丘陵山区多功能茶园管理机变速箱齿轮寿命预测
Life Prediction of Gearbox Gear for Multifunctional Tea Garden Management Machine in Hilly and Mountainous Areas

为预测丘陵山区多功能茶园管理机变速箱齿轮的失效部位以及使用寿命，采用CAXA CAD和Solidworks软件建立茶园管理机变速箱齿轮副三维有限元模型.通过分析齿轮副在载荷作用下的力学特性，得到齿轮的范·米塞斯（Von Mises）应力、位移及应变分布情况，最大范·米塞斯应力约为209.63 MPa，小于材料的屈服极限，齿轮根部不会发生断裂.运用极大似然估计法建立齿轮的三参数Weibull分布函数和概率密度函数.预测齿轮的失效概率和平均失效时间，得到齿轮工作1 000 h失效概率为98.04%，平均失效时间约为642 h.运用Simulation疲劳分析模块对齿轮进行疲劳寿命分析，仿真结果表明，齿轮工作700 h左右完全失效.该研究分别从齿轮失效概率和疲劳失效两个角度对其使用寿命进行预测，并且得到相近的结果，从而为茶园管理机变速箱的维护提供参考.
In order to predict the failure location and service life of the gearbox gear of the multifunctional tea garden management machine in the hilly areas, a three-dimensional finite element model of the gearbox of the tea garden management machine gearbox was established, using CAXA CAD and Solidworks software. By analyzing the mechanical properties of the gear pair under load, the Von Mises stress, displacement and strain distribution of the gear were obtained. The maximum van Mises stress was less than the yield limit of the material, being about 209.63 MPa, and no breakage would occur at the root of the gear. The three-parameter Weibull distribution function and the probability density function of the gear were established with the maximum likelihood estimation method. Based on the prediction of the failure probability and the average failure time of the gear, the failure probability of the gear working 1000h was estimated to be 98.04%, and the average failure time about 642 h. The fatigue life analysis of the gear was carried out with the simulation fatigue analysis module, and simulation results showed that the gear would become completely ineffective after about 700 h. The study predicted the service life of the gear from the two aspects of gear failure probability and fatigue failure, and similar results were obtained, which was expected to provide useful reference for the maintenance of the tea garden management machine gearbox