EP0276346B1 - Control throttle for a vacuum pump, especially a cryogenic pump - Google Patents

Control throttle for a vacuum pump, especially a cryogenic pump Download PDF

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Publication number
EP0276346B1
EP0276346B1 EP87101153A EP87101153A EP0276346B1 EP 0276346 B1 EP0276346 B1 EP 0276346B1 EP 87101153 A EP87101153 A EP 87101153A EP 87101153 A EP87101153 A EP 87101153A EP 0276346 B1 EP0276346 B1 EP 0276346B1
Authority
EP
European Patent Office
Prior art keywords
pump
strips
throttle
flange
actuating rod
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.)
Expired - Lifetime
Application number
EP87101153A
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German (de)
French (fr)
Other versions
EP0276346A1 (en
Inventor
Wilhelm Strasser
Axel Veit
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.)
Balzers und Leybold Deutschland Holding AG
Original Assignee
Leybold AG
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 Leybold AG filed Critical Leybold AG
Priority to EP87101153A priority Critical patent/EP0276346B1/en
Priority to DE8787101153T priority patent/DE3773646D1/en
Priority to US07/148,629 priority patent/US4803845A/en
Publication of EP0276346A1 publication Critical patent/EP0276346A1/en
Application granted granted Critical
Publication of EP0276346B1 publication Critical patent/EP0276346B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/06—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means
    • F04B37/08—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for evacuating by thermal means by condensing or freezing, e.g. cryogenic pumps
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S417/00—Pumps
    • Y10S417/901—Cryogenic pumps
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87265—Dividing into parallel flow paths with recombining
    • Y10T137/8741—With common operator
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87265—Dividing into parallel flow paths with recombining
    • Y10T137/87507—Electrical actuator

Definitions

  • the invention relates to an adjustable throttle for a vacuum pump, in particular a cryopump, with a separate flange, with which the throttle can be placed on the cryopump, with a frame fastened in a separate flange, on which strip-shaped elements can be rotated about a longitudinal axis and thereby in their inclination are adjustably supported, as well as with an actuating rod which serves to adjust the inclination of the strips and which is guided through a radially directed bore in the flange.
  • a throttle valve of this type is known from EP-A-0 102 787. It comprises sector-shaped strips which are arranged in a star shape and rotatable about their longitudinal axis within the flange. The strips are operated together with the aid of a cable which is guided over disks connected radially on the outside to the sector-shaped closure strips. One of these washers is equipped with a shaft that is guided outwards through a hole in the flange. The throttle valve is actuated by means of a rotary movement via this shaft.
  • a choke of this type is relatively high and requires a large number of sector strips to be moved in a coordinated manner.
  • Throttles are known from DE-A-29 36 931 and DE-A-32 16 591, which are permanently installed in at least two-stage cryopumps. They are each arranged in the area of the inlet opening of the cryopump and essentially have two functions.
  • the components of the throttle form pump surfaces for gases with a relatively high condensation temperature (hereinafter generally referred to as vapors), for example water vapor.
  • vapors a relatively high condensation temperature
  • the throttle is connected to the first stage of the refrigerator with good thermal conductivity. As a result, it takes on an operating temperature of approx. 50 K to 80 K.
  • the fixed throttles also have the task of protecting the inner pump surfaces in the event of excessive steam.
  • the inner pump surfaces have a temperature of approximately 10 K to 30 K and essentially serve for the cryocondensation of low-boiling, heavier gases (hereinafter generally referred to as permanent gases), for example argon.
  • permanent gases for example argon.
  • areas covered with adsorption materials for the sorption of light gases such as hydrogen and helium are generally provided on the inner pump surfaces.
  • a temporarily large increase in steam occurs, for example, in sputtering processes in which cryopumps are used with increasing frequency. If the vapors reach the inner pump surfaces, they are covered with an ice layer in a short time, so that permanent gases and light gases can then no longer be effectively pumped out.
  • the throttle known from DE-A 29 36 931 is designed as a diaphragm with a stator plate and a rotor plate. These plates each have corresponding ones sector-shaped recesses whose size is selected so that the recesses of the stator plate can be opened and closed by rotating the rotor plate. In the event of increased steam, the throttle is brought into its closed position so that the inner pump surfaces are protected.
  • a throttle designed in this way can open a maximum of 40% of the inlet opening of a cryopump, so that at maximum opening it represents a relatively large obstacle for the inflowing permanent gases.
  • a choke of this type cannot additionally take on the function of a baffle, which has the task of protecting the cold surfaces in the pump housing from direct heat radiation.
  • baffle which effects "optical tightness" must also be used.
  • Usual baffle also take up about 50% of the inlet opening, so that the baffle and throttle together block the way to the inner cold surfaces by at least 80%.
  • a further impairment of the pumping speed arises from the need to arrange the baffle and throttle one behind the other, so that there are relatively long pumping paths.
  • the practically achievable permanent pumping speed of a cryopump equipped with a baffle and throttle is therefore a maximum of 20% of the theoretically possible pumping speed, even with the throttle fully open.
  • the throttle known from DE-A-32 16 591, FIGS. 3 and 4, firmly installed in a cryopump, comprises strips arranged parallel to one another and adjustable in their inclination, which have a width that is constant over their longitudinal extent and whose axes of rotation are parallel to one another.
  • the strips are actuated with the aid of a cable which is guided through a separate connector on the pump housing into a side chamber. In this there is a rotating disc to which the cable is attached.
  • the cable pull exposed to high temperature fluctuations is not permanently reliable.
  • the actuating rotary movement requires a vacuum-tight rotating union.
  • the present invention has for its object to provide a throttle of the type mentioned, which no longer have the aforementioned disadvantages.
  • a throttle with the features according to the invention is a completely independent modular component which consists of relatively few individual components and yet has a relatively large degree of opening. High vacuum tight rotating unions are no longer required. Cables that impair functional safety have also been eliminated. The height of the outer flange can be kept very small.
  • the throttle according to the invention can be placed on the inlet opening of commercially available vacuum pumps without significantly increasing the overall height. The use of the throttle for regulating the pumping speed of cryopumps is particularly advantageous. Custom-made products are no longer required.
  • the throttle according to the invention is not only able to to fulfill both functions "pump surfaces for vapors" and "protection of the inner pump surfaces in case of increased steam generation"; it can also - with a suitable design of the inner pump surfaces - also fulfill the usual function of a baffle, namely to protect the inner pump surfaces from direct heat radiation.
  • the figures show the upper part of a cryopump 1, on the flange 2 of which forms the inlet opening, a throttle 3 according to the invention is placed.
  • the pump surfaces 4 and 5 of the cryopump 1 are cooled with the aid of a two-stage refrigerator 6.
  • the pump surface 5 attached to the first stage 7 of the refrigferator 6 is cup-shaped and encloses the second stage 8 and the pump surfaces 4 attached thereto up to 80 K, so that vapors can be bound to these surfaces by cryocondensation.
  • the inner pumping surfaces 4 consist of two flat sections 11 and 12 which are arranged parallel to one another and are in good heat-conducting connection with the second refrigerator stage 8. As a result, they assume a temperature of approx. 10 to 20 K during the operation of the cryopump. Permanent gases accumulate on these surfaces through cryocondensation. Are the inner surfaces of the gates 11 and 12 with z. B. activated carbon, then the cryosorption of light gases takes place.
  • the throttle 3 according to the invention comprises the flange 14 with which it is placed on the flange 2 of the cryopump.
  • a frame 13 is held within the flange 14, to which strips 15 to 18 arranged parallel to one another are fastened so as to be rotatable about longitudinal axes 21 to 24.
  • the strip groups 15, 16 and 17, 18 move in opposite directions to one another and are each coupled to one another via a lever 25 or 26.
  • An actuating rod 27 is used to actuate the strip movement and is guided outwards through a bore 28 in the flange 14.
  • the actuating rod 27 is articulated on the strip 17 above the axes of rotation 21 to 24.
  • a lever 29 engages, which is articulated below the axes of rotation 21 to 24 to the strip 16 of the other strip group.
  • a longitudinal displacement of the actuating rod 27, as a result of the articulated chain composed of the levers 25, 26 and 29, brings about the desired opposite movement of the strip groups 15, 16 and 17, 18.
  • the actuating rod 27 is articulated to a pivot lever 32 arranged essentially perpendicular to the actuating rod 27, the fixed pivot axis of which is designated 33.
  • a drive 35 (electric, pneumatic or the like) is assigned to the pivot lever 32 which is led out of the chamber 31 through the opening 34, the drive axis 36 engaging the pivot lever 32 via the lever 37.
  • the swivel bellows 38 is provided, which is connected in a vacuum-tight manner on the one hand to a collar on the swivel lever 32 and on the other hand to the chamber wall having the opening 34.
  • Figure 1 shows the throttle according to the invention in an open position, while the throttle is shown closed in the plan view of Figure 2.
  • the strips 16 and 17 rest on a fixed baffle plate 41, so that the desired tightness of the throttle in its closed position is also ensured in the central area.
  • the end faces of the strips 15 to 18 and 41 are curved and adapted to the inlet opening of the cryopump.
  • the throttle 3 according to the invention is also designed so that it can perform two further functions in a cryopump, namely the pump function and the usual baffle function. To fulfill these functions, it is necessary for the throttle 3 to assume sufficiently low temperatures.
  • the frame 3 is held as thermally insulated as possible (for example via as few ceramic pins 42 as possible) within the flange 14.
  • the frame 13 has contact surfaces 43 with which it bears against the upper edge of the cup-shaped pump surface 5.
  • the frame 13, the strips 14 to 18 and the stationary baffle plate 41 fastened to the frame 13 assume the temperature of the pump surface 5 and are therefore sufficiently cold to bind vapors by cryocondensation.
  • the two U-shaped brackets 44 connected to the strip 41 are used, which are fastened with screws 45 to the existing fastening points (base 46) on the pump surface 5 (FIG. 3).
  • the strips 15 and 18 are thermally contacted with the ring 13 with two copper strips 47 (FIG. 1).
  • baffle plate 41 The dimensions of the baffle plate 41 and the width and swiveling ranges of the strips 15 to 18 are selected so that the pump surfaces 4 are protected against direct heat radiation in each position of the throttle 3.
  • the axes of rotation 21 to 24 are outside of that of the cylindrical Inner wall of the flange 14 formed space, in the direction of the pump surfaces 4.
  • the throttle 3 can replace a fixed baffle usually arranged in this area.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Description

Die Erfindung bezieht sich auf eine regelbare Drossel für eine Vakuumpumpe, insbesondere Kryopumpe, mit einem separaten Flansch, mit dem die Drossel auf die Kryopumpe aufgesetzt werden kann, mit einem im separaten Flansch befestigten Rahmen, an dem streifenförmige Elemente um eine Längsachse drehbar und dadurch in ihrer Neigung einstellbar gehaltert sind, sowie mit einer der Neigungseinstellung der Streifen dienenden Betätigungsstange, die durch eine radial gerichtete Bohrung im Flansch hindurchgeführt ist.The invention relates to an adjustable throttle for a vacuum pump, in particular a cryopump, with a separate flange, with which the throttle can be placed on the cryopump, with a frame fastened in a separate flange, on which strip-shaped elements can be rotated about a longitudinal axis and thereby in their inclination are adjustably supported, as well as with an actuating rod which serves to adjust the inclination of the strips and which is guided through a radially directed bore in the flange.

Aus der EP-A-0 102 787 ist ein Drosselventil dieser Art bekannt. Es umfaßt sektorförmige Streifen, die sternförmig und um ihre Längsachse drehbar innerhalb des Flansches angeordnet sind. Die gemeinsame Betätigung der Streifen erfolgt mit Hilfe eines Seilzuges, der über radial außen mit den sektorförmigen Verschlußstreifen verbundenen Scheiben geführt ist. Eine dieser Scheiben ist mit einer durch eine Bohrung im Flansch nach außen geführten Welle ausgerüstet. Über diese Welle erfolgt die Betätigung des Drosselventils mittels einer Drehbewegung. Eine Drossel dieser Art baut relativ hoch und benötigt eine Vielzahl von koordiniert zueinander zu bewegenden Sektorstreifen. Eine Reduzierung der Anzahl der Sektorstreifen wäre denkbar; dann aber müßte eine noch größere Drossel-Bauhöhe gewählt werden, da die maximale Breite der Sektorstreifen umso größer zu wählen ist, je weniger Sektorstreifen vorhanden sind. Die Abdichtung der zur Übertragung einer Drehbewegung erforderlichen, durch den Flansch nach außen geführten Welle ist bei den üblicherweise vorliegenden Hochvakuum-Bedingungen problematisch. Schließlich ist der hohen Temperaturschwankungen ausgesetzte Seilzug nicht dauerhaft funktionssicher.A throttle valve of this type is known from EP-A-0 102 787. It comprises sector-shaped strips which are arranged in a star shape and rotatable about their longitudinal axis within the flange. The strips are operated together with the aid of a cable which is guided over disks connected radially on the outside to the sector-shaped closure strips. One of these washers is equipped with a shaft that is guided outwards through a hole in the flange. The throttle valve is actuated by means of a rotary movement via this shaft. A choke of this type is relatively high and requires a large number of sector strips to be moved in a coordinated manner. A reduction in the number of sector strips would be conceivable; then, however, an even greater throttle construction height would have to be chosen, since the maximum width of the sector strips is to be chosen, the fewer sector strips are present. The sealing of the shaft, which is required for the transmission of a rotary movement and is guided through the flange to the outside, is problematic in the high vacuum conditions which are usually present. After all, the cable pull exposed to high temperature fluctuations is not permanently reliable.

Aus den DE-A-29 36 931 und DE-A-32 16 591 sind Drosseln bekannt, die in mindestens zweistufigen Kryopumpen fest eingebaut sind. Sie sind jeweils im Beriech der Eintrittsöffnung der Kryopumpe angeordnet und haben im wesentlichen zwei Funktionen. Zum einen bilden die Bauteile der Drossel Pumpflächen für Gase mit relativ hoher Kondensationstemperatur (im folgenden generell mit Dämpfe bezeichnet), zum Beispiel Wasserdampf. Um diese Dämpfe durch Kryokondensation zu binden, wird die Drossel gut wärmeleitend mit der ersten Stufe des Refrigerators verbunden. Sie nimmt dadurch eine Betriebstemperatur von ca. 50 K bis 80 K an. Weiterhin haben die fest eingebauten Drosseln die Aufgabe, die inneren Pumpflächen bei überhöhtem Dampfanfall zu schützen. Die inneren Pumpflächen haben eine Temperatur von etwa 10 K bis 30 K und dienen im wesentlichen der Kryokondensation von niedrigsiedenden schwereren Gasen (im folgenden generell mit Permanentgase bezeichnet), zum Beispiel Argon. Zusätzlich sind in der Regel noch mit Adsorptionsmaterialien belegte Flächen zur Sorption von leichten Gasen wie Wasserstoff und Helium an den inneren Pumpflächen vorgesehen. Ein zeitweise stark erhöhter Dampfanfall tritt zum Beispiel bei Sputterprozessen ein, bei denen Kryopumpen immer häufiger eingesetzt werden. Gelangen die Dämpfe auf die inneren Pumpflächen, dann sind diese in kurzer Zeit mit einer Eisschicht belegt, so daß danach Permanentgase und leichte Gase nicht mehr wirksam abgepumpt werden können.Throttles are known from DE-A-29 36 931 and DE-A-32 16 591, which are permanently installed in at least two-stage cryopumps. They are each arranged in the area of the inlet opening of the cryopump and essentially have two functions. On the one hand, the components of the throttle form pump surfaces for gases with a relatively high condensation temperature (hereinafter generally referred to as vapors), for example water vapor. In order to bind these vapors through cryocondensation, the throttle is connected to the first stage of the refrigerator with good thermal conductivity. As a result, it takes on an operating temperature of approx. 50 K to 80 K. The fixed throttles also have the task of protecting the inner pump surfaces in the event of excessive steam. The inner pump surfaces have a temperature of approximately 10 K to 30 K and essentially serve for the cryocondensation of low-boiling, heavier gases (hereinafter generally referred to as permanent gases), for example argon. In addition, areas covered with adsorption materials for the sorption of light gases such as hydrogen and helium are generally provided on the inner pump surfaces. A temporarily large increase in steam occurs, for example, in sputtering processes in which cryopumps are used with increasing frequency. If the vapors reach the inner pump surfaces, they are covered with an ice layer in a short time, so that permanent gases and light gases can then no longer be effectively pumped out.

Die aus der DE-A 29 36 931 vorbekannte Drossel ist als Blende mit einer Statorplatte und einer Rotorplatte ausgebildet. Diese Platten weisen jeweils einander entsprechende sektorförmige Ausnehmungen auf, deren Größe so gewählt ist, daß die Ausnehmungen der Statorplatte durch Verdrehen der Rotorplatte geöffnet und geschlossen werden können. Bei erhöhtem Dampfanfall wird die Drossel in ihre Schließstellung gebracht, so daß die inneren Pumpflachen geschützt sind. Eine in dieser Weise ausgebildete Drossel kann maximal 40 % der Einlaßöffnung einer Kryopumpe freigeben, so daß sie bei maximaler Öffnung ein relativ großes Hindernis für die einströmenden Permanentgase darstellt. Weiterhin kann eine Drossel dieser Art nicht zusätzlich noch die Funktion eines Baffles übernehmen, das die Aufgabe hat, die im Pumpengehäuse befindlichen Kaltflächen vor unmittelbarer Wärmestrahlung zu schützen. Ist ein derartiger Schutz erwünscht, dann muß neben der durch die DE-OS 29 36 931 bekannten Drossel noch ein die "optische Dichtheit" bewirkendes Baffle verwendet werden. Übliche Baffle nehmen ebenfalls ca. 50 % der Einlaßöffnung ein, so daß Baffle und Drossel zusammen den Weg zu den inneren Kaltflächen um mindestens 80 % versperren. Eine weitere Beeinträchtigung des Saugvermögens ergibt sich durch die Notwendigkeit, Baffle und Drossel hintereinander anordnen zu müssen, so daß sich relativ lange Pumpewege ergeben. Das praktisch erreichbare Permanent-Saugvermögen einer mit Baffle und Drossel ausgerüsteten Kryopumpe liegt deshalb, selbst bei vollständig geöffneter Drossel, maximal bei 20 % des theoretisch möglichen Saugvermögens.The throttle known from DE-A 29 36 931 is designed as a diaphragm with a stator plate and a rotor plate. These plates each have corresponding ones sector-shaped recesses whose size is selected so that the recesses of the stator plate can be opened and closed by rotating the rotor plate. In the event of increased steam, the throttle is brought into its closed position so that the inner pump surfaces are protected. A throttle designed in this way can open a maximum of 40% of the inlet opening of a cryopump, so that at maximum opening it represents a relatively large obstacle for the inflowing permanent gases. Furthermore, a choke of this type cannot additionally take on the function of a baffle, which has the task of protecting the cold surfaces in the pump housing from direct heat radiation. If such protection is desired, then in addition to the choke known from DE-OS 29 36 931, a baffle which effects "optical tightness" must also be used. Usual baffle also take up about 50% of the inlet opening, so that the baffle and throttle together block the way to the inner cold surfaces by at least 80%. A further impairment of the pumping speed arises from the need to arrange the baffle and throttle one behind the other, so that there are relatively long pumping paths. The practically achievable permanent pumping speed of a cryopump equipped with a baffle and throttle is therefore a maximum of 20% of the theoretically possible pumping speed, even with the throttle fully open.

Die aus der DE-A-32 16 591, Figuren 3 und 4, bekannte, fest in eine Kryopumpe eingebaute Drossel umfaßt parallel zueinander angeordnete, in ihrer Neigung einstellbare Streifen, die eine über ihre Längsausdehnung konstante Breite haben und deren Drehachsen parallel zueinander liegen. Die Betätigung der Streifen erfolgt mit Hilfe eines Seilzuges, der durch einen gesonderten Stutzen am Pumpengehäuse in eine seitliche Kammer geführt ist. Darin befindet sich eine drehbare Scheibe, an der der Seilzug befestigt ist. Auch bei dieser vorbekannten, in einer Kryopumpe fest eingebauten Drossel ist der hohen Temperaturschwankungen ausgesetzte Seilzug nicht dauerhaft funktionssicher. Die Betätigungs-Drehbewegung erfordert eine vakuumdichte Drehdurchführung. Schließlich besteht der Nachteil, daß der Aufbau einer Kryopumpe mit einer fest eingebauten Drossel der vorbekannten Art gegenüber einer Kryopumpe, bei der eine regelbare Drosselung des Saugvermögens nicht erforderlich ist, unverhältnismäßig aufwendig und damit kostspielig ist, da insbesondere ein gesonderter Anschlußstutzen für die Herausführung des Seilzuges, eine vakuumdichte Drehdurchführung und eine größere Bauhöhe erforderlich sind.The throttle known from DE-A-32 16 591, FIGS. 3 and 4, firmly installed in a cryopump, comprises strips arranged parallel to one another and adjustable in their inclination, which have a width that is constant over their longitudinal extent and whose axes of rotation are parallel to one another. The strips are actuated with the aid of a cable which is guided through a separate connector on the pump housing into a side chamber. In this there is a rotating disc to which the cable is attached. Even with this known throttle, which is permanently installed in a cryopump, the cable pull exposed to high temperature fluctuations is not permanently reliable. The actuating rotary movement requires a vacuum-tight rotating union. Finally, there is the disadvantage that the construction of a cryopump with a fixed throttle of the known type compared to a cryopump, in which an adjustable throttling of the pumping speed is not necessary, is disproportionately complex and therefore expensive, since in particular a separate connecting piece for the lead-out of the cable , a vacuum-tight rotating union and a larger overall height are required.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, eine Drossel der eingangs genannten Art zu schaffen, welcher die vorerwähnten Nachteile nicht mehr anhaften.The present invention has for its object to provide a throttle of the type mentioned, which no longer have the aforementioned disadvantages.

Erfindungsgemäß wird diese Aufgabe durch die Merkmale des Anspruchs 1 gelöst.According to the invention, this object is achieved by the features of claim 1.

Eine Drossel mit den erfindungsgemäßen Merkmalen ist ein völlig unabhängiges modulares Bauteil, das aus relativ wenigen Einzelbauteilen besteht und dennoch einen relativ großen Öffnungsgrad hat. Hochvakuumdichte Drehdurchführungen sind nicht mehr erforderlich. Auch die Funktionssicherheit beeinträchtigende Seilzüge sind entfallen. Die Höhe des äußeren Flansches kann sehr klein gehalten werden. Die erfindungsgemäße Drossel kann auf die Eintrittsöffnung handelsüblicher Vakuumpumpen aufgesetzt werden, ohne die Gesamtbauhöhe wesentlich zu vergrößern. Besonders vorteilhaft ist der Einsatz der Drossel zur Regelung des Saugvermögens von Kryopumpen. Sonderanfertigungen sind nicht mehr erforderlich. Die erfindungsgemäße Drossel ist nicht nur in der Lage, die beiden Funktionen "Pumpflächen für Dämpfe" und "Schutz der inneren Pumpflächen bei erhöhtem Dampfanfall" zu erfüllen; sie kann darüber hinaus - bei geeigneter Gestaltung der inneren Pumpflächen - auch noch die übliche Funktion eines Baffles erfüllen, nämlich, die inneren Pumpflächen vor direkter Wärmestrahlung zu schützen.A throttle with the features according to the invention is a completely independent modular component which consists of relatively few individual components and yet has a relatively large degree of opening. High vacuum tight rotating unions are no longer required. Cables that impair functional safety have also been eliminated. The height of the outer flange can be kept very small. The throttle according to the invention can be placed on the inlet opening of commercially available vacuum pumps without significantly increasing the overall height. The use of the throttle for regulating the pumping speed of cryopumps is particularly advantageous. Custom-made products are no longer required. The throttle according to the invention is not only able to to fulfill both functions "pump surfaces for vapors" and "protection of the inner pump surfaces in case of increased steam generation"; it can also - with a suitable design of the inner pump surfaces - also fulfill the usual function of a baffle, namely to protect the inner pump surfaces from direct heat radiation.

Weitere Vorteile und Einzelheiten der Erfindung sollen anhand eines in den Figuren 1 bis 3 dargestellten Ausführungsbeispieles erläutert werden.Further advantages and details of the invention will be explained with reference to an embodiment shown in Figures 1 to 3.

Die Figuren zeigen das Oberteil einer Kryopumpe 1, auf deren die Eintrittsöffnung bildenden Flansch 2 eine Drossel 3 nach der Erfindung aufgesetzt ist. Die Pumpflächen 4 und 5 der Kryopumpe 1 werden mit Hilfe eines zweistufigen Refrigerators 6 gekühlt. Die an der ersten Stufe 7 des Refrigferators 6 befestigte Pumpfläche 5 ist topfförmig ausgebildet und umschließt die zweite Stufe 8 und die daran befestigten Pumpflächen 4. Während des Betriebs der Pumpe nimmt die isoliert im Gehäuse 1 angeordnete topffförmige Pumpfläche 5 eine Temperatur von ca. 50 K bis 80 K an, so daß an diesen Flächen Dämpfe durch Kryokondensation gebunden werden können. Die inneren Pumpflächen 4 bestehen aus zwei parallel zueinander angeordneten ebenen Abschnitten 11 und 12, die mit der zweiten Refrigeratorstufe 8 in gut wärmeleitender Verbindung stehen. Dadurch nehmen sie während des Betriebs der Kryopumpe eine Temperatur von ca. 10 bis 20 K an. An diesen Flächen lagern sich Permanentgase durch Kryokondensation an. Sind die Innenflächen der Anschnitte 11 und 12 mit z. B. Aktivkohle belegt, dann findet auch die Kryosorption leichter Gase statt.The figures show the upper part of a cryopump 1, on the flange 2 of which forms the inlet opening, a throttle 3 according to the invention is placed. The pump surfaces 4 and 5 of the cryopump 1 are cooled with the aid of a two-stage refrigerator 6. The pump surface 5 attached to the first stage 7 of the refrigferator 6 is cup-shaped and encloses the second stage 8 and the pump surfaces 4 attached thereto up to 80 K, so that vapors can be bound to these surfaces by cryocondensation. The inner pumping surfaces 4 consist of two flat sections 11 and 12 which are arranged parallel to one another and are in good heat-conducting connection with the second refrigerator stage 8. As a result, they assume a temperature of approx. 10 to 20 K during the operation of the cryopump. Permanent gases accumulate on these surfaces through cryocondensation. Are the inner surfaces of the gates 11 and 12 with z. B. activated carbon, then the cryosorption of light gases takes place.

Die erfindungsgemäße Drossel 3 umfaßt den Flansch 14, mit dem sie auf den Flansch 2 der Kryopumpe aufgesetzt ist.The throttle 3 according to the invention comprises the flange 14 with which it is placed on the flange 2 of the cryopump.

Innerhalb des Flansches 14 ist ein Rahmen 13 gehaltert, an dem parallel zueinander angeordnete Streifen 15 bis 18 um Längsachsen 21 bis 24 drehbar befestigt sind. Die Streifengruppen 15, 16 bzw. 17, 18 bewegen sich gegenläufig zueinander und sind jeweils untereinander über einen Hebel 25 bzw. 26 gekoppelt. Zur Betätigung der Streifenbewegung dient eine Betätigungsstange 27, die durch eine Bohrung 28 im Flansch 14 nach außen herausgeführt ist. Die Betätigungsstange 27 ist oberhalb der Drehachsen 21 bis 24 an dem Streifen 17 angelenkt. An den gleichen Anlenkpunkt greift ein Umlenkhebel 29 an, der unterhalb der Drehachsen 21 bis 24 an den Streifen 16 der anderen Streifengruppe angelenkt ist. Eine Längsverschiebung der Betätigungsstange 27 bewirkt infolge der aus den Hebeln 25, 26 und 29 zusammengesetzten Gelenkkette die gewünschte gegenläufige Bewegung der Streifengruppen 15, 16 bzw. 17, 18.A frame 13 is held within the flange 14, to which strips 15 to 18 arranged parallel to one another are fastened so as to be rotatable about longitudinal axes 21 to 24. The strip groups 15, 16 and 17, 18 move in opposite directions to one another and are each coupled to one another via a lever 25 or 26. An actuating rod 27 is used to actuate the strip movement and is guided outwards through a bore 28 in the flange 14. The actuating rod 27 is articulated on the strip 17 above the axes of rotation 21 to 24. At the same articulation point, a lever 29 engages, which is articulated below the axes of rotation 21 to 24 to the strip 16 of the other strip group. A longitudinal displacement of the actuating rod 27, as a result of the articulated chain composed of the levers 25, 26 and 29, brings about the desired opposite movement of the strip groups 15, 16 and 17, 18.

An die Bohrung 28 im Flansch 14 schließt sich eine vakuumdichte, über die Bohrung 28 mit dem Innenraum der Pumpe verbundene Kammer 31 an. Innerhalb dieser Kammer ist die Betätigungsstange 27 an einen im wesentlichen senkrecht zur Betätigungsstange 27 angeordneten Schwenkhebel 32 angelenkt, dessen ortsfeste Schwenkachse mit 33 bezeichnet ist. Dem aus der Kammer 31 durch die Öffnung 34 herausgeführten Schwenkhebel 32 ist ein Antrtieb 35 (elektrisch, pneumatisch oder dergleichen) zugeordnet, dessen Antriebsachse 36 über den Hebel 37 an den Schwenkhebel 32 angreift. Zur Abdichtung der Öffnung 34 gegenüber dem Innenraum der Kammer 31 ist der Schwenkbalg38 vorgesehen, der einerseits mit einem Kragen am Schwenkhebel 32 und andererseits mit der die Öffnung 34 aufweisenden Kammerwand vakuumdicht verbunden ist.A vacuum-tight chamber 31 connected to the interior of the pump via the bore 28 connects to the bore 28 in the flange 14. Within this chamber, the actuating rod 27 is articulated to a pivot lever 32 arranged essentially perpendicular to the actuating rod 27, the fixed pivot axis of which is designated 33. A drive 35 (electric, pneumatic or the like) is assigned to the pivot lever 32 which is led out of the chamber 31 through the opening 34, the drive axis 36 engaging the pivot lever 32 via the lever 37. To seal the opening 34 from the interior of the chamber 31, the swivel bellows 38 is provided, which is connected in a vacuum-tight manner on the one hand to a collar on the swivel lever 32 and on the other hand to the chamber wall having the opening 34.

Figur 1 zeigt die erfindungsgemäße Drossel in einer Offenstellung, während in der Draufsicht nach Figur 2 die Drossel geschlossen dargestellt ist. In ihrer Schließstellung liegen die Streifen 16 und 17 einem feststehenden Baffleblech 41 auf, so daß die gewünschte Dichtheit der Drossel in ihrer Schließstellung auch im zentralen Bereich sichergestellt ist. Die Stirnseiten der Streifen 15 bis 18 und 41 sind bogenförmig gestaltet und der Eintrittsöffnung der Kryopumpe angepaßt.Figure 1 shows the throttle according to the invention in an open position, while the throttle is shown closed in the plan view of Figure 2. In your In the closed position, the strips 16 and 17 rest on a fixed baffle plate 41, so that the desired tightness of the throttle in its closed position is also ensured in the central area. The end faces of the strips 15 to 18 and 41 are curved and adapted to the inlet opening of the cryopump.

Die erfindungsgemäße Drossel 3 ist darüber hinaus so gestaltet, daß sie bei einer Kryopumpe zwei weitere Funktionen erfüllen kann, und zwar zum einen die Pumpfunktion und zum anderen die übliche Bafflefunktion. Zur Erfüllung dieser Funktionen ist es erforderlich, daß die Drossel 3 ausreichend tiefe Temperaturen annimmt. Dazu ist der Rahmen 3 möglichst wärmeisoliert (zum Beispiel über möglichst wenig Keramikstifte 42) innerhalb des Flansches 14 gehaltert. Außerdem weist der Rahmen 13 Anlageflächen 43 auf, mit denen er dem oberen Rand der topfförmigen Pumpfläche 5 anliegt. Dadurch nehmen der Rahmen 13, die Streifen 14 bis 18 und das ortsfeste, am Rahmen 13 befestigte Baffleblech 41 die Temperatur der Pumpfläche 5 an und sind damit zur Bindung von Dämpfen durch Kryokondensation ausreichend kalt. Zur weiteren thermischen Ankopplung dienen die beiden mit dem Streifen 41 verbundenen U-förmigen Bügel 44, die mit Schrauben 45 an den vorhandenen Befestigungsstellen (Sockel 46) an der Pumpfläche 5 befestigt sind (Fig. 3). Die Streifen 15 und 18 sind mit je zwei Kupferbändern 47 (Fig. 1) thermisch mit dem Ring 13 kontaktiert.The throttle 3 according to the invention is also designed so that it can perform two further functions in a cryopump, namely the pump function and the usual baffle function. To fulfill these functions, it is necessary for the throttle 3 to assume sufficiently low temperatures. For this purpose, the frame 3 is held as thermally insulated as possible (for example via as few ceramic pins 42 as possible) within the flange 14. In addition, the frame 13 has contact surfaces 43 with which it bears against the upper edge of the cup-shaped pump surface 5. As a result, the frame 13, the strips 14 to 18 and the stationary baffle plate 41 fastened to the frame 13 assume the temperature of the pump surface 5 and are therefore sufficiently cold to bind vapors by cryocondensation. For further thermal coupling, the two U-shaped brackets 44 connected to the strip 41 are used, which are fastened with screws 45 to the existing fastening points (base 46) on the pump surface 5 (FIG. 3). The strips 15 and 18 are thermally contacted with the ring 13 with two copper strips 47 (FIG. 1).

Die Abmessungen des Baffleblechs 41 sowie die Breite und Schwenkbereiche der Streifen 15 bis 18 sind so gewählt, daß in jeder Stellung der Drossel 3 die Pumpflächen 4 vor unmittelbar auftreffender Wärmestrahlung geschützt sind.The dimensions of the baffle plate 41 and the width and swiveling ranges of the strips 15 to 18 are selected so that the pump surfaces 4 are protected against direct heat radiation in each position of the throttle 3.

Beim dargestellten Ausführungsbeispiel liegen die Drehachsen 21 bis 24 außerhalb des von der zylindrischen Innenwand des Flansches 14 gebildeten Raumes, und zwar in Richtung Pumpflächen 4. Dadurch ist eine kompakte Bauweise möglich. Die Drossel 3 kann ein üblicherweise in diesem Bereich angeordnetes feststehendes Baffle ersetzen. Um eine Kryopumpe für den Einsatz bei Sputterprozessen, das heißt mit durchsatzregelbarer Eintrittsöffnung zu schaffen, ist es deshalb lediglich erforderlich, das den inneren Pumpflächen zugeordnete Baffle mit unbeweglichen Baffle-Streifen durch die erfindungsgemäße Drossel zu ersetzen. Eine wesentliche Verlängerung der Wege und zusätzliche Leitwertverluste für die zu pumpenden Gase ist vermieden, ohne auf eine Bafflefunktion verzichten zu müssen.In the illustrated embodiment, the axes of rotation 21 to 24 are outside of that of the cylindrical Inner wall of the flange 14 formed space, in the direction of the pump surfaces 4. This enables a compact design. The throttle 3 can replace a fixed baffle usually arranged in this area. In order to create a cryopump for use in sputtering processes, that is to say with an inlet opening which can be regulated throughput, it is therefore only necessary to replace the baffle associated with the inner pump surfaces with immobile baffle strips by the throttle according to the invention. A substantial lengthening of the routes and additional conductance losses for the gases to be pumped are avoided without having to do without a baffle function.

Claims (7)

  1. Adjustable throttle for a vacuum pump, in particular a cryogenic pump, with a separate flange (14), with which the throttle can be mounted on the cryogenic pump, with a frame (13) fixed in the separate flange (14), to which frame strip-like elements (15 to 18) are mounted so as to be rotatable about a longitudinal axis (21 to 24), and therefore so that their inclination is adjustable, and with an actuating rod (27) serving the inclination adjustment of the strips and passing through an approximately radially oriented bore (28) in the flange (14), characterised in that the strip-like elements (15 to 18) have a substantially constant breadth throughout their longitudinal extension, in that the axes of rotation (21 to 24) are parallel to one another, in that two groups of strips (15, 16, and 17, 18 respectively), which are movable in opposite directions and are coupled by means of a link chain (25, 26, 29) are provided, in that, in order to form the link chain, levers (25 and 26 respectively) are provided, which couple the strips together in groups, and a further reversing lever (29) is provided which joins the two groups (15, 16 and 17, 18 respectively) together and which generates contrary motion, in that one end of the actuating rod (27) is coupled to one (17) of the strips, in that, inside a chamber (31) adjacent the bore (28) in the flange (14), the other end of the actuating rod is pivotably connected to a pivoted lever (32) which passes to the outside, and in that the pivoted lever is equipped with a pivoting concertina-type seal (38).
  2. Throttle according to claim 1, characterised in that the strips (15 to 18) are mounted in groups with mutually connecting levers (25, 26) on one side of a face formed by the axes of rotation (21 to 24) and the pivotal point of the actuating rod (27) is located on the other side of said face.
  3. Throttle according to claim 2, characterised in that the axes of rotation (21 to 24) of the strips (15 to 18) are located outside the cylinder chamber defined by the inner surface of the flange (14) and in that the pivotal point of the actuating rod (27) is located inside this cylinder chamber.
  4. Throttle according to one of the preceding claims, characterised in that the frame (13) is mounted inside the flange (14) via means which are a poor conductor of heat, and has faces (43) intended for contact with the pump faces (5) of a cryogenic pump (1).
  5. Two-stage cryogenic pump equipped with a throttle according to claim 4, being equipped with a pot-shaped pump face Tor vapours and two plane, mutually parallel pump faces (4) for permanent gases, characterised in that the strips (15 to 18) of the throttle (3) are mounted parallel to the pump faces (4), and in that the contact faces (43) on the frame (13) abut the upper edge of the pot-shaped pump face (5).
  6. Cryogenic pump according to claim 5, characterised in that at least some of the strips (15 to 18) are connected to the ring (13) via lengths of copper band (47).
  7. Cryogenic pump according to claim 5 or 6 characterised in that for thermal coupling of a fixed central strip (41) to the pot-shaped pump face (5), preferably U-shaped shackles (44) are provided, which are soldered to the central strip (41) and are mounted on fixing bases (46) on the pump face (5).
EP87101153A 1987-01-28 1987-01-28 Control throttle for a vacuum pump, especially a cryogenic pump Expired - Lifetime EP0276346B1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
EP87101153A EP0276346B1 (en) 1987-01-28 1987-01-28 Control throttle for a vacuum pump, especially a cryogenic pump
DE8787101153T DE3773646D1 (en) 1987-01-28 1987-01-28 ADJUSTABLE THROTTLE FOR A VACUUM PUMP, IN PARTICULAR CRYOPUMP.
US07/148,629 US4803845A (en) 1987-01-28 1988-01-26 Controllable throttle for a vacuum pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP87101153A EP0276346B1 (en) 1987-01-28 1987-01-28 Control throttle for a vacuum pump, especially a cryogenic pump

Publications (2)

Publication Number Publication Date
EP0276346A1 EP0276346A1 (en) 1988-08-03
EP0276346B1 true EP0276346B1 (en) 1991-10-09

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Application Number Title Priority Date Filing Date
EP87101153A Expired - Lifetime EP0276346B1 (en) 1987-01-28 1987-01-28 Control throttle for a vacuum pump, especially a cryogenic pump

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US (1) US4803845A (en)
EP (1) EP0276346B1 (en)
DE (1) DE3773646D1 (en)

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Publication number Priority date Publication date Assignee Title
CH686384A5 (en) * 1992-07-21 1996-03-15 Marcel Kohler Cryopump.
US5520002A (en) * 1995-02-01 1996-05-28 Sony Corporation High speed pump for a processing vacuum chamber
IT1302694B1 (en) * 1998-10-19 2000-09-29 Getters Spa MOBILE SHIELDING DEVICE ACCORDING TO THE TEMPERATURE OF THE GETTER TRAPUMP AND TURBOMOLECULAR PUMP CONNECTED IN LINE.
US6122921A (en) * 1999-01-19 2000-09-26 Applied Materials, Inc. Shield to prevent cryopump charcoal array from shedding during cryo-regeneration
CN108105066B (en) * 2017-12-26 2019-04-12 安徽万瑞冷电科技有限公司 A kind of cryogenic pump of variable pumping speed

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Publication number Priority date Publication date Assignee Title
US3973590A (en) * 1974-02-01 1976-08-10 Aeronca, Inc. Mixing valve for air distributing systems
US4064934A (en) * 1975-11-07 1977-12-27 International Harvester Company Radiator air flow control mechanism
US4285710A (en) * 1978-09-18 1981-08-25 Varian Associates, Inc. Cryogenic device for restricting the pumping speed of selected gases
US4341079A (en) * 1980-04-01 1982-07-27 Cvi Incorporated Cryopump apparatus
JPS58160552A (en) * 1982-03-18 1983-09-24 Toyota Motor Corp Ignition timing control method for an internal combustion engine
DE3216591A1 (en) * 1982-05-04 1983-11-10 Leybold-Heraeus GmbH, 5000 Köln Cryogenic pump with shutter-like baffle
US4457336A (en) * 1982-07-14 1984-07-03 Flanders Filters, Inc. Air flow control apparatus
US4393896A (en) * 1982-08-27 1983-07-19 Comptech, Incorporated Radial vane gas throttling valve for vacuum systems
EP0102787B1 (en) * 1982-08-27 1986-07-16 Comptech, Incorporated Cryogenic pump having maximum aperture throttled port
US4531372A (en) * 1982-08-27 1985-07-30 Comptech, Incorporated Cryogenic pump having maximum aperture throttled part
US4479361A (en) * 1983-03-02 1984-10-30 The United States Of America As Represented By The United States Department Of Energy Gas pump with movable gas pumping panels
US4493342A (en) * 1983-10-24 1985-01-15 Bachmann Industries, Inc. Double louver damper

Also Published As

Publication number Publication date
EP0276346A1 (en) 1988-08-03
US4803845A (en) 1989-02-14
DE3773646D1 (en) 1991-11-14

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