EP0421020B1 - Zahnradmaschine zur Verwendung als Pumpe oder Motor - Google Patents

Zahnradmaschine zur Verwendung als Pumpe oder Motor Download PDF

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Publication number
EP0421020B1
EP0421020B1 EP19890118620 EP89118620A EP0421020B1 EP 0421020 B1 EP0421020 B1 EP 0421020B1 EP 19890118620 EP19890118620 EP 19890118620 EP 89118620 A EP89118620 A EP 89118620A EP 0421020 B1 EP0421020 B1 EP 0421020B1
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EP
European Patent Office
Prior art keywords
holes
machine
space
couple
gear
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
EP19890118620
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English (en)
French (fr)
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EP0421020A1 (de
Inventor
Angelo Zanardi
Daniele Mei
Vittorio Toselli
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Sauer Sundstrand SpA
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Sauer Sundstrand SpA
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Publication date
Application filed by Sauer Sundstrand SpA filed Critical Sauer Sundstrand SpA
Priority to ES89118620T priority Critical patent/ES2061870T3/es
Priority to EP19890118620 priority patent/EP0421020B1/de
Priority to DE1989609046 priority patent/DE68909046T2/de
Publication of EP0421020A1 publication Critical patent/EP0421020A1/de
Application granted granted Critical
Publication of EP0421020B1 publication Critical patent/EP0421020B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime 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
    • F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
    • F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
    • F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
    • F04C15/0023—Axial sealings for working fluid
    • F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps

Definitions

  • This invention relates to a gear machine for use as a pump or motor.
  • Gear machines are known to comprise a machine casing closed at its axial ends by respective covers and internally housing two mutually engaging gear wheels.
  • the gear wheels are provided on two rotatable shafts, namely the drive and driven shaft, which are supported by two bushes substantially of "8" shape.
  • Gear machines of the compensation type and of the fixed clearance type are in use.
  • seal gaskets are installed between the bushes and covers to define a space which is hydraulically connected to that part of the machine through which high-pressure fluid flows.
  • axial thrusts are created along the clearance walls defined between the gear wheel sides and the bushes and act on these latter, to be compensated by the axial thrusts created between the covers and the space defined by said gaskets.
  • a gear machine of the compensation type therefore allows the gap along the clearance walls to be taken up, allows the axial thrusts which arise along these latter to be balanced, and results in high volumetric efficiency for pumps and high mechanical efficiency for motors.
  • the machine has certain drawbacks due to the gasket preloading. In this respect, the preloading tends to urge the bushes towards the gear wheels so that on starting the machine there can be considerable friction between the bushes and gear wheels.
  • the machine For operation as a pump, the machine must be connected to a motor (normally electric) which has to overcome this initial separation friction and must therefore have a high starting torque. Consequently a powerful motor must be connected to the pump.
  • French Patent FR 2.246.188 relates to a gear machine (in accordance with the preamble of claim 1) provided with two rigid plates, each axially mobile towards bushes.
  • French Patent FR 2.212.861 relates to a gear machine provided with a flexible plate, which is pushed against bushes by compressed springs.
  • the machine itself is of higher cost and the device (pump or motor) upstream of the machine must be overdimensioned.
  • the object of the present invention is to provide a gear machine for use as a pump or motor which obviates the aforesaid drawbacks by operating as a fixed clearance machine on start-up, but as a compensation machine when under normal running for a predetermined fluid pressure.
  • a gear machine for use as a pump or motor, comprising a machine casing closed at each of its axial ends by a respective cover and internally housing two mutually engaging gear wheels, mounted on two respective rotatable shafts which are supported by two bushes and of which one extends to the outside of said machine casing; said gear machine, further, comprising at least one pressure plate, installed between a first cover of said covers and said machine casing, said plate being provided with a first hydraulic communication between a high pressure zone of said machine casing traversed by high pressure fluid and a first space delimited between said first cover and said plate by a first preloaded gasket assembly and having an area substantially equal to that defined area on said bushes on which axial thrusts are present during operation, and a second hydraulic communication between a low pressure zone of said machine casing traversed by low pressure fluid and a second space delimited between said first cover and said plate by a second gasket assembly; chracterised in that said pressure plate is in the form of a flexible
  • the reference numeral 1 indicates overall a gear machine for use as a pump or motor.
  • the machine 1 comprises a machine casing 2 closed at its axial ends by respective covers 3 and 4.
  • a diaphragm 5 of relatively elastic material such as aluminium is mounted between the cover 3 and the corresponding axial end of the machine casing 2.
  • the diaphragm 5 flexes towards the machine casing 2.
  • the machine casing 2 has an internal shape which reproduces the perimetral shape of the assembly formed from the two gear wheels 6.
  • the casing 2 in correspondence with the zone of engagement between the gear wheels 6 the casing 2 comprises on opposite sides two ports 11, namely an inlet port and outlet port.
  • each bush 8 comprises cavities 12 which with the inner wall of the machine casing 2 define respective fluid channels.
  • each bush 8 comprises two parallel through holes 13, in each of which there is fitted a respective liner 14. Along the whole length of the holes 13 there is provided a recess 15, the purpose of which will be apparent hereinafter.
  • One of the shafts 7 has substantially the same axial length as the machine casing 2, whereas the other extends through a hole 16 in the cover 4 to the outside of the machine 1 to be connected to an electric motor or a mechanical or electromechanical user device according to whether the machine 1 is used as a pump or motor.
  • One gasket 18 makes contact with the inner face of the diaphragm 5 whereas the other makes contact with the inner face of the cover 4.
  • the machine 1 is assembled by tightening down four screws 21, only one of which is shown in Figure 1.
  • the screws 21 pass successively through a hole 22 provided in the cover 3, a hole 23 provided in the diaphragm 5 and a hole 24 provided in the machine casing 2, and are then screwed into a threaded bore 25 provided in the cover 4.
  • the head of the screws 21 abuts against a shoulder formed in the hole 22.
  • the diaphragm 5 comprises two through holes 31 which are coaxial with and face the bores 8 of the closer bush 8. As will be apparent hereinafter, a hydraulic seal is determined mechanically between the bush 8 and diaphragm 5 by the effect of the fluid pressure.
  • the diaphragm 5 there are also provided four small holes, two of which, indicated by, 36'a and 36"a are in line with the channels defined by the cavities 12, whereas the other two indicated by 36b are in line with the gap between the bush 8 and the inner wall of the machine casing 2.
  • the first two holes 36'a and 36"a are symmetrical about a straight line orthogonal to that which joins the holes 36b and vice versa, as shown in Figure 3.
  • the cover 3 comprises two cylindrical recesses 41 coaxial with the holes 31 and communicating by way of two holes 42 which extend from the recesses 41 and intersect in the central part of the cover 3.
  • a threaded bore 43 extends from the recess 41 coaxial to the shorter shaft 7, and into which, on operation as a motor, there is screwed one end of a discharge pipe for drainage reasons which will be apparent hereinafter.
  • the bore 43 is engaged by a sealing plug.
  • the space in which the recesses 41 are provided is delimited by an annular seat 44 housing a retaining gasket 45.
  • the seat 44 and hence the gasket 45 are of "8" shape which substantially copies the perimetral shape of the bush 8.
  • the assembly formed by the gaskets 45 and 47 is contained in an elliptical seat 48 engaged by a corresponding retaining gasket 51 which reproduces substantially the shape of the gasket 18.
  • the seats 46 use part of the extension of the seat 44 and part of the extension of the seat 48.
  • Respective antiextrusion gaskets 52 constructed preferably of a rigid material such as teflon are laid to the inside of the respective retaining gaskets 45 and 47 along the seats 44 and 46. Five spaces 53, 54, 55, 56 and 57 are therefore defined on that face of the cover 3 which faces the diaphragm 5.
  • the space 53 is delimited by the gasket 45, the spaces 54 and 55 oppose each other about the central part of the cover 3 and are delimited by the gaskets 47, and the spaces 56 and 57 oppose each other about the central part of the cover 3 and are delimited by a portion of the gasket 44 and a portion of the gasket 51.
  • the space 53 for hydraulic communication with the holes 31 is in a zone through which low-pressure fluid passes, as is evident from the fact that for motor operation the space 53 is connected to discharge through the bore 43.
  • the spaces 54 and 55 are in hydraulic communication with the cavity 12 in the low pressure zone and with the cavity 12 in the high pressure zone, according to the direction of rotation of the shafts 7.
  • an oblique bore 62 (shown by dashed lines in Figures 1 and 2) which connects the hole 36"a to the intersection of the holes 42.
  • an axial through bore 64 shown by dashed lines in Figure 1 is provided in the shorter shaft 7. If the machine is operated as a motor and is series-connected so that the fluid is not fed to discharge but to a further user device, the spaces 54 and 55 are simultaneously in a high-pressure zone.
  • the spaces 56 and 57 are connected by the holes 36b to a high-pressure zone defined within the machine casing 2.
  • a recess 65 coaxial with the shorter shaft 7.
  • the recess 65 is in hydraulic communication with a seal assembly 67 by way of an oblique bore 66.
  • a pressurised fluid enters the machine casing 2 through one port 11 to rotate the gear wheels 6 and convert hydraulic energy into mechanical energy.
  • the fluid is then discharged at a lower pressure through the other port 11.
  • any fluid which seeps along the holes 13 in the bushes 8 and specifically between the liners 14 and the wall of the holes 13 is drained to the outside through the bore 43.
  • the fluid which seeps along that bush 8 closer to the cover 3 flows out towards the recesses 41, which mutually communicate (hole 42) and of which one is provided along the bore 43.
  • the fluid which seeps along the other bush 8 flows out towards the recess 65 and also along the bore 16, and from this latter through the bore 66 to the recess 65. From this latter the fluid flows towards the bore 43 passing through the bore 64, the hole 31 and the recess 41 in succession.
  • the holes 36b communicate with the maximum pressure zone, which is that relative to those teeth of the gear wheel 6 distant from the engaging teeth.
  • the maximum pressure zone which is that relative to those teeth of the gear wheel 6 distant from the engaging teeth.
  • the bushes 8 therefore move towards the respective covers 3 and 4 to result in absence of friction between the gear wheels 6 and bushes 8. Consequently the gear wheels 6 immediately begin to rotate even if the pressure of the fluid fed into the casing 2 is low.
  • the volumetric efficiency is low because a certain quantity of fluid seeps along said clearance walls without performing any work on the gear wheels 6.
  • the seal assembly contained between the cover 3 and diaphragm 5 comprises gaskets which because they are of greater thickness than the seat which houses them become preloaded on assembly.
  • the thrust exerted by these gaskets is absorbed by the diaphragm and is insufficient to flex the diaphragm 5.
  • the gasket preloading does not affect the clearance between the bush 8 and gear wheels 6 and therefore does not influence the mechanical efficiency, which remains high.
  • a quantity of the fluid fed into the casing 2 occupies the spaces 56 and 57 and one of the spaces 54 or 55 defined between the cover 3 and diaphragm 5.
  • the total contact area between the cover 3 and diaphragm 5 in which high-pressure fluid is present is large and substantially equal to that area of the bush 8 over which said axial thrusts are developed.
  • the motor operation is of the fixed clearance type on starting, but with increasing pressure the diaphragm 5 flexes to an extent dependent on the pressure and on the size of the compensation area between the cover 3 and diaphragm 5. As the diaphragm 5 flexes it takes up the gap along the clearance walls. This gap is not totally taken up because part of the compensation pressure is used in overcoming the reaction produced by the flexure of the diaphragm 5.
  • a machine in which the compensation system, necessary for obtaining high volumetric efficiency, does not penalise mechanical efficiency, to thus ensure highest overall efficiency.
  • the high mechanical efficiency obtained by virtue of the low friction force along the clearance walls is vital in enabling the machine to start if there is a high resistant torque on the shaft 7.
  • one port 11 is connected to a fluid tank and the other port 11 is connected to a user device.
  • the mechanical energy of the motor shaft is converted into hydraulic energy in that the gear wheels 6 draw liquid from the tank and deliver it to the user device.
  • the pressure increases at the outlet port and in all those spaces communicating with it either by virtue of seepage along the bushes 8 and casing 2 as described heretofore or through the channel provided at the outlet port 11.
  • the pump When operating as a pump, there is again a gap along the clearance walls on starting, and this substantially reduces the friction which the electric motor must overcome for initial separation. As the pressure gradually increases, the diaphragm 5 flexes to partially take up the gap and partially compensate axial thrusts, to obtain a volumetric efficiency substantially higher than the initial value.
  • the pump behaves as a fixed clearance pump with all its associated advantages, whereas as pressure increases it behaves as a compensated pump with all the advantages deriving therefrom.
  • the use of the machine 1 obviates the need to use a powerful motor to overcome initial separation friction as is required for balanced pumps of the prior art.
  • the pump volumetric efficiency is greater than that of fixed clearance pumps of the prior art.
  • a second diaphragm 5 can also be installed as described with reference to operation as a motor.
  • the machine 1 comprises one extra component, it is of reduced manufacturing cost as no precision finishing machining is required to define the clearance along the clearance walls and the preload to apply to the gaskets on tightening-down during assembly.
  • the use of the machine 1 as described results in a saving in the members installed upstream or downstream thereof.
  • a respective diaphragm 5 of convenient material and thickness in relation to the flexing pressure can be connected to each cover 3 and 4.
  • the machine 1 is reversible, ie can operate with the gear wheels 6 rotating in one or other direction at choice.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)
  • Hydraulic Motors (AREA)
  • Details And Applications Of Rotary Liquid Pumps (AREA)

Claims (14)

  1. Eine Zahnradmaschine zur Verwendung als eine Pumpe oder Motor, umfassend ein Maschinengehäuse (2), das an jedem seiner axialen Enden durch einen entsprechenden Deckel (3, 4) abgeschlossen ist und im Innern zwei miteinander kämmende Zahnräder (6) enthält, montiert auf zwei entsprechenden rotierenden Wellen (7), die von zwei Buchsen (8) abgestützt sind und von denen eine sich zur Außenseite des Maschinengehäuses erstreckt, welche Zahnradmaschine ferner mindestens eine Druckplatte (5) umfaßt, die installiert ist zwischen einem ersten Deckel (3), der Deckel (3, 4) und dem Maschinengehäuse (2), welche Platte (5) mit einer ersten hydraulischen Verbindung (36'a, 36b) versehen ist zwischen einer Hochdruckzone des Maschinengehäuses (2), durchsetzt von Hochdruckfluid, und einem ersten Raum (56, 57, 54), eingeschlossen zwischen dem ersten Deckel (3) und der Platte (5) durch eine erste vorgespannte Dichtungsbaugruppe (45, 47, 51) und mit einer Fläche im wesentlichen gleich der, die definiert ist auf den Buchsen (8), auf welche Axialbelastungen während des Betriebes ausgeübt wird, und eine zweite hydraulische Verbindung (31, 36"a) zwischen einer Niederdruckzone des Maschinengehäuses (2), durchsetzt von Niederdruckfluid, und einem zweiten Raum (53, 55), eingeschlossen zwischen dem ersten Deckel (3) und der Platte (5) durch eine zweite Dichtungsbaugruppe (45, 47), dadurch gekennzeichnet, daß die Druckplatte (5) die Form einer flexiblen Membran hat, wobei die Vorspanung der ersten Dichtungsbaugruppe (45, 47, 51) nicht hinreichend ist, eine Flexion der Platte (5) bei Betriebsbeginn zu bewirken und demgemäß nicht in der Lage ist, das vorbestimmte Spiel zu beeinflussen, das zwischen den Buchsen (8) und den Zahnrädern (6) existiert, so daß ein schneller Anlauf selbst unter Last sichergestellt ist, während mit zunehmendem Fluiddruck das in dem ersten Raum (56, 57, 54) enthaltene Fluid eine entsprechende Flexion der Platte (5) in Richtung der Buchsen (8) bewirkt, um so allmählich das Spiel zu kompensieren.
  2. Eine Zahnradmaschine nach Anspruch 1, dadurch gekennzeichnet, daß die hydraulische Verbindung zwischen der Hochdruckzone und einem ersten Teil (56, 57) des ersten Raums (56, 57, 54) bewirkt wird durch ein erstes Paar von Durchgangslöchern (36b), das in der Membran (5) in Linie mit dem Spalt vorgesehen ist, der zwischen der Buchse (8) und der Innenwandung des Maschinengehäuses (2) existiert.
  3. Eine Zahnradmaschine nach Anspruch 2, dadurch gekennzeichnet, daß die Membran (5) mit einem zweiten Paar von Durchgangslöchern (36'a, 36"a) versehen ist, wobei ein erstes Loch (36'a) dieses zweiten Paares von Löchern (36'a, 36"a) angeordnet ist für die hydraulische Verbindung eines zweiten Teils (54) des ersten Raums (56, 57, 54) mit der Hochdruckzone und ein zweites Loch (36"a) des zweiten Paares die hydraulische Verbindung eines ersten Teils (55) des zweiten Raums (53, 55) mit der Niederdruckzone herstellt.
  4. Eine Zahnradmaschine nach Anspruch 3, dadurch gekennzeichnet, daß die Löcher (36b) des ersten Paares in symmetrischer Position bezüglich einer geraden Linie sind, die senkrecht verläuft zu jener, die die Löcher (36'a, 36"a) des zweiten Paares verbindet und umgekehrt.
  5. Eine Zahnradmaschine nach Anspruch 4, dadurch gekennzeichnet, daß in dem zentralen Teil der Platte (5) zwei dritte Löcher (31) vorgesehen sind, die koaxial sind mit vierten Löchern (13), vorgesehen in der Buchse (8) zur Abstützung der Welle (7), welche dritte Löcher (31) die Niederdruckzone hydraulisch mit einem zweiten Teil (53) des zweiten Raums (53, 55) über die genannten vierten Löcher (13) verbinden.
  6. Eine Zahnradmaschine nach Anspruch 5, dadurch gekennzeichnet, daß eine entsprechende Ausnehmung (15) längs der vierten Löcher (13) vorgesehen ist zum Ermöglichen des Durchtritts jenes Fluids, das während des Betriebes zwischen den Zahnrädern (6) und den Buchsen (8) in Richtung des zweiten Teils (53) des zweiten Raumes (53, 55) durchsikkert.
  7. Eine Zahnradmaschine nach Anspruch 5 oder 6, dadurch gekennzeichnet, daß jede Buchse (8) auf entgegengesetzten Seiten seiner Außenoberfläche zwei Hohlräume (12) umfaßt, die mit der Innenwandung des Maschinengehäuses (2) entsprechende Kanäle begrenzen, wobei einer angeordnet ist für die hydraulische Verbindung der Hochdruckzone mit dem zweiten Teil (54) des ersten Raums (56, 57, 54) über das erste Loch (36'a) des zweiten Paares von Löchern (36'a, 36"a) und der andere angeordnet ist für die hydraulische Verbindung der Niederdruckzone mit dem ersten Teil (55) des zweiten Raums (53, 55) über das zweite Loch (36"a) des zweiten Paares von Löchern (36'a, 36"a).
  8. Eine Zahnradmaschine nach Anspruch 7, dadurch gekennzeichnet, daß der zweite Teil (53) des zweiten Raums (53, 55) begrenzt wird von einer ersten Dichtung (45) mit einer perimetrischen Form ähnlich der der Buchse (8), wobei innerhalb des zweiten Teils (53) des zweiten Raums (53, 55) zwei erste zylindrische Ausnehmungen (41) vorgesehen sind, koaxial mit den dritten (31) und vierten (13) Löchern und miteinander verbunden über zwei fünfte Löcher (42), die sich von diesen Ausnehmungen (41) wegerstrecken und innerhalb des ersten Deckels (3) schneiden.
  9. Eine Zahnradmaschine nach Anspruch (8), dadurch gekennzeichnet, daß der zweite erste Teil (55) des zweiten Raums (53, 55) begrenzt ist durch eine Dichtung (47) mit einer perimetrischen Form im wesentlichen ähnlich, jedoch weiter ausgedehnt als der Hohlraum (12), mit dem er in hydraulischer Kommunikation über das zweite Loch (36"a) des zweiten Paares von Löchern (36'a, 36"a) steht.
  10. Eine Zahnradmaschine nach Anspruch 9, dadurch gekennzeichnet, daß der zweite Teil (54) des ersten Raums (56, 57, 54) begrenzt wird von einer dritten Dichtung (47) mit einer perimetrischen Form im wesentlichen ähnlich, jedoch ausgedehnter als der Hohlraum (12), mit dem sie in hydraulischer Kommunikation über das erste Loch (36'a) des zweiten Paares von Löchern (36'a, 36"a) steht.
  11. Eine Zahnradmaschine nach Anspruch 10, dadurch gekennzeichnet, daß der erste Teil (56, 57) des ersten Raums (56, 57, 54) außen begrenzt wird durch eine vierte Dichtung (51) und innen durch die erste (45), die zweite (47) und die dritte (47) Dichtung.
  12. Eine Zahnradmaschine nach Anspruch 11, dadurch gekennzeichnet, daß für den Motorbetrieb eine Auslaßöffnung (43) in Übereinstimmung mit einer der Ausnehmungen (41) zur Abfuhr nach außen vorgesehen ist.
  13. Eine Zahnradmaschine nach Anspruch 12, dadurch gekennzeichnet, daß für den Pumpenbetrieb das zweite Loch (36"a) des zweiten Paares von Löchern (36'a, 36"a) in Kommunikation steht mit einem siebenten Durchgangsloch (62), vorgesehen in dem ersten Deckel (3) und sich in den Schnittpunkt der fünften Löcher (42) öffnend.
  14. Eine Zahnradmaschine nach einem der vorangehenden Ansprüche, dadurch gekennzeichnet, daß die Platte (5) aus Aluminium aufgebaut ist.
EP19890118620 1989-10-06 1989-10-06 Zahnradmaschine zur Verwendung als Pumpe oder Motor Expired - Lifetime EP0421020B1 (de)

Priority Applications (3)

Application Number Priority Date Filing Date Title
ES89118620T ES2061870T3 (es) 1989-10-06 1989-10-06 Maquina de engranajes para utilizar como bomba o motor.
EP19890118620 EP0421020B1 (de) 1989-10-06 1989-10-06 Zahnradmaschine zur Verwendung als Pumpe oder Motor
DE1989609046 DE68909046T2 (de) 1989-10-06 1989-10-06 Zahnradmaschine zur Verwendung als Pumpe oder Motor.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19890118620 EP0421020B1 (de) 1989-10-06 1989-10-06 Zahnradmaschine zur Verwendung als Pumpe oder Motor

Publications (2)

Publication Number Publication Date
EP0421020A1 EP0421020A1 (de) 1991-04-10
EP0421020B1 true EP0421020B1 (de) 1993-09-08

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Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890118620 Expired - Lifetime EP0421020B1 (de) 1989-10-06 1989-10-06 Zahnradmaschine zur Verwendung als Pumpe oder Motor

Country Status (3)

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EP (1) EP0421020B1 (de)
DE (1) DE68909046T2 (de)
ES (1) ES2061870T3 (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010048073A1 (de) 2010-04-16 2011-10-20 Robert Bosch Gmbh Maschinengehäuse einer Hydromaschine

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IT224734Z2 (it) * 1991-05-07 1996-06-27 Macchina ad ingranaggi fungente da pompa o motore.
DE102016213696B4 (de) 2016-07-26 2020-06-04 Eckerle Industrie-Elektronik Gmbh Zahnradfluidmaschine
CN112709692B (zh) * 2020-12-29 2023-02-17 西安精密机械研究所 一种提高海水泵容积效率的轴向补偿机构以及海水泵
CN113279956B (zh) * 2021-06-30 2022-09-02 合肥集源穗意液压技术股份有限公司 一种密封效果较好的镶联式齿轮油泵泵体

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB769763A (en) * 1954-05-20 1957-03-13 Air Equipement Improvements in or relating to gear pumps
US2842066A (en) * 1954-05-21 1958-07-08 Plessey Co Ltd Gear pump
FR1426585A (fr) * 1965-03-09 1966-01-28 Perfectionnements apportés à la réalisation d'appareils hydrauliques à engrenages, utilisés en particulier comme pompes ou comme moteurs
GB1172579A (en) * 1966-08-15 1969-12-03 Borg Warner Pressure Loaded Hydraulic Gear Pumps or Motors
DE1553133A1 (de) * 1966-12-23 1970-07-30 Maag Zahnraeder & Maschinen Ag Hochdruck-Zahnradpumpe
FR2212861A5 (de) * 1972-12-28 1974-07-26 Retel
DE2349304C3 (de) * 1973-10-01 1981-07-16 Robert Bosch Gmbh, 7000 Stuttgart Mit Druckflüssigkeit betriebener Zahnradmotor

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102010048073A1 (de) 2010-04-16 2011-10-20 Robert Bosch Gmbh Maschinengehäuse einer Hydromaschine

Also Published As

Publication number Publication date
EP0421020A1 (de) 1991-04-10
DE68909046D1 (de) 1993-10-14
DE68909046T2 (de) 1994-03-31
ES2061870T3 (es) 1994-12-16

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