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 wrist pin and method of reducing wear between members thereof, a piston, a connecting rod, and methods of construction thereof are provided. The wrist pin has a first portion extending between opposite ends configured for receipt in piston pin bores and a second portion extending between opposite ends configured for receipt in the pin bores. The second portion is configured for relative movement with the first portion. The piston includes a piston body having axially aligned pin bores, wherein at least one of the pin bores has a feature to prevent relative rotation of a wrist pin member. The connecting rod includes a connecting rod body having small end bore. The small end bore has a contour to allow relative rotation of a first wrist pin member therein and a feature to prevent relative rotation of a second wrist pin member therein.

A method for the production of a piston made of steel, for an internal combustion engine, in which the upper piston part is produced using the forging method, and the lower piston part is produced using the forging or casting method, and they are subsequently welded to one another. To simplify the production method and make it cheaper, the upper piston part is forged using the method of hot forming and of cold calibration, to finish it to such an extent that further processing of the combustion bowl and of the upper cooling channel regions can be eliminated.

A cooling channel piston for an internal combustion engine which includes a piston bottom and a piston shaft that are joined thereto of a friction welding process. The piston bottom and the piston shaft jointly form a cooling channel. An annular wall which radially delimits the cooling channel towards the outside is formed by the piston bottom and/or the piston shaft. The annular wall can be sealed by a welding process once the piston bottom and the piston shaft have been joined together.

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.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing unitary hollow pistons from a single solid rod as a starting material.

A piston housing manufactured by an additive manufacturing process is provided. The piston housing may comprise a plurality of chambers. The chambers may be in fluid communication with one another via non-linear fluid passageways. The non-linear fluid passageways may be defined in structural members configured to stiffen the piston housing.

A method of constructing a piston, piston formed thereby, and piston body portions are provided. The method includes providing an upper crown portion at least one annular upper rib depending from the upper combustion wall to a free end having a tapered peak. The method further includes providing a lower crown portion having at least one annular lower rib extending to a free end having a tapered peak. Then, moving the upper crown portion and the lower crown portion toward one another and initiating contact between the upper crown portion and the lower crown portion at their respective tapered peaks. Then, continuing moving the upper crown and the lower crown further toward one another after making initial contact at their respective tapered peaks and forming a friction weld joint between the free ends of the at least one upper rib and the at least one lower rib free end.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing hollow pistons from the single piece of starting material.

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.