EP0512514A2 - Machine à engrenages - Google Patents

Machine à engrenages Download PDF

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Publication number
EP0512514A2
EP0512514A2 EP92107651A EP92107651A EP0512514A2 EP 0512514 A2 EP0512514 A2 EP 0512514A2 EP 92107651 A EP92107651 A EP 92107651A EP 92107651 A EP92107651 A EP 92107651A EP 0512514 A2 EP0512514 A2 EP 0512514A2
Authority
EP
European Patent Office
Prior art keywords
machine
fact
seat
presents
machine body
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.)
Withdrawn
Application number
EP92107651A
Other languages
German (de)
English (en)
Other versions
EP0512514A3 (en
Inventor
Angelo Zanardi
Daniele Mei
Fausto Rossi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sauer Sundstrand SpA
Original Assignee
Sauer Sundstrand SpA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sauer Sundstrand SpA filed Critical Sauer Sundstrand SpA
Publication of EP0512514A2 publication Critical patent/EP0512514A2/fr
Publication of EP0512514A3 publication Critical patent/EP0512514A3/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • 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

  • the present invention relates to a geared machine that may be employed as a pump or motor.
  • Known geared machines currently comprise a machine body housing two gears, one of which, in pump operating mode, drives the other.
  • the axial sides of the machine body are closed by plates between which and the machine body provision is made for seals defining gaps between the plates and the bushes supporting the gear hubs. Pressurized fluid is fed into one of the gaps for balancing and compensating the clearance walls defined between the bushes and the top of the gear teeth.
  • Major drawbacks of machines of the aforementioned type are the number of seals required between the cover plates, on one side, and the machine body and bushes on the other; and the amount and high cost of precision machining required of the plate, the machine body and, at times, the bushes, for forming the seal seats.
  • a geared machine functioning as a pump or motor, and comprising: two meshing gears; two bushes located on either side of said gears so as to define respective clearance walls, and supporting the hubs of said gears; a machine body housing the gear-bush assembly; and two cover plates for said machine body; characterized by the fact that, on the side facing said machine body and respective said bush, each said plate presents a seat for a seal formed in one piece and comprising a first annular element, and a second annular element inwards of and joined over a long portion to said first annular element by a thin wall defining, inwards and outwards of said seat, two channels for a high-pressure fluid; said seal defining two gaps, one for low-pressure fluid, defined by said second element, and the other for high-pressure fluid, defined between respective portions of said first and second elements.
  • Number 1 in Fig.1 indicates a gear pump in accordance with the teachings of the present invention, and comprising a machine body 2 closed axially by two lateral cover plates 3 and 4, and housing two meshing gears 5 and 6.
  • Gear 5 is a driven gear having a hub 7 of substantially the same length as machine body 2; while gear 6 is a drive gear having a hub 8, which, on one side, extends through a hole 11 in plate 3 housing a hydraulic sealing assembly 12, and is connected in any manner to the output shaft of a motor (not shown).
  • Hubs 7 and 8 are supported by respective bushes 13 located on either side of gears 5 and 6 and defining respective clearance walls 14 with the top of the gear teeth.
  • machine body 2 is shaped internally to reproduce the contour of gears 5 and 6, i.e. is shaped in the form of an 8, as are bushes 13, each of which presents two parallel through holes 15 engaged by hubs 7 and 8.
  • gears 5 and 6 mesh machine body 2 presents an inlet 16 on one side, and an outlet 17 on the other.
  • the teeth of gears 5 and 6 are of known shape, and such, when meshed, as to prevent hydraulic communication between inlet 16 and outlet 17.
  • the gear teeth are so shaped as to prevent fluid leakage between the adjacent tooth spaces.
  • Pump 1 is a self-compensating, balanced type, as described later on, so that a minimum amount of fluid leakage along clearance walls 14 is required.
  • the hatching in Fig.3 indicates the surface of bush 13 subjected to a pressure (herein referred to as internal pressure) greater than the minimum, i.e. intake, pressure.
  • internal pressure a pressure greater than the minimum, i.e. intake, pressure.
  • the surface subjected to said internal pressure differs in shape from the face (wall 14) of bush 13, so that the center of gravity no longer lies along the axis of symmetry of bush 13. This therefore tends to swing about hubs 7 and 8, thus resulting in fluid leakage along clearance walls 14.
  • Bushes 13 are balanced by compensating, on the plate 3 and 4 side, the pressure exerted on bushes 13 at clearance walls 14.
  • a respective gap is therefore formed containing high-pressure fluid, by virtue of communicating hydraulically with the inner orifice of outlet 17, which communication may be achieved by forming, along the central outer surface portion of bush 13, a recess 21 as shown by the dotted line in Fig.2.
  • a second gap is formed containing low-pressure fluid, by virtue of communicating with the inner orifice of inlet 16 via a second recess 21 formed on the opposite side of bushes 13 to the first.
  • plate 4 presents two round recesses 22 at hubs 7 and 8; and a recess 23 connecting recesses 22 and having a portion facing respective recess 21.
  • Plate 3 presents the same design as plate 4, but with only one recess 22, the place of the other being occupied by hole 11.
  • plates 3 and 4 each present a respective substantially E-shaped recess 24.
  • pump 1 presents a seal 25 formed in one piece and preferably made of soft rubber.
  • Seal 25 defines said gaps, and is housed in a seat 26 formed in each plate 3 and 4, and having a rectangular section consisting of two side walls connected by a bottom wall.
  • Seal 25 comprises a first annular element 27, and a second annular element 28 located inwards of the first and defining said second low-pressure fluid gap; the first high-pressure fluid gap being defined by respective portions of elements 27 and 28.
  • Element 27 is substantially ovaloid in shape, with two opposite straight portions connected by two circular portions, and rests entirely on a corresponding face of machine body 2.
  • Element 28 presents a straight portion parallel to and formed in one piece with a first of said straight portions of element 27; and a curved portion extending from one end of said straight portion, running around part of recesses 22, and connected to the other end of said straight portion.
  • Said first gap is thus E-shaped, being defined by the second straight portion and two circular portions of element 27, and by the curved portion of element 28.
  • the straight portion of element 28 contacts machine body 2, while the curved portion contacts respective bush 13.
  • element 27 presents a rectangular section with two side walls; a bottom wall resting on the bottom wall of seat 26 and, like the latter, joined by said side walls; and a top wall flush with the face of respective plate 3 or 4.
  • Element 27 is double-lipped, in that it presents two parallel projections 31 extending from the top wall over the entire length of element 27 and projecting entirely from seat 26.
  • element 28 presents a rectangular section with two side walls; a bottom wall connecting the side walls and resting on the bottom wall of seat 26; and a top wall projecting beyond seat 26 by substantially the same amount as projections 31 on element 27.
  • the edge defined by the top wall and one of the side walls presents a recess 32 housing a tight-fitting antiextrusion seal 33, the section of which combines with that of recess 32 to produce an element 28-seal 33 assembly having a substantially rectangular section.
  • recess 32 is defined by two oblique faces sloping respectively in relation to the bottom and respective side wall of seat 26.
  • the straight portion of element 28 is connected to the first straight portion of element 27 by a thin wall 34 connecting the side walls of elements 27 and 28, with which it defines two channels 35 and 36.
  • Channel 35 is shallower than channel 36, and defined facing the bottom wall of seat 26; while channel 36 is defined outwards of seat 26 and therefore (in Fig.4) open at the top.
  • seat 26 is wider than the rest, to enable it to house said portion of both elements 27 and 28; and channels 35 and 36 communicate hydraulically with the first gap at each end of the straight portion of element 28.
  • seal 25 is molded in one piece to the finished shape, while seal 33 is also molded in one piece, but from hard silicon-based plastic or nylon material.
  • seal 25 provides for improved hydraulic sealing, as well as for improved performance and seating of antiextrusion seal 33 along element 28, by virtue of channels 35 and 36 defined between the one-piece portions of elements 27 and 28 enabling uniform high fluid pressure to be exerted on both sides of wall 34 for pressing said portions against the respective side walls of seat 26.
  • seal 25 is necessarily fitted tightly in place, thus permanently engaging seals 25 and 33 (since they are assembled simultaneously) and so enabling troublefree handling of the cover plates during assembly.
  • a high-pressure fluid channel is formed which provides for improved hydraulic sealing by pressing elements 27 and 28 towards the opposite side wall of seat 26.
  • Seal 25 is so designed as to enable automatic and hence fast, efficient, low-cost assembly, and to receive an annular antiextrusion seal, thus enabling seal 25 to be made of soft rubber for improving the mechanical efficiency of pump 1.
  • Soft rubber in fact, reacts to a lesser degree to the thrust exerted by the fluid along the clearance walls of bushes 13, as described previously, so that, for a given thickness projecting from seat 26, seal 25 (being preloaded to a lesser degree) reduces the thrust exerted on bushes 13, particularly during startup of pump 1.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Rotary Pumps (AREA)
  • Hydraulic Motors (AREA)
EP19920107651 1991-05-07 1992-05-06 Gear machine Withdrawn EP0512514A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITBO91085U 1991-05-07
IT000085 IT224734Z2 (it) 1991-05-07 1991-05-07 Macchina ad ingranaggi fungente da pompa o motore.

Publications (2)

Publication Number Publication Date
EP0512514A2 true EP0512514A2 (fr) 1992-11-11
EP0512514A3 EP0512514A3 (en) 1993-07-07

Family

ID=11337335

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19920107651 Withdrawn EP0512514A3 (en) 1991-05-07 1992-05-06 Gear machine

Country Status (2)

Country Link
EP (1) EP0512514A3 (fr)
IT (1) IT224734Z2 (fr)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4322240A1 (de) * 1993-07-03 1995-01-19 Eckerle Rexroth Gmbh Co Kg Hydraulische Zahnradmaschine (Pumpe oder Motor), insbesondere Innenzahnradmaschine
EP0656462A1 (fr) * 1993-11-19 1995-06-07 Firma Carl Freudenberg Dispositif d'étanchéité
CN1095025C (zh) * 1997-04-24 2002-11-27 丹福斯有限公司 流体机械
US7117730B2 (en) * 2002-07-12 2006-10-10 Renk Aktiengesellschaft Method and device for simulating slip on vehicle test benches
EP3276127A1 (fr) * 2016-07-26 2018-01-31 Eckerle Technologies GmbH Machine hydraulique à roue dentée

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3895890A (en) * 1974-01-24 1975-07-22 Hydroperfect Int Geared hydraulic apparatus
EP0291722A1 (fr) * 1987-05-18 1988-11-23 Robert Bosch Gmbh Machine à engrenages (pompe ou moteur)
EP0421020A1 (fr) * 1989-10-06 1991-04-10 SAUER-SUNDSTRAND S.p.A. Machine à engrenages pour utilisation comme pompe ou moteur
WO1991012431A1 (fr) * 1990-02-16 1991-08-22 Kabushiki Kaisha Komatsu Seisakusho Garniture d'etancheite pour pompes a engrenages

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3895890A (en) * 1974-01-24 1975-07-22 Hydroperfect Int Geared hydraulic apparatus
EP0291722A1 (fr) * 1987-05-18 1988-11-23 Robert Bosch Gmbh Machine à engrenages (pompe ou moteur)
EP0421020A1 (fr) * 1989-10-06 1991-04-10 SAUER-SUNDSTRAND S.p.A. Machine à engrenages pour utilisation comme pompe ou moteur
WO1991012431A1 (fr) * 1990-02-16 1991-08-22 Kabushiki Kaisha Komatsu Seisakusho Garniture d'etancheite pour pompes a engrenages

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4322240A1 (de) * 1993-07-03 1995-01-19 Eckerle Rexroth Gmbh Co Kg Hydraulische Zahnradmaschine (Pumpe oder Motor), insbesondere Innenzahnradmaschine
DE4345273C2 (de) * 1993-07-03 1997-02-06 Eckerle Rexroth Gmbh Co Kg Hydraulische Zahnradmaschine (Pumpe oder Motor), insbesondere Innenzahnradmaschine
US5674060A (en) * 1993-07-03 1997-10-07 Eckerle-Rexroth Gmbh & Co. Kg Hydraulic internal gear machine having a fluid pressure biased sealing plate
EP0656462A1 (fr) * 1993-11-19 1995-06-07 Firma Carl Freudenberg Dispositif d'étanchéité
CN1095025C (zh) * 1997-04-24 2002-11-27 丹福斯有限公司 流体机械
US7117730B2 (en) * 2002-07-12 2006-10-10 Renk Aktiengesellschaft Method and device for simulating slip on vehicle test benches
EP3276127A1 (fr) * 2016-07-26 2018-01-31 Eckerle Technologies GmbH Machine hydraulique à roue dentée
CN107654260A (zh) * 2016-07-26 2018-02-02 艾可勒工业电子有限公司 齿轮流体机
US10634136B2 (en) 2016-07-26 2020-04-28 Eckerle Technologies GmbH Geared fluid machine with circumferential seal having first and second spaced apart seal limbs
CN107654260B (zh) * 2016-07-26 2020-06-05 艾可勒工业电子有限公司 齿轮流体机

Also Published As

Publication number Publication date
ITBO910085V0 (it) 1991-05-07
IT224734Z2 (it) 1996-06-27
EP0512514A3 (en) 1993-07-07
ITBO910085U1 (it) 1992-11-07

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