矿用磨机铸钢大齿轮断齿原因分析

Causal analysis of teeth breaking of big cast steel gear in mine mill

材质为ZG45CrMo的矿用磨机铸钢大齿轮在使用过程中发生断齿失效现象。通过现场检测,宏观分析,并采用化学成分分析、力学性能检测、金相分析及微观断口分析等检测手段对断齿部位进行分析。结果表明:大齿轮结合面间隙过大,在啮合过程中非正常接触造成局部弯曲应力较大,是导致大齿轮断齿的主要原因,同时铸造疏松缺陷降低了大齿轮的疲劳寿命,促进了大齿轮早期疲劳裂纹产生。

The big cast steel gear made of ZG45CrMo in mine mill was broken in the process of service.By means of field detection,macroscopic analysis,chemical composition analysis,mechanical property inspection,metallographic analysis and microcosmic fracture analysis,the location of broken tooth was analyzed.The results showed that large clearance between the joint surface of the big gear brought about abnormal contact during meshing process and large local bending stress,which caused the teeth breaking of the large gear.Meanwhile,casting porosity decreased the fatigue lifespan of the large gear,which led to early production of fatigue crack.