STEEL-MADE COMBINED OIL CONTROL RING

摘要

PROBLEM TO BE SOLVED: To prevent the wear of irregularities formed on a lug part in a steel- made oil control ring for arresting the relative rotation of a steel-made side rail by means of the irregularities formed on the circumferential surface of the lug part of a spacer expander to abut on the side rail, and also to prevent the reduction in life of a metal mold for forming the irregularities. SOLUTION: Circumferential irregularities 4 formed of two or more axially extending groove parts 6 and three or more flat parts 5 are formed on the circumferential surface of the lug part 3 of the spacer expander 2 on which the side rail abuts, and the total circumferential width of the flat parts 5 is set to 30-70% of the circumferential width of the lug part.