中介轴承多点故障动力学建模和仿真分析

Dynamic Modeling and Simulation Analysis of Inter-Shaft Bearing with Multi-Point Faults

关键词:  中介轴承  时变位移激励  多点故障  动力学模型  特征参数

Key words:  Inter-shaft bearing  Time-varying displacement excitation  Multi-point faults  Dynamic model  Characteristic parameters

摘要:

针对中介轴承故障理论尚不完善这个缺点，特别是中介轴承多点故障机理认识不清，基于非线性Hertz接触理论，采用时变位移激励函数对中介轴承内、外圈同时存在的故障进行描述，建立中介轴承多点故障4自由度动力学模型。搭建中介轴承故障实验台，对中介轴承多点故障进行试验模拟，通过对比试验数据与动力学数值仿真结果发现，故障特征频率仿真结果与实验结果误差小于1%，验证动力学模型的有效性。基于此模型分析了缺陷宽度、径向载荷和转速比对典型故障特征参数的影响。研究表明：随着缺陷宽度、径向载荷和转速比的增大，峰值和均方根值均呈现增大趋势，而峭度因子变化规律较为复杂。轴承存在故障时，峭度因子始终大于3，波形因子则对故障不敏感。

Abstract:

In view of the shortcoming that the theory of inter-shaft bearing fault is not perfect， especially the mechanism of multi-point faults of inter -shaft bearing is unclear， based on the nonlinear Hertz contact theory， the time-varying displacement excitation function is used to describe the simultaneous faults in the inner and outer rings of the inter-shaft bearing， and a 4 degrees of freedom dynamic model of the inter-shaft bearing multi-point faults is established. An inter-shaft bearing fault test bench is built to simulate the multi-point faults of the inter-shaft bearing. By comparing the experimental data with the dynamic numerical simulation results， it is found that the error between the simulation results and the experimental results of fault characteristic frequency is less than 1%， which verifies the validity of the dynamic model. Based on the model， the effects of defect width， radial load and speed ratio on characteristic parameters of typical faults are analyzed. The results show that with the increase of defect width， radial load and speed ratio， both the peak value and the root mean square value tend to increase， but the kurtosis factor changes in a complicated way. When the bearing is in fault mode， the kurtosis factor is always larger than 3， while the waveform factor is not sensitive to the fault.