增压器压气机叶轮在高原环境下的失效分析与改进

针对高原环境下增压器超速引起的压气机叶片断裂的问题,介绍了故障定位、故障分析、故障再现以及改进等处理全过程。从增压器工作载荷谱入手,分析了叶轮的应力分布、叶片模态变化,确定了叶片不同部位的失效模式。从降低转速、提高叶片固有频率和提高出口处叶片的抗疲劳强度三方面优化了压气机叶轮,通过故障再现的对比性试验、性能对比试验等验证,结果表明,改进后的增压器最高许用转速提高10%,满足了发动机变海拔的使用要求。

Failure Analysis and Improvement of Turbocharger Compressor Impeller under Plateau Condition

For the fracture problem of impeller blade due to turbocharger overspeed at plateau, the whole process of fault location, fault analysis, fault reproduction and improvement was introduced.Based on the working load spectrum of turbocharger, the stress distribution and the blade mode change of impeller were analyzed and the failure modes for different parts of the blade were determined.Finally, the compressor impeller was optimized by decreasing the rotation speed, increasing the natural frequency of blade and improving the fatigue strength of the impeller exit.The fault reproduction test and the compressor performance test show that the maximum allowable speed of turbocharger increases by 10%, meeting the working requirements desired by the engine for different altitudes.