Troubles

causes

Severe vibration of bearing box

1.The shaft of fan is not parallel with that of motor; the coupling is misalignment.

2.friction between casing or inlet and impeller.

3.The foundation is not rigid enough or firm enough.

4.loosing of rivets in impeller or deformation of impeller.

5.Loose matching of shaft with impeller main disc.

6.Loosing of the bolts which connect casing and bearing with support, bearing with its cover.

7.Installation of fan inlet and outlet ducts is improper, which causes vibration.

8.The rotor is unbalance.

High temperature-rise of bearing

1.Severe vibration of bearing box.

2.Lubricant is poor in quality, deteriorated, mixed with dust, sand, contamination and etc.

3.Connection of bearing box cover and pedestal is over tight or Loose.

4.Fixing position between shaft and rolling bearing is slant, the front and back bearing are out of alignment.

5.wornout of rolling bearing.

Over current and high temperature-rise in motor

1.Gate or damper in the inlet and outlet pipes are not closed when starting-up.

2.Flow rate exceeds the specific value or air duct leaks.

3.Air density delivered by fan is over strong or contain visco-materials.

4.Input voltage of motor is low or is cut out in a single phase.

5.Coupling connecting is out of alignment the belt is too tight or the clearance is not uniform.

6.Influence caused by severe vibration of bearing box.

7.Influence caused by fan in parallel operation condition is worse or trouble happened.

Belt sliding

Two belts are not in the center line. The belt slides down from a small belt pulley.

Bet chattering

The distance of two belt pulleys is too short or the belt is too long.