多源激励对联合收割机螺栓连接处振动特性试验研究

联合收割机各部件通过螺栓及其连接件相连,在工作过程中互相影响、互为激励源且冲击、磨损和不平衡碰撞较为严重。针对以上问题,文章旨在表征螺栓连接处松动程度及主要振动。通过提取工作过程中联合收割机主要工作部件螺栓及连接件处响应时域特征进行分析。通过分析螺栓及其连接件主频及倍频响应。结果表明,在正常工作过程中振动筛边缘螺栓各时域特征数值均处于极高水平且频率成分也最为复杂。其余测点频率集中主频34.7195Hz及倍频无明显边频带产生,但振动筛螺栓除本身主频2.302Hz及其高倍频外,不受发动机转频及其倍频影响。可以得出振动筛螺栓连接处受载最严重与复杂,为振动筛处螺栓及连接件防松和失效在线监测奠定了基础。

Experimental study on vibration characteristics of bolt joint of combine harvester under multi-source excitation

The components of the combine are connected by bolts and their connecting pieces, which affect each other and act as excitation sources in the working process. And the impact, wear and imbalance collision are relatively serious. In view of the above problems, the paper aims to characterize the degree of looseness and main vibration of the bolted joints. By extracting the response time domain characteristics of the bolts and connectors of the main working parts of the combine during the working process, the analysis was carried out. Combined with frequency spectrum analysis, the main frequency and double frequency responses of bolts and their connectors were analyzed. The results show that the time domain characteristic values of the edge bolts of the vibrating screen are at a very high level and the frequency components are the most complex in the normal working process. The dominant frequency of 34.7195Hz and its octave frequency in the frequency concentration of other measuring points have no obvious side band, but the bolt connection of the shale shaker is not affected by the engine rotation frequency and its octave frequency except its own dominant frequency of 2.302Hz and its high octave frequency. It can be concluded that the bolt of the shale shaker is the most seriously and complex loaded, which provides a reference for the processing and manufacturing of bolts and connectors at the shale shaker from the perspective of vibration failure.