DC Motor Bearing Damage

A DC motor is a motor that converts DC power and mechanical energy to each other. It consists of two parts, the stator and the rotor, with a certain air gap between them. In the use we will encounter the problem of bearing damage, let us know the reason for the damage:

1. Bearing damage due to mixing of different types of grease;

2, the bearing itself has manufacturing quality problems, such as raceway rust, inflexible rotation, over-standard clearance, cage deformation, etc.;

3, the standby machine does not run for a long time, the grease deteriorates, the bearing is rusty and has not been repaired. Because the temperature rise of the motor body is too high, and the bearing is supplemented with grease, the bearing is short of oil or even burned;

4. Due to the axial misalignment of the stator and rotor core or the lack of precision after machining the shaft, the inner and outer rings of the bearing are not on one cutting surface, causing the bearing to run “eat differently” and then the temperature rises until it burns;

5. The bearing is replaced again. After the motor end cover is nested, the interference is large or the ellipticity exceeds the standard, causing the bearing ball clearance to be too small or uneven, resulting in an increase in the friction force when the bearing is running, and the temperature rises sharply until it burns;

6. The bearing cavity is not cleaned or the grease is not clean. For example, the tiny rigid material in the bearing cage is not completely cleaned, and the bearing raceway is damaged during operation, causing the temperature rise to be too high to burn the bearing;

7. Improper assembly of the bearing. If the inner ring of the bearing is unevenly hit during cold assembly, the shaft is subject to wear, resulting in loss of interference or loss of interference between the inner ring of the bearing and the bearing. The uneven tapping causes the end cap bearing chamber to cooperate with the outer ring of the bearing to loosen the outer ring phenomenon. Whether running the inner ring or running the outer ring will cause the bearing temperature rise to rise sharply and burn out, especially if the running inner ring fault will cause serious wear and bending of the rotating shaft. However, the intermittent running outer ring generally does not cause a sharp rise in the bearing temperature. As long as the bearing is intact, the intermittent running outer ring phenomenon is allowed.

Regarding the cause of the damage of the DC motor bearing, the paper has analyzed according to the specific situation. According to the bearing damage of different situations, the different causes of damage are explained. In the future operation and practicality, if you encounter the problems explained in the text, According to the reasons given in the article, the root cause of the damage can be found and repaired.