Abstract: Provided is a hard carbon film, which is to be used in a sliding member, more specifically, at a sliding site thereof in contact with a counter member. The hard carbon film contains at least one of cobalt and nickel in a total content within the range of more than 1.4 to less than 39 atom % and contains cobalt and nickel aggregates having a diameter of beyond 5 nm within a predetermined ratio or less. In this way, the hard carbon film reduced in friction coefficient than ever, manufactured in a simple process, and effectively working in a wide variety of lubricating oils can be provided.

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 sliding device is comprised of a first sliding member which is rotatable on an axis of the first sliding member, a second sliding member which slidably supports the first member through viscous fluid and at least a pit which is formed on a surface of at least one of the first and second sliding members so as to promote a viscous fluid flow, which has a component of a rotational direction of the shaft when the first member is rotated.

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: 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 2.0 ?m and a surface roughness Ry (?m) satisfying the following equation (A): Ry<{(0.75?Hk/8000)×h+0.07/0.8}??(A) where h is the thickness (?m) of the hard carbon film; and Hk is the knoop hardness (kg/mm2) of the hard carbon film. By imparting durability, reliability and a low friction coefficient to the hard carbon film that is said to be low in ductility to prevent the hard carbon film from becoming cracked and separated when applied to the sliding portion.

Abstract: There is provided a sliding member including a base substrate and a hard carbon coating formed on the base substrate to define at least a surface for sliding contact with an opposing member. The hard carbon coating contains therein at least one of cobalt and nickel in an amount of 1.4 to 39 atomic %.

Abstract: In a lash adjuster of a valve gear which employs a serration-shaped thread mechanism, the formation of a tribochemical reactive film is suppressed by using as the materials for its adjuster screw and nut member (or the materials for their thread surfaces) materials that, even if FM oil is used, the friction coefficient will not extremely decrease. The nut member is provided on the underside of an end plate of a lifter body. The adjuster screw is threadedly engaged in a threaded hole of the nut member. The adjuster screw is biased by a return spring. The female threads of the threaded hole and the male threads of the adjuster screw are serration shaped. One or both of the nut member and the adjuster screw, or the pressured thread surfaces of one or both of them, are formed of a material that will not react with oil additives of FM oil to suppress the formation of tribochemical reactive film, thereby stabilizing the operation of the lash adjuster.

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 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 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: A sliding device is comprised of a first sliding member which is rotatable on an axis of the first sliding member, a second sliding member which slidably supports the first member through viscous fluid and at least a pit which is formed on a surface of at least one of the first and second sliding members so as to promote a viscous fluid flow, which has a component of a rotational direction of the shaft when the first member is rotated.

Abstract: A reciprocating engine with a variable compression ratio mechanism is disclosed. A lubrication system of the engine is improved by controlling an oil pressure according to a compression ratio setting. The lubrication system includes various combinations of control valves and oil passages. The oil relief passage is opened at a high compression ratio setting applied to a low engine load range and is otherwise closed at a low compression ratio setting applied to a high engine load range.

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 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: 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 gear comprised of a tooth surface and a hard carbon film formed on at least a part of the tooth surface. When the gear is used in lubricant including a specific component, a friction of a tooth surface of the gear is largely decreased, and therefore the gear performs an excellent power transmission efficiency. Further, when the gear is employed in a planetary gear mechanism or speed reducing mechanism which has a plurality of meshing portions of gears, the power transmission efficiency of the mechanism is also improved.

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 low-friction sliding mechanism of the present invention comprises first and second sliding members slidable relative to each other at sliding surfaces thereof and a lubricant being applied to the sliding surfaces of the first and second sliding members. The first and second members are made of a diamond-like carbon material and an iron-based material, respectively, and the lubricant comprises 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.

Abstract: A reciprocating engine with a variable compression ratio mechanism is disclosed. A lubrication system of the engine is improved by controlling an oil pressure according to a compression ratio setting. The lubrication system includes various combinations of control valves and oil passages. The oil relief passage is opened at a high compression ratio setting applied to a low engine load range and is otherwise closed at a low compression ratio setting applied to a high engine load range.