Overview

This standard has been prepared by the Rolling Bearings and Plain Bearings Standards Committee, Working Committee NA 118-01-08 "Tragzahlen und Lebensdauer" ("Load ratings and life"). This standard is the German version of ISO/TS 16281:2008, which has been prepared by ISO/TC 4/SC 8 "Load ratings and life", with the participation of German experts of NA 118-01-08 AA. This standard also contains Corrigendum ISO/TS 16281:2009 Technical Corrigendum 1. The international document ISO/TS 16281:2008 has been prepared on the basis of DIN ISO 281, Supplement 4:2003-04. Since publication of ISO 281 in 1990, additional knowledge has been gained regarding the influence on bearing life of contamination, lubrication, internal stresses from mounting, stresses from hardening, fatigue load limit of the material, and so on. It is therefore now possible to consider factors that have influence on bearing life in a more complete way in the life calculation. ISO 281:2007 now provides a method to put this new knowledge into practice in a consistent way when the modified rating life of a bearing is calculated. However, the calculation methods given in ISO 281:2007 cannot consider the influence on life of tilted or misaligned bearings and the influence on life of bearing clearance during operation. This standard describes an advanced calculation method, which also makes it possible to consider these influences, and in addition provide the most accurate support for estimating the influence of contamination and other factors. This standard contains recommendations for the calculation of the modified reference rating life taking into consideration lubrication, contamination and fatigue load limit of the bearing material, as well as tilting or misalignment, operating clearance of the bearing and internal load distribution on rolling elements. The calculation method provided in this standard covers influencing parameters additional to those described in ISO 281. The directions and limitations given in ISO 281 apply to this standard. The fatigue life of the bearings is calculated. Other mechanisms of failure, like wear or microspalling (gray staining), are not taken into account in this standard. This standard applies to tilted single-row radial ball bearings, subjected to radial and axial load and with radial clearance and tilt taken into account. It also applies to tilted single-row roller bearings, subjected to pure radial load and with radial clearance, edge stress and tilt taken into account. References to methods for the analysis of the internal load distribution under general load are given. The analysis of internal load distribution and modified reference rating life for multi-row bearings or bearings of a more complex geometry can be derived from the equations given in this standard. For these bearings, the load distribution for each individual row has to be considered. This standard is primarily intended to be used for computer programs and together with ISO 281 covers the information needed for life calculations. For accurate life calculations and for determining the dynamic equivalent reference load for different loading conditions and under the aforementioned operating conditions, it is recommended that this Technical Specification or advanced computer calculations provided by bearing manufacturers shall be used. With respect to DIN ISO 281, Supplement 4:2003-04, the symbols have been changed, the standard has been slightly technically revised, a reference for the calculation of the life modification factor a_ISO to ISO 281 has been included instead of providing information in the document, a reference regarding information about the contamination factor e_C to ISO 281 has been included instead of providing information in the document, and the normative references have been updated.

Document: references other documents

Responsible national committee

NA 118-01-08 AA - Load ratings and rating life