1 Misoperation occurred when switching the oil system during operation, and the monitoring of the lubricating oil pressure was not strengthened. When the lubricating oil pressure dropped, the bearings were cut off and the bushes burned.
2 The unit stopped the speed-regulating oil pump after starting the fixed speed. The oil pressure was not noticed. Due to the abnormal working of the air inlet of the injector, the main oil pump lost pressure and the lubricating oil pressure was reduced without linkage. Several aspects were combined to break the bearing Oil, causing bearing bushes to burn.
3 A large amount of air accumulated in the oil system was not removed in time, which caused the bearing pads to cut off oil instantly.
4 During the start and stop of the turbo-generator set, the high and low pressure oil systems fail at the same time.
5 The oil level of the main oil tank drops below zero, and air enters the injector, causing the main oil pump to malfunction.
6 The power supply to the plant is interrupted, and the DC oil pump cannot be turned on in time.
7 During maintenance, sundries such as cotton yarn and rust are left in the oil system, and the oil pipe is blocked.
8 The bearing was reversed during maintenance or shifted during operation.
9 The unit vibrates strongly, causing the bearing pads to be ground and damaged.
The causes of unit vibration are: unbalanced centrifugal force of the rotor; coupling defect or rotor center deviation; generator electromagnetic force imbalance; self-excited oscillation of bearing oil film; steam oscillation; thermal deformation and thermal bending of the rotor; frictional vibration; Stable and so on.
10 Due to poor quality of overhaul and installation, the bearing clearance and tightening force are not suitable, resulting in poor bearing lubrication
Existing problems: The inspection and acceptance of the unit during infrastructure construction are not strict, resulting in poor installation quality.
11 Lubricant oil quality is poor (water, foreign particles, etc.) or insufficient oil supply.
12 Water in oil will emulsify and deteriorate the oil. Water supply to the oil supply system is generally caused by excessive leakage pressure of the shaft seal of the high pressure end of the steam turbine or improper adjustment of the shaft seal supply pressure, which causes the steam to enter the oil supply system through the bearing oil retaining ring. After the oil supply system enters the water, it will cause the emulsification of the lubricating oil, corrode various parts of the adjustment system, cause accidents in the adjustment system, and affect the lubrication of the bearings.
13 Poor bearing alloy quality or poor casting quality.
14 Bearing load distribution is unreasonable.
15 The top shaft hydraulic system is not working properly.
The symbol of burned bearing bush is that the bearing bushing temperature and bearing oil return temperature rise sharply. Once the oil film breaks, the unit vibration increases and the bearing bush smokes. At this time, you should immediately hit the emergency guard and destroy the vacuum emergency stop.