Abstract: A piston for an opposed-piston, internal combustion engine includes a crown with an end surface having a bowl shaped to form a combustion chamber with an end surface of an opposing piston in the opposed-piston engine. A substantially circumferential top land of the crown meets the end surface at a substantially circular peripheral edge, and a skirt comprising a sidewall extends from a substantially circumferential belt region of the crown. A wristpin bore with a wristpin axis opens through the sidewall. The end surface of the piston includes a pair of injection regions across which fuel is injected into the bowl. The injection regions are disposed in substantially diametrically-opposed quadrants of the end surface which are defined by the wristpin axis and a connecting rod envelope axis substantially orthogonal to the wristpin axis. Each injection region extends along a respective arc concentric with the substantially circular peripheral edge.

Abstract: A piston for an internal combustion opposed-piston engine includes a crown part, a skirt part, and an outer part. The crown part includes a first ring belt region for supporting compression rings and an end surface shaped to form a combustion chamber with an end surface of an opposing piston. The skirt part includes a sidewall and a wristpin bore with a first opening and a second opening formed in the sidewall. The outer part includes a second ring belt region for supporting oil control rings. The crown part is joined to an upper end of the sidewall with one or more welding seams. The outer part is joined to a lower end of the sidewall with a welding seam.

Abstract: In an opposed-piston engine, a piston has a top land. The piston top land has a non-cylindrical shape which affords more clearance with a piston bore to thrust and anti-thrust sides than to front-facing and rear facing sides.

Abstract: In an opposed-piston engine, a piston has a top land. The piston top land has a non-cylindrical shape which affords more clearance with a piston bore to thrust and anti-thrust sides than to front-facing and rear facing sides.

Abstract: Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

Abstract: A piston for an opposed-piston, internal combustion engine includes a crown with an end surface having a bowl shaped to form a combustion chamber with an end surface of an opposing piston in the opposed-piston engine. A substantially circumferential top land of the crown meets the end surface at a substantially circular peripheral edge, and a skirt comprising a sidewall extends from a substantially circumferential belt region of the crown. A wristpin bore with a wristpin axis opens through the sidewall. The end surface of the piston includes a pair of injection regions across which fuel is injected into the bowl. The injection regions are disposed in substantially diametrically-opposed quadrants of the end surface which are defined by the wristpin axis and a connecting rod envelope axis substantially orthogonal to the wristpin axis. Each injection region extends along a respective arc concentric with the substantially circular peripheral edge.

Abstract: 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.

Abstract: A piston for an internal combustion opposed-piston engine includes a crown part, a skirt part, and an outer part. The crown part includes a first ring belt region for supporting compression rings and an end surface shaped to form a combustion chamber with an end surface of an opposing piston. The skirt part includes a sidewall and a wristpin bore with a first opening and a second opening formed in the sidewall. The outer part includes a second ring belt region for supporting oil control rings. The crown part is joined to an upper end of the sidewall with one or more welding seams. The outer part is joined to a lower end of the sidewall with a welding seam.

Abstract: 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.

Abstract: Pressurized lubricating oil is accumulated in the bearings of opposed pistons and accumulated oil is dispensed therefrom for bearing lubrication and also for cooling the undercrowns of the pistons by jets of oil emitted from the bearings.

Abstract: An opposed-piston engine includes pistons, each piston having an annular cavity in the piston's sidewall and positioned between its crown and ring grooves to block transfer of heat from the crown to the piston body.

Abstract: 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.

Abstract: A piston for an opposed-piston, internal combustion engine includes a crown with an end surface shaped to form a combustion chamber with an end surface of an opposing piston in the opposed-piston engine, a skirt part including a piston sidewall extending from the crown to an open end of the skirt part, a wristpin bore with first and second openings through the sidewall, a wristpin disposed in the wristpin bore, and at least two caps received in the first and second openings of the wristpin bore for sealing the wristpin bore and retaining the wristpin against axial movement.

Abstract: Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

Abstract: A combustion chamber for an opposed-piston engine has an elongated asymmetrical shape in longitudinal section that runs along a chamber centerline, between diametrically-opposed openings of the combustion chamber through which fuel is injected. The asymmetry apportions combustion chamber volume to provide additional clearance on a side of the chamber centerline toward which swirl is directed, thereby giving a fuel plume space to swing without hindrance in response to swirl.

Abstract: Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

Abstract: A piston construction with an end surface is equipped with a pattern of insulating cavities embedded in an upper end of the piston, between the end surface and interior portions of the piston that are cooled by circulating liquid coolant.

Abstract: Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

Abstract: Pistons for opposed-piston engines include an interior annular cooling gallery. The gallery is provided with inlet and drain passageways constructed to shield a jet of liquid coolant entering the gallery, thereby reducing interference between the incoming jet and liquid coolant circulating in the gallery.

Abstract: 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.