EP0528254B1 - Control arrangement for positive displacement pumps - Google Patents

Control arrangement for positive displacement pumps Download PDF

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Publication number
EP0528254B1
EP0528254B1 EP92113259A EP92113259A EP0528254B1 EP 0528254 B1 EP0528254 B1 EP 0528254B1 EP 92113259 A EP92113259 A EP 92113259A EP 92113259 A EP92113259 A EP 92113259A EP 0528254 B1 EP0528254 B1 EP 0528254B1
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EP
European Patent Office
Prior art keywords
control
control rod
pressure
piston
throttle
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
Application number
EP92113259A
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German (de)
French (fr)
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EP0528254A2 (en
EP0528254A3 (en
Inventor
Reiner Mayer
Wolgang Hohl
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ZF Friedrichshafen AG
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ZF Friedrichshafen AG
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Publication of EP0528254A2 publication Critical patent/EP0528254A2/en
Publication of EP0528254A3 publication Critical patent/EP0528254A3/en
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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04CROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C14/00Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/24Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves
    • F04C14/26Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by using valves controlling pressure or flow rate, e.g. discharge valves or unloading valves using bypass channels

Definitions

  • the invention relates to a control device for positive displacement pumps, in particular for vane pumps, in which a pressure chamber is connected via a throttle device to an outlet connected to a consumer. Furthermore, a flow control piston which is displaceable in a housing bore is provided, the end face of which closes a bore section which has a connection to the pressure chamber. Another end face of the flow control piston projects into a space which is connected to an outlet downstream of the throttle device. The flow control piston releases a connection from the pressure chamber to a pump inlet channel as a function of a differential pressure acting on the two end faces.
  • a control pin with a control contour extends on the pressure outlet side into a stationary bushing, which is designed such that, together with an opening, there is a variable passage cross section.
  • a throttle device cooperating with a control device according to the preamble of claim 1 is already known from EP-A-26 586.
  • a flow control piston is provided, the displacement of which is used at the same time to regulate the consumer flow.
  • a conical control pin rests under spring force on its end face of the flow control piston, the control pin, depending on the cut-off position of the flow control piston, releasing with its conical area a more or less large ring cross section at a throttle opening of a bushing.
  • Such a throttle device must be installed directly behind the flow control piston because of the contact with it.
  • the dependence of the throttle device on the position of the flow control piston gives one pressure-dependent flow.
  • the flow rate characteristic which should not rise again after the cut-off point at approx. 1,000 rpm, therefore shows a more or less steep increase, depending on the outlet pressure.
  • the aim is to maintain a characteristic curve that is as falling or horizontal as possible, in particular for the supply of power steering systems, at all pressures.
  • a flow control piston is designed so that it not only connects the pressure side of the pump to a return line as a function of speed, but at the same time the pressure side via a variable ring cross-section, in accordance with the aforementioned document, connects to the consumer outlet.
  • the throttle bore which can be changed via a fixed control pin, is located in the flow control piston, so that this flow rate also receives a pressure dependency with the characteristic curve deviation explained above.
  • the invention has for its object to provide a control device which provides a pressure-independent, falling flow rate over the speed, the throttle device should be designed so that a variety of modifications of the flow rate characteristic are possible in a simple manner. Another essential requirement is to retrofit the throttle device into the pressure outlet of existing pumps with little construction, so that the characteristic curve can be modified depending on the intended use.
  • Claims 2 to 6 contain advantageous embodiments of the invention.
  • the function of the throttle device is independent of the flow control piston in the pressure outlet the pump, the control pin being fixed.
  • a piston that can be moved against the force of a spring by the differential pressure surrounds the control pin and forms the variable control orifice with it.
  • the throttle device can also be inexpensively installed in already existing pumps, it is advantageously carried out as a press-in or screw-in cartridge.
  • the simple construction also contributes to the fact that the control pin is held in a guide part pressed into the cartridge.
  • a conical control contour of the control pin is provided.
  • the control contour can also have a concave or convex shape.
  • tapered control contour produces a continuously falling characteristic curve
  • concave design results in a disproportionately low and the convex curve a disproportionately falling curve.
  • a step-shaped control contour with a largest diameter in the rear area results in a step-wise falling characteristic.
  • a drive shaft 3 is mounted in a housing 2 closed by a cover 1.
  • the drive shaft 3 carries a rotor 4 in a conventional manner on a spline.
  • Radially movable vanes 5 are guided in radial slots of the rotor 4 and slide along them sealingly in a cam ring 6.
  • a pressure plate 7 lies sealingly on the pump package consisting of rotor 4, blades 5 and cam ring 6.
  • Another pressure plate 8 is also due to the force of a spring 10 on the pump package.
  • the wings 5 enclose not visible delivery chambers between them, which are connected to a suction port 11.
  • the pumped pressure oil enters a pressure chamber 12 via the pressure openings 8 of the pressure plate 8, which are also not visible.
  • the pressure chamber 12 has part-annular channels 13 and 14 with under wing spaces 15 and 16 connection. This makes it possible to press the vanes passing through the pressure zone outwards into the cam ring 6.
  • a flow control valve 18 and a throttle device 20 are installed coaxially with one another.
  • a piston 21 of the flow control valve 18 controls, in a known manner, an inlet channel 23 with a control collar 22 Starting position, the control collar 22 rests against the throttle device 20 under the load of a spring 24.
  • the inlet channel 23 is closed by the control collar 22.
  • a bore section 17A to the right of the control collar, which also represents the pressure outlet, can be connected to the inlet channel 23.
  • In the bore section 17A there is a pipe screw connection 25 connected to a consumer, for example an auxiliary power steering system.
  • An inlet channel 26 connects the pressure chamber 12 to the bore section 17A.
  • the throttle device 20 is designed as a press-in or screw cartridge 27, which contains a control pin 28 and a throttle piston 30 surrounding the control pin.
  • the throttle piston 30 is supported in its starting position under the force of a spring on a stop 32.
  • the control pin 28 is held in a guide part 33 which also supports the spring 31.
  • Fig. 2 shows the guide member 33 as a narrow web which is pressed into the cartridge 27. In this way there is enough space on the side for oil to pass through.
  • the control pin 28 has a conical central section 34 as the control contour. Depending on the desired characteristic curve, however, the central section can also be stepped, convex or concave. Other control contours are also conceivable.
  • a space 35 receiving the spring 24 of the flow control piston 21 is connected to an outlet 40 of the pipe screw connection 25 via a control line 36 indicated by a broken line, an annular groove 37 and a throttle point 38.
  • the control device works as follows: The entire delivery flow of the pump flows via the inlet channel 26 into the bore section 17A. Up to the cut-off point at a pump speed of, for example 1 000 min -1 the flow flows past the front of the control collar 22 over to the outlet 40. The flow corresponds to the cross section drawn between the control pin 28 and the throttle piston 32. The flow control piston 21 adjusts slightly to the left, but the control collar 22 still does not begin with the opening of the inlet channel 23.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)
  • Details And Applications Of Rotary Liquid Pumps (AREA)

Description

Die Erfindung betrifft eine Regeleinrichtung für Verdrängerpumpen, insbesondere für Flügelzellenpumpen, in welcher ein Druckraum über eine Drosseleinrichtung mit einem an einen Verbraucher angeschlossenen Auslaß in Verbindung steht. Weiter ist ein in einer Gehäusebohrung verschiebbarer Stromregelkolben vorgesehen, dessen eine Stirnfläche einen Bohrungsabschnitt abschließt, der mit dem Druckraum Verbindung hat. Eine andere Stirnfläche des Stromregelkolbens ragt in einen Raum, der mit einem Auslaß stromabwärts der Drosseleinrichtung verbunden ist. Der Stromregelkolben gibt in Abhängigkeit eines auf die beiden Stirnflächen wirkenden Differenzdruckes eine Verbindung vom Druckraum zu einem Pumpeneinlaßkanal frei. In eine ortsfeste Buchse erstreckt sich auf der Druckauslaßseite ein Regelstift mit einer Steuerkontur, die so ausgeführt ist, daß sich zusammen mit einer Öffnung ein veränderbarer Durchtrittsquerschnitt ergibt.The invention relates to a control device for positive displacement pumps, in particular for vane pumps, in which a pressure chamber is connected via a throttle device to an outlet connected to a consumer. Furthermore, a flow control piston which is displaceable in a housing bore is provided, the end face of which closes a bore section which has a connection to the pressure chamber. Another end face of the flow control piston projects into a space which is connected to an outlet downstream of the throttle device. The flow control piston releases a connection from the pressure chamber to a pump inlet channel as a function of a differential pressure acting on the two end faces. A control pin with a control contour extends on the pressure outlet side into a stationary bushing, which is designed such that, together with an opening, there is a variable passage cross section.

Eine mit einer Regeleinrichtung zusammenwirkende Drosseleinrichtung nach dem Oberbegriff des Anspruches 1 ist bereits aus der EP-A-26 586 bekannt. In dieser Druckschrift ist ein Stromregelkolben vorgesehen, dessen Verschiebeweg gleichzeitig zur Regelung des Verbraucherstromes benutzt wird. Ein konischer Regelstift liegt dazu unter Federkraft an seiner Stirnseite des Stromregelkolbens an, wobei der Regelstift, je nach Abregelstellung des Stromregelkolbens, mit seinem konischen Bereich einen mehr oder weniger großen Ringquerschnitt an einer Drosselöffnung einer Buchse freigibt. Eine solche Drosseleinrichtung muß wegen des Kontaktes mit dem Stromregelkolben unmittelbar hinter diesem eingebaut sein. Durch die Abhängigkeit der Drosseleinrichtung von der Stellung des Stromregelkolbens erhält man einen druckabhängigen Förderstrom. Die Förderstromkennlinie, die nach dem Abregelpunkt bei ca. 1 000 U/min nicht mehr ansteigen soll, zeigt daher, je nach Ausgangsdruck, einen mehr oder weniger steilen Anstieg. Ziel ist es aber, insbesondere für die Versorgung von Hilfskraftlenkungen, bei allen Drücken eine möglichst fallende oder waagerechte Kennlinie zu erhalten.A throttle device cooperating with a control device according to the preamble of claim 1 is already known from EP-A-26 586. In this document, a flow control piston is provided, the displacement of which is used at the same time to regulate the consumer flow. For this purpose, a conical control pin rests under spring force on its end face of the flow control piston, the control pin, depending on the cut-off position of the flow control piston, releasing with its conical area a more or less large ring cross section at a throttle opening of a bushing. Such a throttle device must be installed directly behind the flow control piston because of the contact with it. The dependence of the throttle device on the position of the flow control piston gives one pressure-dependent flow. The flow rate characteristic, which should not rise again after the cut-off point at approx. 1,000 rpm, therefore shows a more or less steep increase, depending on the outlet pressure. The aim, however, is to maintain a characteristic curve that is as falling or horizontal as possible, in particular for the supply of power steering systems, at all pressures.

Eine weitere, ganz ähnliche Drosseleinrichtung zeigt die DE-A 22 49 149. Dort ist ein Stromregelkolben so ausgeführt, daß er nicht nur die Druckseite der Pumpe drehzahlabhängig an einen Rücklauf anschließt, sondern gleichzeitig die Druckseite über einen veränderbaren Ringquerschnitt, entsprechend der vorgenannten Druckschrift, mit dem Verbraucher-Auslaß verbindet. Die den Ringquerschnitt über einen feststehenden Regelstift veränderbare Drosselbohrung befindet sich im Stromregelkolben, so daß auch dieser Förderstrom eine Druckabhängigkeit mit der zuvor erläuterten Kennlinienabweichung erhält.Another, very similar throttle device is shown in DE-A 22 49 149. There, a flow control piston is designed so that it not only connects the pressure side of the pump to a return line as a function of speed, but at the same time the pressure side via a variable ring cross-section, in accordance with the aforementioned document, connects to the consumer outlet. The throttle bore, which can be changed via a fixed control pin, is located in the flow control piston, so that this flow rate also receives a pressure dependency with the characteristic curve deviation explained above.

Der Erfindung liegt die Aufgabe zugrunde, eine Regeleinrichtung zu schaffen, die einen druckunabhängigen, fallenden Förderstrom über der Drehzahl bereitstellt, wobei die Drosseleinrichtung so gestaltet sein soll, daß eine Vielzahl von Abwandlungen der Förderstromkennlinie auf einfache Weise möglich sind. Eine weitere wesentliche Forderung besteht darin, die Drosseleinrichtung mit geringem Bauaufwand in den Druckausgang vorhandener Pumpen auch nachträglich einzubauen, so daß die Kennlinie, je nach Einsatzzweck, abwandelbar ist.The invention has for its object to provide a control device which provides a pressure-independent, falling flow rate over the speed, the throttle device should be designed so that a variety of modifications of the flow rate characteristic are possible in a simple manner. Another essential requirement is to retrofit the throttle device into the pressure outlet of existing pumps with little construction, so that the characteristic curve can be modified depending on the intended use.

Diese Aufgabe ist durch die Merkmale des Anspruches 1 gelöst. Die Ansprüche 2 bis 6 enthalten vorteilhafte Ausgestaltungen der Erfindung. Die Drosseleinrichtung sitzt in ihrer Funktion unabhängig vom Stromregelkolben im Druckausgang der Pumpe, wobei der Regelstift fest angeordnet ist. Ein gegen die Kraft einer Feder durch den Differenzdruck verschiebbarer Kolben umgibt den Regelstift und bildet mit diesem die veränderbare Regelblende. Damit sich die Drosseleinrichtung kostengünstig auch in bereits vorhandene Pumpen einbauen läßt, führt man diese vorteilhaft als Einpreß- oder Schraubpatrone aus. Zur einfachen Bauweise trägt weiterhin bei, daß der Regelstift in einem in die Patrone eingepreßten Führungsteil gehalten ist. Zur Erzielung einer fallenden Kennlinie sieht man eine kegelige Steuerkontur des Regelstiftes vor. Die Steuerkontur kann in weiterer Ausgestaltung der Erfindung auch konkav oder konvex geformt sein. Während man durch die kegelige Steuerkontur eine stetig fallende Kennlinie erzeugt, erhält man durch die konkave Ausführung einen überproportional und durch die konvexe einen unterproportional fallenden Kennlinienverlauf. Eine stufenförmige Steuerkontur mit einem größten Durchmesser im hinteren Bereich ergibt eine stufenförmig fallende Kennlinie.This object is solved by the features of claim 1. Claims 2 to 6 contain advantageous embodiments of the invention. The function of the throttle device is independent of the flow control piston in the pressure outlet the pump, the control pin being fixed. A piston that can be moved against the force of a spring by the differential pressure surrounds the control pin and forms the variable control orifice with it. So that the throttle device can also be inexpensively installed in already existing pumps, it is advantageously carried out as a press-in or screw-in cartridge. The simple construction also contributes to the fact that the control pin is held in a guide part pressed into the cartridge. To achieve a falling characteristic curve, a conical control contour of the control pin is provided. In a further embodiment of the invention, the control contour can also have a concave or convex shape. While the tapered control contour produces a continuously falling characteristic curve, the concave design results in a disproportionately low and the convex curve a disproportionately falling curve. A step-shaped control contour with a largest diameter in the rear area results in a step-wise falling characteristic.

Ein Ausführungsbeispiel der Erfindung ist anhand der Zeichnung näher erläutert.
Es zeigen:

Fig. 1
eine Flügelzellenpumpe mit einer Regeleinrichtung im Längsschnitt und
Fig. 2
einen vergrößerten Schnitt nach der Linie II-II in Fig. 1.
An embodiment of the invention is explained in more detail with reference to the drawing.
Show it:
Fig. 1
a vane pump with a control device in longitudinal section and
Fig. 2
an enlarged section along the line II-II in Fig. 1st

In einem durch einen Deckel 1 verschlossenen Gehäuse 2 ist eine Antriebswelle 3 gelagert. Die Antriebswelle 3 trägt in üblicher Weise auf einer Keilverzahnung einen Rotor 4.A drive shaft 3 is mounted in a housing 2 closed by a cover 1. The drive shaft 3 carries a rotor 4 in a conventional manner on a spline.

In radialen Schlitzen des Rotors 4 sind radial bewegliche Flügel 5 geführt, die in einem Kurvenring 6 dichtend entlanggleiten. Eine Druckplatte 7 liegt dichtend an dem aus Rotor 4, Flügeln 5 und Kurvenring 6 bestehenden Pumpenpaket an. Eine weitere Druckplatte 8 liegt durch die Kraft einer Feder 10 gleichfalls am Pumpenpaket an. Die Flügel 5 schließen nicht sichtbare Förderkammern zwischen sich ein, die mit einem Sauganschluß 11 in Verbindung stehen. Das geförderte Drucköl tritt aus den Förderkammern über ebenfalls nicht sichtbare Drucköffnungen der Druckplatte 8 in eine Druckkammer 12 ein. Die Druckkammer 12 hat über teilringförmige Kanäle 13 und 14 mit Unterflügelräumen 15 und 16 Verbindung. Dadurch ist es möglich, die jeweils die Druckzone durchlaufenden Flügel nach außen in den Kurvenring 6 zu drücken.Radially movable vanes 5 are guided in radial slots of the rotor 4 and slide along them sealingly in a cam ring 6. A pressure plate 7 lies sealingly on the pump package consisting of rotor 4, blades 5 and cam ring 6. Another pressure plate 8 is also due to the force of a spring 10 on the pump package. The wings 5 enclose not visible delivery chambers between them, which are connected to a suction port 11. The pumped pressure oil enters a pressure chamber 12 via the pressure openings 8 of the pressure plate 8, which are also not visible. The pressure chamber 12 has part-annular channels 13 and 14 with under wing spaces 15 and 16 connection. This makes it possible to press the vanes passing through the pressure zone outwards into the cam ring 6.

In einer Gehäusebohrung 17 im unteren Teil der Pumpe sind gleichachsig zueinander ein Stromregelventil 18 und eine Drosseleinrichtung 20 eingebaut. Ein Kolben 21 des Stromregelventils 18 steuert in bekannter Weise mit einem Steuerbund 22 einen Einlaßkanal 23. In der gezeichneten Ausgangsstellung liegt der Steuerbund 22 unter Belastung einer Feder 24 an der Drosseleinrichtung 20 an. Der Einlaßkanal 23 ist dabei durch den Steuerbund 22 verschlossen. Ein rechts von dem Steuerbund liegender Bohrungsabschnitt 17A, der zugleich den Druckausgang darstellt, ist an den Einlaßkanal 23 anschließbar. In dem Bohrungsabschnitt 17A sitzt eine mit einem Verbraucher, zum Beispiel einer Hilfskraftlenkung, verbundene Rohrverschraubung 25. Ein Zulaufkanal 26 schließt die Druckkammer 12 an den Bohrungsabschnitt 17A an.In a housing bore 17 in the lower part of the pump, a flow control valve 18 and a throttle device 20 are installed coaxially with one another. A piston 21 of the flow control valve 18 controls, in a known manner, an inlet channel 23 with a control collar 22 Starting position, the control collar 22 rests against the throttle device 20 under the load of a spring 24. The inlet channel 23 is closed by the control collar 22. A bore section 17A to the right of the control collar, which also represents the pressure outlet, can be connected to the inlet channel 23. In the bore section 17A there is a pipe screw connection 25 connected to a consumer, for example an auxiliary power steering system. An inlet channel 26 connects the pressure chamber 12 to the bore section 17A.

Die Erfindung besteht darin, daß die Drosseleinrichtung 20 als Einpreß- oder Schraubpatrone 27 ausgeführt ist, die einen Regelstift 28 und einen den Regelstift umgebenden Drosselkolben 30 enthält. Der Drosselkolben 30 stützt sich in seiner Ausgangsstellung unter der Kraft einer Feder an einem Anschlag 32 ab. Der Regelstift 28 ist in einem Führungsteil 33 gehalten, das auch die Feder 31 abstützt. Fig. 2 zeigt das Führungsteil 33 als schmalen Steg, der in die Patrone 27 eingepreßt ist. Auf diese Weise bleibt seitlich genügend Freiraum für den Öldurchtritt. Der Regelstift 28 hat in der gezeichneten Ausführung als Steuerkontur einen kegeligen Mittelabschnitt 34. Der Mittelabschnitt kann je nach gewünschter Kennlinie jedoch auch gestuft, konvex oder konkav gekrümmt sein. Darüber hinaus sind noch andere Steuerkonturen denkbar.The invention is that the throttle device 20 is designed as a press-in or screw cartridge 27, which contains a control pin 28 and a throttle piston 30 surrounding the control pin. The throttle piston 30 is supported in its starting position under the force of a spring on a stop 32. The control pin 28 is held in a guide part 33 which also supports the spring 31. Fig. 2 shows the guide member 33 as a narrow web which is pressed into the cartridge 27. In this way there is enough space on the side for oil to pass through. In the embodiment shown, the control pin 28 has a conical central section 34 as the control contour. Depending on the desired characteristic curve, however, the central section can also be stepped, convex or concave. Other control contours are also conceivable.

Ein die Feder 24 des Stromregelkolbens 21 aufnehmender Raum 35 steht über eine gestrichelt angedeutete Steuerleitung 36, eine Ringnut 37 und eine Drosselstelle 38 mit einem Auslaß 40 der Rohrverschraubung 25 in Verbindung.A space 35 receiving the spring 24 of the flow control piston 21 is connected to an outlet 40 of the pipe screw connection 25 via a control line 36 indicated by a broken line, an annular groove 37 and a throttle point 38.

Die Regeleinrichtung arbeitet wie folgt: Der gesamte Förderstrom der Pumpe fließt über den Zulaufkanal 26 in den Bohrungsabschnitt 17A. Bis zum Abregelpunkt bei einer Pumpendrehzahl von zum Beispiel 1 000 min-1 fließt der Förderstrom an der Stirnseite des Steuerbundes 22 vorbei zum Auslaß 40. Der Förderstrom entspricht dem gezeichneten Durchtrittsquerschnitt zwischen dem Regelstift 28 und dem Drosselkolben 32. Dabei verstellt sich der Stromregelkolben 21 geringfügig nach links, wobei der Steuerbund 22 jedoch noch nicht mit dem Öffnen des Einlaßkanals 23 beginnt.The control device works as follows: The entire delivery flow of the pump flows via the inlet channel 26 into the bore section 17A. Up to the cut-off point at a pump speed of, for example 1 000 min -1 the flow flows past the front of the control collar 22 over to the outlet 40. The flow corresponds to the cross section drawn between the control pin 28 and the throttle piston 32. The flow control piston 21 adjusts slightly to the left, but the control collar 22 still does not begin with the opening of the inlet channel 23.

Sobald der Abregelpunkt erreicht ist und die Pumpendrehzahl weiter ansteigt, überwindet die auf die Stirnseite des Steuerbundes 22 wirkende Druckkraft die gemeinsame Kraft aus der Feder 24 plus der Kraft des Druckes auf die gegenüberliegende Stirnseite im Raum 35. Der im Bohrungsabschnitt 17A wirkende Differenzdruck verschiebt den Stromregelkolben 21 nach links, bis ein Teil des Förderstromes über den Einlaßkanal 23 zur Saugseite abströmen kann.As soon as the cut-off point is reached and the pump speed increases further, the pressure force acting on the end face of the control collar 22 overcomes the common force from the spring 24 plus the force of the pressure on the opposite end face in the space 35. The differential pressure acting in the bore section 17A displaces the flow control piston 21 to the left until part of the flow can flow out through the inlet channel 23 to the suction side.

Da der Förderstrom mit der Drehzahl proportional ansteigt, erzeugt dieser über den Drosselkolben 30 einen entsprechend ansteigenden Differenzdruck, der den Kolben 30 gegen die Kraft der Feder 31 verschiebt. Dabei verkleinert sich der Durchtrittsquerschnitt zwischen dem Kolben 30 und dem kegeligen Mittelabschnitt 34 stetig. Dies hat zur Folge, daß der Differenzdruck weiter wächst und dadurch der Steuerbund 22 einen entsprechend größeren Abregelquerschnitt zum Einlaßkanal 23 freigibt. Auf diese Weise erzielt man mit der dargestellten Ausführung eine fallende Kennlinie des Verbrauchernutzstromes am Auslaß 40.Since the flow increases proportionally with the speed, it generates a correspondingly increasing differential pressure via the throttle piston 30, which pushes the piston 30 against the force of the spring 31. The passage cross section between the piston 30 and the tapered central section 34 is steadily reduced. The result of this is that the differential pressure continues to increase and the control collar 22 thereby releases a correspondingly larger regulating cross section to the inlet duct 23. In this way, a falling characteristic of the consumer useful flow at outlet 40 is achieved with the embodiment shown.

BezugszeichenReference numerals

11
Deckelcover
22nd
Gehäusecasing
33rd
Antriebswelledrive shaft
44th
Rotorrotor
55
Flügelwing
66
KurvenringCurve ring
77
Druckplatteprinting plate
88th
Druckplatteprinting plate
99
--
1010th
Federfeather
1111
SauganschlußSuction connection
1212th
DruckkammerPressure chamber
1313
teilringförmiger Kanalpartially annular channel
1414
teilringförmiger Kanalpartially annular channel
1515
UnterflügelraumLower wing room
1616
UnterflügelraumLower wing room
1717th
GehäusebohrungHousing bore
17A17A
Bohrungsabschnitt (Druckausgang)Bore section (pressure outlet)
1818th
StromregelventilFlow control valve
1919th
--
2020th
DrosseleinrichtungThrottle device
2121
Kolbenpiston
2222
SteuerbundTax union
2323
EinlaßkanalInlet duct
2424th
Federfeather
2525th
RohrverschraubungPipe fitting
2626
ZulaufkanalInlet channel
2727
EinpreßpatronePress-in cartridge
2828
RegelstiftControl pin
2929
--
3030th
DrosselkolbenThrottle piston
3131
Federfeather
3232
Anschlagattack
3333
FührungsteilGuide part
3434
kegeliger Mittelabschnittconical middle section
3535
Raumroom
3636
SteuerleitungControl line
3737
RingnutRing groove
3838
DrosselstelleThrottling point
3939
--
4040
AuslaßOutlet

Claims (6)

  1. A control device for positive-displacement pumps, more particularly vane pumps, having the following features:
    - a pressure chamber (12) is connected via a throttle device (20) to an outlet (40) connected to a consumer;
    - an end face of a flow regulating piston (21), which is displaceable in a housing bore (17), seals off a bore section (17A) which is in communication with the pressure chamber (12);
    - a further end face of the flow regulating piston (21) seals off a chamber (35) which is connected to the outlet (40);
    - as a function of a differential pressure acting on the two end faces, the flow regulating piston (21) releases a connection from the pressure chamber (12) to an inlet duct (23);
    - a control rod (28) extends in a fixed bushing (27) on the pressure outlet side, the control contour of the control rod being designed in such a manner that it cooperates with an opening to provide a variable through cross section (control orifice),
    characterised by the following features:
    - the throttle device sits in the bore section (pressure outlet) (17A) of the pump in which the control rod (28) is fixedly arranged, the throttle device being independent in its function of the flow regulating piston (21);
    - a throttle piston (30), which is displaceable into the fixed bushing (27) by the differential pressure against the force of a spring (31), encloses the control rod (28) and forms the variable control orifice therewith.
  2. A control device according to claim 1, characterised in that the throttle device (20) is constructed as a press-in or screw cartridge (27).
  3. A control device according to claim 1, characterised in that the control rod (28) is held in a guide element (33) which is pressed into the cartridge (27).
  4. A control device according to claim 1, characterised in that the control contour of the control rod (28) is conical.
  5. A control device according to claim 1, characterised in that the control contour of the control rod (28) is stepped.
  6. A control device according to claim 1, characterised in that the control contour of the control rod (28) is concave or convex.
EP92113259A 1991-08-08 1992-08-04 Control arrangement for positive displacement pumps Expired - Lifetime EP0528254B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE4126217 1991-08-08
DE4126217A DE4126217A1 (en) 1991-08-08 1991-08-08 CONTROL DEVICE FOR DISPLACEMENT PUMPS

Publications (3)

Publication Number Publication Date
EP0528254A2 EP0528254A2 (en) 1993-02-24
EP0528254A3 EP0528254A3 (en) 1993-10-20
EP0528254B1 true EP0528254B1 (en) 1996-11-13

Family

ID=6437898

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92113259A Expired - Lifetime EP0528254B1 (en) 1991-08-08 1992-08-04 Control arrangement for positive displacement pumps

Country Status (2)

Country Link
EP (1) EP0528254B1 (en)
DE (2) DE4126217A1 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4335376A1 (en) * 1993-10-16 1995-04-20 Luk Fahrzeug Hydraulik Valve arrangement
DE4426652C1 (en) * 1994-07-15 1995-11-23 Luk Fahrzeug Hydraulik Valve fitting
DE19652420A1 (en) * 1996-12-09 1998-06-10 Luk Fahrzeug Hydraulik Flow control arrangement for a hydraulic conveyor
DE19832719B4 (en) * 1998-07-21 2006-10-26 Zf Friedrichshafen Ag Vane pump
DE10233579A1 (en) * 2002-07-24 2004-02-05 Zf Lenksysteme Gmbh Impeller pump flow regulation valve has a control spring with lengths having different spring constants so that the pump characteristic curve is linear, even at high flow rates

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB510737A (en) * 1937-08-23 1939-08-08 Maschb Ag Improvements in or relating to stepless discharge control of piston compressors
US3359913A (en) * 1965-10-22 1967-12-26 Chrysler Corp Hydraulic pump
GB1356906A (en) * 1971-10-08 1974-06-19 Ford Motor Co Rotary positive displacement pump
DE2704754A1 (en) * 1977-02-04 1978-08-17 Speck Kolbenpumpen Fabrik VALVE ARRANGEMENT
US4251193A (en) * 1979-09-27 1981-02-17 General Motors Corporation Flow control valve

Also Published As

Publication number Publication date
DE4126217A1 (en) 1993-02-11
EP0528254A2 (en) 1993-02-24
DE59207514D1 (en) 1996-12-19
EP0528254A3 (en) 1993-10-20

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