EP0743450A1 - Radial piston pump - Google Patents

Radial piston pump Download PDF

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Publication number
EP0743450A1
EP0743450A1 EP96107532A EP96107532A EP0743450A1 EP 0743450 A1 EP0743450 A1 EP 0743450A1 EP 96107532 A EP96107532 A EP 96107532A EP 96107532 A EP96107532 A EP 96107532A EP 0743450 A1 EP0743450 A1 EP 0743450A1
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EP
European Patent Office
Prior art keywords
piston
eccentric
radial
bore
piston pump
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.)
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Application number
EP96107532A
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German (de)
French (fr)
Inventor
Ulrich Hilteman
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.)
Magna Powertrain Hueckeswagen GmbH
Original Assignee
LuK Automobiltechnik GmbH and Co KG
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Publication date
Application filed by LuK Automobiltechnik GmbH and Co KG filed Critical LuK Automobiltechnik GmbH and Co KG
Publication of EP0743450A1 publication Critical patent/EP0743450A1/en
Withdrawn legal-status Critical Current

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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
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/053—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement with actuating or actuated elements at the inner ends of the cylinders
    • F04B1/0535—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement with actuating or actuated elements at the inner ends of the cylinders the piston-driving cams being provided with inlets and outlets
    • 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
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/0404—Details or component parts
    • 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
    • F04B9/00—Piston machines or pumps characterised by the driving or driven means to or from their working members
    • F04B9/02—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being mechanical
    • F04B9/04—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being mechanical the means being cams, eccentrics or pin-and-slot mechanisms
    • F04B9/045—Piston machines or pumps characterised by the driving or driven means to or from their working members the means being mechanical the means being cams, eccentrics or pin-and-slot mechanisms the means being eccentrics

Definitions

  • the invention relates to a radial piston pump with pistons guided in a bore in at least one piston ring and moved by an eccentric in the bore.
  • Radial piston pumps of the type mentioned here are known. They have at least one piston which is moved radially from an eccentric to its axis of rotation and which is supported in its end facing the axis of rotation on the eccentric surface or on a ring moved by the eccentric.
  • the ring can also be designed as a polygon ring.
  • the pistons are arranged in the piston ring accommodated in the housing of the radial piston pump in such a way that their center lines intersect at a point which lies on the axis of rotation of the eccentric.
  • a tilting moment which is dependent on the operating pressure, the eccentricity of the eccentric and the angular position, acts on the piston during the operation of the rotary piston pump.
  • a large contact surface of the piston in the bore receiving it is required, that is to say that the piston — viewed in the radial direction — must be relatively long and have a so-called long guide. This forces a relatively large diameter of the piston ring and thus the housing of the radial piston pump.
  • the arrangement of the pistons also exerts a torque on the eccentric or on the race or polygon ring arranged between the eccentric and the piston crown.
  • the race of the eccentric is excited to rotate, since considerable torques arise.
  • These also lead to heavy wear between the bottom of the piston facing the axis of rotation of the eccentric and the surface of the eccentric or the race or polygon ring which cooperates with the piston head.
  • the contact surface is therefore subject to heavy wear, so that the desired sealing effect between the piston crown and the contact surface diminishes.
  • An embodiment of the radial piston pump is preferred in which the central axis of the piston is offset parallel to the imaginary line.
  • an embodiment of the radial piston pump is preferred in which the central axis of the piston - seen in the direction of rotation of the eccentric - lags behind the imaginary radial line. This arrangement reduces the disadvantages of the known pump particularly effectively.
  • the invention is explained below with reference to the drawing.
  • the single figure shows a cross section through a piston ring of a radial piston pump.
  • the piston ring 1 shown in the sectional view is provided with a central bore 3 which receives the eccentric 5 of a drive shaft 7.
  • the drive shaft 7 can also be mounted centrally in the housing and cover relative to the piston ring 1.
  • the eccentric is surrounded by a race 9, the cylindrical outer surface 11 of which is provided with at least one, here with three flat surfaces 13. A recess 15 is made in each of these flat surfaces 13, which opens to the bore 3 and breaks through the flat surface 13.
  • Each flat surface 13 is assigned a hollow piston 17, the flat bottom of which rests on the flat surface 19.
  • the cylindrical wall 21 of the piston 17 extending from the base 19 lies with its outer surface on the inner surface of a bore 23 made in the piston ring 1. This breaks through both the inner surface facing the bore 3 25 of the piston ring 1 as well as its circumferential surface 27.
  • the opening of the bore 23 facing the circumferential surface 27 is closed by a suitable closure cover 29 which is firmly anchored in the base body of the piston ring 1.
  • an elastic spring element is supported, here a helical spring 31, which is under tension and presses the piston 17 against the flat surface 13 of the race 9.
  • the eccentric 5 rotates while the race 9 performs a wobble movement, the distance between the plane surfaces 13 and the axis of rotation 33 of the drive shaft changing.
  • the pistons 17 are pushed within the bores 23 to a greater or lesser extent in the direction of the peripheral surface 27 of the piston ring 1 against the force of the helical spring 31.
  • the volume enclosed between the closure cap 29 and the bottom 19 of the piston 17 and the wall of the bore 23 changes.
  • a fluid can be drawn in through a central inlet opening 35 in the base 19 via the recess 15 in the suction area formed by the bore 3.
  • the bottom 19 moves relative to the flat surface 13, so that the connection between the suction area and the interior enclosed by the piston 17 is temporarily interrupted.
  • the operation of such a radial piston pump is known, so that it will not be discussed further here.
  • the sectional view shows that the central axis 37 of the pistons 17 is offset from an imaginary line 39 which intersects the axis of rotation 33 of the eccentric 5 or the drive shaft 7.
  • the central axis 37 and the line 39 run parallel to one another at a distance s in the exemplary embodiment shown here.
  • the central axes 37 are set back or "lagging" with respect to the line 39.
  • the size of the distance s can be varied in a range from 0.1e to 1e, preferably 0.4e to 0.7e.
  • the distance s is in particular 0.6e.
  • e denotes the eccentricity.
  • the size of the tilting and torque depends not only on the pressure built up during operation of the radial piston pump in the interior between the closure cover 29 and piston 17 but also on the eccentricity e of the eccentric 5 and its angular position.
  • the offset of the central axis 37 with respect to the imaginary radial line 39 ensures that the tilting moment on the piston 17 and the torque acting on the race 9 are reduced.
  • the resulting torque acting on the race 9 can be influenced so that it changes its sign. Due to the design of the rotary piston pump shown in the figure, that is, the parallel offset of the pistons 17, the inclination of the race 9 can be significantly reduced. This significantly reduces the wear between the underside of the base 9 and the flat surface 13, so that an optimal sealing effect is maintained here.
  • the tilting moment acting on the piston is ultimately significantly reduced, so that on the one hand the wear between the piston surface and the bore 23 is reduced.
  • the pumps described here are very easy to manufacture, so that the mentioned offset can be implemented inexpensively.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Compressors, Vaccum Pumps And Other Relevant Systems (AREA)

Abstract

The pump has at least one piston (17) displaced within a radial bore (23) in a piston ring (1) via an eccentric (5). The centre axis (37) of the piston is offset from a straight line (39) through the piston intersecting the axis of rotation (33) of the eccentric. Pref. the latter straight line and the centre axis of the piston are parallel to one another, with a distance between them of between 0.4 and 0.7 times the eccentricity of the eccentric.

Description

Die Erfindung betrifft eine Radialkolbenpumpe mit wenigstens in einem Kolbenring in einer Bohrung geführten, von einem Exzenter in der Bohrung bewegten Kolben. Radialkolbenpumpen der hier angesprochenen Art sind bekannt. Sie weisen mindestens einen von einem Exzenter radial zu dessen Drehachse bewegten Kolben auf, der sich in seinem der Drehachse zugewandten Ende auf der Exzenteroberfläche oder auf einem von dem Exzenter bewegten Ring abstützt. Der Ring kann auch als Polygonring ausgebildet sein. Die Kolben sind so in dem im Gehäuse der Radialkolbenpumpe untergebrachten Kolbenring angeordnet, daß sich ihre Mittellinien in einem Punkt schneiden, der auf der Drehachse des Exzenters liegt. Dadurch wirkt während des Betriebs der Rotationskolbenpumpe ein von dem Betriebsdruck, der Exzentrizität des Exzenters und der Winkellage abhängiges Kippmoment an dem Kolben. Um einem dadurch erzeugten Verschleiß entgegenzuwirken, bedarf es einer großen Anlagefläche des Kolbens in der diesen aufnehmenden Bohrung, das heißt, der Kolben muß -in radialer Richtung gesehen- relativ lang ausgebildet sein und eine sogenannte lange Führung aufweisen. Dies erzwingt einen relativ großen Durchmesser des Kolbenrings und damit des Gehäuses der Radialkolbenpumpe.The invention relates to a radial piston pump with pistons guided in a bore in at least one piston ring and moved by an eccentric in the bore. Radial piston pumps of the type mentioned here are known. They have at least one piston which is moved radially from an eccentric to its axis of rotation and which is supported in its end facing the axis of rotation on the eccentric surface or on a ring moved by the eccentric. The ring can also be designed as a polygon ring. The pistons are arranged in the piston ring accommodated in the housing of the radial piston pump in such a way that their center lines intersect at a point which lies on the axis of rotation of the eccentric. As a result, a tilting moment, which is dependent on the operating pressure, the eccentricity of the eccentric and the angular position, acts on the piston during the operation of the rotary piston pump. In order to counteract wear caused thereby, a large contact surface of the piston in the bore receiving it is required, that is to say that the piston — viewed in the radial direction — must be relatively long and have a so-called long guide. This forces a relatively large diameter of the piston ring and thus the housing of the radial piston pump.

Durch die Anordnung der Kolben wird überdies ein Drehmoment auf den Exzenter beziehungsweise auf den Zwischen Exzenter und Kolbenboden angeordneten Laufring beziehungsweise Polygonring ausgeübt. Der Laufring des Exzenters wird zu einer Rotation angeregt, da sich erhebliche Drehmomente einstellen. Diese führen auch zu einem starken Verschleiß zwischen dem der Drehachse des Exzenters zugewandten Boden des Kolbens und der mit dem Kolbenboden zusammenwirkenden Fläche des Exzenters beziehungsweise Lauf- oder Polygonrings. Die Berührungsfläche unterliegt daher einem starken Verschleiß, so daß die gewünschte Dichtwirkung zwischen Kolbenboden und Auflagefläche nachläßt.The arrangement of the pistons also exerts a torque on the eccentric or on the race or polygon ring arranged between the eccentric and the piston crown. The race of the eccentric is excited to rotate, since considerable torques arise. These also lead to heavy wear between the bottom of the piston facing the axis of rotation of the eccentric and the surface of the eccentric or the race or polygon ring which cooperates with the piston head. The contact surface is therefore subject to heavy wear, so that the desired sealing effect between the piston crown and the contact surface diminishes.

Es ist daher Aufgabe der Erfindung, eine Radialkolbenpumpe der eingangs genannten Art zu schaffen, die diese Nachteile nicht aufweist.It is therefore an object of the invention to provide a radial piston pump of the type mentioned which does not have these disadvantages.

Diese Aufgabe wird bei einer Radialkolbenpumpe gemäß Oberbegriff des Anspruchs 1 mit Hilfe der in diesem Anspruch genannten Merkmale gelöst. Dadurch, daß die Mittelachse des Kolbens gegenüber einer gedachten, die Drehachse des Exzenters schneidenden Linie versetzt angeordnet ist, werden das auf den Kolben wirkende Kippmoment und das auf den Exzenter beziehungsweise dessen Lauf- beziehungsweise Polygonrings wirkende Drehmoment so reduziert, daß der Verschleiß deutlich vermindert und die Dichtwirkung verbessert werden.This object is achieved in a radial piston pump according to the preamble of claim 1 with the help of the features mentioned in this claim. Characterized in that the central axis of the piston is offset from an imaginary line intersecting the axis of rotation of the eccentric, the tilting moment acting on the piston and the torque acting on the eccentric or its barrel or polygon ring are reduced so that the wear is significantly reduced and the sealing effect can be improved.

Bevorzugt wird eine Ausführungsform der Radialkolbenpumpe, bei der die Mittelachse des Kolbens parallel zu der gedachten Linie versetzt ist. Diese Anordnung führt zu einer besonders wirksamen Reduzierung des Kipp- und Drehmoments und damit des Verschleißes.An embodiment of the radial piston pump is preferred in which the central axis of the piston is offset parallel to the imaginary line. These Arrangement leads to a particularly effective reduction of the tilting and torque and thus the wear.

Schließlich wird eine Ausführungsform der Radialkolbenpumpe bevorzugt, bei der die Mittelachse des Kolbens -in Drehrichtung des Exzenters gesehen- der gedachten radial verlaufenden Linie nacheilt. Durch diese Anordnung werden die genannten Nachteile der bekannten Pumpe besonders wirksam reduziert.Finally, an embodiment of the radial piston pump is preferred in which the central axis of the piston - seen in the direction of rotation of the eccentric - lags behind the imaginary radial line. This arrangement reduces the disadvantages of the known pump particularly effectively.

Die Erfindung wird im folgenden anhand der Zeichnung näher erläutert. Die einzige Figur zeigt einen Querschnitt durch einen Kolbenring einer Radalkolbenpumpe.The invention is explained below with reference to the drawing. The single figure shows a cross section through a piston ring of a radial piston pump.

Der in der Schnittdarstellung gezeigte Kolbenring 1 ist mit einer zentrischen Bohrung 3 versehen, die den Exzenter 5 einer Antriebswelle 7 aufnimmt. Die Antriebswelle 7 kann auch in Gehäuse und Deckel zentrisch zum Kolbenring 1 gelagert sein. Der Exzenter ist von einem Laufring 9 umgeben, dessen zylindrische Außenfläche 11 mit mindestens einer, hier mit drei Planflächen 13 versehen ist. In diese Planflächen 13 ist je eine Ausnehmung 15 eingebracht, die sich zur Bohrung 3 öffnet und die Planfläche 13 durchbricht.The piston ring 1 shown in the sectional view is provided with a central bore 3 which receives the eccentric 5 of a drive shaft 7. The drive shaft 7 can also be mounted centrally in the housing and cover relative to the piston ring 1. The eccentric is surrounded by a race 9, the cylindrical outer surface 11 of which is provided with at least one, here with three flat surfaces 13. A recess 15 is made in each of these flat surfaces 13, which opens to the bore 3 and breaks through the flat surface 13.

Jeder Planfläche 13 ist ein hohler Kolben 17 zugeordnet, dessen ebener Boden auf der Planfläche 19 aufliegt. Die von dem Boden 19 ausgehende zylindrische Wandung 21 des Kolbens 17 liegt mit Ihrer Außenfläche an der Innenfläche einer in den Kolbenring 1 eingebrachten Bohrung 23 an. Diese durchbricht sowohl die der Bohrung 3 zugewandte Innenfläche 25 des Kolbenrings 1 als auch dessen Umfangsfläche 27. Die der Umfangsfläche 27 zugewandte Öffnung der Bohrung 23 ist durch einen geeigneten Verschlußdeckel 29 abgeschlossen, der fest im Grundkörper des Kolbenrings 1 verankert ist. An der Innenfläche des Verschlußdeckels 29 an der Innenseite des Bodens 19 des Kolbens 17 stützt sich ein elastisches Federelement, hier eine Schraubenfeder 31 ab, die unter Vorspannung steht und den Kolben 17 gegen die Planfläche 13 des Laufrings 9 andrückt.Each flat surface 13 is assigned a hollow piston 17, the flat bottom of which rests on the flat surface 19. The cylindrical wall 21 of the piston 17 extending from the base 19 lies with its outer surface on the inner surface of a bore 23 made in the piston ring 1. This breaks through both the inner surface facing the bore 3 25 of the piston ring 1 as well as its circumferential surface 27. The opening of the bore 23 facing the circumferential surface 27 is closed by a suitable closure cover 29 which is firmly anchored in the base body of the piston ring 1. On the inner surface of the cover 29 on the inside of the bottom 19 of the piston 17, an elastic spring element is supported, here a helical spring 31, which is under tension and presses the piston 17 against the flat surface 13 of the race 9.

Wird die Antriebswelle 7 beispielsweise im Uhrzeigersinn gedreht, rotiert der Exzenter 5 während der Laufring 9 eine Taumelbewegung durchführt, wobei sich der Abstand der Planflächen 13 zur Drehachse 33 der Antriebswelle ändert. Damit werden die Kolben 17 innerhalb der Bohrungen 23 gegen die Kraft der Schraubenfeder 31 mehr oder weniger weit in Richtung zur Umfangsfläche 27 des Kolbenrings 1 gedrängt. Dabei ändert sich das zwischen dem Verschlußdeckel 29 und dem Boden 19 des Kolbens 17 sowie der Wandung der Bohrung 23 eingeschlossene Volumen. Bei einer Abwärtsbewegung des Kolbens 23 kann durch eine zentrale Einlaßöffnung 35 im Boden 19 über die Außnehmung 15 dem von der Bohrung 3 gebildeten Saugbereich ein Fluid angesaugt werden. Während der Drehung des Laufrings 9 verschiebt sich der Boden 19 gegenüber der Planfläche 13, so daß die Verbindung zwischen dem Saugbereich und dem von dem Kolben 17 eingeschlossenen Innenraum zeitweise unterbrochen wird. Die Funktionsweise einer derartigen Radialkolbenpumpen ist bekannt, so daß hier nicht weiter darauf eingegangen werden soll.If the drive shaft 7 is rotated clockwise, for example, the eccentric 5 rotates while the race 9 performs a wobble movement, the distance between the plane surfaces 13 and the axis of rotation 33 of the drive shaft changing. Thus, the pistons 17 are pushed within the bores 23 to a greater or lesser extent in the direction of the peripheral surface 27 of the piston ring 1 against the force of the helical spring 31. The volume enclosed between the closure cap 29 and the bottom 19 of the piston 17 and the wall of the bore 23 changes. When the piston 23 moves downward, a fluid can be drawn in through a central inlet opening 35 in the base 19 via the recess 15 in the suction area formed by the bore 3. During the rotation of the race 9, the bottom 19 moves relative to the flat surface 13, so that the connection between the suction area and the interior enclosed by the piston 17 is temporarily interrupted. The operation of such a radial piston pump is known, so that it will not be discussed further here.

Die Schnittdarstellung läßt erkennen, daß die Mittelachse 37 der Kolben 17 gegenüber einer einer gedachten, die Drehachse 33 des Exzenters 5 beziehungsweise der Antriebswelle 7 schneidenden Linie 39 versetzt ist. Die Mittelachse 37 und die Linie 39 verlaufen bei dem hier dargestellten Ausführungsbeispiel parallel zueinander in einem Abstand s.The sectional view shows that the central axis 37 of the pistons 17 is offset from an imaginary line 39 which intersects the axis of rotation 33 of the eccentric 5 or the drive shaft 7. The central axis 37 and the line 39 run parallel to one another at a distance s in the exemplary embodiment shown here.

Geht man von einer Rotation der Antriebswelle 7 im Uhrzeigersinn aus, so sind die Mittelachsen 37 gegenüber der Linie 39 zurückversetzt beziehungsweise "nacheilend" angeordnet. Die Größe des Abstandes s kann variiert werden und zwar in einem Bereich von 0,1e bis 1e, vorzugsweise 0,4e bis 0,7e. Der Abstand s beträgt insbesondere 0,6e. Mit e wird in diesem Zusammenhang die Exzentrizität bezeichnet.If one assumes a rotation of the drive shaft 7 in a clockwise direction, the central axes 37 are set back or "lagging" with respect to the line 39. The size of the distance s can be varied in a range from 0.1e to 1e, preferably 0.4e to 0.7e. The distance s is in particular 0.6e. In this context, e denotes the eccentricity.

Es ist bekannt, daß bei herkömmlichen Radialkolbenpumpen aufgrund des im Innenraum zwischen Verschlußdeckel 29 und Kolben 17 aufgebauten Drucks ein Kippmoment auf den Kolben 17 wirkt, das den Kolben 17 entgegen dem Uhrzeigersinn belastet. Gleichzeitig wirkt ein Drehmoment auf den Laufring 9, das diesen im Uhrzeigersinn belastet.It is known that in conventional radial piston pumps, due to the pressure built up in the interior between the sealing cover 29 and the piston 17, a tilting moment acts on the piston 17, which loads the piston 17 counterclockwise. At the same time, torque acts on the race 9, which loads it in a clockwise direction.

Die Größe des Kipp- und Drehmoments hängt nicht nur von dem während des Betriebs der Radialkolbenpumpe aufgebauten Druck im Innenraum zwischen Verschlußdeckel 29 und Kolben 17 ab sondern auch von der Exzentrizität e des Exzenters 5 und dessen Winkellage.The size of the tilting and torque depends not only on the pressure built up during operation of the radial piston pump in the interior between the closure cover 29 and piston 17 but also on the eccentricity e of the eccentric 5 and its angular position.

Aufgrund dieser Momente liegt die Unterseite des Kolbens 17 bei herkömmlichen Radialkolbenpumpen nicht mehr plan an der Planfläche 13 an. Dadurch wird der von der Bohrung 3 umschlossene Saugraum nicht mehr druckdicht abgeschlossen gegenüber dem zwischen Verschlußdeckel 29 und Kolben 17 liegenden Innenraum. Überdies ergibt sich an der Kolbenunterseite und an der Planfläche 13 ein erhöhter Verschleiß.Because of these moments, the underside of the piston 17 lies in conventional radial piston pumps no longer flat on face 13. As a result, the suction space enclosed by the bore 3 is no longer closed in a pressure-tight manner with respect to the interior lying between the closure cover 29 and the piston 17. In addition, there is increased wear on the underside of the piston and on the flat surface 13.

Durch den Versatz der Mittelachse 37 gegenüber der gedachten radial verlaufenden Linie 39 wird erreicht, daß das Kippmoment auf den Kolben 17 und das auf den Laufring 9 wirkende Drehmoment reduziert werden. Je nach Wahl des Abstandes s kann das am Laufring 9 wirkende resultierende Drehmoment so beeinflußt werden, daß es sein Vorzeichen ändert. Durch die in der Figur dargestellte Ausbildung der Rotationskolbenpumpe, also durch den Parallelversatz der Kolben 17 kann die Drehneigung des Laufrings 9 wesentlich reduziert werden. Dadurch vermindert sich der zwischen der Unterseite des Bodens 9 und der Planfläche 13 gegebene Verschleiß wesentlich, so daß hier eine optimale Dichtwirkung aufrechterhalten wird. Überdies wird schließlich das auf den Kolben wirkende Kippmoment deutlich reduziert, so daß einerseits der Verschleiß zwischen Kolbenoberfläche und Bohrung 23 vermindert wird. Es ist außerdem möglich, die Führungslänge des Kolbens 17 in der Bohrung 23 zu vermindern, das heißt die in radialer Richtung gemessene Länge des Kolbens 17 beziehungsweise die Länge der Bohrung 23 zu reduzieren. Dadurch nimmt auch der Gesamtdurchmesser des Kolbenrings 1 ab, so daß die Radalkolbenpumpe kleiner baut.The offset of the central axis 37 with respect to the imaginary radial line 39 ensures that the tilting moment on the piston 17 and the torque acting on the race 9 are reduced. Depending on the choice of the distance s, the resulting torque acting on the race 9 can be influenced so that it changes its sign. Due to the design of the rotary piston pump shown in the figure, that is, the parallel offset of the pistons 17, the inclination of the race 9 can be significantly reduced. This significantly reduces the wear between the underside of the base 9 and the flat surface 13, so that an optimal sealing effect is maintained here. In addition, the tilting moment acting on the piston is ultimately significantly reduced, so that on the one hand the wear between the piston surface and the bore 23 is reduced. It is also possible to reduce the guide length of the piston 17 in the bore 23, that is to say to reduce the length of the piston 17 measured in the radial direction or the length of the bore 23. As a result, the overall diameter of the piston ring 1 also decreases, so that the radial piston pump is smaller.

Insgesamt wird deutlich, daß durch eine auf einfache Weise realisierbare Abwandlung der Bauform der Radialkolbenpumpe, nämlich durch den Versatz der Mittelachse 37 der Kolben 17 gegenüber einer gedachten, radial verlaufenden Linie 19, der Drehmomentenverlauf wesentlich verbessert wird. Das heißt, die Drehmomentschwankungen im Betrieb der Pumpe werden deutlich reduziert. Dasselbe gilt auch für das Kippmoment am Kolben 17. Dieses Ergebnis stellt sich unabhängig davon ein, wie viele Kolben 17 in den Kolbenring 1 eingebaut sind. Bei der Schnittdarstellung sind lediglich beispielhaft drei Kolben vorgesehen. Die hier vorgeschlagene Bauform läßt sich selbstverständlich auch bei Radialkolbenpumpen mit mehr Kolben beispielsweise mit sechs Kolben realisieren.Overall, it is clear that the torque curve is significantly improved by a modification of the design of the radial piston pump that can be implemented in a simple manner, namely by the offset of the central axis 37 of the pistons 17 with respect to an imaginary, radially extending line 19. This means that the torque fluctuations during the operation of the pump are significantly reduced. The same applies to the tilting moment on the piston 17. This result is obtained regardless of how many pistons 17 are installed in the piston ring 1. In the sectional view, only three pistons are provided by way of example. The design proposed here can of course also be implemented in radial piston pumps with more pistons, for example with six pistons.

Im übrigen ist es noch wesentlich hervorzustellen, daß der Versatz zwischen der Mittelachse 37 und der gedachten radial verlaufenden Linie 39 auch bei anderen Bauformen von Radialkolbenpumpen realisiert werden kann.In addition, it is essential to emphasize that the offset between the central axis 37 and the imaginary radial line 39 can also be realized with other types of radial piston pumps.

Die hier beschriebenen Pumpen sind sehr einfach herstellbar, so daß der angesprochene Versatz kostengünstig realisierbar ist.The pumps described here are very easy to manufacture, so that the mentioned offset can be implemented inexpensively.

Aus dem oben Gesagten wird ohne weiteres ersichtlich, daß das hier beschriebene Prinzip der exzentrisch angeordneten Radialkolben auf sämtliche Radialkolbenpumpen übertragbar ist, unabhängig davon, wie diese im einzelnen aufgebaut sind. Die Kolben der Radialkolbenpumpe können also anstelle der im Boden 19 vorgesehenen Zentralöffnung 35 auch mit Einlaßöffnungen versehen sein, die die seitliche Wandung 21 der Kolben 17 durchbrechen. Im Betrieb derartiger Radialkolbenpumpen muß sichergestellt sein, daß die die Wandung durchbrechenden Bohrungen während einer Ansaugphase in Fluidverbidnung mit der Bohrung 3 stehen und das zu fördernde Medium in das Innere des Kolbens 17 einlassen können. Für das Prinzip der exzentrisch angeordneten Kolben spielt es überdies keine Rolle, ob die Kolben an Planflächen des Exzenters anliegen, oder ob dieser eine zylindrische Außenfläche aufweist.From what has been said above, it is readily apparent that the principle of the eccentrically arranged radial piston described here can be applied to all radial piston pumps, regardless of how they are constructed in detail. The pistons of the radial piston pump can also be provided with inlet openings instead of the central opening 35 provided in the bottom 19, which openings are the lateral ones Break through wall 21 of piston 17. In the operation of such radial piston pumps, it must be ensured that the bores that break through the wall are in fluid communication with the bore 3 during a suction phase and can admit the medium to be pumped into the interior of the piston 17. For the principle of the eccentrically arranged pistons, it is also irrelevant whether the pistons rest against the flat surfaces of the eccentric or whether it has a cylindrical outer surface.

Claims (4)

Radialkolbenpumpe mit wenigstem einem in einem Kolbenring in einer Bohrung geführten, von einem Exzenter in der Bohrung bewegten Kolben, dadurch gekennzeichnet, daß die Mittelachse (37) des Kolbens (17) gegenüber einer gedachten, die Drehachse (33) des Exzenters (5) schneidenden Linie (39) versetzt ist.Radial piston pump with at least one piston guided in a bore in a piston ring and moved by an eccentric in the bore, characterized in that the central axis (37) of the piston (17) is opposite an imaginary one that intersects the axis of rotation (33) of the eccentric (5) Line (39) is offset. Radialkolbenpumpe nach Anspruch 1, dadurch gekennzeichnet, daß die Mittelachse (37) des Kolbens (17) parallel zu der gedachten Linie (39) versetzt ist.Radial piston pump according to claim 1, characterized in that the central axis (37) of the piston (17) is offset parallel to the imaginary line (39). Radialkolbenpumpe nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß die Mittelachse (37) gegenüber der Linie (39) um ca. 0,1e bis 1e, vorzugsweise um 0,4e bis 0,7e, insbesondere um 0,6e versetzt ist.Radial piston pump according to claim 1 or 2, characterized in that the central axis (37) is offset from the line (39) by approximately 0.1e to 1e, preferably by 0.4e to 0.7e, in particular by 0.6e. Radialkolbenpumpe nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Mittelachse (37) des Kolbens (17) -in Drehrichtung des Exzenters (5) gesehen- der gedachten Linie (39) nacheilt.Radial piston pump according to one of the preceding claims, characterized in that the central axis (37) of the piston (17) - seen in the direction of rotation of the eccentric (5) - lags behind the imaginary line (39).
EP96107532A 1995-05-18 1996-05-11 Radial piston pump Withdrawn EP0743450A1 (en)

Applications Claiming Priority (2)

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DE1995118198 DE19518198A1 (en) 1995-05-18 1995-05-18 Radial piston pump
DE19518198 1995-05-18

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EP0743450A1 true EP0743450A1 (en) 1996-11-20

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JP (1) JPH094559A (en)
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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998014704A1 (en) * 1996-10-01 1998-04-09 Mannesmann Rexroth Ag Radial piston pump
WO2007141058A1 (en) * 2006-06-06 2007-12-13 Continental Automotive Gmbh Fluid pump having a crank mechanism
WO2009098095A1 (en) * 2008-02-04 2009-08-13 Robert Bosch Gmbh Cam free of transverse force for common-rail high-pressure pumps

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE10027425A1 (en) * 2000-06-02 2001-12-06 Zf Batavia Llc Radial piston pump, e.g. lubricant pump in internal combustion engine, has connecting bore to eccentric drive element chamber in base of piston controlled by excess pressure valve
JP2017025871A (en) * 2015-07-27 2017-02-02 株式会社アドヴィックス Pump device and vehicular brake device including the same
CN111779669A (en) * 2020-08-04 2020-10-16 赣州市闻誉科技有限公司 Self-suction type water suction pump for low-lying

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Publication number Priority date Publication date Assignee Title
DE3921635A1 (en) * 1988-07-01 1990-01-04 Kayaba Industry Co Ltd HYDRO RADIAL PISTON PUMP
DE3942223C1 (en) * 1989-12-21 1991-06-20 Asea Brown Boveri Ag, 6800 Mannheim, De Piston-cylinder for electrical switching drive unit - has piston driven against spring by eccentric to off set piston axis w.r.t. eccentric centre point
WO1992014056A1 (en) * 1991-01-30 1992-08-20 Barmag Luk Automobiltechnik Gmbh & Co. Kg Radial-piston pump
EP0520286A2 (en) * 1991-06-27 1992-12-30 LuK Automobiltechnik GmbH & Co. KG Radial piston pump
DE4310062A1 (en) * 1993-03-27 1994-09-29 Teves Gmbh Alfred Radial piston machine
EP0687814A2 (en) * 1994-05-25 1995-12-20 Sumitomo Electric Industries, Limited Plunger pump

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3921635A1 (en) * 1988-07-01 1990-01-04 Kayaba Industry Co Ltd HYDRO RADIAL PISTON PUMP
DE3942223C1 (en) * 1989-12-21 1991-06-20 Asea Brown Boveri Ag, 6800 Mannheim, De Piston-cylinder for electrical switching drive unit - has piston driven against spring by eccentric to off set piston axis w.r.t. eccentric centre point
WO1992014056A1 (en) * 1991-01-30 1992-08-20 Barmag Luk Automobiltechnik Gmbh & Co. Kg Radial-piston pump
EP0520286A2 (en) * 1991-06-27 1992-12-30 LuK Automobiltechnik GmbH & Co. KG Radial piston pump
DE4310062A1 (en) * 1993-03-27 1994-09-29 Teves Gmbh Alfred Radial piston machine
EP0687814A2 (en) * 1994-05-25 1995-12-20 Sumitomo Electric Industries, Limited Plunger pump

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1998014704A1 (en) * 1996-10-01 1998-04-09 Mannesmann Rexroth Ag Radial piston pump
WO2007141058A1 (en) * 2006-06-06 2007-12-13 Continental Automotive Gmbh Fluid pump having a crank mechanism
WO2009098095A1 (en) * 2008-02-04 2009-08-13 Robert Bosch Gmbh Cam free of transverse force for common-rail high-pressure pumps

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JPH094559A (en) 1997-01-07
DE19518198A1 (en) 1996-11-21

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