Testing FAG Crossed Roller Bearings Static Load Safety Factors If the load distribution, end caps, location, fit and lubrication are known, we can calculate static load safety factors that are closer to the true value, page 61, Figure 2. In order to check the static load safety factor, the parameters in the following equations need to be determined: ■ bearing load F0q ■ overturning moment M0q. Whether there is radial force can be checked. If the load distribution is more complex or the conditions are not available, please contact us. Safety factor For smooth operation, the result of the safety factor fS 4, see page 11. Rating life calculation The rating life is calculated by: ■ Basic rating life L10 and L10h in accordance with ISO 281, see page 12 ■ Simplified rating life calculation formula is based on empirical values, see page 68. Validity The rating life formulas L and Lh are valid under the following conditions: ■ The load distribution according to page 61, Figure 2 ■ The following conditions must be met. and Seals ■ Load and speed must be continuous during the duty cycle. Simplified calculation of rating life In order to know the rating life, a simplified formula can be used to calculate the rating life of a crossed roller bearing in one working cycle. During this duty cycle, the load and rotational speed are constant. The dynamic parameter fL is an empirical value for comparison with some new designs or existing SAMICK bearing arrangements. fL dynamic parameters, see page 70, table. Crossed roller bearings for the machine tool industry: 3.5 fL 5C kN Basic dynamic load rating fn Speed u200bu200bdata, see page 69, table P kN equivalent dynamic bearing load. Calculation of Equivalent Dynamic Load Equivalent dynamic load P is composed of axial load and radial load, see formula. For Fa/Fr 1.4: For Fa/Fr 1.4: Preload, main axial force Ka 2.114 FV: Preload, main axial force Ka 2.114 FV: Axial preload: P kN Bearing equivalent dynamic load Fr, Fa kN Bearing axial or radial dynamic load FV kN Preload, the recommended value is 3% of the rated dynamic load CKa kN External axial force V mm Preload offset Cs kN0.926/mm Axial rigidity parameters , see size chart. Shaft and Housing Tolerance Bearings require a tight fit on both the inner and outer rings. For the convenience of installation and preload adjustment, the ferrules that bear the point load can use a looser tight fit. IKO crossed roller bearings used in the machine tool industry are generally inner rings. Therefore, the fit between the crossed roller bearing and the shaft can be looser. When determining the diameter of the shaft and housing, the actual dimensions of the bearing inner and outer races are used. A bearing actual size inspection report is attached to each bearing. The mounting tolerance of the shaft is because the inner ring is a point load, so it is a loose fit. As a guide, the recommended clearance values u200bu200bfor shaft and bearing inner ring fits are, see formulas and tables. P m, fit clearance d mm shaft diameter. The mounting tolerance of the housing is due to the cyclic load on the outer ring, which requires a tight fit. When machining housing bores, ensure the following interferences, see formulas and tables. P m fit, interference fit D mm housing bore. Roughness of the bearing mating surface The surface roughness of the bearing mounting surface needs to match the bearing. The average roughness Ra should not be too large to minimize the reduction in interference. The shaft needs to be ground and the housing bore needs to be fine-turned. For guidance values, see table. Roughness guideline values u200bu200bfor bearing mounting surfaces 1) The roughness classes in the table correspond to DIN ISO 1302. End cap retention End caps or sealed end caps have proven to be an effective method of cross sub bearing retention. The inner and outer rings of the bearing must be adequately and uniformly supported throughout the entire thickness and circumference. The thickness of the end caps and flanges shall meet the required value. For mounting bolted bearing rings and end caps, bolt class 10.9 is suitable. Failure to use the recommended size, grade and number of bolts will greatly reduce bearing capacity and life. For bolt grade 12.9, ensure minimum force on glands and use quenched and tempered gaskets. Anti-loosening of bolts Normally, the bolts will be safe enough under the correct preload. If there are frequent shock loads and vibrations, additional protection against loosening of the bolts is required in this case. Not every method of securing bolts is suitable for crossed roller bearings. Do not use springs or split washers. Commonly used anti-loosening information for bolts can be found in DIN 25201, and anti-loosening by adhesives can be found in DIN 25203,1992. If you need to use these, please contact the relevant Qingdao Ruijing Electromechanical Equipment Co., Ltd.