A bearing assembly comprising a first component and a second component, the first and second components being slidably disposed with respect to each other, wherein the first component slides relative to the second component in a first direction, wherein the first component comprises a plurality of first recesses formed in a first surface facing the second component, wherein the first recesses are distributed in a second direction perpendicular to the first direction with neighboring first recesses being spaced apart in the second direction with a first spacing, wherein the second component comprises a plurality of second recesses formed in a second surface facing the first surface of the first component, wherein the second recesses are distributed in the second direction with neighboring second recesses being spaced apart in the second direction with a second spacing, wherein the first recesses are sized to fit within the second spacings and the second recesses are sized to fit within the first spacings, and wherein the first and second components are urged into a relative position in the second direction in which the first and second recesses do not overlap one another.

A ringset is configured to be arranged on a piston for sealing a gas in a high-pressure region of a cylinder in the absence of oil or other liquid lubricant. The ringset includes one or more rings made from a high-strength material as a sealing element. The ringset also includes a solid lubricant applicator configured to provide lubrication between the one or more rings and a bore of the cylinder. For example, the ring can support pressure loads from high-pressure gas without breaking, while the applicator need not act as a seal. As the piston reciprocates in the bore, the applicator slides against the bore and applies solid lubricant material to the bore, resulting in a solid lubricant film on the bore against which the sealing element may slide. The applicator includes a material such as a graphite, a polymer, or other suitable solid lubricant.

A ringset is configured to be arranged on a piston for sealing a gas in a high-pressure region of a cylinder in the absence of oil or other liquid lubricant. The ringset includes one or more rings made from a high-strength material as a sealing element. The ringset also includes a solid lubricant applicator configured to provide lubrication between the one or more rings and a bore of the cylinder. For example, the ring can support pressure loads from high-pressure gas without breaking, while the applicator need not act as a seal. As the piston reciprocates in the bore, the applicator slides against the bore and applies solid lubricant material to the bore, resulting in a solid lubricant film on the bore against which the sealing element may slide. The applicator includes a material such as a graphite, a polymer, or other suitable solid lubricant.

A piston includes a piston body and a piston ring fitted into a ring groove. The piston ring has a top surface that includes: a convex portion formed between an inner edge position and a central position at which a radial direction thickness is , with the piston ring in a free state, and a planar portion or an inclined peripheral portion continuous with the convex portion on a radially outer side of the convex portion. In a predetermined status of the piston body and the piston ring, an angle between the top surface of the ring groove and the planar portion or the inclined peripheral portion is at least 18 arcminutes in a cross-section that is parallel to a central axis of the piston body and includes the central axis.

The present disclosure relates to powders and wires made from a copper-containing alloy. The copper-containing alloy is a copper-nickel-tin alloy or a copper-nickel-silicon-chromium alloy. Articles formed from the metal powder exhibit high thermal conductivity, high wear resistance, and thermal stability. The powders and wire also be used as a feed material for thermal spraying and copper-containing coatings are disclosed. The copper-containing alloy material promotes increased life of engine components and fuel efficiency when used as a cylindrical liner in an internal combustion engine.

To provide a piston ring excellent in thermal setting resistance, and also excellent in side surface wear resistance even under such a high-temperature high-pressure environment as to be more than 300 C. and up to 400 C., the base metal of the piston ring is a steel containing, by mass %, C: 0.30 to 0.65%, Si: 0.80 to 1.20%, Mn: 0.20 to 0.60%, Cr: 4.50 to 5.70%, Cu: 0.01 to 0.5%, and at least one of Mo, V, W, and Co: 0.2 to 5.4%.

A ringset is configured to be arranged on a piston for sealing a gas in a high-pressure region of a cylinder in the absence of oil or other liquid lubricant. The ringset includes one or more rings made from a high-strength material as a sealing element. The ringset also includes a solid lubricant applicator configured to provide lubrication between the one or more rings and a bore of the cylinder. For example, the ring can support pressure loads from high-pressure gas without breaking, while the applicator need not act as a seal. As the piston reciprocates in the bore, the applicator slides against the bore and applies solid lubricant material to the bore, resulting in a solid lubricant film on the bore against which the sealing element may slide. The applicator includes a material such as a graphite, a polymer, or other suitable solid lubricant.

A ringset is configured to be arranged on a piston for sealing a gas in a high-pressure region of a cylinder in the absence of oil or other liquid lubricant. The ringset includes one or more rings made from a high-strength material as a sealing element. The ringset also includes a solid lubricant applicator configured to provide lubrication between the one or more rings and a bore of the cylinder. For example, the ring can support pressure loads from high-pressure gas without breaking, while the applicator need not act as a seal. As the piston reciprocates in the bore, the applicator slides against the bore and applies solid lubricant material to the bore, resulting in a solid lubricant film on the bore against which the sealing element may slide. The applicator includes a material such as a graphite, a polymer, or other suitable solid lubricant.

A piston assembly for an internal combustion engine of a motor includes a piston head having an outer diameter surface spaced a first distance from the longitudinal axis and an annular surface spaced a second distance from the longitudinal axis, with the second distance being less than the first distance. Upper and lower walls extend between the annular surface and the outer diameter surface so as to define an annular groove in the outer diameter surface. A piston ring is received within the annular groove and includes an inner diameter surface facing the annular surface of the piston head. The inner diameter surface of the piston ring and the annular surface of the piston head cooperate with one another to define a plurality of pockets angularly spaced from one another about the longitudinal axis and configured to receive oil.

A piston for an internal combustion engine may include a piston head, an encircling fire land, and at least one annular groove structured to receive a piston ring and disposed contiguous to the fire land. The piston may include a first fire land portion having a first axial height h1, a second fire land portion having a second axial height h2, and a third fire land portion having a third axial height h3. The first fire land portion may have an upper external diameter D1. The third fire land portion may have a lower external diameter D3. A transition from the first to the second fire land portion may have a first external diameter D12. A transition from the second to the third fire land portion may have a second external diameter D23. The relationship (D12D23)/h2>(D23D3)/h3 may apply.