A piston for an internal combustion engine may include a ring belt, a groove, and an additional groove. The ring belt may extend along an axial direction. The groove may be arranged on the outer circumference of the ring belt and may be configured to receive an oil scraper ring. The additional groove may be arranged on the outer circumference spaced apart from the groove with respect to the axial direction. The additional groove may include a first groove side axially facing away from the groove and a second groove side axially facing the groove. The first groove side may include an axial step.

A piston for use in 4 Cycle reciprocating Internal Combustion Engines. The one embodiment includes a multifunctional Engraving or Imprint that is machined into the crown of the piston. This “Imprint” consists of concentric circles of metal removed in a machining process resulting in the compartments of the functional areas within the crown of the piston connected by either the height and or cross drillings within the Imprint. The functional result is to create low and high pressure zones within the crown of the piston as it proceeds upward on the compression stroke facilitating the creation of an active moving rotational swirl in the outer 25% on the top surface area of the piston circumference. The active swirl pattern results in ultimate homogenization of the air fuel mixture leaving no area of the combustion chamber with weak or separated air and fuel molecules resulting in enhanced power and complete combustion.

A piston for use in 4 Cycle reciprocating Internal Combustion Engines. The one embodiment includes a multifunctional Engraving or Imprint that is machined into the crown of the piston. This “Imprint” consists of concentric circles of metal removed in a machining process resulting in the compartments of the functional areas within the crown of the piston connected by either the height and or cross drillings within the Imprint. The functional result is to create low and high pressure zones within the crown of the piston as it proceeds upward on the compression stroke facilitating the creation of an active moving rotational swirl in the outer 25% on the top surface area of the piston circumference. The active swirl pattern results in ultimate homogenization of the air fuel mixture leaving no area of the combustion chamber with weak or separated air and fuel molecules resulting in enhanced power and complete combustion.

A ducted combustion system is disclosed. The ducted combustion system includes a combustion chamber bound by a flame deck surface of a cylinder head of an internal combustion engine and by a piston top surface of a piston disposed within the internal combustion engine. The system includes a fuel injector including a plurality of orifices, the plurality of orifices injecting fuel into the combustion chamber as a plurality of fuel jets. The system includes a duct structure defining a plurality of ducts and disposed within the combustion chamber between the flame deck surface and the piston top surface, the plurality of ducts being disposed such that each of the plurality of fuel jets at least partially enters one of the plurality of ducts upon being injected into the combustion chamber.

A galleryless piston and method of construction provide a piston body forged from a single piece of material having an upper combustion surface extending around a longitudinal center axis along which the piston reciprocates for exposure to a combustion chamber of an internal combustion engine. The upper combustion surface has an asymmetric geometry relative to a center plane extending along the central longitudinal axis in generally perpendicular relation to a pin bore axis.

A galleryless piston and method of construction provide a piston body forged from a single piece of material having an upper combustion surface extending around a longitudinal center axis along which the piston reciprocates for exposure to a combustion chamber of an internal combustion engine. The upper combustion surface has an asymmetric geometry relative to a center plane extending along the central longitudinal axis in generally perpendicular relation to a pin bore axis.

A piston crown for a piston of a pair of pistons in a two-stroke, opposed-piston, compression ignition combustion engine has a barrier layer and a conductive layer. The barrier layer at least partially surrounds a combustion chamber formed by the piston crown and an end surface of an opposing piston. The conductive layer connects the crown to the rest of the piston body. The barrier layer and the conductive layer are joined either through welding or through the fabrication process. Optionally, the piston crown includes an insulating layer between the barrier and conductive layers.

The present disclosure relates to a piston for a reciprocating-piston internal combustion engine, comprising a piston head and a piston barrel, wherein the piston head has an encircling ring belt with at least one ring groove for a piston ring and has, in the region of the ring belt, an encircling cooling duct. The cooling duct extends from the ring belt as far as a wall of the piston barrel in order to increase an oil film temperature of the oil film in the cylinder liner between the piston barrel and cylinder and to thereby reduce the piston barrel friction.

A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.

A piston for a reciprocating piston machine includes a piston crown, a piston recess, and an annular groove formed in the piston crown. The annular groove extends in a radial direction of the piston outwards and a cross-section of the annular groove has a half-teardrop shape. The half-teardrop shape has a first radius and a second radius where the second radius is directly contiguous with the first radius outwards in the radial direction of the piston and where the second radius is greater than the first radius.