Finite Element Analysis Of Spiral Ladder Cavity Hybrid Bearing Under Water Lubrication

Ship Stern bearing is an important part of ship stern tube propulsion system,and as a key hub for internal and external exchange of the power system,the performance of propeller is closely related to the lubricating characteristics of stern bearing.Therefore,the design of new structure of ship stern bearing is of great significance to improve the transmission efficiency of shafting system,improve the lubrication effect,prolong its fatigue life.This paper designs and develops a new type of stern bearing—spiral ladder cavity hybrid bearing.Firstly,the fluid characteristic of the new bearing is analyzed to ensure the feasibility of the structure.Secondly,the influence of the structure parameters of the new bearing on its statics performance is analyzed systematically.Then the modal analysis and the vibration characteristic of the new bearing is analyzed.Finally,the method of combination of orthogonal test and control variable is applied,and the assembly model of stern shaft and bearing is established.the nonlinear contact analysis is carried out and the sensitivity distribution of the structural parameters to its mechanical properties is obtained by the analysis of the extreme difference.1)Set up three-dimensional model of spiral ladder cavity hybrid bearing and traditional type hybrid bearing.Then introduce Ansys Workbench to extract fluid domain,divide hexahedral grid in Icem,use fluent to simulate and analyze the fluid and compare and analyze the two difference between the carrying capacity.Afterwards,the fluid-solid coupling analysis of the new bearing was carried out to explore the influence of the water film pressure on the mechanical properties of rubber liner.2)Considering the structure parameters of the new bearing cavity length,cavity number,helix angle,depth cavity ratio,inlet/outlet hole diameter and so on,the static analysis is carried out by Ansys Workbench to preliminarily explore the influence rule of each structural parameter on its stress,strain and displacement.3)According to the situation that the propeller will produce impact load in the course of operation,so this paper uses Ansys Workbench to analyze the modal analysis and deeply studies the variation regularity of the bearing vibration pattern.Then probes into the response relation of bearing stress and displacement under each characteristic frequency,providing theoretical guidance to avoid resonance phenomenon.4)Aiming at the "edge effect" in the operation of the propeller,the interaction between the various structural parameters of the bearing and the nonlinearity of the rubber material are comprehensively considered.While the assembly model of the stern shaft and the bearing is established by using the orthogonal test method and the control variable method to make contact analysis of it.Based on the results of contact analysis,this paper gives an analysis of the influence of the structural parameters on the mechanical properties.The influence of other single factors on bearing contact performance is also explored.Therefore,it provides an effective reference for improving the mechanical properties of the bearing and improving the actual working condition of the contact area of the stern bearing.