Research On Lightweight Of Front Steering Drive Axle Of Tractor In Hilly Area

In recent years,the Ministry of Agriculture has proposed to vigorously develop portable agricultural machinery in Hilly areas.As the mother machine of agricultural production in Hilly areas,tractors play an important role in the process of sowing,rotary tillage and harvesting.In order to adapt to the characteristics of large field drop and poor road conditions in Hilly areas,the design and development process to increase the strength and stiffness of the whole machine to meet the requirements of agricultural machinery operation in Hilly areas,resulting in the overweight of the whole machine,which is not conducive to the development of portable agricultural machinery in hilly areas,it was necessary to carry out lightweight design of the whole machine.The lightweight design was very important to reduce the weight of tractor,which was one of the heavy parts of driving axle tractor.However,at present,the domestic research on the lightweight of tractor drive axle is basically on the lightweight of the drive axle housing.Few studies have been carried out on the lightweight of the drive axle components,ignoring the influence of internal component forces on the strength of the drive axle housing,and no specific evaluation system has been proposed to evaluate the lightweight effect of the drive axle housing.In this paper,the front steering drive axle of tractor in hilly area was taken as the research object.The influence of internal force of components of the front steering drive axle on the strength of the front steering drive axle was analyzed,and the lightweight effect evaluation system of the front steering drive axle was put forward.The research work and results of this paper provide meaningful reference value for the lightweight research of tractor components and the whole tractor.The main research contents are as follows:1.Static calculation and analysis of front steering drive axle of tractor in Hilly area.Firstly,the front steering drive axle was simplified and the three-dimensional geometric model of the front steering drive axle was established.Then the forward steering drive axle housing assembly,transmission assembly,leveling cylinder lever and steering knuckle assembly of the front steering drive axle were calculated and analyzed respectively.The maximum equivalent stress and displacement deformation of the four components of the front steering drive axle were obtained.The results show that the strength and stiffness margins of the front steering drive axle housing assembly and steering knuckle assembly were large.It was necessary to carry on the static calculation and analysis of the front steering drive axle housing Lightweight design.2.Lightweight design of front steering drive axle of tractor in Hilly area.Variable parameters are identified by using the joint simulation platform of Solidworks and Workbench.Based on response surface method,the structural dimensions of front steering drive axle housing and steering knuckle assembly were optimized.The relationship between the input parameters such as the inner hole diameter at the lower end of the connecting body of the front steering drive axle assembly and the output parameters such as the weight,maximum equivalent stress,maximum displacement and deformation of the front steering drive axle assembly,as well as the input and output functions of the single variable and the combined variable was studied and analyzed.The constraints and objective functions of the optimal design are defined,and the response surface optimization results are obtained.Static analysis of the front steering drive axle housing and steering knuckle components before and after lightening shows that the maximum stress and displacement deformation of the two components after lightening design have increased to a certain extent,but they still meet the strength and stiffness requirements of the front steering drive axle.The total weight of the front steering drive axle has been reduced by 5.7 kg and by about 5%.3.Modal analysis of front steering drive axle of tractor in hilly area before and after lightening.The natural frequencies and modes of the front steering drive axle housing components before and after the lightweight design were analyzed in free and constrained modes.It was found that the first-order natural frequencies of both free and constrained modes are higher than the external excitation frequencies,which indicates that the forward steering drive axle housing assembly will not resonate with the excitation frequencies,and the natural frequencies of the lightweight forward steering drive axle housing assembly have a certain increase compared with the lightweight one,which indicates that the structural layout of the forward steering drive axle housing assembly was more reasonable.Lightweight constrained modal analysis of the steering knuckle assembly shows that the first mode natural frequency of the steering knuckle assembly far exceeds the engine excitation frequency,which indicates that the structure of the steering knuckle assembly is reliable and does not resonate with the external excitation frequency.4.Research on lightweight effect evaluation method and lightweight effect evaluation of front steering drive axle of tractor in Hilly and mountainous areas.The lightweight performance index parameters of components or whole machine are classified,the lightweight effect factors of each performance index parameter are calculated,and the calculation method of lightweight effect evaluation coefficient of components or whole machine is established.According to the calculation method of lightweight effect evaluation coefficient,the lightweight effect factors of production cost,weight,strength and stiffness of front steering drive axle are calculated respectively.Finally,the lightweight effect evaluation coefficient of the front steering drive axle was calculated.