EP0445529A1 - Hydraulic device - Google Patents

Hydraulic device Download PDF

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Publication number
EP0445529A1
EP0445529A1 EP19910101440 EP91101440A EP0445529A1 EP 0445529 A1 EP0445529 A1 EP 0445529A1 EP 19910101440 EP19910101440 EP 19910101440 EP 91101440 A EP91101440 A EP 91101440A EP 0445529 A1 EP0445529 A1 EP 0445529A1
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EP
European Patent Office
Prior art keywords
pressure
line
gear
sealing plate
control
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP19910101440
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German (de)
French (fr)
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EP0445529B1 (en
Inventor
Dieter Dipl.-Ing. Weigle
Gottfried Dipl.-Ing. Olbrich
Hayno Dipl.-Ing. Rustige
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication of EP0445529A1 publication Critical patent/EP0445529A1/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
    • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/24—Control 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
    • F04C14/26—Control 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
    • F04C14/265—Control 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 being obtained by displacing a lateral sealing face

Definitions

  • the invention relates to a hydraulic system with a gear pump regulating its flow.
  • the load pressure which prevails at a consumer directly acts on a pressure field which acts on the sealing plate.
  • Such control of the sealing plate is not particularly precise.
  • the hydraulic system with the characterizing feature of the main claim has the advantage that the delivery rate of the gear pump used in the hydraulic system can be controlled very precisely. Further advantages result from the subclaims.
  • FIG. 1 a hydraulic system in a schematic representation
  • Figure 2 a modification of the embodiment of Figure 1
  • Figure 3 an application in a gear motor
  • Figure 4 another variant
  • Figure 5 a longitudinal section through a gear pump
  • Figure 6 a section along II- II according to FIG. 5.
  • 10 denotes a gear pump, which sucks pressure medium out of a container 12 via a suction line 11 and displaces it into a delivery line 13.
  • Several directional control valves 14, 15 can be connected to the delivery line, of which consumer lines 16, 17 lead to consumers 18 and not shown.
  • Each directional valve has a metering orifice 19 or 20 on the control slide, which are connected to chambers (not shown) to which a control line 21 is connected.
  • a control line 23 is connected to the delivery line 13, which leads to the one end face 24 A of a pressure compensator 24.
  • a branch line 25 branches off from the control line 21 and penetrates into a control line 26, which on the one hand opens at the end face 24 B of the pressure compensator 24 opposite the end face 24 A, and on the other hand at a pressure limiting valve 27.
  • a control spring 28 also acts on the end face 24 B.
  • a line 29 branches off from the control line 23, which opens into a line 30 which leads from the pressure compensator 24 to the gear pump and opens there at a sealing plate 31, which is discussed in more detail further on.
  • a throttle 32 is arranged in line 29.
  • a return line 34 leads from the interior of the gear pump 10 to the container.
  • the outlet line 35 emanating from the pressure compensator 24 also opens into this return line, into which the outlet line 36 of the pressure limiting valve 27 in turn penetrates.
  • a throttle 37 is arranged in the control line 21 before the line branch 25.
  • the pressure compensator closes due to the signal pressure in line 21, which corresponds to that in line 13, so that no pressure medium can flow from the line 30 into the return line 35 via the pressure compensator 24.
  • the pressure prevailing in the lines 13, 23, 29 and 30 presses the sealing plate 31 against the gear side surfaces, that is to say no pressure medium can flow out from the inside of the high pressure side to the low pressure side of the gear pump.
  • the pressure in the delivery line 13 and the consumer line 16 now increases, and the load pressure at the consumer, that is to say that behind the throttle 19, is transmitted via the control line 21 to the end face 24 B of the pressure compensator.
  • the pressure compensator opens, whereupon the pressure in the line 30 drops, that is to say a control pressure for the sealing plate 31 is formed in this line, but which is designed so that it is significantly lower than the pressure in line 23. If there is a pressure of 153 bar in the delivery line, for example, a pressure of 150 bar in control line 21 - the pressure difference arises at throttle 19 - so forms the pressure compensator in line 30, for example, a pressure of 120 bar. In this way, a pressure drop in line 30 is obtained, which contributes to improving the control sensitivity.
  • the pressure relief valve 27 is a maximum pressure valve. If, for example, the maximum pressure in the hydraulic system is reached and the pressure relief valve 27 opens, the pressure compensator 24 immediately goes into the open position and thus relieves the pressure on the sealing plate 31 completely, so that all pressure medium conveyed by the gear pump 10 immediately flows from the high pressure to the low pressure side . So you get an internal pressure limitation.
  • the throttle 37 is used to generate differential pressure for the pressure compensator control.
  • Figure 2 differs from the above only in that it is a hydraulic system in which directional control valves are used in an open-center construction. In principle, however, this system works in the same way.
  • the pressure compensator does not work to control the current for the consumer 18, but only as a maximum pressure limitation together with the pilot valve 27.
  • the embodiment according to FIG. 3 is to a certain extent the reverse of the examples mentioned above, that is to say here a flow control of a gear motor with a sealing plate and pressure compensator takes place.
  • the pressure difference required for the control is generated by an adjustable throttle 40, which is in the return line 41 is arranged from the gear motor 42 to the container.
  • the pressure drop across the throttle 40 acts on the pressure compensator 24.
  • the control pressure is generated in a line 45 which is connected to a line 29 which starts from the pressure line, specifically at a point upstream of the throttle 32
  • the pressure compensator is controlled via the throttle 40 so that there is a low control pressure in the control line 45 when the pressure compensator is open, so that the sealing plate 31 has lifted off the gear side surfaces.
  • the exemplary embodiment according to FIG. 4 differs from the previous one in that two gear pumps 10, 50 are provided which are driven by a common shaft.
  • the sealing plate 31 is arranged on the gear pump 50, which is connected via its delivery line 51 to the delivery line 13 of the pump 10.
  • the directional control valves 14, 15 are again designed as in the exemplary embodiment according to FIG. 1, where the load pressure-carrying control line 52 is brought to a pressure compensator 53, the other side of which is acted upon via a line 54 connected to the delivery line 13.
  • a control line 55 leads from the pressure compensator 53 to the sealing plate 31.
  • FIGS. 5 and 6 show the gear pump 10 used in the hydraulic system. However, this is not shown in all its constructive details. It has a housing 60 which is closed on both sides by covers 61, 62. In the interior of the housing, two gearwheels 63, 64 mesh with one another in external engagement, the shafts 65, 66 of which are arranged in bearing bodies 67, 68. Between the bearing body 68 and the gear wheels, the sealing plate 31 is arranged, which has the contour of the interior and covers the gear wheels. The bearing body 67, 68 and the sealing plate 31 and also the gears are mounted in the housing 60 with little axial play.
  • two pressure fields A and B are formed, of which the pressure field A is continuously acted upon by high pressure, which prevails in a housing bore 70 which penetrates from the outside into a recess 71 at the level of the gearwheels, which extends along of the housing interior extends.
  • the high-pressure side HD to which the delivery line 13 is connected is located at the bore 70.
  • a bore 72 is formed in the housing, which opens into a recess 73, which likewise runs along the interior.
  • the bore 72 is the low-pressure side ND, from which the line 11 leads to the container 12, from which the gear pump sucks in pressure medium.
  • the pressure field B is the controlled pressure field to which the line 30 according to FIG. 1 is connected. It is identified in FIG. 6 as a short, dot-dash hole.
  • the sealing plate can be pressed onto the gearwheels 63, or when the pressure field B is relieved, the sealing plate 31 is lifted off the gearwheels, since the high pressure of the machine prevails below it.
  • the sealing plate is somewhat movable in the axial direction. When it has lifted off the gearwheel side surfaces, the pumped pressure medium flows directly from the high pressure side HD along the gearwheels and below the sealing plate to the tank side. The gear pump then delivers in neutral circulation.

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

Abstract

The hydraulic device has a gear pump (10), the delivery flow of which can be controlled with the aid of a sealing plate (31) which can be placed against the side faces of the gear. This is effected with the aid of a control pressure produced by a pressure balance (24) which is subjected, on the one hand, to the delivery pressure of the pump and, on the other hand, for example, to the load pressure at loads. An internal bypass which depends on the distance between the sealing plate and the side faces of the gear and effects control of the delivery rate is created. <IMAGE>

Description

Stand der TechnikState of the art

Die Erfindung betrifft eine Hydraulikanlage mit einer ihren Förderstrom regelnden Zahnradpumpe. Bei einer derartigen bekannten Pumpe beaufschlagt der Lastdruck, welcher an einem Verbraucher herrscht, unmittelbar ein Druckfeld, welches auf die Dichtplatte einwirkt. Eine derartige Steuerung der Dichtplatte ist nicht besonders genau.The invention relates to a hydraulic system with a gear pump regulating its flow. In such a known pump, the load pressure which prevails at a consumer directly acts on a pressure field which acts on the sealing plate. Such control of the sealing plate is not particularly precise.

Vorteile der ErfindungAdvantages of the invention

Die Hydraulikanlage mit dem kennzeichnenden Merkmal des Hauptanspruchs hat demgegenüber den Vorteil, daß die Fördermenge der in der Hydraulikanlage verwendeten Zahnradpumpe sehr genau geregelt werden kann. Weitere Vorteile ergeben sich aus den Unteransprüchen.The hydraulic system with the characterizing feature of the main claim has the advantage that the delivery rate of the gear pump used in the hydraulic system can be controlled very precisely. Further advantages result from the subclaims.

Zeichnungdrawing

Ausführungsbeispiele der Erfindung sind in der nachfolgenden Beschreibung und Zeichnung wiedergegeben. Letztere zeigt in Figur 1 eine Hydraulikanlage in schematischer Darstellung, in Figur 2 eine Abwandlung des Ausführungsbeispiels nach Figur 1, in Figur 3 eine Anwendung bei einem Zahnradmotor, in Figur 4 eine weitere Variante, in Figur 5 einen Längsschnitt durch eine Zahnradpumpe und in Figur 6 einen Schnitt längs II-II nach Figur 5.Exemplary embodiments of the invention are shown in the following description and drawing. The latter is shown in FIG. 1 a hydraulic system in a schematic representation, in Figure 2 a modification of the embodiment of Figure 1, in Figure 3 an application in a gear motor, in Figure 4 another variant, in Figure 5 a longitudinal section through a gear pump and in Figure 6 a section along II- II according to FIG. 5.

Beschreibung der AusführungsbeispieleDescription of the embodiments

In Figur 1 ist mit 10 eine Zahnradpumpe bezeichnet, die Druckmittel über eine Saugleitung 11 aus einem Behälter 12 ansaugt und dieses in eine Förderleitung 13 verdrängt. An die Förderleitung können mehrere Wegeventile 14, 15 angeschlossen sein, von denen Verbraucherleitungen 16, 17 zu Verbrauchern 18 und nicht weiter dargestellten führen. Jedes Wegeventil hat am Steuerschieber in bekannter Weise eine Meßblende 19 bzw. 20, welche mit nicht weiter dargestellten Kammern in Verbindung stehen, an die eine Steuerleitung 21 angeschlossen ist. An die Förderleitung 13 ist eine Steuerleitung 23 angeschlossen, welche an die eine Stirnseite 24 A einer Druckwaage 24 heranführt. Von der Steuerleitung 21 zweigt eine Stichleitung 25 ab, die in eine Steuerleitung 26 eindringt, welche einerseits an der der Stirnseite 24 A gegenüberliegenden Stirnseite 24 B der Druckwaage 24 mündet, andererseits an einem Druckbegrenzungsventil 27. Auf die Stirnseite 24 B wirkt auch eine Regelfeder 28 ein. Von der Steuerleitung 23 zweigt eine Leitung 29 ab, welche in eine Leitung 30 mündet, die von der Druckwaage 24 zur Zahnradpumpe führt und dort an einer Dichtplatte 31 mündet, auf welche weiter hinten näher eingegangen ist. In der Leitung 29 ist eine Drossel 32 angeordnet. Vom Innenraum der Zahnradpumpe 10 führt eine Rückleitung 34 zum Behälter. In diese Rückleitung mündet auch die von der Druckwaage 24 ausgehende Ablaufleitung 35, in welche wiederum die Ablaufleitung 36 des Druckbegrenzungsventils 27 eindringt. In der Steuerleitung 21 ist vor der Leitungsabzweigung 25 noch eine Drossel 37 angeordnet.In FIG. 1, 10 denotes a gear pump, which sucks pressure medium out of a container 12 via a suction line 11 and displaces it into a delivery line 13. Several directional control valves 14, 15 can be connected to the delivery line, of which consumer lines 16, 17 lead to consumers 18 and not shown. Each directional valve has a metering orifice 19 or 20 on the control slide, which are connected to chambers (not shown) to which a control line 21 is connected. A control line 23 is connected to the delivery line 13, which leads to the one end face 24 A of a pressure compensator 24. A branch line 25 branches off from the control line 21 and penetrates into a control line 26, which on the one hand opens at the end face 24 B of the pressure compensator 24 opposite the end face 24 A, and on the other hand at a pressure limiting valve 27. A control spring 28 also acts on the end face 24 B. a. A line 29 branches off from the control line 23, which opens into a line 30 which leads from the pressure compensator 24 to the gear pump and opens there at a sealing plate 31, which is discussed in more detail further on. A throttle 32 is arranged in line 29. A return line 34 leads from the interior of the gear pump 10 to the container. The outlet line 35 emanating from the pressure compensator 24 also opens into this return line, into which the outlet line 36 of the pressure limiting valve 27 in turn penetrates. A throttle 37 is arranged in the control line 21 before the line branch 25.

Wenn die Pumpe 10 eingeschaltet wird und wenn sich die Wegeventile 14, 15 in Neutralstellung befinden, fließt das geförderte Druckmittel über die von den Zahnrädern abgehobene Dichtplatte 31 und Leitung 34 zurück zum Behälter. Die Druckwaage ist dabei über die Leitung 21 (Y) entlastet, so daß die Pumpe nur gegen einen sehr geringen Druck fördert.When the pump 10 is switched on and when the directional control valves 14, 15 are in the neutral position, the pumped pressure medium flows back to the container via the sealing plate 31 and line 34 lifted off the gear wheels. The pressure compensator is relieved via line 21 (Y) so that the pump delivers only against a very low pressure.

Wird beispielsweise das Wegeventil 14 zugeschaltet, dann schließt die Druckwaage durch den Signaldruck in Leitung 21, der dem in Leitung 13 entspricht, so daß aus der Leitung 30 kein Druckmittel über die Druckwaage 24 in die Rückleitung 35 fließen kann. Der in den Leitungen 13, 23, 29 und 30 herrschende Druck drückt die Dichtplatte 31 an die Zahnradseitenflächen, das heißt es kann kein Druckmittel im Inneren von der Hochdruckseite zur Niederdruckseite der Zahnradpumpe abströmen. Dadurch steigt nun der Druck in der Förderleitung 13 und der Verbraucherleitung 16, und der Lastdruck am Verbraucher, das heißt derjenige hinter der Drossel 19, wird über die Steuerleitung 21 auf die Stirnseite 24 B der Druckwaage übertragen. Übersteigt die Druckkraft einschließlich der Kraft der Ringfeder 28 die Druckkraft aus der Druckleitung 23 auf die Stirnseite 24 A, so öffnet sich die Druckwaage, worauf der Druck in der Leitung 30 absinkt, das heißt in dieser Leitung wird ein Steuerdruck für die Dichtplatte 31 gebildet, der aber so ausgelegt ist, daß er wesentlich niedriger ist als der Druck in der Leitung 23. Herrscht in der Förderleitung beispielsweise ein Druck von 153 bar, in der Steuerleitung 21 ein Druck von 150 bar - die Druckdifferenz entsteht an der Drossel 19 - so bildet die Druckwaage in der Leitung 30 beispielsweise einen Druck von 120 bar. Auf diese Weise erhält man eine Druckabsenkung in der Leitung 30, was zur Verbesserung der Steuerempfindlichkeit beiträgt. Entsprechend der Steuerschiebereinstellung und damit dem geöffneten Querschnitt der Blende 19 wird nun stets in der Leitung 30 ein solcher Druck gebildet, daß die Dichtplatte 31 entweder an den Zahnradseitenflächen anliegt oder etwas von diesen abgehoben wird. In letzterem Falle kann Druckmittel unmittelbar von der Hochdruck- zur Niederdruckseite abströmen. Daraus ist zu erkennen, daß man hiermit auf einfachste Weise, das heißt mit nur einer Druckwaage und einer Dichtplatte 31, eine exakte Förderstromregelung einer Zahnradpumpe erhält. Das intern in diese abströmende Druckmittel fließt über die Leitung 34 zum Behälter 12. Die Drossel 32 dient zur Begrenzung des der Druckwaage zu- bzw. an dieser abfließenden Druckmittels.For example, if the directional control valve 14 is switched on, the pressure compensator closes due to the signal pressure in line 21, which corresponds to that in line 13, so that no pressure medium can flow from the line 30 into the return line 35 via the pressure compensator 24. The pressure prevailing in the lines 13, 23, 29 and 30 presses the sealing plate 31 against the gear side surfaces, that is to say no pressure medium can flow out from the inside of the high pressure side to the low pressure side of the gear pump. As a result, the pressure in the delivery line 13 and the consumer line 16 now increases, and the load pressure at the consumer, that is to say that behind the throttle 19, is transmitted via the control line 21 to the end face 24 B of the pressure compensator. If the pressure force, including the force of the ring spring 28, exceeds the pressure force from the pressure line 23 to the end face 24 A, the pressure compensator opens, whereupon the pressure in the line 30 drops, that is to say a control pressure for the sealing plate 31 is formed in this line, but which is designed so that it is significantly lower than the pressure in line 23. If there is a pressure of 153 bar in the delivery line, for example, a pressure of 150 bar in control line 21 - the pressure difference arises at throttle 19 - so forms the pressure compensator in line 30, for example, a pressure of 120 bar. In this way, a pressure drop in line 30 is obtained, which contributes to improving the control sensitivity. According to the spool setting and thus the open cross-section of the aperture 19, such a pressure is now always formed in the line 30 that the sealing plate 31 either bears on the side faces of the gearwheels or some of them is lifted off. In the latter case, pressure medium can flow off directly from the high pressure to the low pressure side. From this it can be seen that in the simplest way, that is to say with only one pressure compensator and a sealing plate 31, an exact flow rate control of a gear pump is obtained. The pressure medium flowing internally into this flows via the line 34 to the container 12. The throttle 32 serves to limit the pressure medium flowing to and from the pressure compensator.

Das Druckbegrenzungsventil 27 ist ein Maximaldruckventil. Ist beispielsweise der maximale Druck in der Hydraulikanlage erreicht und öffnet das Druckbegrenzungsventil 27, so geht auch sofort die Druckwaage 24 in geöffnete Stellung und entlastet damit die Dichtplatte 31 vollständig, so daß sämtliches von der Zahnradpumpe 10 geförderte Druckmittel sofort von der Hochdruck- zur Niederdruckseite abströmt. Damit erhält man also eine interne Druckbegrenzung. Die Drossel 37 dient dabei der Differenzdruckerzeugung für die Druckwaagenansteuerung.The pressure relief valve 27 is a maximum pressure valve. If, for example, the maximum pressure in the hydraulic system is reached and the pressure relief valve 27 opens, the pressure compensator 24 immediately goes into the open position and thus relieves the pressure on the sealing plate 31 completely, so that all pressure medium conveyed by the gear pump 10 immediately flows from the high pressure to the low pressure side . So you get an internal pressure limitation. The throttle 37 is used to generate differential pressure for the pressure compensator control.

Das Ausführungsbeispiel nach Figur 2 unterscheidet sich von Obigem lediglich dadurch, daß es sich hier um eine Hydraulikanlage handelt, bei welcher Wegeventile in open-center-Konstruktion verwendet sind. Im Prinzip funktioniert jedoch diese Anlage auf dieselbe Weise.The embodiment of Figure 2 differs from the above only in that it is a hydraulic system in which directional control valves are used in an open-center construction. In principle, however, this system works in the same way.

Hier arbeitet die Druckwaage jedoch nicht zur Stromregelung für den Verbraucher 18, sondern nur als Maximaldruckbegrenzung zusammen mit dem Vorsteuerventil 27.Here, however, the pressure compensator does not work to control the current for the consumer 18, but only as a maximum pressure limitation together with the pilot valve 27.

Beim Ausführungsbeispiel nach Figur 3 handelt es sich gewissermaßen um die Umkehrung oben genannter Beispiele, das heißt hier findet eine Förderstromregelung eines Zahnradmotors mit Dichtplatte und Druckwaage statt. Die für die Regelung notwendige Druckdifferenz wird erzeugt durch eine verstellbare Drossel 40, welche in der Rückleitung 41 vom Zahnradmotor 42 zum Behälter angeordnet ist. Der Druckabfall an der Drossel 40 wirkt an der Druckwaage 24. Der Steuerdruck wird in einer Leitung 45 erzeugt, welche an eine Leitung 29 angeschlossen ist, die von der Druckleitung ausgeht, und zwar an einer Stelle stromaufwärts der Drossel 32. Um ein leichtes Anfahren des Zahnradmotors 42 zu erreichen, wird die Druckwaage über die Drossel 40 so gesteuert, daß in der Steuerleitung 45 bei geöffneter Druckwaage ein geringer Steuerdruck herrscht, so daß die Dichtplatte 31 sich von den Zahnradseitenflächen abgehoben hat. Diese übt nun keine Reibungskraft auf die Zahnräder aus, so daß der Zahnradmotor leicht anlaufen kann. Bei zunehmender Belastung des Zahnradmotors wird die Dichtplatte mehr und mehr an die Zahnradseitenflächen angelegt, so daß die interne Hochdruck- Niederdruckverbindung unterbrochen wird und der Zahnradmotor sein volles Drehmoment erreicht. Je nach den Bedingungen am Verbraucher bzw. Einstellung der Drossel 40 kann nun die Drehzahl des Zahnradmotors 42 mit Hilfe der Druckwaage 24 leicht geregelt werden.The embodiment according to FIG. 3 is to a certain extent the reverse of the examples mentioned above, that is to say here a flow control of a gear motor with a sealing plate and pressure compensator takes place. The pressure difference required for the control is generated by an adjustable throttle 40, which is in the return line 41 is arranged from the gear motor 42 to the container. The pressure drop across the throttle 40 acts on the pressure compensator 24. The control pressure is generated in a line 45 which is connected to a line 29 which starts from the pressure line, specifically at a point upstream of the throttle 32 To reach the gear motor 42, the pressure compensator is controlled via the throttle 40 so that there is a low control pressure in the control line 45 when the pressure compensator is open, so that the sealing plate 31 has lifted off the gear side surfaces. This now exerts no frictional force on the gears, so that the gear motor can start easily. With increasing load on the gear motor, the sealing plate is placed more and more on the gear side surfaces, so that the internal high-pressure low-pressure connection is interrupted and the gear motor reaches its full torque. Depending on the conditions on the consumer or the setting of the throttle 40, the speed of the gear motor 42 can now be easily controlled using the pressure compensator 24.

Das Ausführungsbeispiel nach Figur 4 weicht insofern gegenüber den vorherigen ab, als hier zwei Zahnradpumpen 10, 50 vorgesehen sind, die von einer gemeinsamen Welle angetrieben sind. Die Dichtplatte 31 ist an der Zahnradpumpe 50 angeordnet, die über ihre Förderleitung 51 an die Förderleitung 13 der Pumpe 10 angeschlossen ist. Die Wegeventile 14, 15 sind wiederum so ausgebildet wie im Ausführungsbeispiel nach Figur 1, wo die lastdruckführende Steuerleitung 52 an eine Druckwaage 53 herangeführt ist, deren andere Seite über eine an die Förderleitung 13 angeschlossene Leitung 54 beaufschlagt ist. Von der Druckwaage 53 führt eine Steuerleitung 55 an die Dichtplatte 31. Man erreicht auf diese Weise, daß die abschaltbare Zahnradpumpe 50 über die Dichtplatte 31 gesteuert wird, das heißt deren Fördermenge, und die das Steuersignal von der Druckwaage 53 erhält. Es handelt sich also um eine Anlage, in der die Pumpe 10 stets den vollen Förderstrom in die Anlage fördert, während die fördermengengeregelte Pumpe 50 je nach Bedarf vom Lasdrucksignal eine entsprechende Druckmittelmenge zusteuert, die zwischen Null und maixmal liegt.The exemplary embodiment according to FIG. 4 differs from the previous one in that two gear pumps 10, 50 are provided which are driven by a common shaft. The sealing plate 31 is arranged on the gear pump 50, which is connected via its delivery line 51 to the delivery line 13 of the pump 10. The directional control valves 14, 15 are again designed as in the exemplary embodiment according to FIG. 1, where the load pressure-carrying control line 52 is brought to a pressure compensator 53, the other side of which is acted upon via a line 54 connected to the delivery line 13. A control line 55 leads from the pressure compensator 53 to the sealing plate 31. In this way it is achieved that the gear pump 50 which can be switched off is controlled via the sealing plate 31, that is to say its delivery quantity, and which receives the control signal from the pressure compensator 53. It is therefore a system in which the pump 10 always delivers the full flow into the system, while the flow-regulated Pump 50 controls a corresponding amount of pressure medium from the laser pressure signal, which is between zero and maximum times, as required.

Die Ausführungsbeispiele nach den Figuren 5 und 6 zeigen die in der Hydraulikanlage verwendete Zahnradpumpe 10. Diese ist jedoch nicht in allen kontruktiven Einzelheiten gezeigt. Sie weist ein Gehäuse 60 auf, das beidseitig durch Deckel 61, 62 verschlossen ist. Im Inneren des Gehäuses kämmen zwei Zahnräder 63, 64 im Außeneingriff miteinander, deren Wellen 65, 66 in Lagerkörpern 67, 68 angeordnet sind. Zwischen dem Lagerkörper 68 und den Zahnrädern ist die Dichtplatte 31 angeordnet, welche die Kontur des Innenraums aufweist und die Zahnräder überdeckt. Die Lagerkörper 67, 68 sowie die Dichtplatte 31 und auch die Zahnräder sind mit geringem axialem Spiel im Gehäuse 60 gelagert. Zwischen der Dichtplatte 31 und dem Lagerkörper 68 sind zwei Druckfelder A und B ausgebildet von denen das Druckfeld A dauernd vom Hochdruck beaufschlagt ist, welcher in einer Gehäusebohrung 70 herrscht, welche in Höhe der Zahnräder von außen her in eine Ausnehmung 71 eindringt, welche sich entlang des Gehäuseinnenraums erstreckt. An der Bohrung 70 liegt die Hochdruckseite HD, an welche die Förderleitung 13 angeschlossen ist. Ihr gegenüber und achsgleich ist im Gehäuse eine Bohrung 72 ausgebildet, welche in eine Ausnehmung 73 mündet, welche ebenfalls entlang des Innenraums verläuft. Die Bohrung 72 ist die Niederdruckseite ND, von ihr führt die Leitung 11 zum Behälter 12, aus welcher die Zahnradpumpe Druckmittel ansaugt.The exemplary embodiments according to FIGS. 5 and 6 show the gear pump 10 used in the hydraulic system. However, this is not shown in all its constructive details. It has a housing 60 which is closed on both sides by covers 61, 62. In the interior of the housing, two gearwheels 63, 64 mesh with one another in external engagement, the shafts 65, 66 of which are arranged in bearing bodies 67, 68. Between the bearing body 68 and the gear wheels, the sealing plate 31 is arranged, which has the contour of the interior and covers the gear wheels. The bearing body 67, 68 and the sealing plate 31 and also the gears are mounted in the housing 60 with little axial play. Between the sealing plate 31 and the bearing body 68, two pressure fields A and B are formed, of which the pressure field A is continuously acted upon by high pressure, which prevails in a housing bore 70 which penetrates from the outside into a recess 71 at the level of the gearwheels, which extends along of the housing interior extends. The high-pressure side HD to which the delivery line 13 is connected is located at the bore 70. Opposite and axially aligned, a bore 72 is formed in the housing, which opens into a recess 73, which likewise runs along the interior. The bore 72 is the low-pressure side ND, from which the line 11 leads to the container 12, from which the gear pump sucks in pressure medium.

Das Druckfeld B ist das gesteuerte Druckfeld, an welches die Leitung 30 nach Figur 1 angeschlossen ist. Sie ist in Figur 6 als kurze strichpunktierte Bohrung gekennzeichnet. Durch entsprechende Beaufschlagung des Druckfelds B kann die Dichtplatte an die Zahnräder 63 angedrückt werden bzw. bei Entlastung des Druckfelds B wird die Dichtplatte 31 von den Zahnrädern abgehoben, da unterhalb dieser der Hochdruck der Maschine herrscht. Wie oben ausgeführt, ist die Dichtplatte in axialer Richtung etwas beweglich. Wenn sie von den Zahnradseitenflächen abgehoben hat, fließt das geförderte Druckmittel unmittelbar von der Hochdruckseite HD entlang der Zahnräder und unterhalb der Dichtplatte zur Tankseite. Die Zahnradpumpe fördert dann im Neutralumlauf. Je stärker die Dichtplatte an die Zahnräder angelegt wird, desto weniger Druckmittel kann diesen internen Kurzschluß benutzen und desto mehr des geförderten Druckmittels fließt in die Förderleitung 13. Auf diese und die oben geschilderte Weise erhält man also eine ziemlich exakte Förderstromregelung einer Zahnradpumpe bzw. Drehzahlregelung eines Zahnradmotors mit Hilfe einer ein Druckfeld steuernden Druckwaage.The pressure field B is the controlled pressure field to which the line 30 according to FIG. 1 is connected. It is identified in FIG. 6 as a short, dot-dash hole. By appropriately acting on the pressure field B, the sealing plate can be pressed onto the gearwheels 63, or when the pressure field B is relieved, the sealing plate 31 is lifted off the gearwheels, since the high pressure of the machine prevails below it. As stated above, the sealing plate is somewhat movable in the axial direction. When it has lifted off the gearwheel side surfaces, the pumped pressure medium flows directly from the high pressure side HD along the gearwheels and below the sealing plate to the tank side. The gear pump then delivers in neutral circulation. The more the sealing plate is applied to the gearwheels, the less pressure medium can use this internal short circuit and the more of the pressure medium pumped flows into the delivery line 13. In this and the manner described above, one obtains a pretty exact flow rate control of a gear pump or speed control of a Gear motor using a pressure compensator that controls a pressure field.

Claims (5)

Hydraulikanlage mit einer den Förderstrom regelnden Zahnradpumpe (10) mit Hilfe einer sich an die Zahnradseitenflächen anlegenden, axial geringfügig beweglichen und von einem Steuerdruck, insbesondere dem Lastdruck an Verbrauchern beaufschlagten Dichtplatte (31), die je nach Entfernung von den Zahnradseitenflächen einen mehr oder weniger großen Teil des von ihr erzeugten Förderstroms unmittelbar von der Hochdruck (HD) zur Niederdruckseite (ND) abströmen läßt, dadurch gekennzeichnet, daß parallel an die Förderleitung (13) der Zahnradpumpe eine Druckwaage (24) angeschlossen ist, die einerseits vom Förderdruck der Zahnradpumpe beaufschlagt ist, andererseits vom Steuerdruck bzw. Lastdruck von an die Förderleitung angeschlossenen Verbrauchern, wobei der Lastdruck in bekannter Weise an einer Steuerkante (19, 20) des dem betreffenden Verbraucher vorgeschalteten Wegeventils (14, 15) abgenommen wird, und daß die Druckwaage einen Steuerdruck zum Beaufschlagen der Dichtplatte erzeugt.Hydraulic system with a gear pump (10) that regulates the flow rate with the aid of a sealing plate (31) that lies axially slightly on the gear side surfaces and is acted upon by a control pressure, in particular the load pressure on consumers, which, depending on the distance from the gear side surfaces, has a more or less large one Part of the delivery flow generated by it can flow off directly from the high pressure (HD) to the low pressure side (LP), characterized in that a pressure compensator (24) is connected in parallel to the delivery line (13) of the gear pump, which is acted upon on the one hand by the delivery pressure of the gear pump , on the other hand from the control pressure or load pressure of consumers connected to the delivery line, the load pressure being removed in a known manner at a control edge (19, 20) of the directional control valve (14, 15) connected upstream of the consumer in question, and in that the pressure compensator applies a control pressure the sealing plate t. Anlage nach Anspruch 1, dadurch gekennzeichnet, daß der Druckwaage (24) ein Druckbegrenzungsventil (27) für Maximaldruckeinstellung zugeordnet ist.System according to claim 1, characterized in that the pressure compensator (24) is assigned a pressure relief valve (27) for maximum pressure adjustment. Anlage nach Anspruch 1 und/oder 2, dadurch gekennzeichnet, daß von der Druckwaage (24) eine Steuerleitung (30) zu einem Druckfeld (B) in der Zahnradpumpe führt, in welcher die Andrückkraft für die Dichtplatte (31) erzeugt wird.System according to claim 1 and / or 2, characterized in that a control line (30) leads from the pressure compensator (24) to a pressure field (B) in the gear pump, in which the pressing force for the sealing plate (31) is generated. Anlage nach Anspruch 1, dadurch gekennzeichnet, daß zwei Zahnradpumpen (10, 50) vorgesehen sind, von denen eine mit Hilfe der Dichtplatte (31) förderstromgeregelt ist und entsprechend den Anforderungen bzw. dem Lastdruck an Verbrauchern eine entsprechende Druckmittelmenge in den Hydraulikkreis einbringt, wobei die Druckwaage (53) in den Wegeventilblock integriert ist.System according to claim 1, characterized in that two gear pumps (10, 50) are provided, one of which is flow-regulated by means of the sealing plate (31) and introduces a corresponding quantity of pressure medium into the hydraulic circuit in accordance with the requirements or the load pressure on consumers, whereby the pressure compensator (53) is integrated in the directional valve block. Hydraulikanlage mit einem Zahnradmotor, dadurch gekennzeichnet, daß die Drehzahl des Zahnradmotors (42) mit Hilfe einer Dichtplatte (31) regelbar ist, die über eine Steuerleitung (45) von einer Druckwaage (24) gesteuert wird, und daß die Druckwaage (24) selbst wieder vom Differenzdruck einer verstellbaren Drossel (40) gesteuert ist, welche sich in der Rückleitung 41 des Zahnradmotors befindet.Hydraulic system with a gear motor, characterized in that the speed of the gear motor (42) can be regulated with the aid of a sealing plate (31) which is controlled by a pressure compensator (24) via a control line (45), and that the pressure compensator (24) itself is again controlled by the differential pressure of an adjustable throttle (40), which is located in the return line 41 of the gear motor.
EP91101440A 1990-03-07 1991-02-04 Hydraulic device Expired - Lifetime EP0445529B1 (en)

Applications Claiming Priority (2)

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DE4007073A DE4007073A1 (en) 1990-03-07 1990-03-07 Method of controlling delivery flow of gear pump
DE4007073 1990-03-07

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EP0445529B1 EP0445529B1 (en) 1994-10-19

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2706541A1 (en) * 1993-06-11 1994-12-23 Renault Vehicules Ind Method for regulating the pressure and delivery flow rate of a positive-displacement pump, and positive-displacement pump for implementing the method
EP1048879A3 (en) * 1999-04-30 2001-01-17 Hydraulik-Ring GmbH Pressure fluid supply of a CVT
WO2007068233A1 (en) * 2005-12-17 2007-06-21 Luk Lamellen Und Kupplungsbau Beteiligungs Kg Rotary transmission leadthrough and torque transmission device with a rotary transmission leadthrough

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19917593C2 (en) 1999-04-19 2002-05-02 Hydraulik Ring Gmbh Hydraulic displacement machine
DE19924855A1 (en) * 1999-04-30 2000-11-02 Hydraulik Ring Gmbh Pressure medium supply for a CVT transmission
DE102014216038A1 (en) 2014-08-13 2016-02-18 Robert Bosch Gmbh Gear machine with switchable internal circulation

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1080123A (en) * 1952-05-24 1954-12-07 Borg Warner Improvements in hydraulic transmission systems
DE1040904B (en) * 1952-05-21 1958-10-09 Borg Warner Hydraulic pump system
GB1031667A (en) * 1962-04-05 1966-06-02 Cessna Aircraft Co Hydraulic motor system with delayed pressure loading
DE2335054A1 (en) * 1972-07-10 1974-01-31 Komatsu Mfg Co Ltd GEAR PUMP OR GEAR MOTOR

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1040904B (en) * 1952-05-21 1958-10-09 Borg Warner Hydraulic pump system
FR1080123A (en) * 1952-05-24 1954-12-07 Borg Warner Improvements in hydraulic transmission systems
GB1031667A (en) * 1962-04-05 1966-06-02 Cessna Aircraft Co Hydraulic motor system with delayed pressure loading
DE2335054A1 (en) * 1972-07-10 1974-01-31 Komatsu Mfg Co Ltd GEAR PUMP OR GEAR MOTOR

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2706541A1 (en) * 1993-06-11 1994-12-23 Renault Vehicules Ind Method for regulating the pressure and delivery flow rate of a positive-displacement pump, and positive-displacement pump for implementing the method
EP1048879A3 (en) * 1999-04-30 2001-01-17 Hydraulik-Ring GmbH Pressure fluid supply of a CVT
WO2007068233A1 (en) * 2005-12-17 2007-06-21 Luk Lamellen Und Kupplungsbau Beteiligungs Kg Rotary transmission leadthrough and torque transmission device with a rotary transmission leadthrough
DE112006003469B4 (en) * 2005-12-17 2015-07-02 Schaeffler Technologies AG & Co. KG Rotary feedthrough and torque transmission device with a rotary feedthrough

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DE4007073A1 (en) 1991-09-12
EP0445529B1 (en) 1994-10-19
DE59103251D1 (en) 1994-11-24

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