EP3133290A1 - Vacuum pump - Google Patents

Vacuum pump Download PDF

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Publication number
EP3133290A1
EP3133290A1 EP15181767.3A EP15181767A EP3133290A1 EP 3133290 A1 EP3133290 A1 EP 3133290A1 EP 15181767 A EP15181767 A EP 15181767A EP 3133290 A1 EP3133290 A1 EP 3133290A1
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EP
European Patent Office
Prior art keywords
rotor
stator
axial distance
vacuum pump
section
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.)
Granted
Application number
EP15181767.3A
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German (de)
French (fr)
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EP3133290B1 (en
Inventor
Florian Bader
Jan Hofmann
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.)
Pfeiffer Vacuum GmbH
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Pfeiffer Vacuum GmbH
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Publication date
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Priority to EP15181767.3A priority Critical patent/EP3133290B1/en
Publication of EP3133290A1 publication Critical patent/EP3133290A1/en
Application granted granted Critical
Publication of EP3133290B1 publication Critical patent/EP3133290B1/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
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D19/00—Axial-flow pumps
    • F04D19/02—Multi-stage pumps
    • F04D19/04—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps
    • F04D19/042—Turbomolecular vacuum pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D19/00—Axial-flow pumps
    • F04D19/02—Multi-stage pumps
    • F04D19/04—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps
    • F04D19/048—Multi-stage pumps specially adapted to the production of a high vacuum, e.g. molecular pumps comprising magnetic bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
    • F04D29/056—Bearings
    • F04D29/059—Roller bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
    • F04D29/00—Details, component parts, or accessories
    • F04D29/26—Rotors specially for elastic fluids
    • F04D29/32—Rotors specially for elastic fluids for axial flow pumps
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05D—INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS
    • F05D2230/00—Manufacture
    • F05D2230/50—Building or constructing in particular ways
    • F05D2230/53—Building or constructing in particular ways by integrally manufacturing a component, e.g. by milling from a billet or one piece construction

Definitions

  • the present invention relates to a vacuum pump, in particular turbomolecular pump, having at least one rotor having a rotor shaft and a plurality of arranged on the rotor shaft, axially along the rotor shaft spaced rotor sections, each comprising a plurality of circumferentially distributed rotor blades, and at least one rotor associated stator having at least one stator section with a plurality of circumferentially spaced stator blades, wherein the stator in the axial direction between a first and a second rotor portion and adjacent to these two rotor sections each adjacent, and wherein between the first rotor section and the stator a first axial distance is provided and a second axial distance is provided between the stator section and the second rotor section.
  • a plurality of rotor sections and a plurality of stator sections are provided, which are arranged alternately in the axial direction, wherein a respective stator section is located centrally between two respectively adjacent rotor sections.
  • the rotor sections may each be formed either integrally with the rotor shaft or may be provided in the form of a separately manufactured and rotatably connected to the rotor shaft rotor disk.
  • the object is achieved by a vacuum pump according to claim 1, and in particular by the fact that the second axial distance is different from the first axial distance.
  • the arrangement of the rotor and stator sections can be adapted to the movement of the molecules to be delivered, so that the pumping action is improved.
  • the operation of the invention is described below in particular with reference to Fig. 2 explained in more detail.
  • the invention allows an existing construction of a vacuum pump to be improved by merely changing the position of the stator sections relative to the rotor sections. This can e.g. be realized by changing spacers between individual stator sections in a particularly simple manner. The invention thus improves the performance of a vacuum pump using particularly simple means, without the overall construction of the vacuum pump has to be changed.
  • the stator section is arranged between two rotor sections adjacent to it.
  • a stator portion and each of the two rotor portions adjacent to each other are arranged in the respective axial direction in direct succession.
  • No further stator or rotor sections are arranged between the stator section and the adjacent rotor section.
  • the stator section has in each case an adjacent rotor section in both axial directions.
  • the first rotor section can be arranged in the pumping direction in front of the stator section and the second rotor section can be arranged in the pumping direction downstream of the stator section.
  • the first axial distance may be smaller than the second axial distance.
  • the first axial distance in the pumping direction can be smaller than the second axial distance in the pumping direction.
  • the first axial distance can be made as small as possible.
  • a certain minimum distance greater than zero is maintained between a stator section and an adjacent rotor section.
  • the second axial distance may become relatively large, it has been found that the second axial distance does not exert so much an influence on the pumping power, so that overall pumping performance is improved as the first axial distance is reduced.
  • the first axial distance is less than 0.7 times the second axial distance. In this embodiment, a particularly good pump performance has resulted. Even better pumping powers may result if, according to a further embodiment, the first axial distance is less than or equal to half of the second axial distance.
  • the rotor shaft is mounted on the inlet side, in particular in a high vacuum region, by means of a lubrication-free bearing, in particular a magnetic bearing.
  • a lubrication-free bearing in particular a magnetic bearing.
  • the rotor shaft can alternatively or additionally on the outlet side, in particular in a medium or low vacuum range, by a lubricated bearing, in particular a rolling bearing such as a ball bearing to be stored.
  • a lubricated bearing in particular a rolling bearing such as a ball bearing to be stored.
  • At least one rotor section is integrally formed with the rotor shaft.
  • all rotor sections are integrally formed with the rotor shaft.
  • Such a designed rotor is also referred to as a solid rotor.
  • at least one rotor section can be formed by a rotor disk produced separately from the rotor shaft and fastened to the rotor shaft.
  • all rotor sections can be formed by separately produced rotor disks. This is also referred to as a disk rotor.
  • At least one stator section is designed as a stator disk made of sheet metal.
  • the production of the stator and thus also those of the vacuum pump is technically simplified and cheaper.
  • the stator is stamped from sheet metal, which further simplifies the manufacturing process.
  • the rotor blades and the stator blades can each be inclined to an at least substantially perpendicular to a rotation axis extending plane, wherein the rotor blades have an angle and the stator blades have an angle and the sum of the angle of attack of the stator blades and the angle of attack of the rotor blades at least substantially 90th ° is.
  • a respective stator blade in particular with a radially outer region, can be aligned at least substantially perpendicular to a respective rotor blade, in particular to its radially outer region.
  • the molecules to be conveyed move away from a respective blade surface of the rotor in the direction of the stator section, as shown below Fig. 2 explained in more detail. So if the stator blades are parallel to In this direction of movement of the molecules are aligned, they provide the molecules with minimal resistance and the pump power is optimized.
  • the angle of attack of the rotor blades is at least substantially 45 °, whereby the performance of the pump can be further improved.
  • An exemplary turbomolecular pump vacuum pump (not shown), which may be further developed by the invention and also by at least one embodiment disclosed herein, includes an inlet surrounded by an inlet flange and a plurality of pumping stages for delivering the gas present at the inlet to an outlet ,
  • the turbomolecular pump may have a lateral tap.
  • the turbomolecular pump comprises a stator with a static housing and a rotor arranged in the housing with a rotor shaft rotatably mounted about a rotation axis.
  • the turbomolecular pump comprises a plurality of pump-connected in series with each other in series turbomolecular pumping stages with a plurality of connected to the rotor shaft, formed as a turbomolecular rotor disks rotor sections and arranged in the axial direction between the rotor disks and fixed in the housing, designed as a turbomolecular stator disks stator sections formed by spacers in a desired axial distance are held to each other.
  • the rotor discs and stator discs provide in a scoop area an axial pumping action directed in the pumping direction.
  • the turbomolecular pump also comprises three Holweck pump stages, which are arranged one inside the other in the radial direction and pump-connected with one another in series.
  • the rotor-side part of the Holweck pump stages comprises two cylinder jacket-shaped Holweck rotor sleeves fastened to and carried by the rotor shaft, which are oriented coaxially to the axis of rotation and are nested one inside the other.
  • two cylindrical jacket-shaped Holweck stator sleeves are provided, which are also oriented coaxially to the axis of rotation and nested in one another.
  • the pump-active surfaces of the Holweck pump stages are each formed by the radial lateral surfaces opposite one another, forming a narrow radial Holweck gap, namely in each case a Holweck rotor sleeve and a Holweck stator sleeve.
  • one of the pump-active surfaces is smooth, in the present case, for example, the Holweck rotor sleeve, wherein the opposite pump-active surface of the respective Holweck stator sleeve has a structuring with helically around the rotation axis in the axial direction extending grooves, in which by the rotation the rotor propelled the gas and thereby pumped.
  • the rotatable mounting of the rotor shaft is effected by a rolling bearing in the region of the outlet and a permanent magnet bearing in the region of the inlet.
  • the permanent magnet bearing comprises a rotor-side bearing half and a stator-side bearing half, each comprising a ring stack of a plurality of stacked in the axial direction of permanent magnetic rings, the magnetic rings facing each other with formation of a radial bearing gap.
  • an emergency or fishing camp is provided, which is designed as an unlubricated rolling and idle in normal operation of the vacuum pump without touching and passes only at an excessive radial deflection of the rotor relative to the stator into engagement with a radial stop for the rotor to form, which prevents a collision of the rotor-side structures with the stator-side structures.
  • a conical injection nut is provided on the rotor shaft with an outer diameter increasing towards the rolling bearing, which is provided with a scraper of a plurality with a working medium, such as e.g. a lubricant, soaked absorbent discs containing operating fluid in sliding contact.
  • a working medium such as e.g. a lubricant, soaked absorbent discs containing operating fluid in sliding contact.
  • the operating medium is transferred by capillary action from the working fluid reservoir via the scraper to the rotating injection nut and due to the centrifugal force along the injection nut in the direction of the increasing outer diameter of the injection nut to the rolling bearing promotes out, where, for example. fulfills a lubricating function.
  • the turbomolecular pump includes a drive motor for rotatably driving the rotor whose rotor is formed by the rotor shaft.
  • a control unit controls the drive motor.
  • Fig. 1 shows a rotor shaft 14 of a rotor of a turbomolecular pump according to the invention shown here only partially, with the rotor shaft 14, two rotor disks 16 formed as rotor sections are rotatably connected.
  • a respective rotor disk 16 has a plurality of circumferentially spaced, not shown rotor blades.
  • stator section is arranged, which is not connected to the rotor shaft 14, but statically connected to a housing of the turbomolecular pump, not shown.
  • the stator disc 22 has a plurality of circumferentially spaced, also not shown stator blades.
  • first axial distance A1 between the upper rotor disk 16 and the stator disk 22 and a second axial distance A2 exists between the stator disk 22 and the lower rotor disk 16.
  • the first axial distance A1 is smaller than the second axial distance A2.
  • the axial distance A1 is about 0.4 times the second axial distance A2.
  • stator section is arranged outside an axial center between the first rotor section, in this case the upper rotor disk 16, and the second rotor section, here the lower rotor disk 16.
  • stator section in the axial direction that is along the rotor shaft 14, viewed closer to one of the adjacent rotor sections, namely closer to the upper rotor disk 16, as arranged on the respective other rotor section.
  • a pumping direction P describes a desired direction of movement of gas molecules to be delivered during a pumping operation.
  • the gap following in the pumping direction P directly on the upper rotor disk 16, which is assigned to the first axial distance A1, is smaller than the second gap in the pumping direction, which directly follows the stator disk 22 and the associated with the second axial distance A2. It may be desirable to make the first axial distance A1 as low as possible in order to further improve the pumping power of the turbomolecular pump.
  • rotor blades 18 and stator blades 24 are shown simplified, namely as a simplified developed view in the radial direction, ie in the direction of the rotor shaft 14 shown here only as a dashed line.
  • the rotor blades 18 are part of a rotor disk, not shown in detail, which in the pumping direction P directly in front of a stator blades 24 comprehensive, also not shown stator is arranged.
  • the rotor blades 18 move at high speed during the pumping operation Fig. 2 to the right (direction of rotation) while the stator blades 24 are fixed, ie do not move.
  • the rotor blades 18 and the stator blades 24 are arranged obliquely at a respective angle of attack of 45 °, wherein the stator blades 24 are oriented obliquely opposite to the rotor blades 18.
  • the angle of attack is in each case measured starting from a plane perpendicular to the rotor shaft 14 extending plane.
  • a molecule to be delivered which gets into the axial region of the rotor blades 18, is to a certain extent trapped by the obliquely downwardly directed surface of a rapidly moving rotor blade 18, the molecule being adsorbed to the surface. Subsequently, the molecule desorbs from the surface, moving away from the rotor blade. In this case, the molecule assumes a preferred direction, which is perpendicular to the surface from which the molecule has previously been desorbed. In Fig.
  • stator blades 24 aligned perpendicular to the obliquely downward surfaces of the rotor blades 18, so that a molecule which moves in the preferred direction can pass parallel to the stator blades 24 and thus almost unhindered through the axially adjacent stator disk 22, with only the - relatively small thickness of the stator blades 24 precluding this movement.
  • the probability of penetration for a respective molecule to be conveyed increases when the stator disk is arranged as close as possible to the rotor disk and thus, with high probability, the molecule does not already have a direction of movement deviating from the preferred direction when it reaches the stator disk.
  • the axial distance between the stator disk and the rotor disk following in the pumping direction has less influence on the pumping power.
  • the molecule to be promoted can be actively captured by the rotor disk, essentially independently of its direction of movement, and thereby further transported.
  • the pumping power of the turbomolecular pump is therefore improved, in particular in the molecular working range, by the invention.

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  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
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Abstract

Vakuumpumpe, insbesondere Turbomolekularpumpe, mit wenigstens einem Rotor, der eine Rotorwelle und mehrere an der Rotorwelle angeordnete, axial längs der Rotorwelle beabstandete Rotorabschnitte aufweist, welche jeweils eine Mehrzahl von in Umfangsrichtung verteilt angeordneten Rotorschaufeln umfassen, und wenigstens einem dem Rotor zugeordneten Stator, der zumindest einen Statorabschnitt mit einer Mehrzahl von in Umfangsrichtung verteilt angeordneten Statorschaufeln aufweist, wobei der Statorabschnitt in axialer Richtung zwischen einem ersten und einem zweiten Rotorabschnitt und zu diesen beiden Rotorabschnitten jeweils benachbart angeordnet ist, wobei zwischen dem ersten Rotorabschnitt und dem Statorabschnitt ein erster axialer Abstand vorgesehen ist und zwischen dem Statorabschnitt und dem zweiten Rotorabschnitt ein zweiter axialer Abstand vorgesehen ist, und wobei der zweite axiale Abstand von dem ersten axialen Abstand verschieden ist.Vacuum pump, in particular turbomolecular pump, having at least one rotor having a rotor shaft and a plurality of arranged on the rotor shaft, axially along the rotor shaft spaced rotor sections each comprising a plurality of circumferentially distributed rotor blades, and at least one rotor associated stator, the at least a stator section having a plurality of stator blades distributed in the circumferential direction, the stator section being arranged in the axial direction between a first and a second rotor section and adjacent to these two rotor sections, wherein a first axial spacing is provided between the first rotor section and the stator section and a second axial distance is provided between the stator portion and the second rotor portion, and wherein the second axial distance is different from the first axial distance.

Description

Die vorliegende Erfindung betrifft eine Vakuumpumpe, insbesondere Turbomolekularpumpe, mit wenigstens einem Rotor, der eine Rotorwelle und mehrere an der Rotorwelle angeordnete, axial längs der Rotorwelle beabstandete Rotorabschnitte aufweist, welche jeweils eine Mehrzahl von in Umfangsrichtung verteilt angeordneten Rotorschaufeln umfassen, und wenigstens einem dem Rotor zugeordneten Stator, der zumindest einen Statorabschnitt mit einer Mehrzahl von in Umfangsrichtung verteilt angeordneten Statorschaufeln aufweist, wobei der Statorabschnitt in axialer Richtung zwischen einem ersten und einem zweiten Rotorabschnitt und zu diesen beiden Rotorabschnitten jeweils benachbart angeordnet ist, und wobei zwischen dem ersten Rotorabschnitt und dem Statorabschnitt ein erster axialer Abstand vorgesehen ist und zwischen dem Statorabschnitt und dem zweiten Rotorabschnitt ein zweiter axialer Abstand vorgesehen ist.The present invention relates to a vacuum pump, in particular turbomolecular pump, having at least one rotor having a rotor shaft and a plurality of arranged on the rotor shaft, axially along the rotor shaft spaced rotor sections, each comprising a plurality of circumferentially distributed rotor blades, and at least one rotor associated stator having at least one stator section with a plurality of circumferentially spaced stator blades, wherein the stator in the axial direction between a first and a second rotor portion and adjacent to these two rotor sections each adjacent, and wherein between the first rotor section and the stator a first axial distance is provided and a second axial distance is provided between the stator section and the second rotor section.

Typischerweise sind eine Vielzahl von Rotorabschnitten und eine Vielzahl von Statorabschnitten vorgesehen, die in axialer Richtung abwechselnd angeordnet sind, wobei ein jeweiliger Statorabschnitt sich mittig zwischen zwei jeweils benachbarten Rotorabschnitten befindet. Die Rotorabschnitte können jeweils entweder einstückig mit der Rotorwelle ausgebildet oder in Form einer separat hergestellten und drehfest mit der Rotorwelle verbundenen Rotorscheibe vorgesehen sein.Typically, a plurality of rotor sections and a plurality of stator sections are provided, which are arranged alternately in the axial direction, wherein a respective stator section is located centrally between two respectively adjacent rotor sections. The rotor sections may each be formed either integrally with the rotor shaft or may be provided in the form of a separately manufactured and rotatably connected to the rotor shaft rotor disk.

Es ist eine Aufgabe der Erfindung, die Leistung einer derartigen Vakuumpumpe zu verbessern.It is an object of the invention to improve the performance of such a vacuum pump.

Die Aufgabe wird durch eine Vakuumpumpe gemäß Anspruch 1 gelöst, und insbesondere dadurch, dass der zweite axiale Abstand von dem ersten axialen Abstand verschieden ist.The object is achieved by a vacuum pump according to claim 1, and in particular by the fact that the second axial distance is different from the first axial distance.

Durch die Erfindung lässt sich die Anordnung der Rotor- und Statorabschnitte an die Bewegung der zu fördernden Moleküle anpassen, sodass die Pumpwirkung verbessert wird. Die Wirkungsweise der Erfindung wird nachstehend insbesondere anhand von Fig. 2 näher erläutert.By the invention, the arrangement of the rotor and stator sections can be adapted to the movement of the molecules to be delivered, so that the pumping action is improved. The operation of the invention is described below in particular with reference to Fig. 2 explained in more detail.

Außerdem erlaubt die Erfindung, dass eine bestehende Konstruktion einer Vakuumpumpe dadurch verbessert werden kann, dass lediglich die Lage der Statorabschnitte relativ zu den Rotorabschnitten verändert wird. Dies kann z.B. durch veränderte Distanzringe zwischen einzelnen Statorabschnitten in besonders einfacher Weise realisiert werden. Die Erfindung verbessert also die Leistung einer Vakuumpumpe unter Einsatz besonders einfacher Mittel, ohne dass die Gesamtkonstruktion der Vakuumpumpe verändert werden muss.In addition, the invention allows an existing construction of a vacuum pump to be improved by merely changing the position of the stator sections relative to the rotor sections. This can e.g. be realized by changing spacers between individual stator sections in a particularly simple manner. The invention thus improves the performance of a vacuum pump using particularly simple means, without the overall construction of the vacuum pump has to be changed.

Der Statorabschnitt ist zwischen zwei ihm benachbarten Rotorabschnitten angeordnet. Mit anderen Worten sind ein Statorabschnitt und jeder der beiden ihm benachbarten Rotorabschnitte in der jeweiligen axialen Richtung unmittelbar aufeinanderfolgend angeordnet. Zwischen dem Statorabschnitt und dem benachbarten Rotorabschnitt sind keine weiteren Stator- oder Rotorabschnitte angeordnet. Der Statorabschnitt weist in beiden axialen Richtungen jeweils einen benachbarten Rotorabschnitt auf.The stator section is arranged between two rotor sections adjacent to it. In other words, a stator portion and each of the two rotor portions adjacent to each other are arranged in the respective axial direction in direct succession. No further stator or rotor sections are arranged between the stator section and the adjacent rotor section. The stator section has in each case an adjacent rotor section in both axial directions.

Im Stand der Technik wird davon ausgegangen, dass eine optimale Leistung der Vakuumpumpe erzielt wird, wenn der Statorabschnitt genau in der Mitte zwischen zwei benachbarten Rotorabschnitten angeordnet ist. Erfindungsgemäß wurde jedoch erkannt, dass der erste axiale Abstand und der zweite axiale Abstand einen unterschiedlichen Einfluss auf die Pumpwirkung haben können, sodass sich die Pumpwirkung durch unterschiedliche Wahl der beiden Abstände vorteilhaft beeinflussen lässt.In the prior art, it is believed that optimum performance of the vacuum pump is achieved when the stator section is located exactly midway between two adjacent rotor sections. According to the invention, however, it has been recognized that the first axial distance and the second axial distance may have a different influence on the pumping action, so that the Pump effect can be favorably influenced by different choice of the two distances.

Der erste Rotorabschnitt kann dabei in Pumprichtung vor dem Statorabschnitt angeordnet sein und der zweite Rotorabschnitt kann in Pumprichtung nach dem Statorabschnitt angeordnet sein. Dabei kann der erste axiale Abstand kleiner als der zweite axiale Abstand sein. Mit anderen Worten kann also der in Pumprichtung erste axiale Abstand kleiner als der in Pumprichtung zweite axiale Abstand sein. Dabei kann der erste axiale Abstand möglichst klein ausgeführt sein. Dabei wird zwischen einem Statorabschnitt und einem benachbarten Rotorabschnitt ein gewisser Mindestabstand größer Null eingehalten. Obwohl durch Verkleinern des ersten axialen Abstands der zweite axiale Abstand relativ groß werden kann, hat sich gezeigt, dass der zweite axiale Abstand keinen so starken Einfluss auf die Pumpleistung ausübt, sodass insgesamt die Pumpleistung verbessert wird, wenn der erste axiale Abstand verkleinert wird.The first rotor section can be arranged in the pumping direction in front of the stator section and the second rotor section can be arranged in the pumping direction downstream of the stator section. In this case, the first axial distance may be smaller than the second axial distance. In other words, therefore, the first axial distance in the pumping direction can be smaller than the second axial distance in the pumping direction. In this case, the first axial distance can be made as small as possible. In this case, a certain minimum distance greater than zero is maintained between a stator section and an adjacent rotor section. Although, by decreasing the first axial distance, the second axial distance may become relatively large, it has been found that the second axial distance does not exert so much an influence on the pumping power, so that overall pumping performance is improved as the first axial distance is reduced.

Bei einer Ausführungsform der Erfindung beträgt der erste axiale Abstand weniger als das 0,7-fache des zweiten axialen Abstands. Bei dieser Ausgestaltung hat sich eine besonders gute Pumpleistung ergeben. Noch bessere Pumpleistungen können sich ergeben, wenn gemäß einer weiteren Ausführungsform der erste axiale Abstand kleiner als die oder gleich der Hälfte des zweiten axialen Abstands ist.In one embodiment of the invention, the first axial distance is less than 0.7 times the second axial distance. In this embodiment, a particularly good pump performance has resulted. Even better pumping powers may result if, according to a further embodiment, the first axial distance is less than or equal to half of the second axial distance.

Bei einer weiteren Ausführungsform ist die Rotorwelle einlassseitig, insbesondere in einem Hochvakuumbereich, durch ein schmierungsfreies Lager, insbesondere ein Magnetlager, gelagert. Dadurch lässt sich die einlassseitige Lagerung nicht nur wartungsfrei ausführen, sondern eine Kontamination des Vakuums durch die Lagerung wird außerdem aufgrund fehlender Schmierstoffe verhindert.In a further embodiment, the rotor shaft is mounted on the inlet side, in particular in a high vacuum region, by means of a lubrication-free bearing, in particular a magnetic bearing. As a result, the inlet-side storage not only perform maintenance-free, but also a contamination of the vacuum by the storage is prevented due to lack of lubricants.

Die Rotorwelle kann alternativ oder zusätzlich auslassseitig, insbesondere in einem Mittel- oder Niedrigvakuumbereich, durch ein geschmiertes Lager, insbesondere ein Wälzlager wie z.B. ein Kugellager, gelagert sein. Dies erlaubt eine kostengünstige und mit relativ wenig Spiel behaftete Lagerung, während die Kontaminationsproblematik an der Auslassseite entfällt.The rotor shaft can alternatively or additionally on the outlet side, in particular in a medium or low vacuum range, by a lubricated bearing, in particular a rolling bearing such as a ball bearing to be stored. This allows a cost-effective and with relatively little game afflicted storage, while eliminating the problem of contamination on the outlet side.

Bei einer Ausführungsform ist zumindest ein Rotorabschnitt mit der Rotorwelle einstückig ausgebildet ist. Insbesondere sind dabei alle Rotorabschnitte mit der Rotorwelle einstückig ausgebildet. Ein derart ausgestalteter Rotor wird auch als Vollrotor bezeichnet. Im Gegensatz dazu kann zumindest ein Rotorabschnitt durch eine separat von der Rotorwelle hergestellte und an der Rotorwelle befestigte Rotorscheibe gebildet sein. Insbesondere können alle Rotorabschnitte durch separat hergestellte Rotorscheiben gebildet sein. Man spricht hierbei auch von einem Scheibenrotor.In one embodiment, at least one rotor section is integrally formed with the rotor shaft. In particular, all rotor sections are integrally formed with the rotor shaft. Such a designed rotor is also referred to as a solid rotor. In contrast, at least one rotor section can be formed by a rotor disk produced separately from the rotor shaft and fastened to the rotor shaft. In particular, all rotor sections can be formed by separately produced rotor disks. This is also referred to as a disk rotor.

Bei einer weiteren Ausführungsform ist zumindest ein Statorabschnitt als aus Blech hergestellte Statorscheibe ausgeführt. Dadurch wird die Herstellung der Statorscheibe und damit auch jene der Vakuumpumpe technisch vereinfacht und kostengünstiger. Insbesondere ist die Statorscheibe aus Blech gestanzt, was den Herstellungsvorgang weiter vereinfacht.In a further embodiment, at least one stator section is designed as a stator disk made of sheet metal. As a result, the production of the stator and thus also those of the vacuum pump is technically simplified and cheaper. In particular, the stator is stamped from sheet metal, which further simplifies the manufacturing process.

Die Rotorschaufeln und die Statorschaufeln können jeweils zu einer zumindest im Wesentlichen senkrecht zu einer Rotationsachse verlaufenden Ebene schräg gestellt sein, wobei die Rotorschaufeln einen Anstellwinkel und die Statorschaufeln einen Anstellwinkel aufweisen und die Summe aus dem Anstellwinkel der Statorschaufeln und dem Anstellwinkel der Rotorschaufeln zumindest im Wesentlichen 90° beträgt. Mit anderen Worten kann eine jeweilige Statorschaufel, insbesondere mit einem radial äußeren Bereich, zumindest im Wesentlichen senkrecht zu einer jeweiligen Rotorschaufel, insbesondere zu deren radial äußerem Bereich, ausgerichtet sein. Die zu fördernden Moleküle entfernen sich vornehmlich senkrecht von einer jeweiligen Schaufelfläche des Rotors in Richtung des Statorabschnitts, wie unten anhand von Fig. 2 näher erläutert. Wenn also die Statorschaufeln parallel zu dieser Bewegungsrichtung der Moleküle ausgerichtet sind, setzen sie den Molekülen einen minimalen Widerstand entgegen und die Pumpleistung wird optimiert.The rotor blades and the stator blades can each be inclined to an at least substantially perpendicular to a rotation axis extending plane, wherein the rotor blades have an angle and the stator blades have an angle and the sum of the angle of attack of the stator blades and the angle of attack of the rotor blades at least substantially 90th ° is. In other words, a respective stator blade, in particular with a radially outer region, can be aligned at least substantially perpendicular to a respective rotor blade, in particular to its radially outer region. The molecules to be conveyed move away from a respective blade surface of the rotor in the direction of the stator section, as shown below Fig. 2 explained in more detail. So if the stator blades are parallel to In this direction of movement of the molecules are aligned, they provide the molecules with minimal resistance and the pump power is optimized.

Bei einer Ausführungsform der Erfindung beträgt der Anstellwinkel der Rotorschaufeln zumindest im Wesentlichen 45°, wodurch die Leistung der Pumpe weiter verbessert werden kann.In one embodiment of the invention, the angle of attack of the rotor blades is at least substantially 45 °, whereby the performance of the pump can be further improved.

Weitere Ausführungsformen der Erfindung sind in den abhängigen Ansprüchen, der Beschreibung und den Figuren angegeben.Further embodiments of the invention are indicated in the dependent claims, the description and the figures.

Die Erfindung wird nachfolgend lediglich beispielhaft unter Bezugnahme auf die schematische Zeichnung erläutert.

Fig. 1
zeigt eine erfindungsgemäße Anordnung zweier Rotorscheiben mit einer dazwischenliegenden Statorscheibe, und
Fig. 2
zeigt Rotor- und Statorschaufeln zur Veranschaulichung der Wirkungsweise der Erfindung.
The invention will now be described by way of example only with reference to the schematic drawing.
Fig. 1
shows an inventive arrangement of two rotor disks with an intermediate stator, and
Fig. 2
shows rotor and stator blades to illustrate the operation of the invention.

Eine beispielhafte, als Turbomolekularpumpe ausgebildete Vakuumpumpe (nicht gezeigt), welche durch die Erfindung und auch durch zumindest eine der hier offenbarten Ausführungsformen weitergebildet werden kann, umfasst einen von einem Einlassflansch umgebenen Einlass sowie mehrere Pumpstufen zur Förderung des an dem Einlass anstehenden Gases zu einem Auslass. Die Turbomolekularpumpe kann eine seitliche Anzapfung aufweisen. Die Turbomolekularpumpe umfasst einen Stator mit einem statischen Gehäuse und einen in dem Gehäuse angeordneten Rotor mit einer um eine Rotationsachse drehbar gelagerten Rotorwelle.An exemplary turbomolecular pump vacuum pump (not shown), which may be further developed by the invention and also by at least one embodiment disclosed herein, includes an inlet surrounded by an inlet flange and a plurality of pumping stages for delivering the gas present at the inlet to an outlet , The turbomolecular pump may have a lateral tap. The turbomolecular pump comprises a stator with a static housing and a rotor arranged in the housing with a rotor shaft rotatably mounted about a rotation axis.

Die Turbomolekularpumpe umfasst mehrere pumpwirksam miteinander in Serie geschaltete turbomolekulare Pumpstufen mit mehreren mit der Rotorwelle verbundenen, als turbomolekulare Rotorscheiben ausgebildeten Rotorabschnitten und mit mehreren in axialer Richtung zwischen den Rotorscheiben angeordneten und in dem Gehäuse festgelegten, als turbomolekulare Statorscheiben ausgebildeten Statorabschnitten, die durch Distanzringe in einem gewünschten axialen Abstand zueinander gehalten sind. Die Rotorscheiben und Statorscheiben stellen in einem Schöpfbereich eine in Pumprichtung gerichtete axiale Pumpwirkung bereit.The turbomolecular pump comprises a plurality of pump-connected in series with each other in series turbomolecular pumping stages with a plurality of connected to the rotor shaft, formed as a turbomolecular rotor disks rotor sections and arranged in the axial direction between the rotor disks and fixed in the housing, designed as a turbomolecular stator disks stator sections formed by spacers in a desired axial distance are held to each other. The rotor discs and stator discs provide in a scoop area an axial pumping action directed in the pumping direction.

Die Turbomolekularpumpe umfasst zudem drei in radialer Richtung ineinander angeordnete und pumpwirksam miteinander in Serie geschaltete Holweck-Pumpstufen. Der rotorseitige Teil der Holweck-Pumpstufen umfasst zwei an der Rotorwelle befestigte und von dieser getragene zylindermantelförmige Holweck-Rotorhülsen, die koaxial zu der Rotationsachse orientiert und ineinander geschachtelt sind. Ferner sind zwei zylindermantelförmige Holweck-Statorhülsen vorgesehen, die ebenfalls koaxial zu der Rotationsachse orientiert und ineinander geschachtelt sind. Die pumpaktiven Oberflächen der Holweck-Pumpstufen sind jeweils durch die einander unter Ausbildung eines engen radialen Holweck-Spalts gegenüberliegenden radialen Mantelflächen, nämlich jeweils einer Holweck-Rotorhülse und einer Holweck-Statorhülse, gebildet. Dabei ist jeweils eine der pumpaktiven Oberflächen glatt ausgebildet, im vorliegenden Fall beispielsweise die der Holweck-Rotorhülse, wobei die gegenüberliegende pumpaktive Oberfläche der jeweiligen Holweck-Statorhülse eine Strukturierung mit schraubenlinienförmig um die Rotationsachse herum in axialer Richtung verlaufenden Nuten aufweist, in denen durch die Rotation des Rotors das Gas vorangetrieben und dadurch gepumpt wird.The turbomolecular pump also comprises three Holweck pump stages, which are arranged one inside the other in the radial direction and pump-connected with one another in series. The rotor-side part of the Holweck pump stages comprises two cylinder jacket-shaped Holweck rotor sleeves fastened to and carried by the rotor shaft, which are oriented coaxially to the axis of rotation and are nested one inside the other. Furthermore, two cylindrical jacket-shaped Holweck stator sleeves are provided, which are also oriented coaxially to the axis of rotation and nested in one another. The pump-active surfaces of the Holweck pump stages are each formed by the radial lateral surfaces opposite one another, forming a narrow radial Holweck gap, namely in each case a Holweck rotor sleeve and a Holweck stator sleeve. In each case, one of the pump-active surfaces is smooth, in the present case, for example, the Holweck rotor sleeve, wherein the opposite pump-active surface of the respective Holweck stator sleeve has a structuring with helically around the rotation axis in the axial direction extending grooves, in which by the rotation the rotor propelled the gas and thereby pumped.

Die drehbare Lagerung der Rotorwelle wird durch ein Wälzlager im Bereich des Auslasses und ein Permanentmagnetlager im Bereich des Einlasses bewirkt. Das Permanentmagnetlager umfasst eine rotorseitige Lagerhälfte und eine statorseitige Lagerhälfte, die jeweils einen Ringstapel aus mehreren in axialer Richtung aufeinander gestapelten permanentmagnetischen Ringen umfassen, wobei die Magnetringe unter Ausbildung eines radialen Lagerspalts einander gegenüberliegen.The rotatable mounting of the rotor shaft is effected by a rolling bearing in the region of the outlet and a permanent magnet bearing in the region of the inlet. The permanent magnet bearing comprises a rotor-side bearing half and a stator-side bearing half, each comprising a ring stack of a plurality of stacked in the axial direction of permanent magnetic rings, the magnetic rings facing each other with formation of a radial bearing gap.

Innerhalb des Permanentmagnetlagers ist ein Not- oder Fanglager vorgesehen, das als ungeschmiertes Wälzlager ausgebildet ist und im normalen Betrieb der Vakuumpumpe ohne Berührung leer läuft und erst bei einer übermäßigen radialen Auslenkung des Rotors gegenüber dem Stator in Eingriff gelangt, um einen radialen Anschlag für den Rotor zu bilden, der eine Kollision der rotorseitigen Strukturen mit den statorseitigen Strukturen verhindert.Within the permanent magnet bearing, an emergency or fishing camp is provided, which is designed as an unlubricated rolling and idle in normal operation of the vacuum pump without touching and passes only at an excessive radial deflection of the rotor relative to the stator into engagement with a radial stop for the rotor to form, which prevents a collision of the rotor-side structures with the stator-side structures.

Im Bereich des Wälzlagers ist an der Rotorwelle eine konische Spritzmutter mit einem zu dem Wälzlager hin zunehmenden Außendurchmesser vorgesehen, die mit einem Abstreifer eines mehrere mit einem Betriebsmittel, wie z.B. einem Schmiermittel, getränkte saugfähige Scheiben umfassenden Betriebsmittelspeichers in gleitendem Kontakt steht. Im Betrieb wird das Betriebsmittel durch kapillare Wirkung von dem Betriebsmittelspeicher über den Abstreifer auf die rotierende Spritzmutter übertragen und infolge der Zentrifugalkraft entlang der Spritzmutter in Richtung des größer werdenden Außendurchmessers der Spritzmutter zu dem Wälzlager hin gefördert, wo es z.B. eine schmierende Funktion erfüllt.In the area of the rolling bearing, a conical injection nut is provided on the rotor shaft with an outer diameter increasing towards the rolling bearing, which is provided with a scraper of a plurality with a working medium, such as e.g. a lubricant, soaked absorbent discs containing operating fluid in sliding contact. In operation, the operating medium is transferred by capillary action from the working fluid reservoir via the scraper to the rotating injection nut and due to the centrifugal force along the injection nut in the direction of the increasing outer diameter of the injection nut to the rolling bearing promotes out, where, for example. fulfills a lubricating function.

Die Turbomolekularpumpe umfasst einen Antriebsmotor zum drehenden Antreiben des Rotors, dessen Läufer durch die Rotorwelle gebildet ist. Eine Steuereinheit steuert den Antriebsmotor an.The turbomolecular pump includes a drive motor for rotatably driving the rotor whose rotor is formed by the rotor shaft. A control unit controls the drive motor.

Fig. 1 zeigt eine Rotorwelle 14 eines hier nur teilweise dargestellten Rotors einer erfindungsgemäßen Turbomolekularpumpe, wobei mit der Rotorwelle 14 zwei als Rotorscheiben 16 ausgebildete Rotorabschnitte drehfest verbunden sind. Eine jeweilige Rotorscheibe 16 weist eine Mehrzahl von in Umfangsrichtung beabstandet angeordneten, nicht dargestellten Rotorschaufeln auf. Fig. 1 shows a rotor shaft 14 of a rotor of a turbomolecular pump according to the invention shown here only partially, with the rotor shaft 14, two rotor disks 16 formed as rotor sections are rotatably connected. A respective rotor disk 16 has a plurality of circumferentially spaced, not shown rotor blades.

Zwischen den Rotorscheiben 16 ist ein als Statorscheibe 22 ausgebildeter Statorabschnitt angeordnet, welcher nicht mit der Rotorwelle 14, sondern statisch mit einem nicht dargestellten Gehäuse der Turbomolekularpumpe verbunden ist. Die Statorscheibe 22 weist eine Mehrzahl von in Umfangsrichtung beabstandet angeordneten, ebenfalls nicht dargestellten Statorschaufeln auf.Between the rotor discs 16 designed as a stator 22 stator section is arranged, which is not connected to the rotor shaft 14, but statically connected to a housing of the turbomolecular pump, not shown. The stator disc 22 has a plurality of circumferentially spaced, also not shown stator blades.

Zwischen der oberen Rotorscheibe 16 und der Statorscheibe 22 besteht ein erster axialer Abstand A1 und zwischen der Statorscheibe 22 und der unteren Rotorscheibe 16 besteht ein zweiter axialer Abstand A2. Der erste axiale Abstand A1 ist kleiner als der zweite axiale Abstand A2. Hierbei beträgt der axiale Abstand A1 etwa das 0,4-fache des zweiten axialen Abstands A2. Dieses Abstandsverhältnis ist rein beispielhaft und kann erfindungsgemäß grundsätzlich jeden beliebigen Wert annehmen.There is a first axial distance A1 between the upper rotor disk 16 and the stator disk 22 and a second axial distance A2 exists between the stator disk 22 and the lower rotor disk 16. The first axial distance A1 is smaller than the second axial distance A2. Here, the axial distance A1 is about 0.4 times the second axial distance A2. This distance ratio is purely exemplary and according to the invention can in principle assume any desired value.

Der Statorabschnitt ist hier also, mit anderen Worten, außerhalb einer axialen Mitte zwischen dem ersten Rotorabschnitt, hier der oberen Rotorscheibe 16, und dem zweiten Rotorabschnitt, hier der unteren Rotorscheibe 16, angeordnet. Wiederum mit anderen Worten ist der Statorabschnitt in axialer Richtung, also längs der Rotorwelle 14, betrachtet näher an einem der benachbarten Rotorabschnitte, nämlich näher an der oberen Rotorscheibe 16, als an dem jeweils anderen Rotorabschnitt angeordnet.In other words, the stator section is arranged outside an axial center between the first rotor section, in this case the upper rotor disk 16, and the second rotor section, here the lower rotor disk 16. In other words, in other words, the stator section in the axial direction, that is along the rotor shaft 14, viewed closer to one of the adjacent rotor sections, namely closer to the upper rotor disk 16, as arranged on the respective other rotor section.

Eine Pumprichtung P beschreibt eine erwünschte Bewegungsrichtung von zu fördernden Gasmolekülen während eines Pumpvorgangs. Der in Pumprichtung P unmittelbar auf die obere Rotorscheibe 16 folgende Zwischenraum, welcher dem ersten axialen Abstand A1 zugeordnet ist, ist kleiner als der in Pumprichtung zweite Zwischenraum, welcher unmittelbar auf die Statorscheibe 22 folgt und dem zweiten axialen Abstand A2 zugeordnet ist. Dabei kann es wünschenswert sein, den ersten axialen Abstand A1 möglichst gering auszuführen, um die Pumpleistung der Turbomolekularpumpe weiter zu verbessern.A pumping direction P describes a desired direction of movement of gas molecules to be delivered during a pumping operation. The gap following in the pumping direction P directly on the upper rotor disk 16, which is assigned to the first axial distance A1, is smaller than the second gap in the pumping direction, which directly follows the stator disk 22 and the associated with the second axial distance A2. It may be desirable to make the first axial distance A1 as low as possible in order to further improve the pumping power of the turbomolecular pump.

Die Wirkungsweise der Erfindung soll nun anhand von Fig. 2 und eines vereinfachten physikalischen Modells genauer veranschaulicht werden.The operation of the invention will now be described with reference to Fig. 2 and a simplified physical model.

In Fig. 2 sind dazu Rotorschaufeln 18 und Statorschaufeln 24 vereinfacht dargestellt, und zwar als vereinfachte abgewickelte Ansicht in radialer Richtung, d.h. in Richtung auf die hier nur als gestrichelte Linie dargestellte Rotorwelle 14. Die Rotorschaufeln 18 sind Teil einer nicht näher dargestellten Rotorscheibe, welche in Pumprichtung P unmittelbar vor einer die Statorschaufeln 24 umfassenden, ebenfalls nicht näher dargestellten Statorscheibe angeordnet ist.In Fig. 2 For this purpose, rotor blades 18 and stator blades 24 are shown simplified, namely as a simplified developed view in the radial direction, ie in the direction of the rotor shaft 14 shown here only as a dashed line. The rotor blades 18 are part of a rotor disk, not shown in detail, which in the pumping direction P directly in front of a stator blades 24 comprehensive, also not shown stator is arranged.

Die Rotorschaufeln 18 bewegen sich während des Pumpvorgangs mit hoher Geschwindigkeit in Fig. 2 nach rechts (Rotationsrichtung), während die Statorschaufeln 24 fest sind, d.h. sich nicht bewegen. Die Rotorschaufeln 18 sowie die Statorschaufeln 24 sind schräg unter einem jeweiligen Anstellwinkel von 45°angeordnet, wobei die Statorschaufeln 24 zu den Rotorschaufeln 18 entgegengesetzt schräg ausgerichtet sind. Der Anstellwinkel wird hierbei jeweils ausgehend von einer senkrecht zur Rotorwelle 14 verlaufenden Ebene gemessen.The rotor blades 18 move at high speed during the pumping operation Fig. 2 to the right (direction of rotation) while the stator blades 24 are fixed, ie do not move. The rotor blades 18 and the stator blades 24 are arranged obliquely at a respective angle of attack of 45 °, wherein the stator blades 24 are oriented obliquely opposite to the rotor blades 18. The angle of attack is in each case measured starting from a plane perpendicular to the rotor shaft 14 extending plane.

Ein zu förderndes Molekül, welches in den axialen Bereich der Rotorschaufeln 18 gerät, wird durch die schräg nach unten gerichtete Fläche einer sich schnell nach rechts bewegenden Rotorschaufel 18 gewissermaßen eingefangen, wobei das Molekül an der Fläche adsorbiert. Anschließend desorbiert das Molekül von der Fläche, wobei es sich von der Rotorschaufel entfernt. Dabei nimmt das Molekül eine Vorzugsrichtung an, welche senkrecht zu der Fläche steht, von welcher das Molekül zuvor desorbiert ist. In Fig. 2 sind auch die Statorschaufeln 24 senkrecht zu den schräg nach unten gerichteten Flächen der Rotorschaufeln 18 ausgerichtet, so dass ein Molekül, welches sich in der Vorzugsrichtung bewegt, parallel zu den Statorschaufeln 24 und somit nahezu ungehindert durch die axial nachfolgende Statorscheibe 22 hindurchtreten kann, wobei lediglich die - relativ geringe-Dicke der Statorschaufeln 24 dieser Bewegung entgegensteht.A molecule to be delivered, which gets into the axial region of the rotor blades 18, is to a certain extent trapped by the obliquely downwardly directed surface of a rapidly moving rotor blade 18, the molecule being adsorbed to the surface. Subsequently, the molecule desorbs from the surface, moving away from the rotor blade. In this case, the molecule assumes a preferred direction, which is perpendicular to the surface from which the molecule has previously been desorbed. In Fig. 2 are also the stator blades 24 aligned perpendicular to the obliquely downward surfaces of the rotor blades 18, so that a molecule which moves in the preferred direction can pass parallel to the stator blades 24 and thus almost unhindered through the axially adjacent stator disk 22, with only the - relatively small thickness of the stator blades 24 precluding this movement.

Je weiter allerdings die Strecke ist, welche das Molekül nach der Desorption von der Rotorschaufel 18 beim Eintreten in den axialen Bereich der nachfolgenden Statorscheibe 22 bereits zurückgelegt hat, desto wahrscheinlicher weicht seine Bewegungsrichtung von der oben erwähnten Vorzugsrichtung ab. Dies wird zum Beispiel durch Stöße mit der Gehäusewand, der Rotorwelle oder anderen Molekülen begründet und kann auch als "Verwischen" bezeichnet werden. Erfindungsgemäß wurde erkannt, dass die Durchtrittswahrscheinlichkeit für ein jeweiliges zu förderndes Molekül steigt, wenn die Statorscheibe möglichst nahe an der Rotorscheibe angeordnet ist und dadurch mit hoher Wahrscheinlichkeit das Molekül nicht bereits eine von der Vorzugsrichtung abweichende Bewegungsrichtung aufweist, wenn es die Statorscheibe erreicht. Dagegen nimmt der axiale Abstand der Statorscheibe zur in Pumprichtung nachfolgenden Rotorscheibe weniger Einfluss auf die Pumpleistung. Denn hier kann das zu fördernde Molekül im Wesentlichen unabhängig von seiner Bewegungsrichtung durch die Rotorscheibe aktiv eingefangen und dadurch weitertransportiert werden. Die Pumpleistung der Turbomolekulerpumpe wird also insbesondere im molekularen Arbeitsbereich durch die Erfindung verbessert.However, the further the distance that the molecule has already traveled after desorption from the rotor blade 18 when entering the axial area of the following stator disk 22, the more likely its direction of movement deviates from the preferred direction mentioned above. This is for example due to impacts with the housing wall, the rotor shaft or other molecules and can also be referred to as "blurring". According to the invention, it has been recognized that the probability of penetration for a respective molecule to be conveyed increases when the stator disk is arranged as close as possible to the rotor disk and thus, with high probability, the molecule does not already have a direction of movement deviating from the preferred direction when it reaches the stator disk. In contrast, the axial distance between the stator disk and the rotor disk following in the pumping direction has less influence on the pumping power. For here, the molecule to be promoted can be actively captured by the rotor disk, essentially independently of its direction of movement, and thereby further transported. The pumping power of the turbomolecular pump is therefore improved, in particular in the molecular working range, by the invention.

BezugszeichenlisteLIST OF REFERENCE NUMBERS

1414
Rotorwellerotor shaft
1616
Rotorscheiberotor disc
1818
Rotorschaufelrotor blade
2222
Statorscheibestator
2424
Statorschaufelstator
PP
Pumprichtungpumping direction

Claims (11)

Vakuumpumpe, insbesondere Turbomolekularpumpe, mit
wenigstens einem Rotor, der eine Rotorwelle (14) und mehrere an der Rotorwelle (14) angeordnete, axial längs der Rotorwelle (14) beabstandete Rotorabschnitte (16) aufweist, welche jeweils eine Mehrzahl von in Umfangsrichtung verteilt angeordneten Rotorschaufeln (18) umfassen, und
wenigstens einem dem Rotor zugeordneten Stator, der zumindest einen Statorabschnitt (22) mit einer Mehrzahl von in Umfangsrichtung verteilt angeordneten Statorschaufeln (24) aufweist,
wobei der Statorabschnitt (22) in axialer Richtung zwischen einem ersten und einem zweiten Rotorabschnitt (16) und zu diesen beiden Rotorabschnitten (16) jeweils benachbart angeordnet ist,
wobei zwischen dem ersten Rotorabschnitt (16) und dem Statorabschnitt (22) ein erster axialer Abstand (A1) vorgesehen ist und zwischen dem Statorabschnitt (22) und dem zweiten Rotorabschnitt (16) ein zweiter axialer Abstand (A2) vorgesehen ist,
und wobei der zweite axiale Abstand (A2) von dem ersten axialen Abstand (A1) verschieden ist.Vacuum pump, in particular turbomolecular pump, with
at least one rotor having a rotor shaft (14) and a plurality of on the rotor shaft (14) arranged axially along the rotor shaft (14) spaced rotor sections (16), each comprising a plurality of circumferentially distributed rotor blades (18) comprise, and
at least one stator associated with the rotor, which has at least one stator section (22) with a plurality of stator blades (24) distributed in the circumferential direction,
the stator section (22) being arranged in the axial direction between a first and a second rotor section (16) and adjacent to these two rotor sections (16),
wherein a first axial distance (A1) is provided between the first rotor portion (16) and the stator portion (22) and a second axial distance (A2) is provided between the stator portion (22) and the second rotor portion (16),
and wherein the second axial distance (A2) is different from the first axial distance (A1). Vakuumpumpe nach Anspruch 1,
dadurch gekennzeichnet, dass
der erste Rotorabschnitt (16) in Pumprichtung (P) vor dem Statorabschnitt (22) angeordnet ist und der zweite Rotorabschnitt (16) in Pumprichtung (P) nach dem Statorabschnitt (22) angeordnet ist, wobei der erste axiale Abstand (A1) kleiner ist als der zweite axiale Abstand (A2).Vacuum pump according to claim 1,
characterized in that
the first rotor section (16) is arranged in the pumping direction (P) in front of the stator section (22) and the second rotor section (16) is arranged in the pumping direction (P) downstream of the stator section (22), the first axial spacing (A1) being smaller as the second axial distance (A2). Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
der erste axiale Abstand (A1) weniger als das 0,7-fache des zweiten axialen Abstands (A2) beträgt.Vacuum pump according to one of the preceding claims,
characterized in that
the first axial distance (A1) is less than 0.7 times the second axial distance (A2). Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
der erste axiale Abstand (A1) kleiner ist als die Hälfte des zweiten axialen Abstands (A2).Vacuum pump according to one of the preceding claims,
characterized in that
the first axial distance (A1) is less than half the second axial distance (A2). Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
die Rotorwelle (14) einlassseitig durch ein schmierungsfreies Lager, insbesondere ein Magnetlager, gelagert ist.Vacuum pump according to one of the preceding claims,
characterized in that
the rotor shaft (14) on the inlet side by a lubrication-free bearing, in particular a magnetic bearing, is mounted. Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
die Rotorwelle (14) auslassseitig durch ein geschmiertes Lager, insbesondere ein Wälzlager, gelagert ist.Vacuum pump according to one of the preceding claims,
characterized in that
the rotor shaft (14) on the outlet side by a lubricated bearing, in particular a roller bearing, is mounted. Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
zumindest ein Rotorabschnitt (16) mit der Rotorwelle (14) einstückig ausgebildet ist.Vacuum pump according to one of the preceding claims,
characterized in that
at least one rotor section (16) is integrally formed with the rotor shaft (14). Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
zumindest ein Statorabschnitt (22) als aus Blech hergestellte Statorscheibe ausgeführt ist.Vacuum pump according to one of the preceding claims,
characterized in that
at least one stator section (22) is designed as a stator disk made of sheet metal. Vakuumpumpe nach Anspruch 8,
dadurch gekennzeichnet, dass
die Statorscheibe aus Blech gestanzt ist.Vacuum pump according to claim 8,
characterized in that
the stator disk is stamped from sheet metal. Vakuumpumpe nach einem der vorhergehenden Ansprüche,
dadurch gekennzeichnet, dass
die Rotorschaufeln (18) und die Statorschaufeln (24) jeweils zu einer zumindest im Wesentlichen senkrecht zu einer Rotationsachse (R) verlaufenden Ebene schräg gestellt sind, wobei die Rotorschaufeln (18) einen Anstellwinkel und die Statorschaufeln (24) einen Anstellwinkel aufweisen und die Summe aus dem Anstellwinkel der Statorschaufeln (24) und dem Anstellwinkel der Rotorschaufeln (18) zumindest im Wesentlichen 90° beträgt.Vacuum pump according to one of the preceding claims,
characterized in that
the rotor blades (18) and the stator blades (24) are each inclined to an at least substantially perpendicular to a rotation axis (R) extending plane, wherein the rotor blades (18) have an angle and the stator blades (24) have an angle and the sum from the angle of attack of the stator blades (24) and the angle of attack of the rotor blades (18) is at least substantially 90 °. Vakuumpumpe nach Anspruch 10,
dadurch gekennzeichnet, dass
der Anstellwinkel der Rotorschaufeln (18) zumindest im Wesentlichen 45° beträgt.Vacuum pump according to claim 10,
characterized in that
the angle of attack of the rotor blades (18) is at least substantially 45 °.
EP15181767.3A 2015-08-20 2015-08-20 Vacuum pump Active EP3133290B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP15181767.3A EP3133290B1 (en) 2015-08-20 2015-08-20 Vacuum pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP15181767.3A EP3133290B1 (en) 2015-08-20 2015-08-20 Vacuum pump

Publications (2)

Publication Number Publication Date
EP3133290A1 true EP3133290A1 (en) 2017-02-22
EP3133290B1 EP3133290B1 (en) 2021-06-09

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ID=53887009

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113187743A (en) * 2021-04-08 2021-07-30 日扬科技股份有限公司 Long-acting running rotor structure

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE29516599U1 (en) * 1995-10-20 1995-12-07 Leybold AG, 50968 Köln Friction vacuum pump with intermediate inlet
DE19804768A1 (en) * 1998-02-06 1999-08-12 Pfeiffer Vacuum Gmbh Thermal expansion compensation system for rotor bearings in a gas friction pump
JP2000257586A (en) * 1999-03-08 2000-09-19 Koyo Seiko Co Ltd Turbo molecular pump
JP2003003987A (en) * 2001-06-22 2003-01-08 Osaka Vacuum Ltd Molecular pump
EP2757266A1 (en) * 2013-01-22 2014-07-23 Agilent Technologies, Inc. Rotary vacuum pump

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE29516599U1 (en) * 1995-10-20 1995-12-07 Leybold AG, 50968 Köln Friction vacuum pump with intermediate inlet
DE19804768A1 (en) * 1998-02-06 1999-08-12 Pfeiffer Vacuum Gmbh Thermal expansion compensation system for rotor bearings in a gas friction pump
JP2000257586A (en) * 1999-03-08 2000-09-19 Koyo Seiko Co Ltd Turbo molecular pump
JP2003003987A (en) * 2001-06-22 2003-01-08 Osaka Vacuum Ltd Molecular pump
EP2757266A1 (en) * 2013-01-22 2014-07-23 Agilent Technologies, Inc. Rotary vacuum pump

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113187743A (en) * 2021-04-08 2021-07-30 日扬科技股份有限公司 Long-acting running rotor structure

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