收获机变速器箱体静力学分析与结构改进

Static analysis andstructural improvement of gearbox case of harvester

变速器是收获机动力总成的核心部件,要求变速器结构和功能必须可靠。分析变速器的工况和功能对箱体的要求,应用有限元数值模拟技术,通过添加约束和载荷,计算并分析箱体的静力学特性,发现在轴承载荷和驻车产生的载荷共同作用下将引起箱体端盖孔较大径向变形、应力和应变,且箱体强度和刚度不足。在考虑箱体质量不变的前提下,通过改变壁厚,设置加强筋、圆角等方式进行箱体结构改进,对比分析发现改进后的箱体的总变形减小52.1%,应变降低49.9%,应力降低41.1%,且应变和应力分布更为合理,强度和刚度明显提高。

Gearbox is a core component of harvester power train,and structure and function of the gearbox are asked to be very reliable.Design requirements for gearbox case were presented and analyzed according to working conditions and functions of the gearbox firstly.Constraints and loads were applied to model of the gearbox case,and static characteristics of the gearbox case were computed and analyzed with numerical simulation of finite element.The simulation results show that hole of an end cover has larger radial deformations,stress and strain caused by bearing loads and parking loads,leading to insufficient strength and stiffness.On the premise of having the same weight,structure of the gearbox housing was improved by changing wall thickness and setting stiffener ribs and fillet features.In contrast to the former simulations,the results indicate that the total deformation,strain and stress of the improved gearbox case are reduced by 52.1%,49.9% and 41.1%,respectively.Distributions of strain and stress are more reasonable,and strength and stiffness are clearly enhanced.