Caterpillar Inc.

Jay E Tomaseski

Alan Ray Stockner

Scott F Shafer

Chuong Q Dam

Michael C Long

Norval J Wiemken

Clifford E Cotton, Iii

Charles Bates

Joseph Angelino

Colby Buckman

A thin film coating for a low allow steel or tool steel components in a fuel injector (), such as a fuel injector needle valve () is disclosed. A thin film coating () consists of a metal carbon material layer less than 2.0 microns thick applied to a low alloy steel substrate () or tool steel substrate () used in fuel injector components, such as the fuel injector needle valve () or a portion thereof. Optionally, a thin bond layer () of chromium is deposited between the steel substrate () and the primary metal carbon material coating (). The thin film coating () minimizes abrasive and adhesive wear associated with the needle valve () and cooperating nozzle surfaces () of the fuel injector ().

Thin film coatings for fuel injector components

A nozzle insert that is capable of being irreversibly attached to a needle valve tube such that the resulting needle valve member can be used in a nested needle valve configuration for a dual mode fuel injector.

Nozzle insert for dual mode fuel injector

A thin film coating for a low alloy steel or tool steel components in a fuel injector ( ), such as a fuel injector needle valve ( ) is disclosed. A thin film coating ( ) consists of a metal carbon material layer less than 2.0 microns thick applied to a low alloy steel substrate ( ) or tool steel substrate ( ) used in fuel injector components, such as the fuel injector needle valve ( ) or a portion thereof. Optionally, a thin bond layer ( ) of chromium is deposited between the steel substrate ( ) and the primary metal carbon material coating ( ). The thin film coating ( ) minimizes abrasive and adhesive wear associated with the needle valve ( ) and cooperating nozzle surfaces ( ) of the fuel injector ( ).

Thin film coating for fuel injector components

A cyclic high pressure fluid seal for a fuel injector includes an injector body that defines a cyclic high pressure space connected to a low pressure space by a bore. A member with a pressure face end and a side surface is mounted to reciprocate in the bore between a retracted position and an advanced position. An O-ring is positioned in contact with the side surface of the member and the injector body within the bore. A portion of the member and the bore define a pressure accumulation volume positioned between the O-ring and the pressure face end. The pressure accumulation volume is positioned such that fluid pressure in the pressure accumulation volume changes with that of the cyclic high pressure space.

Fluid seal for cyclic high pressures within a fuel injector

A fuel injector includes an injector body with a plunger bore that opens to a nozzle outlet. A plunger having a pressure face and a side surface is positioned to reciprocate in the plunger bore between an advanced position and a retracted position. A portion of the plunger bore and the plunger define a fuel pressurization chamber that opens to the nozzle outlet. A needle valve is positioned in the injector body adjacent the nozzle outlet and is moveable between an open position which opens the nozzle outlet and a closed position in which the nozzle outlet is closed to the fuel pressurization chamber. An O-ring is in contact with the side surface of the plunger and the plunger bore on the injector body and serves to seal against fuel leakage past the plunger. Pressure acting on the O-ring is attenuated by providing either a pressure accumulation volume between the pressure face end of the plunger and the O-ring and/or a pressure release passage that opens the plunger bore to a low pressure return line below the O-ring.

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Gainesville, GA, United States of America

Jay E Tomaseski