As the main components of mechanical equipment, FAG bearings will directly affect the normal operation performance of mechanical equipment during operation. Therefore, if there is any abnormal state in the bearing, it will also cause the mechanical equipment to not operate normally. Here, Eric Bearing Limited, based on the understanding of bearings, shares some common abnormal conditions during the use of FAG bearings, as well as the corresponding causes and countermeasures. I hope that everyone will be helpful when encountering such conditions.
It is unavoidable that abnormal conditions occur during the operation of FAG bearings. Our common abnormalities are mainly noise, abnormal temperature rise, large vibration (shaft beating), excessive lubricant leakage, discoloration and other factors. What are the specific reasons for this abnormal state? How to deal with the abnormal state of the bearing. Eric bearing Limited made a detailed answer.
1. FAG bearing noise
If the FAG bearing is in a good continuous rotation state, it will emit a low whining or buzzing sound. If there is a sharp hiss, squeak and other irregular sounds, it often indicates that the bearing is in a poor continuous rotation condition. The sharp squeaking noise may be caused by improper lubrication. Inappropriate bearing clearance can also cause metallic noise.
There are three main types of common noise in FAG bearings: large metal noise, regular noise and irregular noise.
(1) Large metal noise
The main reasons for the large metal noise of FAG bearings are abnormal load, poor installation, insufficient lubricant, and unsuitable contact with rotating parts.
Countermeasures to cause abnormal load of FAG bearings: modify the fit, study the bearing clearance, adjust the preload, and modify the position of the housing shoulder.
Countermeasures for poor installation of FAG bearings: machining accuracy of shafts and housings, improvement of installation accuracy, and installation methods.
Countermeasures for insufficient lubricants for FAG bearings: replenish lubricants and select appropriate lubricants.
The countermeasure to cause the rotating parts of the FAG bearing to contact: modify the contact part of the curved seal.
(2) Regular noise
Sometimes FAG bearings will have "intermittent and regular sound" during operation. This is a regular noise, and the main reasons for regular noise are: indentation, rust, and scars on the rolling surface of foreign matter, ( After steel carburization) surface deformation and raceway surface fracture. FAG super precision bearing B71907-E-T-P4S-DUL on line , pls click here :
Bearing countermeasures that cause indentation, rust and scars on the rolling surface of foreign matter: replace the bearing, clean the relevant parts, improve the sealing device, and use a clean lubricant.
Countermeasures for surface deformation of FAG bearings (after steel carburization): Replace the bearing and pay attention to its use.
The countermeasures that lead to the fracture of the raceway surface of the FAG bearing: replace the bearing
(3) Irregular noise
For example, “irregular sound, sound that does not change with the change of rotation speed” sometimes occurs during the operation of FAG bearings. This situation is irregular noise, which is more common in small FAG bearings. The main causes of this situation are : Three situations: excessive clearance, foreign body intrusion and ball damage and fracture.
Countermeasures to cause excessive FAG bearing clearance: study the fit and bearing clearance, and modify the preload.
Countermeasures against foreign matter intrusion in FAG bearings: study the replacement of bearings, clean relevant parts, improve sealing devices, and use clean lubricants
Countermeasures for FAG bearing ball damage or fracture: Replace the bearing.
2. Abnormal temperature rise of FAG bearing
The FAG bearing will heat up after it starts to run. After a period of time, it will run at a lower temperature (usually 10-40 degrees higher than the room temperature).
It is normal, and the bearing can also vary according to the size, speed of rotation and changes in the surrounding heat release conditions. In the meantime, when the FAG bearing temperature has not reached the normal state and the abnormal temperature rise occurs, we have to consider the bad factors.
(1) Too much or too little lubricant
Countermeasures: reduce or replenish lubricants, use them in appropriate amounts, regularly replace lubricating oil or grease for bearings according to work requirements, and choose harder grease.
(2) Unsuitable lubricant
The lubricant of FAG bearings does not meet the requirements or is contaminated, the selection of lubricating grease is inappropriate, it is not easy to form a uniform lubricating oil film, it is impossible to reduce the friction and wear inside the bearing, the lubrication is insufficient, and the bearing temperature rises.
Countermeasures: Should choose appropriate lubricants for bearing lubrication.
(3) Abnormal load
Countermeasures: modify the fit, study the bearing clearance, adjust the preload and modify the position of the housing shoulder.
(4) Poor installation
Improper installation is another important reason for the heating of FAG bearings. Because the bearing is installed correctly or not, it has a direct impact on its life and the accuracy of the main engine, so the center line of the shaft and the bearing hole must be coincident during installation.
Countermeasures: Improve the machining accuracy, installation accuracy and installation method of the shaft housing.
(5) Creep of the mating surface, excessive friction of the sealing device
Countermeasures: Replace bearings, study coordination, modify the shaft housing, and change the form of the sealing device.
3. Large vibration (shaft beating)
The main reasons for the large vibration of FAG bearings are (after steel carburization) surface deformation, fracture, poor installation and foreign matter intrusion.
(After steel carburization) Countermeasures for surface deformation: pay attention to bearing replacement and operation.
Countermeasures for FAG bearing fracture: replace the bearing.
Countermeasures for poor installation of FAG bearings: modify the right angles of the shaft, housing shoulder and the side of the gasket.
Countermeasures against foreign matter intrusion in FAG bearings: replace bearings, clean parts, improve sealing devices, etc.
For example, poor process does not meet the requirements, the rotor has dynamic and static imbalance, the foundation rigidity is poor, the foot is virtual, rotating stall and surging. During the operation of some rotors, due to the corrosion of the medium or the abrasion of solid impurities, or the bending of the shaft, unbalanced centrifugal force will be generated, which will cause the FAG bearing to generate heat and vibration, and the raceway will be severely worn until it is destroyed.
4. Lubricant leakage and discoloration
The causes of bearing lubricant leakage and discoloration are: too much lubricant, foreign matter intrusion and friction powder.
Countermeasures: Use lubricants appropriately, study changing and choosing lubricants, study the replacement of FAG bearings, and clean the housing.