Development Of An Electromagnetic Loading Experimental Rig For Ship’s Stern Shaft Bearing

Ship stern shaft bearing is an important part of ship propulsion shafting.Its application on ships must be approved.It is an effective method to accurately study and master the lubrication characteristics of bearing by carrying out the simulation test by bearing test rig.It is of great practical significance to design a set of ship stern shaft test device for bearing effectiveness verification and lubricant effectiveness verification.The traditional bearing test device usually uses mechanical and hydraulic loading mode to simulate the bearing load.This type of loading mode can not easily realize the dynamic adjustment and control the load,especially the loading force can not reflect the actual dynamic load in working condition.With the development of electromagnetic technology,electromagnetic bearings are more and more used in various fields of engineering.It can stabilize the shaft at the working point by controlling the electromagnetic force.Therefore,based on the principle of electromagnetic bearing,a bearing test device is designed with magnetic force as the loading force.This type can effectively overcome the shortcomings of the test device with traditional loading mode.The main contents of this paper are as follows:1.From the principle of dynamic lubrication of the stern shaft bearing of the ship,it is proved that the shaft bearing can stabilize the shaft in a certain position in the bearing when the tail shaft bearing is subjected to various loads.The relationship between the position of the stern shaft and the working load is established,and the theoretical basis for the reaction load is established through the position of the shaft.2.Aanalyze the mathematical model of the loading device,determine the relationship between the electromagnetic force and the coil current and air gap length,and the length of the air gap is the distance between the core and the shaft.Therefore,the effect of electromagnetic force on bearing is consistent with the effect of external load on bearing when the rotating shaft works in the same working position,which proves the feasibility of using electromagnetic force to simulate the external load.3.Through the target load,the relevant parameters design of the magnetic loading device is completed,and the loading ability of the electromagnet is checked.4.According to the state equation of the loading device,combined with the specific parameters of the electromagnetic loading,and combining the characteristics of the system,the control system is designed.5.Complete the design of bearing test rig except loading part.Summary: This design innovatively applies the principle of electromagnetic bearing to the shipbuilding industry,and puts forward new ideas for the construction of the ship tail bearing structure design,material selection and the choice of the tail shaft lubrication medium.This design also extends the application of the electromagnetic bearing to the shipbuilding industry.