Abstract: A monobloc piston has a piston head with a combustion bowl formed in its upper surface and a plurality of ring grooves formed in an outer surface of a ring belt. An oil cooling gallery is formed in the piston head which is defined in part by a wall of the combustion bowl and ring belt. The piston has a unitized, immovable piston skirt which is formed as one piece with the pin bosses and fixed at its upper end to the ring belt. Piston rings are disposed in each of the ring grooves, and the piston head is further formed with an oil drainage groove which is located below the lowest of the ring grooves. The oil drainage groove is closed in the vicinity between adjacent pin bores but is open across outer side faces of the pin bores such that oil collected in the oil drainage is drained to the crank case across the open side faces to better manage the flow of oil scraped from the walls of the piston cylinder during operation of the piston to reduce oil consumption and hydrocarbon emissions.

Abstract: A monobloc piston has at least two steel parts welded together to define an inner cooling gallery. An outer ring belt is spaced from an inner annular support wall and is joined by a combustion bowl and a lower wall. A pair of pin bosses have axially aligned pin bores. A skirt is formed as one immovable piece with the pin bores.

Abstract: A piston for diesel engines includes a piston body having a closed oil gallery and a pair of pin bosses with axially aligned pin bores. The inner faces of the pin bosses are separated from one another by an intervening space between the pin bosses for receiving the upper end of a connecting rod, which has associated outer faces adjacent the inner faces of the pin bosses. Oil passages extend from the gallery and open to the inner faces of the pin bosses for providing direct lubrication to the inner faces.

Abstract: A piston for diesel engines includes a piston body having a closed oil gallery and a pair of pin bosses with axially aligned pin bores. The inner faces of the pin bosses are separated from one another by an intervening space between the pin bosses for receiving the upper end of a connecting rod, which has associated outer faces adjacent the inner faces of the pin bosses. Oil passages extend from the gallery and open to the inner faces of the pin bosses for providing direct lubrication to the inner faces.

Abstract: A steel monobloc piston for diesel engines is formed with a relatively short piston skirt whose lower edge resides below the axis of the pin bores of the piston, but located at or above a lowest tangent point of the pin bores. The piston body preferably has a closed oil cooling gallery and the skirt is preferably joined at its upper end to an outer wall of the piston in which a plurality of ring grooves are formed.

Abstract: A steel monobloc piston for diesel engines is formed with a relatively short piston skirt whose lower edge resides below the axis of the pin bores of the piston, but located at or above a lowest tangent point of the pin bores. The piston body preferably has a closed oil cooling gallery and the skirt is preferably joined at its upper end to an outer wall of the piston in which a plurality of ring grooves are formed.

Abstract: A piston for diesel engines includes a piston body formed with a closed oil gallery and a pair of pin bosses having axially aligned pin bores whose surfaces are spaced from one another about their circumference across an intervening gap between the pin bosses. The pin bore surfaces are each formed with a recess which extends in the axial direction of the pin bores across the full width of each of the pin bore surfaces. An oil passage leads from the gallery to each of the recesses and feeds the recesses with lubricating oil from the gallery. The recesses act as retention basins or reservoirs which collect and supply the pin bore surfaces with lubricating oil during the fall cycle of the piston.

Abstract: A closed gallery piston includes a piston body having a closed gallery for cooling oil defined in part by a bottom wall and outer wall of the piston body. At least one oil hole is formed in the bottom wall to accommodate a flow of cooling oil within the gallery. The bottom wall is locally thickened in the area bordering the oil hole with an oil hole boss to reinforce the bottom wall in the vicinity of the oil hole. The oil hole boss preferably joins with the outer wall to provide added structural integrity to the piston body at the juncture between the outer wall and bottom wall near the oil hole.

Abstract: A multi-axially forged mono-bloc piston includes a lower crown part forged of steel and including a pair of pin bosses and an integral skirt formed as one piece with the pin bosses 20. The lower crown part is friction welded to an upper crown part to form at least one closed oil gallery within the piston head. The lower crown part is forged in the longitudinal direction of the piston as well as laterally to impart longitudinal and laterally forged features of the piston. The laterally forged features may comprise undercut recesses formed in the piston skirt to reduce material in the overall piston structure. The lateral forging may also result in the piston skirt portion being discoupled from the piston head by laterally forged slots formed in the lower crown part 14 between the skirt and head.

Abstract: A piston (10) particularly suited for heavy duty diesel engine applications includes upper and lower crown sections (28, 30) joined by a friction weld (32) to define an annular ring belt (14) formed with ring groves (22) and having a lower end (20) and an internal piston cooling chamber (34). A pair of pin bosses (40) depend from the ring belt (14) and are formed as one piece with the lower crown section (30). A skirt (46) is also formed as one piece with the pin bosses (40) and has an upper end (48) that is spaced from the lower end (20) of the ring belt (14) to define a space (52) therebetween which effectively uncouples the skirt (46) from the ring belt (14).