Causes of vibration of diesel generator sets

In the operation of Diesel Generator sets, the situation of diesel Generator sets is often encountered. The direct sales manufacturers of diesel generators have concluded from experience that this is actually caused by the motor. The main reasons are summarized as the following three types: loose parts and mechanical failures. And electromagnetic failure.
1. The unbalance of the rotating part is mainly caused by the imbalance of the rotor, the coupler, the coupling and the transmission wheel (brake wheel).
Treatment: First find the rotor balance. If there are large drive wheels, brake wheels, couplers, and couplings, separate the balance from the rotor. Then there is the mechanical looseness of the rotating part. For example, the iron core bracket is loose, the oblique key and the pin are loose, and the rotor is not tied tightly, which will cause the rotating part to be unbalanced.
2. The main problems of mechanical parts are as follows:
(1) The shaft part of the linkage part is misaligned, the center line does not coincide, and the centering is incorrect. The cause of this failure is mainly caused by poor alignment and improper installation during the installation process. There is also a case where some of the center lines of the interlocking parts are coincident in the cold state, but after a period of operation, the center line is broken due to the deformation of the rotor fulcrum and the foundation, thereby generating vibration.
(2) There are problems with the gears and couplings associated with the motor. This kind of failure mainly manifests as poor gear occlusion, serious tooth wear, poor lubrication of the wheel, skewing and misalignment of the coupling, tooth profile of the gear coupling, incorrect tooth pitch, excessive clearance or serious wear, which will cause certain vibration.
(3) Defects in the structure of the motor itself and installation problems. This kind of failure mainly manifests as the ellipse of the journal, the bending of the shaft, the gap between the shaft and the bearing bush is too large or too small, and the rigidity of the bearing seat, the foundation plate, a part of the foundation and even the entire motor installation base is insufficient, and the motor and the base plate are fixed. Not secure, the foot bolts are loose, and the bearing housing and the base plate are loose. The excessive or too small gap between the shaft and the bearing bush can not only cause vibration but also cause abnormal lubrication and temperature of the bearing bush.
(4) The load transmitted by the motor is transmitted and transmitted. For example: steam turbine vibration of a turbine generator, fan driven by a motor, vibration of a Water Pump, causing motor vibration.
3. The fault of the electrical part of the Generator Set is caused by electromagnetic reasons, including: AC motor stator wiring error, winding-type asynchronous motor rotor winding short circuit, synchronous motor excitation winding turn-to-turn short circuit, synchronous motor excitation coil connection error, cage The rotor of the asynchronous motor is broken, and the deformation of the rotor core causes the stator and rotor air gap to be uneven, which causes the air gap flux to be unbalanced and cause vibration.