Design And Simulation Of Crawler Driving System Of Amphibious Ship

In recent years,the rivers in China are often flooded with water and grass,and it is timeconsuming and laborious to rely on workers to harvest them.Therefore,mowing ships have become a common way at present,and the common mowing ships are usually driven by bright wheels or propellers,so they can't travel on land.That is to say,the mowing ship must be lifted by means of crane,which is time-consuming,laborious,expensive and inconvenient to transfer.Based on the application of waterways,lakes and reservoirs,the team plans to develop a kind of amphibious ship.Considering that the working environment of the amphibious ship is mostly small channel,beach,swamp and so on,ordinary wheels can easily sink into mud in this kind of working environment,so the crawler is used as the land walking device in this paper.According to the working environment requirements of amphibious ship,this paper completed the design of the crawler driving system and the transmission system,and completed the threedimensional model of the crawler driving system by using SolidWorks.The dynamic simulation of the crawler system of amphibious ship is carried out by RecurDyn,and the force condition of the system is obtained under three working conditions: straight ground,side brake turn and climbing 20 °slope.The finite element analysis of crawler frame,drive shaft and chassis loadbearing beam is carried out by HyperMesh,and the maximum displacement and maximum stress of track frame under various working conditions are obtained.The modal analysis of the chassis frame is carried out with HyperMesh.The natural frequency of the chassis frame is compared with the frequency of the engine,and the conclusion is that the chassis frame will not be excited.The main research work and design in this paper are as follows:1.The necessity of cleaning river grass and the research status of tracked vehicles are introduced,and the design scheme of amphibious ship track driving system is determined.2.Complete the design of crawler driving system and transmission system,including track selection,thrust wheel,driving wheel,guide wheel and riding wheel,tensioning device and transmission gear,and use SolidWorks to complete the three-dimensional model of crawler driving system.3.The driving principle of tracked vehicle is briefly described.Calculate and check the ground specific pressure of the crawler driving system,the driving force and driving power required on straight road,and the driving force and driving power required for one-side braking turn and 20 °slope running of amphibious ship on clay ground.Based on the above information,the type selection and verification of engine and reducer assembly are completed.4.The dynamic simulation of the crawler system of amphibious ship is carried out by using RecurDyn.The force of the crawler system is obtained under three working conditions,namely,straight ground,side brake turn and 20 °climbing.The results show that the load condition of each thrust wheel is similar under two conditions of flat ground straight running and side brake turning,and the force of each thrust wheel under 20 °climbing condition is larger than that under 20 °climbing condition.It is decided that the finite element analysis only add loads on flat ground straight running and 20 °climbing.5.HyperMesh is used to pre-process the crawler frame,and according to the results of dynamic analysis,the finite element analysis is carried out.It is concluded that the maximum displacement is 0.194 mm and the maximum stress of the crawler frame is 143 MPa under the condition of flat-road straight running,and that the maximum displacement is 0.275 mm and the maximum stress is 202 MPa under the condition of climbing 20 °slope,which is less than the allowable stress of the material.Through pre-process and finite element analysis of chassis load-bearing beam,it is found that the maximum displacement of chassis load-bearing beam is 1.910 mm and the maximum stress is 149 MPa under the condition of flat-road straight running,and the maximum displacement of chassis-bearing beam is 2.598 mm and The maximum stress is 202 MPa,which is less than the allowable stress of the material.Therefore,the crawler walking device designed in this paper meets the strength requirement.The modal analysis of the chassis frame of crawler driving system is carried out.The results show that the first ten order natural frequency of the chassis frame is less than the engine frequency so the chassis frame will not be resonated.