We have investigated mechanical face seals used as sealing devices of pumps in cooling systems of automobile engines. Sometimes the mechanical face seals generate undesired acoustic emissions: ringing. Ringing phenomena in mechanical face seals are one of the inconveniences that appears under certain conditions but they are rarely studied because of the difficulty in reproducing these phenomena. Seals may operate in any of the following three lubrication regimes: full film lubrication, mixed lubrication and boundary lubrication.
The problem is examined through a lumped parameters model together with a mixed friction tribological model. Numerical simulations compared with experimental results demonstrate that the phenomenon is caused by the insurgence of stick-slip vibrations. In addition, the stability threshold is investigated and the influences of some design parameters are evaluated.