The processing accuracy of the bearings for the hot rolling machines is required to reach the P6 level. This also means that the operating conditions of the bearings in the steel mills must match the level of the bearings.

The common hot rolling conditions do not meet the usage requirements of the bearings. The aging of the bearing housing seals leads to water entering the bearings, which is one of the important reasons for the premature damage of the bearings.

The production rolling lines of hot rolling mills have seriously aged, which has become a common phenomenon. Many steel mills, in order to save production costs, purchase bearings in a package manner. This leads to the failure to purchase bearing-related parts in a timely manner or the failure to replace the aging sealing rings in a timely manner. The phenomenon of hot rolling machine bearings getting water and oxidized skin due to the failure of the sealing to meet the requirements is very common. Bearings lubricated by grease that adopt a non-contact type of two-sided asymmetric sealing structure have unqualified sealing aging, which is also very common. Moreover, some steel mills do not install sealing rubber rings at all, and the two sides of the bearings are directly exposed to the outside.

Given the actual working conditions of the hot rolling lines, to ensure the online service life of the rolling machine bearings, a new type of non-contact, two-sided asymmetric sealing, four-row cylindrical roller bearing that does not change the original structure of the bearings has been optimized and designed. This type of bearing has a double seal on one side, which can prevent the emulsified liquid and oxidized skin from entering the interior of the bearing, and can also prevent the loss of lubricating grease inside the bearing. The other side adopts a non-contact single seal to prevent the loss of lubricating grease inside the bearing. This sealing structure of the bearing can effectively prevent water and impurities from entering the bearing and will effectively ensure the purity of the lubricating grease inside the bearing, enhance the lubrication performance of the bearing, and increase the online service life of the bearing. See the figure below;

Original structure

Optimized non-contact asymmetric sealing structure

  The design of the non-contact sealing bearing is optimized based on the actual operating conditions of a certain hot-rolled narrow-strip production line. This design can effectively prevent the loss of lubricating grease and protect the internal lubricating oil film of the rolling mill bearings from being damaged. In this steel mill, the bearing housing is not equipped with sealing gaskets, resulting in severe loss of lubricating grease. A large number of bearings have been damaged due to lack of oil. The pictures of bearing damage will not be shown here one by one.

The optimization of the sealing structure has gradually become the mainstream of the optimization design for rolling mill bearings. The design concept of the rolling mill has already undergone a qualitative leap. Currently, the design of rolling mill bearings still remains based on the original theory and structure. To adapt to the rapid development of modern steel rolling industry, the design of rolling mill bearings also needs to be based on the on-site operating conditions, adopt a leapfrog thinking mode, and design more durable rolling mill bearings.