Abstract: A lubricating oil used in a friction-type drive power transmission apparatus which includes: at least one of two additives; a first additive selected from at least one of an aliphatic amine having a saturated or unsaturated hydrocarbon group with a carbon number of 12 to 20 (Chemical Formula 1) and an aliphatic amine ethylene oxide adduct having a saturated or unsaturated hydrocarbon group with a carbon number of 12 to 20 (Chemical Formula 2).

Abstract: A plurality of microscopic grooves are created on the surface of the teeth of planetary gears, and thus, irregular unevenness is created. This irregular unevenness includes a plurality of first microscopic grooves which function as lubricant grooves and a plurality of second microscopic grooves which are shallower than the first microscopic grooves.

Abstract: A formation method of a coating that coats a coated body with the coating includes: generating cylindrical plasma in a vacuum deposition chamber as well as supplying material gas into the vacuum deposition chamber; applying pulse voltage to the coated body; and attaching a shield member that shields an uncoated member to an uncoated part where the coating of the coated body is not formed with separation spacing over a coated part where the coating is to be formed for preventing decrease of hardness of the coating in the coated part.

Abstract: A propeller shaft includes a first shaft and a second shaft. The first shaft has a torque transmission face in which a plurality of fine grooves extending in a first direction (face width direction) is formed. The second spline shaft is coupled to the first spline shaft so as to be movable relative to the first spline shaft in the axial direction of the first spline shaft, and has a torque transmission face in which a plurality of second fine grooves extending in a second direction that crosses the first direction is formed.

Abstract: To control initial shudder in a wet paper friction plate, the frictional sliding surface of a wet paper friction member is preconditioned by frictional sliding contact with a mating plate until its bearing length ratio tp at a cutting depth of 10 ?m is in the range from 70 to 85%. The preconditioning is optionally preceded by grinding, preferably before the wet paper friction member is attached to a base plate.

Abstract: A spline shaft that can suppress occurrence of stick slip by measures other than just simply making the surface roughness smaller. The spline shaft includes a first shaft with an outer-peripheral spline formed, and a second shaft with an inner-peripheral spline, which engages with the outer-peripheral spline peripherally and that is made slidable axially, formed. And, at least either one of the outer-peripheral spline and the inner-peripheral spline includes a substrate whose surface is formed to a predetermined surface roughness, and an amorphous carbon-system hard thin film, which coats and forms the surface of substrate.

Abstract: A friction clutch includes an iron inner clutch plate and two iron outer clutch plates. Each clutch plate has a sliding surface that friction-engages with the other clutch plates. A diamond-like carbon film containing silicon, which functions as a solid lubricant, is formed on the sliding surface of each outer clutch plate through a conventional method such as plasma chemical vapor deposition. The diamond-like carbon film contains 1 wt % to 80 wt % of silicon. A coupling device includes a pilot clutch mechanism that has the friction clutch and an electromagnetic actuator. As a result, the friction clutch has an improved resistance to wear, and the coupling device is durable.

Abstract: An amorphous carbon film forming apparatus according to the present invention is characterized by being provided with a film forming furnace 11; plural workpiece fixtures 23 for supporting plural plate-like workpieces 22 in a state that the same are piled up vertically in parallel with the interval between facing surfaces of two vertically adjoining of the plate-like workpieces 22 being in a range of 2 to 30 millimeters, the plural workpiece fixtures 23 being arranged within the film forming furnace 11 at a regular angular interval on a circle and being connected to a negative electrode; nozzles 31, 32 provided for supplying a processing gas and including at least one nozzle arranged at a center of the circle on which the plural workpiece fixtures 23 are arranged and plural nozzles arranged at a regular angular interval on another circle which surrounds the workpieces fixtures 23 radially outside thereof; and a plasma power supply connected to at least the workpiece fixtures 23.

Abstract: A sliding member has a base material whose surface is at least partially covered with a DLC film, wherein an intermediate layer is interposed between the base material and the DLC film, and the intermediate layer has a multilayer structure obtained by stacking a first Cr layer, a CrN layer and a second Cr layer successively from the side closer to the base material.

Abstract: A spline shaft that can suppress occurrence of stick slip by measures other than just simply making the surface roughness smaller. The spline shaft includes a first shaft with an outer-peripheral spline formed, and a second shaft with an inner-peripheral spline, which engages with the outer-peripheral spline peripherally and that is made slidable axially, formed. And, at least either one of the outer-peripheral spline and the inner-peripheral spline includes a substrate whose surface is formed to a predetermined surface roughness, and an amorphous carbon-system hard thin film, which coats and forms the surface of substrate.

Abstract: A drive force transmission device has an outer clutch plate and an inner clutch plate, which are rotatable relative to each other about a common rotational axis. The inner and outer clutch plates become frictionally engaged with each other with lubricant oil provided in between. The outer and inner clutch plates each have a sliding surface. The sliding surfaces face each other. A diamond-like carbon film is formed on the sliding surface of the outer clutch plate. Fine grooves are formed in the sliding surface of the inner clutch plate. The proportion of the sliding area to the sliding surface of the inner clutch plate at the initial stage of use is 55 to 90%.

Abstract: A constant velocity universal joint includes an inner race having an outer peripheral face on which inner grooves are formed, an outer race having an inner peripheral face on which outer grooves are formed, a plurality of balls each engaging with each pair of inner groove and outer groove, and an annular cage disposed between the inner race and the outer race and including window portions for retaining respective balls. A coefficient of sliding friction between the ball and a rolling face on the inner groove with which the ball is in contact, and a coefficient of sliding friction between the ball and a rolling face on the outer groove with which the ball is in contact are larger than a coefficient of sliding friction between the ball and a sliding face on the window portion with which the ball is in contact.

Abstract: To control initial shudder in a wet paper friction plate, the frictional sliding surface of a wet paper friction member is preconditioned by frictional sliding contact with a mating plate until its bearing length ratio tp at a cutting depth of 10 ?m is in the range from 70 to 85%. The preconditioning is optionally preceded by grinding, preferably before the wet paper friction member is attached to a base plate.

Abstract: An amorphous carbon film forming apparatus according to the present invention is characterized by being provided with a film forming furnace 11; plural workpiece fixtures 23 for supporting plural plate-like workpieces 22 in a state that the same are piled up vertically in parallel with the interval between facing surfaces of two vertically adjoining of the plate-like workpieces 22 being in a range of 2 to 30 millimeters, the plural workpiece fixtures 23 being arranged within the film forming furnace 11 at a regular angular interval on a circle and being connected to a negative electrode; nozzles 31, 32 provided for supplying a processing gas and including at least one nozzle arranged at a center of the circle on which the plural workpiece fixtures 23 are arranged and plural nozzles arranged at a regular angular interval on another circle which surrounds the workpieces fixtures 23 radially outside thereof; and a plasma power supply connected to at least the workpiece fixtures 23.

Abstract: A plurality of microscopic grooves are created on the surface of the teeth of planetary gears, and thus, irregular unevenness is created. This irregular unevenness includes a plurality of first microscopic grooves which function as lubricant grooves and a plurality of second microscopic grooves which are shallower than the first microscopic grooves.

Abstract: An amorphous-carbon coated member includes a conductive substrate, and an amorphous carbon film. The amorphous carbon film is fixed onto a part of a surface of the substrate at least, and includes a compositionally gradient film. The compositionally gradient film has an outer side and a substrate side, and is composed of carbon, silicon and hydrogen. The silicon concentration inclines continuously from the lowest to the highest in the direction away from the outer side to the substrate side. The hydrogen concentration inclines continuously from the highest to the lowest in the direction away from the outer side to the substrate side. The amorphous-carbon coated member exhibits not only good wear resistance but also low aggressiveness against mating member simultaneously.

Abstract: The invention provides a lubricating oil composition comprising a lubricating base oil, a phosphorus compound and at least one organic acid salt selected from among alkaline earth metal sulfonates, alkaline earth metal phenates and alkaline earth metal salicylates, wherein the contents of the phosphorus compound and organic acid salt satisfy the conditions represented by the following formulas (1) to (3). In formulas (1)-(3), W(P) represents the content of phosphorus compound, in terms of phosphorus element, based on the total amount of the lubricating oil composition, and W(M) represents the content of organic acid salt content, in terms of alkaline earth metal elements, based on the total amount of the lubricating oil composition. 0.01?W(P)?0.2 ??(1) 0.01?W(M)?0.2 ??(2) 0.

Abstract: A drive force transmission device has an outer clutch plate and an inner clutch plate, which are rotatable relative to each other about a common rotational axis. The inner and outer clutch plates become frictionally engaged with each other with lubricant oil provided in between. The outer and inner clutch plates each have a sliding surface. The sliding surfaces face each other. A diamond-like carbon film is formed on the sliding surface of the outer clutch plate. Fine grooves are formed in the sliding surface of the inner clutch plate. The proportion of the sliding area to the sliding surface of the inner clutch plate at the initial stage of use is 55 to 90%.

Abstract: An amorphous-carbon coated member includes a conductive substrate, and an amorphous carbon film. The amorphous carbon film is fixed onto a part of a surface of the substrate at least, and includes a compositionally gradient film. The compositionally gradient film has an outer side and a substrate side, and is composed of carbon, silicon and hydrogen. The silicon concentration inclines continuously from the lowest to the highest in the direction away from the outer side to the substrate side. The hydrogen concentration inclines continuously from the highest to the lowest in the direction away from the outer side to the substrate side. The amorphous-carbon coated member exhibits not only good wear resistance but also low aggressiveness against mating member simultaneously.

Abstract: A constant velocity universal joint includes an inner race having an outer peripheral face on which inner grooves are formed, an outer race having an inner peripheral face on which outer grooves are formed, a plurality of balls each engaging with each pair of inner groove and outer groove, and an annular cage disposed between the inner race and the outer race and including window portions for retaining respective balls. A coefficient of sliding friction between the ball and a rolling face on the inner groove with which the ball is in contact, and a coefficient of sliding friction between the ball and a rolling face on the outer groove with which the ball is in contact are larger than a coefficient of sliding friction between the ball and a sliding face on the window portion with which the ball is in contact.