行星机构的结构设计缺陷、制造与安装误差、支撑构件刚度不足等原因可能会使系统发生一定程度的偏载,从而会影响整个机构的使用寿命与可靠性。利用最小次序统计量的概念建立了行星齿轮系的可靠度计算模型,模型反映了偏载对齿轮系可靠性的影响。首先,对行星机构进行了详细的运动学和力学分析,计算得到了各个齿轮的随机载荷历程。根据Miner线性疲劳累积损伤法则,将随机载荷历程转化为等效恒幅载荷谱,并将其作为可靠性模型的载荷输入变量。然后,将特定齿轮的疲劳寿命数据进行统计处理,将统计结果作为可靠性模型的强度输入变量。最后,根据模型的计算结果定量地说明了偏载对行星齿轮系可靠性的影响程度,同时利用随机截尾数据处理方法对可靠性模型的有效性进行了验证。
For a planetary mechanism,structural design defects,manufacturing and installation errors,lack of stiffness of the support structure and other factors may cause to a certain degree unequal load sharing,thus affecting the life and reliability of the entire body.A reliability prediction model for the planetary gear set is established by using the concept of minimum order statistics,and the model reflects the influence of partial load on the reliability of the planetary gear set.A detailed kinematics and mechanics analysis of the mechanism is carried out,and the random load histories of each gear are calculated.According to the law of Miner linear fatigue cumulative damage,the random load histories are transformed into equivalent constant amplitude load spectrums,which are taken as the load input variable for the reliability model.The fatigue life data of specific gears are then statistically processed,and the treated life information is used as the strength input variable for the reliability model.According to the prediction result of the model,the adverse effects of partial load on the reliability of the planetary gear set are quantitatively explained,and the effectiveness of the model is verified by randomly censored data processing.