Bearing interaction with shaft and end cap
Most motors use rolling bearings. The friction between the rolling elements of the bearing and the inner and outer rings is rolling friction. The friction between the two contact surfaces is very small. The fit of bearings and shafts, bearings and end caps is generally an interference fit, and in a few cases a transition fit. The mutually squeezing forces are relatively large, so that static friction is generated, the bearing and the shaft, the bearing and the end cover are relatively stationary, and the mechanical energy is transmitted by the rotation between the rolling body and the inner ring (or outer ring).
If the bearing and the shaft, the bearing chamber with the clearance fit, the torsion will damage the relative static state and produce sliding, the so-called "running circle" occurs, the bearing inner ring and the shaft sliding is called running inner ring, bearing outer ring and Sliding in the bearing chamber is called running outside the ring.
Bearing race appearance and hazard
If bearing circling occurs, the temperature of the bearing part will be high and the vibration will be large. The dismantling inspection reveals that the surface of the shaft (bearing chamber) has slips, and even the shaft or the surface of the bearing chamber grinds the groove. From this situation it can be concluded that the bearing laps.
The negative impact caused by the outer ring of the bearing on the equipment is very large, which will aggravate the wear of the mating parts, even scrap, and even affect the accuracy of the supporting equipment; in addition, because of the increased friction, a large amount of energy will be converted into heat energy and noise. Greatly reduced motor efficiency.