关键词: 重卡 AMT；下壳体断裂；拨叉

Abstract: As a core component of the heavy-duty truck automated mechanical transmission (AMT) assembly, the shift actuator completes the shift commands issued by the transmission control unit (TCU) during the gear shifting process, while also withstanding various active and passive stresses in multiple directions. Addressing the issue of lower housing fracture during the front auxiliary section durability test, this paper proposes a new research approach. First, a strain test is conducted on the actuator fork to obtain the maximum force experienced by the fork. This maximum force is then used as an input for finite element analysis to calculate the maximum stress at the fracture location, enabling targeted improvement of the housing strength. After structural optimization, the stress at the housing fracture is reduced by 60%, and the housing ultimately passes 1.4 million shift durability cycles, validating the effectiveness of the proposed improvement solution.

Key words: heavy-duty truck AMT; lower housing fracture; shift fork