EP0175105B1 - Membrane pump, especially for dosing liquids - Google Patents

Membrane pump, especially for dosing liquids Download PDF

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Publication number
EP0175105B1
EP0175105B1 EP85109557A EP85109557A EP0175105B1 EP 0175105 B1 EP0175105 B1 EP 0175105B1 EP 85109557 A EP85109557 A EP 85109557A EP 85109557 A EP85109557 A EP 85109557A EP 0175105 B1 EP0175105 B1 EP 0175105B1
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EP
European Patent Office
Prior art keywords
membrane
valve
pump according
membrane pump
spring
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Expired
Application number
EP85109557A
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German (de)
French (fr)
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EP0175105A1 (en
Inventor
Klaus Dipl. Ing. Müller
Sieghard Dipl. Ing. Oberacker
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WOLFGANG EICHLER KG
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Wolfgang Eichler KG
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Publication of EP0175105A1 publication Critical patent/EP0175105A1/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
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
    • F04B43/06—Pumps having fluid drive
    • F04B43/067—Pumps having fluid drive the fluid being actuated directly by a piston
    • 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
    • F04B43/00—Machines, pumps, or pumping installations having flexible working members
    • F04B43/12—Machines, pumps, or pumping installations having flexible working members having peristaltic action
    • F04B43/14—Machines, pumps, or pumping installations having flexible working members having peristaltic action having plate-like flexible members

Definitions

  • the invention relates to a diaphragm pump, in particular for dosing liquids with a diaphragm delimiting a dosing chamber with suction and pressure valve on the one hand, and a hydraulic working chamber with drive piston and pressure relief valve on the other hand, which delimits a chamber connected to the working chamber via at least one overflow channel, in the area of the Overflow duct a plunger is guided with a valve plate for the opposite openings of the overflow duct and that the valve unit consisting of the plunger and the valve plates is operatively connected to the membrane.
  • Diaphragm pumps of this type which are also referred to as piston diaphragm pumps, are known in a large number of embodiments. Their principle of operation is that the elastically deformable membrane executes its stroke under changing hydraulic pressure in the work area, whereby it sucks in the liquid to be delivered during the suction stroke, in which it enlarges the metering space, via the suction valve and during the pressure stroke, during which it moves into the Moved the dosing chamber in, pressed the pressure valve.
  • the pressure change in the work area is generated by a piston which closes the latter and is actuated by an oscillating drive, for example an eccentric.
  • the membrane Since the membrane has a comparatively small wall thickness due to the required elasticity and the necessary working stroke, it is sensitive to excessive stress. Such overloading can occur, for example, when the suction head is too high or when the suction line is closed or blocked, or else when there are leaks in the suction or pressure valve. It manifests itself in the fact that the membrane is overstretched and possibly permanently deformed or even tears in extreme cases. This not only makes the diaphragm pump inoperative, it can also mix hydraulic working fluid and dosing medium, which leads to corresponding consequential damage.
  • support devices which limit the membrane stroke.
  • These support devices generally consist of disks shaped like spherical caps, which are provided with a plurality of channels in order - depending on the arrangement of the support devices - to allow the working medium or dosing medium to pass through.
  • the membrane contacts the calotte.
  • damage can still occur if the membrane is deformed into the channels if the pressure difference is too high, so that permanent deformations or even cracks occur.
  • a chamber is provided between the dosing space and the working space, which chamber adjoins the dosing space via the membrane and is connected to the working space via an overflow channel.
  • a valve rod is guided, each of which has a valve disk for the opposite openings of the overflow channel.
  • the diaphragm is attached to this valve unit consisting of valve rod and valve plates by means of a screw connection.
  • Another known device also shows a valve unit which is firmly connected to the membrane.
  • One end of the valve unit attached to the membrane uses it as a support and guide, the other end of the valve unit being guided in a drawer bearing.
  • the valve unit receives no support in the area of the overflow channel, so that the membrane is also exposed to the forces resulting from the fixing of the valve unit in addition to the suction and pressure forces.
  • This and the aforementioned device also have the disadvantage that by fixing one end of the valve unit, the homogeneity and the elastic structure of the membrane is disturbed and can therefore tear easily at higher pressure differences.
  • the invention has for its object to provide a diaphragm pump which is equipped with a functionally reliable and effective against any kind of overload membrane protection.
  • valve unit lies loosely against the diaphragm under the action of a weak spring via a support disk.
  • the function of the diaphragm pump is as follows: In normal metering operation, in which the diaphragm is moved back and forth by the hydraulic working medium, the tappet with the valve unit follows this movement, the working medium coming from the working space through the overflow channels into the chamber and at the back the membrane is present.
  • the distance between the valve disks from one another or their distance from the opposite openings of the overflow channels is dimensioned such that the valve unit does not reach the closed position at least during the pressure stroke, since otherwise the delivery rate would be impaired.
  • the membrane is therefore not as in generic state of the art - held in their limit positions by mechanical support devices, but lies loosely on the valve unit on the support disc, so that any overuse is excluded. This membrane protection is absolutely reliable in any operating situation.
  • the valve unit of the membrane is under the action of a weak spring force, which is advantageously dimensioned so small that it makes no active contribution to the deflection of the membrane.
  • the spring force is only intended to overcome the frictional forces of the tappet guide and the inertial forces of the system, that is, it should always ensure that the valve unit is in contact with the diaphragm during the pressure stroke.
  • it provides no or no significant resistance to the movement of the membrane during the suction stroke.
  • an insert is provided between the chamber and the hydraulic working space, in which the tappet of the valve unit is guided on the one hand and the overflow channel is arranged on the other hand.
  • a plurality of overflow channels surrounding the tappet or its guide are preferably provided in the insert, the opposite openings of which on each side of the partition are covered by one of the valve disks of the valve unit. Each valve disk therefore closes all openings on one side of the overflow channels.
  • a conical seat is incorporated on both sides of the insert, the small diameter of which corresponds approximately to the diameter of the outer enveloping circle of the openings of the overflow channels. This creates a single central sealing surface for all overflow channels.
  • the valve disks also advantageously have a conical surface as a sealing surface.
  • the spring generating the spring force is arranged between the two valve plates and is supported on the one hand within the insert and on the other hand on the valve plate facing the membrane.
  • the spring is a helical spring which is supported on the one hand on the support disk and on the other hand on the opposite side of the insert and surrounds the tappet.
  • the inventive design of the membrane protection which prevents overstressing or damage to the membrane even in extreme operating conditions, makes it possible to use a very thin-walled membrane and thus also one made of plastic, in particular PTFE.
  • the membrane pump according to FIG. 1 has a multi-part housing, which consists of a tank 1 for the hydraulic working medium, a piston housing 2, a valve head 3 and a metering head 4, which are mounted axially one behind the other.
  • a drive motor 5 with a worm gear 6 which drives an eccentric 7.
  • the eccentric 7 acts on a hollow piston 8 which is guided in the piston housing 2 and is provided in the region of its drive side with a transverse bore 9 for the transfer of the hydraulic medium from the tank 1 into the cavity of the piston.
  • the piston 8 is also overlapped by a control slide 10 which, as a gate control, enables the working stroke to be adjusted.
  • the piston 8 is finally under the action of a spring 11 which keeps it in contact with the eccentric 7.
  • the cavity of the piston 8 and a space 12 in front of it in the piston housing 2 and a chamber 13 arranged in the valve head 3 form the working space of the metering pump, the space 12 being connected to the tank 1 via a pressure relief valve 27.
  • the chamber 13 is delimited on the front by a metering diaphragm 14, which at the same time forms the rear end of a metering chamber 15.
  • the dosing chamber 15 is connected to the medium to be conveyed via a suction valve and also has a pressure valve 17.
  • the chamber 13 is also equipped with a vent valve 18.
  • a plurality of overflow channels 19 are arranged concentrically about a common axis in a partition wall formed by the valve head 3, as can be seen in particular from FIGS. 2 and 3.
  • a tappet 20 is axially aligned within the valve head and is concentrically surrounded by the overflow channels 19 in the region of the guide.
  • the plunger 20 has on both sides of the partition wall formed by the valve head 3 each a valve plate 21, 22, which cooperate with a corresponding conical seat 23 or 28, which are incorporated in the partition wall and expand the overflow channels 19 to the outside.
  • the tappet 20 with the valve disks 21, 22 and the conical seats 23, 28 form the valve unit 30 serving to protect the membrane 14.
  • the plunger 20 has an extension 29 at the end opposite the valve plate 21 a support disc 24, which is supported on the other valve plate 22 via a spacer sleeve 25.
  • the support disk 24 lies loosely against the membrane 14 under the action of a spring 26, which is supported on the wall of the chamber 13.
  • FIG. 2 The extreme position of the diaphragm 14 during the pressure stroke can be seen in FIG. 2, in which the vantile cone 21 closes the overflow channels 19 with respect to the working space 12, the piston 8, while FIG. 3 shows the other limit position during the suction stroke, in which the valve cone 22 overflows the overflow channels 19 closes.
  • the membrane In both limit positions, the membrane is hydraulically decoupled from the work area so that it cannot be loaded beyond the limit positions.
  • FIG. 4 shows a modified embodiment of the valve unit 30, which has particular advantages in terms of production and assembly. It in turn has a tappet 20, on each of which ends a valve plate 21, 22 is attached, which in turn cooperate with conical seats 23, 28.
  • the conical seats 23, 28, like the overflow channels 19, are arranged on an insert 31, which in turn is inserted tightly into the valve head 3 (FIG. 1).
  • the insert 31 has a bore of larger diameter between the overflow channels 19 and the valve plate 22 facing the membrane 14 (FIG. 1), in which the spring 26 is arranged, which is supported on the one hand in the insert 31 and on the other hand on the valve plate 22 and thus the valve unit 30 urges towards the membrane 14.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)

Description

Die Erfindung betrifft eine Membranpumpe, insbesondere zum Dosieren von Flüssigkeiten mit einer einerseits einen Dosierraum mit Saug- und Druckventil, andererseits einen hydraulischen Arbeitsraum mit Antriebskolben und Überdruckventil begrenzenden Membran, die eine mit dem Arbeitsraum über wenigstens einen Überströmkanal verbundene Kammer abgrenzt, wobei im Bereich des Überströmkanal ein Stößel mit je einem Ventilteller für die gegenüberliegenden Öffnungen des Überströmkanals geführt ist und daß die aus dem Stößel und den Ventiltellern bestehende Ventileinheit in Wirkverbindung mit der Membran steht.The invention relates to a diaphragm pump, in particular for dosing liquids with a diaphragm delimiting a dosing chamber with suction and pressure valve on the one hand, and a hydraulic working chamber with drive piston and pressure relief valve on the other hand, which delimits a chamber connected to the working chamber via at least one overflow channel, in the area of the Overflow duct a plunger is guided with a valve plate for the opposite openings of the overflow duct and that the valve unit consisting of the plunger and the valve plates is operatively connected to the membrane.

Membranpumpen dieser Art, die auch als Kolbenmembranpumpen bezeichnet werden, sind in einer Vielzahl von Ausführungsformen bekannt. Ihr Arbeitsprinzip besteht darin, daß die elastisch verformbare Membran unter wechselndem hydraulischem Druck im Arbeitsraum ihren Hub ausführt, wobei sie die zu fördernde Flüssigkeit beim Saughub, bei dem sie den Dosierraum vergrößert, über das Saugventil ansaugt und beim Druckhub, bei dem sie sich in den Dosierraum hineinbewegt, über das Druckventil abdrückt. Der Druckwechsel im Arbeitsraum wird durch einen diesen abschließenden Kolben erzeugt, der von einem oszillierenden Antrieb, beispielsweise einem Exzenter betätigt wird.Diaphragm pumps of this type, which are also referred to as piston diaphragm pumps, are known in a large number of embodiments. Their principle of operation is that the elastically deformable membrane executes its stroke under changing hydraulic pressure in the work area, whereby it sucks in the liquid to be delivered during the suction stroke, in which it enlarges the metering space, via the suction valve and during the pressure stroke, during which it moves into the Moved the dosing chamber in, pressed the pressure valve. The pressure change in the work area is generated by a piston which closes the latter and is actuated by an oscillating drive, for example an eccentric.

Da die Membran aufgrund der von ihr geforderten Elastizität und dem notwendigen Arbeitshub eine vergleichsweise geringe Wandstärke besitzt, ist sie gegen Überbeanspruchung empfindlich. Eine solche Überbeanspruchung kann beispielsweise bei zu großer Saughöhe oder bei verschlossener bzw. blockierter Saugleitung oder aber auch bei Undichtheiten im Saug- oder Druckventil auftreten. Sie äußert sich darin, daß die Membran überdehnt und gegebenenfalls bleibend verformt wird oder gar im Extremfall reißt. Damit wird die Membranpumpe nicht nur funktionsuntüchtig, sondern es können sich auch hydraulisches Arbeitsmedium und Dosiermedium mischen, was zu entsprechenden Folgeschäden führt.Since the membrane has a comparatively small wall thickness due to the required elasticity and the necessary working stroke, it is sensitive to excessive stress. Such overloading can occur, for example, when the suction head is too high or when the suction line is closed or blocked, or else when there are leaks in the suction or pressure valve. It manifests itself in the fact that the membrane is overstretched and possibly permanently deformed or even tears in extreme cases. This not only makes the diaphragm pump inoperative, it can also mix hydraulic working fluid and dosing medium, which leads to corresponding consequential damage.

Um eine zu starke Auslenkung der Membran und die dadurch gegebene Gefährdung zu vermeiden, sind gesonderte Stützeinrichtungen vorgesehen, die den Membranhub begrenzen. Diese Stützeinrichtungen bestehen im allgemeinen aus kalottenähnlich geformten Scheiben, die mit mehreren Kanälen versehen sind, um - je nach Anordnung der Stützeinrichtungen - den Durchtritt des Arbeitsmediums bzw. Dosiermediums zu ermöglichen. Die Membran legt sich beim Hubmaximum an die Kalotte an. Auch hierbei kann es aber noch zu Schäden kommen, indem bei zu hoher Druckdifferenz die Membran in die Kanäle hineinverformt wird, so daß sich wiederum bleibende Verformungen oder gar Risse einstellen.In order to avoid excessive deflection of the membrane and the resulting danger, separate support devices are provided which limit the membrane stroke. These support devices generally consist of disks shaped like spherical caps, which are provided with a plurality of channels in order - depending on the arrangement of the support devices - to allow the working medium or dosing medium to pass through. At the maximum stroke, the membrane contacts the calotte. Here too, however, damage can still occur if the membrane is deformed into the channels if the pressure difference is too high, so that permanent deformations or even cracks occur.

Bei einer bekannten Vorrichtung (GB-PS-887 774) ist zwischen dem Dosierraum und dem Arbeitsraum eine Kammer vorgesehen, die zum Dosierraum über die Membran angrenzt und über einen Überströmkanal mit dem Arbeitsraum verbunden ist. Im Bereich des Überströmkanals ist eine Ventilstange geführt, die je einen Ventilteller für die gegenüberliegenden Öffnungen des Überströmkanals aufweist. An diese aus Ventilstange und Ventiltellern bestehende Ventileinheit ist über eine Schraubverbindung die Membran festgelegt.In a known device (GB-PS-887 774), a chamber is provided between the dosing space and the working space, which chamber adjoins the dosing space via the membrane and is connected to the working space via an overflow channel. In the area of the overflow channel, a valve rod is guided, each of which has a valve disk for the opposite openings of the overflow channel. The diaphragm is attached to this valve unit consisting of valve rod and valve plates by means of a screw connection.

Eine weitere bekannte Vorrichtung (US-PS-2 303 597) zeigt ebenfalls eine Ventileinheit die mit der Membran fest verbunden ist. Dabei benutzt das eine Ende der an der Membran festgelegten Ventileinheit diese als Stütze und Führung, wobei das andere Ende der Ventileinheit in einem Schublager geführt wird. Im Bereich des Überströmkanals erfährt die Ventileinheit keinerlei Unterstützung, so daß die Membran neben den Saug- und Druckkräften zusätzlich noch den von der Festlegung der Ventileinheit herrührenden Kräften ausgesetzt wird. Diese und die vorgenannte Vorrichtung haben zudem den Nachteil, daß durch das Festlegen des einen Endes der Ventileinheit die Homogenität und die elastische Struktur der Membran gestört ist und diese deshalb bei höheren Druckdifferenzen leicht einreißen kann.Another known device (US-PS-2 303 597) also shows a valve unit which is firmly connected to the membrane. One end of the valve unit attached to the membrane uses it as a support and guide, the other end of the valve unit being guided in a drawer bearing. The valve unit receives no support in the area of the overflow channel, so that the membrane is also exposed to the forces resulting from the fixing of the valve unit in addition to the suction and pressure forces. This and the aforementioned device also have the disadvantage that by fixing one end of the valve unit, the homogeneity and the elastic structure of the membrane is disturbed and can therefore tear easily at higher pressure differences.

Der Erfindung liegt die Aufgabe zugrunde, eine Membranpumpe zu schaffen, die mit einem funktionssicheren und gegen jede Art von Überbelastung wirksamen Membranschutz ausgestattet ist.The invention has for its object to provide a diaphragm pump which is equipped with a functionally reliable and effective against any kind of overload membrane protection.

Ausgehend von einer Membranpumpe des zuvor geschilderten Aufbaus wird diese Aufgabe dadurch gelöst, daß die Ventileinheit unter Wirkung einer schwachen Feder über eine Stützscheibe lose der Membran anliegt.Starting from a diaphragm pump of the construction described above, this object is achieved in that the valve unit lies loosely against the diaphragm under the action of a weak spring via a support disk.

Die Funktionsweise der Membranpumpe ist folgende: Bei normalem Dosierbetrieb, bei dem die Membran durch das hydraulische Arbeitsmedium hin und her bewegt wird, folgt der Stößel mit der Ventileinheit dieser Bewegung, wobei das Arbeitsmedium aus dem Arbeitsraum über die Überströmkanäle in die Kammer gelangt und rückseitig an der Membran ansteht. Der Abstand der Ventilteller voneinander bzw. ihr Abstand zu den gegenüberliegenden Öffnungen der Überströmkanäle ist so bemessen, daß die Ventileinheit zumindest beim Druckhub nicht in die Schließlage gelangt, da anderenfalls die Förderleistung beeinträchtigt würde. Erst dann, wenn die Membran in der einen oder anderen Richtung über den Maximalhub hinaus ausgelenkt wird, gelangt - je nach Richtung der Auslenkung - der eine oder andere Ventilteller in die Schließlage, so daß die Kammer und damit die Membran vom Arbeitsmedium abgekoppelt ist, eine weitere Druckerniedrigung also nicht mehr stattfinden kann. Erfindungsgemäß ist die Membran demzufolge nicht wie beim gattungsgemäßen Stand der Technik - in ihren Grenzlagen durch mechanische Stützeinrichtungen gehalten, sondern liegt der Ventileinheit über die Stützscheibe lose an, so daß jegliche Überbeanspruchung ausgeschlossen ist. Dieser Membranschutz ist in jeder Betriebssituation absolut funktionssicher.The function of the diaphragm pump is as follows: In normal metering operation, in which the diaphragm is moved back and forth by the hydraulic working medium, the tappet with the valve unit follows this movement, the working medium coming from the working space through the overflow channels into the chamber and at the back the membrane is present. The distance between the valve disks from one another or their distance from the opposite openings of the overflow channels is dimensioned such that the valve unit does not reach the closed position at least during the pressure stroke, since otherwise the delivery rate would be impaired. Only when the diaphragm is deflected in one direction or the other beyond the maximum stroke does one or the other valve plate enter the closed position, depending on the direction of the deflection, so that the chamber and thus the diaphragm are decoupled from the working medium further pressure reduction can therefore no longer take place. According to the invention, the membrane is therefore not as in generic state of the art - held in their limit positions by mechanical support devices, but lies loosely on the valve unit on the support disc, so that any overuse is excluded. This membrane protection is absolutely reliable in any operating situation.

Erfindungsgemäss liegt die Ventileinheit der Membran unter Wirkung einer schwachen Federkraft an, die mit Vorteil so gering bemessen ist, daß sie keinen aktiven Beitrag zur Auslenkung der Membran leistet. Die Federkraft soll bei hydraulischem Gleichgewicht auf beiden Seiten der Membran lediglich die Reibungskräfte der Stößelführung und die Trägheitskräfte des Systems überwinden, also beim Druckhub stets für eine Anlage der Ventileinheit an der Membran sorgen. Andererseits stellt sie beim Saughub der Bewegung der Membran keinen bzw. keinen nennenswerten Widerstand entgegen.According to the invention, the valve unit of the membrane is under the action of a weak spring force, which is advantageously dimensioned so small that it makes no active contribution to the deflection of the membrane. With hydraulic equilibrium on both sides of the diaphragm, the spring force is only intended to overcome the frictional forces of the tappet guide and the inertial forces of the system, that is, it should always ensure that the valve unit is in contact with the diaphragm during the pressure stroke. On the other hand, it provides no or no significant resistance to the movement of the membrane during the suction stroke.

Gemäß einem Ausführungsbeispiel ist zwischen der Kammer und dem hydraulischen Arbeitsraum ein Einsatz vorgesehen, in dem einerseits der Stößel der Ventileinheit geführt, andererseits der Überströmkanal angeordnet ist. Dabei sind vorzugsweise in dem Einsatz mehrere den Stößel bzw. seine Führung umgebende Überströmkanäle vorgesehen, deren gegenüberliegende Öffnungen an beiden Seiten der Trennwand von jeweils einem der Ventilteller der Ventileinheit überdeckt sind. Jeder Ventilteller verschließt also sämtliche Öffnungen an der einen Seite der Überströmkanäle.According to one embodiment, an insert is provided between the chamber and the hydraulic working space, in which the tappet of the valve unit is guided on the one hand and the overflow channel is arranged on the other hand. A plurality of overflow channels surrounding the tappet or its guide are preferably provided in the insert, the opposite openings of which on each side of the partition are covered by one of the valve disks of the valve unit. Each valve disk therefore closes all openings on one side of the overflow channels.

In besonders vorteilhafter Ausführung ist an den beiden Seiten des Einsatzes ein Kegelsitz eingearbeitet, dessen kleiner Durchmesser etwa dem Durchmesser des äußeren Hüllkreises der Öffnungen der Überströmkanäle entspricht. Damit ist eine einzige zentrische Dichtfläche für sämtliche Überströmkanäle geschaffen. Mit Vorteil weisen bei dieser Ausführung auch die Ventilteller als Dichtfläche eine Kegelfläche auf.In a particularly advantageous embodiment, a conical seat is incorporated on both sides of the insert, the small diameter of which corresponds approximately to the diameter of the outer enveloping circle of the openings of the overflow channels. This creates a single central sealing surface for all overflow channels. In this embodiment, the valve disks also advantageously have a conical surface as a sealing surface.

Gemäß einem Ausführungsbeispiel ist die die Federkraft erzeugende Feder zwischen den beiden Ventiltellern angeordnet und stützt sich einerseits innerhalb des Einsatzes, andererseits an dem der Membran zugekehrten Ventilteller ab. Bei einer anderen Ausführungsform ist die Feder eine sich einerseits an der Stützscheibe, andererseits an der ihr gegenüberliegenden Seite des Einsatzes abstützende, den Stößel umgebenden Schraubenfeder.According to one embodiment, the spring generating the spring force is arranged between the two valve plates and is supported on the one hand within the insert and on the other hand on the valve plate facing the membrane. In another embodiment, the spring is a helical spring which is supported on the one hand on the support disk and on the other hand on the opposite side of the insert and surrounds the tappet.

Durch die erfindungsgemäße Ausbildung des Membranschutzes, der auch bei extremen Betriebszuständen eine Überbeanspruchung oder Beschädigung der Membran verhindert, ist es möglich, eine sehr dünnwandige Membran und damit auch eine solche aus Kunststoff, insbesondere aus PTFE, zu verwenden. Dadurch lassen sich einerseits auch hoch agressive Medien fördern, was bisher nicht oder nur mit sehr teueren Verbundwerkstoffen möglich war, andererseits auch beliebig hohe Drücke realisieren, die nicht durch die Membranfestigkeit begrenzt sind.The inventive design of the membrane protection, which prevents overstressing or damage to the membrane even in extreme operating conditions, makes it possible to use a very thin-walled membrane and thus also one made of plastic, in particular PTFE. On the one hand, this means that highly aggressive media can be pumped, which was previously not possible or only possible with very expensive composite materials, and on the other hand that pressures of any desired level can be achieved, which are not limited by the membrane strength.

Nachstehend ist die Erfindung anhand eines in der Zeichnung dargestellten Ausführungsbeispiels beschrieben:The invention is described below with reference to an embodiment shown in the drawing:

In der Zeichnung zeigen:

  • Figur 1 einen Schnitt durch eine Ausführungsform einer Membranpumpe;
  • Figur 2 einen vergrößerten Detailschnitt der Ventileinheit in der einen Grenzlege;
  • Figur 3 die Ventileinheit gemäß Figur 1 in der enderen Grenzlage und
  • Figur 4 einen Schnitt durch eine andere Ausführungsform der Ventileinheit.
The drawing shows:
  • 1 shows a section through an embodiment of a diaphragm pump;
  • FIG. 2 shows an enlarged detail section of the valve unit in one boundary layer;
  • 3 shows the valve unit according to FIG. 1 in the end limit position and
  • Figure 4 shows a section through another embodiment of the valve unit.

Die Membranpumpe gemäß Figur 1 weist ein mehrteiliges Gehäuse auf, des aus einem Tank 1 für das hydraulische Arbeitsmedium, einem Kolbengehäuse 2, einem Ventilkopf 3 und einem Dosierkopf 4 besteht, die axial hintereinander montiert sind. Auf dem Tank 1 sitzt ein Antriebsmotor 5 mit einem Schneckengetriebe 6, das einen Exzenter 7 entreibt. Der Exzenter 7 wirkt auf einen Hohlkolben 8, der im Kolbengehäuse 2 geführt und im Bereich seiner Antriebsseite mit einer Querbohrung 9 für den Übertritt des Hydraulikmediums aus dem Tank 1 in den Hohlreum des Kolbens versehen ist. Im Bereich der Antriebsseite ist der Kolben 8 ferner von einem Steuerschieber 10 übergriffen, der als Anschnittsteuerung eine Einstellung des Arbeitshubs ermöglicht. Der Kolben 8 steht schließlich unter Wirkung einer Feder 11, die ihn in Anlage am Exzenter 7 hält. Der Hohlraum des Kolbens 8 sowie ein ihm vorgelegerter Raum 12 im Kolbengehäuse 2 und eine im Ventilkopf 3 angeordnete Kammer 13 bilden den Arbeitsraum der Dosierpumpe, wobei der Raum 12 über ein Überdruckventil 27 mit dem Tank 1 verbunden ist.The membrane pump according to FIG. 1 has a multi-part housing, which consists of a tank 1 for the hydraulic working medium, a piston housing 2, a valve head 3 and a metering head 4, which are mounted axially one behind the other. On the tank 1 there is a drive motor 5 with a worm gear 6 which drives an eccentric 7. The eccentric 7 acts on a hollow piston 8 which is guided in the piston housing 2 and is provided in the region of its drive side with a transverse bore 9 for the transfer of the hydraulic medium from the tank 1 into the cavity of the piston. In the area of the drive side, the piston 8 is also overlapped by a control slide 10 which, as a gate control, enables the working stroke to be adjusted. The piston 8 is finally under the action of a spring 11 which keeps it in contact with the eccentric 7. The cavity of the piston 8 and a space 12 in front of it in the piston housing 2 and a chamber 13 arranged in the valve head 3 form the working space of the metering pump, the space 12 being connected to the tank 1 via a pressure relief valve 27.

Die Kammer 13 wird vorderseitig von einer Dosiermembren 14 begrenzt, die zugleich den rückseitigen Abschluß eines Dosierraums 15 bildet. Der Dosierraum 15 ist über ein Saugventil an das zu fördernde Medium angeschlossen und weist ferner ein Druckventil 17 auf. Schließlich ist die Kammer 13 noch mit einem Entlüftungsventil 18 ausgestattet.The chamber 13 is delimited on the front by a metering diaphragm 14, which at the same time forms the rear end of a metering chamber 15. The dosing chamber 15 is connected to the medium to be conveyed via a suction valve and also has a pressure valve 17. Finally, the chamber 13 is also equipped with a vent valve 18.

Zwischen dem Raum 12 und der Kammer 13 sind in einer vom Ventilkopf 3 gebildeten Trennwand mehrere Überströmkanäle 19 konzentrisch um eine gemeinsame Achse engeordnet, wie insbesondere aus Figur 2 und 3 ersichtlich. Achsgleich ist innerhalb des Ventilkopfs ein Stößel 20 geführt, der im Bereich der Führung von den Uberströmkanälen 19 konzentrisch umgeben ist. Der Stößel 20 weist beiderseits der vom Ventilkopf 3 gebildeten Trennwand je einen Ventilteller 21, 22 auf, die mit einem entsprechenden Kegelsitz 23 bzw. 28, die in die Trennwand eingearbeitet sind und die Überströmkanäle 19 nach außen hin erweitern, zusammenwirken. Der Stößel 20 mit den Ventiltellern 21,22 und den Kegelsitzen 23, 28 bilden die dem Schutz der Membran 14 dienende Ventileinheit 30.Between the chamber 12 and the chamber 13, a plurality of overflow channels 19 are arranged concentrically about a common axis in a partition wall formed by the valve head 3, as can be seen in particular from FIGS. 2 and 3. A tappet 20 is axially aligned within the valve head and is concentrically surrounded by the overflow channels 19 in the region of the guide. The plunger 20 has on both sides of the partition wall formed by the valve head 3 each a valve plate 21, 22, which cooperate with a corresponding conical seat 23 or 28, which are incorporated in the partition wall and expand the overflow channels 19 to the outside. The tappet 20 with the valve disks 21, 22 and the conical seats 23, 28 form the valve unit 30 serving to protect the membrane 14.

Bei dem gezeigten Ausführungsbeispiel weist der Stößel 20 an dem dem Ventilteller 21 gegenüberliegenden Ende einen Ansatz 29 mit einer Stützscheibe 24 auf, die sich über eine Distanzbüchse 25 an dem anderen Ventilteller 22 abstützt. Die Stützscheibe 24 liegt unter Wirkung einer Feder 26, die sich an der Wandung der Kammer 13 abstützt, der Membran 14 lose an.In the exemplary embodiment shown, the plunger 20 has an extension 29 at the end opposite the valve plate 21 a support disc 24, which is supported on the other valve plate 22 via a spacer sleeve 25. The support disk 24 lies loosely against the membrane 14 under the action of a spring 26, which is supported on the wall of the chamber 13.

In Figur 2 ist die Extremlage der Membran 14 beim Druckhub erkennbar, bei der der Vantilkegel 21 die Überströmkanäle 19 gegenüber dem Arbeitsraum 12 das Kolbens 8 verschließt, während in Figur 3 die andere Grenzlage beim Saughub gezeigt ist, bei der der Ventilkegel 22 die Überströmkanäle 19 verschließt. In beiden Grenzlagen ist die Membran also vom Arbeitsraum hydraulisch abgekoppelt, so daß sie über die Grenzlagen hinaus nicht belastet werden kann.The extreme position of the diaphragm 14 during the pressure stroke can be seen in FIG. 2, in which the vantile cone 21 closes the overflow channels 19 with respect to the working space 12, the piston 8, while FIG. 3 shows the other limit position during the suction stroke, in which the valve cone 22 overflows the overflow channels 19 closes. In both limit positions, the membrane is hydraulically decoupled from the work area so that it cannot be loaded beyond the limit positions.

Figur 4 zeigt eine abgewandelte Ausführungsform der Ventileinheit 30, die insbesondere fertigungs- und montagetechnische Vorteile hat. Sie weist wiederum einen Stößel 20 auf, an dessen beiden Enden je ein Ventilteller 21, 22 befestigt ist, die wiederum mit Kegelsitzen 23, 28 zusammenwirken. Die Kegelsitze 23, 28 sind wie auch die Überströmkanäle 19 an einem Einsatz 31 angeordnet, der seinerseits wiederum dicht in den Ventilkopf 3 (Figur 1) eingesetzt ist. Der Einsatz 31 weist zwischen den Überströmkanälen 19 und dem der Membran 14 (Figur 1) zugewandten Ventilteller 22 eine Bohrung größeren Durchmessers auf, in der die Feder 26 angeordnet ist, die sich einerseits im Einsatz 31, andererseits am Ventilteller 22 abstützt und somit die Ventileinheit 30 in Richtung zur Membran 14 drängt.FIG. 4 shows a modified embodiment of the valve unit 30, which has particular advantages in terms of production and assembly. It in turn has a tappet 20, on each of which ends a valve plate 21, 22 is attached, which in turn cooperate with conical seats 23, 28. The conical seats 23, 28, like the overflow channels 19, are arranged on an insert 31, which in turn is inserted tightly into the valve head 3 (FIG. 1). The insert 31 has a bore of larger diameter between the overflow channels 19 and the valve plate 22 facing the membrane 14 (FIG. 1), in which the spring 26 is arranged, which is supported on the one hand in the insert 31 and on the other hand on the valve plate 22 and thus the valve unit 30 urges towards the membrane 14.

Claims (10)

1. Membrane pump, particularly for dosing liquids with a membrane defining on one side a dosing zone with suction and pressure valve and on the other side a hydraulic working zone with driving piston and overpressure valve, said membrane defining a chamber connected to the working zone via at least one overflow pipe and in the vicinity of the overflow pipe is guided a plunger with in each case one valve disk for the facing openings of the overflow pipe and the valve unit comprising the plunger and the valve disk is in operative connection with the membrane, characterized in that the valve unit (30) loosely engages on the membrane via a supporting plate (24) under the action of a weak spring (26).
2. Membrane pump according to claim 1, characterized in that spring (26), in the case of hydraulic equilibrium on either side of the membrane (14), merely has a spring tension overcoming the frictional forces of the plunger guide and the forces of inertia.
3. Membrane pump according to claims 1 or 2, characterized in that the valve unit (30) has a lug {29) passing through chamber (13) and said lug has the supporting plate engaging the membrane (14).
4. Membrane pump according to one of the claims 1 to 4, characterized in that between the chamber (13) and the hydraulic working zone (12) is provided an insert (31), in which is guided the punger (20) of valve unit (30) and in which is arranged the overflow pipe (19).
5. Membrane pump according to one of the claims 1 to 4, characterized in that the insert (31) contains several overflow pipes (19) surrounding the plunger (20) or its guide and whose facing openings are covered on either side of the partition by in each cae one of the valve disks (21 or 22) of valve unit (3).
6. Membrane pump according to one of the claims 1 to 5, characterized in that a cone seat (23, 28) is formed on either side of insert (31) and its small diameter roughly corresponds to the diameter of the outer envelope circle of the openings of overflow pipes (19).
7. Membrane pump according to claim 6, characterized in that the valve disks (21, 22) as a sealing surface also have a conical surface.
8. Membrane pump according to one of the claims 1 to 7, characterized in that spring (26) is arranged between the two valve disks (21, 22) and is supported on the one hand within the insert and on the other on the valve disk (22) facing membrane (14).
9. Membrane pump according to one of the claims, 1 to 7, characterized in that the spring is a helical spring (26) supported on the one hand on the supporting plate (24) and on the other on the side of chamber (13) opposite thereto.
10. Membrane pump according to one of the claims 1 to 9, characterized in that the membrane (14) is made from plastic.
EP85109557A 1984-08-21 1985-07-30 Membrane pump, especially for dosing liquids Expired EP0175105B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19843430721 DE3430721A1 (en) 1984-08-21 1984-08-21 DIAPHRAGM PUMP, ESPECIALLY FOR DOSING LIQUIDS
DE3430721 1984-08-21

Publications (2)

Publication Number Publication Date
EP0175105A1 EP0175105A1 (en) 1986-03-26
EP0175105B1 true EP0175105B1 (en) 1987-10-14

Family

ID=6243546

Family Applications (1)

Application Number Title Priority Date Filing Date
EP85109557A Expired EP0175105B1 (en) 1984-08-21 1985-07-30 Membrane pump, especially for dosing liquids

Country Status (4)

Country Link
US (1) US4619589A (en)
EP (1) EP0175105B1 (en)
JP (1) JPS6161990A (en)
DE (2) DE3430721A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109458316A (en) * 2018-09-29 2019-03-12 陕西科技大学 A kind of sulfuric acid feed pump

Families Citing this family (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5163820A (en) * 1987-11-16 1992-11-17 Karldom Corporation Airless sprayer with adjustable pressure unloading valve
DE8816172U1 (en) * 1988-12-30 1989-02-16 Alltech Dosieranlagen Gmbh, 7504 Weingarten, De
JPH03149371A (en) * 1989-11-02 1991-06-25 Nippon Fuiidaa Kogyo Kk Diaphragm pump
US5186615A (en) * 1990-06-26 1993-02-16 Karldom Corporation Diaphragm pump
US5165869A (en) * 1991-01-16 1992-11-24 Warren Rupp, Inc. Diaphragm pump
US5249932A (en) * 1991-10-07 1993-10-05 Erik Van Bork Apparatus for controlling diaphragm extension in a diaphragm metering pump
DE4141670C2 (en) * 1991-12-17 1994-09-29 Ott Kg Lewa Hydraulically driven diaphragm pump with diaphragm stroke limitation
EP0997643B1 (en) * 1998-09-25 2006-07-12 ALLDOS Eichler GmbH Diaphragm metering pump
US6264432B1 (en) 1999-09-01 2001-07-24 Liquid Metronics Incorporated Method and apparatus for controlling a pump
US6350110B1 (en) * 2000-03-31 2002-02-26 B&G International Multiport metering pump
US6689503B2 (en) 2001-02-15 2004-02-10 Asia Pacific Fuel Cell Technologies, Ltd. Fuel cell with uniform compression device
TW488111B (en) 2001-04-16 2002-05-21 Asia Pacific Fuel Cell Tech Anode stream recirculation system for a fuel cell
TW499778B (en) 2001-04-16 2002-08-21 Asia Pacific Fuel Cell Tech Generating system for a fuel cell, and heat waste recirculating and cooling system of the generating system
TW533620B (en) 2001-07-24 2003-05-21 Asia Pacific Fuel Cell Tech Metal hydride hydrogen storage canister design and its manufacture
TW518797B (en) * 2001-08-14 2003-01-21 Asia Pacific Fuel Cell Tech Enhanced heat conductive device for supply device of hydrogen source, and supply device of hydrogen source having the same
CN1407644A (en) * 2001-08-23 2003-04-02 亚太燃料电池科技股份有限公司 Diaphragm pump of fuel battery and anodic gas circulating system therewith
JP4330323B2 (en) * 2001-10-24 2009-09-16 株式会社タクミナ Reciprocating pump
ATE373172T1 (en) * 2002-10-09 2007-09-15 Tacmina Corp RECIPIENT PUMP AND NON-CHECK VALVE
FR2895036B1 (en) * 2005-12-20 2008-02-22 Milton Roy Europ Sa HYDRAULICALLY ACTUATED MEMBRANE PUMP WITH LEAK COMPENSATION DEVICE
CN101245777B (en) * 2007-02-13 2010-09-08 米尔顿罗伊欧洲公司 Hydraulic pressure driven membrane pump with leakage compensation equipment
DE102008028772A1 (en) * 2008-06-17 2009-12-24 Hansen, Bernd, Dipl.-Ing. Device for filling containers
US9719504B2 (en) 2013-03-15 2017-08-01 Integrated Designs, L.P. Pump having an automated gas removal and fluid recovery system and method
DE102013108672A1 (en) 2013-08-09 2015-02-12 Aker Wirth Gmbh displacement
US10024311B2 (en) * 2015-08-06 2018-07-17 Caterpillar Inc. Cryogenic pump for liquefied natural gas
DE202021106223U1 (en) * 2021-11-15 2021-11-19 Feluwa Pumpen Gmbh Diaphragm piston pump

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE7420951U (en) * 1975-01-16 Lewa H Kg Diaphragm pump
US2303597A (en) * 1940-05-09 1942-12-01 Infilco Inc Measuring pump
US2993446A (en) * 1957-06-01 1961-07-25 Pleuger Diaphragm piston pump
GB887774A (en) * 1959-06-26 1962-01-24 Charles Wilfred Simpson Improvements in and relating to diaphragm pumps
US3392674A (en) * 1966-10-28 1968-07-16 Paul W. Schlosser Pump with piston and diaphragm
DE7303301U (en) * 1973-01-30 1974-04-04 Feluwa Schlesiger & Co Kg Diaphragm piston pump
US3957399A (en) * 1975-03-20 1976-05-18 Graco Inc. Diaphragm pump
FR2492473B1 (en) * 1980-10-17 1985-06-28 Milton Roy Dosapro COMPENSATION MEMBRANE PUMP IN THE HYDRAULIC CONTROL CHAMBER

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109458316A (en) * 2018-09-29 2019-03-12 陕西科技大学 A kind of sulfuric acid feed pump

Also Published As

Publication number Publication date
JPS6161990A (en) 1986-03-29
DE3430721A1 (en) 1986-03-06
US4619589A (en) 1986-10-28
DE3560776D1 (en) 1987-11-19
EP0175105A1 (en) 1986-03-26

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