外圈与轴承座配合间隙对齿轮-轴-轴承系统振动性能的影响

Effects of Fit Clearance Between the Outer Ring and the Housing on Vibration Characters of the Gear-shaft-bearing System

齿轮-轴-轴承系统是现代机械工业常用的传动机构。当轴承外圈与轴承座出现配合间隙时,传动系统会产生复杂的振动响应,使运行状态识别变得十分困难。建立了36自由度的齿轮-轴-配合间隙轴承系统动力学模型,该模型结合齿轮副系统和轴承系统,考虑了配合间隙引起的碰摩;并通过Hertz理论中的非线性接触和库仑摩擦模型计算了轴承外圈和轴承座之间的接触力。结果表明,当轴承外圈与轴承座之间产生配合间隙后,传动系统的时域响应受到轴承外滚道故障频率的调幅,配合间隙越大,调幅现象越严重;由于衰减次数的增加,响应频谱上出现齿轮副和轴承的超谐波频率,传动系统的超谐波响应被激发;随着轴承外圈配合间隙的增加,更高阶的超谐波响应会被激发。最后,通过实验验证了所建立模型和对既得结果分析的正确性。

Gear-shaft-bearing systems are commonly used in transmission mechanisms.When there are fit clearances between the bearing outer ring and the bearing housing,complex vibration responses will be gener⁃ated,which makes the recognition of operating status more difficult.Thus,a 36 DOFs model of the gear-shaft-bearing system with bearing fit clearances is established.In this model,the gear pair system and the bearing sys⁃tem are combined,the collision force and friction force caused by the fit clearance are considered,which are cal⁃culated by the nonlinear contact in Hertz theory and Coulomb friction model.The results show that when there are fit clearances on the bearing,the amplitude modulation of the bearing outer raceway to the system time-do⁃main response is exacerbated.The larger the fit clearance is,the more serious the amplitude modulation will be.Due to the increase in the number of attenuations,the multiple harmonic components of gear pairs and bearings are generated on the spectrum.As the bearing fit clearance is increased,the higher multiple harmonic compo⁃nents will be generated.Finally,the established model and the analysis of the results are verified by experiments.