The Optimal Design Of Gear System Of Hilly Tractor Gearbox

In order to meet the diverse demands of operation and higher transmission efficiency of the tractor gearbox which could be adapt to the complex transportation and operation environment in Hilly and mountainous areas.A hilly tractor gearbox was designed and its transmission efficiency was analyzed and optimized in this paper.The main contents are as follows:1)A new transmission scheme was proposed to meet the needs of the work in Hilly and mountainous areas according to the working requirements of hilly tractor gearbox.The main parameters of transmission system were designed by the professional gearbox design software KISSsoft which can improve the quality and efficiency of the gearbox design.2)The formula of the meshing efficiency of the spur gear transmission was derived.The calculation method of the friction coefficient between the gear teeth and the factors that affect the gear meshing efficiency were analyzed.The finite element model of the gear meshing transmission was set up and the analysis of the gear meshing transmission was carried out by finite element method.The relationships between the gear meshing efficiency and its parameters were studied which could be the foundation of optimizing the meshing efficiency of the gear system.3)In addition to the meshing loss of gear transmission,other factors,such as bearing loss,oil seal loss and oil agitation loss,were analyzed.And the mechanism and calculation methods of them were introduced respectively.The calculation and test of the total transmission efficiency of the hilly tractor gearbox designed in this paper were carried out.4)According to the two design targets of lightweight and high efficiency of hilly tractor gearbox,a double objective optimization mathematical model of gear system was set up with the total of the minimum gear volume and the total of maximum meshing efficiency.Based on the non-dominated sorting genetic algorithm with the elite strategy,the optimization mathematical model was solved by using the Matlab.And the optimal parameters of the gear system were obtained.The gearbox designed in this paper can adapt to the complex working condition in hilly and mountainous areas and meet the need of various task requirements.The analysis and calculation of gear meshing efficiency and transmission efficiency of gearbox were made,which is of great significance for guiding improve the transmission efficiency of the gearbox.By optimizing the gear system of the gearbox,the total meshing efficiency and the total weight of the gear are improved,which provides a new idea for the study of the optimal design of the gearbox gear system.