Beachtenswerte Vorgänge bei hochtouriger hydrodynamischer Lagerschmierung

Summary

Flow conditions in the lubricating gap of a hydro-dynamically lubricated sleeve bearing at extremely high speed have been investigated theoretically. It is known that hydrodynamic lubrication requires a copious oil supply so as not to interrupt the flow and consequently the generation of pressure. However, it is found that with certain running conditions there may be lack of oil in the lubricating gap despite ample supply of oil in the grooves. This is caused by the fact that the oil discharge may be larger than the amount of oil that can be supplied at the beginning of the gap. The result is a vacuum combined with air evaporation and the formation of bubbles, which endanger the running surfaces locally by denuding them of the protective oil film.

The results are explained by an example. This shows that under certain circumstances the region of critical speed can still be attained in practice.