A piston and cylinder arrangement is disclosed in which a field of spaced pockets is provided on the walls of a piston skirt and/or the cylinder to create a seal equivalent between the piston and the cylinder. The pockets may be provided in a pattern having a plurality of vertically spaced rows.

A piston for an internal combustion engine has a plurality of recesses formed in a skirt including an upper, a lower, and a central portion. The recesses in the upper portion close to an upper boundary of the central portion have lower ends located upwardly at a given distance away from the upper boundary. The recesses in the central portion close to the upper boundary have upper ends located downwardly at the given distance away from the upper boundary. The recesses in the lower portion close to the lower boundary have upper ends located downwardly at the given distance away from the lower boundary. The recesses in the central portion closer to the lower boundary have lower ends located upwardly at the given distance away from the lower boundary. This enhances lubrication between the piston and an inner wall of a cylinder bore and reduces a friction loss of the piston.

Piston (1) of an internal combustion engine, which piston is designed in structured construction, comprising two oppositely arranged load-bearing skirt wall portions (2), wherein a connecting wall (3) respectively extends, starting from a pin boss (4), in the direction of the side edge of the load-bearing skirt wall portions (2), characterized in that in an interior of the piston (1) is (are) disposed at least one rib (5, 6, 7), preferably three ribs (5, 6, 7), and the material of the regions around the at least one rib (5, 6, 7) is reduced.

Piston (1) of an internal combustion engine, which piston is designed in structured construction, comprising two oppositely arranged load-bearing skirt wall portions (2), wherein a connecting wall (3) respectively extends, starting from a pin boss (4), in the direction of the side edge of the load-bearing skirt wall portions (2), characterized in that in an interior of the piston (1) is (are) disposed at least one rib (5, 6, 7), preferably three ribs (5, 6, 7), and the material of the regions around the at least one rib (5, 6, 7) is reduced.

A projecting-shape portion projecting toward a first sliding surface in a section along a sliding direction of a second sliding surface is provided on the second sliding surface which slides relative to the first sliding surface, and an apical portion, which is a most projecting part, and a bottom edge portion, which is at a position that is most spaced apart from the first sliding surface, are provided on the projecting-shape portion, and when a gap between the first sliding surface and the second sliding surface at the apical portion is assumed to be a minimum gap h1 and a gap at the bottom edge portion is assumed to be a maximum gap h2, h1 is set to be within a range of 0.5 m to 40 m and h2/h1 is set to be within a range of 1.5 to 5.0.

A sliding member includes a base substrate and a coating layer formed on the base substrate. The coating layer includes a copper alloy part derived from a plurality of precipitation hardening copper alloy particles. The copper alloy parts are bonded to each other via interfaces between the copper alloy parts. The copper alloy part contains nickel and silicon as additive elements. The copper alloy part contains 2 to 5 percent by mass of nickel.

A sliding member for an internal combustion engine includes the sliding member at a sliding part of the internal combustion engine.

A sliding member includes a base substrate and a coating layer formed on the base substrate. The coating layer includes a copper alloy part derived from a plurality of precipitation hardening copper alloy particles. The copper alloy parts are bonded to each other via interfaces between the copper alloy parts. The copper alloy part contains nickel and silicon as additive elements. The copper alloy part contains 2 to 5 percent by mass of nickel.

A sliding member for an internal combustion engine includes the sliding member at a sliding part of the internal combustion engine.

A brake master cylinder comprising a housing having an inner surface defining a bore, and a piston movable in the bore along a piston axis. The piston includes two spaced apart lands defining the radially outermost surfaces capable of contacting the inner surface. At least one of the lands is longitudinally curved at the radially outermost surface. For example, the land can be curved at a radius of less than 1 inch (e.g., between 0.15 inch and 0/75 inch) and preferably less than 0.5 inch. In one embodiment, the longitudinally curved land includes two edges that define an axial length of the land. The two edges have a radius of less than 0.2 inch, and preferably about 0.1 inch. The relative position of the edges and lands is such that neither of the two edges is capable of contacting the inner surface of the bore during reciprocating movement of the piston in the bore.

A brake master cylinder comprising a housing having an inner surface defining a bore, and a piston movable in the bore along a piston axis. The piston includes two spaced apart lands defining the radially outermost surfaces capable of contacting the inner surface. At least one of the lands is longitudinally curved at the radially outermost surface. For example, the land can be curved at a radius of less than 1 inch (e.g., between 0.15 inch and 0/75 inch) and preferably less than 0.5 inch. In one embodiment, the longitudinally curved land includes two edges that define an axial length of the land. The two edges have a radius of less than 0.2 inch, and preferably about 0.1 inch. The relative position of the edges and lands is such that neither of the two edges is capable of contacting the inner surface of the bore during reciprocating movement of the piston in the bore.

A Stirling cryocooler includes a displacer having a displacer base portion disposed on a center axis and a displacer tip portion aligned along the center axis, extending from the displacer base portion to a working-gas expansion space, and a regenerator disposed surrounding the displacer tip portion such as to guide reciprocating travel of the displacer along the center axis. The displacer tip portion includes a plurality of platelike components arranged along the center axis, with each of the plurality of platelike components being furnished with a component side surface defining a portion of the outer surface of the displacer tip portion. The plurality of platelike components form working gas layers between pairs of adjoining components, and/or are formed of a synthetic resin material.