EP0740016B1 - Extended nip press roll for a paper machine - Google Patents

Extended nip press roll for a paper machine Download PDF

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Publication number
EP0740016B1
EP0740016B1 EP96101385A EP96101385A EP0740016B1 EP 0740016 B1 EP0740016 B1 EP 0740016B1 EP 96101385 A EP96101385 A EP 96101385A EP 96101385 A EP96101385 A EP 96101385A EP 0740016 B1 EP0740016 B1 EP 0740016B1
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EP
European Patent Office
Prior art keywords
shoe
pressure
pressing shoe
pressure chamber
pressing
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.)
Expired - Lifetime
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EP96101385A
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German (de)
French (fr)
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EP0740016A1 (en
Inventor
Christian Schiel
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Voith Patent GmbH
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Voith Sulzer Papiertechnik Patent GmbH
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Publication of EP0740016A1 publication Critical patent/EP0740016A1/en
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    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21FPAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
    • D21F3/00Press section of machines for making continuous webs of paper
    • D21F3/02Wet presses
    • D21F3/0209Wet presses with extended press nip
    • D21F3/0218Shoe presses

Definitions

  • the invention relates to a shoe press device according to the preamble of claim 1.
  • a shoe press device of this type is known from DE 43 19 323 A1 known.
  • the press shoe of the shoe press roll is by a hydraulic pressure unit can be pressed against the counter roller, the hydraulic pressure unit essentially in Longitudinal direction of the press shoe extends.
  • a hydraulic Pressure unit Within the hydraulic Pressure unit is a plurality of hydraulic pressure or relief units arranged to along the longitudinal extent of the press shoe to a dosage of the pressing force enable.
  • the pressure or relief units include one hydraulic piston each in a cylindrical Axial recess of the support body by means of a sealing ring slidably and tiltable to a certain extent.
  • the hydraulic piston is located by means of an annular sealing surface at the bottom of the press shoe. Because during operation the press shoe z. B.
  • the amount can be tilted in the known version the piston by a coil spring against the bottom of the Press shoe pressed to avoid hydraulic fluid from the hydraulic chamber laterally between the sealing surface and the Exit press shoe when tilted.
  • the piston in the known version is also the piston by a chain on the support body is secured against escaping during assembly. This chain is by means of a bolt on a continuous Radial web of the piston secured by the pressure chamber upwards, towards the press shoe, is limited.
  • a disadvantage of the known arrangement has been the relative complicated structure and the relatively complicated assembly as a result the spiral spring and the safety chain.
  • the object of the invention is therefore a shoe press device of the type mentioned in such a way that improve and assembly in the simplest and cheapest possible way are feasible.
  • deflection adjustment rollers basically known to the principle of the hydrostatic bearing, Pressure pockets to support a revolving hydrostatic supported metal jacket over throttling points with pressure supply, however, this fact does not make the invention suggested since this is a completely different task acts, namely instead of a positioning aid only when starting is a permanent supply of a hydrostatic lubrication gap with lubricating oil the target next to an adjustment of the deflection curve by adjusting the pressure.
  • the throttle point according to the invention is the hydraulic one Support of the press shoe provided, the flow through the throttle point is practically zero during operation.
  • one or more sealing rings for sealing in the sealing surface can be inserted against the press shoe.
  • a cylinder of the cylinder / piston unit to be arranged between the press shoe and the supporting body and to provide the associated piston in the support body.
  • the cylinder / Piston unit comprises a recess on the support body in which a Piston axially displaceable and tiltable by means of a seal is led.
  • the cylinder / piston unit can be used for additional Pressure elements such as coil springs and the like are dispensed with be, so that with the embodiment of the invention significantly simplified creation and assembly results.
  • the first is Pressure chamber of the piston opposite to the second pressure chamber a loose washer completed under the action of hydraulic pressure in the first pressure chamber on a projection of the piston is present.
  • This disc which is similar to a valve disk is formed, in the event of sudden pressure relief from the Projection of the piston, which is preferably designed as an annular web is, take off so that any compressed air from the top Pressure chamber over the enlarged relief cross section on Circumference of the disc can escape.
  • a shoe press is schematic in the area of Press nip 14 outlines a shoe press roll 10 with a Compressed shoe 16, which is associated with a counter roller 12.
  • a press jacket in a known manner 18 passed over the press shoe 16, which is on a hydrodynamic Lubrication wedge largely frictionless over the press shoe 16 circulates.
  • a press nip 14 is also to be dewatered Paper web 22 usually together with at least one felt web 20 led.
  • the press shoe 16 is by means of a plurality of hydraulic elements can be pressed against the counter roller 12, which is on a underlying supporting body 24 according to FIG. 2 support.
  • Each hydraulic element is a cylinder / piston unit 26 executed, which has a cylindrical recess 48 in Carrying body 24 comprises, in which a piston 40 is guided.
  • the piston 40 has at its lower, the cylindrical Recess 48 facing the end of an outer collar 42, inside an annular groove 44 is provided in which a seal 46 is provided in the form of a sealing ring.
  • the piston 40 is with the seal 46 on the inner surface 50 of the cylindrical Recess 48 axially displaceable and by a certain amount guided tiltable.
  • the piston 40 lies at its end facing the press shoe 16 with an annular sealing surface 36 on a flat contact surface 17 of the press shoe 16. Inside the ring-shaped Sealing surface 36, an annular groove 38 is provided in the one Sealing ring 34 is held.
  • two pressure chambers are formed, namely one first pressure chamber 28 between the cylindrical recess 48 and the piston 40, which are opposite a second pressure chamber 30 between the piston 40 and the press shoe 16 by a radial web 54 is separated, which forms a piston crown.
  • the diameter of the throttle point 32 is such that at approximately static conditions when the press shoe 16 with its flat contact surface 17 completely on the sealing surface 36 of the piston 40 rests in the second pressure chamber 30 same pressure as in the first pressure chamber 28, so that the via a hydraulic channel 52 in the first pressure chamber 28 transmitted hydraulic pressure directly via the second pressure chamber 30 is transferred to the press shoe 16.
  • the diameter is at most about 5 mm, preferably about 1 to 4 mm.
  • the diameter is correspondingly smaller.
  • the piston 40 ' is a modification of that previously described Execution upwards not completed by a piston crown, but only through a loose disc 64, which is from the central throttle point 32 'is penetrated.
  • This disk 64 is designed similar to a valve plate and is underneath Pressure on an annular web 56 of the piston 40 '.
  • the disc 64 in uniform Angular distances of 90 ° four outer projections 58, by means of which is centered on the inner surface 60 of the piston 40 '.
  • the disk 64 can move from the Lift off ring web 56 and laterally in the pressure chamber if necessary 30 existing compressed air can thus over the enlarged relief cross section on the circumference of the disk 64 relax quickly.
  • Such Spring can also be provided, provided a complete Tightness of the cylinder / piston unit also when starting is desired.
  • this spring is much weaker than formed in conventional hydraulic elements because they preferably less than about 20% of the contact pressure on the Press shoe 16 transmits.
  • an insert is also used in the support body 24 can be in which the cylindrical recess 48th can be formed in which the piston is guided with its seal is.
  • recess 48 is not cylindrical must be trained, but also a rectangular or can have a differently shaped cross section.

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  • Paper (AREA)
  • Rolls And Other Rotary Bodies (AREA)

Abstract

A shoe press roll for a paper machine which, together with a backing roll, forms a press nip through which a press jacket guided over the shoe press roll travels together with a paper web. The shoe press roll comprises a press shoe which can be pressed by at least one hydraulic element against the backing roll. The hydraulic element is developed as a cylinder/piston unit that acts between a stationary support member and the press shoe. The unit includes a first pressure chamber which can be acted on by hydraulic pressure and is in communication via a small diameter throttle point passing through the piston with a second pressure chamber which is open toward the press shoe. The edge of the piston rests with a sealing surface against the press shoe. Hydraulic pressure is transmitted from the first pressure chamber under approximately static conditions, to the second pressure chamber through the throttle point and thus to the press shoe. Should the press shoe tilt permitting pressure to escape from the second chamber at the shoe, the throttle point prevents rapid continuous flow of hydraulic pressure out of the first pressure chamber. The tilting produces a pressure drop in the second pressure chamber which causes the press shoe to apply itself against the cylinder/piston unit as a result of the external pressure applied from the first pressure chamber.

Description

Die Erfindung betrifft eine Schuhpreßeinrichtung gemäß dem Oberbegriff des Anspruches 1. The invention relates to a shoe press device according to the preamble of claim 1.

Eine Schuhpreßeinrichtung dieser Art ist aus der DE 43 19 323 A1 bekannt.A shoe press device of this type is known from DE 43 19 323 A1 known.

Bei der bekannten Schuhpreßeinrichtung ist der Preßschuh der Schuhpreßwalze durch eine hydraulische Anpreßeinheit gegen die Gegenwalze anpreßbar, wobei sich die hydraulische Anpreßeinheit im wesentlichen in Längsrichtung des Preßschuhs erstreckt. Innerhalb der hydraulischen Anpreßeinheit ist eine Mehrzahl von hydraulischen Anpreß- bzw. Entlastungseinheiten angeordnet, um entlang der Längserstreckung des Preßschuhs eine Dosierung der Preßkraft zu ermöglichen. Die Anpreß- bzw. Entlastungseinheiten umfassen jeweils einen Hydraulikkolben, der in einer zylindrischen Ausnehmung des Tragkörpers mittels eines Dichtringes axial verschiebbar und um einen gewissen Grad verkippbar geführt ist. Der Hydraulikkolben liegt mittels einer ringförmigen Dichtfläche an der Unterseite des Preßschuhs an. Da während des Betriebes der Preßschuh z. B. infolge von wärmebedingten Längenänderungen oder Laständerungen gegenüber dem Tragkörper um einen gewissen Betrag verkippt werden kann, wird bei der bekannten Ausführung der Kolben durch eine Spiralfeder gegen die Unterseite des Preßschuhs angepreßt, um zu vermeiden, daß Hydraulikmittel aus der Hydraulikkammer seitlich zwischen der Dichtfläche und dem Preßschuh bei Verkippung austreten. Bei der bekannten Ausführung ist ferner der Kolben durch eine Kette, die am Tragkörper befestigt ist, gegen ein Entweichen bei der Montage gesichert. Diese Kette ist mittels eines Bolzens an einem durchgehenden Radialsteg des Kolbens gesichert, durch den die Druckkammer nach oben, in Richtung zum Preßschuh hin, begrenzt ist. In the known shoe press device, the press shoe of the shoe press roll is by a hydraulic pressure unit can be pressed against the counter roller, the hydraulic pressure unit essentially in Longitudinal direction of the press shoe extends. Within the hydraulic Pressure unit is a plurality of hydraulic pressure or relief units arranged to along the longitudinal extent of the press shoe to a dosage of the pressing force enable. The pressure or relief units include one hydraulic piston each in a cylindrical Axial recess of the support body by means of a sealing ring slidably and tiltable to a certain extent. The hydraulic piston is located by means of an annular sealing surface at the bottom of the press shoe. Because during operation the press shoe z. B. due to heat-related changes in length or load changes compared to the supporting body by a certain amount The amount can be tilted in the known version the piston by a coil spring against the bottom of the Press shoe pressed to avoid hydraulic fluid from the hydraulic chamber laterally between the sealing surface and the Exit press shoe when tilted. In the known version is also the piston by a chain on the support body is secured against escaping during assembly. This chain is by means of a bolt on a continuous Radial web of the piston secured by the pressure chamber upwards, towards the press shoe, is limited.

Um eine vollständige Übertragung des hydraulischen Druckes aus der Druckkammer an die Unterseite des Preßschuhs zu gewährleisten und um die Bildung eines Luftpolsters zu verhindern, ist in dem Radialsteg eine große Bohrung vorgesehen, so daß die oberhalb der Druckkammer gebildete zweite, zum Preßschuh offene Druckkammer vollständig mit der ersten Druckkammer kommuniziert und der Hydraulikdruck unmittelbar auf die Unterseite des Preßschuhs übertragen wird.To make a complete transfer of hydraulic pressure to ensure the pressure chamber to the bottom of the press shoe and to prevent the formation of an air cushion is in the radial web a large hole is provided so that the above the pressure chamber formed second pressure chamber open to the press shoe fully communicates with the first pressure chamber and the hydraulic pressure directly on the underside of the press shoe is transmitted.

Als nachteilig bei der bekannten Anordnung hat sich der relativ komplizierte Aufbau und die relativ komplizierte Montage infolge der Spiralfeder und der Sicherungskette erwiesen.A disadvantage of the known arrangement has been the relative complicated structure and the relatively complicated assembly as a result the spiral spring and the safety chain.

Die Aufgabe der Erfindung besteht demnach darin, eine Schuhpreßeinrichtung der eingangs genannten Art derart zu verbessern, daß Aufbau und Montage auf möglichst einfache und kostengünstige Weise durchführbar sind.The object of the invention is therefore a shoe press device of the type mentioned in such a way that improve and assembly in the simplest and cheapest possible way are feasible.

Diese Aufgabe wird durch die im Anspruch 1 bzw. 2 beschriebene Einrichtung gelöst, wobei die Unteransprüche besondere Ausführungsformen dastellen.This object is achieved by the in claims 1 and 2 respectively described device solved, the subclaims represent special embodiments.

Erfindungsgemäß wird der Durchlaß zwischen den beiden Druckkammern als Drosselstelle ausgebildet.According to the passage formed between the two pressure chambers as a throttle.

Auf diese Weise kann auf den Einbau einer Spiralfeder und eines entsprechenden Sicherungselementes verzichtet werden, da die Drosselstelle derart dimensioniert werden kann, daß bei an der Dichtfläche anliegendem Preßschuh im wesentlichen der gleiche Druck in beiden Druckkammern herrscht. Dies hat zur Folge, daß im Normalbetrieb, wenn der Kolben mit seiner Dichtfläche unmittelbar am Preßschuh anliegt, der Hydraulikdruck vollständig auf den Preßschuh übertragen wird. Sollte sich jedoch der Preßschuh beim Betrieb um eine gewissen Grad verkippen, so kann aus der zweiten Druckkammer seitlich Hydrauliköl zwischen dem Preßschuh und der Dichtfläche austreten. Infolge der Drosselwirkung im Durchlaß wird jedoch das Nachfließen von Hydraulikflüssigkeit aus der ersten Druckkammer stark eingeschränkt, so daß der Druck in der zweiten Druckkammer sofort stark abfällt und nur geringe Mengen an Hydraulikflüssigkeit seitlich zwischen dem Preßschuh und der Dichtfläche austreten können. Somit läßt der Druck jenseits des Durchlasses nach, so daß sich der Preßschuh infolge des höheren Druckes diesseits des Durchlasses wieder an die Dichtfläche der zweiten Druckkammer anlegt.That way on the installation of a spiral spring and one corresponding securing element can be dispensed with, since the throttle point can be dimensioned such that at on the sealing surface press shoe essentially the there is the same pressure in both pressure chambers. This has to Consequence that in normal operation when the piston with its sealing surface hydraulic pressure is applied directly to the press shoe is completely transferred to the press shoe. Should, however tilt the press shoe to a certain degree during operation, so hydraulic oil can laterally between the second pressure chamber emerge from the press shoe and the sealing surface. As a result of the throttling effect in the passage, however, the hydraulic fluid continues to flow severely restricted from the first pressure chamber, so that the pressure in the second pressure chamber immediately drops sharply and only small amounts of hydraulic fluid laterally between the press shoe and the sealing surface can escape. Thus leaves the pressure beyond the passage, so that the Press shoe due to the higher pressure on this side of the passage again against the sealing surface of the second pressure chamber.

Zwar ist es bei sogenannten Durchbiegungseinstellwalzen nach dem Prinzip des hydrostatischen Lagers grundsätzlich bekannt, Drucktaschen zur Abstützung eines umlaufenden hydrostatisch gestützten Metallmantels über Drosselstellen mit Druck zu versorgen, jedoch wird durch diese Tatsache die Erfindung nicht nahegelegt, da es sich hierbei um eine gänzlich andere Aufgabe handelt, nämlich statt einer Positionierhilfe nur beim Anfahren ist eine Dauerversorgung eines hydrostatischen Schmierspaltes mit Schmieröl das Ziel neben einer Einstellung der Durchbiegungskurve durch eine Anpassung des Druckes.It is true with so-called deflection adjustment rollers basically known to the principle of the hydrostatic bearing, Pressure pockets to support a revolving hydrostatic supported metal jacket over throttling points with pressure supply, however, this fact does not make the invention suggested since this is a completely different task acts, namely instead of a positioning aid only when starting is a permanent supply of a hydrostatic lubrication gap with lubricating oil the target next to an adjustment of the deflection curve by adjusting the pressure.

Erfindungsgemäß ist dagegen die Drosselstelle zur hydraulischen Stützung des Preßschuhs vorgesehen, wobei der Durchfluß durch die Drosselstelle beim Betrieb praktisch Null ist.In contrast, the throttle point according to the invention is the hydraulic one Support of the press shoe provided, the flow through the throttle point is practically zero during operation.

Es versteht sich, daß in zweckmäßiger Weiterbildung der Erfindung in der Dichtfläche ein oder mehrere Dichtringe zur Abdichtung gegen den Preßschuh eingelegt sein können.It is understood that in an expedient development of the invention one or more sealing rings for sealing in the sealing surface can be inserted against the press shoe.

Grundsätzlich ist es möglich, einen Zylinder der Zylinder-/Kolbeneinheit zwischen dem Preßschuh und dem Tragkörper anzuordnen und den zugeordneten Kolben im Tragkörper vorzusehen. Basically, it is possible to have a cylinder of the cylinder / piston unit to be arranged between the press shoe and the supporting body and to provide the associated piston in the support body.

Es ist erfindungsgemäß jedoch bevorzugt, daß die Zylinder-/ Kolbeneinheit eine Ausnehmung am Tragkörper umfaßt, in der ein Kolben mittels einer Dichtung axial verschieblich und verkippbar geführt ist.However, it is preferred according to the invention that the cylinder / Piston unit comprises a recess on the support body in which a Piston axially displaceable and tiltable by means of a seal is led.

Auf diese Weise ergibt sich eine besonders einfache Konstruktion.This results in a particularly simple construction.

Infolge der selbstregulierenden Anlage des Preßschuhs an der Zylinder-/Kolbeneinheit kann erfindungsgemäß auf zusätzliche Anpreßelemente wie Schraubenfedern und dergleichen verzichtet werden, so daß sich mit der erfindungsgemäßen Ausführung eine deutlich vereinfachte Erstellung und Montage ergibt.As a result of the self-regulating system of the press shoe on the According to the invention, the cylinder / piston unit can be used for additional Pressure elements such as coil springs and the like are dispensed with be, so that with the embodiment of the invention significantly simplified creation and assembly results.

Gemäß einer weiteren Ausführung der Erfindung ist die erste Druckkammer des Kolbens gegenüber der zweiten Druckkammer durch eine lose Scheibe abgeschlossen, die unter Wirkung des Hydraulikdruckes in der ersten Druckkammer an einem Vorsprung des Kolbens anliegt. Diese Scheibe, die ähnlich wie ein Ventilteller ausgebildet ist, kann bei plötzlicher Druckentlastung von dem Vorsprung des Kolbens, der vorzugsweise als Ringsteg ausgebildet ist, abheben, so daß etwaige komprimierte Luft aus der oberen Druckkammer über dem vergrößerten Entlastungsquerschnitt am Umfang der Scheibe entweichen kann.According to a further embodiment of the invention, the first is Pressure chamber of the piston opposite to the second pressure chamber a loose washer completed under the action of hydraulic pressure in the first pressure chamber on a projection of the piston is present. This disc, which is similar to a valve disk is formed, in the event of sudden pressure relief from the Projection of the piston, which is preferably designed as an annular web is, take off so that any compressed air from the top Pressure chamber over the enlarged relief cross section on Circumference of the disc can escape.

Weitere Merkmale und Vorteile der Erfindung ergeben sich aus der nachfolgenden Beschreibung eines bevorzugten Ausführungsbeispiels unter Bezugnahme auf die Zeichnung. Further features and advantages of the invention result from the following description of a preferred embodiment with reference to the drawing.

Darin zeigen:

Fig. 1
eine skizzenhafte Darstellung der Verhältnisse an einem Preßspalt einer Schuhpresse;
Fig. 2
einen vergrößerten Schnitt durch eine erfindungsgemäße Schuhpreßwalze im Bereich des Preßschuhs und einer Zylinder-/Kolbeneinheit;
Fig. 3
eine gegenüber Fig. 2 abgewandelte Ausführung der Erfindung und
Fig. 4
eine Aufsicht der Scheibe gemäß Fig. 3.
In it show:
Fig. 1
a sketchy representation of the conditions on a press nip of a shoe press;
Fig. 2
an enlarged section through a shoe press roller according to the invention in the area of the press shoe and a cylinder / piston unit;
Fig. 3
a modified version of FIG. 2 of the invention and
Fig. 4
3 shows a top view of the pane according to FIG. 3.

In Fig. 1 ist eine Schuhpresse schematisch im Bereich des Preßspaltes 14 skizziert, die eine Schuhpreßwalze 10 mit einem Preßschuh 16 umfaßt, der eine Gegenwalze 12 zugeordnet ist. Durch den Preßspalt 14 ist in bekannter Weise ein Preßmantel 18 über den Preßschuh 16 geführt, der auf einem hydrodynamischen Schmierkeil weitgehend reibungsfrei über dem Preßschuh 16 umläuft. Durch den Preßspalt 14 ist ferner eine zu entwässernde Papierbahn 22 in der Regel zusammen mit mindestens einer Filzbahn 20 geführt.In Fig. 1 a shoe press is schematic in the area of Press nip 14 outlines a shoe press roll 10 with a Compressed shoe 16, which is associated with a counter roller 12. Through the press nip 14 is a press jacket in a known manner 18 passed over the press shoe 16, which is on a hydrodynamic Lubrication wedge largely frictionless over the press shoe 16 circulates. Through the press nip 14 is also to be dewatered Paper web 22 usually together with at least one felt web 20 led.

Der Preßschuh 16 ist mittels einer Mehrzahl von Hydraulikelementen gegen die Gegenwalze 12 anpreßbar, die sich auf einem darunterliegenden stationären Tragkörper 24 gemäß Fig. 2 abstützen. Jedes Hydraulikelement ist als Zylinder-/Kolbeneinheit 26 ausgeführt, die eine zylinderförmige Ausnehmung 48 im Tragkörper 24 umfaßt, in der ein Kolben 40 geführt ist. The press shoe 16 is by means of a plurality of hydraulic elements can be pressed against the counter roller 12, which is on a underlying supporting body 24 according to FIG. 2 support. Each hydraulic element is a cylinder / piston unit 26 executed, which has a cylindrical recess 48 in Carrying body 24 comprises, in which a piston 40 is guided.

Der Kolben 40 weist an seinem unteren, der zylinderförmigen Ausnehmung 48 zugewandten Ende einen Außenbund 42 auf, innerhalb dessen eine Ringnut 44 vorgesehen ist, in der eine Dichtung 46 in Form eines Dichtrings vorgesehen ist. Der Kolben 40 ist mit der Dichtung 46 an der Innenfläche 50 der zylinderförmigen Ausnehmung 48 axial verschieblich und um einen gewissen Betrag verkippbar geführt.The piston 40 has at its lower, the cylindrical Recess 48 facing the end of an outer collar 42, inside an annular groove 44 is provided in which a seal 46 is provided in the form of a sealing ring. The piston 40 is with the seal 46 on the inner surface 50 of the cylindrical Recess 48 axially displaceable and by a certain amount guided tiltable.

Der Kolben 40 liegt an seinem dem Preßschuh 16 zugewandten Ende mit einer ringförmigen Dichtfläche 36 an einer ebenen Anlagefläche 17 des Preßschuhs 16 an. Innerhalb der ringförmigen Dichtfläche 36 ist eine Ringnut 38 vorgesehen, in der ein Dichtring 34 gehalten ist.The piston 40 lies at its end facing the press shoe 16 with an annular sealing surface 36 on a flat contact surface 17 of the press shoe 16. Inside the ring-shaped Sealing surface 36, an annular groove 38 is provided in the one Sealing ring 34 is held.

Zwischen dem Kolben 40, der zylinderförmigen Ausnehmung 48 und dem Preßschuh 16 sind zwei Druckkammern gebildet, nämlich eine erste Druckkammer 28 zwischen der zylinderförmigen Ausnehmung 48 und dem Kolben 40, die gegenüber einer zweiten Druckkammer 30 zwischen dem Kolben 40 und dem Preßschuh 16 durch einen radialen Steg 54 getrennt ist, der einen Kolbenboden bildet.Between the piston 40, the cylindrical recess 48 and the press shoe 16, two pressure chambers are formed, namely one first pressure chamber 28 between the cylindrical recess 48 and the piston 40, which are opposite a second pressure chamber 30 between the piston 40 and the press shoe 16 by a radial web 54 is separated, which forms a piston crown.

Innerhalb des radialen Steges 54 ist eine dünne Drosselstelle 32 vorgesehen, durch die eine Verbindung zwischen der ersten Druckkammer 28 und der zweiten Druckkammer 30 gebildet ist.There is a thin throttle point within the radial web 54 32 provided through which a connection between the first Pressure chamber 28 and the second pressure chamber 30 is formed.

Der Durchmesser der Drosselstelle 32 ist so bemessen, daß bei annähernd statischen Verhältnissen, wenn der Preßschuh 16 mit seiner ebenen Anlagefläche 17 vollständig an der Dichtfläche 36 des Kolbens 40 anliegt, in der zweiten Druckkammer 30 der gleiche Druck wie in der ersten Druckkammer 28 herrscht, so daß der über einen Hydraulikkanal 52 in die erste Druckkammer 28 übertragene Hydraulikdruck unmittelbar über die zweite Druckkammer 30 auf den Preßschuh 16 übertragen wird. Wird nur eine Drosselstelle verwendet, so beträgt der Durchmesser höchstens etwa 5 mm, vorzugsweise etwa 1 bis 4 mm. Werden mehrere Drosselstellen verwendet, so ist der Durchmesser entsprechend kleiner.The diameter of the throttle point 32 is such that at approximately static conditions when the press shoe 16 with its flat contact surface 17 completely on the sealing surface 36 of the piston 40 rests in the second pressure chamber 30 same pressure as in the first pressure chamber 28, so that the via a hydraulic channel 52 in the first pressure chamber 28 transmitted hydraulic pressure directly via the second pressure chamber 30 is transferred to the press shoe 16. Will only be one Throttle point used, the diameter is at most about 5 mm, preferably about 1 to 4 mm. Are multiple throttling points used, the diameter is correspondingly smaller.

Sollte nun im Betrieb eine gewisse Verkippung des Preßschuhs 16 gegenüber dem Kolben 40 auftreten, so kann aus der zweiten Druckkammer 30 durch den dann zwischen der Anlagefläche 17 des Preßschuhs 16 und der Dichtfläche 36 des Kolbens 40 gebildeten Spalt seitlich Hydrauliköl austreten.Should now be a certain tilt of the press shoe during operation 16 with respect to the piston 40 can occur from the second Pressure chamber 30 through the then between the contact surface 17 of the Press shoe 16 and the sealing surface 36 of the piston 40 are formed Escape hydraulic oil on the side.

Infolge des geringen Durchmessers der Drosselstelle wird jedoch ein schnelles Nachfließen von Hydrauliköl aus der ersten Druckkammer 28 verhindert, so daß sich ein starker Druckabfall in der zweiten Druckkammer 30 ergibt und sich der Preßschuh 16 infolge des äußeren von der Gegenwalze ausgeübten Druckes wieder an den Kolben 40 anlegt. Infolge der nun wieder abgeschlossenen zweiten Druckkammer 30 kann sich in der zweiten Druckkammer 30 wieder ein Hydraulikdruck aufbauen, der dem Hydraulikdruck in der ersten Druckkammer 28 entspricht.However, due to the small diameter of the throttle point a quick flow of hydraulic oil from the first Pressure chamber 28 prevented, so that there is a sharp drop in pressure results in the second pressure chamber 30 and the press shoe 16 due to the external pressure exerted by the counter roller again on the piston 40. As a result of the now completed second pressure chamber 30 can be in the second Pressure chamber 30 build up a hydraulic pressure that the Hydraulic pressure in the first pressure chamber 28 corresponds.

Eine alternative Ausführung der Erfindung ist in den Figuren 3 und 4 dargestellt. Hierbei werden für gleiche Teile gleiche Bezugsziffern verwendet.An alternative embodiment of the invention is in the figures 3 and 4. The same parts are the same Reference numbers used.

Der Kolben 40' ist in Abwandlung von der zuvor beschriebenen Ausführung nach oben nicht durch einen Kolbenboden abgeschlossen, sondern lediglich durch eine lose Scheibe 64, die von der zentralen Drosselstelle 32' durchsetzt ist. Diese Scheibe 64 ist ähnlich wie ein Ventilteller ausgebildet und liegt unter Druck an einem Ringsteg 56 des Kolbens 40' an. Wie aus Fig. 4 näher zu ersehen ist, weist die Scheibe 64 in gleichmäßigen Winkelabständen von 90° vier äußere Vorsprünge 58 auf, mittels derer sie an der Innenfläche 60 des Kolbens 40' zentriert ist. The piston 40 'is a modification of that previously described Execution upwards not completed by a piston crown, but only through a loose disc 64, which is from the central throttle point 32 'is penetrated. This disk 64 is designed similar to a valve plate and is underneath Pressure on an annular web 56 of the piston 40 '. As from Fig. 4 can be seen in more detail, the disc 64 in uniform Angular distances of 90 ° four outer projections 58, by means of which is centered on the inner surface 60 of the piston 40 '.

Bei plötzlicher Druckentlastung kann die Scheibe 64 von dem Ringsteg 56 abheben, und seitlich gegebenenfalls in der Druckkammer 30 vorhandene komprimierte Luft kann sich so über den vergrößerten Entlastungsquerschnitt am Umfang der Scheibe 64 rasch entspannen.In the event of a sudden release of pressure, the disk 64 can move from the Lift off ring web 56 and laterally in the pressure chamber if necessary 30 existing compressed air can thus over the enlarged relief cross section on the circumference of the disk 64 relax quickly.

Zusätzlich ist in Fig. 3 noch eine Feder 62 zum Anpressen des Kolbens 40' an den Preßschuh 16 dargestellt. Eine derartige Feder kann zusätzlich vorgesehen sein, sofern eine vollständige Dichtheit der Zylinder-/Kolbeneinheit auch beim Anfahren gewünscht ist. Diese Feder ist jedoch wesentlich schwächer als bei herkömmlichen Hydraulikelementen ausgebildet, da sie vorzugsweise weniger als etwa 20 % der Anpreßkraft auf den Preßschuh 16 überträgt.In addition, in Fig. 3 is a spring 62 for pressing the Piston 40 'shown on the press shoe 16. Such Spring can also be provided, provided a complete Tightness of the cylinder / piston unit also when starting is desired. However, this spring is much weaker than formed in conventional hydraulic elements because they preferably less than about 20% of the contact pressure on the Press shoe 16 transmits.

Statt einer Drosselstelle können natürlich auch mehrere entsprechend dimensionierte Drosselstellen vorgesehen sein.Instead of one choke point, several can of course be used accordingly Dimensioned throttling points may be provided.

Es versteht sich, daß im Tragkörper 24 auch ein Einsatz eingesetzt sein kann, in dem die zylinderförmige Ausnehmung 48 gebildet sein kann, in der der Kolben mit seiner Dichtung geführt ist.It is understood that an insert is also used in the support body 24 can be in which the cylindrical recess 48th can be formed in which the piston is guided with its seal is.

Es versteht sich ferner, daß die Ausnehmung 48 nicht zylinderförmig ausgebildet sein muß, sondern auch einen rechteckigen oder anders geformten Querschnitt aufweisen kann.It is also understood that the recess 48 is not cylindrical must be trained, but also a rectangular or can have a differently shaped cross section.

Claims (7)

  1. Pressing shoe device for a paper making machine having a pressing shoe roll (10) which includes a pressing shoe (16) and a pressing jacket (18) which is led over the pressing shoe (16), wherein the pressing shoe roll (10) forms, with a counter roll (12), a pressing gap (14), through which the pressing jacket (18) circulates, together with a paper web (22), wherein the pressing shoe (16) can be pressed via at least one hydraulic element against the counter roll (12), wherein the at least one hydraulic element is formed as a piston-in-cylinder unit (26, 26') between a stationary support body (24) and the pressing shoe (16) and includes a first pressure chamber (28), which can be loaded with hydraulic pressure and which communicates via a passage with a second pressure chamber (30) which is open towards the pressing shoe (16) and which has a sealing surface (36) at its margin which contacts the pressing shoe (16), characterized in that the passage is formed as a restrictor (32, 32') and the restrictor (32, 32') has a diameter of at most 5 mm.
  2. Pressing shoe device for a paper making machine having a pressing shoe roll (10) which includes a pressing shoe (16) and a pressing jacket (18) which is led over the pressing shoe (16), wherein the pressing shoe roll (10) forms, with a counter roll (12), a pressing gap (14), through which the pressing jacket (18) circulates, together with a paper web (22), wherein the pressing shoe (16) can be pressed via at least one hydraulic element against the counter roll (12), wherein the at least one hydraulic element is formed as a piston-in-cylinder unit (26, 26') between a stationary support body (24) and the pressing shoe (16) and includes a first pressure chamber (28), which can be loaded with hydraulic pressure and which communicates via a passage with a second pressure chamber (30) which is open towards the pressing shoe (16) and which has a sealing surface (36) at its margin which contacts the pressing shoe (16), characterized in that the passage is formed as a restrictor (32, 32') and the restrictor (32, 32') is dimensioned such that when the pressing shoe (16) contacts the sealing surface (36), substantially the same pressure prevails in both pressure chambers (38, 30) and in that, when the pressing shoe (16) is tilted relative to the sealing surface (6), the pressure in the second pressure chamber (13) drops off strongly in order to aid a resetting of the pressure shoe (16) against the sealing surface (36), and to minimize an escape of hydraulic fluid between sealing surface (36) and pressing shoe (16).
  3. Pressing shoe device in accordance with claim 2, characterized in that the restrictor (32, 32') has a diameter of at most 5 mm.
  4. Pressing shoe device in accordance with one of the preceding claims, characterized in that a sealing ring (34) is inserted into the sealing surface (36) for the seal relative to the pressing shoe (16).
  5. Pressing shoe device in accordance with one of the preceding claims, characterized in that the piston-in-cylinder unit (26, 26') includes a cutout (48) at the support body, in which a piston (40) is axially displaceably and tiltably guided by means of a seal (46).
  6. Pressing shoe device in accordance with claim 5, characterized in that the seal (46) is formed as a radial sealing ring, which is guided at the inner surface (50) of the cylinder-like cutout (48).
  7. Pressing shoe device in accordance with one of the preceding claims, characterized in that the first pressure chamber (28) of the piston (40') is closed off relative to the second pressure chamber (30) by a loose disc (64), which contacts a projection (56) of the piston (40') under the action of the hydraulic pressure in the first pressure chamber (28).
EP96101385A 1995-04-29 1996-02-01 Extended nip press roll for a paper machine Expired - Lifetime EP0740016B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19515832 1995-04-29
DE19515832A DE19515832C1 (en) 1995-04-29 1995-04-29 Hydraulic piston for flexing shoe press on paper:making machine

Publications (2)

Publication Number Publication Date
EP0740016A1 EP0740016A1 (en) 1996-10-30
EP0740016B1 true EP0740016B1 (en) 2000-05-10

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP96101385A Expired - Lifetime EP0740016B1 (en) 1995-04-29 1996-02-01 Extended nip press roll for a paper machine

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US (1) US5688375A (en)
EP (1) EP0740016B1 (en)
JP (1) JPH08302582A (en)
AT (1) ATE192800T1 (en)
CA (1) CA2173890A1 (en)
DE (1) DE19515832C1 (en)
FI (1) FI113068B (en)

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DE19607211C2 (en) * 1995-04-29 2003-11-20 Voith Sulzer Papiermasch Gmbh Shoe press roll for a paper machine
US6093283A (en) * 1997-09-30 2000-07-25 Valmet-Karlstad Ab Shoe press and method for supporting a press shoe in a shoe press
US5997696A (en) * 1997-09-30 1999-12-07 Valmet-Karlstad Ab Shoe press
US6159342A (en) * 1997-09-30 2000-12-12 Valmet-Karlstad Ab Shoe press
US6017422A (en) * 1997-09-30 2000-01-25 Valmet-Karlstad Ab Shoe press
US6139691A (en) * 1997-09-30 2000-10-31 Valmet-Karlstad Ab Shoe press
SE510609C2 (en) * 1997-09-30 1999-06-07 Valmet Karlstad Ab Shoe press for a paper or cardboard machine
SE510551C2 (en) * 1997-09-30 1999-05-31 Valmet Karlstad Ab Shoe press for paper or cardboard machines
SE510553C2 (en) * 1997-09-30 1999-05-31 Valmet Karlstad Ab Shoe press for a paper or cardboard machine
SE510552C2 (en) * 1997-09-30 1999-05-31 Valmet Karlstad Ab Shoe press and way to store a press shoe in a shoe press
SE510550C2 (en) * 1997-09-30 1999-05-31 Valmet Karlstad Ab Shoe press for paper or cardboard machines
SE510610C2 (en) * 1997-09-30 1999-06-07 Valmet Karlstad Ab Shoe press for a paper or cardboard machine, and a pressing cylinder unit for such
US6042694A (en) * 1997-09-30 2000-03-28 Valmet-Karlstad Ab Shoe press
US6083352A (en) * 1998-01-30 2000-07-04 Valmet Corporation Shoe press
DE29900914U1 (en) * 1998-01-30 1999-12-23 Valmet Corp., Helsinki Shoe press
US6248210B1 (en) 1998-11-13 2001-06-19 Fort James Corporation Method for maximizing water removal in a press nip
FI19992824A (en) * 1999-12-30 2001-07-01 Valmet Karlstad Ab Device for forming a nip
FI107063B (en) * 2000-06-19 2001-05-31 Metso Paper Inc Long nip press for a papermaking or board-making machine
FI116854B (en) 2004-02-19 2006-03-15 Vaahto Oy Method and apparatus for shoe press
FI118088B (en) 2004-02-19 2007-06-29 Vaahto Oy Shoe press loading device
DE102006021428A1 (en) * 2006-05-05 2007-11-08 Andritz Küsters GmbH & Co. KG Device for forming at least one extended nip
DE102007004607A1 (en) * 2007-01-30 2008-07-31 Gapcon Gmbh Loading device for shoe press, for managing requirements in paper machine and for production of paper, has hydraulic apparatus with guiding device for linear guidance of cylinder case

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FI73301C (en) * 1986-05-30 1987-09-10 Valmet Oy STOEDARRANGEMANG FOER GLIDSKORNA AV EN ZONREGLERBAR BOEJNINGSKOMPENSERAD VALS.
DE3705241A1 (en) * 1986-12-24 1988-07-07 Escher Wyss Gmbh METHOD FOR MECHANICAL-THERMAL DRAINAGE OF A FIBER web
CH672823A5 (en) * 1987-03-10 1989-12-29 Escher Wyss Ag
DE4319323A1 (en) * 1993-06-11 1993-11-04 Voith Gmbh J M Paper-making press section - has units to reduce pressure at web edges to ends of the press shoe to eliminate pressure peaks
US5447605A (en) * 1994-08-22 1995-09-05 Beloit Technologies, Inc. Position control for self-loading roll

Also Published As

Publication number Publication date
FI960908A0 (en) 1996-02-27
ATE192800T1 (en) 2000-05-15
US5688375A (en) 1997-11-18
FI113068B (en) 2004-02-27
JPH08302582A (en) 1996-11-19
CA2173890A1 (en) 1996-10-30
DE19515832C1 (en) 1996-05-02
FI960908A (en) 1996-10-30
EP0740016A1 (en) 1996-10-30

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