A galleryless piston for an internal combustion engine is provided. The piston has a monolithic piston body including an upper wall forming an upper combustion surface with first and second portions. The first portion extends annularly along an outer periphery of the upper wall and the second portion includes a combustion bowl. The first portion can also include valve pockets formed therein to reduce weight. The upper wall has an undercrown surface directly opposite the second portion of the upper combustion surface. To enhance cooling, a center portion of the undercrown surface is concave, such that oil is channeled during reciprocation of the piston from one side to the opposite side of the piston.

A piston assembly and method of construction thereof for an internal combustion engine are provided. The assembly includes a piston head having an upper combustion wall with an undercrown surface and a ring belt region. The piston head has a floor with an upper surface and a bottom surface. The floor is spaced beneath the upper combustion wall in radial alignment with the ring belt region. A substantially enclosed, annular cooling gallery is bounded by the undercrown surface and the floor. A pair of pin bores depends directly from the floor of the cooling gallery. The assembly further includes a pin having ends configured for oscillating receipt in the pin bores. A pin bearing surface extends within the pin bores and between the pin bores in the lower surface of the floor. The assembly includes a connecting rod with an end fixed to the pin for conjoint oscillation therewith.

A steel piston for coupling to a connecting rod and wrist pin is provided. The piston includes a body with an upper crown presenting a combustion surface for exposure to a combustion chamber. The upper crown presents an undercrown surface which is openly exposed as viewed from an underside of the piston and not bounded by a cooling gallery. The body includes a ring belt and pin bosses depending from the ring belt and presenting a pin bore for receiving the wrist pin. The body also includes ribs disposed along the undercrown surface. The body includes a ratio of compression height to outer diameter (CH/D) ranging from 34.8% to 42.0%. The piston also includes a low heat transfer coating on the combustion surface, and the low heat transfer coating has a thermal conductivity of about 0.20 to 0.80 W/m.Math.K.

A galleryless piston for an internal combustion engine and method of construction thereof are provided. The piston has a monolithic piston body extending along a central longitudinal axis. The piston body has an upper wall forming an upper combustion surface with first and second portions, with the first portion extending annularly along an outer periphery of the upper wall and the second portion forming a combustion bowl. The upper wall has an undercrown surface on an underside of the combustion bowl directly opposite the second portion of the upper combustion surface. The undercrown surface has an openly exposed 2-dimensional surface area, as viewed looking along the central longitudinal axis, between about 35-60 percent of an area defined by a maximum outer diameter of the piston body, thereby providing an expansive area against which oil being splashed or sprayed can freely contact to cool the piston.

A piston, (1) incorporates a pair of tear-drop shaped springs (6) acting, in use, between the crown (2) of the piston and an associated connecting rod (4) so as to bias the connecting rod away from the piston crown (2). The springs (6) are supported by support members (7 and 8), the springs being located substantially in the region of the piston crown (2). A carrier (5) is positioned within the piston (1), the carrier being slidably mounted within the piston for axial movement relative thereto, and being connected to the connecting rod (4) in such a manner that the springs (6) permit the carrier (5) to move axially relative to the piston crown (2). The springs (6) are made of a beta titanium alloy such as gum metal.

A piston for an internal combustion engine. The piston comprises a piston head and an articulated piston skirt. The piston head includes a crown and pin bosses depending from the crown. The piston skirt includes opposed thrust walls, opposed sidewalls, and a transverse bridge extending diametrically across the piston skirt, between the opposed sidewalls. A circumferential cooling gallery is encompassed within an outer circumferential ring belt section of the crown and is in fluid communication with a central cooling passage that extends between the crown and the piston skirt. The central cooling passage extends diametrically across the piston skirt, beneath at least a portion of the ring belt section and beneath at least a portion of an inner combustion bowl section of the crown.

An assembly for a combustion engine may include a piston and a connecting rod. The piston may include a piston crown, a piston skirt, and respective portions for accommodating a piston pin through which the piston is intended to be supported on the connecting rod. The piston skirt may have a completely closed bottom part and apertures may be provided in the portion for accommodating the piston pin. The apertures may seal against the piston pin to enclose a bottom part of the piston crown as well as the piston crown portion for accommodating the piston pin. The connecting rod may have a fork shape in an end facing the piston.

A piston assembly for internal combustion diesel engine having a piston diameter of 160-650 mm, the piston assembly including a top part, a body part and a gudgeon pin connectable to each other, the top part defining, when installed in a cylinder, the piston side of a combustion chamber, and the body part having an aperture for a gudgeon pin, bosses for distributing forces between the piston and the gudgeon pin, the body part having an interior, an outer surface and operable connecting surfaces, the gudgeon pin for pivotally connecting the piston to a connecting rod, is configured to be assembled and lockable by locking elements to the body part aperture in a given rotational orientation such that there is provided a conduit for supplying cooling oil from the connecting rod via the gudgeon pin to the bosses and to a cooling gallery between the top and body parts.

A piston structure for an engine is provided. The piston structure includes a piston for reciprocating within a cylinder, a connecting rod having a smaller-end part and a larger-end part in both ends, respectively, the smaller-end part coupled to the piston, the larger-end part coupled to a crankshaft, a cross-sectionally hollow piston pin coupling the piston to the smaller-end part, and a dynamic absorber provided inside the piston pin, including a fixed part fixed to the piston pin and a movable part pivotally supported by the fixed part, and for suppressing the piston, the piston pin, and the smaller-end part from integrally resonating with respect to the larger-end part of the connecting rod on combustion stroke. The dynamic absorber includes an assemblable dynamic absorber in which the movable part is formed by attaching a mass adjusting part to the fixed part.

A piston for an internal combustion engine. The piston comprises a piston head and an articulated piston skirt. The piston head includes a crown and pin bosses depending from the crown. The piston skirt includes opposed thrust walls, opposed sidewalls, and a transverse bridge extending diametrically across the piston skirt, between the opposed sidewalls. A circumferential cooling gallery is encompassed within an outer circumferential ring belt section of the crown and is in fluid communication with a central cooling passage that extends between the crown and the piston skirt. The central cooling passage extends diametrically across the piston skirt, beneath at least a portion of the ring belt section and beneath at least a portion of an inner combustion bowl section of the crown.