Crosshead turbocharged large 2-stroke uniflow scavenger piston ring used in internal combustion engine piston ring packs

摘要

PROBLEM TO BE SOLVED: To provide a piston ring capable of increasing the output and a new type of fuel, reducing scuffing of a mating member, and extending its own life. SOLUTION: A ring body 50 of a piston ring used for a piston ring pack in an annular ring groove on a side wall of a piston of a crosshead type turbocharged large 2-stroke uniflow scavenger internal combustion engine is axially separated at a ring height Hr. It has a first lateral surface 46 and a second lateral surface 47, and an outer peripheral surface 41 that is axially distributed over the entire ring height, and is a first surface between the outer peripheral surface and the first lateral surface. The transition portion is rounded, and the second transition portion between the outer peripheral surface and the second lateral surface is also rounded. The central portion of the axial range of the outer peripheral surface has a first hardness. The first edge portion distributed from the central portion to the first transition portion has a second hardness. The second edge portion distributed from the central portion to the second transition portion also has the second hardness. The first hardness is harder than the second hardness. [Selection diagram] FIG. 13