Abstract: A method and device for joining assembled hollow shafts which consist of a tube and several attachable parts such as cams, flanges, bearing sleeves, pulse generating devices, toothed gears and chain gears slid on to the tube, wherein the tube, inside the attachable parts, is radially plastically expanded in individual portions by applying internal pressure in such a way that the attachable parts are secured to the tube by a permanent press fit, wherein the attachable parts and the tube are individually positioned and fixed relative to one another and wherein the tube is sequentially plastically expanded in individual portions associated with the individual attachable parts.

Abstract: A camshaft assembly (11) having a tubular shaft (12) and a plurality of cams (14) which are each provided with a through-aperture and which are slid on to the tubular shaft (12) and secured thereto at distances from one another, wherein the tubular shaft (12), between the cams (14), includes inwardly hot-formed lateral indentations (22). A method and device for producing the camshaft assembly are also provided.

Abstract: A method and device for joining assembled hollow shafts which consist of a tube and several attachable parts such as cams, flanges, bearing sleeves, pulse generating devices, toothed gears and chain gears slid on to the tube, wherein the tube, inside the attachable parts, is radially plastically expanded in individual portions by applying internal pressure in such a way that the attachable parts are secured to the tube by a permanent press fit, wherein the attachable parts and the tube are individually positioned and fixed relative to one another and wherein the tube is sequentially plastically expanded in individual portions associated with the individual attachable parts.

Abstract: A process is provided for the production of a cam to be joined to a hollow shaft to form a camshaft. In order to make the cam suitable for stable long-term operation on the camshaft, the internal compressive stresses achieved in the cam track before the joining of the cam to the camshaft being so high that the tensile stresses resulting from joining are permanently overcompensated, it is provided that the material selected for the cam is a steel in which the carbon can be dissolved easily as cementite in the pearlite and martensite or is in the form of a fine composite carbide. The cam, which is composed of a hardenable steel, should be fully hardened and, during tempering in the hardening operation, the basic hardness should be set in a range of between 25 and 40 HRC. The cam should then be edge-zone-hardened in a two-stage heating process by induction hardening at a medium frequency of 10-35 kHz, after the preheating stage of the heating process, the introduction of heat being interrupted for 0.3-1.

Abstract: A fan-type manifold for multi-cylinder internal-combustion engines has several first individual pipe sections which are connected in pairs to respective ones of second pipe sections. The first individual pipe sections are undeformed on the end and are cut off at a specific angle. The second pipe sections are produced by an internal high pressure deforming process. The first pipe sections are plugged into the second pipe sections at respective Y-type combining points to form Y-shaped connections and are sealingly welded to each other via surrounding fillet welds. One of the second pipe sections has an additional Y-type combining point for the lateral connection of the other second pipe sections, which are sealingly welded thereto via surrounding fillet welds.

Abstract: An exhaust manifold for an internal combustion engine with at least two cylinders includes at least two adjacent connection branches which are interconnected by collection pipe sections having an expansion compensating bellows for accommodating differential thermal expansion therebetween and a gas flow guide pipe structure which extends into the bellows. At least one of the collection pipe sections comprises a multi-layered pipe wall with which the expansion compensating bellows is integrally formed.

Abstract: An exhaust manifold for an internal combustion engine includes an inner duct with flanges for connection to an engine. The inner duct is enclosed by an envelope consisting of two shells which are interconnected at their edges by seams. Between the inlet flanges, the seams are disposed at a substantially greater distance from the inner duct than in other areas such that, in a cross-sectional plane disposed between, and extending normal to, the flanges, the envelope has drop-like shape.