柴油机前端齿轮室总成异响源识别分析与改进

针对柴油机前端齿轮室总成在常用转速下产生异响的问题,采用EEMD小波时频分析方法进行了异响源的识别分析;通过整车定置试验和台架试验分析,提取了异响源的时频特征;通过有限元模型仿真分析,计算了齿轮室总成结构的约束模态频率和振型。综合上述分析结果发现,异响原因是壳体件结构局部刚度不足引起的系统共振。通过改进齿轮室总成结构,提高了固有频率,消除了齿轮室总成异响。

Identification Analysis and Improvement on Abnormal Noise Source for Front Gear Chamber Assembly of Diesel Engine

In the light of the abnormal noise problem occurred in the commonly used speed for front gear chamber assembly of diesel engine, wavelet time-frequency analysis method based on EEMD(ensemble empirical mode decomposition) was applied to identify abnormal noise source. The time-frequency characteristics of abnormal noise source were extracted by the analysis of vehicle set-test and chassis dynamometer test; the natural frequencies and modal shapes of constrained mode of gear chamber assembly were calculated by the simulation analysis of its finite element model. The reason led to abnormal noise was discovered by comprehensive analysis results. It is found that the low local stiffness of its shell structure results in system resonance. The inherent frequency of gear chamber assembly is improved by the way of improving its shell structure, the abnormal noise was removed finally.