Kloubová oka Fluro

21 FLURO ® -Gelenklager GmbH Technical Information C/F ( v m ) exist Bearing life calculations In the case of a static load it is not necessary to calcu- late the working life. The permissible limit set at 80% of the breaking point allows the forces to act indefinitely. In the case of dynamic loads calculating the bearing life is problematic. There are many, sometimes interdepen- dent influences, that cannot always be taken into con- sideration.Therefore, a calculation of the bearing life can only be approximate. As an approximation the bearing has an increased life proportional to its load rating and also when used at a moderate speed. Additional influences can be taken into account by making use of the factors in formula (11). (11) G h ≈ 3 . f L . f T . f G . f V [h] f L = Direction of load to table 7 f T = Temperature factor to table 4 f G = Glide factor to table 8 f V = Relubrication factor to table 9 C/F = Load ratio v m = Mean glide speed [m/s] The direction of load factor indicates whether the direction of load is uni-directional, constant, variable or oscillating. Direction of load Steel/Steel Steel/Bz Steel/PTFE unidirectional 1 1 1 varying 2,5 2 1 Table 7: Directional load factors f L The slip factor f G takes into account the materials used on the mating surfaces of a bearing. As a result the only distinction that can be made is between being mainte- nance-free (not lubricated) and where lubrication is necessary. (C/F) exist 1,5 2 3 4 6 8 10 15 20 maint. free 1,5 2,0 2,5 3,0 3,5 4,0 4,3 4,7 5,0 greased 1,1 1,2 1,3 1,4 1,6 1,8 2,1 2,4 2,5 Table 8: Glide factors f G The relubrication factor f v takes into account the exten- sion of the bearing life G h when regularly lubricated. The greater the surface pressure p exist the more often the bearing has to be relubricated. If the bearing is only lubricated on commissioning as in the case of bearings with PTFE liners, f v = 1 has be inserted. p exist [N/mm 2 ] 5 10 25 40 Regular regreasing 6 4 3 2 regreasable bearing Initial greasing + PTFE 1 1 1 1 Table 9: Relubrication factors f v Lubrication intervals are dependent on load conditions and therefore have to be set by the operator.