Abstract: Aiming at the common phenomenon of offset load in gear contact of heavy truck transmission, this paper puts forward a method of gear spiral angle modification, which can improve gear contact offset load by adjusting gear spiral angle modification slope and changing the spiral angle size. Taking the 12-speed transmission of heavy truck as the research object, the finite element simulation is used to numerically simulate the gear pair, and the contact spot test, noise test and fatigue test are carried out. The results show that the contact stress distribution of the improved tooth surface is uniform, the contact spot is in the middle, the noise does not change significantly and still meets the fatigue test requirements, indicating that the contact condition of the gearbox gear pair is effectively improved, and the feasibility of the proposed modification method is verified. The research provides theoretical basis and experimental reference for the correction of offset load gear of heavy truck transmission.

Key words: Transmission; Gear; Spiral angle; Axial modification; Contact spot

摘要： 针对重卡变速器齿轮接触普遍出现的偏载现象，文章提出了一种变速箱齿轮螺旋角修 形方法，通过调整齿轮螺旋角修形斜度以及改变螺旋角大小，改善齿轮接触偏载现象。以重 卡 12 挡变速箱为研究对象，利用有限元仿真对齿轮副进行了数值模拟，并开展了接触斑试验、 噪声试验和疲劳试验。结果表明，改进后的齿面接触应力分布均匀，接触斑居中，噪声无明 显变化且仍满足疲劳试验要求，说明变速箱齿轮副的接触状况得到有效改善，验证了所提修 形方法的可行性。该研究为重卡变速器偏载齿轮修正提供了理论依据与试验参考。

关键词: 变速器；齿轮；螺旋角；齿向修形；接触斑点