PISTON Russian patent published in 1995 - IPC

FIELD: pump engineering. SUBSTANCE: trapezium hollows are provided in the face surfaces of piston rings over whole their thickness. The hollows are arranged uniformly over the periphery of the ring and shifted relatively to each other from both sides by half step. One face surface of the ring is provided with projections interposed between the hollows. The projections interact with grooves made in the separating flange. Cogs- locators constructed as projections are made on the inner cylindrical surfaces of the piston rings. The projections prevent against axial movement of the rings between middle and side flanges. EFFECT: improved design. 3 dwg