Tenneco Inc.
PISTON RING, PISTON ASSEMBLY INCLUDING PISTON RING, AND METHODS OF MANUFACTURING

Abstract:

An oil ring for a piston of an internal combustion engine is provided. The oil ring is disposed in a ring groove of the piston and includes a counterbore along an inner diameter surface. A land in the piston which is located above the ring groove containing the oil ring includes a plurality of holes extending radially inwardly to the ring groove behind the counterbore of the oil ring. During operation, the oil ring will be energized during the power stroke by channeling combustion pressure from the piston land above the oil ring through the holes and to the area in the ring groove behind the oil ring. The oil ring is not energized during the remaining strokes, which results in a reduction of oil ring friction while still maintaining oil film control.