EP0226039A1 - Pompe à vide - Google Patents

Pompe à vide Download PDF

Info

Publication number
EP0226039A1
EP0226039A1 EP86115640A EP86115640A EP0226039A1 EP 0226039 A1 EP0226039 A1 EP 0226039A1 EP 86115640 A EP86115640 A EP 86115640A EP 86115640 A EP86115640 A EP 86115640A EP 0226039 A1 EP0226039 A1 EP 0226039A1
Authority
EP
European Patent Office
Prior art keywords
pump
gas
stage
suction port
vacuum
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86115640A
Other languages
German (de)
English (en)
Inventor
Takashi Nagaoka
Masahiro Mase
Ichiro Gyobu
Kazuhiko Hitachi Komeiryo Ikemura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Publication of EP0226039A1 publication Critical patent/EP0226039A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D19/00—Axial-flow pumps
    • F04D19/02—Multi-stage pumps
    • F04D19/04—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps
    • F04D19/046—Combinations of two or more different types of pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
    • F04D17/08—Centrifugal pumps
    • F04D17/16—Centrifugal pumps for displacing without appreciable compression
    • F04D17/168—Pumps specially adapted to produce a vacuum
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D23/00—Other rotary non-positive-displacement pumps
    • F04D23/008—Regenerative pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D25/00—Pumping installations or systems
    • F04D25/16—Combinations of two or more pumps ; Producing two or more separate gas flows

Definitions

  • the present invention relates to a vacuum pump apparatus of the type in which the discharge side of the pump is maintained at the atmospheric pressure. More particularly, the present invention is concerned with a vacuum pump apparatus of unitary construction type which is capable of producing a high level of vacuum at its suction side when used in sucking gases having small mole­cular weights, such as hydrogen, helium, and so forth.
  • a vacuum pump apparatus of unitary construction type in which a turbo molecular pump is combined with other types of vacuum pump.
  • An example of such a vacuum pump apparatus as of unitary construction type is disclosed in United States Patent No. 3,969,039.
  • This pump has a plurality of stages: namely, a first stage constituted by an axial turbo-molecular pump, a second stage constituted by a spiral molecular drag pump, a third stage constituted by a centrifugal compressor, and a final stage constituted by a vortex diode pump. These stages are arranged in series within a common housing and between suction and discharge ports of the unitary-construction type vacuum pump.
  • the centrifugal compressor stage and the vortex diode pump stage operate in the viscous flow region of a gas.
  • the compression ratio between the centrifugal compressor stage and across the vortex diode pump stage vary depending on the molecular weight of the gas flowing through these pumps. In general, the greater the molecular weight, the greater the compres­sion reatio and, the smaller the molecular weight, the smaller the compression ratio.
  • the compression ratio across the stages con­stituted by the centrifugal compression pump and the vortex diode pumps is so small that the axial turbo-­molecular pump and the spiral molecular drag pump dis­posed upstream thereof are obliged to operate in the viscous flow region rather than in the intermediate or molecular flow region.
  • the compression ratio across the vaccum pump is too small accordingly. That is, the vacuum pump apparatus cannot establish the desired very level of vacuum when it is used for sucking a gas having a comparatively small molecular weight.
  • the prior art has not paid any attention to this point.
  • a vacuum pump apparatus having a plurality of pump stages of different types arranged in series between suction and discharge ports of a housing and a gas passage means through which a gas different from the gas sucked through the suction port is introduced into the pump stage which is spaced downstream from the suction port by more than one pump stage.
  • a vacuum pump apparatus having a plurality of pump stages of different types arranged in series between suction and discharge ports in a housing and a gas passage means through which a gas different from the gas sucked through the suction port is introduced into the pump stage which operates in viscous flow region.
  • a rotary shaft 1 extends through a hous­ing 4 having a suction port 2 and a discharge port 3.
  • the shaft 1 is rotatably supported by the housing 4 through bearings 18 and is connected at its lower end to a motor 19.
  • a centrifugal compressor stage 5 and a circumferent­ial-flow pump stage 6 are arranged in series in the housing 4 between the suction port 2 and the discharge port 3.
  • the centrifugal compressor stage 5 has open-­type impellers 7 mounted on the shaft 1 and stationary disks 8 which are fixed to the inner surface of the hous­ing 4.
  • the impellers 7 and the stationary disks 8 are arranged alternately in the axial direction.
  • each impeller 7 has one side pro­vided with a plurality of vanes 9 which are curved such that they progressively approach the axis of rotation of the impeller 7 as viewed in the direction of rotation.
  • Figs. 2 to 3 each impeller 7 has one side pro­vided with a plurality of vanes 9 which are curved such that they progressively approach the axis of rotation of the impeller 7 as viewed in the direction of rotation.
  • each stationary disk 8 is provided with a plurality of stationary vanes 10 which are formed on the surface thereof which faces the rear surface of the adjacent impeller 7, i.e., the surface of the impeller 7 having no vane.
  • the stationary vanes 10 also are curved such that they progressively approach the axis of rotation as viewed in the direction of rotation of the impeller 7.
  • the circumferential-­flow pump stage 6 has a plurality of impellers 12 mounted on the shaft 1 and a plurality of stationary disks 13 fixed to the inner surface of the housing 4.
  • the impellers 12 and the stationary disks 13 are arranged alternately in the axial direction.
  • Each impeller 12 has one side provided with a plurality of radial vanes 11 formed in its radially outer peripheral zone, while each stationary disk 13 is provided with a circumferentially extending groove 14 of a U-shaped section formed in the surface thereof facing the radial vanes 11 on an adjacent impeller 12.
  • a port 15 is formed in each stationary disk 13 at one terminal end of the U-­shaped groove 14.
  • the port 15 and the groove 14 constitute a gas passage 16.
  • a reference numeral 17 designates a member such as a pipe which provides a communication between a gas inlet 4a formed in the housing 14 and a port 13a formed in the stationary disk 13 of the first stage of the circum­ferential-flow pump stage 6.
  • the arrangement is such that a gas of a small molecular weight which is to be pumped by the vacuum pump apparatus is sucked through the suction port 2, while another kind of gas having a greater molecular weight is introduced into the inlet side of the circumferential-flow pump stage 6 from the gas inlet 4a in the housing 4 through the pipe 17.
  • the circumferential-flow com­pression pump stage 6 In operation, when the gas sucked through the suction port 2 has a large molecular weight as in the case of air or nitrogen, the circumferential-flow com­pression pump stage 6 operates in the viscous flow region so that a large compression ratio is obtained across each stage of the circumferential-flow compression pump 6. In consequence, a high level of vacuum, say less than several Torr., is established at the inlet side of the circumferential-flow compression stage. 6. This in turn causes the centrifugal compressor stage 5 to operate as a spiral molecular drag pump in the intermediate flow region or molecular flow region so as to develop a large pressure difference across this stage. Consequently, a very high level of vacuum on the order of 10 ⁇ 3 to 10 ⁇ 4 Torr. is established at the inlet port 2 of the vacuum pump appa­ratus.
  • the molecular weight and the specific heat ratio of air are 29 and 1.4, respectively, while those of helium gas are 4 and 1.67, respectively.
  • a compression pump stage can produce a compres­sion ratio of 2 when it compresses air at 20°C. If the same pump stage is used for helium gas, the compression ratio is as small as 1.11.
  • a vacuum pump system is constituted by 8 (eight) such stages and that the discharge pressure is the atmospheric pressure, the pressure levels at the suction side of the vacuum pump system are 3 Torr. for air and 300 Torr. for helium gas.
  • the conventional vacuum pump system could not pro­vide very high degree of vacuum when used for pumping gases of small molecular weights.
  • this problem is overcome by introducing a gas of a larger molecular weight than the gas sucked through the suction port 2, e.g., nitrogen or air into one of the compression pump stages which is spaced downstream from the suction port 2 by more than one stage, i.e., into the circum­ferential-flow compression pump stage 6, through the pipe 17 connected between the gas inlet 4a provided in the wall of the housing 4 and the inlet port 13a in the sta­tionary disk 13 of the first stage of the circumferential-­flow compression pump stage 6.
  • the gas having large molecular weight advantageously increases the compression ratios across subsequent stages, so that a high degree of vacuum is established at the suction side of the vacuum pump apparatus.
  • the gas of the larger molecular weight introduced through the pipe 17 causes the circumferential-­flow compression pump stage 6 to operate in the viscous flow region, so that the pressure at the inlet side of this pump stage 6 can be lowered to several Torr.
  • the flow through this pump stage becomes to be equal to the total of the amount of the gas supplied and the amount of the gas discharged, with a result that the pumping effect of this pump stage is lowered undesirably. It will be understood that, by supplying a gas of a large molecular weight in the viscous flow region, it is possible to enable the pump stage to operate to pump a gas of small molecular weight with a large compression ratio and a high efficiency.
  • Figs. 8 to 10 show another embodiment of the vacuum pump apparatus according to the present invention.
  • This embodiment comprises a first pump stage constituted by a spiral molecular drag pump 20, an intermediate stage constituted by a centrifugal compression pump or compressor 5 and a final stage constituted by a circumferential-­flow compression pump 6.
  • the pump stages are arranged between the suction port 2 and the discharge port 3 within the housing 4.
  • a gas passage 17 provides a communication between a gas inlet 4a formed in the housing 4 and the inlet side of the centrifugal compressor stage 5.
  • the constructions of the centrifugal compressor stage 5 and the circumferential-flow compression pump stage 6 are the same as those in the first embodiment and, therefore, detailed description thereof is omitted.
  • the spiral molecular drag pump 20 has rotary disks 21 fixed to the rotary shaft 1 and stationary disks 22 fixed to the inner surface of the housing 4.
  • the rotary disks 21 and the stationary disks 22 are arranged alternately in the direction of the axis of the rotary shaft 1.
  • Each of the stationary disks 22 is provided with a spiral groove 23 formed in the surface thereof facing the adjacent rotary disk 21.
  • the gas passage 17 may alternatively be connec­ted to the inlet side of the circumferential-flow compres­sion pump stage 6 constituting the final stage, rather than to the inlet side of the centrifugal compressor stage 5 as in the illustrated embodiment.
  • each pump stage of the vacuum pump apparatus can produce large compression ratio due to introduction of a gas having a large molecular weight into an intermediate or final pump stage, so that a high degree of vacuum can be obtained at the suction side of the vacuum pump appa­ratus even when a gas sucked through the suction port has a small molecular weight.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Non-Positive Displacement Air Blowers (AREA)
EP86115640A 1985-11-13 1986-11-11 Pompe à vide Withdrawn EP0226039A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP25271185A JPS62113887A (ja) 1985-11-13 1985-11-13 真空ポンプ
JP252711/85 1985-11-13

Publications (1)

Publication Number Publication Date
EP0226039A1 true EP0226039A1 (fr) 1987-06-24

Family

ID=17241183

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86115640A Withdrawn EP0226039A1 (fr) 1985-11-13 1986-11-11 Pompe à vide

Country Status (2)

Country Link
EP (1) EP0226039A1 (fr)
JP (1) JPS62113887A (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208895A (en) * 1987-08-24 1989-04-19 Pfeiffer Vakuumtechnik Multi-stage molecular pump
EP0340685A2 (fr) * 1988-04-30 1989-11-08 Nippon Ferrofluidics Corporation Pompe à vide composite
EP0445855A1 (fr) * 1990-03-09 1991-09-11 VARIAN S.p.A. Pompe turbomoléculaire améliorée
US5238362A (en) * 1990-03-09 1993-08-24 Varian Associates, Inc. Turbomolecular pump
EP0643227A1 (fr) * 1993-09-10 1995-03-15 The BOC Group plc Pompes à vide
EP0731278A1 (fr) * 1995-03-10 1996-09-11 Balzers-Pfeiffer GmbH Pompe à vide moléculaire avec dispositif pour le gaz de refroidissement
EP0959253A2 (fr) * 1998-05-20 1999-11-24 The BOC Group plc Pompe à vide
GB2360066A (en) * 2000-03-06 2001-09-12 Boc Group Plc Vacuum pump
EP1363027A1 (fr) * 1996-05-03 2003-11-19 The BOC Group plc Pompe à vide
WO2004055378A1 (fr) * 2002-12-17 2004-07-01 The Boc Group Plc Agencement de pompage a vide et procede associe
WO2008142435A1 (fr) * 2007-05-18 2008-11-27 Edwards Limited Procédé d'actionnement d'un outil de lithographie
US7645116B2 (en) * 2005-04-28 2010-01-12 Ebara Corporation Turbo vacuum pump
WO2015132196A1 (fr) * 2014-03-03 2015-09-11 Nuovo Pignone Srl Procédé et système permettant de faire fonctionner un compresseur dos à dos avec un soutirage latéral

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2559436B2 (ja) * 1987-12-23 1996-12-04 株式会社日立製作所 ガスパージつき真空ポンプ
US5020969A (en) * 1988-09-28 1991-06-04 Hitachi, Ltd. Turbo vacuum pump

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2408257A1 (de) * 1974-02-21 1975-09-04 Leybold Heraeus Gmbh & Co Kg Verfahren und vorrichtung zum betrieb einer turbomolekularvakuumpumpe
DE2507430A1 (de) * 1975-02-21 1976-08-26 Franz Josef Dipl Phys Schittke Molekularvakuumpumpe mit hohem kompressionsverhaeltnis fuer leichte molekuele
DE2526164A1 (de) * 1975-06-12 1976-12-30 Leybold Heraeus Gmbh & Co Kg Turbomolekularvakuumpumpe mit zumindest teilweise glockenfoermig ausgebildetem rotor
EP0143684A1 (fr) * 1983-10-25 1985-06-05 Bertin & Cie Machine de compression d'un fluide, à plusieurs étages de compression en série

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2408257A1 (de) * 1974-02-21 1975-09-04 Leybold Heraeus Gmbh & Co Kg Verfahren und vorrichtung zum betrieb einer turbomolekularvakuumpumpe
DE2507430A1 (de) * 1975-02-21 1976-08-26 Franz Josef Dipl Phys Schittke Molekularvakuumpumpe mit hohem kompressionsverhaeltnis fuer leichte molekuele
DE2526164A1 (de) * 1975-06-12 1976-12-30 Leybold Heraeus Gmbh & Co Kg Turbomolekularvakuumpumpe mit zumindest teilweise glockenfoermig ausgebildetem rotor
EP0143684A1 (fr) * 1983-10-25 1985-06-05 Bertin & Cie Machine de compression d'un fluide, à plusieurs étages de compression en série

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2208895A (en) * 1987-08-24 1989-04-19 Pfeiffer Vakuumtechnik Multi-stage molecular pump
GB2208895B (en) * 1987-08-24 1991-01-23 Pfeiffer Vakuumtechnik Multi-stage molecular pump
EP0340685A2 (fr) * 1988-04-30 1989-11-08 Nippon Ferrofluidics Corporation Pompe à vide composite
EP0340685A3 (en) * 1988-04-30 1990-08-01 Nippon Ferrofluidics Corporation Composite vacuum pump
EP0445855A1 (fr) * 1990-03-09 1991-09-11 VARIAN S.p.A. Pompe turbomoléculaire améliorée
US5238362A (en) * 1990-03-09 1993-08-24 Varian Associates, Inc. Turbomolecular pump
EP0643227A1 (fr) * 1993-09-10 1995-03-15 The BOC Group plc Pompes à vide
US5611660A (en) * 1993-09-10 1997-03-18 The Boc Group Plc Compound vacuum pumps
EP0731278A1 (fr) * 1995-03-10 1996-09-11 Balzers-Pfeiffer GmbH Pompe à vide moléculaire avec dispositif pour le gaz de refroidissement
EP1363027A1 (fr) * 1996-05-03 2003-11-19 The BOC Group plc Pompe à vide
EP0959253A3 (fr) * 1998-05-20 2001-03-14 The BOC Group plc Pompe à vide
EP0959253A2 (fr) * 1998-05-20 1999-11-24 The BOC Group plc Pompe à vide
GB2360066A (en) * 2000-03-06 2001-09-12 Boc Group Plc Vacuum pump
WO2004055378A1 (fr) * 2002-12-17 2004-07-01 The Boc Group Plc Agencement de pompage a vide et procede associe
US7645116B2 (en) * 2005-04-28 2010-01-12 Ebara Corporation Turbo vacuum pump
US7938619B2 (en) 2005-04-28 2011-05-10 Ebara Corporation Turbo vacuum pump
WO2008142435A1 (fr) * 2007-05-18 2008-11-27 Edwards Limited Procédé d'actionnement d'un outil de lithographie
WO2015132196A1 (fr) * 2014-03-03 2015-09-11 Nuovo Pignone Srl Procédé et système permettant de faire fonctionner un compresseur dos à dos avec un soutirage latéral
CN106062374A (zh) * 2014-03-03 2016-10-26 诺沃皮尼奥内股份有限公司 用于运行带有侧流的背靠背的压缩机的方法和系统
RU2667563C2 (ru) * 2014-03-03 2018-09-21 Нуово Пиньоне СРЛ Способ и система для эксплуатации сдвоенного компрессора с приточным потоком
CN106062374B (zh) * 2014-03-03 2019-09-10 诺沃皮尼奥内股份有限公司 用于运行带有侧流的背靠背的压缩机的方法和系统
US10473109B2 (en) 2014-03-03 2019-11-12 Nuovo Pignone Srl Method and system for operating a back-to-back compressor with a side stream

Also Published As

Publication number Publication date
JPS62113887A (ja) 1987-05-25

Similar Documents

Publication Publication Date Title
EP0568069B1 (fr) Pompes à vide turbomoléculaires
US5238362A (en) Turbomolecular pump
EP0226039A1 (fr) Pompe à vide
US5020969A (en) Turbo vacuum pump
EP0805275B1 (fr) Pompe à vide
US5893702A (en) Gas friction pump
US4668160A (en) Vacuum pump
US5810557A (en) Fan wheel for an inline centrifugal fan
JP2002515568A (ja) ステータとロータを備えた摩擦真空ポンプ
JP2636356B2 (ja) 分子ポンプ
US5062766A (en) Turbo compressor
EP0445855B1 (fr) Pompe turbomoléculaire améliorée
US5611660A (en) Compound vacuum pumps
US6409477B1 (en) Vacuum pump
CN100429405C (zh) 真空泵
US6676384B2 (en) Gas friction pump
US20100266426A1 (en) Increased volumetric capacity of axial flow compressors used in turbomolecular vacuum pumps
KR890004933B1 (ko) 터어보분자펌프
US5451147A (en) Turbo vacuum pump
US6890146B2 (en) Compound friction vacuum pump
JPH0219694A (ja) オイルフリー型真空ポンプ
KR100339550B1 (ko) 터보 압축기의 디퓨져 구조
USRE33129E (en) Vacuum pump
JPS61283794A (ja) タ−ボ分子ポンプ
JP3045418B2 (ja) ターボ真空ポンプ

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19861111

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): CH DE FR LI

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 19871009

RIN1 Information on inventor provided before grant (corrected)

Inventor name: IKEMURA, KAZUHIKOHITACHI KOMEIRYO

Inventor name: GYOBU, ICHIRO

Inventor name: MASE, MASAHIRO

Inventor name: NAGAOKA, TAKASHI