Which caused the frequent damage of rolling mill bearings?

After analysis of effective data, the main forms of rolling mill bearing damage are fracture, wear and pitting.

Damage form one: Fracture: inner and outer ring fracture, rolling element rupture, cage fracture

The outer ring fracture is mainly caused by the excessive load and the insufficient bearing pressure.

In addition to the cyclic load, the inner ring is connected with the roll neck by the interference fit during installation. There is a positive tensile peripheral stress. As long as micro cracks are formed on the inner ring, they will rapidly spread and then cause fracture.

In addition to the above reasons, another reason for the fracture is that the oil and gas supply in the roller box is insufficient or interrupted, causing the bearing to heat up and then lock, and then causing damage to the inner and outer rings, the cage and the rolling elements.

Damage form two:  How is wear and pitting caused?

Most of the wear is caused by the relative rotation of the roll neck and the inner hole.

There are two main reasons for pitting: the bearing material is unqualified, caused by improper heat treatment. Foreign matter enters into the roller box, and pitting occurs during the running of the bearing.

In addition, due to improper operation, the copper bracket is deformed. When the roller enters the bearing housing, the ball rubs against the inner sleeve and then scratches the inner sleeve, so that the roller is inflexible during operation, causing bearing failure.

The height of the roll gap on both sides of the rolling mill is inconsistent, which causes the bearing to be stressed at a certain point due to uneven force during the running of the roll, thus causing bearing failure.