WO1995016128A1 - Moteur hydraulique a pistons - Google Patents

Moteur hydraulique a pistons Download PDF

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Publication number
WO1995016128A1
WO1995016128A1 PCT/DK1994/000445 DK9400445W WO9516128A1 WO 1995016128 A1 WO1995016128 A1 WO 1995016128A1 DK 9400445 W DK9400445 W DK 9400445W WO 9516128 A1 WO9516128 A1 WO 9516128A1
Authority
WO
WIPO (PCT)
Prior art keywords
recess
piston engine
hydraulic piston
engine according
pressure fluid
Prior art date
Application number
PCT/DK1994/000445
Other languages
English (en)
Inventor
Vagn Bender
Jens Jørgen NIELSEN
Hardy Peter Jepsen
Original Assignee
Danfoss A/S
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 Danfoss A/S filed Critical Danfoss A/S
Priority to AU11912/95A priority Critical patent/AU1191295A/en
Priority to DE4499555A priority patent/DE4499555C2/de
Priority to DE4499555T priority patent/DE4499555T1/de
Publication of WO1995016128A1 publication Critical patent/WO1995016128A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
    • F03C1/00—Reciprocating-piston liquid engines
    • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
    • F03C1/04—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement
    • F03C1/0403—Details, component parts specially adapted of such engines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
    • F03C1/00—Reciprocating-piston liquid engines
    • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
    • F03C1/04—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement
    • F03C1/053—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement the pistons co-operating with an actuated element at the inner ends of the cylinders
    • F03C1/0531—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement the pistons co-operating with an actuated element at the inner ends of the cylinders with cam-actuated distribution members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2225/00—Synthetic polymers, e.g. plastics; Rubber
    • F05C2225/08—Thermoplastics
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
    • F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
    • F05C2225/00—Synthetic polymers, e.g. plastics; Rubber
    • F05C2225/12—Polyetheretherketones, e.g. PEEK

Definitions

  • the present invention relates to a hydraulic piston engine for operation with a lubricant-free, water-based pressure fluid, with a rotatable shaft which is coupled to work pistons and supported in at least one journal bearing, in which a first sliding surface of metal faces a second slid ⁇ ing surface of plastic material.
  • the hydraulic piston engines known in practice, through which a lubricant-free, water-based pressure fluid flows, comprise closed, oil-lubricated journal bearings.
  • the reason is that up to now it has been impossible to design a hydraulic piston engine with journal bearings, where a lubricant-free, water-based pressure fluid flows through the engine. In practice it has proved impossible to make these hydraulic piston engines work, especially under high loads with the resulting high pressures of e.g. 200 bar and high rotational speeds.
  • a hydraulic piston pump is known of the type mentioned in the introduction, where the drive shaft is made of metal, and where the bearing liners of the radial journal bearings are made of highly stable thermo- plastic material based on polyetheretherketone.
  • the piston pump also comprises pistons of metal, which are running in cylinder liners of the plastic material mentioned with a well-defined annular gap, which ensures a cooling flow of water in operation.
  • the pump shaft further comprises cool- ing passages for admission of water to the radial journal bearings.
  • the specification supplies no directions towards solving the problems concerning the journal bearings, which have appeared in practice when the pump must be driven at high temperatures and/or high rotational speeds. Therefore the purpose of the present invention is to pro ⁇ vide a hydraulic piston engine of the type mentioned in the introduction, which can be reliably operated with a lubricant-free, water-based pressure fluid.
  • the hydraulic piston engine according to the present inven ⁇ tion is characterised in that in the journal bearing, in a load area which at the influence of the work pistons in operation is permanently under load, at least one recess is provided, which is supplied with pressure fluid to absorb at least part of the load.
  • the design according to the present invention reduces the frictional load, and thereby the mechanical wear in the journal bearing. Therefore a water-driven hydraulic piston engine according to the invention can achieve a consider ⁇ ably longer life that the design known from EP 0 512 138. This applies in particular to intermittent duty, where the engine is frequently started and stopped.
  • a hydrostatic pressure fluid pocket will be built up continuously in the recess of the journal bearing.
  • the pressure fluid pocket will support and cool the facing sliding surface.
  • the surface pressure between the sliding surfaces outside the recess will be essentially reduced, thereby reducing the friction and the resulting frictional heat.
  • an increased rotational speed can be realised at unchanged operating pressure, or alternatively an increased operat ⁇ ing pressure at unchanged rotational speed. This must also be assumed to be a result of the reduced surface pressure and the separating and cooling effect of the pressure fluid supplied.
  • a further advantage of the design according to the present invention is the easier starting of the engine. It has proved that a hydraulic engine with journal bearings designed according to the invention can yield a consider ⁇ ably higher starting torque than an engine where the jour ⁇ nal bearings are not designed in the manner indicated. The easier starting must be assumed to be the result of the essentially reduced bearing friction.
  • the invention can be used to make the hydraulic engine cheaper, because the reduced mechanical loading and the reduced wear in the journal bearing allow the use of a cheaper plastic material with lower strength properties and higher temperature sensitivity without reducing the per ⁇ formance of the engine.
  • the embodiment according to claim 2 is particularly advan- tageous when it is desirable to facilitate the starting of the engine without reducing its volumetric efficiency.
  • the pressure fluid in the recess will tend to press the sliding surfaces apart, so that a gap is formed between the sliding surfaces.
  • Journal bearings of the type described are normally designed with a relatively large bearing clearance of up to one or several tenths of millimetres - considerably larger than in the case of oil-driven hydraulic engines.
  • the potential gap formation will allow a quite considerable pressure fluid flow during operation, considering the low viscosity of water.
  • the throttling causes the pressure in the recess and thereby the gap width to fall with increasing leakage flow, so that the leakage from the recess becomes self- stabilising, and may be reduced to an acceptable level.
  • the embodiment according to claim 3 is particularly simple in production. However, other embodiments may be imagined, where the throttling is effected by a valve arrangement, because the throttling can be made dependant on external parameters such as load, rotational speed, pressure fluid flow, etc.
  • a water-driven hydraulic engine has the particular advantage that it makes the leakage from the recess independent of the general bearing clearance.
  • an engine designed in this manner will be less sensitive to extraneous loadings of the shaft, which counteract the mechanical load from the work pistons.
  • a movable slide shoe may follow any movements in the bearing, thereby maintaining the width of the leakage gap around the recess constant.
  • the embodiment with a land around the recess allows a constructive setting of the leakage rate independently of the bearing clearance.
  • the claims 5, 6 and 7 indicate suitable constructive embodiments.
  • the area ratio between the recess with the surrounding land and the other end surface of the slide shoe, respectively, cf. claim 7, is decisive for the force acting upon the slide shoe in the direction towards the facing sliding surface, and therefore influences the leak ⁇ age rate and the resulting wear of the sliding surfaces.
  • the shaft rotates in relation to the work pistons, and where the journal bearing is a radial bearing, there will normally be an area on a sliding sur ⁇ face on the shaft which is permanently subjected to mechan- ical load from the pistons.
  • the shaft may be provided with an eccentric, which during the rotation of the shaft is alternately acted upon by the work pistons, as in a radial piston motor, cf. the embodiment in claim 8.
  • the loaded area in the journal bearing covers a certain area around a geometric position in relation to the eccentric, and is therefore stationary in relation to the shaft, whereas the loading on the facing sliding surface in the radial bearing will be rotating.
  • One of the two facing sliding surfaces of the radial journals ⁇ nal bearing is of metal, preferably steel, and the other surface of the journal bearing is of a thermoplastic material, especially from the group of highly stable thermoplastic materials based on polyaryletherketone, especially polyetheretherketone (PEEK) , polya ine, polyace- taline, polyarylether, polyethylenephthalephthalate, poly- phenylenesulphide, polysulphone, polyethersulphone, poly- etherimide, polyamidimide, polyacrylate, which may comprise fillers of glass, graphite, polytetrafluoroethylene or carbon, especially in fibre form.
  • PEEK polyetheretherketone
  • the hydraulic piston engine according to the present inven- tion can be used with particular advantage in a hydraulic plant which is driven with water as pressure fluid.
  • a hydraulic plant which is driven with water as pressure fluid.
  • it may be sterile water in a hydraulic plant used in a food processing production such as a slaughtery.
  • Fig. 1 shows in axial section a hydraulic radial piston motor according to the present invention.
  • Fig. 2 a section along the line II-II in fig. 1 through the radial journal bearing of the radial piston motor
  • Fig. 3 a section along the line III-III in fig. 1 to illus ⁇ trate the placing of the five pistons of the motor.
  • the radial piston motor shown in fig. 1 comprises a sur ⁇ rounding housing 2, through which there is a flow of lubricant-free, water-based pressure fluid such as corpor ⁇ ation water, which is supplied via a pressure inlet 3.
  • the radial piston motor 1 may comprise five pistons 4, which via an eccentric part 5 makes the drive shaft 6 of the motor rotate.
  • the drive shaft 6 is made of steel and comprises external sliding surfaces 7, which are supported against internal sliding surfaces 8 on bearing liners 9 placed in the hous ⁇ ing 2.
  • the bearing liners may be designed as a bushing of a highly stable thermoplastic material on poly- etheretherketone basis reinforced with carbon fibre, but it may also be made of thermoplastic materials of inferior strength such as polyamide.
  • the whole housing 2 may also be made of a plastic material, however, so that the bearing liners or the bushings are incorporated in the housing material.
  • the drive shaft 6 comprises a pressure fluid carrying duct 10 with an inlet 11, which may be provided with a valve.
  • the pressure fluid carrying duct leads to a recess 12 made in a radially movable bearing part in the drive shaft 6.
  • the valve and the duct may be designed to throttle the pressure fluid supply to the recess 12.
  • the bearing part is shaped as a pressure piston 13 of circular cross section, which is secured by means of an intermediary 0-ring 14 in a radial bore 15 in the drive shaft 6.
  • the pressure piston 13 is preferably made of the same metallic material as drive shaft 6, but also other materials may be used.
  • the pressure piston 13 comprises a bearing pressure rim or land 16, which delimits the recess 12 as well as a facing, hydrostatically actuated pressure surface or end surface 17, which acts on the pressure piston 13 with a force in the direction outwards towards the sliding surface 8 of the radial bushing 9.
  • the pressure fluid will be fed into the recess 12 to form a hydrostatic pressure fluid pocket, which will support and cool the bearing surfaces, when the drive shaft 6 begins to rotate.
  • additional, not shown ducts in the pressure piston 13 can be arranged for the purpose of creating circulation of the pressure fluid in the hydrostatic pressure fluid pocket 12.
  • the axial piston motor shown in fig. 4 comprises a housing 21, which via an inlet 22 is passed by a flow of lubricant- free, water-based fluid under pressure.
  • the axial piston motor 20 comprises pistons 23, which via a tilted disk 24 are connected to and cause the drive shaft 25 of the motor 20 to rotate.
  • the drive shaft 25 is made of steel and is supported in radial journal bearings at bearing bushings 26 of polyetheretherketone reinforced with carbon fibres, and is supported in the housing 21.
  • each radial journal bearing which is permanently influenced by a force from the work pistons, is situated on the bearing surface of the drive shaft as a consequence of the stationary, static loading by the radial piston motor of the drive shaft via the eccentric.
  • the loaded area in the journal bearing covers a certain area around a geometric position in relation to the eccentric, and thus it is stationary in relation to the shaft, while the loading on the facing sliding surface in the radial bearing is rotary.
  • the work pistons run synchronously with the rotation of the shaft in a stationary housing, and therefore the transmission of power from the pistons is effected on a reaction surface in fixed relation to the housing. Therefore the high load area of the tilting disk 24 is situated on the sliding surface of the bearing liner or bearing bushing as a consequence of the stationary, static loading by the radial piston motor of the bearing liner during operation, where the trans- mission of power from the pistons to the drive shaft is effected by the tilting disk 24.
  • the pressure pistons 27 with the recess 28 are therefore arranged as a radially displaceable part of the bearing liners 26 of the radial journal bearings. The same condition applies con- cerning the mode of operation and working of the radial journal bearings of the axial piston motor, as described above with reference to the radial journal bearings of the radial piston motor.
  • the axial piston pump 30 shown in fig. 5 (which may also be used as a motor), comprises a pump housing 31, in which a drive shaft 32 of steel is supported in a radial journal bearing with a bearing bushing 33 of polyetheretherketone (PEEK) or polyamide, and which is supported by a particu- larly large diameter near the external periphery of the "housing 31.
  • PEEK polyetheretherketone
  • the bearing bushing 33 is therefore provided with a recess 36, which is supplied with water-based pressure fluid via a pressure inlet 37.
  • the axial piston pump shown in fig. 5 is provided instead of the recess 36 with a pressure piston 38, which may be shaped as described under reference to the previous embodiments shown in figs. 1-4.
  • the pressure piston 38 is secured in the housing 31 by means of a threaded plug 39.
  • the pump can be provided with a bearing liner of a cheaper plastic material such as polyamide, and which does not necessarily need to be included in the group of highly stable structural plastic materials mentioned initially, such as polyetheretherketone.
  • piston motors or pumps according to the present invention can be used with particular advantage in connection with hydraulic plants which include corporation water or even sterile water as pressure fluid, and particularly in plant in connection with food processing as for example slaughteries.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)
  • Details Of Reciprocating Pumps (AREA)

Abstract

Moteur hydraulique à pistons, tel qu'un moteur à pistons radiaux, entraîné par un fluide sous pression à base aqueuse et dépourvu de lubrifiant. L'arbre moteur (6) est en acier et porté par des paliers lisses du type radial placés sur des coussinets (9) en matière plastique. L'arbre moteur est pourvu, au niveau d'une zone fixe soumise à des charges élevées, d'une poche de fluide sous pression hydrostatique, ménagée dans un évidement (12), qui supporte et refroidit le palier. Ceci permet d'obtenir un moteur hydraulique à pistons du type mentionné dont le fonctionnement demeure fiable dans toutes les conditions, même lorsqu'il est soumis à des charges élevées et fonctionne à des vitesses de rotation élevées.
PCT/DK1994/000445 1993-12-08 1994-11-30 Moteur hydraulique a pistons WO1995016128A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
AU11912/95A AU1191295A (en) 1993-12-08 1994-11-30 Hydraulic piston engine
DE4499555A DE4499555C2 (de) 1993-12-08 1994-11-30 Hydraulische Kolbenmaschine
DE4499555T DE4499555T1 (de) 1993-12-08 1994-11-30 Hydraulische Kolbenmaschine

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DK137393A DK137393D0 (da) 1993-12-08 1993-12-08 Hydraulisk stempelmaskine
DK1373/93 1993-12-08

Publications (1)

Publication Number Publication Date
WO1995016128A1 true WO1995016128A1 (fr) 1995-06-15

Family

ID=8104151

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/DK1994/000445 WO1995016128A1 (fr) 1993-12-08 1994-11-30 Moteur hydraulique a pistons

Country Status (4)

Country Link
AU (1) AU1191295A (fr)
DE (2) DE4499555T1 (fr)
DK (1) DK137393D0 (fr)
WO (1) WO1995016128A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997009532A1 (fr) * 1995-09-05 1997-03-13 Danfoss A/S Machine hydraulique a piston radial
WO2008046868A1 (fr) 2006-10-20 2008-04-24 Commissariat A L'energie Atomique Verin rotatif a palette apte a utiliser l'eau comme fluide moteur
US20110052432A1 (en) * 2008-05-06 2011-03-03 Cunningham Christopher E Pump with magnetic bearings
CN105275734A (zh) * 2015-11-16 2016-01-27 宁波汉竹液压马达有限公司 一种轴配油摆缸柱塞式液压马达

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002097268A1 (fr) 2001-05-26 2002-12-05 Robert Bosch Gmbh Pompe haute pression pour un systeme de carburant d'un moteur a combustion interne
DE102010039256A1 (de) * 2010-08-12 2012-02-16 Continental Automotive Gmbh Hochdruckpumpe
DE102012212833A1 (de) * 2012-07-23 2014-02-06 Zf Friedrichshafen Ag Radialkolbenmaschine mit wenigstens einem in einem gehäusefesten Zylinder verschiebbaren Kolben

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4224859A (en) * 1978-04-10 1980-09-30 Fuerstlich Hohenzollernsche Huettenverwaltung, Lauchertal Axial piston machine
EP0512138A1 (fr) * 1991-05-07 1992-11-11 Hauhinco Maschinenfabrik G. Hausherr, Jochums Gmbh & Co. Kg Pompe à eau à haute pression pour eau purifiée

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3734926A1 (de) * 1986-10-23 1988-05-11 Zahnradfabrik Friedrichshafen Kolbenmotor, insbesondere radialkolbenmotor

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4224859A (en) * 1978-04-10 1980-09-30 Fuerstlich Hohenzollernsche Huettenverwaltung, Lauchertal Axial piston machine
EP0512138A1 (fr) * 1991-05-07 1992-11-11 Hauhinco Maschinenfabrik G. Hausherr, Jochums Gmbh & Co. Kg Pompe à eau à haute pression pour eau purifiée

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997009532A1 (fr) * 1995-09-05 1997-03-13 Danfoss A/S Machine hydraulique a piston radial
WO2008046868A1 (fr) 2006-10-20 2008-04-24 Commissariat A L'energie Atomique Verin rotatif a palette apte a utiliser l'eau comme fluide moteur
FR2907520A1 (fr) 2006-10-20 2008-04-25 Commissariat Energie Atomique Verin rotatif a palette apte a utiliser l'eau comme fluide moteur.
US20110052432A1 (en) * 2008-05-06 2011-03-03 Cunningham Christopher E Pump with magnetic bearings
US8696331B2 (en) * 2008-05-06 2014-04-15 Fmc Technologies, Inc. Pump with magnetic bearings
US8777596B2 (en) 2008-05-06 2014-07-15 Fmc Technologies, Inc. Flushing system
CN105275734A (zh) * 2015-11-16 2016-01-27 宁波汉竹液压马达有限公司 一种轴配油摆缸柱塞式液压马达

Also Published As

Publication number Publication date
DE4499555C2 (de) 1998-11-12
AU1191295A (en) 1995-06-27
DK137393D0 (da) 1993-12-08
DE4499555T1 (de) 1996-11-14

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