EP1476661B1 - Vacuum pump - Google Patents

Vacuum pump Download PDF

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Publication number
EP1476661B1
EP1476661B1 EP03702650A EP03702650A EP1476661B1 EP 1476661 B1 EP1476661 B1 EP 1476661B1 EP 03702650 A EP03702650 A EP 03702650A EP 03702650 A EP03702650 A EP 03702650A EP 1476661 B1 EP1476661 B1 EP 1476661B1
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EP
European Patent Office
Prior art keywords
rotor
seal
bearing
oil
vacuum pump
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
EP03702650A
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German (de)
French (fr)
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EP1476661A1 (en
Inventor
Thomas Dreifert
Wolfgang Giebmanns
Hans-Rochus Gross
Hartmut Kriehn
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
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Publication date
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Publication of EP1476661A1 publication Critical patent/EP1476661A1/en
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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
    • F04C27/008—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids for other than working fluid, i.e. the sealing arrangements are not between working chambers of the machine
    • F04C27/009—Shaft sealings specially adapted for pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2220/00—Application
    • F04C2220/40—Pumps with means for venting areas other than the working chamber, e.g. bearings, gear chambers, shaft seals

Definitions

  • the invention relates to a vacuum pump with at least one rotor shaft, which has a rotor section with a rotor, a bearing section with a bearing and axially between the rotor section and the bearing section a shaft seal arrangement.
  • Such vacuum pumps can be designed, inter alia, as screw pumps, side channel blower, and Roots pumps.
  • the mentioned vacuum pumps have in common that they are dry-compressing vacuum pumps with oil or grease lubricated bearings and / or gearboxes. These pumps are typically used to generate pre-vacuum.
  • the task of the sealing arrangement between the actual rotor and the bearing or gearbox is firstly to prevent gas from passing from the rotor section to the bearing section and secondly to prevent the passage of fluid from the bearing section into the rotor section.
  • rotor speeds and small rotor shaft diameters For example, in the form of radial shaft seals, slip rings, etc.
  • only contact-free shaft seals can be used, which, however, can not completely exclude leaks due to the design.
  • a known non-contact shaft seal assembly consists of one or more piston seals as a gas seal and an oil spray ring as an oil seal.
  • this can not achieve a reliable and high sealing effect.
  • the gas compressed in the rotor section should not come into contact with the oil from the bearing section, since the oil may be decomposed thereby and thereby lose its lubricity.
  • the escaping oil, gas or gas mixture can also be toxic or explosive and therefore dangerous.
  • the object of the invention is therefore to improve in a vacuum pump, the gas seal and an oil seal having shaft seal.
  • the shaft seal arrangement is designed such that between the rotor-side gas seal and the bearing-side oil seal a surrounding the rotor shaft separation chamber is provided which is vented through at least one separation chamber ventilation duct.
  • the ventilation duct Through the ventilation duct, the separation chamber is adjusted to a desired gas pressure. This ensures that the drop across the gas seal pressure difference and the above the oil seal decreasing pressure difference can be adjusted.
  • the separation chamber can be acted upon by the ventilation duct, for example, with atmospheric gas pressure or with the bearing-side gas pressure, so that the gas pressure in the separation chamber is not below the bearing-side gas pressure. In this way it can be avoided that the oil migrates from the bearing side through the oil seal towards the separation chamber.
  • the separation chamber gas pressure can be set higher, so that explosive and / or toxic gases from the rotor section can not escape through the gas seal.
  • a shaft seal arrangement is realized, which prevents a passage of gas from the rotor section into the bearing section and oil from the bearing section in the rotor section in a simple manner and reliably even with structurally imperfect gas and oil seals.
  • For the separation chamber only a small manufacturing effort and space is required, so that a small and effective means a compact and effective shaft seal arrangement is realized.
  • the separation chamber ventilation channel opens outside the pump into the surrounding atmosphere. In this way prevails in the separation chamber always atmospheric pressure and the same gas pressure as in the bearing housing, since this is also vented to the environment. The pressure gradient across the oil seal is then practically equal to zero, so that due to lack of pressure difference and no oil from the bearing section in the direction of separation chamber or rotor section is pressed.
  • the gas seal and the oil seal are each designed as non-contact seals.
  • the shaft seal arrangement can also be used in vacuum pumps be used with high speeds and high rotor shaft diameters.
  • the gas seal is designed as a gap seal or as a labyrinth seal, with piston rings or with floating sealing rings.
  • the gas seal is in any case a contact-free throttle seal, which reduces the gas passage to an unavoidable minimum.
  • the labyrinth seal of the gas seal has at least one piston ring, which projects into an annular groove of the rotor shaft.
  • the piston ring is biased outwards and therefore fixed on the housing side and fixed.
  • the piston ring protrudes into the rotor shaft annular groove, whereby a labyrinth-like gap is formed between the piston ring and the annular groove, which acts as a throttle seal.
  • the gas seal may have a plurality of such labyrinth seals arranged axially one behind the other.
  • the oil seal on the rotor shaft on a rotating slinger which projects into a housing-side annular centrifugal chamber, which is connected to an oil return passage to the bearing housing. In this way, an effective non-contact oil seal is created.
  • radial and / or axial non-conical or conical gaps are formed between the oil slinger and the housing-side Schleuderschdonn.
  • the slinger and the opposing fixed walls are designed so that the incoming oil is thrown outwards with the rotor shaft rotating and the unsprayed oil runs down into the return channel.
  • the oil seal on the axial rotor side of the oil slinger preferably has at least one annular trap chamber with an oil drain channel which opens into the bearing housing.
  • the oil seal thus consists of two or more axially behind one another centrifugal or catch chambers with an oil drain channel.
  • the oil drainage channels can be combined in a single channel, but it can also be associated with each separate centrifugal or catching chamber own separate oil drain channel. As a result, mutual disturbances in the oil flow are excluded, so that the oil seal is only slightly affected even in case of disturbances in an oil drain channel in their sealing effect.
  • each spin or catch chamber of the oil seal is assigned at least one ventilation duct.
  • the ventilation duct can be outwardly to the atmosphere but should preferably be led back to the bearing housing.
  • the centrifugal chambers can be ventilated via a single common ventilation duct, or else via at least one separate ventilation duct in each case. Ventilation through the ventilation channels ensures that there is no pressure difference within the oil seal, ie between the individual centrifugal chambers. A gas flow and thus entrainment of oil in the direction of separation chamber or rotor section is thus practically impossible. The transfer of gases from the separation chamber in the direction of the bearing housing is therefore largely prevented.
  • the separation chamber venting channel opens in the vicinity of the lowest point of the separation chamber and has a slope, so that any leaking liquid can drain from the separation chamber. Even if oil or other liquids from the storage section or from the Rotor section should reach the separation chamber, this could run outward. This ensures that no liquid can accumulate in the separation chamber.
  • the bearing is formed axially capped on the rotor side.
  • a first barrier for oil is already between the bearing and the shaft seal arrangement. or other liquids from the warehouse realized.
  • the rotor shaft is designed as a flying rotor shaft, which is mounted only on the pressure side of the rotor section, on the suction side of the rotor section
  • the rotor shaft is designed to be free of bearings. In this way, a bearing in the range of greater negative pressure is avoided, so that even with large pressure differences problematic shaft seal arrangement is avoided on the suction side of the rotor shaft.
  • flying rotor shafts have a relatively large shaft diameter. Only by the present shaft seal arrangement and the provision of a separation chamber between the gas seal and the oil seal can be sealed with large rotor shaft diameters high peripheral velocities must be taken without an unreasonably large leakage in purchasing.
  • a barrier gas source is connected to the separation chamber ventilation duct through which a sealing gas is introduced into the separation chamber under overpressure. This is necessary and useful if toxic and / or explosive gases are conveyed in the rotor section. By feeding the separation gas, a small separation gas flow is generated from the separation chamber in the direction of the rotor section. In this way, the escape of gas from the rotor section can be prevented.
  • a barrier gas for example, air or nitrogen can be used.
  • a seal gas line is additionally provided from the seal gas source to the bearing housing or the bearing portion. This ensures that there is no significant pressure drop across the oil seal.
  • the sealing gas has a pressure of, for example, 1.3 bar.
  • the in the FIGS. 1 to 4 illustrated vacuum pump 10 is a screw vacuum pump for generating an advance vacuum.
  • the vacuum pump 10 is essentially formed by a housing in which two rotor shafts are rotatably mounted, of which in the Figures 1-4 only the main rotor shaft 12 is shown.
  • Rotor shaft 12 has a rotor portion 14 with a helical rotor 16, a bearing portion 18 with two rolling bearings 20 and axially between the rotor portion 14 and the bearing portion 18 has a portion with a shaft seal assembly 22. At the rotor-side end 24 of the rotor shaft 12, no rolling bearing is provided.
  • a gas is drawn in at the flying ends of the rotor sections 14 through a suction line, not shown, in order to generate a negative pressure in a recipient connected to the suction line.
  • the sucked gas is compressed by interaction of the illustrated rotor 16 with a second rotor of a second rotor shaft, not shown, to the pressure side of the rotor section 14 and there discharged at approximately atmospheric pressure via a gas outlet, not shown.
  • bearing portion 18 of the rotor shaft 12 two rolling bearings are provided for rotatable mounting, of which only the rotor-side roller bearing 20 is shown. Furthermore, the rotor shaft 12 in the bearing portion 18, a gear 26, via which the rotor shaft 12 is driven. For lubrication and cooling of the rolling bearing 20 and the gear or wheels 26 of the bearing housing 28 formed by the bearing housing interior 30 contains an oil reservoir.
  • the shaft seal arrangement has essentially three axial sections, namely a gas seal 32 on the rotor side, an oil seal 34 on the bearing side and a separation chamber 36 therebetween.
  • the shaft seal arrangement 22 is surrounded by a seal housing 66.
  • the gas seal 32 is formed by three piston rings 38, which are arranged axially one behind the other.
  • the piston rings 38 are biased outwardly and therefore non-positively connected to the stationary housing.
  • the piston rings 38 engage in each case in an annular groove 40 of the rotor shaft 12, so that results in a meandering gap in longitudinal section through the three piston rings 38 in the annular grooves 40. In this way, a non-contact labyrinth seal is formed, which ensures a satisfactory gas seal at pressure differences of less than 0.5 bar.
  • the oil seal 34 consists of several parts.
  • the bearing-side portion of the oil seal 34 has rotor shaft side to an oil slinger 42, which has a wave-like profile in longitudinal section.
  • an oil slinger 42 which has a wave-like profile in longitudinal section.
  • the oil slinger 42 is surrounded on the housing side by an annular centrifugal chamber 48, which serves to receive and discharge the oil slid by the slinger 42 outwardly through the oil return passage 46.
  • the oil seal 34 has on the oil slinger 42 axially on the rotor side, then two annular oil-trapping chambers 50,52, which rotor shaft side is assigned in each case a circumferential annular groove 58.
  • the oil slinger 48 has a larger volume than the two axially adjacent oil trapping chambers 50,52.
  • Both the annular rotating centrifugal chamber 48 and the likewise annular oil collecting chambers 50,52 each have their own ventilation duct 59 near their highest point, which leads in each case in the axial direction in the bearing housing 28.
  • the three ventilation channels 59 are arranged offset from one another in the circumferential direction.
  • the two oil trapping chambers 50, 52 each have, near their lowest point, an oil return passage 54, 56, through which oil, if any, can flow back into the bearing housing 28.
  • waiving one or both oil-collecting chambers 50,52 may be used in the annular grooves 58 of the rotor shaft 12 and piston rings to prevent further creep of oil axially in the direction of the rotor.
  • the annular and relatively large volume separation chamber 36 between the gas seal 32 and the oil seal 34 has near its highest point a separation chamber vent passage 60 through which the separation chamber is vented to the environment or through which it is connected to a purge gas source.
  • the separation chamber ventilation channel 60 has an axial section on the separation chamber side and, at right angles thereto, a radial section which leads to the outside. There is no pressure difference and no oil is pressed by a pressure difference in the direction of the rotor through the oil seal, as well as the bearing housing is vented to the environment or since it is also acted upon by the same barrier gas pressure as the separation chamber.
  • a further separation chamber ventilation channel 62 is provided, which has a downward slope and opens into a vertical outlet 64.
  • the separation chamber ventilation channel 62 also serves as a drain for optionally up to here reached oil, or for liquids from the rotor section.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Sealing Using Fluids, Sealing Without Contact, And Removal Of Oil (AREA)
  • Sealing Devices (AREA)

Abstract

The vacuum pump (10) comprises at least one rotor shaft (12) having a rotor section (14) with a rotor (16), a bearing section (18) with a bearing (20), and a shaft sealing system (22) that is axially situated between the rotor section (14) and the bearing section (18). The shaft sealing system (22) axially comprises, on the side of the rotor, a gas seal (32) and, on the side of the bearing, an oil seal (34). The shaft sealing system (22) additionally comprises, between the gas seal (32) and the oil seal (34), a separating chamber, which surrounds the rotor shaft (12) and is ventilated by at least one separating chamber ventilation duct (60, 62). This enables the pressure differential that decreases via the gas seal and the pressure differential that decreases via the oil seal to be adjusted. An appropriate adjustment can prevent oil on the bearing side from passing through the oil seal toward the separating chamber.

Description

Die Erfindung bezieht sich auf eine Vakuumpumpe mit mindestens einer Rotorwelle, die einen Rotorabschnitt mit einem Rotor, einen Lagerabschnitt mit einem Lager und axial zwischen dem Rotorabschnitt und dem Lagerabschnitt eine Wellendichtungsanordnung aufweist.The invention relates to a vacuum pump with at least one rotor shaft, which has a rotor section with a rotor, a bearing section with a bearing and axially between the rotor section and the bearing section a shaft seal arrangement.

Derartige Vakuumpumpen können u.a. als Schraubenpumpen, Seitenkanalverdichter, und Rootspumpen ausgebildet sein. Den genannten Vakuumpumpen ist gemeinsam, dass sie trockenverdichtende Vakuumpumpen mit öl- oder fettgeschmierten Lagern und/oder Getrieben sind. Diese Pumpen werden in der Regel zur Erzeugung von Vorvakuum eingesetzt. Die Aufgabe der Dichtungsanordnung zwischen dem eigentlichen Rotor und dem Lager bzw. Getriebe liegt zum einen in der Vermeidung von Gasdurchtritt von dem Rotorabschnitt zu dem Lagerabschnitt und andererseits in der Vermeidung von Flüssigkeitsdurchtritt von dem Lagerabschnitt in den Rotorabschnitt. Bei niedrigen Rotordrehzahlen und geringen Rotorwellendurchmessern. können relativ gut dichtende berührende Dichtungen eingesetzt werden, beispielsweise in Form von Radialwellendichtringen, Gleitringen etc. Bei höheren Drehzahlen und größeren Rotorwellendurchmessern können nur berührungsfreie Wellendichtungen eingesetzt werden, die je- doch konstruktionsbedingt Leckagen nicht völlig ausschließen können.Such vacuum pumps can be designed, inter alia, as screw pumps, side channel blower, and Roots pumps. The mentioned vacuum pumps have in common that they are dry-compressing vacuum pumps with oil or grease lubricated bearings and / or gearboxes. These pumps are typically used to generate pre-vacuum. The task of the sealing arrangement between the actual rotor and the bearing or gearbox is firstly to prevent gas from passing from the rotor section to the bearing section and secondly to prevent the passage of fluid from the bearing section into the rotor section. At low rotor speeds and small rotor shaft diameters. For example, in the form of radial shaft seals, slip rings, etc. At higher speeds and larger rotor shaft diameters, only contact-free shaft seals can be used, which, however, can not completely exclude leaks due to the design.

Eine bekannte berührungslose Wellendichtungsanordnung besteht aus einem oder mehreren Kolbendichtringen als Gasdichtung und einem Ölspritzring als Öldichtung. Hiermit lässt sich jedoch keine zuverlässige und hohe Dichtungswirkung erzielen. Das in dem Rotorabschnitt verdichtete Gas soll jedoch nicht mit dem Öl aus dem Lagerabschnitt in Verbindung kommen, da das Öl hier- durch ggf. zersetzt werden und seine Schmierfähigkeit hierdurch verlieren kann. Das austretende Öl, Gas oder Gasgemisch kann auch toxisch oder explosiv und daher gefährlich sein.A known non-contact shaft seal assembly consists of one or more piston seals as a gas seal and an oil spray ring as an oil seal. However, this can not achieve a reliable and high sealing effect. However, the gas compressed in the rotor section should not come into contact with the oil from the bearing section, since the oil may be decomposed thereby and thereby lose its lubricity. The escaping oil, gas or gas mixture can also be toxic or explosive and therefore dangerous.

Aus der Gebrauchsmusterschrift DE 295 22 263 U1 ist eine Mehrwellenvakuumpumpe zur Förderung von Gasen mit Öldichtungen bekannt. Diese zwischen dem Lager-/ Getriebegehäuse und einer Trennkammer angeordnete Öldichtung ist als Schleifdichtung ausgebildet. Die Dichtung erfolgt über schleifende Dichtlippen, wobei die Trennkammer zusätzlich mit Sperrgas beaufschlagt wird.From the utility model DE 295 22 263 U1 is a multi-shaft vacuum pump for conveying gases with oil seals known. This arranged between the bearing / gear housing and a separation chamber oil seal is designed as a sliding seal. The seal is made by sliding sealing lips, wherein the separation chamber is additionally acted upon by sealing gas.

Aufgabe der Erfindung ist es daher, bei einer Vakuumpumpe die eine Gasdichtung und eine Öldichtung aufweisende Wellendichtung zu verbessern.The object of the invention is therefore to improve in a vacuum pump, the gas seal and an oil seal having shaft seal.

Diese Aufgabe wird erfindungsgemäß mit den Merkmalen des Anspruchs 1 gelöst.This object is achieved with the features of claim 1.

Bei der erfindungsgemäßen Vakuumpumpe ist die Wellendichtungsanordnung derart ausgebildet, dass zwischen der rotorseitigen Gasdichtung und der lagerseitigen Öldichtung eine die Rotorwelle umgebende Trennkammer vorgesehen ist, die durch mindestens einen Trennkammer-Lüftungskanal belüftet wird. Durch den Lüftungskanal wird die Trennkammer auf einen gewünschten Gasdruck eingestellt. Hierdurch wird erreicht, dass die über der Gasdichtung abfallende Druckdifferenz und die über der Öldichtung abfallende Druckdifferenz eingestellt werden können. So kann die Trennkammer durch den Lüftungskanal beispielsweise mit atmosphärischem Gasdruck oder mit dem lagerseitigen Gasdruck beaufschlagt werden, so dass der Gasdruck in der Trennkammer nicht unter dem lagerseitigen Gasdruck liegt. Hierdurch kann vermieden werden, dass das Öl von der Lagerseite durch die Öldichtung Richtung Trennkammer wandert. Gegenüber dem Gasdruck auf der Rotorseite der Gasdichtung kann der Trennkammer-Gasdruck höher eingestellt sein, so dass explosive und/oder toxische Gase aus dem Rotorabschnitt nicht durch die Gasdichtung entweichen können. Auf diese Weise wird eine Wellendichtungsanordnung realisiert, die auch bei konstruktionsbedingt nicht vollständig dichtenden Gas- und Öldichtungen einen Übertritt von Gas aus dem Rotorabschnitt in den Lagerabschnitt und von Öl aus dem Lagerabschnitt in den Rotorabschnitt auf einfache Weise und zuverlässig verhindert. Für die Trennkammer ist nur ein geringer Herstellungsaufwand und Raumbedarf erforderlich, so dass mit geringen Mitteln eine kompakte und wirkungsvolle Wellendichtungsanordnung realisiert wird.In the vacuum pump according to the invention, the shaft seal arrangement is designed such that between the rotor-side gas seal and the bearing-side oil seal a surrounding the rotor shaft separation chamber is provided which is vented through at least one separation chamber ventilation duct. Through the ventilation duct, the separation chamber is adjusted to a desired gas pressure. This ensures that the drop across the gas seal pressure difference and the above the oil seal decreasing pressure difference can be adjusted. Thus, the separation chamber can be acted upon by the ventilation duct, for example, with atmospheric gas pressure or with the bearing-side gas pressure, so that the gas pressure in the separation chamber is not below the bearing-side gas pressure. In this way it can be avoided that the oil migrates from the bearing side through the oil seal towards the separation chamber. Compared to the gas pressure on the rotor side of the gas seal, the separation chamber gas pressure can be set higher, so that explosive and / or toxic gases from the rotor section can not escape through the gas seal. In this way, a shaft seal arrangement is realized, which prevents a passage of gas from the rotor section into the bearing section and oil from the bearing section in the rotor section in a simple manner and reliably even with structurally imperfect gas and oil seals. For the separation chamber only a small manufacturing effort and space is required, so that a small and effective means a compact and effective shaft seal arrangement is realized.

Der Trennkammer-Lüftungskanal mündet außerhalb der Pumpe in die umgebende Atmosphäre. Auf diese Weise herrscht in der Trennkammer stets Atmosphärendruck und der gleiche Gasdruck wie in dem Lagergehäuse, da dieses ebenfalls zur Umgebung entlüftet wird. Das Druckgefälle über der Öldichtung ist dann praktisch gleich Null, so dass wegen fehlender Druckdifferenz auch kein Öl von dem Lagerabschnitt in Richtung Trennkammer bzw. Rotorabschnitt gepresst wird.The separation chamber ventilation channel opens outside the pump into the surrounding atmosphere. In this way prevails in the separation chamber always atmospheric pressure and the same gas pressure as in the bearing housing, since this is also vented to the environment. The pressure gradient across the oil seal is then practically equal to zero, so that due to lack of pressure difference and no oil from the bearing section in the direction of separation chamber or rotor section is pressed.

Die Gasdichtung und die Öldichtung sind jeweils als berührungsfreie Dichtungen ausgebildet. Hierdurch kann die Wellendichtungsanordnung auch in Vakuumpumpen mit hohen Drehzahlen und hohen Rotorwellendurchmessern eingesetzt werden.The gas seal and the oil seal are each designed as non-contact seals. As a result, the shaft seal arrangement can also be used in vacuum pumps be used with high speeds and high rotor shaft diameters.

Vorzugsweise ist die Gasdichtung als Spaltdichtung oder als Labyrinthdichtung, mit Kolbenringen oder mit schwimmenden Dichtringen ausgebildet. Die Gasdichtung ist in jedem Fall eine berührungsfreie Drosseldichtung, durch die der Gasdurchtritt auf ein unvermeidbares Minimum reduziert wird.Preferably, the gas seal is designed as a gap seal or as a labyrinth seal, with piston rings or with floating sealing rings. The gas seal is in any case a contact-free throttle seal, which reduces the gas passage to an unavoidable minimum.

Vorzugsweise weist die Labyrinthdichtung der Gasdichtung mindestens einen Kolbenring auf, der in eine Ringnut der Rotorwelle hineinragt. Der Kolbenring ist nach außen vorgespannt und daher gehäuseseitig fixiert und feststehend. Der Kolbenring ragt in die Rotorwellen-Ringnut hinein, wodurch zwischen dem Kolbenring und der Ringnut ein labyrinthartig verlaufender Spalt gebildet wird, der als Drosseldichtung wirkt. Die Gasdichtung kann mehrere axial hintereinander angeordnete derartige Labyrinthdichtungen aufweisen.Preferably, the labyrinth seal of the gas seal has at least one piston ring, which projects into an annular groove of the rotor shaft. The piston ring is biased outwards and therefore fixed on the housing side and fixed. The piston ring protrudes into the rotor shaft annular groove, whereby a labyrinth-like gap is formed between the piston ring and the annular groove, which acts as a throttle seal. The gas seal may have a plurality of such labyrinth seals arranged axially one behind the other.

Vorzugsweise weist die Öldichtung auf der Rotorwelle einen umlaufenden Ölschleuderring auf, der in eine gehäuseseitige ringförmige Schleuderkammer hineinragt, die an einen Ölrücklaufkanal zu dem Lagergehäuse angeschlossen ist. Auf diese Weise wird eine effektive berührungsfreie Öldichtung geschaffen.Preferably, the oil seal on the rotor shaft on a rotating slinger, which projects into a housing-side annular centrifugal chamber, which is connected to an oil return passage to the bearing housing. In this way, an effective non-contact oil seal is created.

Gemäß einer bevorzugten Ausgestaltung sind zwischen dem Ölschleuderring und den gehäuseseitigen Schleuderkammerwänden radiale und/oder axiale nicht-konische oder konische Spalte gebildet. Der Ölschleuderring und die gegenüberliegenden feststehenden Wände sind so ausgebildet, dass das eintretende Öl bei rotierender Rotorwelle nach außen abgeschleudert wird und das nicht abgeschleuderte Öl nach unten in den Rücklaufkanal abläuft.According to a preferred embodiment, radial and / or axial non-conical or conical gaps are formed between the oil slinger and the housing-side Schleuderkammerwänden. The slinger and the opposing fixed walls are designed so that the incoming oil is thrown outwards with the rotor shaft rotating and the unsprayed oil runs down into the return channel.

Vorzugsweise weist die Öldichtung axialrotorseitig des Ölschleuderrings mindestens eine ringförmige Fangkammer mit einem Ölablaufkanal auf, der in das Lagergehäuse mündet. Die Öldichtung besteht also aus zwei oder mehr axial hintereinanderliegenden Schleuder- bzw. Fangkammern mit einem Ölablaufkanal. Die Ölablaufkanäle können in einem einzigen Kanal zusammengefasst sein, es kann jedoch auch jeder Schleuder- bzw. Fangkammer ein eigener getrennter Ölablaufkanal zugeordnet sein. Hierdurch werden gegenseitige Störungen beim Ölablauf ausgeschlossen, so dass die Öldichtung auch bei Störungen in einem Ölablaufkanal in ihrer Dichtungswirkung nur geringfügig beeinflusst wird.The oil seal on the axial rotor side of the oil slinger preferably has at least one annular trap chamber with an oil drain channel which opens into the bearing housing. The oil seal thus consists of two or more axially behind one another centrifugal or catch chambers with an oil drain channel. The oil drainage channels can be combined in a single channel, but it can also be associated with each separate centrifugal or catching chamber own separate oil drain channel. As a result, mutual disturbances in the oil flow are excluded, so that the oil seal is only slightly affected even in case of disturbances in an oil drain channel in their sealing effect.

Vorzugsweise ist jeder Schleuder- bzw. Fangkammer der Öldichtung mindestens ein Lüftungskanal zugeordnet. Der Lüftungskanal kann zwar nach außen zur Atmosphäre sollte aber vorzugsweise zum Lagergehäuse zurück geführt sein. Die Schleuderkammern können über einen einzigen gemeinsamen Lüftungskanal, oder aber über jeweils mindestens einen eigenen Lüftungskanal belüftet werden. Durch die Belüftung durch die Belüftungskanäle wird sichergestellt, dass sich auch innerhalb der Öldichtung, also zwischen den einzelnen Schleuderkammern keine Druckdifferenz bildet. Eine Gasströmung und damit eine Mitnahme von Öl in Richtung Trennkammer bzw. Rotorabschnitt ist damit praktisch ausgeschlossen. Auch der Übertritt von Gasen aus der Trennkammer in Richtung Lagergehäuse wird daher weitgehend unterbunden.Preferably, each spin or catch chamber of the oil seal is assigned at least one ventilation duct. Although the ventilation duct can be outwardly to the atmosphere but should preferably be led back to the bearing housing. The centrifugal chambers can be ventilated via a single common ventilation duct, or else via at least one separate ventilation duct in each case. Ventilation through the ventilation channels ensures that there is no pressure difference within the oil seal, ie between the individual centrifugal chambers. A gas flow and thus entrainment of oil in the direction of separation chamber or rotor section is thus practically impossible. The transfer of gases from the separation chamber in the direction of the bearing housing is therefore largely prevented.

Gemäß einer bevorzugten Ausgestaltung mündet der Trennkammer-Lüftungskanal in der Nähe vom tiefsten Punkt der Trennkammer und weist ein Gefälle auf, so dass eine eventuell austretende Flüssigkeit aus der Trennkammer ablaufen kann. Selbst wenn Öl oder andere Flüssigkeiten aus dem Lagerabschnitt oder aus dem Rotorabschnitt bis zur Trennkammer gelangen sollten, könnte diese nach außen ablaufen. Hierdurch wird sichergestellt, dass sich keine Flüssigkeit in der Trennkammer ansammeln kann.According to a preferred embodiment of the separation chamber venting channel opens in the vicinity of the lowest point of the separation chamber and has a slope, so that any leaking liquid can drain from the separation chamber. Even if oil or other liquids from the storage section or from the Rotor section should reach the separation chamber, this could run outward. This ensures that no liquid can accumulate in the separation chamber.

Vorzugsweise ist das Lager axial rotorseitig gedeckelt ausgebildet. Hierdurch wird bereits zwischen dem Lager und der Wellendichtungsanordnung eine erste Barriere für Öl. bzw. andere Flüssigkeiten aus dem Lager realisiert.Preferably, the bearing is formed axially capped on the rotor side. As a result, a first barrier for oil is already between the bearing and the shaft seal arrangement. or other liquids from the warehouse realized.

Gemäß einer bevorzugten Ausgestaltung ist die Rotorwelle als fliegende Rotorwelle ausgebildet, die nur an der Druckseite des Rotorabschnittes gelagert ist, an der Saugseite des Rotorabschnittes der Rotorwelle jedoch lagerfrei ausgebildet ist. Auf diese Weise wird ein Lager im Bereich größerer Unterdrücke vermieden, so dass auch die bei großen Druckunterschieden problematische Wellendichtungsanordnung auf der Saugseite der Rotorwelle vermieden wird. Fliegende Rotorwellen weisen aus Stabilitätsgründen einen relativ großen Wellendurchmesser auf. Erst durch die vorliegende Wellendichtungsanordnung und das Vorsehen einer Trennkammer zwischen der Gasdichtung und der Öldichtung können die mit großen Rotorwellendurchmessern verbundenen hohen Umfangsgeschwindigkeiten abgedichtet werden, ohne eine unzumutbar große Leckage in Kauf nehmen müssen.According to a preferred embodiment, the rotor shaft is designed as a flying rotor shaft, which is mounted only on the pressure side of the rotor section, on the suction side of the rotor section However, the rotor shaft is designed to be free of bearings. In this way, a bearing in the range of greater negative pressure is avoided, so that even with large pressure differences problematic shaft seal arrangement is avoided on the suction side of the rotor shaft. For reasons of stability, flying rotor shafts have a relatively large shaft diameter. Only by the present shaft seal arrangement and the provision of a separation chamber between the gas seal and the oil seal can be sealed with large rotor shaft diameters high peripheral velocities must be taken without an unreasonably large leakage in purchasing.

Gemäß einem nebengeordneten Patentanspruch ist an den Trennkammer-Lüftungskanal eine Sperrgasquelle angeschlossen, durch die unter Überdruck ein Sperrgas in die Trennkammer eingeleitet wird. Dies ist dann erforderlich und sinnvoll wenn in dem Rotorabschnitt giftige und/oder explosive Gase gefördert werden. Durch die Einspeisung des Trenngases wird ein kleiner Trenngasstrom von der Trennkammer in Richtung Rotorabschnitt erzeugt. Auf diese Weise kann der Austritt von Gas aus dem Rotorabschnitt verhindert werden. Als Sperrgas können beispielsweise Luft oder Stickstoff verwendet werden.According to a sibling claim, a barrier gas source is connected to the separation chamber ventilation duct through which a sealing gas is introduced into the separation chamber under overpressure. This is necessary and useful if toxic and / or explosive gases are conveyed in the rotor section. By feeding the separation gas, a small separation gas flow is generated from the separation chamber in the direction of the rotor section. In this way, the escape of gas from the rotor section can be prevented. As a barrier gas, for example, air or nitrogen can be used.

Zur Vermeidung jeder Druckdifferenz zwischen dem Lagerabschnitt und der Trennkammer ist zusätzlich eine Sperrgasleitung von der Sperrgasquelle zu dem Lagergehäuse bzw. dem Lagerabschnitt vorgesehen. Auf diese Weise wird sichergestellt, dass über der Öldichtung kein nennenswertes Druckgefälle entsteht. Das Sperrgas hat einen Druck von beispielsweise 1,3 bar.In order to avoid any pressure difference between the bearing portion and the separation chamber, a seal gas line is additionally provided from the seal gas source to the bearing housing or the bearing portion. This ensures that there is no significant pressure drop across the oil seal. The sealing gas has a pressure of, for example, 1.3 bar.

Im folgenden wird unter Bezugnahme auf die Zeichnungen ein Ausführungsbeispiel der Erfindung näher erläutert.In the following an embodiment of the invention will be explained in more detail with reference to the drawings.

Es zeigen:

Fig. 1
eine Vakuum-Schraubenpumpe im Längsschnitt,
Fig. 2
das Gehäuse der Schraubenvakuumpumpe der Fig. 1 im Querschnitt,
Fig. 3
ein Ausschnitt eines Längsschnittes entlang der Schnittlinie X-III des Pumpengehäuses der Fig. 2, und
Fig. 4
einen Längsschnitt des Pumpengehäuses der Fig. 2 entlang der Schnittlinie X-IV.
Show it:
Fig. 1
a vacuum screw pump in longitudinal section,
Fig. 2
the housing of the screw vacuum pump of Fig. 1 in cross section,
Fig. 3
a section of a longitudinal section along the section line X-III of the pump housing the Fig. 2 , and
Fig. 4
a longitudinal section of the pump housing the Fig. 2 along the section line X-IV.

Die in den Fign. 1 bis 4 dargestellte Vakuumpumpe 10 ist eine Schraubenvakuumpumpe zur Erzeugung eines Vorvakuums. Die Vakuumpumpe 10 wird im Wesentlichen von einem Gehäuse gebildet, in dem zwei Rotorwellen drehbar gelagert sind, von denen in den Figuren 1-4 nur die Hauptrotorwelle 12 dargestellt ist. DieThe in the FIGS. 1 to 4 illustrated vacuum pump 10 is a screw vacuum pump for generating an advance vacuum. The vacuum pump 10 is essentially formed by a housing in which two rotor shafts are rotatably mounted, of which in the Figures 1-4 only the main rotor shaft 12 is shown. The

Rotorwelle 12 weist einen Rotorabschnitt 14 mit einem schraubenförmigen Rotor 16, einen Lagerabschnitt 18 mit zwei Wälzlagern 20 und axial zwischen dem Rotorabschnitt 14 und dem Lagerabschnitt 18 einen Abschnitt mit einer Wellendichtungsanordnung 22 auf. An dem rotorseitigen Ende 24 der Rotorwelle 12 ist kein Wälzlager vorgesehen.Rotor shaft 12 has a rotor portion 14 with a helical rotor 16, a bearing portion 18 with two rolling bearings 20 and axially between the rotor portion 14 and the bearing portion 18 has a portion with a shaft seal assembly 22. At the rotor-side end 24 of the rotor shaft 12, no rolling bearing is provided.

Durch die Drehung der schraubenförmigen Rotoren wird an deren fliegenden Enden der Rotorabschnitte 14 ein Gas durch eine nichtdargestellte Ansaugleitung angesaugt, um auf diese Weise in einem an die Ansaugleitung angeschlossenen Rezipienten einen Unterdruck zu erzeugen. Das angesaugte Gas wird durch Zusammenwirken des dargestellten Rotors 16 mit einem zweiten Rotor einer zweiten nicht dargestellten Rotorwelle zur Druckseite des Rotorabschnittes 14 hin verdichtet und dort mit ungefähr atmosphärischem Druck über einen nicht dargestellten Gasauslass abgeführt.As a result of the rotation of the helical rotors, a gas is drawn in at the flying ends of the rotor sections 14 through a suction line, not shown, in order to generate a negative pressure in a recipient connected to the suction line. The sucked gas is compressed by interaction of the illustrated rotor 16 with a second rotor of a second rotor shaft, not shown, to the pressure side of the rotor section 14 and there discharged at approximately atmospheric pressure via a gas outlet, not shown.

In dem Lagerabschnitt 18 der Rotorwelle 12 sind zur drehbaren Lagerung zwei Wälzlager vorgesehen, von denen nur das rotorseitige Wälzlager 20 dargestellt ist. Ferner weist die Rotorwelle 12 in dem Lagerabschnitt 18 ein Zahnrad 26 auf, über das die Rotorwelle 12 angetrieben wird. Zur Schmierung und zur Kühlung der Wälzlager 20 und des bzw. der Zahnräder 26 enthält der von dem Lagergehäuse 28 gebildete Lagergehäuseinnenraum 30 einen Ölvorrat.In the bearing portion 18 of the rotor shaft 12, two rolling bearings are provided for rotatable mounting, of which only the rotor-side roller bearing 20 is shown. Furthermore, the rotor shaft 12 in the bearing portion 18, a gear 26, via which the rotor shaft 12 is driven. For lubrication and cooling of the rolling bearing 20 and the gear or wheels 26 of the bearing housing 28 formed by the bearing housing interior 30 contains an oil reservoir.

Die Wellendichtungsanordnung weist im Wesentlichen drei axiale Abschnitte auf, nämlich rotorseitig eine Gasdichtung 32, lagerseitig eine Öldichtung 34 und dazwischen eine Trennkammer 36. Die Wellendichtungsanordnung 22 wird von einem Dichtungsgehäuse 66 umgeben.The shaft seal arrangement has essentially three axial sections, namely a gas seal 32 on the rotor side, an oil seal 34 on the bearing side and a separation chamber 36 therebetween. The shaft seal arrangement 22 is surrounded by a seal housing 66.

Die Gasdichtung 32 wird von drei Kolbenringen 38 gebildet, die axial hintereinanderliegend angeordnet sind. Die Kolbenringe 38 sind nach außen vorgespannt und daher kraftschlüssig mit dem feststehenden Gehäuse verbunden. Die Kolbenringe 38 greifen jeweils in eine Ringnut 40 der Rotorwelle 12 ein, so dass sich durch die drei Kolbenringe 38 in den Ringnuten 40 ein im Längsschnitt mäanderartig verlaufender Spalt ergibt. Auf diese Weise ist eine berührungsfreie Labyrinthdichtung gebildet, die bei Druckdifferenzen von weniger als 0,5 bar eine zufriedenstellende Gasabdichtung gewährleistet.The gas seal 32 is formed by three piston rings 38, which are arranged axially one behind the other. The piston rings 38 are biased outwardly and therefore non-positively connected to the stationary housing. The piston rings 38 engage in each case in an annular groove 40 of the rotor shaft 12, so that results in a meandering gap in longitudinal section through the three piston rings 38 in the annular grooves 40. In this way, a non-contact labyrinth seal is formed, which ensures a satisfactory gas seal at pressure differences of less than 0.5 bar.

Die Öldichtung 34 besteht aus mehreren Teilen. Der lagerseitige Abschnitt der Öldichtung 34 weist rotorwellenseitig einen Ölschleuderring 42 auf, der im Längsschnitt ein wellenartiges Profil aufweist. Hierdurch und durch entsprechend komplementäre Ausformung des den Ölschleuderring 42 umgebenden Gehäuses 44 wird sichergestellt, dass das Öl aus dem Lagerabschnitt 18 kommend bei rotierender Rotorwelle 12 durch den rotierenden Ölschleuderring 42 nach außen abgeschleudert wird, und durch eine entsprechende feststehende Rinne nach unten abgeleitet wird, von wo aus es durch einen Ölrücklaufkanal 46 zurück in das Lagergehäuse ablaufen muss. Der Ölschleuderring 42 ist gehäuseseitig von einer ringförmigen Schleuderkammer 48 umgeben, die der Aufnahme und Ableitung des von dem Ölschleuderring 42 nach außen geschleuderten Öles durch den Ölrücklaufkanal 46 dient. Die Öldichtung 34 weist an den Ölschleuderring 42 axial rotorseitig anschließend zwei ringförmige Öl-Fangkammern 50,52 auf, denen rotorwellenseitig jeweils eine umlaufende Ringnut 58 zugeordnet ist. Die Ölschleuderkammer 48 hat ein größeres Volumen als die beiden sich axial anschließenden Öl-Fangkammern 50,52. Sowohl die ringförmig umlaufende Schleuderkammer 48 als auch die ebenfalls ringförmig ausgebildeten Öl-Fangkammern 50,52 weisen in der Nähe ihres höchsten Punkts jeweils einen eigenen Lüftungskanal 59 auf, der in axialer Richtung jeweils in das Lagergehäuse 28 führt. Die drei Lüftungskanäle 59 sind in Umfangsrichtung versetzt zueinander angeordnet. Die beiden Öl-Fangkammern 50,52 weisen in der Nähe ihres tiefsten Punkts jeweils einen Öl-Rücklaufkanal 54,56 auf, durch den bis hierhin gelangtes Öl ggf. in das Lagergehäuse 28 zurückfließen kann. Alternativ können unter Verzicht auf eine oder auch beide Öl-fangkammern 50,52 in die ringförmigen Nuten 58 der Rotorwelle 12 auch Kolbenringe eingesetzt sein, um ein Weiterkriechen von Öl axial in Richtung Rotor zu verhindern.The oil seal 34 consists of several parts. The bearing-side portion of the oil seal 34 has rotor shaft side to an oil slinger 42, which has a wave-like profile in longitudinal section. In this way, and by correspondingly complementary shaping of the housing 42 surrounding the oil slinger 42, it is ensured that the oil coming from the bearing section 18 is thrown outwards with the rotating rotor shaft 12 through the rotating slinger 42 and is discharged downwards through a corresponding stationary channel where it must drain through an oil return passage 46 back into the bearing housing. The oil slinger 42 is surrounded on the housing side by an annular centrifugal chamber 48, which serves to receive and discharge the oil slid by the slinger 42 outwardly through the oil return passage 46. The oil seal 34 has on the oil slinger 42 axially on the rotor side, then two annular oil-trapping chambers 50,52, which rotor shaft side is assigned in each case a circumferential annular groove 58. The oil slinger 48 has a larger volume than the two axially adjacent oil trapping chambers 50,52. Both the annular rotating centrifugal chamber 48 and the likewise annular oil collecting chambers 50,52 each have their own ventilation duct 59 near their highest point, which leads in each case in the axial direction in the bearing housing 28. The three ventilation channels 59 are arranged offset from one another in the circumferential direction. The two oil trapping chambers 50, 52 each have, near their lowest point, an oil return passage 54, 56, through which oil, if any, can flow back into the bearing housing 28. Alternatively, waiving one or both oil-collecting chambers 50,52 may be used in the annular grooves 58 of the rotor shaft 12 and piston rings to prevent further creep of oil axially in the direction of the rotor.

Die ringförmige und relativ großvolumige Trennkammer 36 zwischen der Gasdichtung 32 und der Öldichtung 34 weist in der Nähe ihres höchsten Punktes einen Trennkammer-Lüftungskanal 60 auf, durch den die Trennkammer zur Umgebung belüftet wird oder durch den sie mit einer Sperrgasquelle verbunden ist. Der Trennkammer-Lüftungskanal 60 weist trennkammerseitig einen axialen Abschnitt und rechtwinklig davon anschließend einen radialen Abschnitt auf, der zur Außenseite führt. Es herrscht keine Druckdifferenz und kein Öl wird durch eine Druckdifferenz in Richtung Rotor durch die Öldichtung gepresst, da auch das Lagergehäuse zur Umgebung belüftet ist bzw. da es ebenfalls mit dem gleichen Sperrgasdruck wie die Trennkammer beaufschlagt wird.The annular and relatively large volume separation chamber 36 between the gas seal 32 and the oil seal 34 has near its highest point a separation chamber vent passage 60 through which the separation chamber is vented to the environment or through which it is connected to a purge gas source. The separation chamber ventilation channel 60 has an axial section on the separation chamber side and, at right angles thereto, a radial section which leads to the outside. There is no pressure difference and no oil is pressed by a pressure difference in the direction of the rotor through the oil seal, as well as the bearing housing is vented to the environment or since it is also acted upon by the same barrier gas pressure as the separation chamber.

In der Nähe des tiefsten Punkt der Trennkammer 36 ist ein weiterer Trennkammer-Lüftungskanal 62 vorgesehen, der ein Gefälle nach unten aufweist und in einem vertikalen Ablauf 64 mündet. Der Trennkammer-Lüftungskanal 62 dient auch als Ablauf für gegebenenfalls bis hierher gelangtes Öl, bzw. für Flüssigkeiten aus dem Rotorabschnitt.In the vicinity of the lowest point of the separation chamber 36, a further separation chamber ventilation channel 62 is provided, which has a downward slope and opens into a vertical outlet 64. The separation chamber ventilation channel 62 also serves as a drain for optionally up to here reached oil, or for liquids from the rotor section.

Durch das Vorsehen der Trennkammer 36 wird auf einfache und kompakte Weise sichergestellt, dass Fluide weder vom dem Rotorabschnitt 14 zu dem Lagerabschnitt 18 noch von dem Lagerabschnitt 18 zu dem Rotorabschnitt 14 gelangen können.By providing the separation chamber 36, it is ensured in a simple and compact manner that fluids can neither pass from the rotor section 14 to the bearing section 18 nor from the bearing section 18 to the rotor section 14.

Claims (12)

  1. Vacuum pump, comprising at least one rotor shaft (12) with a rotor section (14) having a rotor (16), a bearing section (18) with a bearing (20) in a bearing housing (28), and a shaft sealing system (22) that is axially situated between the rotor section (14) and the bearing section (18),
    the shaft sealing system (22) axially comprising, on the side of the rotor, a gas seal (32) and, axially on the side of the bearing, an oil seal (34), the oil seal being designed as a contactless seal,
    the shaft sealing system (22) comprises, between the gas seal (32) and the oil seal (34), a separating chamber (36) surrounding the rotor shaft (12) and being ventilated by at least one separating chamber ventilation duct (60,62) leading outward to the ambient atmosphere, and
    the bearing housing (28) is ventilated with the ambient atmosphere so that the same gas pressure prevails in the separating chamber (36) as in the bearing housing (28).
  2. Vacuum pump according to claim 1, characterized in that the gas seal (32) is configured as a gap seal or a labyrinth seal.
  3. Vacuum pump according to claim 2, characterized in that the labyrinth seal comprises at least one piston ring (38) projecting into an annular groove (40) of the rotor shaft (12).
  4. Vacuum pump according to one of claims 1 - 3, characterized in that the oil seal (34) comprises a circumferential oil splash ring (42) at the rotor shaft (12), which projects into an annular centrifugal chamber (48) on the side of the housing, said chamber being connected to an oil return duct (46) leading to the bearing housing (28).
  5. Vacuum pump according to one of claims 1 - 4, characterized in that radial or axial conical or non-conical gaps are provided between the oil splash ring (42) and the centrifugal chamber walls on the side of the housing.
  6. Vacuum pump according to one of claims 1 - 5, characterized in that the oil seal (34) axially comprises, on the rotor side of the oil splash ring, at least one annular oil reception chamber (50,52) with at least one oil drain duct (54,56) leading into a bearing housing (28) surrounding the bearing (20).
  7. Vacuum pump according to one of claims 4 - 6, characterized in that each reception and centrifugal chamber (48,50,52) of the oil seal (34) has at least one ventilation duct allocated thereto.
  8. Vacuum pump according to one of claims 1 - 7, characterized in that the rotor shaft (12) is floatingly supported and configured so as to be free of a bearing at the suction side of the rotor section (14).
  9. Vacuum pump according to one of claims 1 - 8, characterized in that the separating chamber ventilation duct (60,62) opens in the region of the lowest point of the separating chamber (36) and has a descendent slope so that a liquid is able to drain off the separating chamber (36).
  10. Vacuum pump according to one of claims 1 - 9, characterized in that the bearing is configured so as to be axially covered on the side of the rotor.
  11. Vacuum pump, comprising at least one rotor shaft (12) with a rotor section (14) having a rotor (16), a bearing section (18) with a bearing (20) in a bearing housing (28), and a shaft sealing system (22) that is axially situated between the rotor section (14) and the bearing section (18),
    the shaft sealing system (22) axially comprising, on the side of the rotor, a gas seal (32) and, axially on the side of the bearing, an oil seal (34), the oil seal being designed as a contactless seal,
    the shaft sealing system (22) comprises, between the gas seal (32) and the oil seal (34), a separating chamber (36) surrounding the rotor shaft (12) and being ventilated by at least one separating chamber ventilation duct (60,62) leading outward to the ambient atmosphere, and
    a seal gas source is connected to the bearing housing (28) and to the ventilation duct (60), so that approximately the same pressure prevails in the separating chamber (36) as in the bearing housing (28).
  12. Vacuum pump of claim 11, characterized by the additional features of one of claims 2 - 10.
EP03702650A 2002-02-23 2003-02-18 Vacuum pump Expired - Lifetime EP1476661B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE10207929A DE10207929A1 (en) 2002-02-23 2002-02-23 vacuum pump
DE10207929 2002-02-23
PCT/EP2003/001598 WO2003071134A1 (en) 2002-02-23 2003-02-18 Vacuum pump

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EP1476661A1 EP1476661A1 (en) 2004-11-17
EP1476661B1 true EP1476661B1 (en) 2012-01-11

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JP (2) JP2005517866A (en)
AU (1) AU2003205775A1 (en)
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WO (1) WO2003071134A1 (en)

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Also Published As

Publication number Publication date
JP2009270581A (en) 2009-11-19
JP2005517866A (en) 2005-06-16
US7153093B2 (en) 2006-12-26
JP5135301B2 (en) 2013-02-06
AU2003205775A1 (en) 2003-09-09
DE10207929A1 (en) 2003-09-04
WO2003071134A1 (en) 2003-08-28
EP1476661A1 (en) 2004-11-17
US20050147517A1 (en) 2005-07-07

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