Study On Static And Dynamic Characteristics Of Lubricating Oil Film For Marine Thrust Bearing And Its Application

The propeller shaft of ship is typically rotor-bearing system,consisting of a shaft rotor and a bearing non-rotor.The crucial feature of the rotor is lubrication,which is the significant difference between non-rotor structure and rotor structure.Traditionally,in the study of the longitudinal vibration of the ship propulsion shaft,the longitudinal vibration of the propeller shaft is equivalent to the longitudinal vibration of the rod,ignoring the rotor characteristics of the propeller shaft and lacking a quantitative study on the axial dynamic characteristics of the lubricating oil film.The thrust ring between the thrust ring and the thrust pad of the bearing acts as a carrier and transmits the thrust of the propeller.When the thrust ring is vibrated under the thrust of the propeller pulsating thrust,the thrust ring squeezes the lubricating oil film before and after its equilibrium position Lubricating oil film generated pressure pulsation,and then show the dynamic characteristics.Obviously,in the process of advancing the longitudinal vibration of the shaft,the dynamic characteristics of the lubricating oil film are objective.This kind of dynamic characteristic is caused by the longitudinal vibration of the propeller shaft,which inevitably reacts to the propulsion shaft system,and has some influence on its longitudinal vibration characteristic and force transmission characteristic.Although the longitudinal vibration analysis of the thrust shaft system is based on the basic theory of longitudinal vibration of the rod,the dynamic characteristics of the lubricating oil film must be reflected in the dynamic model.In recognition of the impact of lubricating oil film to promote the vertical vibration characteristics of the shaft after the object,to specify the extent of its impact.In this paper,the dynamic characteristics of the lubricating oil film must be studied quantitatively.The calculation results are taken as the data input of the longitudinal vibration analysis model of the propeller shaft.The influence of the lubricating oil film is determined by comparing the calculation results of the lubricating oil film.The relationship between the longitudinal vibration of the propeller shaft and the dynamic characteristics of the longitudinal vibration of the propeller shaft can be explained by analyzing the dynamic characteristics of the connection between the rotation and the longitudinal vibration.In this paper,the static and dynamic characteristics of the lubricating oil film between the thrust ring and the thrust plate are analyzed and the following work is done:In the first chapter,the background and significance of this research is combed.The research on the longitudinal vibration control of the shafting system at home and abroad and the analysis of the static and dynamic characteristics of the lubricating oil film of the tilting pad thrust bearing are carried out.In the second chapter,the theoretical model of dynamic pressure lubrication of tilting pad thrust bearing is established,and then the static model of oil film is established from the Reynolds equation,energy equation and film thickness equation of lubricating oil film movement.Based on the known static characteristics of oil film,the dynamic characteristic analysis model of oil film was established by Taylor series expansion method.In the third chapter,the governing equations of static and dynamic analysis of oil film are dimensionless,and then the Reynolds equation and the energy equation are discretized by finite difference method and step method.Finally,based on the balance between the bearing capacity of the oil film and the external load,the moment balance of the tilting groove is proposed,and the theoretical basis of the nested dichotomous numerical calculation is proposed.In the fourth chapter,the nested dichotomy is used to calculate the structural size of the lubricating oil film with the actual thrust bearing,and compares the results of the shaft vibration test.The correctness of the numerical algorithm is verified from the trend and the load and speed are analyzed.The dynamic coefficient of oil film does not change with the rotation speed.Then,according to the static performance of the oil film obtained by the relevant finite element software,the accuracy of the numerical algorithm is compared.Finally,we can compute the static and dynamic characteristics of the lubricating oil film of tilting pad thrust bearing lubricating oil film,and can calculate the static and dynamic characteristics of lubricating oil film with different thrust bearing structure size,arbitrary speed and arbitrary load.In the fifth chapter,the longitudinal vibration characteristics and longitudinal vibration analysis methods of the main propulsion shaft are studied.The influence of the lubricating oil film on the longitudinal vibration of the shaft is analyzed,including the influence on the stiffness,the influence of the natural frequency and the sensitivity analysis.In the last chapter,the author chooses the summary,summarizes the main conclusions,innovates the innovation and puts forward the research direction.