Piston oil-scraper ring - has internal electroplated chrome coating and external sprayed ferrous chrome one

摘要

The piston oil-scraper ring comprises top and bottom parts with an expander acting between them. The top and bottom parts (5a,5b) are coated along their inner peripheries with chrome deposited by galvanising or electroplating (2a,2b), while a ferrous chrome coating is sprayed onto their outer peripheries (6a,6b). The surfaces of the expander (7) in contact with these parts have a coating formed by soft nitriding. One or more of the compression rings can have its face working against the cylinder wall sprayed with a ferrous chrome layer.