1、BRITISH STANDARD BS ISO 76:2006 Rolling bearings Static load ratingsICS 21.100.20 BS ISO 76:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2006 BSI 2006 ISBN 0 580 48456 4 National foreword This British Standard reproduces verbat
2、im ISO 76:2006 and implements it as the UK national standard. It supersedes BS 5645:1987 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee MCE/7, Rolling bearings, which has the responsibility to: A list of organizations represented on this committee ca
3、n be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of
4、the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid e
5、nquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This docu
6、ment comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank page, pages 1 to 14, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Da
7、te Comments Reference number ISO 76:2006(E)INTERNATIONAL STANDARD ISO 76 Third edition 2006-05-01 Rolling bearings Static load ratings Roulements Charges statiques de base BS ISO 76:2006ii iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 1
8、4 Symbols . 3 5 Radial ball bearings 4 5.1 Basic static radial load rating 4 5.2 Static equivalent radial load 6 6 Thrust ball bearings 7 6.1 Basic static axial load rating . 7 6.2 Static equivalent axial load 7 7 Radial roller bearings . 7 7.1 Basic static radial load rating 7 7.2 Static equivalent
9、 radial load 8 8 Thrust roller bearings. 9 8.1 Basic static axial load rating . 9 8.2 Static equivalent axial load 9 9 Static safety factor 10 9.1 General. 10 9.2 Ball bearings . 10 9.3 Roller bearings 11 Annex A (informative) Discontinuities in the calculation of basic static load ratings 12 BS ISO
10、 76:2006iv Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject fo
11、r which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on
12、all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees ar
13、e circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held r
14、esponsible for identifying any or all such patent rights. ISO 76 was prepared by Technical Committee ISO/TC 4, Rolling bearings, Subcommittee SC 8, Load ratings and life. This third edition cancels and replaces the second edition (ISO 76:1987), which has been technically revised. It incorporates ISO
15、 76:1987/Amd 1:1999 in Annex A. BS ISO 76:2006v Introduction Permanent deformations appear in rolling elements and raceways of rolling bearings under static loads of moderate magnitude and increase gradually with increasing load. It is often impractical to establish whether the deformations appearin
16、g in a bearing in a specific application are permissible by testing the bearing in that application. Other methods are therefore required to establish the suitability of the bearing selected. Experience shows that a total permanent deformation of 0,000 1 of the rolling element diameter, at the centr
17、e of the most heavily loaded rolling element/raceway contact, can be tolerated in most bearing applications without the subsequent bearing operation being impaired. The basic static load rating is, therefore, given a magnitude such that, approximately, this deformation occurs when the static equival
18、ent load is equal to the load rating. Tests in different countries indicate that a load of the magnitude in question can be considered to correspond to a calculated contact stress of 4 600 MPa 1)for self-aligning ball bearings, 4 200 MPa for all other ball bearings, and 4 000 MPa for all roller bear
19、ings, at the centre of the most heavily loaded rolling element/raceway contact. The equations and factors for the calculation of the basic static load ratings are based on these contact stresses. The permissible static equivalent load could be smaller than, equal to or greater than the basic static
20、load rating, depending on the requirements for smoothness of operation and friction, as well as on actual contact surface geometry. Bearing users without previous experience of these conditions will need to consult the bearing manufacturer. 1) 1 bar = 0,1 MPa = 10 5 Pa; 1 MPa = 1 N/mm 2BS ISO 76:200
21、6blank1 Rolling bearings Static load ratings 1 Scope This International Standard specifies methods of calculating the basic static load rating and the static equivalent load for rolling bearings within the size ranges shown in the relevant ISO standards, manufactured from contemporary, commonly used
22、, high quality, hardened bearing steel in accordance with good manufacturing practice and basically of conventional design as regards the shape of the rolling contact surfaces. Calculations carried out in accordance with this International Standard do not yield satisfactory results for bearings in w
23、hich, because of application conditions and/or internal design, there is a considerable truncation of the area of contact between the rolling elements and the ring raceways. The same limitation applies where application conditions cause deviations from a normal load distribution in the bearing, for
24、example misalignment, preload or extra large clearance or where special surface treatment or coatings are used. Where there is reason to assume that such conditions prevail, the user should consult the bearing manufacturer for recommendations and the evaluation of the static equivalent load. This In
25、ternational Standard is not applicable 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 surface it replaces. Double-row radial bearings and double-direction thrust bearings are, when referred to in
26、this International Standard, presumed to be symmetrical. In addition, guidelines are given for static safety factors to be applied in heavy loaded applications. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, onl
27、y the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 5593, Rolling bearings Vocabulary ISO 15241, Rolling bearings Symbols for quantities ISO/TR 10657:1991, Explanatory notes on ISO 76 3 Terms and definitions For t
28、he purposes of this document, the terms and definitions given in ISO 5593 and the following apply. 3.1 static load load acting on a bearing when the speed of rotation of its rings or washers in relation to each other is zero BS ISO 76:20062 3.2 basic static radial load rating radial load which corre
29、sponds to a calculated contact stress at the centre of the most heavily loaded rolling element/raceway contact of 4 600 MPa for self-aligning ball bearings, 4 200 MPa for all other radial ball bearings types, and 4 000 MPa for all radial roller bearings NOTE 1 In the case of a single-row angular con
30、tact 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. NOTE 2 For these contact stresses, under static load, a total permanent deformation of rolling element and raceway occurs which i
31、s approximately 0,000 1 of the rolling element diameter. 3.3 basic static axial load rating static centric axial load which corresponds to a calculated contact stress at the centre of the most heavily loaded rolling element/raceway contact of 4 200 MPa for thrust ball bearings, and 4 000 MPa for all
32、 thrust roller bearings NOTE For these contact stresses, under static load, a total permanent deformation of rolling element and raceway occurs which is approximately 0,000 1 of the rolling element diameter. 3.4 static equivalent radial load static radial load which would cause the same contact stre
33、ss at the centre of the most heavily loaded rolling element/raceway contact as that which occurs under the actual load conditions 3.5 static equivalent axial load static centric axial load which would cause the same contact stress at the centre of the most heavily loaded rolling element/raceway cont
34、act as that which occurs under the actual load conditions 3.6 static safety factor ratio between the basic static load rating and the static equivalent load, giving a margin of safety against inadmissible permanent deformation on rolling elements and raceways 3.7 roller diameter calculation of load
35、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 small end of the roller. NOTE 2
36、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. 3.8 effective roller length calculation of load ratings theoretical maximum length of contact between a roller and that race
37、way where the contact is shortest BS ISO 76:20063 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. 3.9 nominal contact angle angle be
38、tween 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 determined by the contact with the rible
39、ss raceway. 3.10 pitch diameter of ball set diameter of the circle containing the centres of the balls in one row in a bearing 3.11 pitch diameter of roller set diameter of the circle intersecting the roller axes at the middle of the rollers in one row in a bearing 4 Symbols For the purposes of this
40、 document, the symbols given in ISO 15241 and the following apply. C 0abasic static axial load rating, in newtons C 0rbasic static radial load rating, in newtons D pwpitch diameter of ball or roller set, in millimetres D wnominal ball diameter, in millimetres D weroller diameter applicable in the ca
41、lculation of load ratings, in millimetres F abearing axial load (axial component of actual bearing load), in newtons F rbearing radial load (radial component of actual bearing load), in newtons f 0factor for calculation of basic static load rating i number of rows of rolling elements L weeffective r
42、oller length applicable in the calculation of load ratings, in millimetres P 0astatic equivalent axial load, in newtons P 0rstatic equivalent radial load, in newtons S 0static safety factor X 0static radial load factor Y 0static axial load factor Z number of rolling elements in a single-row bearing;
43、 number of rolling elements per row of a multi-row bearing with the same number of rolling elements per row nominal contact angle, in degrees BS ISO 76:20064 5 Radial ball bearings 5.1 Basic static radial load rating 5.1.1 Basic static radial load rating for single bearings The basic static radial l
44、oad rating for radial ball bearings is given by the equation: C 0r= f 0i Z D w 2cos (1) where the values of f 0are as given in Table 1. The equation applies to bearings with a cross-sectional raceway groove radius not larger than 0,52D win radial and angular contact ball bearing inner rings, and 0,5
45、3D win radial and angular contact ball bearing outer rings and self-aligning ball bearing inner rings. The load-carrying ability of a bearing is not necessarily increased by the use of a smaller groove radius, but is reduced by the use of a groove radius larger than those indicated in the previous p
46、aragraph. In the latter case, a correspondingly reduced value of f 0shall be used. Calculation of this reduced value of f 0may be carried out by means of Equation (3-18) given in ISO/TR 10657:1991. 5.1.2 Basic static radial load rating for bearing combinations 5.1.2.1 Two single-row radial contact b
47、all bearings operation as a unit The basic static radial load rating for two similar single-row radial contact ball bearings mounted side by side on the same shaft, such that they operate as a unit (paired mounting), is twice the basic static radial load rating of one single-row bearing. 5.1.2.2 Bac
48、k-to-back and face-to-face arrangements of single-row angular contact ball bearings The basic static radial load rating for two similar single-row angular contact ball bearings mounted side by side on the same shaft, such that they operate as a unit (paired mounting) in a back-to-back or face-to-fac
49、e arrangement, is twice the basic static radial load rating of one single-row bearing. 5.1.2.3 Tandem arrangement The basic static radial load rating for two or more similar single-row radial contact ball bearings or two or more similar single-row angular contact ball bearings mounted side by side on the same shaft, such that they operate as a unit (paired or stack mounting) in a tandem arrangement, is the number of bearings multiplied by the basic static radial
