Optimization Design Of Suspension System For Boat-type Tractor

Boat-type tractors are better suited to paddy environments in South China than wheel tractors.At present,the large power consumption and high oil temperature of the suspension system affects the working efficiency and performance of boat-type tractor,which also restricts its use and promotion.Aiming at the shortcomings of boat-type tractor suspension system,this dissertation puts forward a new suspension system design scheme.The suspension system is analyzed and optimized by combining theoretical calculation with simulation analysis,and verified by test.The work done is as follows:(1)According to the characteristics of the boat-type tractor,a three-point suspension mechanism and a suspension hydraulic system suitable for the operation of the boat-type tractor are designed.The stress and strain of three-point suspension mechanism are analyzed,and the design of suspension hydraulic system and key components and the selection of other components are completed.(2)The pressure loss of suspension the hydraulic system for boat-type tractors is analyzed.The pressure loss of the hydraulic system is mainly composed of pressure loss along the way and local pressure loss.AMESim is used to build the simulation model of the suspension hydraulic system of Boat-type tractor.The simulation analysis shows that the pipeline pressure loss accounts for 20.5% of the system pressure loss.The suspension hydraulic system was optimized by optimizing the pipeline layout,increasing the inner diameter of the oil return pipeline and replacing the pipe joints.After optimization,the pressure loss of the pipeline is reduced by 21.9% and the total pressure loss is reduced by 19.5%,which is verified by experiments.(3)The thermal balance analysis of the suspension hydraulic system of Boat-type tractor is carried out.The maximum temperature of the suspension hydraulic system when it reaches thermal balance is obtained by simulation calculation.The influence of key components on the thermal balance of the system is analyzed.The thermo-hydraulic model of the suspension hydraulic system of Boat-type tractor is established by using AMESim software,and the relevant parameters in the model are analyzed,so as to optimize and improve the parts of hydraulic pump,tank and pipeline which have great influence on the thermal balance of the system,so that the maximum temperature of the suspension hydraulic system can be reduced by 12.5% when it reaches the thermal balance.Finally,the validity of the optimization scheme is verified by comparing the experimental value with the simulation value.In summary,after optimizing the suspension hydraulic system of boat-type tractor,the pipeline pressure loss was reduced by 21.9%,the lifting speed of three-point suspension mechanism was increased by 68.8%,and the maximum oil temperature of the system was reduced by 12.5%.The research results of this dissertation provide reference for the design of the suspension system of the boat-type tractor,which is of great significance to improve the performance of the boat-type tractor.