The Design And Optimization Of Main Gearbox About High-speed Transplanter

The speed change mechanism of high-speed rice transplanter have a great impact on dynamic performance,fuel economy,reliability and portability of shift control,stability and efficiency of transmission,realization of the function,etc.Taking the main gearbox about high-speed rice transplanter as the research object,the transmission characteristics is researched.Based on the mechanical analysis of the main gearbox,it makes optimized design for gearbox.And,the prototype of the main gearbox is processing out.The main research work is as follows:1) Reviewing the domestic and external study status of the chassis transmission of high-speed rice transplanter,the main problems are analysised.Then,the working principle and characteristics of various types of chassis transmission about high-speed transplanter are researched.2) The transmission scheme of high-speed transplanter is made,and the allocation designs of the transmission ratio of the overall machine is done.Taking out the idea of modular design about the main gearbox,which can combine with the HST or mechanical transmission,the main gearbox is created.Through static force analysis on the designed main gearbox,it paves way for the back structure analysis and optimization.3) Using3D software UG to make a model of the transimission,though virtually assembly interference detection and motion simulation,verifys the correctness and rationality of the model.Import the transmission structure model into ANSYS,taking the planting working gears of high-speed transplanter which bears the largest load and works in the stable state as example,the finite element theory is combined with to analyse the structure of lines and nonlinear for each shaft and meshing gear of transmission in the ANSYS environment.Then,the strength and stiffness of shaft and the bending strength of root tooth and the contact strength of transmission are checked.4) According to the operating requirement character of the lighter the well of high-speed transplanter,design parameters with gears and shafts of transmission are taken as design variables.The weight reduction is taken as optimization objectives.The design criterion and performance conditions of transmission are taken as constraint.Thus,the mathematical model of optimization with gears and shafts about transmission is established.Then,in order to achieve the lightweight target and reduce production costs,using the tool box of MATLAB which is a mathematica computing software,the Sequential Quadratic Progranning(SQP method) is selected to make structural optimization design for the gears and shafts about transmission by calling the fmincon function. And,it gets a good optimization results.5) Through statics analysis of the whole machine on the planting condition,the data of the gearbox is got.Then,import it into the finite element model of the box in the ANSYS Workbench software and solve it.It improves the strength of the front axle,after checking the strength of the gearbox and strengthen the case structure. Based on the statics analysis in the planting condition with the complete machines, stress distributions in the gearbox casing are studied. This basic data is channeled into the finite element model and solved with ANSYS Workbench software. The gearbox body static finite element analysis is carried. The strength of shell is calculated and improved, and therefore the strength of front axle is greatly increased.6) The work of design and manufacture of the main gearbox about high-speed rice transplanter is fulfilled,and the prototype is developed.The field trials proved that the design of the machine achieves the agricultural requirements,and the planting effect is perfect.