计算齿轮和螺旋齿轮的载荷能力 - 第3部分:牙齿弯曲强度的计算

[中文适用范围]： 本文件规定了渐开线外齿轮或内齿轮的齿弯应力计算基本公式，外齿轮的齿缘厚度 sR > 0.5 ht，内齿轮的齿缘厚度 sR > 1.75 mn。在使用过程中，内齿轮可能会出现除齿弯疲劳以外的其他故障模式，即从齿根直径开始断裂并径向向外发展。本文件未提供针对除齿弯疲劳以外的其他故障模式的充分安全性。所有载荷对齿根应力的影响都包括在内，只要它们是齿轮传递的载荷的结果，并且可以定量评估。本文件包括基于测试和理论研究的程序，例如 Hirt[11]、Strasser[14] 和 Brossmann[10] 的研究。结果与其他方法（参考文献 [5]、[6]、[7] 和 [12]）非常一致。给出的公式适用于齿廓符合 ISO 53 中标准化基本齿条的直齿轮和斜齿轮。如果虚拟重合度 εαn 小于 2.5，则它们也可用于与其他基本齿条共轭的齿。根据允许弯曲应力确定的负载能力称为“齿弯曲强度”。结果与其他方法在 ISO 6336-1 范围内所示的范围内一致。如果不适用此范围，请参阅 ISO 6336-1:2019，第 4 条。 [外文原描述]： This document specifies the fundamental formulae for use in tooth bending stress calculations for involute external or internal spur and helical gears with a rim thickness s R > 0,5 h t for external gears and s R > 1,75 m n for internal gears. In service, internal gears can experience failure modes other than tooth bending fatigue, i.e. fractures starting at the root diameter and progressing radially outward. This document does not provide adequate safety against failure modes other than tooth bending fatigue. All load influences on the tooth root stress are included in so far as they are the result of loads transmitted by the gears and in so far as they can be evaluated quantitatively. This document includes procedures based on testing and theoretical studies such as those of Hirt [11] , Strasser [14] and Brossmann [10] . The results are in good agreement with other methods (References [5], [6], [7] and [12]). The given formulae are valid for spur and helical gears with tooth profiles in accordance with the basic rack standardized in ISO 53. They can also be used for teeth conjugate to other basic racks if the virtual contact ratio ε α n is less than 2,5. The load capacity determined on the basis of permissible bending stress is termed "tooth bending strength". The results are in good agreement with other methods for the range, as indicated in the scope of ISO 6336‑1. If this scope does not apply, refer to ISO 6336-1:2019, Clause 4.