The impeller is the heart of the fan, the fan is a main component a pressure energy transfer. Therefore, once the wheel balance problems, it will directly affect the normal operation of the fan.

2 wind turbine factory put into operation, the bearing vibration seriously overweight, drive side bearing horizontal vibration up to 124Lm, vertical vibration reaches 53Lm, axial vibration is 23Lm; non-drive side bearing horizontal vibration up to 98Lm, vertical direction vibration reaches 43Lm, axial vibration is 18Lm (fan speed is 653r / min, with the amount of displacement is more appropriate to measure vibration). At the same time, bearing the impact of sound, after a period of operation The sound did not disappear and reduce vibration.

From this analysis, the unit may be due to the screw shaft and impeller disc with ordinary bolt connection, between the impeller and shaft design to take into account the thermal expansion factor a gap of 5mm, loose impeller therefore more serious during operation, so that impact bolts for bearing an impact vibration. After running for some time, due to the bolts and axle plate, impeller at high temperatures, corrosive gas effect and bonded together, the impact sound disappears, while the impeller lost its original balance.

When removing the impeller and shaft bolts found plate, glass printer impeller bonded together, dismantling very difficult, and the contact at one side is worn around 5mm, for this situation, re-reamed coupling bolt hole plate and the impeller shaft, reconstituted material for 40Cr (formerly made of 45 # steel), non-standard A-level Hexagon fit bolt hole, using an interference fit, bolt performance rating of 8.8, surface treatment, and the use of the locking bolt in the head coupling the pad to ensure tightness.