NO750280L

NO750280L -

Info

Publication number: NO750280L
Application number: NO750280A
Authority: NO
Inventors: J F Butler
Original assignee: Doxford Hawthorn Res
Priority date: 1974-02-01
Filing date: 1975-01-30
Publication date: 1975-08-25
Also published as: DK33875A; AU7774075A; NL7500992A; IT1027446B; ES434302A1; JPS50113654A; FR2259991A1; LU71775A1; FR2259991B1; FI750244A; BE825059A; SE7501032L; DE2503984A1

Description

Oppfinnelsen vedrorer stempler og stempelringer. Stemplene er av den type som egner seg for bruk i en forbrenningsmotor eller en annen maskin med frem og tilbakegående stempler, f.eks. en kompressor, og stemplene kan være anordnet vertikalt, horisontalt eller i en skrå-vinkel i forhold til vertikalen. The invention relates to pistons and piston rings. The pistons are of the type suitable for use in an internal combustion engine or other machine with reciprocating pistons, e.g. a compressor, and the pistons can be arranged vertically, horizontally or at an oblique angle in relation to the vertical.

Ved konstruksjonen av et stempel og tilhorende sylinder for en forbrenningsmotor har man en optimal relativ orientering mellom hver stempelrings arbeidsflate og sylinderveggen, slik at man kan oppnå de beste arbeidsbetingelser. Har f.eks. stempelringen en plan arbeidsflate,, så har man funnet at dersom ringens kontaktflate ligger med en meget liten vinkel i forhold til sylinderveggen så blir minimum-olje-filmtykkelsen sterkt redusert sammenlignet med den minimum-oljefilm-tykkelse som man får når kontaktflaten er parallell med sylinderveggen. For en stempelring med en plan kontaktflate er det således', dersom man ikke onsker slik reduksjon i minimumtykkelsen av oljefilmen, vesentlig å holde ringens kontaktflate parallell med sylinderveggen. En stempelring med en annerledes utformet kontaktflate, f.eks. en bombeformet kontaktflate, vil også ha en optimal stilling som er nbdvendig for å oppnå onskede arbeidsbetingelser.- When designing a piston and associated cylinder for an internal combustion engine, there is an optimal relative orientation between the working surface of each piston ring and the cylinder wall, so that the best working conditions can be achieved. Has e.g. the piston ring a flat working surface,, it has been found that if the contact surface of the ring lies at a very small angle in relation to the cylinder wall, the minimum oil film thickness is greatly reduced compared to the minimum oil film thickness that is obtained when the contact surface is parallel to the cylinder wall . For a piston ring with a flat contact surface, it is thus essential, if one does not wish such a reduction in the minimum thickness of the oil film, to keep the ring's contact surface parallel to the cylinder wall. A piston ring with a differently designed contact surface, e.g. a bomb-shaped contact surface will also have an optimal position which is necessary to achieve the desired working conditions.-

I praksis har det vist seg at under motorens drift vil stempelringens kontaktflate ha en tendens til å endre sin stilling i forhold til sylinderveggen. Når f.eks. stemplet blir varmt vil stemplet ha en tendens til å påvirke stempelringen slik at den endrer sin stilling i forhold til sylinderveggen, slik at stempelringens kontaktflate ikke lenger ligger i den onskede optimale stilling i forhold til sylinderveggen. In practice, it has been shown that during the operation of the engine, the contact surface of the piston ring will tend to change its position in relation to the cylinder wall. When e.g. the piston becomes hot, the piston will tend to affect the piston ring so that it changes its position in relation to the cylinder wall, so that the contact surface of the piston ring is no longer in the desired optimal position in relation to the cylinder wall.

Ifolge oppfinnelsen er et stempel forsynt med en stempelring anordnet i et periferielt spor i stemplet, og i det minste én av stempelringens radielt forlopende flater har en avstand fra den hosliggende sporkant ved hjelp av en anordning som muliggjor en relativ According to the invention, a piston is provided with a piston ring arranged in a circumferential groove in the piston, and at least one of the radially extending surfaces of the piston ring has a distance from the adjacent groove edge by means of a device which enables a relative

svingebevegelse mellom stemplet og stempelringen.swing movement between the piston and the piston ring.

I det tilfellet at stemplet er anordnet vertikalt eller med en vinkel i forhold til vertikalen, foretrekkes det at den nevnte radielt forlopende flate på stempelringen er bunnflaten til stempelringen, og at i det minste en del av den nevnte ahferdning som muliggjor den relative svingebevegelse mellom stemplet og stempelringen, understotter stempelringen over stempelringsporets bunnkant. Det kan også være onskelig at den nevnte radielt forlopende stempelringflate er toppflaten i stempelringen, eller alternativt at både toppflaten og bunnflaten på stempelringen har adgang fra de respektive hosliggende stempelringsporkanter ved hjelp av en egnet anordning. In the event that the piston is arranged vertically or at an angle in relation to the vertical, it is preferred that the said radially extending surface of the piston ring is the bottom surface of the piston ring, and that at least part of the said bearing which enables the relative pivoting movement between the piston and the piston ring, supports the piston ring above the bottom edge of the piston ring groove. It may also be desirable that the aforementioned radially extending piston ring surface is the top surface of the piston ring, or alternatively that both the top surface and the bottom surface of the piston ring have access from the respective adjacent piston ring slot edges by means of a suitable device.

Det foretrekkes at svingeaksen har en avstand fra veggen i sylinderen som er mindre enn avstanden mellom stempelringens radielt forlopende flate som ligger lengst fra svingeaksen og den respektive kant av stempelringsporet som ligger nærmest svingeaksen, og fortrinnsvis ligger mellom en tredjedel og to tredjedeler av denne avstand. It is preferred that the pivot axis has a distance from the wall of the cylinder that is smaller than the distance between the radially extending surface of the piston ring which is furthest from the pivot axis and the respective edge of the piston ring groove which is closest to the pivot axis, and preferably lies between one third and two thirds of this distance.

En slik plasering av svingeaksen muliggjbr begrenset relativ bevegelse mellom stemplet og stempelringen slik at kontaktflaten til stempelringen kan bibeholde sin onskede optimale orientering i forhold til sylinderveggen. Such a placement of the pivot axis enables limited relative movement between the piston and the piston ring so that the contact surface of the piston ring can maintain its desired optimal orientation in relation to the cylinder wall.

Fortrinnsvis innbefatter avstandsanordningen minst ett fremspring som danner en ring mellom stempelringens radielt forlopende flate og stempelringsporets hosliggende kant. Eksempelvis kan det være anordnet et ringformet fremspring som rager opp ifra stempel-'ringsporets hosliggende kant og er beregnet for samvirke med stempelringens motliggende radielt forlopende flate. Alternativt kan et ringformet fremspring rage ut fra stempelringens flate og være beregnet for samvirke med den hosliggende stempelringsporkant. Eksempelvis kan også et forste ringformet' fremspring rage ut fra den hosliggende stempelringsporkant, mens et andre ringformet fremspring rager ut fra stemplets motliggende radielt forlopende flate, pg fremspringene kan Preferably, the spacer device includes at least one projection which forms a ring between the radially extending surface of the piston ring and the adjoining edge of the piston ring groove. For example, an annular projection can be arranged which protrudes from the adjacent edge of the piston ring groove and is intended to cooperate with the opposite radially extending surface of the piston ring. Alternatively, an annular projection can protrude from the surface of the piston ring and be designed to cooperate with the adjacent piston ring groove edge. For example, a first annular projection can also project from the adjacent piston ring groove edge, while a second annular projection projects from the opposite radially extending surface of the piston, because the projections can

da ligge enten i flukt med hverandre, slik at de samvirker med hverandre, eller de kan være forskjovet i forhold til hverandre. I samtlige tilfeller kan det eller de ringformede fremspring være utformet i ett med henholdsvis stemplet og stempelringen. Fremspringene kan også være separate elementer anordnet f.eks. i et ringspor i stempel-singsporets kant eller i stempelringens radielle flate. then either lie flush with each other, so that they interact with each other, or they can be offset in relation to each other. In all cases, the ring-shaped projection or protrusions can be designed in one with the piston and the piston ring, respectively. The protrusions can also be separate elements arranged e.g. in an annular groove in the edge of the piston ring groove or in the radial surface of the piston ring.

Avstandsorganene som muliggjor en svingebevegelse mellom stemplet og stempelringen kan ha flate- eller linjekontakt med de akt-uelle deler. The spacers which enable a pivoting movement between the piston and the piston ring can have surface or line contact with the actual parts.

Oppfinnelsen vedrorer også et stempel forsynt med anordninger som nevnt foran, hvilken anordning rager ut fra minst en kant i et stempelringspord slik at denne kant., kan holdes i en avstand fra den hosliggende radielt forlopende flate på tilhorende stempelring i sporet. The invention also relates to a piston provided with devices as mentioned above, which device projects from at least one edge in a piston ring slot so that this edge can be kept at a distance from the adjacent radially extending surface of the corresponding piston ring in the slot.

Oppfinnelsen vedrorer også en stempelring beregnet for plasering i et stempelringspord i et stempel, hvilken stempelring har en anordning som beskrevet foran, hvilken anordning rager ut fra minst en av de radielle stempelringflater for å holde denne flate i en avstand fra hosliggende kant i det tilhoreraide stempelringspord. The invention also relates to a piston ring intended for placement in a piston ring slot in a piston, which piston ring has a device as described above, which device projects from at least one of the radial piston ring surfaces to keep this surface at a distance from the adjacent edge of the associated piston ring slot .

Oppfinnelsen vedrorer også en forbrenningsmotor eller en maskin med frem- og tilbakegående stempler, f.eks. en kompressor, forsynt med et stempel eller en stempelring som beskrevet ovenfor. The invention also relates to an internal combustion engine or a machine with reciprocating pistons, e.g. a compressor, provided with a piston or piston ring as described above.

Oppfinnelsen skal beskrives nærmere under henvisning til tegningene hvor. The invention shall be described in more detail with reference to the drawings where.

Fig. 1 til 13 viser ulike utforelsesformer av et stempel med tilhorende stempelring. Fig. 1 to 13 show different embodiments of a piston with associated piston ring.

I fig. 1 betegner 20 et stempel i en forbrenningsmotor eller en kompressor. Stemplet beveger seg frem og tilbake i en vertikal sylinder 21. Stemplet 20 har et stempelringspor 22 med en stempelring 23. Stempelringen 23 har en plan vertikal flate 2.% beregnet for kontakt med sylinderveggen 21. Den nedre radielle flate 25 og stempelringen 23 er også plan og ligger i en avstand over en hosliggende bunnkant 26 i stempelringsporej'. Denne avstand holdes ved hjelp av et ringformet fremspring 27 som altså rager opp ifra bunnkanten til stempelringsporet og er utformet i ett med stemplet. Fremp-springet 27 tilveiebringer en delvis toroidal flate som understøtter stempelringen0%tillater en relativ svingebevegelse mellom stempelringen, slik den er sett i tverrsnitt i figuren, og stemplet, slik at på den måten kontaktflaten '24 på stempelringen kan bibeholde sin paral-lelle stilling i forhold til sylinderveggen uansett små endringer i stemplets stilling. Avstanden mellom svingeaksen og sylinderveggen er mindre enn hoyden til den ovre radielle flate 28 på stempelringen, dvs., den radielle flate på stempelringenssom ligger lengst fra svingeaksen, regnet fra bunnkanten i stempelringsporet, dvs. den kan i stempelringsporet som er nærmest svingeaksen. Fordelaktig utgjor av- In fig. 1 denotes 20 a piston in an internal combustion engine or a compressor. The piston moves back and forth in a vertical cylinder 21. The piston 20 has a piston ring groove 22 with a piston ring 23. The piston ring 23 has a flat vertical surface 2.% intended for contact with the cylinder wall 21. The lower radial surface 25 and the piston ring 23 are also plane and lies at a distance above an adjacent bottom edge 26 in the piston ring groovej'. This distance is maintained by means of an annular projection 27 which thus protrudes from the bottom edge of the piston ring groove and is designed as one with the piston. The protrusion 27 provides a partially toroidal surface which supports the piston ring 0% allowing a relative pivoting movement between the piston ring, as seen in cross-section in the figure, and the piston, so that in this way the contact surface '24 of the piston ring can maintain its parallel position in relation to the cylinder wall regardless of small changes in the position of the piston. The distance between the pivot axis and the cylinder wall is less than the height of the upper radial surface 28 of the piston ring, i.e. the radial surface of the piston ring which is farthest from the pivot axis, counted from the bottom edge of the piston ring groove, i.e. it can be in the piston ring groove that is closest to the pivot axis. Beneficially constitutes of-

standen mellom en tredjedel og to tredjedeler av denne hbyde.the stand between one-third and two-thirds of this hbyde.

I praksis vil kontaktflaten 24 presses mot sylinderveggen av gasstrykket i stempelringsporet. Man har funnet at den mulige relative bevegelse mellom -stempelringen og stemplet tillater stempelringen å bibeholde den onskede optimale orientering av sin flate 24 i forhold til sylinderveggen. I praksis vil derfor bevegelser i stemplet som folge av at det blir varmt, ikke bevirke en redusert minimumtykk-else av oljefilmen. In practice, the contact surface 24 will be pressed against the cylinder wall by the gas pressure in the piston ring groove. It has been found that the possible relative movement between the piston ring and the piston allows the piston ring to maintain the desired optimum orientation of its surface 24 relative to the cylinder wall. In practice, therefore, movements in the piston as a result of it becoming hot will not cause a reduced minimum thickness of the oil film.

Fig. 2 til 13 viser andre utforelsesformer av stempel og stempelring og er benyttet i samme henvisningstall hvor det er aktuelt. Fig. 2 to 13 show other embodiments of piston and piston ring and are used in the same reference number where relevant.

I fig. 2 er det ringformede fremspring 27 utformet med en bredere anleggsflate mot bunnflaten 25 pa stempelringen 23. Stbtte-ringens bredde er ikke mer enn halvparten av den radielle tykkelsen In fig. 2, the annular projection 27 is designed with a wider contact surface against the bottom surface 25 of the piston ring 23. The width of the support ring is not more than half of the radial thickness

.til stempelringen..to the piston ring.

Fig. 3°g 4 viser i omvendt utforelse av de som er vist i fig. 1 og 2, idet fremspringet 30 er anordnet på stempelringen og er utformet i ett med denne. I begge tilfeller er bunnkanten 26 i dstem-pelringsporet 22 plan. Fig. 5 viser en utforelse som ligner den i fig. 3°S 4>men fremspringet 31 nar linjekontakt med bunnkanten 26 i stempelringsporet. Fremspringets toppunkt dannes av to plane konuser som krysser hverandre. Fig. 6 viser en utforelse som kan betraktes someen omvendt utforelse av den som er vist i fig. 5* Et fremspring 32 rager opp fra bunnkanten 26 i stempelringsporet og har linjekontakt med bunnflaten på stempelringen. Stempelringen er vist som en avtrappet stempelring 33* Fig. 3 and 4 show in reverse embodiment of those shown in fig. 1 and 2, in that the projection 30 is arranged on the piston ring and is designed in one with this. In both cases, the bottom edge 26 of the stamp ring groove 22 is flat. Fig. 5 shows an embodiment similar to that in fig. 3°S 4>but the protrusion 31 makes line contact with the bottom edge 26 in the piston ring groove. The apex of the projection is formed by two plane cones that cross each other. Fig. 6 shows an embodiment which can be considered as an inverted embodiment of the one shown in fig. 5* A projection 32 protrudes from the bottom edge 26 in the piston ring groove and has linear contact with the bottom surface of the piston ring. The piston ring is shown as a stepped piston ring 33*

Utforelsen i fig. 7 til 10 adskiller seg fra de tidligere beskrevne ved at fremspringet er utformet som et separat element be-tegnet med henholdsvis 34» 35» 3^ °S 37* Disse elementene er anordnet i og rager ut fra et ringformet spor i bunnkanten til stempelringsporet slik som det fremgår av fig. 7°S 8, henholdsvis et ringformet spor i bunnflaten på stempelringen slik det er vist i fig. 9 og lo. The embodiment in fig. 7 to 10 differ from those previously described in that the projection is designed as a separate element denoted respectively by 34" 35" 3^ °S 37* These elements are arranged in and protrude from an annular groove in the bottom edge of the piston ring groove as as can be seen from fig. 7°S 8, respectively an annular groove in the bottom surface of the piston ring as shown in fig. 9 and laughed.

Fig. 10 viser dessuten en stempelring med kileformet tverrsnitt og stempelringsporet 39 er utformet tilsvarende. Utforelsen i fig. 1 til 9°S 11 til 13 kan naturligvis også modifiseres med hen-syn til stempelringens tverrsnitt, f. eks. slik som vist i fig. 10. Samtlige utforelseseksempler kan også modifiseres slik at stempelringen har bombert form eller en annen flateform som har kontakt med Fig. 10 also shows a piston ring with a wedge-shaped cross-section and the piston ring groove 39 is designed accordingly. The embodiment in fig. 1 to 9°S 11 to 13 can of course also be modified with regard to the cross section of the piston ring, e.g. as shown in fig. 10. All exemplary embodiments can also be modified so that the piston ring has a domed shape or another surface shape that is in contact with

Claims

the cylinder wall.

Fig. 11 shows an embodiment similar to that in fig. 1, with the exception that the piston 20 is arranged in an inclined cylinder.

The projection 3$ is here arranged at the top and therefore acts against the upper radially extending surface 28 of the piston ring 23 and keeps this at a distance from the adjacent upper edge 39' in the piston ring's groove 22.

A modified embodiment is shown in fig. 12. The piston moves back and forth in a vertical cylinder, but the piston 20 here has a protrusion /\. 0 between the bottom surface 25 of the piston ring 23 and the bottom edge 26 in the piston ring groove 22, and has another projection 41 between the top surface 28 of the piston ring and the top edge 39 in the piston ring groove.

Fig. 13 shows an embodiment where mutually aligned protrusions /\ 2, 43 are used respectively on the bottom surface 25 of the piston ring 23 and the bottom edge 26 of the piston ring groove 22. The two protrusions interact with each other and hold the piston ring at the desired distance above the bottom edge of the piston ring groove as follows that you can get the desired swing movement.

In -all examples of embodiment, it is assumed that the projection' should be a continuous ring projection, but it can of course also be a discontinuous one. For example, the protrusion may consist of several protrusions which may be spaced apart but together form the necessary support.

The embodiment examples only show vertical and inclined cylinders and associated pistons, but of course the invention can also • be used for pistons that move in horizontally lying cylinders.

Patent claims

1. Piston with a piston ring arranged in a circumferential groove 1. piston, characterized in that at least one (25) of the radially extending surfaces (25,28) on the piston ring (23) is arranged at a distance from the adjacent edge 26 in the groove (22) by means of a device (27) which allows a relative pivoting movement between the piston (20) and the piston ring.

2. Piston according to claim 1, characterized in that the piston (20) is arranged vertically or at an angle in relation to the vertical, the said one radially extending surface on the piston ring being the bottom surface (25) of the piston ring (23) and the said device ( 27) which allows a relative pivoting movement between the piston and the piston ring, supports the piston ring above the bottom edge (26) of the piston ring groove (22).

3" Piston according to claim 1, characterized in that the piston (20) is arranged vertically or at an angle in relation to the vertical, and in that the said radially extending surface on the piston ring is the top surface (28) of the piston ring (23).

4. Piston according to one of the preceding claims, characterized in that both radially extending surfaces (25,28) on the piston ring (23) are arranged at a distance from the respective adjacent edges (26,39) 1 the piston ring groove (22) by means of suitable devices (40.4D.

5. Piston according to one of the preceding claims, characterized in that the said spacer device(s) (27) is extended so that the axis of rotation has a distance from the wall of the cylinder (21) which is smaller than the distance between the respective radially extending surface (2' 8 ) on the piston ring (23) which is furthest from the pivot axis and the respective edge (26) in the piston ring groove (22) which is adjacent to the pivot axis.

6. Stamp according to requirements. 5, characterized in that the device or devices (27) are such that the axis of rotation has a distance from the cylinder wall (21) equal to between one-third and two-thirds of the distance between the radially extending surface (28) of the piston ring (23) which lies farthest from the axis of rotation and the edge (26) in the piston ring groove (22) which is adjacent to the pivot axis.

7. Piston according to one of the preceding claims, characterized in that the spacer device includes at least one projection (27) which forms a ring which lies between the aforementioned radially extending surface (25) on the piston ring (23) and the adjacent edge (26) in the piston ring groove (22).

8. Piston according to claim 7, characterized in that an annular projection (27) 34) is arranged which protrudes from the aforementioned adjacent edge (26) in the piston ring groove (22) to cooperate with the aforementioned extending surface (25) on the piston ring ( 23).

9. Piston according to claim 7, characterized in that an annular projection (3OJ 36) s <p> m protrudes from the aforementioned radially extending surface (25) on the piston ring (23) for cooperation with the adjacent edge (26) in the piston ring groove (22).

10. Piston according to claim 7, characterized in that there is arranged a first annular projection (43) which protrudes from the aforementioned adjacent edge (26) in the piston ring groove (22) and a second annular projection (42) which protrudes from the said radially extending surface (25) on the piston ring (23).

11. Piston according to one of the claims 8 to 10, characterized in that the ring-shaped projection or projections (27; 3^) 43» 4-2) are extended in one with the piston (20) or the piston ring (23).

12. Piston according to one of claims 8 to 10, characterized in that the ring-shaped projection or protrusions (§4> 3^) are extended as a separate element arranged in an annular groove in the adjacent edge (26) in the piston ring groove (22) or in the radially extending surface (25) of the piston ring (23), and protrudes from this groove.

13. Piston according to one of the preceding claims, characterized in that the device or devices (27 in 32) which allow pivoting movement between the piston (20) and the piston ring (23) provide surface or line contact between the respective radially extending surface of the piston ring or a posts that protrude from this, and that

adjacent edge in the piston ring groove (22) or an insert that protrudes from this.

14. Piston with a piston ring groove for receiving a piston ring, characterized in that the piston (20) has devices (27) 34) which project from at least one edge (26) in the piston ring groove (22) to thereby keep this edge at a distance from the adjacent radially extending surface (25, 28) on the piston ring (23) when it is inserted into the groove.

15. Piston ring for recording in a piston ring groove in a piston, characterized in that the piston ring (23) has devices (30" 36) which project from at least one (25) of the radially extending surfaces (25, 28) in order thereby to keep this surface at a distance from the adjacent edge (26) in the piston ring groove (22) when the piston ring is inserted in the groove.

16. Internal combustion engine or other machine with reciprocating piston or pistons, characterized in that it has a piston (20) according to one of claims 1 to 14, or a piston ring (23) according to claim 15.