Abstract: A single-piece oil control ring for a piston may include a body having at least one upper portion and at least one lower portion each facing towards a cylinder wall of an internal combustion engine. At least one of the upper portion and the lower portion may respectively define a first surface extending substantially perpendicular to the body and a receding second surface extending from the first surface substantially at an incline. The first surface may protrude towards the cylinder wall in relation to the second surface. The first surface may have a first area of contact with the cylinder wall, and at least 95% of the first area may contact the cylinder wall.

Abstract: A single-piece oil control ring for a piston may include a body having at least one upper portion and at least one lower portion each facing towards a cylinder wall of an internal combustion engine. At least one of the upper portion and the lower portion may respectively define a first surface extending substantially perpendicular to the body and a receding second surface extending from the first surface substantially at an incline. The first surface may protrude towards the cylinder wall in relation to the second surface. The first surface may have a first area of contact with the cylinder wall, and at least 95% of the first area may contact the cylinder wall.

Abstract: A three-piece oil control ring is provided for use in a piston groove of an internal combustion engine. The ring comprises a first annular segment and a second annular segment, associated to an expanding element. The expander has a substantially annular shape and comprises a first end facing the internal wall of the groove when the ring is mounted on the piston and a second opposite end. The ring further comprises an intermediate portion having at least one protrusion for association with the segments. Still further, the first end exhibits first thickness value (E1), the second end exhibits second thickness value (E2) and the substantially intermediate portion exhibits third thickness value (E3), wherein the value of (E1) is substantially lower than the value of (E3) and lower or similar to the value of (E2), the difference between (E1) and (E3) being substantially higher than that between (E1) and (E2).

Abstract: A three-piece oil control ring is provided for use in a piston groove of an internal combustion engine. The ring comprises a first annular segment and a second annular segment, associated to an expanding element. The expander has a substantially annular shape and comprises a first end facing the internal wall of the groove when the ring is mounted on the piston and a second opposite end. The ring further comprises an intermediate portion having at least one protrusion for association with the segments. Still further, the first end exhibits first thickness value (E1), the second end exhibits second thickness value (E2) and the substantially intermediate portion exhibits third thickness value (E3), wherein the value of (E1) is substantially lower than the value of (E3) and lower or similar to the value of (E2), the difference between (E1) and (E3) being substantially higher than that between (E1) and (E2).

Abstract: This invention refers to the solution of problem of spalling of the nitrided layer in piston rings for Flex-fuel engines, without jeopardizing the wear resistance, suggesting for such purpose a nitrided piston ring (100,100?) equipped with two nitrided layers (1,2), with metallic base (3) composed mainly of iron and whose superficial hardness presented is of about 800 Vickers, decreasing in a substantially linear manner up to about 400 Vickers for a distance to the surface of up to 90 microns (?m).

Abstract: This invention refers to the solution of problem of spalling of the nitrided layer in piston rings for Flex-fuel engines, without jeopardizing the wear resistance, suggesting for such purpose a nitrided piston ring (100,100?) equipped with two nitrided layers (1,2), with metallic base (3) composed mainly of iron and whose superficial hardness presented is of about 800 Vickers, decreasing in a substantially linear manner up to about 400 Vickers for a distance to the surface of up to 90 microns (?m).

Abstract: An oil-control ring for an internal combustion engine, to be mounted between the sidewalls of a respective groove of a piston has two ring segments and an annular expander disposed between the two ring segments and presenting a support body defining a seating plane for each ring segment. The ring has at least one expander portion axially projecting from the support body of the expander, beyond at least one of the seating planes of a ring segment, and at least one superficial irregularity provided in at least one of the ring segments and which is dimensioned to be contained in the thickness of the respective ring segment and to interfere with at least one expander portion, in order to rotatively lock the ring segment in relation to the expander.

Abstract: An oil-control ring for an internal combustion engine, to be mounted between the sidewalls of a respective groove (10) of a piston (P) and comprising two ring segments (20) and an annular expander (30) disposed between the two ring segments (20) and presenting a support body (31) defining a seating plane for each ring segment (20), the ring further comprising: at least one expander portion (40) axially projecting from the support body (31) of the expander (30), beyond at least one of the seating planes of a ring segment (20); and at least one superficial irregularity (50) provided in at least one of the ring segments (20) and which is dimensioned to be contained in the thickness of the respective ring segment (20) and to interfere with at least one expander portion (40), in order to rotatively lock said ring segment (20) in relation to the expander (30).

Abstract: An oil ring for an internal combustion engine, comprising a metallic annular body (10) to be mounted around a piston (P) reciprocating inside a cylinder (C) of the engine, said annular body (10) having opposite lateral faces (11), an internal face (12) onto which will be seated a resilient expander (M), and an external contact face (13) to be seated against the internal face of the cylinder (C) and having a height (h) that is substantially smaller than the height (H) of the internal face (12). Each lateral face (11) is defined by one or more lateral face portions (11a, 11b), which are designed to reduce the moment of inertia of the annular body (10), giving higher conformability to the latter. Preferentially, but not exclusively, the annular body (10) can be further provided with channels (15, 16), extended along at least part of the ring hight and which are radially spaced back in relation to the external contact face (13).

Abstract: An oil ring for an internal combustion engine, comprising a metallic annular body (10) to be mounted around a piston (P) reciprocating inside a cylinder (C) of the engine, said annular body (10) having opposite lateral faces (11), an internal face (12) onto which will be seated a resilient expander (M), and an external contact face (13) to be seated against the internal face of the cylinder (C) and having a height (h) that is substantially smaller than the height (H) of the internal face (12). Each lateral face (11) is defined by one or more lateral face portions (11a, 11b), which are designed to reduce the moment of inertia of the annular body (10), giving higher conformability to the latter. Preferentially, but not exclusively, the annular body (10) can be further provided with channels (15, 16), extended along at least part of the ring hight and which are radially spaced back in relation to the external contact face (13).