Judgment and disassembly of motor rolling bearings
First, the basis of the motor using rolling bearings
The motor shaft adopts a double support structure, and each support is composed of one bearing. The main basis for the selection of rolling bearings is the load on the motor and the direction of the load. Due to the lighter load on the non-load end of the motor, ball bearings are often used, and the load end is subjected to heavier loads. Roller bearings are often used. For motors with a pure radial load, radial ball bearings or radial cylindrical roller bearings or thrust ball bearings or tapered roller bearings are available.
Second, the judgment of motor rolling bearing failure
1 motor rolling bearing inspection
During the operation of the motor, during the operation of the motor, a screwdriver can be used to abut the bearing cover of the motor, and the ear is attached to the handle to listen to the sound. If there is a "grass" or "grid" sound, it indicates a fault. It can also be inspected with a bearing inspection instrument.
The inspection of the rolling bearing heat is measured by a thermometer to measure the bearing temperature. The ambient temperature should be controlled below 35 °C, and the allowable temperature of the rolling bearing should be controlled below 60 °C.
After the bearing is removed, check the bearing, remove the waste oil, wash the oil with gasoline or kerosene, dry it with a cloth or blow it with compressed air, and then check it. The intact bearing, the processing plane is clean, no scratches, cracks or rust; the inner and outer bearing rings have no cracks; the hand rolling is light, flexible, uniform, without blockage, jamming or looseness; the bearing wear is checked by the feeler gauge .
2 motor rolling bearing failure
Bearing failures are mainly characterized by overheating and abnormal sound.
If the bearing temperature exceeds 90 °C during the operation of the motor, it indicates that the bearing has an overheating fault. The main reason is that the assembly is not correct, and the end caps are not tightly closed, so that the bearing holes at both ends are not concentric or the bearings are damaged, which will cause the bearings to rub and heat. The inner and outer rings of the bearing are broken, rusted, the balls are broken and loose; the holes of the bearing cover are rubbed against the rotating shaft or the bearing cover is too much pressure on the bearing. In addition, there is friction between the outer ring of the bearing and the end cap or between the inner ring of the bearing and the rotating shaft.
The intact bearing is in operation and should be sound even and the sound is normal.
Common anomalous sounds are:
Significant rolling and vibration sounds indicate excessive bearing clearance. The sound is dull and the tone is heavy, probably because the lubricant has impurities. Irregular impact sounds indicate cracking of the ball or bearing ring. If the bearing has squeaks and has a rolling sound, it indicates a serious lack of oil.
If the bearing fails, it can usually be eliminated according to the cause and corresponding measures. If the bearing clearance is too large or damaged, it is generally impossible to repair, just replace the qualified bearing of the same type.
