US3707339A - Vacuum pumps - Google Patents

Vacuum pumps Download PDF

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Publication number
US3707339A
US3707339A US45879A US3707339DA US3707339A US 3707339 A US3707339 A US 3707339A US 45879 A US45879 A US 45879A US 3707339D A US3707339D A US 3707339DA US 3707339 A US3707339 A US 3707339A
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United States
Prior art keywords
pump
oil
pressure
stage
valve
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US45879A
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English (en)
Inventor
Leslie J Budgen
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BOC Group Ltd
Original Assignee
British Oxigen Ltd
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Filing date
Publication date
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Publication of US3707339A publication Critical patent/US3707339A/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
    • F04C28/00—Control of, monitoring of, or safety arrangements for, pumps or pumping installations specially adapted for elastic fluids
    • F04C28/28—Safety arrangements; Monitoring
    • 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
    • F04C29/021—Control systems for the circulation of the lubricant

Definitions

  • 418/97 A11 011 sealed mechan caivacuum pump havmg stages 51 161.01 ..F0lc 21/04, F04C 27/02, F04C 25/02 has means for PP Y F B to Pq P throflgh a 5 Field of Search 418/13 4" 7 88 97 00 duct that presents an impedance WhlCh 1S a functlon 0f 41 5; 417 250 253 the mean inlet pressure of the pumped gas except the v A first stage.
  • the oil When the compression member approaches the end of the outlet passage the oil is forced into the passage and travels towards the main outlet valve, sweeping with it any gas which is being compressed in the compression chamber of the pump.
  • the gas load When the pump is operating at or near its ultimate vacuum, the gas load may be very small, and it is only the action of the oil in travelling up the outlet passage which sweeps the gas to the outlet valve and provides the force necessary to open the outlet valve to expel the oil-entrained gas.
  • the relative importance of the functions carried out by the oil varies with pumping conditions, as does the quantity of oil necessary to perform these functions.
  • the flow of oil required for lubrication is small and is usually less than that required for sealing except, perhaps, in the high vacuum stage of a two-stage rotary vacuum pump.
  • the flow of oil necessary for sealing depends on the average pressure difference between the inlet and outlet of the pump, i.e. between the vacuum and compression chambers, being high when the pressure difference is high.
  • the present invention aims at reducing or eliminating hydraulic knock in an oil-sealed mechanical vacuum pump irrespective of the degree of vacuum under which it is operating.
  • the present invention provides an oilsealed mechanical vacuum pump which is as claimed in the appended claims.
  • FIG. 1 is a diagrammatic view of a known vacuum pump of the sliding-vane type
  • FIG. 2 is a sectional view of a vacuum pump of the present invention having a gas pumping stage, a scavenger stage and an oil control device and FIGS. 3,4 and 5 are views of alternative forms of oilfeed control devices.
  • pumps of the sliding-vane type are illustrated, it is to be understood that the present invention is applicable to any type of oil-sealed multi-stage mechanical vacuum pump having an inlet adapted to be placed in communication with the equipment to be evacuated, and having an outlet through which is ejected the gas being pumped.
  • multi-stage in this specification is meant having two or more stages.
  • a rotor 2 has two sliding vanes 4 which cooperate with the cylindrical wall of a housing 6.
  • the housing has an inlet passage 8 and an outlet passage 10, the latter being closed by a main outlet valve 12 which is illustrated as being of the flap type but which can be of any suitable alternative construction.
  • the passages by which oil is introduced into the interior of the pump are not illustrated.
  • the oil tends to be swept up by the vanes 4, as indicated at 14.
  • the volume of gas in the compression chamber 16 reduces, but not that of the oil, so that a stage is reached (as indicated at 1 8) in which the oil completely fills the space in front of the vane 4 and the outlet passage 10, the gas originally present in the compression chamber being either dissolved or entrained in the oil. This applies only when the pump is operating at or near its ultimate vacuum: at lower degrees of vacuum there is still a significant proportion of ga present in the region 18.
  • the plunger 30 is a sliding fit inthe end wall of the cylinder 24, and its outer end 34 is shaped to function as a valve memberv cooperating with a seat 36 formed in one end of a conduit 38 up which oil is fed under pressure (which may be atmospheric) to a chamber 40. Oil entering the chamber 40 through the annular space between the valve member 34 and valve seat 36 escapes through a conduit 42 from which it flows to the usual oil-ways (not shown) in the housing 6.
  • the device operates as follows:
  • the conduit may have an appreciable impedance to the flow of fluid along it, whereby transient fluctuations in the pressure in the chamber 54 are damped out to some extent.
  • the pressure in the cylinder 24 closely approximates to the average pressure.
  • the characteristics of the different components in the device 22 are chosen so that the flow of oil to the pump is restricted as the pump is approaching its ultimate vacuum. This restriction in supply reduces the amount of oil in the pump to a level such that hydraulic knock is at least reduced if not eliminated.
  • the oil supply to the pump may be greatly reduced because the scavenger stage replaces the liquid piston (discussed with reference to FIG. 1) as the means for extracting the effluent .oil together with residual traces of gasfrom the outlet of the main stage, and for compressing these for discharge into the oil reservoir at atmospheric pressure.
  • the amount of air which enters the pump entrained with the oil is proportional to the amount of oil feed, so that reducing the amount of oil results in an improvement of the ultimate vacuum attainable by the pump. Also, as the amount of work done on ejecting the oil (and its gas content) back to the reservoir is reduced, the power requirements of the pump are reduced and the pump runs cooler compared with conventional pumps of the same capacity.
  • a conduit (not shown in the drawing) is connected to the compression chamber of the pump and to a valve (not shown) by means of which a controlled bleed of gas may be introduced into the compression chamber 16 to gas ballast the pump.
  • a controlled bleed of gas may be introduced into the compression chamber 16 to gas ballast the pump.
  • the chamber 54 functions as the inlet chamber to the outlet stage of the pump.
  • the outlet stage is intended to act primarily as an oil-scavenger pump, but obviously is assists in pumping gas.
  • the outlet of stage 50 is exhausted into the overlying oil reservoir 58 through an outlet valve 60, which is shown composite with outlet valve 12 from chamber 54.
  • the displacement ratio of the two stages is large, about 20: l This ensures that there is an appreciable interstage pressure, except when the gas load is very small.
  • the oilfeed control device is responsive to the pressure in the inlet of the last or outlet stage.
  • the oilfeed device is buffered from the transient pressure fluctuations produced there, so that it has characteristics closer to the desired values than would otherwise be the case.
  • the principal difference in the FIG. 3 embodiment is that the head 28 of the plunger 30 is exposed directly to the reference pressure, being influid-tight engagement with an annular seal 61.
  • the seal may be in sliding contact with the head 28 or it may be axially resilient or introvertible.
  • the device 22 functions as described above.
  • a resilient diaphragm 62 carries a stem 64 connected to a valve member 66 which is adapted to cooperate with a passage 68 in a partition in a housing 70.
  • a compression spring 74 Seated in a chamber 72 to which the pressure transfer conduit 20 leads is a compression spring 74 which biasses the valve member 66 out of engagement with the seat provided by the I passage 68.
  • a high pressure in chamber 72 cooperates with the spring 74 in keeping the passageway open so that oil is able to pass freely between the conduits 38 and 42.
  • the reduction in pressure in the chamber 72 allows the oil pressure on the upstream side of the partition 69 to flex the diaphragm 62 to bring the valve member 66 into sealing engagement with the passage 58 so that the flow of oil is reduced as required.
  • the reference pressure is provided by a sealed aneroid capsule having one wall in contact with a fixed wall of a housing 82 and having its other wall'in contact with the head 28 of the plunger 30.
  • the volume occupied by the capsule 80 decreases to allow the thickness of the capsule 80 to reduce to permit the valve member 34 to move away from the seat 36.
  • the capsule 80 expands to move the plunger 30 to restrict or reduce to a minimum the flow of oil to the pump.
  • oilfeed control device 22 Although four different types of oilfeed control device 22 have been illustrated, these are only by way of example: numerous equivalent devices could be used.
  • the device has been described with particular reference to its use in conjunction with a multi-stage pump having a final scavenging stage (as described in our copending patent application Ser. No. 45,880, filed June 12, 1970) it may also be applied to a multi-stage pump when no oil scavenger stage is provided.
  • An example of such an application is the use of the device to control the supply of oil to the inlet stage of a multistage pump by responding to the inlet pressure of the subsequent stage.
  • the advantage sought in this case is a generous supply for lubrication of the inlet stage under arduous duties when a high gas load is being pumped, and a reduced supply of oil when the pump is used on high vacuum duties such that the release of dissolved air from an over-generous oil supply would degrade the vacuum.
  • An oil-sealed mechanical vacuum pump having two or more stages comprising means for supplying oil to the pump including a duct, a fluid flow control valve in the duct, a pressure-responsive movable member in the control valve which presents an impedance to the flow of oil that is a function of the mean inlet pressure of the pumped gas to any one of the stages except the first, the impedance being variable by the action of this pressure on the movable member of the fluid control valve.
  • An oil-sealed mechanical vacuum pump having two or more stages as claimed in claim 1, the last stage including an inlet and a final outlet, in which the impedance of the said duct to the flow of oil is a function of the mean pumped gas pressure in the inlet of said last stage of the pump.
  • a pump as claimed in claim 1 one stage being a control stage for the oil supply means, the inlet of the oil supply controlling stage being isolated from the outlet of the immediately-preceding stage by means of a non-return valve.
  • said fluid flow control valve including a seat for its pressure-responsive movable member, spring means biasing the movable member away from its seat, a conduit through which oil is supplied through the space between the valve seat and the movable member continuously while the pump is working, a conduit establishing communication between the outlet side of the seat and the reservoir, and said pressure-responsive movable member being biased towards valve closing position on the seat by a control pressure of the pumped gas which is variable as a function of the pressure in the inlet to the oil supply control stage.
  • n which the displacement of the last stage is of the order of one-twentieth of that of the immediately-preceding stage.
  • valve member is movable with a flexible diaphragm of which one side is exposed to a reference pressure and of which the other side is exposed to the control pressure of the pumped gas.
  • valve member is movable with a plunger defining a movable wall of a chamber having its interior in communication with the inlet to the outlet stage, the plunger being sealed to the chamber in a fluid-tight manner and having its outer surface exposed to a reference pressure.
  • valve member is movable with a flexible diaphragm of which one side is exposed to the oil inlet pressure

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Actuator (AREA)
  • Reciprocating Pumps (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
US45879A 1969-06-12 1970-06-12 Vacuum pumps Expired - Lifetime US3707339A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2990869 1969-06-12

Publications (1)

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US3707339A true US3707339A (en) 1972-12-26

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Family Applications (1)

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US45879A Expired - Lifetime US3707339A (en) 1969-06-12 1970-06-12 Vacuum pumps

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US (1) US3707339A (es)
DE (1) DE2028603A1 (es)
FR (1) FR2051122A5 (es)
GB (1) GB1303430A (es)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4054401A (en) * 1976-01-16 1977-10-18 Central Scientific Company, Inc. Vacuum pump with lubricant control system to interrupt lubricant flow upon loss of pump pressure
US4407641A (en) * 1980-07-23 1983-10-04 Societe Anonyme Dite: Compagnie Industrielle Des Telecommunications Cit-Alcatel Electrically-driven rotary vane pump
DE3315748A1 (de) * 1983-04-30 1984-10-31 Westfalia Separator Ag, 4740 Oelde Oeldosiervorrichtung fuer vakuumpumpen von melkanlagen
US4483667A (en) * 1981-12-17 1984-11-20 Leybold-Heraeus Gmbh Vacuum pump and method of operating the same
US4525129A (en) * 1981-12-17 1985-06-25 Leybold-Heraeus Gmbh Oil-sealed vacuum pump
US4697994A (en) * 1983-12-28 1987-10-06 Seiko Seiki Kabushiki Kaisha Multistage discharge type rotary vacuum pump
US5066202A (en) * 1989-06-06 1991-11-19 Leybold Aktiengesellschaft Method and apparatus for delivering oil to a multi-stage pump
US5181414A (en) * 1990-08-28 1993-01-26 Alcatel Cit Pumping apparatus for pumping a gas by means of an oil-sealed vane pump and application to helium leak detectors
US5871338A (en) * 1993-07-28 1999-02-16 Leybold Aktiengesellschaft Vacuum pump with a gas ballast device
US6149414A (en) * 1995-07-19 2000-11-21 Leybold Vakuum Gmbh Oil-sealed vane-type rotary vacuum pump with an oil pump
DE102006016241A1 (de) * 2006-03-31 2007-10-04 Joma-Hydromechanic Gmbh Rotorpumpe
US20100239440A1 (en) * 2006-04-10 2010-09-23 Wabco Automotive Uk Limited Vacuum Pump
US20170122321A1 (en) * 2014-06-27 2017-05-04 Ateliers Busch Sa Method of Pumping in a System of Vacuum Pumps and System of Vacuum Pumps
US9683570B2 (en) 2011-08-17 2017-06-20 Wabco Automotive Uk Limited Vacuum pump
US20180180045A1 (en) * 2015-08-21 2018-06-28 Magna Powertrain Bad Homburg GmbH Pump and system for supplying a consumer
US20190186303A1 (en) * 2017-12-20 2019-06-20 Joma-Polytec Gmbh Oil supply device for a vacuum pump of an internal combustion engine
DE102006058837B4 (de) * 2006-12-13 2020-03-05 Pfeiffer Vacuum Gmbh Schmiermittelgedichtete Drehschiebervakuumpumpe
US10995757B2 (en) * 2016-06-22 2021-05-04 Pierburg Pump Technology Gmbh Dry-running gas vane pump having a first fluid outlet and a second fluid outlet associated with the pump chamber with the second fluid outlet permanently open to atmosphere without being impeded
US11203330B2 (en) * 2015-10-13 2021-12-21 Robert Bosch Gmbh Hydraulic unit
US20220128051A1 (en) * 2020-10-23 2022-04-28 Hamilton Sundstrand Corporation Dual vane pump with pre-pressurization passages

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ZA883753B (en) * 1987-06-18 1989-03-29 Bethlehem Steel Corp Process for chemical stabilization of heavy metal bearing dusts and sludge,such as eaf dust
DE4325283A1 (de) * 1993-07-28 1995-02-02 Leybold Ag Betriebsabhängig steuerbares Ventilsystem für eine Vakuumpumpe
DE102008017955A1 (de) * 2008-04-09 2009-10-15 Oerlikon Leybold Vacuum Gmbh Fluidgedichtete oder fluidgeschmierte Vakuum-Pumpe

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US846933A (en) * 1904-05-20 1907-03-12 Moore Electrical Co Rotary vacuum-pump.
US2126553A (en) * 1938-08-09 Vacuum pump
DE687116C (de) * 1937-10-19 1940-01-23 Harry Sauveur Dipl Ing Einrichtung zur Entlastung der zur Abdichtung dienenden Biegehaeute an stopfbuchsenlosen Pumpen oder Antriebsmaschinen
US2215256A (en) * 1938-05-06 1940-09-17 Kinney Mfg Company High vacuum pump apparatus
US3233651A (en) * 1962-05-28 1966-02-08 Holley Carburetor Co Fluid metering system
US3265295A (en) * 1964-07-31 1966-08-09 New York Air Brake Co Pump

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2126553A (en) * 1938-08-09 Vacuum pump
US846933A (en) * 1904-05-20 1907-03-12 Moore Electrical Co Rotary vacuum-pump.
DE687116C (de) * 1937-10-19 1940-01-23 Harry Sauveur Dipl Ing Einrichtung zur Entlastung der zur Abdichtung dienenden Biegehaeute an stopfbuchsenlosen Pumpen oder Antriebsmaschinen
US2215256A (en) * 1938-05-06 1940-09-17 Kinney Mfg Company High vacuum pump apparatus
US3233651A (en) * 1962-05-28 1966-02-08 Holley Carburetor Co Fluid metering system
US3265295A (en) * 1964-07-31 1966-08-09 New York Air Brake Co Pump

Cited By (26)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4054401A (en) * 1976-01-16 1977-10-18 Central Scientific Company, Inc. Vacuum pump with lubricant control system to interrupt lubricant flow upon loss of pump pressure
US4407641A (en) * 1980-07-23 1983-10-04 Societe Anonyme Dite: Compagnie Industrielle Des Telecommunications Cit-Alcatel Electrically-driven rotary vane pump
US4483667A (en) * 1981-12-17 1984-11-20 Leybold-Heraeus Gmbh Vacuum pump and method of operating the same
US4525129A (en) * 1981-12-17 1985-06-25 Leybold-Heraeus Gmbh Oil-sealed vacuum pump
DE3315748A1 (de) * 1983-04-30 1984-10-31 Westfalia Separator Ag, 4740 Oelde Oeldosiervorrichtung fuer vakuumpumpen von melkanlagen
US4697994A (en) * 1983-12-28 1987-10-06 Seiko Seiki Kabushiki Kaisha Multistage discharge type rotary vacuum pump
US5066202A (en) * 1989-06-06 1991-11-19 Leybold Aktiengesellschaft Method and apparatus for delivering oil to a multi-stage pump
US5181414A (en) * 1990-08-28 1993-01-26 Alcatel Cit Pumping apparatus for pumping a gas by means of an oil-sealed vane pump and application to helium leak detectors
US5871338A (en) * 1993-07-28 1999-02-16 Leybold Aktiengesellschaft Vacuum pump with a gas ballast device
US6149414A (en) * 1995-07-19 2000-11-21 Leybold Vakuum Gmbh Oil-sealed vane-type rotary vacuum pump with an oil pump
DE102006016241A1 (de) * 2006-03-31 2007-10-04 Joma-Hydromechanic Gmbh Rotorpumpe
US8628317B2 (en) * 2006-04-10 2014-01-14 Wabco Automotive Uk Limited Vacuum pump with an axial oil feed conduit
US20100239440A1 (en) * 2006-04-10 2010-09-23 Wabco Automotive Uk Limited Vacuum Pump
DE102006058837C5 (de) 2006-12-13 2022-05-05 Pfeiffer Vacuum Gmbh Schmiermittelgedichtete Drehschiebervakuumpumpe
DE102006058837B4 (de) * 2006-12-13 2020-03-05 Pfeiffer Vacuum Gmbh Schmiermittelgedichtete Drehschiebervakuumpumpe
US9683570B2 (en) 2011-08-17 2017-06-20 Wabco Automotive Uk Limited Vacuum pump
US10371148B2 (en) 2011-08-17 2019-08-06 Wabco Automotive Uk Limited Vacuum pump
US10760573B2 (en) * 2014-06-27 2020-09-01 Ateliers Busch Sa Method of pumping in a system of vacuum pumps and system of vacuum pumps
US20170122321A1 (en) * 2014-06-27 2017-05-04 Ateliers Busch Sa Method of Pumping in a System of Vacuum Pumps and System of Vacuum Pumps
US20180180045A1 (en) * 2015-08-21 2018-06-28 Magna Powertrain Bad Homburg GmbH Pump and system for supplying a consumer
US11098714B2 (en) * 2015-08-21 2021-08-24 Hanon Systems Efp Deutschland Gmbh Pump and system for supplying a consumer
US11203330B2 (en) * 2015-10-13 2021-12-21 Robert Bosch Gmbh Hydraulic unit
US10995757B2 (en) * 2016-06-22 2021-05-04 Pierburg Pump Technology Gmbh Dry-running gas vane pump having a first fluid outlet and a second fluid outlet associated with the pump chamber with the second fluid outlet permanently open to atmosphere without being impeded
US20190186303A1 (en) * 2017-12-20 2019-06-20 Joma-Polytec Gmbh Oil supply device for a vacuum pump of an internal combustion engine
US20220128051A1 (en) * 2020-10-23 2022-04-28 Hamilton Sundstrand Corporation Dual vane pump with pre-pressurization passages
US11519407B2 (en) * 2020-10-23 2022-12-06 Hamilton Sundstrand Corporation Dual vane pump with pre-pressurization passages

Also Published As

Publication number Publication date
DE2028603A1 (es) 1970-12-23
GB1303430A (es) 1973-01-17
FR2051122A5 (es) 1971-04-02

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