1、BRITISH STANDARD AEROSPACE SERIES BS EN 3446:1995 Bearings, precision ball without flange in corrosion resisting steel, for instruments and equipment Dimensions and loads The European Standard EN 3446:1995 has the status of a British StandardBSEN3446:1995 This British Standard, having been prepared
2、under the directionof the Engineering SectorBoard, was published underthe authority of the Standards Board and comes intoeffect on 15June1995 BSI 10-1999 The following BSI references relate to the work on this standard: Committee reference ACE/14 Draft for comment 93/709726 DC ISBN 0 580 23850 4 Com
3、mittees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee ACE/14, Aerospace details and parts, upon which the following bodies were represented: Civil Aviation Authority Institute of Petroleum Ministry of Defence Society of British Ae
4、rospace Companies Ltd. Amendments issued since publication Amd. No. Date CommentsBSEN3446:1995 BSI 10-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 1 Scope 3 2 Normative references 3 3 Symbols 3 4 Required characteristics 4 5 Classification of bores a
5、nd outside diameters 8 6 Designation 9 7 Marking 9 8 Technical specification 9 Figure 1 4 Figure 2 4 Table 1 5 Table 2 5 Table 3 5 Table 4 6 Table 5 6 Table 6 6 Table 7 7 Table 8 7 Table 9 8 List of references Inside back coverBSEN3446:1995 ii BSI 10-1999 National foreword This British Standard has
6、been prepared by Technical Committee ACE/14 and is the English language version of EN3446:1995 Aerospace series Bearings, without flange in corrosion resisting steel for instruments and equipment Dimensions and loads, published by the European Committee for Standardization (CEN). EN 3446:1995 was pr
7、oduced as a result of international discussions in which the UnitedKingdom took an active part. There are no British Standards corresponding to EN2030 and EN2130 referred to in the text. British Standards identical in title and number will be published in due course. A British Standard does not purp
8、ort to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Cross-references Publication referred to Corresponding British Standard I
9、SO 15:1981 BS 6267:1982 Specification for rolling bearings: boundary dimensions for radial bearings ISO 1132:1980 BS 6107 Rolling bearings: tolerances Part 1:1981 Glossary of terms ISO 1224 BS 3469:1985 Specification for instrument precision rolling bearings (ball bearings) Summary of pages This doc
10、ument comprises a front cover, an inside front cover, pages i and ii, theENtitle page, pages2 to10, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front c
11、over.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 3446 February 1995 ICS 49.040.30 Descriptors: Aircraft industry, aircraft instruments, precision bearings, ball bearings, dimensions English version Aerospace series Bearings, precision ball without flangein corrosion resisting steel, for ins
12、truments and equipment Dimensions and loads Srie arospatiale Roulements billes de prcision sans collet en acier rsistant la corrosion pour instruments et quipements Dimensions et charges Luft- und Raumfahrt Przisionskugellager ohne Flansch aus korrosionsbestndigem Stahl fr Instrumente und Gerte Mae
13、und Belastungen This European Standard was approved by CEN on 1995-02-01. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliogr
14、aphical references concerning such national standards may be obtained on application to the Central 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 translation under the responsibility of a
15、CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spa
16、in, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 Copyright reserved to CEN members Ref. No. EN 3446:1995 EEN3446:1995 BSI 10-1999 2 Forewor
17、d This European Standard has been prepared by the European Association of Aerospace Manufacturers (AECMA). After inquiries and votes carried out in accordance with the rules of this Association, this Standard has successively received the approval of the National Associations and the Official Servic
18、es of the member countries of AECMA, prior to its presentation to CEN. According to the CEN/CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlan
19、ds, Norway, Portugal, Spain, Sweden, Switzerland, UnitedKingdom.EN3446:1995 BSI 10-1999 3 1 Scope This standard specifies the required characteristics for precision ball bearings in corrosion resisting steel: without flange; with radial contact; with deep groove; without filling slot; for use in ins
20、truments and aircraft equipment. 2 Normative references This European Standard incorporates by dated or undated reference provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, su
21、bsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies. ISO 15, Rolling bearings Radial bearings Boundary dimensions Gener
22、al plan. ISO 1132, Rolling bearings Tolerances Definitions. ISO 1224, Rolling bearings Instrument precision bearings. EN 2030, Steel FE-PM43 Hardened and tempered Bars D k 150mm Aerospace series 1) . EN 2130, Aerospace series Precision ball bearings in corrosion resisting steel for instruments and e
23、quipment Technical specification 2) . 3 Symbols The following symbols are in conformity with ISO1224. Definitions to ISO1132. 1) Published as AECMA Standard at the date of publication of this standard 2) In preparation at the date of publication of this standard d : Nominal bore diameter % ds : Devi
24、ation of a single bore diameter % dmp : Single plane mean bore diameter deviation V dp : Bore diameter variation in a single radial plane V dmp : Mean bore diameter variation D : Nominal outside diameter % Ds : Deviation of a single outside diameter % Dmp : Single plane mean outside diameter deviati
25、on V Dp : Outside diameter variation in a single radial plane V Dmp : Mean outside diameter variation B : Nominal width of the rings % Bs : Deviation of a single ring width V Bs : Variation in the width of the rings r s min. : Smallest permissible single chamfer dimension r s max. : Largest permissi
26、ble single chamfer dimension K ia : Radial runout of assembled bearing inner ring K ea : Radial runout of assembled bearing outer ring S d : Face runout with bore S d1 : Variation of bore generatrix inclination with face S D : Variation of outside surface generatrix inclination with face S ia : Asse
27、mbled bearing inner ring face runout with raceway S ea : Assembled bearing outer ring face runout with racewayEN3446:1995 4 BSI 10-1999 4 Required characteristics 4.1 Materials Rings and balls: steel EN2030, minimum hardness =650HV5 Cages, shields and circlips: corrosion resisting steel Seals: polyt
28、etrafluoroethylene (PTFE) or PTFE plastic material reinforced with glass fibre 4.2 Dimensions Radial clearances Tolerances Loads Configuration: seeFigure 1 andFigure 2; the design and mounting of seals and shields (Figure 2) and the choice of cages are at the discretion of the manufacturer. Dimensio
29、ns: seeTable 1. Clearances: seeTable 2 andTable 3. Tolerances: seeTable 4, Table 5, Table 6 and Table 7. Loads: seeTable 8. 4.3 Lubrication Ester type grease: code 1 Synthetic oil: code 2 For essential characteristics: see EN2130. 4.4 Surface roughness Closure type SeeFigure 1andFigure 2. Figure 1 F
30、igure 2 EN3446:1995 BSI 10-1999 5 Table 1 4.5 Normal internal radial clearance SeeTable 2. Table 2 4.6 Reduced internal radial clearance SeeTable 3. Table 3 4.7 Tolerances group K Shall conform to those of class5A from ISO1224. Dimensions in millimetres Code d D B r s min. r s max. Series: a nom. no
31、m. nom. radial axial diam. dimen. 103 1,0 3 1,0 0,05 0,10 0,10 8 18 154 1,5 4 2,0 0,05 0,10 0,10 8 38 155 1,5 5 2,0 0,15 0,30 0,30 9 19 205 2,0 5 2,3 0,08 0,16 0,30 8 38 206 2,0 6 2,3 0,15 0,30 0,60 9 19 256 2,5 6 2,6 0,08 0,16 0,30 8 38 257 2,5 7 3,5 0,15 0,30 0,60 9 39 307 3,0 7 3,0 0,10 0,20 0,40
32、 8 38 308 3,0 8 4,0 0,15 0,30 0,60 9 39 310 3,0 10 4,0 0,15 0,30 0,60 2 02 409 4,0 9 4,0 0,10 0,20 0,40 8 38 411 4,0 11 4,0 0,15 0,30 0,60 9 19 413 4,0 13 5,0 0,20 0,50 0,80 2 02 511 5,0 11 5,0 0,15 0,30 0,60 8 38 513 5,0 13 4,0 0,20 0,50 0,80 9 19 516 5,0 16 5,0 0,30 0,60 1,00 2 02 613 6,0 13 5,0 0
33、,15 0,30 0,60 8 28 615 6,0 15 5,0 0,20 0,50 0,80 9 19 714 7,0 14 5,0 0,15 0,30 0,60 8 28 816 8,0 16 6,0 0,20 0,50 0,80 8 38 a Series conforming to ISO15. d nominal Clearance m mm Group A Group B Group C 1 to 8 0 to 6 4 to 11 10 to 20 d nominal Clearance m mm Group D Group E Group F Group G Group H G
34、roup J 1 to 8 1 to 5 4 to 8 7 to 11 10 to 15 14 to 20 18 to 28EN3446:1995 6 BSI 10-1999 4.7.1 Inner ring SeeTable 4. Table 4 NOTEThe tolerance of face runout with bore (S d ) may be obtained by the approximate formula: where F is the inner ring raceway contact diameter. F may be indicated by each ma
35、nufacturer or, when the ball diameter (D 2 ) is known, the following approximate value may be used for F: 4.7.2 Outer ring SeeTable 5. Table 5 4.8 Tolerances group L Shall conform to those of class4A from ISO1224. 4.8.1 Inner ring SeeTable 6. Table 6 d nominal mm Tolerances m % dmp % ds V dp max. V
36、dmp max. % Bs V Bs max. K ia max. S d1 max. S ia max. 1 to 8 0 5 0 5 3 3 0 25 5 3,5 7 7 D nominal mm Tolerances m Types MNPQ Type R B K ea S D S ea % Dmp % Ds V Dp max. V Dmp max. % Ds V Dp max. V Dmp max. % Bs V Bs max. max. max. 3 to 16 0 5 + 1 6 5 5 0 5 3 3 0 25 5 5 8 8 d nominal mm Tolerances m
37、% dmp % ds V dp max. V dmp max. % Bs V Bs max. K ia max. S d1 max. S ia max. 1 to 8 0 5 0 5 2,5 2,5 0 25 2,5 2,5 3 3 NOTESee note on4.7.1.EN3446:1995 BSI 10-1999 7 4.8.2 Outer ring SeeTable 7. Table 7 4.9 Bearing types, load ratings and mass SeeTable 8. Table 8 D nominal mm Tolerances m Types MNPQ T
38、ype R B K ea S D S ea % Dmp % Ds V Dp max. V Dmp max. % Ds V Dp max. V Dmp max. % Bs V Bs max. max. max. 3 to 16 0 5 + 0 5 5 5 0 5 2,5 2,5 0 25 2,5 3,5 4 5 Code Types of bearing a Mass b g Dynamic radial load rating min.N Basic static radial load rating N 103 R 0,03 38 16 154 R, P, Q 0,12 55 22 155
39、R, P, Q 0,20 88 36 205 R, P, Q 0,21 88 36 206 R, P, Q 0,32 120 54 256 R, P, Q 0,33 120 52 257 R, P, Q 0,65 120 62 307 R, P, Q 0,52 180 80 308 R, P, Q 0,95 240 120 310 R, M, N, P, Q 1,57 300 140 409 R, M, N, P, Q 1,12 240 120 411 R, M, N, P, Q 1,82 380 185 413 R, M, N, P, Q 3,31 540 270 511 R, M, N,
40、P, Q 2,08 360 180 513 R, M, N, P, Q 2,49 450 250 516 R, M, N, P, Q 5,00 620 340 613 R, M, N, P, Q 2,88 450 250 615 R, M, N, P, Q 4,09 620 340 714 R, M, N, P, Q 3,18 540 270 816 R, M, N, P, Q 4,98 790 370 a See Figure 1 and Figure 2. b Approximative mass calculated using the following formula: where:
41、 M is the approximate mass, in gramms; $ is the density of material, in gramms per cubic millimeter. M ;$ 4 - 0,7B D 2 d 2 () =EN3446:1995 8 BSI 10-1999 5 Classification of bores and outside diameters When required for selective assembly to shafts and housings, instrument precision rolling bearings
42、may be classified into specific size groups in accordance with the following provisions. 5.1 Classification It shall be carried out prior to mounting of the seals or shields. The bore and outside diameter may each be classified into two or four groups as shown inTable 9. Table 9 NOTEDue to difficult
43、ies in gauge correlation between manufacturer and user, the classification shall be considered only as guides for selective assembly and not as absolute size segregations in borderline cases. Code numbers and/or letters shall be included in the identity block for this purpose. The classification cod
44、e for the bore shall always precede that of the outside diameter. Should classification not be required for one of the diameters, code T shall be substituted. If no classification is required, the code TT shall be used. 5.2 Method of size determination Outside diameter: the largest diameter measured
45、 Bore diameter: the smallest diameter measured Tolerance range Tolerance range p Code p Code m m 2,5 k p k 0 5k p 2,5 1 2 1,25k p k 0 2,5k p 1,25 3,75 k p 2,5 5k p 3,75 A B C D EXAMPLE 1: 1A = Range of tolerance of bore diameter : 2,5 m k p k 0 Range of tolerance of outside diameter : 1,25 m k p k 0
46、 EXAMPLE 2: CB = Range of tolerance of bore diameter : 3,75 m k p 2,5 m Range of tolerance of outside diameter : 2,5 m k p 1,25 m EXAMPLE 3: TT = Bore and outside diameter not classified.EN3446:1995 BSI 10-1999 9 6 Designation EXAMPLE: NOTEIf necessary, the code I9005 shall be placed between the des
47、cription block and the identity block. 7 Marking In addition to the manufacturers own marking, all packages shall be marked using the identity block, see6. 8 Technical specification See EN 2130.10 blankBSEN3446:1995 BSI 10-1999 List of references See national foreword.BS EN 3446:1995 BSI 389 Chiswic
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49、dment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside fron
