| 摘要 |
PROBLEM TO BE SOLVED: To provide a three-piece oil ring capable of reducing lubricating oil consumption even in a case of reducing a width of the oil ring more and of reducing tension thereof more.SOLUTION: In a three-piece oil ring 3, a spacer expander includes: lug parts respectively projecting in the axial direction to push inner peripheries of a first and a second side rails inside in the radial direction; and side rail support parts respectively projecting in the axial direction to support axial end surfaces of the first and the second side rails. A ratio 2X/Y of a total distance 2X of respective axial projecting distances of the side rail support parts to a distance Y between both the axial end surfaces of both the lugs is 0.13-0.25, and a ratio P/Y of a pitch P between projecting parts or recessed parts of the spacer expander to the distance Y is 1.35-1.65. |
