(a) Insufficient lubrication of bearing oil mist
Because the aluminum foil rolling mill generally runs at a high rolling speed, the rolling speed of the roughing mill is usually 700 ~ 900 m/min. When such a high rolling speed acts on the bearing, the bearing speed is above 850 rpm, and the lubrication of the work roll bearing of aluminum foil mill usually adopts oil mist lubrication. When the bearing rotates at high speed, it generates huge heat, and the bearing roller expands due to heat, which leads to the reduction of bearing clearance, thus squeezing the inner and outer rings of the bearing, which leads to the intensified wear of the tapered roller and insufficient lubrication of the bearing, which can not take away the heat generated when the bearing rotates at high speed in time, and will eventually lead to the bearing locking.
(b) Improper assembly of the work roll bearing box.
Aluminum foil rolling requires high quality of roll profile and roll body surface. Aluminum foil mill needs to change the work roll frequently and disassemble the bearing box many times. Pay full attention to the roller bearing clearance every time you remove the bearing box. When the clearance is small, the tapered roller squeezes the inner and outer rings of the bearing. When the bearing rotates at high speed, the wear of tapered roller is aggravated, and the bearing temperature rises rapidly, which leads to bearing sintering. After the rolling mill is installed in the new work roll system, the bearing is locked in a short time. When the clearance is too large, the stress range of tapered roller bearing decreases, which leads to local fatigue damage of the bearing and reduces the service life of the bearing.
(c) The quality of the bearing itself.
The quality problem of the bearing itself is also one of the reasons why the roller bearing is locked, and sometimes it is removed for processing.
After the roller locks the bearing, it will be found that the cage of the tapered roller bearing is completely broken, which can be concluded to be caused by the quality problem of the bearing itself. Because it is found through many practices that the cage of tapered roller bearing is good.
When cracks appear, if the bearing rotates at a high speed and continues to bear the load, the cage breaks and the roller can't rotate normally, which leads to the burning of the bearing and eventually leads to the bearing locking.
(D) the impact of aluminum foil rolling process
Because the bending and inclination of the work roll are often used in the aluminum foil rolling process, sometimes the operator uses too much inclination when the incoming material shape is not good. For the bearing, the axial load is too large, which is easy to damage the bearing and lead to the bearing locking. With the continuous improvement of operation level and rolling process, the phenomenon of work roll bearing locking caused by this reason has rarely occurred.