EP0078031A1 - Pressure accumulator - Google Patents

Pressure accumulator Download PDF

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Publication number
EP0078031A1
EP0078031A1 EP82109758A EP82109758A EP0078031A1 EP 0078031 A1 EP0078031 A1 EP 0078031A1 EP 82109758 A EP82109758 A EP 82109758A EP 82109758 A EP82109758 A EP 82109758A EP 0078031 A1 EP0078031 A1 EP 0078031A1
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EP
European Patent Office
Prior art keywords
piston
chamber
recess
piston head
cylinder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP82109758A
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German (de)
French (fr)
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EP0078031B1 (en
Inventor
Douglas Millard Gage
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Deere and Co
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Deere and Co
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Publication date
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Publication of EP0078031A1 publication Critical patent/EP0078031A1/en
Application granted granted Critical
Publication of EP0078031B1 publication Critical patent/EP0078031B1/en
Expired legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/02—Installations or systems with accumulators
    • F15B1/04—Accumulators
    • F15B1/08—Accumulators using a gas cushion; Gas charging devices; Indicators or floats therefor
    • F15B1/24—Accumulators using a gas cushion; Gas charging devices; Indicators or floats therefor with rigid separating means, e.g. pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/20—Accumulator cushioning means
    • F15B2201/205—Accumulator cushioning means using gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/30—Accumulator separating means
    • F15B2201/31—Accumulator separating means having rigid separating means, e.g. pistons
    • F15B2201/312—Sealings therefor, e.g. piston rings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/30—Accumulator separating means
    • F15B2201/32—Accumulator separating means having multiple separating means, e.g. with an auxiliary piston sliding within a main piston, multiple membranes or combinations thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/40—Constructional details of accumulators not otherwise provided for
    • F15B2201/41—Liquid ports
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B2201/00—Accumulators
    • F15B2201/40—Constructional details of accumulators not otherwise provided for
    • F15B2201/415—Gas ports
    • F15B2201/4155—Gas ports having valve means

Definitions

  • the invention relates to a cylinder-piston arrangement in which, in a housing forming the cylinder, a displaceable piston arrangement, two cylinder chamber sections, one of which contains a pressure fluid, seals against one another by means of seals slidingly engaging on the cylinder wall.
  • a cylinder-piston arrangement is particularly suitable for use as a pressure accumulator.
  • a pressure accumulator has two main functions when used as part of a hydraulic circuit.
  • the first function is to hold a predetermined supply of hydraulic fluid under pressure so that it can be supplied to the hydraulic circuit should the fluid under pressure be needed in an emergency.
  • the second main function of an accumulator is to absorb pressure peaks in the hydraulic system.
  • An accumulator generally consists of a housing that forms a cylinder that is closed at each end.
  • a piston is slidably guided in the cylinder, which divides the cylinder into a first and a second chamber.
  • the first chamber contains a pressurized gas while the second chamber contains the hydraulic fluid reservoir under system pressure. Should the system pressure drop unexpectedly for any reason, the pressurized gas drives the piston, which carries the hydraulic fluid from the second chamber into the system feeds so that it is available there for emergency operations. When the system pressure returns, the second chamber receives a corresponding amount of hydraulic fluid against the pre-pressure of the gas.
  • the cylinder-piston arrangement be particularly suitable to be used as an accumulator.
  • the piston arrangement itself consists of several, preferably two, pistons which are independent of one another, and two pistons each contain an incompressible barrier fluid. Any number of pistons can be arranged, the incompressible barrier fluid being arranged between every two pistons. As a rule, however, two such pistons are sufficient.
  • the pistons are preferably floating and displaceably arranged piston heads, which seal the intermediate space receiving the incompressible barrier fluid from the respectively adjacent cylinder chamber sections. Due to the enclosed and pressurized incompressible barrier liquid, a fluid seal is obtained between the two main or working chambers of the cylinder or accumulator.
  • Each piston head can have an endless recess on its circumference, which is open towards the cylinder wall.
  • Each of these recesses can receive a fluid, specifically through an opening in the associated piston head, so as to obtain a further sealing ability. It was found that the new cylinder-piston arrangement creates a pressure equalization over the piston head, which prevents any creeping out or leakage of the pressurized fluid or gas from the first working chamber into the second working chamber, even under difficult conditions.
  • FIG. 1 A conventional accumulator is shown in FIG. 1, which has a housing 11. In this a cylindrical chamber 12 is formed, which is closed at both ends by end caps 27 and 29. In the chamber 12, a piston 13 is slidably mounted. The piston contains an annular recess 15 and an opening 17 which leads from the recess to the rear end face of the piston. Sealing devices are provided between the piston 13 and the wall of the cylindrical chamber 12. For this purpose, annular seal packs 19 and 21 are used, which are arranged on both sides of the recess 15. The piston 13 divides the chamber 12 into two working chamber sections 23 and 25.
  • the end cap or end cap 27 has an oil connection opening 39 through which hydraulic fluid can get into the chamber 25 and from there into the hydraulic system.
  • the closure cap 29 at the other end has a compressed gas valve 49 through which compressed gas can be introduced into the chamber 23.
  • the conventional accumulator of Fig. 1 shows a tendency to lose its gas pressure over time, under certain extreme conditions.
  • a possible reason for the loss of gas pressure can be caused by the total amount of hydraulic supply being expelled from the second chamber 25, so that the piston 15 comes into contact with the closure cap 27. This creates a pressure imbalance across the seal packs 19 and 21. This can lead to a loss of gas under pressure in the recess 15, with the result that the biasing pressure of the gas decreases.
  • Another possibility can occur if the accumulator is used under extremely low temperatures. This reduces the flexibility of the seal packs 19 and 21, so that the seal loses its effect and gas can leak into the recess 25.
  • FIG. 2 This shows a new type of accumulator.
  • the accumulator comprises a housing 50 which delimits a cylindrical chamber 51.
  • a piston arrangement 52 consists of two freely floating piston heads 52a and 52b. These are slidably arranged in the cylinder chamber 51.
  • the pistons 52a and 52b each have endless recesses 54 and 64 which are open on their circumference towards the cylinder wall.
  • the pistons also have corresponding openings 56 and 66. These extend rearward from the respective recesses 54 and 64.
  • a first stack of gasket 58 lies in front of the endless recess 54 and comprises a packing ring which is supported between two support rings.
  • a second seal stack 60 comprises a packing ring, behind which a support ring lies.
  • This seal pack is arranged behind the recess 54.
  • Another stack of sealing rings 68 lies in front of the endless recess 64 in the piston head 52b.
  • a sealing ring stack 70 lies behind the recess 54.
  • the sealing ring stacks 68 and 70 are each designed to match the sealing ring stacks 58 and 60.
  • the piston heads 52a and 52b divide the accumulator into a first chamber section 72 for receiving the gas under pressure and a second chamber section 74, in which the hydraulic fluid is received. Between the piston heads 52a and 52b, which are spaced from one another, a generally incompressible fluid of relatively high density is enclosed, including the cylinder wall. The trapped fluid completely occupies the space between the piston heads 52a and 52b so that the piston heads 52a and 52b make a synchronous or common movement. One can therefore speak of the piston heads 52a and 52b and the enclosed incompressible fluid move in the longitudinal direction of the cylinder chamber 51 as a unit. The ends of the housing 50 are sealed by caps 80 and 82.
  • the closure cap 80 is firmly and sealingly attached to the housing 50 by appropriate measures, for example by a weld 90, in order to enclose the chamber section 72.
  • the closure cap 80 has a conventional gas valve 92 through which the bias gas can be introduced into the chamber section 72.
  • the closure cap 82 is fixedly and sealingly mounted on the housing 52 with the aid of a snap ring 86 in the usual way.
  • a sealing ring stack 84 which corresponds to the sealing ring stack 58, lies in front of the snap ring 86.
  • An opening or bore 88 extends through the closure cap 82 in order to introduce the hydraulic fluid into the chamber section 74 or to lead it out of this into the hydraulic system.
  • the piston head 52b has a filling opening in the end face 76, which is subsequently closed pressure-tight and tightly by a stopper 78.

Abstract

1. Pressure accumulator having a housing (50) defining an elongated cylindrical chamber in which a multi-piston arrangement (52) is slidably disposed, with at least two pistons arranged in series in the longitudinal direction of the housing so as to enclose a generally incompressible fluid between them, each piston having a circumferential sealing arrangement (54, 58, 60 and 64, 68, 70, respectively), and so as to divide the chamber into a first and a second zone (72 and 74, respectively), the first of which is closed and sealed by an end cap (80) having a gas valve (92) and the second by an end cap (82) having a fluid connection bore (88), characterised in that the multipiston arrangement (52) consists of piston heads (52a, 52b) independent of one another and arranged to float freely and which are disposed at a mutual spacing in the longitudinal direction of the housing (50), the piston head (52a) facing the first zone (72) of the chamber has a continuous circumferential recess (54) with a connecting duct (56) extending from the recess (54) to that side of the piston head (52a) which faces away from the first zone (72) of the chamber and the sealing arrangement associated with this piston head has a sealing ring (58) between the recess (54) and the first zone (72) of the chamber, and the piston head (52b) facing the second zone (74) of the chamber has a continuous circumferential recess (64) with a connecting duct (66) extending from the recess (64) to that side of the piston head (52b) which faces the second zone (74) of the chamber and the sealing arrangement associated with this piston head has a selaing ring (68) between the recess (64) and that side of the piston head (52b) which faces away from the second zone (74) of the chamber.

Description

Die Erfindung betrifft eine Zylinder-Kolben-Anordnung, bei der in einem den Zylinder bildenden Gehäuse eine verschiebliche Kolbenanordnung,zwei Zylinderkammerabschnitte, von denen einer ein Druckfluid enthält, mittels an der Zylinderwand gleitend angreifenden Dichtungen gegeneinander abdichtet. Eine solche Zylinder-Kolben-Anordnung ist besonders geeignet für den Einsatz als Druckakkumulator.The invention relates to a cylinder-piston arrangement in which, in a housing forming the cylinder, a displaceable piston arrangement, two cylinder chamber sections, one of which contains a pressure fluid, seals against one another by means of seals slidingly engaging on the cylinder wall. Such a cylinder-piston arrangement is particularly suitable for use as a pressure accumulator.

Ein Druckakkumulator hat zwei Hauptfunktionenbeiseiner Verwendung als Teil eines hydraulischen Kreises zu erfüllen. Die erste Funktion besteht darin, einen vorbestimmten Vorrat an von Druck beeinflußten hydraulischen Fluid bereitzuhalten, so daß dieser dem hydraulischen Kreis zugeleitet werden kann, sollte vom Druck beeinflußtes Fluid in einem Notfall benötigt werden. Die zweite Hauptfunktion eines Akkumulators besteht darin, Druckspitzen in dem hydraulischen System zu absorbieren.A pressure accumulator has two main functions when used as part of a hydraulic circuit. The first function is to hold a predetermined supply of hydraulic fluid under pressure so that it can be supplied to the hydraulic circuit should the fluid under pressure be needed in an emergency. The second main function of an accumulator is to absorb pressure peaks in the hydraulic system.

Ein Akkumulator besteht generell aus einem Gehäuse, welches einen Zylinder bildet, der an jedem Ende geschlossen ist. Ein Kolben ist in dem Zylinder verschiebbar geführt, der den Zylinder in eine erste und eine zweite Kammer unterteilt. Die erste Kammer enthält ein unter Druck stehendes Gas, während die zweite Kammer den hydraulischen Fluidvorrat unter Systemdruck enthält. Sollte aus irgend einem Grunde der Systemdruck unerwarteterweise fallen treibt das unter Druck stehende Gas den Kolben an, der das hydraulische Fluid aus der zweiten Kammer in das System einspeist, so daß es dort für Notvorgänge zur Verfügung steht. Wenn der Systemdruck wiederkehrt, nimmt die zweite Kammer eine entsprechende Menge von hydraulischem Fluid gegen den Vordruck des Gases wieder auf.An accumulator generally consists of a housing that forms a cylinder that is closed at each end. A piston is slidably guided in the cylinder, which divides the cylinder into a first and a second chamber. The first chamber contains a pressurized gas while the second chamber contains the hydraulic fluid reservoir under system pressure. Should the system pressure drop unexpectedly for any reason, the pressurized gas drives the piston, which carries the hydraulic fluid from the second chamber into the system feeds so that it is available there for emergency operations. When the system pressure returns, the second chamber receives a corresponding amount of hydraulic fluid against the pre-pressure of the gas.

Es wurde festgestellt, daß über längere Zeitperioden der Gasdruck aufgrund von Auslecken absinkt, so daß der Akkumulator nicht mehr weiterhin in der Lage ist hydraulisches Fluid unter ausreichend hohem Druck für Notfälle zur Verfügung zu stellen. Einer von den vermuteten Gründen für den Verlust an Gasdruck besteht darin, daß das Gas aus der ersten Kammer in die zweite Kammer um den Kolben herum ausleckt oder aussickert. Wenn der Kolben in der zweiten Kammer zum Anschlag kommt, entsteht ein Druckungleichgewicht über dem Kolben. Durch die Druckdifferenz kann das Gas veranlaßt sein an den Dichtungspackungen oder Ringen des Kolbens vorbei zu kriechen. Auch dann, wenn Akkumulatoren bei Arbeitsfahrzeugen verwendet werden, die in Gegenden von niedriger Temperatur eingesetzt werden, kann vermutlich die Abnahme der Flexibilität und die mögliche geringe Zusammenziehung des Dichtmaterials um den Kolben dazu führen, daß Gas aus der ersten Kammer in die zweite Kammer entweichen kann. Auch dadurch sinkt der Vordruck.It has been found that the gas pressure drops due to leakage over longer periods of time, so that the accumulator is no longer able to provide hydraulic fluid under high enough pressure for emergencies. One of the suspected reasons for the loss of gas pressure is that the gas leaks or leaks from the first chamber into the second chamber around the piston. When the piston stops in the second chamber, a pressure imbalance arises across the piston. The pressure difference can cause the gas to crawl past the packing or rings of the piston. Even if accumulators are used in work vehicles that are used in areas of low temperature, the decrease in flexibility and the possible slight contraction of the sealing material around the piston can lead to gas being able to escape from the first chamber into the second chamber . This also reduces the form.

Es ist Aufgabe der vorliegenden Erfindung eine Zylinder-Kolben-Anordnung der eingangs näher bezeichneten Art so weiterzubilden, daß die aufgezeigten Probleme vermieden werden und eine sichere Abdichtung zwischen den beiden Hauptkammern des Zylinders auch dann gewährleistet ist, wenn der Kolben in der Hydraulikfluidkammer zum Anschlag kommt oder wenn die Anordnung bei Geräten eingesetzt-ist, die tieferen Temperaturen unterworfen sind. Dabei soll die Zylinder-Kolben-Anordnung . besonders geeignet sein, um als Akkumulator eingesetzt werden zu können.It is an object of the present invention to develop a cylinder-piston arrangement of the type specified in the introduction in such a way that the problems indicated are avoided and a secure seal between the two main chambers of the cylinder is also ensured when the piston comes to a stop in the hydraulic fluid chamber or if the arrangement is used in devices which are subjected to lower temperatures. The cylinder-piston arrangement. be particularly suitable to be used as an accumulator.

Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß die Kolbenanordnung selbst aus mehreren - vorzugsweise aus zwei -, voneinander unabhängigen Kolben besteht, und jeweils zwei Kolben ein inkompressibles Sperrfluid eingeschlossen halten. Es können beliebig viele Kolben angeordnet sein, wobei zwischen jeweils zwei Kolben das inkompressible Sperrfluid angeordnet ist. In der Regel reichen jedoch zwei solche Kolben aus. Die Kolben sind vorzugsweise schwimmend und im gegenseitigen Abstand verschieblich angeordnete Kolbenköpfe, welche den das inkompressible Sperrfluid aufnehmenden Zwischenraum gegenüber den jeweils benachbarten Zylinderkammerabschnitten abdichten. Durch die eingeschlossene und unter Druck stehende inkompressible Sperrflüssigkeit erhält man eine Fluiddichtung zwischen den beiden Haupt- oder Arbeitskammern des Zylinders oder Akkumulators. Jeder Kolbenkopf kann an seinem Umfang eine endlose Ausnehmung aufweisen, die zur Zylinderwand hin offen ist. Jede dieser Ausnehmungen kann ein Fluid aufnehmen, und zwar durch eine öffnung in dem zugehörigen Kolbenkopf, um so eine weitere Abdichtungsfähigkeit zu erhalten. Es konnte festgestellt werden, daß die neue Zylinder-Kolben- Anordnung einen Druckausgleich über den Kolbenkopf erzeugt, der jedes Auskriechen oder Auslecken von dem Druckfluid oder Druckgas aus der ersten Arbeitskammer in die zweite Arbeitskammer auch unter erschwerten Bedingungen verhindert.This object is achieved in that the piston arrangement itself consists of several, preferably two, pistons which are independent of one another, and two pistons each contain an incompressible barrier fluid. Any number of pistons can be arranged, the incompressible barrier fluid being arranged between every two pistons. As a rule, however, two such pistons are sufficient. The pistons are preferably floating and displaceably arranged piston heads, which seal the intermediate space receiving the incompressible barrier fluid from the respectively adjacent cylinder chamber sections. Due to the enclosed and pressurized incompressible barrier liquid, a fluid seal is obtained between the two main or working chambers of the cylinder or accumulator. Each piston head can have an endless recess on its circumference, which is open towards the cylinder wall. Each of these recesses can receive a fluid, specifically through an opening in the associated piston head, so as to obtain a further sealing ability. It was found that the new cylinder-piston arrangement creates a pressure equalization over the piston head, which prevents any creeping out or leakage of the pressurized fluid or gas from the first working chamber into the second working chamber, even under difficult conditions.

Die Erfindung wird nachfolgend anhand schematischer Zeichnungen näher erläutert.The invention is explained in more detail below with the aid of schematic drawings.

Es zeigen:

  • Figur 1 im Längsschnitt einen Druckakkumulator bisheriger Bauart und
  • Figur 2 in ähnlicher Darstellung die Zylinder-Kolben- Anordnung gemäß der Erfindung.
Show it:
  • Figure 1 in longitudinal section a pressure accumulator of the previous type and
  • Figure 2 in a similar representation, the cylinder-piston arrangement according to the invention.

In Figur 1 ist ein herkömmlicher Akkumulator gezeigt, der ein Gehäuse 11 aufweist. In diesem ist eine zylindrische Kammer 12 ausgebildet, die an beiden Enden durch Endkappen 27 und 29 verschlossen ist. In der Kammer 12 ist ein Kolben 13 verschieblich montiert. Der Kolben enthält eine ringförmige Ausnehmung 15 und eine Öffnung 17, die von der Ausnehmung zu der rückwärtigen Stirnfläche des Kolbens führt. Abdichtungseinrichtungen sind zwischen dem Kolben 13 und der Wand der zylindrischen Kammer 12 vorgesehen. Hierzu dienen ringförmige Dichtungspackungen 19 und 21, die auf beiden Seiten der Ausnehmung 15 angeordnet sind. Der Kolben 13 unterteilt die Kammer 12 in zwei Arbeitskammerabschnitte 23 und 25. Die Stirnkappe oder Abschlußkappe 27 weist eine ölverbindungsöffnung 39 auf, durch die hydraulisches Fluid in die Kammer 25 und von dieser in das hydraulische System gelangen kann. Die Verschlußkappe 29 am anderen Ende weist ein Druckgasventil 49 auf, durch das Druckgas in die Kammer 23 eingeleitet werden kann.A conventional accumulator is shown in FIG. 1, which has a housing 11. In this a cylindrical chamber 12 is formed, which is closed at both ends by end caps 27 and 29. In the chamber 12, a piston 13 is slidably mounted. The piston contains an annular recess 15 and an opening 17 which leads from the recess to the rear end face of the piston. Sealing devices are provided between the piston 13 and the wall of the cylindrical chamber 12. For this purpose, annular seal packs 19 and 21 are used, which are arranged on both sides of the recess 15. The piston 13 divides the chamber 12 into two working chamber sections 23 and 25. The end cap or end cap 27 has an oil connection opening 39 through which hydraulic fluid can get into the chamber 25 and from there into the hydraulic system. The closure cap 29 at the other end has a compressed gas valve 49 through which compressed gas can be introduced into the chamber 23.

Der herkömmliche Akkumulator nach Fig. 1 zeigt eine Tendenz,über die Zeit seinen Gasdruck zu verlieren,und zwar unter bestimmten extremen Bedingungen. Ein möglicher Grund für den Verlust an Gasdruck kann veranlaßt werden dadurch, daß die Gesamtmenge an hydraulischem Vorrat aus der zweiten Kammer 25 ausgestoßen wird, so daß der Kolben 15 an der Verschlußkappe 27 zur Anlage kommt. Dadurch entsteht ein Druckungleichgewicht über die Dichtungspackungen 19 und 21. Dies kann zu einem Verlust an unter Vordruck stehendem Gas in die Ausnehmung 15 führen, mit der Folge, daß der Vorspannungsdruck des Gases abnimmt. Eine andere Möglichkeit kann auftreten, wenn der Akkumulator unter extrem niederen Temperaturen eingesetzt wird. Dadurch vermindert sich die Flexibilität der Dichtungspackungen 19 und 21, so daß die Dichtung ihre Wirkung einbüßt und Gas in die Ausnehmung 25 auslecken kann.The conventional accumulator of Fig. 1 shows a tendency to lose its gas pressure over time, under certain extreme conditions. A possible reason for the loss of gas pressure can be caused by the total amount of hydraulic supply being expelled from the second chamber 25, so that the piston 15 comes into contact with the closure cap 27. This creates a pressure imbalance across the seal packs 19 and 21. This can lead to a loss of gas under pressure in the recess 15, with the result that the biasing pressure of the gas decreases. Another possibility can occur if the accumulator is used under extremely low temperatures. This reduces the flexibility of the seal packs 19 and 21, so that the seal loses its effect and gas can leak into the recess 25.

Es wird nunmehr Bezug genommen auf Figur 2. In dieser ist ein Akkumulator neuer Ausführung gezeigt. Der Akkumulator umfaßt ein Gehäuse 50, das eine zylindrische Kammer 51 begrenzt. Eine Kolbenanordnung 52 besteht aus zwei frei schwimmend angeordneten Kolbenköpfen 52a und 52b. Diese sind in der Zylinderkammer 51 verschiebbar angeordnet. Die Kolben 52a und 52b weisen jjeweils auf ihrem Umfang zu der Zylinderwand hin offene endlose Ausnehmungen 54 und 64 auf. Die Kolben besitzen außerdem entsprechende öffnungen 56 und 66. Diese erstrecken sich von der jeweiligen Ausnehmung 54 und 64 nach rückwärts. Ein erster Dichtungsrindstapel 58 liegt vor der endlosen Ausnehmung 54 und umfaßt einen Packungsring, der zwischen zwei Stützringen abgestützt ist. Ein zweiter Dichtungsstapel 60 umfaßt einen Packungsring, hinter dem ein Stützring liegt. Diese Dichtungspackung ist hinter der Ausnehmung 54 angeordnet. Ein weiterer Dichtungsringstapel 68 liegt vor der endlosen Ausnehmung 64 in dem Kolbenkopf 52b. Ein Dichtungsringstapel 70 liegt hinter der Ausnehmung 54. Die Dichtungsringstapel 68 und 70 sind mit den Dichtungsringstapeln 58 und 60 jeweils übereinstimmend ausgebildet.Reference is now made to FIG. 2. This shows a new type of accumulator. The accumulator comprises a housing 50 which delimits a cylindrical chamber 51. A piston arrangement 52 consists of two freely floating piston heads 52a and 52b. These are slidably arranged in the cylinder chamber 51. The pistons 52a and 52b each have endless recesses 54 and 64 which are open on their circumference towards the cylinder wall. The pistons also have corresponding openings 56 and 66. These extend rearward from the respective recesses 54 and 64. A first stack of gasket 58 lies in front of the endless recess 54 and comprises a packing ring which is supported between two support rings. A second seal stack 60 comprises a packing ring, behind which a support ring lies. This seal pack is arranged behind the recess 54. Another stack of sealing rings 68 lies in front of the endless recess 64 in the piston head 52b. A sealing ring stack 70 lies behind the recess 54. The sealing ring stacks 68 and 70 are each designed to match the sealing ring stacks 58 and 60.

Die Kolbenköpfe 52a und 52b teilen den Akkumulator in einen ersten Kammerabschnitt 72 zur Aufnahme des unter Vordruck stehenden Gases und einen zweiten Kammerabschnitt 74, in dem das hydraulische Fluid aufgenommen wird. Zwischen den Kolbenköpfen 52a und 52b, die im gegenseitigen Abstand angeordnet sind, ist unter Einbeziehung der Zylinderwand ein allgemein inkompressibles Fluid von 'relativ hoher Dichte eingeschlossen. Das eingeschlossene Fluid nimmt den Raum zwischen den Kolbenköpfen 52a und 52b vollständig ein, so daß die Kolbenköpfe 52a und 52b eine synchrone oder gemeinsame Bewegung ausführen. Man kann also davon sprechen, daß die Kolbenköpfe 52a und 52b und das eingeschlossene inkompressible Fluid sich in Längsrichtung der Zylinderkammer 51 als Einheit bewegen. Die Enden des Gehäuses 50 sind durch Verschlußkappen 80 und 82 abgedichtet. Die Verschlußkappe 80 ist fest und abdichtend an dem Gehäuse 50 durch entsprechende Maßnahmen, z.B. durch eine Schweißnaht 90 befestigt, um den Kammerabschnitt 72 einzuschließen. Die Verschlußkappe 80 weist ein übliches Gasventil 92 auf, durch das das Vorspannungsgas in den Kammerabschnitt 72 eingeleitet werden kann. Die Verschlußkappe 82 ist an dem Gehäuse 52 mit Hilfe eines Schnappringes 86 in üblicher Weise fest und abdichtend montiert. Ein Dichtringstapel 84, der dem Dichtringstapel 58 entspricht, liegt vor dem Schnappring 86. Eine öffnung oder Bohrung 88 erstreckt sich durch die Verschlußkappe 82, um das hydraulische Fluid in den Kammerabschnitt 74 einzuleiten bzw. aus diesem in das hydraulische System zu führen.The piston heads 52a and 52b divide the accumulator into a first chamber section 72 for receiving the gas under pressure and a second chamber section 74, in which the hydraulic fluid is received. Between the piston heads 52a and 52b, which are spaced from one another, a generally incompressible fluid of relatively high density is enclosed, including the cylinder wall. The trapped fluid completely occupies the space between the piston heads 52a and 52b so that the piston heads 52a and 52b make a synchronous or common movement. One can therefore speak of the piston heads 52a and 52b and the enclosed incompressible fluid move in the longitudinal direction of the cylinder chamber 51 as a unit. The ends of the housing 50 are sealed by caps 80 and 82. The closure cap 80 is firmly and sealingly attached to the housing 50 by appropriate measures, for example by a weld 90, in order to enclose the chamber section 72. The closure cap 80 has a conventional gas valve 92 through which the bias gas can be introduced into the chamber section 72. The closure cap 82 is fixedly and sealingly mounted on the housing 52 with the aid of a snap ring 86 in the usual way. A sealing ring stack 84, which corresponds to the sealing ring stack 58, lies in front of the snap ring 86. An opening or bore 88 extends through the closure cap 82 in order to introduce the hydraulic fluid into the chamber section 74 or to lead it out of this into the hydraulic system.

Es wird bemerkt, daß dann, wenn der das Gas enthaltende Kammerabschnitt 72 unter Druck versetzt wird und hydraulisches Fluid sich in dem zweiten Kammerabschnitt 74 befindet. ein Druckausgleich über der Kolbenanordnung 52 vorliegt, wobei das zwischen den Kolbenköpfen 52a und 52b eingeschlossene inkompressible Fluid als Flüssigkeitsdichtung wirksam ist. Hierdurch wird die Möglichkeit des Aussickern von unter Druck stehendem Gas aus der Kammer 72 in den Kammerabschnitt 74 stark reduziert. Es wird auch bemerkt, daß der Vorteil der Verwendung eines - allgemein inkompressiblen Fluids auch darin besteht, daß sich dieses der Form des Gehäuses genau anpaßt und dadurch eine öldichtung bildet, die durch das unter Druck stehende Gas in der Kammer 72 nicht durchdrungen werden kann. Selbst bei niedrigen Temperaturen bleibt die öldichtung eng an die Form des Gehäsues angepaßt, um die Dichtungsfunktion aufrecht zu erhalten. Auch dann, wenn der Kolben 52b an dem Endverschluß 82 aufgrund vollständiger Entleerung des Kammerabschnittes 74 zur Anlage kommt, bleibt ein Vorspannungsdruck über den zweiten Kolbenkopf aufrechterhalten, so daß auch die Zuverlässigkeit der Dichtung erhalten bleibt. Nachdem der Druckausgleich über die Kolbenanordnung dafür sorgt, daß die Flüssigkeitsdichtung unversehrt bleibt, wird dadurch auch die Möglichkeit des Aussickerns von Gas stark vermindert. Es findet auch ein Druckausgleich über die Abdichtungspackung 58 statt, so daß diese auch wesentlich leichter ihre Dichtungsfunktion beibehalten kann.It is noted that when the gas chamber portion 72 is pressurized and hydraulic fluid is in the second chamber portion 74. there is pressure compensation over the piston arrangement 52, the incompressible fluid enclosed between the piston heads 52a and 52b acting as a liquid seal. This greatly reduces the possibility of gas under pressure leaking out of chamber 72 into chamber section 74. It is also noted that the advantage of using a - generally incompressible fluid is that it conforms to the shape of the housing and thereby forms an oil seal that cannot be penetrated by the pressurized gas in chamber 72. Even at low temperatures, the oil seal remains closely matched to the shape of the housing to maintain the sealing function. Even when the piston 52b abuts the end closure 82 due to the complete emptying of the chamber section 74 comes, a bias pressure is maintained across the second piston head, so that the reliability of the seal is maintained. After the pressure compensation via the piston arrangement ensures that the liquid seal remains intact, the possibility of gas leakage is also greatly reduced. There is also pressure equalization via the sealing pack 58, so that it can also maintain its sealing function much more easily.

Zur Füllung der Zwischenkammer zwischen den Kolben weist im dargestellten Beispiel der Kolbenkopf 52b eine Füllöffnung in der Stirnfläche 76 auf, die nachträglich durch einen Stopfen 78 druckfest und dicht verschlossen ist.To fill the intermediate chamber between the pistons, in the example shown the piston head 52b has a filling opening in the end face 76, which is subsequently closed pressure-tight and tightly by a stopper 78.

Claims (4)

1. Zylinder-Kolben-Anordnung, bei der in einem den Zylinder bildenden Gehäuse eine verschiebliche Kolben- anordnung, zwei Zylinderkammerabschnitte, von denen einer ein Druckfluid enthält, mittels an der Zylinderwand gleitend angreifenden Dichtungen gegeneinander abdichtet, dadurch gekennzeichnet, daß die Kolbenanordnung (52) aus mehreren -vorzugsweise zwei-, voneinander unabhängigen Kolben (52a,52b) besteht und jeweils zwischen zwei Kolben ein inkompressibles Sperrfluid eingeschlossen ist.1. Cylinder-piston arrangement in which, in a housing forming the cylinder, a displaceable piston arrangement, two cylinder chamber sections, one of which contains a pressure fluid, seals against one another by means of seals slidingly engaging on the cylinder wall, characterized in that the piston arrangement (52 ) consists of several, preferably two, pistons (52a, 52b) which are independent of one another and in each case an incompressible barrier fluid is enclosed between two pistons. 2. Zylinder-Kolben-Anordnung nach Anspruch 1, in Form eines Akkumulators, bei dem das Gehäuse durch Endkappen abgeschlossen ist, von denen die eine ein Druckventil und die andere eine Fluidverbindungsöffnung aufweist, dadurch gekennzeichnet, daß die schwimmend in dem Zylinder angeordneten Kolbenköpfe (52a,52b) im gegenseitigen Abstand angeordnet sind und den das inkompressible Sperrfluid aufnehmenden Zwischenraum gegenüber den jeweils benachbarten-Zylinderkammerabschnitten (72,74) abdichten.2. Cylinder-piston arrangement according to claim 1, in the form of an accumulator, in which the housing is closed by end caps, one of which has a pressure valve and the other has a fluid connection opening, characterized in that the piston heads arranged floating in the cylinder ( 52a, 52b) are arranged at a mutual distance and seal the intermediate space receiving the incompressible barrier fluid from the respectively adjacent cylinder chamber sections (72, 74). 3. Akkumulator nach Anspruch 2, dadurch gekennzeichnet, daß jeder Kolbenkopf (52a, 52b) eine sich um seinen Umfang erstreckende endlose Ausnehmung (54,64) aufweist, die zur Zylinderwand hin offen ist, und daß jeder Kolbenkopf eine öffnung (56,66) aufweist, welche von der Ausnehmung zu der das Fluid in dem Zylinderkammerabschnitt haltenden Stirnfläche des Kolbenkopfes führt.3. Accumulator according to claim 2, characterized in that each piston head (52a, 52b) has an endless recess (54,64) which extends around its circumference and is open towards the cylinder wall, and in that each piston head has an opening (56,66 ) which leads from the recess to the end face of the piston head holding the fluid in the cylinder chamber section. 4. Akkumulator nach Anspruch 2, dadurch gekennzeichnet, daß jeder Kolbenkopf (52a ,52b) eine sich um seinen Umfang erstreckende endlose Ausnehmung (54; 64) aufweist, die zur Zylinderwand hin offen ist, daß von der der Fluidverbindungsöffnung (88) zugewandten Stirnfläche des einen Kolbens (52b) eine öffnung (66) zu der Ausnehmung (64) dieses Kolbens (52b) führt, während die übrigen Kolbenköpfe (52a) jeweils eine öffnung (56) aufweisen, welche von der das inkompressible Fluid einschließenden Stirnfläche des Kolbenkopfes zu der zugehörigen Ausnehmung führt.4. Accumulator according to claim 2, characterized in that each piston head (52a, 52b) has an endless recess (54; 64) which extends around its circumference and which is open towards the cylinder wall, that of the end face facing the fluid connection opening (88) of the one piston (52b), an opening (66) leads to the recess (64) of this piston (52b), while the other piston heads (52a) each have an opening (56), which extends from the end face of the piston head enclosing the incompressible fluid the associated recess leads.
EP82109758A 1981-10-26 1982-10-22 Pressure accumulator Expired EP0078031B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US31481281A 1981-10-26 1981-10-26
US314812 1981-10-26

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EP0078031B1 EP0078031B1 (en) 1986-07-09

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EP (1) EP0078031B1 (en)
JP (1) JPS5881202A (en)
CA (1) CA1180979A (en)
DE (1) DE3271950D1 (en)
ES (1) ES516793A0 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0854296A2 (en) 1997-01-16 1998-07-22 Hydac Technology Gmbh Piston-type accumulator with sealing device
WO2004003392A1 (en) * 2002-06-27 2004-01-08 Hydac Technology Gmbh Hydraulic accumulator
WO2007030017A1 (en) * 2005-07-18 2007-03-15 Siem Wis As Pressure accumulator to establish sufficient power to handle and operate external equipment, and use thereof
EP2012020A3 (en) * 2007-07-06 2011-04-06 AGCO GmbH Piston accumulator

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10207181A1 (en) * 2001-11-05 2003-05-15 Continental Teves Ag & Co Ohg Pressure reservoir for electrohydraulic braking systems, consists of cylinder with piston with long skirt and sealing rings trapping high-pressure gas
CN102536928B (en) * 2011-12-26 2014-08-13 辽宁东工装备制造有限公司 One-liquid-chamber two-gas-chamber overpressure buffer balancing device for hydraulic system

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2683467A (en) * 1952-05-23 1954-07-13 Greer Hydraulies Inc Piston accumulator
US2754847A (en) * 1951-07-20 1956-07-17 Electrol Inc Piston-type accumulators
GB956572A (en) * 1960-01-30 1964-04-29 Heinz Teves Sealing means for pistons and piston-rods of hydraulic cylinders
DE1450347A1 (en) * 1964-10-22 1969-03-13 Baumgarten Hydrotech Seal for pistons of hydraulic or pneumatic cylinders
CH591020A5 (en) * 1975-08-15 1977-08-31 Gfeller Hans High pressure storage reservoir - has separator of two longitudinally displaceable pistons

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4186777A (en) * 1978-10-27 1980-02-05 Deere & Company Pressure vessel retained energy measurement system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2754847A (en) * 1951-07-20 1956-07-17 Electrol Inc Piston-type accumulators
US2683467A (en) * 1952-05-23 1954-07-13 Greer Hydraulies Inc Piston accumulator
GB956572A (en) * 1960-01-30 1964-04-29 Heinz Teves Sealing means for pistons and piston-rods of hydraulic cylinders
DE1450347A1 (en) * 1964-10-22 1969-03-13 Baumgarten Hydrotech Seal for pistons of hydraulic or pneumatic cylinders
CH591020A5 (en) * 1975-08-15 1977-08-31 Gfeller Hans High pressure storage reservoir - has separator of two longitudinally displaceable pistons

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0854296A2 (en) 1997-01-16 1998-07-22 Hydac Technology Gmbh Piston-type accumulator with sealing device
EP0854296A3 (en) * 1997-01-16 1999-07-07 Hydac Technology Gmbh Piston-type accumulator with sealing device
WO2004003392A1 (en) * 2002-06-27 2004-01-08 Hydac Technology Gmbh Hydraulic accumulator
US7066208B2 (en) 2002-06-27 2006-06-27 Hydac Technology Gmbh Hydraulic accumulator
WO2007030017A1 (en) * 2005-07-18 2007-03-15 Siem Wis As Pressure accumulator to establish sufficient power to handle and operate external equipment, and use thereof
EA010819B1 (en) * 2005-07-18 2008-12-30 Сиэм Вис Ас Pressure accumulator to establish sufficient power to handle and operate external equipment, and use thereof
AU2006288011B2 (en) * 2005-07-18 2010-07-15 Siem Wis As Pressure accumulator to establish sufficient power to handle and operate external equipment, and use thereof
US8474253B2 (en) 2005-07-18 2013-07-02 Siem Wis As Pressure accumulator to establish sufficient power to handle and operate external equipment and use thereof
EP2012020A3 (en) * 2007-07-06 2011-04-06 AGCO GmbH Piston accumulator

Also Published As

Publication number Publication date
JPS5881202A (en) 1983-05-16
ES8400553A1 (en) 1983-10-16
ES516793A0 (en) 1983-10-16
DE3271950D1 (en) 1986-08-14
EP0078031B1 (en) 1986-07-09
CA1180979A (en) 1985-01-15

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