Elastohydrodynamic Lubrication Analysis of Marine Sterntube Bearing Based on Multi-body Dynamics

Abstract To predict and analyze accurately the lubrication characteristics and its influencing factors of marine sterntube bearings, coupling simulation between EHD and MBD for sterntube bearings of marine diesel engine propulsion system was carried out. FE models for crankshaft and main bearings of a two-stroke low-speed marine diesel engine, intermediate shaft, tailshaft, intermediate bearings and sterntube bearings of a chemical carrier were established, and the results files generated from reduced FE models by employing substructure methods were entered into MBD model. Sterntube bearing forces, load distribution, orbital path, minimum oil film thickness(MOFT) and total friction power loss on fore sterntube bearing and aft sterntube bearing in one working cycle under rated working conditions were investigated. Simulation results show that the sterntube bearings were safe enough for normal operation, the vertical load and the total friction power loss on aft sterntube bearing were significantly higher than that of fore sterntube bearing.