Abstract:
A coating composition is described, containing (a) a metallic matrix based on nickel, cobalt, iron; or combinations thereof; (b) a ceramic phase, containing at least one metal boride or metal silicide compound; and (c) a lubricant phase. Methods of providing wear-resistance and low-friction characteristics to an article (e.g., a gas turbine) are also described, using the coating composition. Related structures are also discussed.
Abstract:
A scroll compressor in which a scroll fixed lap rising from a fixed plate of a fixed scroll and a scroll orbiting lap rising from an orbiting plate of an orbiting scroll are combined with each other to form compression chambers therebetween, the fixed scroll is made of iron-based material, the orbiting scroll is made of aluminum-based material, at least the plate back surface of the orbiting scroll is subjected to surface processing.
Abstract:
The invention relates to a displacement machine, in particular a displacement pump used in an automobile and having two components movable slidably relative to one another. In order to keep the wear on the components low, even in the case of a poorly lubricating operating medium, there is provision for at least one component of the two components to be hardened at least on the surface and to consist of sintered material which contains predominantly ferrite and a constituent for improving the sliding properties. This design is particularly advantageous in automobile pumps operating with transmission oil or feeding fuel.
Abstract:
A three-dimensional piston molding is fabricated from a mixture of chopped, carbon tow filaments of variable length, which are prepregged with carbonaceous organic resins and/or pitches and molded by conventional molding processes into a near net shape, to form a carbon-fiber reinforced organic-matrix composite part. Continuous reinforcement in the form of carbon-carbon composite tapes or pieces of fabric can be also laid in the mold before or during the charging of the mold with the chopped-fiber mixture, to enhance the strength in the crown and wrist-pin areas. The molded chopped-fiber reinforced organic-matrix composite parts are then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. These pyrolized parts are then densified by reimpregnation with resins or pitches, which are subsequently carbonized. Densification is also accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston molds are machined to final piston dimensions, and piston ring grooves are added. To prevent oxidation and/or to seal the piston surface or near surface, the chopped-fiber piston is coated with ceramic and/or metallic sealants; and/or coated with a catalyst.
Abstract:
An improved structure for carbon-carbon composite piston architectures consists of replacing the knitted fiber, three-dimensional piston preform architecture described in U.S. Pat. No. 4,909,133 (Taylor et al.) with a two-dimensional lay-up or molding of carbon fiber fabric or tape. Initially, the carbon fabric or tape layers are prepregged with carbonaceous organic resins and/or pitches and are laid up or molded about a mandrel, to form a carbon-fiber reinforced organic-matrix composite part shaped like a "U" channel, a "T"-bar, or a combination of the two. The molded carbon-fiber reinforced organic-matrix composite part is then pyrolized in an inert atmosphere, to convert the organic matrix materials to carbon. At this point, cylindrical piston blanks are cored from the "U"-channel, "T"-bar, or combination part. These blanks are then densified by reimpregnation with resins or pitches which are subsequently carbonized. Densification is also be accomplished by direct infiltration with carbon by vapor deposition processes. Once the desired density has been achieved, the piston billets are machined to final piston dimensions; coated with oxidation sealants; and/or coated with a catalyst. When compared to conventional steel or aluminum alloy pistons, the use of carbon-carbon composite pistons reduces the overall weight of the engine; allows for operation at higher temperatures without a loss of strength; allows for quieter operation; reduces the heat loss; and reduces the level of hydrocarbon emissions.
Abstract:
Pistons are discribed comprising a crown portion which also includes a piston ring belt and gudgeon-pin bosses and which crown portion comprises a ferrous allow and a seperate articulated skirt portion comprising a casting of aluminum alloy, steel or cast iron which also includes gudgeon-pin bores, the crown portion and the skirt portion having a common gudgeon-pin about which the articulated skirt portion is freely able to move relative to the crown portion.
Abstract:
In an uncooled engine, it is propose to form insulator coatings on the combustion chamber surfaces, and to mechanically protect such coatings against erosion or cracking by means of outer protective layers applied over the insulator coatings. The insulator coatings can be zirconium oxide applied to a thickness of approximately 0.15 inch. The protective layers can be formed of various materials resistant to high temperatures in the vicinity of 2000.degree. F., e.g. silicon nitride, steel or cast iron.
Abstract:
A piston bottom for large capacity internal-combustion engines is made by forging a saucer-shaped blank from refractory-forging steel and then in a second forging step transforming the saucer-shaped blank into a cup configuration with a planar rim of the blank being transformed into a cylindrical shoulder and an annular bulge of the blank being transformed into an annular boss for connecting the piston bottom of the cylindrical body of the piston. The blank has a convexity projecting on one side of the blank opposite that formed with the bulge.