JP5290009B2 - Power supply device for dry vacuum pump and operation method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power device for dry vacuum pump temporarily outputting a large motor-shaft output in a simple configuration and eliminating suck of foreign matters even when the foreign matters enter the pump and sucked and a high-torque operation is required temporarily, without increasing the capacity of the power device. <P>SOLUTION: The power device for dry vacuum pump includes a rectifier; a DC circuit including a smoothing capacitor; and an inverted circuit. The power device converts an AC power from an AC power supply into a DC power by the rectifier, supplies the inverter circuit with the DC power through the DC circuit, converts the DC power into an AC power in a specified frequency by the inverter circuit, and supplies it to a driving motor for dry vacuum pump. The power device for dry vacuum pump includes an auxiliary power circuit and a changeover means that supplies the DC circuit with an auxiliary power at a predetermined timing from the auxiliary power circuit and increases the voltage or current of the DC circuit when the driving motor requires a shaft output larger than a rated one, or stops the supply of the auxiliary power at the fixed timing when the large shaft output is not required. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a power supply device for a dry vacuum pump that supplies driving power to a drive motor for a dry (air-cooled) vacuum pump, and in particular, foreign matter is mixed in the pump without enlarging the capacity of the power supply device. The present invention relates to a power supply device for a dry vacuum pump that can temporarily realize a high shaft output of an electric motor with a simple configuration even when high torque operation is temporarily required, and an operation method thereof.

  In recent years, dry vacuum pumps that can operate from atmospheric pressure and can easily obtain a clean vacuum environment have been used in a wide range of fields such as semiconductor manufacturing facilities. In many cases, an inverter is used in a power supply device that supplies driving power to a driving motor that drives such a dry vacuum pump. There are several reasons for this, and one of them is to increase the rotational speed of the motor by using an inverter to make it higher than the commercial frequency, thereby increasing the rotational speed of the motor and improving the exhaust performance of the vacuum pump. This is because a predetermined vacuum is obtained with a vacuum pump using an electric motor. In addition, when the vacuum pump operation reaches a desired degree of vacuum and the load is light load operation, the output terminal voltage is controlled so that the motor can be operated with high efficiency, This is because it is easy to perform control.

  In recent years, there is a dry vacuum pump unit using a DC brushless motor as an electric motor for driving a dry vacuum pump. FIG. 9 is a block diagram showing a system configuration of the power supply device of the dry vacuum pump. The power supply device 10 for the dry vacuum pump is an inverter power supply device including a rectifier 11, a DC circuit 12, and an inverter circuit 13. AC power from the AC power source 14 is full-wave rectified by the rectifier 11, smoothed by a DC circuit including a rectifying capacitor (smoothing capacitor) 18, converted into DC power, and supplied to the inverter circuit 13. The inverter circuit 13 includes a gate device such as an FET, and the PWM control of the PWM control circuit unit 23 converts the DC voltage from the DC circuit 12 into a three-phase AC of a pseudo sine wave voltage and supplies the DC brushless motor 15 with the DC voltage. It is configured.

JP 2003-333891 A JP-A-9-180895

  In the power supply device for the dry vacuum pump provided with the inverter circuit 13, if foreign matter is mixed in the vacuum pump and the foreign matter enters between the pump rotors or between the pump rotor and the pump casing, Therefore, high torque operation is required. However, in such a power supply device, only a torque within a power range that can be output by the rectifier 11 can be generated, and an operation restriction has occurred such that it cannot be restarted after biting occurs.

  To prevent this biting and sticking, the dry vacuum pump unit is equipped with a large-capacity power supply unit that can output an excessive motor shaft output for use with a normal dry vacuum pump. The system configuration was For example, in a normal dry vacuum pump operation range, a power supply device having a motor shaft output of 5.5 kW is mounted on a power supply device required for a motor shaft output of 2.2 kW. However, it is inconvenient in terms of cost to install a power supply device having an excessive output capability with respect to the operation range of a normal dry vacuum pump because the entire dry vacuum pump unit becomes large.

The present invention has been made in view of the above points, and without increasing the capacity of the power supply device, foreign matter is mixed in the pump and the accumulated foreign matter is generated, and temporarily the high torque of the drive motor is generated. Even when operation is required, a dry vacuum pump that can temporarily output a large motor shaft output with a simple configuration and eliminate biting without changing the capacity of the rectifier or smoothing capacitor on the AC power supply side of the inverter. Power supply device and its operation method

In order to solve the above problems, the present invention includes a rectifier, a DC circuit including a smoothing capacitor, and an inverter circuit, and converts AC power from an AC power source into DC power by the rectifier, and the inverter is connected via the DC circuit. is supplied to the circuit is converted into AC power of a predetermined frequency in the inverter circuit, a power supply device for a dry vacuum pump configured to supply the drive motor of the dry vacuum pump, a dry vacuum pump, the internal pump By driving the accumulated foreign matter, the shaft output of the drive motor temporarily needs a shaft output that exceeds the rated shaft output, and when the bite is eliminated, the shaft output of the drive motor returns to the rated shaft output. The capacity of the rectifier and smoothing capacitor that make up the DC circuit can supply power to the drive motor up to the power corresponding to the rated shaft output. Obtaining power has become a capacity which can not be supplied, the auxiliary and power circuit, the drive if the motor requires a large shaft output temporarily exceeding the rated shaft output, rated shaft output to the DC circuit from the auxiliary power circuit at a predetermined timing And a switching means for stopping the supply of the auxiliary power at a predetermined timing when the auxiliary electric power exceeding 1 is supplied and the shaft output of the drive motor returns to within the rated shaft output .

Further, in the power supply device for the dry vacuum pump according to the present invention, the auxiliary power circuit is an auxiliary power capacitor, and the switching unit temporarily requires a large shaft output that exceeds the rated shaft output . The charged auxiliary power capacitor is connected in parallel to the DC circuit at a predetermined timing, and when the drive motor shaft output returns to within the rated shaft output , the auxiliary power capacitor is disconnected from the DC circuit at a predetermined timing. And

In the dry vacuum pump power supply apparatus according to the present invention, the auxiliary power circuit is an auxiliary power storage device, and the switching unit temporarily requires a large shaft output that exceeds the rated shaft output. Connect the charged auxiliary power capacitor in series with the smoothing capacitor at a predetermined timing, connect the series circuit of the auxiliary power capacitor and the smoothing capacitor in parallel with the DC circuit, and the shaft output of the drive motor is within the rated shaft output. In the case of returning to , the series circuit is disconnected from the DC circuit at a predetermined timing, and the smoothing capacitor is connected in parallel to the DC circuit.

The present invention also includes a rectifier, a DC circuit including a smoothing capacitor, and an inverter circuit. The AC power from the AC power source is converted into DC power by the rectifier and supplied to the inverter circuit via the DC circuit. The dry vacuum pump power supply device is configured to convert the AC power into a predetermined frequency and supply it to the drive motor of the dry vacuum pump, and the dry vacuum pump bites foreign matter accumulated inside the pump. The shaft output of the drive motor temporarily requires a shaft output that exceeds the rated shaft output, and when the bite is eliminated, the shaft output of the drive motor returns to the rated shaft output and constitutes a DC circuit. The capacity of the rectifier and smoothing capacitor is such that power can be supplied to the drive motor up to power that matches the rated shaft output, but power that exceeds the rated shaft output cannot be supplied. And it is an auxiliary power storage battery, when the driving motor requires a large shaft output temporarily exceeding the rated shaft output, in parallel, respectively capacitor and a smoothing capacitor for the auxiliary power charged in the DC circuit at a predetermined timing be connected or, if the capacitor and the smoothing capacitor being charged ancillary electrical series circuit connected in series is connected in parallel to the DC circuit at a predetermined timing, the shaft output of the drive motor has returned to the rated shaft in the output, Switching means for disconnecting the auxiliary power storage device from the DC circuit or disconnecting the series circuit from the DC circuit and connecting the smoothing capacitor to the DC circuit in parallel at a predetermined timing is provided.

The present invention also includes a rectifier, a DC circuit including a smoothing capacitor, and an inverter circuit. The AC power from the AC power source is converted into DC power by the rectifier and supplied to the inverter circuit via the DC circuit. Is a method of operating a power supply device for a dry vacuum pump, which is configured to convert the AC power into a predetermined frequency and supply it to the drive motor of the dry vacuum pump. The dry vacuum pump bites foreign matter accumulated inside the pump. Therefore, the shaft output of the drive motor temporarily requires a shaft output that exceeds the rated shaft output, and when the bite is eliminated, the shaft output of the drive motor returns to the rated shaft output and is in a driving condition. The capacity of the rectifier and smoothing capacitor that make up the circuit can supply power to the drive motor up to the power that matches the rated shaft output, but the power that exceeds the rated shaft output It has become unable to supply capacity, if the drive motor requires a large axial output that exceeds the rated shaft output to supply the amount of the auxiliary power exceeding the rated shaft output at a predetermined timing to the DC circuit from the auxiliary power circuit, the drive When the shaft output of the electric motor returns to within the rated shaft output, the supply of auxiliary power from the auxiliary power circuit is stopped at a predetermined timing .

According to the present invention, when the drive motor temporarily needs a large shaft output that exceeds the rated shaft output , the auxiliary power circuit supplies auxiliary power that exceeds the rated shaft output to the DC circuit at a predetermined timing, When the shaft output of the drive motor returns to within the rated shaft output, a switching means is provided to stop the supply of auxiliary power at a predetermined timing, so that the overall capacity of the power supply device is not increased, and the dry vacuum pump is engaged. When the drive motor temporarily needs a large shaft output that exceeds the rated shaft output, auxiliary power is supplied to the DC circuit to exceed the rated shaft output, and the shaft output of the drive motor is increased. Thus, it is possible to eliminate the biting that is the cause of temporarily increasing the shaft output of the drive motor .

Further, according to the present invention, when the auxiliary electric power storage device and the switching means are provided and the drive motor temporarily requires a large shaft output exceeding the rated shaft output , the charged auxiliary electric power storage device is provided at a predetermined timing. When connected in parallel to the DC circuit and the shaft output of the drive motor returns to within the rated shaft output , the auxiliary power storage device is simply disconnected from the DC circuit at a predetermined timing, increasing the overall capacity of the power supply device as described above. Therefore, it is possible to eliminate the biting that is a cause of temporarily increasing the shaft output of the drive motor .

Further, according to the present invention, when the auxiliary electric power storage device and the switching means are provided and the drive motor temporarily requires a large shaft output exceeding the rated shaft output , the charged auxiliary electric power storage device is provided at a predetermined timing. Connected in series to a smoothing container sensor, and connected in series to the DC circuit in parallel to the auxiliary power storage capacitor and smoothing capacitor, and when the drive motor shaft output returns to the rated shaft output , the series circuit Is the cause of temporarily increasing the shaft output of the drive motor without increasing the overall capacity of the power supply device, just by disconnecting the DC from the DC circuit and connecting the smoothing capacitor in parallel to the DC circuit. Biting and the like can be eliminated.

In addition, according to the present invention, when the auxiliary electric power storage device and the switching means are provided and the drive motor temporarily requires a large shaft output exceeding the rated shaft output, the auxiliary power is charged in the DC circuit at a predetermined timing. or to connect the capacitor and the smoothing capacitor in parallel, and connect a series circuit connecting a capacitor and a smoothing capacitor for the auxiliary power charged in series in parallel to the DC circuit at a predetermined timing, the shaft output of the driving motor Teikakujiku When returning to the output , the auxiliary power storage device is disconnected from the DC circuit at a predetermined timing, or the series circuit is disconnected from the DC circuit, and the smoothing capacitor is connected in parallel to the DC circuit. Without enlarging, it is possible to eliminate the biting or the like that is the cause of temporarily increasing the shaft output of the drive motor .

Further, according to the present invention, when the drive motor requires a large shaft output exceeding the rated shaft output, the auxiliary power circuit supplies the auxiliary power for the amount exceeding the rated shaft output at a predetermined timing from the auxiliary power circuit to the drive. When the shaft output of the motor returns to within the rated shaft output, the supply of the drive motor shaft output can be reduced without increasing the overall capacity of the power supply device by simply stopping the supply of auxiliary power from the auxiliary power circuit at a predetermined timing. Biting and the like , which are temporarily increased, can be eliminated.

It is a block diagram which shows the system configuration | structure of the power supply device for dry vacuum pumps which concerns on this invention. It is a block diagram which shows the other system structure of the power supply device for dry vacuum pumps which concerns on this invention. It is a block diagram which shows the other system structure of the power supply device for dry vacuum pumps which concerns on this invention. It is a figure which shows the operation example of the power supply device for dry vacuum pumps of FIG. It is a figure which shows the operation example of the power supply device for dry vacuum pumps of FIG. It is a figure which shows the voltage waveform of each part of the DC circuit of FIG. It is a figure which shows the operation example of the power supply device for dry vacuum pumps of FIG. It is a figure which shows the voltage waveform of each part of the DC circuit of FIG. It is a block diagram which shows the system configuration | structure of the power supply device of the dry vacuum pump which used the direct-current brushless motor for the drive motor. It is a figure which shows the voltage waveform of each part of the DC circuit of the power supply device in FIG. It is a figure which shows the example of 1 structure of a dry vacuum pump unit. It is a figure which shows the structural example of a direct-current brushless motor.

  Hereinafter, embodiments of the present invention will be described in detail. An inverter power supply device that supplies power to a drive motor of a dry vacuum pump performs full-wave rectification on a sine wave voltage input from a commercial power source using a rectifier such as a rectifier diode. Further, in order to rectify the sine wave pulsation, a DC voltage is obtained by rectification by a smoothing capacitor such as an electrolytic capacitor. The capacitance of the smoothing capacitor is selected according to the rated output power of the inverter power supply device. Specifically, even when the maximum output voltage is generated, the voltage ripple is set to −10%. This is because when the voltage ripple increases, the voltage fluctuation, that is, the amount of charge / discharge to the smoothing capacitor increases, leading to an increase in temperature of the smoothing capacitor body, the life of the capacitor is shortened, and the capacity and size of the capacitor are reduced. Determined from balance.

  A commercial frequency is converted to an arbitrary frequency and output to an inverter power supply device for a dry vacuum pump. Generally, commercial frequency power is converted to direct current by a rectifier, and this direct voltage is equipped with a gate device such as an FET. The pseudo sine wave voltage output is generated by the PWM conversion method using the inverter circuit. For this reason, the maximum value of the output voltage obtained by the PWM conversion method is only equal to the maximum voltage value of the DC circuit.

  Moreover, the fluctuation of the voltage ripple does not become a problem in the operating range where the inverter power supply is assumed to be used normally. However, in the inverter power supply that drives the dry vacuum pump, the load is deposited in the dry vacuum pump. Biting of products or the like occurs. In order to eliminate this biting, a very large motor shaft output is required as compared with the normal operation range. In a general inverter power supply device, when operated under such an excessive load condition, the voltage ripple of the DC circuit becomes very large, and smoothing by the smoothing capacitor may completely lose the effect. That is, since the output load of the inverter power supply device becomes very large, smoothing by the smoothing capacitor is not effective, and the impedance viewed from the input power supply is lowered.

  For this reason, in the worst case, the current supplied from the input power supply increases rapidly, and the breaker installed on the power input side of the inverter power supply device may be cut off. In this embodiment, in a power supply device for a dry vacuum pump using an inverter power supply device, even when the dry vacuum pump is bitten, a high output power can be temporarily output from the inverter circuit by the following method. ing.

  FIG. 1 is a block diagram showing a system configuration of a power supply device for a dry vacuum pump according to the present invention. Here, a DC brushless motor is used as an electric motor for driving a dry vacuum pump. As shown in the figure, the power supply device 10 for the dry vacuum pump includes a rectifier 11, a DC circuit 12, and an inverter circuit 13. The AC power from the AC power supply 14 is full-wave rectified by the rectifier 11 and converted to DC, smoothed by the DC circuit 12 having a rectifying capacitor (smoothing capacitor) 18, and supplied to the inverter circuit 13. The inverter circuit 13 converts the AC power into a predetermined frequency and supplies it to a DC brushless motor 15 that drives a dry vacuum pump (not shown).

  In addition to a rectifying capacitor (smoothing capacitor) 18, an inrush current protection element 20 is connected in series with the anode circuit in the DC circuit 12. Further, an auxiliary power circuit 22 (described in detail later) is connected to the DC circuit 12 via switching elements 21 and 21. The inverter circuit 13 includes U-phase switching elements 13a and 13b, V-phase switching elements 13c and 13d, and W-phase switching elements 13e and 13f. The open / close elements 13a to 13f are composed of gate devices such as FETs, and are ON / OFF controlled at a predetermined timing by PWM control by the PWM control circuit unit 23, respectively.

  As described above, the open / close elements 13a to 13f of the inverter circuit 13 are ON / OFF controlled at a predetermined timing of PWM control by the PWM control circuit unit 23, whereby the DC voltage from the DC circuit 12 is a pseudo sine wave having a predetermined frequency. It is converted into AC power of phase (U phase, V phase, W phase). Then, it is supplied to each phase (U-phase, V-phase, W-phase) stator coils 15 a to 15 f of the DC brushless motor 15. Thereby, the DC brushless motor 15 rotates at a predetermined rotational speed.

  The inrush current protection element 20 has a configuration in which a resistor 20b and a switching element 20a are connected in parallel. In the power supply device for the dry vacuum pump having the above configuration, an excessive inrush current flows when the power supply 14 is turned on. Therefore, by opening the switching element 20a of the inrush current protection element 20, the current from the rectifier 11 is changed to the resistor 20b. Will suppress the excessive inrush current.

  The direct current brushless motor 15 is a kind of direct current motor that determines a rated voltage with respect to a rated rotational speed. Therefore, a device having a capacity within a range in which the DC brushless motor 15 can output a rated output is selected as a device such as the rectifier 11 constituting the power supply device 10 for the dry vacuum pump that supplies power to the DC brushless motor 15. In a dry vacuum pump used to evacuate a process chamber in a semiconductor manufacturing facility or the like, products are deposited in the pump when the process gas is evacuated. This accumulated product penetrates between the rotary rotor and the rotary rotor of the dry vacuum pump or between the rotary rotor and the pump casing, and induces so-called biting that inhibits the smooth rotation of the rotary rotor.

  When the above-described biting state occurs in the pump, the DC brushless motor 15 tries to output a shaft output exceeding the rating in order to eliminate this biting. As described above, since the rectifier 11 and the like constituting the power supply device 10 for the dry vacuum pump use an output capacity corresponding to the rated output of the DC brushless motor 15, the DC brushless motor 15 has a shaft having a rated output or more. The power to output cannot be supplied. However, in order to eliminate the biting, it is necessary to supply a large AC power from the inverter circuit 13 to the DC brushless motor 15.

  Therefore, here, the auxiliary power circuit 22 can be connected to the DC circuit 12 via the switching elements 21 and 21. When biting occurs in the vacuum pump, the open / close elements 21 and 21 are closed, and the DC power necessary for eliminating the biting of the vacuum pump is supplied from the auxiliary power circuit 22 to the DC circuit 12. As a result, the high-axis output that eliminates the biting of the DC brushless motor 15 without increasing the capacity of the devices and components that constitute the AC power supply 14 side of the inverter circuit 13 such as the rectifier 11 of the power supply device 10 for the dry vacuum pump. Can be used to supply temporary power for the output. The auxiliary power circuit 22 has only to have a capacity capable of supplying power for the increased load to the DC circuit 12 when the load is temporarily increased such as when the dry vacuum pump is bitten. A (capacitor) or a storage battery can be used.

  FIG. 2 is a diagram showing a configuration example of a power supply device for a dry vacuum pump that embodies the auxiliary power circuit 22 of FIG. 2, the same reference numerals as those in FIG. 1 denote the same or corresponding parts. The same applies to other drawings. As shown in the figure, the power supply device 10 for the dry vacuum pump has a rectifying capacitor (smoothing capacitor) 18 connected in parallel to a DC circuit 12 located between the rectifier 11 and the inverter circuit 13 via an opening / closing element 24. Auxiliary power capacitor 26 is connected in parallel via switching element 25. The opening / closing element 24 and the opening / closing element 25 are opened / closed (ON / OFF) by a current boost circuit 27.

  The current boost circuit 27 closes the open / close element 24 (ON) and opens the open / close element 25 (OFF) during normal operation of the dry vacuum pump. Accordingly, only the rectifying capacitor (smoothing capacitor) 18 is connected to the DC circuit 12 in parallel as in the power supply device shown in FIG. An electrolytic capacitor is usually used as the rectifying capacitor (smoothing capacitor) 18. As the capacitance of the rectifying capacitor (smoothing capacitor) 18, a value corresponding to the capacitance of the rectifier 11 is selected. Specifically, even when the maximum output power is output, the voltage ripple Vr of the DC circuit 12 is set to be −10% as shown in FIG. As shown in FIG. 10 (b), when the voltage ripple increases, the voltage fluctuation of the DC circuit 12, that is, the amount of charge / discharge to the rectifying capacitor 18 increases, causing the temperature of the rectifying capacitor 18 to rise. Is determined from the balance between the short life and the capacity and size of the rectifying capacitor 18.

  In the state where only the DC circuit 12 is connected in parallel as described above, when a foreign object is caught in the vacuum pump driven by the DC brushless motor 15, in order to eliminate this biting, the DC brushless motor Try to make 15 shaft output more than rated. However, since the capacity of the rectifying capacitor 18 is set so that the voltage ripple is about −10% as described above, the power charged by the rectifying capacitor 18 covers the power necessary to eliminate the biting. I ca n’t. Therefore, in order to eliminate the biting by the power supply device shown in FIG. 9, it is necessary to increase the capacity of the entire power supply device. However, in that case, the dry vacuum pump unit is large, which is inconvenient in terms of cost. Therefore, in this case, when biting occurs in the vacuum pump, the current boost circuit 27 closes the open / close element 25 and connects the auxiliary power capacitor 26 that has been charged (charged) in advance to the DC circuit 12 in parallel. doing.

  As a result, the power capacity of the DC circuit 12 is charged in the auxiliary power capacitor 26 and temporarily increased with DC power to increase the shaft output of the DC brushless motor 15 and eliminate the biting of the pump. By adding the DC power stored in the auxiliary power capacitor 26 to the rated capacity power of the DC circuit 12, the auxiliary power capacitor 26 can eliminate the biting of the DC brushless motor 15 that is the drive motor of the dry vacuum pump. Select a capacity that can provide shaft output. In the inverter circuit 13, the temporarily increased DC power is converted into AC having a predetermined frequency and supplied to the DC brushless motor 15. As a result, the shaft output is enhanced and the biting can be eliminated. The increase and elimination of temporary load such as occurrence and elimination of biting can be detected by monitoring the current supplied to the DC brushless motor 15 or the shaft torque.

  The current boost circuit 27 opens the switching element 25 and disconnects the auxiliary power capacitor 26 from the rectifier when the charging of the auxiliary power capacitor 26 is further completed after the biting state is eliminated and the output load is reduced. . Thereby, the secular change of the auxiliary power capacitor 26 itself can be prevented. In addition, a capacitor having the same capacity as the rectifying capacitor (smoothing capacitor) 18 is used as the auxiliary power capacitor 26, and the switching elements 24 and 25 are periodically controlled to be opened and closed by the current boost circuit 27, thereby rectifying with the auxiliary power capacitor 26. By alternately connecting the capacitors 18 to the DC circuit 12, it is possible to improve the life of the power supply device 10 for the dry vacuum pump, which is an inverter power supply device. As the auxiliary power capacitor 26, various capacitors such as an electrolytic capacitor and an electric double layer capacitor can be used.

  When biting occurs in the vacuum pump as described above, the DC brushless due to the voltage drop of the DC circuit 12 even when the maximum duty (100% ON) is output within the controllable range of the PWM output voltage waveform output from the inverter circuit 13. Even when the DC brushless motor 15 temporarily needs excessive rotational torque by increasing the power capacity of the DC circuit 12 by the auxiliary power capacitor 26 so that the terminal voltage of the motor 15 does not decrease, Sufficient power can be output to cope with this.

  Further, in the power supply device 10 for the dry vacuum pump shown in FIG. 2, if the inrush current protection element 20 including the resistor 20b and the switching element 20a for suppressing the inrush current generated when the AC power supply 14 is turned on is provided, the auxiliary device The power capacitor 26 may be continuously connected to the DC circuit 12.

  FIG. 3 is a diagram showing another configuration example of the power supply device for the dry vacuum pump that embodies the auxiliary power circuit 22 of FIG. As shown in FIG. 3, a backflow prevention diode 19, a switch 29, a switch 30, a switch 31, and a switch 32 are provided in the DC circuit 12 of the power supply device 10 for the dry vacuum pump. The a contact and c contact of the switch 29 and the a contact of the switch 31 are connected to the anode P line of the DC circuit 12. The b contact of the switch 29 and the a contact of the switch 30 are connected. The auxiliary contact capacitor 26 is connected between the connection line of the switch 29 and the contact b of the switch 31, and between the connection line and the connection line of the contact c of the switch 30 and the contact a of the switch 32. Has been. A b-contact and a d-contact of the switch 30 are connected, and a rectifying capacitor (smoothing capacitor) 18 is connected between the connection line and the cathode N line. The b contact of the switch 32 is connected to the cathode N line. Further, the switching device 29, the switching device 30, the switching device 31, and the switching device 32 are controlled to be switched by the voltage / current boost circuit 28, respectively.

  FIG. 4 is a diagram illustrating an operation example of the switch 29, the switch 30, the switch 31, and the switch 32 of the DC circuit 12 of FIG. In normal dry vacuum pump operation where there is no increase in temporary load such as biting, the voltage / current boost circuit 28 is connected to the contacts a and b of the switch 29 and switch 30 as shown in FIG. The contact is closed, the c contact and the d contact are opened, the a contact and the b contact of the switching device 31 are opened, and the a contact and the b contact of the switching device 32 are opened. As a result, as shown in FIG. 4B, only the rectifying capacitor (smoothing capacitor) 18 is connected to the DC circuit 12 in parallel. The operation of the power supply device in this case is the same as that of the dry vacuum pump power supply device 10 shown in FIG.

FIG. 5 is a diagram illustrating an operation example of the switch 29, the switch 30, the switch 31, and the switch 32 of the DC circuit 12 of FIG. When biting occurs in the dry vacuum pump and the shaft output of the DC brushless motor 15 increases, the voltage / current boost circuit 28 is connected to the contacts a and b of the switch 29 and the switch 30 as shown in FIG. The contacts are opened, the contacts c and d are closed, the contacts a and b of the switch 31 are opened, and the contacts a and b of the switch 32 are opened. As a result, as shown in FIG. 5B, the DC circuit 12 is connected in parallel with the DC circuit 12 including the rectifying capacitor (smoothing capacitor) 18 and the auxiliary power capacitor 26. That is, a voltage (V ₁₂ + E) obtained by adding the voltage E charged in the auxiliary power capacitor 26 to the voltage V ₁₂ of the DC circuit 12 charged in the rectifying capacitor (smoothing capacitor) 18 is temporarily a DC circuit. 12 is applied.

As a result, the voltage between the anode P terminal 16 and the cathode N terminal 17 of the DC circuit 12 is temporarily added to the original DC circuit voltage V ₁₂ by the charging voltage E of the auxiliary power capacitor 26 as shown in FIG. The applied voltage (V ₁₂ + E) is applied. The inverter circuit 13 converts the DC voltage into an AC of a predetermined frequency, from the supply to the DC brushless motor 15, if V ₁₂ = E, normal voltage V temporarily DC circuit 12 to the DC brushless motor 15 An AC voltage obtained by converting a DC voltage twice as large as ₁₂ into AC is supplied. As a result, the shaft output of the DC brushless motor 15 temporarily increases, and the biting of the dry vacuum pump can be eliminated.

When biting occurs in the vacuum pump as described above, the switch 29, the switch 30, the switch 31 and the switch 32 are switched by the voltage / current boost circuit 28, and the original DC circuit voltage V ₁₂ is switched to the DC circuit. By applying a voltage (V ₁₂ + E) obtained by adding the charging voltage E of the auxiliary power capacitor 26 to the output power, the output voltage of the inverter circuit 13 is temporarily increased. As a result, the motor current determined by the impedance of the DC brushless motor 15 and the terminal voltage of the DC brushless motor 15 can be temporarily increased. As a result, the shaft output that can be output from the DC brushless motor 15 can be temporarily increased. Even if the voltage of the DC circuit 12 increases to V ₁₂ + E, the backflow prevention diode 19 prevents the backflow from the DC circuit 12 to the rectifier 11 side.

  FIG. 7 is a diagram illustrating an operation example of the switch 29, the switch 30, the switch 31, and the switch 32 of the DC circuit 12 of FIG. When biting occurs in the dry vacuum pump and the shaft output of the DC brushless motor 15 increases, the voltage / current boost circuit 28 is connected to the contacts a and b of the switch 29 and the switch 30 as shown in FIG. The contact is closed, the c contact and the d contact are opened, the a contact and the b contact of the switching device 31 are closed, and the a contact and the b contact of the switching device 32 are closed. Accordingly, as shown in FIG. 7B, the rectifying capacitor (smoothing capacitor) 18 and the auxiliary power capacitor 26 are connected in parallel to the DC circuit 12, respectively.

When the dry vacuum pump bites in this way, the PWM output voltage waveform output from the inverter circuit 13 shown in FIG. 8 can be controlled by connecting the rectifying capacitor 18 and the auxiliary power capacitor 26 in parallel. Even when the maximum duty (100% ON) is output within this range, the voltage V ₁₂ of the DC circuit 12 does not drop. Thus, the power capacity of the DC circuit 12 can be increased by the auxiliary power capacitor 26 so that the terminal voltage of the DC brushless motor 15 does not decrease. Therefore, even when the DC brushless motor 15 temporarily requires excessive rotational torque, it is possible to output sufficient electric power.

  As described above, in the power supply device 10 for the dry vacuum pump, the rated breaking capacity of the overcurrent breaker arranged on the input side of the normal device determines a value corresponding to the rated capacity of the power supply device. As described above, the auxiliary power capacitor 26 and the rectifying capacitor (smoothing capacitor) 18 are connected to the DC circuit 12 in parallel, or the auxiliary power capacitor 26 and the rectifying capacitor (smoothing capacitor) 18 are connected in series. By connecting the DC circuits in parallel, the output of the inverter circuit 13 can be increased without changing the rated breaking capacity of the input-side overcurrent breaker.

  In the dry vacuum pump power supply device 10 having the voltage / current boost circuit 28 shown in FIG. 3, in the continuous high load operation that occurs during the continuous operation of the DC brushless motor 15, the rectifying capacitor of the DC circuit 12 is used. By connecting the auxiliary power capacitor 26 in parallel with the (smoothing capacitor) 18, it can function as a high-capacity inverter power supply device. When a large starting torque is required when the DC brushless motor 15 is started from a stop, a DC circuit in which a rectifying capacitor (smoothing capacitor) 18 and an auxiliary power capacitor 26 are connected in series to the DC circuit 12 is connected in parallel. When connected and the peak value of the voltage output from the inverter circuit 13 is increased, high torque operation at low speed is possible.

  FIG. 11 is a diagram showing a configuration example of the dry vacuum pump unit. The dry vacuum pump unit 1 includes a motor unit 40 and a pump unit 41. The motor unit 40 is a magnet coupling type DC brushless resin mold motor, and the pump unit 41 synchronously reverses a pair of screw rotors to generate gas. This is a vacuum pump for transferring the volume, and a volume transfer type twin screw pump.

  Two rotary shafts 51 a and 51 b are arranged in parallel inside the pump casing 50, and the rotary shafts 51 a and 51 b are supported by bearings 53. A right-hand screw rotor (pump rotor) 52a is fixed to the rotating shaft 51a, and a left-hand screw rotor (pump rotor) 52b is fixed to the rotating shaft 51b. A fluid flow path 56 is formed between the screw rotors 52 a and 52 b and the inner surface of the casing 50, and an inlet 41 a is provided at the upstream end of the fluid flow path 56. Is provided with an exhaust port 41b. The screw rotors 52a and 52b reverse each other in a non-contact manner with a slight clearance, and transfer the gas sucked from the intake port 41a to the exhaust port 41b. In addition, as a screw rotor 52a, 52b, you may use a pair of screw rotor which has an axial cross-sectional shape which contacts only on a pitch line.

  The rotating shafts 51a and 51b are made of SUS material, the screw rotors 52a and 52b are made of an aluminum alloy, and the screw rotors 52a and 52b are shrink-fitted to the rotating shafts 51a and 51b to form a pair of screw rotors. ing. The surfaces of the screw rotors 52a and 52b are subjected to nickel plating. The screw rotors 52a and 52b may be formed on the outer periphery of the rotary shafts 51a and 51b with a resin material. Thereby, the screw rotors 52a and 52b can be manufactured at low cost.

  As shown in FIG. 12, a pair of magnet rotors 54 and 54 having the same configuration are arranged at the shaft ends on the intake side of the rotating shafts 51a and 51b, respectively, and the rotating shafts 51a and 51b are driven in reverse as a DC brushless motor. At the same time, synchronous reversal of the rotating shafts 51a and 51b is secured by magnet coupling. As shown in FIG. 12, each magnet rotor 54 has a ring-shaped magnet 54a around the outer periphery of a magnetic material yoke 54b. In the present embodiment, a magnetized magnet 54a is provided on the outer periphery of the magnet rotor 54, facing each other so that the different magnetic poles of the magnet rotors 54 and 54 attract each other, and arranged with a clearance C maintained. ing. The number of poles of the magnet rotor 54 is an even number such as 4, 6, 8,...

  The screw rotors 52a and 52b are rotated in opposite directions in synchronization by the magnet coupling action of the magnet rotors 54 and 54. Thereby, a screw pump capable of stable two-axis synchronous reversal without a timing gear is configured. Further, the absence of the timing gear means that no lubricating oil is required, non-contact rotation including a safe biaxial synchronization mechanism is possible, and high speed operation of the screw pump is possible.

  A three-phase (U, V, W) motor stator 57 comprising an iron core 57a and windings 57b (stator coils 15a to 15f in FIGS. 1 to 3) is disposed in the vicinity of a part of the outer peripheral surface of each magnet rotor 54. Has been. The three-phase motor stator 57 is disposed on the side opposite to the side where the magnet rotors 54 are magnet-coupled with respect to the rotation axis. Thereby, the magnet coupling force that the magnet rotors 54 attract each other can be canceled by the attraction force acting on the magnet rotor 54 and the motor stator core 57a. The three-phase motor stator magnetic poles correspond to the number of magnetic poles of the magnet rotor 54, and a magnetic field is applied to the four poles of the magnet rotor 54 as shown by arrows D and E in FIG. By supplying a direct current having a required rectangular pulse waveform to the three-phase winding 57b, the two rotary shafts 51a and 51b can be synchronously inverted and driven at an arbitrary rotational speed.

  As described above, in the dry vacuum pump unit 1, when the pump unit 41 exhausts the reaction chamber of the semiconductor manufacturing facility, the product accumulates in the pump casing 50, and the product is accumulated in the screw rotor 52 a and the screw. When so-called biting occurs between the rotor 52b or between the screw rotor 52a or the screw rotor 52b and the casing 50, in order to eliminate the biting, the rated shaft output is output to the rotating shaft of the motor unit 40. Excessive shaft output exceeding is required. In such a case, the biting can be eliminated by employing the dry vacuum pump power supply device 10 having the configuration shown in FIGS. 1 to 3 as the power supply device of the dry vacuum pump unit 1.

  In the above-described embodiment, an example in which the dry vacuum pump unit 1 is adopted as a screw type vacuum pump has been described. However, another type of volume transfer type biaxial vacuum pump such as a roots type may be used. In addition, although a DC brushless motor has been described as an example of a drive motor for driving a dry vacuum pump, the drive motor for driving a dry vacuum pump is not limited to a DC brushless motor, and the dry vacuum pump bite is eliminated. The present invention can be applied to any motor that can cope with a large shaft output required for the purpose.

  The embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims and the specification and drawings. Can be modified. Note that any shape or structure not directly described in the specification and drawings is within the technical scope of the present invention as long as the effects of the present invention are achieved.

  In the present invention, when the auxiliary power circuit and the drive motor require a shaft output larger than the rated shaft output, the auxiliary power circuit supplies auxiliary power to the DC circuit at a predetermined timing, and the voltage or current of the DC circuit is supplied. When a large shaft output becomes unnecessary, a switching unit that stops the supply of auxiliary power at a predetermined timing is provided, so that the dry vacuum pump bites and the like is eliminated. When the drive motor that drives the dry vacuum pump requires a shaft output that exceeds the rated output, the voltage or current of the DC circuit can be temporarily increased to increase the shaft output. It can be used as a power source device for a dry vacuum pump that can eliminate biting and the like without increasing the overall capacity of the vacuum pump.

DESCRIPTION OF SYMBOLS 1 Dry vacuum pump unit 10 Power supply device for dry vacuum pumps 11 Rectifier 12 DC circuit 13 Inverter circuit 14 AC power supply 15 DC brushless motor 16 Anode P terminal 17 Cathode N terminal 18 Rectifier capacitor (smoothing capacitor)
DESCRIPTION OF SYMBOLS 19 Backflow prevention diode 20 Inrush current protection element 21 Switching element 22 Auxiliary power circuit 23 PWM control circuit part 24 Switching element 25 Switching element 26 Auxiliary power capacitor 27 Current boost circuit 28 Voltage / current boost circuit 29 Switcher 30 Switcher 31 Switcher 32 Switcher

Claims (5)

A rectifier, a DC circuit provided with a smoothing capacitor, and an inverter circuit, AC power from an AC power source is converted into DC power by the rectifier, supplied to the inverter circuit via the DC circuit, and the inverter circuit has a predetermined frequency A power supply device for a dry vacuum pump configured to convert the AC power into a dry vacuum pump drive motor,
The dry vacuum pump requires a shaft output temporarily exceeding the rated shaft output for the shaft output of the drive motor by biting foreign matter accumulated inside the pump, and when the bite is eliminated, the shaft of the drive motor The operating conditions are such that the output returns to within the rated shaft output.
The capacity of the rectifier and the smoothing capacitor constituting the DC circuit is a capacity that can supply power to the drive motor up to the power corresponding to the rated shaft output, but cannot supply power exceeding the rated shaft output,
An auxiliary power circuit;
If the drive motor requires a large shaft power exceeding the temporarily rated shaft output to supply the amount of the auxiliary power exceeding the rated shaft output from the auxiliary power circuit in the DC circuit at a predetermined timing, the A power supply device for a dry vacuum pump, comprising: switching means for stopping supply of the auxiliary power at a predetermined timing when the shaft output of the drive motor returns to within the rated shaft output . In the dry vacuum pump power supply device according to claim 1,
The auxiliary power circuit is an auxiliary power capacitor,
The switching means connects the charged auxiliary power accumulator in parallel to the DC circuit at a predetermined timing when the driving motor needs a large shaft output that temporarily exceeds the rated shaft output, and drives the driving A power supply device for a dry vacuum pump, wherein the auxiliary power storage device is disconnected from the DC circuit at a predetermined timing when the shaft output of the electric motor returns to within the rated shaft output . In the dry vacuum pump power supply device according to claim 1,
The auxiliary power circuit is an auxiliary power capacitor,
When the driving motor needs a large shaft output that temporarily exceeds the rated shaft output , the switching means connects the charged auxiliary power storage battery in series to the smoothing capacitor at a predetermined timing , and When a series circuit of a power storage device and a smoothing capacitor is connected in parallel to the DC circuit, and the shaft output of the drive motor returns to the rated shaft output, the series circuit is disconnected from the DC circuit at a predetermined timing, and A power supply device for a dry vacuum pump, wherein the smoothing capacitor is connected in parallel to the DC circuit. A rectifier, a DC circuit provided with a smoothing capacitor, and an inverter circuit, AC power from an AC power source is converted into DC power by the rectifier, supplied to the inverter circuit via the DC circuit, and the inverter circuit has a predetermined frequency A power supply device for a dry vacuum pump configured to convert the AC power into a dry vacuum pump drive motor,
The dry vacuum pump requires a shaft output temporarily exceeding the rated shaft output for the shaft output of the drive motor by biting foreign matter accumulated inside the pump, and when the bite is eliminated, the shaft of the drive motor The operating conditions are such that the output returns to within the rated shaft output.
The capacity of the rectifier and the smoothing capacitor constituting the DC circuit is a capacity that can supply power to the drive motor up to the power corresponding to the rated shaft output, but cannot supply power exceeding the rated shaft output,
Auxiliary power storage,
When the drive motor needs a large shaft output that temporarily exceeds the rated shaft output, the auxiliary power storage device charged in the DC circuit at a predetermined timing and the smoothing capacitor are respectively connected in parallel , or A series circuit in which the charged auxiliary power storage device and the smoothing capacitor are connected in series is connected in parallel to the DC circuit at a predetermined timing, and when the shaft output of the drive motor returns to the rated shaft output, And switching means for disconnecting the auxiliary power storage device from the DC circuit at a timing or disconnecting the series circuit from the DC circuit and connecting the smoothing capacitor in parallel to the DC circuit. Power supply for dry vacuum pump. A rectifier, a DC circuit provided with a smoothing capacitor, and an inverter circuit, AC power from an AC power source is converted into DC power by the rectifier, supplied to the inverter circuit via the DC circuit, and the inverter circuit has a predetermined frequency Is an operation method of a power supply device for a dry vacuum pump configured to convert the AC power into a dry vacuum pump drive motor,
The dry vacuum pump requires a shaft output temporarily exceeding the rated shaft output for the shaft output of the drive motor by biting foreign matter accumulated inside the pump, and when the bite is eliminated, the shaft of the drive motor The operating conditions are such that the output returns to within the rated shaft output.
The capacity of the rectifier and the smoothing capacitor constituting the DC circuit is a capacity that can supply power to the drive motor up to the power corresponding to the rated shaft output, but cannot supply power exceeding the rated shaft output,
If the drive motor requires a large shaft power exceeding the rated shaft output, the minute auxiliary power exceeding the rated shaft output at a predetermined timing to the DC circuit from the auxiliary power circuit supplies, the axis of the drive motor A method of operating a power supply device for a dry vacuum pump, characterized in that when the output returns to within the rated shaft output, the supply of auxiliary power from the auxiliary power circuit is stopped at a predetermined timing .

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