Lubrication Analysis Of Seawater Lubricated UHMWPE Marine Stern Tube Bearing During Start-stop Process Under Vibration And Shock Conditions

As an important part of Marine ship propulsion system,stern bearing is the connecting hinge between propeller and stern shaft and a key link between the shaft system and the external environment.Therefore,the safe operation of stern bearing is of great significance to the normal work and safe operation of the ship.The performance of stern bearing is closely related to its lubrication state.Once the failure of stern bearing is caused by insufficient lubrication,it will affect the whole body and endanger the safety of shafting and ship.Therefore,it is necessary to study the lubrication characteristics of ship stern bearing,especially considering the influence of various operating conditions on the lubrication during actual operation.In view of this,considering the variability and complexity of the lubrication state of the bearing during the start-stop process,the lubrication characteristics during the start-stop mode with different acceleration and deceleration modes are studied.Moreover,the effects of vibration conditions and shock conditions on the start-stop process are also considered.Finally,the vibration and shock conditions are coupled to explore the influence of vibration and shock coupling conditions on bearing lubrication during start-stop process.First of all,the establishment of a water lubricated bearing start-stop process considering the effect of time-varying elastohydrodynamic lubrication model,in a different form of deceleration and stop deceleration of the process of simulation,it is concluded that the bearing contact area pressure and film thickness changing with the time,at the same time we compare results with the empirical formula,and verified the model and the correctness of the result,and combining with the contact area of the film thickness distribution under different moment,analysis it is concluded that the best form of deceleration,optimize the water lubricated stern bearing lubrication performance in the start-stop process.Secondly,considering the changes caused by the axis of normal vibration bearing clearance,compared the presence of start-stop difference under vibration condition,and proves that under vibration conditions using the best form of deceleration and stop for the improvement of the bearing lubrication effect,the system analyzed the different vibration conditions for start-stop's effect on the bearing lubrication,the start-stop process is obtained the most beneficial to the vibration of the lubrication condition and the start-stop time to best.Again,consider the effect of shock waves caused by external load fluctuations,compared the presence of impact under the condition of the difference between the start-stop,proves that under shock conditions using the best form of deceleration and stop for bearing lubrication,also has the systematic analysis of the different impact conditions for bearing lubrication start-stop process,the influence of the start-stop process is obtained the most beneficial to the shock of the shaft and bearing lubrication operation condition.Finally,considering the influence of vibration and shock comprehensively,the lubrication state of bearing contact zone under different working conditions was compared,and the influence of different vibration and shock working conditions on bearing lubrication during start-stop process was analyzed and discussed,and the optimal coupling working conditions and start-stop conditions were obtained.