Faculty of Geoengineering, Mining and Geology, Wroclaw University of Science and Technology, 50-421 Wroclaw, Poland.
Z.I. Nekrasov Iron and Steel Institute of National Academy of Sciences of Ukraine, 49050 Dnipro, Ukraine.
Sensors (Basel). 2020 Dec 18;20(24):7284. doi: 10.3390/s20247284.
The problem solved in this research is the diagnosis of the radial clearances in bearing supports and the loosening of fastening bolts due to their plastic elongation (creep) or weak tightening using vibration signals. This is an important issue for the maintenance of the heavy-duty gearboxes of powerful mining machines and rolling mills working in non-stationary regimes. Based on a comprehensive overview of bolted joint diagnostic methods, a solution to this problem based on a developed nonlinear dynamical model of bearing supports is proposed. Diagnostic rules are developed by comparing the changes of natural frequency and its harmonics, the amplitudes and phases of shaft transient oscillations. Then, the vibration signals are measured on real gearboxes while the torque is increasing in the transmission during several series of industrial trials under changing bearings and bolts conditions. In parallel, dynamical torque is measured and its interrelation with vibration is determined. It is concluded that the radial clearances are the most influencing factors among the failure parameters in heavy-duty gearboxes of industrial machines working under impulsive and step-like loading. The developed diagnostics algorithm allows condition monitoring of bearings and fastening bolts, allowing one to undertake timely maintenance actions to prevent failures.
本研究解决的问题是，在非稳态工况下运行的大功率采矿机械和轧机的重型齿轮箱的维护中，由于轴承支撑中的径向间隙和紧固螺栓的松动（由于塑性伸长或松动而导致的），以及使用振动信号对其进行的弱紧固，而导致的诊断问题。基于对螺栓连接诊断方法的全面概述，提出了一种基于开发的轴承支撑非线性动力学模型的解决方案。通过比较固有频率及其谐波、轴瞬态振动的幅度和相位的变化，制定了诊断规则。然后，在实际齿轮箱上测量振动信号，同时在工业试验的几个系列中，在不断变化的轴承和螺栓条件下，在传动过程中增加扭矩。同时，测量动态扭矩，并确定其与振动的关系。得出的结论是，在冲击和阶跃式载荷下运行的工业机械的重型齿轮箱中，故障参数中径向间隙是最具影响力的因素。开发的诊断算法允许对轴承和紧固螺栓进行状态监测，从而可以及时采取维护措施以防止故障。
