Bearings can be divided into rolling bearings and sliding bearings according to the friction properties of the moving parts. Among them, the rolling bearing has been standardized and serialized, but compared with the sliding bearing, its radial size, vibration and noise are larger, the price is also higher.
Generally, the rolling bearing is composed of four parts: outer ring, inner ring, rolling body and cage. Strictly speaking, it is composed of six parts: outer ring, inner ring, rolling body, cage, seal and lubricating oil. Simply speaking, as long as the outer ring, inner ring, rolling body can be defined as rolling bearing. According to the shape of rolling body, rolling bearing can be divided into ball bearing and roller bearing.
Cause analysis of motor bearing overheating and Countermeasures:
Common faults
Causes
Elimination method
Unreasonable assembly of bearing
When assembling the bearing, the deflection will cause the edge of the inner and outer rings of the bearing not on the same plane, and the end cover is uneven, resulting in the bearing heating
Stable assembly to ensure the accuracy of bearing assembly
Lack of oil and over filling
During the long-term operation of the bearing, the internal lubricating oil is gradually reduced, so that the lubricating oil is insufficient and the friction is increased. When the bearing is short of oil, the "rubbing" sound and slight "Gulu" sound will cause the heating phenomenon. If it is found early, it can be improved after oil filling. If the time of oil shortage is long, the bearing may be damaged. When adding new oil, it is better to add grease to two-thirds of the bearing. Too much lubricating oil causes high temperature of bearing chamber and heating of lubricating oil due to thermal expansion
The amount of oil to be injected should be reasonable and checked frequently to prevent oil shortage or over filling, and the quality of oil should be checked to avoid hard impurities
Belt is too tight or coupling device is uneven
The belt is too tight and the coupling device is uneven, both of which are caused by the increase of bearing load and heating. If the bearing does not heat up during idling, the belt and coupling must be adjusted if the temperature increases a lot under load. Because under normal conditions, bearings that do not heat up during idling will not heat up when they rotate with load. In addition, the device is unbalanced, not calibrated, vibrated when rotating, and the bearing will also heat up when the vibration is severe.
Adjust the belt tightness in the device or adjust the coupling level to eliminate the vibration during the operation of the machine
Bearing damaged or used for too long
If the bearing is damaged, it will be used for too long, which will cause the bearing to heat up
Replacement of bearings
Bearing position wear