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EP0922165B1 - Vacuum pump - Google Patents

Vacuum pump Download PDF

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Publication number
EP0922165B1
EP0922165B1 EP97944768A EP97944768A EP0922165B1 EP 0922165 B1 EP0922165 B1 EP 0922165B1 EP 97944768 A EP97944768 A EP 97944768A EP 97944768 A EP97944768 A EP 97944768A EP 0922165 B1 EP0922165 B1 EP 0922165B1
Authority
EP
European Patent Office
Prior art keywords
vacuum pump
pump according
inlet
valve
opening
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
EP97944768A
Other languages
German (de)
French (fr)
Other versions
EP0922165A1 (en
Inventor
Jürgen Meyer
Rudolf Bahnen
Hans-Josef Burghard
Wolfgang Giebmanns
Bernd Tennemann
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.)
Leybold GmbH
Original Assignee
Leybold Vakuum GmbH
Leybold Vacuum GmbH
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 Vakuum GmbH, Leybold Vacuum GmbH filed Critical Leybold Vakuum GmbH
Publication of EP0922165A1 publication Critical patent/EP0922165A1/en
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Publication of EP0922165B1 publication Critical patent/EP0922165B1/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
    • F04B25/00—Multi-stage pumps
    • F04B25/02—Multi-stage pumps of stepped piston type
    • 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
    • F04B25/00—Multi-stage pumps

Definitions

  • the invention relates to a vacuum pump with the Features of the preamble of claim 1.
  • vacuum pumps in one first pumping phase, starting from atmospheric pressure, relative large amounts of gas are generated. These are through the Pump pumped and compressed by the pump stage (s), what annoying, often harmful overpressures in the pump.
  • a vacuum pump of this type is known from US-A-22 46 932 known. It has two compression levels, the at high suction pressures in parallel, at low suction pressures operated one after the other. A control mechanism automatically initiates the switchover. at high suction pressures flow through the relatively large ones Quantities of gas unhindered the inlet valves. At this Pump has the problem mentioned.
  • a vacuum pump designed as a piston pump, in which the problem mentioned does not exist is from US-A-48 54 825 known.
  • the technology consists of two cylindrical compression chambers on the inlet side of two of the four stepped cylinders in parallel switched and form a first pump stage.
  • the cylindrical compression chamber of a third cylinder forms the second stage of the pump.
  • the ring-shaped Compression chambers of the three cylinders, their cylindrical Compression chambers the first and the second pump stage form, are not equipped with inlets; she have no pump function.
  • the cylindrical compression chamber the fourth cylinder forms a third Stage of the vacuum pump. Your outlet is immediately available the outlet of the pump in connection.
  • the ring-shaped Compression chamber of this stepped cylinder has also pump function; however, it forms together with only a bypass to their inlet and outlet the exit from the third pump stage immediately inflowing gases, i.e. that only a part of the from the Gases escaping from the third pump stage this annular compression chamber to exit the Pump arrives.
  • US 4 171 188 A discloses a compressor with a Inlet valve using an oil pressure cylinder is controlled to be adequate in the initial phase Ensure the oil supply to the compressor.
  • US 4 396 345 A, GB 1 089 694 A and DE 44 32 263 A disclose machines with inlet valves that are also not pressure controlled. The other documents disclose pressure-controlled valves, the However, the object of the present invention purpose lie far away.
  • the present invention is based on the object in a vacuum pump due to the accumulation of large amounts of gas resulting overpressures in a simple manner avoid.
  • a differential pressure controlled inlet valve of the invention Art is simple and robust. constructional Measures in the vacuum pump and / or a second outlet valve are not required.
  • the piston vacuum pump 1 shown in Figure 1 includes the housing 2, the inlet 3 and the outlet 4. Inside there are four cylinder-piston systems in the housing 11, 21, 31 and 41, which are essentially identical are trained. They are opposed to each other in pairs - preferably arranged in one plane - that their pistons have a common crankshaft 5 can be driven.
  • the drive motor is 6 designated.
  • the cylinder-piston system 11 has the cylinder 12 and the piston 13. Both are tiered so that they are in known a cylindrical compression chamber 14 and form an annular compression chamber 15.
  • the cylindrical compression chamber 14 has the Inlet 16 and outlet 17, the annular compression chamber 15 the inlet 18 and the outlet 19 on.
  • the Inlets 16 and 18 are ring grooves in the wall of the Cylinder 12 formed so that the movement of the piston 13 causes the inlets to open and close.
  • the outlets 17 and 19 are not shown in detail Valves equipped.
  • the cylinder-piston system 21, 31 and 41 are corresponding trained and with corresponding reference numerals Mistake.
  • entry is 3 via line 51 - e.g. with the valve 52 - with the Inlets 16, 18, 26, 28 of the compression chambers 14, 15, 24 and 25, which components of the piston-cylinder systems 11 and 21 are connected.
  • the above, in parallel switched compression chambers form a first pump stage the piston vacuum pump 1, indicated by the dash-dotted line 54.
  • Connected to the outlets 17, 19, 27 and 29 of the first stage compression chambers connecting lines all flow into the line 55, with the inlets 36, 38 of the compression chambers 34, 35 are connected. These are part of the piston-cylinder system 31.
  • the also connected in parallel Compression chambers 34, 35 form the second pump stage the piston vacuum pump 1, indicated by the dash-dotted line 57.
  • This compression chamber 44 forms the third pump stage the piston vacuum pump 1 (see dash-dotted line 61).
  • the outlet 47 of the compression chamber 44 protrudes line 62 with inlet 48 of the annular compression chamber 45 in connection, which is also a component of the piston-cylinder system 41.
  • the outlet 49 of the annular compression chamber 45 stands with the Outlet 4 of the piston vacuum pump 1 in connection.
  • the Compression chamber 45 forms the fourth pumping stage Piston vacuum pump 1 (dashed line 63).
  • a nozzle 64 is also indicated in FIG. 1, via which the compression space 45 with the inside of the housing 2 the pump 1 is connected.
  • the size of the nozzle 64 is selected so that there is a vacuum of a few hundred milibars. The requirements for the sealing quality of the gap between the pistons and the cylinders in their neighbors to the inside of the housing This can further reduce areas.
  • FIG 2 shows again the piston-cylinder system 11 with its compression chambers 14 and 15.
  • the inlets 16 and 18 of these chambers (together with the inlets 26, 28 of the second piston-cylinder system 21) via the Valve 52 in connection with the inlet 3 of the vacuum pump.
  • the valve 52 fulfills the function in a first Throttle the pumping phase, relatively large amounts of gas or temporarily withhold to such an extent, that pressures in pump 1 do not occur.
  • To the valve 52 has a chamber 65 with an inlet opening 66, an outlet opening 67 and a passage opening 72 on. Is at the level of the passage opening 72 the chamber is conical.
  • Located in chamber 65 a closure body 68 with a central Bore or opening 69.
  • two axially arranged Springs preferably compression springs 70 and 71 the spherical closure body on the outlet side 68 guided against rotation. Hold without gas flow the compression springs hover the closure body.
  • FIG. 3 shows a modification of the valve 52 according to FIG 2.
  • the closure body 68 is designed as a disc. Its outer edge is one that surrounds the passage opening 72 Seal ring 73 assigned.
  • high e.g. Atmospheric pressure
  • the approximately hemispherical closure body 68 according to Figure 2 the conical section of the chamber 65 (upper illustration of valve 52 in FIG. 2).
  • the disk 68 of the seal lies 73 on.
  • the passage openings 72 are each - except for the hole or opening 69 - closed. Just gas passing through the bore or opening 69 gets into the pump 1. The pumping speed is reduced. The size and length of the bore or opening 69 are selected so that pressures in pump 1 do not occur.
  • Figures 4 to 7 show further variants for a pressure-dependent inlet valve 52.
  • a closure body elastic discs 74 to 77 are provided, which only are attached to the housing at one point.
  • the disks 74, 76 and 77 have central openings 78, 79 and 80, respectively on.
  • the Washer 75 assigned a constantly open bypass opening 81.
  • the outer edges of the discs are 74 to 77 in each case surrounding the passage cross section 72 or 72 ' Seats 82 to 85 assigned.
  • the elastic valve disks are curved in the direction of the inlet opening 66, that they are only in the area of their attachment point fit their seats. Give in their rest position the respective passage opening 72 or 72 ' essentially free.
  • the disks lie 74 to 77 each their seats 82 to 85 completely on.
  • the pumping speed is throttled. It will determined by the size of the openings 78, 79, 80 in the Disks 74, 76, 77 or through the bypass opening 81 (in the embodiment of Figure 5). Relieves the pressure on the inlet side, the disks 74 to 77 lift from their Sit 82 to 84 and each give their passage cross sections 72 or 72 'free. The full pumping speed is then available.
  • valve systems 76, 84 and 77, 85 arranged one behind the other.
  • the Opening 79 in the suction-side disk 76 is larger than the opening 80 in the outlet-side disk 77.
  • FIG. 7 corresponds to the embodiment according to FIG. 5.
  • a rigid disc 8 is provided instead of the elastic disk 75 .
  • the attachment points the disc 88 are under the action of springs 89 and 90, such that one of the springs (spring 89) in the closing direction, the other (spring 90) in the opening direction acts.
  • Figure 8 shows the course of the pumping speed S in dependence to the pressure p for the solutions according to FIGS. 2 to 5 (solid curve 86) and for the solution according to FIG 6 (dash-dotted curve 87), in which two valve systems 76, 83 and 77, 84 arranged one behind the other are.
  • the pumping speed is low at high pressures (greater than p 1 ).
  • the closure bodies or disks 68, 74, 75 each release their passage openings 72.
  • the pumping speed increases up to its maximum value.
  • the valve disk 76 first releases its associated passage opening 72 at p 2 .
  • the pumping speed increases to a value which is determined by the opening 80 in the disk 77 still resting on its seat 85. If the pressure continues to decrease to p3, the disk 76 also opens its passage opening 72 ', so that the pumping speed assumes its maximum value.

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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 Vakuumpumpe mit den Merkmalen des Oberbegriffs des Patentanspruchs 1.The invention relates to a vacuum pump with the Features of the preamble of claim 1.

Bei Vakuumpumpen besteht das Problem, dass in einer ersten Pumpphase, ausgehend von Atmosphärendruck, relativ große Gasmengen anfallen. Diese werden durch die Pumpe gefördert und von der oder den Pumpstufen komprimiert, was störende, häufig schädliche Überdrücke in der Pumpe zur Folge hat.The problem with vacuum pumps is that in one first pumping phase, starting from atmospheric pressure, relative large amounts of gas are generated. These are through the Pump pumped and compressed by the pump stage (s), what annoying, often harmful overpressures in the pump.

Eine Vakuumpumpe dieser Art ist aus der US-A-22 46 932 bekannt. Sie weist zwei Kompressionsstufen auf, die bei hohen Ansaugdrücken parallel, bei niedrigen Ansaugdrücken hintereinander betrieben werden. Ein Steuermechanismus initiiert automatisch die Umschaltung. Bei hohen Ansaugdrücken durchströmen die relativ großen Gasmengen ungehindert die Eintrittsventile. Bei dieser Pumpe besteht das erwähnte Problem.A vacuum pump of this type is known from US-A-22 46 932 known. It has two compression levels, the at high suction pressures in parallel, at low suction pressures operated one after the other. A control mechanism automatically initiates the switchover. at high suction pressures flow through the relatively large ones Quantities of gas unhindered the inlet valves. At this Pump has the problem mentioned.

Eine als Kolbenpumpe ausgebildete Vakuumpumpe, bei der das erwähnte Problem nicht besteht, ist aus der US-A-48 54 825 bekannt. Bei dieser Pumpe nach dem Stand der Technik sind eintrittsseitig zwei zylindrische Kompressionskammern von zwei der vier gestuften Zylinder parallel geschaltet und bilden eine erste Pumpstufe. Die zylindrische Kompressionskammer eines dritten Zylinders bildet die zweite Stufe der Pumpe. Die ringförmigen Kompressionskammern der drei Zylinder, deren zylindrische Kompressionskammern die erste und die zweite Pumpstufe bilden, sind nicht mit Einlässen ausgerüstet; sie haben keine Pumpfunktion. Die zylindrische Kompressionskammer des vierten Zylinders bildet eine dritte Stufe der Vakuumpumpe. Ihr Auslaß steht unmittelbar mit dem Austritt der Pumpe in Verbindung. Die ringförmige Kompressionskammer dieses Stufen-Zylinders hat zwar ebenfalls Pumpfunktion; sie bildet jedoch zusammen mit ihrem Einlaß und ihrem Auslaß lediglich einen Bypass zu den aus der dritten Pumpstufe dem Austritt unmittelbar zuströmenden Gase, d.h., daß nur ein Teil der aus dem Auslaß der dritten Pumpstufe austretenden Gase über diese ringförmige Kompressionskammer zum Austritt der Pumpe gelangt. Eine echte vierte Pumpstufe bildet diese ringförmige Kompressionskammer nicht. Bei dieser Vakuumpumpe werden Überdrücke der geschilderten Art dadurch vermieden, dass der Auslass der ersten Pumpstufe über eine Bypassleitung unmittelbar mit einem als Rückschlagventil ausgebildeten Auslassventil verbunden ist. Diese Lösung ist technisch aufwendig und setzt die Existenz von zwei Aushilfsventilen voraus.A vacuum pump designed as a piston pump, in which the problem mentioned does not exist is from US-A-48 54 825 known. With this pump according to the state of the The technology consists of two cylindrical compression chambers on the inlet side of two of the four stepped cylinders in parallel switched and form a first pump stage. The cylindrical compression chamber of a third cylinder forms the second stage of the pump. The ring-shaped Compression chambers of the three cylinders, their cylindrical Compression chambers the first and the second pump stage form, are not equipped with inlets; she have no pump function. The cylindrical compression chamber the fourth cylinder forms a third Stage of the vacuum pump. Your outlet is immediately available the outlet of the pump in connection. The ring-shaped Compression chamber of this stepped cylinder has also pump function; however, it forms together with only a bypass to their inlet and outlet the exit from the third pump stage immediately inflowing gases, i.e. that only a part of the from the Gases escaping from the third pump stage this annular compression chamber to exit the Pump arrives. This is a real fourth pump stage annular compression chamber is not. With this vacuum pump become overpressures of the kind described avoided that the outlet of the first pump stage over a bypass line immediately with an as Check valve connected exhaust valve connected is. This solution is technically complex and sets the Existence of two auxiliary valves ahead.

Zum Stand der Technik gehört auch noch der Inhalt der Schriften

  • US 4 171 188 A,
  • US 4 396 345 A,
  • GB 1 089 694 A,
  • DE 44 32 263 A,
  • JP 60 085 280 A,
  • EP 0 704 622 und
  • US 2 269 620 A.
    • The content of the writings also belongs to the prior art
  • US 4 171 188 A,
  • US 4,396,345 A,
  • GB 1 089 694 A,
  • DE 44 32 263 A,
  • JP 60 085 280 A,
  • EP 0 704 622 and
  • US 2,269,620 A.

    • Die US 4 171 188 A offenbart einen Kompressor mit einem Eintrittsventil, das mit Hilfe eines Öldruckzylinders gesteuert wird, um in der Anfangsphase eine ausreichende Ölversorgung des Kompressors sicher zu stellen. Die Schriften US 4 396 345 A, GB 1 089 694 A und DE 44 32 263 A offenbaren Maschinen mit Eingangsventilen, die ebenfalls nicht druckgesteuert sind. Die weiteren Dokumente offenbaren zwar druckgesteuerte Ventile, deren Zweck jedoch dem Gegenstand der vorliegenden Erfindung fern liegen.US 4 171 188 A discloses a compressor with a Inlet valve using an oil pressure cylinder is controlled to be adequate in the initial phase Ensure the oil supply to the compressor. US 4 396 345 A, GB 1 089 694 A and DE 44 32 263 A disclose machines with inlet valves that are also not pressure controlled. The other documents disclose pressure-controlled valves, the However, the object of the present invention purpose lie far away.

    Der vorliegenden Erfindung liegt die Aufgabe zugrunde, in einer Vakuumpumpe infolge des Anfallens großer Gasmengen entstehende Überdrücke in einfacher Weise zu vermeiden.The present invention is based on the object in a vacuum pump due to the accumulation of large amounts of gas resulting overpressures in a simple manner avoid.

    Erfindungsgemäß wird diese Aufgabe durch die kennzeichenden Merkmale des Patentanspruches 1 gelöst.According to the invention, this object is achieved by the characterizing Features of claim 1 solved.

    Ein differenzdruckgesteuertes Eintrittsventil der erfindungsgemäßen Art ist einfach und robust. Bauliche Maßnahmen in der Vakuumpumpe und/oder ein zweites Austrittsventil sind nicht erforderlich.A differential pressure controlled inlet valve of the invention Art is simple and robust. constructional Measures in the vacuum pump and / or a second outlet valve are not required.

    Besonders zweckmäßig ist der Einsatz der Erfindung in einer mehrstufigen Kolbenvakuumpumpe, wie sie beispielsweise aus der US-A-48 54 825 bekannt ist. Dieses gilt insbesondere dann, wenn sie entsprechend den Ansprüchen 11 bis 14 ein verbessertes Saugvermögen und eine verbesserte Kompression aufweist. Dadurch, daß eintrittsseitig vier Kompressionskammern parallel geschaltet sind, ergibt sich ein besonders hohes Ansaugvermögen. Außerdem wird durch insgesamt vier Pumpstufen mit insgesamt acht Kompressionskammern eine hohe Kompression erreicht. Mit Pumpen der erfindungsgemäßen Art lassen sich Enddrücke von 10-4 mbar bei relativ hohem Saugvermögen erzeugen, so daß sie bei Applikationen, bei denen Arbeitskammern immer wieder relativ schnell auf niedrige Drücke evakuiert werden müssen, wie zum Beispiel die Schleusen von Halbleiter-Beschichtungsanlagen, besonders geeignet sind. Bei der Herstellung der Zylinder-Kolben-Systeme müssen besonders hohe Toleranzen nicht eingehalten werden. Der Grund dafür liegt in der besonderen Zuordnung der Kompressionskammern. Während des Betriebs der drei Zylinder-Kolben-Systeme, welche die ersten beiden Pumpstufen bilden, herrschen jeweils in den vom Kolben getrennten Kompressionskammern etwa gleiche Drücke, so daß an die Abdichtung zwischen Zylinder und Kolben keine hohen Anforderungen gestellt werden müssen. Beim vierten Zylinder-Kolben-System treten zwar unterschiedliche Drücke in den beiden Kompressionskammern auf; da dieses Zylinder-Kolben-System jedoch austrittsseitig gelegen ist, sind die auftretenden Druckverhältnisse nicht mehr hoch.It is particularly useful to use the invention in a multi-stage piston vacuum pump, as is known, for example, from US Pat. No. 4,854,825. This applies in particular if it has an improved pumping speed and an improved compression in accordance with claims 11 to 14. The fact that four compression chambers are connected in parallel on the inlet side results in a particularly high suction capacity. In addition, a high level of compression is achieved through a total of four pump stages with a total of eight compression chambers. With pumps of the type according to the invention, final pressures of 10 -4 mbar can be generated at a relatively high pumping speed, so that they are particularly useful in applications in which working chambers have to be evacuated relatively quickly to low pressures, such as the locks of semiconductor coating systems are suitable. Particularly high tolerances do not have to be observed when manufacturing the cylinder-piston systems. The reason for this is the special assignment of the compression chambers. During the operation of the three cylinder-piston systems, which form the first two pumping stages, approximately the same pressures prevail in the compression chambers separated from the piston, so that no high demands have to be made on the seal between the cylinder and the piston. With the fourth cylinder-piston system, different pressures occur in the two compression chambers; however, since this cylinder-piston system is located on the outlet side, the pressure conditions that occur are no longer high.

    Weitere Vorteile und Einzelheiten der Erfindung sollen anhand von in den Figuren 1 und 7 schematisch dargestellten Ausführungsbeispielen erläutert werden.Further advantages and details of the invention are intended with the aid of those shown schematically in FIGS Exemplary embodiments are explained.

    Es zeigen

    • Figur 1 ein Ausführungsbeispiel für eine als Kolbenpumpe ausgebildete Vakuumpumpe nach der Erfindung,
    • Figur 2 eines der eintrittsseitig gelegenen Zylinder-Kolben-Systeme mit einem differenzdruckgesteuerten Eintrittsventil,
    • Figuren 3 bis 7 weitere Ausführungsbeispiele für differenzdruckgesteuerte Ventile und
    • Figur 8 ein Diagramm, in dem das Saugvermögen in Abhängigkeit vom Einlassdruck dargestellt ist.
    Show it
    • FIG. 1 shows an exemplary embodiment of a vacuum pump designed as a piston pump according to the invention,
    • FIG. 2 one of the cylinder-piston systems on the inlet side with an inlet valve controlled by differential pressure,
    • Figures 3 to 7 further embodiments for differential pressure controlled valves and
    • Figure 8 is a diagram showing the pumping speed as a function of the inlet pressure.

    Die in Figur 1 dargestellte Kolbenvakuumpumpe 1 umfaßt das Gehäuse 2, den Eintritt 3 und den Austritt 4. Innerhalb des Gehäuses befinden sich vier Zylinder-Kolben-Systeme 11, 21, 31 und 41, die im wesentlichen identisch ausgebildet sind. Sie sind derart paarweise einander gegenüberliegend - vorzugsweise in einer Ebene - angeordnet, daß ihre Kolben über eine gemeinsame Kurbelwelle 5 angetrieben werden können. Der Antriebsmotor ist mit 6 bezeichnet.The piston vacuum pump 1 shown in Figure 1 includes the housing 2, the inlet 3 and the outlet 4. Inside there are four cylinder-piston systems in the housing 11, 21, 31 and 41, which are essentially identical are trained. They are opposed to each other in pairs - preferably arranged in one plane - that their pistons have a common crankshaft 5 can be driven. The drive motor is 6 designated.

    Das Zylinder-Kolben-System 11 weist den Zylinder 12 und den Kolben 13 auf. Beide sind gestuft, so daß sie in an sich bekannter Weise eine zylindrische Kompressionskammer 14 und eine ringförmige Kompressionskammer 15 bilden. Die zylindrische Kompressionskammer 14 weist den Einlaß 16 und den Auslaß 17, die ringförmige Kompressionskammer 15 den Einlaß 18 und den Auslaß 19 auf. Die Einlässe 16 und 18 sind als Ringnuten in der Wandung des Zylinders 12 ausgebildet, so daß die Bewegung des Kolbens 13 das Öffnen und Schließen der Einlässe bewirkt. Die Auslässe 17 und 19 sind mit im einzelnen nicht dargestellten Ventilen ausgerüstet.The cylinder-piston system 11 has the cylinder 12 and the piston 13. Both are tiered so that they are in known a cylindrical compression chamber 14 and form an annular compression chamber 15. The cylindrical compression chamber 14 has the Inlet 16 and outlet 17, the annular compression chamber 15 the inlet 18 and the outlet 19 on. The Inlets 16 and 18 are ring grooves in the wall of the Cylinder 12 formed so that the movement of the piston 13 causes the inlets to open and close. The outlets 17 and 19 are not shown in detail Valves equipped.

    Die Zylinder-Kolben-System 21, 31 und 41 sind entsprechend ausgebildet und mit korrespondierenden Bezugszeichen versehen.The cylinder-piston system 21, 31 and 41 are corresponding trained and with corresponding reference numerals Mistake.

    Entsprechend dem Erfindungsvorschlag ist der Eintritt 3 über die Leitung 51 - z.B. mit dem Ventil 52 - mit den Einlässen 16, 18, 26, 28 der Kompressionskammern 14, 15, 24 und 25, welche Bestandteile der Kolben-Zylinder-Systeme 11 und 21 sind, verbunden. Die genannten, parallel geschalteten Kompressionskammern bilden eine erste Pumpstufe der Kolbenvakuumpumpe 1, angedeutet durch die strichpunktierte Linie 54. Die sich an die Auslässe 17, 19, 27 und 29 der Kompressionskammern der ersten Stufe anschließenden Leitungen münden sämtlich in die Leitung 55, die mit den Einlässen 36, 38 der Kompressionskammern 34, 35 verbunden sind. Diese sind Bestandteile des Kolben-Zylinder-Systems 31. Die ebenfalls parallel geschalteten Kompressionskammern 34, 35 bilden die zweite Pumpstufe der Kolbenvakuumpumpe 1, angedeutet durch die strichpunktierte Linie 57. Die sich an die Auslässe 37, 39 der Kompressionskammern 34, 35 anschließenden Leitungen münden in die Leitung 59, die mit dem Einlaß 46 der zylindrischen Kompressionskammer 44 verbunden ist, welche Bestandteil des Zylinder-Kolben-Systems 41 ist. Diese Kompressionskammer 44 bildet die dritte Pumpstufe der Kolbenvakuumpumpe 1 (siehe strichpunktierte Linie 61). Der Auslaß 47 der Kompressionskammer 44 steht über die Leitung 62 mit dem Einlaß 48 der ringförmigen Kompressionskammer 45 in Verbindung, welche ebenfalls Bestandteil des Kolben-Zylinder-Systems 41 ist. Der Auslaß 49 der ringförmigen Kompressionskammer 45 steht mit dem Austritt 4 der Kolbenvakuumpumpe 1 in Verbindung. Die Kompressionskammer 45 bildet die vierte Pumpstufe der Kolbenvakuumpumpe 1 (gestrichelte Linie 63).According to the proposed invention, entry is 3 via line 51 - e.g. with the valve 52 - with the Inlets 16, 18, 26, 28 of the compression chambers 14, 15, 24 and 25, which components of the piston-cylinder systems 11 and 21 are connected. The above, in parallel switched compression chambers form a first pump stage the piston vacuum pump 1, indicated by the dash-dotted line 54. Connected to the outlets 17, 19, 27 and 29 of the first stage compression chambers connecting lines all flow into the line 55, with the inlets 36, 38 of the compression chambers 34, 35 are connected. These are part of the piston-cylinder system 31. The also connected in parallel Compression chambers 34, 35 form the second pump stage the piston vacuum pump 1, indicated by the dash-dotted line 57. Which adjoins the outlets 37, 39 of the compression chambers 34, 35 connecting lines open into line 59, which with the inlet 46 of the cylindrical compression chamber 44 which is connected Is part of the cylinder-piston system 41. This compression chamber 44 forms the third pump stage the piston vacuum pump 1 (see dash-dotted line 61). The outlet 47 of the compression chamber 44 protrudes line 62 with inlet 48 of the annular compression chamber 45 in connection, which is also a component of the piston-cylinder system 41. The outlet 49 of the annular compression chamber 45 stands with the Outlet 4 of the piston vacuum pump 1 in connection. The Compression chamber 45 forms the fourth pumping stage Piston vacuum pump 1 (dashed line 63).

    Angedeutet ist in Figur 1 noch eine Düse 64, über die der Kompressionsraum 45 mit dem Inneren des Gehäuses 2 der Pumpe 1 in Verbindung steht. Die Größe der Düse 64 ist so gewählt, daß sich im Gehäuse 2 ein Unterdruck von wenigen hundert Milibar einstellt. Die Anforderungen an die Dichtqualität des Spaltes zwischen den Kolben und den Zylindern in ihren dem Gehäuseinnern benachbarten Bereichen können dadurch weiter reduziert werden. A nozzle 64 is also indicated in FIG. 1, via which the compression space 45 with the inside of the housing 2 the pump 1 is connected. The size of the nozzle 64 is selected so that there is a vacuum of a few hundred milibars. The requirements for the sealing quality of the gap between the pistons and the cylinders in their neighbors to the inside of the housing This can further reduce areas.

    Figur 2 zeigt nochmals das Kolben-Zylinder-System 11 mit seinen Kompressionskammern 14 und 15. Die Einlässe 16 und 18 dieser Kammern stehen (zusammen mit den Einlässen 26, 28 des zweiten Kolben-Zylinder-Systems 21) über das Ventil 52 mit dem Eintritt 3 der Vakuumpumpe in Verbindung.Figure 2 shows again the piston-cylinder system 11 with its compression chambers 14 and 15. The inlets 16 and 18 of these chambers (together with the inlets 26, 28 of the second piston-cylinder system 21) via the Valve 52 in connection with the inlet 3 of the vacuum pump.

    Das Ventil 52 erfüllt die Funktion, die in einer ersten Pumpphase anfallenden, relativ großen Gasmengen zu drosseln bzw. in solchem Umfang zeitweise zurückzuhalten, daß Überdrücke in der Pumpe 1 nicht auftreten. Dazu weist das Ventil 52 eine Kammer 65 mit einer Einlaßöffnung 66, einer Auslaßöffnung 67 und einer Durchtrittsöffnung 72 auf. In Höhe der Durchtrittsöffnung 72 ist die Kammer kegelförmig gestaltet. In der Kammer 65 befindet sich ein Verschlußkörper 68 mit einer zentralen Bohrung bzw. Öffnung 69. Mit Hilfe von zwei axial angeordneten Federn, vorzugsweise Druckfedern 70 und 71 ist der austrittsseitig kugelförmig gestaltete Verschlußkörper 68 verdrehsicher geführt. Ohne Gasströmung halten die Druckfedern den Verschlußkörper in der Schwebe.The valve 52 fulfills the function in a first Throttle the pumping phase, relatively large amounts of gas or temporarily withhold to such an extent, that pressures in pump 1 do not occur. To the valve 52 has a chamber 65 with an inlet opening 66, an outlet opening 67 and a passage opening 72 on. Is at the level of the passage opening 72 the chamber is conical. Located in chamber 65 a closure body 68 with a central Bore or opening 69. With the help of two axially arranged Springs, preferably compression springs 70 and 71 the spherical closure body on the outlet side 68 guided against rotation. Hold without gas flow the compression springs hover the closure body.

    Figur 3 zeigt eine Abwandlung des Ventiles 52 nach Figur 2. Der Verschlusskörper 68 ist als Scheibe ausgebildet. Ihrem äußeren Rand ist ein die Durchtrittsöffnung 72 umgebender Dichtring 73 zugeordnet.FIG. 3 shows a modification of the valve 52 according to FIG 2. The closure body 68 is designed as a disc. Its outer edge is one that surrounds the passage opening 72 Seal ring 73 assigned.

    Zur Funktion der Ventile 52 nach den Figuren 2 und 3 folgendes:For the function of the valves 52 according to FIGS. 2 and 3 following:

    Ist der Druck im zu evakuierenden Rezipienten, angeschlossen an den Eintritt 3, hoch, z.B. Atmosphärendruck, liegt der etwa halbkugelförmige Verschlußkörper 68 nach Figur 2 dem kegelförmigen Abschnitt der Kammer 65 an (obere Darstellung des Ventils 52 in Figur 2). Beim Ventil nach Figur 3 liegt die Scheibe 68 der Dichtung 73 auf. Die Durchtrittsöffnungen 72 sind jeweils - bis auf die Bohrung bzw. Öffnung 69 - geschlossen. Nur durch die Bohrung bzw. Öffnung 69 hindurchtretendes Gas gelangt in die Pumpe 1. Das Saugvermögen ist gedrosselt. Größe und Länge der Bohrung bzw. Öffnung 69 sind so gewählt, daß Überdrücke in der Pumpe 1 nicht auftreten.Is the pressure in the recipient to be evacuated connected at entrance 3, high, e.g. Atmospheric pressure, is the approximately hemispherical closure body 68 according to Figure 2 the conical section of the chamber 65 (upper illustration of valve 52 in FIG. 2). In the valve according to FIG. 3, the disk 68 of the seal lies 73 on. The passage openings 72 are each - except for the hole or opening 69 - closed. Just gas passing through the bore or opening 69 gets into the pump 1. The pumping speed is reduced. The size and length of the bore or opening 69 are selected so that pressures in pump 1 do not occur.

    Nimmt der Druck eintrittsseitig ab, hebt sich der Verschlußkörper 68 von seinem Sitz ab, so daß er von Gasen umströmt werden kann. Der Strömungsquerschnitt 72 im Bereich des Ventils 52 nimmt drastisch zu, so daß das Saugvermögen der Pumpe 1 durch das Ventil 52 nicht mehr begrenzt ist. Mit Hilfe der der Druckfedern 70 und 71 ist der Differenzdruck, bei dem das Abheben des Verschlußkörpers 68 von seinem Sitz erfolgt, einstellbar.If the pressure decreases on the inlet side, the closure body rises 68 from his seat so that he is out of gases can flow around. The flow cross section 72 in the area of the valve 52 increases dramatically, so that Pumping capacity of the pump 1 no longer through the valve 52 is limited. With the help of the compression springs 70 and 71 is the differential pressure at which the closure body is lifted off 68 takes place from its seat, adjustable.

    Die Figuren 4 bis 7 zeigen weitere Varianten für ein druckabhängiges Einlassventil 52. Als Verschlusskörper sind elastische Scheiben 74 bis 77 vorgesehen, die nur an einer Stelle am Gehäuse befestigt sind. Die Scheiben 74, 76 und 77 weisen zentrale Öffnungen 78, 79 bzw. 80 auf. Beim Ausführungsbeispiel nach Figur 5 ist der Scheibe 75 eine ständig offene Bypass-Öffnung 81 zugeordnet. Den äußeren Rändern der Scheiben 74 bis 77 sind jeweils den Durchtrittsquerschnitt 72 bzw. 72' umgebende Sitze 82 bis 85 zugeordnet. Die elastischen Ventilscheiben sind derart in Richtung Eintrittsöffnung 66 gekrümmt, dass sie nur im Bereich ihres Befestigungspunktes ihren Sitzen anliegen. In ihrer Ruhestellung geben sie damit die jeweilige Durchtrittsöffnung 72 bzw. 72' im wesentlichen frei.Figures 4 to 7 show further variants for a pressure-dependent inlet valve 52. As a closure body elastic discs 74 to 77 are provided, which only are attached to the housing at one point. The disks 74, 76 and 77 have central openings 78, 79 and 80, respectively on. In the embodiment of Figure 5 is the Washer 75 assigned a constantly open bypass opening 81. The outer edges of the discs are 74 to 77 in each case surrounding the passage cross section 72 or 72 ' Seats 82 to 85 assigned. The elastic valve disks are curved in the direction of the inlet opening 66, that they are only in the area of their attachment point fit their seats. Give in their rest position the respective passage opening 72 or 72 ' essentially free.

    Zur Funktion: Ist der Druck im zu evakuierenden Rezipienten hoch, z.B. Atmosphärendruck, liegen die Scheiben 74 bis 77 jeweils ihren Sitzen 82 bis 85 vollständig auf. Das Saugvermögen ist jeweils gedrosselt. Es wird bestimmt durch die Größe der Öffnungen 78, 79, 80 in den Scheiben 74, 76, 77 bzw. durch die Bypass-Öffnung 81 (beim Ausführungsbeispiel nach Figur 5). Nimmt der Druck eintrittsseitig ab, heben die Scheiben 74 bis 77 von ihren Sitzen 82 bis 84 ab und geben jeweils ihre Durchlassquerschnitte 72 bzw. 72' frei. Das volle Saugvermögen steht dann zur Verfügung.Function: Is the pressure in the recipient to be evacuated high, e.g. Atmospheric pressure, the disks lie 74 to 77 each their seats 82 to 85 completely on. The pumping speed is throttled. It will determined by the size of the openings 78, 79, 80 in the Disks 74, 76, 77 or through the bypass opening 81 (in the embodiment of Figure 5). Relieves the pressure on the inlet side, the disks 74 to 77 lift from their Sit 82 to 84 and each give their passage cross sections 72 or 72 'free. The full pumping speed is then available.

    Beim Ausführungsbeispiel nach Figur 6 sind zwei Ventilsysteme 76, 84 und 77, 85 hintereinander angeordnet. Die Öffnung 79 in der ansaugseitigen Scheibe 76 ist größer als die Öffnung 80 in der auslassseitigen Scheibe 77.In the embodiment of Figure 6 are two valve systems 76, 84 and 77, 85 arranged one behind the other. The Opening 79 in the suction-side disk 76 is larger than the opening 80 in the outlet-side disk 77.

    Die Ausführung nach Figur 7 entspricht der Ausführung nach Figur 5. Anstelle der elastischen Scheibe 75 ist eine starre Scheibe 8 vorgesehen. Mit zwei im wesentlichen einander gegenüberliegenden Stellen des Randes ist sie am Ventilsitz 83 befestigt. Die Befestigungspunkte der Scheibe 88 stehen unter der Wirkung von Federn 89 und 90, und zwar derart, dass eine der Federn (Feder 89) in Schließrichtung, die andere (Feder 90) in Öffnungsrichtung wirkt.The embodiment according to FIG. 7 corresponds to the embodiment according to FIG. 5. Instead of the elastic disk 75 a rigid disc 8 is provided. With two essentially opposite sides of the edge attached to valve seat 83. The attachment points the disc 88 are under the action of springs 89 and 90, such that one of the springs (spring 89) in the closing direction, the other (spring 90) in the opening direction acts.

    Figur 8 zeigt den Verlauf des Saugvermögens S in Abhängigkeit zum Druck p für die Lösungen nach den Figuren 2 bis 5 (ausgezogene Kurve 86) und für die Lösung nach Figur 6 (strichpunktierte Kurve 87), bei welcher zwei Ventilsysteme 76, 83 und 77, 84 hintereinander angeordnet sind.Figure 8 shows the course of the pumping speed S in dependence to the pressure p for the solutions according to FIGS. 2 to 5 (solid curve 86) and for the solution according to FIG 6 (dash-dotted curve 87), in which two valve systems 76, 83 and 77, 84 arranged one behind the other are.

    Bei den Lösungen mit einem einfachen Ventilsystem ist das Saugvermögen bei hohen Drücken (größer p1) niedrig. Bei p1 geben die Verschlusskörper bzw. Scheiben 68, 74, 75 ihre Durchtrittsöffnungen 72 jeweils frei. Das Saugvermögen steigt bis auf seinen maximalen Wert an. Bei der Lösung nach Figur 6 gibt bei p2 zunächst die Ventilscheibe 76 ihre zugehörige Durchtrittsöffnung 72 frei. Das Saugvermögen steigt auf einen Wert, der durch die Öffnung 80 in der ihrem Sitz 85 noch aufliegenden Scheibe 77 bestimmt ist. Nimmt der Druck weiter ab auf p3, gibt auch die Scheibe 76 ihre Durchtrittsöffnung 72' frei, so dass das Saugvermögen seinen maximalen Wert annimmt.In the case of solutions with a simple valve system, the pumping speed is low at high pressures (greater than p 1 ). At p 1 , the closure bodies or disks 68, 74, 75 each release their passage openings 72. The pumping speed increases up to its maximum value. In the solution according to FIG. 6, the valve disk 76 first releases its associated passage opening 72 at p 2 . The pumping speed increases to a value which is determined by the opening 80 in the disk 77 still resting on its seat 85. If the pressure continues to decrease to p3, the disk 76 also opens its passage opening 72 ', so that the pumping speed assumes its maximum value.

    Claims (14)

    1. Vacuum pump with an inlet (3), an outlet (4) and a differential-pressure-controlled inlet valve (52), characterised in that the inlet valve (52) is designed in such a way that it throttles the suction capacity of the vacuum pump at a high inlet pressure, part of the inlet valve (52) being a valve system with a seat and a closure element which assumes its closed position at a high inlet pressure, the valve system being equipped with an opening (69, 78, 79, 80, 81) which is open even in the closed position of the closure element.
    2. Vacuum pump according to Claim 1, characterised in that the opening (69, 78, 79, 80) is provided in the closure element (68, 74, 76, 77).
    3. Vacuum pump according to Claim 1, characterised in that the opening (81) is a bypass opening.
    4. Vacuum pump according to one of Claims 1 to 3, characterised in that the closure element (68) is arranged between two springs (70, 71).
    5. Vacuum pump according to one of Claims 1 to 4, characterised in that the closure element (68) is of hemispherical design and in that its seat surrounding the through-opening (72) has a spherical shape.
    6. Vacuum pump according to one of Claims 1 to 4, characterised in that the closure element has the form of a disc (68, 74, 75, 76, 77, 88).
    7. Vacuum pump according to Claim 6, characterised in that the disc (74, 75, 76, 77) consists of elastic material, is curved in the direction of the inlet and is fastened to the seat at only one place.
    8. Vacuum pump according to Claim 6, characterised in that the disc (88) is rigid and is fastened, at two substantially mutually opposite places on its edge, to the valve seat via springs (89, 90), in such a way that one spring acts in the opening direction and the other in the closing direction.
    9. Vacuum pump according to one of Claims 1 to 8, characterised in that two valve systems (76, 84; 77, 85) are arranged one behind the other.
    10. Vacuum pump according to one of Claims 1 to 10, characterised in that it is a multi-stage reciprocating vacuum pump.
    11. Vacuum pump according to Claim 10, characterised in that it is equipped with an inlet (3), with an outlet (4) and with four stepped cylinders (12, 22, 32, 42) which, together with in each case a stepped piston (13, 23, 33, 43), form in each case a cylindrical compression chamber (14, 24, 34, 44) and an annular compression chamber (15, 25, 35, 45), in that it has four series-connected pumping stages (54, 57, 61, 63) during its normal operation and in that four parallel-connected compression chambers (14, 15, 24, 25) form the first stage.
    12. Vacuum pump according to Claim 11, characterised in that each of the eight compression chambers is equipped with an entrance and with an exit, in that the inlet (3) of the pump (1) is connected to the entrances (16, 18, 26, 28) of the four compression chambers (14, 15, 24, 25) of two cylinders (12, 22), in that the exits (17, 19, 27, 29) of these four compression chambers are connected to the two entrances (36, 38) of the two compression chambers (34, 35) of a third cylinder (32), in that the exits (37, 39) of these two compression chambers (34, 35) are connected to the entrance of the cylindrical compression chamber (44) of the fourth cylinder (41) and in that the exit (47) of this cylindrical compression chamber (44) is connected to the entrance (48) of the annular compression chamber (45) of the fourth cylinder (42).
    13. Vacuum pump according to Claim 11 or 12, characterised in that the cylinder-piston systems (11, 21, 31, 41) are arranged in pairs opposite one another in such a way that their pistons (13, 23, 33, 43) can be driven by a common crankshaft (5).
    14. Vacuum pump according to Claim 11, 12 or 13, characterised in that the pump (1) is equipped with a sealed housing (2) which is connected via a nozzle (64) to one of the compression chambers, preferably to the annular compression chamber (45) located on the outlet side.
    EP97944768A 1996-08-27 1997-08-19 Vacuum pump Expired - Lifetime EP0922165B1 (en)

    Applications Claiming Priority (3)

    Application Number Priority Date Filing Date Title
    DE19634519A DE19634519A1 (en) 1996-08-27 1996-08-27 Piston vacuum pump with inlet and outlet
    DE19634519 1996-08-27
    PCT/EP1997/004509 WO1998009079A1 (en) 1996-08-27 1997-08-19 Inlet valve with a choke effect and multi-stage piston vacuum pump

    Publications (2)

    Publication Number Publication Date
    EP0922165A1 EP0922165A1 (en) 1999-06-16
    EP0922165B1 true EP0922165B1 (en) 2004-11-03

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    ID=7803766

    Family Applications (2)

    Application Number Title Priority Date Filing Date
    EP97936688A Expired - Lifetime EP0922163B1 (en) 1996-08-27 1997-08-06 Vacuum piston pump with an inlet and an outlet
    EP97944768A Expired - Lifetime EP0922165B1 (en) 1996-08-27 1997-08-19 Vacuum pump

    Family Applications Before (1)

    Application Number Title Priority Date Filing Date
    EP97936688A Expired - Lifetime EP0922163B1 (en) 1996-08-27 1997-08-06 Vacuum piston pump with an inlet and an outlet

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    EP (2) EP0922163B1 (en)
    DE (3) DE19634519A1 (en)
    WO (2) WO1998009077A1 (en)

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    DE19926186A1 (en) * 1999-06-09 2000-12-14 Leybold Vakuum Gmbh Piston vacuum pump with outlet valve
    DE19955688A1 (en) 1999-11-19 2001-05-23 Leybold Vakuum Gmbh Piston vacuum pump comprises a piston and a connecting rod which are joined to one another by means of an elastic unit
    DE19962445A1 (en) 1999-12-22 2001-06-28 Leybold Vakuum Gmbh Dry compressing vacuum pump has gas ballast device with valve that only opens when difference between atmospheric pressure and pressure on pump side of valve exceeds set value
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    DE10127082A1 (en) * 2001-06-02 2002-12-05 Leybold Vakuum Gmbh Multiple stage piston vacuum pump has pair of pistons defining multiple pumping stages with inlet and outlet valves

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    Also Published As

    Publication number Publication date
    DE59712067D1 (en) 2004-12-09
    DE59705578D1 (en) 2002-01-10
    WO1998009079A1 (en) 1998-03-05
    EP0922165A1 (en) 1999-06-16
    WO1998009077A1 (en) 1998-03-05
    DE19634519A1 (en) 1998-03-05
    EP0922163B1 (en) 2001-11-28
    EP0922163A1 (en) 1999-06-16

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