发动机石墨密封环断裂分析

Failure Analysis of Graphite Seal Ring in Engine

发动机进行二次装配试车时,发动机燃烧室的石墨封严环发生断裂故障。通过外观检查、断口观察、物理性能检测、尺寸计量等方法对故障件进行分析,对可能导致石墨密封环断裂的原因进行分析。结果表明:失效石墨密封环的物理性能以及结构设计满足要求,但由于石墨密封环为脆性材料,抗冲击性差,在发动机振动时,会引起转子冲击石墨密封环,动静组件发生干摩擦,在轴的冲击下发生脆性断裂。

A graphite seal ring in engine combustion chamber fractured during the secondary assembly testing. In the present work,the failure cause of the graphite seal ring was analyzed by appearance inspection, fracture observation, physical performance testing and size measurement. The analysis results show that the physical performance and structure design of the failed graphite seal ring met the requirement. The graphite seal ring is made of brittle material and its impact resistance is poor.When the engine vibrated,the rotor impacted the graphite seal ring and dry friction happened between dynamic and static components,As a result,brittle fracture occurred to the seal ring under the impact of the shaft.