Eating (technology)

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In technology, seizure means the repeated local welding and tearing away of two sliding partners as a result of poor lubrication. The result is usually a system failure.

Seizures occur on parts subject to high tribological stress when their emergency running properties are inadequate and there is no longer a lubricating film between the sliding elements, i.e. there is no longer any hydrodynamic lubrication . The progressively advancing boundary and mixed friction heats the components increasingly locally, with both processes influencing each other. The sliding partners weld from a temperature dependent on the bearing material and are separated from each other again due to the ongoing movement. In the process, material particles from each component remain on the partner. The process of welding and separating can stop if there are unchangeable operating conditions (speed, load, temperature, pressure) and the surfaces allow stable operation, but there is a risk that the process will start again if the operating conditions change. As a rule, the seizure continues until the energy acting on the moving component is no longer sufficient to overcome the additional friction at the seizure points or to loosen the welded parts. The second is the case when, for example, on piston engines, gas reaches the scuffing points from the working chamber into the crankcase ( blow-by ). However, it is also possible that the seizure causes further damage which then causes the system to fail.

Seizure occurs most frequently on reciprocating piston engines on the sliding partners piston and cylinder ( piston seizure ). Rotating shafts also frequently eat into plain bearings .

The damage caused by false brinelling is also caused by local welding and breaking away on a microscopic level when rolling bearings are only exposed to minimal, oscillating movements.

literature

  • Johann Czochralski, Georg Welter: Bearing metals and their technological evaluation. Springer Verlag, Berlin / Heidelberg 1920.
  • Heinrich Wiegand, Boris Haas: Calculation and design of screw connections. Springer Verlag, Berlin / Heidelberg 1940.

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