JP2007285134A - Turbo-molecular pump, and vacuum device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To air-cool a power supply unit in a configuration for water-cooling a vacuum device and a pump unit. <P>SOLUTION: In a turbo molecular pump 2 for water-cooling a pump unit 3, a mechanism for introducing a pressurized gas for pump purging is provided in a power supply unit 4 for supplying the power to the pump unit 3, a flow passage of the pressurized gas from the inside of the power supply unit 4 to the outside is formed by the differential pressure between the pressure of the pressurized gas and the atmospheric pressure, and the heat in the power supply unit 4 is discharged with the pressurized gas being a medium. The pressurized gas introduced in the power supply unit 4 forms the gas flow passage even in the power supply unit in a semi-hermetic state by using the pressure higher than the atmospheric pressure. The heat generated in the power supply unit is discharged outside the power supply unit with the pressurized gas being the medium, and air-cooling is performed thereby. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbo molecular pump and a vacuum device that is evacuated by the turbo molecular pump, and more particularly, to cooling of a power supply unit for driving the turbo molecular pump.

  In a vacuum apparatus, a vacuum state is formed by sucking the inside of a vacuum container or the like by a suction mechanism such as a turbo molecular pump. In general, a turbo molecular pump includes a pump unit having a stator and a rotor, and the rotor is rotated by driving a power source of a motor to suck and exhaust the inside of the vacuum vessel.

  Usually, the vacuum apparatus is provided with a water pipe in the apparatus itself, and the vacuum apparatus is cooled by flowing cooling water through the pipe. Also, for the turbo molecular pump that evacuates the vacuum device, the pump unit itself is provided with water piping in order to cool the heat generated by the rotation of the rotor in the pump unit.

  In the turbo molecular pump, the motor of the pump unit is driven by driving power supplied from the power supply unit. This power supply unit needs to be cooled because it incorporates a circuit that generates heat, such as an AC / CD converter that converts alternating current into direct current, and an inverter for driving a pump motor.

  The power supply unit can be arranged separately from the pump unit. However, if the power supply unit is arranged separately, a cable for supplying power from the power supply unit to the pump unit must be provided. In order to reduce problems such as space and power loss for installation, it is desirable that the power supply unit and the pump unit are integrated or arranged close to each other.

  Thus, in the case where the power supply unit and the pump unit are integrated or arranged close to each other, the power supply unit is cooled by using the cooling water pipe used for cooling the pump unit.

  At this time, since the power supply unit incorporates a circuit that does not like water leakage, a drip-proof treatment is performed to prevent water leakage from the cooling water pipe.

  FIG. 6 is a schematic diagram for explaining a configuration example of a conventional vacuum apparatus, and FIG. 7 is a schematic diagram for explaining a configuration example of a power supply unit of a turbo molecular pump.

  In FIG. 6, the vacuum apparatus 100 is sucked and evacuated by a pump unit 30 of a turbo molecular pump. The motor of the pump unit 30 is driven by receiving power from the power supply unit 20.

  In the configuration in which the vacuum apparatus 100 is cooled using cooling water, a part of this cooling water is diverted and sent to the turbo molecular pump, and is used for cooling the power supply unit 20 and the pump unit 30.

  FIG. 7 shows a configuration example of a power supply unit of a conventional turbo molecular pump that performs cooling by water cooling. In FIG. 7, a power supply unit 20 includes an AC / DC converter 20b that converts alternating current into direct current, an inverter 20c that converts the frequency of the DC converted to perform speed control, a controller 20a that controls these, and the like. The circuit configuration is provided. Heat generated by these circuit configurations is cooled by cooling water flowing through the water cooling unit 20e via the radiator 20d. Here, in order to prevent condensation, the water cooling unit 20e has a heat insulating structure and a seal structure so as not to conduct heat between portions other than the radiator 20d.

  When the water cooling unit 20e is condensed, electric leakage occurs in circuit parts such as the AC / DC converter unit 20b, the inverter 20c unit, and the control unit 20a, which causes a failure.

  In a conventional vacuum apparatus or turbo molecular pump, when heat generation is cooled using a cooling water pipe, condensation may occur due to a temperature difference caused by temperature difference cooling water in the power supply unit. As a method for preventing this dew condensation, it is conceivable to manage the temperature of the cooling water, but there may be a limitation in use such as the temperature of the cooling water and the capacity of the applicable motor. In addition, as another method for preventing condensation, it is conceivable to provide a heat insulating structure or a seal structure as described above, but such a structure is not a configuration originally required by a turbo molecular pump or a vacuum apparatus. However, there is a problem that the cost of the turbo molecular pump and the vacuum device is increased.

  In a configuration in which the vacuum device or pump unit is cooled with cooling water, water leakage may occur due to mistakes in the installation of cooling water piping, vibration, etc. In the event of water leakage, the power supply unit will leak and pump This may cause unit failure.

  The problem with the power supply unit described above occurs when the power supply unit is cooled together with the cooling water used for cooling the vacuum device or the pump unit. Therefore, if the power supply unit is not air-cooled but air-cooled using a fan, a failure due to water leakage can be eliminated.

  However, the power supply unit is installed close to a vacuum apparatus or a pump unit that performs cooling using cooling water. For this reason, the power supply unit is in an environment that is affected by the cooling water. Therefore, as a drip-proof measure, the power supply unit must have a semi-sealed structure that is sealed except for the minimum openings through which lines such as power lines, signal lines, and control lines are passed. I do not get.

  When air cooling is applied to such a semi-enclosed structure, it is conceivable to perform air cooling by forming an air flow with a fan provided inside. However, since the air flow formed by the fan is hindered by various circuit configurations provided therein, stagnation occurs due to the air flow, and it is difficult to form a sufficient air flow.

  In addition, since the air stays inside the semi-hermetic structure and is not exhausted to the outside, the heat generated inside the power supply unit stays inside almost without being led to the outside, except that it is transmitted through the case member or the like. Therefore, there is a problem that sufficient cooling cannot be expected.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above problems and to cool a power supply unit by air cooling in a configuration in which a vacuum device or a pump unit is cooled by water cooling.

  The turbo molecular pump and the vacuum device including the turbo molecular pump according to the present invention have a configuration in which the pump unit is cooled by water cooling, and the cooling water pipe is adjacent to the power supply unit that supplies power to the pump unit by introducing pressurized gas. Cool even without being affected by water leaks As the pressurized gas, nitrogen gas for purge introduced into the pump unit or compressed air for utility of the vacuum apparatus can be used.

  In the turbo molecular pump according to the present invention, a turbo molecular pump that cools the pump unit by water cooling includes a mechanism for introducing nitrogen gas for pump purge into a power supply unit that supplies power to the pump unit. A flow path of nitrogen gas from the inside of the power supply unit to the outside is formed by the pressure difference from the atmospheric pressure, and heat is discharged from the power supply unit using the nitrogen gas as a medium.

  The nitrogen gas introduced into the power supply unit can form a gas flow path even in the semi-sealed power supply unit by utilizing the fact that the nitrogen gas for pump purge is higher than atmospheric pressure. it can. Heat generated in the power supply unit is discharged outside the power supply unit using this nitrogen gas as a medium, and air cooling is performed.

  The exhaust of nitrogen gas from the inside of the power supply unit to the outside can be performed through a drip-proof seal provided between the power supply unit and the pump unit.

  Since the inside of the power supply unit has a pressure higher than the atmospheric pressure due to the introduced nitrogen gas, even if the surroundings are in a water environment by water cooling, water can be prevented from entering the inside. Moreover, the waterproof effect in a drip-proof seal part increases by exhausting nitrogen gas through the drip-proof seal part.

  Further, the form of the vacuum apparatus of the present invention is a vacuum apparatus that is evacuated by a turbo molecular pump that cools the pump unit with water cooling, and in the power supply unit that supplies power to the pump unit, nitrogen gas for pump purge, or Equipped with a mechanism that introduces compressed air for vacuum equipment as pressurized gas, and forms a flow path of pressurized gas from the inside of the power supply unit to the outside by the pressure difference between the pressurized gas and atmospheric pressure. Heat is discharged from the power supply unit using gas as a medium.

  By utilizing the fact that the pressurized gas of nitrogen gas or compressed air introduced into the power supply unit is higher than atmospheric pressure, a gas flow path can be formed even in a semi-sealed power supply unit. it can. The heat generated in the power supply unit is discharged outside the power supply unit using this pressurized gas as a medium, and air cooling is performed.

  Exhaust of pressurized gas from the inside of the power supply unit to the outside can be performed through a drip-proof seal provided between the power supply unit and the pump unit. Since the pressure inside the power supply unit is higher than the atmospheric pressure by the introduced pressurized gas, even if the surroundings are in a water environment by water cooling, water can be prevented from entering the inside. Moreover, the waterproof effect in a drip-proof seal part increases by exhausting pressurized gas through a drip-proof seal part.

  According to the present invention, the power supply unit can be cooled by air cooling in the configuration in which the vacuum device or the pump unit is cooled by water cooling.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram for explaining a first embodiment of the present invention, and shows a configuration example in which a power supply unit is air-cooled using nitrogen gas for pump purge.

  In FIG. 1, a vacuum apparatus 1 forms a vacuum state by evacuating the inside of a vacuum chamber 100 with a turbo molecular pump 2. The turbo molecular pump 2 includes a pump unit 3 and evacuates together with the auxiliary pump 5.

  The pump unit 3 includes a stator and a rotor, and the inside of the vacuum chamber 100 is evacuated by rotating the rotor driven by a motor. Nitrogen gas for pump purge is introduced into the pump unit 3. Nitrogen gas for pump purge is used according to a process performed in a vacuum apparatus, for example, when the pump is stopped to protect the inside of the pump so that the inside of the pump is not affected by etching in the etching process.

  In an environment using a vacuum device such as a factory, nitrogen gas usually has a pressure of 0.4 MPa to 1.0 MPa, and is purged by the pressure reducing valve 6 because it is used at about 20 kPa when purging with the pump unit 3. The gas purge port 9 of the pump unit 3 is connected via the flow meter 7a with adjustment valve and the open / close valve 8a.

  The pump unit 3 is provided with a power supply unit 4 integrally or adjacent thereto. The power supply unit 4 supplies power to the motor provided in the pump unit 3. The above-described nitrogen gas for pump purge is introduced into the power supply unit 4 via the flow meter 7b with adjustment valve and the opening / closing valve 8b. The gas pressure of the nitrogen gas introduced at this time is set to 0.1 MPa + α, and is introduced into the power supply unit 4 at a gas pressure higher than atmospheric pressure (0.1 MPa). Α represents a setting for adjusting the gas pressure in the power supply unit 4 so as to be always higher than the atmospheric pressure.

  FIG. 2 is a schematic diagram for explaining the flow of gas in the power supply unit. The power supply unit 4 includes an AC-DC converter unit 4b for converting alternating current into direct current, and an inverter unit 4c that performs drive control of the motor by performing voltage control, frequency control, and the like on the direct current converted by the AC-DC converter unit 4b. And a control unit 4a for controlling them. Although not shown in FIG. 2, AC power is supplied to the AC-DC converter unit 4b from the outside, and power is supplied to the motor in the pump unit 3 from the inverter unit 4c. A radiator 4d is provided adjacent to the AC-DC converter unit 4b and the inverter unit 4c or via a member having good heat conduction.

  A pressurized gas is introduced into the power supply unit 4 from the outside. The introduced pressurized gas forms a flow path in the power supply unit 3 and is then exhausted to the outside. The radiator 4d is disposed on the flow path of the pressurized gas, and performs heat exchange with the pressurized gas while the pressurized gas flows. Thereby, the AC-DC converter unit 4b and the inverter unit 4c are deprived of heat and cooled.

  The pressurized gas is discharged from an outlet provided in the power supply unit 4. Although the position of the discharge port can be arbitrarily set, it can be configured to be provided in the portion of the drip-proof seal portion 4e provided between the power supply unit 4 and the pump unit 3.

  The drip-proof seal 4e is a seal that prevents water from entering the power supply unit 4 from the pump unit 3 through which cooling water or the like flows. When an exhaust opening 4f such as a fine opening or a fine slit is provided on the side wall of the power supply unit 4 facing the drip-proof seal 4e, the pressurized gas introduced into the power supply unit 4 has an atmospheric pressure. Is exhausted from the exhaust opening 4f toward the drip-proof seal 4e. Accordingly, a pressure difference is set between the exhaust unit 4f and the drip-proof seal 4e of the power supply unit 4 so that the exhaust port 4f has a high pressure. Intrusion prevention becomes more effective.

  The first embodiment shown in FIG. 1 is configured to air-cool the power supply unit using the nitrogen gas for pump purge of the pump unit. The pressurized gas for air-cooling the power supply unit is nitrogen for pump purge. Not only gas but the compressed air used for the apparatus utility of the vacuum apparatus 100 can be utilized. FIG. 3 is a schematic diagram for explaining a second embodiment using compressed air for apparatus utility.

  3, the vacuum apparatus 1 forms a vacuum state by evacuating the inside of the vacuum chamber 100 with the turbo molecular pump 2 as in the first embodiment shown in FIG. 1, and the turbo molecular pump 2 is a pump unit. 3 and evacuating together with the auxiliary pump 5. Similarly to the first embodiment, the pump unit 3 receives nitrogen gas that has passed through the pressure reducing valve 6, the flow meter 7 a with adjustment valve, the opening / closing valve 8 a (not shown in FIG. 3) via the gas purge port 9. Connected.

  Further, compressed air for apparatus utility is introduced into the vacuum chamber 100 of the vacuum apparatus 1. The pressure of compressed air can be 0.4 MPa-1.0 MPa, for example.

  In the second embodiment, the above-described compressed air for the apparatus utility is introduced to the power supply unit 4 provided integrally or adjacent to the pump unit 3 in place of the nitrogen gas of the first embodiment. The

  Compressed air obtained by dividing the compressed air introduced into the apparatus chamber 100 is introduced into the power supply unit 4 through the flow meter 7b with an adjustment valve and the opening / closing valve 8b. The gas pressure of the compressed air introduced at this time is set to 0.1 MPa + α similarly to the nitrogen gas of the first form, and is introduced into the power supply unit 4 at a gas pressure higher than the atmospheric pressure (0.1 MPa). . Α represents a setting for adjusting the gas pressure in the power supply unit 4 so as to be always higher than the atmospheric pressure.

  The configuration inside the power supply unit 4 can be the same as that shown in FIG. 2, and by using compressed air as the pressurized gas, the heat generated in the AC-DC converter unit 4b and the inverter unit 4c can be cooled by air cooling. .

  In the configuration shown in FIG. 1, the nitrogen gas used for pump purge or cooling is exhausted to the atmosphere as it is. However, the danger and environmental impact caused by releasing the nitrogen gas into the atmosphere are considered. And it can also be set as the structure which collect | recovers the nitrogen gas exhausted from the pump unit 3 or the power supply unit 4. FIG.

  FIG. 4 is a third embodiment of the present invention and shows a configuration example for recovering nitrogen gas. In the third mode shown in FIG. 4, the nitrogen gas exhausted from the pump unit 3 is recovered to the factory exhaust facility by the auxiliary pump 5 in the first mode. Further, the nitrogen gas exhausted from the power supply unit 4 is collected in the factory exhaust facility through the exhaust pipe 10 and the check valve 11.

  With this configuration, the nitrogen gas exhausted from the pump unit 3 and the power supply unit 4 can be recovered in the factory exhaust facility without flowing out to the atmosphere side.

  FIG. 5 is a fourth embodiment of the present invention and shows a configuration example in which a pump unit and a power supply unit are separately arranged. The configuration example shown in FIG. 5 shows an example in which the pump unit and the power supply unit provided integrally or adjacent to each other in the configuration shown in FIG. 1 are separated.

  The pump unit 3 has a pressure higher than the atmospheric pressure supplied from a nitrogen gas source of 0.4 MPa to 1.0 MPa through the pressure reducing valve 6, the flowmeter with adjustment valve 7a, and the open / close valve 8a (for example, about 20 kPa). ) Is introduced through the gas purge port 9 and used as a pump purge.

  Further, nitrogen gas is introduced into the power supply unit 4 arranged separately from the pump unit 3 through the flow meter 7b with adjustment valve and the opening / closing valve 8b, and is used for cooling the power supply unit 4.

  A connection cable 12 is provided between the power supply unit 4 and the pump unit 3, power control is performed in the power supply unit 4, and the motor of the pump unit 3 is driven and controlled via the connection cable 12.

  This separation configuration is more effective when the power supply unit is used in an environment where higher drip-proofing is required because the power supply unit can take a sufficient distance from the pump unit.

  5 shows a configuration in which the power supply unit is cooled using nitrogen gas, but a configuration in which compressed air is used as shown in FIG. 3 may be used.

  According to the embodiment of the present invention, since cooling by air cooling can be performed instead of cooling by conventional water cooling, measures for a heat insulating structure and a seal structure for preventing condensation are unnecessary, and the cost of the turbo molecular pump and the vacuum device is reduced. Can be reduced, and a sufficient cooling effect can be obtained.

  Furthermore, the inside of a voltage unit can be made into a pressurized state by using pressurized gas, and a drip-proof effect can be improved.

  In addition to the drip-proof effect, a moisture-proof effect can be obtained by using a dry gas having a low humidity as the pressurized gas.

  In addition, by cooling the pressurized gas itself, the cooling effect of the power supply unit can be further enhanced.

It is a figure for demonstrating the 1st aspect using the nitrogen gas for pump purge of this invention. It is the schematic for demonstrating the flow of the gas in the power supply unit of this invention. It is a figure for demonstrating the 2nd form using the compressed air for apparatus utility of this invention. It is a figure for demonstrating the 3rd form which collect | recovers the nitrogen gas of this invention. It is a figure for demonstrating the 4th form which arranges the pump unit and power supply unit of this invention separately. It is the schematic for demonstrating the structural example of the conventional vacuum apparatus. It is the schematic for demonstrating the structural example of the power supply unit of the conventional turbomolecular pump.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Vacuum device, 2 ... Turbo molecular pump, 3 ... Pump unit, 4 ... Power supply unit, 4a ... Control part, 4b ... AC-DC converter part, 4c inverter part, 4d ... Radiator, 4e ... Drip-proof seal part, 4f DESCRIPTION OF SYMBOLS ... Opening part, 5 ... Auxiliary pump, 6 ... Pressure reducing valve, 7a, 7b ... Flow meter with adjustment valve, 8a, 8b ... Open / close valve, 9 ... Gas purge port, 10 ... Exhaust piping, 11 ... Check valve, 12 ... Connection cable, 20 ... power supply unit, 20a ... control unit, 20b ... AC-DC converter unit, 20c ... inverter unit, 20d ... radiator, 20e ... water cooling unit, 30 ... pump unit, 100 ... vacuum chamber.

Claims (5)

In the turbo molecular pump that cools the pump unit with water cooling,
A mechanism for introducing nitrogen gas for pump purge into the power supply unit that supplies power to the pump unit,
A turbo-molecular pump that forms a flow path of nitrogen gas from the inside of the power supply unit to the outside by a differential pressure between the nitrogen gas and atmospheric pressure, and discharges heat from the power supply unit using the nitrogen gas as a medium.   The turbo molecular pump according to claim 1, further comprising a drip-proof seal portion between the power supply unit and the pump unit, and exhausting nitrogen gas to the outside through the drip-proof seal portion. In a vacuum device that is evacuated by a turbo molecular pump that cools the pump unit with water cooling,
A mechanism for introducing nitrogen gas for pump purge into the power supply unit that supplies power to the pump unit,
A vacuum apparatus that forms a flow path of nitrogen gas from the inside of the power supply unit to the outside by a differential pressure between the nitrogen gas and atmospheric pressure, and discharges heat from the power supply unit using the nitrogen gas as a medium. In a vacuum device that is evacuated by a turbo molecular pump that cools the pump unit with water cooling,
A power supply unit that supplies power to the pump unit includes a mechanism for introducing compressed air for a vacuum device,
A vacuum apparatus that forms a flow path of compressed air from the inside of the power supply unit to the outside by a differential pressure between the compressed air and atmospheric pressure, and discharges heat in the power supply unit using the compressed air as a medium.   The vacuum apparatus according to claim 3, further comprising a drip-proof seal portion between the power supply unit and the pump unit, and exhausting pressurized gas introduced through the drip-proof seal portion to the outside.

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