Abstract: A piston for an internal combustion engine is formed from an upper part connected to a lower part. The upper part has a combustion bowl, a top land, and a ring belt extending circumferentially around the piston upper part. The lower part contains pin bosses and a piston skirt. A circumferential cooling channel is formed by joining the upper and lower parts. There is an oil inlet formed in one piece with the piston lower part. The inlet has a lower extremity and an upper extremity that terminates at the floor of the cooling channel. A bore extends through the oil inlet from the lower extremity up though the floor of the cooling channel. The circumference of the bore increases from the upper extremity to the lower extremity, so the oil inlet forms a funnel shape.

Abstract: A pre-finished piston part is disclosed that may be used to form a piston assembly. A pre-finished piston may include a lower part defining a piston axis, the lower part having a skirt and forming a lower surface of a cooling gallery. The lower part may include a radially inner bowl surface defining a lower part radially inner mating surface. The pre-finished piston assembly may further include an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint. The upper part may include a radially inner wall defining a radially inner upper part mating surface. The radially inner wall may define a radially inwardly facing surface that defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets the radially innermost edge of the radially inner mating surface.

Abstract: Exemplary pistons and methods of making the same are disclosed. An exemplary piston may include a crown defining a combustion bowl and a ring land extending circumferentially around the combustion bowl. Exemplary pistons may further include a skirt supporting the crown. The skirt may include a pair of pin bosses defining a pin bore configured to receive a piston pin, and two opposing skirt supports defining surfaces configured to slide along a cylinder bore surface. The skirt supports each define a different radial stiffness.

Abstract: A piston for an internal combustion engine is formed from an upper part connected to a lower part. The upper part has a combustion bowl, a top land, and a ring belt extending circumferentially around the piston upper part. The lower part contains pin bosses and a piston skirt. A circumferential cooling channel is formed by joining the upper and lower parts. There is an oil inlet formed in one piece with the piston lower part. The inlet has a lower extremity and an upper extremity that terminates at the floor of the cooling channel. A bore extends through the oil inlet from the lower extremity up though the floor of the cooling channel. The circumference of the bore increases from the upper extremity to the lower extremity, so the oil inlet forms a funnel shape.

Abstract: Exemplary pistons and methods of making the same are disclosed. An exemplary piston may include a crown defining a combustion bowl and a ring land extending circumferentially around the combustion bowl. Exemplary pistons may further include a skirt supporting the crown. The skirt may include a pair of pin bosses defining a pin bore configured to receive a piston pin, and two opposing skirt supports defining surfaces configured to slide along a cylinder bore surface. The skirt supports each define a different radial stiffness.

Abstract: A pre-finished piston part is disclosed that may be used to form a piston assembly. A pre-finished piston may include a lower part defining a piston axis, the lower part having a skirt and forming a lower surface of a cooling gallery. The lower part may include a radially inner bowl surface defining a lower part radially inner mating surface. The pre-finished piston assembly may further include an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint. The upper part may include a radially inner wall defining a radially inner upper part mating surface. The radially inner wall may define a radially inwardly facing surface that defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets the radially innermost edge of the radially inner mating surface.

Abstract: A pre-finished piston part is disclosed that may be used to form a piston assembly. A pre-finished piston may include a lower part defining a piston axis, the lower part having a skirt and forming a lower surface of a cooling gallery. The lower part may include a radially inner bowl surface defining a lower part radially inner mating surface. The pre-finished piston assembly may further include an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint. The upper part may include a radially inner wall defining a radially inner upper part mating surface. The radially inner wall may define a radially inwardly facing surface that defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets the radially innermost edge of the radially inner mating surface.

Abstract: A pre-finished piston part is disclosed that may be used to form a piston assembly. A pre-finished piston may include a lower part defining a piston axis, the lower part having a skirt and forming a lower surface of a cooling gallery. The lower part may include a radially inner bowl surface defining a lower part radially inner mating surface. The pre-finished piston assembly may further include an upper part having a radially outer bowl surface meeting the radially inner bowl surface at a radially inner joint. The upper part may include a radially inner wall defining a radially inner upper part mating surface. The radially inner wall may define a radially inwardly facing surface that defines a non-parallel angle with the radially inner bowl surface where the radially inner bowl surface meets the radially innermost edge of the radially inner mating surface.

Abstract: A piston pin for connecting the small connecting rod eye of a connecting rod to a piston of a combustion engine and a method for manufacturing the piston pin. The piston has boss bores aligned with the small connecting rod eye for receiving the piston pin. The surface of the piston pin is provided with a coating comprising a resin containing suspended solid lubricant particles.

Abstract: A piston pin for connecting the small connecting rod eye of a connecting rod to a piston of a combustion engine and a method for manufacturing the piston pin. The piston has boss bores aligned with the small connecting rod eye for receiving the piston pin. The surface of the piston pin is provided with a coating comprising a resin containing suspended solid lubricant particles.