What causes overheating during bearing use and how to deal with it
1. The rolling bearing is installed incorrectly and the fitting tolerance is too tight or too loose.
Solution: The working performance of rolling bearings not only depends on the manufacturing accuracy of the bearing itself, but also on the dimensional accuracy, geometric tolerance and surface roughness of the shaft and hole it matches, the
selected fit and the correct installation. In general horizontal motors, well-assembled rolling bearings only bear radial stress. However, if the fit between the inner ring of the bearing and the shaft is too tight,
or the fit between the outer ring of the bearing and the end cover is too tight, that is, when the tolerance is too large, the bearing will The bearing clearance will become too small, sometimes even close to zero. In this way, the rotation will be inflexible and
it will generate heat during operation. If the fit between the inner ring of the bearing and the shaft is too loose, or the fit between the outer ring of the bearing and the end cover is too loose, the inner ring of the bearing and the shaft, or the outer ring of the bearing and the end cover
will rotate relative to each other, causing friction and heat, causing the bearing to malfunction. overheat. Usually, the standard moves the tolerance zone of the inner diameter of the bearing inner ring as a reference part below the zero line.
The fit between the tolerance zone of the same shaft and the bearing inner ring is much tighter than the fit between it and the general reference hole. .
2. Improper selection of grease or improper use and maintenance, poor quality or deterioration of grease, or mixing with dust and impurities can cause the bearing to heat up.
Solution: Adding too much or too little grease will also cause the bearing to heat up, because when there is too much grease, there will be a lot of friction between the rotating part of the bearing and the grease,
and when too little grease is added, dryness may occur. Heat due to friction. Therefore, the amount of grease must be adjusted to approximately 1/2-2/3 of the space volume of the bearing chamber.
Unsuitable or deteriorated grease should be cleaned and replaced with suitable clean grease.
3. The axial gap between the outer bearing cover of the motor and the outer circle of the rolling bearing is too small.
Solution: Large and medium-sized motors generally use ball bearings at the non-shaft extension end. The shaft extension end uses roller bearings so that when the rotor expands due to heat, it can extend freely.
Since small motors use ball bearings at both ends, there should be an appropriate gap between the outer bearing cap and the bearing outer ring. Otherwise, the bearing may heat due to excessive axial thermal elongation.
When this phenomenon occurs, the front or rear bearing cover should be removed a little, or a tissue pad should be added between the bearing cover and the end cover to form a sufficient gap between the outer bearing cover at one end and the bearing outer ring. Clearance.
4. The end covers or bearing covers on both sides of the motor are not installed properly.
Solution: If the end caps or bearing caps on both sides of the motor are not installed parallel or the seams are not tight, the balls will rotate out of the track and generate heat. The end caps or bearing caps on both sides must be reinstalled flat and tightened with bolts evenly rotated.
