super precision bearings

FLOATING DISPLACEMENT BEARINGSThe floating bearing function inspindles is a well-known problem.While simple solutions represent acompromise between costs andfunction, demanding solutions offerenhanced functional reliabilitybut involve significantly highercosts at the same time. FAG developedFD bearings especially forapplication as floating bearings inmotor spindles. FD bearings consistof a deep groove ball bearingouter ring and a cylindrical rollerbearing inner ring. This combinationensures a free displacement ofthe outer relative to the inner ringduring operation. Considered indetail, this solution is extremely sophisticated.For this reason the latestfindings in rolling bearing technologywere applied in the designof FAG FD bearings. Ceramic ballsand Cronidur 30 high-performancesteel ensure a contact between innerring and ball appropriate forthe demand. Sufficient load carryingcapacity coupled with extremelyhigh speed-ability opens up newdesign opportunities for the floatingbearing location. A specialbearing clearance was determinedby simulating the applicationwhich, in combination with a cus-FAG · 78