Why don't your bearing always durable aging?
Please note the following - bearing knowledge
Bearing as a indispensable important mining machinery parts, its service life is more and more attention.
But in the daily use, we can clearly observed that under the same working conditions, appearance model is consistent with the bearings, real life is quite different.
Why is this?
Beware of the following points!
01 fit too tight when bearing inner ring compulsory set into the shaft neck, light person will lead to severe wear at the bottom of the raceway of circular trajectory, the person that weigh in the slide, there will be split on the outer ring and ball or peeling.
Why ball with slide clearance is too small, increase torque, friction increases, bearing working temperature is too high, causes the bearing wear and fatigue and failure.
Prevent method to restore the bearing radial clearance, decrease interference.
Bearing assembly quality inspection method has two kinds: visual observation: after the motor end cover bearing chamber with bearing, turn the end cover by hand, if freely rotary bearing, flexible, no vibration and shaking up and down phenomenon, as a qualified.
Feeler gauge method: put the bearing motor end cover assembly on the base check mouth, with 0.
3 mm thick feeler to check bearing radial clearance of the week, if the largest gap position just right in the middle of above (
Motor horizontal installation)
, it is assembled correctly, reliable, otherwise, bad installation.
Should be appropriate to adjust the end cover position, repackaging, until qualified.
02 cause poor lubrication is a serious lack of grease or oil dry aging.
Due to the high speed motor friction heat production, high bearing temperature and oxidation discoloration, show the bearing ball, cage and inner ring and shaft neck place such as brown or blue.
Prevent method: according to the running time of the motor, environment temperature, load conditions, good or bad grease and other four factors, determine the oil and oil change time.
In general, the motor running 6000 ~ 10000 h should fill oil once;
Run 10000 ~ 20000 h should be oil change, oil change quantity for the bearing chamber volume 1/2 ~ 2/3, and should adopt high quality lithium grease.
03 installation if not for the installation of, is not only the bearing slide usu mark, uneven and ball bearing wear trace, also produce deviation, with feeler check bearing radial clearance on either side of the range, and large difference.
The reason may be directly with the iron hammer percussion bearing outer ring;
Belt is pulled (
The driving wheel and driven wheel centerline is not parallel.
When the deviation is greater than 1/1000, will cause the bearing operating temperature is exorbitant, slide and ball bearing severe wear, shaft bending and end cover bolt clamping surface and bolt axis is not perpendicular.
The correct installation method with end surface smooth level off, and the thickness of bearing inner ring of steel pipe sleeve is almost equal, the bearing pressure on the clean and correct position of the journal.
Pressure is fashionable force should be homogeneous, not too hard.
Then according to the motor rotation speed check shaft end radial deflection of allowed value.
04 strong vibration when malfunction with the motor iron core, bearing strong vibration.
Because core heat deformation;
Motor bearing aging;
Shaft bending deformation;
Loose end cover check mouth tighten bolts for vibration;
Foundation is not solid bearing vibration.
Small car, prevent method will core soaking with silicone varnish 1052 aperture and pull open the surface of the silicon steel sheet;
Replace the same model of the new bearing;
Exit the rotor core straightening shaft bending part;
With 180 ° symmetric method;
Tighten the cover through bolts;
Strengthening the foundation, and tighten the anchor bolts.
05 material fatigue due to metal material, bearing raceway and the ball off the surface of the irregular fragments if mixed in lubricating grease, it will make noise increases, the ball was in sliding state, lead to bearing radial clearance increases, and the deflection of shaft end allowed radial value increases 2 ~ 3 times.
Bearing fatigue degree of decision factors include: the motor load, speed, air gap, end cover type, the toughness of the material, the quality of grease, adding amount of grease.
Prevent method according to the motor running records, when light load work for more than 60% of the rating current, running to 2000 ~ 25000 h, medium load working current for rating of 60% ~ 80% run to 15000 ~ 20000 h, heavy work load for current rating of 80% ~ 100% to 10000 ~ 15000 h after operation, all should consider normal bearing material fatigue, replace new bearing the same model.
06 pollution corrosion at this point, the raceway and ball appears on the surface of the red and brown punctate, corrosion, compared with the new bearing noise work noise increases.
Assembly place is not clean, such as presence of moisture, acid, alkali, and toxic gases;
Hand tools and pollution;
USES the lubrication of the inferior quality goods.
Method to prevent bearing assembly shall keep clean environment, tools, and hands;
Clean the bearing thoroughly;
Change the quality of lithium grease.