High Performance Piston Rings for Two-Stroke Marine Diesel Engines
2004 (English)In: Proceedings // 24th CIMAC World Congress on Combustion Engine Technology, 2004Conference paper (Other academic)
The piston ring is a key component in a marine combustion engine. High mechanical loads, relatively high temperatures and corrosive gases and liquids influence its performance in terms of sealing capacity, wear of cylinder liner and the ring itself. Base material of the ring, coating technology and ring geometry design are discussed in the article.
When tailoring cast iron materials suitable as piston ring base material two parameters are of importance; the morphology of the graphite and the constituents of the matrix. To optimize the properties of the cast iron a compromise is needed to achieve a satisfactory performance of the piston rings.
Daros Piston Rings AB is currently developing a second generation of chromium-ceramic coating the so called Z-chrome. The objective of this project has been to increase the maximum operating temperature of the coating and leave the other characteristics of the coating unaffected. The difference between the commercial Daros coating Tritor® and the Z-chrome is the ceramic component included in the coated layer.
Insufficient conformability of piston ring and liner geometry may produce a large local cylinder wall pressure which will destroy the oil film leading to uncontrolled wear and scuffing. Lack of conformability can also produce leakage paths for the combustion gases. Therefore a correct ring shape is of utmost importance. A new design philosophy designated OPCORE® has been developed and is presented here.
Place, publisher, year, edition, pages
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-14415OAI: oai:DiVA.org:liu-14415DiVA: diva2:23467
24th CIMAC World Congress on Combustion Engine Technology, June 7-11, Kyoto, Japan