EP3507496B1 - Trockenverdichtende vakuumpumpe - Google Patents

Trockenverdichtende vakuumpumpe Download PDF

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Publication number
EP3507496B1
EP3507496B1 EP17751770.3A EP17751770A EP3507496B1 EP 3507496 B1 EP3507496 B1 EP 3507496B1 EP 17751770 A EP17751770 A EP 17751770A EP 3507496 B1 EP3507496 B1 EP 3507496B1
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EP
European Patent Office
Prior art keywords
vacuum pump
dry
toothed belt
rotor
compressing
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.)
Active
Application number
EP17751770.3A
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German (de)
English (en)
French (fr)
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EP3507496A1 (de
Inventor
Thomas Dreifert
Dirk Schiller
Wolfgang Giebmanns
Roland Müller
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Leybold GmbH
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Leybold GmbH
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Publication of EP3507496A1 publication Critical patent/EP3507496A1/de
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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
    • 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
    • F04C29/0071—Couplings between rotors and input or output shafts acting by interengaging or mating parts, i.e. positive coupling of rotor and shaft
    • 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
    • F04C25/00—Adaptations of pumps for special use of pumps for elastic fluids
    • F04C25/02—Adaptations of pumps for special use of pumps for elastic fluids for producing high vacuum
    • 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
    • F04C18/084—Toothed wheels
    • 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
    • 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
    • F04C18/14—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 toothed rotary pistons
    • F04C18/16—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 toothed rotary pistons with helical teeth, e.g. chevron-shaped, screw type
    • 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
    • F04C2210/00—Fluid
    • F04C2210/10—Fluid working
    • F04C2210/1005—Air
    • 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
    • F04C2210/00—Fluid
    • F04C2210/22—Fluid gaseous, i.e. compressible
    • F04C2210/221—Air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2220/00—Application
    • F04C2220/10—Vacuum
    • F04C2220/12—Dry running
    • 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
    • F04C2230/00—Manufacture
    • F04C2230/60—Assembly methods
    • F04C2230/602—Gap; Clearance
    • 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
    • F04C2240/00—Components
    • F04C2240/20—Rotors
    • 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
    • F04C2240/00—Components
    • F04C2240/50—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
    • F04C2240/00—Components
    • F04C2240/80—Other components
    • 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
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2210/00—Working fluid
    • F05B2210/10—Kind or type
    • F05B2210/12—Kind or type gaseous, i.e. compressible
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2210/00—Working fluid
    • F05B2210/16—Air or water being indistinctly used as working fluid, i.e. the machine can work equally with air or water without any modification
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2240/00—Components
    • F05B2240/50—Bearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05B—INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
    • F05B2260/00—Function
    • F05B2260/40—Transmission of power
    • F05B2260/402—Transmission of power through friction drives
    • F05B2260/4021—Transmission of power through friction drives through belt drives

Definitions

  • the invention relates to a dry-running vacuum pump, in particular a screw pump.
  • Dry-compressing vacuum pumps such as screw pumps have two rotor elements arranged in a pumping chamber.
  • the rotor elements are designed as helical displacement elements. Each rotor element is carried by a rotor shaft.
  • the two rotor elements are arranged in the scooping space formed by the pump housing.
  • the two rotor shafts protrude through a housing wall that limits the scooping space.
  • Gears are connected to the two shaft ends.
  • the two gears mesh with one another. As a result, the two shafts rotating in opposite directions are synchronized on the one hand, and the two shafts are driven on the other hand. By providing the meshing gears, only one of the two shafts has to be driven.
  • an enlarged effective diameter of typically 0.2 to 0.4 mm would have to be provided for toothed belt wheels. This leads to a forced division error, which worsens the synchronization. Providing However, an enlarged effective diameter significantly shortens the service life of the timing belts used. This is not accepted in the market for dry compressing vacuum pumps.
  • a dry compressing vacuum pump with the features of the preamble of claim 1 is out DE 103 34 481 known.
  • the object of the invention is to provide a dry-compressing vacuum pump which is driven and synchronized with a toothed belt and does not have the above disadvantages.
  • the dry-compressing vacuum pump has a scooping space formed by a pump housing.
  • Two rotor elements are arranged in the scoop chamber, the vacuum pump in particular being a screw pump.
  • Each rotor element is carried by a rotor shaft.
  • the two rotor shafts protrude through a housing wall delimiting the scooping space, so that one shaft end protrudes from the scooping space per rotor shaft.
  • a toothed belt wheel is arranged on each of the two shaft ends. Since the two rotor shafts are driven by a toothed belt, the two toothed belt wheels do not mesh with one another.
  • a drive device such as an electric motor is provided.
  • a pulley is arranged in particular on a drive shaft of the electric motor.
  • the toothed belt is connected to the two toothed belt wheels and the drive device, in particular the pulley of the drive device.
  • a backlash between the two rotor elements of more than ⁇ 0.75 °, in particular more than ⁇ 1 °, is provided according to the invention. Just because The provision of such a large backlash enables the use of toothed belts.
  • the displacement elements arranged on the rotor shaft are preferred, the displacement elements naturally also being able to be formed in one piece with the rotor shaft.
  • the profile engagement gap in the inlet area is decisive for the maximum permissible synchronization error due to the large gradient of the winding of the displacement elements that is present here.
  • Already comparatively small angular deviations lead to undesirable flank contacts in the suction-side displacement elements.
  • a large backlash must be selected.
  • two to three turns are preferably provided in this area.
  • the number of turns in the outlet area i.e. be increased on the pressure side. This results in a lower pressure gradient in the inlet area and thus also a reduced backflow.
  • the turns have a smaller slope. Six to 10 turns are preferably provided here.
  • the two screw rotors it is possible for the two screw rotors to have a plurality of rotor elements or displacement elements or displacement stages. At least two displacement elements or displacement stages are preferably provided.
  • Such a vacuum pump screw rotor preferably has at least two helical displacement elements arranged on a rotor shaft.
  • the at least two displacement elements preferably have different gradients, the gradient being constant for each displacement element.
  • the vacuum pump screw rotor has two displacement elements, a first suction-side displacement element having a larger constant slope and a second pressure-side displacement element having a smaller constant slope.
  • the preferred provision of a plurality of displacement elements, each of which has a constant slope makes the manufacture considerably easier.
  • Each displacement element preferably has at least one helical recess which has the same contour over its entire length.
  • the contours are preferably different for each displacement element.
  • the individual displacement element thus preferably has a constant slope and a constant contour. This considerably simplifies the production, so that the production costs can be greatly reduced.
  • the contour of the suction-side displacement element is designed asymmetrically. Due to the asymmetrical design of the contour or profile, the flanks can be designed in such a way that the leakage areas, the so-called blow holes, in particular completely disappear or at least have a small cross section.
  • a particularly suitable asymmetrical profile is the so-called "Quimby profile". Although such a profile is relatively difficult to manufacture, it has the advantage that there is no continuous blow hole. A short circuit only exists between two neighboring chambers. Since it is an asymmetrical profile with different profile flanks, At least two work steps are required for the production, since the two flanks have to be produced in different work steps due to their asymmetry.
  • the pressure-side displacement element in particular the last displacement element in the pumping direction, is preferably provided with a symmetrical contour.
  • the symmetrical contour has the particular advantage that production is easier.
  • both flanks with a symmetrical contour can be produced in one work step by a rotating end mill or by a rotating side milling cutter.
  • Such symmetrical profiles have only small blowholes, but these are continuous, i.e. not only provided between two adjacent chambers. The size of the blow hole decreases as the slope decreases.
  • such symmetrical profiles can be provided in particular in the case of the pressure-side displacement element, since in a preferred embodiment this has a smaller slope than the suction-side displacement element and preferably also as the displacement element arranged between the suction-side and the pressure-side displacement element.
  • the tightness of such symmetrical profiles is somewhat lower, they have the advantage that the manufacture is significantly easier.
  • a particularly suitable symmetrical profile is the so-called "cycloid profile".
  • the provision of at least two such displacement elements means that the corresponding screw vacuum pump can generate low inlet pressures with low power consumption.
  • the thermal load is also low.
  • the arrangement of at least two such displacement elements, preferably configured in this way, with a constant pitch and constant contour in a vacuum pump essentially leads to same results as for a vacuum pump with a displacement element with changing pitch. With high built-in volume ratios, three or four displacement elements can be provided for each rotor.
  • a pressure-side, that is to say in particular the last, displacement element has a large number of turns. Due to the large number of turns, a larger gap between the screw rotor and the housing can be accepted while maintaining the same performance.
  • the gap can have a cold gap width of 0.05-0.3 mm.
  • a large number of outlet windings or number of windings in the pressure-side displacement element can be produced inexpensively, since this displacement element has a constant slope and in particular also a symmetrical contour. This enables simple and inexpensive production, so that the provision of a large number of turns is acceptable.
  • This pressure-side or last displacement element preferably has more than 6, in particular more than 8 and particularly preferably more than 10 turns.
  • the use of symmetrical profiles has the advantage that both flanks of the profile can be cut simultaneously with one milling cutter.
  • the milling cutter is additionally supported by the opposite flank, so that deformation or bending of the milling cutter during the milling process and inaccuracies caused thereby are avoided.
  • the displacement elements and the rotor shaft are formed in one piece.
  • the change in slope between adjacent displacement elements is discontinuous or erratic educated.
  • the two displacement elements are arranged at a distance from one another in the longitudinal direction, so that a circumferential cylindrical ring-shaped chamber is formed between two displacement elements and serves as a tool outlet. This is particularly advantageous in the case of rotors formed in one piece, since the tool producing the helical line can be brought out in a simple manner in this area. If the displacement elements are manufactured independently of one another and then mounted on a shaft, the provision of a tool outlet, in particular of such a ring-cylindrical region, is not necessary.
  • no tool outlet is provided between two adjacent displacement elements on the change of pitch.
  • both flanks have a defect or recess in order to be able to lead the tool out.
  • Such a flaw has no significant influence on the compression performance of the pump, since it is a flaw or recess that is very local.
  • the vacuum pump screw rotor preferably has a plurality of displacement elements. These can each have the same or different diameters. It is preferred here that the pressure-side displacement element has a smaller diameter than the suction-side displacement element.
  • displacement elements produced independently of the rotor shaft, these are mounted on the shaft by press fits, for example. It is preferred here to provide elements such as dowel pins for fixing the angular position of the displacement elements to one another.
  • the screw rotor In particular in the one-piece configuration of the screw rotor, but also in the case of a multi-piece configuration, it is preferred to remove it To produce aluminum or from an aluminum alloy. It is particularly preferred to manufacture the rotor from aluminum or an aluminum alloy, in particular AISi9Mg or AlSi17Cu4Mg.
  • the alloy preferably has a high silicon content of preferably more than 9%, in particular more than 15%, in order to reduce the coefficient of expansion.
  • the aluminum used for the rotors has a low expansion coefficient. It is preferred if the material has an expansion coefficient of less than 22 ⁇ 10 -6 / K , in particular of less than 20 ⁇ 10 -6 / K.
  • the surface of the displacement elements is coated, in particular a coating against wear and / or corrosion being provided. It is preferred to provide an anodic or other suitable coating depending on the area of application.
  • the vacuum pump has at least two compression stages.
  • the vacuum pump has a maximum delivery rate of at least 75%, in particular at least 85%.
  • the degree of delivery is the quotient of the maximum real volume flow and the theoretically possible volume flow for a loss-free pump in relation to the pump chamber geometry and the operating speed.
  • the maximum delivery rate is usually reached in the range of 1 to 10 mbar.
  • the toothed belt used is not only used to drive but also to synchronize the rotor shafts. In screw pumps, the rotor shafts rotate in opposite directions.
  • the toothed belt is therefore designed as a double-sided toothed belt. In plan view, the toothed belt therefore preferably runs between the two toothed belt wheels connected to the shaft ends.
  • tooth gap play of the two toothed belt wheels of more than 0.10 mm can be accepted.
  • the backlash is defined by the combination of the tooth shape of the toothed belt wheels used and the tooth shape and size of the teeth of the toothed belt. Due to the relatively large gap between teeth, the service life of the toothed belt is significantly increased.
  • the effective diameter is not increased and thus no forced pitch error occurs.
  • a toothed belt for driving and synchronizing the two rotor shafts has the particular advantage that no oil lubrication has to be provided. This has the particular advantage that the sealing of the shaft ends with respect to the scooping space can be made significantly more cost-effective. It is also possible to provide grease-lubricated roller bearings.
  • the two shafts are mounted in the housing wall through which the shaft ends are guided, and these bearings can be grease-lubricated bearings.
  • the opposite shaft ends, which are arranged in the area of the inlet side, are preferably supported by grease-lubricated bearings, but oil-lubricated bearings can also be used.
  • a belt tensioning device can be provided in order to keep the belt constantly tensioned.
  • This is preferably an automatic tensioning device in which the tension is generated, for example, by means of a spring or the like, or a fixed prestress is applied during assembly. It is also possible to tension the belt in that the drive motor is held displaceably.
  • Another advantage of the drive according to the invention by means of toothed belts is that it is possible to change the speed of the vacuum pump in a simple manner. All that is required is to replace the toothed belt pulley connected to the drive device. When replacing the toothed belt pulley, the toothed belt may also need to be replaced.
  • a pump housing 10 is shown in a highly simplified manner.
  • a scoop chamber is formed within the pump housing 10, in which two rotor elements 14 are arranged.
  • the rotor elements 14 in the exemplary embodiment shown are screw rotors.
  • the screw rotors 14 have helical compression elements that interlock.
  • the two screw rotors 14 are driven in opposite directions.
  • the two screw rotors 14 have two pump stages 16, 18.
  • the two rotor elements are each arranged on a rotor shaft 22.
  • the two rotor shafts 22 are mounted on the suction side in a housing cover 24 via bearing elements 26.
  • shaft ends 28 protrude through a housing wall 30.
  • the two rotor shafts 22 are supported in the housing wall 30 via grease-lubricated bearings 32.
  • the dry compressing vacuum pump conveys medium through an inlet 34 to an outlet 36.
  • the two shaft ends 28 are each connected to a toothed belt wheel 38, the two toothed belt wheels 38 not meshing with one another.
  • the synchronization is done by an in Fig. 1 Not shown timing belt 40 ( Fig. 2 ).
  • the toothed belt is designed as a double-sided toothed belt and is guided between them to synchronize the two toothed belt wheels 38 or the two shaft ends 28 connected to the toothed belt wheels.
  • a drive device 42 is provided, the drive shaft 44 of which is connected to a toothed belt pulley 46.
  • Figure 3 schematically shows teeth of a toothed belt pulley 38 or 46 in connection with a toothed belt 40.
  • a tooth 48 of a toothed belt 40 is designed such that a gap is shown hatched in relation to a tooth space 50 between two adjacent teeth 52 of the toothed belt wheel 38.
  • the synchronization of the two rotor shafts 22 is somewhat deteriorated, but the service life of the toothed belt 48 is increased.
  • a toothed belt as shown schematically in Figure 4 shown, be provided. As a so-called zero gap, this has no distances between the tooth space 50 and the tooth 48 of the belt 40.
  • the rotor has two displacement elements 110, 112, which form the two pump stages 16, 18.
  • a first displacement-side displacement element 110 has a large pitch of approximately 50-150 mm / revolution. The slope is constant over the entire displacement element 110. The contour of the helical recess is also constant.
  • the second pressure-side displacement element 112 again has a constant slope and a constant contour of the recess over its length. The slope of the pressure-side displacement element 112 is preferably in the range of 10-30 mm / revolution.
  • An annular cylindrical recess 114 is provided between the two displacement elements. This serves to ensure that due to the one-piece design of the in Fig. 5 shown screw rotor a tool outlet is realized.
  • the one-piece screw rotor has two bearing seats 116 and a shaft end 118.
  • a gearwheel for driving is connected to the shaft end 118.
  • the two displacement elements 110, 112 manufactured separately and then fixed on a rotor shaft 120, for example by pressing. Although this production is somewhat more complex, the cylindrical distance 114 between two adjacent displacement elements 110, 112 is not required as a tool outlet.
  • the bearing seats 116 and the shaft ends 118 can be an integral part of the shaft 120.
  • a continuous shaft 120 can also be made from another material that differs from the displacement elements 110, 112.
  • Fig. 7 shows a schematic sectional view of an asymmetrical profile (for example a Quimby profile).
  • the asymmetrical profile shown is a so-called "Quimby profile”.
  • the sectional view shows two screw rotors which mesh with one another and whose longitudinal direction is perpendicular to the plane of the drawing. The opposite rotation of the rotors is indicated by the two arrows 115.
  • the profiles of the flanks 119 and 121 are designed differently for each rotor.
  • the opposite flanks 119, 121 must therefore be produced independently of one another.
  • the production which is therefore somewhat more complex and difficult, has the advantage, however, that there is no continuous blow hole, but only a short circuit between two adjacent chambers.
  • Such an asymmetrical profile is preferably provided in the suction-side displacement element 110.
  • FIG. 8 The schematic sectional view in Fig. 8 again shows a cross section of two displacement elements or two screw rotors, which in turn rotate in opposite directions (arrows 115). Relative to the axis of symmetry 117, the flanks 123 are formed symmetrically for each displacement element. At the in Fig. 8 The illustrated preferred embodiment of a symmetrically designed contour is a cycloid profile.
  • a symmetrical profile, as in Fig. 8 is preferably provided in the pressure-side displacement elements 112.
  • displacement elements are provided. If necessary, these can also have different head diameters and corresponding foot diameters. It is preferred here that a displacement element with a larger head diameter at the inlet, i.e. is arranged on the suction side in order to achieve a greater pumping speed in this area and / or to increase the built-in volume ratio. Combinations of the above-described embodiments are also possible.
  • one or more displacement elements can be produced in one piece with the shaft or an additional displacement element independent of the shaft and then mounted on the shaft.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
EP17751770.3A 2016-08-30 2017-08-14 Trockenverdichtende vakuumpumpe Active EP3507496B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE202016005208.0U DE202016005208U1 (de) 2016-08-30 2016-08-30 Trockenverdichtende Vakuumpumpe
PCT/EP2017/070626 WO2018041620A1 (de) 2016-08-30 2017-08-14 Trockenverdichtende vakuumpumpe

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EP3507496A1 EP3507496A1 (de) 2019-07-10
EP3507496B1 true EP3507496B1 (de) 2020-07-15

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US (1) US20190186493A1 (pt)
EP (1) EP3507496B1 (pt)
JP (1) JP2019526738A (pt)
KR (1) KR20190043139A (pt)
CN (1) CN109642574B (pt)
BR (1) BR112019002903A2 (pt)
CA (1) CA3034112A1 (pt)
DE (1) DE202016005208U1 (pt)
WO (1) WO2018041620A1 (pt)

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DE202017003046U1 (de) * 2017-06-09 2018-09-14 Leybold Gmbh Trockenverdichtende Vakuumpumpe
EP3499041B1 (de) * 2017-12-15 2020-07-01 Pfeiffer Vacuum Gmbh Schraubenvakuumpumpe
DE202018000178U1 (de) * 2018-01-12 2019-04-15 Leybold Gmbh Kompressor
DE102018210922A1 (de) * 2018-07-03 2020-01-09 Leybold Gmbh Zwei- oder Mehrwellen-Vakuumpumpe
TW202040004A (zh) * 2019-04-19 2020-11-01 亞台富士精機股份有限公司 轉子及螺旋式幫浦
CN111120324A (zh) * 2019-12-30 2020-05-08 浙江思科瑞真空技术有限公司 一种具有多个吸入腔和排气口的螺杆真空泵

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KR20190043139A (ko) 2019-04-25
BR112019002903A2 (pt) 2019-05-21
DE202016005208U1 (de) 2017-12-01
WO2018041620A1 (de) 2018-03-08
CN109642574A (zh) 2019-04-16
CA3034112A1 (en) 2018-03-08
EP3507496A1 (de) 2019-07-10
CN109642574B (zh) 2020-08-04
US20190186493A1 (en) 2019-06-20
JP2019526738A (ja) 2019-09-19

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