First, the bearing box vibrates violently

1. The fan shaft and the motor shaft are not centered, and the coupling is skewed.

2. The negative pressure fan shell or air inlet is rubbed against the impeller.

3. The foundation rigidity is not enough or strong.

4. The impeller rivet is loose or the wheel is deformed.

5. The impeller axle disc and shaft are loose, and the coupling bolt is active.

6. The connection bolt between the negative pressure fan shell and bracket, the bearing box and bracket, the bearing box cover and the exhaust fan base is loose.

Second, the bearing temperature rise is too high

1. The bearing box vibrates violently.

2. Poor quality, deterioration or overposing of grease, containing dust, viscous sand, dirt and other impurities.

3. The tightening force of the negative pressure fan bearing box cover and the connecting bolt of the bearing seat is too large or too small.

4. The shaft and rolling bearings are mounted skewed, and the front and rear bearings are not centered.

5. The rolling bearing is damaged.

Third, the motor current is too large, the temperature rise is too high

1. When driving, the gate valve or throttle valve in the intake pipe is not locked.

2. The flow rate exceeds the specified value or the air duct leaks.

3. The gas conveyed by the fan of the negative pressure fan contains viscous substances, or the air temperature is too low and the gas density is too high.

4. The input voltage of the motor is too low or the fan on the roof of the power supply is cut off by a single phase.

5. Incorrect coupling, overstretched baffle or uneven clearance.

Fourth, the belt slides

The two pulleys of the negative pressure fan correspond to incorrect grooves.