基于齿轮误差与柔度的弯曲强度计算力点研究

Research on the Loading Point of Bending Strength Calculation Based on Gear Error and Flexibility

考虑系统误差和轮齿综合柔度,对齿轮弯曲强度的计算力点进行研究.结合齿轮传动的动力和误差传递均沿工作齿面啮合线的特性,在该方向上建立含主要系统误差项和轮齿复合变形的齿轮误差-变形计算模型.根据基节偏差与齿形误差的随机分布规律,按最大误差法合成啮合齿对有效误差;根据力、变形与刚度的关系,将轮齿刚度分解为挠曲和接触刚度两部分,进而得到啮合齿对的综合柔度.最后基于上述计算模型,推导出齿轮弯曲强度计算力点的位置判别式.分析表明:计算力点位置选取与齿轮加工精度紧密相关,选法不同齿根峰值应力计算值相差很大;研究结果为弯曲强度计算力点的准确选取提供了比较科学的依据.

Considering the system errors of gear drive and teeth synthetic flexibility, the loading point of bending strength was studied. Due to the transmitting force and errors delivered along the action line, the calculating model of gear error-deformation was established, which combined key transmission errors with synthetic compliance of engaging teeth. According to the distribution rule of basic pitch deviation and profile error, the effective error of meshing gears was integrated by the maximum error method. Gear meshing stiffness was decomposed into flexing and contact stiffness on the basis of the relation of loads, deformation and stiffness of gear, and then the synthetic flexibility of meshing gears was attained. Based on the above model, the discriminant for the loading point of bending strength calculation was deduced. The conclusions have shown that the choice of the loading point is relative to the accuracy level of gear, and that different choices influence root stress heavily. The result offers the scientific basis for the exact choice of the loading point when the bending strength is calculated.