Reasons and solutions for the heating of industrial fan motors

After the prolonged operation, any machinery or equipment will generate heat. The same is true for the motor that drives industrial fans. The long-term operation can cause the motor to overheat. It is important to note that overheating of metal components or equipment can lead to machine failure or even damage. Therefore, in order to prevent the possibility of "overheating" of the large industrial fan motor, we should understand the common causes of motor overheating and the corresponding solutions.

1. The small air gap between the motor stator and rotor can easily cause overheating due to collisions between the stator and rotor.

• Cause: In small and medium-sized motors, the air gap is generally between 0.2mm to 1.5mm. When the air gap is too large, a large excitation current is required, which can affect the power factor of the motor. If the air gap is too large, the rotor may experience friction or collision. Generally, the severe bearing deviation and wear and deformation of the inner hole of the end cap can cause the machine base, end cap, and rotor to have different axial centers, which can easily cause the motor to overheat or even burn out.

• Solution: If bearing wear is found, it should be replaced in time. The end cap can be replaced or plated. Another simple solution is to insert a sleeve into the end cap.

2. Abnormal vibration or noise of the motor can cause overheating.

• Cause: If the motor vibrates abnormally during operation, it may be caused by multiple factors, but in most cases, it is due to poor rotor dynamic balance, bearing wear, abnormal sound, changes in the rotating shaft, varying degrees of looseness in fasteners, inability to tighten parts, improper installation of the motor base or other mechanical transmission problems. Vibrations not only generate noise but also create additional loads.

• Solution: The specific situation should be analyzed and the problem should be investigated and resolved accordingly.

3. The abnormal bearing operation will inevitably cause motor overheating.

• Cause: If the bearing cannot operate normally due to wear or lack of oil, it can cause the motor to overheat.

• Solution: The temperature of the bearing end can be measured by hand or thermometer to determine whether it is within the normal range. A listening stick (made of copper) can also be used to contact the bearing housing. If an impact sound is heard, it may indicate that one or more balls have been crushed. If a hissing sound is heard, it indicates that the bearing lubrication oil is insufficient. The motor should replace the lubricating grease after approximately 3,000 to 5,000 hours of operation.