Federal-mogul Corporation

Federal-mogul World Wide, Inc.

Tenneco Gmbh

Jose Rebello

Miguel Azevedo

Carmo Ribeiro

Thomas Egerer

Kevin Hart

A piston and method of construction are provided. The piston includes an upper crown having a combustion surface with an upper land depending therefrom and a lower crown having a pair of pin bosses that depend to a pair of laterally spaced, axially aligned pin bores. The upper crown is constructed as a monolithic piece of a first material having a thermal conductivity within a range of about 7 to 25 W/m-K. The lower crown is constructed from a low grade steel material having a thermal conductivity higher than the upper crown. The upper crown is joined directly to the lower crown, wherein the upper crown acts as a barrier to thermal conductivity and thus, the heat within a combustion chamber housing the piston for reciprocation therein is maintained and maximized.

Low thermal conductivity piston and method of construction thereof

A piston () includes a piston body () having an upper crown portion () with an upper combustion dome () against which combustion forces act. The underside of the upper combustion dome () comprises an under-crown region (). The piston body () also includes a lower crown portion () with a pair of pin bosses () spaced apart for pivotally adjoining a connecting rod. An outer oil gallery () is formed as an inclusion between the upper () and lower () crown portions. The outer oil gallery () has an oil inlet () and an oil outlet (). A tubular cooling nozzle () is affixed in fluid communication with the oil outlet () and extends toward the under-crown region () where oil is discharged during reciprocation of the piston (). Cooling oil from the outer oil gallery () is channeled by the cooling nozzle () to the under-crown region () providing supplemental cooling in a passively actuated system.

Piston with crown cooling nozzle

A piston assembly for heavy duty diesel engine applications comprises a piston having pin bosses formed with pin bores for the accommodations of a wrist pin. The wrist pin is fabricated of steel and is extendable through the small end bore of a steel connecting rod and the bores of the piston body for coupling the piston body to the connecting rod. In lieu of a conventional Cu&mdash;Pb&mdash;Sn bushing usually pressed into the small end bore, a coating of manganese phosphate is applied to either the pin or small end bore of the connecting rod and pin bosses to provide the necessary tribological properties therebetween. The porous coating absorbs and entraps lubricating oil, creating a still lubricant squeeze film between the steel running surfaces under heavy load.

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Ann Arbor, MI, United States of America

Jose Rebello