The Reason and Phenomenon of Bearing Overheating and Its Treatment
Introduction
Bearings, a kind of important power transmission components, can accurately convert mechanical power into engine power and reciprocating motion. They not only play an important role in equipment maintenance, but are also vital parts of the entire machine or system. However, bearings are prone to failure and even cause accidents when they are not suitable to use or improperly operated. Bearing overheating is one kind common failure of bearings. In order to better determine whether the bearing is overheated, firstly we need to know what is bearing overheating, what causes it and how to solve it.
Definition and Phenomenon of Bearing Overheating
Bearing overheating refers to the situation in which the temperature of the bearing and the mated bearing is higher than the highest value allowed in normal working conditions, including most of the rolling bearings and sliding bearings. During the entire working process of bearings, their exterior surfaces maintain a certain temperature, usually lower than 80°C. When the bearing temperature exceeds 80°C, it will begin to happen temperature overshoot. If the temperature is higher than 80°C, it means that the bearing is overheating. Under this condition, different bearings have different temperature phenomena. For example, rolling bearings will cause the surface of the bearing to gradually turn red, while sliding bearings may produce black smoke around their surfaces or even burn out their rings.
Causes of Bearing Overheating
Below are some common causes of bearing overheating:
1. Poor lubrication: Poor lubrication will reduce the contact area between the bearing elements and worsen the motion accuracy of the bearing, leading to frequent rubbing between the two. This will cause the temperature between the elements to rise, leading to rapid increase in the temperature of the surface of the bearing and make it overheat.
2. The bearing connection with the shaft is too loose or too tight: If the bearing connection with the shaft is too loose, it will produce axial splitting force in the bearing and lead to its overrunning heat due to the lack of support from the shaft. If the bearing connection with the shaft is too tight, it will lead to friction heat due to the increased friction.
3. Lack of or low-quality lubricating oil: Oils with too low viscosity or too poor quality will make the bearing lack of protection, heat quicker and overheat easily.
4. Malfunction of the cooling system: Malfunction of the cooling system, such as the blocks of the cooling system, will cause the lubricating oil to be unable to enter the bearing in time and make the temperature of the bearing rise more quickly.
5. Unsuitable loading range: Heavy loading will increase the rolling element stress, and improper load direction will cause the load to increase suddenly. In this way, the internal friction will increase and the bearing will produce too much heat.
Treatment of Bearing Overheating
Bearing overheating will cause various problems, so it is important to treat it in an appropriate way.
1. After turning off the power and unlocking the surrounding parts, check the bearing and mated bearing and check their damge.
2. Replenish the lubricating oil and check its viscosity and condition.
3. Inspect and adjust the bearing connection with the shaft and the connection with the bracket.
4. Check if the bearing is worn, such as if its internal clearance or shapes has changed and if necessary, replace it.
5. Check the cooling system.
Conclusion
Bearing overheating can cause permanent damage to bearings, but most of them can be avoided with appropriate preventive maintenance. A thorough understanding of the reasons for bearing overheating and the timely and proper treatment can effectively reduce bearing damage and ensure the normal operation of equipment.
