（1）叶轮本身不平衡所引起的振动，其产生的原因有：叶轮上的零部件松动、变化、变形或产生不均匀的腐蚀、磨损；工作介质中的固体颗粒沉积在转子上；检修中更换的新零部件重量不均匀；制造中叶轮的材质不匀称；加工精度有误差、装配有偏差等。
(1) The vibration caused by the imbalance of the impeller itself can be caused by loosening, changes, deformation, or uneven corrosion and wear of the components on the impeller; Solid particles in the working medium deposit on the rotor; Uneven weight of new parts replaced during maintenance; The material of the impeller during manufacturing is uneven; Processing accuracy has errors, assembly has deviations, etc.
（2）叶轮与主轴配合间隙过大。
(2) The clearance between the impeller and the main shaft is too large.
（3）主轴发生弯曲。
(3) The spindle is bent.
（4）基础或机座的刚性不够或不牢，基础钢板薄弱、垫铁松动、位移；地脚螺栓松动等。
(4) Insufficient or unstable rigidity of the foundation or base, weak foundation steel plate, loose pad iron, and displacement; Loose foundation bolts, etc.
（5）基础下沉、倾斜或有裂纹。
(5) The foundation sinks, tilts, or has cracks.
（6）机组安装水平度不好，转子挠度有变化。
(6) The installation level of the unit is not good, and the rotor deflection has changed.
（7）由于安装不良造成的联轴器中心找正误差过大。
(7) The alignment error of the coupling center caused by poor installation is too large.
（8）联轴器与轴配合间隙过大；弹性套间隙过大或间隙不均。
(8) Excessive clearance between the coupling and the shaft; Excessive or uneven clearance between elastic sleeves.