Features Ultra-precision cylindrical roller bearings include a solid outer ring, a solid inner ring with a tapered inner hole (taper 1:12) and cylindrical roller and cage components. The cage material is brass or PEEK. Cylindrical roller bearing NN30, the outer ring is movable and can therefore be installed separately from the rest. Cylindrical roller bearing NNU49, the inner ring is movable. Double row bearings are used in occasions with high accuracy requirements and high radial loads. In machine tool applications, they can achieve bearing arrangements with high precision, high radial stiffness and very high load-bearing capacity. They provide radial support for the spindle. The ideal floating bearing has no binding force between the roller and the raceway without ribs, which can compensate for the change in the length direction in the rotating motion, so the cylindrical roller bearing is especially suitable for the floating bearing. The axial force is borne by the thrust bearing. The bearing cylindrical roller bearing NNU49 with a smaller cross-sectional area has a smaller cross-section than other ultra-precision cylindrical roller bearings. Therefore, a smaller shaft spacing can be achieved in a multi-spindle arrangement. Moreover, diameter ranges not shown in the size table can be supplied by agreement. Double row cylindrical roller bearings Cylindrical roller bearings NN30 The rollers in the bearing are guided by the inner ring. The outer ring has a ground cylindrical profile and is movable, Figure 1. NNU49 has a ground and removable cylindrical inner ring. The roller is guided by the outer ring. Sealed cylindrical roller bearings do not have seals. Lubrication Due to the high surface quality of the raceways and rollers, cylindrical roller bearings are particularly suitable for grease lubrication. There are lubricating oil grooves and lubricating holes on the outer ring of oil-lubricated double-row bearings. When choosing a lubricant, the working temperature of the lubricant must be considered. According to the design, the radial bearing can be lubricated by the smaller thrust bearing above in most cases, see page 57. Operating temperature The operating temperature of the bearing ranges from 30 °C to +150 °C. The cage material of double row bearings is solid brass (suffix M). Suffixes For the suffixes of existing designs, please refer to the table. The marking of the existing design bearing is marked on the end face of the bearing ring, Figure 2. Suffix description design S outer ring with lubricating groove and lubricating hole Standard design AS outer ring with lubricating groove and lubricating hole, series NN30 K tapered hole, taper 1:12 M brass cage, roller guide SP precision SP and Internal radial clearance C1NA C2 The internal radial clearance is specially designed in accordance with the standard. UP ultra-high precision and internal radial clearance C1NA can be supplied through agreement. R40-50 Individual internal radial clearance H74 high running accuracy.