A method for manufacturing a hollow camshaft is provided, and more particularly, a method for manufacturing a combined hollow camshaft by an axial-compression upsetting-deformation technique. The present method solves a problem that the current camshaft manufactured in an internal high-pressure expansion manner in the prior art has the insufficient locking force to cause the loosening of a cam. The method is as follows: a camshaft is formed by combining two independent units, namely a cam and a shaft tube. Non-circular countersinks are distributed on two sides of the cam. Thrust steps are formed on the shaft tube correspondingly. The cam is placed between the two thrust steps of the shaft tube. The locking force is applied to the cam by utilizing the thrust steps on the two sides of the cam based on thermal expansion and contraction. Simultaneously, the thrust steps lock the cam with the countersinks.

A tappet assembly including an outer cup having a substantially cylindrical side wall, an annular lip portion disposed at a first end of the side wall, and an annular ledge disposed on the side wall, the annular ledge being disposed in a plane that is transverse to a longitudinal center axis of the tappet assembly. An inner cup includes an annular lip extending outwardly therefrom and a pair of shaft apertures, and is disposed in the outer cup so that the lip abuts the annular ledge of the outer cup and is non-rotatably fixed thereto by the annular lip of the outer cup which abuts the lip of the inner cup. A shaft is received in the shaft apertures, and a roller tappet is rotatably received on the shaft such that a portion of the roller tappet extends axially outwardly beyond the annular lip portion of the outer cup, and an alignment device formed in the outer cup.

The present invention refers to a camshaft with a functional component as an assembly insert and the process of manufacturing said camshaft, wherein said camshaft has at least one functional, component integrated in the camshaft body, taking into account that the material of the functional component and the shaft body are of different materials; and wherein one or more functional components comprises a body of A-type material having an internal bore of suitable geometry to pass through it a B-type melt in a casting process; gripping means which achieve a mechanical, grip between both materials, A-type material and B-type molten material, to give mechanical grip in the longitudinal and circumferential direction with respect to the camshaft body.

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 tappet assembly including an outer cup having a substantially cylindrical side wall, an annular lip portion disposed at a first end of the side wall, and an annular ledge disposed on the side wall, the annular ledge being disposed in a plane that is transverse to a longitudinal center axis of the tappet assembly. An inner cup includes an annular lip extending outwardly therefrom and a pair of shaft apertures, and is disposed in the outer cup so that the lip abuts the annular ledge of the outer cup and is non-rotatably fixed thereto by the annular lip of the outer cup which abuts the lip of the inner cup. A shaft is received in the shaft apertures, and a roller tappet is rotatably received on the shaft such that a portion of the roller tappet extends axially outwardly beyond the annular lip portion of the outer cup, and an anti-rotation feature formed in the outer cup, wherein the outer surface of the outer cup is an unground surface.

A combustion-chamber structure of an engine comprises a combustion chamber which is partitioned by a cylinder block, a cylinder head, a piston, an intake valve, and an exhaust valve. The intake valve (exhaust valve) comprises an intake valve body including an umbrella part having a valve head and a valve face, a heat-insulation layer provided at the valve head and having smaller heat conductivity than the valve body, a heat-barrier layer provided to cover the valve head with the heat-insulation layer and having smaller heat conductivity than the valve body and the heat-insulation layer, and a heat-diffusion layer provided between the heat-insulation layer and the heat-barrier layer and having larger heat conductivity than the heat-insulation layer and the heat-barrier layer. The heat-diffusion layer comprises a contact portion which contacts with the cylinder head when the intake valve is closed.

A novel cylinder head arrangement for an in-line four cylinder or eight cylinder engine. A modified arrangement allows additional space for installation of wider rocker arm assemblies used for variable valve lift (VVL), cylinder deactivation (CDA) and other types of variable valve actuation (VVA). In one embodiment, cam towers adjacent the end two cylinders are not used. At least one end support is used, which may be an outboard bearing on a camshaft for each end. The wider rocker assemblies may then be installed. In another embodiment, cam towers adjacent the inner two cylinders are eliminated and a single camshaft support piece with a support bearing is installed between the inner cylinders to provide support for the camshafts. The wider rocker assemblies may then be installed on at least one of the middle cylinders. A novel oil control valve operates latches in switching rocker arm assemblies.

A method for producing a reduced friction sliding surface on a machine element includes applying a coating comprising amorphous carbon to a surface of the machine element and locally heating the coating with a laser. The coating is heated to a temperature below an evaporation temperature of the coating to achieve a local volumetric increase in the coating and a local increase in a layer thickness of the coating. A surface structure of the coating includes a multiplicity of elevations resulting from a local phase transformation of the coating from amorphous carbon into graphite due to the locally heating.

A roller tappet for a high-pressure fuel pump or for a valve drive of an internal combustion engine is provided. The tappet can be guided in a direction of a longitudinal axis thereof in a housing receptacle and can be driven displaceably by a cam shaft of the internal combustion engine. The tappet includes a tappet body which has a guide cylinder, and a cup-shaped sleeve supported axially and radially on the guide cylinder. The sleeve includes a bearing surface for the pump piston or a valve drive element, and the guide cylinder includes a rotatable roller mounted on support flanks, by means of which roller the roller tappet can be supported on the internal combustion engine camshaft. The sleeve has, at its end region facing away from the bearing surface, a ring-shaped shoulder for radial support and an end ring for axial support on the guide cylinder.

A sliding member of the present invention includes a coating on a base material. The coating contains hard metal particles and corrosion-resistant metal particles that have hardness lower than that of the hard metal particles. The hard metal particles contain particles that have at least Vickers hardness of 600 Hv or higher. The corrosion-resistant metal particles are made of at least one kind of metal selected from the group consisting of copper (Cu), cobalt (Co), chromium (Cr), and nickel (Ni), or are made of an alloy containing said metal. The coating has a cross section in which the hard metal particles are dispersed in an island manner in a particle aggregate of the corrosion-resistant metal particles and in which an area ratio of the corrosion-resistant metal particles is 30% or larger. Thus, corrosion of the hard metal particles in the coating is prevented, whereby the sliding member maintains wear resistance for a long time.