1、BRITISH STANDARDBS EN 1337-7:2004Structural bearings Part 7: Spherical and cylindrical PTFE bearingsThe European Standard EN 1337-7:2004 has the status of a British StandardICS 91.010.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g5
2、5g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 1337-7:2004This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 December 2006 BSI 2006ISBN 0 580 49852 2National forewordThis British Standard was publi
3、shed by BSI. It is the UK implementation of EN 1337-7:2004. It supersedes BS EN 1337-7:2001 which is withdrawn. It partially supersedes BS 5400-9-1:1983 and BS 5400-9-2:1983 which will remain current until the remaining parts of the BS EN 1337 series have been published, the last part being Part 8.
4、The UK participation in its preparation was entrusted to Technical Committee B/522, Structural bearings.A list of organizations represented on B/522 can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsi
5、ble for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 1337-7March 2004ICS 91.010.30 Supersedes EN 1337-7:2000English versionStructural
6、 bearings - Part 7: Spherical and cylindrical PTFEbearingsAppareils dappui structuraux - Partie 7: Appareils dappuicylindriques sphriques comportant du PTFELager im Bauwesen - Teil 7: Kalotten- und Zylinderlager mitPTFEThis European Standard was approved by CEN on 2 January 2004.CEN members are boun
7、d to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Cent
8、ral Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as th
9、e officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,Slovenia, Spain, Sw
10、eden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2004 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Re
11、f. No. EN 1337-7:2004: EEN 1337-7:2004 (E)2ContentspageForeword3Introduction .41 Scope 52 Normative references 53 Terms and definitions, symbols and abbreviations.54 Requirements .95 Material properties.96 Design requirements .97 Manufacturing, assembly and tolerances .128 Conformity evaluation .12A
12、nnex A (informative) Method for calculating the eccentricities in spherical and cylindrical PTFEbearings 13Annex B (informative) Reduced area for curved sliding surfaces .15Annex ZA (informative) Provisions for the CE marking of cylindrical and spherical PTFE bearings (withor without flat sliding el
13、ements) under the EU Construction Products Directive.18EN 1337-7:2004 (E)3ForewordThis document (EN 1337-7:2004) has been prepared by Technical Committee CEN /TC 167, “Structural bearings“,the secretariat of which is held by UNI.This European Standard shall be given the status of a national standard
14、, either by publication of an identical text orby endorsement, at the latest by September 2004, and conflicting national standards shall be withdrawn at thelatest by September 2004.This document has been prepared under a mandate given to CEN by the European Commission and the EuropeanFree Trade Asso
15、ciation, and supports essential requirements of EU Directive(s).For relationship with EU Directive(s), see informative annex ZA, which is an integral part of this document.Annexes A and B are informative.This document supersedes EN 1337-7:2000.This European Standard EN 1337 “Structural bearings”, co
16、nsists of the following 11 Parts:Part 1: General design rulesPart 2: Sliding elementsPart 3: Elastomeric bearingsPart 4: Roller bearingsPart 5: Pot bearingsPart 6: Rocker bearingsPart 7: Spherical and cylindrical PTFE bearingsPart 8: Guide bearings and restrain bearingsPart 9: ProtectionPart 10: Ins
17、pection and maintenancePart 11: Transport, storage and installationAccording to the CEN/CENELEC Internal Regulations, the national standards organizations of the followingcountries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark,Estonia, Finland, Fran
18、ce, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EN 1337-7:2004 (E)4IntroductionThis standard considers a minimum operating temperature of 35C.An extens
19、ion down to 40C will be considered in a future amendment.Applications beyond the range of temperature given in clause 1 need special consideration not covered by thisstandard. Characteristics, requirements and test procedures given in this standard do not apply in such cases.EN 1337-7:2004 (E)51 Sco
20、peThis European Standard deals with the requirements for the design and manufacture of spherical and cylindricalPTFE bearings. The requirements and properties of the curved sliding surfaces are included in EN 1337-2.Spherical and cylindrical bearings with an included angle 2 q 60 and 2 q 75 respecti
21、vely are beyond thescope of this European Standard. (see Figure 6).For the purpose of controlling the degree of freedom the bearings may be combined with flat sliding elements andguides according to EN 1337-2:2004 and restraining rings as per 6.3.4.Cylindrical bearings are susceptible to unexpected
22、moments about the transverse axis of the cylindrical surface.Additional limitation of application to be taken into consideration is given in clause 1 of EN 1337-2:2004.2 Normative referencesThis European Standard incorporates, by dated or undated reference, provisions from other publications. Thesen
23、ormative references are cited at the appropriate places in the text and the publications are listed hereafter. Fordated references, subsequent amendments to or revisions of any of these publications apply to this EuropeanStandard only when incorporated in it by amendment or revision. For undated ref
24、erences the latest edition of thepublication referred to applies (including amendments).EN 1337-1:2000, Structural bearings - Part 1: General design rulesEN 13372:2004, Structural bearings - Part 2: Sliding elementsprEN 13375:1996, Structural bearings - Part 5: Pot bearings3 Terms and definitions, s
25、ymbols and abbreviations3.1 Terms and definitionsFor the purposes of this European Standard, the following terms and definitions apply.3.1.1backing platemetallic component which supports sliding materials3.1.2cylindrical PTFE bearingbearing consisting of a backing plate with a convex cylindrical sur
26、face (rotational element) and a backing plate witha concave cylindrical surface between which a PTFE sheet and the mating material form a curved sliding surface(see Figure 1). Cylindrical PTFE bearings are also used in combination with flat sliding elements and guides to formfree or guided bearings
27、(see Figure 2)NOTE Numbers in brackets in Figures 1 and 2 refer to the examples shown in Figure 1 of EN 1337-1:2000.EN 1337-7:2004 (E)6Keya) Fixed by end stops and sliding surface (7.1)b) Without end stops for displacements in y direction (7.2)Figure 1 Cylindrical PTFE bearingsKeya) Free for displac
28、ements in any direction (7.4)b) Guided by an internal guide for displacements in x direction (7.3)c) Guided by external guides for displacements in x directionFigure 2 Cylindrical PTFE bearings combined with flat sliding elements3.1.3guidesliding element which restrains a sliding bearing from moving
29、 in one axis3.1.4lubricantspecial grease used to reduce the friction and wear in the sliding surfaces3.1.5mating surfacehard smooth metallic surface against which the PTFE slides3.1.6polytetrafluoroethylene (PTFE)thermoplastic material used for its low coefficient of frictionEN 1337-7:2004 (E)73.1.7
30、sliding materialsmaterials which form sliding surfaces3.1.8sliding surfacecombination of a pair of flat or curved surfaces of different materials which allow relative displacements3.1.9spherical PTFE bearingbearing consisting of a backing plate with a convex spherical surface (rotational element) an
31、d a backing plate witha concave spherical surface between which a PTFE sheet and the mating material form a curved sliding surface(see Figure 3)Spherical PTFE bearings are also used in combination with flat sliding elements and guides to form free andguided bearings (see Figures 4 a) to 4 c). Spheri
32、cal PTFE bearings combined with a flat sliding element can beused together with a restraining ring to form fixed bearings (see Figure 4 d)NOTE 1 Numbers in brackets in Figures 3 and 4 refer to the examples shown in Figure 1 of EN 1337-1:2000.NOTE 2 Fixed by sliding surface (3.2).Figure 3 Spherical P
33、TFE bearingKeya) Free for displacements in any direction (3.5)b) Guided by an internal guide for displacements in one direction (3.4)c) Guided by external guides for displacements in one direction (3.3)d) Fixed by a restraining ring (3.1)Figure 4 Spherical PTFE bearings combined with flat sliding el
34、ementsEN 1337-7:2004 (E)83.2 SymbolsThe most frequently occurring symbols are defined below. Those that are local, and unique to a particular clause,are defined at their first appearance.3.2.1 Latin upper case lettersA contact area of sliding surface; projected area of the curved sliding surface mm2
35、L diameter or diagonal of the projected area of the PTFE sheet .mmFigure 5 Plan dimensions of spherical and cylindrical bearingsN axial or normal force N; kNV lateral or shear force . N; kN3.2.2 Latin lower case lettersa minor side of the projection in plan of cylindrical PTFE surfaces mmb major sid
36、e of the projection in plan of cyclindrical PTFE surfaces;distance from the projected area of the curved sliding surface mmc dimension mmd diameter . mme eccentricity . mmf nominal compressive strength . N/mm2h protrusion of PTFE sheet from its recess . mmr radius of curvature mmt thickness mmx long
37、itudinal axisy transverse axisz axis normal to the principal bearing surface3.2.3 Greek lettersa rotation angle. radiansEN 1337-7:2004 (E)9b deviation angle from vertical axis of the line of action of theapplied load. degrees, radiansD z maximum deviation of plane or curved sliding surfaces fromtheo
38、retical surface mmq half included angle of PTFE curved surfaces . degrees, radiansl ratio, coefficientm coefficient of frictions normal pressure . N/mm23.2.4 Subscriptsb backing plated design valuemin minimumpPTFES internal forces and moments from actionsttotal3.3 AbbreviationsPTFE Polytetrafluoroet
39、hyleneNDP Nationally Determined Parameters4 Requirements4.1 GeneralCylindrical PTFE bearings shall permit rotational movements about one axis, spherical PTFE bearings about anyaxis. They shall be capable of transferring specified forces between superstructure and substructure.4.2 Requirements for lo
40、ad bearing capacityThe curved PTFE sheet shall meet the requirements given in 6.2.1 to 6.2.3 and the backing plate with concavesurface those given in 6.3.3.4.3 Requirements for rotation capabilityThe sliding surfaces shall meet the requirements given in 6.2.4 and clause 4 of EN 1337-2:2004.5 Materia
41、l propertiesThe materials to be used and the properties to be verified shall be in accordance with clause 5 of EN 1337-2:2004.6 Design requirementsNOTE This clause gives requirements for the design of components which are specific to spherical and cylindrical bearingsand which are in addition to tho
42、se given in clause 6 of EN 1337-2:2004.EN 1337-7:2004 (E)106.1 Design principlesFor design calculations the principles given in clause 5 of EN 1337-1:2000 shall be taken into account.NOTE The design values of internal forces and moments as well as of movements should be available from a bearingsched
43、ule as shown in annex B of EN 1337-1:2000.6.2 Design verification for curved sliding surfaces6.2.1 GeneralFor the purpose of verifications as per 6.2.2 and 6.2.3 the curved sliding surface shall be replaced by its projectionon a plane surface as shown in Figure 6.Key1 Projected areaFigure 6 Verifica
44、tion scheme for the curved sliding surface (example)Internal forces and moments acting on the curved sliding surface due to frictional resistance, externally appliedhorizontal loads and the rotated condition of the bearing shall be taken into account when determining the resultingtotal eccentricity
45、et of the axial force NS.Secondary effects due to the action of the restraints shall also be considered.NOTE In annex A of this standard, formulae are given for the evaluation of the eccentricities in the most common cases.The frictional resistance shall be determined using the coefficients of frict
46、ion given in Table 11 of EN 1337-2:2004.6.2.2 Separation of sliding surfacesNOTE Separation of the sliding surfaces may lead to wear due to contamination and increased deformation due to lack ofconfinement. As this could endanger long term fitness for use, the condition sp= 0 is considered as servic
47、eability limit state.It shall be verified that sp 0 under the characteristic combination of actions. In doing so the sliding material shallbe assumed to be linear elastic and the backing plates shall be deemed to be rigid. The condition sp 0 is satisfiedwhen the total eccentricity etfalls within the
48、 kernel of the projected area.For spherical bearings this condition is satisfied when:EN 1337-7:2004 (E)11Dimension L is shown in Figure 5.6.2.3 Compressive stress verificationNOTE 1 Excessive pressure may cause loss of the sliding function and this may lead to structural failure or states close tos
49、tructural failure. Therefore this condition is considered as ultimate limit state.The following conditions shall be verified under a fundamental combination of actions:whereNSdis the design axial force at ultimate limit statefk characteristic value of compressive strength for PTFE sheets (see Table 10 of EN 1337-2:2004)Aris the reduced contact area of the curved sliding surfaceNOTE 2 The g m value should be given in NDP. Recommended value is g m = 1,4 (see clause 6.8.3 of EN 1337-2:2004).The reduced area Aris given by the formula:Ar= l AwhereA is the are
