JP2008038764A - Turbo-molecular pump and power source device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a turbo-molecular pump capable of checking the high temperature, by adding the cooling function. <P>SOLUTION: CP is a cooling pipe, and one end side is connected to a compressed air source (unillustrated), and the other end side is wound on an outer peripheral surface of a casing 5 of the turbo-molecular pump TP. A pressure reducing valve DV is interposed in the cooling pipe CP in a front stage of performing winding to this casing 5. Compressed air A is expanded in a thermal insulation state when passing through this pressure reducing valve DV by interposition of this pressure reducing valve DV, and the compressed air A is further lowered in the temperature after passing through the pressure reducing valve DV. Arrangement of the cooling pipe CP to the turbo-molecular pump TP is effectively and preferably performed by a fixing method such as welding, but may be detachably arranged. An illustrated example indicates an example of winding the cooling pipe CP at a specific interval, but can be wound and arranged without an interval. This case has the cooling effect when arranging to a heating position. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a turbo molecular pump that houses a turbo mechanism in a casing and rotates the same at a high speed to exhaust the room to a high vacuum.

  In this type of turbo molecular pump, the rotating body including the turbo mechanism is heated to a high temperature because the turbo mechanism is rotated at a high speed. When the temperature of the rotating body is increased, the rotating body itself is distorted, or the rotating body holding mechanism is also distorted, leading to a decrease in pump function. Therefore, this type of pump is required to take measures against the temperature of the inner rotating body. Therefore, the device which attaches a cooling water pipe is performed (refer patent document 1).

  First, a description will be given according to FIG. 7 showing an example of a conventional turbo molecular pump TP. The turbo mechanism TK, which is the main component of the turbo molecular pump TP, will be described below. A rotating body 4 is crowned on the upper portion of the rotating shaft 3, and the rotating body 4 has a plurality of stages (specifically, on the outer periphery). Is extended from the rotor blades B1 to B8 (in the drawing, only the uppermost rotor blade B1 and the lowermost rotor blade B8 are provided with reference numerals, and the other reference numerals are omitted). The rotor blades B1 to B8 are arranged with a constant interval in the axial direction. The rotary shaft 3 and the rotary blades B1 to B8 are integral. On the other hand, from the inner peripheral side of the casing 5 in which the intake port 6 is formed on the upper side, fixed blades T1 to T7 (in the drawing, only the uppermost fixed blade T1 and the lowermost fixed blade T7 are denoted by the reference numerals and other However, the turbo mechanism TK is configured by alternately providing the rotor blades B1 to B8. In FIG. 7, S is a spacer for holding the fixed blades T1 to T7 at a constant interval. 7 is an exhaust port.

  The rotary shaft 3 is rotatably held by an axial magnetic bearing 8A installed on the lower casing 5B and a radial magnetic bearing 8R, and is coupled to the motor 2. On the other hand, a rotor 2M constituting one side of the motor 2 is fitted on the rotary shaft 3 and attached integrally. The rotor 2M forms a motor 2 in cooperation with the motor stator coil 1 installed on the lower casing 5B. Electric energy is supplied to the motor 2 from the power supply device ES, and the rotary shaft 3 is rotated at high speed.

  Further, a cylindrical portion 4N is integrally formed at a part of the rotating body 4, that is, specifically below, and the outer periphery of the cylindrical portion 4N is joined to the inner periphery of the casing 5 that also serves as a machine base. It corresponds to the inner peripheral surface of the ring 9 close to it. A thread groove N is formed on the inner peripheral surface of the stator ring 9. The thread groove N is formed so that the groove depth becomes shallower as it goes downward. The combination of the stator ring 9 and the cylindrical portion 4N constitutes a thread groove pump NP. This thread groove pump NP functions as a drag pump and draws and exhausts molecules in the viscous flow region.

Such a turbo molecular pump TP is an organic combination of the turbo pump function by the turbo mechanism TK and the thread groove pump function by the thread groove pump NP, and is usually called a hybrid turbo molecular pump. As the turbo molecular pump TP, such a hybrid type has good exhaust characteristics and is often used. Thus, the rotating body 4 provided with the exhaust mechanism is integrated with the rotating shaft 3, and is rotated by the motor 2 while being supported in a non-contact manner under the control of the axial magnetic bearing 8A and the radial magnetic bearing 8R. Is done. Electric power energy to the magnetic bearings 8A and 8R is supplied from the power supply device ES via the cable CL. In FIG. 7, 5B denotes a lower casing of the turbo molecular pump TP, and 5F denotes a flange of the casing 5.
JP 07-005051 A

  This type of turbo molecular pump TP generates a large amount of heat because the turbo mechanism TK is rotated at a high speed. When the turbo molecular pump TP is heated to a high temperature due to heat generation, distortion occurs in the configuration of each part, and damage may occur due to repeated expansion and contraction, which may lead to a major accident. For this reason, the turbo molecular pump TP employs forced air cooling in which outside air is introduced in the normal power supply device ES or a cooling method in which cooling water is guided by piping. Forced air cooling that blows outside air or a method of guiding cooling water by piping is adopted. Normally, the power supply device ES employs forced air cooling that introduces outside air or cooling by introducing cooling water through a pipe.

However, in the case of a turbo molecular pump that consumes a large amount of power, the forced air cooling method using outside air is usually insufficiently cooled, and a water cooling method is usually employed. In this water-cooling system, when water leaks, the exhaust function deteriorates, or an electrical short circuit due to water occurs, so-called short-circuiting. Waterproof treatment and water leakage treatment are also required.
Furthermore, when cooling the power supply, the water-cooling method tends to cause a short circuit in the electrical system, and basically it is not applicable and becomes the air-cooling type. However, the air-cooling type has a weak cooling function and cannot prevent the high-temperature power supply unit from being raised. It is in.

  In order to solve the above-described problems, the turbo molecular pump provided by the present invention is configured such that a cooling pipe is provided at a heat generating portion and compressed air is circulated through the cooling pipe. In addition, the compressed air piping is configured to interpose a means for adiabatically expanding the compressed air at the heat generating portion, specifically, a pressure reducing valve. Therefore, the temperature of the compressed air is lowered by adiabatic expansion, and cooling is performed more effectively.

Furthermore, a turbo molecular pump provided by the present invention secondly has a compressed air pipe disposed in a casing of the turbo molecular pump. According to this configuration, the cooling pipe comes into contact with the air in the turbo molecular pump, and the air in the casing is cooled.
Furthermore, a third device provided by the present invention is such that a cooling pipe is provided in a power supply device for supplying and adjusting electric energy to the turbo molecular pump, and compressed air is circulated through the cooling pipe. Further, this cooling pipe is provided with means for adiabatic expansion, specifically, a pressure reducing valve. Accordingly, the temperature of the compressed air is further lowered by adiabatic expansion.

  Furthermore, a fourth aspect of the present invention provides a power supply apparatus for a turbo molecular pump, in which a turbo molecular pump and a power supply apparatus are integrated, and a cooling pipe for circulating compressed air is disposed in each of the turbo molecular pump and a cooling pipe in a heat generating portion. Further, a means for adiabatic expansion, that is, a pressure reducing valve is interposed. Therefore, the turbo molecular pump and the power supply device can be cooled at the same time.

According to the present invention, compressed air or gas is used instead of water or liquid, and the handling is good and the safety is high. Even if leakage from the cooling pipe occurs due to this property, it is safe.
Further, according to the present invention, the compressed air used for cooling is directly discharged to the outside, but can be cooled by being injected into the turbo molecular pump or by being injected into the heat generating portion inside the power supply device.

The basic features of the turbo molecular pump and the power supply device provided by the present invention are that a cooling pipe is provided for them, and the compressed air is circulated through the cooling pipe, and the compressed air is insulated in the cooling pipe. The means for inflating is interposed.
More specifically, the cooling pipe is installed in the turbo molecular pump and the power supply device, and the cooling is more effective. The best mode for carrying out the present invention is a configuration provided with all of these features.

The first embodiment provided by the present invention is an embodiment in which a cooling pipe for circulating compressed air is arranged in a turbo molecular pump, and its configuration is as shown in FIG.
In FIG. 1, parts denoted by the same reference numerals as those shown in FIG. 7 are the same as the parts shown in FIG. 7, and detailed description thereof is omitted.
FIG. 1 shows an external appearance of the embodiment, and a part thereof is shown in cross section to show the internal configuration of the turbo molecular pump TP. In the figure, CP is a cooling pipe, one end is connected to a compressed air source (not shown), and the other end is wound around the outer peripheral surface of the casing 5 of the turbo molecular pump TP. A pressure reducing valve DV is interposed in the cooling pipe CP before the winding of the casing 5 is performed.

  The compressed air A is expanded in an adiabatic state when the pressure reducing valve DV passes through the pressure reducing valve DV, and the compressed air A after passing the pressure reducing valve DV is further cooled. The cooling pipe CP is arranged on the turbo molecular pump TP by an effective fixing method by welding or the like, but may be detachably attached. In the illustrated example, the cooling pipe CP is wound with a certain interval. However, the cooling tube CP can be wound with a certain interval. In this case, it has a cooling effect when attached to the heat generating position.

  A second embodiment provided by the present invention is shown in FIG. FIG. 2 shows the turbo molecular pump TP in a longitudinal section. As is apparent from FIG. 2, the feature of the second embodiment is that the cooling pipe CP is arranged inside the turbo molecular pump TP. It is in. In this case, the cooling pipe CP disposed in the turbo molecular pump TP may be disposed almost entirely in the turbo molecular pump TP, or a part thereof, for example, about half of the entire length may be disposed. . You may concentrate on the site | part with a big heat_generation | fever, and you may arrange | position in the form wound around the inner peripheral surface of the casing 5. FIG. Furthermore, a spiral groove having a semicircular cross section is formed on the outer peripheral surface of the casing 5, and a cooling pipe CP is disposed in the groove, so that the cooling function can be made more effective. In this case, it is easy to implement because it is not disposed inward.

  The example shown in FIG. 2 is an example in which a part of the cooling pipe CP is installed in the turbo molecular pump TP, and the installed cooling pipe CP is fixed near the inner peripheral surface of the casing 5 and outside the rotor blade B2. is set up. Therefore, it is effective for lowering the temperature of the turbo mechanism that is a part of the heat generating portion. In addition, in the illustrated example, the pressure reducing valve DV is interposed in the middle, and the cooling effect becomes more reliable.

  The third embodiment provided by the present invention is an embodiment in which the cooling pipe CP is disposed in the power supply device ES for the turbo molecular pump TP, and the configuration thereof is as shown in FIG. FIG. 3 schematically shows a configuration in which electric energy is supplied from the power supply ES to the turbo molecular pump TP via the cable CL, and a cooling pipe CP is disposed in the power supply ES. The arrangement is U-shaped in the illustrated example, but may be wound, and the method is not limited to the illustrated example. The DV is a pressure reducing valve that is interposed in the cooling pipe CP in the previous stage of the power supply device ES, and is devised to make the cooling function effective. In FIG. 3, parts indicated by the same reference numerals as those shown in FIG. 7 are the same as the parts shown in FIG. 7, and detailed description thereof is omitted.

  The fourth embodiment provided by the present invention is as shown in FIG. 4, but in the third embodiment, the pressure reducing valve DV is disposed in the heat sink (heat generating portion) HS portion of the power supply device ES. Is. In particular, the cooling effect is further enhanced by interposing in the heat generating portion. In FIG. 4, parts denoted by the same reference numerals as those shown in FIG. 7 are the same as the parts shown in FIG. 7, and detailed description thereof is omitted.

  In the fifth embodiment provided by the present invention, as shown in FIG. 5, the power supply device ES is integrated with the turbo molecular pump TP, and the cooling pipe CP is simultaneously arranged in both the turbo molecular pump TP and the power supply device ES. It is set. In order to simplify the configuration, only one cooling pipe CP is used, and the length thereof is increased, and the cooling pipe CP is connected to the turbo molecular pump TP from the power supply device ES. In the power supply device ES, the cooling pipe CP is meandered. However, a method of inserting the power supply device ES may be used. Furthermore, the turbo molecular pump TP can be disposed not only on the outer peripheral surface but also inserted into the turbo molecular pump TP. Further, it is preferable that the cooling pipe CP is longer and a pressure reducing valve DV is interposed in the middle. In FIG. 5, parts denoted by the same reference numerals as those shown in FIG. 7 are the same as the parts shown in FIG.

  In the sixth embodiment provided by the present invention, as shown in FIG. 6, the power supply device ES is integrated with the turbo molecular pump TP, and the cooling pipe CP is simultaneously arranged on both the turbo molecular pump TP and the power supply device ES. It is set. The compressed air A from the cooling pipe CP is jetted to the heat sink (heat generating part) HS portion of the power supply device ES. In FIG. 6, parts indicated by the same reference numerals as those shown in FIG. 7 are the same as the parts shown in FIG.

  Although six examples from the first to the sixth are illustrated as examples of the present invention, the present invention is not limited to these six examples. The first feature of the present invention is that the cooling pipe CP is disposed in the turbo molecular pump TP, and the compressed air A is circulated inside thereof. The second feature is that adiabatic expansion means such as a pressure reducing valve DV is provided in the cooling pipe CP. The third feature is that the compressed air is guided to the power supply device ES through the cooling pipe CP. Therefore, the present invention can be modified in addition to the above six embodiments by various combinations of these three characteristic configurations. For example, the cooling pipe CP can be inserted into the power supply device ES. Further, a ring-shaped pipe line may be formed in the lower casing 5B of the turbo molecular pump TP, and the exhaust gas may be guided into the pipe line as compressed air A. The cooling pipe CP may be disposed below the flange 5F of the casing 5. The present invention includes all these modifications.

It is a figure which shows the 1st Example of this invention. It is a figure which shows the 2nd Example of this invention. It is a figure which shows the 3rd Example of this invention. It is a figure which shows the 4th Example of this invention. It is a figure which shows the 5th Example of this invention. It is a figure which shows the 6th Example of this invention. It is a figure which shows the structure of the conventional turbo-molecular pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coil 2 Motor 2M Rotor 3 Rotating shaft 4 Rotating body 4N Cylindrical part 5 Casing 5B Lower casing 5F Flange 6 Intake port 7 Exhaust port 8A, 8R Magnetic bearing 9 Stator ring A Compressed air B1-B8 Rotary blade CP Cooling pipe DV Decompression Valve ES Power supply HS Heat sink N Thread groove NP Thread groove pump S Spacers T1 to T7 Fixed blade TK Turbo mechanism TP Turbo molecular pump

Claims (11)

  In the turbo molecular pump that has a turbo mechanism in the casing and performs a vacuum pump function by the operation of this turbo mechanism, a cooling pipe is arranged at the heat generating part and compressed air is circulated through this cooling pipe. Turbo molecular pump characterized by   The turbo molecular pump according to claim 1, wherein means for adiabatic expansion of compressed air is interposed in the cooling pipe.   The turbo molecular pump according to claim 2, wherein the means for adiabatic expansion is a pressure reducing valve.   A turbo molecular pump characterized in that at least a part of the cooling pipe is disposed in a casing of the turbo molecular pump.   The turbo molecular pump according to claim 4, wherein adiabatic expansion means is interposed in a cooling pipe disposed in a casing of the turbo molecular pump.   A power supply apparatus for a turbo molecular pump, characterized in that a cooling pipe is provided in a power supply apparatus for supplying, adjusting or controlling electric energy to the turbo molecular pump and compressed air is circulated through the cooling pipe. .   7. The power supply device for a turbo molecular pump according to claim 6, wherein adiabatic expansion means is interposed in the cooling pipe at the site of the power supply device.   A turbo molecular pump and a power supply device for the turbo molecular pump are integrally configured, and a cooling pipe is disposed between the turbo molecular pump and the power supply apparatus, and compressed air is circulated through the cooling pipe. Turbo molecular pump characterized by   The turbo molecular pump according to claim 8, wherein means for adiabatic expansion of compressed air is interposed in the cooling pipe.   The turbo molecular pump according to claim 9, wherein the adiabatic expansion means is interposed in a cooling pipe at a site of the turbo molecular pump.   10. The turbo molecular pump according to claim 9, wherein the adiabatic expansion means is interposed in a cooling pipe at a site of the power supply device.

Images