FAG super-precision bearing installation process guidance

FAG super-precision bearing manufacturing process maintains an extremely high standard of clean environment, is very strict inspection, and is protected by high-quality packaging. In order not to affect the high performance of the bearing, care must be taken during installation. It is best to have a separate and clean installation room. Preparation of parts Only approved parts can be used for installation. Depending on the part, the approval procedure includes dimensional inspections, optical inspections or pre-equilibrium processes. The matching installation of components has a decisive influence on the function of the bearing. Therefore, it is sometimes necessary to match the bearing with the main shaft or the housing. For spindle bearings, the bore and outer diameter tolerances are divided into several groups, where the average tolerance of each group is marked on the package and bearing. The actual bearing width is also marked on the bearing.

  Matching procedure In order to obtain the best performance or achieve accurate positioning of the main shaft relative to the bearing housing, special adjustments must be made, such as the end cap for the axial clamping of the outer ring of the bearing in the housing, before the tightening and the bearing housing. There is a gap in the end face. For high-speed spindles, spacers are recommended to compensate for the effects of mounting and preloading on the expansion of the ferrule. Grease FAG super precision bearings do not need to be cleaned before filling with grease. See Table 4 on page 179 for grease loading. Refill grease must be carried out under extremely clean conditions. The amount of grease filled is very high for filling and measuring equipment. Therefore, it is recommended to choose bearings that are greased and sealed by Schaeffler.


Installation: When the bearing is mounted on the shaft or bearing housing, the rolling elements cannot withstand the load. Prior to installation, parts with tight fit (interference fit) are heated. If the induction heating device in Figure 3 is used, the heating process is simple, fast and clean. Table 4 and Table 5 show the clamping force of the inner ring of the bearing locked by the lock nut. To avoid installation in place, tighten the nut 3 times the given torque, release it, and tighten it with the specified torque. INSTALLATION GUIDELINES INSTALLATION, OPERATION AND GREASE DISTRIBUTION OF SUPER-PRECISION BEARINGS For grease-lubricated bearings, grease running must be performed before the spindle runs. Grease filling amount and grease running process guide please refer to appendix.

 Locknut Recommendation: The locknut is often used to clamp the inner ring of the spindle bearing and fix it on the shaft. A lock nut with an axial bore holds the bearing on the shaft better than a lock nut with a radial groove because it has minimal air turbulence at high speeds. The mounting surface of the lock nut must be ground on the same fixture as the thread. The axial runout is recommended to be less than 2μm. The spacers of the clamps are ground with the thread and the end face of the lock nut, which prevents skewing during clamping. Spindle Bearing Installation To ensure quality, it is recommended to record the following measurements: • Journal diameter, interference • spacer size difference • Steady-state temperature • Radial and axial runout values.