
[0027]
The threaded spacer 131 is a cylindrical member made of a metal such as aluminum, copper, stainless steel, iron, or an alloy containing these metals as components, and has a plurality of spiral screw grooves 131a on its inner peripheral surface. It is engraved.
The spiral direction of the screw groove 131a is a direction in which when the molecules of the exhaust gas move in the rotational direction of the rotating body 103, the molecules are transferred to the exhaust port 133.
[0028]
The rotor 102d is suspended from the lowermost portion of the rotor 103 following the rotor 102a, 102b, 102c,. The outer peripheral surface of the rotary wing 102d is cylindrical and protrudes toward the inner peripheral surface of the threaded spacer 131, and comes close to the inner peripheral surface of the threaded spacer 131 with a predetermined gap. I have.
[0029]
The base 129 is a disk-shaped member that forms the base of the turbo-molecular pump 100, and is generally made of a metal such as iron, aluminum, and stainless steel. Further, since the base portion 129 physically holds the turbo-molecular pump 100 and also has a function of a heat conduction path, a metal having high rigidity and high thermal conductivity such as iron, aluminum, or copper is used. Is desirable.
[0030]
In this configuration, when the rotor shaft 113 is driven by the motor 121 and rotates together with the rotary wing 102, the exhaust gas from the chamber is sucked through the air inlet 101 by the action of the rotary wing 102 and the fixed wing 123.
[0031]
Exhaust gas sucked from the inlet 101 passes between the rotary blade 102 and the fixed blade 123 and is transferred to the base 129. At this time, the temperature of the rotary blade 102 rises due to frictional heat generated when the exhaust gas contacts the rotary blade 102 or conduction of heat generated by the motor 121, but this heat is generated by radiation or gaseous exhaust gas. It is transmitted to the fixed wing 123 side by conduction by molecules and the like.
[0032]
The fixed wing spacers 125 are joined to each other at their outer peripheral portions, and transmit the heat received by the fixed wings 123 from the rotary wings 102 and the frictional heat generated when the exhaust gas comes into contact with the fixed wings 123 to the outside.
The exhaust gas transferred to the base 129 is sent to the exhaust port 133 while being guided by the thread groove 131a of the threaded spacer 131.
[0033]
In the above description, it has been described that the threaded spacer 131 is provided on the outer periphery of the rotary blade 102d, and the thread groove 131a is formed on the inner peripheral surface of the threaded spacer 131. However, conversely, a thread groove may be formed on the outer peripheral surface of the rotating blade 102d, and a spacer having a cylindrical inner peripheral surface may be arranged around the groove.
[0034]
Further, the gas sucked from the intake port 101 enters the electrical unit including the motor 121, the lower radial electromagnet 105, the lower radial sensor 108, the upper radial electromagnet 104, the upper radial sensor 107, and the like. In order to prevent this, the electric component is covered with a stator column 122, and the inside of the electric component is maintained at a predetermined pressure by a purge gas.
[0035]
Therefore, a pipe (not shown) is provided in the base portion 129, and a purge gas is introduced through this pipe. The introduced purge gas is sent to the exhaust port 133 through the gap between the protective bearing 120 and the rotor shaft 113, between the rotor and the stator of the motor 121, and between the stator column 122 and the rotor 102.
[0036]
Here, the turbo-molecular pump 100 needs control based on unique parameters individually adjusted (for example, specification of a model, various characteristics corresponding to the model). In order to store the control parameters, the turbo molecular pump 100 has an electronic circuit section 141 in its main body.
[0037]
The electronic circuit section 141 includes a semiconductor memory such as an EEP-ROM, an electronic component such as a semiconductor element for accessing the semiconductor memory, and a board 143 for mounting the semiconductor memory.
The electronic circuit section 141 is housed in a lower part near the center of a base part 129 constituting a lower part of the turbo-molecular pump 100, and is closed by an airtight bottom cover 145.
[0038]
Incidentally, the process gas may be introduced into the chamber at a high temperature in order to increase the reactivity. When these process gases are exhausted and cooled to a certain temperature, they become solids and may deposit products in an exhaust system.
Then, this type of process gas becomes low temperature in the turbo-molecular pump 100 to be solid and adheres and deposits inside the turbo-molecular pump 100.
[0039]
For example, SiCl is used as a process gas in an Al etching apparatus. ₄ Is used, a low vacuum (760 [torr] to 10) ^-2 [Torr]) and at a low temperature (about 20 ° C.), a solid product (eg, AlCl ₃ It can be seen from the vapor pressure curve that) is deposited and adheres and deposits inside the turbo-molecular pump 100.
When deposits of the process gas accumulate inside the turbo-molecular pump 100, the deposits narrow the pump flow path and cause the performance of the turbo-molecular pump 100 to deteriorate.
[0040]
Here, the above-mentioned product was in a state of being easily solidified and adhered in a portion having a low temperature in the vicinity of the exhaust port, particularly in the vicinity of the rotary blade 102 and the threaded spacer 131. In order to solve this problem, a heater (not shown) or an annular water cooling tube 149 (not shown) is conventionally wound around the outer periphery of the base portion 129, and a temperature sensor (for example, a thermistor) not shown is embedded in the base portion 129, for example. Heating of the heater and control of cooling by the water cooling pipe 149 (hereinafter referred to as TMS; TMP: Temperature Management System) are performed so as to keep the temperature of the base portion 129 at a constant high temperature (set temperature) based on a signal from the sensor. .
[0041]
[Problems to be solved by the invention]
By the way, as shown in FIG. 7, when a plurality of turbo molecular pumps 100A, 100B, 100C, and 100D are used as vacuum pumps, conventionally, independent control is performed on the control devices 200A, 200B, 200C, and 200D, respectively. Had been
[0042]
In this case, each of the control devices 200A, 200B, 200C, and 200D sets the rotation speed of the rotating body 103 of each of the turbo-molecular pumps 100A, 100B, 100C, and 100D, for example, with respect to a rated rotation speed of 48,000 rpm (800 Hz). , Can be set with high accuracy within the range of several Hz.
[0043]
However, even when the rated rotation speed of the rotating body 103 of each of the turbo molecular pumps 100A, 100B, 100C, and 100D is set to the same value, the turbo molecular pump 100A side has 48, 000 rpm (800 Hz), while the turbo molecular pump 100B side is operated at 48,060 rpm (801 Hz), so that the rotation speed of the rotating body 103 of each of the turbo molecular pumps 100A, 100B, 100C, 100D is slightly reduced. Sometimes there was a difference.
[0044]
At this time, the difference between the rotation speeds of the rotating body 103 causes the turbo molecular pumps 100A, 100B, 100C, and 100D to beat, and due to the beat, the turbo molecular pumps 100A, 100B, 100C, and 100D In some cases, low frequency vibration was generated.
[0045]
Since it is difficult to completely remove such low-frequency vibration even by the damper interposed between the turbo molecular pumps 100A, 100B, 100C, and 100D and the chamber 300, the vibration is generated. When transmitted from the turbo molecular pumps 100A, 100B, 100C, and 100D to the chamber 300 side, it may affect the measurement of an electron microscope and the like housed in the chamber 300 and the manufacture of semiconductors.
[0046]
The present invention has been made in view of such a conventional problem, and even when a plurality of vacuum pumps are provided, by matching the number of rotations and the phase of the rotating body of each vacuum pump, the beat is increased. An object of the present invention is to provide a vacuum pump system that prevents low-frequency vibration.
[0047]
[Means for Solving the Problems]
For this reason, the present invention provides a rotating body and a motor for rotating the rotating body, and N vacuum pumps mounted in parallel with the target equipment to suction a predetermined gas from the target equipment. And a control device connected to the vacuum pump and controlling a rotation speed and / or a rotation phase of the rotating body, wherein a stop unit for stopping the vacuum pump; Setting means for setting any one of the control devices as a master control device, and setting N-1 devices other than the master control device as a slave control device; Master detecting means for detecting the rotation state of the rotating body of the master vacuum pump, and rotating the rotating body of the slave vacuum pump to which the slave control device is connected among the vacuum pumps. Slave detecting means for detecting a state, and control means for controlling the rotation state of the rotating body detected by the slave detecting means to be synchronized with the rotating state of the rotating body detected by the master detecting means. The control means, when the master vacuum pump is stopped by the stop means, changes the rotation state of the rotating body detected by the slave detection means to a reference rotation speed and / or a reference rotation speed set in the slave vacuum pump. Alternatively, it is controlled based on a comparison with the rotation phase.
[0048]
The rotation state of the rotating body of the master vacuum pump is output from the master control device. On the other hand, in the slave control device, the rotation state of the rotating body of the master vacuum pump is captured. Then, the control means controls the rotation state of the rotating body of the slave vacuum pump to be synchronized with the rotation state of the rotating body of the master vacuum pump.
When the master vacuum pump is stopped, the rotational state of the rotating body of the slave vacuum pump is controlled based on comparison with a reference rotational speed and / or rotational phase.
Thus, even when a plurality of vacuum pumps are provided, it is possible to prevent the beat and low-frequency vibration by matching the rotation speed and the rotation phase of the rotating body of each vacuum pump. Further, even when the master control device is stopped, the operation can be continued without stopping the slave control device.
[0049]
The present invention also provides a rotating body and a motor for rotating the rotating body, and N vacuum pumps mounted in parallel with the target equipment to suction a predetermined gas from the target equipment. And a control device connected to the vacuum pump and controlling a rotation speed and / or a rotation phase of the rotating body, wherein a stop unit for stopping the vacuum pump; Setting means for setting any one of the control devices as a master control device, and setting N-1 devices other than the master control device as a slave control device; Detecting means for detecting the rotation state of the rotating body of the master vacuum pump, and rotation of the rotating body of the slave vacuum pump to which the slave controller is connected among the vacuum pumps Slave detecting means for detecting a state, control means for controlling the rotation state of the rotator detected by the slave detection means to be synchronized with the rotation state of the rotator detected by the master detection means, And resetting means for resetting any one of the slave control devices as the master control device when the master vacuum pump is stopped by the stopping means.
[0050]
When the master vacuum pump stops, one of the devices on the slave side is switched as a new master control device, and operation is started again using this as the master control device.
Thus, even when the master controller stops, it is possible to continue the synchronous operation only with the remaining slave controllers without stopping the slave controllers.
[0051]
Further, the present invention is characterized in that the resetting by the resetting means is performed based on a predetermined ranking.
[0052]
If the master controller stops, one of the slave controllers is switched to the master controller according to a predetermined ranking.
The predetermined ranking may be determined automatically based on, for example, the operating time of the vacuum pump, the capacity of the pump, the failure history, and the like. Further, it may be set manually by an operator or the like.
[0053]
Furthermore, the present invention provides the control means, wherein the master vacuum pump is stopped by the stop means, and when all but one of the slave vacuum pumps are stopped, the remaining slave vacuum pump is stopped. Is controlled based on comparison with a reference rotation speed and / or rotation phase set for the slave vacuum pump.
[0054]
When the number of slave vacuum pumps becomes one, the rotation state of the rotating body of the slave vacuum pump is compared with a reference rotation speed and / or rotation phase, and the rotation of the rotating body is controlled based on the result of the comparison. .
Thus, the operation can be continued even if the number of vacuum pumps becomes one.
[0055]
Further, the present invention includes failure detection means for detecting a failure of the control device and / or the vacuum pump, and the stopping means stops the vacuum pump for which a failure has been detected by the failure detection means. And
[0056]
When the failure of the control device or the vacuum pump is detected by the failure detection means, the failed vacuum pump is stopped.
[0057]
Further, the present invention provides a rotating body, a motor for rotating the rotating body, a detecting means for detecting a rotation speed and / or a rotating phase which is a rotating state of the rotating body, and a detecting means for detecting the rotating state. Internal comparing means for comparing the rotation state of the rotating body with a reference rotation speed and / or rotation phase; and external comparing means for comparing the rotation state of the rotating body detected by the detection means with an external synchronization signal. The transmission of the synchronization signal to the outside or the reception of the synchronization signal from the outside is selected based on a predetermined switching signal, and the comparison result of the internal comparison means and the comparison result of the external comparison means are input and the input is performed. One of which is selected based on the predetermined switching signal and is output as an output signal, and a rotation control means that controls a rotation state of the rotator based on the output signal output from the switching means. To Ete was constructed.
[0058]
The switching means selects transmission or reception of the synchronization signal based on a predetermined switching signal.
The switching means selects whether the rotation state of the rotating body is controlled with respect to a reference rotation speed and / or rotation phase or is controlled with respect to an external synchronization signal based on the predetermined switching signal. Is done.
This facilitates switching of control to the master vacuum pump or the slave vacuum pump.
[0059]
Further, in the present invention, the predetermined switching signal is a signal for setting any one of the control devices as a master control device and setting N-1 devices excluding the master control device as a slave control device. When the master control device side is set by the predetermined switching signal, the switching unit transmits the rotation state of the rotating body detected by the detection unit to the outside as a synchronization signal while comparing the rotation state of the rotating body with the internal comparison unit. When a result is selected and the slave control device side is set by the predetermined switching signal, the switching unit selects the comparison result of the external comparing unit while the synchronization signal is received from the outside. I do.
[0060]
The control device is set as a master control device or a slave control device by a predetermined switching signal.
From the master control device, the rotation state of the rotating body is output to the outside as a synchronization signal, and the rotation state of the rotating body of the master vacuum pump is controlled based on a comparison result with a reference rotation speed and / or rotation phase. Is done.
On the other hand, in the slave control device, the synchronization signal output from the master control device is received, and the rotation state of the rotating body of the slave vacuum pump is controlled based on a comparison with the synchronization signal.
Thus, the rotation state of the rotating body of the slave vacuum pump is controlled to be synchronized with the rotation state of the rotating body of the master vacuum pump.
[0061]
Further, the present invention is characterized in that the synchronization signal is communicated by wire or wirelessly.
[0062]
This makes it possible to select a method that facilitates communication in consideration of the situation of the place where the control device and the like are arranged.
[0063]
Further, according to the present invention, the rotating body has a rotor blade and a rotor shaft arranged at the center of the rotor blade, and magnetically levitates the rotor shaft in the air to adjust the position in the radial direction and / or the axial direction. A magnetic bearing means is provided.
[0064]
Even when the rotating body rotates at high speed while being magnetically levitated by the magnetic bearing means, it is possible to prevent beats and low-frequency vibrations by adjusting the rotation speed and phase of the rotating body.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of the present invention will be described.
FIG. 1 shows a simplified configuration diagram of a pump system according to a first embodiment of the present invention, and FIG. 2 shows a circuit configuration diagram of a motor and a motor control circuit. 7 and 9 are denoted by the same reference numerals, and description thereof will be omitted.
[0065]
1, the pump system according to the present embodiment includes a synchronous operation controller 500. The synchronous operation controller 500 can communicate with each of the control devices 400A, 400B, 400C, and 400D.
[0066]
Specifically, the synchronous operation controller 500 outputs a master / slave signal 502 to each of the control devices 400A, 400B, 400C, and 400D. The master / slave signal 502 is a signal that determines which of the control devices 400A, 400B, 400C, and 400D is to be the master device and which device is to be the slave device, as described later. ing.
[0067]
On the other hand, the control devices 400A, 400B, 400C, and 400D communicate with each other by the rotation synchronization signal 501.
2, the control device 400 includes an output switch 402, an input switch 403, a synchronization signal comparison circuit 405, and a mode changeover switch 401 as compared with the conventional control device 200.
[0068]
The output switch 402 receives the detection signal of the rotation detection sensor 124A, and can output this detection signal as a rotation synchronization signal 501. The output switch 402 is controlled by a master / slave signal 502 and switches whether or not to output a rotation synchronization signal 501.
[0069]
On the other hand, the input switch 403 receives the rotation synchronization signal 501 and can output the rotation synchronization signal 501 to the synchronization signal comparison circuit 405 as a predetermined signal (hereinafter, referred to as a comparison signal). Similarly to the output switch 402, the input switch 403 is controlled by the master / slave signal 502 to switch whether or not to take in the rotation synchronization signal 501.
[0070]
The detection signal of the rotation detection sensor 124A is input to the synchronization signal comparison circuit 405. The synchronization signal comparison circuit 405 includes a phase locked circuit (hereinafter, referred to as a PLL circuit) as a phase control circuit, and compares the detection signal of the rotation detection sensor 124A with the output of the input switch 403. A phase comparison with a signal is performed, and the result of the comparison is output to the mode switch 401.
[0071]
The mode switch 401 is capable of switching between the output of the synchronization signal comparison circuit 405 (hereinafter, referred to as a synchronous mode side) and the output of the comparator 242 (hereinafter, referred to as an asynchronous mode side). The mode changeover switch 401 is also controlled by the master / slave signal 502 and outputs an output on the switched side to the gate signal generation circuit 246.
[0072]
In such a configuration, during the synchronous operation, the output switch 402, the input switch 403, and the mode switch 401 are controlled by the master / slave signal 502 as follows.
[0073]
How the switches are switched by the master / slave signal 502 will be described with reference to FIG. In the description of the present embodiment, the control device 400A is a device on the master side, and the control devices 400B, 400C, and 400D are devices on the slave side. In this case, the master / slave signal 502 is on the master side in the control device 400A, and is on the slave side in the control devices 400B, 400C, and 400D.
[0074]
In FIG. 3, the control device 400A (master column in the figure) on the master side has its output switch 402 in a state of “outputting a rotation synchronization signal”, and the input switch 403 has “do not capture a rotation synchronization signal”. State, and the mode switch 401 is set to the “asynchronous mode side”.
[0075]
That is, the rotation synchronization signal 501 is output from the control device 400A on the master side via the output switch 402.
In the control device 400A, the output of the comparator 242 is transmitted to the gate signal generation circuit 246 because the mode changeover switch 401 is switched to the asynchronous mode side. Therefore, the control of the rotation of the rotor shaft 113 in the control device 400A on the master side is performed by a method similar to the conventional method.
[0076]
On the other hand, in the control devices 400B, 400C, and 400D on the slave side (the slave column in the figure), the respective output switches 402 are in a state of “do not output the rotation synchronization signal”, and the input switch 403 is “outputting the rotation synchronization signal”. The mode changeover switch 401 is set to the “synchronous mode side”.
[0077]
That is, in the control devices 400B, 400C, and 400D on the slave side, the rotation synchronization signal 501 is captured via the respective input switches 403, and a comparison signal corresponding to the rotation synchronization signal 501 is sent to the synchronization signal comparison circuit 405. Is output.
[0078]
Then, the synchronization signal comparison circuit 405 detects the phase of each signal from the rise / fall of the detection signal of the rotation detection sensor 124A and the rise / fall of the comparison signal. The synchronization signal comparison circuit 405 determines whether the phases of the respective signals match or not.
[0079]
The result of the comparison in the synchronization signal comparison circuit 405 is transmitted to the gate signal generation circuit 246 because the mode changeover switch 401 is tilted to the synchronization mode side. The gate signal generation circuit 246 raises or lowers the rotation speed of the rotor shaft 113 based on the result of the comparison by the synchronization signal comparison circuit 405, and changes the phase of the detection signal of the rotation detection sensor 124A and the phase of the rotation synchronization signal 501. A matching process is performed. FIG. 4 shows a state of the phase matching processing in the slave device.
[0080]
In FIG. 4, in case 1, the phase of the detection signal of the rotation detection sensor 124A is later than the phase of the rotation synchronization signal 501. Therefore, the synchronization signal comparison circuit 405 controls the gate signal generation circuit 246 to increase the rotation speed of the rotor shaft 113.
[0081]
On the other hand, in case 2, the phase of the detection signal of the rotation detection sensor 124A is ahead of the phase of the rotation synchronization signal 501. Therefore, the synchronization signal comparison circuit 405 controls the gate signal generation circuit 246 such that the rotation speed of the rotor shaft 113 is reduced.
[0082]
The gate signal generation circuit 246 under such control controls the gate signals of the transistors 226, 228, 230, 232, 234, and 236 of the motor drive circuit 222 and controls the rotation of the rotor shaft 113 in the same manner as in the related art. Vary the speed.
As a result, the rotational speeds and phases of the respective rotor shafts 113 of the turbo molecular pumps 100A, 100B, 100C, and 100D become the same.
[0083]
Therefore, no beat is generated in the turbo molecular pumps 100A, 100B, 100C, and 100D, and no low-frequency vibration is generated.
Accordingly, even when a plurality of turbo-molecular pumps 100 are provided, the number of rotations and the phase of the rotor shaft 113 of each of the turbo-molecular pumps 100 are made to coincide with each other, so that a pump that does not generate beats or low-frequency vibrations is formed. System can be achieved.
[0084]
In the present embodiment, the control device 400A has been described as being a device on the master side. However, even when one of the other control devices 400B, 400C, and 400D is a device on the master side, the control is not performed. The same is true.
[0085]
At this time, the method of selecting the master device from among the plurality of control devices 400 may be predetermined by an operator of the pump system or the like, or may be automatically set by the synchronous operation controller 500. May be decided.
[0086]
In the present embodiment, an example in which four turbo molecular pumps 100 and four control devices 400 are provided is shown. However, the present invention is not limited to this, and the same applies to the case where two, three, or five or more devices are provided. is there.
[0087]
Further, in the present embodiment, the rotation synchronization signal 501 is communicated by wire between the control devices 400A, 400B, 400C, and 400D, but the present invention is not limited to this, and the communication may be wireless.
This makes it possible to select a method in which the rotation synchronization signal 501 is easily communicated in consideration of the situation of the place where the control device 400 and the like are arranged.
[0088]
Next, a second embodiment of the present invention will be described.
The pump system according to the first embodiment communicates between the synchronous operation controller and the control device by a master / slave signal. However, the pump system according to the second embodiment further includes an operation / stop signal and an alarm. They are communicated by signals.
[0089]
FIG. 5 shows a simplified configuration diagram of a pump system according to a second embodiment of the present invention. The same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.
Each of the control devices 400A, 400B, 400C, and 400D outputs an alarm signal 503 to the synchronous operation controller 500. Note that the alarm signal 503 is a signal for notifying a failure of the turbo-molecular pump 100 and the control device 400 and indicating a maintenance time for these.
[0090]
The synchronous operation controller 500 outputs an operation / stop signal 504 to each of the control devices 400A, 400B, 400C, and 400D. The operation / stop signal 504 is a signal for operating or stopping the turbo molecular pump 100 and the control device 400.
[0091]
In such a configuration, as in the first embodiment, the rotation speed and the phase of the rotor shaft 113 of each of the turbo molecular pumps 100A, 100B, 100C, and 100D are controlled so as to match each other.
[0092]
Also, during such a synchronous operation, when any of the control devices 400A, 400B, 400C, and 400D outputs an alarm signal 503 due to a failure or the like, the synchronous operation controller 500 performs its own control to control the failed control. An operation / stop signal 504 is output to the device 400, and the control device 400 and the turbo molecular pump 100 are stopped. This is to prevent the failed control device 400 from adversely affecting other control devices 400.
[0093]
When the control device 400 stopped due to a failure or the like is the device on the slave side, the device on the slave side only takes in the rotation synchronization signal 501, so that the other control devices 400 performing the synchronous operation include: No effect. Therefore, the synchronous operation is continued only by the remaining normal control devices.
[0094]
On the other hand, when the control device 400 stopped due to a failure or the like is the device on the master side, the rotation synchronization signal 501 is not output from the device on the master side, so that there is a possibility that the other devices on the slave side may not be able to operate. is there.
[0095]
However, in the present embodiment, the synchronous operation controller 500 controls the operation / stop of the control device 400 and also outputs the master / slave signal 502 as in the first embodiment. It can be determined whether the device 400 is a master side.
[0096]
Therefore, when the device on the master side stops, the synchronous operation controller 500 stops the synchronous operation on the device on the slave side, and controls so that all the devices on the slave side can operate independently.
[0097]
In this case, the output switch 402, the input switch 403, and the mode switch 401 in the slave device are switched by the master / slave signal 502 as shown in FIG.
[0098]
That is, in all the control devices 400 that perform the independent operation (in the figure, the column of the independent operation), the output switch 402 is in the state of “do not output the rotation synchronization signal”, and the input switch 403 is “do not capture the rotation synchronization signal”. , And the mode changeover switch 401 is set to the “asynchronous mode side”.
[0099]
Therefore, the control device 400 controls the rotation speed of the rotor shaft 113 of the turbo-molecular pump 100 and the like under the control of itself as in the related art.
As a result, even if the device on the master side fails during the synchronous operation, the operation can be continued without stopping the device on the slave side.
[0100]
Note that, in the present embodiment, the synchronous operation controller 500 outputs the operation / stop signal 504 to the failed master-side control device 400 and stops it under its own control, and controls all other slave-side controllers. Although it has been described that the device 400 is operated independently, the present invention is not limited to this.
[0101]
That is, when the alarm signal 503 is output from the failed control device 400, the maintenance operator of the pump system stops the control device 400 by pressing a stop button (not shown) of the master control device 400 or the like. Alternatively, all other slave devices may be operated independently.
[0102]
Next, a third embodiment of the present invention will be described.
The pump system according to the second embodiment is controlled such that, when the device on the master side fails during the synchronous operation, the device on the slave side is operated independently. However, the pump system according to the third embodiment is controlled by the master system. Even if the device on the slave side breaks down, control is performed such that only the remaining devices on the slave side operate synchronously.
[0103]
The configuration of the pump system according to the present embodiment is similar to the configuration (FIG. 5) of the pump system according to the second embodiment.
In such a configuration, as in the second embodiment, when any of the control devices 400A, 400B, 400C, and 400D outputs an alarm signal 503 due to a failure or the like during the synchronous operation, the synchronous operation controller 500 causes the failure to occur. The control device 400 and the turbo-molecular pump 100 that have been stopped are stopped.
[0104]
Then, similarly to the second embodiment, when the control device 400 stopped due to a failure or the like is the device on the master side, the other devices on the slave side may not be able to operate.
[0105]
However, in this embodiment, when the device on the master side stops, one of the devices on the slave side is switched as a new device on the master side, and control is performed such that the synchronous operation is started again using the device as the master side. .
[0106]
FIG. 6 shows how the control device switches between the slave side and the master side.
In FIG. 6, during normal operation, as described above, the control device 400A is a device on the master side, and the control devices 400B, 400C, and 400D are devices on the slave side.
[0107]
Here, it is assumed that the control device 400A on the master side has stopped due to a failure or the like. In this case, one of the control devices 400B, 400C, and 400D, which are slaves that have not failed, is switched to the device on the master side in a predetermined order. In the description of the present embodiment, it is assumed that the switching order is set in advance in the order of (1) the control device 400B → (2) the control device 400C → (3) the control device 400D by the maintenance operator of the pump system. I do.
[0108]
Therefore, the control device 400B is controlled to be a device on the master side. That is, the output switch 402, the input switch 403, and the mode switch 401 of the control device 400B are switched from the “slave” state in FIG. 3 to the “master” state by the master / slave signal 502.
Then, the three control devices 400B, 400C, and 400D restart the synchronous operation under the same control as in the first embodiment.
[0109]
Further, it is assumed that the control device 400B, which has newly become the master device, stops during such operation.
Also in this case, the control device 400C is controlled to be the master device in accordance with the above-described predetermined order.
Then, synchronous operation of control devices 400C and 400D is restarted.
[0110]
Further, it is assumed that the control device 400C stops during such operation.
In this case, since only one control device 400D is in operation, the control device 400D is controlled so as to stop the synchronous operation and operate independently to continue the operation. The output switch 402, the input switch 403, and the mode switch 401 of the control device 400D are switched from the "slave" state in FIG.
Then, only the control device 400D controls the number of revolutions of the rotor shaft 113 and the like by the same control as the conventional one.
[0111]
As a result, even when the master device breaks down during the synchronous operation, the synchronous operation can be continued only by the slave device without stopping the slave device.
[0112]
It is desirable that the device on the master side having a failure or the like be separated from the device on the slave side so as not to adversely affect the operation of the control device 400 serving as a new master device.
For this reason, the device on the master side that has caused a failure or the like may be switched to, for example, the state of “independent operation” shown in FIG.
[0113]
Further, in the present embodiment, it has been described that the devices on the slave side are switched according to the order determined in advance by an operator or the like, but the present invention is not limited to this.
That is, for example, selection may be automatically performed in a random order under the control of the synchronous operation controller 500 itself.
[0114]
【The invention's effect】
As described above, according to the present invention, since the rotation state of the rotating body of the slave vacuum pump is configured to be synchronized with the rotation state of the rotating body of the master vacuum pump, even when a plurality of vacuum pumps are provided. In addition, it is possible to prevent the beat and low-frequency vibration by matching the rotation speed and the phase of the rotating body of each vacuum pump.
[0115]
Further, since the rotation state of the rotating body is controlled based on comparison with the reference rotation speed and / or rotation phase set for each of the slave vacuum pumps, even when the master control device is stopped, the slave It is possible to continue operation without stopping the control device.
[Brief description of the drawings]
FIG. 1 is a simplified configuration diagram of a pump system according to a first embodiment of the present invention.
FIG. 2 is a circuit configuration diagram of a motor and a motor control circuit according to the first embodiment of the present invention.
FIG. 3 is a diagram showing a state of switching by a master / slave signal;
FIG. 4 is a diagram showing a state of a phase matching process in a device on the slave side.
FIG. 5 is a simplified configuration diagram of a pump system according to a second embodiment of the present invention.
FIG. 6 is a diagram showing a state of switching between a slave side and a master side of the control device.
FIG. 7 is a simplified configuration diagram of a conventional pump system.
FIG. 8 is a longitudinal sectional view of a turbo molecular pump.
FIG. 9 is a circuit configuration diagram of a conventional motor and a motor control circuit.
[Explanation of symbols]
100 turbo molecular pump
103 rotating body
104 Upper radial electromagnet
105 Lower radial electromagnet
106A, 106B axial electromagnet
107 Upper radial sensor
108 Lower radial sensor
109 Axial direction sensor
113 Rotor shaft
121 motor
124A, 124B, 124C rotation detection sensor
200, 400 control device
222 Motor drive circuit
240 speed detection circuit
242 comparator
244 Reference value setting circuit
246 Gate signal generation circuit
300 chambers
401 Mode switch
402 Output switch
403 Input switch
405 Sync signal comparison circuit
500 Synchronous operation controller

Claims (9)

A rotator, and a motor for rotating the rotator, and N vacuum pumps mounted side by side with the target equipment for sucking a predetermined gas from the target equipment;
A vacuum pump system comprising: a control device connected to the vacuum pump to control a rotation speed and / or a rotation phase of the rotating body,
Stopping means for stopping the vacuum pump,
Setting means for setting any one of the control devices as a master control device and setting N-1 devices excluding the master control device as slave control devices;
Master detection means for detecting the rotation state of the rotating body of the master vacuum pump to which the master control device is connected among the vacuum pumps,
Slave detection means for detecting the rotation state of the rotating body of the slave vacuum pump to which the slave control device is connected among the vacuum pumps;
Control means for controlling the rotation state of the rotating body detected by the slave detection means to be synchronized with the rotation state of the rotation body detected by the master detection means,
The control means includes:
When the master vacuum pump is stopped by the stopping means, the rotation state of the rotating body detected by the slave detecting means is compared with a reference rotation speed and / or rotation phase set in the slave vacuum pump. A vacuum pump system characterized by being controlled under pressure. A rotator, and a motor for rotating the rotator, and N vacuum pumps mounted side by side with the target equipment for sucking a predetermined gas from the target equipment;
A vacuum pump system comprising: a control device connected to the vacuum pump to control a rotation speed and / or a rotation phase of the rotating body,
Stopping means for stopping the vacuum pump,
Setting means for setting any one of the control devices as a master control device and setting N-1 devices excluding the master control device as slave control devices;
Master detection means for detecting the rotation state of the rotating body of the master vacuum pump to which the master control device is connected among the vacuum pumps,
Slave detection means for detecting the rotation state of the rotating body of the slave vacuum pump to which the slave control device is connected among the vacuum pumps;
Control means for controlling the rotation state of the rotator detected by the slave detection means to be synchronized with the rotation state of the rotator detected by the master detection means;
A vacuum pump system, comprising: resetting means for resetting any one of the slave control devices as a master control device when the master vacuum pump is stopped by the stopping device. 3. The vacuum pump system according to claim 2, wherein the resetting by the resetting means is performed based on a predetermined ranking. The control means includes:
When the master vacuum pump is stopped by the stopping means, and all but one of the slave vacuum pumps are stopped, the rotational state of the rotating body of the remaining slave vacuum pump is changed to the slave vacuum pump. 4. The vacuum pump system according to claim 2, wherein the vacuum pump system is controlled based on comparison with a reference rotation speed and / or rotation phase set for the pump. A failure detection unit that detects a failure of the control device and / or the vacuum pump;
The stopping means,
The vacuum pump system according to any one of claims 1 to 4, wherein the vacuum pump in which a failure is detected by the failure detection unit is stopped. A rotating body,
A motor that rotationally drives the rotating body;
Detecting means for detecting a rotational speed and / or a rotational phase, which is the rotational state of the rotating body, and an internal unit for comparing the rotational state of the rotating body detected by the detecting means with a reference rotational speed and / or rotational phase Means of comparison;
External comparison means for comparing the rotation state of the rotating body detected by the detection means with an external synchronization signal,
Transmission of the synchronization signal to the outside or reception of the synchronization signal from the outside is selected based on a predetermined switching signal, and the comparison result of the internal comparison unit and the comparison result of the external comparison unit are input and the input A switching unit, one of which is selected based on the predetermined switching signal and output as an output signal,
A rotation control unit for controlling a rotation state of the rotating body based on an output signal output from the switching unit. The predetermined switching signal is:
A signal for setting any one of the control devices as a master control device and setting N-1 devices excluding the master control device as slave control devices;
When the master control device side is set by the predetermined switching signal, the switching unit transmits the rotation state of the rotating body detected by the detection unit to the outside as a synchronization signal, while comparing the comparison result of the internal comparison unit. Selected,
7. The comparison means according to claim 6, wherein when the slave control device is set by the predetermined switching signal, the switching means selects the comparison result of the external comparing means while receiving the synchronization signal from outside. Vacuum pump system. The synchronization signal is
The vacuum pump system according to claim 7, wherein the communication is performed by wire or wirelessly. The rotor has a rotor blade and a rotor shaft disposed at the center of the rotor blade,
The vacuum pump system according to any one of claims 1 to 8, further comprising magnetic bearing means for magnetically levitating the rotor shaft in the air and adjusting a position in a radial direction and / or an axial direction.

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