Abstract: In order to improve the torque limit of spline usage and reduce the risk of spline shaft torsion and fracture under high torque, a verification method combining theoretical calculation and experimentation is proposed. Firstly, according to the theoretical formula, the program is written to calculate the strength of the spline and the fatigue life of the shaft torsion. The spline life is combined with the fatigue life of the shaft torsion for verification, and the design meets the requirements of the load spectrum. Then, the torsional fatigue limit torque of the axle shaft head is explored, and the metallographic structure, hardness, and material composition of the spline section are analyzed to verify that the spine shaft material is qualified. This article proposes for the first time to consider spline shafts as shaft components with shaft shoulders. The research results provide a basis for product structural design and improvement, and have important reference value.

Key words: axle; spline; torsion and fracture; fatigue life

摘要： 为了提高花键使用扭矩极限，同时降低大扭矩下花键轴的扭断风险，提出了理论计算 和试验结合的验证方法。首先根据理论公式编写程序计算花键强度和轴扭转疲劳寿命，将花 键寿命与轴扭转疲劳寿命相结合进行校核，设计均满足载荷谱要求。然后探究车桥轴头扭转 疲劳极限扭矩，检测花键断面分析金相组织，硬度和材料成分，验证花键轴材料合格。文章 首次提出将花键轴看作带轴肩的轴件，研究成果为产品结构设计和改进提供了依据，具有重 要的参考价值。

关键词: 车桥；花键；扭断；疲劳寿命