1、January 2009DEUTSCHE NORM English price group 11No part of this standard 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).ICS 21.100.20!$ULD“1504133
2、www.din.deDDIN ISO 76Rolling bearings Static load ratings (ISO 76:2006)English version of DIN ISO 76:2009-01Wlzlager Statische Tragzahlen (ISO 76:2006)Englische Fassung DIN ISO 76:2009-01SupersedesDIN ISO 76:1988-10www.beuth.deDocument comprises 18 pages2 Contents Page National foreword 3 National A
3、nnex NA (informative) Bibliography .3 Introduction.4 1 Scope .5 2 Normative references 5 3 Terms and definitions .5 4 Symbols 7 5 Radial ball bearings.8 5.1 Basic static radial load rating.8 5.2 Static equivalent radial load 10 6 Thrust ball bearings . 11 6.1 Basic static axial load rating . 11 6.2
4、Static equivalent axial load 11 7 Radial roller bearings . 11 7.1 Basic static radial load rating 11 7.2 Static equivalent radial load 12 8 Thrust roller bearings. 13 8.1 Basic static axial load rating . 13 8.2 Static equivalent axial load 13 9 Static safety factor 14 9.1 General. 14 9.2 Ball bearin
5、gs . 14 9.3 Roller bearings 15 Annex A (informative) Discontinuities in the calculation of basic static load ratings 16 DIN ISO 76:2009-01 3 National foreword This standard has been prepared by Technical Committee ISO/TC 4 “Rolling bearings”, Subcommittee SC 8 “Load ratings and life” (Secretariat: D
6、IN, Germany). The responsible German body involved in its preparation was the Normenausschuss Wlz- und Gleitlager (Rolling Bearings and Plain Bearings Standards Committee), Technical Committee NA 118-01-08 AA Trag-zahlen und Lebensdauer. The DIN Standards corresponding to the International Standards
7、 referred to in this document are as follows: ISO 5593 DIN ISO 5593 ISO/TR 10657 DIN ISO 76 Supplement 1 Amendments This standard differs from DIN ISO 76:1988-10 as follows: a) The text of ISO 76/AMD 1 has been incorporated in Annex A of this standard. b) The standard has been editorially revised. P
8、revious editions DIN 622-1: 1942-08 DIN 622-2: 1963-04, 1973-03 DIN 622-3: 1962-04 DIN ISO 76: 1979-02, 1988-10 National Annex NA (informative) Bibliography DIN ISO 5593, Rolling bearings Vocabulary DIN ISO 76 Supplement 1, Rolling bearings Static load ratings Explanatory notes to ISO 76 DIN ISO 76:
9、2009-01 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 appearing in a bearing in a specific application
10、 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 centre of the most heavily loaded rolling ele
11、ment/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 equivalent load is equal to the load rating. Te
12、sts 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 MPa1)for self-aligning ball bearings, 4 200 MPa for all other ball bearings, and 4 000 MPa for all roller bearings, at the centre of the most heavily l
13、oaded 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 load rating, depending on the requirement
14、s 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 = 105 Pa; 1 MPa = 1 N/mm2Rolling bearings Static load ratings 4 DIN ISO 76:2009-0
15、1 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, high quality, hardened bearing steel in a
16、ccordance 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 which, because of application conditions and
17、/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 example misalignment, preload or extra larg
18、e 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 International Standard is not applicable to d
19、esigns 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 this International Standard, presumed to be
20、 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, only the edition cited applies. For undated re
21、ferences, 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 the purposes of this document, the terms and
22、 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 5 DIN ISO 76:2009-01 3.2 basic static radial load rating radial load which corresponds to a calculated contact stress
23、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 contact bearing, the radial load rating r
24、efers 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 is approximately 0,000 1 of the rolling
25、 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 thrust roller bearings NOTE For these
26、 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 stress at the centre of the most heavily l
27、oaded 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 contact as that which occurs under the act
28、ual 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 ratings theoretical diameter in a radi
29、al 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 For an asymmetrical convex roller, the
30、 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 raceway where the contact is shortest 6 DI
31、N ISO 76:2009-01 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 between a plane perpendicular to a
32、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 ribless raceway. 3.10 pitch diameter o
33、f 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 document, the symbols given in I
34、SO 15241 and the following apply. C0abasic static axial load rating, in newtons C0rbasic static radial load rating, in newtons Dpwpitch diameter of ball or roller set, in millimetres Dwnominal ball diameter, in millimetres Dweroller diameter applicable in the calculation of load ratings, in millimet
35、res Fabearing axial load (axial component of actual bearing load), in newtons Frbearing radial load (radial component of actual bearing load), in newtons f0factor for calculation of basic static load rating i number of rows of rolling elements Lweeffective roller length applicable in the calculation
36、 of load ratings, in millimetres P0astatic equivalent axial load, in newtons P0rstatic equivalent radial load, in newtons S0static safety factor X0static radial load factor Y0static axial load factor Z number of rolling elements in a single-row bearing; number of rolling elements per row of a multi-
37、row bearing with the same number of rolling elements per row nominal contact angle, in degrees 7 DIN ISO 76:2009-01 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 load rating for radial ball bearings is giv
38、en by the equation: C0r= f0i Z Dw2cos (1) where the values of f0are as given in Table 1. The equation applies to bearings with a cross-sectional raceway groove radius not larger than 0,52Dwin radial and angular contact ball bearing inner rings, and 0,53Dwin radial and angular contact ball bearing ou
39、ter 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 paragraph. In the latter case, a correspondingly r
40、educed value of f0shall be used. Calculation of this reduced value of f0may 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 ball bearings operation as a unit The basic static r
41、adial 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 Back-to-back and face-to-face arrangements of single-r
42、ow 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-face arrangement, is twice the basic static radial loa
43、d 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
44、(paired or stack mounting) in a tandem arrangement, is the number of bearings multiplied by the basic static radial load rating of one single-row bearing. The bearings need to be properly manufactured and mounted for equal distribution of the load between them. 8 DIN ISO 76:2009-01 Table 1 Values of
45、 factor f0for ball bearings Factor f0Radial ball bearings wpwcosDDradial and angular contact self-aligning Thrust ball bearings 0 0,01 0,02 0,03 0,04 0,05 0,06 0,07 0,08 0,09 0,1 0,11 0,12 0,13 0,14 0,15 0,16 0,17 0,18 0,19 0,2 0,21 0,22 0,23 0,24 0,25 0,26 0,27 0,28 0,29 0,3 0,31 0,32 0,33 0,34 0,3
46、5 0,36 0,37 0,38 0,39 0,4 14,7 14,9 15,1 15,3 15,5 15,7 15,9 16,1 16,3 16,5 16,4 16,1 15,9 15,6 15,4 15,2 14,9 14,7 14,4 14,2 14 13,7 13,5 13,2 13 12,8 12,5 12,3 12,1 11,8 11,6 11,4 11,2 10,9 10,7 10,5 10,3 10 9,8 9,6 9,4 1,9 2 2 2,1 2,1 2,1 2,2 2,2 2,3 2,3 2,4 2,4 2,4 2,5 2,5 2,6 2,6 2,7 2,7 2,8 2,
47、8 2,8 2,9 2,9 3 3 3,1 3,1 3,2 3,2 3,3 3,3 3,4 3,4 3,5 3,5 3,6 3,6 3,7 3,8 3,8 61,6 60,8 59,9 59,1 58,3 57,5 56,7 55,9 55,1 54,3 53,5 52,7 51,9 51,2 50,4 49,6 48,8 48 47,3 46,5 45,7 45 44,2 43,5 42,7 41,9 41,2 40,5 39,7 39 38,2 37,5 36,8 36 35,3 34,6 NOTE This table is based on the Hertzian point con
48、tact equation with a modulus of elasticity of 2,07 105MPa and a Poissons ratio of 0,3. It is assumed that the load distribution results in a maximum ball load of r5cosFZ for radial ball bearings and a maximum ball load of asinFZ for thrust ball bearings. Values of f0for intermediate values of wpwcos
49、DDcan be obtained by linear interpolation. 9 DIN ISO 76:2009-01 5.2 Static equivalent radial load 5.2.1 Static equivalent radial load for single bearings The static equivalent radial load for radial ball bearings is the greater of the two values given by the equations: 0r 0 r 0 aPXFYF=+ (2) 0r rPF= (3) where the values of factors X0and Y0are as given in Table 2. These factors apply to bearings with cross-sectional groove radii according to 5.1.1. For other groove radii, calculation of X0and Y0may be carried out by means of ISO/TR 10
