High-power Crawler Tractor Farming Unit Stability Study

As a common farmland working machine,the crawler tractor not only has the advantages of low ground contact pressure and good traction performance,but also has good driving stability when working.As my country attaches great importance to agricultural mechanization in hilly and mountainous areas,it is very important to carry out research on the working stability of crawler tractors.The structure of the equipment attached to the tractor,the parameters of the soil,and the flatness of the soil block will all have an impact on the working stability of the crawler tractor.This paper uses classical mechanics analysis,three-dimensional modeling,dynamic simulation and other methods to study the working stability of crawler tractors in the following aspects:(1)First,use the classical mechanics theory to analyze the force of the shovel tip and shovel handle when the subsoil shovel is working,and obtain the main structural parameters that affect the resistance of the subsoil shovel and the working resistance of the subsoil shovel under different conditions.Calculate;then use the kinematics theory to analyze the trajectory of the rotary tiller blade when the rotary tiller is working,obtain the soil-entry condition of the rotary tiller blade,and estimate the power and force of the rotary tiller blade when working;analyze the performance of crossing trench and steering,and get the mathematical model of the maximum height of the whole machine over obstacles and the maximum width of crossing trench,as well as the expressions of crawler traction force,braking force and steering resistance torque when turning.(2)Secondly,in Recurdyn/Track(LM),the simulation analysis of the crawler tractor sub-soiling unit is carried out.The results show that the stability of the whole machine when working on clay is the best when working on different soils;when the whole machine is working at different speeds the stability when working in low gear is the best;when the whole machine is working at different tillage depths,it has the best stability when working with 40 cm tillage depth;the whole machine is in three steering modes: in-situ steering,differential steering,and trimming steering.When turning,the stability of the trimming steering is the best;at the same time,the comparison and analysis of the ability of crossing obstacles and the ability of crossing trenches of the three driving states of the tractor draw conclusions.In Recurdyn/Track(LM),the crawler tractor rotary tillage unit is simulated and analyzed by the orthogonal test method,and it is found that the tractor driving speed has a significant influence on the stability of the whole machine and the most stable factor combination when the crawler tractor rotary tillage unit is working.(3)Finally,combined with the simulation conclusions and related parameters to test,the test shows that the three driving states have the best stability when the tractor is not connected to the implement when over obstacles with heights of 100 mm,150mm,and200mm;the three driving states are crossing over obstacles.The maximum width of the trench is not much different from the simulation results,and the accuracy of the conclusion can basically be verified;in the stability test of the rotary tiller,the comparison with the simulation data shows that the tractor travel speed has a significant impact on the stability of the whole machine.The combination of factors showing the most stable working condition is that the crawler tractor has a traveling speed of 0.64m/s,the crawler tractor’s output speed is 1000r/min,and the rotary tiller has a tillage depth of 15 cm.