In the active magnetic bearings (AMBs) supported rotating machinery, touchdown bearings are considered as safety devices to support the rotor in the deficiency of electromagnetic field. Generally, the industrial AMB machines do not have force sensors for touchdown bearings and the system is only equipped with the position sensors to monitor the rotor displacement that disables the opportunity to measure the forces during dropdown events that might be destructive for the safe operation of the rotor system. This study explores the relative severity of dropdowns that are evaluated from a computational rotor model using the rotor displacement data recorded from the position sensors installed in the machine as an input. The model for double-row angular contact ball bearing type touchdown bearings is integrated with the rotor model. The simulation model is verified by comparing the simulated rotor orbits against measured orbits at four different dropdowns. The Fast Fourier transform (FFT) is used to observe the studied dropdown events in frequency domain revealing from the rotor response the following details: harmonics of the operation speed, rub-impact frequencies, pendulum motion of the rotor and the first two bending frequencies of the rotor settled on the touchdown bearings. The critical speed map also verifies the bending frequencies and identified support properties. The model-based approach can be used to evaluate and compare a single dropdown event with respect to previous events providing an insight for decision making whether touchdown bearing should be replaced.

在有源电磁轴承（AMB）支撑的旋转机械中，接地轴承被认为是在电磁场不足的情况下支撑转子的安全装置。通常，工业AMB机器没有用于接地轴承的力传感器，并且系统仅配备有位置传感器来监控转子的位移，从而无法在下降事件期间测量力的机会，而这可能会破坏传感器的安全运行。转子系统。这项研究探索了使用从安装在机器中的位置传感器记录的转子位移数据作为输入从计算转子模型评估的下拉菜单的相对严重性。双列角接触球轴承型着陆轴承的模型与转子模型集成在一起。通过在四个不同的下拉菜单中将仿真的转子轨道与测量的轨道进行比较，可以验证仿真模型。快速傅里叶变换（FFT）用于观察频域中的下降事件，并从转子响应中揭示以下细节：运行速度的谐波，摩擦冲击频率，转子的摆运动以及转子的前两个弯曲频率转子固定在着陆轴承上。临界速度图还验证了弯曲频率和确定的支撑特性。基于模型的方法可用于评估和比较单个下降事件与以前的事件，从而为决策是否应更换接地轴承提供了见识。快速傅里叶变换（FFT）用于观察频域中的下降事件，并从转子响应中揭示以下细节：运行速度的谐波，摩擦冲击频率，转子的摆运动以及转子的前两个弯曲频率转子固定在着陆轴承上。临界速度图还验证了弯曲频率和确定的支撑特性。基于模型的方法可用于评估和比较单个下降事件与以前的事件，从而为决策是否应更换接地轴承提供了见识。快速傅里叶变换（FFT）用于观察频域中的下降事件，并从转子响应中揭示以下细节：运行速度的谐波，摩擦冲击频率，转子的摆运动以及转子的前两个弯曲频率转子固定在着陆轴承上。临界速度图还验证了弯曲频率和确定的支撑特性。基于模型的方法可用于评估和比较单个下降事件与以前的事件，从而为决策是否应更换接地轴承提供了见识。转子的摆运动和转子的前两个弯曲频率确定在接地轴承上。临界速度图还验证了弯曲频率和确定的支撑特性。基于模型的方法可用于评估和比较单个下降事件与以前的事件，从而为决策是否应更换接地轴承提供了见识。转子的摆运动和转子的前两个弯曲频率确定在接地轴承上。临界速度图还验证了弯曲频率和确定的支撑特性。基于模型的方法可用于评估和比较单个下降事件与以前的事件，从而为决策是否应更换接地轴承提供了见识。