JP2003278680A - Multi-stage vacuum pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-stage vacuum pump device capable of preventing the liquid stagnating in the pumping parts of vacuum pumps on the atmospheric pressure side from being fed backward into the pumping parts of the vacuum pumps on the vacuum side when the vacuum pumps are stopped. <P>SOLUTION: The multi-stage vacuum pump device consists in a row of vacuum pumps 100, 200, 300, 400 equipped with pumping parts 110, 210, 310, 410 to send the working fluid by pressure, wherein the arrangement includes gas supplying devices 130, 230, 330, 430, 730 to supply gas to the vacuum pumps 100, 200, 300, 400 or their suction sides when they 100, 200, 300, 400 are stopped. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-stage vacuum pump device in which a plurality of vacuum pumps having a pump portion for pumping a working fluid are arranged in a row, and particularly to a pump portion when the operation of the vacuum pump is stopped. The present invention relates to a device including a gas supply device that supplies gas.

[0002]

2. Description of the Related Art As a prior art vacuum pump related to the present invention, there is a multi-stage vacuum pump device shown in FIG. The multi-stage vacuum pump device of FIG. 3 has vacuum pumps 10, 20, 30, 4
It is composed of four stages of vacuum pumps in which 0s are arranged in a row.

The working fluid pumped by the pump portion of the vacuum pump 10 flows into the vacuum pump 20 through the flange. The working fluid that has flowed into the vacuum pump 20 is further compressed by the pump unit and sequentially sent to the vacuum pumps 30 and 40 that are arranged in series. In this way, the vacuum pump 10,
By arranging 20, 30, and 40 in a row, a high degree of vacuum can be obtained. The pressure-fed working fluid is finally exhausted to the atmosphere through the working fluid exhaust port.

[0004]

However, the multi-stage vacuum pump device is designed such that each vacuum pump 10,
The intake pressures of 20, 30, and 40 are different. For example, in a four-stage multi-stage vacuum pump device, the suction pressure of the vacuum pump 10 is 1 Pa and the suction pressure of the vacuum pump 20 is 100 P.
a, the suction pressure of the vacuum pump 30 is 1000 Pa, and the suction pressure of the vacuum pump 40 is 20000 Pa. If the working fluid to be sucked contains water, the vacuum pump 10,
Water vapor (gaseous state) is present inside the pump 20 and 300 K of water inside the pump parts of the vacuum pumps 30 and 40.
Since the vapor pressure at is 3700 Pa, it liquefies and wets the inside of the pump unit.

In this state, the vacuum pumps 10, 20, 30,
When the operation of 40 is stopped, the air flowing in from the working fluid exhaust port moves from the vacuum pump 40 on the atmospheric pressure side to the vacuum pump 1
Although it flows in toward 0 (backflow), at this time, the water adhering to the inside of the pump portions of the vacuum pumps C and D is entrained in the backflowed air and carried to the vacuum pumps A and B. When the liquefied water is carried into the pump parts of the vacuum pumps A and B, the water penetrates into the bearings and the like inside the pump parts, which causes grease to leak and rust. Further, when water enters the gear chamber space, the lubricating oil is turbid with water, and the oil easily foams. In this state, vacuum pumps 10, 20, 30,
When driving 40, when the vacuum is drawn from atmospheric pressure,
The foamed oil penetrates into the bearing and elutes the grease in the bearing, resulting in bearing failure.

According to the present invention, when the vacuum pump is stopped, the liquid accumulated inside the pump portion of the vacuum pump on the atmospheric pressure side is prevented from being carried back by flowing back into the pump portion of the vacuum pump on the vacuum side. It is an issue to be solved.

[0007]

According to claim 1 of the present invention,
`` In a multi-stage vacuum pump device comprising a plurality of vacuum pumps provided in a row with a pump portion for pumping a working fluid, when the operation of the vacuum pump is stopped, a gas is supplied to the vacuum pump or a suction side of the vacuum pump. And a gas supply device for supplying the gas. "

According to the first aspect of the present invention, by providing a gas supply device for supplying gas to the pump portion of the vacuum pump or the suction side of the vacuum pump, when the operation of the vacuum pump is stopped, gas or the like is supplied from the gas supply device. Is supplied, the pressure inside the pump section can be increased to the pressure at the working fluid exhaust port. When the pressure inside the pump becomes the same as the pressure at the working fluid exhaust port, there is no inflow (backflow) of air, etc. from the working fluid exhaust port to the vacuum pump, so that the pump section of the vacuum pump at the working fluid exhaust port side It is possible to prevent the liquid accumulated inside from being carried to the pump section of the vacuum side vacuum pump.

When the vacuum pump is operated under atmospheric pressure, the pressure of the working fluid exhaust port becomes atmospheric pressure. When the on-off valve provided in the pipe that supplies gas etc. to the pump section of the vacuum pump is opened when the vacuum pump is stopped, air flows into the pump section through the on-off valve and the inside of the pump section becomes the same as atmospheric pressure. Boost to pressure. When the pressure inside the pump reaches the same atmospheric pressure as the working fluid exhaust port, there is no inflow of air from the vacuum pump on the working fluid exhaust port side, so the liquid accumulated inside the pump section of the vacuum pump on the working fluid exhaust port side It can be prevented from being carried to the pump section of the vacuum pump on the vacuum side. Note that the supply of gas or the like by the open / close valve is not limited to atmospheric pressure. For example, when the entire multi-stage vacuum pump device is covered, the pressure of the working fluid exhaust port may be different from the atmospheric pressure. At that time, by supplying the gas of the same pressure as the working fluid exhaust port from the gas supply device, the liquid accumulated inside the pump section of the vacuum pump at the working fluid exhaust port side is also pumped by the pump section of the vacuum side vacuum pump. Can be prevented from being carried to.

[0010] According to a second aspect of the present invention, "the gas supplied from the gas supply device to the vacuum pump is for pumping the working fluid through a bearing provided in the vacuum pump. It is supplied to the pump section ".

According to the second aspect of the present invention, it is possible to prevent the water accumulated in the pump chamber of the pump section from entering the bearing when the operation of the vacuum pump is stopped, so that the grease of the bearing may flow out,
Failure due to bearing rust can be prevented. Further, it is possible to prevent the foaming of the oil due to the mixing of water in the gear chamber space. Therefore, when the operation of the vacuum pump is started, the foamed oil becomes a foam and enters the bearing, eluting grease in the bearing and causing a problem of poor lubrication.

Further, a third aspect of the present invention is characterized in that "the gas supply device is provided with an on-off valve which automatically opens and closes in conjunction with the operation of the vacuum pump".

According to the third aspect of the invention, the solenoid valve that automatically opens and closes in conjunction with the operation of the vacuum pump is used as the on-off valve of the gas supply device, so that the pump is automatically pumped according to the operating state of the vacuum pump. It becomes possible to control the supply of gas to the
It is possible to prevent the liquid accumulated inside the pump section of the vacuum pump on the working fluid exhaust port side from being carried to the pump section of the vacuum pump on the vacuum side and entering the bearing of the vacuum pump.

According to claim 4 of the present invention, "at least one of the vacuum pumps is a drain tank for storing the liquid accumulated in the pump, and a drain drainage device for draining the liquid accumulated in the drain tank. Is provided ".

According to the fourth aspect of the invention, by providing the drain tank for storing the liquid accumulated in the vacuum pump, it is possible to prevent the liquid from accumulating inside the pump portion of the vacuum pump. Therefore, it is possible to suppress the occurrence of water lock phenomenon and rust due to the accumulation of liquid inside the pump portion. The liquid accumulated in the drain tank can be drained from the drain drainage device when the vacuum pump is stopped.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A multistage vacuum pump device of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a four-stage multi-stage vacuum pump device according to the present invention, which includes vacuum pumps 100, 200 and 30.
0 and 400 are lined up. Vacuum pump 100, 200, 3
00 and 400 are gas supply devices 13 that supply air (gas) when the operation of the multi-stage vacuum pump device is stopped.
0, 230, 330, 430 are provided. Further, the working fluid intake port 700 on the suction side of the vacuum pump 100 includes a gas supply device 730 that supplies air (gas) when the operation of the multi-stage vacuum pump device is stopped.

The working fluid of the vacuum object 710 is passed through the working fluid intake port 700, and then the pump portion 1 of the vacuum pump 100.
It is inhaled to 10. The working fluid pumped by the pump unit 110 is pumped by the pump unit 210 of the vacuum pump 200, and the pump unit 310 and the vacuum pump 40 of the vacuum pump 300 are sequentially arranged.
It is pumped by the pump unit 410 of 0. The working fluid pumped by the pump unit 410 is water (liquid) mixed in the working fluid.
Through the drain rank 500 for accumulating the electric energy, and flows into the silencer 600 for attenuating the sound generated by the vacuum pumps 100, 200, 300, 400. The working fluid that has flowed into the silencer 600 is the working fluid exhaust port 80.
It is released into the atmosphere from zero.

Vacuum pumps 100, 200, 300, 40
Gas supply devices 130, 230, 330, 4 arranged at 0.
Reference numeral 30 denotes pipes 131, 231, 331, 431 communicating with the pump units 110, 210, 310, 410 of the vacuum pumps 100, 200, 300, 400, and the vacuum pump 10.
Solenoid valves 132, 232, 332, 432 that automatically open and close in conjunction with the operation of 0, 200, 300, 400
(Open / close valve). Vacuum pump 100, 20
When the operation of 0, 300, 400 is stopped, the solenoid valves 132, 232, 33 receive a signal from a control device (not shown).
2, 432 are opened and piping 131, 231, 331, 4
Air is introduced from 31 to the pump units 110, 210, 310, 410. When air is introduced into the pump units 110, 210, 310, 410 from the pipes 131, 231, 331, 431, the pressure of the pump units 110, 210, 310, 410 becomes the same atmospheric pressure as the working fluid exhaust port 800. When operating the vacuum pumps 100, 200, 300, 400, the solenoid valves 132, 232, 332, 432 are closed, and air from the pipes 131, 231, 331, 431 to the pump units 110, 210, 310, 410 is closed. Prevent the inflow of.

The gas supply device 730 disposed on the suction side of the vacuum pump 100 includes a pipe 731 communicating with the working fluid intake port 700 and an electromagnetic valve 732 (opening / closing operation) which is automatically opened / closed in association with the operation of the vacuum pump. Valve). When the operation of the vacuum pumps 100, 200, 300, 400 is stopped, the electromagnetic valve 732 is opened by receiving a signal from a control device (not shown), and the working fluid intake port 70 is supplied from the pipe 731.
Introduce air to 0. Piping 731 to working fluid intake 7
When air is introduced to 00, the suction side pressure of the vacuum pump 100 becomes the same atmospheric pressure as the working fluid exhaust port 800. When operating the vacuum pumps 100, 200, 300, 400, the solenoid valve 732 is closed to prevent air from flowing into the working fluid intake port 700 from the pipe 731.

A drain tank 500 is arranged below the vacuum pump 400. A drain drainage device 530 is arranged in the drain tank 500. Drain drainage device 530
Is composed of a pipe 531 communicating with the drain tank 500 and an opening / closing valve 532. Vacuum pump 300 of this embodiment
The intake pressure is about 1000 Pa, and the intake pressure of the vacuum pump 400 is about 20000 Pa. Since the vapor pressure of water at 300K is 3700 Pa, the water contained in the working fluid is liquefied in the pump units 310 and 410. The water liquefied in the pump parts 310 and 410 drops and collects in the drain tank 500. The water in the drain tank 500 is drained to the outside from the pipe 531 via the opening / closing valve 532 when the vacuum pumps 100, 200, 300, 400 are stopped.

Vacuum pumps 100, 200, 300, 40
Gas supply device 1 for supplying air to the suction side of the vacuum pump 100 or the pump unit 110, 210, 310, 410 of 0.
By providing 30, 230, 330, 430, 730, when the operation of the multi-stage vacuum pump device is stopped,
Gas supply device 130, 230, 330, 430, 730
By supplying more air, the pump units 110, 210,
The pressure inside 310, 410 can be increased to the same atmospheric pressure as the working fluid exhaust port 800 of the multi-stage vacuum pump device. When the pressure inside the pump parts 110, 210, 310, 410 becomes substantially the same as the pressure at the working fluid exhaust port 800, the inflow (backflow) of air from the working fluid exhaust port 800 disappears, so that the working fluid exhaust port 800 side Vacuum pump 300,
Moisture accumulated inside the pump units 310 and 410 of 400 is the pump unit 11 of the vacuum pumps 100 and 200 on the vacuum side.
It can be prevented from being carried to 0, 210.

Incidentally, the gas supply devices 130, 230, 33.
The supply of gas from 0, 430, and 730 is not limited to air. For example, when the entire multi-stage vacuum pump device is covered, the pressure of the working fluid exhaust port 800 may be different from the atmospheric pressure. At that time, by supplying gas (for example, nitrogen) having the same pressure as the working fluid exhaust port 800 from the gas supply devices 130, 230, 330, 430, 730, the vacuum pump 30 on the working fluid exhaust port 800 side.
Gas supply devices 130, 230, 330 capable of preventing moisture (liquid) accumulated inside the pump units 310, 410 of 0, 400 from being carried to the pump units 110, 210 of the vacuum pumps 100, 200 on the vacuum side. 430, 730
In addition, solenoid valves 132, 23 that automatically open and close in conjunction with the operation of the vacuum pumps 100, 200, 300, 400.
By using 2, 332, 432, and 732, it is possible to automatically control the supply of gas to the pump units 110, 210, 310, and 410 according to the operating states of the vacuum pumps 100, 200, 300, and 400. Working fluid exhaust port 800
Side pump units 310, 41 of the vacuum pumps 300, 400
The water accumulated inside 0 is the vacuum side vacuum pump 100,
It can be prevented from being carried to the pump unit 110, 210 of 200.

By providing the drain tank 500 for storing the liquid accumulated in the vacuum pump, the vacuum pump 300,
It is possible to prevent water from accumulating inside the pump units 310 and 410 of 400. Therefore, it is possible to suppress the occurrence of water lock phenomenon and rust due to the accumulation of water inside the pump parts 310 and 410.

FIG. 2 is a sectional view of the vacuum pump 100 of the present invention. The vacuum pump 100 includes a pump unit 110, a motor unit 120, and a gas supply device 130. The working fluid sent to the pump unit 110 is compressed in the pump unit 110 by driving the motor unit 120, which is a power source, and sent under pressure to the vacuum pump 200.

The pump unit 110 of this embodiment is a roots type pump, and a pair of rotors 111a and 111b and a rotor 11 are used.
Oil seal 1 which is fitted into one end of 1a and 111b
12a and 112b and oil seals 112a and 112b
Bearings 113a and 113b mounted adjacent to the bearings, and a gear 114 mounted adjacent to the bearings 113a and 113b.
a, 114b and grease-lubricated bearings 115a, 11 mounted on the other ends of the rotors 111a, 111b.
5b, a housing 116 that functions to partition the inside of the pump unit 110 from the atmosphere, the housing 116 and the gear 1
Gear chamber space 117 formed between 14a and 114b,
A pump chamber 118 formed between the rotors 111a and 111b and the housing 116, and a space 119 formed on the motor portion 120 side of the bearings 115a and 115b.
Gears 114a and 114b and oil (not shown) for lubricating the oil seals 112a and 112b are enclosed in the gear chamber space 117.

The output shaft 122 protruding from the motor 121 of the motor section 120 and the joint 123 are fitted to each other, and the motor 1
The power from 21 is transmitted to the rotors 111a and 111b. The pump unit 110 and the motor unit 120 are sealed to the atmosphere side by a sealing structure, and even when the pump unit 110 and the motor unit 120 are assembled, their surfaces have a sealing function. The structure is completely sealed against the atmosphere.

The space 119 communicates with the pipe 131 of the gas supply device 130, and the solenoid valve 1 is operated while the vacuum pump 100 is in operation.
It is sealed by 32. The space 119 is the piping 13
3 communicates with the gear chamber space 117.

At the stage before the vacuum pump 100 starts to operate, the gear chamber space 117, the pump chamber 118, the space 11
9 is at atmospheric pressure. When the vacuum pump 100 is operated, the pressure in the gear chamber space 117, the pump chamber 118, and the space 119 decreases. Air in the gear chamber spaces 117 and 119 is drawn into the pump chamber 118 via the bearings 115a and 115b. On the other hand, when the vacuum pump 100 stops operating, the solenoid valve 132 opens and air flows into the space 119 through the pipe 131. The air that has flowed into the space 119 passes through the bearings 115a and 115b, and then the pump unit 110.
Are sent to the gear chamber space 117 through the pump chamber 118 inside and the pipe 133, respectively, and have the same atmospheric pressure as the working fluid exhaust port 800.

Therefore, it is possible to prevent the water accumulated in the pump chamber 118 of the pump section 110 from entering the bearings 115a and 115b when the operation of the vacuum pump 100 is stopped, and to prevent the grease from flowing out of the bearings 115a and 115b and the bearings. It is possible to prevent failures due to rust. Also, the gear chamber space 1
It is possible to prevent the foaming of the oil due to the mixing of water with the oil 17. Therefore, when the operation of the vacuum pump 100 is started, the foamed oil becomes foam and the bearings 115a, 115
It is possible to prevent the grease in the bearings 115a and 115b from eluting from entering the 5b.

In this embodiment, since the working fluid is discharged from the working fluid exhaust port 800 to the atmosphere, the pressure of the working fluid exhaust port 800 is atmospheric pressure and the gas supply devices 130, 230, 33.
Air at atmospheric pressure was supplied from 0, 430, and 730. However, when the pressure of the working fluid exhaust port 800 is equal to or higher than the atmospheric pressure, the gas supply devices 130, 230, 330, 430,
730 pipes 131, 231, 331, 431, 731
A cylinder or the like may be provided at the end of the pump so that the working fluid exhaust port 800 and the pump parts 110, 210, 310, 410 have the same pressure.

In this embodiment, the vacuum pump 100 of the multi-stage vacuum pump device has been described in detail.
The same applies to 00, 300, and 400. Further, the present invention is 4
The present invention is not limited to a multi-stage vacuum pump device with multiple stages,
Any multi-stage type vacuum pump device may be used in which two or more vacuum pumps are arranged in a row.

[0032]

According to the multi-stage vacuum pump device of the present invention, when the operation of the multi-stage vacuum pump device is stopped by providing a gas supply device for supplying air to the pump portion of the vacuum pump or the suction side of the vacuum pump. In addition, by supplying gas from the gas supply device, the pressure inside the pump part can be raised to the same pressure as the working fluid exhaust port of the multi-stage vacuum pump device, and the inflow of air etc. from the working fluid exhaust port (backflow). Can be eliminated. Therefore, it is possible to prevent the liquid accumulated inside the pump section of the vacuum pump on the working fluid exhaust port side from being carried to the pump section of the vacuum pump on the vacuum side.

Further, by using an electromagnetic valve that automatically opens and closes in conjunction with the operation of the vacuum pump in the gas supply device, it is possible to automatically control the supply of gas to the pump section according to the operating state of the vacuum pump. It will be possible.

Further, by providing a drain tank for accumulating the liquid accumulated in the vacuum pump, it is possible to prevent the liquid from accumulating inside the pump portion of the vacuum pump. Therefore, it is possible to suppress the occurrence of water lock phenomenon and rust due to the accumulation of liquid inside the pump portion.

Further, it is possible to prevent the liquid accumulated in the pump chamber of the pump section from entering the bearing when the operation of the vacuum pump is stopped, and to prevent the grease from flowing out of the bearing and the failure caused by the rust of the bearing. . Further, it is possible to prevent the foaming of the oil due to the mixing of water in the gear chamber space. Therefore, when the operation of the vacuum pump is started, the foamed oil becomes a foam and enters the bearing, eluting grease in the bearing and causing a problem of poor lubrication.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a multistage vacuum pump device of the present invention.

FIG. 2 is a sectional view of the vacuum pump of the present invention.

FIG. 3 is a conventional multi-stage vacuum pump device.

[Explanation of symbols]

100, 200, 300, 400 Vacuum pump 110, 210, 310, 410 Pump part 115a, 115b Bearing 130, 230, 330, 430, 730 Gas supply device 132, 232, 332, 432, 732 Electromagnetic valve (open / close valve) 500 Drain tank 530 Drain drain port 700 Working fluid intake port 800 Working fluid exhaust port

Continued front page    (72) Inventor Koichi Nakayama             Aichi, 2-chome, Asahi-cho, Kariya city, Aichi prefecture             Within Seiki Co., Ltd. F term (reference) 3H029 AA01 AA06 AA17 AB06 BB37                       BB41 BB47 BB54 BB57 CC12                       CC22 CC60 CC61 CC82                 3H076 AA12 AA16 AA21 AA38 AA40                       BB14 BB28 BB31 BB43 CC07                       CC51 CC94 CC99

Claims (4)

[Claims] 1. A multi-stage vacuum pump apparatus comprising a plurality of vacuum pumps arranged in a row, each pump having a pump section for pumping a working fluid, wherein when the vacuum pump is stopped, the vacuum pump or the vacuum pumps A multistage vacuum pump device comprising a gas supply device for supplying gas to the suction side. 2. The gas supplied from the gas supply device to the vacuum pump is supplied to the pump section for pumping the working fluid via a bearing provided in the vacuum pump. The multi-stage vacuum pump device according to claim 1, which is characterized in that. 3. The multi-stage according to claim 1, wherein the gas supply device includes an opening / closing valve that automatically opens and closes in conjunction with the operation of the vacuum pump. Type vacuum pump 4. At least one of the vacuum pumps comprises a drain tank for storing the liquid accumulated in the pump, and a drain drainage device for draining the liquid accumulated in the drain tank. Item 5. A multistage vacuum pump device according to any one of items 1 to 3.