Powertrain component with amorphous hydrogenated carbon film
AssigneeFord Motor Company
InventorsPierre A. Willermet, Arup K. Gangopadhyay, Michael A. Tamor, William C. Vassell
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Abstract
A powertrain component such as a valve lifter (10) for use in an internal combustion engine (12), the valve lifter (10) being positioned between a cam (14) and a valve stem (16). An amorphous hydrogenated carbon film (28) is formed on the component, the film (28) imparting the characteristics of low friction and wear resistance. Also disclosed is an interlayer which improves adherence by imparting the properties of improved absorption of mechanical stresses and chemical compatibility between the film (28) and the substrate (10). Methods for forming the film (28) and interlayer are also disclosed.
Claims17
A powertrain component in an internal combustion engine, the powertrain component including a valve lifter interposed between a cam and a valve stem, and being provided with a hollow cylindrical body with a sidewall culminating at its upper end in a cam-facing surface which cooperate with the cam, and a stem-facing surface which cooperates with the valve stem, the component comprising:
- an amorphous hydrogenated carbon formed on at least a portion of an outer surface of the component without detrimental change in the physical properties of the component, the film imparting characteristics of low friction and wear resistance to the component;
- an interlayer formed between the amorphous hydrogenated carbon film and the component, the interlayer being selected from a group comprising at least one of a non-carbon form of tungsten, titanium, and germanium, the interlayer accommodating stresses engendered by formation of the amorphous hydrogenated carbon film, thereby improving adherence of the amorphous hydrogenated carbon film to the component.
An internal combustion engine having a valve lifter therein, the valve lifter being positioned between a cam and a valve stem, the valve lifter having:
- a hollow cylindrical aluminum body with a continuous sidewall;
- an amorphous hydrogenated carbon film formed on at least a portion of an outer surface of the lifter, the film imparting characteristics of low friction and wear resistance to the valve lifter;
- and
- an interlayer formed between the amorphous hydrogenated carbon film and the lifter, the interlayer accommodating stresses engendered by formation of the amorphous hydrogenated carbon film, the interlayer thereby improving adherence of the amorphous hydrogenated carbon film to the lifter, the interlayer being selected from the group comprising at least one of a non-carbon form of a tungsten, titanium, and germanium.
Dependencies are inferred from the claim text.