INA thrust bearings is a bearing adopting thin grease and oil mist lubrication method, and it is an essential component in contemporary machinery and equipment. The primary function is to support the mechanical rotating body, reduce the friction coefficient during its movement, and ensure its rotation accuracy.
1. Before installing the bearings on the shaft, you must firstly remove the fixing pin of bearings jacket, and at the same time, polishing the surface of journal to smooth and clean, and apply oil to prevent rust and lubrication at the journal (allow the bearing to rotate slightly on the shaft).
2. Lubricate the bearings seat and bearing mating surface, and install the INA bearing in the bearings seat. Then put the assembled bearings on the shaft together with the bearing seat. Push to the required position for installation.
3. Do not tighten the bolts that fix the bearing block first and make the bearing jacket rotate in the bearing block. At the same time, install the bearing and seat on the other end of the same shaft, turn the shaft a few times, and let the INA bearing itself correct the position automatically. Then tighten the bearing seat bolts.
4. Install an eccentric sleeve. First, the eccentric sleeve is placed on the unconventional step of the bearing inner sleeve and tightened by hand in the direction of shaft rotation. Then insert small iron rod and press against the counterbore on eccentric sleeve. Useing the hammer to tap the small iron rod in the rotation direction of the shaft. Make the eccentric sleeve securely installed, and finally tighten the hex screw on the eccentric sleeve.
Cause of issue
1.Failure of INA thrust bearings
The severe damage of INA thrust bearings is often not caused by a single purpose, but under the combined effects of several aspects, a vicious cycle is generated under harsh operating conditions, resulting in severe burnout of the bearings. Therefore, it is often difficult to determine cause after an accident. What causes it will also bring us some difficulties in formulating related measures. For the convenience of discussion, we will analyze the cause of bearing failure from several aspects.
2. Abnormal wear of INA bearings
When the INA bearing is used for some time, the bearing inner ring, rolling elements, cage, outer ring, raceway, etc. have certain defects and scars, resulting in inadequate lubrication of the bearing, causing the bearing to generate heat, and prolonged heating will cause:
(1). Dilution of bearing lubricant.
(2). Accelerate the fatigue of material and reduce the hardness. Due to the above reason, a vicious cycle is further formed, which accelerates overheating and causes the bearings to burn out. Severe bearing inner ring displacement, rolling elements out of round, impact heat, and finally welded together. Therefore, when running on the line, if the bearing is found to be extremely hot and smoke, do not stop it. Instead, keep running to the first station, because the overheated bearing is in a molten state at this moment. Once it is cooled down, it can no longer walk and block the mainline.
3. Impact of installation on bearings
The interference gap between the inner ring of the INA imported bearing, and the shaft does not match, and it is also easy to cause bearing failure. The large interference amount is likely to cause the bearing inner ring to crack due to excessive tensile stress, and the interference amount is too small. It is easy to produce the bearing inner circle to "loose."
Improper assembly of bearings and clearances can also cause bearing failures. Flat removals can easily cause frictional heating of rollers and raceways. As the temperature continues to rise, the bearing inner ring, rolling elements, cage, outer ring, end cover.
The temperature is not the same, there is a temperature difference between each other, so the expansion amount is also slightly different, which will cause the further reduction of the fit clearance, and according to the bearing's heat generation.
If the permission is too large, the vibration of the roller will increase, which will aggravate the impact of the roller and raceway. At the same time, it will easily causes uneven internal load distribution, reduce the load roller, and overload the central roller.