The first unidirectional Needle roller bearings after cleaning, check its raceway surface, rolling surface, a mating face of state, can determine whether the bearing can continue to re-use.
1, an inner ring, an outer ring, rolling elements, the retainer on any one of a crack or gap;
2, the ferrule, the rolling element on any one of a fracture;
3, raceway, significantly hurt the card on the wall, rolling body;
4, the retainer wear significantly, or rivets significant relaxation;
5, the raceway surface, the rolling body rust, injury;
6 raceway, rolling body a serious indentation and Divots;
7, an inner ring and an inner diameter surface or outer diameter surface significantly creep;
8, discoloration caused by heat;
9, grease-sealed bearings, seals or dust cover damaged obvious.
Bearing showed late failure characteristics to a serious failure (generally one-way needle roller bearing damage, such as axle, burns, sand frame Spallation raceway beads wear, etc.) time it tends to be more than a week, and larger capacity equipment, speed The faster the shorter the interval. Therefore, the actual bearing fault diagnosis, Once advanced fault feature is found, should be decisive judgment defective bearings, arranged as soon as possible overhaul.
Bearing manufacture popular through forging, heat renew, turning, grinding and assembly multi-channel processing. Reasonable process, advanced, stability can also affect the life of the bearing. Hot renew, and grinding processes affect the quality of the one-way needle roller bearings, often has a more direct relationship with the failure of the bearing. Studies have shown that the transformation layer of the bearing surface in recent years, the close relationship of the grinding process and the bearing surface quality.
Exercise time, vibration and noise to maintain a certain level, single spectrum appears only one, second harmonic. Very rare triple-frequency spectrum above, very stable, one-way needle bearing state into a stable period. Continue into use late run, bearing vibration and noise begins to increase, sometimes a different tone, but the change of vibration increases more slowly, at this time, bearing kurtosis values start suddenly reaches a certain value. We believe that, at this time the bearing that showed initial failure.
The decommissioning of the one-way use of needle bearing life parsed primary obligation is based on a lot with King, analyze data and failure style pattern to identify the primary elements that constitute a bearing failure, so that the targeted improvement measures are proposed, delay bearings the bearing to avoid angry burst of early failure.


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