With the high development of the construction, mining and other industries, the rolling mill equipment is becoming more and more widespread. To ensure the metal rolling to be efficient, high-quality rolls are necessary, for the rolls are the important parts to the plastic deformation of the metal. For the support rolls in rolling mills, four-row tapered roller bearings play a key role. Not so long ago, Lily Bearing helped a client from the US customize a solution about four-row tapered roller bearings. This client is mainly engaged in the production of the rolling mill equipment and its technology is excellent. Whether in steel making or in continuous casting, whether in hot rolling or in cold rolling, whether in finishing or in cutting, the client has been ahead of the other competitors.
After having a good knowledge of the client's working conditions, engineers from Lily Bearing showed that four-row tapered roller bearings are the most common roller bearings and they are the bearings for I-beam rolling mills. These TQO four-row bearings have a huge bearing capacity, both the radial load and the axial load. In terms of the radial load, four-row tapered roller bearings have more significant advantages. Further, such bearings can also withstand a large axial load and a radial load at the same time or axial loads from two directions. Judging from the experience, the load capacity of four-row tapered roller bearings is 2.5-3.5 times that of Single Row Tapered Roller Bearings. The limit speeds of four-row tapered roller bearings are not as high as Four-Row Cylindrical Roller Bearings. Their limit speeds are much lower. That's why four-row tapered roller bearings are commonly used in applications with low or medium speeds. The client's I-beam mill support rolls are a case in point.
In terms of the process as well as the design, the four-row tapered roller bearings were made of the carburized steel. Cages of these four-row tapered roller bearings were steel plate stamping cages. When designing the cages of these carburized steel tapered roller bearings, the nitriding treatment was used. This process can help increase the strength of the cages and ensure long-lasting toughness. In addition, while designing these four-row tapered roller bearings, engineers made a creative idea on the basis of the traditional way. The adopted a style with a middle spacer on the small end face, that is, the middle ring and the bearing ring were integrated. This way can help reduce the width tolerance of the inner ring. Actually, this is an approach of a septum-less design. It is said that this design can help increase the bearing load capacity and extend the life of four-row tapered roller bearings. It can also simplify the axial positioning on the roll journal as well as the installation process. Furthermore, the way of the design can improve the distribution of the four-row roller load, reduce the wear as well as maintenance costs and thus extend the service life.
Engineers also mentioned that four-row tapered roller bearings can also be used in two-way axial positioning. If you want to change the the axial and radial clearance of the four-row tapered roller bearings in order to meet the needs of the working conditions, you can adjust the thickness of the spacer between the inner ring and the outer ring. In addition, to make the loading and unloading easy, engineers recommended that a clearance fit should be kept between the four-row tapered roller bearings and the roll necks. Nevertheless, although the looser fit is convenient for replacing rolls, it also has shortcomings. When the inner rings of the four-row tapered roller bearings creep on their bases under the conditions of the main load, they often trigger the wear of the bases for the hardness of the bases is much lower than that of the bearing rings. For this reason, the engineers of Lily Bearing gave a recommendation on how to reduce the influences of loose fit. They said that the lubricant can be delivered to the contact surface of the inner ring and the base through the oil groove on the side of the inner ring. By doing this, it is easy to reduce the friction coefficient of the four-row tapered roller bearings as well as the probability of wear and thus ensure the bearings have sufficient strength and rigidity. This is also a good means for the four-row tapered roller bearings used in rolling mills to cope with the heavier and more variable workloads.
The above case is a custom-made solution for four-row tapered roller bearings, which won the praise of the client in the end. As a matter of fact, whether choosing standardized TQO Four-row tapered roller bearings or custom bearings, Lily’s engineers are always ready to help clients to locate the best bearing solution. They consider not only various technical parameters such as the inner and outer diameter tolerance, static and dynamic load and the limit speed, but also the clients' real needs and working conditions. As is known, Lily Bearing has always had a good reputation in the bearing industry, which is inseparable from its rich experience of bearing manufacturing, its strong team of professional engineers as well as its client-focused philosophy.