Analysis and Design of Advanced Stern-Tube Lip Seals.

摘要

Lip-type seals are employed in oil-lubricated stern-tube sealing systems of large modern ships. The seals are made of elastomers and appear to fail frequently due to a variety of reasons. Prominent among these reasons is the heat generated in the sliding contact within the sealing assembly. In order to shed more light on the performance characteristics of the stern-tube sealing system,particularly to reduce the heat generation and stress,an analysis of the lip seal was conducted. Deformation behavior,stress distribution,and radial tightening force of the lip under statcally loaded conditions were theretically analyzed employing a general-purpose finite-element stress analysis program MARC-CDC. Large deformation of the seal was explained by flagging nonlinear analysis in the code. Stress contours and deformation of the seal were plotted at different pressure drops across the seal lip for seal-lip configurations currently in use in stern tubes. To further reduce the radial loading and stress levels two new cross-sectional condifurations of the lip seal are recommended.