大马力拖拉机车轮有限元分析

Finite Element Analysis of Large Horsepower Tractor Wheels

【目的】为了尽可能地使轮辋、轮辐、螺栓座及螺栓等实现强度设计,避免某零件强度过剩,降低产品的制造成本。【方法】研究小组利用有限元分析技术,基于Pro/E 5.0自带的热力分析模块Mechanic,以车轮扭转疲劳、侧向负载疲劳试验方法为依据,通过对某品牌70马力拖拉机后驱动车轮(W12×30)进行有限元分析,计算车轮的应力分布、变形量和疲劳寿命。【结果】1)对车轮加载扭矩M_(1)后,轮辐、支架与轮辋焊道处、支架的最大静应力分别为135 MPa、221 MPa、190 MPa,轮辐的最大位移量约为0.13 mm,车轮最低疲劳寿命约10^(5.3)。2)对车轮加载弯矩M_(2)后,轮辐螺栓孔周围区域应力较大,部分区域的应力已经超过348 MPa;支架和轮辋焊道处的应力大部分在285 MPa以下,只有个别位置的应力稍微超过材料的屈服极限;支架折弯处的最大应力约为169 MPa;轮辐的最大位移量约为0.846 mm;车轮螺栓孔处的疲劳寿命为10^(3.7)~10^(4.6)。【结论】该型号车轮在侧向负载作用下疲劳寿命较短,主要薄弱点出现在轮辐螺栓孔处,主要有两种改进方法:1)增加螺栓孔分布圆直径,以此加大侧向负载的对抗力矩力臂,需同步更改驱动轮轴的法兰直径;2)通过旋压成型工艺加工轮辐,实现轮辐各部分厚度不一致,或在轮辐安装面上焊接一个加强盘,实现强度设计,提高其抗变形能力。

[Objective] In order to achieve strength design of rims,spokes,bolt seats and bolts as much as possible,avoid excess strength of a part,and reduce the manufacturing cost of products.[Method] The research group used finite element analysis technology,based on the thermal analysis module Mechanic that comes with Pro/E 5.0,based on the test methods of wheel torsional fatigue and side load fatigue,this paper calculates the stress distribution,deformation and fatigue life of a brand of 70horsepower tractor rear drive wheel(W12×30) by finite element analysis.[Result] 1) After loading the wheel torque M_1,the maximum static stress of the spoke,bracket and rim weld bead and bracket were 135 MPa,221 MPa and 190 MPa,respectively,the maximum displacement of the spokes was about 0.13 mm,and the minimum fatigue life of the wheel was about 10~(5.3).2)After loading the wheel with bending moment M_2,the stress around the spoke bolt hole is large,and the stress in some areas has exceeded 348 MPa.Most of the stresses at the bracket and rim weld beads are below 285 MPa,and only the stresses at individual locations slightly exceed the yield limit of the material.The maximum stress at the bend of the bracket is about 169 MPa.The maximum displacement of the spokes is about 0.846 mm.The fatigue life at the wheel bolt hole is 10~(3.7)~10~(4.6).[Conclusion] The fatigue life of this model wheel under the action of side load is short,and the main weak point appears in the spoke bolt hole,there are two main improvement methods:1) increase the diameter of the bolt hole distribution circle,so as to increase the countertorque arm of the side load,and the flange diameter of the drive wheel axle needs to be changed synchronously;2) process the spokes through the spinning molding process to achieve inconsistent thickness of each part of the spokes,or weld a reinforcement disc on the spokes mounting surface to achieve strength design and improve its deformation resistance.