EP0209099A1 - Stator for a helical gear pump - Google Patents

Stator for a helical gear pump Download PDF

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Publication number
EP0209099A1
EP0209099A1 EP86109623A EP86109623A EP0209099A1 EP 0209099 A1 EP0209099 A1 EP 0209099A1 EP 86109623 A EP86109623 A EP 86109623A EP 86109623 A EP86109623 A EP 86109623A EP 0209099 A1 EP0209099 A1 EP 0209099A1
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EP
European Patent Office
Prior art keywords
lining
axis
stator
thickness
concave
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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
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EP86109623A
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German (de)
French (fr)
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EP0209099B1 (en
Inventor
Eugen Unterstrasser
Johann Kreidl
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Netzsch Pumpen and Systeme GmbH
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Netzsch Pumpen and Systeme GmbH
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Priority to AT86109623T priority Critical patent/ATE39731T1/en
Publication of EP0209099A1 publication Critical patent/EP0209099A1/en
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Publication of EP0209099B1 publication Critical patent/EP0209099B1/en
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C2/00—Rotary-piston machines or pumps
    • F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
    • F04C2/10—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member
    • F04C2/107—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth
    • F04C2/1071—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth the inner and outer member having a different number of threads and one of the two being made of elastic materials, e.g. Moineau type
    • F04C2/1073—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member with helical teeth the inner and outer member having a different number of threads and one of the two being made of elastic materials, e.g. Moineau type where one member is stationary while the other member rotates and orbits
    • F04C2/1075—Construction of the stationary member

Definitions

  • the invention relates to a stator for eccentric screw pumps with a rigid tubular jacket, the inner surface of which forms a multi-thread, and an elastic lining, which bears against the jacket over the entire axial length, is symmetrical with respect to the central longitudinal axis of the stator and has an inner surface which also forms a multi-start thread, in cross-section it consists of a number of sections near the axis that is equal to the number of threads of the thread and an equally large number of concave bends that connect to the sections near the axis with continuous transitions, the lining of the concave bends each having a minimum thickness.
  • the rigid tubular jacket is circular-cylindrical inside and out and accordingly the outer surface of the lining is circular-cylindrical.
  • the inner surface of the lining is double-threaded and has an essentially oval cross-section with two sections near the axis and two semicircular arches which connect the sections near the axis to one another.
  • the two sections close to the axis are slightly convex, that is to say they are curved towards the central longitudinal axis of the stator; this is said to provide a better seal between the stator and a rotor can be achieved, which has a circular cross section and is coiled coherently.
  • the inner surface of the rigid tubular jacket and the outer surface of the elastic lining have a shape which corresponds approximately to the double-coiled inner surface of the lining, but the near-axis Sections of the inner surface of the lining, where the highest sliding speeds of the associated rotor occur, in turn have convex elevations which are curved inwards and the lining on these sections near the axis also has elevations which protrude radially outwards, the thickness of which is of the order of magnitude of ten greater than the thickness of the inner elevations.
  • the outer elevations of the lining are received in corresponding hollows on the inside of the rigid tubular jacket. This should result in a more uniform clamping of the rotor in the stator and a better efficiency and at the same time a longer service life.
  • stator (DE-OS 28 17 280) has an elastic lining, the inner wall of which is also twisted and the outer wall approximates a corresponding two-helix, but is divided into several axially adjacent sections, the axial extension of which is one eighth each full helix and each have a cylindrical surface form an oval plan. If one cuts such a stator section in a plane normal to the central longitudinal axis of the stator, which lies in the center of the section in question, the straight sections of their oval outer surface extend parallel to the straight sections of the inner surface.
  • the invention is based on the knowledge that a considerable part of the wear occurring on the lining is related to the constantly recurring formation and rolling over of these beads.
  • the thickness maxima are therefore no longer in the central region of each of the sections near the axis in which the sliding speed of the rotor has a maximum, but the thickness maxima of the lining are laid on the edges of the sections near the axis or even in the initial areas of the adjacent concave arches, with the result that the lining in the middle of each of its axially proximate sections has a thickness which is less than the maximum thickness.
  • the result of this is that the rotor can roll over the bulge that has built up in front of it more easily at the entry into one of the concave arches of the inner surface than in known stators of the generic type, thereby protecting the lining.
  • the inner surface of the casing and the inner surface of the lining are geometrically similar to one another, but are rotated by 5 to 15 ° relative to one another about the central longitudinal axis.
  • the lining has only one end of each axis near the axis cut a thickness maximum; consequently, the rotor may only rotate in a certain direction so that it can roll over the bead of the lining which is forming in front of it at a maximum thickness.
  • the definition of a certain direction of rotation is not unusual for eccentric screw pumps and does not limit their possible use.
  • the thickness of the lining has a minimum in the middle of its concave arches and an additional minimum in the middle of each section close to the axis. In this way it is ensured that the bulge of the lining which forms in front of the rotor is displaced in each of the two possible directions of rotation of the rotor when it enters a concave arc, without unnecessary flexing work and heating occurring.
  • This embodiment of the invention can be further developed in that the thickness of the lining at the additional minima is not greater than at the minima in the middle of the concave arches.
  • a tubular jacket 10 which consists of rigid material, such as cast steel or aluminum.
  • the jacket 10 is overall symmetrical with respect to a central longitudinal axis A, is cylindrical on the outside and has an inner surface which is coiled in two directions and is therefore oval in any cross section.
  • the inner surface includes two straight sections 12 which are close to the axis and which extend parallel to a main axis 14 between two transverse axes 16 and are connected to one another by semicircular arches 18.
  • the jacket 10 encloses a lining 20 made of an elastomer, the outer surface of which rests without gaps on the inner surface 12, 18 of the jacket 10, that is to say, just like this inner surface, is coiled with two threads and is thus oval in any cross section.
  • the lining 20 has an inner surface which is also oval in any cross section and has two sections 22 which are just near the axis and which extend parallel to a main axis 24.
  • the sections 22 close to the axis could also be slightly convex.
  • the two straight sections 22 near the axis are delimited by two transverse axes 26 and connected to one another by two semicircular arches 28.
  • Each of the transverse axes 26 intersects the adjacent transverse axis 16 at an angle of likewise 10 °.
  • the inner surface 22, 28 of the lining 20 has two vertices I and V, in which it is cut by the main axis 24, as well as four transitions II, IV, VI and VIII, in which it extends from the transverse axes 26, as in any other cross section is cut.
  • the axially close sections 22 extend between the transitions II and IV or VI and VIII and each have a center point III or VII.
  • the concave arches 28 extend between the transitions VIII and II or IV and VI and each have one of the apices I or V as the center.
  • the outer and inner surfaces of the lining 20 are geometrically similar to one another, but limit because of the twist the main axes 14 and 24 zones of different thickness.
  • the lining 20 has two thickness minima 30, which - viewed in a clockwise direction - are just before the vertices I and V, and two thickness maxima 32, which are located just behind the transitions VI and II, respectively between the transverse axes 16 and 26.
  • a single-start rotor 34 of circular cross section with radial preload is inserted into the lining 20.
  • the rotor 34 rotates in the direction of the arrow; its greatest sliding speed v g occurs at point VII.
  • This sliding speed v g is composed of the translation of the rotor 34 at the speed v t and the rotation of the rotor about its own axis.
  • the lining 20 has a double-helical inner surface 22, 28, which as such corresponds to that shown in FIG. 1.
  • this inner surface 22, 28 is not twisted with respect to the inner surface of the jacket 10, which is also coiled with two threads, and is not geometrically similar.
  • the inner surface of the casing 10, against which the outer surface of the lining 20 rests without gaps, has two opposing convex regions 12 of approximately sinusoidal shape and two concave arches 18 which are approximately semicircular but are somewhat flattened in the region of the main axis 14.
  • the elastic lining 20 has two thickness minima 30 which lie on the coinciding main axes 14 and 24, four thickness maxima 32 which lie in pairs on the likewise coincident transverse axes 16 and 26, and two additional thickness minima 36 at the centers III and VII of the regions 22 near the axis .

Abstract

The stator comprises a rigid tubular casing and an elastic lining which is tightly enclosed by the casing and symmetrical with respect to the longitudinal center axis of the stator. The inner surface of the lining forms a multiple thread and, in cross section, consists of a number of sections near the axis equal to the number of courses of the thread and an equally great number of concave arcs. The lining has a minimum thickness each at the concave arcs and a maximum thickness each near at least two of the transitions between the sections near the axis and the concave arcs.

Description

Die Erfindung betrifft einen Stator für Exzenter­schneckenpumpen mit einem starren rohrförmigen Mantel, dessen Innenfläche ein mehrängiges Gewinde bildet, und einer elastischen Auskleidung, die am Mantel über die ganze axiale Länge anliegt, in Bezug auf die Mittel­längsachse des Stators symmetrisch ist und eine Innen­fläche aufweist, welche ebenfalls ein mehrgängiges Ge­winde bildet, im Querschnitt aus einer der Gangzahl des Gewindes gleichen Anzahl achsnaher Abschnitte sowie einer ebensogroßen Anzahl konkaver Bogen besteht, die sich mit stetigen Übergängen an die achsnahen Abschnitte anschlie­ßen, wobei die Auskleidung an den konkaven Bogen je ein Dickenminimum aufweist.The invention relates to a stator for eccentric screw pumps with a rigid tubular jacket, the inner surface of which forms a multi-thread, and an elastic lining, which bears against the jacket over the entire axial length, is symmetrical with respect to the central longitudinal axis of the stator and has an inner surface which also forms a multi-start thread, in cross-section it consists of a number of sections near the axis that is equal to the number of threads of the thread and an equally large number of concave bends that connect to the sections near the axis with continuous transitions, the lining of the concave bends each having a minimum thickness.

Bei einem bekannten Stator (DE-PS 2017620), der eine Vor­stufe dieser Gattung darstellt, ist der starre rohrför­mige Mantel innen wie außen kreiszylindrisch und dement­sprechend ist auch die Außenfläche der Auskleidung kreis­zylindrisch. Die Innenfläche der Auskleidung ist zwei­gängig und hat einen im wesentlichen ovalen Querschnitt mit zwei achsnahen Abschnitten und zwei halbkreisförmigen Bogen, welche die achsnahen Abschnitte miteinander ver­binden. Die beiden achsnahen Abschnitte sind leicht kon­vex, also zur Mittellängsachse des Stators hin gewölbt; dadurch soll eine bessere Abdichtung zwischen dem Stator und einem Rotor erzielt werden, der einen kreisförmigen Querschnitt aufweist und eingängig gewendelt ist. Dabei ist es jedoch nachteilig, daß die besonders dicken Zonen der elastischen Auskleidung, die deren achsnahe Abschnit­te bilden, bei dem im Betrieb auftretenden Druck eines Fördermediums stärker verformbar sind und weniger gut imstande sind, Verlustwärme an den rohrförmigen Mantel abzuleiten als die dünnen Zonen der Auskleidung.In a known stator (DE-PS 2017620), which is a preliminary stage of this type, the rigid tubular jacket is circular-cylindrical inside and out and accordingly the outer surface of the lining is circular-cylindrical. The inner surface of the lining is double-threaded and has an essentially oval cross-section with two sections near the axis and two semicircular arches which connect the sections near the axis to one another. The two sections close to the axis are slightly convex, that is to say they are curved towards the central longitudinal axis of the stator; this is said to provide a better seal between the stator and a rotor can be achieved, which has a circular cross section and is coiled coherently. It is disadvantageous, however, that the particularly thick zones of the elastic lining, which form their sections near the axis, are more deformable under the pressure of a conveying medium occurring during operation and are less able to dissipate heat loss to the tubular jacket than the thin zones of the lining .

Deshalb haben bei einem anderen bekannten Stator (DE-PS 2709502), der die eingangs beschriebene Gattung bildet, die Innenfläche des starren rohrförmigen Mantels und die Außenfläche der elastischen Auskleidung eine Form, die ungefähr der zweigängig gewendelten Innenfläche der Aus­kleidung entspricht, wobei aber die achsnahen Abschnitte der Innenfläche der Auskleidung, dort wo die größten Gleitgeschwindigkeiten des zugehörigen Rotors auftreten, wiederum konvex nach innen gewölbte Erhebungen aufweisen und die Auskleidung an diesen achsnahen Abschnitten auch radial nach außen vorspringende Erhebungen aufweist, de­ren Dicke in der Größenordnung einer Zehnerpotenz größer als die Dicke der inneren Erhebungen ist. Die äußeren Er­hebungen der Auskleidung sind in entsprechenden Aushöh­lungen an der Innenseite des starren rohrförmigen Mantels aufgenommen. Daraus soll sich eine gleichmäßigere Ein­spannung des Rotors im Stator ergeben und ein besserer Wirkungsgrad sowie gleichzeitig eine längere Lebensdauer erreicht werden.Therefore, in another known stator (DE-PS 2709502), which forms the type described in the introduction, the inner surface of the rigid tubular jacket and the outer surface of the elastic lining have a shape which corresponds approximately to the double-coiled inner surface of the lining, but the near-axis Sections of the inner surface of the lining, where the highest sliding speeds of the associated rotor occur, in turn have convex elevations which are curved inwards and the lining on these sections near the axis also has elevations which protrude radially outwards, the thickness of which is of the order of magnitude of ten greater than the thickness of the inner elevations. The outer elevations of the lining are received in corresponding hollows on the inside of the rigid tubular jacket. This should result in a more uniform clamping of the rotor in the stator and a better efficiency and at the same time a longer service life.

Ein weiterer bekannter Stator (DE-OS 28 17 280) hat eine elastische Auskleidung, deren Innenwand ebenfalls zwei­gängig gewendelt ist und deren Außenwand einer entspre­chenden zweigängigen Wendel angenähert, jedoch in mehrere axial nebeneinanderliegende Abschnitte unterteilt ist, die in ihrer axialen Erstreckung je einem Achtel einer vollen Wendel entsprechen und je eine Zylinderfläche mit ovalem Grundriß bilden. Schneidet man einen solchen Sta­torabschnitt in einer zur Mittellängsachse des Stators normalen Ebene, die in der Mitte des betreffenden Ab­schnittes liegt, so erstrecken sich die geradlinigen Abschnitte ihrer ovalen Außenfläche parallel zu den ge­radlinigen Abschnitten der Innenfläche. Schneidet man einen solchen Statorabschnitt dagegen in einer zur Längs­mittelachse des Stators normalen Ebene mit Abstand von der genannten Mittelebene, so ist das Oval der Außenkon­tur eines solchen Schnittes gegen das Oval von dessen In­nenkontur um die Mittellängsachse in der einen oder an­deren Richtung verdreht, je nachdem auf welcher Seite der achsnormalen Mittelebene des betreffenden Statorabschnit­tes die Schnittebene liegt. In der Mittelebene sind in jeden der Statorabschnitte von außen her zwei Tangential­nuten einander diametral gegenüberliegend eingearbeitet, die sich parallel zu den geraden, achsnahen Abschnitten der Innenfläche erstrecken. Die Tangentialnuten bilden Freiräume, welche die Anlagekraft zwischen den achsnahmen Bereichen der Innenwand der elastischen Auskleidung und dem zugehörigen Rotor herabsetzen und dadurch die Reibung vermindern.Another known stator (DE-OS 28 17 280) has an elastic lining, the inner wall of which is also twisted and the outer wall approximates a corresponding two-helix, but is divided into several axially adjacent sections, the axial extension of which is one eighth each full helix and each have a cylindrical surface form an oval plan. If one cuts such a stator section in a plane normal to the central longitudinal axis of the stator, which lies in the center of the section in question, the straight sections of their oval outer surface extend parallel to the straight sections of the inner surface. If, on the other hand, such a stator section is cut in a plane normal to the longitudinal central axis of the stator at a distance from said central plane, the oval of the outer contour of such a cut against the oval of its inner contour is rotated in one direction or the other about the central longitudinal axis, depending on which side of the axis-normal central plane of the stator section in question is the cutting plane. In the center plane, two tangential grooves are machined diametrically opposite each other from the outside in each of the stator sections, which extend parallel to the straight, near-axis sections of the inner surface. The tangential grooves form free spaces which reduce the contact force between the axial areas of the inner wall of the elastic lining and the associated rotor and thereby reduce the friction.

Es ist ferner bekannt (Druckschrift "Wirkungsweise von Exzenterschneckenpumpen" der Firma Bornemann Pumpen, D-3063 Obernkirchen), daß wegen der zur Abdichtung zwi­schen Rotor und Stator erforderlichen elastischen Vor­spannung, mit der die Auskleidung den Rotor umschließt, und infolge der Relativbewegung zwischen Rotor und Sta­tor, die Auskleidung im Betrieb in den Zonen größter Gleitgeschwindigkeiten des Rotors Wulste bildet, die dem Rotor voranlaufen. Der Rotor überrollt diese Wulste je­weils in dem Maß, in dem er in einen der konkaven Bogen der Auskleidung eindringt; anschließend bilden sich neue Wulste, die dem Rotor voraneilen in dem Maß, in dem er sich aus dem konkaven Bogen entfernt.It is also known (publication "Effect of eccentric screw pumps" from Bornemann Pumpen, D-3063 Obernkirchen) that because of the elastic preload required for sealing between the rotor and stator, with which the lining encloses the rotor, and as a result of the relative movement between the rotor and Stator, the lining forms during operation in the zones of the highest sliding speeds of the rotor beads that lead the rotor. The rotor rolls over these beads to the extent that it penetrates into one of the concave arches of the lining; then new beads are formed which lead the rotor to the extent that it moves away from the concave arc.

Der Erfindung liegt die Erkenntnis zugrunde, daß ein er­heblicher Teil des an der Auskleidung auftretenden Ver­schleißes mit dem ständig wiederkehrenden Entstehen und Überrollen dieser Wulste zusammenhängt.The invention is based on the knowledge that a considerable part of the wear occurring on the lining is related to the constantly recurring formation and rolling over of these beads.

Es ist deshalb Aufgabe der Erfindung, diese Art des Verschleißes und die dadurch entstehenden Undichtigkeiten zu vermindern.It is therefore an object of the invention to reduce this type of wear and the resulting leaks.

Diese Aufgabe ist bei einem Stator der eingangs beschrie­benen Gattung erfindungsgemäß dadurch gelöst, daß die Dicke der Auskleidung jeweils in der Richtung, in der sich die Rotations- und Translationsbewegung des zugehö­rigen Rotors addieren, mindestens von der Mitte des achs­nahen Abschnitts bis zu einem Dickenmaximum am Übergang in den konkaven Bogen kontinuierlich zunimmt und bis zum Dickenminimum im Bereich des konkaven Bogens kontinuier­lich abnimmt.This object is achieved according to the invention in a stator of the type described at the outset in that the thickness of the lining in each case in the direction in which the rotational and translational movement of the associated rotor add up, at least from the center of the section near the axis to a maximum thickness at the transition increases continuously in the concave arc and decreases continuously up to the minimum thickness in the area of the concave arc.

Erfindungsgemäß liegen also die Dickenmaxima nicht mehr im mittleren Bereich jedes der achsnahen Abschnitte, in denen die Gleitgeschwindigkeit des Rotors ein Maximum hat, sondern die Dickenmaxima der Auskleidung sind an die Ränder der achsnahen Abschnitte oder sogar in die An­fangsbereiche der angrenzenden konkaven Bogen verlegt mit der Folge, daß die Auskleidung in der Mitte jedes ihrer achsnahen Abschnitte eine Dicke hat, die geringer als die maximale Dicke ist. Damit wird erreicht, daß der Rotor den Wulst, der sich vor ihm aufgebaut hat, jeweils am Eintritt in einen der konkaven Bogen der Innenfläche leichter als bei bekannten gattungsgemäßen Statoren überrollen kann, wodurch die Auskleidung geschont wird.According to the invention, the thickness maxima are therefore no longer in the central region of each of the sections near the axis in which the sliding speed of the rotor has a maximum, but the thickness maxima of the lining are laid on the edges of the sections near the axis or even in the initial areas of the adjacent concave arches, with the result that the lining in the middle of each of its axially proximate sections has a thickness which is less than the maximum thickness. The result of this is that the rotor can roll over the bulge that has built up in front of it more easily at the entry into one of the concave arches of the inner surface than in known stators of the generic type, thereby protecting the lining.

Bei einer Ausführungsform der Erfindung sind die Innen­fläche des Mantels und die Innenfläche der Auskleidung einander geometrisch ähnlich, jedoch um die Mittellängs­achse um 5 bis 15° gegeneinander verdreht. In diesem Fall hat die Auskleidung nur an einem Ende jedes achsnahen Ab­ schnittes ein Dickenmaximum; demzufolge darf sich der Ro­tor nur in einer bestimmten Richtung drehen, damit er den sich vor ihm bildenden Wulst der Auskleidung jeweils an einem Dickenmaximum überrollen kann. Die Festlegung auf eine bestimmte Drehrichtung ist jedoch bei Exzenter­schneckenpumpen nicht ungewöhnlich und begrenzt deren Einsatzmöglichkeit nicht.In one embodiment of the invention, the inner surface of the casing and the inner surface of the lining are geometrically similar to one another, but are rotated by 5 to 15 ° relative to one another about the central longitudinal axis. In this case, the lining has only one end of each axis near the axis cut a thickness maximum; consequently, the rotor may only rotate in a certain direction so that it can roll over the bead of the lining which is forming in front of it at a maximum thickness. However, the definition of a certain direction of rotation is not unusual for eccentric screw pumps and does not limit their possible use.

Für Fälle, in denen eine Festlegung auf eine bestimmte Drehrichtung vermieden werden soll, ist bei einer anderen Ausführungsform der Erfindung vorgesehen, daß die Dicke der Auskleidung in der Mitte ihrer konkaven Bogen je ein Minimum und in der Mitte jedes achsnahen Abschnitts ein zusätzliches Minimum hat. Auf diese Weise ist dafür ge­sorgt, daß der Wulst der Auskleidung, der sich vor dem Rotor bildet, bei jeder der beiden möglichen Drehrich­tungen des Rotors jeweils bei dessen Eintritt in einen konkaven Bogen verdrängt wird, ohne daß unnötige Walk­arbeit und Erwärmung entstehen.For cases in which a determination of a certain direction of rotation is to be avoided, it is provided in another embodiment of the invention that the thickness of the lining has a minimum in the middle of its concave arches and an additional minimum in the middle of each section close to the axis. In this way it is ensured that the bulge of the lining which forms in front of the rotor is displaced in each of the two possible directions of rotation of the rotor when it enters a concave arc, without unnecessary flexing work and heating occurring.

Diese Ausführungsform der Erfindung kann dadurch weiter­gebildet sein, daß die Dicke der Auskleidung an den zu­sätzlichen Minima nicht größer als an den Minima in der Mitte der konkaven Bogen ist.This embodiment of the invention can be further developed in that the thickness of the lining at the additional minima is not greater than at the minima in the middle of the concave arches.

Im folgenden werden zwei Ausführungsbeispiele der Erfin­dung anhand je einer schematischen Zeichnung mit weiteren Einzelheiten erläutert. Fig. 1 und 2 zeigen je einen axi­alen Schnitt einer Exzenterschneckenpumpe.Two exemplary embodiments of the invention are explained below with the aid of a schematic drawing, each with further details. 1 and 2 each show an axial section of an eccentric screw pump.

In Fig. 1 ist ein rohrförmiger Mantel 10 dargestellt, der aus starrem Werkstoff, beispielsweise Stahl- oder Alumi­niumguß, besteht. Der Mantel 10 ist insgesamt symmetrisch in Bezug auf eine Mittellängsachse A, ist außen zylin­drisch und hat eine Innenfläche, die zweigängig gewendelt und somit in jedem beliebigen Querschnitt oval ist. Zur Innenfläche gehören zwei gerade, achsnahe Abschnitte 12, die sich parallel zu einer Hauptachse 14 zwischen zwei Querachsen 16 erstrecken und durch Halbkreisbogen 18 mit­einander verbunden sind.In Fig. 1, a tubular jacket 10 is shown, which consists of rigid material, such as cast steel or aluminum. The jacket 10 is overall symmetrical with respect to a central longitudinal axis A, is cylindrical on the outside and has an inner surface which is coiled in two directions and is therefore oval in any cross section. To The inner surface includes two straight sections 12 which are close to the axis and which extend parallel to a main axis 14 between two transverse axes 16 and are connected to one another by semicircular arches 18.

Der Mantel 10 umschließt eine Auskleidung 20 aus einem Elastomer, deren Außenfläche lückenlos an der Innenfläche 12, 18 des Mantels 10 anliegt, also ebenso wie diese In­nenfläche zweigängig gewendelt und somit in jedem belie­bigen Querschnitt oval ist. Die Auskleidung 20 hat eine Innenfläche, die ebenfalls in jedem beliebigen Quer­schnitt oval ist und zwei gerade achsnahe Abschnitte 22 aufweist, die sich parallel zu einer Hauptachse 24 er­strecken. Die achsnahen Abschnitte 22 könnten auch leicht konvex sein. Die Hauptachse 24 schneidet ebenso wie die Hauptachse 14 die Mittellängsachse A unter einem rechten Winkel; außerdem schneiden die Hauptachsen 14 und 24 ein­ander unter einem Winkel von im dargestellten Beispiel 10°. Die beiden geraden achsnahen Abschnitte 22 sind durch zwei Querachsen 26 begrenzt und durch zwei Halb­kreisbogen 28 miteinander verbunden. Jede der Querachsen 26 schneidet die benachbarte Querachse 16 unter einem Winkel von ebenfalls 10°.The jacket 10 encloses a lining 20 made of an elastomer, the outer surface of which rests without gaps on the inner surface 12, 18 of the jacket 10, that is to say, just like this inner surface, is coiled with two threads and is thus oval in any cross section. The lining 20 has an inner surface which is also oval in any cross section and has two sections 22 which are just near the axis and which extend parallel to a main axis 24. The sections 22 close to the axis could also be slightly convex. The main axis 24, like the main axis 14, intersects the central longitudinal axis A at a right angle; in addition, the main axes 14 and 24 intersect at an angle of 10 ° in the example shown. The two straight sections 22 near the axis are delimited by two transverse axes 26 and connected to one another by two semicircular arches 28. Each of the transverse axes 26 intersects the adjacent transverse axis 16 at an angle of likewise 10 °.

Die Innenfläche 22, 28 der Auskleidung 20 hat im dar­gestellten wie in jedem anderen Querschnitt zwei Scheitel I und V, in denen sie von der Hauptachse 24 geschnitten wird, sowie vier Übergänge II, IV, VI und VIII, in denen sie von den Querachsen 26 geschnitten wird. Die achsnahen Abschnitte 22 erstrecken sich zwischen den Übergängen II und IV bzw. VI und VIII und haben je einen Mittelpunkt III bzw. VII. Die konkaven Bogen 28 erstrecken sich zwi­schen den Übergängen VIII und II bzw. IV und VI und haben je einen der Scheitel I bzw. V als Mittelpunkt.The inner surface 22, 28 of the lining 20 has two vertices I and V, in which it is cut by the main axis 24, as well as four transitions II, IV, VI and VIII, in which it extends from the transverse axes 26, as in any other cross section is cut. The axially close sections 22 extend between the transitions II and IV or VI and VIII and each have a center point III or VII. The concave arches 28 extend between the transitions VIII and II or IV and VI and each have one of the apices I or V as the center.

Außen- und Innenfläche der Auskleidung 20 sind einander geometrisch ähnlich, begrenzen aber wegen der Verdrehung der Hauptachsen 14 und 24 Zonen unterschiedlicher Dicke. Die Auskleidung 20 hat zwei Dickenminima 30, die - bei einem Umlauf im Uhrzeigersinn betrachtet - kurz vor den Scheitelpunkten I und V liegen, sowie zwei Dickenmaxima 32, die kurz hinter den Übergängen VI bzw. II jeweils zwischen den Querachsen 16 und 26 liegen.The outer and inner surfaces of the lining 20 are geometrically similar to one another, but limit because of the twist the main axes 14 and 24 zones of different thickness. The lining 20 has two thickness minima 30, which - viewed in a clockwise direction - are just before the vertices I and V, and two thickness maxima 32, which are located just behind the transitions VI and II, respectively between the transverse axes 16 and 26.

In die Auskleidung 20 ist ein eingängiger Rotor 34 von kreisförmigem Querschnitt mit radialer Vorspannung einge­setzt. Der Rotor 34 dreht sich in Richtung des einge­zeichneten Pfeils; dabei tritt seine größte Gleitge­schwindigkeit vg am Punkt VII auf. Diese Gleitgeschwin­digkeit vg setzt sich zusammen aus der Translation des Rotors 34 mit der Geschwindigkeit vt und der Drehung des Rotors um seine eigene Achse.A single-start rotor 34 of circular cross section with radial preload is inserted into the lining 20. The rotor 34 rotates in the direction of the arrow; its greatest sliding speed v g occurs at point VII. This sliding speed v g is composed of the translation of the rotor 34 at the speed v t and the rotation of the rotor about its own axis.

Bei dem in Fig. 2 dargestellten Ausführungsbeispiel hat die Auskleidung 20 eine zweigängig gewendelte Innenfläche 22, 28, die als solche mit der in Fig. 1 dargestellten übereinstimmt. Diese Innenfläche 22, 28 ist jedoch gegen­über der ebenfalls zweigängig gewendelten Innenfläche des Mantels 10 nicht verdreht und ist dieser geometrisch nicht ähnlich. Die Innenfläche des Mantels 10, an der die Auskleidung 20 mit ihrer Außenfläche lückenlos anliegt, hat zwei einander gegenüberliegende konvexe achsnahe Be­reiche 12 von ungefähr sinusförmigem Verlauf und zwei konkave Bogen 18, die annähernd halbkreisförmig sind, im Bereich der Hauptachse 14 jedoch etwas abgeflacht sind. Die elastische Auskleidung 20 hat zwei Dickenminima 30, die auf den zusammenfallenden Hauptachsen 14 und 24 lie­gen, vier Dickenmaxima 32, die paarweise auf den eben­falls zusammenfallenden Querachsen 16 und 26 liegen, so­wie zwei zusätzliche Dickenminima 36 an den Mittelpunkten III und VII der achsnahen Bereiche 22.In the exemplary embodiment shown in FIG. 2, the lining 20 has a double-helical inner surface 22, 28, which as such corresponds to that shown in FIG. 1. However, this inner surface 22, 28 is not twisted with respect to the inner surface of the jacket 10, which is also coiled with two threads, and is not geometrically similar. The inner surface of the casing 10, against which the outer surface of the lining 20 rests without gaps, has two opposing convex regions 12 of approximately sinusoidal shape and two concave arches 18 which are approximately semicircular but are somewhat flattened in the region of the main axis 14. The elastic lining 20 has two thickness minima 30 which lie on the coinciding main axes 14 and 24, four thickness maxima 32 which lie in pairs on the likewise coincident transverse axes 16 and 26, and two additional thickness minima 36 at the centers III and VII of the regions 22 near the axis .

Bei dem in Fig. 2 dargestellten Querschnittsprofil der elastischen Auskleidung 20 ist es gleichgültig, ob der Rotor 34 sich in Richtung des eingezeichneten Pfeils oder in entgegengesetzter Richtung dreht.In the cross-sectional profile of the elastic lining 20 shown in FIG. 2, it does not matter whether the rotor 34 rotates in the direction of the arrow shown or in the opposite direction.

Claims (5)

1. Stator für Exzenterschneckenpumpen mit einem starren rohrförmigen Mantel (10), dessen Innenfläche (12, 18) ein mehrgängiges Gewinde bildet, und einer elastischen Aus­kleidung (20), die am Mantel (10) über die ganze axiale Länge anliegt, in Bezug auf die Mittellängsachse (A) des Stators symmetrisch ist und eine Innenfläche (22, 28) aufweist, welche ebenfalls ein mehrgängiges Gewinde bil­det, im Querschnitt aus einer der Gangzahl des Gewindes gleichen Anzahl achsnaher Abschnitte (22) sowie einer ebensogroßen Anzahl konkaver Bogen (28) besteht, die sich mit stetigen Übergängen (II, IV, VI, VIII) an die achs­nahen Abschnitte (22) anschliessen, wobei die Auskleidung (20) an den konkaven Bogen (28) je ein Dickenminimum (30) aufweist,
dadurch gekennzeichnet , daß die Dicke der Auskleidung (20) jeweils in der Richtung, in der sich Ro­tations- und Translationsbewegung des zugehörigen Rotors (34) addieren, mindestens von der Mitte des achsnahen Ab­schnitts (22) bis zu einem Dickenmaximum (32) am Übergang in den konkaven Bogen (28) kontinuierlich zunimmt und bis zum Dickenminimum (30) im Bereich des konkaven Bogens (28) kontinuierlich abnimmt.1. Stator for eccentric screw pumps with a rigid tubular jacket (10), the inner surface (12, 18) of which forms a multi-start thread, and an elastic lining (20) which bears against the jacket (10) over the entire axial length with respect to the central longitudinal axis (A) of the stator is symmetrical and has an inner surface (22, 28), which also forms a multi-start thread, in cross-section from a number of sections (22) close to the axis of the thread and an equal number of concave bends (28) consists of continuous transitions (II, IV, VI, VIII) adjoining the sections (22) close to the axis, the lining (20) on the concave bend (28) each having a minimum thickness (30),
characterized in that the thickness of the lining (20) in each case in the direction in which the rotational and translational movement of the associated rotor (34) add up, at least from the center of the section (22) close to the axis up to a maximum thickness (32) at the transition in the concave arc (28) increases continuously and decreases continuously to the minimum thickness (30) in the region of the concave arc (28). 2. Stator nach Anspruch 1,
dadurch gekennzeichnet, daß die Innen­fläche (12, 18) des Mantels (10) und die Innenfläche (22, 28) der Auskleidung (20) einander geometrisch ähnlich, jedoch um die Mittellängsachse (A) um 5 bis 15° gegen­einander verdreht sind.2. stator according to claim 1,
characterized in that the inner surface (12, 18) of the casing (10) and the inner surface (22, 28) of the lining (20) are geometrically similar to one another, but are rotated by 5 to 15 ° relative to one another about the central longitudinal axis (A). 3. Stator nach Anspruch 2,
dadurch gekennzeichnet, daß die Innen­fläche (12, 18) des Mantels (10) und die Innenfläche (22, 28) der Auskleidung (20) um 8 bis 12° gegeneinander ver­dreht sind.3. stator according to claim 2,
characterized in that the inner surface (12, 18) of the casing (10) and the inner surface (22, 28) of the lining (20) are rotated by 8 to 12 ° relative to one another. 4. Stator nach Anspruch 1,
dadurch gekennzeichnet, daß die Dicke der Auskleidung (20) in der Mitte (I, V) ihrer konkaven Bogen (28) je ein Minimum (30) und in der Mitte (III, VII) jedes achsnahen Abschnitts (22) ein zusätzliches Minimum (36) hat.4. stator according to claim 1,
characterized in that the thickness of the lining (20) in the middle (I, V) of its concave arches (28) has a minimum (30) and in the center (III, VII) of each section (22) close to the axis an additional minimum ( 36) has. 5. Stator nach Anspruch 4,
dadurch gekennzeichnet, daß die Dicke der Auskleidung (20) an den zusätzlichen Minima (36) nicht größer als an den Minima (30) in der Mitte (I,V) der konkaven Bogen (28) ist.5. stator according to claim 4,
characterized in that the thickness of the lining (20) at the additional minima (36) is not greater than at the minima (30) in the middle (I, V) of the concave arches (28).
EP86109623A 1985-07-17 1986-07-14 Stator for a helical gear pump Expired EP0209099B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT86109623T ATE39731T1 (en) 1985-07-17 1986-07-14 STATOR FOR ECCENTRIC SCREW PUMPS.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3525529 1985-07-17
DE3525529A DE3525529C1 (en) 1985-07-17 1985-07-17 Stator for eccentric screw pumps

Publications (2)

Publication Number Publication Date
EP0209099A1 true EP0209099A1 (en) 1987-01-21
EP0209099B1 EP0209099B1 (en) 1989-01-04

Family

ID=6276006

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86109623A Expired EP0209099B1 (en) 1985-07-17 1986-07-14 Stator for a helical gear pump

Country Status (6)

Country Link
US (1) US4863359A (en)
EP (1) EP0209099B1 (en)
JP (1) JPH071035B2 (en)
AT (1) ATE39731T1 (en)
BR (1) BR8603356A (en)
DE (2) DE3525529C1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0459740A1 (en) * 1990-05-31 1991-12-04 Mono Pumps Limited Helical gear pump and stator
GB2272730A (en) * 1992-11-11 1994-05-25 Arnold Jaeger Eccentric screw pump

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5120204A (en) * 1989-02-01 1992-06-09 Mono Pumps Limited Helical gear pump with progressive interference between rotor and stator
US5832604A (en) * 1995-09-08 1998-11-10 Hydro-Drill, Inc. Method of manufacturing segmented stators for helical gear pumps and motors
DE19950258A1 (en) * 1999-10-18 2001-04-26 Wilhelm Kaechele Gmbh Elastome Eccentric worm pump or motor has stator with end ring with through opening of essentially similar shape to stator interior, threaded with same pitch and number of turns over ring thickness
US6604921B1 (en) 2002-01-24 2003-08-12 Schlumberger Technology Corporation Optimized liner thickness for positive displacement drilling motors
WO2005042910A2 (en) * 2003-10-27 2005-05-12 Dyna-Drill Technologies, Inc. Asymmetric contouring of elastomer liner on lobes in a moineau style power section stator
US8888474B2 (en) 2011-09-08 2014-11-18 Baker Hughes Incorporated Downhole motors and pumps with asymmetric lobes
KR102582599B1 (en) * 2021-01-19 2023-09-22 무사시 엔지니어링 가부시키가이샤 Fluid transport device, application device having the same device, and application method
JP7199128B1 (en) * 2022-01-18 2023-01-05 兵神装備株式会社 Uniaxial eccentric screw pump
JP7138382B1 (en) * 2022-01-18 2022-09-16 兵神装備株式会社 Uniaxial eccentric screw pump
JP7138383B1 (en) * 2022-01-18 2022-09-16 兵神装備株式会社 Uniaxial eccentric screw pump

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GB970619A (en) * 1962-01-17 1964-09-23 Robbins & Myers Helical gear pump with stator compression
GB1181193A (en) * 1967-04-19 1970-02-11 Seeberger K G Maschinen Und Ge Improvements in or relating to Worm Pumps
DE2017620A1 (en) * 1970-04-13 1971-11-04 Gummi-Jäger KG, 3000 Hannover Eccentric screw pump
DE2408186A1 (en) * 1974-02-20 1975-08-21 Lonza Werke Gmbh Eccentric pump with screw rotor and stator - has cavities between stator and housing
DE2817280A1 (en) * 1978-04-20 1979-10-25 Streicher Foerdertech STATOR FOR ECCENTRIC SCREW PUMPS
DE3147663A1 (en) * 1981-12-02 1983-06-09 Gummi-Jäger KG GmbH & Cie, 3000 Hannover Stator for spiral pumps
DE2709502C2 (en) * 1976-03-09 1984-12-20 Société Générale de Mécanique et de Métallurgie (S.G.M.M.), Vanves Stator for screw pumps

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DE1653897A1 (en) * 1967-04-19 1971-07-01 Seeberger Kg Maschinen Und Ger Screw pump
DE1653899A1 (en) * 1967-08-12 1971-09-30 Seeberger Kg Maschinen Und Ger Screw pump
JPS6017954B2 (en) * 1981-04-23 1985-05-08 兵神装備株式会社 Single shaft eccentric screw pump
US4676725A (en) * 1985-12-27 1987-06-30 Hughes Tool Company Moineau type gear mechanism with resilient sleeve

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB970619A (en) * 1962-01-17 1964-09-23 Robbins & Myers Helical gear pump with stator compression
GB1181193A (en) * 1967-04-19 1970-02-11 Seeberger K G Maschinen Und Ge Improvements in or relating to Worm Pumps
DE2017620A1 (en) * 1970-04-13 1971-11-04 Gummi-Jäger KG, 3000 Hannover Eccentric screw pump
DE2408186A1 (en) * 1974-02-20 1975-08-21 Lonza Werke Gmbh Eccentric pump with screw rotor and stator - has cavities between stator and housing
DE2709502C2 (en) * 1976-03-09 1984-12-20 Société Générale de Mécanique et de Métallurgie (S.G.M.M.), Vanves Stator for screw pumps
DE2817280A1 (en) * 1978-04-20 1979-10-25 Streicher Foerdertech STATOR FOR ECCENTRIC SCREW PUMPS
DE3147663A1 (en) * 1981-12-02 1983-06-09 Gummi-Jäger KG GmbH & Cie, 3000 Hannover Stator for spiral pumps

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0459740A1 (en) * 1990-05-31 1991-12-04 Mono Pumps Limited Helical gear pump and stator
US5145343A (en) * 1990-05-31 1992-09-08 Mono Pumps Limited Helical gear pump and stator with constant rubber wall thickness
GB2272730A (en) * 1992-11-11 1994-05-25 Arnold Jaeger Eccentric screw pump
US5358390A (en) * 1992-11-11 1994-10-25 Jaeger Arnold Eccentric screw pump
GB2272730B (en) * 1992-11-11 1995-09-27 Arnold Jaeger Eccentric screw pump

Also Published As

Publication number Publication date
EP0209099B1 (en) 1989-01-04
US4863359A (en) 1989-09-05
DE3661645D1 (en) 1989-02-09
DE3525529C1 (en) 1986-08-07
JPS6220684A (en) 1987-01-29
JPH071035B2 (en) 1995-01-11
BR8603356A (en) 1987-02-24
ATE39731T1 (en) 1989-01-15

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