EP0290663B1 - Single or multistage two-shaft vacuum pump - Google Patents

Single or multistage two-shaft vacuum pump Download PDF

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Publication number
EP0290663B1
EP0290663B1 EP87107090A EP87107090A EP0290663B1 EP 0290663 B1 EP0290663 B1 EP 0290663B1 EP 87107090 A EP87107090 A EP 87107090A EP 87107090 A EP87107090 A EP 87107090A EP 0290663 B1 EP0290663 B1 EP 0290663B1
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EP
European Patent Office
Prior art keywords
pump according
expansion
pump
housing
pistons
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
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EP87107090A
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German (de)
French (fr)
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EP0290663A1 (en
Inventor
Ralf Steffens
Hans-Peter Dr. Kabelitz
Hanns-Peter Dr. Berges
Hartmut Kriehn
Wolfgang Leier
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Balzers und Leybold Deutschland Holding AG
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Leybold AG
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Filing date
Publication date
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Priority to EP87107090A priority Critical patent/EP0290663B1/en
Priority to DE8787107090T priority patent/DE3786917D1/en
Priority to US07/192,559 priority patent/US4983107A/en
Priority to JP63115016A priority patent/JP2650041B2/en
Publication of EP0290663A1 publication Critical patent/EP0290663A1/en
Application granted granted Critical
Publication of EP0290663B1 publication Critical patent/EP0290663B1/en
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    • 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
    • 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 vacuum pump with the features of the preamble of claim 1.
  • Two-shaft pumps are e.g. Root pumps, the rotary lobes of which are approximately 8-shaped on average, Northey pumps with claw rotors, screw pumps and the like.
  • the pairs of rotary lobes rotate in a contact-free manner with respect to one another and to the walls of the pump chamber and cause the pumping medium to be conveyed from the inlet to the outlet of the pump.
  • the two-shaft pumps mentioned are particularly suitable for use as vacuum pumps, since there is no need for sealants and coolants in the suction chamber, so there is no risk of contamination due to the sealant.
  • twin-shaft pumps of this type are therefore defined by the ratio of the amount of gas actually pumped to the theoretically pumpable amount of gas.
  • the selection of any small games is not possible due to thermal reasons.
  • the pump heats up during operation. There is a reduction in the existing games, so that there is a risk of the pistons starting up on the housing. With an increase in the speeds, which for If the construction volume is to be reduced, these difficulties increase because of the increased power density.
  • twin-shaft vacuum pumps with claw-type rotors as are known, for example, from DE-A-20 07 880.
  • measures to overcome the difficulties have not been disclosed.
  • the housing there is the possibility of dissipating the heat by water or air cooling.
  • the heat from the rotating pistons is essentially dissipated only by the medium itself, which either transfers the heat of the piston to the housing or removes it itself. Since only a few molecules are available to dissipate the heat when the twin-shaft pumps are operated in a vacuum, the thermal problems in this area of application are particularly critical.
  • a root pump is known in which the rotary lobes and the housing consist of different materials, the coefficient of expansion of the rotary lobe material being smaller than the coefficient of expansion of the housing material. This allows the housing to expand in the radial direction, but not in the axial direction.
  • the present invention has for its object to reduce the adverse effects of thermal expansion occurring in two-shaft vacuum pumps of the type mentioned, both in the radial and in the axial direction.
  • the pistons are made of gray cast iron or ceramic and the associated housing ring is made of aluminum, then the less warming housing can follow the expansion of the more warming rotors, since aluminum is much larger Has coefficient of expansion as gray cast iron or ceramic.
  • the housing even because of the very small coefficient of expansion of ceramic, it may be necessary to cool the housing so that the play between the rotor and the housing does not increase when the pistons are heated up strongly and the housing is heated up less.
  • the claws of these rotors are made of ceramic, for example, in order to delay radial play or prevent them from occurring.
  • a rotor of this type is less expensive to manufacture than a rotor made entirely of ceramic.
  • bushings are arranged which consist of a material whose coefficient of expansion is smaller than the coefficient of expansion of the rotor material. Such bushings expand less when heated than the rotary pistons, so that a relative displacement of the pistons relative to the housing is fully or partially compensated. Overall, it is achieved that the housing follows the expansion movements of the more warming rotary lobes, i.e. that the housing "breathes".
  • a further advantageous measure consists in cooling the outer side shields, but not the housing ring (s) and the intermediate shields present in multi-stage pumps. This keeps the bearing temperature low and reduces the rotor temperature somewhat, while the housing temperature takes on higher values. This enables the housing to take part in the expansion movements of the rotors, which heat up more strongly (to "breathe”). This applies in particular if the pump housing is encapsulated and the heat emission is further reduced.
  • the temperature of the rotors can be further reduced if they are equipped with cooling.
  • the rotary pistons are of the claw type (cf. FIG. 2) and rotate in the scoops 11, 12, 13, which are formed by the shields 14 to 17 and the housing rings 18 to 20.
  • the shafts 2, 3 are arranged vertically. This also applies to the drive motor, not shown, which is arranged next to the pump housing. Below the lower bearing plate 17, the shafts 2, 3 are equipped with gear wheels 23, 24 of the same diameter, which serve to synchronize the movement of the rotor pairs 4, 5 or 6, 7 or 8, 9.
  • the drive motor also has a gear on its underside. The drive connection is established by a further gearwheel 26 which is in engagement with the gearwheel of the drive motor and the gearwheel 24 of the synchronizing gear.
  • the shafts 2, 3 are supported by roller bearings 27.
  • the upper end plate 14 is equipped with a horizontally arranged connecting flange 28, which forms the inlet 29 of the pump.
  • the inlet channel 31 opens at the end (opening 32) into the scoop chamber 11 of the first stage.
  • the end opening of the first stage is designated 33 and leads into the connecting channel 34.
  • the connecting channel 34 located in the shield 15 is connected to the inlet opening 35 of the second stage.
  • the end shield 16 is designed accordingly.
  • Below the lowest (third) pump stage is the outlet 36, which is connected to the front outlet opening 37 in the lower end plate 17.
  • An oil-containing space 40 formed by a common shaft trough 41, is provided below the system consisting of the pump housing and motor.
  • An oil pump 42 connected to the shaft 2 projects into this shaft trough 41.
  • Lubricant channels not shown in detail, extend from the oil pump to the points of the pump (bearings, engagements of the gearwheels 23 to 26, oil seals or the like) which require oil lubrication .
  • cooling water channels 43 and 44 are provided in the side plates 14 and 17. Cooling water inlet and outlet are labeled 45 and 46 (upper plate 14) and 47 and 48 (lower plate 17).
  • a cooling water drain 49 is arranged at the lowest point of the channel system 44, so that a simple cooling water drain is possible and complete emptying is ensured.
  • the rotors 4 to 9 are pushed onto and held on the shafts 2, 3 in such a way that their positions are not influenced by a longitudinal play of the shafts. Torque transmission must be possible without play.
  • the upper bearings 27 are designed as roller or needle bearings, which form a longitudinal expansion play of the shafts.
  • pairs of bushings 51 to 53 are provided, which are located at the level of the intermediate shields 15, 16 and in the lower end shield 17.
  • the packages consisting of bushings and rotors are spring-loaded on the shafts with the help of disc springs 54, 55 and nuts 56, 57.
  • the material of the bushings is steel or ceramic and therefore has a smaller coefficient of expansion than pistons made of gray cast iron, for example.
  • Thermal operational safety is further improved if the side shields 14, 17 are cooled, but the housing rings 18 to 20 and the intermediate shields 15, 16 are not. An effective movement of the housing and the intermediate shields is thereby achieved. Storage temperatures can be kept low. In addition, piston cooling is associated with this to a small extent.
  • the side shields 14, 17 are flowed through essentially horizontally.
  • the cooling water outlet 46 of the upper plate 14 is connected to the cooling water inlet 47 of the lower plate 17 and the outlet 48 of the lower plate 17 to the inlet 45 of the upper plate 14 by two connecting lines 58 and 59.
  • a closed cooling circuit is formed, in which a circuit of the cooling medium occurs only by conventional means. This convection flow is increased when the cooling water inlet 45, 47 is respectively lower than the cooling water outlet 46, 48.
  • a fresh water supply line 61 with a valve 62 is connected to the line 59.
  • the valve opens when the temperature of the cooling medium exceeds a specified value (measuring point 63).
  • the cold cooling medium supplied initially mixes with the existing warm coolant, so that the pump is not subjected to a cold shock.
  • a container 64 is connected to the line 58, which receives excess cooling water and serves as an expansion vessel.
  • Fig. 3 shows a piston 4 to 9 of the claw type.
  • the central section 65 and the claw 66 are separate components, each with a flat surface. The two parts are screwed together (screw connection 67) in such a way that the flat surfaces lie against one another.
  • the central body 65 is made of gray cast iron, for example, while the claw 66 is made of ceramic. When a piston of this type is heated, the axial expansion is reduced.
  • FIGS. 1 and 4 show a single-stage, likewise vertically arranged two-shaft vacuum pump 1.
  • Parts of the exemplary embodiments according to FIGS. 1 and 4 which correspond to one another are provided with the same reference numerals.
  • To reduce excessive heating and thus expansion of the pistons 4, 5, these are equipped with cooling.
  • the shafts 2, 3 are extended downward and passed through the oil space 40 and the oil pan 41.
  • the radial shaft sealing rings 71, 72 serve to seal the shafts 2, 3 in the oil pan.
  • the shafts 2, 3 are each provided with a blind hole 73, 74 which is open at the bottom. With their lower ends, the shafts 2, 3 protrude into a coolant tank 75, which is arranged below the oil space 40. Coolant supply lines 76, 77 protrude into the blind bores 73, 74 from below and extend with open ends to approximately the center of the rotors 4, 5.
  • the coolant supply lines 76, 77 are connected to a feed pump 78, the inlet side of which is connected to the coolant tank 75 via the line 79.
  • a heat exchanger 81 is expediently switched on in line 79 so that a sufficiently low temperature of the coolant is ensured.
  • the coolant is injected into the blind bores 73, 74 and flows back into the coolant tank 75 due to gravity. From there it passes through line 79 and the heat exchanger back to the feed pump 78.
  • Water is expediently considered as a coolant. Oil or compressed air can also be used. If oil is used for lubricating the bearings and / or gearwheels at the same time, separate oil and coolant containers 40 and 75 can be dispensed with, so that seals 71 and 72 can also be dispensed with.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Non-Positive Displacement Air Blowers (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Description

Die Erfindung bezieht sich auf eine Zweiwellenvakuumpumpe mit den Merkmalen des Oberbegriffs des Patentanspruchs 1.The invention relates to a twin-shaft vacuum pump with the features of the preamble of claim 1.

Zweiwellenpumpen sind z.B. Rootspumpen, deren Drehkolben im Schnitt etwa 8-förmig ausgebildet sind, Northey-Pumpen mit Klauen-Rotoren, Schraubenpumpen und dergleichen. Die Drehkolbenpaare rotieren zueinander und zu den Schöpfraumwandungen berührungsfrei und bewirken eine Förderung des Pumpmediums vom Einlaß zum Auslaß der Pumpe. Für die Verwendung als Vakuumpumpen sind die genannten Zweiwellenpumpen besonders geeignet, da auf Dicht- und Kühlmittel im Schöpfraum verzichtet werden kann, eine Kontaminationsgefahr infolge des Dichtmittels also nicht besteht.Two-shaft pumps are e.g. Root pumps, the rotary lobes of which are approximately 8-shaped on average, Northey pumps with claw rotors, screw pumps and the like. The pairs of rotary lobes rotate in a contact-free manner with respect to one another and to the walls of the pump chamber and cause the pumping medium to be conveyed from the inlet to the outlet of the pump. The two-shaft pumps mentioned are particularly suitable for use as vacuum pumps, since there is no need for sealants and coolants in the suction chamber, so there is no risk of contamination due to the sealant.

Wegen der berührungsfreien Anordnung der Kolben im Gehäuse sind Rückströmungen des geförderten Mediums unvermeidbar. Der volumetrische Wirkungsgrad von Zweiwellenpumpen dieser Art ist deshalb definiert durch das Verhältnis von der effektiv geförderten Gasmenge zur theoretisch förderbaren Gasmenge. Je geringer das Spiel der Kolben zueinander und zur Schöpfraumwandung ist, desto geringer ist die Rückströmung, das heißt, desto besser ist ihr volumetrischer Wirkungsgrad. Die Wahl beliebig kleiner Spiele ist jedoch aus thermischen Gründen nicht möglich. Während des Betriebs erwärmt sich die Pumpe. Es kommt zu einer Reduktion der vorhandenen Spiele, so daß die Gefahr des Anlaufens der Kolben am Gehäuse besteht. Bei einer Steigerung der Drehzahlen, welche zur Verkleinerung der Bauvolumina erwünscht ist, nehmen diese Schwierigkeiten wegen der erhöhten Leistungsdichte zu. Dieses gilt insbesondere für Zweiwellenvakuumpumpen mit Rotoren vom Klauentyp, wie sie beispielsweise aus der DE-A-20 07 880 bekannt sind. Maßnahmen zur Beseitigung der Schwierigkeiten sind jedoch nicht offenbart.Because of the non-contact arrangement of the pistons in the housing, backflows of the pumped medium are unavoidable. The volumetric efficiency of twin-shaft pumps of this type is therefore defined by the ratio of the amount of gas actually pumped to the theoretically pumpable amount of gas. The less the clearance of the pistons to each other and to the wall of the pumping chamber, the lower the backflow, that is, the better their volumetric efficiency. The selection of any small games is not possible due to thermal reasons. The pump heats up during operation. There is a reduction in the existing games, so that there is a risk of the pistons starting up on the housing. With an increase in the speeds, which for If the construction volume is to be reduced, these difficulties increase because of the increased power density. This applies in particular to twin-shaft vacuum pumps with claw-type rotors, as are known, for example, from DE-A-20 07 880. However, measures to overcome the difficulties have not been disclosed.

Bezüglich des Gehäuses besteht die Möglichkeit, die Wärme durch eine Wasser- oder Luftkühlung abzuführen. Die Abführung der Wärme von den rotierenden Kolben erfolgt jedoch im wesentlichen nur durch das geförderte Medium selbst, das entweder die Wärme des Kolbens auf das Gehäuse überträgt oder selbst mit abführt. Da beim Betrieb der Zweiwellenpumpen im Vakuum nur relativ wenig Moleküle zur Abführung der Wärme zur Verfügung stehen, sind die thermischen Probleme in diesem Einsatzgebiet besonders kritisch.With regard to the housing, there is the possibility of dissipating the heat by water or air cooling. However, the heat from the rotating pistons is essentially dissipated only by the medium itself, which either transfers the heat of the piston to the housing or removes it itself. Since only a few molecules are available to dissipate the heat when the twin-shaft pumps are operated in a vacuum, the thermal problems in this area of application are particularly critical.

Aus der GB 21 41 486 ist eine Rootspumpe bekannt, bei der die Drehkolben und das Gehäuse aus unterschiedlichen Werkstoffen bestehen, wobei der Ausdehnungskoeffizient des Drehkolbenwerkstoffes kleiner ist als der Ausdehnungskoeffizient des Gehäusematerials. Damit ist eine Dehnung des Gehäuses in radialer Richtung möglich, in axialer Richtung jedoch nicht.From GB 21 41 486 a root pump is known in which the rotary lobes and the housing consist of different materials, the coefficient of expansion of the rotary lobe material being smaller than the coefficient of expansion of the housing material. This allows the housing to expand in the radial direction, but not in the axial direction.

Der vorliegenden Erfindung liegt die Aufgabe zugrunde, bei Zweiwellenvakuumpumpen der eingangs genannten Art die nachteiligen Auswirkungen von auftretenden Wärmedehnungen zu reduzieren, und zwar sowohl in radialer als auch in axialer Richtung.The present invention has for its object to reduce the adverse effects of thermal expansion occurring in two-shaft vacuum pumps of the type mentioned, both in the radial and in the axial direction.

Erfindungsgemäß wird diese Aufgabe durch die kennzeichnenden Merkmale des Anspruchs 1 gelöst. Die Anwendung dieser Merkmale bei mehrstufigen Pumpen mit Drehkolbenpaaren vom Klauentyp bewirkt, daß die geschilderten, sich in radialer und axialer Richtung auswirkenden Wärmedehnungsprobleme nicht mehr bestehen.According to the invention, this object is achieved by the characterizing features of claim 1. The use of these features in multi-stage pumps with pairs of rotary lobes of the claw type means that the heat expansion problems described, which have an effect in the radial and axial directions, no longer exist.

Bestehen zum Beispiel die Kolben aus Grauguß oder Keramik und der zugehörige Gehäusering aus Aluminium, dann kann das sich weniger erwärmende Gehäuse den Dehnungen der sich stärker erwärmenden Rotoren folgen, da Aluminium einen wesentlich größeren Ausdehnungskoeffizienten hat als Grauguß oder Keramik. Bei einem Kolben aus Keramik kann es sogar wegen des sehr kleinen Ausdehnungskoeffizienten von Keramik erforderlich sein, das Gehäuse zu kühlen, damit das Spiel zwischen Rotor und Gehäuse bei einer starken Erwärmung der Kolben und bei einer geringeren Erwärmung des Gehäuses nicht zunimmt.For example, if the pistons are made of gray cast iron or ceramic and the associated housing ring is made of aluminum, then the less warming housing can follow the expansion of the more warming rotors, since aluminum is much larger Has coefficient of expansion as gray cast iron or ceramic. In the case of a ceramic piston, even because of the very small coefficient of expansion of ceramic, it may be necessary to cool the housing so that the play between the rotor and the housing does not increase when the pistons are heated up strongly and the housing is heated up less.

Bei einer mehrstufigen Pumpe mit Rotoren des Klauentyps reicht es aus, wenn die Klauen dieser Rotoren zum Beispiel aus Keramik bestehen, um eine radiale Spielaufzehrung zu verzögern oder nicht eintreten zu lassen. Ein Rotor dieser Art ist kostengünstiger herstellbar als ein vollständig aus Keramik bestehender Rotor. Auf den Wellen zur Lagefixierung der Rotoren sind Buchsen angeordnet, die aus einem Material bestehen, dessen Ausdehnungskoeffizient kleiner ist als der Ausdehnungskoeffizient des Rotormaterials. Derartige Buchsen dehnen sich damit bei einer Erwärmung weniger stark aus als die Drehkolben, so daß eine relative Verschiebung der Kolben gegenüber dem Gehäuse ganz oder teilweise kompensiert wird. Insgesamt wird erreicht, daß das Gehäuse die Dehnungsbewegungen der sich stärker erwärmenden Drehkolben mitmacht, d.h. daß das Gehäuse "mitatmet".In the case of a multi-stage pump with claw-type rotors, it is sufficient if the claws of these rotors are made of ceramic, for example, in order to delay radial play or prevent them from occurring. A rotor of this type is less expensive to manufacture than a rotor made entirely of ceramic. On the shafts for fixing the position of the rotors, bushings are arranged which consist of a material whose coefficient of expansion is smaller than the coefficient of expansion of the rotor material. Such bushings expand less when heated than the rotary pistons, so that a relative displacement of the pistons relative to the housing is fully or partially compensated. Overall, it is achieved that the housing follows the expansion movements of the more warming rotary lobes, i.e. that the housing "breathes".

Eine weitere vorteilhafte Maßnahme besteht darin, die äußeren Seitenschilde zu kühlen, den oder die Gehäusering(e) und die bei mehrstufigen Pumpen vorhandenen Zwischenschilde jedoch nicht. Dadurch wird die Lagertemperatur niedrig gehalten und die Rotortemperatur etwas reduziert, während die Gehäusetemperatur höhere Werte annimmt. Das Gehäuse wird dadurch in die Lage versetzt, die Dehnungsbewegungen der sich stärker erwärmenden Rotoren mitzumachen (mitzu"atmen"). Dieses gilt insbesondere dann, wenn das Gehäuse der Pumpe gekapselt und damit die Wärmeabgabe weiter reduziert wird.A further advantageous measure consists in cooling the outer side shields, but not the housing ring (s) and the intermediate shields present in multi-stage pumps. This keeps the bearing temperature low and reduces the rotor temperature somewhat, while the housing temperature takes on higher values. This enables the housing to take part in the expansion movements of the rotors, which heat up more strongly (to "breathe"). This applies in particular if the pump housing is encapsulated and the heat emission is further reduced.

Die Temperatur der Rotoren kann weiter reduziert werden, wenn diese mit einer Kühlung ausgerüstet sind.The temperature of the rotors can be further reduced if they are equipped with cooling.

Weitere Vorteile und Einzelheiten der Erfindung sollen anhand von in den Figuren 1 bis 4 dargestellten Ausführungsbeispielen erläutert werden. Es zeigen:

Fig. 1
einen Längsschnitt durch eine dreistufige Zweiwellenvakuumpumpe nach der Erfindung,
Fig. 2
einen Querschnitt durch ein Rotorpaar,
Fig. 3
einen Querschnitt durch einen Rotor des Klauentyps mit aus Keramik bestehender Klaue und
Fig. 4
einen Längsschnitt durch eine einstufige Zweiwellenvakuumpumpe mit Rotorkühlung.
Further advantages and details of the invention will be explained on the basis of the exemplary embodiments illustrated in FIGS. 1 to 4. Show it:
Fig. 1
2 shows a longitudinal section through a three-stage two-shaft vacuum pump according to the invention,
Fig. 2
a cross section through a pair of rotors,
Fig. 3
a cross section through a rotor of the claw type with ceramic claw and
Fig. 4
a longitudinal section through a single-stage twin-shaft vacuum pump with rotor cooling.

Bei dem in Fig. 1 dargestellten Ausführungsbeispiel handelt es sich um eine dreistufige Vakuumpumpe 1 mit zwei Wellen 2 und 3 sowie drei Rotorpaaren 4, 5 bzw. 6, 7 bzw. 8, 9. Die axiale Länge der Rotoren nimmt von der Saugseite zur Druckseite ab. Die Drehkolben sind vom Klauentyp (vergleiche Fig. 2) und rotieren in den Schöpfräumen 11, 12, 13, welche von den Schilden 14 bis 17 und den Gehäuseringen 18 bis 20 gebildet werden.1 is a three-stage vacuum pump 1 with two shafts 2 and 3 and three pairs of rotors 4, 5 and 6, 7 and 8, 9. The axial length of the rotors increases from the suction side to the pressure side from. The rotary pistons are of the claw type (cf. FIG. 2) and rotate in the scoops 11, 12, 13, which are formed by the shields 14 to 17 and the housing rings 18 to 20.

Die Wellen 2, 3 sind vertikal angeordnet. Dieses gilt ebenfalls für den neben dem Pumpengehäuse angeordneten, nicht dargestellten Antriebsmotor. Unterhalb des unteren Lagerschildes 17 sind die Wellen 2, 3 mit Zahnrädern 23, 24 gleichen Durchmessers ausgerüstet, welche der Synchronisation der Bewegung der Rotorpaare 4, 5 bzw. 6, 7 bzw. 8, 9 dienen. Auch der Antriebsmotor weist an seiner Unterseite ein Zahnrad auf. Die Antriebsverbindung wird hergestellt durch ein weiteres Zahnrad 26, das mit dem Zahnrad des Antriebsmotors und dem Zahnrad 24 des Synchronisationsgetriebes in Eingriff steht.The shafts 2, 3 are arranged vertically. This also applies to the drive motor, not shown, which is arranged next to the pump housing. Below the lower bearing plate 17, the shafts 2, 3 are equipped with gear wheels 23, 24 of the same diameter, which serve to synchronize the movement of the rotor pairs 4, 5 or 6, 7 or 8, 9. The drive motor also has a gear on its underside. The drive connection is established by a further gearwheel 26 which is in engagement with the gearwheel of the drive motor and the gearwheel 24 of the synchronizing gear.

In dem oberen Lagerschild 14 und dem unteren Lagerschild 17 stützen sich die Wellen 2, 3 über Wälzlager 27 ab. Der obere Lagerschild 14 ist mit einem horizontal angeordneten Anschlußflansch 28 ausgerüstet, welcher den Einlaß 29 der Pumpe bildet. Der Einlaßkanal 31 mündet stirnseitig (Öffnung 32) in den Schöpfraum 11 der ersten Stufe.In the upper end plate 14 and the lower end plate 17, the shafts 2, 3 are supported by roller bearings 27. The upper end plate 14 is equipped with a horizontally arranged connecting flange 28, which forms the inlet 29 of the pump. The inlet channel 31 opens at the end (opening 32) into the scoop chamber 11 of the first stage.

Die stirnseitig angeordnete Auslaßöffnung der ersten Stufe ist mit 33 bezeichnet und führt in den Verbindungskanal 34. Der im Schild 15 befindliche Verbindungskanal 34 steht mit der Einlaßöffnung 35 der zweiten Stufe in Verbindung. Der Lagerschild 16 ist entsprechend gestaltet. Unterhalb der untersten (dritten) Pumpstufe befindet sich der Auslaß 36, der mit der stirnseitigen Auslaßöffnung 37 im unteren Lagerschild 17 in Verbindung steht.The end opening of the first stage is designated 33 and leads into the connecting channel 34. The connecting channel 34 located in the shield 15 is connected to the inlet opening 35 of the second stage. The end shield 16 is designed accordingly. Below the lowest (third) pump stage is the outlet 36, which is connected to the front outlet opening 37 in the lower end plate 17.

Unterhalb des aus Pumpengehäuse und Motor bestehenden Systems ist ein Öl enthaltender Raum 40, gebildet von einer gemeinsamen Wellenwanne 41, vorgesehen. In diese Wellenwanne 41 hinein ragt eine mit der Welle 2 verbundene Ölpumpe 42. Von der Ölpumpe aus erstrecken sich im einzelnen nicht dargestellte Schmiermittelkanäle zu den Stellen der Pumpe (Lager, Eingriffe der Zahnräder 23 bis 26, Simmerringe oder dergleichen), welche einer Ölschmierung bedürfen.An oil-containing space 40, formed by a common shaft trough 41, is provided below the system consisting of the pump housing and motor. An oil pump 42 connected to the shaft 2 projects into this shaft trough 41. Lubricant channels, not shown in detail, extend from the oil pump to the points of the pump (bearings, engagements of the gearwheels 23 to 26, oil seals or the like) which require oil lubrication .

Das dargestellte Ausführungsbeispiel der dreistufigen Zweiwellenvakuumpumpe ist wassergekühlt. Dazu sind in den Seitenschilden 14 und 17 Kühlwasserkanäle 43 und 44 vorgesehen. Kühlwassereintritt und -austritt sind mit 45 und 46 (oberes Schild 14) bzw. 47 und 48 (unteres Schild 17) bezeichnet. Ein Kühlwasserablaß 49 ist an der untersten Stelle des Kanalsystems 44 angeordnet, so daß ein einfacher Kühlwasserablaß möglich und eine vollständige Entleerung sichergestellt sind.The illustrated embodiment of the three-stage two-shaft vacuum pump is water-cooled. For this purpose, cooling water channels 43 and 44 are provided in the side plates 14 and 17. Cooling water inlet and outlet are labeled 45 and 46 (upper plate 14) and 47 and 48 (lower plate 17). A cooling water drain 49 is arranged at the lowest point of the channel system 44, so that a simple cooling water drain is possible and complete emptying is ensured.

Die Rotoren 4 bis 9 sind auf die Wellen 2, 3 derart aufgeschoben und gehaltert, daß ihre Positionen von einem Längsspiel der Wellen unbeeinflußt sind. Eine Drehmomentübertragung muß dabei spielfrei möglich sein. Die oberen Lager 27 sind als Rollen- oder Nadellager ausgebildet, die ein Längsdehnungsspiel der Wellen gestalten.The rotors 4 to 9 are pushed onto and held on the shafts 2, 3 in such a way that their positions are not influenced by a longitudinal play of the shafts. Torque transmission must be possible without play. The upper bearings 27 are designed as roller or needle bearings, which form a longitudinal expansion play of the shafts.

Um die richtigen Positionen der Rotoren 4 bis 9 auf den Wellen 2, 3 sicherzustellen, sind Buchsenpaare 51 bis 53 vorgesehen, die sich in Höhe der Zwischenschilde 15, 16 und im unteren Lagerschild 17 befinden. Die aus Buchsen und Rotoren bestehenden Pakete sind mit Hilfe von Tellerfedern 54, 55 und Muttern 56, 57 auf den Wellen federnd eingespannt.In order to ensure the correct positions of the rotors 4 to 9 on the shafts 2, 3, pairs of bushings 51 to 53 are provided, which are located at the level of the intermediate shields 15, 16 and in the lower end shield 17. The packages consisting of bushings and rotors are spring-loaded on the shafts with the help of disc springs 54, 55 and nuts 56, 57.

Das Material der Buchsen ist Stahl oder Keramik und hat damit einen kleineren Ausdehnungskoeffizienten als die zum Beispiel aus Grauguß bestehenden Kolben.The material of the bushings is steel or ceramic and therefore has a smaller coefficient of expansion than pistons made of gray cast iron, for example.

Bei einer Erwärmung des in dieser Weise aufgebauten Rotorsystems bewirken die Buchsen 51 bis 53, die sich weniger stark ausdehnen als die Rotoren, daß eine relative Verschiebung der Kolben gegenüber dem Gehäuse, welche sich im Bereich der ersten Stufe besonders stark auswirken würde, ganz oder teilweise kompensiert wird. Sind darüber hinaus die Gehäuseringe 18 bis 20 aus Aluminium hergestellt, dann dehnt sich das Gehäuse trotz geringfügiger Erwärmung stärker aus, so daß es den Ausdehnungsbewegungen der Kolben folgt. Insgesamt sind Pumpen dieser Art thermisch wesentlich höher belastbar und erlauben deshalb eine Erhöhung der Drehzahl und/oder einen Betrieb mit höheren Druckdifferenzen.When the rotor system constructed in this way is heated, the bushings 51 to 53, which expand less than the rotors, cause a relative displacement of the pistons relative to the housing, which would have a particularly strong effect in the region of the first stage, in whole or in part is compensated. In addition, if the housing rings 18 to 20 are made of aluminum, the housing expands more despite slight heating, so that it follows the expansion movements of the pistons. Overall, pumps of this type are thermally much more resilient and therefore allow an increase in speed and / or an operation with higher pressure differences.

Die thermische Betriebssicherheit wird weiterhin verbessert, wenn die Seitenschilde 14, 17 gekühlt werden, die Gehäuseringe 18 bis 20 und die Zwischenschilde 15, 16 jedoch nicht. Eine wirksame Mitbewegung des Gehäuses und der Zwischenschilde wird dadurch erreicht. Die Lagertemperaturen können niedrig gehalten werden. Außerdem ist damit in geringem Maße eine Kolbenkühlung verbunden.Thermal operational safety is further improved if the side shields 14, 17 are cooled, but the housing rings 18 to 20 and the intermediate shields 15, 16 are not. An effective movement of the housing and the intermediate shields is thereby achieved. Storage temperatures can be kept low. In addition, piston cooling is associated with this to a small extent.

Bei dem in Fig. 1 dargestellten Ausführungsbeispiel mit vertikalen Wellen 2, 3 sind die Seitenschilde 14, 17 im wesentlichen horizontal durchströmt. Durch zwei Verbindungsleitungen 58 und 59 sind der Kühlwasseraustritt 46 des oberen Schildes 14 mit dem Kühlwassereintritt 47 des unteren Schildes 17 bzw. der Austritt 48 des unteren Schildes 17 mit dem Eintritt 45 des oberen Schildes 14 verbunden. Dadurch wird ein geschlossener Kühlkreislauf gebildet, in dem ein Kreislauf des Kühlmediums allein durch Konvenktion eintritt. Diese Konvektionsströmung wird verstärkt, wenn der Kühlwassereintritt 45, 47 jeweils tiefer liegt als der Kühlwasseraustritt 46, 48.In the embodiment shown in FIG. 1 with vertical shafts 2, 3, the side shields 14, 17 are flowed through essentially horizontally. The cooling water outlet 46 of the upper plate 14 is connected to the cooling water inlet 47 of the lower plate 17 and the outlet 48 of the lower plate 17 to the inlet 45 of the upper plate 14 by two connecting lines 58 and 59. As a result, a closed cooling circuit is formed, in which a circuit of the cooling medium occurs only by conventional means. This convection flow is increased when the cooling water inlet 45, 47 is respectively lower than the cooling water outlet 46, 48.

Im Bereich des oberen Kühlwasseraustrittes 46 ist eine Frischwasserzuführungsleitung 61 mit einem Ventil 62 an die Leitung 59 angeschlossen. Das Ventil öffnet sich, wenn die Temperatur des Kühlmediums einen festgelegten Wert überschreitet (Meßstelle 63). Das zugeführte kalte Kühlmedium vermischt sich zunächst mit dem vorhandenen warmen Kühlmittel, so daß die Pumpe nicht durch einen Kälteschock belastet wird. Im Bereich des oberen Kühlwassereintrittes 45 ist an die Leitung 58 ein Behälter 64 angeschlossen, der überschüssiges Kühlwasser aufnimmt und als Dehnungsgefäß dient.In the area of the upper cooling water outlet 46, a fresh water supply line 61 with a valve 62 is connected to the line 59. The valve opens when the temperature of the cooling medium exceeds a specified value (measuring point 63). The cold cooling medium supplied initially mixes with the existing warm coolant, so that the pump is not subjected to a cold shock. In the area of the upper cooling water inlet 45, a container 64 is connected to the line 58, which receives excess cooling water and serves as an expansion vessel.

Fig. 3 zeigt einen Kolben 4 bis 9 vom Klauentyp. Der zentrale Abschnitt 65 und die Klaue 66 sind separate Bauteile mit jeweils einer Planfläche. Die beiden Teile sind derart miteinander verschraubt (Verschraubung 67), daß die Planflächen einander anliegen. Der zentrale Körper 65 besteht zum Beispiel aus Grauguß, während die Klaue 66 aus Keramik besteht. Bei einer Erwärmung eines Kolbens dieser Art ist die axiale Ausdehnung reduziert.Fig. 3 shows a piston 4 to 9 of the claw type. The central section 65 and the claw 66 are separate components, each with a flat surface. The two parts are screwed together (screw connection 67) in such a way that the flat surfaces lie against one another. The central body 65 is made of gray cast iron, for example, while the claw 66 is made of ceramic. When a piston of this type is heated, the axial expansion is reduced.

Fig. 4 zeigt eine einstufige, ebenfalls vertikal angeordnete Zweiwellenvakuumpumpe 1. Einander entsprechende Teile der Ausführungsbeispiele nach den Figuren 1 und 4 sind mit gleichen Bezugszeichen versehen. Zur Reduzierung einer zu starken Erwärmung und damit Ausdehnung der Kolben 4, 5 sind diese mit einer Kühlung ausgerüstet. Dazu sind die Wellen 2, 3 nach unten verlängert sowie durch den Ölraum 40 und die Ölwanne 41 hindurchgeführt. Der Abdichtung der Wellen 2, 3 in der Ölwanne dienen die Radialwellendichtringe 71, 72.4 shows a single-stage, likewise vertically arranged two-shaft vacuum pump 1. Parts of the exemplary embodiments according to FIGS. 1 and 4 which correspond to one another are provided with the same reference numerals. To reduce excessive heating and thus expansion of the pistons 4, 5, these are equipped with cooling. For this purpose, the shafts 2, 3 are extended downward and passed through the oil space 40 and the oil pan 41. The radial shaft sealing rings 71, 72 serve to seal the shafts 2, 3 in the oil pan.

Die Wellen 2, 3 sind jeweils mit einer Sackbohrung 73, 74 versehen, die nach unten offen ist. Mit ihren unteren Enden ragen die Wellen 2, 3 in einen Kühlmittelbehälter 75 hinein, der unterhalb des Ölraumes 40 angeordnet ist. In die Sackbohrungen 73, 74 ragen von unten Kühlmittelzuführungsleitungen 76, 77 hinein, die mit offenen Enden bis etwa in das Zentrum der Rotoren 4, 5 reichen. Die Kühlmittelzuführungsleitungen 76, 77 stehen mit einer Förderpumpe 78 in Verbindung, deren Einlaßseite über die Leitung 79 mit dem Kühlmittelbehälter 75 in Verbindung steht. Zweckmäßigerweise ist in die Leitung 79 ein Wärmetauscher 81 eingeschaltet, damit eine ausreichend niedrige Temperatur des Kühlmittels sichergestellt ist.The shafts 2, 3 are each provided with a blind hole 73, 74 which is open at the bottom. With their lower ends, the shafts 2, 3 protrude into a coolant tank 75, which is arranged below the oil space 40. Coolant supply lines 76, 77 protrude into the blind bores 73, 74 from below and extend with open ends to approximately the center of the rotors 4, 5. The coolant supply lines 76, 77 are connected to a feed pump 78, the inlet side of which is connected to the coolant tank 75 via the line 79. A heat exchanger 81 is expediently switched on in line 79 so that a sufficiently low temperature of the coolant is ensured.

Während des Betriebs wird das Kühlmittel in die Sackbohrungen 73, 74 eingespritzt und strömt infolge der Schwerkraft in den Kühlmittelbehälter 75 zurück. Von dort aus gelangt es durch die Leitung 79 und den Wärmetauscher wieder zur Förderpumpe 78.During operation, the coolant is injected into the blind bores 73, 74 and flows back into the coolant tank 75 due to gravity. From there it passes through line 79 and the heat exchanger back to the feed pump 78.

Als Kühlmittel kommt zweckmäßigerweise Wasser infrage. Auch Öl oder Preßluft können verwendet werden. Bei der Verwendung von gleichzeitig der Lager- und/oder Zahnradschmierung dienendem Öl kann auf separate Öl- und Kühlmittelbehälter 40 und 75 verzichtet werden, so daß auch die Abdichtungen 71 und 72 entfallen können.Water is expediently considered as a coolant. Oil or compressed air can also be used. If oil is used for lubricating the bearings and / or gearwheels at the same time, separate oil and coolant containers 40 and 75 can be dispensed with, so that seals 71 and 72 can also be dispensed with.

Claims (11)

  1. Twin-shaft vacuum pump having a suction chamber, having a pair of rotary pistons (4, 5; 6, 7; 8, 9) situated in the suction chamber (11, 12, 13), having guard plates (14, 15, 16, 17) which laterally delimit the suction chamber and having a housing ring (18, 19, 20) which peripherally delimits the suction chamber, in which pump the coefficient of expansion of the rotary piston material is lower than the coefficient of expansion of the housing material, characterized in that the pump is of a multi-stage design, that the pairs of rotary pistons (4 to 9) are of the claw type, that bushes (51 to 53) are provided on the shafts (2, 3) for fixing the pairs of rotary pistons (4 to 9) in position and that the bushes (51 to 53), the rotary pistons (4 to 9) and the housing rings (18 to 20) are made of different materials, with the coefficient of expansion of the bushes being lower than the coefficient of expansion of the rotary piston material.
  2. Pump according to claim 1, characterized in that the bushes (51 to 53) are made of steel.
  3. Pump according to claim 1 or 2, characterized in that the pistons (4 to 9) are made of grey cast iron.
  4. Pump according to claim 1, 2 or 3, characterized in that the housing rings (18 to 20) are made of aluminium.
  5. Pump according to one of the preceding claims, characterized in that the bushes (51 to 53) and pistons (4 to 9) pushed onto the shaft are fixed in position with the aid of springs (54, 55).
  6. Pump according to one of the preceding claims, characterized in that the outer two lateral guard plates (14, 17) are provided with water cooling and that the housing rings (18 to 20) are uncooled, preferably being fully enclosed.
  7. Pump according to claim 6, characterized in that the shafts (2, 3) are disposed vertically and that the two lateral guard plates (14, 17) are swept substantially at right angles to the rotor axis and are so connected via two external connection lines (58, 59) to one another to form a single cooling system that, as a result of the temperature differences, a convectional flow of the cooling medium in the circuit occurs.
  8. Pump according to claim 7, characterized in that the cooling water inlet (45, 47) to the lateral guard plates (14, 17) is in each case lower than the cooling water outlet (46, 48).
  9. Pump according to claim 7 or 8, characterized in that a fresh water supply (61) is connected in the region of the top cooling water outlet (46).
  10. Pump according to claim 9, characterized in that disposed in the fresh water supply line (61) is a valve (62) which is operable in dependence upon the temperature in the cooling circuit.
  11. Pump according to one of claims 7 to 10, characterized in that connected in the region of the top cooling water inflow (43) is an expansion tank (64) which is simultaneously used to receive heated cooling water during the supply of fresh water.
EP87107090A 1987-05-15 1987-05-15 Single or multistage two-shaft vacuum pump Expired - Lifetime EP0290663B1 (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
EP87107090A EP0290663B1 (en) 1987-05-15 1987-05-15 Single or multistage two-shaft vacuum pump
DE8787107090T DE3786917D1 (en) 1987-05-15 1987-05-15 SINGLE OR MULTI-STAGE TWO-SHAFT VACUUM PUMP.
US07/192,559 US4983107A (en) 1987-05-15 1988-05-11 Multistage rotary piston vacuum pump having sleeves to fix shaft positions
JP63115016A JP2650041B2 (en) 1987-05-15 1988-05-13 2-axis vacuum pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP87107090A EP0290663B1 (en) 1987-05-15 1987-05-15 Single or multistage two-shaft vacuum pump

Publications (2)

Publication Number Publication Date
EP0290663A1 EP0290663A1 (en) 1988-11-17
EP0290663B1 true EP0290663B1 (en) 1993-08-04

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP87107090A Expired - Lifetime EP0290663B1 (en) 1987-05-15 1987-05-15 Single or multistage two-shaft vacuum pump

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US (1) US4983107A (en)
EP (1) EP0290663B1 (en)
JP (1) JP2650041B2 (en)
DE (1) DE3786917D1 (en)

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE59200347D1 (en) * 1991-02-01 1994-09-08 Leybold Ag DRY TWO-SHAFT VACUUM PUMP.
EP0497995A1 (en) * 1991-02-01 1992-08-12 Leybold Aktiengesellschaft Dry running vacuum pump
DE4233142A1 (en) * 1992-10-02 1994-04-07 Leybold Ag Method for operating a claw vacuum pump and claw vacuum pump suitable for carrying out this operating method
GB9604486D0 (en) * 1996-03-01 1996-05-01 Boc Group Plc Improvements in vacuum pumps
DE19736017A1 (en) * 1997-08-20 1999-02-25 Peter Frieden Vacuum pump or compressor for compacting gases
DE19820523A1 (en) * 1998-05-08 1999-11-11 Peter Frieden Spindle screw pump assembly for dry compression of gases
US7077159B1 (en) * 1998-12-23 2006-07-18 Applied Materials, Inc. Processing apparatus having integrated pumping system
DE19963171A1 (en) * 1999-12-27 2001-06-28 Leybold Vakuum Gmbh Screw-type vacuum pump used in cooling circuits has guide components located in open bores in shafts serving for separate guiding of inflowing and outflowing cooling medium
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
DE10040482A1 (en) * 2000-08-18 2002-02-28 Univ Ilmenau Tech Twin-shaft Roots pump has hollow shafts to carry the lubricating oil for the pair of drive cogwheels, with an oil pump at one shaft
JP3673743B2 (en) * 2001-09-27 2005-07-20 大晃機械工業株式会社 Screw type vacuum pump
GB0223769D0 (en) * 2002-10-14 2002-11-20 Boc Group Plc A pump
GB2426036A (en) * 2005-05-10 2006-11-15 Bernard Whicher Vertical Northey compressor
DE102014101113A1 (en) * 2014-01-30 2015-07-30 Pfeiffer Vacuum Gmbh vacuum pump
WO2018132019A2 (en) * 2017-01-10 2018-07-19 John Fleming Improvements in rotary claw pumps
CN111594439A (en) * 2020-04-23 2020-08-28 浙江佳成机械有限公司 Three-stage screw compressor
JP7008955B1 (en) * 2021-07-16 2022-01-25 オリオン機械株式会社 Claw pump

Family Cites Families (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US901539A (en) * 1905-06-14 1908-10-20 John George Leyner Multiple-stage air-compressor.
US1653814A (en) * 1926-01-02 1927-12-27 William E Mild Rotary compressor
US2014932A (en) * 1933-03-17 1935-09-17 Gen Motors Corp Roots blower
GB525761A (en) * 1939-02-28 1940-09-04 Milo Ab Improvements in or relating to rotary compressors
US2367463A (en) * 1939-03-18 1945-01-16 Heimbach Bruno Rotary blower
DE758120C (en) * 1939-03-19 1953-10-05 Bosch Gmbh Robert Rotary piston blower
GB529059A (en) * 1939-05-11 1940-11-13 James Pontus Johnson Improvements in or relating to air pumps
US2708548A (en) * 1953-10-12 1955-05-17 Hosdreg Company Inc Blower
US2938664A (en) * 1955-01-17 1960-05-31 Leybold S Nachfolger Fa E Pump
CH365821A (en) * 1959-03-17 1962-11-30 Balzers Hochvakuum Process for operating mechanical vacuum pumps and vacuum pumps for carrying out this process
US3150593A (en) * 1961-04-24 1964-09-29 Waukesha Foundry Co Metering pump
DE1425080A1 (en) * 1962-05-04 1969-03-13 Ohe Ernst Von Der Hollow cylinder rotor based on a modular system in type standardization
DE2007880A1 (en) * 1970-02-20 1971-09-02 Brown, Arthur Corning N Y (VStA) Rotary displacement machine
JPS4857706U (en) * 1971-10-29 1973-07-23
US4035112A (en) * 1974-02-20 1977-07-12 Outboard Marine Corporation Rotary engine cooling and exhaust system
FR2389784B1 (en) * 1977-05-06 1984-02-24 Siebec Filtres
GB2088957B (en) * 1980-12-05 1984-12-12 Boc Ltd Rotary positive-displacement fluidmachines
DE3124247C1 (en) * 1981-06-19 1983-06-01 Boge Kompressoren Otto Boge Gmbh & Co Kg, 4800 Bielefeld Screw compressor
JPS58160585A (en) * 1982-03-19 1983-09-24 Hitachi Ltd Screw rotor
US4504201A (en) * 1982-11-22 1985-03-12 The Boc Group Plc Mechanical pumps
DE3321718A1 (en) * 1983-06-16 1984-12-20 Arthur Pfeiffer Vakuumtechnik Wetzlar Gmbh, 6334 Asslar ROLLING PISTON PUMP
IT1179911B (en) * 1984-04-16 1987-09-16 Gilardini Spa Automotive engine pressure-charger
JPS61152991A (en) * 1984-12-26 1986-07-11 Hitachi Ltd Screw fluid machine
DE3545821A1 (en) * 1985-12-23 1987-07-02 Wankel Gmbh LIQUID-COOLED HOUSING OF A ROTARY PISTON INTERNAL COMBUSTION ENGINE

Also Published As

Publication number Publication date
JP2650041B2 (en) 1997-09-03
US4983107A (en) 1991-01-08
JPS63302193A (en) 1988-12-09
EP0290663A1 (en) 1988-11-17
DE3786917D1 (en) 1993-09-09

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