The Reason for Motor Bearing Overheating

Time：2020.10.22  Source：Roller Bearings Suppliers

Bearing overheating is a common fault when the motor is running, and its reasons are varied, sometimes it is difficult to accurately diagnose, so in many cases if the treatment is not timely, the result is often to cause more damage to the motor, motor life shorten, so that the impact of work and production.

Common factors of motor bearing overheating and solutions:

1.Improper installation of rolling bearing, too tight or too loose fitting tolerance.

Solution: the working performance of the rolling bearing not only depends on the manufacturing precision of the bearing itself, but also on the dimensional precision, shape and position tolerance and surface roughness of the shaft and hole fitted with it, as well as the selection and installation of the correct or not.

In general horizontal motors, well-assembled rolling bearings only bear radial stress. However, if the inner ring of the bearing is too tightly fitted with the shaft, or the outer ring of the bearing is too tightly fitted with the end cover, that is, when the balance is too large, the bearing clearance will become too small after assembly, sometimes even close to zero.So the rotation is not flexible, running will be hot.If the bearing inner ring is too loose in coordination with the shaft, or the bearing outer ring is too loose in coordination with the end cover, then the bearing inner ring and the shaft, or the bearing outer ring and the end cover will rotate relative to each other, resulting in friction and heat, resulting in overheating of the bearing.

In general, the standard moves the tolerance zone of bearing inner ring inner diameter as the reference part below the zero line, which fits the tolerance zone of the same shaft with the bearing inner ring much more closely than it

does with the general reference hole.Need WSBC 22208 E,click here to learn more.

2. Improper selection of grease or improper use and maintenance, poor quality or deterioration of the grease, or mixed with dust and impurities, etc. can cause bearing heating.

Solution: too much or too little grease will also cause bearing heating, because too much grease, the bearing rotation part and grease will produce great friction, and too little grease, may appear dry friction and heating.Therefore, the amount of grease must be adjusted to approximately 1/2 to 2/3 of the bearing chamber space volume.Improper or deteriorated grease should be cleaned and replaced with appropriate clean grease.

3. The axial clearance between the outer bearing cover of the motor and the outer circle of the rolling bearing is too small.

Solution: Large and medium motors generally use ball bearings at non-shaft ends.Roller bearings are used at the shaft extension end, so that the rotor can be expanded freely when heated.As both ends of the small motor adopt ball bearings, there should be an appropriate clearance between the outer bearing cover and the bearing outer ring, otherwise, the bearing may be heated due to too much axial thermal elongation.When this phenomenon occurs, the front or rear side of the bearing cover car to a point, or between the bearing cover and the end cover to pad a thin paper pad, so that one end of the outer

bearing cover and the bearing outer ring to form an adequate clearance.

4. End caps or bearing caps on both sides of the motor are not installed properly.

Solution: if the motor on both sides of the end cover or bearing cover is not parallel or not close to the stop, it will make the ball off the track rotation and heat.Both sides of the end cover or bearing cover must be reinstalled flat and fixed with bolts rotating evenly.Click here to learn more about WSBC 22209 CA/W33

5. Ball bearings, rollers, inner and outer rings, ball bearings are seriously worn or metal is peeled off.

Solution: The bearings should be updated at this point.

6. Poor connection with load machinery.The main reasons are as follows: poor coupling assembly, too much belt tension, not consistent with the load of the mechanical axis, too small belt wheel diameter, belt wheel is too far from the bearing, the axial or radial load suffered by too much.

Solution: Correct incorrect connections and avoid abnormal forces on the bearing.

7. The axis is bent.

Solution: The bearing force is no longer pure radial force, thus causing bearing heating.Try to straighten or replace a bent shaft.