调速电动机行星摩擦轮断裂分析

Fracture Analysis of Planet Frictional Wheel of Speed Regulation Electric Motor

为找出行星摩擦轮无级调速电动机摩擦轮一再发生断裂的原因及防止措施,用成分化验、硬度测试、宏观断口观察和金相显微组织观察等方法进行了分析研究,查清了摩擦轮的断裂属于脆性断裂。断裂的原因一是热处理时淬火加热温度过高,严重的过热淬火使GCr15钢形成脆性极大的片状马氏体和许多淬火裂纹;二是磨削加工时进磨量过大,造成磨削烧伤和磨削裂纹,致使零件过脆。防止措施首先是更换热处理炉的控温仪表,准确控制淬火加热温度,防止过热淬火。其次是合理控制磨削的进磨量,防止磨削烧伤。

In order to find out the cause of fracture of planet frictional wheel of stepless speed regulation electric motor and the corresponding preventive measures, by testing the ingredients, measuring hardness,macro-observing the fracture place,and observing the metallographic micro-texture, We found that the fracture of frictional wheel belongs to fragile fracture,One reason is that the heating temperature of quenching during heat treatment is too high, the overheating quenching causes high fragile flake martensitie and many quenching crack to form on GCr15 steel; The other is that the excessive feed wearing during cutter sharpen causes burns and corresponding cracks,therefore the wheel is over fragile. The preventive measures includes replacing the temperature control panel on heat treatment stove to preciely control the heating temperature of quenching and prevent overheating quenching,and selecting the suitable feed wearing to prevent burns caused by cutter sharpen.