Full loaded cylindrical roller bearings are designed to withstand heavy loads. In the same width, compared with the traditional bearing with cage, this bearing has high bearing capacity, small radial section, and can save space, but the speed is relatively low. In order to make the bearing work normally, under the condition of continuous operation, the bearing must bear a certain minimum load, that is, C / P < 25. Otherwise, the wear will be increased due to insufficient lubrication and high-speed operation. All multi row cylindrical roller bearings have a lubricating groove and a lubricating hole on the outer ring.