EP0415315A1 - Primary vacuum pump - Google Patents

Primary vacuum pump Download PDF

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Publication number
EP0415315A1
EP0415315A1 EP90116376A EP90116376A EP0415315A1 EP 0415315 A1 EP0415315 A1 EP 0415315A1 EP 90116376 A EP90116376 A EP 90116376A EP 90116376 A EP90116376 A EP 90116376A EP 0415315 A1 EP0415315 A1 EP 0415315A1
Authority
EP
European Patent Office
Prior art keywords
stator
rotor
clearance
vacuum pump
primary 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Withdrawn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
EP90116376A
Other languages
German (de)
French (fr)
Inventor
Jean-Marie Crinquette
Jacques Long
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.)
Alcatel CIT SA
Original Assignee
Alcatel CIT SA
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 Alcatel CIT SA filed Critical Alcatel CIT SA
Publication of EP0415315A1 publication Critical patent/EP0415315A1/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F04C28/26—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels
    • F04C28/265—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels being obtained by displacing a lateral sealing face
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
    • F01C21/10—Outer members for co-operation with rotary pistons; Casings
    • F01C21/102—Adjustment of the interstices between moving and fixed parts of the machine by means other than fluid pressure
    • 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
    • F04D19/044—Holweck-type 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
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/052—Axially shiftable rotors
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/60—Mounting; Assembling; Disassembling
    • F04D29/64—Mounting; Assembling; Disassembling of axial pumps
    • F04D29/642—Mounting; Assembling; Disassembling of axial pumps by adjusting the clearances between rotary and stationary parts

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Non-Positive Displacement Air Blowers (AREA)
  • Rotary Pumps (AREA)

Abstract

Primary vacuum pump, comprising a stator and a rotor rotating in the stator, a predetermined leakage play relative to the latter being preserved, characterised in that, since the rotor (21, 25) and stator (22, 26) are frustoconical or hemispherical, the play (24) is variable, during pumping, as a result of a relative axial displacement of the rotor in relation to the stator, and in that this displacement is obtained by control means. <IMAGE>

Description

La présente invention concerne une pompe à vide primaire, comportant un stator et au moins un rotor tournant dans le stator en conservant un jeu de fuite prédéterminé par rapport à celui-ci.The present invention relates to a primary vacuum pump, comprising a stator and at least one rotor rotating in the stator while retaining a predetermined leakage relative to the latter.

Des pompes à vide primaire, seules ou en série, sont capables de créer de pressions totales d'environ 10⁻³ à 10⁻⁴ mbar en refoulant contre la pression atmosphérique. Les molécules d'oxygène et d'azote sont entraînées dans une telle pompe en régime visqueux et/ou turbulent. La caractéristique débit/volumique S/pression P d'une telle pompe, est essentiellement fonction du jeu j existant entre le rotor et le stator. Cette fonction est représentée sur la figure 1 ci-jointe, en prenant la pression p en mbar comme abscisse et le débit S en m³/h en ordonnée. Chacune des cinq courbes représentées en traits pleins correspond à un jeu donné, le jeu augmentant d'une courbe à l'autre en direction de la flèche j.Primary vacuum pumps, alone or in series, are capable of creating total pressures of approximately 10⁻³ to 10⁻⁴ mbar by driving against atmospheric pressure. The oxygen and nitrogen molecules are entrained in such a pump in a viscous and / or turbulent regime. The flow / volume S / pressure P characteristic of such a pump is essentially a function of the clearance j existing between the rotor and the stator. This function is shown in Figure 1 attached, taking the pressure p in mbar as the abscissa and the flow rate S in m³ / h on the ordinate. Each of the five curves shown in solid lines corresponds to a given clearance, the clearance increasing from one curve to another in the direction of the arrow j.

Au cours du pompage d'un volume important, vis-à-vis du débit volumique de la pompe, la température du ou des rotors croît beaucoup plus rapidement que la température du stator. Afin d'éviter un grippage éventuel, le constructeur est conduit à imposer le jeu stator-rotor le plus grand, correspondant au maximum de la dilatation différentielle. Ce grand jeu correspond à une caractéristique moyenne débit volumique/pression, qui, au surplus, évolue avec les températures respectives du rotor et du stator.During the pumping of a large volume, with respect to the volume flow rate of the pump, the temperature of the rotor or rotors increases much faster than the temperature of the stator. In order to avoid possible seizure, the manufacturer is required to impose the largest stator-rotor clearance, corresponding to the maximum of the differential expansion. This large clearance corresponds to a medium volume flow / pressure characteristic, which, moreover, changes with the respective temperatures of the rotor and the stator.

Par ailleurs, les gaz tels que l'hydrogène, le propane, le pentane, etc, ont des viscosités absolues 10 fois plus faibles que l'air. Les fuites massiques internes sont donc beaucoup plus grandes qu'avec de l'air, et par conséquent, la caractéristique débit volumique/pression, à jeu constant, est nettement plus faible qu'avec l'air. Il est donc intéressant de pouvoir adapter le jeu en fonction de la viscosité du gaz pur ou du mélange pompé.Furthermore, gases such as hydrogen, propane, pentane, etc., have absolute viscosities 10 times lower than air. Internal mass leaks are therefore much greater than with air, and therefore, the volume flow / pressure characteristic, at constant clearance, is significantly lower than with air. It is therefore advantageous to be able to adapt the play as a function of the viscosity of the pure gas or of the pumped mixture.

De ce fait, il est impossible de construire des pompes ayant un faible jeu et donc d'excellentes caractéristiques, c'est-à-dire
- à la pression atmosphérique, un débit élevé et une dérivée dS/dp très faible,
- au débit nul, une pression basse et une dérivée dS/dp aussi grande que possible.Therefore, it is impossible to build pumps with a small clearance and therefore excellent characteristics, that is to say
- at atmospheric pressure, a high flow rate and a very low dS / dp derivative,
- at zero flow, low pressure and also a dS / dp derivative great as possible.

En outre, dans certaines applications (fabrication de semiconducteurs, mais aussi en spectrométrie de masse, en détection de fuites par gaz traceur hélium ou néon, en simulation spatiale, etc ...) on désire commander le débit de la pompe indépendamment de la pression. Or, pour ce faire, l'homme de l'art a deux possibilités à sa disposition, à savoir la mise en série avec la pompe d'une conductance variable, ou la réduction de la vitesse de rotation de la pompe.In addition, in certain applications (manufacturing of semiconductors, but also in mass spectrometry, in detection of leaks by helium or neon tracer gas, in spatial simulation, etc.) it is desired to control the flow rate of the pump independently of the pressure . However, to do this, a person skilled in the art has two possibilities at his disposal, namely placing the variable conductance in series with the pump, or reducing the speed of rotation of the pump.

Le but de l'invention est de concevoir une pompe qui permet d'atteindre un jeu très faible et une modification rapide de la caractéristique, même en cours de pompage, afin de pouvoir optimiser la variation de pression en fonction du temps dans une enceinte à laquelle la pompe est associée.The object of the invention is to design a pump which makes it possible to achieve a very small clearance and a rapid modification of the characteristic, even during pumping, in order to be able to optimize the pressure variation as a function of time in an enclosure at which the pump is associated with.

Selon l'invention, ce but est atteint par le fait que le jeu entre stator et rotor est rendu variable pendant le pompage.According to the invention, this object is achieved by the fact that the clearance between stator and rotor is made variable during pumping.

L'invention a ainsi pour objet une pompe à vide primaire comportant un stator et un rotor tournant dans le stator en conservant un jeu de fuite prédéterminé par rapport à celui-ci, caractérisé en ce que le rotor (21, 25) et le stator (22, 26) étant tronconiques ou hémisphériques, le jeu (24) est variable pendant le pompage grâce à un déplacement relatif axial du rotor par rapport au stator et que ce déplacement est obtenu par un moyen de commande.The invention thus relates to a primary vacuum pump comprising a stator and a rotor rotating in the stator while retaining a predetermined leakage with respect to the latter, characterized in that the rotor (21, 25) and the stator (22, 26) being frustoconical or hemispherical, the clearance (24) is variable during pumping thanks to a relative axial displacement of the rotor relative to the stator and that this displacement is obtained by a control means.

L'invention sera décrite ci-après plus en détail à l'aide de quelques exemples de réalisation et des dessins.

  • La figure 1 représente la fonction débit volumique/pression pour de pompes à jeux différents.
  • La figure 2 montre schématiquement une pompe à rotor tronconique selon l'invention dont le jeu est modifié par déplacement de ce rotor ou du stator.
  • La figure 3 montre une pompe similaire à la précédente, dont le rotor est hémisphérique.
The invention will be described below in more detail with the aid of a few exemplary embodiments and the drawings.
  • FIG. 1 represents the volume flow / pressure function for pumps with different clearances.
  • FIG. 2 schematically shows a frustoconical rotor pump according to the invention, the clearance of which is modified by displacement of this rotor or of the stator.
  • Figure 3 shows a pump similar to the previous one, whose rotor is hemispherical.

En se référant à la figure 2, on voit une pompe dont le rotor 21 et le stator 22 ont chacun une forme tronconique et symétrique autour de l'axe 23 de rotation. On peut modifier le jeu 24 entre rotor et stator en déplaçant le rotor axialement dans le stator, ou inversement, par une action qui peut être purement mécanique. Il a été indiqué en pointillés sur cette figure une autre position relative du rotor conduisant à un jeu 24′ plus réduit.Referring to Figure 2, we see a pump whose rotor 21 and stator 22 each have a frustoconical and symmetrical shape around the axis 23 of rotation. The clearance 24 between rotor and stator can be modified by moving the rotor axially in the stator, or vice versa, by an action which can be purely mechanical. It has been indicated in dotted lines in this figure another relative position of the rotor leading to a more reduced play 24 ′.

Le déplacement du rotor dans le stator peut être obtenu par tout moyen d'action convenable, tel que des électro-aimants, des pressions d'un fluide, un électromoteur ou un système de commande purement mécanique.
Ce principe n'est pas limité à une forme tronconique, mais s'applique aussi à d'autres formes, telles que celles représentées sur la figure 3. Il s'agit ici d'une forme hémisphérique, le rotor tournant dans le stator 26 autour de son axe 27 de symétrie. On voit par cet exemple qu'il n'est pas absolument nécessaire de réduire uniformément le jeu en question, et qu'il suffit d'agir sur ce jeu dans des zones où les fuites de gaz sont particulièrement importantes.The displacement of the rotor in the stator can be obtained by any suitable means of action, such as electromagnets, fluid pressures, an electromotor or a purely mechanical control system.
This principle is not limited to a frustoconical shape, but also applies to other shapes, such as those represented in FIG. 3. It is here a hemispherical shape, the rotor turning in the stator 26 around its axis 27 of symmetry. We see by this example that it is not absolutely necessary to uniformly reduce the clearance in question, and that it suffices to act on this clearance in areas where gas leaks are particularly significant.

Claims (1)

Pompe à vide primaire, comportant un stator et un rotor tournant dans le stator en conservant un jeu de fuite prédéterminé par rapport à celui-ci, caractérisé en ce que le rotor (21, 25) et le stator (22, 26) étant tronconiques ou hémisphériques, le jeu (24) est variable pendant le pompage grâce à un déplacement relatif axial du rotor par rapport au stator et que ce déplacement est obtenu par un moyen de commande.Primary vacuum pump, comprising a stator and a rotor rotating in the stator while preserving a predetermined leakage with respect to the latter, characterized in that the rotor (21, 25) and the stator (22, 26) being frustoconical or hemispherical, the clearance (24) is variable during pumping thanks to an axial relative displacement of the rotor relative to the stator and that this displacement is obtained by a control means.
EP90116376A 1989-08-28 1990-08-27 Primary vacuum pump Withdrawn EP0415315A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8911302 1989-08-28
FR8911302A FR2651280A1 (en) 1989-08-28 1989-08-28 PRIMARY VACUUM PUMP.

Publications (1)

Publication Number Publication Date
EP0415315A1 true EP0415315A1 (en) 1991-03-06

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ID=9384945

Family Applications (1)

Application Number Title Priority Date Filing Date
EP90116376A Withdrawn EP0415315A1 (en) 1989-08-28 1990-08-27 Primary vacuum pump

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EP (1) EP0415315A1 (en)
JP (1) JPH0388997A (en)
FR (1) FR2651280A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19609308A1 (en) * 1995-03-31 1996-10-02 Japan Atomic Energy Res Inst Vacuum pump with spiral channel, for use with fusion reactors

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19708954A1 (en) * 1997-03-05 1998-09-17 Busch Gmbh K Side channel compressor with bladed rotor wheel
US8555799B2 (en) 2011-02-04 2013-10-15 Yamaha Hatsudoki Kabushiki Kaisha Personal watercraft

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR556556A (en) * 1922-09-26 1923-07-23 Hardoll Soc Rotary pump
US2134153A (en) * 1936-02-05 1938-10-25 S H Johnston Gear pump
DE848441C (en) * 1948-11-30 1952-09-04 Ernst Dr Schnabel poetry
FR2157353A5 (en) * 1971-10-14 1973-06-01 Atlas Copco Ab
FR2290133A6 (en) * 1973-02-09 1976-05-28 Materiel Processing Internal Centrifugal pump with sealing plate - has inner part of plate movable in axial direction of impeller

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3168870A (en) * 1962-12-12 1965-02-09 Ingersoll Rand Co Centrifugal pump with adjustable capacity
DE2555595C2 (en) * 1974-12-13 1986-01-23 Nippon Piston Ring K.K., Tokio/Tokyo Vane pump
DE2922835C2 (en) * 1979-06-06 1985-06-05 MTU Motoren- und Turbinen-Union München GmbH, 8000 München Circumferential gap seal on axial flow machines
DE3119568A1 (en) * 1981-05-16 1982-12-02 Big Dutchman (International) AG, 8090 Wezep Eccentric worm screw pump
JPS63154891A (en) * 1986-12-18 1988-06-28 Osaka Shinku Kiki Seisakusho:Kk Theread groove type vacuum pump
FR2641582B1 (en) * 1989-01-09 1991-03-22 Cit Alcatel GAEDE CHANNEL TYPE VACUUM PUMP

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR556556A (en) * 1922-09-26 1923-07-23 Hardoll Soc Rotary pump
US2134153A (en) * 1936-02-05 1938-10-25 S H Johnston Gear pump
DE848441C (en) * 1948-11-30 1952-09-04 Ernst Dr Schnabel poetry
FR2157353A5 (en) * 1971-10-14 1973-06-01 Atlas Copco Ab
FR2290133A6 (en) * 1973-02-09 1976-05-28 Materiel Processing Internal Centrifugal pump with sealing plate - has inner part of plate movable in axial direction of impeller

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19609308A1 (en) * 1995-03-31 1996-10-02 Japan Atomic Energy Res Inst Vacuum pump with spiral channel, for use with fusion reactors
DE19609308C2 (en) * 1995-03-31 2002-01-17 Japan Atomic Energy Res Inst T Vacuum pump with thread channel

Also Published As

Publication number Publication date
JPH0388997A (en) 1991-04-15
FR2651280A1 (en) 1991-03-01

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