The Root Reasons and Solution of High Temperature Motor Bearings

Time：2021.07.01  Source：Roller Bearings Suppliers

As an important part of the motor, the speed of the bearing will directly affect the performance of the motor. If the speed is too low, the motor will not be brought up. If the speed is too high, the motor will burn out at high temperature,In general, bearing overheating refers to the rolling temperature rise of more than 55℃, the sliding bearing temperature rise of more than 40℃.

The root causes and solutions of excessive motor bearing temperature:

1.Rolling bearing is not installed correctly, and the fitting tolerance is too tight or too loose.

The working performance of rolling bearings depends not only on the manufacturing accuracy of the bearing itself, but also on the dimensional accuracy, geometric tolerance and surface roughness of the matching shaft and hole, as well as the selection of matching and correct installation.

In general horizontal motors, assembled rolling bearings only bear radial stress, but if the inner ring of the bearing is too tight with the shaft, or the outer ring of the bearing is too tight with the end cover, that is, when the amount of interference is too large, the bearing clearance after assembly is too small, sometimes even close to zero.Need WSBC 22226 E,click here to learn more.

In this way, the rotation is not flexible, and heat will be generated during the operation.If the bearing inner ring is too loose with the shaft, or the bearing outer ring is too loose with the end cover, the bearing inner ring is relatively rotating with the shaft or the bearing outer ring and the end cover, resulting in bearing friction heating and overheating.In general, the tolerance zone of the inner diameter of the bearing inner ring as a reference part moves below the zero line in the standard.The fitting of the tolerance zone of the same shaft with the bearing inner ring is much more important than the fitting of the tolerance zone with the general reference hole.

2. Improper selection or use and maintenance of grease, poor quality or deterioration of grease, or mixed with dust and impurities will cause bearing fever.

Too much or too little grease will also cause bearing fever, because too much grease will make the rotating part of the bearing and the grease produce greater friction, and too little grease will cause dry friction and fever.

Therefore, the amount of grease must be adjusted so that it is about 1/2-2/3 of the space volume of the bearing chamber.Unsuitable or spoiled grease should be cleaned and replaced with suitable and 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.

Large and medium-sized motors generally adopt ball bearings at the non-shaft extension end.Roller bearings are used at the extension end of the shaft, so that the rotor can be freely extended when heated and expanded.Due to the use of ball bearings at both ends of the small motor, there should be appropriate clearance between the outer cover of the bearing and the outer ring of the bearing, otherwise the bearing may be heated due to excessive axial thermal extension.

When this phenomenon occurs, the front and rear bearing cover should be removed, or a thin paper pad should be added between the bearing cover and the end cover to form enough clearance between the outer bearing cover and the outer bearing ring.

4. The end cover or bearing cover on both sides of the motor is not installed correctly.

If the end cover or bearing cover on both sides of the motor is not parallel to the installation or the stop block is not tight, the ball will rotate out of orbit and generate heat.Click here to learn more about WSBC 22311 E.

End caps or bearing caps on both sides must be reinstalled flat and secured with uniformly rotating bolts.

5. ball, roller, inner and outer rings, ball frame serious wear or metal peeling.

The bearing should be replaced at this time.

6. Bad connection with loader.Including: coupling assembly is poor, belt tension is too large, load machine axis is different, pulley diameter is too small, bearing distance is too far, axial or radial load is too large, etc..

Correct wrong connection to avoid bearing bearing bearing abnormal force.

7. The shaft is bent.

At this point, the bearing force of the shaft is no longer a simple radial force, so it will lead to bearing heating.Try straightening the bent shaft or replacing it with a new one.