Rolling bearing overheating is a common and harmful fault of rotating equipment. This will reduce the service life of bearings and increase maintenance costs. When the bearing temperature rises rapidly and the temperature exceeds the standard, it’s easy to cause an unplanned shutdown or reduced load operation of the unit. 

Therefore, to quickly determine the cause of the failure and take appropriate measures to solve it is the guarantee for the continuous and safe operation of the equipment.

1. Poor lubrication
If the lubrication is insufficient or excessive, the quality of the lubricating oil does not meet the requirements, deteriorated, or has debris. 

2. Not enough cooling
If you make the pipeline blocked, the cooler is inappropriate, and the cooling effect is poor;

3. Abnormal bearing
If the bearing has damage, the assembly process of the bearing is poor, and the gap adjustment of each part of the bearing box does not meet the requirements;

4. Large vibration
If the coupling alignment process does not meet the requirements, the rotor has a dynamic and static imbalance. Consequently, foundation rigidity is poor, the foot is virtual, rotating stall, and surge.

1. The amount of oil is not appropriate, too little, or too much grease. 

You should oil the bearing box regularly in accordance with the requirements of the work. However, the temperature may sometimes be high after refueling the bearing, the main reason is excessive refueling. At this time, the temperature continues to rise. After reaching a certain point (generally around 10℃~15℃ higher than normal operating temperature), it will remain unchanged, and then it will gradually decrease.

2. The bearing grease does not meet the requirements or it has impurities. 

Inappropriate selection of lubricating grease makes it difficult to form a uniform lubricating film. Insufficient bearing lubrication cannot reduce internal friction and wear of the bearing, so the bearing temperature rises. Thus, when you mix different types of grease, a chemical reaction may occur, causing the grease to deteriorate, agglomerate, and reduce the lubricating effect. 

Contaminated grease will also increase the bearing temperature. Dust falls in the process of adding grease, causing grease pollution, and deterioration of grease in the bearing box, destroying bearing lubrication, and increasing temperature. 

Therefore, you should select the appropriate bearing grease. And clean the bearing box and bearing during maintenance. Check and unblock the fueling pipeline. Don't mix different types of grease, if you change other types of grease, you should first clean up the original grease. Add grease regularly during operation and maintenance, and you should store the grease properly for moisture and dust prevention measures. 

3. Not enough cooling

Check whether the pipeline has a plug, whether the inlet oil temperature and the return water temperature exceed the standard. If you don't choose properly the cooler, the cooling effect will be poor. Therefore it cannot meet the requirements of use. you should replace a new cooler in time.

4. After confirming that the above problems do not exist, check the alignment of the coupling and the bearing 

The alignment of the coupling must meet the process standards. Also, you should consider the thermal expansion of the equipment during operation when aligning axial-flow induced draft fans and fluid couplings. Furthermore, due to thermal expansion on the impeller side of the induced draft fan, the bearing box temperature rises.