Tiêu chuẩn iso 12131 2 2016

INTERNATIONAL STANDARD ISO 12131-2 Second edition 2016-09-15 Plain bearings — Hydrodynamic plain thrust pad bearings under steadystate conditions — Part 2: Functions for the calculation of thrust pad bearings Paliers lisses — Butées hydrodynamiques patins géométrie fixe fonctionnant en régime stationnaire — Partie 2: Fonctions pour le calcul des butées segments Reference number ISO 12131-2:2016(E) © ISO 2016 ISO 12131-2:2016(E) COPYRIGHT PROTECTED DOCUMENT © ISO 2016, Published in Switzerland All rights reserved Unless otherwise specified, no part o f this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission Permission can be requested from either ISO at the address below or ISO’s member body in the country o f the requester ISO copyright o ffice Ch de Blandonnet • CP 401 CH-1214 Vernier, Geneva, Switzerland Tel +41 22 749 01 11 Fax +41 22 749 09 47 copyright@iso.org www.iso.org ii © ISO 2016 – All rights reserved ISO -2 : 01 6(E) Contents Page iv Introduction v Scope Normative references Functions for the thrust pad bearing Effective dynamic viscosity of the lubricant, η eff, as a function of the effective lubricant film temperature, Teff Bibliography Foreword © ISO 2016 – All rights reserved iii ISO 12131-2:2016(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies) The work o f 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-governmental, in liaison with ISO, also take part in the work ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters o f electrotechnical standardization The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part In particular the different approval criteria needed for the di fferent types o f ISO documents should be noted This document was dra fted in accordance with the editorial rules of the ISO/IEC Directives, Part (see www.iso.org/directives) Attention is drawn to the possibility that some o f the elements o f this document may be the subject o f patent rights ISO shall not be held responsible for identi fying any or all such patent rights Details o f any patent rights identified during the development o f the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents) Any trade name used in this document is in formation given for the convenience o f users and does not constitute an endorsement For an explanation on the meaning o f ISO specific terms and expressions related to formity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword.html The committee responsible for this document is ISO/TC 123, Plain bearings This second edition cancels and replaces the first edition (ISO 12131-2:2001), o f which it constitutes a minor revision ISO 12131 consists of the following parts, under the general title Plain bearings — Hydrodynamic plain thrust pad bearings under steady-state conditions: — Part 1: Calculation of thrust pad bearings — Part 2: Functions for the calculation of thrust pad bearings — Part 3: Guide values for the calculation of thrust pad bearings iv © ISO 2016 – All rights reserved ISO -2 : 01 6(E) Introduction Assuming hydrodynamic conditions with full lubrication, the functions o f the type covered by this part o f ISO 12131 are necessary for the calculation o f oil-lubricated pad thrust bearings in accordance with ISO 12131-1 They are based on the premises and boundary conditions specified The values necessary for the calculation can be determined by means o f the given formulae, as well as from diagrams and tables The formulae in this part o f ISO 12131 are approximations o f the numerically determined values traced as curves according to Reference [2 ] The explanation of the symbols, as well as examples for the calculation, are included in ISO 12131-1 © ISO 2016 – All rights reserved v INTERNATIONAL STANDARD ISO 12131-2:2016(E) Plain bearings — Hydrodynamic plain thrust pad bearings under steady-state conditions — Part 2: Functions for the calculation of thrust pad bearings Scope T h i s p ar t o f I S O s p e c i fie s func tion s for th ru s t p ad b e ari ngs I t a l s o covers the e ffe c t o f dyna m ic vi s co s ity on lubric ant fi l m temp eratu re Normative references T he fol lowi ng i nd i s p en s able c u ments , i n whole or i n p ar t, are normatively re ference d i n th i s c u ment a nd are for its appl ic ation For date d re ference s , on ly the e d ition cite d appl ie s For u ndate d re ference s , the late s t e d ition o f the re ference d c u ment (i nclud i ng any amend ments) appl ie s ISO 12131-1, Plain bearings — Hydrodynamic plain thrust bearings under steady-state conditions — Part 1: Calculation of thrust pad bearings Functions for the thrust pad bearing 3.1 C haracteris tic value o f lo ad carrying cap acity, and the relative minimum lub ricant film thicknes s , Approximation of the curves of Figure    l FB* = ×   wed  L    * FB , as a function of the relative bearing length, B/L, / h Cwed (range o f appl ic ation: ,1 ≤ h C wed ≤ 10) 2   h  ×   C   wed  + hmin / C wed  × ln +  h / C wed       l h  ×  × + ×  − wed      l wed L           l wed  l wed    1 + ×  − × ×  + 4× −       L   h / C wed  L  h / C wed      l l wed l × ×  − wed  − ×  wed  L L h / C wed  L       1 A +B × 1−  + C* ×  −      / / h C h C   wed wed     × ×   h  −2  / C wed  B  +α ×  L  2   h   h   −2×  +      C  C wed wed        10 α= ×   h +  h   +  C wed  C wed     + h / C wed − h     h  12 × + ×    × ln   + ×     C wed  h / C wed  C wed    * * © ISO 2016 – All rights reserved             ISO -2 : 01 6(E) B  B  B  A = 1, 205 − 0, 243 44 ×   + 0, 126 25 ×   − 0, 021 554 ×   L  L  L  * B  B  B  B = − 0, 256 34 + 0, 361 14 ×   − 0, 199 58 ×   + 0, 038 633 ×   L  L  L  * C * B  B  B   − 0, 002 752 ×   + 0, 000 184 46 ×   L  L  L  = − 0, 010 765 + 0, 009 350 ×  Figure — C haracteris tic value of load carrying capacity for thrust pad bearings, * F B , as a B/L , and the relative minimum lubricant film thickness, h min/Cwed , for lwed/L = 0,75 function of the relative bearing width, © ISO 2016 – All rights reserved ISO -2 : 01 6(E) Table — Values to Figure where / 10 0,5 0,33 0,2 0,1 h Cwed 0,000 0,026 0,134 0,522 1,010 2,067 4,52 * FB = f(B/L, h min/Cwed, lwed/L = 0,75) / 0,000 0,016 0,086 0,355 0,716 1,547 3,62 B L 1,5 0,000 0,023 0,116 0,462 0,908 1,887 4,21 0,75 0,000 0,012 0,063 0,27 0,559 1,252 3,08 0,5 0,000 0,006 0,036 0,161 0,348 0,83 2,24 Characteristic value of friction for thrust pad bearings, fB* , as a function of the relative bearing width, B/L h /Cwed , and the relative minimum lub ricant film thicknes s , Approximation of the curves of Figure (range o f appl ic ation: ,1 ≤ h ≤ 10) C wed    l l h h  × wed × ×  × + ×  − wed   L C L l wed  C wed  * wed h × ln + h / C wed +  − l wed  −  f B =  4× L × C    h L wed / C wed    h   h  l  ×   +  − × wed  × + ×  −    C    C L  wed  wed     −2   B   × × +   × α  × A* × × B*     L  h / C wed      10 α= ×   h    + ×   C wed    2   h +  h   +       C C wed wed      12 ×   2  h  h    1−2 × +       C C wed wed      + h / C wed h −2  + ×  × ln C wed  h m i n / C wed  B B B  A = −0, 21459 + 0, 88071 ×   − 0, 297 60 ×   + 0, 037 91 ×   L L L * For h / C wed ≥ 0, is B * = For h / C wed < 0, is B * = 1, 1251 ×  B       l wed    L                   −0 , 12939 L © ISO 2016 – All rights reserved ISO -2 : 01 6(E) * f B , as a function of the relative bearing width, B L , and the relative minimum lubricant film thickness, h Cwed , for lwed L = 0,75 Figure — C haracteris tic value of friction for pad thrus t bearings, / Table — Values to Figure where / 10 0,5 0,33 0,2 0,1 h Cwed 0,096 0,444 0,844 1,599 2,301 3,574 6,194 / / 1,5 0,096 0,442 0,834 1,568 2,249 3,488 6,061 fB* = f(B/L, h min/Cwed, lwed/L = 0,75) / 0,096 0,438 0,818 1,511 2,151 3,324 5,804 B L 0,75 0,096 0,436 0,805 1,467 2,071 3,185 5,574 0,5 0,096 0,433 0,790 1,410 1,965 2,987 5,223 © ISO 2016 – All rights reserved ISO -2 : 01 6(E) 3 Relative lub ricant flo w rates , * Q1 and Q *3 , as a function of the relative bearing width, B/L, and the h / Cwed relative minimum lub ricant film thicknes s , Approximation of the curves of Figures and Q * i =   +  C wed h   l  ×  − wed + L    h  + × C wed  C wed h (range o f app l ic ation: ,1 ≤    × + × 1−   A i B i  h / C wed     l wed h  × +2× 1+  ×  L C wed   with constants Ai and Bi h C wed ≤ 10)         l  ×  − wed  L    C wed h for Q *i = Q 1* : A i = A1 = 7655 − 524 23 ×  B  + 118 05 ×  B  , , L , L B  B  B i = B1 = −1, 004 + 0, 788 80 ×   − 0, 19357 ×   L L for Q *i = Q *3 : A i = A3 B i = B3   B   B   = × 0, 434 − 0, 308 23 ×   + 0, 06952 ×     L   L   2  B  B    = × −0, 470 + 0, 375 67 ×   − 0, 09217 ×    L  L    © ISO 2016 – All rights reserved ISO -2 : 01 6(E) * / Q , as a function of the relative bearing width, B L , and the relative minimum lubricant film thickness, h Cwed , for lwed L = 0,75 Figure — Relative lubricant flow rate, Table — Values to Figure where / 10 0,5 0,33 0,2 0,1 h Cwed 0,526 0,614 0,698 0,828 0,942 1,144 1,646 1,5 0,529 0,63 0,733 0,904 1,06 1,340 2,034 / Q1* / = f(B/L, h min/Cwed, lwed/L = 0,75) / 0,533 0,657 0,794 1,041 1,276 1,706 2,771 B L 0,75 0,537 0,678 0,841 1,147 1,447 2,004 3,390 0,5 0,541 0,702 0,898 1,278 1,663 2,387 4,208 © ISO 2016 – All rights reserved ISO -2 : 01 6(E) Figure — Relative lubricant flow rate, Q * the relative minimum lubricant film thickness, h Table — Values to Figure where Q h min/Cwed 0,012 0,061 0,117 0,220 0,320 0,506 0,963 10 0,5 0,33 0,2 0,1 1,5 0,016 0,083 0,160 0,303 0,443 0,701 1,340 * eff For l iqu id lubric ants , the Vo gel η = K2    T + K   formu la min/Cwed, for lwed/L = 0,75 = ×( / , B L h / 0,025 0,121 0,236 0,453 0,667 1,065 2,051 B L Effective dynamic viscosity of the lubricant, lubricant film temperature, T / , as a function of the relative bearing width, B L , and min/Cwed , lwed/L = 0,75) 0,75 0,030 0,15 0,293 0,569 0,845 1,362 2,647 0,5 0,037 0,183 0,362 0,713 1,07 1,744 3,434 η eff, as a function of the effective i s genera l ly appl ic able [3]  K I × exp  For m i nera l oi l s , th i s formu la © ISO 2016 – All rights reserved = 95 °C [4] c an b e comple te d with s u fficient acc u rac y by the s tant K ISO -2 : 01 6(E) Reference [2 ] shows the operational viscosity, η , for mineral oils can also be calculated directly from the ISO VG With density, ρ, in kg/m , it gives: ln  159, 56  η ρ × VG = − 0, 181 913  × ln  η x  T + 95 ° C 10 × η x  In this formula, η x = 0, 18 × 10 −3 Pas , and is a constant coe fficient The viscosity o f ISO-compliant oils is given for a mean density ρ = 900 kg/m in Figure Engine and gear box oils for road vehicles are standardized according to international viscosity classes SAE The SAE classification o f these lubricants can only be compared incompletely with the ISO VG classification The classification is inaccurate that for especially precise calculations, the supplier is requested to supply viscosity data As compared with pure mineral oils, multi-grade oils have more even viscosity-temperature behaviour Synthetic oils very o ften reach such conditions without intrinsically viscous additives as required for mineral oils © ISO 2016 – All rights reserved ISO 12131-2:2016(E) Figure — Effective dynamic viscosity, η eff, as a function o f the e ffective lubricant film temperature, Teff, at a density ρ = 90 kg/m © ISO 2016 – All rights reserved ISO -2 : 01 6(E) Bibliography [1] [2] ISO 12131-3, Plain bearings — Hydrodynamic plain thrust pad bearings under steady-state conditions — Part 3: Guide values for the calculation of thrust pad bearings Rodermund H Berechnung der Temperaturabhängigkeit der Viskosität von Mineralölen aus dem Viskositätsgrad (C a lc u l ation o f temp erature dep endence o f m i nera l oi l vi s co s ity b a s e d on the vi s co s ity grade) S ch m ier te ch ni k u nd Trib olo gie 2/19 78 , pp -5 [3] Vogel H Das Temperaturabhängigkeitsgesetz der Viskosität von Flüssigkeiten for vi s co s ity o f flu id s) Phys Z 22 1921, pp 645–646 A The Principles of Lubrication Longmans, London, 1966 (The temperature dep endence law [4] 10 C ameron © ISO 2016 – All rights reserved ISO -2 : 01 6(E) ICS  21.100.10 Price based on 10 pages © ISO 2016 – All rights reserved