1、October 2010 Translation by DIN-Sprachendienst.English price group 22No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).IC
2、S 21.100.20!$kV“1725190www.din.deDDIN ISO 281Rolling bearings Dynamic load ratings and rating life (ISO 281:2007)English translation of DIN ISO 281:2010-10Wlzlager Dynamische Tragzahlen und nominelle Lebensdauer (ISO 281:2007)Englische bersetzung von DIN ISO 281:2010-10Roulements Charges dynamiques
3、de base et dure nominale (ISO 281:2007)Traduction anglaise de DIN ISO 281:2010-10SupersedesDIN ISO 281:1993-01, withdrawn2009-01,DIN ISO 281:2009-01,DIN ISO 281/A1:2001-09,withdrawn 2009-01,DIN ISO 281/A2:2001-09,withdrawn 2009-01www.beuth.deDocument comprises pagesIn case of doubt, the German-langu
4、age original shall be considered authoritative.5610.10 DIN ISO 281:2010-10 2 A comma is used as the decimal marker. Contents Page National foreword .3 National Annex NA (informative) Bibliography.4 Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions7 4 Symbols 9 5 Radial ball
5、bearings .11 5.1 Basic dynamic radial load rating11 5.2 Dynamic equivalent radial load 14 5.3 Basic rating life 15 6 Thrust ball bearings.15 6.1 Basic dynamic axial load rating .15 6.2 Dynamic equivalent axial load17 6.3 Basic rating life 18 7 Radial roller bearings 18 7.1 Basic dynamic radial load
6、rating18 7.2 Dynamic equivalent radial load 20 7.3 Basic rating life 21 8 Thrust roller bearings21 8.1 Basic dynamic axial load rating .21 8.2 Dynamic equivalent axial load24 8.3 Basic rating life 24 9 Modified rating life.25 9.1 General25 9.2 Life modification factor for reliability.25 9.3 Life mod
7、ification factor for systems approach.26 Annex A (informative) Detailed method for estimating the contamination factor 37 Annex B (informative) Calculation of the fatigue load limit 47 Annex C (informative) Discontinuities in the calculation of basic dynamic load ratings 52 Bibliography 56 DIN ISO 2
8、81:2010-10 3 National foreword This standard has been prepared by Technical Committee ISO/TC 4 “Rolling bearings”, Subcommittee SC 8 “Load ratings and life” (Secretariat: DIN, Germany). The responsible German body involved in its preparation was the Normenausschuss Wlz- und Gleitlager (Rolling Beari
9、ngs and Plain Bearings Standards Committee), Working Committee NA 118-01-08 AA Trag-zahlen und Lebensdauer. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 76 DIN ISO 76 ISO 5593 DIN ISO 5593 ISO/TR 8646 DIN SPEC 1281-1 ISO/TS 16281 DIN
10、 26281 Amendments This standard differs from DIN ISO 281:1993-01, DIN ISO 281/A1:2001-09 and DIN ISO 281/A2:2001-09 as follows: a) DIN ISO 281/A1, DIN ISO 281/A2, DIN ISO 281 Supplement 1, ISO/TS 16799 and parts of DIN ISO 281 Supplement 4 have been incorporated in this standard; b) the standard has
11、 been editorially revised. Compared with DIN ISO 281:2009-01, the following corrections have been made to the German translation only and therefore do not affect the English text: c) in Subclause 5.1.2.3 “Tandem arrangement”, it shall read: “Anzahl Lager hoch 0,7 multipliziert mit der Tragzahl eines
12、 einreihigen Lagers” (instead of “Anzahl der Lager multipliziert mit der 0,7fachen Tragzahl eines einreihigen Lagers”); d) in Subclause 7.1.2.3 “Tandem arrangement”, it shall read: “Anzahl Lager hoch 0,7 multipliziert mit der Tragzahl eines einreihigen Lagers” (instead of “Anzahl der Lager multipliz
13、iert mit der (7/9)-Potenz der Tragzahl eines einreihigen Lagers”). Previous editions DIN 622-1: 1942-08 DIN 622-2: 1963-04, 1973-03 DIN 622-3: 1962-04 DIN ISO 281: 1993-01 DIN ISO 281/A1: 2001-09 DIN ISO 281/A2: 2001-09 DIN ISO 281-1: 1979-02 DIN ISO 281: 2009-01 DIN ISO 281:2010-10 4 National Annex
14、 NA (informative) Bibliography DIN 51819-1, Testing of lubricants Mechanical-dynamic testing in the roller bearing test apparatus FE8 Part 1: General working principles DIN ISO 76, Rolling bearings Static load ratings DIN ISO 5593, Rolling bearings Vocabulary DIN SPEC 1281-1, Rolling bearings Explan
15、atory notes on ISO 281 Part 1: Basic dynamic load rating and basic rating life DIN 26281, Rolling bearings Methods for calculating the modified reference rating life for universally loaded bearings Introduction It is often impractical to establish the suitability of a bearing selected for a specific
16、 application by testing a sufficient number of bearings in that application. However, life, as defined in 3.1, is a primary representation of the suitability. A reliable life calculation is therefore considered to be an appropriate and convenient substitute for testing. The purpose of this Internati
17、onal Standard is to provide the required basis for life calculation. Since ISO 281 was published 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 ma
18、terial, etc. In ISO 281:1990/Amd. 2:2000, a general method was presented to consider such influences in the calculation of a modified rating life of a bearing. This amendment is incorporated in this International Standard, which also provides a practical method to consider the influence on bearing l
19、ife of lubrication condition, contaminated lubricant and fatigue load of bearing material. ISO/TS 162811introduced advanced calculation methods which enable the user to take into account the influence on bearing life of bearing-operating clearance and misalignment under general loading conditions. T
20、he user can also consult the bearing manufacturer for recommendations and evaluation of equivalent load and life for these operation conditions and other influences as, for example, rolling element centrifugal forces or other high-speed effects. Calculations according to this International Standard
21、do not yield satisfactory results for bearings subjected to such application conditions and/or of such internal design which result in considerable truncation of the area of contact between the rolling elements and the ring raceways. Unmodified calculation results are thus not applicable, for exampl
22、e, to ball bearings with filling slots that project substantially into the ball/raceway contact area when the bearing is subjected to axial loading in the application. Bearing manufacturers should be consulted in such cases. The life modification factors for reliability, a1, have been slightly chang
23、ed and extended to 99,95 % reliability.Revisions of this document will be required from time to time, as the result of new developments or in the light of new information concerning specific bearing types and materials. Background information regarding the derivation of equations and factors in this
24、 document is given in ISO/TR 86461)and ISO/TR 1281-22. 1) Under revision. Will be published under the reference ISO/TR 1281-1. Rolling bearings Dynamic load ratings and rating life DIN ISO 281:2010-10 5 1 Scope This International Standard specifies methods of calculating the basic dynamic load ratin
25、g of rolling bearings within the size ranges shown in the relevant ISO publications, manufactured from contemporary, commonly used, high quality hardened bearing steel, in accordance with good manufacturing practice and basically of conventional design as regards the shape of rolling contact surface
26、s. This document also specifies methods of calculating the basic rating life, which is the life associated with 90 % reliability, with commonly used high quality material, good manufacturing quality and with conventional operating conditions. In addition, it specifies methods of calculating the modi
27、fied rating life, in which various reliabilities, lubrication condition, contaminated lubricant and fatigue load of the bearing are taken into account. This International Standard does not cover the influence of wear, corrosion and electrical erosion on bearing life. This document is not applicable
28、to designs where the rolling elements operate directly on a shaft or housing surface, unless that surface is equivalent in all respects to the bearing ring (or washer) raceway it replaces. Double-row radial bearings and double-direction thrust bearings are, when referred to in this document, presume
29、d to be symmetrical. Further limitations concerning particular types of bearings are included in the relevant clauses. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated r
30、eferences, the latest edition of the referenced document (including any amendments) applies. ISO 76, Rolling bearings Static load ratings ISO 5593, Rolling bearings Vocabulary ISO/TR 8646:1985, Explanatory notes on ISO 281/1-19772)ISO 15241, Rolling bearings Symbols for quantities 2) Under revision.
31、 Will be published under the reference ISO/TR 1281-1. DIN ISO 281:2010-10 6 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 5593 and the following apply. 3.1 life of an individual rolling bearing number of revolutions which one of the bearing rings o
32、r washers makes in relation to the other ring or washer before the first evidence of fatigue develops in the material of one of the rings or washers or one of the rolling elements NOTE Life may also be expressed in number of hours of operation at a given constant speed of rotation. 3.2 reliability i
33、n the context of bearing life for a group of apparently identical rolling bearings, operating under the same conditions, the percentage of the group that is expected to attain or exceed a specified life NOTE The reliability of an individual rolling bearing is the probability that the bearing will at
34、tain or exceed a specified life. 3.3 rating life predicted value of life based on a basic dynamic radial load rating or a basic dynamic axial load rating 3.4 basic rating life rating life associated with 90 % reliability for bearings manufactured with commonly used high quality material, of good man
35、ufacturing quality, and operating under conventional operating conditions 3.5 modified rating life rating life modified for 90 % or other reliability, bearing fatigue load, and/or special bearing properties, and/or contaminated lubricant, and/or other non-conventional operating conditions NOTE The t
36、erm “modified rating life” is new in this document and replaces “adjusted rating life”. 3.6 basic dynamic radial load rating constant stationary radial load which a rolling bearing can theoretically endure for a basic rating life of one million revolutions NOTE In the case of a single-row angular co
37、ntact bearing, the radial load rating refers to the radial component of that load which causes a purely radial displacement of the bearing rings in relation to each other. 3.7 basic dynamic axial load rating constant centric axial load which a rolling bearing can theoretically endure for a basic rat
38、ing life of one million revolutions 3.8 dynamic equivalent radial load constant stationary radial load under the influence of which a rolling bearing would have the same life as it would attain under the actual load conditions 3.9 dynamic equivalent axial load constant centric axial load under the i
39、nfluence of which a rolling bearing would have the same life as it would attain under the actual load conditions DIN ISO 281:2010-10 7 3.10 fatigue load limit bearing load under which the fatigue stress limit, u, is just reached in the most heavily loaded raceway contact 3.11 roller diameter applica
40、ble in the calculation of load ratings theoretical diameter in a radial plane through the middle of the roller length for a symmetrical roller NOTE 1 For a tapered roller, the applicable diameter is equal to the mean value of the diameters at the imaginary sharp corners at the large end and at the s
41、mall end of the roller. NOTE 2 For an asymmetrical convex roller, the applicable diameter is an approximation of the diameter at the point of contact between the roller and the ribless raceway at zero load. 3.12 effective roller length applicable in the calculation of load ratings theoretical maximu
42、m length of contact between a roller and that raceway where the contact is shortest NOTE This is normally taken to be either the distance between the theoretically sharp corners of the roller minus the roller chamfers or the raceway width, excluding the grinding undercuts, whichever is the smaller.
43、3.13 nominal contact angle angle between a plane perpendicular to a bearing axis (a radial plane) and the nominal line of action of the resultant of the forces transmitted by a bearing ring or washer to a rolling element NOTE For bearings with asymmetrical rollers, the nominal contact angle is deter
44、mined by the contact with the non-ribbed raceway. 3.14 pitch diameter of ball set diameter of the circle containing the centres of the balls in one row in a bearing 3.15 pitch diameter of roller set diameter of the circle intersecting the roller axes at the middle of the rollers in one row in a bear
45、ing 3.16 conventional operating conditions conditions which may be assumed to prevail for a bearing which is properly mounted and protected from foreign matter, adequately lubricated, conventionally loaded, not exposed to extreme temperature and not run at exceptionally low or high speed 3.17 viscos
46、ity ratio actual kinematic oil viscosity at operating temperature divided by the reference kinematic viscosity for adequate lubrication 3.18 film parameter ratio of lubricant film thickness to composite r.m.s. surface roughness, used to estimate the influence of lubrication on bearing life 3.19 pres
47、sure-viscosity coefficient parameter characterizing the influence of oil pressure on the oil viscosity in the rolling element contact DIN ISO 281:2010-10 8 3.20 viscosity index index characterizing the degree of influence of temperature on the viscosity of lubricating oils 4 Symbols For the purposes
48、 of this document, the symbols given in ISO 15241 and the following apply. aISOlife modification factor, based on a systems approach of life calculation a1life modification factor for reliability bmrating factor for contemporary, commonly used, high quality hardened bearing steel in accordance with
49、good manufacturing practices, the value of which varies with bearing type and design Cabasic dynamic axial load rating, in newtons Crbasic dynamic radial load rating, in newtons Cufatigue load limit, in newtons C0abasic static axial load rating3), in newtons C0rbasic static radial load rating3), in newtons D bearing outside diameter, in millimetres Dpwpitch diameter of ball or roller set, in millimetres Dwnominal ball diameter, in millimetres Dweroller diameter applicable in the calculation of load ratings, in millimetres d bearing bore diameter, i
