Meaning of junk ring in English:

junk ring

noun

Engineering
  • 1(In various mechanisms) a metal ring which secures packing or stuffing that prevents leakage of fluid around a piston rod or other moving part.

  • 2A metal ring forming a tight seal against leakage in the cylinder of a steam engine or internal combustion engine, typically fitted either to the top of the piston or inside the head of the cylinder.

Origin

Mid 19th century; earliest use found in Robert Spencer Robinson (1809–1889), naval administrator.