METHOD FOR WORKING BARREL PROFILE OF PISTON RINGS Russian patent published in 1999 - IPC

FIELD: plastic working of metal in manufacture of piston rings for internal combustion engines. SUBSTANCE: method involves loosely fitting pack of piston rings on mandrel between beveled thrust washers; placing pack in grinding casing; imparting rotational and reciprocating motion along casing axis to mandrel and simultaneously imparting precessional motion to individual pin of each ring at frequency W equal to rotational speed of mandrel and additional oscillatory nutation motion at frequency Ω equal to reciprocating motion frequency, with nutation frequency exceeding precession frequency (Ω ≥ ω. W). Nutation changes angle between pins of rings from α to β, with α being less than 2 deg and β being within the range of 3-5 deg. EFFECT: increased efficiency, wider range of shapes of barrel profiles and improved quality of piston rings. 2 dwg