Abstract: Asynchronous motors are widely used in the petroleum and petrochemical industry. Taking 3.8MW asynchronous motor as the research object, the vertical vibration problem of the non-driving end of the motor is studied. By analyzing the frequency characteristics to detect the natural frequency of the motor, it is determined that there is a resonance of 50Hz at power frequency in the motor system. We perform dynamic balance test on the motor to confirm the fault characteristic frequency that causes vibration. The cause of the vibration is determined to be weak foundation and bearing bush wear. We adjust the bearing bush clearance after disassembling and checking the motor bearing bush. After the motor runs under load, we measure and analyze the motor operation data. The results show that when the problem of weak motor foundation cannot be solved in the short term, adjusting the bearing bush clearance reasonably has a certain effect on reducing vertical vibration.The vibration control analysis method in the article can provide reference for vibration control of large-capacity motors.

Key words: non-driving end, natural frequency, resonance, dynamic balance, bearing bush clearance

摘要： 异步电动机在石油石化行业应用广泛,以3.8MW异步电动机作为研究对象,对电机非轴伸端垂直振动问题进行研究,通过频率特性分析检测电机固有频率,判断电机系统存在工频50Hz的共振。对电机进行动平衡试验,确认引起振动的故障特征频率,判断振动原因为基础不牢固和轴瓦磨损,对电机轴瓦拆检后调整轴瓦间隙。电机带载运行后,对电机运行数据进行测量与分析,结果显示,在短期内不能解决电机基础不牢问题时,合理调整轴瓦间隙对降低垂直振动具有一定作用。文中振动治理分析方法可为大容量电机振动治理提供参考。

关键词: 非轴伸端, 固有频率, 共振, 动平衡, 轴瓦间隙