Modelling rotary lip seals

A numerical model that predicts the behavior of the rotary lip seal, under normal operating conditions and with an ingested meniscus, has been constructed. Under normal conditions, the meniscus that separates the sealed liquid from the atmosphere lies on the air side of the seal. As the shaft speed is increased, the meniscus moves closer to the edge of the lip, until a critical speed is reached. Above that critical speed, the meniscus is ingested into the sealing zone. Under such ingested conditions, multiple equilibrium meniscus locations exist. Thus, the seal operation no longer depends only on the seal design and steady stare operating conditions, but also depends on the history of the seal. (C) 1997 Elsevier Science S.A.