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CN-121986226-A - Piston ring device and piston for hydrogen engine

CN121986226ACN 121986226 ACN121986226 ACN 121986226ACN-121986226-A

Abstract

The invention relates to a piston ring device for a hydrogen engine, which comprises a sealing system piston ring and a compression ring, wherein the sealing system piston ring and the compression ring are respectively arranged on an oil control ring and an oil scraper ring. Wherein the piston ring arrangement is adapted to control the pressure rise between the sealing system piston ring and the compression ring due to blow-by such that the pressure between the sealing system piston ring and the compression ring is higher than the pressure in the combustion chamber of the cylinder, in particular between 60 ° and 450 ° after the second part of the working stroke, i.e. the ignition top dead centre, preferably between 50 ° and 540 ° after the ignition top dead centre, more preferably between 20 ° and 540 ° after the ignition top dead centre, even more preferably between 0 ° and 540 ° after the ignition top dead centre. These pressure conditions are achieved at an engine speed of between 60 and 5000 rpm, preferably between 1500 and 4500 rpm, more preferably between 2000 and 4000 rpm, most preferably between 2500 and 3500 rpm.

Inventors

  • Richard mitler
  • Florian Schellenberg
  • Fei Bian.luhe

Assignees

  • 辉门布尔沙伊德公司

Dates

Publication Date
20260505
Application Date
20241002
Priority Date
20231006

Claims (18)

  1. 1. Piston ring arrangement for a hydrogen engine, comprising a piston ring set of three piston rings and an additional sealing system arranged above a first piston ring of the piston ring set, characterized in that the piston ring arrangement is adapted to control the pressure rise below the additional sealing system due to blow-by such that the pressure curve above the first piston ring and below the additional sealing system, in particular the second part of the working stroke between 60 ° and 540 ° after ignition top dead center, exceeds the combustion chamber pressure curve and is higher than the combustion chamber pressure curve within at least 80% of this defined range.
  2. 2. The piston ring apparatus for a hydrogen engine of claim 1, wherein said additional sealing system comprises one or more sealing system piston rings.
  3. 3. A piston ring arrangement for a hydrogen engine according to claim 1 or 2, wherein the piston ring set is moved in an axial direction towards the crankcase in order to make room for the additional sealing system.
  4. 4. A piston ring arrangement for a hydrogen engine according to claim 1, 2 or 3, wherein the additional sealing system is arranged above the original position of the first piston ring of the piston ring set.
  5. 5. A piston ring arrangement for a hydrogen engine according to claim 1,2,3 or 4, characterized in that the pressure curve above the first piston ring and below the additional sealing system is always above the pressure curve below the first piston ring of the ring set.
  6. 6. The piston ring arrangement for a hydrogen engine according to any of claims 1 to 5, wherein the blow-by of the first piston ring of the sealing group is increased by leakage compared to a conventional piston ring of low blow-by, for example, by adjusting the endplay to between 0.1 and 5mm, targeted side leakage or by using other design features.
  7. 7. A piston ring arrangement for a hydrogen engine according to any one of the preceding claims, wherein the volume is increased by an expansion tank.
  8. 8. Piston ring arrangement for a hydrogen engine according to any of the preceding claims 1 to 7, wherein the blow-by of the sealing system piston ring is increased by leakage (compared to conventional piston rings with low blow-by), for example by adjusting the endplay to between 0.1 and 5mm, targeted side leakage or by using other design features.
  9. 9. A piston ring arrangement for a hydrogen engine according to any preceding claim, wherein the pressure is maintained by adjusting the endplay.
  10. 10. A piston ring arrangement for a hydrogen engine according to any one of the preceding claims, wherein the height of the first piston ring of the piston ring set is reduced axially under the additional sealing system to reduce the inertial force of the first piston ring.
  11. 11. A piston ring arrangement for a hydrogen engine according to any one of the preceding claims, wherein at least one piston ring of the ring set is provided as a rectangular ring having an annular groove in the running surface below the pivot point.
  12. 12. A piston ring arrangement for a hydrogen engine comprising a sealing system piston ring and a first piston ring of a piston ring set, which is provided as a first compression ring, provided on an oil control ring and an oil scraper ring, wherein the piston ring arrangement is adapted to control the pressure rise between the sealing system piston ring and the first compression ring due to blow-by such that the pressure between the sealing system piston ring and the compression ring is higher than the pressure in the combustion chamber of the cylinder, in particular between 60 ° and 450 ° after the top dead centre of ignition, preferably between 50 ° and 540 ° after the top dead centre of ignition, still preferably between 20 ° and 540 ° after the top dead centre of ignition, even more preferably between 0 ° and 540 ° after the top dead centre of ignition (relative to the top dead centre of the working stroke), wherein these pressure conditions are achieved when the engine speed is between 60 and 5000 revolutions per minute, preferably between 4500 revolutions per minute, still preferably between 2000 and 4000 revolutions per minute, most preferably between 2500 and 3500 revolutions per minute.
  13. 13. Piston for a hydrogen internal combustion engine, comprising at least four piston ring grooves and being arranged for receiving a piston ring arrangement for a hydrogen engine according to any of the preceding claims, wherein at least one upper piston ring groove is arranged for receiving a sealing system piston ring and wherein at least one piston ring groove located below the at least one upper piston ring groove is arranged for receiving at least one first piston ring of the piston ring set.
  14. 14. Piston according to claim 13, further comprising at least one groove arranged between the two upper piston ring grooves and increasing the volume between the two upper compression piston rings, wherein the groove is preferably designed as at least one expansion groove.
  15. 15. Piston according to claim 13 and/or 14, wherein the at least one groove is provided as a number of circumferentially extending annular grooves forming a groove seal, and/or wherein a number of grooves form a grid circumferentially and axially, wherein the grid of grooves or recesses thereby forms a two-dimensional lattice seal, which seal restricts the flow of gas axially and circumferentially in the area between the upper two compression ring grooves.
  16. 16. A combination for a hydrogen engine of a piston ring arrangement according to any one of claims 1 to 12 and a piston according to any one of claims 13 to 15, wherein the combination further comprises at least one oil scraper ring and one oil control ring.
  17. 17. Internal combustion engine with at least one piston according to claims 13 to 15.
  18. 18. Internal combustion engine according to claim 17, comprising at least one cylinder provided with a DLC coating at least in the area in contact with the compression piston ring of the at least one piston, and/or wherein the internal combustion engine comprises a crankcase ventilation system with an oil separator.

Description

Piston ring device and piston for hydrogen engine Technical Field The present invention relates to a piston ring device and a piston for a hydrogen engine, in particular a hydrogen internal combustion engine. Background Hydrogen engines have problems with pre-ignition of the lubricating oil at high power levels, which can lead to spontaneous combustion of lubricating oil droplets entering the combustion chamber from between the upper compression ring and the cylinder wall through the previous intake stroke during the compression stroke. Different combustion boundary conditions may be achieved according to the injection principles of Direct Injection (DI) or manifold injection (PFI). As with conventional diesel engines, the compression stroke produces nearly adiabatic compression of the cylinder charge, resulting in a rise in temperature of the gases in the combustion chamber. The hydrogen and air mixture has a relatively high auto-ignition temperature of 585 ℃, which cannot be reached by conventional or higher compression ratios (at least without preheating the intake air). Because of the relatively high combustion speed of the hydrogen and air mixture, a pressure overlap is created during continued operation of the crankshaft after ignition, delivering individual droplets of oil to the combustion chamber, which droplets are also delivered by the gas volumetric flow. Another disadvantage is that the oil consumption of a hydrogen engine is expected to be similar to that of a corresponding conventional internal combustion engine, with about 5 litres of engine being expected to consume 100 ml of oil per 2500 kilometer, i.e. 4 ml of oil per hundred kilometers, for a fuel consumption of about 5 litres per hundred kilometers. Thus, hydrogen engines, while producing little carbon monoxide and carbon dioxide, do not have completely zero emissions. Therefore, it is necessary to further reduce the already very low oil consumption of the internal combustion engine. Disclosure of Invention According to a first aspect of the invention, a piston ring arrangement for a hydrogen engine is provided, comprising a piston ring set of three piston rings and an additional sealing system extending above a first piston ring of the piston ring set, characterized in that the piston ring arrangement is adapted to control the pressure rise below the additional sealing system due to blow-by such that the pressure curve above the first piston ring and below the additional sealing system, in particular between 60 ° and 450 ° after the second part of the working stroke, i.e. the ignition top dead center, is at least 80% higher than the combustion chamber pressure curve. In another embodiment of a piston ring assembly for a hydrogen engine, the additional sealing system includes one or more sealing system piston rings. In yet other embodiments of piston ring arrangements for hydrogen engines, the piston ring sets are moved axially in the direction of the crankcase to make room for an additional sealing system. In another additional embodiment of a piston ring arrangement for a hydrogen engine, an additional sealing system is located above the original position of the first piston ring of the piston ring set. In a further additional embodiment of the piston ring arrangement for a hydrogen engine, the pressure curve above the first piston ring and below the additional sealing system is always higher than the pressure curve below the first piston ring of the piston ring set. In another additional embodiment of a piston ring arrangement for a hydrogen engine, the blow-by of the first element of the seal assembly is increased by specifically providing a leak, as compared to a conventional piston ring of low blow-by. For example, this can be achieved by adjusting the endplay to between 0.1 and 5mm, targeted side leakage, or by using other design features or very large seal gaps or special undersize. In an exemplary additional embodiment of a piston ring arrangement for a hydrogen engine, the volume is increased by an expansion tank. The groove may be provided at will on the piston ring, thereby increasing the final volume between the piston and the cylinder wall. In another exemplary embodiment of a piston ring arrangement for a hydrogen engine, the blow-by of the sealing system piston ring is increased by leakage compared to a conventional sealing system piston ring of low blow-by, for example, by adjusting the endplay to between 0.1 and 5 millimeters, targeted side leakage, or employing other design features. In a further additional embodiment of a piston ring arrangement for a hydrogen engine according to any of the preceding claims, the pressure is maintained by adjusting the endplay. The endplay is here adjusted by endplay adjusting means, such as files. In a further additional embodiment of the piston ring arrangement for a hydrogen engine, the height of the first piston ring of the piston ring group is reduced in the axial direction under