Exploring the structure of four row tapered roller bearings

Four row tapered roller   bearings are widely used in medium and low speed rolling mills. This kind of   bearing has compact structure and can bear large radial and axial shock load in   a limited space. Generally speaking, no additional thrust bearing is required   in the bearing configuration. This means that the shaft neck diameter of the   roll can be relatively short and housing on both sides of the roll can be the   same. In order to be able to change the roll quickly, this kind of bearing   must have clearance fit on the roll journal. The disadvantage of clearance   fit is that the inner ring slides on its base under load, which usually   causes the wear of the base with lower hardness than the bearing ring. In   order to reduce the influence of clearance fit, that is to reduce wear, the   bearing has a spiral groove in the inner ring bore or an oil groove on the   side of the inner ring. These grooves deliver lubricant to the contact   surfaces of the inner race and the base.

TQO type:

This type of bearing features two double   raceway inner rings, one double raceway outer ring, and two single raceway   outer rings with spacers between the inner and outer rings for clearance   adjustment. Its performance is essentially equivalent to that of double row   bearings in terms of its ability to withstand large radial loads; however, it   has a lower limit speed. It is primarily utilized in heavy machinery   applications such as rolling mills with stamped steel cages. Revised sentence: Generally, bearings with an outer   diameter exceeding 650mm or those designed for special applications are   equipped with welded pin cages. (As shown below)