试验研究立式电动机滚动轴承-转子系统存在支承松动缺陷时的典型振动频谱特征及治理措施.应用于某核电厂的同类型凝结水泵组驱动电动机存在异常振动,频谱分析认为属于支承松动导致的非线性振动,解体检查发现圆柱滚子轴承径向间隙偏大,且存在跑外圈现象.根据非线性转子动力学理论建立立式电动机滚动轴承-转子系统支承松动时的动力学模型,理论分析其振动特性.试验发现增加止动垫片、添加油脂、减小径向间隙能短时间降低振幅,但1/2X频率分量等非线性振动特征仍然存在,将圆柱滚子轴承换型为深沟球轴承后振动正常.研究表明,受电动机立式支承形式及圆柱滚子自身结构影响,圆柱滚子轴承工作时缺乏稳定的重力载荷作用使得径向载荷偏小,轴承的径向间隙容易导致非线性振动,更换为深沟球轴承后能有效避免该类故障.%The typical vibration spectrum character and treatment are researched through testing method when supporting loose failure exists in vertical motor rolling bearing-rotor system.When there were abnormal vibration phenomenon with condensate pumps' vertical drive motors in a nuclear power station,it was found that the motor's vibration spectrum contained 1/2X component and so on,which fit the supporting loose failure sign.It was also found a rather large radial clearance in the cylindrical roll beating and beating outer ring run through strip inspection.A vertical motor rolling bearing-rotor system's dynamics model has been established based on nonlinear-rotor-dynamics theory,by which the influence factor of vibration is analyzed theoretically.Some treatments were executed in order to check damping effectiveness and spectrum variation,test result showed that the vibration value decreased temporarily by adding stopping gasket,grease lubricant and decreasing the cylindrical roll beating's clearance,but the 1/2X component also existed and vibration value rose slowly.When the cylindrical roll bearing was replaced by deep groove ball bearing,the vibration keeps normal.The research shows that the cylindrical roll bearing's clearance is likely lead to nonlinear vibration.There is lower radical load when cylindrical roll bearing working in lack of steady gravity force by the influences of motor's vertical supporting and cylindrical roll's structure.And the deep groove ball bearing could avoid that problem.
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