Abstract: There is provided a sliding member including a base body and a hard carbon coating formed on the base body to define a sliding surface for sliding contact with an opposing member under lubrication according to one embodiment of the present invention. The hard carbon coating has an outermost surface portion lower in hydrogen content than a remaining portion thereof, or an outermost coating layer lower in hydrogen content than at least one other coating layer.

Abstract: A sliding structure for an automotive engine includes a sliding member with a sliding portion and a lubricant applied to the sliding portion so that the sliding portion can make sliding contact with a counterpart member via the lubricant. The sliding member is either of a piston ring, a piston pin, a cam lobe, a cam journal, a plain bearing, a rotary vane and a timing chain. The sliding portion has a base made of a steel or aluminum material and a hard carbon film formed on the base to coat the sliding portion. The hard carbon film has a thickness of 0.3 to 2.0 ?m, a Knoop hardness of 1500 to 4500 kg/mm2, a surface roughness Ry (?m) satisfying the following equation: Ry<{(0.75?Hk/8000)×h+0.07/0.8}, where h is the thickness (?m) of the film; and Hk is the Knoop hardness (kg/mm2) of the film.

Abstract: There is provided a fuel lubricated sliding mechanism including a pair of sliding parts having respective sliding portions slidable relative to each other in the presence of fuel. At least one of the sliding portions of the sliding parts has a hard carbon coating formed with a hydrogen content of 30 atomic % or less. The fuel is selected from the group consisting of gasoline, light oil, alcohol fuel, biodiesel fuel and GTL fuel.

Abstract: There is provided a structure for connecting a piston to a crankshaft in an internal combustion engine, including a piston pin fitted into the piston, a crankpin integral with the crankshaft and a connecting rod having a piston pin bearing portion slidably engaged with an outer cylindrical portion of the piston pin and a crankpin bearing portion slidably engaged with an outer cylindrical portion of the crankpin. At least one of the piston pin bearing portion of the connecting rod and the outer cylindrical portion of the piston pin and at least one of the crankpin bearing portion of the connecting rod and the outer cylindrical portion of the crankpin have hard carbon coatings formed thereon with a hydrogen content of 20 atomic % or less.

Abstract: A low-friction sliding member such as a piston, a piston ring, a piston skirt section and a cylinder liner section of an internal combustion engine. The low-friction sliding member includes a base material having a surface. A hard carbon thin film is formed at at least a part of the surface of the base material. Here, a tribo-film having at least one functional group selected from the group consisting of ether linkage, oxido and hydroxyl group is formed on the hard carbon thin film when the hard carbon thin film is in slidable contact with an opposite member in presence of an organic oxygen-containing compound.

Abstract: A valve train for an internal combustion engine is comprised of a lubricating oil, and a camshaft which is made of an iron-based material and comprises a cam lobe and a camshaft journal. The camshaft slidingly moves on a counterpart thereof through the lubricating oil. A hard carbon film is formed on at least one of a sliding portion of the camshaft and the counterpart made of an iron-based material. A hydrogen amount of the hard carbon film is 10 atomic percent or less.

Abstract: A sintered sprocket has a high overall density and excellent contact pressure resistance. The sprocket is produced from a sintered alloy selected from the following alloys ((1) to (3)), is densified to have a relative density of 95% or higher in the surface layer of the gear teeth by forming by rolling, having a surface hardness of 700 HV or higher, and is useful for a crankshaft, a cam shaft, a balancer shaft, or a water pump shaft of an internal combustion engine: (1) an Fe—Mo—C based sintered alloy containing Mo at 1.0 to 2.0% by mass; (2) an Fe—Mo—Ni—C based sintered alloy containing Mo at more than 1.0 and not more than 2.0% by mass, and Ni at more than 1.0 and not more than 2.5% by mass, or (3) an Fe—Mo—Ni—Cu—C based sintered alloy containing Mo at 0.3 to 1.0% by mass, Ni at not less than 1.5 to less than 3.0% by mass, and Cu at 1.0 to 2.5% by mass.

Abstract: A chain drive system includes a drive sprocket, a driven sprocket and a chain looped over the drive sprocket and the driven sprocket. The chain and the sprocket having respective sliding surfaces slidable relative to each other in the presence of lubricating oil, and any adjacent chain components of the chain having respective sliding surfaces slidable relative to each other in the presence of lubricating oil. At least one of the sliding surfaces between the chain and the sprocket and at least one of the sliding surfaces between any adjacent chain components have hard carbon coatings formed on base portions thereof. Each of the hard carbon coatings has a hydrogen content of 10 atomic % or less.

Abstract: A fuel injection valve for an automotive internal combustion engine comprises a needle valve and an opposite member which are in slidable contact with each other in presence of fuel. A hard carbon thin film is coated on at least one of the sliding sections of the base materials of the needle valve and the opposite member. The hard carbon thin film has a surface hardness ranging from 1500 to 4500 kg/mm2 in Knoop hardness, a film thickness ranging from 0.3 to 2.0 ?m, and a surface roughness (Ry) (?m) which satisfies a relationship represented by the following formula (A): Ry<(0.75?Hk/8000)×h+0.0875??(A) where h is the thickness (?m) of the hard carbon thin film; Hk is the surface hardness in Knoop hardness (kg/mm2) of the hard carbon thin film.

Abstract: A sintered sprocket for a silent chain is obtained from a material with few addition elements by a simple densifying method. The sintered sprocket is made of an ferrous material having an ovarall composition containing Cu at 1 to 2%, C at 0.5 to 0.8%, Mn as an inevitable impurity at 0.10% or less, and balance of Fe and other inevitable impurities by mass and has a density of 7.1 Mg/m3 or higher, 65 HRA or higher as a hardness in the gear teeth, and a martensite, sorbite, bainite, or their mixed structure as a cross-sectional microscopic structure in at least the gear teeth and the peripheral area of the gear teeth.

Abstract: A slidably movable member such as an adjusting shim used in a valve operating mechanism of an internal combustion engine of an automotive vehicle. The slidably movable member is used in contact with lubricating oil and comprises a substrate. A hard carbon-based film is coated on a surface of the substrate. The hard carbon-based film has a surface section which contains at least one of nitrogen and oxygen in an amount ranging from 0.5 to 30 at % and/or hydrogen in an amount of not more than 10 at %.

Abstract: A piston for an internal combustion engine of an automotive vehicle. The piston has a piston ring and a piston skirt section each of which has a sliding section in slidable contact with a cylinder bore section of a cylinder block in presence of a lubricating oil. The cylinder bore section is formed of eutectic or hyper-eutectic aluminum alloy. Additionally, a hard carbon thin film is coated on the sliding section of the piston and contains hydrogen atom in an amount of not more than 1 atomic %. Here, the lubricating oil contains at least one selected from the group consisting of ashless fatty acid ester friction modifier, ashless aliphatic amine friction modifier, polybutenyl succinimide, derivative of polybutenyl succinimide, zinc dithiophosphate, and derivative of zinc dithiophosphate.

Abstract: An engine piston-pin sliding structure includes a piston pin slidably engaged into a pin boss of an engine piston and having a base and a hard carbon coating formed on the base so as to define a sliding surface slidable over a bearing surface of the pin boss and a lubricant interposed between the sliding surface of the piston pin and the bearing surface of the pin boss. The hard carbon coating contains 25 atomic % or less of hydrogen, and the lubricant contains at least one of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

Abstract: A machine tool is used for machining a workpiece in the presence of a cutting oil composition. The machine tool includes a tool base and a hard carbon coating formed on the tool base. The hard carbon coating has 1 atomic % or less of hydrogen. The cutting oil composition contains a base oil and at least one of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

Abstract: A low friction sliding combination of a cam and a cam follower which are in slidable contact with each other in presence of a lubricating oil. The cam follower includes a cylindrical and hollow outer roller having an outer peripheral surface in slidable contact with the cam. A fixed pin is coaxially disposed inside the outer roller and rotatably movable relative to the outer roller. A diamond-like carbon material is coated on a sliding surface of at least one of the outer roller and the fixed pin. The lubricating oil contains at least one of ashless fatty acid ester friction modifier and ashless aliphatic amine friction modifier.

Abstract: A sliding structure including first and second sliding elements made of metal and including first and second sliding surfaces relatively slidable via a lubricating oil film therebetween, in which at least one of the first and second sliding surfaces having a microscopic surface structure including a base portion, dimples inward recessed from the base portion and separated from one another, and a peripheral portion defining the opening area of each of the dimples and extending along a periphery of each of the dimples. A ratio of a sum of opening areas of the dimples to an area of the at least one of the first and second surfaces is in a range of 5% to 60%. The peripheral portion has a height smaller than a thickness of the lubricating oil film.

Abstract: Disclosed is a shim or a valve lifter for an automotive engine valve driving system that slides against a cam lobe of a camshaft to drive an intake/exhaust valve of an internal combustion engine. The shim or lifter has the top of a sliding surface thereof opposing the cam lobe and being coated with a hard carbon film. The hard carbon film has a surface hardness of 1500 to 4500 kg/mm2 in terms of Knoop hardness, a thickness of 0.3 to 2.

Abstract: A sintered body is produced by preparing a metal powder mixture, compacting the metal powder mixture to provide a green compact and then sintering the green compact. The metal powder mixture includes a fine metal powder having a particle size of 75 &mgr;m or smaller, a graphite powder in an amount of 0.1 to 1.0% by mass and a powder lubricant in an amount of 0.05 to 0.80% by mass based on a total mass of the metal powder mixture.

Abstract: A low-friction sliding mechanism includes first and second sliding members having respective sliding surfaces slidable relative to each other and a lubricant applied to the sliding surfaces of the first and second sliding members. At least the sliding surface of the first sliding member is made of a diamond-like carbon material, and at least the sliding surface of the second sliding member is made of either an aluminum-based alloy material, a magnesium-based alloy material or a diamond-like carbon material. The lubricant contains a base oil and at least one of an ashless fatty-ester friction modifier and an ashless aliphatic-amine friction modifier.

Abstract: A sliding structure including first and second sliding elements made of metal and including first and second sliding surfaces relatively slidable via a lubricating oil film therebetween, in which at least one of the first and second sliding surfaces having a microscopic surface structure including a base portion, dimples inward recessed from the base portion and separated from one another, and a peripheral portion defining the opening area of each of the dimples and extending along a periphery of each of the dimples. A ratio of a sum of opening areas of the dimples to an area of the at least one of the first and second surfaces is in a range of 5% to 60%. The peripheral portion has a height smaller than a thickness of the lubricating oil film.