1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 3548-3:2012Plain bearings Thin-walledhalf bearings with or withoutflangePart 3: Measurement of peripheral lengthBS ISO 3548-3:2012 BRITISH STANDARDNational forewordThis Br
2、itish Standard is the UK implementation of ISO 3548-3:2012.The UK participation in its preparation was entrusted to TechnicalCommittee MCE/12, Plain bearings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include
3、all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 74534 8ICS 21.100.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This British S
4、tandard was published under the authority of theStandards Policy and Strategy Committee on 31 December 2012.Amendments issued since publicationDate Text affectedBS ISO 3548-3:2012 ISO 2012Plain bearings Thin-walled half bearings with or without flange Part 3: Measurement of peripheral lengthPaliers
5、lisses Demi-coussinets minces collerette ou sans collerette Partie 3: Mesurage de la longueur dveloppeINTERNATIONAL STANDARDISO3548-3First edition2012-12-01Reference numberISO 3548-3:2012(E)BS ISO 3548-3:2012ISO 3548-3:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All ri
6、ghts reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of t
7、he requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 3548-3:2012ISO 3548-3:2012(E) ISO 2012 All rights reserved iiiContents PageForeword v1 Scope . 12 Normative references 13
8、Terms and definitions . 14 Symbols 25 Purpose of checking 36 Checking methods . 46.1 Method A 46.2 Method B 47 Choice and designation of checking method . 57.1 Choice of checking method . 57.2 Designation of checking method . 68 Measuring equipment . 69 Measuring equipment requirements 89.1 General
9、. 89.2 Tolerance on checking load setting . 89.3 Speed of approach of measuring head . 99.4 Construction of measuring head . 99.5 Accuracy of the measuring plane for metering bars 99.6 Accuracy of the dial gauge . 910 Gauging tools for establishing the datum . 910.1 General . 910.2 Master checking b
10、lock (used alone) 1010.3 Series checking block used alone . 1010.4 Series checking block with master shell 1011 Checking block requirements 1011.1 General 1011.2 Reference tooling: master checking block General .1111.3 Series gauging tools . 1312 Master shell and comparison shell requirements 1512.1
11、 Master shell requirements . 1512.2 Comparison shell requirements 1713 Correction factors .1813.1 Reference tooling: master checking block correction factor, Fcor,cbm1813.2 Series control tooling . 1813.3 Marking 1913.4 Reference setting 1914 Typical checking procedure.1915 Conditions of the half be
12、arings to be checked 2016 Measuring errors 2016.1 Errors due to measuring equipment . 2016.2 Errors due to the checking block 2016.3 Errors due to the correction factor . 2116.4 Errors due to the half bearing . 2116.5 Error due to the choice of checking method 2117 Accuracy of methods used .2117.1 C
13、hecking conditions 21BS ISO 3548-3:2012ISO 3548-3:2012(E)iv ISO 2012 All rights reserved17.2 Limits 2117.3 Calculation . 2118 Specifications on bearing drawings .2119 Specifications for the control of the checking means .21Annex A (normative) Determination of the correction factor of the master chec
14、king block Method A 23Annex B (normative) Determination of the correction factor of the master checking block Method B 27Annex C (normative) Determination of the correction factor of the series checking block used alone .31Annex D (normative) Determination of the correction factor of the master shel
15、l or comparison shell .33Annex E (normative) Tests and calculation of repeatability, reproducibility and comparability .35BS ISO 3548-3:2012ISO 3548-3:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). T
16、he work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-go
17、vernmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.T
18、he main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vot
19、e.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 responsible for identifying any or all such patent rights.ISO 3548-3 was prepared by Technical Committee ISO/TC 123, Plain Bearings, Subcommittee SC 5, Qualit
20、y analysis and assurance.This first edition of ISO 3548-3 cancels and replaces ISO 6524:1992, which has been technically revised.ISO 3548 consists of the following parts, under the general title Plain bearings Thin walled half bearings with or without flange: Part 1: Tolerances, design features and
21、methods of test Part 2: Measurement of wall thickness and flange thickness Part 3: Measurement of peripheral length ISO 2012 All rights reserved vBS ISO 3548-3:2012BS ISO 3548-3:2012Plain bearings Thin-walled half bearings with or without flange Part 3: Measurement of peripheral length1 ScopeThis pa
22、rt of ISO 3548 specifies, according to ISO 12301, the checking of the peripheral length of thin-walled half bearings with or without flange, and describes the necessary checking methods and measuring equipment.Thin-walled half bearings are flexible and, in the free condition, do not conform to a cyl
23、indrical profile. This is one reason the peripheral length of the half bearings can only be measured under a constraining load by use of specialized measuring equipment.In addition, measuring equipment different from that illustrated in this part of ISO 3548 can be used, provided the measuring accur
24、acy of the equipment is consistent with the specifications given in Clause 17.This part of ISO 3548 does not include measurement of the parting line taper.This part of ISO 3548 applies to thin-walled half bearings, the specifications of which are given in ISO 3548-1.2 Normative referencesThe followi
25、ng documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 3548-1, Plain b
26、earings Thin-walled half bearings with or without flange Tolerances, design features and methods of testISO 12301, Plain bearings Quality control techniques and inspection of geometrical and material quality characteristics3 Terms and definitionsFor the purposes of this document, the following terms
27、 and definitions apply.3.1peripheral lengthcircumferential length, which runs from one parting line face to the other3.2crush heightavalue by which a half bearing, fitted in a checking block of bore diameter, dcb, under a predetermined checking load, F, exceeds the defined peripheral length of the c
28、hecking block bore See Figure 1.NOTE In practice, the datum serves as a basis for measuring a (see Figure 1).INTERNATIONAL STANDARD ISO 3548-3:2012(E) ISO 2012 All rights reserved 1BS ISO 3548-3:2012ISO 3548-3:2012(E)Figure 1 Crush height, a3.3repeatabilitycloseness of agreement between successive r
29、esults obtained with the same method on the same test piece, under the same conditions (same operator, same measuring equipment, same checking place and time intervals)NOTE Repeatability is assessed from the standard deviation of repeatability (see Annex E).3.4reproducabilitycloseness of agreement b
30、etween individual results obtained with the same method on the same test piece but under different conditions (identical or different operator, measurement equipment, checking place and times)NOTE For the purposes of this part of ISO 3548, reproducibility is the difference between the two averages o
31、btained from two sets of measuring equipment (see Annex E).3.5comparabilityaccuracy in the case of operators working in different checking places at different periods and each of them achieving individual results, one using method A and the other using method B, on the same plain bearing test piece
32、in different checking blocksNOTE Comparability is assessed from the difference between the two averages obtained from the two methods (see Annex E).4 SymbolsFor the purposes of this document, the following symbols apply.Table 1 Symbols and unitsSymbol Parameter UnitaAor aB1+aB2Crush height mmB Width
33、 of the half bearing without flange mmB1Checking block width (construction for flanged half bearings) mmB2Checking block width mmB3Checking block width (construction for half bearings without flange) mmBmsMaster shell width mmdcbDiameter of the checking block bore mmDbsOutside diameter of the half b
34、earing to be checked mm2 ISO 2012 All rights reservedBS ISO 3548-3:2012ISO 3548-3:2012(E)Symbol Parameter UnitDmsOutside diameter of the master shell mmE Elasticity modulus MPaF Friction coefficient in calculation of deflection under load F = F1= F2Checking load NFcorCorrection factor mmH Fillet rad
35、ius between back and flange on flanged half bearing mmHcbDistance from the bottom of the checking block bore to the datum face mmHcbElastic deformation of the height of the checking block under load mmK1Checking block chamfer (construction for half bearings without flange) mmK2Checking block chamfer
36、 (construction for flanged half bearings) mmL Peripheral length mml Deviation of the actual peripheral length of the checking block mmpEElastic depression of the metering bar mmRaSurface roughness mscsWall thickness of the comparison shell mmsmsWall thickness of the master shell mmstotTotal wall thi
37、ckness of the half bearing mmU Uncertainty of measurementW Width of the metering bar contact area mmZ Distance between flanges of the flanged half bearing mmEmpirical correction to compensate for the difference in elastic deflec-tions under load between method A and method BmmxCorrection, estimated
38、by calculation mm Standard deviation mmThe characteristic subscripts are given in Table 2.Table 2 SubscriptsSubscript bs bearing to be checkedcb checking blockcbm master checking blockcbs series checking blockcs comparison shellM measuredms master shellth theoretical5 Purpose of checkingIn order to
39、ensure the required mounting compression (interference fit) for the half bearings in the housing bore, it is necessary to keep to the crush height tolerances as specified in ISO 3548-1 and ISO 12301.Table 1 (continued) ISO 2012 All rights reserved 3BS ISO 3548-3:2012ISO 3548-3:2012(E)6 Checking meth
40、ods6.1 Method AThe checking load, F, is directly applied via the measuring head with a pivoting metering bar to one parting line face of the half bearing while the other parting line face is in contact with a fixed stop (see Figure 2).anpAA= ()/ (1)Key1 fixed stop2 dial gauge3 movable measuring head
41、4 datum5 metering bar6 checking blockFigure 2 Measuring principle of method A6.2 Method BThe checking loads, F1and F2, are applied via the measuring head and two metering bars to both parting line faces of the half bearing (see Figure 3).4 ISO 2012 All rights reservedBS ISO 3548-3:2012ISO 3548-3:201
42、2(E)aa aaBB1B2=+= (2)Key1 dial gauge2 datum3 rigid metering bara4 checking block5 pivoting toe pieceaBearings may also be checked using two pivoting metering bars.Figure 3 Measuring principle of method BNOTE In the case of method A, the fixed stop exerts the required counterforce, which, in the case
43、 of method B, is applied directly by the measuring equipment via two metering bars.EXAMPLE Method A F = 6 000 NMethod B F1= 6 000 NF2= 6 000 N7 Choice and designation of checking method7.1 Choice of checking methodRecommendations for choosing either method A or method B, based on dimensions of the h
44、alf bearings to be checked, are given in Table 3. ISO 2012 All rights reserved 5BS ISO 3548-3:2012ISO 3548-3:2012(E)However, any size of bearing may be tested by either method by agreement between the manufacturer and user. In that case, a correction, , should be applied to compensate for the differ
45、ence in deflections at parting line face(s) under load between method A and method B, and be such that:aa aAB1B2=+ (3)The value of shall be determined empirically by actual measurements obtained on the two different types of equipment used. Since the detailed design of the checking feature shall be
46、varied between different manufacturers, the value of established by one manufacturer cannot be transferred to another, who shall determine it separately. See example in Annex E.For general guidance, the value of may be derived from the formula used in the mathematical analysis of belt friction, whic
47、h gives:pipi=+( )dFsB Efeeffcb,mms ms12122/(4)With a value of the friction coefficient f = 0,15, Formula (4) becomes:xdFsB= 7107 cb,mms ms(5)(See also 16.5.)Table 3 Selection of checking methodDbsmmRecommended checking methodDbs 200 A, B200 160 mm.These values are necessary for calculating the corre
48、ction factor, Fcor,cbm(see 13.1), which is based on the peripheral length, determined from Formula (6):ld Hdcbm,Mcbm,M cbm,Mcbm,M=+ pi222(6)11.2.4 Permissible wear limitThe tolerance specified in 11.2.2 for the master checking block shall not be exceeded through wear. If wear occurs within the speci
49、fied tolerance range, it may be necessary to change the correction factor.11.3 Series gauging tools11.3.1 Series checking block used aloneSince the peripheral length of this checking block bore is determined by comparison with the master checking block (11.2), larger tolerances for dcbsand Hcbsare acceptable.11.3.2 Manufacturing limits, correction factor and permissible wear limit11.3.2.1 Manufacturing limitsManufacturing limits and specifications for the series checking b
