super precision bearings

HANDLING OF SUPER PRECISION BEARINGSMountingHandling of Super PrecisionBearingsFAG super precision bearings aremanufactured in clean surroundings,undergo intensive inspectionsand are packaged with great care.In order to preserve the full performancecapacity of the bearings,they have to be handled carefullyduring mounting. A separate, cleanmounting room offers the bestconditions here. Mounting can besubdivided into the followingsteps:Preparation of PartsOnly approved parts should beused for mounting. Depending onthe component, the approval procedureconsists of a dimensionalinspection, optical inspection oran additional pre-balancing procedure.Calibration of PartsFits have a decisive influence onbearing function. Therefore it issometimes advisable to calibratebearings to the spindle or housingdiameter. In the case of spindlebearings the bore and housing tolerancesare divided into groups,the mean tolerance of which is indicatedon the packaging and thebearing itself. The spindle bearingwidth as a deviation of the nominaldimension is also indicated onthe bearing (see “Bearing Code”,page 184).Matching ProceduresIn order to obtain optimum performanceor achieve an accurate positionof the spindle in relation tothe housing, it may be necessary tomake special adjustments. This appliesfor instance to the cover thatserves for axially clamping thebearings in the housing. Prior toclamping the bearing shouldfeature an adequate gap (Illustration38).An adjustment of spacers is advisablefor high-speed spindles, so ase.g. to compensate for the influenceof fit and ring expansion onpreload.Lubricating GreasesFAG super precision bearings arepreserved in such a way that thewashing of bearing prior to greasingis not required. The grease fillingcan be obtained from Tables 24and 25 (page 144f). Precise greasequantities and a good distributionof the grease in the bearing can beachieved in a simple way by usinga syringe.MountingGap before tightening offace cover boltsBearing bore d ≤ 100:0.01 - 0.03 mmBearing bore d > 100:0.02 - 0.04 mmWhen mounting the bearing ontothe shaft or inside the housing,forces must under no circumstancesbe borne by the rolling elements.Components that have tobe mounted with tight fits (interferencefits) should be heated prior tomounting. This can be done in asimple, quick and clean way by usinginductive heating devices. Valuesfor the axial clamping of bear-38: Recommended adjustment of face covers39: Preloading forces and correspondingnut tighteningtorques for spindle bearinginner rings (opposite page)FAG · 178