DIN ISO 281 Bb.3:2009
Rolling bearings - Dynamic load ratings and rating life - Supplement 3: Estimating of the contamination factor respectively the contamination level for rolling bearings in closed industrial gear units; English version of DIN ISO 281 Supplement 3:2009-07

Standard No.

DIN ISO 281 Bb.3:2009

Release Date

2009

Published By

German Institute for Standardization

Status

Be replaced

Replace By

DIN ISO 281 Beiblatt 3:2009-07

Latest

DIN ISO 281 Beiblatt 5:2011-10

Replace

DIN ISO 281 Bb.3:2008

Scope

This supplement applies for rolling bearings in oil-lubricated closed industrial gear units. It does not contain any standardized specifications; instead, it describes informatively, using examples, how, in the modified rating life calculation for rolling bearings according to DIN ISO 281, the level of contamination of the lubrication or, in the modified reference life calculation according to ISO/TS 16281, the purity class of the oil can each be estimated as a function of measures to keep the gear units clean. The degree of contamination should be applied in connection with the procedure for the calculation of the modified rating life Lnm specified in DIN ISO 281 according to Table 13. The oil purity class should be used in connection with the procedure for the calculation of the modified reference working life Lnm specified in ISOFFS 16281 in accordance with DIN ISO 281, Figures A.1 to A.9. The following aspects are to be taken into consideration: -- Cleanliness of the interior of the gear unit and the internal components after gear assembly; -- Cleanliness of the lubricant circulation system; -- Cleanliness of the gear oil on initial filling and all later fillings; -- Screening of the interior of the gear unit, the bearings and the lubricant circulation system to prevent penetration by contaminants; -- Removal of friction particles from the oil during the gear running-in phase and later operation through oil filtering, particle separators and/or regular oil changes or oil cleaning. The more effort is made, from design through assembly, trial runs, installation, commissioning, running-in phase and operation to maintenance and repair, to keep the gear unit free from contaminants, the longer the life of the rolling bearings can be expected to be. In particular, it is recommended that, if the gear unit is used in surroundings with a highly contaminating effect, the bearing points of the connection shafts are protected by special design measures against the penetration of dirt particles. For further measures, see Clause 8.

DIN ISO 281 Bb.3:2009 history

• 1970 DIN ISO 281 Beiblatt 5:2011-10
• 2011 DIN ISO 281 Bb.5:2011 Rolling bearings - Dynamic load ratings and rating life - Supplement 5: Load ratings for hybrid bearings
• 2010 DIN ISO 281:2010-10 Rolling bearings - Dynamic load ratings and rating life (ISO 281:2007)
• 2010 DIN ISO 281:2010 Rolling bearings - Dynamic load ratings and rating life (ISO 281:2007)
• 2009 DIN ISO 281 Beiblatt 3:2009-07 Rolling bearings - Dynamic load ratings and rating life - Supplement 3: Estimating of the contamination factor respectively the contamination level for rolling bearings in closed industrial gear units
• 2009 DIN ISO 281 Bb.3:2009 Rolling bearings - Dynamic load ratings and rating life - Supplement 3: Estimating of the contamination factor respectively the contamination level for rolling bearings in closed industrial gear units; English version of DIN ISO 281 Supplement 3:2009-07
• 0000 DIN ISO 281 Bb.3:2008