EP0084085B1 - Vakuumpumpe mit einem Saugstutzen-Ventil und Betriebsverfahren dafür - Google Patents

Vakuumpumpe mit einem Saugstutzen-Ventil und Betriebsverfahren dafür Download PDF

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Publication number
EP0084085B1
EP0084085B1 EP82109589A EP82109589A EP0084085B1 EP 0084085 B1 EP0084085 B1 EP 0084085B1 EP 82109589 A EP82109589 A EP 82109589A EP 82109589 A EP82109589 A EP 82109589A EP 0084085 B1 EP0084085 B1 EP 0084085B1
Authority
EP
European Patent Office
Prior art keywords
oil
piston
vacuum pump
pressure
cylinder
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
Application number
EP82109589A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0084085A1 (de
Inventor
Hanns-Peter Dr. Berges
Peter Frieden
Hans-Peter Dr. Kabelitz
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 Heraeus GmbH
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Filing date
Publication date
Application filed by Leybold Heraeus GmbH filed Critical Leybold Heraeus GmbH
Publication of EP0084085A1 publication Critical patent/EP0084085A1/de
Application granted granted Critical
Publication of EP0084085B1 publication Critical patent/EP0084085B1/de
Expired 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
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/24—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • 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
    • F04C27/00—Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids
    • F04C27/02—Liquid sealing for high-vacuum pumps or for compressors
    • 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
    • F04C29/02—Lubrication; Lubricant separation

Definitions

  • the invention relates to a vacuum pump with a suction port valve, which has a closure element connected to the piston of a cylinder-piston device, one end of a pressure medium line opening into the cylinder, the other end of which is assigned a valve, which depends on the pressure medium line opens or closes from the operating state of the pump.
  • the invention also relates to an expedient operating method for a vacuum pump with a suction nozzle valve which operates as a function of the operating state of the pump.
  • Rotating vacuum pumps are operated with sealing liquids, preferably oil, in order to achieve high final vacuum levels.
  • the oil is used to lubricate bearings and to cool the pump. After stopping such pumps - be it due to a normal shutdown, power failure or any other malfunction - there is a risk that oil will rise in the recipient, especially if it is under vacuum, and cause undesirable contamination there.
  • a number of solutions are known which are described in the essay “Intake manifold block prevents oil return on rotating vacuum pumps •, Maschinengon, Würzburg, 79 (1973), 54, pages 1191 to 1193.
  • Air serves as the pressure medium.
  • the inlet opening of the pressure medium line is closed or open, depending on the operating state of the pump.
  • a centrifugal switch is provided on the pump shaft, with the help of which the inlet opening of the pressure medium line is closed when the pump starts up. This causes the opening movement of the closure element of the suction nozzle valve. If, for whatever reason, the vacuum pump comes to a standstill, the centrifugal switch releases the inlet opening, so that air at atmospheric pressure penetrates into the cylinder with the piston of the suction nozzle valve and thereby causes the closing movement of the suction nozzle valve.
  • a nozzle is provided, via which the pump chamber is ventilated after the closing movement of the suction nozzle valve has been initiated.
  • a disadvantage of the previously known solution is that the undesirable air intake, which causes an increase in pressure in the recipient connected to the suction port, is still present, since it cannot be completely avoided that part of the air causing the movement of the piston of the suction port valve between the pistons and the cylinder already enters the suction chamber at a time when the suction port valve has not yet reached its closed position.
  • air penetrates through the nozzle for ventilation of the pump chamber into the suction chamber, thereby increasing the air intake.
  • the air intake could only be achieved by a very tight play between the piston and the cylinder and by dispensing with a nozzle which later served to vent the pump.
  • the present invention has for its object to provide a vacuum pump with a suction port valve of the type mentioned, in which, despite the presence of a relatively large tolerance in the cylinder-piston device for the suction port valve, the undesirable air intake practically no longer occurs.
  • this object is achieved in that an oil reservoir open to the atmosphere is located above the inlet opening of the pressure medium line for the purpose of superimposing this inlet opening with oil, and in that the oil quantity overlying the inlet opening is so small that it essentially only during the closing process of the suction nozzle valve serves to seal the gap existing between the piston and the cylinder. If a pump designed in this way is shut down, then - at least initially - not oil but oil gets under the pistons which serve to actuate the suction nozzle valve, so that an air swallow can no longer occur. After the oil has performed its sealing function, air gets under the piston.
  • Such a hydropneumatic actuation of the suction nozzle valve has the advantage of significantly shorter closing times compared to a fully hydraulic actuation.
  • Another advantage in the context of the invention consists in the fact that the control of the suction nozzle valve can be operated in such a way that it takes place depending on the oil pressure in an oil circuit serving among other things to supply the bearings of the vacuum pump. This enables a hydro-pneumatic actuation of the suction nozzle valve to be implemented in a particularly simple and safe manner.
  • the oil circuit of the pump is formed by the intake line 11, via which oil is conveyed from the oil supply 2 into the oil pressure line 13 by means of the oil pump 12.
  • a throttle 15 is arranged, which ensures the maintenance of the desired oil pressure (between 1.5 and 2 bar, preferably 1.7 bar) and via which the pressure is reduced to the pressure in the oil box 1 he follows.
  • the bearings in the pump are supplied with pressure oil via branches 16, 17, 18.
  • Three oil supply lines (16, 17, 18) are required in the case of a two-stage pump, in which two end bearings and an intermediate bearing of the two rotors have to be supplied with oil. In the case of a single-stage pump, two of the three branch lines are sufficient. After the bearings have flowed through, the oil that has entered the branch lines 16, 17, 18 returns to the oil reservoir 2.
  • An oil filter 19 is switched on in the pressure oil line 13 immediately behind the oil pump 12, so that it is ensured that only cleaned oil flows through the line 13 and through the branch lines connected to it.
  • Another branch line 21 opens into the control cylinder 22, in which the control piston 23 is located.
  • the pressure medium line 24 opens into the cylinder 22, the other end of which is connected to the cylinder 9 on the side of the piston 8 facing away from the valve plate 7.
  • the inlet opening 25 of the pressure medium line 24 in the cylinder 22 is designed as a valve seat.
  • a plug 26 with a sealing bead 27 is inserted into the inlet openings 25.
  • the end face 28 of a cylindrical projection 29 on the control piston 23 with a reduced diameter compared to the control piston serves as the closure member.
  • the control piston 23 is under the action of a spring 31, which is arranged between the control piston 23 and the end wall 32 with the inlet opening 25 of the pressure medium line 24 and is designed as a compression spring.
  • the cylindrical projection 29 can be screwed into the control piston 23 by means of the thread 33, so that the force of the spring 31 acting in the closed state of the control valve 27, 28 can be influenced.
  • a further line 34 opens into the cylinder 22 and is connected to an oil reservoir 35 of small volume which is open at the top.
  • the junction of the line 34 in the cylinder 22 lies on the side of the control piston 23 opposite the junction of the line 21.
  • the oil pump 12 conveys oil from the oil supply 2 into the oil pressure line 13.
  • the oil pump 12 can be designed as a rotary vane pump or gear pump and is coupled in a known manner to the pump shaft as a drive (cf. GB-PS 875 444).
  • the delivery characteristics of the pump 12 and the size of the throttle 15 are dimensioned such that the desired oil pressure builds up and is maintained in the line 13 after the vacuum pump has started. This pressure acts on the piston 23 and overcomes the force of the spring 31, so that the inlet opening 25 of the pressure medium line 24 is closed.
  • the suction nozzle valve 4 is in its open position, so that the recipient connected to the suction nozzle 3 is evacuated.
  • the inlet opening 25 is opened so that, owing to the atmospheric pressure prevailing on the surface of the oil in the oil reservoir 35, oil is pressed into the pressure medium line 24 and reaches cylinder 9 under the piston 8.
  • the amount of oil located below the piston 23 and in the oil reservoir 35 is so small that the oil entering the cylinder 9 serves essentially only to seal the piston 8 against its cylinder wall.
  • the actual pressure medium for actuating the piston 8 is the air which, following the oil, passes through the oil supply 35 into the pressure medium line 24.
  • the total amount of oil in the cylinder 22 and in the oil reservoir 35 is therefore chosen so large or small that on the one hand a seal of the gap between the piston 8 and the cylinder wall 9 is ensured during the closing process and on the other hand the pump is ventilated shortly after being switched off.
  • a particular advantage of the described embodiment of the suction nozzle valve 4 and its control means which operate as a function of the oil pressure is that both cylinder-piston devices 8, 9 and 22, 23 are hardly susceptible to tolerances because of the desired gap between the piston and the cylinder and therefore without special costs can be produced.
  • the control means can be adjusted in such a way that even with relatively small pressure drops in the oil circuit (e.g. a drop in the set pressure of approx. 1.7 bar to 1.4 bar) the inlet opening 25 of the pressure medium line 24 is released.
  • the response time of the suction nozzle valve 4 is so small due to the hydropneumatic actuation that it is ensured that the suction nozzle valve is closed before the vacuum pump finally runs out.
  • the control of the suction nozzle valve by the oil pressure in an oil circuit which is supplied by an oil pump arranged on the pump shaft, has the advantage of fast and safe operation, since the operating state of the pump can clearly be derived from the oil pressure in the oil circuit.
  • the outlet opening 14 of the line 13 is assigned a resilient cover 41 which - together with a special design of the wall 42 in the region of the outlet opening 14 - fulfills several functions.
  • the outlet opening 14 is surrounded by a concentric groove 43 in the wall 42 which extends into a bore 44 through which the oil serving to supply the pump chamber passes.
  • This bore is also equipped with a throttle 45, the size of which is adapted to the suction power or the oil requirement of the respective pump.
  • the resilient cover 41 which preferably consists of an elastic steel band section, covers both the outlet opening 14 of the oil pressure line 13 and the bore 44. Their force and the distance of the fastening points 46, 47 from the oil channels 13, 44 are selected in this way.
  • the pressure oil is expanded to the pressure in the oil box as a result of the throttle 15 and initially flows into the groove 43 surrounding the outlet opening 14. Part of the oil flows out of this groove, which is connected to the bore 44, as a result of the Suction effect of the pump chamber through the bore 44 or throttle 45. Excess oil is returned to oil reservoir 2.
  • the resilient cover 41 ensures that only such oil flows through the bore 44 and the throttle 45 that has emerged from the outlet opening 14. Therefore, only oil that has flowed through the oil filter 19 enters the pump chamber. The pump room is therefore no longer affected by dirty oil. Nevertheless, the pump works like a self-priming pump, i.e. that is, it determines the amount of oil it needs itself. B. small amounts of oil through the throttle 45, so that undesirably high proportions of oil vapor are not present in the pumped media emerging from the pump. Regardless of this, it is ensured that the bearings are supplied with pressure oil.
  • the resilient cover and the special groove design ensure that the oil is shut off when the pump is not running.
  • the negative pressure acting through the bore 44 in the pump chamber causes the resilient cover to bear tightly against the wall 42.
  • the cover completely blocks the bore 44, so that the oil supply to the vacuum pump is stopped.
  • Fig. 2 shows a rotary vane vacuum pump.
  • the conveyed gases pass through the suction nozzle 3, the open suction nozzle valve 4, via the suction channel 51, which is not visible in the drawing plane and is therefore shown as an arrow, into the pump chamber 52, in which the rotor 53 with the slides 54 is located.
  • the compressed gases pass through the outlet channel 55 into the oil box 1, which is filled with oil up to the line 56, so that the resilient cover 41 lies below the oil level.
  • the actual exhaust pipe is not shown.
  • the end wall 42 of the pump body 57 arranged in the oil box 1 is shown in view in its lower part.
  • Figures 3 and 4 show sections through this end wall at the level of lines 111-111 and IV-IV.
  • the oil pressure line 13 ends with the throttle point 15.
  • the lubrication of the bearing of the pump shaft (not shown) arranged in the end wall 42 via the branch line 17 designed as a bore. This bore is closed to the outside by the plug 58.
  • the resilient cover 41 (shown in broken lines in FIG. 2) is fastened on the end wall 42 by means of the screws 46, 47. It covers the two openings 14 and 44 and the groove 43 surrounding the opening 14.
  • the nozzle 15 is produced by drilling the end wall 42 on both sides.
  • the nozzle 45 is screwed into the end wall 42 by means of a thread 59, so that different nozzles can be used depending on the suction power of the pump.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Applications Or Details Of Rotary Compressors (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
EP82109589A 1981-12-17 1982-10-16 Vakuumpumpe mit einem Saugstutzen-Ventil und Betriebsverfahren dafür Expired EP0084085B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19813150033 DE3150033A1 (de) 1981-12-17 1981-12-17 Vakuumpumpe mit einem saugstutzen-ventil und betriebsverfahren dafuer
DE3150033 1981-12-17

Publications (2)

Publication Number Publication Date
EP0084085A1 EP0084085A1 (de) 1983-07-27
EP0084085B1 true EP0084085B1 (de) 1985-08-07

Family

ID=6149004

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82109589A Expired EP0084085B1 (de) 1981-12-17 1982-10-16 Vakuumpumpe mit einem Saugstutzen-Ventil und Betriebsverfahren dafür

Country Status (4)

Country Link
US (1) US4483667A (ja)
EP (1) EP0084085B1 (ja)
JP (1) JPS58107894A (ja)
DE (2) DE3150033A1 (ja)

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT1207829B (it) * 1987-02-04 1989-06-01 Galileo Spa Off Perfezionamento nel circuito di lubrificazione delle pompe rotative per vuoto.
US4903505A (en) * 1989-01-30 1990-02-27 Hoshizaki Electric Co., Ltd. Automatic ice manufacturing apparatus
US4968221A (en) * 1989-04-03 1990-11-06 Dresser Industries, Inc. Intake valve for vacuum compressor
GB9223806D0 (en) * 1992-11-13 1993-01-06 Boc Group Plc Improvements in vacuum pumps
DE4325282A1 (de) * 1993-07-28 1995-02-02 Leybold Ag Vakuumpumpe mit Zusatzeinrichtung
US6190149B1 (en) 1999-04-19 2001-02-20 Stokes Vacuum Inc. Vacuum pump oil distribution system with integral oil pump
KR100408153B1 (ko) 2001-08-14 2003-12-01 주식회사 우성진공 드라이 진공펌프
US6821099B2 (en) * 2002-07-02 2004-11-23 Tilia International, Inc. Rotary pump
KR100519567B1 (ko) * 2003-09-22 2005-10-11 김덕겸 로터리 베인형 진공펌프
US20050245614A1 (en) * 2004-03-04 2005-11-03 Xanodyne Pharmaceuticals, Inc. Tranexamic acid formulations
DE102006058837C5 (de) * 2006-12-13 2022-05-05 Pfeiffer Vacuum Gmbh Schmiermittelgedichtete Drehschiebervakuumpumpe
CN102725532B (zh) * 2010-01-29 2015-09-23 Ulvac机工株式会社 泵
DE102013210854A1 (de) * 2013-06-11 2014-12-11 Oerlikon Leybold Vacuum Gmbh Vakuumpumpe sowie Verfahren zum Betreiben einer Vakuumpumpe

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE567479C (de) * 1933-01-04 Oerlikon Maschf Vakuumabschlussvorrichtung fuer in OEl laufende Drehkolben-Vakuumpumpen
US930843A (en) * 1903-08-28 1909-08-10 Geo Westinghouse Apparatus for controlling the flow of fluids.
CH157121A (de) * 1931-07-25 1932-09-15 Oerlikon Maschf Abschlussvorrichtung für in Öl laufende Drehkolben-Vakuumpumpen.
DE1190134B (de) * 1957-02-07 1965-04-01 Edwards High Vacuum Ltd Drehkolben-Vakuumpumpe mit oelueberlagertem Auspuffventil
US3057546A (en) * 1957-02-07 1962-10-09 Edwards High Vacuum Ltd Rotary vacuum pumps
DE1179666B (de) * 1958-02-26 1964-10-15 Leybold S Nachfolger K G E Drehkolbenpumpe zur Vakuumerzeugung
US3191854A (en) * 1960-06-02 1965-06-29 Atlas Copco Ab Compressor units
US3105630A (en) * 1960-06-02 1963-10-01 Atlas Copco Ab Compressor units
FR1282666A (fr) * 1960-12-14 1962-01-27 Alsacienne D Electronique Et D Dispositif d'étanchéité pour pompes à vide du type mécanique
GB970900A (en) * 1962-09-04 1964-09-23 Alan Sydney Darling Improvements in and relating to rotary vacuum pumps
US3168236A (en) * 1963-09-05 1965-02-02 Jaeger Machine Co Oil scavenging system for a rotary compressor
GB1069811A (en) * 1964-01-30 1967-05-24 Genevac Ltd Improvements in or relating to rotary vacuum pumps
GB1195361A (en) * 1966-03-28 1970-06-17 N G N Ltd Improvements in and relating to Vacuum Pumping apparatus including a Rotary Vacuum Pump
GB1303430A (ja) * 1969-06-12 1973-01-17
GB1383569A (en) * 1971-08-25 1974-02-12 Hokuetsu Kogyo Co Minimising power consumption of oillubricated rotary compressors
FR2383335A1 (fr) * 1977-03-08 1978-10-06 Leybold Heraeus Sogev Pompe mecanique a joint d'huile
US4366834A (en) * 1980-10-10 1983-01-04 Sargent-Welch Scientific Company Back-flow prevention valve

Also Published As

Publication number Publication date
DE3150033A1 (de) 1983-07-14
EP0084085A1 (de) 1983-07-27
JPS58107894A (ja) 1983-06-27
JPH0324594B2 (ja) 1991-04-03
US4483667A (en) 1984-11-20
DE3265261D1 (en) 1985-09-12

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