EP0072275A1 - Diaphragm pump for a vacuum free of oil - Google Patents

Diaphragm pump for a vacuum free of oil Download PDF

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Publication number
EP0072275A1
EP0072275A1 EP82401332A EP82401332A EP0072275A1 EP 0072275 A1 EP0072275 A1 EP 0072275A1 EP 82401332 A EP82401332 A EP 82401332A EP 82401332 A EP82401332 A EP 82401332A EP 0072275 A1 EP0072275 A1 EP 0072275A1
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EP
European Patent Office
Prior art keywords
membrane
pump
vacuum
discharge
chamber
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EP82401332A
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German (de)
French (fr)
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EP0072275B1 (en
Inventor
Robert Evrard
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Individual
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Individual
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Priority to AT82401332T priority Critical patent/ATE26870T1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B45/00—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids
    • F04B45/06—Pumps or pumping installations having flexible working members and specially adapted for elastic fluids having tubular flexible members
    • F04B45/073—Pumps having fluid drive
    • F04B45/0736—Pumps having fluid drive the actuating fluid being controlled by one or more valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B37/00—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00
    • F04B37/10—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use
    • F04B37/14—Pumps having pertinent characteristics not provided for in, or of interest apart from, groups F04B25/00 - F04B35/00 for special use to obtain high vacuum

Definitions

  • the present invention relates to a dry membrane vacuum pump, more particularly intended to constitute at least one stage of a vacuum pump for obtaining a vacuum free of oil contamination.
  • the only "clean" mechanical pumps in use are diaphragm pumps. Their limit vacuum in single-stage systems is of the order of at least 10 4 Pascals. This relatively high limit is due, among other things, to the use of valves. In particular, the conductance of an intake valve decreases with the pressure of the vacuum system and tends towards zero. The valves are also generating what is called a "dead volume"; at the end of each cycle, a small volume of pumped gas is trapped at the discharge pressure and returns to the emptied enclosure. Finally, the movement of the membrane is obtained by rigid coupling with a mechanical device. The flexibility of the membrane is thus considerably reduced, which further increases the dead volume. But above all the discharge conductance for the parts remote from the discharge valve becomes very low. A certain quantity of gas is then trapped at high pressure, deforming the membrane and considerably increasing the dead volume.
  • the subject of the present invention is a means of obtaining a "clean" primary vacuum with a diaphragm pump, corresponding to a much lower limit pressure than that obtained with existing devices.
  • the discharge orifices communicate via the in. valve intermediate with a capacity maintained at a pressure below atmospheric pressure by an auxiliary vacuum pump; on the other hand it includes a distribution mechanism for alternately communicating the control chamber with the atmosphere and with the suction of an auxiliary vacuum pump.
  • the same auxiliary vacuum pump is used both to maintain a vacuum downstream of the discharge valve, and to create the vacuum applied cyclically to the control chamber.
  • the auxiliary vacuum pump intended to create a vacuum in the control chamber is constituted by a second waterproof elastic membrane surrounding the second body, between the second body and the first membrane; on the other hand the pump includes a distribution mechanism for communicating the space between the second body and the second membrane alternately with the atmosphere and with a distribution of compressed air, with means for making the phase coincide compressed air supply with the venting phase of the control chamber and vice versa.
  • the pump is constituted by a first hollow rigid body 1 whose inner wall is in the form of two trunks of cones joined by their bases.
  • the body 1 has a suction orifice 2 in an end region with a small internal diameter, while the discharge orifice 3 is located in the central part with a large internal diameter.
  • the suction port 2 is connected by a tube 4 to the enclosure 5 in which we want to create a vacuum.
  • the discharge orifice 3 is provided with a valve 7 constituted by a simple elastic sheet, one end of which is fixed at 8 to the body 1, while its other end is free to press against the body or to move away from it according to pressure variations on either side of the body.
  • the valve 7 is inside a small delivery chamber 9 provided with a nozzle 10.
  • the center of the hollow body 1 is occupied by a cylindrical body 11 covered with a waterproof tubular elastic membrane 12, for example in a product sold under the trademark "NEOPRENE".
  • the natural internal diameter of the membrane 12 is less than the external diameter of the body 11, so that it is applied under tension against the body 11.
  • the membrane 12 is distended at each end to enclose an outer flange 13; each flange 13, by tightening the screws 14 engaged on the body 11, tightly blocks each end of the membrane 12 on the end faces of the body 1.
  • the chamber 15 between the membrane 12 and the body 1 constitutes the actual pumping chamber, where both the suction and discharge orifices 2 and 3 open.
  • the chamber 16 between the membrane 12 and the body 11, constitutes the control chamber under the action of a distribution system to which it is connected by the conduit 17.
  • the chamber 16 is in made cut into two parts, each at one end of the body 11, but connected by the balancing duct 18.
  • the conduit 17, via the T-conduit 19, is connected to two two-way solenoid valves 20 and 21.
  • the other path of the solenoid valve 20 communicates directly with the atmosphere.
  • the other path of the solenoid valve 21 is connected by the conduit 22 to an auxiliary vacuum pump 23.
  • a tube 24 connects the nozzle 10 of the discharge chamber 9 to a nozzle 25 on the conduit 22, in the vicinity of the solenoid valve 21.
  • the type and connection of electrical supply of the coils of the solenoid valves 20 and 21 are such that they operate in opposition, that is to say that one is necessarily open while the other is closed, and vice versa.
  • the solenoid valve 20 is normally closed and the solenoid valve 21 normally open, and the two coils are supplied in parallel from a line 26, by means of an oscillating relay 27 which cyclically energizes and cuts the power to the two coils.
  • the first phase of evacuating the enclosure 5 can be ensured by the conventional auxiliary pump 23.
  • the solenoid valves 20 and 21 are de-energized with the oscillating relay 27 in the rest position as shown in FIG. 1.
  • the pump 23 sucks then directly into the enclosure 5 through the tube 4, the orifice 2, the chamber 15, the orifice 3, the valve 7 open, and the tube 24; at the same time it maintains the chamber 16 in depression, which allows the membrane 12 to remain pressed against the body 11 by its own elasticity.
  • the pump according to the invention is actuated by activating the relay 27.
  • the relay switches to take the position shown in FIG. 2 the coils of the solenoid valves 20 and 21 are powered; 21 is closed and 20 open.
  • the atmospheric pressure is then established in the chamber 16 and the membrane 12 is inflated from the inside to come to be pressed against the internal biconical face of the body 1.
  • the membrane firstly closes the suction orifice 2 , then the progressive reduction in volume of the chamber 16 flushes out by compressing the gas it contained towards the discharge orifice 3.
  • the combined action of the compression upstream of the valve 7 and of the vacuum maintained continuously in downstream by the auxiliai pump re 23 is sufficient to lift the valve and expel the gas towards the pipe 24.
  • the valve 6, although constituted by a simple elastic sheet, functions in fact like a complex valve with pneumatic control: at the start of the intake phase the solenoid valve 21 opens and the air return solenoid valve 20 closes. The air accumulated in the chamber 16 under the membrane 12 spreads in the auxiliary circuit 22-24 and the pressure downstream of the discharge valve 7 rises suddenly. This valve is thus pressed energetically on its seat and the "return flow” is practically canceled in the critical intake phase. The downstream pressure, continuously pumped by the auxiliary pump 23 will then decrease continuously.
  • the air re-entry valve 20 opens while the valve 21 closes to isolate the auxiliary pumping circuit downstream from the valve.
  • the pressure in the discharge chamber 9 therefore continues to decrease during compression in the chamber 15 and the gas can be easily evacuated through the valve 7 made soft by a minimum plating force.
  • This optimization of the operation of the discharge valve eliminates the drawbacks of "stiff" discharge valves as they exist in conventional devices.
  • the membrane 12 may have a smaller thickness at the ends.
  • the inlet 2 is closed off at an earlier point in the compression phase.
  • the tubular membrane 12 with a diameter less than the outside diameter of the cylinder 11 is here still taut. It therefore retracts for a reasonable vacuum between it and the cylinder 11, even if the vacuum between it and the body 1 is already very high.
  • the symmetrical shape of 1, with the discharge opening in the center ensures that at the end of compression the residual discharge cavity is exactly opposite the corresponding opening 3. The real "dead volume" is thus reduced to a minimum.
  • the rate of pressure increase in the chamber 15, between the suction position of Figure 1 and the discharge position of Figure 2 is of the order of at least 500.
  • the new pump could thus play the role of a "boost pump”. Its coupling with existing coarse vacuum dry pumps transforms them into high performance pumps and divides the limit vacuum by a factor of at least 500.
  • the pumping speed depends essentially on the frequency of the intake cycle, ie the pumping speed of the auxiliary pump.
  • the vacuum required for operation is of the order of 2.10 4 Pascals or more, and corresponds to a pressure range where the pumping speed of conventional diaphragm pumps is high.
  • the "boost pump” not only considerably improves the limit pressure, but allows the conventional pump to be used under optimum pressure conditions for pumping speed.
  • FIGS. 3 and 4 show in a simplified manner another device operating purely pneumatically and performing the same functions as the combination of two solenoid valves 20 and 21.
  • the device which constitutes a vacuum dynamometer with piston and return spring, comprises a tubular body in bronze 30, closed by two bottoms 31 and 32.
  • a piston 33 slides freely in the bore of the body 30, which it seals in two chambers 34 and 35.
  • the piston 33 is returned by a tension spring 36 until 'in a position in abutment on a shoulder 37.
  • the conduit 17 of the chamber 16 is connected by a U-shaped conduit 39 to the inner chamber 34 of the body 30.
  • a conduit 40 connected to the conduit 22 for connection with the auxiliary pump 23.
  • An orifice 41 also opens facing the other branch of the conduit 39 to communicate the chamber 34 with the outside.
  • the bottom 31 has an exhaust valve 43 and a calibrated orifice 44 between the chamber 35 and the outside.
  • the internal bent conduit 45 opens onto the lateral face of the piston 33, a usual guide not shown being provided to prevent the latter from rotating during its longitudinal stroke, so that the lateral outlet of the conduit 45 passes in front of the branches of the conduit 39.
  • the device is equivalent to the two solenoid valves 20 and 21 in their positions in FIG. 1.
  • the chamber 16 communicates with the auxiliary pump via 17, 39, 34 40 and 22, while communication with the atmosphere is cut off by the piston 33 which closes the orifice 41.
  • the vacuum generated in the chamber 34 causes the piston 33 to be sucked to the left, against the return action of the spring 36. But this movement is slowed down by the calibrated orifice 44 which lets the air penetrate only very gradually into the chamber 35.
  • the piston cuts the communication with the atmosphere of the chamber 16 and re-establishes the vacuum therein of the pump 23, which corresponds to a new suction cycle.
  • FIGS. 5 and 6 for an alternative embodiment with an integrated control auxiliary pump.
  • the general geometry is the same, but the central cylindrical body 11 is surrounded by another thick waterproof elastic membrane 50, of tubular and tight shape hermetically by its ends on the body 11 by means of collars 51.
  • the conduit 54 is in communication with the atmosphere.
  • the solenoid valve communicates the conduit 54 with the conduit 57 connected to a compressed air distribution 58, autonomous compressor or distribution network.
  • the electrical supply connection of the solenoid valves 20 and 55 is such that when the valve 20 is closed the valve 55 puts the conduit 54 into the atmosphere, and when the valve 20 is open the valve 55 supplies the conduit 54 and the chamber 52 in compressed air.
  • the coils of the solenoid valves 20 and 55 are supplied in parallel from a line 26, by means of an oscillating relay 27 which cyclically energizes and cuts the supply of the two coils.
  • the delivery chamber 9 downstream from the valve 7 is maintained in permanent vacuum; this is achieved here by connecting its nozzle 10 to a compressed air ejector 60.
  • the atmospheric pressure established by the opening of the valve 20 in the chamber 16 delivers the membrane 12 to the internal face of the body 1.
  • the compressed air brought into the chamber 52 by the valve 55 inflates the membrane 50 which comes into contact with the membrane 12 and minimizes the volume of the chamber 16.
  • the depression in the chamber 16 in turn allows the membrane 12 to retract towards the membrane 50 and the body 11, which causes a strong depression in the pumping chamber 15 and the suction as soon as the orifice 2 is uncovered .
  • the internal membrane 50 and its inflating operation with compressed air or deflating plays the same role as the auxiliary pump 23 of the first variant to create the vacuum under the main membrane 12 during the suction phase.
  • the vacuum chamber 9 is kept under vacuum by the independent ejector 60.
  • the pumping speed depends essentially on the flow rate of the supply circuit used.
  • the intake volume is much greater than in mechanically coupled diaphragm pumps and the pumping speed can be increased considerably.

Abstract

Dry vacuum diaphragm pump, for pumping between an inlet port (2) and an exhaust port (3), and comprising a tubular diaphragm (12) retained by its resilience on a central body (11) in the biconical interior volume of a body (1), in such manner as to form a pumping chamber (15) into which debouch inlet and exhaust ports, and a control chamber (16). Port (3) communicates through a valve (7) with a capacity (9) maintained under partial vacuum by an auxiliary vacuum pump (23). The distribution mechanism (20, 21, 27) places the chamber (16) in communication alternatively with atmosphere and with the intake of the auxiliary pump (23).

Description

La présente invention concerne une pompe à vide sèche à membrane, plus particulièrement destinée à constituer au moins un étage d'une pompe à vide pour l'obtention d'un vide exempt de contamination d'huile.The present invention relates to a dry membrane vacuum pump, more particularly intended to constitute at least one stage of a vacuum pump for obtaining a vacuum free of oil contamination.

Pour beaucoup d'applications de la technique du vide, l'obtention d'un vide "propre", sans contamination d'huile, est un besoin essentiel. C'est ainsi que les pompes à diffusion d'huile sont de plus en plus souvent remplacées par des pompes ioniques, cryogéniques, etc .... Malheureusement ces pompes modernes ne peuvent être mises en oeuvre que si l'on a œjà obtenu une pression "primaire" de l'ordre de 1 Pascal ou moins. Ce vide primaire doit bien entendu être propre lui aussi. Dans l'état actuel de la technique ce résultat ne peut être obtenu que par des pompes à sorption, refroidies à l'azote liquide, avec tous les inconvénients que cela comporte.For many applications of the vacuum technique, obtaining a "clean" vacuum, without oil contamination, is an essential need. This is how oil diffusion pumps are more and more often replaced by ionic, cryogenic, etc. pumps. Unfortunately, these modern pumps can only be implemented if one has already obtained a "primary" pressure of the order of 1 Pascal or less. This primary vacuum must of course be clean too. In the current state of the art, this result can only be obtained by sorption pumps, cooled with liquid nitrogen, with all the disadvantages that this entails.

Les seules pompes mécaniques "propres"en usage sont les pompes à membrane. Leur vide limite dans les systèmes à un étage est de l'ordre de quelques 104 Pascals au moins. Cette limite relativement élevée est due, entre autres choses, à l'usage de soupapes. En particulier la conductance d'une soupape d'admission diminue avec la pression du système à vide et tend vers zéro. Les soupapes sont d'autre part génératrices de ce que l'on appelle un "volume mort" ; à la fin de chaque cycle, un petit volume de gaz pompé est emprisonné à la pression de refoulement et retourne dans l'enceinte vidée. Enfin, le mouvement de la membrane est obtenu par couplage rigide avec un dispositif mécanique. La flexibilité de la membrane est ainsi considérablement diminuée, ce qui augmente encore le volume mort. Mais surtout la conductance de refoulement pour les parties éloignées de la soupape de refoulement devient très faible. Une certaine quantité de gaz est alors piégée à haute pression, déformant la membrane et augmentant considérablement le volume mort.The only "clean" mechanical pumps in use are diaphragm pumps. Their limit vacuum in single-stage systems is of the order of at least 10 4 Pascals. This relatively high limit is due, among other things, to the use of valves. In particular, the conductance of an intake valve decreases with the pressure of the vacuum system and tends towards zero. The valves are also generating what is called a "dead volume"; at the end of each cycle, a small volume of pumped gas is trapped at the discharge pressure and returns to the emptied enclosure. Finally, the movement of the membrane is obtained by rigid coupling with a mechanical device. The flexibility of the membrane is thus considerably reduced, which further increases the dead volume. But above all the discharge conductance for the parts remote from the discharge valve becomes very low. A certain quantity of gas is then trapped at high pressure, deforming the membrane and considerably increasing the dead volume.

La présente invention a pour objet un moyen d'obtenir avec une pompe à membrane un vide primaire "propre", correspondant à une pression limite bien plus basse que celle obtenue avec les dispositifs existants.The subject of the present invention is a means of obtaining a "clean" primary vacuum with a diaphragm pump, corresponding to a much lower limit pressure than that obtained with existing devices.

L'invention concerne donc une pompe à vide sèche à membrane pour transférer un gaz d'au moins un orifice d'aspiration à au moins un orifice de refoulement, constituée par une membrane élastique tendue entre un premier et un deuxième corps rigides, de telle sorte que le volume entre la membrane et le premier corps rigide constitue une chambre de pompage où débouchent les oriices d'aspiration et les orifices de refoulement, et que le volume de l'autre côté de la membrane constitue une chambre de commande pour manoeuvrer la membrane en yiaisant varier cycliquement la pression pour engendrer alternativement :

  • a) un mouvement de refoulement en plaquant la membrane progressivement contre le premier corps rigide, obturant ainsi d'abord les orifices d'admission et refoulant ensuite le gaz vers les orifices de refoulement,
  • b) un mouvement d'aspiration en ramenant la membrane vers le deuxième corps rigide, entrainant d'abord la fermeture des soupapes de refoulement et dégageant ensuite les orifices d'admission.
The invention therefore relates to a dry membrane vacuum pump for transferring a gas from at least one suction orifice to at least one discharge orifice, constituted by an elastic membrane stretched between a first and a second rigid body, such so that the volume between the membrane and the first rigid body constitutes a pumping chamber where outlet the suction ports and the discharge ports, and that the volume on the other side of the membrane constitutes a control chamber for operating the membrane by varying the pressure cyclically therein to generate alternately:
  • a) a discharge movement by pressing the membrane progressively against the first rigid body, thereby first blocking the intake orifices and then discharging the gas towards the discharge orifices,
  • b) a suction movement by bringing the membrane towards the second rigid body, first causing the closing of the discharge valves and then releasing the intake orifices.

Selon l'invention les orifices de refoulement communiquent par l'in. termédiaire de soupapes avec une capacité maintenue à une pression inférieure à la pression atmosphérique par une pompe à vide auxiliaire ; d'autre part elle comporte un mécanisme de distribution pour faire alternativement communiquer la chambre de commande avec l'atmosphère et avec l'aspiration d'une pompe à vide auxiliaire.According to the invention, the discharge orifices communicate via the in. valve intermediate with a capacity maintained at a pressure below atmospheric pressure by an auxiliary vacuum pump; on the other hand it includes a distribution mechanism for alternately communicating the control chamber with the atmosphere and with the suction of an auxiliary vacuum pump.

Selon une forme particulière de réalisation de l'invention,

  • - la surface interne du premier corps rigide a la forme de deux troncs de cônes accolés par leurs bases, les orifices de refoulement étant disposés dans la zone médiane de plus fort diamètre et les orifices d'aspiration dans les zones d'extrémité de plus faible diamètre,
  • - le deuxième corps est coaxial au premier,
  • - la membrane élastique est de forme tubulaire de diamètre naturel inférieur au diamètre extérieur du deuxième corps, et est fixée de façon étanche par ses extrémités aux extrémités du premier corps.
According to a particular embodiment of the invention,
  • - the internal surface of the first rigid body has the form of two trunks of cones joined by their bases, the delivery orifices being arranged in the middle zone of larger diameter and the suction orifices in the end zones of smaller diameter,
  • - the second body is coaxial with the first,
  • - The elastic membrane is of tubular shape with a natural diameter less than the outside diameter of the second body, and is fixed in leaktight manner at its ends to the ends of the first body.

Selon une variante de réalisation, la même pompe à vide auxiliaire est utilisée à la fois pour entretenir une dépression en aval de la soupape de refoulement, et pour créer la dépression appliquée cycliquement à la chambre de commande.According to an alternative embodiment, the same auxiliary vacuum pump is used both to maintain a vacuum downstream of the discharge valve, and to create the vacuum applied cyclically to the control chamber.

Selon une autre variante de réalisation, la pompe à vide auxiliaire destinée à créer une dépression dans la chambre de commande est constituée par une deuxième membrane élastique étanche entourant le deuxième corps, entre le deuxième corps et la première membrane; d'autre part la pompe comporte un mécanisme de distribution pour faire communiquer l'espace compris entre le deuxième corps et la deuxième membrane alternativement avec l'atmosphère et avec une distribution d'air comprimé, avec des moyens pour faire coïncider la phase d'alimentation en air comprimé avec la phase de mise à l'atmosphère de la chambre de commande et inversement.According to another alternative embodiment, the auxiliary vacuum pump intended to create a vacuum in the control chamber is constituted by a second waterproof elastic membrane surrounding the second body, between the second body and the first membrane; on the other hand the pump includes a distribution mechanism for communicating the space between the second body and the second membrane alternately with the atmosphere and with a distribution of compressed air, with means for making the phase coincide compressed air supply with the venting phase of the control chamber and vice versa.

L'invention sera meixu comprise en se référant à des modes particuliers de réalisation, donnés à titre d'exemple et représentés par les dessins annexés.The invention will be understood more fully with reference to particular embodiments, given by way of example and represented by the accompanying drawings.

  • Les figures 1 et 2 représentent de façon simplifiée, et en coupe longitudinale, une pompe réalisée selon l'invention munie d'une pompe à vide auxiliaire extérieure. La figure 1 montre la pompe en fin de phase d'aspiration ; la figure 2 en fin de phase de refoulement.Figures 1 and 2 show in simplified manner, and in longitudinal section, a pump produced according to the invention provided with an external auxiliary vacuum pump. Figure 1 shows the pump at the end of the suction phase; Figure 2 at the end of the delivery phase.
  • Les figures 3 et 4 représentent une variante de réalisation du mécanisme de distribution, appliqué à la pompe des figures 1 et 2, respectivement en position de commande d'aspiration et de refoulement.Figures 3 and 4 show an alternative embodiment of the dispensing mechanism, applied to the pump of Figures 1 and 2, respectively in the suction and discharge control position.
  • Les figures 5 et 6 représentent dans les mêmes conditions qu'aux figures 1 et 2, respectivement en fin d'aspiration et en fin de refoulement, une variante de réalisation à pompe auxiliaire de commande intégrée.Figures 5 and 6 show in the same conditions as in Figures 1 and 2, respectively at the end of suction and at the end of delivery, an alternative embodiment with an integrated control auxiliary pump.

En se référant tout d'abord aux figures 1 et 2 on verra que la pompe est constituée par un premier corps rigide creux 1 dont la paroi intérieure est en forme de deux troncs de cônes accolés par leurs bases. Le corps 1 comporte un orifice d'aspiration 2 dans une zone d'extrémité de faible diamètre intérieur, tandis que l'orifice de refoulement 3 est situé dans la partie centrale de plus fort diamètre intérieur. L'orifice d'aspiration 2 est relié par une tubulure 4 à l'enceinte 5 dans laquelle on veut faire le vide. L'orifice de refoulement 3 est muni d'une soupape 7 constituée par une simple feuille élastique dont une extrémité est fixée en 8 au corps 1, tandis que son autre extrémité est libre de se plaquer contre le corps ou de s'en écarter selon les variations de pression de part et d'autre du corps. La soupape 7 est à l'intérieur d'une petite chambre de refoulement 9 munie d'un ajutage 10.By first referring to Figures 1 and 2 we will see that the pump is constituted by a first hollow rigid body 1 whose inner wall is in the form of two trunks of cones joined by their bases. The body 1 has a suction orifice 2 in an end region with a small internal diameter, while the discharge orifice 3 is located in the central part with a large internal diameter. The suction port 2 is connected by a tube 4 to the enclosure 5 in which we want to create a vacuum. The discharge orifice 3 is provided with a valve 7 constituted by a simple elastic sheet, one end of which is fixed at 8 to the body 1, while its other end is free to press against the body or to move away from it according to pressure variations on either side of the body. The valve 7 is inside a small delivery chamber 9 provided with a nozzle 10.

Le centre du corps creux 1 est occupé par un corps cylindrique 11 recouvert d'une membrane élastique tubulaire étanche 12, par exemple en un produit vendu sous la marque commerciale "NEOPRENE". Le diamètre intérieur naturel de la membrane 12 est inférieur au diamètre extérieur du corps 11, si bien qu'elle s'applique sous tension contre le corps 11.The center of the hollow body 1 is occupied by a cylindrical body 11 covered with a waterproof tubular elastic membrane 12, for example in a product sold under the trademark "NEOPRENE". The natural internal diameter of the membrane 12 is less than the external diameter of the body 11, so that it is applied under tension against the body 11.

La membrane 12 est distendue à chaque extrémité pour enserrer un flasque extérieur 13 ; chaque flasque 13, par serrage des vis 14 engagées sur le corps 11, bloque de façon étanche chaque extrémité de la membrane 12 sur les faces d'extrémité du corps 1. On obtient ainsi deux chambres intérieures. La chambre 15 entre la membrane 12 et le corps 1 constitue la chambre de pompage proprement dite, où débouchent à la fois les orifices d'aspiration et de refoulement 2 et 3. La chambre 16 entre la membrane 12 et le corps 11, constitue la chambre de commande sous l'action d'un système de distribution auquel elle est reliée par le conduit 17. Lorsque, comme sur la figure 1, la membrane 12 est plaquée sur le corps 11, la chambre 16 est en fait coupée en deux parties, chacune à une extrémité du corps 11, mais reliées par le conduit d'équilibrage 18.The membrane 12 is distended at each end to enclose an outer flange 13; each flange 13, by tightening the screws 14 engaged on the body 11, tightly blocks each end of the membrane 12 on the end faces of the body 1. This gives two interior chambers. The chamber 15 between the membrane 12 and the body 1 constitutes the actual pumping chamber, where both the suction and discharge orifices 2 and 3 open. The chamber 16 between the membrane 12 and the body 11, constitutes the control chamber under the action of a distribution system to which it is connected by the conduit 17. When, as in FIG. 1, the membrane 12 is pressed against the body 11, the chamber 16 is in made cut into two parts, each at one end of the body 11, but connected by the balancing duct 18.

Le conduit 17, par le conduit en T 19, est relié à deux électrovannes à deux voies 20 et 21. L'autre voie de l'électrovanne 20 communique directement avec l'atmosphère. L'autre voie de l'électrovanne 21 est reliée par le conduit 22 à une pompe à vide auxiliaire 23. Une tubulure 24 relie l'ajutage 10 de la chambre de refoulement 9 à un piquage 25 sur le conduit 22, au voisinage de l'électrovanne 21.The conduit 17, via the T-conduit 19, is connected to two two-way solenoid valves 20 and 21. The other path of the solenoid valve 20 communicates directly with the atmosphere. The other path of the solenoid valve 21 is connected by the conduit 22 to an auxiliary vacuum pump 23. A tube 24 connects the nozzle 10 of the discharge chamber 9 to a nozzle 25 on the conduit 22, in the vicinity of the solenoid valve 21.

Le type et le branchement d'alimentation électrique des bobines des électrovannes 20 et 21 sont tels qu'elles fonctionnent en opposition, c'est-à-dire que l'une est nécessairement ouverte pendant que l'autre est fermée, et inversement. Dans l'exemple représenté aux figures 1 et 2, l'électrovanne 20 est normalement fermée et l'électrovanne 21 normalement ouverte, et les deux bobines sont alimentées en parallèle à partir d'une ligne 26, au moyen d'un relais oscillant 27 qui cycliquement met sous tension et coupe l'alimentation des deux bobines.The type and connection of electrical supply of the coils of the solenoid valves 20 and 21 are such that they operate in opposition, that is to say that one is necessarily open while the other is closed, and vice versa. In the example shown in Figures 1 and 2, the solenoid valve 20 is normally closed and the solenoid valve 21 normally open, and the two coils are supplied in parallel from a line 26, by means of an oscillating relay 27 which cyclically energizes and cuts the power to the two coils.

La première phase de mise sous vide de l'enceinte 5 peut être assurée par la pompe auxiliaire classique 23. Les électrovannes 20 et 21 sont hors tension avec le relais oscillant 27 en position de repos comme représenté à la figure 1. La pompe 23 aspire alors directement dans l'enceinte 5 par la tubulure 4, l'orifice 2, la chambre 15, l'orifice 3, la soupape 7 ouverte, et la tubulure 24 ; en même temps elle maintient en dépression la chambre 16, ce qui permet à la membrane 12 de rester plaquée sur le corps 11 par son élasticité propre.The first phase of evacuating the enclosure 5 can be ensured by the conventional auxiliary pump 23. The solenoid valves 20 and 21 are de-energized with the oscillating relay 27 in the rest position as shown in FIG. 1. The pump 23 sucks then directly into the enclosure 5 through the tube 4, the orifice 2, the chamber 15, the orifice 3, the valve 7 open, and the tube 24; at the same time it maintains the chamber 16 in depression, which allows the membrane 12 to remain pressed against the body 11 by its own elasticity.

Lorsque le vide atteint la limite pratique de 1 à 2.104 Pascals on met en action la pompe selon l'invention en mettant en action le relais 27. Lorsque le relais bascule pour prendre la position représentée à la figure 2 les bobines des électrovannes 20 et 21 sont alimentées ; 21 est fermée et 20 ouverte. La pression atmosphérique s'établit alors dans la chambre 16 et la membrane 12 est gonflée de l'intérieur pour venir se plaquer sur la face interne biconique du corps 1. Dans ce mouvement la membrane ferme d'abord l'orifice d'aspiration 2, puis la réduction progressive de volume de la chambre 16 chasse en le comprimant le gaz qu'elle contenait vers l'orifice de refoulement 3. L'action conjuguée de la compression en amont de la soupape 7 et de la dépression entretenue en permanence en aval par la pompe auxiliaire 23 suffit pour soulever la soupape et chasser le gaz vers la tubulure 24.When the vacuum reaches the practical limit of 1 to 2.10 4 Pascals, the pump according to the invention is actuated by activating the relay 27. When the relay switches to take the position shown in FIG. 2 the coils of the solenoid valves 20 and 21 are powered; 21 is closed and 20 open. The atmospheric pressure is then established in the chamber 16 and the membrane 12 is inflated from the inside to come to be pressed against the internal biconical face of the body 1. In this movement the membrane firstly closes the suction orifice 2 , then the progressive reduction in volume of the chamber 16 flushes out by compressing the gas it contained towards the discharge orifice 3. The combined action of the compression upstream of the valve 7 and of the vacuum maintained continuously in downstream by the auxiliai pump re 23 is sufficient to lift the valve and expel the gas towards the pipe 24.

Quand le relais 27 reprend la position de la figure 1, Ta chambre 16 est à nouveau mise en dépression et l'élasticité de la membrane ramène celle-ci au contact du corps central 11. Ce mouvement entraine d'abord la fermeture de la soupape de refoulement 7, puis une très forte dépression dans la chambre de pompage 15 car le conduit d'aspiration reste obturé par la membrane jusqu'à la dernière partie du mouvement de retrait de celle-ci. Lorsque l'orifice 2 est découvert une partie du gaz restant dans l'enceinte 5 est aspiré dans la chambre 15 et une nouvelle phase de refoulement peut commencer par une nouvelle inversion de position du relais 27 et des électrovannes 20 et 21.When the relay 27 returns to the position of FIG. 1, the chamber 16 is again placed under vacuum and the elasticity of the membrane brings it back into contact with the central body 11. This movement firstly causes the valve to close. discharge 7, then a very high vacuum in the pumping chamber 15 because the suction pipe remains closed by the membrane until the last part of the withdrawal movement thereof. When the orifice 2 is discovered, part of the gas remaining in the enclosure 5 is sucked into the chamber 15 and a new delivery phase can begin with a new position reversal of the relay 27 and of the solenoid valves 20 and 21.

On remarquera que dans le système décrit, la soupape 6, bien que constituée par une simple feuille élastique, fonctionne en fait comme une soupape complexe à commande pneumatique : au début de la phase d'admission l'électrovanne 21 s'ouvre et l'électrovanne de rentrée d'air 20 se ferme. L'air accumulé dans la chambre 16 sous la membrane 12 se répand dans le circuit auxiliaire 22-24 et la pression en aval de la soupape de refoulement 7 remonte brusquement. Cette soupape est ainsi plaquée énergiquement sur son siège et le "flux en retour" est pratiquement annulé dans la phase critique d'admission. La pression en aval, continuellement pompée par la pompe auxiliaire 23 va ensuite décroître continuellement. Au début de la phase de compression la vanne de rentrée d'air 20 s'ouvre alors que la vanne 21 se ferme pour isoler le circuit de pompage auxiliaire en aval de la soupape. La pression dans la chambre de refoulement 9 continue donc de décroître pendant la compression dans la chambre 15 et le gaz peut être facilement évacué à travers la soupape 7 rendue molle par une force de plaquage minimale. Cette optimisation du fonctionnement de la soupape de refoulement élimine les inconvénients des soupapes de refoulement "raides" telles qu'elles existent dans les dispositifs classiques.It will be noted that in the system described, the valve 6, although constituted by a simple elastic sheet, functions in fact like a complex valve with pneumatic control: at the start of the intake phase the solenoid valve 21 opens and the air return solenoid valve 20 closes. The air accumulated in the chamber 16 under the membrane 12 spreads in the auxiliary circuit 22-24 and the pressure downstream of the discharge valve 7 rises suddenly. This valve is thus pressed energetically on its seat and the "return flow" is practically canceled in the critical intake phase. The downstream pressure, continuously pumped by the auxiliary pump 23 will then decrease continuously. At the start of the compression phase, the air re-entry valve 20 opens while the valve 21 closes to isolate the auxiliary pumping circuit downstream from the valve. The pressure in the discharge chamber 9 therefore continues to decrease during compression in the chamber 15 and the gas can be easily evacuated through the valve 7 made soft by a minimum plating force. This optimization of the operation of the discharge valve eliminates the drawbacks of "stiff" discharge valves as they exist in conventional devices.

Pour faciliter l'action du flux en retour pour plaquer énergiquement la soupape 7 sur son siège au début de la phase d'admission, on cherchera à créer une forte conductance entre la chambre 9 en aval de la soupape 7 et l'orifice d'aspiration 17 de la chambre de commande 16. Ceci sera réalisé si le piquage 25 sur le conduit 22 est proche de l'électrovanne 21.To facilitate the action of the return flow to forcefully place the valve 7 on its seat at the start of the intake phase, we will seek to create a strong conductance between the chamber 9 downstream of the valve 7 and the orifice. suction 17 of the control chamber 16. This will be achieved if the tap 25 on the duct 22 is close to the solenoid valve 21.

Pour améliorer encore le fonctionnement, la membrane 12 peut avoir une épaisseur plus faible aux extrémités. L'obturation de l'orifice d'admission 2 intervient alors à un instant plus précoce de la phase de compression.To further improve operation, the membrane 12 may have a smaller thickness at the ends. The inlet 2 is closed off at an earlier point in the compression phase.

Le choix de cette géométrie est dicté par les considérations suivantes : la membrane tubulaire 12 de diamètre inférieur au diamètre extérieur du cylindre 11 est ici toujours tendue. Elle se rétracte donc pour une dépression raisonnable entre elle et le cylindre 11, même si le vide entre elle et le corps 1 est déjà très poussé. Par ailleurs, la forme symétrique de 1, avec l'orifice de refoulement au centre, assure qu'en fin de compression la cavité résiduelle de refoulement se trouve exactement en vis à vis de l'orifice correspondant 3. Le 'volume mort" réel est ainsi réduit au minimum.The choice of this geometry is dictated by the following considerations: the tubular membrane 12 with a diameter less than the outside diameter of the cylinder 11 is here still taut. It therefore retracts for a reasonable vacuum between it and the cylinder 11, even if the vacuum between it and the body 1 is already very high. Furthermore, the symmetrical shape of 1, with the discharge opening in the center, ensures that at the end of compression the residual discharge cavity is exactly opposite the corresponding opening 3. The real "dead volume" is thus reduced to a minimum.

Le taux de multiplication de pression dans la chambre 15, entre la position d'aspiration de la figure 1 et la position de refoulement de la figure 2 est de l'ordre de 500 au moins. La nouvelle pompe eut ainsi jouer le rôle d'une "pompe de suralimentation". Son couplage avec les pompes sèches à vide grossier existantes transforme celles-ci en pompes à hautes performances et divise le vide limite par un facteur 500 au moins.The rate of pressure increase in the chamber 15, between the suction position of Figure 1 and the discharge position of Figure 2 is of the order of at least 500. The new pump could thus play the role of a "boost pump". Its coupling with existing coarse vacuum dry pumps transforms them into high performance pumps and divides the limit vacuum by a factor of at least 500.

La vitesse de pompage dépend essentiellement de la fréquence du cycle d'admission, c'est-à-dire de la vitesse de pompage de la pompe auxi- taire. La dépression nécessaire au fonctionnement est de l'ordre de 2.104 Pascals ou plus, et correspond à une gamme de pression où la vitesse de pompage des pompes classiques à membrane est grande.The pumping speed depends essentially on the frequency of the intake cycle, ie the pumping speed of the auxiliary pump. The vacuum required for operation is of the order of 2.10 4 Pascals or more, and corresponds to a pressure range where the pumping speed of conventional diaphragm pumps is high.

La "pompe de suralimentation" améliore non seulement considérablement la pression limite, mais permet d'utiliser la pompe classique dans les conditions de pression optimum pour la vitesse de pompage.The "boost pump" not only considerably improves the limit pressure, but allows the conventional pump to be used under optimum pressure conditions for pumping speed.

Il est clair que les électrovannes pilotées par relais oscillant ne constituent qu'une forme de réalisation parmi d'autres du dispositif de distribution pour faire alternativement communiquer la chambre de commande 16 avec l'atmsophère et avec la pompe auxiliaire 23. Les figures 3 et 4 représentent de façon simplifiée un autre dispositif fonctionnant de façon purement pneumatique et réalisant les mêmes fonctions que l'association de deux électrovannes 20 et 21. Le dispositif, qui constitue un dynamomètre à dépression à piston et ressort de rappel, comporte un corps tubulaire en bronze 30, fermé par deux fonds 31 et 32. Un piston 33 coulisse librement dans l'alésage du corps 30, qu'il sépare de façon étanche en deux chambres 34 et 35. Le piston 33 est rappelé par un ressort de traction 36 jusqu'à une position en butée sur un épaulement 37. Le conduit 17 de la chambre 16 est relié par un conduit en U 39 à la chambre intérieure 34 du corps 30. Dans la chambre 34 et face à une branche du conduit 39, débouche également un conduit 40 raccordé au conduit 22 de liaison avec la pompe auxiliaire 23. Un orifice 41 débouche également face à l'autre branche du conduit 39 pour faire communiquer la chambre 34 avec l'extérieur. Le fond 31 comporte une soupape d'échappement 43 et un orifice calibré 44 entre la chambre 35 et l'extérieur. Enfin, le conduit coudé interne 45 débouche sur la face latérale du piston 33, un guidage usuel non représenté étant prévu pour empêcher celui-ci de tourner pendant sa course longitudinale, de façon que le débouché latéral du conduit 45 passe devant les branches du conduit 39.It is clear that the solenoid valves controlled by an oscillating relay constitute only one embodiment among others of the distribution device for alternately communicating the control chamber 16 with the atmosphere and with the auxiliary pump 23. FIGS. 3 and 4 show in a simplified manner another device operating purely pneumatically and performing the same functions as the combination of two solenoid valves 20 and 21. The device, which constitutes a vacuum dynamometer with piston and return spring, comprises a tubular body in bronze 30, closed by two bottoms 31 and 32. A piston 33 slides freely in the bore of the body 30, which it seals in two chambers 34 and 35. The piston 33 is returned by a tension spring 36 until 'in a position in abutment on a shoulder 37. The conduit 17 of the chamber 16 is connected by a U-shaped conduit 39 to the inner chamber 34 of the body 30. In the chamber 34 and facing a branch of the c unduit 39, also opens a conduit 40 connected to the conduit 22 for connection with the auxiliary pump 23. An orifice 41 also opens facing the other branch of the conduit 39 to communicate the chamber 34 with the outside. The bottom 31 has an exhaust valve 43 and a calibrated orifice 44 between the chamber 35 and the outside. Finally, the internal bent conduit 45 opens onto the lateral face of the piston 33, a usual guide not shown being provided to prevent the latter from rotating during its longitudinal stroke, so that the lateral outlet of the conduit 45 passes in front of the branches of the conduit 39.

Dans la position représentée à la figure 3, le dispositif est équivalent aux deux électrovannes 20 et 21 dans leurs positions de la figure 1. En effet, la chambre 16 communique avec la pompe auxiliaire par 17,39, 34 40 et 22, tandis que la communication avec l'atmosphère est coupée par le piston 33 qui obture l'orifice 41. La dépression engendrée dans la chambre 34 entraîne l'aspiration du piston 33 vers la gauche, contre l'action de rappel du ressort 36. Mais ce mouvement est ralenti par l'orifice calibré 44 qui ne laisse pénétrer l'air que très progressivement dans la chambre 35.In the position shown in FIG. 3, the device is equivalent to the two solenoid valves 20 and 21 in their positions in FIG. 1. In fact, the chamber 16 communicates with the auxiliary pump via 17, 39, 34 40 and 22, while communication with the atmosphere is cut off by the piston 33 which closes the orifice 41. The vacuum generated in the chamber 34 causes the piston 33 to be sucked to the left, against the return action of the spring 36. But this movement is slowed down by the calibrated orifice 44 which lets the air penetrate only very gradually into the chamber 35.

Lorsque le piston approche de sa fin de course, il obture à la fois le conduit 40 et la branche de gauche du conduit 39, ce qui fait cesser l'aspiration dans la chambre 16, équivalant à la fermeture de l'âectrovanne 21 de lasolution électrique. Sous l'effet de la temporisation le piston poursuit légèrement sa course vers la gauche bien que le reste de la chambre 34, toujours en dépression, soit isolé. Le piston découvre alors l'orifice 41 et la branche de droite du conduit 39, ce qui met brutalement la chambre 16 en communication avec l'atmosphère par 17, 39, 35 et 41 équivalant à l'ouverture de l'électrovanne 20. Sous l'action cette fois plus brutale de la pression atmosphérique dans la chambre 35, le piston 33 termine sa course vers la gauche jusqu'au moment où le conduit 45 se présente devant la branche de gauche de 39 (figure 4). La pression atmosphérique s'établit alors sur les deux faces du piston 33, qui est ramené rapidement vers la droite par le ressort 36, sans freinage pneumatique car l'air de la chambre 35 s'échappe librement par la soupape 43.When the piston approaches its end of stroke, it closes both the conduit 40 and the left branch of the conduit 39, which stops the suction in the chamber 16, equivalent to the closing of the solenoid valve 21 of the solution electric. Under the effect of the time delay, the piston continues its stroke slightly to the left although the rest of the chamber 34, still under vacuum, is isolated. The piston then discovers the orifice 41 and the right branch of the conduit 39, which suddenly puts the chamber 16 in communication with the atmosphere via 17, 39, 35 and 41 equivalent to the opening of the solenoid valve 20. Under the action this time more brutal of the atmospheric pressure in the chamber 35, the piston 33 ends its course to the left until the conduit 45 is presented in front of the left branch of 39 (Figure 4). The atmospheric pressure is then established on the two faces of the piston 33, which is brought quickly to the right by the spring 36, without pneumatic braking because the air in the chamber 35 freely escapes through the valve 43.

Dans ce mouvement de recul le piston coupe la communication avec l'atmosphère de la chambre 16 et y rétablit la dépression de la pompe 23, ce qui correspond à un nouveau cycle d'aspiration.In this recoil movement, the piston cuts the communication with the atmosphere of the chamber 16 and re-establishes the vacuum therein of the pump 23, which corresponds to a new suction cycle.

On se référera maintenant aux figures 5 et 6 pour une variante de réalisation à pompe auxiliaire de commande intégrée. Ici la géométrie générale est la même, mais le corps cylindrique central 11 est entouré d'une autre membrane élastique étanche épaisse 50, de forme tubulaire et serrée hermétiquement par ses extrémités sur le corps 11 au moyen de colliers 51.Reference will now be made to FIGS. 5 and 6 for an alternative embodiment with an integrated control auxiliary pump. Here the general geometry is the same, but the central cylindrical body 11 is surrounded by another thick waterproof elastic membrane 50, of tubular and tight shape hermetically by its ends on the body 11 by means of collars 51.

On obtient ainsi, entre la surface interne biconique du corps 1 et le corps central 11, successivement :

  • - la chambre de pompage proprement dite 15, où débouchent comme dans la première variante les orifices d'aspiration 2 et de refoulement 3,
  • - la chambre de commande 16 qui ne communique ici par le conduit 17 qu'avec une seule électrovanne 20 normalement fermée, et dont l'autre sortie est à l'atmosphère,
  • - une chambre interne 52 qui constitue la chambre de manoeuvre de la pompe auxiliaire intégrée. La chambre 52 communique, par le conduit 53 intérieur au corps 11, puis par le conduit 54 qui le prolonge en traversant le flasque 13, avec la voie centrale d'un distributeur constitué ici par exemple par une électrovanne à trois voies 55.
There is thus obtained, between the internal biconical surface of the body 1 and the central body 11, successively:
  • the actual pumping chamber 15, where, as in the first variant, the suction 2 and discharge 3 ports open,
  • the control chamber 16 which here communicates via the conduit 17 only with a single solenoid valve 20 normally closed, and the other outlet of which is in the atmosphere,
  • - An internal chamber 52 which constitutes the operating chamber of the integrated auxiliary pump. The chamber 52 communicates, by the conduit 53 inside the body 11, then by the conduit 54 which extends it by crossing the flange 13, with the central channel of a distributor constituted here for example by a three-way solenoid valve 55.

Au repos, quand la bobine de l'électrovanne n'est pas alimentée, comme représenté à la figure 5, le conduit 54 est en communication avec l'atmosphère. Quand la bobine est sous tension l'électrovanne fait communiquer le conduit 54 avec le conduit 57 relié à une distribution d'air comprimé 58, compresseur autonome ou réseau de distribution.At rest, when the solenoid valve coil is not supplied, as shown in Figure 5, the conduit 54 is in communication with the atmosphere. When the coil is energized, the solenoid valve communicates the conduit 54 with the conduit 57 connected to a compressed air distribution 58, autonomous compressor or distribution network.

Le branchement d'alimentation électrique des électrovannes 20 et 55 est tel que lorsque la vanne 20 est fermée la vanne 55 met le conduit 54 à l'atmosphère, et lorsque la vanne 20 est ouverte la vanne 55 alimente le conduit 54 et la chambre 52 en air comprimé. Les bobines des électrovannes 20 et 55 sont alimentées en parallèle à partir d'une ligne 26, au moyen d'un relais oscillant 27 qui cycliquement met sous tension et coupe l'alimentation des deux bobines.The electrical supply connection of the solenoid valves 20 and 55 is such that when the valve 20 is closed the valve 55 puts the conduit 54 into the atmosphere, and when the valve 20 is open the valve 55 supplies the conduit 54 and the chamber 52 in compressed air. The coils of the solenoid valves 20 and 55 are supplied in parallel from a line 26, by means of an oscillating relay 27 which cyclically energizes and cuts the supply of the two coils.

Comme dans la variante des figures 1 et 2 la chambre de refoulement 9 en aval de la soupape 7 est maintenue en dépression permanente ; ceci est ici réalisé en reliant son ajutage 10 à un éjecteur à air comprimé 60.As in the variant of FIGS. 1 and 2, the delivery chamber 9 downstream from the valve 7 is maintained in permanent vacuum; this is achieved here by connecting its nozzle 10 to a compressed air ejector 60.

Dans la position représentée à la figure 6, correspondant à la fin de la phase de refoulement, la pression atmosphérique établie par l'ouverture de la vanne 20 dans la chambre 16 refoule la membrane 12 sur la face interne du corps 1. En même temps, l'air comprimé amené dans la chambre 52 par la vanne 55 gonfle la membrane 50 qui vient au contact de la membrane 12 et réduit au minimum le volume de la chambre 16. Le basculement du relais 27 coupe ensuite l'alimentation des bobines des deux électrovannes 20 et 55 qui prennent les positions représentées à la figure 5. La mise l'atmosphère à / de la chambre 52 laisse la membrane 50 reprendre sa position normale pour venir se plaquer sur le corps 11. Par son retrait la membrane 50 crée une forte dépression dans la chambre 16 sous la membrane 12 car la vanne 20 fermée empêche l'air d'y entrer. La dépression dans la chambre 16 permet à son tour à la membrane 12 de se rétracter vers la membrane 50 et le corps 11, ce qui provoque une forte dépression dans la chambre de pompage 15 et l'aspiration dès que l'orifice 2 est découvert.In the position shown in FIG. 6, corresponding to the end of the delivery phase, the atmospheric pressure established by the opening of the valve 20 in the chamber 16 delivers the membrane 12 to the internal face of the body 1. At the same time , the compressed air brought into the chamber 52 by the valve 55 inflates the membrane 50 which comes into contact with the membrane 12 and minimizes the volume of the chamber 16. The switching of the relay 27 then cuts the supply of the coils of the two solenoid valves 20 and 55 which take the positions shown in FIG. 5. Setting the atmosphere in / of the chamber 52 lets the membrane 50 return to its normal position in order to be pressed against the body 11. By its removal the membrane 50 creates a strong vacuum in the chamber 16 under the membrane 12 because the closed valve 20 prevents air from entering it. The depression in the chamber 16 in turn allows the membrane 12 to retract towards the membrane 50 and the body 11, which causes a strong depression in the pumping chamber 15 and the suction as soon as the orifice 2 is uncovered .

On voit que la membrane interne 50 et sa manoeuvre de gonflage à l'air comprimé ou dégonflage joue le même rôle que la pompe auxiliaire 23 de la première variante pour créer la dépression sous la membrane principale 12 pendant la phase d'aspiration. Mais ici le maintien en dépression de la chambre de refoulement 9 est assuré par l'éjecteur indépendant 60.It can be seen that the internal membrane 50 and its inflating operation with compressed air or deflating plays the same role as the auxiliary pump 23 of the first variant to create the vacuum under the main membrane 12 during the suction phase. However, here the vacuum chamber 9 is kept under vacuum by the independent ejector 60.

Dans cette version à air comprimé, la vitesse de pompage dépend essentiellement du débit du circuit d'alimentation utilisé. Le volume d'admission est bien plus grand que dans les pompes à membrane à couplage mécanique et la vitesse de pompage peutêtrq&rtement augmentée.In this compressed air version, the pumping speed depends essentially on the flow rate of the supply circuit used. The intake volume is much greater than in mechanically coupled diaphragm pumps and the pumping speed can be increased considerably.

Ces nouvelles pompes sont donc tout naturellement destinées aux applications où un vide primaire propre très inférieur à 102 Pa doit être obtenu avec des moyens pratiques et simples, par exemple pour l'amorçage des pompes ioniques, cryogéniques ou turbomoléculaires, largement utilisées dans les laboratoires de recherche et l'industrie électronique.These new pumps are therefore quite naturally intended for applications where a clean primary vacuum much less than 10 2 Pa must be obtained with practical and simple means, for example for priming ionic, cryogenic or turbomolecular pumps, widely used in laboratories. research and electronics industry.

Claims (9)

1.- Pompe à vide sèche à membrane pour transférer un gaz d'au moins un orifice d'aspiration (2) à au moins un orifice de refoulement (3), constituée par une membrane élastique (12) tendue entre un premier et un deuxième corps rigides, de telle sorte que le volume entre la membrane (12) et le premier corps rigide (1) constitue une chambre de pompage (15) où débouchent les orifices d'aspiration et les orifices de refoulement, et que le volume de l'autre côté de la membrane (12) constitue une chambre de commande (16) pour manoeuvrer la membrane en y faisant varier cycliquement la pression pour engendrer alternativement : a) un mouvement de refoulement en plaquant la membrane (12) progressivement contre le premier corps rigide (1), obturant ainsi d'abord les orifices d'admission et refoulant ensuite le gaz vers les orifices de refoulement, b) un mouvement d'aspiration en ramenant la membrane (12) vers le deuxième corps rigide (11) entraînant d'abord la fermeture des soupapes de refoulement et dégageant ensuite les orifices d'admission, caractérisée par le fait que les orifices de refoulement (3) communiquent par l'intermédiaire de soupapes (7) avec une capacité (9) maintenue à une pression inférieure à la pression atmosphérique par une pompe à vide auxiliaire (23),
et par le fait qu'elle comporte un mécanisme (20-21) de distribution pour faire alternativement communiquer la chambre de commande (16) avec l'atmosphère et avec l'aspiration d'une pompe à vide auxiliaire. 1.- Dry membrane vacuum pump for transferring a gas from at least one suction orifice (2) to at least one discharge orifice (3), constituted by an elastic membrane (12) stretched between a first and a second rigid body, such that the volume between the membrane (12) and the first rigid body (1) constitutes a pumping chamber (15) into which the suction orifices and discharge orifices open, and that the volume of the other side of the membrane (12) constitutes a control chamber (16) for maneuvering the membrane by varying the pressure therein cyclically to generate alternately: a) a discharge movement by pressing the membrane (12) progressively against the first rigid body (1), thus first blocking the intake ports and then discharging the gas towards the discharge ports, b) a suction movement by bringing the membrane (12) towards the second rigid body (11) first causing the closing of the discharge valves and then releasing the intake orifices, characterized in that the discharge orifices (3) communicate via valves (7) with a capacity (9) maintained at a pressure below atmospheric pressure by an auxiliary vacuum pump (23),
and by the fact that it comprises a distribution mechanism (20-21) for alternately communicating the control chamber (16) with the atmosphere and with the suction of an auxiliary vacuum pump. 2.- Pompe selon la revendication 1,
caractérisée par le fait que : - la surface interne du premier corps rigide (1) a la forme de deux troncs de cônes accolés par leurs bases, les orifices de refoulement (3) étant disposés dans la zone médiane de plus fort diamètre et les orifices d'aspiration (2) dans les zones d'extrémité de plus faible diamètre, - le deuxième corps (11) est coaxial au premier, - la membrane élastique (12) est de forme tubulaire de diamètre naturel inférieur au diamètre extérieur du deuxième corps (11), et est fixée de façon étanche par ses extrémités aux extrémités du premier corps (1). 2.- pump according to claim 1,
characterized by the fact that: - The internal surface of the first rigid body (1) has the shape of two trunks of cones joined by their bases, the discharge orifices (3) being arranged in the middle zone of larger diameter and the suction orifices (2) in the smaller diameter end zones, - the second body (11) is coaxial with the first, - The elastic membrane (12) is of tubular shape with a natural diameter less than the outside diameter of the second body (11), and is fixed in leaktight manner at its ends to the ends of the first body (1). 3.- Pompe selon l'une quelconque des revendications 1 ou 2, cara_ctériséppar le fait que la même pompe à vide auxiliaire (23) est utilisée à la fois pour entretenir une dépression en aval de la soupape de refoulement (7) et pour créer la dépression appliquée cycliquement à la chambre de commande (16).3.- Pump according to any one of claims 1 or 2, cara_ctériséppar the fact that the same auxiliary vacuum pump (23) is used both to maintain a vacuum downstream of the discharge valve (7) and to create the vacuum applied cyclically to the control chamber (16). 4.- Pompe selon la revendication 3, caractériséepar le fait que le conduit d'aspiration de la pompe auxiliaire unique (23) comporte une branche (22 - 24) à forte conductance entre l'aval de la soupape de refoulement (7) et le conduit (17) d'aspiration dans la chambre de commande (16).4.- Pump according to claim 3, characterized in that the suction pipe of the single auxiliary pump (23) comprises a branch (22 - 24) with high conductance between the downstream of the discharge valve (7) and the suction pipe (17) in the control chamber (16). 5.- Pompe selon l'une quelconque des revendications 1 à 4, caractériséepar le fait que le mécanisme de distribution est constitué par deux électrovannes (20 - 21) à deux voies raccordées en parallèle par une de leurs voies au conduit (17) de manoeuvre de la chambre de commande, et par leur autre voie respectivement à l'atmosphère et à l'aspiration de la pompe auxiliaire (23), les deux électrovannes étant commandées en opposition au moyen d'un même relais oscillant (27).5.- Pump according to any one of claims 1 to 4, characterized in that the distribution mechanism is constituted by two solenoid valves (20 - 21) with two channels connected in parallel by one of their channels to the conduit (17) of operation of the control chamber, and by their other path respectively to the atmosphere and to the suction of the auxiliary pump (23), the two solenoid valves being controlled in opposition by means of the same oscillating relay (27). 6;- Pompe selon l'une quelconque des revendications 1 à 4, caractérisé par le fait que le mécanisme de distribution est constitué par un dynamomètre à dépression (30), à piston (33) et ressort de rappel (36).6; - Pump according to any one of claims 1 to 4, characterized in that the distribution mechanism is constituted by a vacuum dynamometer (30), piston (33) and return spring (36). 7.- Pompe selon revendication 2, caractérisé par le fait que la pompe à vide auxiliaire destinée à créer une dépression dans la chambre de commande (16) est constituée par une deuxième membrane élastique étanche (50) entourant le deuxième corps entre le deuxième corps (11) et la première membrane (12), et par le fait que la pompe comporte un mécanisme de distribution (20-55) pour faire communiquer l'espace (52) compris entre le deuxième corps (11) et la deuxième membrane (50) alternativement avec l'atmosphère et avec une distribution d'air comprimé (58), avec des moyens pour faire cotncider la phase dalimentation en air comprimé avec la phase de mise à l'atmosphère de la chambre de commande (16) et inversement.7.- Pump according to claim 2, characterized in that the auxiliary vacuum pump intended to create a vacuum in the control chamber (16) is constituted by a second waterproof elastic membrane (50) surrounding the second body between the second body (11) and the first membrane (12), and by the fact that the pump includes a distribution mechanism (20-55) for communicating the space (52) between the second body (11) and the second membrane ( 50) alternately with the atmosphere and with a compressed air distribution (58), with means for making the compressed air supply phase coincide with the phase of venting the control chamber (16) and vice versa . 8.- Pompe selon la revendication 71 caractérisé par le fait que le mécanisme de distribution relatif à l'espace compris entre le deuxième corps et la deuxième membrane est un distributeur (55) à commande électrique commandé à partir d'un même relais oscillant (27) qui commande aussi la mise à l'atmosphère de la chambre de commande (16).8.- Pump according to claim 7 1 characterized in that the distribution mechanism relating to the space between the second body and the second membrane is a distributor (55) electrically controlled from a single oscillating relay (27) which also controls the venting of the control chamber (16). 9.- Pompe selon l'une quelconque des revendications précédentes, caractérisé par le fait que la première membrane (12) présente une épaisseur réduite dans la zone des orifices d'admission( 2).9.- Pump according to any one of the preceding claims, characterized in that the first membrane (12) has a reduced thickness in the region of the intake orifices (2).
EP82401332A 1981-07-24 1982-07-16 Diaphragm pump for a vacuum free of oil Expired EP0072275B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82401332T ATE26870T1 (en) 1981-07-24 1982-07-16 DIAPHRAGM PUMP FOR OIL-FREE VACUUM.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8114489 1981-07-24
FR8114489A FR2510203A1 (en) 1981-07-24 1981-07-24 MEMBRANE DRY PRIMARY PUMP

Publications (2)

Publication Number Publication Date
EP0072275A1 true EP0072275A1 (en) 1983-02-16
EP0072275B1 EP0072275B1 (en) 1987-04-29

Family

ID=9260865

Family Applications (1)

Application Number Title Priority Date Filing Date
EP82401332A Expired EP0072275B1 (en) 1981-07-24 1982-07-16 Diaphragm pump for a vacuum free of oil

Country Status (5)

Country Link
US (1) US4452572A (en)
EP (1) EP0072275B1 (en)
AT (1) ATE26870T1 (en)
DE (1) DE3276188D1 (en)
FR (1) FR2510203A1 (en)

Cited By (1)

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EP0783077A1 (en) 1996-01-03 1997-07-09 Büchi Labortechnik AG Diaphragm vacuum pump and cylinder head for a diaphragm vacuum pump

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DE60142179D1 (en) 2000-12-22 2010-07-01 Draeger Medical Systems Inc ROCKER FOR CHILDREN
US6572259B2 (en) * 2001-04-20 2003-06-03 Burnett Lime Co., Inc. Apparatus and method to dispense a slurry
EP2379889B1 (en) 2008-12-19 2015-09-30 Stobbe Tech A/s Electronically controlled diaphragm pump
NL1038329C2 (en) * 2010-10-25 2012-04-26 Lely Patent Nv Milking installation with milk pump.
US8951419B2 (en) 2010-12-17 2015-02-10 Burnett Lime Company, Inc. Method and apparatus for water treatment
EP2965768B1 (en) * 2012-01-10 2017-11-29 KCI Licensing, Inc. Systems for delivering fluid to a wound therapy dressing
CN103075328A (en) * 2013-01-25 2013-05-01 沈阳大学 Hydrodynamic diaphragm pump
MX2018011265A (en) * 2016-03-18 2019-07-04 Deka Products Lp Pressure control gaskets for operating pump cassette membranes.

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US2494529A (en) * 1945-02-23 1950-01-10 Axel M Wirtanen Vacuum rupture operated pump
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DE203854C (en) *
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FR689893A (en) * 1929-04-19 1930-09-12 Diaphragm compressor
US2494529A (en) * 1945-02-23 1950-01-10 Axel M Wirtanen Vacuum rupture operated pump
CH284883A (en) * 1950-11-29 1952-08-15 Oerlikon Maschf Vacuum pump.

Cited By (1)

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Publication number Priority date Publication date Assignee Title
EP0783077A1 (en) 1996-01-03 1997-07-09 Büchi Labortechnik AG Diaphragm vacuum pump and cylinder head for a diaphragm vacuum pump

Also Published As

Publication number Publication date
US4452572A (en) 1984-06-05
FR2510203B1 (en) 1984-01-06
ATE26870T1 (en) 1987-05-15
EP0072275B1 (en) 1987-04-29
FR2510203A1 (en) 1983-01-28
DE3276188D1 (en) 1987-06-04

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