裂纹故障下轴承浪型保持架的动态特性分析

Analysis of dynamic characteristics of bearing wave cages with crack faults

由于深沟球轴承浪型保持架的故障特性复杂,其特征参数难以提取,因而无法对保持架故障进行有效的诊断,针对这一问题,在分析了浪型保持架裂纹故障表现形式的基础上,提出了一种基于多体动力学的轴承保持架故障动态特性分析方法。首先,为了更好地还原保持架的实际运行情况,通过虚拟物理样机ADAMS求解器求解了深沟球轴承的动力学微分方程;其次,搭建了深沟球轴承的多体动力学模型,完全保留保持架的6个自由度,并用柔性保持架替代了刚体保持架实现刚柔耦合;最后,对不同裂纹深度下的柔体保持架进行了动力学仿真,分析了不同裂纹尺寸下保持架的质心涡动轨迹、保持架转速的概率密度函数,以及保持架兜孔与球的接触力的区别,结果表明:在浪型保持架裂纹萌生、扩展到断裂的过程中,其保持架动态特性的质心涡动轨迹及特定转速的概率密度分布改变明显。研究结果表明:此方法可有效应用于深沟球轴承浪型保持架裂纹故障诊断中。

Aiming at the problems of complex fault characteristics of bearing wave cages,difficult extraction of fault parameters and ineffective fault diagnosis,the manifestations of crack faults of wave cages were studied from the perspective of dynamic mechanism,and a method based on multi-body dynamics simulation to study the dynamic characteristics of bearing cages was proposed.Firstly,in order to better show the actual situation of cage operation,the dynamic differential equation of ball bearing was solved by the solver of virtual physical prototype ADAMS.Secondly,the six degrees of freedom of the cage were completely retained in the dynamic model,and the rigid-flexible coupling was realized by replacing the rigid body cage with the flexible body cage.Finally,for the simulation results,the vortex trajectory of the barycenter of the cage,the probability density function of the speed of the cage,and the difference of the contact force between the cage pocket and the ball under different crack cages were emphatically studied.The analysis results show that the dynamic characteristics of the centroidal vortex trajectory and the probability density distribution of the specific rotational speed change significantly from the process of crack initiation to fracture of the wave cages,which can be effectively applied to the crack fault diagnosis of the wave cages of the ball bearing.