电梯曳引机用铸造锌合金蜗轮的失效分析

Failure Analysis of Zinc Alloy Worm Gear in Elevator Traction Machine

利用电子万能试验机、光谱分析仪、光学金相显微镜和扫描电镜等手段,分析了电梯曳引机用锌合金蜗轮的室温及高温力学性能、化学成分、显微组织。结果表明,夹杂物、缩松、气孔等铸造缺陷和偏载过量是导致锌合金蜗轮失效的主要原因。提高采用合理的铸造工艺消除这些铸造缺陷,并提高蜗轮副的加工精度,减小曳引机偏载过量的可能,保障电梯安全、有效地运行。

The mechanical properties at room and high temperature, chemical composition, microstructure of the zinc alloy （ZA27 alloy） worm gear in elevator traction machine were analyzed by electron uni- versal test machine, spectrum analyzer, metallurgical microscope and scanning electron microscope. The results show that inclusion, shrinkage porosity, pore and partial over-loading are responsible for failure of the zinc alloy worm gear. Some feasible ways were presented to eliminate casting defects, and the working accuracy was improved to reduce the possibility of partial over-loading, ensuring the safe and effective runing of the elevator.