Design and safety guidelines Load capacity and service life Bearing arrangements with FAG super-precision cylindrical roller bearings are typically used where high load capacity, high stiffness and high precision are required. In practice, fatigue-induced failure of these bearings is rare. Therefore the calculation of the rated life L10 according to DIN ISO 281 to determine the working life is not accurate. Equivalent static bearing load Equivalent static load P0 is calculated from the axial and radial loads of the bearing. Super-precision cylindrical roller bearings are only subjected to radial forces. For bearings under static load, the following formula is used: P0 N bearing equivalent static load N bearing radial static load. Static load safety factor Whether the static load bearing capacity is sufficient for a given static load can be verified by the static load safety factor S0. S0 Static load safety factor C0 N Basic static load rating P0 N Bearing equivalent static load. To take advantage of the high precision of the bearing, a static load safety factor S0 3 is necessary (S0 8 u003d fatigue resistance). Clearance Adjustment of Cylindrical Roller Bearings Cylindrical roller bearings with tapered bore can be mounted with clearance, without clearance or with preload, see table, page 126. For vertical lathes, an interference of 5 m has proven effective. The limit speed nG given in the speed dimension table is only suitable for grease lubrication or oil lubrication with minimum oil quantity, and this speed must not be exceeded. Cylindrical roller bearings, the achievable speed in motion is determined by the internal radial clearance, see table. Achievable speed dM u003d (d + D)/2 These values u200bu200bare guidelines when the temperature difference T between the inner and outer rings does not exceed 5 K. For applications with large temperature differences, please consult the Industrial Applications Department of the Schaeffler Group. Radial rigidity The radial rigidity cr is the ratio of radial load to radial displacement. cr N/m radial stiffness, see dimension table Fr N radial force r radial displacement. Clearance or preload attainable speed m min1 5 to 0 to 0.5 nG Grease2 105 dM 0.5 to 0.75 nG Grease4 105 dM 0.75 to 1 nG Grease1 104 dM 1 nG Oil bearing arrangement designed to take full advantage of super precision cylindrical rollers The performance of the sub-bearing, the adjacent structure must be properly designed, Figure 3. d u003d nominal diameter of the shaft d u003d diameter of the small end of the tapered shaft (u003d d + lower deviation, see page 129, table) d1 u003d diameter of the large end of the tapered shaft d1 u003d d + 1/12 LL u003d tapered shaft Length L u003d 0.95 B (bearing width) t1 u003d Cylindricity according to DIN ISO 1101 t2 u003d Roundness according to DIN ISO 1101 t3 u003d Flatness according to DIN ISO 1101 t4 u003d Axial runout according to DIN ISO 1101 t5 u003d Concentricity according to DIN ISO 1101 ATD u003d Taper tolerance according to DIN ISO 7178 Ra u003d Geometrical tolerance of average surface roughness according to DIN ISO 4768 Figure 3 Machining tolerance of the taper angle The taper angle tolerance ATD is measured perpendicular to the journal and is defined as the differential diameter. If using the FAG taper gauge MGK132, the ATD value in the table must be halved (tilt angle tolerance). For the taper shaft length table among the listed values, the taper angle tolerance ATD can be obtained by interpolation. Taper deviation The taper angle deviation of the taper shaft mating surfaces for bearings of tolerance class SP, see table. The main dimensions of precision bearings conform to standard DIN 620-1. Dimensional and geometrical tolerances conform to tolerance class SP. Super-precision cylindrical roller bearings in higher tolerance class UP are also available by agreement. Bearings are available with cylindrical or tapered bores and corresponding dimensional tolerances, see figure 4 and table on page 134. u003d Angle of inclination at the end of the cone u003d 2 23 9.4 2 u003d Angle of the cone at the end of the cone u003d 4 46 18.8 B u003d Width of the inner ring d u003d Nominal diameter of the bearing bore d1 u003d Diameter of the big end of the cone dmp u003d Single radial Aperture Deviation of Flat Nominal Diameter Figure 4 Tolerance of Tapered Bore.