Abstract: A joint-site structure for a shaft/disk composite workpiece, in particular for joining a shaft 1 to a connection flange 2 of a hub part of the disk by means of friction welding. A respective defined gap 4, 4? is incorporated between shaft 1 and connection flange 2 of the hub part in front of and behind a joint site 3, this gap 4, 4? preventing the spread of the material softened during the friction welding. The joint-site structure is used, for example, during the joining of a crankshaft and a hub part of a drive wheel.

Abstract: A composite shaft/disc workpiece which is assembled from a disc with a passage hole and from a shaft by friction welding is disclosed. The outer wall of the shaft has a plurality of steps in the connection region with the disc, the radius of the steps becoming larger in a direction of the axis. The passage hole of the disc is provided with webs, the radius of which likewise becomes larger in a direction of the axis and between which annular recesses are present. The webs and steps to be connected overlap in the radial direction, so that, during the welding of the shaft and disc, annular connecting portions are obtained in the region of the webs and steps, annular cavities being formed between the connecting portions. The cavities represent a weight saving, as compared with composite shaft/disc workpices made of solid material, and can also be used as parts of media ducts.

Abstract: A welded crankshaft having a number of individual elements and cavities formed in the region of the main bearing journals and crank journals. The individual elements are configured so that oil passages in the overlap region between the main bearing journals and crank journals run substantially in the axial direction, and transition via radial orifices directly into the journal surface. The cavities of the main bearing journals and crank journals can be made very large, so that the weight of the crankshaft is kept light. In addition, because of the simple geometry of the oil passages, the crankshaft can be manufactured in modular fashion from the individual elements.

Abstract: A process for the production of cup tappets for reciprocating-piston machines having a pressure plate made from wear-resistant alloyed tool steel and a cup casing, welded to the pressure plate, and made from cheap and cold-extrudable steel utilizes a friction welding process to weld the two parts to one another in a crack-free manner. The cup casing blank is produced by the cold-extrusion process and is carbonized before the welding so that good welding results can thereby be achieved despite the considerable strength differences and cross-sectional differences between the pressure plate and cup casing blanks. As a result of a preheating of the pressure plate, an impairment of the cup casing blank during the frictional heating can be compensated and cracks in the workpiece during or immediately after the welding can thereby be avoided.