EP0108944A1 - Positive displacement member of a piston pump - Google Patents

Positive displacement member of a piston pump Download PDF

Info

Publication number
EP0108944A1
EP0108944A1 EP83110319A EP83110319A EP0108944A1 EP 0108944 A1 EP0108944 A1 EP 0108944A1 EP 83110319 A EP83110319 A EP 83110319A EP 83110319 A EP83110319 A EP 83110319A EP 0108944 A1 EP0108944 A1 EP 0108944A1
Authority
EP
European Patent Office
Prior art keywords
piston
blind hole
adapter
threaded
recess
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
EP83110319A
Other languages
German (de)
French (fr)
Other versions
EP0108944B1 (en
Inventor
Wilhelm Libhafsky
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.)
Feldmuehle AG
Original Assignee
Feldmuehle AG
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 Feldmuehle AG filed Critical Feldmuehle AG
Priority to AT83110319T priority Critical patent/ATE18790T1/en
Publication of EP0108944A1 publication Critical patent/EP0108944A1/en
Application granted granted Critical
Publication of EP0108944B1 publication Critical patent/EP0108944B1/en
Expired legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
    • F04B53/14—Pistons, piston-rods or piston-rod connections
    • F04B53/144—Adaptation of piston-rods
    • F04B53/147—Mounting or detaching of piston rod

Definitions

  • the invention relates to a displacement part of a piston pump for abrasive and / or corrosive liquids, consisting of a piston rod and a piston made of an oxide-ceramic material fastened to it by means of a releasable connection, the piston having a blind hole running in the direction of the piston head.
  • Pump pistons of high-pressure pumps for washing units are subject to high loads.
  • the pumps are generally designed as piston pumps in which 2-6 cylinders work on a crankshaft. They reach pressures that are between 80 and 18o bar. Sharp alkalis are usually used as the cleaning liquid. The temperatures of the cleaning fluids are 80 and more degrees C.
  • the coated or hard chrome-plated steel sleeves previously used as pistons were connected to the piston rod by means of a clamping screw. As an alternative to these steel sleeves, corresponding sleeves made of sintered oxide ceramic were used, which were connected in an analogous manner.
  • As a metal for the piston rod was a stainless material, so generally a high-alloy steel was used.
  • the arrangement of the O-ring for the seal additionally required a chamfer to be ground into the engagement area of the O-ring in the ceramic tube in order to prevent the risk of the O-ring being crushed during assembly.
  • the crushing resulted in a defective seal, which led to corrosion within the piston or to the piston being destroyed by higher internal pressure in the suction stroke.
  • Even the attachment of the chamfer did not completely prevent the risk of an O-ring being crushed during quick assembly. Because the pistons have to be released after a certain working time in order to remove the worn sealing sleeves that slide on this piston change, it is absolutely necessary that the connection between the piston and the piston rod cannot corrode, that is, must be completely separated from the medium.
  • oxide ceramic materials or oxide ceramics in the sense of the present invention is the short name for ceramics of pure oxides, oxide compounds and oxide mixtures, insofar as they are almost free of SiO 2 , this term serving as a differentiation from conventional silicate ceramics.
  • this term is understood to mean sintered products made from the oxides of aluminum, beryllium, magnesium, zirconium and thorium, and also from spinel, that is to say MgO Al 2 O 3 .
  • the term also includes the titanates and the uranium oxide, as well as the rare earth oxides and also some heavy metal oxides, all of which are used in high purity. However, the term high purity does not exclude that certain percentages of several oxides are mixed together and then sintered.
  • Oxide-ceramic materials such as aluminum oxide
  • Oxide-ceramic materials are sintered according to the aluminum oxide content of the materials at temperatures above 1500 ° C.
  • the parts manufactured as green bodies initially shrink considerably, ie in the range from 18 to 23%.
  • this shrinkage is not completely uniform everywhere, especially not if there are different wall thicknesses.
  • One must therefore proceed in such a way that the required thread is subsequently grinded in diamond-tipped grinding wheels are introduced or reworked.
  • such a complex method cannot be implemented for a simple body such as that represented by a pump piston for reasons of price.
  • the prior art therefore envisaged sintering ceramic tubes, which were ground on both ends and could be screwed onto the piston rod by means of a bolt.
  • the disadvantage of this construction is the complicated sealing, without which the piston cannot be released. It was also necessary to grind both end faces.
  • the invention is therefore based on the object of finding a connection between the piston and the piston rod which can also be released after a long period of time when used in corrosive and abrasive media and to reduce the grinding work during piston production.
  • the invention has a number of advantages. First, the number of surfaces to be machined after the piston sintering process is reduced to two, ie only the outer surface and the end face of the piston head have to be machined.
  • the blind hole, as well as the recess, are introduced into the piston in the green state and, like the piston crown, do not require any post-processing after the sintering process.
  • the tolerances of the blind hole and the recess are therefore relatively large, because the required socket, that is to say the piston is sufficient, is carried out on the adapter.
  • a preferred embodiment of the invention provides for the adapter to center the piston head. It is therefore an outer centering of the piston, in which there is enough play for the threaded elements without losing the accuracy of the centering.
  • the adapter is expediently provided with a threaded pin which is screwed through the blind hole into the threaded piece.
  • the threaded piece itself expediently consists of a simple piece of round steel which is drilled perpendicularly to its longitudinal extent and is threaded. Instead of a round steel, any profile steel can be used that has a threaded hole. It is only important that the threaded pin of the adapter has enough play in the blind hole and that the threaded piece in the recess has enough play to allow attachment.
  • the adapter is to be connected to the piston rod, which is expediently carried out by plugging or plugging the piston rod onto or into the adapter; however it is possible to provide this connection as a screw connection.
  • the piston 2 made of sintered oxide ceramic has a chamfer 17 in the region of the piston head 3, to which the jacket 6 of the piston 2 is connected.
  • a blind hole 5 extends from the piston head 4 in the direction of the piston head 3, which was introduced in the green state of the piston 2, without a machining step following after the sintering process. This blind hole 5 is cut perpendicularly from the recess 7, which was also made by drilling in the initial state of the piston 2.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Details Of Reciprocating Pumps (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
  • Lubricants (AREA)
  • Photoreceptors In Electrophotography (AREA)
  • Fertilizing (AREA)
  • Reciprocating Pumps (AREA)

Abstract

1. Displacement component of a piston pump for abrasive and/or corrosive liquids, comprising a piston rod and a piston made of oxide-ceramic material that is secured to the rod by means of a detachable connection, the piston having a blind hole extending in the direction of the piston crown, characterised by the following combination of features : the blind hole (5) is cut by a recess (7) that passes through the skirt (6) of the piston (2), a threaded component (8) is introduced into this recess (7), the base (4) of the piston is held by an adaptor (9) secured thereto by means of a screw connection which engages the threaded component through the blind hole (5) and coupled to the piston rod (1).

Description

Die Erfindung betrifft ein Verdrängerteil einer Kolbenpumpe für abrasive und/oder korrosive Flüssigkeiten, bestehend aus einer Kolbenstange und einem an dieser mittels einer lösbaren.Verbindung befestigten Kolben aus einem oxidkeramischen Material, wobei der Kolben ein in Richtung des Kolbenbodens verlaufendes Sackloch aufweist.The invention relates to a displacement part of a piston pump for abrasive and / or corrosive liquids, consisting of a piston rod and a piston made of an oxide-ceramic material fastened to it by means of a releasable connection, the piston having a blind hole running in the direction of the piston head.

Pumpenkolben von Hochdruckpumpen für Waschaggregate, wie sie beispielsweise in der Landwirtschaft zum Abspritzen von Ställen oder zum Reinigen von Maschinen, wie auch im Automobilsektor zum Autoreinigen eingesetzt werden, unterliegen hohen Beanspruchungen. Die Pumpen sind dabei im allgemeinen als Kolbenpumpen ausgeführt, bei denen 2 - 6 Zylinder auf einer Kurbelwelle arbeiten. Sie erreichen Drücke, die zwischen 80 und 18o bar liegen. Als Reinigungsflüssigkeit werden meist scharfe Alkalien eingesetzt. Die Temperaturen der Reinigungsflüssigkeiten'betragen 80 und mehr Grad C. Die bisher als Kolben eingesetzten beschichteten oder hartverchromten Stahlhülsen wurden über eine Spannschraube mit der Kolbenstange verbunden. Alternativ zu diesen Stahlhülsen hat man entsprechende Hülsen aus gesinterter Oxidkeramik eingesetzt, die analog verbunden waren. Als Metall für die Kolbenstange wurde ein nichtrostendes Material also im allgemeinen ein hochlegierter Stahl verwandt.Pump pistons of high-pressure pumps for washing units, such as those used in agriculture for hosing down stables or cleaning machines, as well as in the automotive sector for car cleaning, are subject to high loads. The pumps are generally designed as piston pumps in which 2-6 cylinders work on a crankshaft. They reach pressures that are between 80 and 18o bar. Sharp alkalis are usually used as the cleaning liquid. The temperatures of the cleaning fluids are 80 and more degrees C. The coated or hard chrome-plated steel sleeves previously used as pistons were connected to the piston rod by means of a clamping screw. As an alternative to these steel sleeves, corresponding sleeves made of sintered oxide ceramic were used, which were connected in an analogous manner. As a metal for the piston rod was a stainless material, so generally a high-alloy steel was used.

Mit dem Einsatz einer Keramikhülse als Kolben, konnte bereits weitgehend die Anforderung an die Verschleißfestigkeit und chemische Beständigkeit des Kolbens, sowie Lebensdauer der Manschette, berücksichtigt werden. Schwierigkeiten ergaben sich jedoch durch die Befestigung dieser Keramikhülse auf der Kolbenstange. In vielen Fällen korrodierte die Schraube oder vertrug sich nicht mit dem Fördermedium, in das sie eintaucht. In allen Fällen war es erforderlich, eine Abdichtung gegenüber der Keramikhülse zu fertigen, die ausgesprochen aufwendig war. Nur durch einen O-Ring mit dahinter angeordnetem Führungsring und einer Kupferscheibe konnte gewähr-.. leistet werden, daß die Abdichtung über einen längeren Zeitraum Bestand hatte. Außerdem mußten beide Stirnseiten der Keramikhülse plangeschliffen werden, um ein Zerstören des Kolbens durch beim Verspannen auftretende Biegekräfte zu vermeiden.With the use of a ceramic sleeve as the piston, the requirements regarding the wear resistance and chemical resistance of the piston, as well as the service life of the sleeve, could already be largely taken into account. Difficulties arose, however, from attaching this ceramic sleeve to the piston rod. In many cases, the screw corroded or was not compatible with the medium in which it was immersed. In all cases it was necessary to produce a seal against the ceramic sleeve, which was extremely complex. Only with an O-ring with a guide ring behind it and a copper washer could it be ensured that the seal would last over a longer period of time. In addition, both end faces of the ceramic sleeve had to be ground flat in order to prevent the piston from being destroyed by bending forces that occur during tensioning.

Die Anordnung des-O-Rings für die Dichtung erforderte zusätzlich das Einschleifen einer Fase im Eingriffsbereich des O-Ringes in das Keramikrohr, um die Gefahr des Zerquetschens des O-Ringes bei der Montage zu verhindern. Das Zerquetschen ergab eine mangelhafte Dichtung, die zur Korrosion innerhalb des Kolbens führte oder im Saughub den Kolben durch höheren Innendruck zerstörte. Auch durch das Anbringen der Fase wurde die Gefahr, daß ein O-Ring bei schneller Montage zerquetscht wurde, nicht völlig verhindert. Da die Kolben nach einer gewissen Arbeitszeit gelöst werden müssen, um die verschlissenen Dichtmanschetten, die auf diesem Kolben gleiten, auszuwechseln, ist es absolut erforderlich, daß die Verbindung zwischen Kolben und Kolbenstange nicht korrodieren kann, d.h., vom Fördermedium völlig getrennt sein muß.The arrangement of the O-ring for the seal additionally required a chamfer to be ground into the engagement area of the O-ring in the ceramic tube in order to prevent the risk of the O-ring being crushed during assembly. The crushing resulted in a defective seal, which led to corrosion within the piston or to the piston being destroyed by higher internal pressure in the suction stroke. Even the attachment of the chamfer did not completely prevent the risk of an O-ring being crushed during quick assembly. Because the pistons have to be released after a certain working time in order to remove the worn sealing sleeves that slide on this piston change, it is absolutely necessary that the connection between the piston and the piston rod cannot corrode, that is, must be completely separated from the medium.

Der Begriff oxidkeramische Materialien oder Oxidkeramik im Sinne der vorliegenden Erfindung,ist die Kurzbezeichnung für Keramik der reinen Oxide, Oxidverbindungen und Oxidgemische, soweit sie nahezu Si02-frei sind, wobei dieser Begriff als Abgrenzung gegen die herkömmliche Silikatkeramik dient. Insbesondere sind unter diesem Begriff Sinterprodukte aus den Oxiden von Aluminium, Beryllium, Magnesium, Zirkonium und Thorium, sowie dem Spinell,'also MgO Al2O3 zu verstehen. Der Begriff umfaßt ferner die Titänate und das Uranoxid, sowie die Oxide der seltenen Erden und auch einige Schwermetalloxide, wobei alle diese Materialien in hoher Reinheit verwendet werden. Der Begriff hohe Reinheit schließt jedoch nicht aus, daß bestimmte Prozentsätze mehrerer Oxide miteinander vermischt und dann gesintert werden.The term oxide ceramic materials or oxide ceramics in the sense of the present invention is the short name for ceramics of pure oxides, oxide compounds and oxide mixtures, insofar as they are almost free of SiO 2 , this term serving as a differentiation from conventional silicate ceramics. In particular, this term is understood to mean sintered products made from the oxides of aluminum, beryllium, magnesium, zirconium and thorium, and also from spinel, that is to say MgO Al 2 O 3 . The term also includes the titanates and the uranium oxide, as well as the rare earth oxides and also some heavy metal oxides, all of which are used in high purity. However, the term high purity does not exclude that certain percentages of several oxides are mixed together and then sintered.

Oxidkeramische Materialien, wie beispielsweise Aluminiumoxid, werden entsprechend dem Aluminiumoxidgehalt der Massen bei Temperaturen oberhalb 1500°C gesintert. Bei dieser Sinterung schrumpfen zunächst die als Grünkörper gefertigten Teile erheblich, d.h., im Bereich von 18 bis 23 %. Diese Schrumpfung ist in Abhängigkeit von der Gestalt der zu sinternden Materialien nicht überall völlig gleichmäßig, insbesondere dann nicht, wenn unterschiedliche Wandstärken vorhanden sind. Aus diesem Grunde ist es äußerst schwierig, ein exakt passendes Gewinde für eine Maschinenschraube in einen Oxidsinterkörper direkt einzusintern. Man muß demnach so vorgehen, daß das erforderliche Gewinde nachträglich durch Einschleifen mit diamantbestückten Schleifkörpern eingebracht, bzw. nachbearbeitet wird. Ein derart aufwendiges Verfahren ist jedoch für einen solchen einfachen Körper, wie ihn ein Pumpenkolben darstellt, aus Preisgründen nicht realisierbar. Der Stand der Technik sah daher vor, aus Keramik Rohre zu sintern, die an beiden Stirnseiten geschliffen wurden und mittels eines Bolzens auf die-Kolbenstange aufgeschraubt werden konnten. Der Nachteil dieser-Konstruktion besteht in der komplizierten Abdichtung, ohne die ein Lösen des Kolbens nicht möglich ist. Ferner war es erforderlich, beide Stirnflächen planzuschleifen.Oxide-ceramic materials, such as aluminum oxide, are sintered according to the aluminum oxide content of the materials at temperatures above 1500 ° C. During this sintering, the parts manufactured as green bodies initially shrink considerably, ie in the range from 18 to 23%. Depending on the shape of the materials to be sintered, this shrinkage is not completely uniform everywhere, especially not if there are different wall thicknesses. For this reason, it is extremely difficult to directly sinter a precisely fitting thread for a machine screw into an oxide sintered body. One must therefore proceed in such a way that the required thread is subsequently grinded in diamond-tipped grinding wheels are introduced or reworked. However, such a complex method cannot be implemented for a simple body such as that represented by a pump piston for reasons of price. The prior art therefore envisaged sintering ceramic tubes, which were ground on both ends and could be screwed onto the piston rod by means of a bolt. The disadvantage of this construction is the complicated sealing, without which the piston cannot be released. It was also necessary to grind both end faces.

Der Erfindung liegt daher die Aufgabe zu Grunde, eine Verbindung zwischen Kolben und Kolbenstange zu finden, die auch beim Einsatz in korrosiven und abrasiven Medien nach langer Laufzeit lösbar ist und die Schleifarbeit bei der Kolbenherstellung zu reduzieren.The invention is therefore based on the object of finding a connection between the piston and the piston rod which can also be released after a long period of time when used in corrosive and abrasive media and to reduce the grinding work during piston production.

Die Aufgabe wird durch die Kombination folgender Merkmale gelöst:

  • Das Sackloch wird von einer den Mantel des Kolbens durchdringenden Ausnehmung geschnitten, in diese Ausnehmung ist ein Gewindestück eingebracht, der Kolbenkopf wird von einem Adapter erfaßt, der mittels einer Schraubverbindung, die durch das Sackloch in das Gewindestück eingreift, an ihm befestigt und mit der Kolbenstange gekuppelt ist.
The task is solved by combining the following features:
  • The blind hole is cut by a recess penetrating the jacket of the piston, a threaded piece is introduced into this recess, the piston head is gripped by an adapter which is fastened to it by means of a screw connection which engages through the blind hole in the threaded piece and to the piston rod is coupled.

Durch die Erfindung ergeben sich eine Vielzahl von Vorteilen. Zunächst wird die Zahl der nach dem Sintervorgang des Kolbens zu bearbeitenden Flächen auf zwei reduziert, d.h., nur noch die Mantelfläche und die Stirnfläche des Kolbenkopfes müssen bearbeitet werden. Das Sackloch, sowie auch die Ausnehmung, werden im Grünzustand in den Kolben eingebracht und bedürfen, wie auch der Kolbenboden, keiner Nachbearbeitung nach dem Sintervorgang. Die Toleranzen von Sackloch und Ausnehmung sind also relativ groß, weil die erforderliche Fassung, also das Ausreichten des Kolbens erst.am Adapter erfolgt. Eine bevorzugte Ausgestaltung der Erfindung sieht vor, daß der Adapter den Kolbenkopf zentrierend umfaßt. Es handelt sich also um eine Außenzentrierung des Kolbens, bei dem für die Gewindeelemente genügend Spiel bleibt, ohne daß dadurch die Genauigkeit der Zentrierung verloren geht.The invention has a number of advantages. First, the number of surfaces to be machined after the piston sintering process is reduced to two, ie only the outer surface and the end face of the piston head have to be machined. The blind hole, as well as the recess, are introduced into the piston in the green state and, like the piston crown, do not require any post-processing after the sintering process. The tolerances of the blind hole and the recess are therefore relatively large, because the required socket, that is to say the piston is sufficient, is carried out on the adapter. A preferred embodiment of the invention provides for the adapter to center the piston head. It is therefore an outer centering of the piston, in which there is enough play for the threaded elements without losing the accuracy of the centering.

Zweckmäßig ist dabei der Adapter mit einem Gewindezapfen versehen, der durch das Sackloch in das Gewindestück eingeschraubt ist. Das Gewindestück selbst besteht zweckmäßig aus einem einfachen Stück Rundstahl, das senkrecht zu seiner Längsausdehnung durchbohrt und mit Gewinde versehen ist. Statt eines Rundstahles kann auch jeder beliebige Profilstahl eingesetzt werden, der analog eine Gewindebohrung aufweist. Von Bedeutung ist lediglich, daß der Gewindezapfen des Adapters im Sackloch genügend Spiel hat und daß das Gewindestück in der Ausnehmung genügend Spiel hat, um eine Befestigung zu ermöglichen.The adapter is expediently provided with a threaded pin which is screwed through the blind hole into the threaded piece. The threaded piece itself expediently consists of a simple piece of round steel which is drilled perpendicularly to its longitudinal extent and is threaded. Instead of a round steel, any profile steel can be used that has a threaded hole. It is only important that the threaded pin of the adapter has enough play in the blind hole and that the threaded piece in the recess has enough play to allow attachment.

Selbstverständlich ist es auch möglich, statt eines Gewindezapfens, der fest mit dem Adapter verbunden ist, den Adapter mit einer Bohrung auszuführen und durch diese eine Maschinenschraube in das Gewindestück einzudrehen. In jedem Fall ist der Adapter jedoch mit der Kolbenstange zu verbinden, was zweckmäßig durch Auf- oder Einstecken der Kolbenstange auf, bzw. in den Adapter erfolgt; jedoch ist es auch möglich, diese Verbindung als Schraubverbindung vorzusehen.Of course, it is also possible, instead of a threaded pin that is firmly connected to the adapter, to design the adapter with a bore and to screw a machine screw into the threaded part through this. In any case, however, the adapter is to be connected to the piston rod, which is expediently carried out by plugging or plugging the piston rod onto or into the adapter; however it is possible to provide this connection as a screw connection.

Die Erfindung wird nachstehend an Hand der Zeichnungen beschrieben.

  • Die Fig. 1 zeigt einen Kolben, der über einen Adap- ter mit Gewindezapfen mit der Kolbenstange verbunden ist,
  • die Fig. 2 einen mittels einer Maschinenschraube am Adapter befestigten Kolben.
The invention is described below with reference to the drawings.
  • Figs. 1 shows a piston which via a Adap - ter is connected with threaded pin to the piston rod,
  • 2 shows a piston attached to the adapter by means of a machine screw.

Der Kolben 2 aus gesinterter Oxidkeramik weist im Bereich des Kolbenbodens 3 eine Fase 17 auf, an die sich der Mantel 6 des Kolbens 2 anschließt. Vom Kolbenkopf 4 erstreckt sich ein Sackloch 5 in Richtung des Kolbenbodens 3, das im Grünzustand des Kolbens 2 eingebracht wurde, ohne daß sich nach dem Sinterverfahren eine Bearbeitungsstufe anschloß. Dieses Sackloch 5 wird senkrecht von der Ausnehmung 7 geschnitten, die ebenfalls durch einen Bohrvorgang im Gründzustand des Kolbens 2 eingebracht wurde.The piston 2 made of sintered oxide ceramic has a chamfer 17 in the region of the piston head 3, to which the jacket 6 of the piston 2 is connected. A blind hole 5 extends from the piston head 4 in the direction of the piston head 3, which was introduced in the green state of the piston 2, without a machining step following after the sintering process. This blind hole 5 is cut perpendicularly from the recess 7, which was also made by drilling in the initial state of the piston 2.

In dieser Ausnehmung 7 liegt das Gewindestück 8, ein beidseitig angefastes Stück Rundstahl, das mittig mit einer Gewindebohrung 18 versehen wurde. Der Gewindezapfen lo, der Teil des Adapters 9 ist, ist in die Gewindebohrung 18 des Gewindestückes 8 eingedreht und verbindet dadurch den Kolben 2 mit dem Adapter 9. Der Adapter 9 seinerseits ist auf der dem Gewindezapfen lo gegenüberliegenden Seite nit einem Gewindeansatz 11 versehen, auf den die Kolbenstange 1 aufgeschraubt wird. Eine alternative Lösung ist in der Fig. 2 dargestellt, wo statt des Gewindezapfens lo eine Maschinenschraube 12 eingesetzt wird, die die Bohrung 13 im Adapter 9 durchdringt und in das Gewindestück 8 eingreift. An die Bohrung 13 schließt sich eine Aussenkung 14 an, die den Kopf der Maschinenschraube 12 aufnimmt..Der Adapter 9 ist mit einem Ansatz 16 versehen, auf den die als Rohr ausgeführte Kolbenstange 1 aufgeschoben und mittels eines Kerbstiftes 15 befestigt ist.In this recess 7 is the threaded piece 8, a piece of round steel chamfered on both sides, which was provided in the center with a threaded bore 18. The threaded pin lo, which is part of the adapter 9, is screwed into the threaded bore 18 of the threaded piece 8 and thereby connects the piston 2 to the adapter 9. The adapter 9 in turn is provided with a threaded shoulder 11 on the side opposite the threaded pin lo which the piston rod 1 is screwed on. An alternative solution is shown in FIG. 2, where a machine screw 12 is inserted instead of the threaded pin 10 is set, which penetrates the bore 13 in the adapter 9 and engages in the threaded piece 8. At the bore 13 there is a counterbore 14, which receives the head of the machine screw 12. The adapter 9 is provided with a shoulder 16 onto which the piston rod 1 designed as a tube is pushed and fastened by means of a notch pin 15.

Claims (3)

1. Verdrängerteil einer Kolbenpumpe für abrasive und/oder korrosive Flüssigkeiten, bestehend aus einer Kolbenstange und einem an dieser mittels einer lösbaren Verbindung befestigten Kolben aus oxidkeramischem Material, wobei der Kolben ein in Richtung des.Kolbenbodens verlaufendes Sackloch aufweist, gekennzeichnet durch die Kombination folgender Merkmale: das Sackloch (5) wird von einer den Mantel (6) des Kolbens (2) durchdringenden Ausnehmung (7) geschnitten, in diese Ausnehmung (7) ist ein Gewindestück (8) eingebracht, der Kolbenkopf (4) wird von einem Adapter (9) erfaßt, der mittels einer Schraubverbindung, die durch das Sackloch (5) in das Gewindestück (8) eingreift, an ihm befestigt ist und mit der Kolbenstange gekuppelt ist. 1. Displacement part of a piston pump for abrasive and / or corrosive liquids, consisting of a piston rod and a piston made of oxide-ceramic material attached to it by means of a releasable connection, the piston having a blind hole running in the direction of the piston crown, characterized by the combination of the following features : the blind hole (5) is cut by a recess (7) penetrating the jacket (6) of the piston (2), a threaded piece (8) is introduced into this recess (7), the piston head (4) is replaced by an adapter (9 ) detected, which is fastened to it by means of a screw connection which engages through the blind hole (5) in the threaded piece (8) and is coupled to the piston rod. 2. Verdrängerteil nach Anspruch 1, dadurch gekennzeichnet, daß der Adapter (9) den Kolbenkopf (4) zentrierend umfaßt.2. Displacer part according to claim 1, characterized in that the adapter (9) comprises the piston head (4) centering. 3. Verdrängerteil nach einem der Ansprüche 1 und 2, dadurch gekennzeichnet, daß der Adapter (9) mit einem Gewindezapfen (lo) versehen ist, der durch das Sackloch (5) in das Gewindestück (8)'geschraubt ist.3. Displacement part according to one of claims 1 and 2, characterized in that the adapter (9) is provided with a threaded pin (lo) which is screwed through the blind hole (5) into the threaded piece (8) '.
EP83110319A 1982-10-19 1983-10-15 Positive displacement member of a piston pump Expired EP0108944B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT83110319T ATE18790T1 (en) 1982-10-19 1983-10-15 DISPLACEMENT SECTION OF A PISTON PUMP.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19823238667 DE3238667A1 (en) 1982-10-19 1982-10-19 DISPLACEMENT PART OF A PISTON PUMP
DE3238667 1982-10-19

Publications (2)

Publication Number Publication Date
EP0108944A1 true EP0108944A1 (en) 1984-05-23
EP0108944B1 EP0108944B1 (en) 1986-03-26

Family

ID=6176063

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83110319A Expired EP0108944B1 (en) 1982-10-19 1983-10-15 Positive displacement member of a piston pump

Country Status (5)

Country Link
EP (1) EP0108944B1 (en)
AT (1) ATE18790T1 (en)
DE (2) DE3238667A1 (en)
DK (1) DK452983A (en)
FI (1) FI73793C (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014063966A1 (en) * 2012-10-23 2014-05-01 Robert Bosch Gmbh Pump element for a hydraulic unit having a pump piston
IT201800004176A1 (en) * 2018-04-03 2019-10-03 PISTON IN CERAMIC MATERIAL
IT201900006680A1 (en) * 2019-05-09 2020-11-09 Annovi Reverberi Spa PISTON IN CERAMIC MATERIAL

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4741254A (en) * 1986-06-12 1988-05-03 Taylor Julian S Pump plunger
DE3702446A1 (en) * 1987-01-28 1988-08-11 Kaercher Gmbh & Co Alfred HIGH PRESSURE CLEANING DEVICE WITH A SWASHPLATE PISTON PUMP
DE3914333A1 (en) * 1989-04-29 1990-10-31 Hoechst Ceram Tec Ag PUMP PISTON FOR AXIAL PISTON PUMPS

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1195546A (en) * 1916-08-22 Pump-piston
DE2939284A1 (en) * 1979-09-28 1981-04-02 Feldmühle AG, 4000 Düsseldorf Piston made of sintered oxide ceramic, esp. alumina - where metal shaft is screwed into piston and bonded by adhesive, so piston can be attached to piston rod

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1195546A (en) * 1916-08-22 Pump-piston
DE2939284A1 (en) * 1979-09-28 1981-04-02 Feldmühle AG, 4000 Düsseldorf Piston made of sintered oxide ceramic, esp. alumina - where metal shaft is screwed into piston and bonded by adhesive, so piston can be attached to piston rod

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2014063966A1 (en) * 2012-10-23 2014-05-01 Robert Bosch Gmbh Pump element for a hydraulic unit having a pump piston
CN104755755A (en) * 2012-10-23 2015-07-01 罗伯特·博世有限公司 Pump element for a hydraulic unit having a pump piston
IT201800004176A1 (en) * 2018-04-03 2019-10-03 PISTON IN CERAMIC MATERIAL
WO2019193437A1 (en) * 2018-04-03 2019-10-10 Annovi Reverberi S.P.A. Piston made of ceramic material
US11149850B2 (en) 2018-04-03 2021-10-19 Annovi Reverberi S.P.A. Piston made of ceramic material
IT201900006680A1 (en) * 2019-05-09 2020-11-09 Annovi Reverberi Spa PISTON IN CERAMIC MATERIAL

Also Published As

Publication number Publication date
DK452983D0 (en) 1983-09-30
DE3238667A1 (en) 1984-04-26
FI73793C (en) 1987-11-09
FI833740A (en) 1984-04-20
DE3362709D1 (en) 1986-04-30
FI833740A0 (en) 1983-10-14
ATE18790T1 (en) 1986-04-15
EP0108944B1 (en) 1986-03-26
FI73793B (en) 1987-07-31
DK452983A (en) 1984-04-20

Similar Documents

Publication Publication Date Title
DE2317666C2 (en) Hydraulic cylinder
EP0108944B1 (en) Positive displacement member of a piston pump
DE202019004569U1 (en) Working cylinder
EP0103906B1 (en) Positive displacement member of a piston pump
DE10115263A1 (en) Hydraulic piston for cylinder block of hydrostatic drive unit has long cylindrical body inside of which is cavity with second end which is open and ends inside plane running through second end of body
DE1259816B (en) Piston for hydraulic pit ram or the like.
EP1410846B1 (en) High pressure jet nozzle
DE1675337A1 (en) Hose connection
DE8229300U1 (en) DISPLACEMENT PART OF A PISTON PUMP
DE1231979B (en) Working cylinder for pressure medium systems
DE10145062B4 (en) beam head
DE3208037A1 (en) Displacement element of a high pressure pump
DE3305647A1 (en) Displacement element of a piston pump
DE3136472C2 (en)
DE1552257C3 (en) Hydraulic clamping device designed as a mandrel or chuck for tools or workpieces
DE1427720C (en)
DE8513328U1 (en) Diamond core bit with shaft tube and pipe thread connection
DE10042304B4 (en) Device for face milling on shaft ends
DE1270330B (en) Coupling for power tools, especially pruning shears or the like.
DE444638C (en) Mouthpiece for acetylene burner
DE1911824A1 (en) Clamping device for tool holders in tool holder holders
DE20106205U1 (en) tapping attachment
AT239619B (en) Gate valve for high pressure lines
DE950998C (en) Multi-part drill pipe clamp for large holes
DE3530795A1 (en) Plug-in coupling for hose and pipelines

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19831027

AK Designated contracting states

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

ITF It: translation for a ep patent filed

Owner name: STUDIO INGG. FISCHETTI & WEBER

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT BE CH DE FR GB IT LI LU NL SE

REF Corresponds to:

Ref document number: 18790

Country of ref document: AT

Date of ref document: 19860415

Kind code of ref document: T

ET Fr: translation filed
REF Corresponds to:

Ref document number: 3362709

Country of ref document: DE

Date of ref document: 19860430

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19861031

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: LU

Payment date: 19890823

Year of fee payment: 7

Ref country code: DE

Payment date: 19890823

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19890828

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19890831

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19890905

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19890930

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: AT

Payment date: 19891027

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: SE

Payment date: 19891030

Year of fee payment: 7

ITTA It: last paid annual fee
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19891031

Year of fee payment: 7

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19901015

Ref country code: AT

Effective date: 19901015

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SE

Effective date: 19901016

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19901031

Ref country code: CH

Effective date: 19901031

Ref country code: BE

Effective date: 19901031

BERE Be: lapsed

Owner name: FELDMUHLE A.G.

Effective date: 19901031

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Effective date: 19910501

GBPC Gb: european patent ceased through non-payment of renewal fee
NLV4 Nl: lapsed or anulled due to non-payment of the annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19910628

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19910702

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

EUG Se: european patent has lapsed

Ref document number: 83110319.7

Effective date: 19910603