Disclosed are novel bridged bi-aromatic phenol ligands and transition metal catalyst compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds, and polymerization processes utilizing the transition metal compounds for the production of olefin polymers.

In a method for producing a piston (10) for an internal combustion engine, a melt treatment is performed at least in regions in particular in the region of a combustion chamber depression (14), the depth of said melt treatment being varied in the circumferential direction.

A piston for an internal combustion engine and method of construction thereof is provided. The piston has a piston body including an upper part and a lower part. The upper part has an upper combustion surface configured for direct exposure to combustion gases within a cylinder bore with an undercrown surface beneath the upper combustion surface. The body has a ring belt region configured for receipt of at least one piston ring adjacent the upper combustion surface with an annular cooling gallery configured radially inwardly from the ring belt region. The cooling gallery has a floor, wherein the floor has at least one through opening. A coolant medium is disposed in the cooling gallery, and a sealing member is disposed in the at least one through opening to seal off the coolant medium in the coolant gallery.

A piston with a cooling gallery containing an open cell radiator is provided. The radiator has a large thermally conductive surface area that acts as a heat-sink to remove heat from the piston. Heat from the piston is transmitted from the radiator to cooling oil that enters the cooling gallery via an oil inlet formed in a floor of the cooling gallery and exits the cooling gallery via an oil outlet. The piston comprises a piston body including an upper part presenting an upper combustion surface and an undercrown surface. A ring belt depends from the upper combustion surface, and the cooling gallery extends around the piston body beneath the undercrown surface radially inwardly of the ring belt. The radiator includes a plurality of fins extending annularly around the cooling gallery. The fins of the radiator are spaced from one another by gaps extending annularly around the cooling gallery.

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.

A piston for an internal combustion engine and method of construction thereof is provided. The piston has a top part and a bottom part. The top part has an upper combustion surface including a top surface with a combustion bowl recessed therein. An annular combustion bowl rim extends between the top surface and a side wall of the combustion bowl. The bottom part has a bottom wall and a pair of pin bosses depending therefrom. The top part is fixed to the bottom part with an annular cooling gallery defined therebetween. The side wall of the combustion bowl has a radially outwardly facing side bounding a portion of the cooling gallery, wherein an annular recessed channel is formed therein adjacent the combustion bowl rim. A cooling ring is disposed in the annular channel. The cooling ring channels coolant adjacent the combustion bowl rim to facilitate cooling the combustion bowl rim.

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.

The arrangement relates to a method for producing a cooling duct piston for an internal combustion engine, having the steps of producing a top piston part by introducing a combustion bowl, a cooling space of a part of a cooling duct and overflow ducts, producing a bottom piston part by introducing a part of a cooling duct, and joining the piston parts, wherein at least one transfer duct is created by bores. A cooling duct piston produced by the method is disclosed.

The present invention relates to a multi-piece, in particular at least two-piece, piston (1) for an internal combustion engine having a longitudinal axis (L), comprising a piston outer part (10) having a closed piston head (11), which in the fitted state defines a combustion chamber, and a piston body (13) extending axially away from the piston head (11), and a piston inner part (20), which in the fitted state is connected to a connecting rod. An outer surface (2) radially defining the piston (1) is formed exclusively by at least one portion of the piston body (13) of the piston outer part (10). The piston inner part (20), viewed in an axial direction, is arranged radially entirely inside the piston body (13) or its circumferential surface.

Disclosed are novel bridged bi-aromatic phenol ligands and transition metal catalyst compounds derived therefrom. Also disclosed are methods of making the ligands and transition metal compounds, and polymerization processes utilizing the transition metal compounds for the production of olefin polymers.