FAG bearing premature aging will result in equipment downtime, the combination of motor repair practice the author introduces rolling bearing, to prevent premature aging of the experience. Cause of the rolling bearing premature aging: with the tight, poor lubrication, the installation is not on, strong vibration, fatigue, corrosion and pollution.
1 with the tight
When the FAG is forced into the bearing inner ring shaft neck, the light will make the raceway at the bottom of the annular track badly worn, or in the chute, the outer ring and ball are there are gaps or peeling. Reason: the clearance of the ball and slide pressure was too small, torque increase, friction increases, the operating temperature of the bearing is too high, so that the bearing wear and fatigue intensifies and failure.
Methods: to prevent the recovery of FAG bearing radial clearance, reduce the amount of interference.
There are two ways to check the assembly quality of FAG bearings:
Visual method: when the motor end cover bearing chamber is arranged on the bearing, end cover is rotated by hand, if the FAG bearings, flexible rotation, no vibration and shake up and down, as qualified.
Check with feeler gauge method: motor with FAG bearing end cover assembled on the frame rabbet, use feeler to check bearing radial clearance of 0.03mm thick for a week, if the maximum gap position is just in the middle (motor above the horizontal installation), for the correct assembly, reliable installation, otherwise, is bad. Should be appropriate to adjust the end cap assembly position, again, until the qualified.
2 bad lubrication
The reason is a serious lack of grease or oil dry aging. Because of the high-speed motor friction heat, resulting in bearing high temperature oxidation discoloration, the performance of the FAG bearing ball, cage, inner ring and shaft neck, brown or blue.
Method: according to prevent running time, the motor temperature, load condition, grease or other 4 factors, determine its oil supply and oil change time. Under normal circumstances, the motor running 6000~10000h should fill oil 1 times; run 10000~20000h Oil 1, oil 2 or 4 above the motor for FAG bearing chamber volume of 1/2~2/3, and should be of high quality lithium base grease using (code ZL-2).
3 the installation is not in
If the installation is not, is not only the FAG bearing way with bead mark, but the ball wear track irregularity, also produce deviation, radial gap feeler to check on both sides of the bearing is different, and the difference is large. The reason may be the use of iron hammer directly into the outer ring of the bearing; the drive belt tension (gearing) is too tight; the center line of the driving wheel and the driven wheel is not parallel. When the deviation is greater than 1/1000, may cause high temperature FAG bearings, ball slide and serious wear and tear, shaft bending and the end cover bolts and bolt axis is not perpendicular to the surface.
The correct installation methods: steel pipe sleeve with face smooth, and FAG bearing inner ring thickness is almost equal, the bearing in the correct position on the clean journal. Pressing force should be uniform, not too hard. Then according to the different speed check radial motor shaft end of the allowed deflection value.