by 
When the search and inspection of the disassembled NTN bearing is suspended during the regular Matters Needing maintenance and operation of NTN bearing equipment and the replacement of peripheral parts,
it is required to judge whether the secondary NTN bearing parts can be reused and record the good or bad application conditions. We Matters Needing should also make great efforts to inquire, visit and record the removed NTN bearings and appearance conditions.
In order to find out and inquire Matters Needing about the remaining amount of lubricant, after sampling, clean the NTN bearing well.
Secondly, check the raceway Matters Needing surface, rolling surface and joint surface of NTN bearing and the wear condition of standoff frame for damage and abnormal conditions. In particular, check the running track of raceway surface.
To judge whether NTN bearings can be used again, we should think about the damage level of Matters Needing NTN bearings, mechanical function, priority, operation premise, search and inspection cycle, etc.
If NTN bearing is found damaged and abnormal, please find out the notice and formulate countermeasures according to the phenomenon of NTN bearing damage. In addition, the search and inspection results show that if there are the following defects, the NTN bearing can no longer be used, and a new NTN bearing needs to be replaced.
a. Any one of the inner and outer rings, rolling elements and confrontation frame has cracks and fragments.
b. Any one of the inner and outer rings and rolling elements has peeling.
c. The raceway surface, retaining edge and rolling element are significantly jammed.
d. The standoff frame is severely worn or the rivets are loose and ferocious.
e. The raceway surface and rolling element are rusty and scarred.
f. The rolling surface and rolling body have significant indentation and indentation.
g. There is creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.
h. Overheating and discoloration are fierce.
i. The sealing ring and dust cover of grease sealed NTN bearing are damaged seriously.
1. Maintenance of imported bearings
In order to maintain the original Matters Needing performance of imported bearings in good condition for as long as possible, they must be maintained and overhauled in order to prevent accidents, ensure the reliability of operation and improve productivity and economy.
Maintain the operation standard of corresponding mechanical Matters Needing operation conditions and carry out it regularly. The contents include monitoring the operation status, replenishing or changing the lubricant, and regular disassembly inspection.
As maintenance items in operation, there are rotating Matters Needing sound, vibration, temperature, lubricant state of imported bearings, etc.
2. Maintenance of imported bearings
Cleaning of imported bearing: when disassembling the imported bearing for maintenance, first record the appearance of the imported bearing, confirm the residual amount of lubricant, and wash the imported bearing after sampling the lubricant for inspection. As a cleaning agent, generally use cleaning agent and kerosene.
The cleaning of the disassembled inlet bearing is divided into coarse cleaning and fine cleaning. They are placed in the container Matters Needing respectively. First, put the metal mesh bottom so that the inlet bearing does not directly contact the dirt of the container.
During rough cleaning, if the imported bearing rotates with dirt, it will damage the rolling surface of the imported bearing, which Matters Needing should be paid attention to. In the coarse cleaning oil, use a brush to remove the grease and adhesion. After it is roughly clean, turn to fine cleaning.
Fine cleaning is to carefully clean the imported bearing while rotating in the cleaning oil. In addition, the cleaning oil should always be kept clean.
Maintenance and judgment of imported bearing: in order to judge whether the disassembled imported bearing can be used, it shall be checked after the imported bearing is cleaned.
Check the state of the raceway surface, rolling surface and mating surface, the wear of the cage, the increase of the clearance of the inlet bearing and the damage of irrelevant dimensional accuracy. For non separable small ball imported bearings, support the inner ring horizontally with one hand and rotate the outer ring to confirm whether it is smooth.
The tapered roller inlet bearing is a separable inlet bearing, and the raceway surface of the rolling element and outer ring can be inspected respectively.
Since large imported bearings cannot be rotated by hand, pay attention to the appearance of rolling elements, raceway surfaces, cages, edge retaining surfaces, etc. the higher the importance of imported bearings, the more careful the inspection is.