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Needle roller bearings equipped with thin and long roller (roller diameter D ≤ 5mm, L / D ≥ 2.5, L is the roller length), so the radial structure is compact, its inner diameter size and load capacity and other types of bearings the same , The smallest diameter, especially for radial installation size limited support results. Depending on the use of different occasions, the choice of non-inner ring bearing or needle roller and cage assembly, this time with the bearing surface of the journal and shell hole directly as the bearing inner and outer rolling surface, in order to ensure load capacity and running performance The same with a ring bearing, shaft or shell hole raceway surface hardness, machining accuracy and surface quality should be similar with the bearing raceway raceway. Such bearings can only bear radial load.
Note: Needle bearing bearing capacity, suitable for mounting dimensions limited support structure, the journal surface hardened as a rolling surface, the bearing press fit into the seat hole, no need for axial positioning of it. The bearing should be filled with the proper amount of grease before installation. Under normal circumstances, the bearing should not be relubricated after assembly. BK bearings are used for bearings without overhanging pins. The end faces are sealed to seal and can withstand small axial motions.
Causes of damage: In general, 33.3% of needle roller bearings are damaged due to fatigue damage, 33.3% of needle roller bearings are poorly lubricated and the other 33.3% are due to contaminants entering the bearings or improper handling of the equipment.
Dust: Clean bearings and the surrounding environment, the naked eye can see the fine dust are powerful killer bearings, it can increase bearing wear, vibration and noise.
Stamping: In the use of equipment to form a strong stamping, it is most likely to cause damage to the needle roller bearings or the hammer directly hit the bearing, the pressure transmission through the body rolling and so on.
Impact of non-professional tools installation: Use of suitable, accurate equipment Things try to use special things, you can try to avoid the use of cloth and staple fiber and the like. Needle bearings in both laboratory tests or in internship applications, can be clearly seen under the same operating conditions, the same appearance of the needle roller bearings, the actual life of it is very different.