EP0290664B1 - Two-shaft pump - Google Patents

Two-shaft pump Download PDF

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Publication number
EP0290664B1
EP0290664B1 EP87107091A EP87107091A EP0290664B1 EP 0290664 B1 EP0290664 B1 EP 0290664B1 EP 87107091 A EP87107091 A EP 87107091A EP 87107091 A EP87107091 A EP 87107091A EP 0290664 B1 EP0290664 B1 EP 0290664B1
Authority
EP
European Patent Office
Prior art keywords
shaft
pot
rotor
pump according
shaft 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
EP87107091A
Other languages
German (de)
French (fr)
Other versions
EP0290664A1 (en
Inventor
Heinz Frings
Karl-Heinz Ronthaler
Ralf Steffens
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Balzers und Leybold Deutschland Holding AG
Original Assignee
Leybold AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Leybold AG filed Critical Leybold AG
Priority to EP87107091A priority Critical patent/EP0290664B1/en
Priority to DE8787107091T priority patent/DE3775553D1/en
Priority to JP63115015A priority patent/JPS63302195A/en
Priority to US07/194,252 priority patent/US4917583A/en
Publication of EP0290664A1 publication Critical patent/EP0290664A1/en
Application granted granted Critical
Publication of EP0290664B1 publication Critical patent/EP0290664B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C18/12—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type
    • F04C18/126—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of other than internal-axis type with radially from the rotor body extending elements, not necessarily co-operating with corresponding recesses in the other rotor, e.g. lobes, Roots type
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
    • F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
    • F01C21/02—Arrangements of bearings
    • 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
    • F04C18/00—Rotary-piston pumps specially adapted for elastic fluids
    • F04C18/08—Rotary-piston pumps specially adapted for elastic fluids of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C18/082—Details specially related to intermeshing engagement type pumps
    • F04C18/086—Carter
    • 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
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/0042—Driving elements, brakes, couplings, transmissions specially adapted for pumps
    • F04C29/005—Means for transmitting movement from the prime mover to driven parts of the pump, e.g. clutches, couplings, transmissions
    • 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
    • F04C29/00—Component parts, details or accessories of pumps or pumping installations, not provided for in groups F04C18/00 - F04C28/00
    • F04C29/04—Heating; Cooling; Heat insulation

Definitions

  • the invention relates to a twin-shaft pump with a pumping chamber, with a pair of rotors located in the pumping chamber, with side flanges for frontal support of the rotors by means of roller bearings and with a drive which engages on one of the rotor end faces.
  • the shaft seals of the pumping chamber and the shaft bearings are also arranged one behind the other. This results in a relatively large bearing distance, which results in an increased overall length of the entire pump, an increased bending load on the piston shaft ends, an unfavorable dynamic behavior and a limited length-diameter ratio of the rotary lobes.
  • the space available for the shaft seal is very narrow in the axial direction, so that different sealing principles can only be accommodated with great effort.
  • the two-shaft pumps of the type mentioned also include single- or multi-stage pumps, the rotary lobes of which have different profiles, as are disclosed, for example, in DE-OSes 31 47 824 and 33 12 117.
  • the use of helical rotors is also known in two-shaft vacuum pumps.
  • the invention relates to multi-stage two-shaft vacuum pumps, the stages of which are equipped with differently designed pairs of pistons.
  • a screw compressor with different tooth space volumes is known from FR-A-12 90 239.
  • a kinematically reversed bearing is provided on the suction side, which is supported on a fixed pin which penetrates the hollow-bored rotor.
  • the prior art includes the content of FR-A-986 715, which discloses a rotary lobe pump.
  • the pair of rotary pistons is kinematically reversed on extensions in bearings, whereby the bearing inner ring is supported on a fixed pin.
  • the present invention has for its object to provide a twin-shaft pump of the type mentioned, which is significantly more compact, has a simpler structure and advantageously enables a modular design.
  • the Roots vacuum pump 1 shown in FIG. 1 essentially comprises the following components: housing 2, side plate 3 on the drive side, side plate 4 opposite the drive side, and rotors 5 and 6, which rotate in the pumping chamber 7. Sections through the rotors 5 and 6 are shown within the scooping chamber 7, specifically perpendicular to their position within the Roots pump 1.
  • cup-shaped designs 8 are provided which are formed by cup-shaped components 11 and 12 in the exemplary embodiment shown in FIG. 1.
  • the rotors 5 and 6 each have a central stub shaft 13 to 16 on each end face. With a likewise central, bottom-side opening 17 and 18, the components 11 and 12 encompass the associated shaft end 13 and 15, respectively.
  • the components 11, 12 are fastened by means of screws on the respective end face of the rotor 5 and 6, respectively. A fixed and central position of the components 11 and 12 is ensured by this type of fastening.
  • the rotor bearings 19 which in the embodiment shown in FIG. 1 consist of deep groove ball bearings. These bearings 19 are supported on the one hand on the inner wall of the pot-shaped components 11 and 12. To support the fixed inner bearing ring, a shaft end 21 protruding into the cup-shaped component 11 or 12 is provided in each case.
  • the side plate 4 has circular openings with the cup-shaped components 11 and 12 directly surrounding inner walls 22.
  • the covers 24 are provided, to which the stationary stumps 21 are attached. Lid 24 and stump 21 are preferably formed in one piece.
  • sealing gas seal is shown in connection with component 11.
  • sealing gas eg inert gas
  • annular channel 26 arranged in the inner wall 22 of the side plate 4 via the channel 27.
  • a slight gas flow flows continuously to the exhaust chamber 7, so that possibly aggressive gases located therein cannot get into the storage room.
  • a piston ring labyrinth seal is shown.
  • the outside of the component 12 is equipped with grooves 28, in which piston rings 29 are arranged, which are supported on the inner wall 22 of the side plate 4 and thus form the labyrinth.
  • the two gear wheels 31 and 32 which are responsible for the synchronous movement of the rotors 5 and 6, are arranged on the drive side in the region of the side plate 3.
  • the gear 31 forms the cup-shaped design 8, which receives the bearing 19.
  • the stump 21 fixed to the housing is fastened to the cover 33.
  • the drive shaft 34 is connected to the right end face of the lower piston 6.
  • the drive motor itself is not shown.
  • the rotor-side end of the drive shaft 34 is fastened to the rotor in the same way as the cup-shaped components 11 and 12 and the gear 31. This gives the advantage of using identical rotors.
  • the gearwheel 32 is fastened on the drive shaft 34 by means of a clamping element 35 known per se, which allows the necessary play adjustment of the rotors 5 and 6.
  • the motor flange 36 is fastened to the bearing flange 3 with a flange 37 in which there is a bearing 38 for the drive shaft 34.
  • This arrangement makes it easy to mount different drive variants (canned motors, built-in motors, motors with different speeds). It is only necessary that the end of the respective drive shaft to be connected to the rotor 6 has similar fastening means.
  • the motor flange 36 is a turned part that can be produced inexpensively.
  • FIG. 2 again shows an exemplary embodiment for the drive side of a two-shaft pump according to the invention with an upstream gear stage 41.
  • the drive shaft 42 is coupled to the first gear wheel 43.
  • the deep groove ball bearings 44 and 45 are provided for mounting the gear wheel 43 and the drive shaft 34.
  • the driven gear 46 is coupled to the stub shaft 34, which is connected to the rotor 6 in the manner described for FIG. 1.
  • FIG. 2 also shows further variants for sealing concepts which, as shown, are not restricted to use with the synchronization gears 31 and 32.
  • the gear wheel 31 In the area of the associated rotor end face, the gear wheel 31 has a radially inwardly directed step 48, into which a component 49 fixed to the housing projects.
  • a recess 51 is provided in the gear wheel end face facing this part 49, in which a sealing ring 52 rotating with the gear wheel is accommodated.
  • the sealing ring is under the action of the compression spring 53 and is thereby pressed onto the parts 49 fixed to the housing, so that a contacting seal is present.
  • a non-contact labyrinth seal is shown in connection with the gear 32.
  • the housing-fixed part 49 is equipped with annular projections and recesses 54, to which corresponding projections and recesses 55 in the gear 32 are assigned.
  • FIG. 3 shows rotor bearings in which components 11 and 12 with cup-shaped designs 8 are respectively arranged in front of the rotors 5 and 6.
  • the components 11 and 12 are further designed as gear wheels with an identical diameter and form the synchronization gear for the pistons 5 and 6.
  • a preferably grease-lubricated version is shown again.
  • the storage room is completed by the profile ring 62, which forms a gap seal with the step 63 on the stump 21.
  • a cooling ring 81 is provided in the storage space, namely between the profile ring 62 and the bearing 19, which is supplied by the stump 21 in a manner not shown. This cooling ring 81 forms additional protection against lubricant vapors emerging from the storage space.
  • the upper part of FIG. 5 shows an advantageous possibility of connecting the component 11 upstream of the piston 5 to the rotor 5, regardless of whether it simultaneously functions as a gear or not.
  • a depression 77 equipped with a gradation, the lower section of which is equipped with a thread 78.
  • a stump 79 with a design corresponding to the depression 77 is fastened to the component 11.
  • the stump 79 takes over the centering between the component 11 and the rotor 5, the thread 78 serves to fasten the two parts 5 and 11 together.
  • FIG. 3 shows a preferably oil-lubricated version.
  • a radial shaft sealing ring 65 is provided instead of a gap seal.
  • the cooling ring 81 which is located as far radially as possible, is connected to the stump 21 via a closed ring web 82, so that it forms a dynamic seal with an outer oil ring. Effective cooling of the oil is also achieved.
  • a bore 77 is again provided in the rotor 6, in which a stump 79 fastened to the component 12 is fastened centering via the screw connection 80.
  • the stump 79 can be both cylindrical and conical for centering.
  • the embodiment shown in FIG. 3 not only has the advantage of using identical rotors;
  • the roters can be made from extruded sections that can be cut to length, since stub shafts are no longer required.
  • FIG. 4 again shows a section through the drive-side plate 3, which is equipped with a drive gear stage, formed by the gear wheels 83 and 84.
  • a drive side designed in this way can be combined with a synchronization gear which is arranged on the side opposite the drive (compare, for example, FIG. 5).
  • the bearing 38 in the motor flange 37 serves to support the shaft 34.
  • the foot of the shaft 34 is connected to the gear 83 via the clamping element 35.
  • the bearing 19 of the rotor 6 lies in the cup-shaped design 8, which is embedded in the end face of the rotor 6.
  • the fixed ring of the bearing 19 is supported on the stump 21 which protrudes into the cup-shaped design 8.
  • a plate 87, which is located between the piston 6 and the gear 83 and is screwed to the side window 3, serves to hold and fasten the stump 21.
  • an output gear 91 of a gear 91, 92 serving for the drive and the associated synchronization gear 31 are fastened on the rotor 5 coaxially.
  • the cup-shaped design 8 is provided, within which the bearing 19 is accommodated in the manner already described.
  • the drive gear 92 is expediently (not shown) mounted on the drive shaft of the electric motor, while a cup-shaped design 8 can be provided in the second synchronization gear 32 for mounting the rotor 6 (see Fig. 1, gear 31). In this way, all four rotor bearings are designed in the manner according to the invention.
  • FIG. 6 shows a drive-side mounting of the rotor 6 with the aid of a cup-shaped design 8 in the synchronization or gear wheel 32, 91, in which the drive shaft 34 is coupled to the rotor 6 at the same time.
  • cover 24 and stump 21 are equipped with a central bore 93 and the gearwheel with a central bore 94 through which the drive shaft 34 extends. This is inserted with its free end into the gear 32 and firmly connected to the rotor 6.
  • Fig. 7 shows an embodiment of a drive-side bearing, in which the rotor bearing of the driven piston and the pump-side drive shaft bearing are identical.
  • the drive shaft 34 is inserted into the synchronization gear 32 which is firmly connected to the rotor 6 and is supported in the motor flange 37 via the bearing 38.
  • This bearing 38 also forms the rotor bearing.
  • the interface for connecting different motors can be placed behind the drive gear that has already been synchronized. The synchronization is not disturbed. Overdeterminations (2 motor bearings, 1 drive-side rotor bearing) are no longer necessary.
  • a two-shaft vacuum pump according to the invention has a much simpler structure than previously known pumps of this type. Castings previously required can be replaced by turned parts. The number of sealing grooves that must be present in castings is significantly reduced, so that considerable Manufacturing advantages result. The side plate 4 and the housing 2 can be formed in one piece, so that the number of parts to be manufactured and the areas to be sealed is further reduced. Finally, the compactness achieved and the reduced weight are associated with a not inconsiderable price reduction.
  • the thermal operational reliability is increased.
  • the temperature of the rotors rotating in a non-contact vacuum does not increase as much as that of conventional double-shaft vacuum pumps, so that contact between the rotors and the surrounding housing, which can give off its heat much better than the rotary pistons, is reduced.
  • a uniform expansion of the rotors and the housing is thereby achieved, that is, an excessive temperature difference and the resulting thermal expansion differences between the rotary piston and the housing, caused by different heat emissions, are avoided.
  • the cooling devices located in the storage area it is prevented that temperature differences across the bearings and the absolute storage temperatures become too great.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Rotary Pumps (AREA)

Description

Die Erfindung bezieht sich auf eine Zweiwellenpumpe mit einem Schöpfraum, mit einem im Schöpfraum befindlichen Rotorpaar, mit Seitenflanschen zur stirnseitigen Abstützung der Rotoren mittels Wälzlagern und mit einem Antrieb, der an einer der Rotorstirnseiten angreift.The invention relates to a twin-shaft pump with a pumping chamber, with a pair of rotors located in the pumping chamber, with side flanges for frontal support of the rotors by means of roller bearings and with a drive which engages on one of the rotor end faces.

Aus der DE-OS 19 39 717 ist ein typischer Vertreter einer heute auf dem Markt befindlichen Zweiwellenpumpe bekannt. Es handelt sich um eine Wälzkolbenpumpe mit den folgenden Hauptbauteilen: Deckel, Schilde beziehungsweise Lagerflansche auf beiden Seiten des Schöpfraumes, Gehäuse und Motorflansch. Diese Bauteile sind relativ groß und schwer und damit auch aufwendig in der Bearbeitung (Gußteile). Auch die Handhabung (Montage, Service usw.) ist aufwendig, da die einzelnen Teile gegeneinander gedichtet und verschraubt werden müssen. Insgesamt ergeben sich dadurch die folgenden Nachteile: großes Bauvolumen, großes Gewicht und hoher Preis, Probleme bei der Abdichtung der einzelnen Bauteile sowie hoher Aufwand bezüglich Fertigung, Montage und Service. Die Seitenräume, in denen sich das Synchronisationsgetriebe einerseits und die Verbindung zur Motorwelle andererseits befinden, sind relatiov groß und bilden schädliche Totvolumina neben dem Schöpfraum. Schließlich werden vom Markt immer häufiger in Abhängigkeit von der Applikation unterschiedliche Dichtsysteme, unterschiedliche Antriebssysteme und dergleichen gewünscht. Bei dem Aufbau bekannter Wälzkolbenpumpen sind die Realisierungsmöglichkeiten für einen modularen Aufbau ungünstig.From DE-OS 19 39 717 a typical representative of a twin-shaft pump currently on the market is known. It is a Roots pump with the following main components: cover, shields or bearing flanges on both sides of the pumping chamber, housing and motor flange. These components are relatively large and heavy and therefore also complex to process (castings). Handling (assembly, service, etc.) is also complex because the individual parts must be sealed and screwed together. Overall, this results in the following disadvantages: large construction volume, great weight and high price, problems with the sealing of the individual components and high expenditure in terms of production, assembly and service. The side spaces, in which the synchronization gearbox is located on the one hand and the connection to the motor shaft on the other, are relatively large and form harmful dead volumes next to the scooping space. Finally, depending on the application, different sealing systems, different drive systems and the like are increasingly desired by the market. When constructing known Roots pumps, the implementation options for a modular structure are unfavorable.

Bei der vorbekannten Wälzkolbenpumpe sind weiterhin die Wellenabdichtungen des Schöpfraumes und die Wellenlagerungen hintereinander angeordnet. Dadurch ergibt sich ein relativ großer Lagerabstand mit der Folge einer erhöhten Baulänge der gesamten Pumpe, einer erhöhten Biegebelastung der Kolbenwellenenden, eines ungünstigen dynamischen Verhaltens sowie eines begrenzten Längen-Durchmesser-Verhältnisses der Drehkolben. Der für die Schöpfraumwellenabdichtung vorhandene Bauraum ist in axialer Richtung sehr eng begrenzt, so daß unterschiedliche Dichtprinzipien nur mit hohem Aufwand darin untergebracht werden können.In the previously known Roots pump, the shaft seals of the pumping chamber and the shaft bearings are also arranged one behind the other. This results in a relatively large bearing distance, which results in an increased overall length of the entire pump, an increased bending load on the piston shaft ends, an unfavorable dynamic behavior and a limited length-diameter ratio of the rotary lobes. The space available for the shaft seal is very narrow in the axial direction, so that different sealing principles can only be accommodated with great effort.

Zu den Zweiwellenpumpen der eingangs genannten Art gehören weiterhin ein- oder mehrstufige Pumpen, deren Drehkolben andere Profile aufweisen, wie sie zum Beispiel in den DE-OSen 31 47 824 und 33 12 117 offenbart sind. Auch die Verwendung von schraubenförmigen Rotoren ist bei Zweiwellen-Vakuumpumpen bekannt. Schließlich betrifft die Erfindung mehrstufige Zweiwellen-Vakuumpumpen, deren Stufen mit unterschiedlich gestalteten Kolbenpaaren ausgerüstet sind.The two-shaft pumps of the type mentioned also include single- or multi-stage pumps, the rotary lobes of which have different profiles, as are disclosed, for example, in DE-OSes 31 47 824 and 33 12 117. The use of helical rotors is also known in two-shaft vacuum pumps. Finally, the invention relates to multi-stage two-shaft vacuum pumps, the stages of which are equipped with differently designed pairs of pistons.

Ein Schraubenverdichter mit unterschiedlichen Zahnlückenvolumina ist aus der FR-A-12 90 239 bekannt. Um den Eintrittsquerschnitt zu erhöhen, ist saugseitig eine kinematisch umgekehrte Lagerung vorgesehen, die sich auf einem feststehenden, den hohlgebohrten Rotor durchsetzenden Zapfen abstützt. Schließlich gehört zum Stand der Technik der Inhalt der FR-A-986 715, die eine Drehkolbenpumpe offenbart. Das Drehkolbenpaar wird auf Verlängerungen in Lagern kinematisch umgekehrt gelagert, wobei sich der Lagerinnenring jeweils auf einem feststehenden Zapfen abstützt. Diese Zapfen sind sehr stark ausgeführt, ragen jeweils weit in die Rotoren hinein und bilden gleichzeitig die (feststehende) Kolbentaille, um die das Kopfzahngebilde rotiert.A screw compressor with different tooth space volumes is known from FR-A-12 90 239. In order to increase the inlet cross-section, a kinematically reversed bearing is provided on the suction side, which is supported on a fixed pin which penetrates the hollow-bored rotor. Finally, the prior art includes the content of FR-A-986 715, which discloses a rotary lobe pump. The pair of rotary pistons is kinematically reversed on extensions in bearings, whereby the bearing inner ring is supported on a fixed pin. These pins are very strong, each protrude far into the rotors and at the same time form the (fixed) piston waist, around which the head tooth structure rotates.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, eine Zweiwellenpumpe der eingangs genannten Art zu schaffen, die wesentlich kompakter ist, einen einfacheren Aufbau hat und eine modulare Bauweise vorteilhaft ermöglicht.The present invention has for its object to provide a twin-shaft pump of the type mentioned, which is significantly more compact, has a simpler structure and advantageously enables a modular design.

Erfindungsgemäß wird diese Aufgabe durch die kennzeichnenden Merkmale des Patentanspruchs 1 gelöst. Bei einer Pumpe mit diesen Merkmalen ist das topfförmige Bauteil der Rotorstirnseite vorgelagert. Dadurch ist auf seiner Außenseite ausreichend Raum für unterschiedliche Dichtkonzepte. Da der Lagerraum und die Wellendichtung nicht mehr axial hintereinander angeordnet werden müssen und da auch ein Getriebezahnrad gleichzeitig ein topfförmiges Bauteil bildet, ergibt sich eine Reduzierung der Baulänge mit der Folge, daß auch das Gewicht der Pumpe reduziert ist. Der Abstand der Rotorlagerungen ist kleiner als bei den vorbekannten Vakuumpumpen, was in Bezug auf das dynamische Verhalten der Drehkolben und deren Längen-Durchmesser-Verhältnis Vorteile hat. Schließlich ergibt sich eine erhöhte Montage- und Servicefreundlichkeit, da die Zugänglichkeit zu den Wellendichtungen nicht mehr durch vorgebaute Kolbenlager beeinträchtigt ist.According to the invention, this object is achieved by the characterizing features of patent claim 1. In the case of a pump with these features, the cup-shaped component is located in front of the rotor face. This means that there is enough space on the outside for different sealing concepts. Since the storage space and the shaft seal no longer have to be arranged axially one behind the other and since a gear wheel also forms a cup-shaped component at the same time, the overall length is reduced, with the result that the weight of the pump is also reduced. The distance between the rotor bearings is smaller than with the known vacuum pumps, which has advantages in relation to the dynamic behavior of the rotary lobes and their length-diameter ratio. Finally, there is an increased ease of installation and servicing, since access to the shaft seals is no longer impaired by pre-assembled piston bearings.

Weitere Vorteile und Einzelheiten der Erfindung sollen anhand von in den Figuren 1 bis 7 dargestellten Ausführungsbeispielen erläutert werden. Es zeigen:

Fig. 1
einen Längsschnitt durch eine Zweiwellen-Vakuumpumpe nach der Erfindung,
Fig. 2
einen Längsschnitt durch einen Lagerflansch mit dem Synchronistationsgetriebe und einer vorgelagerten Antriebs-Getriebestufe,
Fig. 3
eine Schnitt durch den der Antriebsseite gegenüberliegenden Lagerflansch
Fig. 4
einen Schnitt durch den antriebsseitigen Lagerflansch mit Antriebs-Getriebestufe und
Figuren 5 bis 7
weitere Ausführungen für antriebsseitige Lagerungen.
Further advantages and details of the invention will be explained on the basis of the exemplary embodiments illustrated in FIGS. 1 to 7. Show it:
Fig. 1
2 shows a longitudinal section through a two-shaft vacuum pump according to the invention,
Fig. 2
a longitudinal section through a bearing flange with the synchronizing gear and an upstream drive gear stage,
Fig. 3
a section through the bearing flange opposite the drive side
Fig. 4
a section through the drive side bearing flange with drive gear stage and
Figures 5 to 7
further versions for bearings on the drive side.

Die in Fig. 1 dargestellte Wälzkolben-Vakuumpumpe 1 umfaßt im wesentlichen die folgenden Bauteile: Gehäuse 2, antriebsseitige Seitenplatte 3, der Antriebsseite gegenüberliegende Seitenplatte 4 sowie die Rotoren 5 und 6, die im Schöpfraum 7 rotieren. Schnitte durch die Rotoren 5 und 6 sind innerhalb des Schöpfraumes 7 dargestellt, und zwar senkrecht zu ihrer Lage innerhalb der Wälzkolbenpumpe 1.The Roots vacuum pump 1 shown in FIG. 1 essentially comprises the following components: housing 2, side plate 3 on the drive side, side plate 4 opposite the drive side, and rotors 5 and 6, which rotate in the pumping chamber 7. Sections through the rotors 5 and 6 are shown within the scooping chamber 7, specifically perpendicular to their position within the Roots pump 1.

Um die Rotoren 5 und 6 auf der dem im einzelnen nicht dargestellten Antrieb abgewandten Seite zu lagern, sind topfförmige Gestaltungen 8 vorgesehen, die bei dem in Fig. 1 dargestellten Ausführungsbeispiel von topfförmigen Bauteilen 11 und 12 gebildet werden. Die Rotoren 5 und 6 weisen auf jeder Stirnseite jeweils einen zentralen Wellenstumpf 13 bis 16 auf. Mit jeweils einer ebenfalls zentralen, bodenseitigen Öffnung 17 und 18 umfassen die Bauteile 11 und 12 den zugehörigen Wellenstumpf 13 bzw. 15. Außerdem sind die Bauteile 11, 12 mittels Schrauben auf der jeweiligen Stirnseite des Rotors 5 bzw. 6 befestigt. Eine feste und zentrale Position der Bauteile 11 und 12 ist durch diese Befestigungsart sichergestellt.In order to support the rotors 5 and 6 on the side facing away from the drive (not shown in detail), cup-shaped designs 8 are provided which are formed by cup-shaped components 11 and 12 in the exemplary embodiment shown in FIG. 1. The rotors 5 and 6 each have a central stub shaft 13 to 16 on each end face. With a likewise central, bottom-side opening 17 and 18, the components 11 and 12 encompass the associated shaft end 13 and 15, respectively. In addition, the components 11, 12 are fastened by means of screws on the respective end face of the rotor 5 and 6, respectively. A fixed and central position of the components 11 and 12 is ensured by this type of fastening.

Innerhalb der topfförmigen Bauteile 11 und 12 befinden sich die Rotorlager 19, die bei dem in Fig. 1 dargestellten Ausführungsbeispiel aus Rillenkugellagern bestehen. Diese Lager 19 stützen sich einerseits auf der Innenwand der topfförmigen Bauteile 11 und 12 ab. Zur Abstützung des feststehenden, inneren Lagerrings ist jeweils ein in das topfförmige Bauteil 11 bzw. 12 von außen hineinragender Wellenstumpf 21 vorgesehen.Within the cup-shaped components 11 and 12 are the rotor bearings 19, which in the embodiment shown in FIG. 1 consist of deep groove ball bearings. These bearings 19 are supported on the one hand on the inner wall of the pot-shaped components 11 and 12. To support the fixed inner bearing ring, a shaft end 21 protruding into the cup-shaped component 11 or 12 is provided in each case.

Die Seitenplatte 4 weist kreisförmige Durchbrechungen mit die topförmigen Bauteile 11 und 12 unmittelbar umgebenden Innenwandungen 22 auf. Zum dichten Verschluß dieser Durchbrechungen sind die Deckel 24 vorgesehen, an denen die ruhenden Stümpfe 21 befestigt sind. Deckel 24 und Stumpf 21 sind vorzugsweise einstückig ausgebildet.The side plate 4 has circular openings with the cup-shaped components 11 and 12 directly surrounding inner walls 22. For the tight closure of these openings, the covers 24 are provided, to which the stationary stumps 21 are attached. Lid 24 and stump 21 are preferably formed in one piece.

Es ist bekannt, zur Abdichtung des Schöpfraumes 7 gegenüber den Lagerräumen die unterschiedlichsten Dichtprinzipien zu verwenden. Bei den vorbekannten Zweiwellen-Vakuumpumpen ist es erforderlich, Dichtung und Lagerung hintereinander anzuordnen. Bei einer Rotorlagerung nach Fig. 1 ist das nicht mehr erforderlich. Auf der Außenseite der Bauteile 11 und 12 ist ausreichend Platz für die unterschiedlichsten Dichtkonzepte vorhanden. Im Zusammenhang mit dem Bauteil 11 ist eine Sperrgasdichtung dargestellt. Dazu wird einem in der Innenwandung 22 der Seitenplatte 4 angeordneten Ringkanal 26 über den Kanal 27 Sperrgas (z.B. Inertgas) zugeführt. Ein geringfügiger Gasstrom strömt ständig zum Schöfraum 7, so daß darin befindliche, möglicherweise aggressive Gase nicht in den Lagerraum gelangen können. Im Zusammenhand mit dem topfförmigen Bauteil 12 ist eine Kolbenring-Labyrinthdichtung dargestellt. Die Außenseite des Bauteils 12 ist mit Nuten 28 ausgerüstet, in denen Kolbenringe 29 angeordnet sind, die sich an der Innenwandung 22 der Seitenplatte 4 abstützen und so das Labyrinth bilden.It is known to use a wide variety of sealing principles to seal the scoop chamber 7 from the storage rooms. In the known twin-shaft vacuum pumps, it is necessary to arrange the seal and the bearing one behind the other. 1 is no longer necessary. On the outside of components 11 and 12 there is sufficient space for a wide variety of sealing concepts. A sealing gas seal is shown in connection with component 11. For this purpose, sealing gas (eg inert gas) is supplied to an annular channel 26 arranged in the inner wall 22 of the side plate 4 via the channel 27. A slight gas flow flows continuously to the exhaust chamber 7, so that possibly aggressive gases located therein cannot get into the storage room. Together with the cup-shaped component 12, a piston ring labyrinth seal is shown. The outside of the component 12 is equipped with grooves 28, in which piston rings 29 are arranged, which are supported on the inner wall 22 of the side plate 4 and thus form the labyrinth.

Beim dargestellten Ausführungsbeispiel sind auf der Antriebsseite im Bereich der Seitenplatte 3 die beiden Zahnräder 31 und 32 angeordnet, die für die synchrone Bewegung der Rotoren 5 und 6 verantwortlich sind. Beim oberen Rotor 5 bildet das Zahnrad 31 die topfförmige Gestaltung 8, die die Lagerung 19 aufnimmt. Der gehäusefeste Stumpf 21 ist am Deckel 33 befestigt. Mit der rechten Stirnseite des unteren Kolbens 6 ist die Antriebswelle 34 verbunden. Der Antriebsmotor selbst ist nicht dargestellt. Das rotorseitige Ende der Antriebswelle 34 ist in gleicher Weise wie die topfförmigen Bauteile 11 und 12 sowie das Zahnrad 31 mit dem Rotor befestigt. Dadurch ergibt sich der Vorteil der Verwendung identischer Rotoren. Auf der Antriebswelle 34 ist das Zahnrad 32 mittels eines an sich bekannten Spannelementes 35 befestigt, welches die Vornahme der erforderlichen Spieleinstellung der Rotoren 5 und 6 erlaubt. Der Motorflansch 36 ist mit einem Flansch 37, in dem sich ein Lager 38 für die Antriebswelle 34 befindet, auf dem Lagerflansch 3 befestigt. Diese Anordnung ermöglicht es in einfacher Weise, unterschiedliche Antriebsvarianten (Spaltrohrmotoren, Einbaumotoren, Motoren mit unterschiedlichen Drehzahlen) zu montieren. Es ist lediglich erforderlich, daß das mit dem Rotor 6 zu verbindende Ende der jeweiligen Antriebswelle gleichartige Befestigungsmittel aufweist. Vorteilhafterweise handelt es sich bei dem Motorflansch 36 um ein günstig herstellbares Drehteil.In the exemplary embodiment shown, the two gear wheels 31 and 32, which are responsible for the synchronous movement of the rotors 5 and 6, are arranged on the drive side in the region of the side plate 3. In the upper rotor 5, the gear 31 forms the cup-shaped design 8, which receives the bearing 19. The stump 21 fixed to the housing is fastened to the cover 33. The drive shaft 34 is connected to the right end face of the lower piston 6. The drive motor itself is not shown. The rotor-side end of the drive shaft 34 is fastened to the rotor in the same way as the cup-shaped components 11 and 12 and the gear 31. This gives the advantage of using identical rotors. The gearwheel 32 is fastened on the drive shaft 34 by means of a clamping element 35 known per se, which allows the necessary play adjustment of the rotors 5 and 6. The motor flange 36 is fastened to the bearing flange 3 with a flange 37 in which there is a bearing 38 for the drive shaft 34. This arrangement makes it easy to mount different drive variants (canned motors, built-in motors, motors with different speeds). It is only necessary that the end of the respective drive shaft to be connected to the rotor 6 has similar fastening means. Advantageously, the motor flange 36 is a turned part that can be produced inexpensively.

Fig. 2 zeigt noch einmal ein Ausführungsbeispiel für die Antriebsseite einer erfindungsgemäßen Zweiwellenpumpe mit einer vorgelagerten Getriebestufe 41. Die Antriebswelle 42 ist mit dem ersten Getrieberad 43 gekoppelt. Zur Lagerung des Getriebezahnrades 43 und der Antriebswelle 34 sind die Rillenkugellager 44 und 45 vorgesehen. Das Abtriebs-Zahnrad 46 ist mit dem Wellenstumpf 34 gekoppelt, der in der zu Fig. 1 beschriebenen Weise mit dem Rotor 6 verbunden ist.FIG. 2 again shows an exemplary embodiment for the drive side of a two-shaft pump according to the invention with an upstream gear stage 41. The drive shaft 42 is coupled to the first gear wheel 43. The deep groove ball bearings 44 and 45 are provided for mounting the gear wheel 43 and the drive shaft 34. The driven gear 46 is coupled to the stub shaft 34, which is connected to the rotor 6 in the manner described for FIG. 1.

Fig. 2 zeigt außerdem weitere Varianten für Dichtungskonzepte, welche nicht - wie dargestellt - auf die Verwendung bei den Synchronisationszahnrädern 31 und 32 beschränkt sind. Das Zahnrad 31 weist im Bereich der Zugehörigen Rotorstirnseite eine radial nach innen gerichtete Abstufung 48 auf, in die ein gehäusefestes Bauteil 49 hineinragt. In der diesem gehäusefesten Teil 49 zugewandten Zahnradstirnseite ist eine Aussparung 51 vorgesehen, in der ein mit dem Zahnrad rotierender Dichtring 52 untergebracht ist. Der Dichtring steht unter der Wirkung der Druckfeder 53 und wird dadurch auf des gehäusefeste Teile 49 gedrückt, so daß eine berührende Dichtung vorhanden ist.FIG. 2 also shows further variants for sealing concepts which, as shown, are not restricted to use with the synchronization gears 31 and 32. In the area of the associated rotor end face, the gear wheel 31 has a radially inwardly directed step 48, into which a component 49 fixed to the housing projects. A recess 51 is provided in the gear wheel end face facing this part 49, in which a sealing ring 52 rotating with the gear wheel is accommodated. The sealing ring is under the action of the compression spring 53 and is thereby pressed onto the parts 49 fixed to the housing, so that a contacting seal is present.

Im Zusammenhang mit dem Zahnrad 32 ist eine berührungsfreie Labyrinthdichtung dargestellt. Das gehäusefeste Teil 49 ist mit ringförmigen Vorsprüngen und Aussparungen 54 ausgerüstet, denen korrespondierende Vorsprünge und Aussparungen 55 im Zahnrad 32 zugeordnet sind.A non-contact labyrinth seal is shown in connection with the gear 32. The housing-fixed part 49 is equipped with annular projections and recesses 54, to which corresponding projections and recesses 55 in the gear 32 are assigned.

Fig. 3 zeigt Rotorlagerungen, bei denen den Rotoren 5 und 6 jeweils Bauteile 11 beziehungsweise 12 mit topfförmigen Gestaltungen 8 vorgelagert sind. Die Bauteile 11 und 12 sind weiterhin als Zahnräder mit identischem Durchmesser ausgebildet und bilden das Synchronisationsgetriebe für die Kolben 5 und 6.FIG. 3 shows rotor bearings in which components 11 and 12 with cup-shaped designs 8 are respectively arranged in front of the rotors 5 and 6. The components 11 and 12 are further designed as gear wheels with an identical diameter and form the synchronization gear for the pistons 5 and 6.

Im oberen Teile der Fig. 3 ist wieder eine vorzugsweise fettgeschmierte Version dargestellt. Der Lagerraum ist durch den Profilring 62 abgeschlossen, der mit der Abstufung 63 am Stumpf 21 eine Spaltdichtung bildet. Zusätzlich ist im Lagerraum, und zwar zwischen dem Profilring 62 und dem Lager 19, ein Kühlring 81 vorgesehen, der in nicht näher dargestellter Weise durch den Stumpf 21 versorgt wird. Dieser Kühlring 81 bildet einen zusätzlichen Schutz vor aus dem Lagerraum austretenden Schmiermittelndämpfen. Zusätzlich zeigt der obere Teil der Fig. 5 eine vorteilhafte Möglichkeit, das dem Kolben 5 vorgelagerte Bauteil 11, unabhängig davon, ob es gleichzeitig die Funktion eines Zahnrades hat oder nicht, mit dem Rotor 5 zu verbinden. Im Rotor 5 ist eine mit einer Abstufung ausgerüstete Vertiefung 77 vorgesehen, deren unterer Abschnitt mit einem Gewinde 78 ausgerüstet ist. Am Bauteil 11 ist ein Stumpf 79 mit einer der Vertiefung 77 korrespondierenden Gestaltung befestigt. Der Stumpf 79 übernimmt die Zentrierung zwischen Bauteil 11 und Rotor 5, das Gewinde 78 dient der Befestigung der beiden Teile 5 und 11 miteinander.In the upper part of Fig. 3, a preferably grease-lubricated version is shown again. The storage room is completed by the profile ring 62, which forms a gap seal with the step 63 on the stump 21. In addition, a cooling ring 81 is provided in the storage space, namely between the profile ring 62 and the bearing 19, which is supplied by the stump 21 in a manner not shown. This cooling ring 81 forms additional protection against lubricant vapors emerging from the storage space. In addition, the upper part of FIG. 5 shows an advantageous possibility of connecting the component 11 upstream of the piston 5 to the rotor 5, regardless of whether it simultaneously functions as a gear or not. Provided in the rotor 5 is a depression 77 equipped with a gradation, the lower section of which is equipped with a thread 78. A stump 79 with a design corresponding to the depression 77 is fastened to the component 11. The stump 79 takes over the centering between the component 11 and the rotor 5, the thread 78 serves to fasten the two parts 5 and 11 together.

Der untere Teil der Fig. 3 zeigt eine vorzugsweise ölgeschmierte Version. An Stelle einer Spaltdichtung ist ein Radialwellendichtring 65 vorgesehen. Der möglichst weit radial außen liegende Kühlring 81 ist über einen geschlossenen Ringsteg 82 mit dem Stumpf 21 verbunden, so daß er mit einem äußeren Ölring eine dynamische Dichtung bildet. Weiterhin wird eine wirksame Kühlung des Öles erreicht. Im Rotor 6 ist wieder eine Bohrung 77 vorgesehen, in der ein am Bauteil 12 befestigter Stumpf 79 zentrierend über die Verschraubung 80 befestigt ist. Der Stumpf 79 kann zur Zentrierung sowohl zylindrisch als auch konisch ausgeführt sein.The lower part of Fig. 3 shows a preferably oil-lubricated version. A radial shaft sealing ring 65 is provided instead of a gap seal. The cooling ring 81, which is located as far radially as possible, is connected to the stump 21 via a closed ring web 82, so that it forms a dynamic seal with an outer oil ring. Effective cooling of the oil is also achieved. A bore 77 is again provided in the rotor 6, in which a stump 79 fastened to the component 12 is fastened centering via the screw connection 80. The stump 79 can be both cylindrical and conical for centering.

Mit der in Figur 3 dargestellten Ausführung ist nicht nur der Vorteil der Verwendung identischer Rotoren verbunden; darüber hinaus können die Roteren aus ablängbaren Strangpreßprofilen gefertigt werden, da Wellenstümpfe nicht mehr erforderlich sind.The embodiment shown in FIG. 3 not only has the advantage of using identical rotors; In addition, the roters can be made from extruded sections that can be cut to length, since stub shafts are no longer required.

Fig. 4 zeigt nochmals einen Schnitt durch die antriebsseitige Seitenplatte 3, die mit einer Antriebs-Getriebsstufe, gebildet von den Zahnrädern 83 und 84, ausgerüstet ist. Eine in dieser Weise gestaltete Antriebsseite ist kombinierbar mit einem Synchronisationsgetriebe, das auf der dem Antrieb gegenüberliegenden Seite angeordnet ist (vergleiche z. B. Fig. 5). Zur Abstützung der Welle 34 dient das Lager 38 im Motorflansch 37. Der Fuß der Welle 34 ist über das Spannelement 35 mit dem Zahnrad 83 verbunden. Die Lagerung 19 des Rotors 6 liegt in der topfförmigen Gestaltung 8, die in die Stirnseite des Rotors 6 eingelassen ist. Der feststehende Ring des Lagers 19 stützt sich auf dem Stumpf 21 ab, der in die topfförmige Gestaltung 8 hineinragt. Der Halterung und Befestigung des Stumpfes 21 dient ein Platte 87, die sich zwischen dem Kolben 6 und dem Zahnrad 83 befindet und mit der Seitenscheibe 3 verschraubt ist.FIG. 4 again shows a section through the drive-side plate 3, which is equipped with a drive gear stage, formed by the gear wheels 83 and 84. A drive side designed in this way can be combined with a synchronization gear which is arranged on the side opposite the drive (compare, for example, FIG. 5). The bearing 38 in the motor flange 37 serves to support the shaft 34. The foot of the shaft 34 is connected to the gear 83 via the clamping element 35. The bearing 19 of the rotor 6 lies in the cup-shaped design 8, which is embedded in the end face of the rotor 6. The fixed ring of the bearing 19 is supported on the stump 21 which protrudes into the cup-shaped design 8. A plate 87, which is located between the piston 6 and the gear 83 and is screwed to the side window 3, serves to hold and fasten the stump 21.

Bei der in Fig. 5 dargestellten antriebsseitigen Lagerung sind ein Abtriebsrad 91 eines dem Antrieb dienenden Getriebes 91, 92 und das zugehörige Synchronisationszahnrad 31 gleichachsig auf dem Rotor 5 befestigt. In dem äußeren Abtriebsrad 91 ist die topfförmige Gestaltung 8 vorgesehen, innerhalb der die Lagerung 19 in der bereits beschriebenen Weise untergebracht ist. Das Antriebszahnrad 92 wird zweckmäßigerweise (nicht dargestellt) auf der Antriebswelle des Elektromotors gelagert, während für die Lagerung des Rotors 6 eine topfförmige Gestaltung 8 im zweiten Synchronisationszahnrad 32 vorgesehen werden kann (vergleiche Fig. 1, Zahnrad 31). Auf diese Weise sind alle vier Rotorlager in der erfindungsgemäßen Weise ausgebildet.In the drive-side bearing arrangement shown in FIG. 5, an output gear 91 of a gear 91, 92 serving for the drive and the associated synchronization gear 31 are fastened on the rotor 5 coaxially. In the outer driven gear 91, the cup-shaped design 8 is provided, within which the bearing 19 is accommodated in the manner already described. The drive gear 92 is expediently (not shown) mounted on the drive shaft of the electric motor, while a cup-shaped design 8 can be provided in the second synchronization gear 32 for mounting the rotor 6 (see Fig. 1, gear 31). In this way, all four rotor bearings are designed in the manner according to the invention.

Fig. 6 zeigt eine antriebsseitige Lagerung des Rotors 6 mit Hilfe einer topfförmigen Gestaltung 8 im Synchronisations- oder Getriebezahnrad 32, 91, bei welcher gleichzeitig die Antriebswelle 34 mit dem Rotor 6 gekoppelt ist. Dazu sind Deckel 24 und Stumpf 21 mit einer zentralen Bohrung 93 sowie das Zahnrad mit einer zentralen Bohrung 94 ausgerüstet, durch die sich die Antriebswelle 34 erstreckt. Diese ist mit ihrem freien Ende in das Zahnrad 32 eingesetzt und darüber fest mit dem Rotor 6 verbunden. Auch bei einer Lösung dieser Art können alle vier Rotorlagerungen in der erfindungsgemäßen Weise mit den beschriebenen Vorteilen ausgeführt sein.FIG. 6 shows a drive-side mounting of the rotor 6 with the aid of a cup-shaped design 8 in the synchronization or gear wheel 32, 91, in which the drive shaft 34 is coupled to the rotor 6 at the same time. For this purpose, cover 24 and stump 21 are equipped with a central bore 93 and the gearwheel with a central bore 94 through which the drive shaft 34 extends. This is inserted with its free end into the gear 32 and firmly connected to the rotor 6. Even with a solution of this type, all four rotor bearings can be designed in the manner according to the invention with the advantages described.

Fig. 7 zeigt eine Ausführungsform einer antriebsseitigen Lagerung, bei der das Rotorlager des getriebenen Kolbens und das pumpenseitige Antriebswellenlager identisch sind. Die Antriebswelle 34 ist in das fest mit dem Rotor 6 verbundene Synchronisationszahnrad 32 eingesetzt und stützt sich im Motorflansch 37 über das Lager 38 ab. Dieses Lager 38 bildet gleichzeitig die Rotorlagerung. Bei dieser Ausführungsform kann die Schnittstelle für den Anschluß verschiedener Motoren hinter das bereits synchronisierte Antriebszahnrad gelegt werden. Die Synchronisation wird nicht gestört. Überbestimmungen (2 Motorlager, 1 antriebsseitiges Rotorlager) entfallen.Fig. 7 shows an embodiment of a drive-side bearing, in which the rotor bearing of the driven piston and the pump-side drive shaft bearing are identical. The drive shaft 34 is inserted into the synchronization gear 32 which is firmly connected to the rotor 6 and is supported in the motor flange 37 via the bearing 38. This bearing 38 also forms the rotor bearing. In this embodiment, the interface for connecting different motors can be placed behind the drive gear that has already been synchronized. The synchronization is not disturbed. Overdeterminations (2 motor bearings, 1 drive-side rotor bearing) are no longer necessary.

Grundsätzlich hat eine Zweiwellen-Vakuumpumpe nach der Erfindung einen wesentlich einfacheren Aufbau als vorbekannte Pumpen dieser Art. Bisher erforderliche Gußteile können durch Drehteile ersetzt werden. Die Anzahl der Dichtnuten, die in Gußteilen vorhanden sein müssen, ist wesentlich reduziert, so daß sich erhebliche Fertigungsvorteile ergeben. Die Seitenplatte 4 und das Gehäuse 2 können einstückig ausgebildet sein, so daß die Anzahl der zu fertigenden Teile und der abzudichtenden Bereiche weiterhin reduziert ist. Mit der erzielten Kompaktheit und dem reduzierten Gewicht ist schließlich eine nicht unerhebliche Preisreduzierung verbunden.Basically, a two-shaft vacuum pump according to the invention has a much simpler structure than previously known pumps of this type. Castings previously required can be replaced by turned parts. The number of sealing grooves that must be present in castings is significantly reduced, so that considerable Manufacturing advantages result. The side plate 4 and the housing 2 can be formed in one piece, so that the number of parts to be manufactured and the areas to be sealed is further reduced. Finally, the compactness achieved and the reduced weight are associated with a not inconsiderable price reduction.

Infolge der bei einigen Ausführungsbeispielen dargestellten Kühleinrichtungen wird die thermische Betriebssicherheit erhöht. Die Temperatur der sich im Vakuum berührungsfrei drehenden Rotoren nimmt nicht so stark zu wie die bei Zweiwellen-Vakuumpumpen herkömmlicher Bauart, so daß ein berührender Kontakt der Rotoren mit dem umliegenden Gehäuse, das seine Wärme deutlich besser als die Drehkolben abgeben kann, reduziert ist. In besonderen Fällen kann es zweckmäßig sein, die zu schnelleWärmeabgabe des Gehäuses durch eine Kapselung, wie sie in Fig. 1 dargestellt und mit 90 bezeichnet ist, vorzusehen. Eine gleichmäßige Dehnung der Rotoren und des Gehäuses wird dadurch erreicht, das heißt, eine zu stark Temperaturdifferenz und daraus resultierende thermische Ausdehnungsunterschiede zwischen Drehkolben und Gehäuse, hervorgerufen durch unterschiedliche Wärmeabgaben, wird so vermieden. Infolge der im Lagerbereich befindlichen Kühleinrichtungen wird verhindert, daß Temperaturdifferenzen über den Lagern und die absoluten Lagertemperaturen zu groß werden.As a result of the cooling devices shown in some exemplary embodiments, the thermal operational reliability is increased. The temperature of the rotors rotating in a non-contact vacuum does not increase as much as that of conventional double-shaft vacuum pumps, so that contact between the rotors and the surrounding housing, which can give off its heat much better than the rotary pistons, is reduced. In special cases, it may be expedient to provide the housing with rapid heat dissipation by means of an encapsulation, as shown in FIG. 1 and designated by 90. A uniform expansion of the rotors and the housing is thereby achieved, that is, an excessive temperature difference and the resulting thermal expansion differences between the rotary piston and the housing, caused by different heat emissions, are avoided. As a result of the cooling devices located in the storage area, it is prevented that temperature differences across the bearings and the absolute storage temperatures become too great.

Claims (19)

  1. Two-shaft vacuum pump having a suction chamber (7), a pair of rotors (5, 6) situated in the suction chamber, lateral flanges (3, 4) for frontal support of the rotors with the aid of rolling bearings (19) and a drive which acts upon one of the rotor faces, characterised by the following features:
    - the rotor faces, which lie on the side of the pump remote from the drive, and the rotor face, which is adjacent to the driven rotor face, each have a substantially pot-shaped component (11, 12, 31, 84, 91) supported in front of the relevant rotor face;
    - the pot-shaped components (11, 12, 31, 84, 91) take the form of separate components and are fastened on the relevant faces of the rotors (5, 6);
    - the pot-shaped component, which is situated on the rotor face adjacent to the driven rotor face, is formed by a synchronisation or gearing toothed wheel (31, 84, 91);
    - the rolling bearings (19) associated with the rotor faces are each supported on the inner wall of the pot-shaped component (11, 12, 31, 84, 91) and on a static butt end (21) which projects into the pot;
    - sealing means (26 to 29; 48 to 55) are associated with the pot-shaped components (11, 12, 31, 84, 91) for the purpose of sealing off the suction chamber (7) of the vacuum pump from the ambient atmosphere.
  2. Two-shaft pump according to claim 1, characterised in that a shaft portion (34) forming a separate component is provided for coupling to a drive motor, and that said shaft portion is connected in the same manner as the pot-shaped components to the rotor.
  3. Two-shaft pump according to claim 2, characterised in that the bearing system (38) at the rotor face connected to the drive shaft (34) simultaneously forms the drive shaft bearing system on the rotor side.
  4. Two-shaft pump according to claim 1, characterised in that a gearing or synchronisation toothed wheel (32, 91) is supported in front of the face of the rotor connected to the drive shaft (34), that the pot-shaped configuration (8) is situated in the toothed wheel, and that central bores (93, 94) for the shaft (34) to pass through are provided in the toothed wheel, in the lid (24) and in the butt end (21).
  5. Two-shaft pump according to claim 1, 2, 3 or 4, characterised in that a synchronisation wheel (32) and a gearing toothed wheel (91) are fastened coaxially on the rotor (6), and that the pot-shaped configuration (8) is situated in the outer gearing toothed wheel.
  6. Two-shaft pump according to one of the preceding claims, characterised in that the sealing means associated with the pot-shaped components take the form of a labyrinth seal (28, 29).
  7. Two-shaft pump according to one of claims 1 to 5, characterised in that the sealing means take the form of a contact seal (49, 52).
  8. Two-shaft pump according to one of claims 1 to 5, characterised in that the pot (8) has a graduation (48) on its outer side, and that an axial seal (49, 52) is provided as a sealing means.
  9. Two-shaft pump according to one of the preceding claims, characterised in that the pot-shaped components (11, 12) project with a shaft butt end (79) into a guide bore (77) in the rotor and are screw-connected to the rotor.
  10. Two-shaft pump according to one of claims 1 to 8, characterised in that the pot-shaped components (11, 12) have a threaded butt end (77) which is screwed into a threaded bore (78) in the rotor.
  11. Two-shaft pump according to one of the preceding claims, characterised in that the bearings (19) are lubricated with grease.
  12. Two-shaft pump according to one of claims 1 to 10, characterised in that the bearings (19) are lubricated with oil, and that a rotary shaft lip seal (65) is provided for sealing off the pot interior.
  13. Two-shaft pump according to claim 12, characterised in that the sealing lip of the lip seal (65) is associated with the butt end (21) which projects into the pot.
  14. Two-shaft pump according to claim 13, characterised in that the strength of the sealing lip contact pressure is so selected that it lifts off upon rotation of the rotor.
  15. Two-shaft pump according to one of the preceding claims, characterised in that cooling means (81) for the bearing (19) and/or the rotors (5, 6) are provided in the region of the pot-shaped configurations (8).
  16. Two-shaft pump according to claim 15, characterised in that a cooling ring (81) supplied through the casing-fixed butt end (21) is provided.
  17. Two-shaft pump according to claim 16, characterized in that the cooling ring (81) is disposed in the region of the pot opening.
  18. Two-shaft pump according to claim 17, characterized in that the cooling ring (81) is disposed between the bearing (19) and a lip seal (62) and is supported by means of an annular web (82) on the casing-fixed butt end (21), and that the web and the cooling ring virtually close the pot-shaped configuration (8).
  19. Two-shaft pump according to one of the preceding claims, characterized in that the pump casing (2) and the bearing flange (4) are made in one piece.
EP87107091A 1987-05-15 1987-05-15 Two-shaft pump Expired - Lifetime EP0290664B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP87107091A EP0290664B1 (en) 1987-05-15 1987-05-15 Two-shaft pump
DE8787107091T DE3775553D1 (en) 1987-05-15 1987-05-15 TWO SHAFT PUMP.
JP63115015A JPS63302195A (en) 1987-05-15 1988-05-13 Biaxial pump
US07/194,252 US4917583A (en) 1987-05-15 1988-05-16 Bearing support for a twin-shaft pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP87107091A EP0290664B1 (en) 1987-05-15 1987-05-15 Two-shaft pump

Publications (2)

Publication Number Publication Date
EP0290664A1 EP0290664A1 (en) 1988-11-17
EP0290664B1 true EP0290664B1 (en) 1991-12-27

Family

ID=8196998

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87107091A Expired - Lifetime EP0290664B1 (en) 1987-05-15 1987-05-15 Two-shaft pump

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US (1) US4917583A (en)
EP (1) EP0290664B1 (en)
JP (1) JPS63302195A (en)
DE (1) DE3775553D1 (en)

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DE19724643A1 (en) * 1997-06-11 1998-12-17 Sihi Gmbh & Co Kg Screw compressor and method of operating the same
US6095781A (en) * 1997-09-11 2000-08-01 Viking Pump, Inc. Timed element, high pressure, industrial rotary lobe pump
US5916139A (en) * 1997-09-16 1999-06-29 My-D Han-D Mfg. Co. Inc. Hydraulic system and pump
DE19839501A1 (en) * 1998-08-29 2000-03-02 Leybold Vakuum Gmbh Dry compacting screw pump
DE19963172A1 (en) * 1999-12-27 2001-06-28 Leybold Vakuum Gmbh Screw-type vacuum pump has shaft-mounted rotors each with central hollow chamber in which are located built-in components rotating with rotor and forming relatively narrow annular gap through which flows cooling medium
JP4670729B2 (en) 2006-05-08 2011-04-13 株式会社デンソー Gas compressor
JP4784484B2 (en) * 2006-11-02 2011-10-05 株式会社豊田自動織機 Electric pump
JP5389833B2 (en) * 2011-01-11 2014-01-15 アネスト岩田株式会社 2-axis rotor pump
DE202014007117U1 (en) * 2014-09-05 2015-12-09 Oerlikon Leybold Vacuum Gmbh claw pump
CN108916047A (en) * 2018-09-14 2018-11-30 安徽达来电机有限公司 A kind of two impeller shafts and associated gear of Anti-dislocation
FR3136261B1 (en) * 2022-06-03 2024-05-17 Pfeiffer Vacuum Vertical vacuum pump

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Also Published As

Publication number Publication date
DE3775553D1 (en) 1992-02-06
US4917583A (en) 1990-04-17
EP0290664A1 (en) 1988-11-17
JPS63302195A (en) 1988-12-09

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