Locomotive Diesel Engine 6ЧН 21/21 Piston Ring Set

Used in the pistons of the 6-cylinder, two-stroke diesel engine 6ChN 21/21 commonly found in Russian/Soviet-built diesel locomotives (e.g., TGM series shunting locomotives).
The piston rings for the 6ChN 21/21 locomotive diesel engine are critical cast iron sealing components, often chrome-plated, comprising compression rings and a multi-piece oil control ring. They function to seal combustion gases, manage heat transfer, and regulate cylinder wall lubrication within the approximately 210mm bore cylinders of this common Russian 6-cylinder two-stroke engine.

 

Provide critical sealing between the piston and the cylinder liner:

Compression Rings (Top/Middle): Seal the combustion chamber, preventing high-pressure gases from escaping into the crankcase (blow-by) and transferring heat from the piston to the liner.

Oil Control Ring (Bottom): Regulate the amount of lubricating oil on the cylinder wall, scraping excess oil back into the crankcase to prevent excessive oil consumption and smoke.

 

Material: Typically made from high-grade cast iron with specific alloying elements for strength, wear resistance, and heat tolerance. Often feature wear-resistant coatings like chromium plating on the running faces of the top compression ring(s).

 

Compression Rings: Usually feature a barrel-faced or tapered profile for better sealing and oil control. May have a positive twist design.

Oil Control Ring: Often a 3-piece design consisting of two thin steel rails (scrapers) and an expander/spacer.

 

Nominal Diameter: Approximately 210 mm (based on the"21"in 21/21, which signifies cylinder bore in cm).

Radial Width (Height): Several millimeters (specific dimensions vary per ring groove).

Axial Thickness: Several millimeters.