振动筛轴承双冲击现象动力学建模及故障识别

Dynamic modeling and fault identification of double impact phenomenon of vibrating screen bearing

根据轴承故障特征,采用Hertz接触理论分析了接触变形过程与缺陷尺寸之间的关系,在载荷分布区中,构建的轴承外环损伤故障双冲击模型,将轴承缺陷部位形成的双冲击间隔作为故障定量指标,依次在故障宽度0.5、1.0 mm处开展振动筛轴承测试。仿真信号分析结果表明:当转速保持恒定时,双冲击间隔和裂纹宽度保持线性关系。该仿真频率与故障特征频率理论值一致,由此判断该频率特征属于故障频率。实验验证结果表明:在脉冲冲击信号中存在明显双冲击情况,相邻2次冲击起振点间隔非常接近仿真结果,达到99.68%的高准确率。故障宽度尺寸对应的轴承双冲击信号准确率均值依次为96.51%和97.40%。推断采用本文构建的轴承外环损伤故障双冲击模型进行分析可以满足准确性要求。

According to the fault characteristics of bearings and the Hertz contact theory,the relationship between the contact deformation process and the defect size was analyzed.The double impact simulation test of the bearing outer ring damage fault was constructed in the load distribution area,and the double impact interval formed by the bearing defect site was taken as the quantitative analysis index of the fault.The vibration screen bearing test is carried out at the fault width of 0.5 mm and 1.0 mm successively.The results of simulation signal analysis show that the relationship between the double impact interval and the crack width is linear when the speed is kept constant.The simulation frequency is consistent with the theoretical value of the fault characteristic frequency,so it can be judged that the frequency characteristic belongs to the fault frequency.The experimental results show that there are obvious double shocks in the impulse impulse signal,and the spacing of adjacent secondary shock starting points is very close to the simulation results,reaching a high accuracy of 99.68%.The average accuracy of bearing double impact signal corresponding to fault width size is 96.51%and 97.40%,respectively.It is concluded that the double impact model of bearing outer ring damage failure established in this paper can meet the accuracy requirements.