Various embodiments of the present disclosure are directed to liquid-cooled cylinder heads. In one example embodiment, a cylinder head is disclosed including a component which extends into a combustion chamber, an upper cooling jacked, a lower cooling jacket, a plurality of valves arranged around the component, a plurality of cylinder head screws, an oil deck, a fire deck, a plurality of valve guides, and a fixed connection. The fixed connection is arranged from each valve guide to the component, and is a ring having at least one support. The support and the ring extend at least from the oil deck to the fire deck thereby hounding the combustion chamber, and the component is connected to the plurality of cylinder head screws.

A sealing device seals a rod having a cylindrical part and a cylindrical guide that guides reciprocation of the rod in an axial direction of the rod. The sealing device includes an elastic ring formed of an elastic material, and a rigid ring formed of a rigid material fixed to the elastic ring for reinforcing the elastic ring. The elastic ring includes a lip with which an outer peripheral surface of the rod is in slidable contact. The rigid ring includes a rigid-ring cylindrical part located radially outside an end portion of the guide. The rigid-ring cylindrical part includes multiple hook hasps engaged into at least one recess formed on an outer peripheral surface of the guide. Each of the multiple hook hasps includes a root portion and a distal end portion located radially inward of the root portion and fitted into the recess. A thin portion is formed at the root portion of the hook hasp, the thin portion being thinner than other parts of the hook hasp.

A sealing device seals a rod having a cylindrical part and a cylindrical guide that guides reciprocation of the rod in an axial direction of the rod. The sealing device includes an elastic ring formed of an elastic material, and a rigid ring formed of a rigid material fixed to the elastic ring for reinforcing the elastic ring. The elastic ring includes a lip with which an outer peripheral surface of the rod is in slidable contact. The rigid ring includes a rigid-ring cylindrical part located radially outside an end portion of the guide. The rigid-ring cylindrical part includes multiple hook hasps engaged into at least one recess formed on an outer peripheral surface of the guide. Each of the multiple hook hasps includes a root portion and a distal end portion located radially inward of the root portion and fitted into the recess. A thin portion is formed at the root portion of the hook hasp, the thin portion being thinner than other parts of the hook hasp.

According to one aspect of the present invention, a sliding member includes: a sliding surface against which an outer surface of a cam abuts; and a groove having a spiral shape or a plurality of grooves having an annular shape, which are provided on the sliding surface. The sliding surface includes a central region having a circular shape and including a center of the sliding surface, and a first annular region located outside the central region. A ratio R.sub.C of a width L2 of the groove to a pitch L1 of the groove in the central region is larger than a ratio R.sub.O1 of the width L2 of the groove to the pitch L1 of the groove in the first annular region.

According to one aspect of the present invention, a sliding member includes: a sliding surface against which an outer surface of a cam abuts; and a groove having a spiral shape or a plurality of grooves having an annular shape, which are provided on the sliding surface.

The sliding surface includes a central region having a circular shape and including a center of the sliding surface, and a first annular region located outside the central region. A ratio R.sub.C of a width L2 of the groove to a pitch L1 of the groove in the central region is larger than a ratio R.sub.O1 of the width L2 of the groove to the pitch L1 of the groove in the first annular region.

Intended is to improve the corrosion resistance of an overlay used in a nuclear power plant, and to reduce dissolution of cobalt from an overlay. The corrosion and wear resistant overlay 7 is formed along a surface of a base 2 by laser lamination modeling, and is configured from a plurality of metal layers 1a, 1b, 1c, and 1d of a Co-base alloy. The thickness of carbide eutectics that precipitate in the metal layers 1a, 1b, 1c, and 1d is the largest in the metal layer 1a closest to the base 2, and is gradually smaller in the metal layers 1b, 1c, and 1d farther away from the base 2. The intensity of the laser beam applied to form layers by laser lamination modeling is adjusted so that the carbide eutectics that precipitate in at least the outermost metal layer 1d have a controlled size of 10 μm or less.

Intended is to improve the corrosion resistance of an overlay used in a nuclear power plant, and to reduce dissolution of cobalt from an overlay. The corrosion and wear resistant overlay 7 is formed along a surface of a base 2 by laser lamination modeling, and is configured from a plurality of metal layers 1a, 1b, 1c, and 1d of a Co-base alloy. The thickness of carbide eutectics that precipitate in the metal layers 1a, 1b, 1c, and 1d is the largest in the metal layer 1a closest to the base 2, and is gradually smaller in the metal layers 1b, 1c, and 1d farther away from the base 2. The intensity of the laser beam applied to form layers by laser lamination modeling is adjusted so that the carbide eutectics that precipitate in at least the outermost metal layer 1d have a controlled size of 10 μm or less.

A rocker arm includes a pair of sidewalls disposed along a heightwise direction so as to be opposed to each other. The sidewalls define a space to house a roller and have opposed portions extending in the heightwise direction relative to adjacent portions which are adjacent to the opposed portions. The opposed portions have thinner portions having smaller thicknesses than the adjacent portions.

A valve arrangement is provided for supplying air to a combustion chamber of an internal combustion engine, the valve arrangement including a first valve, the first valve including a first valve head, a first valve stem and an internal cavity, which is partly located in the first valve stem and open towards a lower surface of the first valve head, a valve guide arranged to surround a portion of the first valve stem such that the first valve stem is movable in the valve guide along a longitudinal direction between an upper, closed position of the valve, and a lower, open position, in which open position air may be supplied to the combustion chamber past the first valve head, the valve guide including an air passage allowing supply of additional air to the combustion chamber via the internal cavity in the first valve, when the first valve is in its closed position. The valve arrangement includes a guide leakage preventing means for preventing liquid from leaking from a region externally of the first valve stem to the valve guide air passage.

A valve arrangement is provided for supplying air to a combustion chamber of an internal combustion engine, the valve arrangement including a first valve, the first valve including a first valve head, a first valve stem and an internal cavity, which is partly located in the first valve stem and open towards a lower surface of the first valve head, a valve guide arranged to surround a portion of the first valve stem such that the first valve stem is movable in the valve guide along a longitudinal direction between an upper, closed position of the valve, and a lower, open position, in which open position air may be supplied to the combustion chamber past the first valve head, the valve guide including an air passage allowing supply of additional air to the combustion chamber via the internal cavity in the first valve, when the first valve is in its closed position. The valve arrangement includes a guide leakage preventing means for preventing liquid from leaking from a region externally of the first valve stem to the valve guide air passage.