A piston ring having a ring-shaped body with at least one internal wall surface configured to bear against the piston, an exterior wall surface, and at least a top wall surface extending from the exterior wall surface to the at least one internal wall surface and capable of intersecting a top surface of the piston to form an extended top surface of the piston when mounted on the piston. The top wall surface of the ring cooperates with the piston top surface to form a reservoir that collects liquid scraped off the cylinder wall, thereby reducing or eliminating blow-by of contaminants to the crankcase.

A piston ring having a ring-shaped body with at least one internal wall surface configured to bear against the piston, an exterior wall surface, and at least a top wall surface extending from the exterior wall surface to the at least one internal wall surface and capable of intersecting a top surface of the piston to form an extended top surface of the piston when mounted on the piston. The top wall surface of the ring cooperates with the piston top surface to form a reservoir that collects liquid scraped off the cylinder wall, thereby reducing or eliminating blow-by of contaminants to the crankcase.

The piston ring assembly having a first and a second endless sealing ring and an elastic ring carrier, the first and the second sealing ring extending in a circumferential direction (U) and each having an outer circumferential surface, the first sealing ring having a first center point (M1) with respect to its outer circumferential surface and the second sealing ring having a second center point (M2) with respect to its outer circumferential surface, the first and second sealing rings each having a longitudinal axis (L) running perpendicular to the circumferential direction (U), wherein the ring carrier runs in the circumferential direction (U), and wherein the ring carrier and the first and second sealing rings are designed to be mutually adapted in such a way that the first and second sealing rings are arranged one after the other in the ring carrier in the direction of the longitudinal axis (L), and in that their first and second centers (M1, M2) are arranged at a distance from one another radially with respect to the longitudinal axis (L), the sealing rings being pressed in opposite directions against the inner wall of a cylinder when the piston ring assembly is used in accordance with the invention.

The piston ring assembly having a first and a second endless sealing ring and an elastic ring carrier, the first and the second sealing ring extending in a circumferential direction (U) and each having an outer circumferential surface, the first sealing ring having a first center point (M1) with respect to its outer circumferential surface and the second sealing ring having a second center point (M2) with respect to its outer circumferential surface, the first and second sealing rings each having a longitudinal axis (L) running perpendicular to the circumferential direction (U), wherein the ring carrier runs in the circumferential direction (U), and wherein the ring carrier and the first and second sealing rings are designed to be mutually adapted in such a way that the first and second sealing rings are arranged one after the other in the ring carrier in the direction of the longitudinal axis (L), and in that their first and second centers (M1, M2) are arranged at a distance from one another radially with respect to the longitudinal axis (L), the sealing rings being pressed in opposite directions against the inner wall of a cylinder when the piston ring assembly is used in accordance with the invention.

In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.

In some two-stroke engines, a stationary ring is disposed in a groove in the cylinder liner. However, it is a challenge to install such a stationary ring while maintaining a narrow gap to minimize gas flow through the gap. A ring system for an internal combustion engine is disclosed that includes an L-shaped, split ring with a reentrant angle and a nested, split ring with a convex quadrilateral cross section nested with the L-shaped ring proximate the reentrant angle. The two rings are affixed so that the two gaps of the split rings cannot align. Or, in other embodiments, the two are allowed to rotate relative to each other over a predetermined angle.