Research On Dynamic Bearing Load Evaluation Technology Of Large Shipping Shafting

The ship propulsion shafting plays a role in connecting the main engine and the propeller and transmitting the power of the main engine to the propeller in the ship power system,and is an important component of the entire ship power plant.Safe,efficient and smooth operation of the shafting is an important factor in the normal navigation of the ship.However,in the actual operation process,the shaft system is subjected to complex static and dynamic loads from its own gravity,diesel engine load,propeller thrust,hull vibration and deformation.If the shaft load is too large,it will cause bearing wear and so on.The problem threatens the normal navigation of the ship.In addition,as the ship develops toward large-scale,the increase of the size parameters such as the shaft diameter and the length of the shaft system makes the load of the shaft system and the bearing more complicated,so it is necessary to monitor the bearing load to prevent the occurrence of the fault.The dynamic load of the bearing is an important indicator to reflect the operating state of the shafting.It can not only monitor the operating state of the shafting,but also evaluate the quality of the shafting alignment,which is of great significance to the ship.At present,there is no measurement system that can measure the dynamic load of bearings.This paper first calculates the bearing load from the perspective of simulation.Firstly,according to the dimensional parameters of the components of the shafting experimental rig,combined with the actual model,the three-dimensional modeling software SolidWorks^TM and the multi-body dynamics software ADAMS^TM are used to establish the multi-rigid dynamic model of the shafting experimental platform,and then the finite element is used.After the software ANSYS^TMM establishes the shaft flexible body,the rigid body shaft in the multi-rigid model is replaced to establish a rigid-flexible coupling model.Based on the two models,the dynamics simulation is carried out to obtain the curves of angular velocity,angular acceleration and bearing force.It is found that the rigid-flexible coupling model is closer to reality,and the load spectrum of the bearing in this model is derived from ADAMS^TM and used as the load of finite element analysis.The transient dynamic analysis of the intermediate bearing is carried out to obtain the stress and strain distribution cloud map of the bearing.Secondly,with reference to the simulation calculation results and the actual situation,the bearing load evaluation technology is studied from the perspective of test measurement.Taking the shafting experimental platform as the research object,the hardware includes the selection,setting and installation of strain sensors,data acquisition cards and other equipment.Use LabVIEW^TM software to control the test,collect data,store,analyze and process data.Under the operating condition of the shafting system,the complete strain waveform is acquired,and the measured bearing force is obtained after signal processing and analysis.Finally,the simulation results are compared with the experimental measurements.It is found that the results of the two methods have similar trends,the bearing force amplitude is relatively close,the error of each parameter is within a reasonable range,and the result is more accurate.It is further proved that the research on bearing dynamic load evaluation technology in this paper has certain feasibility.