杨铭^1,2，丁保安^1,2，王剑雄^1,2，李秀山^1,2，郭鑫^1,2，郭凯^1,2

1.内燃机可靠性国家重点实验室，山东 潍坊 261061；

2.潍柴动力股份有限公司，山东 潍坊 261061

摘要：为解决某轻型自卸车发动机在运行过程中频繁出现的飞轮壳开裂故障，建立飞轮壳、离合器壳有限元模型并进行应力计算，对整车动力总成噪声、振动与声振粗糙度（noise vibration harshness,NVH）进行测试和模态分析，分析故障产生机理；优化动力总成柔性体模态、变速箱和后桥速比并进行模态及振动试验和实车运行验证。结果表明：飞轮壳处存在明显共振现象，传动轴激励大，动力总成柔性体模态与传动轴激励耦合产生共振共同导致飞轮壳开裂；优化后各测点振幅较小，且动力总成无显著共振；整车运行40 000 km不再出现飞轮壳开裂故障，优化方案有效，可有效解决飞轮壳开裂故障。

关键词：轻型自卸车；飞轮壳；应力计算；NVH；模态分析

Abstract：In order to solve the cracking failure of the flywheel housing of the engine for a light dump truck, the finite element models of the flywheel housing and clutch housing are established and the stress is calculated. The noise, vibration and harshness (NVH) of the whole vehicle powertrain are tested and modal analysis is carried out to analyze the failure mechanism. The powertrain flexible body mode, gearbox and rear axle speed ratio are then optimized, and validated by modal and vibration tests and real vehicle operation verification. The results show that there is obvious resonance phenomena at the flywheel housing, the drive shaft is excited greatly, and the coupling resonance between the flexible body mode of the powertrain and the drive shaft excitation results in the cracking of the flywheel housing. After optimization, the amplitude of each measuring point is small, and the powertrain has no significant resonance. When the whole vehicle runs for 40 000 km, the flywheel housing cracking fault will not occur again. The optimized scheme is effective and can effectively solve the flywheel housing cracking fault.

Keywords:light dump truck; flywheel housing; stress calculation; NVH; modal analysis