Disclosed is a method for the production of a valve body of a hollow chamber valve, said method comprising: providing a bowl-shaped semi-finished product having an annular wall, which surrounds a hollow chamber, and a bottom portion, followed by a lengthening of the wall and a final reducing of an outer diameter of the annular wall in order to obtain a predetermined valve shaft outside diameter of a valve that is to be produced. Further disclosed is a hollow chamber valve produced by means of said method.

A valve cover module includes a unitary cover and carrier made of a carbon fiber composite. The unitary cover and carrier has a lower side with a peripheral edge for attaching to a cylinder head. The lower side of the unitary cover and carrier also has a series of cavities interconnected with aligned apertures defining bearing surfaces. A plurality of cam lobes is disposed in the series of cavities. Also, the valve cover module includes a camshaft rotatable on the bearing surfaces and extending through the aligned apertures to couple with the cam lobes.

A method for mounting a camshaft module may involve a module that includes a module cover in which a camshaft is accommodated. The camshaft may comprise a main shaft and a plurality of displacement elements with cam tracks formed thereon for valve-control purposes. The displacement elements may be arranged at predetermined positions in the module cover. The main shaft may be guided along a shaft axis through accommodating passages of the displacement elements. The method may involve arranging a first displacement element in the module cover, introducing the main shaft into the module cover and guiding the main shaft through the accommodating passage of the first displacement element, arranging a second displacement element in the module cover, rotating the main shaft about the shaft axis by an angular amount, and advancing and guiding the main shaft through the accommodating passage of the second displacement element. Further, the displacement elements are arranged in the model cover with an identical rotary orientation about the shaft axis.

An adjustable camshaft, which can be utilized in a motor vehicle, may include at least one fixed cam arranged rotationally fixed on at least one outer shaft segment and at least one adjusting cam arranged rotationally fixed to an inner shaft extending concentrically within the outer shaft segment. A method for producing such an adjustable camshaft may involve arranging an outer shaft segment on an inner shaft, generating a surface modification on a surface of the inner shaft to generate at least one arranging section, arranging a fixed cam on at least one section of the outer shaft segment, and arranging the adjusting cam on the arranging section of the inner shaft.

A pivot bearing (1) for a hydraulic clearance compensation element (2), especially of a valve train of an internal combustion engine, is provided in which the pivot bearing (1) has a first part (3) projecting in an axial direction (a) with a surface (4) that is convex at least in some sections and also a second part (5) with a surface (6) that is concave at least in some sections for at least partially holding the first part (3). To optimize the production of such a pivot bearing and to minimize the associated costs, the invention provides that the first part (3) is constructed at least partially as a ball, wherein the second part (5) surrounds the ball (3) with undercut in the axial direction (a).

A rolling-contact shaft member, which is made of high-carbon steel and whose outer peripheral surface serves as a rolling-contact surface that rolling-contacts a mating material, includes: a carbonitrided layer having a carbon concentration of 1.1 to 1.6 wt % and a nitrogen concentration of 0.05 to 0.6 wt % in the range from the surface to the depth of 10 μm. The rolling-contact shaft member has a Vickers hardness of 700 to 840 HV at the outer peripheral surface and has a Vickers hardness of 600 HV or less in its central portion. A maximum value of an absolute value of a gradient of a change in the Vickers hardness from the outer peripheral surface to the central portion is 100 to 340 HV/mm.

A roller lifter includes a first member having a pair of opposed portions opposed to each other and a connecting part connecting the opposed portions to each other, a shaft mounted between the opposed portions to rotatably support a roller brought into contact with a cam, a second member independent of the first member and having a cylindrical portion and an elastic mount elastically held between the opposed portions and the cylindrical portion to mount the first member to the second member.

A valve-actuating lever for reciprocating-piston internal combustion engines is proposed, wherein this lever is supported on a cylinder head of the internal combustion engine or a part of this cylinder head, is in active connection with a cam of a camshaft, has an essentially inverted U-shaped cross section, is made from steel sheet metal by a punching, bending, and/or deep-drawing measure, and has, in addition to a support plate (5) for a shaft of a gas-exchange valve or for an intermediate piece, lateral guide cheeks (3, 4). A height of the lateral guide cheeks (3, 4) can be changed with regard to the support plate (5) by an embossing procedure.

A camshaft adjuster is produced that includes a stator and a rotor, which is rotatable relative to the stator, wherein the stator and the rotor are produced with first planar surfaces on a first end face and with second planar surfaces on a second end face, which is formed to be opposite the first end face when viewed in an axial direction; wherein the rotor and/or the stator is produced according to a powder-metallurgical method, wherein the first planar surfaces or the second planar surfaces of the stator and the rotor are ground or finished, and the respective other planar surfaces of the first and second planar surfaces of the stator and the rotor are calibrated and left unground.

A camshaft adjuster is produced that includes a stator and a rotor, which is rotatable relative to the stator, wherein the stator and the rotor are produced with first planar surfaces on a first end face and with second planar surfaces on a second end face, which is formed to be opposite the first end face when viewed in an axial direction and wherein the rotor and/or the stator is or are produced according to a powder-metallurgical method, The first planar surfaces and the second planar surfaces of the stator and the rotor are ground or finished, and the lateral surface of the stator and the lateral surface of the rotor are left uncalibrated.