Abstract: A coated sliding member 10 for use under an environment where it is in contact with lubricant, comprising: a base material 12; and a first hard carbon layer 14 having a thickness of 3 ?m or more formed on a surface of the base material by a vacuum arc method using carbon and consisting of diamond-like carbon, containing substantially no hydrogen and being configured only of carbon, and a second hard carbon layer 15 formed on a surface of the first hard carbon layer by a vacuum arc method using carbon and consisting of diamond-like carbon, containing substantially no hydrogen and being configured only of carbon and nitrogen, the film thickness of the second hard carbon layer being 3 to 35% of the film thickness of the first hard carbon layer.

Abstract: [Object] To provide a seal ring that realizes excellent sealability irrespective of magnitude of hydraulic pressure. [Solving Means] A seal ring includes an outer surface and side surfaces formed symmetrically about a plane perpendicular to a central axis. The outer surface includes a peak portion, first tapered surfaces, and second tapered surfaces. The peak portion is provided along the plane. A diameter of each of the first tapered surfaces is reduced with increased distance from the peak portion, each of the first tapered surfaces forming a first angle with respect to the central axis. Each of the second tapered surfaces is closer to each of the side surfaces than each of the first tapered surfaces is, a diameter of each of the second tapered surfaces being reduced with increased distance from each of the first tapered surfaces, each of the second tapered surfaces forming a second angle with respect to the central axis, the second angle being larger than the first angle.

Abstract: A combined oil control ring comprising a pair of annular side rails each having a gap, and an axially corrugated spacer expander arranged between the side rails; the corrugated spacer expander having on the inside seating tabs for pushing inner peripheral surfaces of the side rails; the side-rail-pushing surface of each seating tab being provided with a nitrided layer; an entire surface of each spacer expander except for those provided with the nitrided layer being coated with a plating film; and the plating film having Vickers hardness HV0.01 of 300 or less.

Abstract: A piston ring includes an annular body having: an inner circumferential surface and an outer circumferential surface; one side surface and the other side surface substantially orthogonal to the inner circumferential surface; and a pair of joint ends. The outer circumferential surface includes an inclined surface and an abutment surface. In a direction connecting the one side surface and the other side surface, a maximum width W1 of the abutment surface at the joint end is 80% to 150% of a maximum width W2 of the abutment surface in a portion other than the joint end. In the body, a two-axis difference (d2?d1) between a diameter d1 in a first axis direction passing through a central position of the joint and a diameter d2 in a second axis direction orthogonal to the first axis direction is greater than ?0.25 mm and less than +0.36 mm.

Abstract: To provide a press-fit, sintered valve seat having high valve coolability and wear resistance for use in a high-efficiency engine, and its production method, Cu powder having an average particle size of 45 ?m or less and purity of 99.5% or more is used to form a network-connected Cu matrix, even though a relatively large amount of hard Co-based alloy particles are added; and Fe—P alloy powder is used for densification by liquid-phase sintering.

Abstract: A piston ring has an annular body including an inner circumferential surface, an outer circumferential surface and first and second side surfaces connecting the inner circumferential surface and the outer circumferential surface, and a joint section. The joint section includes a first protrusion portion, a first reception portion, a second protrusion portion, a second reception portion, a first male portion, a first female portion, a second male portion and a second female portion. The first male portion includes a first mating surface and a first contact surface located adjacent the first mating surface and including either an inclined surface or a curved surface. The second male portion includes a second mating surface and a second contact surface located adjacent the second mating surface including either an inclined surface or a curved surface.

Abstract: Provided is a piston ring excellent in peeling resistance, wear resistance, and thermal conductivity. A piston ring 1 includes: an annular main body 2 having a pair of side faces 2a and 2b, an outer peripheral face 2d, and an inner peripheral face 2c; and a hard coating 11 provided on the outer peripheral face 2d. When a width of the main body 2 in a first direction D1 perpendicular to the pair of side faces 2a and 2b is set to h1 mm, a width of the hard coating 11 in the first direction D1 is set to W mm, and a thickness of the hard coating 11 in a second direction D2 perpendicular to the outer peripheral face 2d is set to L mm, the following Formula (1) is satisfied: 0.003?(L·h1)/W?0.151.

Abstract: A roller-type rocker arm had a function for transmitting a rotational motion of a cam to an intake and exhaust valve. The roller-type rocker arm includes a roller shaft, an inner ring roller slidably attached to an outer circumference surface of the roller shaft, and an outer ring roller slidably attached to an outer circumference surface of the inner ring roller. The inner ring roller is made of a resin material.

Abstract: A seal ring includes a center axis, an outer peripheral surface, an inner peripheral surface, a side surface, and a groove. The center axis is a rotation center. The outer peripheral surface is an outward cylindrical surface whose center is positioned at the central axis. The inner peripheral surface is an inward cylindrical surface disposed between the center axis and the outer peripheral surface whose center is positioned at the central axis. The side surface connects the outer peripheral surface and the inner peripheral surface. The groove is formed in a dented groove from the side surface, extends along a radial direction spaced from the outer peripheral surface, has a first end connected to the inner peripheral surface and a second end at an opposite side of the first end, and returns oil entered from the first end to an inner peripheral surface side via the second end.

Abstract: To provide a combined oil control ring comprising a pair of upper and lower side rails and an axially corrugated spacer expander having upper and lower portions for automobile engines, which is capable of keeping an excellent oil-controlling function without sticking between a spacer expander and side rails even in a long period of engine operation, the upper and lower portions of the spacer expander have tabs pushing inner peripheral surfaces of the side rails, projections supporting the side rails, and intermediate portions between the tabs and the projections; and each intermediate portion opposing the side rail has a center-raised bottom having a center-raised shape when viewed along a substantially circumferential direction center-raised shape and a radial direction.

Abstract: The present invention provides a valve seat of a Co-free, sintered iron-based alloy having excellent heat resistance, oxidation resistance and wear resistance, as well as excellent machinability, which is usable for internal combustion engines using a gas fuel. The valve seat is produced by using a prealloy containing 12% or more by mass of Cr in a matrix for, and hard particles having high strength and hardness at high temperatures are used, such that the entire valve seat has a composition comprising by mass 5.0-20.0% of Cr, 0.4-2.0% of Si, 2.0-6.0% of Ni, 5.0-25.0% of Mo, 0.1-5.0% of W, 0.5-5.0% of V, 1.0% or less of Nb, and 0.5-1.5% of C, the balance being Fe and inevitable impurities.

Abstract: To provide a piston ring of low-alloy steel having excellent nitridability, namely, a piston ring of low-alloy steel having excellent thermal conductivity and capable of being provided with a sufficient nitrided layer, steel comprising by mass 0.45-0.65% of C, 0.15-0.35% of Si, 0.65-1.00% of Mn and 0.60-1.10% of Cr as indispensable alloy elements, and less than 0.35% of Mo, less than 0.25% of V and less than 0.001% of B as optional alloy elements, the total amount of the indispensable alloy elements and the optional alloy elements being less than 3.0% by mass, is formed into a piston ring; and the nitrided layer is formed on its surface.

Abstract: A piston ring includes an annular body having: an inner circumferential surface and an outer circumferential surface; one side surface and the other side surface substantially orthogonal to the inner circumferential surface; and a pair of joint ends. The outer circumferential surface includes an inclined surface and an abutment surface. In a direction connecting the one side surface and the other side surface, a maximum width W1 of the abutment surface at the joint end is 80% to 150% of a maximum width W2 of the abutment surface in a portion other than the joint end. In the body, a two-axis difference (d2?d1) between a diameter d1 in a first axis direction passing through a central position of the joint and a diameter d2 in a second axis direction orthogonal to the first axis direction is greater than ?0.25 mm and less than +0.36 mm.

Abstract: An oil ring (1) includes an oil ring body (10) and a coil expander (20). The oil ring body (10) includes a pair of rail portions (12) each including an end portion of an outer periphery having a land (30) formed protruding radially outward from each rail portion (12). The land (30) includes an upper axial portion (31) and a lower axial portion (32) facing opposite to each other in an axial direction, a tapered portion (33) having one axial end contiguous to the upper axial portion (31) via a first curved portion (35), and a protruding portion (34) having one of axial ends contiguous to the tapered portion (33) and the other axial end contiguous to the lower axial portion (32) via a second curved portion (36). The protruding portion (34) is protruding in a direction perpendicular to the tapered portion (33).

Abstract: A roller-type rocker arm includes a roller shaft. A sliding surface of an outer circumference surface of the roller shaft includes a number of dimples. An inner ring roller is slidably attached to the outer circumference surface of the roller shaft. An inner circumference surface and an outer circumference surface of the inner ring roller include a number of dimples. An outer ring roller is slidably attached to the outer circumference surface of the inner ring roller. An inner circumference surface of the outer ring roller includes a number of dimples.

Abstract: The present invention provides a piston ring having excellent abrasion resistance to an aluminum alloy cylinder or cylinder liner formed of a mating material and is therefore capable of decreasing abrasion of the mating material. An exemplary piston ring has a hard carbon coating formed on an outer peripheral surface, and the hard carbon coating contains 0.5 atom % or more to less than 5 atom % of tungsten (W).

Abstract: To provide a press-fitting, sintered valve seat having excellent valve coolability enabling use in high-efficiency engines, as well as excellent deformation resistance and wear resistance, first and second hard particles differing in hardness are dispersed in a total amount of 25-70% by mass in a network-shaped Cu matrix, the second hard particles having hardness of 300-650 HV0.1, lower than that of the first hard particles, and 0.08-2.2% by mass of P is contained in the sintered valve seat.

Abstract: The provided sliding member has both excellent wear resistance and excellent coating adhesion even under harsh sliding conditions. The disclosed sliding member (100) is used in the presence of a lubricating oil and includes a base member (10), a metal intermediate layer (12) formed on the sliding surface (10A) side of the base member, a layered carbon coating (18) formed on the metal intermediate layer and having a first carbon coating (14) and a second carbon coating (16) layered alternately therein, and a hard carbon coating (20) formed on the layered carbon coating. Under bright-field observation with a transmission electron microscope, an image of the first carbon coating (14) is brighter than an image of the second carbon coating (16). Furthermore, 10 nm<T2?1000 nm and 0.010?T1/T2?0.60, where T1 and T2 are the thicknesses of the first and second carbon coatings (14, 16).

Abstract: Provided is a sliding member capable of achieving excellent wear resistance and high coating adhesion under harsh sliding conditions without subjecting a base member to nitriding treatment. The sliding member includes a base member made of a steel material and a hard coating that is formed on the base member and having a surface serving at least as a sliding surface. The hard coating has a Young's modulus having a distribution to increase first in a depth direction directed from an interface between the hard coating and the base member to the surface, to become maximum at a predetermined depth, and then to decrease in the depth direction directed from the interface to the surface.

Abstract: A combination of a cylinder 62 of an internal combustion engine and a piston ring 40 for sliding an inner periphery of the cylinder, wherein at least a sliding face of the cylinder is composed of an aluminum alloy including 8 mass % to 22 mass % of Si and at least one or more particles selected from the group consisting of Si, Al2O3 and SiO2 particles each having a diameter of 3 ?m or more, and at least an outer periphery of the piston ring is coated with a hard carbon coating 14 composed only of hydrogen and carbon.