A coupling element for a multi-joint crank drive of an internal combustion engine includes a coupling lever having a first eye for a piston connecting rod, and a second eye for an articulation connecting rod. A bearing cover forms with the coupling lever a third eye for a crank pin. The coupling lever and the bearing cover are connected to each other by bolts which defined parallel longitudinal central axes. The coupling lever and the bearing cover abut each other at an outer periphery of the third eye at adjacent contact surfaces on both sides of the third eye to define a separating plane which extends through a center of the third eye at an acute angle with respect to a further plane which passes through the center of the third eye and extends perpendicular to the longitudinal central axes of the bolts.

A rotary joint includes a socket rod having a socket rod flange with a basically spheroid con-cave bearing surface at a first end, a housing nut encircling the socket rod and having a threaded wrenching head, a ball rod having a basically spheroid convex bearing surface and threaded side walls around the convex bearing surface, and a joint actuator configured to actuate relative movement of the socket rod flange and the ball rod. A diameter of the threaded side walls of the ball rod corresponds to a diameter of the threaded wrenching head of the housing nut.

A screw connection is formed between steering components, namely a push rod and a fork, in particular of a rear axle steering system. By means of a screw screwed coaxially into one of the two steering components and inserted through an opening in the other steering component, an annular disc-shaped end face of the one steering component is pressed against a likewise annular disc-shaped face of the other steering component. Furthermore, cylindrical mating faces contacting one another are formed by the steering components. In at least one of the two steering components, a transition region is formed between the annular disc-shaped face and the cylindrical mating face, which has at least two different radii of curvature.

A connecting rod for an internal combustion engine may include a connecting rod shank, a large connecting rod eye, and a small connecting rod eye with a pin bore. An end face of the small connecting rod eye may also include at least one overhang, the overhang running parallel to a central axis of the pin bore over its entire width transverse to the central axis of the pin bore. An edge of the overhang may also run parallel to the central axis of the pin bore.

A fracture-separated engine component and a method for manufacturing same is described. The engine component includes first and second parts each having a fracture surface extending along a fracture plane. Prior to fracture separation, the engine component is case-hardened by nitriding and has a nitriding hardness depth of 0.4 to 0.7 mm. After the nitriding, the engine component is cooled such that each one of the subsequent fracture surfaces reaches a temperature below 100 C. The fracture separation is then performed. After, the engine component has two fracture surfaces along a fracture plane, the fracture surfaces having hardened peripheral areas and unhardened core sections. No point of the unhardened core sections located in the fracture plane is located at a distance greater than 1.1 mm from a nearest hardened peripheral area. Each one of the fracture surfaces includes elongated partial fracture surfaces with a width of less than 3.2 mm.

The link for an aircraft comprises at least two portions respectively made of metal and of composite material together forming a common section of a middle segment of the link in a plane perpendicular to a longitudinal direction of the link.

A rotary joint includes a socket rod having a socket rod flange with a basically spheroid con-cave bearing surface at a first end, a housing nut encircling the socket rod and having a threaded wrenching head, a ball rod having a basically spheroid convex bearing surface and threaded side walls around the convex bearing surface, and a joint actuator configured to actuate relative movement of the socket rod flange and the ball rod. A diameter of the threaded side walls of the ball rod corresponds to a diameter of the threaded wrenching head of the housing nut.

A fail-safe push-pull rod has two load paths that are separated from each other, of which always only one takes up the load transmission and which automatically detects possible damage to or functional failure of the first load path so that in such a case then the second load path takes over the load transmission, whereby the functional change from the first to the second load path can be determined during the routine maintenance inspection by an inspection hole irreversibly showing the damage or the failure of the first load path.