Abstract: A power cylinder assembly for an internal combustion engine is provided. The power cylinder assembly includes a cylinder wall having a channel formed therein and a piston body with a skirt. A piston ring is seated within the channel of the cylinder wall and is sealed against the skirt of the piston body. Specifically, the piston ring has a ring body with an inner face that presents two radially inwardly extending ridges spaced axially from one another by a valley region, and the outer face presents a groove which receives a spring to bias the ridges into sliding engagement with the outer surface of the skirt of the piston body. The ring body also has at least one oil drainage port which extends radially between the valley region of the inner surface and the groove of the outer face for conveying oil from between the ridges into the groove.

Abstract: A piston ring including a base coating, for example a chromium-based material with an intentionally etched crack network is provided. The cracks of the base coating are filled with a sliding material, which is expected to improve scuff resistance. The sliding material includes polyamideimide (PAI) and Fe2O3. The sliding material can also include solid lubricant and hard materials. Alternatively, the base coating is formed of diamond-like carbon and applied to the piston ring by physical vapor deposition (PVD). In this case, the base coating includes protuberances or bumps, and the sliding material is disposed between protuberances of the base coating.

Abstract: A piston assembly comprises a piston body, a connecting rod, and a wrist pin. The piston body includes a pair of first cross bores presenting a piston sliding surface. The connecting rod includes a second cross bore presenting a rod sliding surface which is axially aligned with the first cross bores of the piston body. A wrist pin is disposed in the aligned cross bores and couples the piston body to the connecting rod. The wrist pin also presents a pin sliding surface facing the rod sliding surface and the piston sliding surfaces. A coating is applied to at least one of the sliding surfaces, such as by dipping, brushing, atomizing, spraying, printing, or screen printing. The coating includes a polymer matrix, such as polyamide imide (PAI), and hard particles, such as Fe2O3, disposed throughout the polymer matrix. The hard particles have a hardness of at least 600 HV/0.5.

Abstract: A cast iron having high strength, hardness, and thermal conductivity for a cylinder liner of an internal combustion engine is provided. The cast iron includes 3.2 wt. % to 3.8 wt. % carbon, 2.2 wt. % to 3.2 wt. % silicon, 0.5 wt. % to 1.3 wt. % copper, and at least 75.0 wt. % iron, based on the total weight of the cast iron. The cast iron further includes 0.01 wt. % to 0.5 wt. % manganese, 0.01 wt. % to 0.2 wt. % chromium, up to 0.3 wt. % phosphorous, up to 0.05 wt. % sulfur, up to 0.2 wt. % tin, and up to 0.1 wt. % magnesium, based on the total weight of the cast iron. Preferably, the cast iron is free of molybdenum, nickel, and vanadium. The cast iron is also heat treated and solidifies to achieve fully spheroidal graphite.

Abstract: A piston ring including a base coating, for example a chromium-based material with an intentionally etched crack network is provided. The cracks of the base coating are filled with a sliding material, which is expected to improve scuff resistance. The sliding material includes polyamideimide (PAI) and Fe2O3. The sliding material can also include solid lubricant and hard materials. Alternatively, the base coating is formed of diamond-like carbon and applied to the piston ring by physical vapor deposition (PVD). In this case, the base coating includes protuberances or bumps, and the sliding material is disposed between protuberances of the base coating.

Abstract: An engine component, for example a piston ring, including a wear resistant coating applied by physical vapor deposition (PVD) is provided. The coating includes tetrahedral amorphous carbon (ta-C), the carbon of the coating includes sp3 hybrid orbitals, and the coating includes boron in an amount of 0.1 wt. % to 4.0 wt. %, based on the total weight of the coating. The doped boron makes the coating less sensitive to the ion energy during the physical vapor deposition (PVD) process, improves adhesion of the coating, and expected to reduce compressive stress in the coating. Thus, the boron-doped ta-C coating can be applied to a greater thickness compared to ta-C coatings without the doped boron. In addition, there is a strong indication that the addition of boron will maintain a high level of sp3 bonded carbon and a high microhardness.

Abstract: A sliding element, such as a piston ring, including a substrate, base coating, and relatively thin sliding coating is provided. The base coating is typically applied to a running surface of the substrate by PVD, CVD, galvanic deposition, electrodeposition, or a thermal spray process. The sliding coating includes a polymer matrix and hard particles disposed throughout the matrix. The sliding coating is applied to the base coating when the base coating is still in its as-applied condition and has a surface roughness of at least 4.0 ?m. During use of the sliding element, the thin sliding coating acts as a sacrificial run-in layer. In addition, as the polymer matrix of the sliding coating wears away, the hard particles polish the rough surface of the base coating. Thus, polishing or lapping of the as-applied base coating prior to use of the sliding element is not required.

Abstract: A cast iron having high strength, hardness, and thermal conductivity for a cylinder liner of an internal combustion engine is provided. The cast iron includes 3.2 wt. % to 3.8 wt. % carbon, 2.2 wt. % to 3.2 wt. % silicon, 0.5 wt. % to 1.3 wt. % copper, and at least 75.0 wt. % iron, based on the total weight of the cast iron. The cast iron further includes 0.01 wt. % to 0.5 wt. % manganese, 0.01 wt. % to 0.2 wt. % chromium, up to 0.3 wt. % phosphorous, up to 0.05 wt. % sulfur, up to 0.2 wt. % tin, and up to 0.1 wt. % magnesium, based on the total weight of the cast iron. Preferably, the cast iron is free of molybdenum, nickel, and vanadium. The cast iron is also heat treated and solidifies to achieve fully spheroidal graphite.

Abstract: A sliding element, such as a piston ring, including a substrate, base coating, and relatively thin sliding coating is provided. The base coating is typically applied to a running surface of the substrate by PVD, CVD, galvanic deposition, electrodeposition, or a thermal spray process. The sliding coating includes a polymer matrix and hard particles disposed throughout the matrix. The sliding coating is applied to the base coating when the base coating is still in its as-applied condition and has a surface roughness of at least 4.0 ?m. During use of the sliding element, the thin sliding coating acts as a sacrificial run-in layer. In addition, as the polymer matrix of the sliding coating wears away, the hard particles polish the rough surface of the base coating. Thus, polishing or lapping of the as-applied base coating prior to use of the sliding element is not required.

Abstract: A sliding element, such as a piston ring, including a substrate, base coating, and relatively thin sliding coating is provided. The base coating is typically applied to a running surface of the substrate by PVD, CVD, galvanic deposition, electrodeposition, or a thermal spray process. The sliding coating includes a polymer matrix and hard particles disposed throughout the matrix. The sliding coating is applied to the base coating when the base coating is still in its as-applied condition and has a surface roughness of at least 4.0 ?m. During use of the sliding element, the thin sliding coating acts as a sacrificial run-in layer. In addition, as the polymer matrix of the sliding coating wears away, the hard particles polish the rough surface of the base coating. Thus, polishing or lapping of the as-applied base coating prior to use of the sliding element is not required.

Abstract: A piston ring for sealing a cylinder wall to a piston body is provided. The piston ring includes a ring body of an elastically deformable material which extends substantially circumferentially around an axis and has an inner face that faces the axis. The inner face includes a plurality of axially spaced and radially inwardly extending contact features. The ring body configured to bias the contact features into engagement with the piston body to establish a seal therebetween. At least one of the contact features extends substantially continuously around a circumference for establishing a substantially continuous seal around the piston body, and at least one of the contact features is non-continuous and has at least one recessed area for allowing the passage of oil and gas therethrough.

Abstract: A sliding element, such as a piston ring, including a substrate, base coating, and relatively thin sliding coating is provided. The base coating is typically applied to a running surface of the substrate by PVD, CVD, galvanic deposition, electrodeposition, or a thermal spray process. The sliding coating includes a polymer matrix and hard particles disposed throughout the matrix. The sliding coating is applied to the base coating when the base coating is still in its as-applied condition and has a surface roughness of at least 4.0 ?m. During use of the sliding element, the thin sliding coating acts as a sacrificial run-in layer. In addition, as the polymer matrix of the sliding coating wears away, the hard particles polish the rough surface of the base coating. Thus, polishing or lapping of the as-applied base coating prior to use of the sliding element is not required.

Abstract: A piston ring for sealing a cylinder wall to a piston body is provided. The piston ring includes a ring body that extends about an axis and has inner and outer faces. The inner face presents a pair of ridges that extend in a radially inward direction, and the outer face presents a groove. A spring of an elastomeric material substantially circumferentially surrounds the ring body and is seated in the groove on the inner face. The spring biases the ring body in the radially inward direction to seal the ridges against the piston body. The ring body also has at least one oil drainage port which extends at an angle relative to the radially inward direction from the inner face to a location on the outer face on one axial side of the spring for conveying oil out of a space between the ridges.