A piston in which a solid lubricant resin layer made of a resin containing a solid lubricant is formed at a skirt portion. A guide groove absent area where no guide groove is formed, which is provided in a predetermined range of the solid lubricant resin layer at a center portion in a width direction. The guide grooves directing from the both ends in the width direction of the guide groove absent area to both ends in the width direction of the skirt portion. The end portions of the guide grooves extended to end edges of the solid lubricant resin layer to form open ends. The solid lubricant resin layer and the guide grooves are formed at least at a thrust side skirt portion. The guide grooves are formed in a shape inclined upward from the guide groove absent area toward the end edges of the solid lubricant resin layer.

A piston (10) for an internal combustion engine includes a groove (16) for an oil wiper ring and a recess (18) between the groove (16) and at least one shaft wall (20). A lower edge of the groove (16), which is closer to the shaft wall (20), has a larger diameter than a lower edge of the recess (18).

The present disclosure is to provide a piston assembly in which a particle does not leak out of a cylinder, and including, in an embodiment, a piston body; a piston rod connected to the piston body; a first groove formed in an outer surface of the piston body; and a particle discharge flow path extending from an internal space of the piston body to the outer surface of the piston body.

The present disclosure is to provide a piston assembly in which a particle does not leak out of a cylinder, and including, in an embodiment, a piston body; a piston rod connected to the piston body; a first groove formed in an outer surface of the piston body; and a particle discharge flow path extending from an internal space of the piston body to the outer surface of the piston body.

To provide a piston for an internal combustion engine configured to ensure a required amount of cooling oil to be effectively guided to portions that need to be cooled and to achieve a lightweight structure. A piston 3 comprises a piston crown portion 24 including a top portion 21 and a pair of pin boss portions each having a piston pin hole to allow insertion of a piston pin and configures to be cooled by a cooling oil injected from an oil jet apparatus having a nozzle toward a back surface 30a of the top portion 21. The top portion 21 comprises cooling voids 29a, 29b provided near at least one of the pin boss portions inside the top portion 21 and inlet openings 35a, 35b provided on the back surface 30a and configured to guide the oil injected from the nozzle toward the cooling voids 29a and 29b.

A piston for an internal combustion engine includes a skirt and a crown coupled to the skirt. The crown is produced in isolation from the skirt using an additive manufacturing process. The piston includes a first air gap between the crown and the skirt. According to an example embodiment, the crown includes a plurality of sections produced in isolation from the skirt. The crown may include a second air gap disposed between two of the plurality of sections.

An engine includes a cylinder liner and a piston movable within the cylinder liner, a crevice formed between a top land of the piston and the cylinder liner, and an oil entry clearance formed between a top ring of the piston and the cylinder liner. The engine also includes an abnormal combustion inhibitor having an oil recapture surface exposed to the crevice and oriented to limit migration of oil from the crevice toward a combustion chamber in the engine. The abnormal combustion inhibitor includes a groove structure having as a substrate at least one of the cylinder liner or the piston. Related methodology is also disclosed.

A piston for a hydraulic unit of a cam phaser, wherein the piston is configured cylindrical and wherein the piston is received axially movable in a cam phaser opening of the cam phaser, wherein according to a positioning of the piston a plurality of connections, in particular operating connections of the cam phaser are opened and closed, wherein the piston includes an outer contour that is configured for opening or closing the connections wherein the outer contour is configured complementary to an inner contour of the cam phaser opening in order to provide opening and/or closing of the connections. The invention also relates to a cam phaser.

A piston for a hydraulic unit of a cam phaser, wherein the piston is configured cylindrical and wherein the piston is received axially movable in a cam phaser opening of the cam phaser, wherein according to a positioning of the piston a plurality of connections, in particular operating connections of the cam phaser are opened and closed, wherein the piston includes an outer contour that is configured for opening or closing the connections wherein the outer contour is configured complementary to an inner contour of the cam phaser opening in order to provide opening and/or closing of the connections. The invention also relates to a cam phaser.

It is an object of the present invention to provide a novel internal-combustion engine piston which makes it possible to achieve both an improvement in thermal efficiency and a reduction in exhaust harmful components, and to suppress the occurrence of abnormal combustion such as knocking and pre-ignition. A cooling passage is formed in a piston, and on a top face of the piston are provided a first heat shielding layer composed of a material having a lower thermal conductivity and volumetric specific heat than those of a piston base material, and a second heat shielding layer composed of a material having a lower thermal conductivity and volumetric specific heat than those of the first heat shielding layer, wherein a first distance between the first heat shielding layer and the cooling passage is set to be less than a second distance between the second heat shielding layer and the cooling passage. A cooling loss can be reduced by the second heat shielding layer, and the vaporization of fuel adhering to the piston can be promoted by the first heat shielding layer to reduce exhaust gas harmful components. Since the first distance is less than the second distance, the temperature of the first heat shielding layer does not rise excessively, whereby the occurrence of knocking and pre-ignition can be suppressed.