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EP4314212A1 - Piston-cylinder unit, method for producing the piston-cylinder unit - Google Patents

Piston-cylinder unit, method for producing the piston-cylinder unit

Info

Publication number
EP4314212A1
EP4314212A1 EP23700581.4A EP23700581A EP4314212A1 EP 4314212 A1 EP4314212 A1 EP 4314212A1 EP 23700581 A EP23700581 A EP 23700581A EP 4314212 A1 EP4314212 A1 EP 4314212A1
Authority
EP
European Patent Office
Prior art keywords
piston
seal
cylinder
cylinder unit
chlorine
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.)
Pending
Application number
EP23700581.4A
Other languages
German (de)
French (fr)
Inventor
Hermann Schneider
Rainer Sauer
Frank Born
Martin Schleich
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Stabilus GmbH
Original Assignee
Stabilus GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Stabilus GmbH filed Critical Stabilus GmbH
Publication of EP4314212A1 publication Critical patent/EP4314212A1/en
Pending legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F9/00—Springs, vibration-dampers, shock-absorbers, or similarly-constructed movement-dampers using a fluid or the equivalent as damping medium
    • F16F9/32—Details
    • F16F9/36—Special sealings, including sealings or guides for piston-rods
    • F16F9/362—Combination of sealing and guide arrangements for piston rods
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M169/00—Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/162—Special parts or details relating to lubrication or cooling of the sealing itself
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/324—Arrangements for lubrication or cooling of the sealing itself
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3284—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings characterised by their structure; Selection of materials
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2205/00—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions
    • C10M2205/02—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers
    • C10M2205/028—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms
    • C10M2205/0285—Organic macromolecular hydrocarbon compounds or fractions, whether or not modified by oxidation as ingredients in lubricant compositions containing acyclic monomers containing aliphatic monomers having more than four carbon atoms used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
    • C10M2209/00—Organic macromolecular compounds containing oxygen as ingredients in lubricant compositions
    • C10M2209/10—Macromolecular compoundss obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • C10M2209/103—Polyethers, i.e. containing di- or higher polyoxyalkylene groups
    • C10M2209/1033—Polyethers, i.e. containing di- or higher polyoxyalkylene groups used as base material
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/06—Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/10—Inhibition of oxidation, e.g. anti-oxidants
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/36—Seal compatibility, e.g. with rubber
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
    • C10N2030/40—Low content or no content compositions
    • C10N2030/41—Chlorine free or low chlorine content compositions
    • C—CHEMISTRY; METALLURGY
    • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
    • C10N2040/00—Specified use or application for which the lubricating composition is intended
    • C10N2040/08—Hydraulic fluids, e.g. brake-fluids
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2224/00—Materials; Material properties
    • F16F2224/02—Materials; Material properties solids
    • F16F2224/025—Elastomers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2226/00—Manufacturing; Treatments
    • F16F2226/04—Assembly or fixing methods; methods to form or fashion parts
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16F—SPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F2230/00—Purpose; Design features
    • F16F2230/04—Lubrication

Definitions

  • Designation of the invention Piston-cylinder unit, method for producing the piston-cylinder unit
  • the invention relates to a piston-cylinder unit, comprising a cylinder filled with a fluid, a piston guided displaceably in the cylinder, a piston rod attached to the piston, a seal and a lubricant in contact with the seal and with the cylinder, the piston and/or the piston rod.
  • the invention also relates to a method for producing the piston-cylinder unit.
  • WO 2006 007 087 A1 shows examples of piston-cylinder units of the aforementioned type in the form of gas pressure springs.
  • the object of the invention is to create an inexpensive and durable piston-cylinder unit with low friction, especially after long periods of inactivity.
  • the present invention provides a piston-cylinder unit according to claim 1 that solves the technical problem.
  • the object is also achieved by a method for producing the piston-cylinder unit STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
  • the piston-cylinder unit comprises a cylinder filled with a fluid.
  • the piston-cylinder unit is designed, for example, as a gas pressure spring or as a hydraulic damper.
  • the fluid is, for example, a gas, in particular nitrogen, which can have an overpressure compared to the surroundings of the cylinder.
  • the cylinder is preferably shaped as a hollow cylinder and can be made of a metal, in particular steel.
  • the piston-cylinder unit comprises a in the cylinder, preferably along a longitudinal axis of the cylinder, slidably guided piston, which preferably divides the cylinder into two chambers.
  • the piston can be made of a plastic, in particular a thermoplastic material, or of a metal, in particular zinc or aluminum.
  • the piston-cylinder unit includes a piston rod attached to the piston, which is preferably arranged coaxially to the central longitudinal axis of the cylinder.
  • the piston rod can be made of a metal, in particular steel.
  • the piston-cylinder unit comprises at least one seal, in particular for the fluid-tight sealing of the cylinder relative to an environment of the cylinder and/or for the fluid-tight sealing of the chambers of the cylinder against one another.
  • the piston-cylinder unit comprises a lubricant in contact with the seal and with the cylinder, with the seal and the piston and/or with the seal and the piston rod to reduce friction between the seal and the cylinder and/or between the seal and the piston and/or between the seal and the piston rod.
  • the lubricant is a polyalphaolefin oil, also called PAO oil, or a polyalkylene glycol oil, also called PAG oil or polyglycol oil.
  • a polyalphaolefin oil is a synthetic oil that consists of at least 50%, in particular at least 75%, preferably 85% to 95% of polyalphaolefins.
  • a polyalkylene glycol oil is a synthetic oil STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER which consists of at least 50%, in particular at least 75%, preferably 85% to 95% of polyalkylene glycols.
  • the seal consists of acrylonitrile butadiene rubber, also called AB rubber, NBR, nitrile butadiene rubber or nitrile rubber.
  • acrylonitrile-butadiene rubber is chlorine-free, which means that the seal does not contain any deliberately added chlorine or chlorine compounds, nor chlorine or chlorine compounds that have migrated into the seal during manufacture, for example from auxiliary materials such as reaction retarders.
  • Customary seals made of acrylonitrile-butadiene rubber contain chlorine compounds, for example from - usually chlorine-containing - reaction retardants that are used in the manufacture of the seals. Retarders are necessary to produce the seal from an acrylonitrile butadiene rubber melt by injection molding or transfer molding without the melt solidifying prematurely.
  • the piston-cylinder unit according to the invention shows reduced initial friction without increased corrosion compared to conventional piston-cylinder units when a polyalphaolefin oil or a polyalkylene glycol oil is used as the lubricant and the seal is made of chlorine-free acrylonitrile-butadiene rubber.
  • the seal is preferably a piston rod seal, wherein the piston rod, in particular coaxially to the central longitudinal axis of the cylinder, is led out through the seal from the cylinder, and the seal tightly closes the cylinder for the fluid.
  • the problem of increased initial friction described above occurs particularly severely on the piston rod seal, so that the stated advantages of the invention are particularly evident here.
  • the seal is preferably halogen-free. Because the seal not only contains no chlorine, but also no other halogens or halogen compounds, corrosion by halogens or halogen compounds can be ruled out. In this embodiment, the seal contains neither specifically added halogens or halogen compounds nor halogens or halogen compounds that have unintentionally migrated into the seal during the production of the seal.
  • the lubricant preferably contains at least one swelling additive for swelling the seal, the swelling additive being an ester.
  • the ester is preferably soluble in the polyalphaolefin oil or polyalkylene glycol oil and does not chemically interact with the polyalphaolefin oil, polyalkylene glycol oil or additives contained therein under the operating conditions of the piston-cylinder unit.
  • an acrylonitrile butadiene rubber seal may shrink. Shrinkage can impair the sealing effect of the gasket and lead to leakage. This effect is prevented by the swelling additive.
  • the lubricant preferably contains at least one friction reducing additive for reducing friction between the seal and the cylinder, the piston and/or the piston rod, the friction reducing additive being an amphiphilic substance STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER functionalized polymer, an organic molybdenum compound or a fatty acid ester.
  • the friction reducing additive can reduce friction, for example, by forming an interface between the lubricant and the seal, cylinder, piston and/or piston rod.
  • the lubricant preferably contains at least one anti-corrosion additive to reduce corrosion of the cylinder, the piston and/or the piston rod, the anti-corrosion additive being a sulfonate, a cycloalkanoate, a carboxylate, an alkyl succinic acid derivative or a polyol ester.
  • the anti-corrosion additive acts, for example, like a non-ferrous metal deactivator and forms a water-impermeable protective film on a surface of the cylinder, the piston and/or the piston rod.
  • the anti-corrosion additive can be suitable for neutralizing acidic reaction products, for example from the breakdown of additives.
  • the lubricant contains the anti-corrosion additive and the friction-reducing additive, there may be competition between the two additives for occupation of the surface of the cylinder, piston and/or piston rod.
  • the lubricant contains only a small proportion of the anti-corrosion additive. Since the anti-corrosion additive in these configurations competes only slightly with the polyalphaolefin oil, the polyalkylene glycol oil or a friction-reducing additive for occupation of the surface of the cylinder, the piston and/or the piston rod, particularly low friction is achieved in these configurations.
  • the anti-corrosion additive is not completely dispensed with, since it may be necessary during operation of the piston-cylinder unit STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER water can penetrate into the piston-cylinder unit due to hydrodynamic effects. Without an anti-corrosion additive, this water could cause corrosion, particularly on an interior surface of the cylinder.
  • the method according to the invention serves to produce a piston-cylinder unit according to the invention and includes a chlorine-free production of the seal of the piston-cylinder unit from acrylonitrile-butadiene rubber.
  • the method includes, preferably after manufacture, assembling the seal with the cylinder, the piston and the piston rod of the piston-cylinder unit.
  • the method comprises, preferably after assembly, filling the piston-cylinder unit with the lubricant of the piston-cylinder unit, the lubricant being a polyalphaolefin oil or a polyalkylene glycol oil.
  • the preparation preferably includes retarding a solidification of an acrylonitrile butadiene rubber melt with a chlorine-free reaction retarder.
  • reaction retarder allows the melt to be formed into the seal, for example by injection molding or transfer molding, without the latter solidifying prematurely or having to be additionally heated in order not to solidify. If the reaction retarder is chlorine-free, in particular halogen-free, this results in the above-mentioned advantages of the chlorine-free, in particular halogen-free, seal.
  • the manufacture includes injection molding or transfer molding of the seal from an acrylonitrile butadiene rubber melt.
  • Figure 1 shows a schematic representation of a piston-cylinder unit according to the invention.
  • FIG. 2 shows the friction force acting on the piston rod of a piston-cylinder unit with a mineral oil or a polyalkylene glycol oil as a lubricant.
  • Figure 3 shows the degree of corrosion of steel fingers in contact with a polyalkylene glycol oil as a lubricant with a seal made of chlorine-containing or chlorine-free acrylonitrile-butadiene rubber.
  • Figure 1 shows a schematic representation of a piston-cylinder unit 100 according to the invention as a longitudinal section along a stroke axis H of the piston-cylinder unit, which is, for example, a gas pressure spring.
  • the illustrated piston-cylinder unit 100 comprises a cylinder 110 filled with a fluid 150, for example with nitrogen gas that is at an overpressure relative to the area surrounding the cylinder, and a piston 120 that is displaceably guided in the cylinder 110 along the stroke axis H.
  • a fluid 150 for example with nitrogen gas that is at an overpressure relative to the area surrounding the cylinder
  • a piston 120 that is displaceably guided in the cylinder 110 along the stroke axis H.
  • the illustrated piston-cylinder unit 100 comprises a piston rod 130 attached to the piston 120 and a seal 140.
  • the seal 140 is, for example, a piston rod seal, the piston rod 130 STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER is guided out of the cylinder 110 through the seal 140, and the seal 140 closes the cylinder 110 for the fluid 150 tightly.
  • the illustrated piston-cylinder unit 100 includes a lubricant (not shown) in contact with at least the seal 140 and the piston rod 130.
  • the lubricant is a polyalphaolefin oil or a polyalkylene glycol oil and the seal 140 is made of chlorine-free acrylonitrile butadiene rubber.
  • Figure 2 shows the frictional force F in N acting on the piston rod of a piston-cylinder unit designed as a gas pressure spring from the prior art with a mineral oil (black columns) or a polyalkylene glycol oil (hatched columns) as a lubricant.
  • FIG. 3 shows the degree of corrosion of steel fingers in contact with a polyalkylene glycol oil as a lubricant, in which a seal made of chlorine-containing a or chlorine-free b, c acrylonitrile-butadiene rubber is inserted.
  • the degree of corrosion is determined using a steel finger test based on DIN ISO 7120, Method B. A steel pin is hung in a glass with the seal, the polyalkylene glycol oil and water. After STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER a predetermined reaction time of, for example, 24 hours at a constant temperature of, for example, 60 °C, the degree of corrosion is evaluated on a scale from 0 (no corrosion) to 5 (complete corrosion of the surface of the steel pin).

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Organic Chemistry (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Sealing Devices (AREA)

Abstract

The invention relates to a piston-cylinder unit (100) comprising a cylinder (110) filled with a fluid (150), a piston (120) which is displaceable guided in the cylinder (110), a piston rod (130) attached to the piston (120), a seal (140), and a lubricant which is in contact with the seal (140) and the cylinder (110), the piston (120) and/or the piston rod (130). The lubricant is a polyalphaolefin oil or a polyalkylene glycol oil. The seal (140) consists of chlorine-free acrylonitrile butadiene rubber. The invention further relates to a method for producing the piston-cylinder unit (100).

Description

STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNERSTA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
Beschreibung Description
Bezeichnung der Erfindung: Kolben-Zylinder-Einheit, Verfahren zur Herstellung der Kolben-Zylinder-EinheitDesignation of the invention: Piston-cylinder unit, method for producing the piston-cylinder unit
Technisches Gebiet technical field
[0001] Die Erfindung betrifft eine Kolben-Zylinder-Einheit, umfassend einen mit einem Fluid gefüllten Zylinder, einen in dem Zylinder verschieblich geführten Kolben, eine an dem Kolben befestigte Kolbenstange, eine Dichtung und ein Schmiermittel in Kontakt mit der Dichtung und mit dem Zylinder, dem Kolben und/oder der Kolbenstange. Die Erfindung betrifft außerdem ein Verfahren zur Herstellung der Kolben-Zylinder-Einheit. The invention relates to a piston-cylinder unit, comprising a cylinder filled with a fluid, a piston guided displaceably in the cylinder, a piston rod attached to the piston, a seal and a lubricant in contact with the seal and with the cylinder, the piston and/or the piston rod. The invention also relates to a method for producing the piston-cylinder unit.
Stand der Technik State of the art
[0002] Die Druckschriften DE 294 20 29 A1 , EP 325 80 56 B1 und The documents DE 294 20 29 A1, EP 325 80 56 B1 and
WO 2006 007 087 A1 zeigen beispielhaft Kolben-Zylinder-Einheiten der vorgenannten Art in Form von Gasdruckfedern. WO 2006 007 087 A1 shows examples of piston-cylinder units of the aforementioned type in the form of gas pressure springs.
[0003] Bei bekannten Kolben-Zylinder-Einheiten wird als Schmiermittel üblicherweise ein Mineralöl verwendet. Daraus ergibt sich der Nachteil, dass es bei einer ersten Bewegung des Kolbens im Zylinder der Kolben-Zylinder- Einheit nach einer längeren Standzeit zu einer erhöhten Anfangsreibung und damit verbundenem erhöhten Verschleiß kommt, wodurch die Lebensdauer der Kolben-Zylinder-Einheit beeinträchtigt wird. In known piston-cylinder units, a mineral oil is usually used as a lubricant. This results in the disadvantage that when the piston moves for the first time in the cylinder of the piston-cylinder unit after a long period of standstill, there is increased initial friction and associated increased wear, which impairs the service life of the piston-cylinder unit.
Technische Aufgabe Technical task
[0004] Die Aufgabe der Erfindung ist es, eine kostengünstige und langlebige Kolben-Zylinder-Einheit mit geringer Reibung, insbesondere nach längeren Standzeiten, zu schaffen. The object of the invention is to create an inexpensive and durable piston-cylinder unit with low friction, especially after long periods of inactivity.
Technische Lösung Technical solution
[0005] Die vorliegende Erfindung stellt eine Kolben-Zylinder-Einheit gemäß Anspruch 1 bereit, die die technische Aufgabe löst. Ebenso wird die Aufgabe durch ein Verfahren zur Herstellung der Kolben-Zylinder-Einheit gemäß STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNERThe present invention provides a piston-cylinder unit according to claim 1 that solves the technical problem. The object is also achieved by a method for producing the piston-cylinder unit STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
Anspruch 7 gelöst. Vorteilhafte Ausgestaltungen sind Gegenstand der abhängigen Ansprüche. Claim 7 solved. Advantageous configurations are the subject matter of the dependent claims.
[0006] Die Kolben-Zylinder-Einheit umfasst einen mit einem Fluid gefüllten Zylinder. Die Kolben-Zylinder-Einheit ist beispielsweise als Gasdruckfeder oder als Hydraulikdämpfer ausgestaltet. Das Fluid ist beispielsweise ein Gas, insbesondere Stickstoff, das gegenüber einer Umgebung des Zylinders einen Überdruck haben kann. Der Zylinder ist vorzugsweise hohlzylindrisch geformt und kann aus einem Metall, insbesondere aus Stahl, bestehen. The piston-cylinder unit comprises a cylinder filled with a fluid. The piston-cylinder unit is designed, for example, as a gas pressure spring or as a hydraulic damper. The fluid is, for example, a gas, in particular nitrogen, which can have an overpressure compared to the surroundings of the cylinder. The cylinder is preferably shaped as a hollow cylinder and can be made of a metal, in particular steel.
[0007] Die Kolben-Zylinder-Einheit umfasst einen in dem Zylinder, vorzugsweise entlang einer Längsachse des Zylinders, verschieblich geführten Kolben, der den Zylinder vorzugsweise in zwei Kammern teilt. Der Kolben kann aus einem Kunststoff, insbesondere aus einem thermoplastischen Kunststoff, oder aus einem Metall, insbesondere aus Zink oder Aluminium, bestehen. The piston-cylinder unit comprises a in the cylinder, preferably along a longitudinal axis of the cylinder, slidably guided piston, which preferably divides the cylinder into two chambers. The piston can be made of a plastic, in particular a thermoplastic material, or of a metal, in particular zinc or aluminum.
[0008] Die Kolben-Zylinder-Einheit umfasst eine an dem Kolben befestigte Kolbenstange, die vorzugsweise koaxial zur Mittellängsachse des Zylinders angeordnet ist. Die Kolbenstange kann aus einem Metall, insbesondere aus Stahl, bestehen. The piston-cylinder unit includes a piston rod attached to the piston, which is preferably arranged coaxially to the central longitudinal axis of the cylinder. The piston rod can be made of a metal, in particular steel.
[0009] Die Kolben-Zylinder-Einheit umfasst zumindest eine Dichtung, insbesondere zur für das Fluid dichten Abdichtung des Zylinders gegenüber einer Umgebung des Zylinders und/oder zur für das Fluid dichten Abdichtung der Kammern des Zylinders gegeneinander. The piston-cylinder unit comprises at least one seal, in particular for the fluid-tight sealing of the cylinder relative to an environment of the cylinder and/or for the fluid-tight sealing of the chambers of the cylinder against one another.
[0010] Die Kolben-Zylinder-Einheit umfasst ein Schmiermittel in Kontakt mit der Dichtung und mit dem Zylinder, mit der Dichtung und dem Kolben und/oder mit der Dichtung und der Kolbenstange zur Reibungsreduzierung zwischen Dichtung und Zylinder und/oder zwischen Dichtung und Kolben und/oder zwischen Dichtung und Kolbenstange. The piston-cylinder unit comprises a lubricant in contact with the seal and with the cylinder, with the seal and the piston and/or with the seal and the piston rod to reduce friction between the seal and the cylinder and/or between the seal and the piston and/or between the seal and the piston rod.
[0011] Das Schmiermittel ist ein Polyalphaolefin-Öl, auch PAO-ÖI genannt, oder ein Polyalkylenglykol-Öl, auch PAG-ÖI oder Polyglykol-Öl genannt. Ein Polyalphaolefin-Öl ist ein synthetisches Öl, das zumindest zu 50 %, insbesondere zumindest zu 75 %, bevorzugt zu 85 % bis 95 % aus Polyalphaolefinen besteht. Ein Polyalkylenglykol-Öl ist ein synthetisches Öl, STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER das zumindest zu 50 %, insbesondere zumindest zu 75 %, bevorzugt zu 85 % bis 95 % aus Polyalkylenglykolen besteht. The lubricant is a polyalphaolefin oil, also called PAO oil, or a polyalkylene glycol oil, also called PAG oil or polyglycol oil. A polyalphaolefin oil is a synthetic oil that consists of at least 50%, in particular at least 75%, preferably 85% to 95% of polyalphaolefins. A polyalkylene glycol oil is a synthetic oil STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER which consists of at least 50%, in particular at least 75%, preferably 85% to 95% of polyalkylene glycols.
[0012] Die Dichtung besteht aus Acrylnitril-Butadien-Kautschuk, auch AB- Kautschuk, NBR, Nitrile Butadiene Ruber oder Nitrilkautschuk genannt. Der Acrylnitril-Butadien-Kautschuk ist chlorfrei, das heißt, die Dichtung enthält weder gezielt zugesetztes Chlor oder Chlorverbindungen noch bei der Herstellung der Dichtung, beispielsweise aus Hilfsstoffen wie Reaktionsverzögerern, in die Dichtung übergegangenes Chlor oder Chlorverbindungen. The seal consists of acrylonitrile butadiene rubber, also called AB rubber, NBR, nitrile butadiene rubber or nitrile rubber. The acrylonitrile-butadiene rubber is chlorine-free, which means that the seal does not contain any deliberately added chlorine or chlorine compounds, nor chlorine or chlorine compounds that have migrated into the seal during manufacture, for example from auxiliary materials such as reaction retarders.
Vorteilhafte Wirkungen beneficial effects
[0013] Versuche haben gezeigt, dass die Anfangsreibung der Kolben-Zylinder- Einheit nach einer längeren Standzeit reduziert wird, wenn anstelle eines üblichen Mineralöls ein synthetisches Öl, ausgewählt aus einem Polyalphaolefin-Öl und einem Polyalkylenglykol-Öl als Schmiermittel verwendet wird. Dabei wurde jedoch in Verbindung mit einer üblichen Dichtung aus Acrylnitril-Butadien-Kautschuk eine gegenüber der Verwendung eines Mineralöls erhöhte Korrosion der Kolben-Zylinder-Einheit beobachtet. Experiments have shown that the initial friction of the piston-cylinder unit is reduced after a longer period if a synthetic oil selected from a polyalphaolefin oil and a polyalkylene glycol oil is used as a lubricant instead of a conventional mineral oil. However, in connection with a conventional seal made of acrylonitrile-butadiene rubber, increased corrosion of the piston-cylinder unit was observed compared with the use of a mineral oil.
[0014] Übliche Dichtungen aus Acrylnitril-Butadien-Kautschuk enthalten Chlorverbindungen, beispielsweise aus - üblicherweise chlorhaltigen - Reaktionsverzögerern, die bei der Herstellung der Dichtungen verwendet werden. Reaktionsverzögerer sind notwendig, um die Dichtung durch Spritzgießen oder Spritzpressen aus einer Acrylnitril-Butadien-Kautschuk- Schmelze herzustellen, ohne dass die Schmelze vorzeitig erstarrt. Customary seals made of acrylonitrile-butadiene rubber contain chlorine compounds, for example from - usually chlorine-containing - reaction retardants that are used in the manufacture of the seals. Retarders are necessary to produce the seal from an acrylonitrile butadiene rubber melt by injection molding or transfer molding without the melt solidifying prematurely.
[0015] Überraschenderweise zeigt die erfindungsgemäße Kolben-Zylinder-Einheit gegenüber üblichen Kolben-Zylinder-Einheiten eine verringerte Anfangsreibung ohne erhöhte Korrosion, wenn ein Polyalphaolefin-Öl oder ein Polyalkylenglykol-Öl als Schmiermittel verwendet wird und die Dichtung aus chlorfreiem Acrylnitril-Butadien-Kautschuk besteht. Surprisingly, the piston-cylinder unit according to the invention shows reduced initial friction without increased corrosion compared to conventional piston-cylinder units when a polyalphaolefin oil or a polyalkylene glycol oil is used as the lubricant and the seal is made of chlorine-free acrylonitrile-butadiene rubber.
[0016] Somit führt die erfindungsgemäße Kombination von Schmiermittel und Material der Dichtung zu einer kostengünstigen und langlebigen Kolben- STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNERThus, the inventive combination of lubricant and material of the seal leads to a cost-effective and durable piston STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
Zylinder-Einheit mit verringerter Reibung, insbesondere nach längeren Standzeiten. Cylinder unit with reduced friction, especially after long periods of inactivity.
Beschreibung der Ausführungsarten Description of execution types
[0017] Die Dichtung ist vorzugsweise eine Kolbenstangendichtung, wobei die Kolbenstange, insbesondere koaxial zur Mittellängsachse des Zylinders, durch die Dichtung aus dem Zylinder herausgeführt ist, und die Dichtung den Zylinder für das Fluid dicht verschließt. Das zuvor beschriebene Problem der erhöhten Anfangsreibung tritt besonders stark an der Kolbenstangendichtung auf, sodass die genannten Vorteile der Erfindung hier besonders stark hervortreten. The seal is preferably a piston rod seal, wherein the piston rod, in particular coaxially to the central longitudinal axis of the cylinder, is led out through the seal from the cylinder, and the seal tightly closes the cylinder for the fluid. The problem of increased initial friction described above occurs particularly severely on the piston rod seal, so that the stated advantages of the invention are particularly evident here.
[0018] Die Dichtung ist vorzugsweise halogenfrei. Dadurch, dass die Dichtung nicht nur kein Chlor, sondern auch keine anderen Halogene oder Halogenverbindungen enthält, kann eine Korrosion durch Halogene oder Halogenverbindungen ausgeschlossen werden. In dieser Ausgestaltung enthält die Dichtung weder gezielt zugesetzte Halogene oder Halogenverbindungen noch unbeabsichtigt bei der Herstellung der Dichtung in die Dichtung übergegangene Halogene oder Halogenverbindungen. The seal is preferably halogen-free. Because the seal not only contains no chlorine, but also no other halogens or halogen compounds, corrosion by halogens or halogen compounds can be ruled out. In this embodiment, the seal contains neither specifically added halogens or halogen compounds nor halogens or halogen compounds that have unintentionally migrated into the seal during the production of the seal.
[0019] Das Schmiermittel enthält vorzugsweise zumindest ein Schwell-Additiv zur Schwellung der Dichtung enthält, wobei das Schwell-Additiv ein Ester ist. Der Ester ist vorzugsweise in dem Polyalphaolefin-Öl oder Polyalkylenglykol- Öl löslich und zeigt unter Betriebsbedingungen der Kolben-Zylinder-Einheit keine chemischen Wechselwirkungen mit dem Polyalphaolefin-Öl, dem Polyalkylenglykol-Öl oder darin enthaltenen Additven. The lubricant preferably contains at least one swelling additive for swelling the seal, the swelling additive being an ester. The ester is preferably soluble in the polyalphaolefin oil or polyalkylene glycol oil and does not chemically interact with the polyalphaolefin oil, polyalkylene glycol oil or additives contained therein under the operating conditions of the piston-cylinder unit.
[0020] In Kontakt mit einem Polyalphaolefin-Öl oder Polyalkylenglykol-Öl kann eine Dichtung aus Acrylnitril-Butadien-Kautschuk schrumpfen. Ein Schrumpfen kann die Dichtwirkung der Dichtung beeinträchtigen und zu Leckagen führen. Dieser Effekt wird durch das Schwell-Additiv verhindert. In contact with a polyalphaolefin oil or polyalkylene glycol oil, an acrylonitrile butadiene rubber seal may shrink. Shrinkage can impair the sealing effect of the gasket and lead to leakage. This effect is prevented by the swelling additive.
[0021 ] Das Schmiermittel enthält vorzugsweise zumindest ein Reibungsreduzierungs-Additiv zur Reduzierung von Reibung zwischen der Dichtung und dem Zylinder, dem Kolben und/oder der Kolbenstange, wobei das Reibungsreduzierungs-Additiv eine amphiphile Substanz, ein STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER funktionalisiertes Polymer, eine organische Molybdänverbindung oder ein Fettsäureester ist. The lubricant preferably contains at least one friction reducing additive for reducing friction between the seal and the cylinder, the piston and/or the piston rod, the friction reducing additive being an amphiphilic substance STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER functionalized polymer, an organic molybdenum compound or a fatty acid ester.
[0022] Das Reibungsreduzierungs-Additiv kann die Reibung beispielsweise reduzieren, indem es eine Grenzschicht zwischen dem Schmiermittel und der Dichtung, dem Zylinder, dem Kolben und/oder der Kolbenstange bildet. The friction reducing additive can reduce friction, for example, by forming an interface between the lubricant and the seal, cylinder, piston and/or piston rod.
[0023] Das Schmiermittel enthält vorzugsweise zumindest ein Korrosionsschutz- Additiv zur Reduzierung von Korrosion des Zylinders, des Kolbens und/oder der Kolbenstange, wobei das Korrosionsschutz-Additiv ein Sulfonat, ein Cycloalkanat, ein Carboxylat, ein Alkyl-Bernsteinsäurederivat oder ein Polyolester ist. The lubricant preferably contains at least one anti-corrosion additive to reduce corrosion of the cylinder, the piston and/or the piston rod, the anti-corrosion additive being a sulfonate, a cycloalkanoate, a carboxylate, an alkyl succinic acid derivative or a polyol ester.
[0024] Das Korrosionsschutz-Additiv wirkt beispielsweise wie eine Buntmetalldesaktivator und bildet einen wasserundurchlässigen Schutzfilm auf einer Oberfläche des Zylinders, des Kolbens und/oder der Kolbenstange. Das Korrosionsschutz-Additiv kann dazu geeignet sein, saure Reaktionsprodukte, beispielsweise aus dem Abbau von Additiven, zu neutralisieren. The anti-corrosion additive acts, for example, like a non-ferrous metal deactivator and forms a water-impermeable protective film on a surface of the cylinder, the piston and/or the piston rod. The anti-corrosion additive can be suitable for neutralizing acidic reaction products, for example from the breakdown of additives.
[0025] Wenn das Schmiermittel das Korrosionsschutz-Additiv und das Reibungsreduzierungs-Additiv enthält, kann es zu einer Konkurrenz zwischen den beiden Additiven um die Besetzung der Oberfläche des Zylinders, des Kolbens und/oder der Kolbenstange kommen. When the lubricant contains the anti-corrosion additive and the friction-reducing additive, there may be competition between the two additives for occupation of the surface of the cylinder, piston and/or piston rod.
[0026] Aufgrund der geringen Korrosionsneigung der erfindungsgemäßen Kolben- Zylinder-Einheit kann ein guter Korrosionsschutz auch dann erreicht werden, wenn das Schmiermittel nur einen geringen Anteil des Korrosionsschutz- Additivs enthält. Da das Korrosionsschutz-Additiv in diesen Ausgestaltungen nur geringfügig mit dem Polyalphaolefin-Öl, dem Polyalkylenglykol-Öl oder einem Reibungsreduzierungs-Additiv um die Besetzung der Oberfläche des Zylinders, des Kolbens und/oder der Kolbenstange konkurriert, wird in diesen Ausgestaltungen eine besonders geringe Reibung erreicht. Due to the low corrosion tendency of the piston-cylinder unit according to the invention, good corrosion protection can also be achieved when the lubricant contains only a small proportion of the anti-corrosion additive. Since the anti-corrosion additive in these configurations competes only slightly with the polyalphaolefin oil, the polyalkylene glycol oil or a friction-reducing additive for occupation of the surface of the cylinder, the piston and/or the piston rod, particularly low friction is achieved in these configurations.
[0027] Auch bei einer erfindungsgemäßen Kolben-Zylinder-Einheit wird vorteilhafterweise nicht vollständig auf das Korrosionsschutz-Additiv verzichtet, da eventuell während des Betriebs der Kolben-Zylinder-Einheit STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER durch hydrodynamische Effekte Wasser in die Kolben-Zylinder-Einheit eindringen kann. Ohne Korrosionsschutz-Additiv könnte dieses Wasser zu Korrosion, insbesondere an einer Innenfläche des Zylinders, führen. Advantageously, even with a piston-cylinder unit according to the invention, the anti-corrosion additive is not completely dispensed with, since it may be necessary during operation of the piston-cylinder unit STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER water can penetrate into the piston-cylinder unit due to hydrodynamic effects. Without an anti-corrosion additive, this water could cause corrosion, particularly on an interior surface of the cylinder.
[0028] Das erfindungsgemäße Verfahren dient zur Herstellung einer erfindungsgemäßen Kolben-Zylinder-Einheit und umfasst ein chlorfreies Herstellen der Dichtung der Kolben-Zylinder-Einheit aus Acrylnitril-Butadien- Kautschuk. The method according to the invention serves to produce a piston-cylinder unit according to the invention and includes a chlorine-free production of the seal of the piston-cylinder unit from acrylonitrile-butadiene rubber.
[0029] Das Verfahren umfasst, vorzugsweise nach dem Herstellen, ein Zusammenbauen der Dichtung mit dem Zylinder, dem Kolben und der Kolbenstange der Kolben-Zylinder-Einheit. The method includes, preferably after manufacture, assembling the seal with the cylinder, the piston and the piston rod of the piston-cylinder unit.
[0030] Das Verfahren umfasst, vorzugsweise nach dem Zusammenbauen, ein Einfüllen des Schmiermittels der Kolben-Zylinder-Einheit in die Kolben- Zylinder-Einheit, wobei das Schmiermittel ein Polyalphaolefin-Öl oder ein Polyalkylenglykol-Öl ist. The method comprises, preferably after assembly, filling the piston-cylinder unit with the lubricant of the piston-cylinder unit, the lubricant being a polyalphaolefin oil or a polyalkylene glycol oil.
[0031] Aus den genannten Verfahrensschritten ergeben sich die oben genannten Vorteile und Ausgestaltungsmöglichkeiten der erfindungsgemäßen Kolben- Zylinder-Einheit. [0031] The above-mentioned advantages and possible configurations of the piston-cylinder unit according to the invention result from the method steps mentioned.
[0032] Das Herstellen umfasst vorzugsweise ein Verzögern einer Erstarrung einer Acrylnitril-Butadien-Kautschuk-Schmelze mit einem chlorfreien Reaktionsverzögerer. The preparation preferably includes retarding a solidification of an acrylonitrile butadiene rubber melt with a chlorine-free reaction retarder.
[0033] Die Verwendung eines Reaktionsverzögerers erlaubt es, die Schmelze, beispielsweise durch Spritzgießen oder Spritzpressen, zu der Dichtung zu formen, ohne dass diese vorzeitig erstarrt oder zusätzlich beheizt werden muss, um nicht zu erstarren. Wenn der Reaktionsverzögerer chlorfrei, insbesondere halogenfrei, ist, ergeben sich daraus die oben genannten Vorteile der chlorfreien, insbesondere halogenfreien, Dichtung. The use of a reaction retarder allows the melt to be formed into the seal, for example by injection molding or transfer molding, without the latter solidifying prematurely or having to be additionally heated in order not to solidify. If the reaction retarder is chlorine-free, in particular halogen-free, this results in the above-mentioned advantages of the chlorine-free, in particular halogen-free, seal.
[0034] Die gegenüber chlorhaltigen Reaktionsverzögerern erhöhten Kosten des chlorfreien Reaktionsverzögerers können erfindungsgemäß beispielsweise durch einen geringeren Bedarf an Korrosionsschutz-Additiv und/oder eine durch verringerte Korrosion verlängerte Lebensdauer der Kolben-Zylinder- Einheit kompensiert werden. STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNERThe higher costs of the chlorine-free reaction retardant compared to chlorine-containing reaction retardants can be compensated according to the invention, for example, by a lower need for anti-corrosion additive and/or a longer service life of the piston-cylinder unit due to reduced corrosion. STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
[0035] Das Herstellen umfasst ein Spritzgießen oder ein Spritzpressen der Dichtung aus einer Acrylnitril-Butadien-Kautschuk-Schmelze. Diese Verfahren haben die Vorteile, dass die Dichtung dadurch in nahezu beliebiger Form vollautomatisch, schnell und kostengünstig hergestellt werden kann. The manufacture includes injection molding or transfer molding of the seal from an acrylonitrile butadiene rubber melt. These methods have the advantage that the seal can be produced fully automatically, quickly and inexpensively in almost any shape.
Kurze Beschreibung der Zeichnungen Brief description of the drawings
[0036] Weitere Vorteile, Ziele und Eigenschaften der Erfindung werden anhand nachfolgender Beschreibung und anliegender Zeichnungen erläutert, in welchen beispielhaft erfindungsgemäße Gegenstände dargestellt sind. Further advantages, aims and properties of the invention are explained with reference to the following description and attached drawings, in which objects according to the invention are shown by way of example.
[0037] Figur 1 zeigt eine schematische Darstellung einer erfindungsgemäßen Kolben-Zylinder-Einheit. Figure 1 shows a schematic representation of a piston-cylinder unit according to the invention.
[0038] Figur 2 zeigt die auf die Kolbenstange einer Kolben-Zylinder-Einheit wirkenden Reibkraft mit einem Mineralöl oder einem Polyalkylenglykol-Öl als Schmiermittel. FIG. 2 shows the friction force acting on the piston rod of a piston-cylinder unit with a mineral oil or a polyalkylene glycol oil as a lubricant.
[0039] Figur 3 zeigt den Korrosionsgrad von Stahlfingern in Kontakt mit einem Polyalkylenglykol-Öl als Schmiermittel mit einer Dichtung aus chlorhaltigem oder chlorfreien Acrylnitril-Butadien-Kautschuk. Figure 3 shows the degree of corrosion of steel fingers in contact with a polyalkylene glycol oil as a lubricant with a seal made of chlorine-containing or chlorine-free acrylonitrile-butadiene rubber.
Fig.1 Fig.1
[0040] Figur 1 zeigt eine schematische Darstellung einer erfindungsgemäßen Kolben-Zylinder-Einheit 100 als Längsschnitt entlang einer Hubachse H der Kolben-Zylinder-Einheit, die beispielsweise eine Gasdruckfeder ist. Figure 1 shows a schematic representation of a piston-cylinder unit 100 according to the invention as a longitudinal section along a stroke axis H of the piston-cylinder unit, which is, for example, a gas pressure spring.
[0041] Die dargestellte Kolben-Zylinder-Einheit 100 umfasst einen mit einem Fluid 150, beispielsweise mit gegenüber einer Umgebung des Zylinders unter einem Überdruck stehendem Stickstoff-Gas, gefüllten Zylinder 110 und einen in dem Zylinder 110 entlang der Hubachse H verschieblich geführten Kolben 120. The illustrated piston-cylinder unit 100 comprises a cylinder 110 filled with a fluid 150, for example with nitrogen gas that is at an overpressure relative to the area surrounding the cylinder, and a piston 120 that is displaceably guided in the cylinder 110 along the stroke axis H.
[0042] Die dargestellte Kolben-Zylinder-Einheit 100 umfasst eine an dem Kolben 120 befestigte Kolbenstange 130 und eine Dichtung 140. Die Dichtung 140 ist beispielsweise eine Kolbenstangendichtung, wobei die Kolbenstange 130 STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER durch die Dichtung 140 aus dem Zylinder 110 herausgeführt ist, und die Dichtung 140 den Zylinder 110 für das Fluid 150 dicht verschließt. The illustrated piston-cylinder unit 100 comprises a piston rod 130 attached to the piston 120 and a seal 140. The seal 140 is, for example, a piston rod seal, the piston rod 130 STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER is guided out of the cylinder 110 through the seal 140, and the seal 140 closes the cylinder 110 for the fluid 150 tightly.
[0043] Die dargestellte Kolben-Zylinder-Einheit 100 umfasst ein Schmiermittel (nicht gezeigt) zumindest in Kontakt mit der Dichtung 140 und der Kolbenstange 130. The illustrated piston-cylinder unit 100 includes a lubricant (not shown) in contact with at least the seal 140 and the piston rod 130.
[0044] Das Schmiermittel ist ein Polyalphaolefin-Öl oder ein Polyalkylenglykol-Öl, und die Dichtung 140 besteht aus chlorfreiem Acrylnitril-Butadien-Kautschuk. The lubricant is a polyalphaolefin oil or a polyalkylene glycol oil and the seal 140 is made of chlorine-free acrylonitrile butadiene rubber.
Fig.2 Fig.2
[0045] Figur 2 zeigt die auf die Kolbenstange einer als Gasdruckfeder ausgestalteten Kolben-Zylinder-Einheit aus dem Stand der Technik mit einem Mineralöl (schwarze Säulen) oder einem Polyalkylenglykol-Öl (schraffierte Säulen) als Schmiermittel wirkende Reibkraft F in N. Figure 2 shows the frictional force F in N acting on the piston rod of a piston-cylinder unit designed as a gas pressure spring from the prior art with a mineral oil (black columns) or a polyalkylene glycol oil (hatched columns) as a lubricant.
[0046] Dargestellt sind jeweils die Reibkraft F beim ersten Hub 1a, beim zweiten Hub 1b und beim dritten Hub 1c direkt nach der Montage der Kolben- Zylinder-Einheit sowie die Reibkraft F beim ersten Hub 2a, beim zweiten Hub 2b und beim dritten Hub 2c, nachdem die Kolben-Zylinder-Einheit einem Dauerlauftest ausgesetzt und dann für 24 h gelagert wurde, sodass die Oberfläche der Kolbenstange beim ersten Hub jeweils trocken ist. Shown are the frictional force F during the first stroke 1a, the second stroke 1b and the third stroke 1c directly after the assembly of the piston-cylinder unit as well as the frictional force F during the first stroke 2a, the second stroke 2b and the third stroke 2c after the piston-cylinder unit has been subjected to an endurance test and then stored for 24 hours so that the surface of the piston rod is dry during the first stroke.
[0047] Es ist erkennbar, dass die Reibkraft F mit dem Polyalkylenglykol-Öl geringer ist als mit dem Mineralöl. Dieser Effekt ist beim jeweils ersten Hub nach der Montage und nach der Lagerung besonders stark und auch bei den weiteren Hüben noch zu sehen. It can be seen that the frictional force F with the polyalkylene glycol oil is lower than with the mineral oil. This effect is particularly strong during the first stroke after assembly and after storage and can also be seen in subsequent strokes.
Fig.3 Fig.3
[0048] Figur 3 zeigt den Korrosionsgrad von Stahlfingern in Kontakt mit einem Polyalkylenglykol-Öl als Schmiermittel, in das eine Dichtung aus chlorhaltigem a oder chlorfreien b, c Acrylnitril-Butadien-Kautschuk eingelegt ist. FIG. 3 shows the degree of corrosion of steel fingers in contact with a polyalkylene glycol oil as a lubricant, in which a seal made of chlorine-containing a or chlorine-free b, c acrylonitrile-butadiene rubber is inserted.
[0049] Der Korrosionsgrad wird mit einem an DIN ISO 7120, Methode B angelehnten Stahlfingertest bestimmt. Dabei wird ein Stift aus Stahl in ein Glas mit der Dichtung, dem Polyalkylenglykol-Öl und Wasser gehängt. Nach STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER einer vorbestimmten Reaktionszeit von beispielsweise 24 h bei konstanter Temperatur von beispielsweise 60 °C wird der Korrosionsgrad auf einer Skala von 0 (keine Korrosion) bis 5 (vollständige Korrosion der Oberfläche des Stahlstiftes) bewertet. The degree of corrosion is determined using a steel finger test based on DIN ISO 7120, Method B. A steel pin is hung in a glass with the seal, the polyalkylene glycol oil and water. After STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER a predetermined reaction time of, for example, 24 hours at a constant temperature of, for example, 60 °C, the degree of corrosion is evaluated on a scale from 0 (no corrosion) to 5 (complete corrosion of the surface of the steel pin).
[0050] Während der Stahlstift in Kontakt mit dem Polyalkylenglykol-Öl mit einer chlorhaltigen Dichtung einen hohen Korrosionsgrad zeigt, ist der Korrosionsgrad unter den gleichen Bedingungen in Kontakt mit dem Polyalkylenglykol-Öl mit einer chlorfreien Dichtung wesentlich geringer.While the steel pin shows a high degree of corrosion in contact with the polyalkylene glycol oil with a chlorine-containing seal, the degree of corrosion is much lower under the same conditions in contact with the polyalkylene glycol oil with a chlorine-free seal.
Liste der Bezugszeichen List of References
[0051] [0051]
100 Kolben-Zylinder-Einheit 140 Dichtung 100 piston-cylinder unit 140 gasket
110 Zylinder 150 Fluid 110 cylinder 150 fluid
120 Kolben F Reibkraft 120 piston F friction force
130 Kolbenstange H Hubachse 130 piston rod H lifting axis

Claims

STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER Ansprüche STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER Claims
1. Kolben-Zylinder-Einheit (100), umfassend a. einen mit einem Fluid (150) gefüllten Zylinder (110), b. einen in dem Zylinder (110) verschieblich geführten Kolben (120), c. eine an dem Kolben (120) befestigte Kolbenstange (130), d. eine Dichtung (140) aus Acrylnitril-Butadien-Kautschuk und e. ein Schmiermittel in Kontakt mit der Dichtung (140) und mit dem Zylinder (110), dem Kolben (120) und/oder der Kolbenstange (130), dadurch gekennzeichnet, dass f. das Schmiermittel ein Polyalphaolefin-Öl oder ein Polyalkylenglykol-Öl ist, und g. die Dichtung (140) chlorfrei ist, wobei die Dichtung (140) weder gezielt zugesetztes Chlor oder Chlorverbindungen noch bei der Herstellung der Dichtung (140) in die Dichtung (140) übergegangenes Chlor oder Chlorverbindungen enthält . A piston-cylinder unit (100) comprising a. a cylinder (110) filled with a fluid (150), b. a piston (120) displaceably guided in the cylinder (110), c. a piston rod (130) attached to the piston (120), d. a seal (140) made of acrylonitrile butadiene rubber and e. a lubricant in contact with the seal (140) and with the cylinder (110), the piston (120) and/or the piston rod (130), characterized in that f. the lubricant is a polyalphaolefin oil or a polyalkylene glycol oil, and g. the seal (140) is chlorine-free, the seal (140) containing neither deliberately added chlorine or chlorine compounds nor chlorine or chlorine compounds transferred into the seal (140) during the manufacture of the seal (140).
2. Kolben-Zylinder-Einheit (100) nach Anspruch 1 , dadurch gekennzeichnet, dass die Dichtung (140) eine Kolbenstangendichtung ist, wobei a. die Kolbenstange (130) durch die Dichtung (140) aus dem Zylinder (110) herausgeführt ist, und b. die Dichtung (140) den Zylinder (110) für das Fluid (150) dicht verschließt. 2. Piston-cylinder unit (100) according to claim 1, characterized in that the seal (140) is a piston rod seal, wherein a. the piston rod (130) is led out of the cylinder (110) through the seal (140), and b. the seal (140) tightly closes the cylinder (110) for the fluid (150).
3. Kolben-Zylinder-Einheit (100) nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass die Dichtung (140) halogenfrei ist, wobei die Dichtung (140) weder gezielt zugesetzte Halogene oder Halogenverbindungen noch bei der Herstellung der Dichtung (140) in die Dichtung (140) übergegangene Halogene oder Halogenverbindungen enthält. 3. Piston-cylinder unit (100) according to Claim 1 or 2, characterized in that the seal (140) is halogen-free, the seal (140) containing neither halogens or halogen compounds added in a targeted manner nor halogens or halogen compounds transferred into the seal (140) during the manufacture of the seal (140).
4. Kolben-Zylinder-Einheit (100) nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, dass STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER das Schmiermittel zumindest ein Schwell-Additiv zur Schwellung der Dichtung (140) enthält, wobei das Schwell-Additiv ein Ester ist. 4. Piston-cylinder unit (100) according to any one of claims 1 to 3, characterized in that STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER the lubricant contains at least one swelling additive for swelling the seal (140), the swelling additive being an ester.
5. Kolben-Zylinder-Einheit (100) nach einem der Ansprüche 1 bis 4, dadurch gekennzeichnet, dass das Schmiermittel zumindest ein Reibungsreduzierungs-Additiv zur Reduzierung von Reibung zwischen der Dichtung (140) und dem Zylinder (110), dem Kolben (120) und/oder der Kolbenstange (130) enthält, wobei das Reibungsreduzierungs-Additiv eine amphiphile Substanz, ein funktionalisiertes Polymer, eine organische Molybdänverbindung oder ein Fettsäureester ist. 5. Piston-cylinder unit (100) according to one of Claims 1 to 4, characterized in that the lubricant contains at least one friction-reducing additive for reducing friction between the seal (140) and the cylinder (110), the piston (120) and/or the piston rod (130), the friction-reducing additive being an amphiphilic substance, a functionalized polymer, an organic molybdenum compound or a fatty acid ester.
6. Kolben-Zylinder-Einheit (100) nach einem der Ansprüche 1 bis 5, dadurch gekennzeichnet, dass das Schmiermittel zumindest ein Korrosionsschutz-Additiv zur Reduzierung von Korrosion des Zylinders (110), des Kolbens (120) und/oder der Kolbenstange (130) enthält, wobei das Korrosionsschutz -Additiv ein Sulfonat, ein Cycloalkanat, ein Carboxylat, ein Alkyl-Bernsteinsäurederivat oder ein Polyolester ist. 6. Piston-cylinder unit (100) according to one of Claims 1 to 5, characterized in that the lubricant contains at least one anti-corrosion additive to reduce corrosion of the cylinder (110), the piston (120) and/or the piston rod (130), the anti-corrosion additive being a sulfonate, a cycloalkane, a carboxylate, an alkyl succinic acid derivative or a polyol ester.
7. Verfahren zur Herstellung einer Kolben-Zylinder-Einheit (100) nach einem der Ansprüche 1 bis 6, gekennzeichnet durch folgende Schritte: a. chlorfreies Herstellen der Dichtung (140) der Kolben-Zylinder-Einheit (100) aus Acrylnitril-Butadien-Kautschuk, sodass die Dichtung (140) weder gezielt zugesetztes Chlor oder Chlorverbindungen noch bei dem Herstellen der Dichtung (140) in die Dichtung (140) übergegangenes Chlor oder Chlorverbindungen enthält, b. Zusammenbauen der Dichtung (140) mit dem Zylinder (110), dem Kolben (120) und der Kolbenstange (130) der Kolben-Zylinder-Einheit (100) und c. Einfüllen des Schmiermittels der Kolben-Zylinder-Einheit (100) in die Kolben-Zylinder-Einheit (100), wobei das Schmiermittel ein Polyalphaolefin-Öl oder ein Polyalkylenglykol-Öl ist. STA51-P1303PC00 03.01.2023 PREUSCHE & PARTNER7. A method for producing a piston-cylinder unit (100) according to any one of claims 1 to 6, characterized by the following steps: a. chlorine-free manufacture of the seal (140) of the piston-cylinder unit (100) from acrylonitrile-butadiene rubber, so that the seal (140) contains neither deliberately added chlorine or chlorine compounds nor chlorine or chlorine compounds transferred into the seal (140) during the manufacture of the seal (140), b. assembling the seal (140) with the cylinder (110), the piston (120) and the piston rod (130) of the piston-cylinder unit (100) and c. Filling the lubricant of the piston-cylinder unit (100) into the piston-cylinder unit (100), the lubricant being a polyalphaolefin oil or a polyalkylene glycol oil. STA51-P1303PC00 01/03/2023 PREUSCHE & PARTNER
8. Verfahren nach Anspruch 7, dadurch gekennzeichnet, dass das Herstellen ein Verzögern einer Erstarrung einer Acrylnitril-Butadien-8. The method according to claim 7, characterized in that the preparation delaying a solidification of an acrylonitrile-butadiene
Kautschuk-Schmelze mit einem chlorfreien Reaktionsverzögerer umfasst. Rubber melt with a chlorine-free reaction retarder.
9. Verfahren nach Anspruch 7 oder 8, dadurch gekennzeichnet, dass das Herstellen ein Spritzgießen oder ein Spritzpressen der Dichtung (140) aus einer Acrylnitril-Butadien-Kautschuk-Schmelze umfasst. 9. The method according to claim 7 or 8, characterized in that the production comprises injection molding or transfer molding of the seal (140) from an acrylonitrile butadiene rubber melt.
EP23700581.4A 2022-01-21 2023-01-03 Piston-cylinder unit, method for producing the piston-cylinder unit Pending EP4314212A1 (en)

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DE102022101447.9A DE102022101447B4 (en) 2022-01-21 2022-01-21 Piston-cylinder unit, method for producing the piston-cylinder unit
PCT/EP2023/050043 WO2023138910A1 (en) 2022-01-21 2023-01-03 Piston-cylinder unit, method for producing the piston-cylinder unit

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EP (1) EP4314212A1 (en)
KR (1) KR20240141125A (en)
CN (1) CN117136227A (en)
DE (1) DE102022101447B4 (en)
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WO (1) WO2023138910A1 (en)

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DE2942029C2 (en) 1979-10-17 1982-06-09 Kaspar 8000 München Lochner Hydraulically acting shock and vibration damper
US8118285B2 (en) 2004-07-01 2012-02-21 Avm Industries Gas spring with integrated lead screw drive
DE102007024008A1 (en) 2007-05-22 2008-11-27 Lanxess Deutschland Gmbh nitrile rubbers
DE102007024010A1 (en) * 2007-05-22 2008-11-27 Lanxess Deutschland Gmbh nitrile rubbers
DE102012010603B4 (en) 2011-06-29 2013-11-21 Carl Freudenberg Kg Coated sealing article
DE102014014392A1 (en) 2014-10-01 2016-04-07 Carl Freudenberg Kg Sealing body for dynamic applications
CN107532099A (en) * 2015-04-28 2018-01-02 Ｋｙｂ株式会社 Oleo-gear working oil and oleo-gear
EP3258056B1 (en) 2016-06-13 2019-07-24 VAREL EUROPE (Société par Actions Simplifiée) Passively induced forced vibration rock drilling system
IT201900016034A1 (en) 2019-09-11 2021-03-11 Skf Ab SEALING DEVICE IN PARTICULAR FOR SHOCK ABSORBER STEMS
DE102020111403A1 (en) 2020-04-27 2021-10-28 Klüber Lubrication München Se & Co. Kg Lubricant composition and its use

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DE102022101447B4 (en) 2024-04-18
CN117136227A (en) 2023-11-28
MX2023012308A (en) 2023-10-31
KR20240141125A (en) 2024-09-25
WO2023138910A1 (en) 2023-07-27

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