Marginally lubricated

Lubrication4Area 1 of Fig. 7The bearing will operate with boundarylubrication.The pU factor will be the major determinantof bearing life.DX bearing performance can be estimatedfrom the following:Calculate Effective pU Factor from Section5.8If epU/η ≤0.2 then(4.5.1) [h]2000L H= ------------------------⎛epU---------- ⎞ 0,5 ⋅ a Q⋅ a T⋅ a•S⎝ η ⎠If 0.2 < epU/η ≤1.0 then(4.5.2) [h]1000L H= ---------------- ⋅a Q⋅a T⋅a S⎛epU---------- ⎞⎝ η ⎠Area 2 of Fig. 7The bearing will operate with mixed filmlubrication.pU factor is no longer a significant parameterin determining the bearing life.Area 3 of Fig. 7The bearing will operate with hydrodynamiclubrication. Bearing wear will bedetermined only by the cleanliness of theArea 4 of Fig. 7• These are the most demanding operatingconditions.• The bearing is operated under eitherhigh speed or high bearing load to viscosityratio, or a combination of both.• These conditions may causeIf epU/η >1.0 then(4.5.3) [h]1000L H= -------------------⎛epU---------- ⎞ 2 ⋅a Q⋅a T⋅ a S⎝ η ⎠epU ver (5.8), pág 18DX bearing performance will depend uponthe nature of the fluid and the actual serviceconditions.lubri-cant and the frequency of start up andshut down.- excessive operating temperature- and/or high wear rate.• Bearing performance may be improved:- by use of unindented DX lining- by the addition of one or more groovesto the bearing- by shaft surface finish R a