During the actual operation of the bearing, many factors can cause problems with the bearing and cause the machine to malfunction. This article lists four common reasons. Let's take a look at what they are.

01. Bearing overheating

Overheating is the culprit of bearing failure, mainly because bearing heating is generally an alarm signal of abnormal machine operation. If it is not handled quickly, it will cause a chain reaction such as machine damage.

Common causes of bearing heating include:

(1) Low bearing accuracy and improper selection. The bearing accuracy does not meet the standard or there is a difference in the selection. Because the machine cannot meet the operating conditions, it will directly cause the bearing to heat up. Solution: Choose bearings with the official accuracy level.

(2) Large vibration, such as the coupling alignment process does not meet the requirements, the rotor has dynamic and static imbalance, poor foundation rigidity, weak foundation, rotation stall and surge. Some rotors are corroded by the medium or worn by solid impurities during operation, or the shaft is bent, which will cause unbalanced centrifugal force, causing the bearing to heat up, vibrate, and the raceway to be severely worn, and even damaged.

(3) Insufficient cooling Insufficient cooling usually manifests itself as: pipe blockage, inappropriate cooler selection, poor cooling effect, etc. Scale blockage of the cooler in the lubrication pipe will cause the cooling effect to deteriorate, especially in summer production. Severe cooler scaling and frequent alarms of excessive bearing temperature are encountered in many production sites. The more effective solution is to pickle and descale the cooler before summer every year.

(4) Improper installation Improper installation is another important reason for bearing heating. Because the correct installation of the bearing has a direct impact on its life and the accuracy of the main machine, the center line of the shaft and the bearing hole must coincide during installation.

If the bearing is not installed correctly, the accuracy is low, and the bearing has deflection, it will generate torque when rotating, causing the bearing to heat up or wear. In addition, the bearing will also generate vibration and noise, which will also increase the temperature rise.

Precision bearings

02. Dust and pollution

On precision machines, motors and other equipment with high environmental requirements, various suspended particles in the air will enter the bearing working environment and cause various hazards. Corrosive particles may wear parts, and conductive particles may interfere with the current of parts. Once the particles accumulate and clog the periphery of the bearing, they will accelerate overheating. Obviously, choosing the correct IP protection level can alleviate this problem to a certain extent. In outdoor equipment or general conditions, although the entire bearing system has corresponding protection, it should also be protected as much as possible to avoid secondary damage from sand, gravel and dust. In addition, it is easy to be humid outdoors, and moisture will corrode bearing components. When moisture and particulate pollutants in the air are mixed, it is a fatal injury to the bearing, further shortening the life of the machine.

03. Power supply problem

Harmonic currents caused by high-frequency switching and pulse width modulation may cause voltage and current distortion, overload and overheating. Thereby shortening the life of the machine and bearings and increasing long-term equipment costs.

Damage is always caused by partial discharge. The oil film between the inner ring groove and the steel ball of the bearing acts as a dielectric (capacitor) and is charged by the bearing current.

Once the voltage is high enough, short-circuit discharge occurs. This periodic discharge will corrode the metal, and the speed of the rotor will accelerate the corrosion. Higher rotation produces thicker oil film, and the higher the voltage, the greater the damage; at low speeds, the oil film "contact" area is larger, and the risk of damage is much lower. The higher the speed, the higher the rated power, and the higher the DC voltage, the greater the risk of damage.

Once the damaged steel ball surface is corroded, it will cause vibration of the inner and outer rings.

04. Improper lubrication

Lubrication is a necessary condition to ensure the normal operation of the bearing. Lubrication has an important impact on the fatigue life, friction, wear, vibration, etc. of the rolling bearing. About 40% of bearing damage is related to poor lubrication. The purpose of bearing lubrication is to form an oil film between the rolling surfaces of the bearing to prevent direct contact between metal and metal.

The effects of lubrication on rolling bearings are as follows:

1. Reduce friction and wear and extend the life of the bearing;

2. Expel friction heat to prevent excessive temperature rise of the bearing;

3. Prevent foreign matter from invading and play a sealing role;

4. Prevent metal corrosion.