Xin Feng Classroom | Ventilator Series: Fan Failures and Troubleshooting

01  

Vibration Caused by Rotor Imbalance  

1. Cause: Severe corrosion or wear of fan blades.  

   Remedy: Repair or replace fan blades.  

2. Cause: After final assembly, the fan blades remain stationary. Due to the combined weight of the impeller and main shaft, the shaft bends.  

   Remedy: Re-inspect and overhaul. If the unit remains unused for extended periods after final assembly, periodically rotate the shaft to prevent bending.

3. Cause of Failure:

 Uneven deposits on the impeller surface, such as rust or accumulated dust.     Solution: Remove the deposits. 

4. Cause of Failure: Impeller deformation due to transportation, installation, or other factors, resulting in impeller imbalance.     Solution: Repair the impeller and perform dynamic and static balancing tests again. 

5. Cause: Balance weights detached from the impeller or imbalance not restored after maintenance.     

Solution: Replace missing balance weights, perform dynamic balancing, then restore overall balance.

    02 

 Resonance Caused by Fan Mounting Components 

   1. Cause: Insufficient foundation rigidity due to lightweight concrete base, poor grouting, or undersized foundation dimensions. This causes separation between fan base and foundation, loosening of anchor bolts, and unstable frame connections.     Solution: Reinforce foundation or regrout, tighten nuts. 

2. Cause: Insufficient rigidity of fan base or volute.     Solution: Enhance structural rigidity.

3. Cause of Failure: Inlet and outlet ducts connected to the fan lack supports or flexible connections. Solution: Install supports and flexible connections.

 4. Cause of Failure: Adjacent structures are too close to the fan foundation or have insufficient rigidity. Solution: Increase the distance from adjacent structures and enhance foundation rigidity.

03

Bearing Overheating

1. Cause: Friction between the spindle or components on the spindle and the bearing housing.

Action: Inspect the friction location and address it.

2. Cause: Misalignment between the motor shaft and fan shaft, causing the inner rolling bearing in the bearing housing to seize.

Solution: Adjust the concentricity of the two shafts (alignment).】

 3. Cause: Excessive grease in the bearing housing. Solution: Maintain grease level at 1/3 to 1/2 of the housing volume.

 4. Cause: Looseness due to clearance between bearing and housing bore; housing bolts overtightened or under-tightened. Solution: Adjust the bolts.

04

Bearing Wear

1. Cause of Failure: Pitting, abrasion marks, rust stains, or similar phenomena appear on the surface of rolling bearing balls.

2. Remedy: Repair or replace.

2. Cause of Failure: Clearance between the inner bore of the cylindrical bearing and the outer diameter of the rolling bearing exceeds 0.1mm. Solution: Replace the bearing housing or enlarge the housing bore and insert an inner sleeve.