中文摘要：

以一台直列六缸发动机为研究对象,建立发动机齿轮传动系统（曲轴、曲轴齿轮、中间齿轮、凸轮轴齿轮和凸轮轴）的模型,运用ADAMS多体动力学仿真软件,模拟分析凸轮轴齿轮在正常运行和断齿故障及凸轮轴轴向窜动和中间齿轮径向振动两种故障下,凸轮轴齿轮的频率变化情况,并与实际故障案例进行了对比分析。结果表明,当凸轮轴齿轮发生断齿故障时,其基频、三倍频和四倍频均会增加,且各阶频率都会增大,这与实际故障案例非常吻合;当凸轮轴发生轴向窜动和中间齿轮径向振动时,便会引起凸轮轴运动过程中的基频、三倍频和四倍频的增大,各阶频率的明显增大,因此以上两种情况都有可能造成齿轮不平稳运行,导致断齿故障的发生。

英文摘要：

The model of diesel gear transmission system （ crank, crank gear, the inte/mediate gear, cam- shaft gear and camshaft） in an inline six- cylinder diesel engine is established to study. The multi -body dy- namics simulation software ADAMS is used to simulate the frequency change of camshaft gear in normal and the fault of broken teeth, camshaft axial moving and intermediate gear radial vibration. Then the results are com- pared with the experimental data of gear broken tooth of diesel engine and comparison result shows that, when camshaft gear break tooth, each order frequency will increase, especially the fundamental frequency, three fre- quency multiplication, and four frequency multiplication. The phenomenon is identical with the actual failure case. When camshaft axial moving and intermediate gear radial vibration, each order frequency will increase significantly, especially the fundamental frequency, three frequency multiplication, and four frequency multipli- cation. Therefore, both cases may have resulted gear does not run smoothly, resulting in broken teeth failure.