Research On The Influence Of Shafting Alignment By Considering Oil Film Characteristic Of Ship Stern Tube Aft Bearing

During the normal navigation of ships, the main propulsion shafts usually take complex force from outside. To keep the main propulsion shafts running normally, satisfied alignment quality must be undertaken after fixing shafts. In this paper, based on rational shafting alignment and improving the bearings’support pattern, the influence of shafting alignment is researched by considering oil film characteristics of stern tube aft bearing.According to the structure and fixing characteristic of the main propulsion shafts, ANSYS software could be applied to calculate rational shafting alignment. With the data supplied from shafting alignment calculating files, shafting physical model is built and calculated in ANSYS software. Change the traditional rigid supports to elastic ones by calculating bearings’stiffness, and analyzes the different influence of bearings’load. Besides, improve the traditional single-support model for stern tube aft bearing and analyze the bearing load distribution under multi-support condition.As a dynamic factor influencing shafting alignment, oil film characteristic of stern tube aft bearing is studied to analyze the aft bearing reaction force during shaft normal running. Based on the theory of journal bearing lubrication, this paper applies MATLAB software to numerically calculate the dynamic parameters of lubricating oil film, which build foundation for the research on the influence of shafting alignment is researched by considering oil film characteristics of stern tube aft bearing.Based on oil film stiffness method, the dynamic parameters of oil film which is equal to elastic elements are calculated in rational shafting alignment model. In this way, the supporting model is changed to make the shafting model satisfy for the real shaft running condition. With a 176000DWT bulk carrier shafting model, shafting alignment considering oil film dynamic characteristic is calculated in ANSYS and MATLAB software to analyze the influence of shafting alignment is researched by considering oil film characteristics of stern tube aft bearing.