Research On The Driving Performance Of Boat-tractor's Driving Wheel

The boat-type tractor can better adapt to the paddy-field working environment compared to conventional wheeled tractor.However,there is also some problem of the boat-type tractor when it works in the paddy-field,such as insufficient driving force and high slip rate,most of it's power loss come from the lugged wheel.So that the popularization and application of the boat-type tractor is restricted.At present,the theoretical research on the mechanism of the interaction between the lugs and the soil is mainly based on the mechanical analysis and empirical formula,there are many simplifications in the research process,and there is a large error in comparison with practical working conditions.The experimental study on the lugged wheel is subject to the experimental conditions,which can hardly consider the influencing factors comprehensively.This article adopts Finite Element Method(FEM)and Smoothed Particle Hydrodynamics(SPH)Method,can optimize the structure of lugged wheel by overall consideration of lugged wheel structure,soil parameters and lugged wheel-soil contact characteristics from the perspective of engineering application.Thus,the power loss of the lugged wheel is reduced,the driving force is increased,and the slip rate of the tractor is reduced.First of this article,the paddy-field soil physical parameters is tested,such as moisture content,density,internal friction and cohesion angle.The nonlinear material model of paddy-field soil is studied,the boundary conditions are set up according to the principle of simulation calculation with actual conditions of the boat-type tractor.Then the dynamic simulation model of the single lug-soil is established.Secondly,according to the result of the simulation calculation and the details of interaction between single lug and soil,analysis the mechanism of lug-soil interaction based on the pull and lift force of single lug come from the soil reaction,the principle of improving the driving efficiency of the lug is put forward from the point of the force on the lug.Through the simulation calculation of the different structural parameters of single lug,and combined with the mechanism of lug-soil interaction,the influence of the structural parameters of lug on the driving efficiency is analyzed,The optimum lug structure is determined so that the driving efficiency of the lug is maximized.Finally,based on the optimization of the single lug structure,through the simulation calculation of the lugged wheel's different lug number,and the study of the mechanism of lugged wheel-soil interaction.The influence of the number of lugs on the driving performance of lugged wheel is analyzed,the optimum lugged wheel structure is determined so that the slip rate of the lugged wheel is lowest and the width of the lug's holes are reduced significantly.Based on the research above,after optimized,the lug's driving efficiency increase by 20.35% on the basis of reducing the lift force and increasing the pull force of the lug,the lugged wheel's slip rate decrease by 21.96%,the width of lug's holes decrease by13.31% compared with the prototype boat-type tractor.The research results provide guidance for the design of the lugged wheel structure,which is of great importance to improve the working efficiency of the boat-type tractor.