A piston galleryless piston capable achieving improved thermal efficiency, fuel consumption, and engine performance is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses, and a pair of skirt panels coupled to the pin bosses by struts. The piston includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, struts, and pin bosses. The piston also includes a pair of outer pockets extending along the undercrown surface and each being surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Each pin boss includes an opening extending from the inner undercrown region to one of the outer pockets for conveying cooling oil. The opening is located between a pin bore of the associated pin boss and the undercrown surface.

A galleryless piston having a reduced weight and a reduced operating temperature is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses each presenting a pin bore, and skirt panels depending from the ring belt and coupled to the pin bosses by strut. The piston further includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, the struts, and the pin bosses. The piston also includes outer pockets each extending along the undercrown surface and each surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Cutouts are located in the pin bosses above the pin bores to increase the area of the undercrown surface and thus allow cooling oil to remove more heat from the undercrown surface.

Methods for forging a piston blank are disclosed such that the forged piston blank is in a near-net shape and size of a final piston. Bending a flange to form a cooling channel can be done with reduced or no preliminary machining away of core material relative prior to bending the flange.

A method for producing a piston for an internal combustion engine may include the steps of: producing a piston upper part from a first blank via a deformation process; producing a piston lower part from a second blank via at least one of a deformation process and a casting process; connecting the first blank of the piston upper part and the second blank of the piston lower part to form a piston body via a welding process; and performing at least one of a secondary machining process and a finish machining process of the piston body to produce the piston.

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.

Methods for forging a piston blank are disclosed such that the forged piston blank is in a near-net shape and size of a final piston. Bending a flange to form a cooling channel can be done with reduced or no preliminary machining away of core material relative prior to bending the flange.

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, particularly a piston for use in a diesel engine, particularly a heavy duty diesel engine, is formed from a billet of metal, such that the finished piston has a mass that is at least 50%, and, more preferably, up to about 62%, of the mass of the billet. Other than finishing steps, the piston is formed with a closed gallery, without loss of mass through machining processes.

Pin body has lightening hole having one-end-side and another-end-side large diameter parts formed on both end sides in the longitudinal direction; a central small diameter part; one-end-side and another-end-side first rounded parts each being provided between the large diameter part and the central small diameter part, having an inner diameter decreasing from each large diameter part side toward the central small part side, and having a rate of change of the inner diameter increasing from each large diameter part side toward the central small diameter part side; and one-end-side and another-end-side second rounded parts each being provided between each first rounded part and the central small diameter part, having an inner diameter decreasing from each first rounded part toward the central small diameter part side, and having a rate of change of the inner diameter decreasing from each first rounded part toward the central small diameter part side.