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
  • F04D17/00—Radial-flow pumps, e.g. centrifugal pumps; Helico-centrifugal pumps
  • F04D17/08—Centrifugal pumps
  • F04D17/16—Centrifugal pumps for displacing without appreciable compression
  • F04D17/168—Pumps specially adapted to produce a vacuum
• • 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
• • 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
• • 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

Definitions

• the invention relates to a multi-stage vacuum pump
• Multi-stage vacuum pumps are, for example, multi-inlet vacuum pumps with at least two inlets and one outlet.
• the inlets are connected to different vacuum levels of the multi-inlet pump, with each inlet creating a different vacuum.
• the highest vacuum is usually generated with the inlet connected to the first stage of the multi-inlet pump, and the second highest vacuum, etc. with the inlet connected to the second vacuum stage.
• Such vacuum pumps with a plurality of vacuum stages have a housing in a shaft which is driven by an electric motor usually surrounding the shaft.
• the electric motor is not arranged between the two bearings but outside of the bearing.
• the rotor is in turn disposed on the cantilever shaft approach and thus also has the disadvantages of flying storage. Furthermore, the bearing distance is also very low. This leads to an unfavorable center of gravity and the resulting high bearing loads.
• the object of the invention is to provide a cost effective and effective storage arrangement for multi-stage vacuum pumps, in particular to be able to increase the overall length.
• the rotor is separated into at least two rotor elements.
• the two rotor elements are thus separate, in particular connected to the Weüe.
• an inner bearing element which is usually a roller bearing, such as a ball bearing, between the two rotor elements.
• the rotor element is thus arranged on a shaft projection projecting relative to the inner bearing element.
• the second rotor element may for example be arranged between an inner and an outer bearing element, in particular fixedly connected to the shaft.
• the inner bearing element is preferably not located in the region of high vacuum, but is disposed within the outer, the high vacuum stage comprising rotor element, the bearing is not exposed to the extremely low pressures prevail in the high vacuum.
• This has the advantage according to the invention that In particular grease-lubricated bearings, such as ball bearings can be used.
• the arrangement of a ball bearing has the particular advantage that ball bearings have a significantly lower design.
• the provision of a particular grease-lubricated ball bearing in this area has the advantage that no additional emergency storage must be present. This is mandatory for magnetic bearings, otherwise no emergency running properties are guaranteed in case of failure of the magnetic bearing.
• the inner bearing element is fixed by a Haiteelement.
• the holding element has at least one throughflow opening.
• the retaining element is preferably connected to the pump housing. It is particularly preferred that the holding element has a plurality of throughflow openings and in particular is designed in the shape of a star.
• the individual, preferably regularly arranged and preferably identically designed through-flow openings are preferably part-ring segmented. Since the inner bearing element is arranged in the conveying direction within the Rotoreiements, which includes the high vacuum stage, the medium flows through the flow openings only when exiting the high vacuum stage or when entering the next stage. The conductance losses generated by the holding element are thus significantly lower than when such a holding element is provided in the region of the high-vacuum stage, ie in the region of the gas inlet of the high-vacuum stage.
• at least two Rotoreiemente are provided, wherein both the inner bearing element and the retaining element between these two Rotoreiementen is arranged.
• the inner Lagereiement is arranged in the axial direction at least partially within a Rotoreiements.
• this is the rotor element comprising the high-vacuum stage.
• the rotor element is still arranged in front of the inner bearing element in the flow direction.
• the inner bearing element is furthermore arranged between two rotor elements, in particular between the two attachment areas of the rotor elements on the shaft , By overlapping at least partially in the axial direction of the inner bearing element by a Teii the Rotoreiements the projecting shaft extension can be shortened. This results in a further improvement of the storage mechanism.
• an outer bearing element is arranged such that arranged between the two bearing elements, a Rotoreiement, in particular fixedly connected to the shaft.
• the outer bearing element is thus preferably arranged outside of the lowest stage forming Rotoreiements. It is particularly preferred in this case that the drive element between the outer Lagereiement and the lowest vacuum stage forming rotor element is arranged. This has the advantage that the two bearing elements have a very large bearing distance, whereby the storage mechanism is improved.
• the outer bearing member is disposed between two rotor members. These are preferably the two rotor elements, which are the lowest Forming vacuum levels, wherein a Rotoreiement may optionally form a plurality of vacuum levels.
• the outer bearing element is fixed via a retaining element.
• the holding element preferably has passage openings and is formed corresponding to the Haiteelement of the inner bearing element.
• the inner Lagereiement is preferably a rolling bearing. However, it is also mögüch to provide a magnetic bearing, in particular a permanent magnetic bearing, which optionally additionally a fishing camp is provided.
• the multi-stage vacuum pump according to the invention is a multi-inlet vacuum pump.
• This has at least one additional inlet next to the main inlet.
• the additional inlets are in this case preferably arranged in each case between two adjacent vacuum stages.
• a pressure of IxIO "5 mbar to IxIO " 9 mbar can be achieved on the high-vacuum side.
• a pressure of IxIO "2 mbar to IxIO " 5 mbar can be achieved.
• a second interim intake is intended, a pressure of IxIO "2 mbar to SxIO '1 mbar can be reached at this.
• Fig. 1 is a sectional view of a schematic diagram of a first
• Fig. 2 is a Schnlttansicht a schematic diagram of a first
• Fig. 3 is a schematic plan view of a Haiteelements.
• a WeNe 12 is arranged in a pump housing 10.
• the shaft 12 carries the two separate or separate rotor elements 14, 16 according to the invention. These are firmly connected to the shaft 12.
• the rotor element 14 forms a first vacuum stage 18, in which the highest vacuum is generated.
• the gas to be delivered is sucked in here through a first inlet opening 20.
• the first vacuum stage is a vacuum stage formed by a turbomolecular pump. With the rotor 14, a stator 22 connected to the housing 10 cooperates.
• the second vacuum stage 24 is likewise formed by a turbomolecular pump, wherein a stator 28 is likewise connected to the housing 10.
• the third stage 26 is a Holweck stage, in which the helically shaped projection 30 engages in a corresponding helical recess.
• the second vacuum stage 24 draws in medium through an inlet opening 34 and the third vacuum stage 26 through an inlet opening 36.
• the aspirated medium is conveyed from all three stages 18, 24, 26 to the ejection opening 38.
• an electric motor 40 for driving the shaft 12 is provided in the region of the third stage.
• the electric motor 40 surrounds the shaft 12 in a preferred embodiment.
• the Holweck stage preferably surrounds the electric motor 40.
• the bearing of the shaft 12 via an inner Lagereiernent 42 and an outer bearing member 44.
• the inner bearing member 42 is disposed between the two Rotoreiementen 14, 16. If the inner bearing element 42 is a roller bearing, an inner bearing ring is pressed onto the shaft 12, for example.
• An outer bearing ring is fixed by a Haiteelement 46.
• the holding element 46 shown in plan view in FIG. 3 has a plurality of, in particular regularly arranged, partial-ring-segment-shaped passage openings 48 through which the medium conveyed by the first stage 18 flows.
• the outer bearing element 44 is arranged in the illustratedariessbeispiei outside the lowest or third stage 26.
• the bearing element 44 is preferably also a roller bearing,
• the inner bearing member is disposed in the axial direction 50 within the rotor member 14.
• the rotor element 14 has a cross-sectionally substantially annular recess 52.
• FIG. 2 In the exemplary embodiment shown in FIG. 2, three rotor elements 14, 66, 68 are shown on the shaft 64. In the illustrated exemplary embodiment (FIG. 2), all rotor elements 14, 66, 68 are shown as rotor elements of moiekular pumps, wherein it is Of course, it can also be about other rotor elements. Furthermore, even in this embodiment, individual rotor elements can form a plurality of stages.
• the inner bearing element 42 is arranged between two rotor elements 14, 66 and likewise fixed by a holding element 46 (FIG. 3) or connected to the housing.
• the drive motor 40 is disposed between the two rotor elements 14, 66.
• the second or outer bearing element 44 is arranged between the two rotor elements 66, 68 (FIG. 2) and fixed in the illustrated embodiment via a holding element 46.
• a flow through the individual pump stages formed by the rotor elements 14, 66, 68 occurs in succession.
• a suction of gas through a further inlet opening in the direction of the arrow 62 Via a Beipass or connecting channel (arrow 64) is in both Direction of the arrow 62 and in the direction of arrow 54 sucked gas to the next stage (rotor element 66) passed.
• the arrows 54, 62, 56 and 68 correspond to inlet openings or intake openings.
• the arrow 60 corresponds to the ejection opening.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Non-Positive Displacement Air Blowers (AREA)
• Applications Or Details Of Rotary Compressors (AREA)

Applications Claiming Priority (2)

Publications (1)

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ID=40873510

Family Applications (1)

Country Status (5)

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Family Cites Families (21)

• 2008
  • 2008-05-23 DE DE102008024764A patent/DE102008024764A1/de not_active Withdrawn
• 2009
  • 2009-05-05 US US12/994,245 patent/US20110135506A1/en not_active Abandoned
  • 2009-05-05 EP EP09749712A patent/EP2288812A1/de not_active Withdrawn
  • 2009-05-05 JP JP2011509914A patent/JP5560263B2/ja not_active Expired - Fee Related
  • 2009-05-05 WO PCT/EP2009/055397 patent/WO2009141222A1/de active Application Filing

Non-Patent Citations (1)

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