1、BS ISO4378-4:2009ICS 01.040.21; 21.100.10NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPlain bearings Terms, definitions,classification andsymbolsPart 4: Basic symbolsThis British Standardwas published underthe authority of theStandards Policy andStrategy Comm
2、ittee on 30September 2009 BSI 2009ISBN 978 0 580 58567 8Amendments/corrigenda issued since publicationDate CommentsBS ISO 4378-4:2009National forewordThis British Standard is the UK implementation of ISO 4378-4:2009.The UK participation in its preparation was entrusted to TechnicalCommittee MCE/12,
3、Plain bearings.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer i
4、mmunityfrom legal obligations.BS ISO 4378-4:2009Reference numberISO 4378-4:2009(E)ISO 2009INTERNATIONAL STANDARD ISO4378-4Second edition2009-09-01Plain bearings Terms, definitions, classification and symbols Part 4: Basic symbols Paliers lisses Termes, dfinitions, classification et symboles Partie 4
5、: Symboles de base BS ISO 4378-4:2009ISO 4378-4:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the com
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8、e Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2009 All rights 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 perm
9、ission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2009 All rights rese
10、rvedBS ISO 4378-4:2009ISO 4378-4:2009(E) ISO 2009 All rights reserved iiiContents Page Foreword iv Introduction.v 1 Scope1 2 Normative references1 3 Basic characters1 4 Additional signs.2 4.1 Subscripts 2 4.2 Superscripts.2 5 Application and distinction by means of basic characters, subscripts and s
11、uperscripts 2 6 Symbols and terms .2 6.1 General .2 6.2 Basic characters of the Roman alphabet2 6.3 Basic characters of the Greek alphabet5 7 Additional signs.6 7.1 Subscripts 6 7.2 Superscripts.11 BS ISO 4378-4:2009ISO 4378-4:2009(E) iv ISO 2009 All rights reservedForeword ISO (the International Or
12、ganization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The 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 establ
13、ished 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 of electrotechnical standardizati
14、on. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The 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.
15、 Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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 pa
16、tent rights. ISO 4378-4 was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 6, Terms and common items. This second edition cancels and replaces the first edition (ISO 4378-4:1997) and ISO 7904-1:1995, which have been technically revised. ISO 4378 consists of the following
17、 parts, under the general title Plain bearings Terms, definitions, classification and symbols: Part 1: Design, bearing materials and their properties Part 2: Friction and wear Part 3: Lubrication Part 4: Basic symbols Part 5: Application of symbols BS ISO 4378-4:2009ISO 4378-4:2009(E) ISO 2009 All r
18、ights reserved vIntroduction As there is a large number of multiple designations in the domain of plain bearings, there is a considerable risk of error in the interpretation of standards and technical literature. This uncertainty leads to the continuous addition of supplementary designations, which
19、only serves to increase the misunderstanding. This part of ISO 4378 is an attempt to elaborate a uniform basic system of symbols. BS ISO 4378-4:2009BS ISO 4378-4:2009INTERNATIONAL STANDARD ISO 4378-4:2009(E) ISO 2009 All rights reserved 1Plain bearings Terms, definitions, classification and symbols
20、Part 4: Basic symbols 1 Scope This part of ISO 4378 defines basic symbols for use in the field of plain bearings. Additional signs are also defined for use as superscripts and subscripts. The characters employed are drawn from the Latin and Greek alphabets, Arabic numerals and other signs, for examp
21、le points, commas, horizontal lines or asterisks. In the simplest case, an application symbol consists of the basic character alone; in the most complex, of the basic character with subscripts and superscripts (additional signs). For the purposes of international applicability, all basic symbols and
22、 additional signs have been derived from English words, and designations used in technical literature up to now have been adopted as far as possible. Wide conformity of the symbols for all types of plain bearings has been attempted. This classification is established for use in calculations and tech
23、nological and geometrical determinations, as well as in the quality assurance of plain bearings. Quantities having a fixed value for a certain construction are designated by capital letters, where possible. Depending on the special field of application, the basic characters specified are for stand-a
24、lone use or appropriately combined with additional signs, where necessary, to minimize the risk of confusion; multiple designations can be avoided by suitable indexing with additional signs. 2 Normative references The following referenced documents are indispensable for the application of this docum
25、ent. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 4378-5, Plain bearings Terms, definitions, classification and symbols Part 5: Application of symbols 3 Basic characters Basic chara
26、cters consist of one or, in exceptional cases, two capital or Iower-case Ietters. Variables shall be in italic typeface, abbreviations shall be in Roman typeface. EXAMPLE N = rotational speed, VG = Viscosity Grade. BS ISO 4378-4:2009ISO 4378-4:2009(E) 2 ISO 2009 All rights reserved4 Additional signs
27、 4.1 Subscripts Subscripts may consist of one, two or three letters, digits or letter/digit combinations. In general, the first letter of a subscript corresponds to the first Ietter of the English concept, which is referred to by the subscript. Subsequent letters shall also follow this concept. The
28、expressions used should be as short as possible. When the signs correspond to a variable, they shall be in italic typeface; when they refer to an abbreviation, they shall be in Roman typeface. EXAMPLE c = circular, cr = critical, cal = calculated. If subscripts are combined, they shall be separated
29、by means of commas but without a space between. For example, the permissible minimum lubricant film thickness at the transition to mixed friction would then be designated as hlim,tr. As such expressions are rather awkward, use of substitute expressions in these cases is also permitted, such as one s
30、ingle letter or (better still) one digit as subscript which has not yet been used, e.g. h1instead of hlim,tr. 4.2 Superscripts Superscripts shall consist of points, lines, commas, asterisks or other characteristic signs. A maximum of two superscripts are permitted per letter symbol. EXAMPLE *u 5 App
31、lication and distinction by means of basic characters, subscripts and superscripts Angles and directions of rotation are defined positively as rotating in a left-hand (anticlockwise) direction; the same applies to rotational frequencies and peripheral and angular velocities. A parameter is represent
32、ed by the basic character with an asterisk (*), e.g. F* for the bearing force parameter. If the bearing force parameter of a journal bearing is to be distinguished from that of a thrust bearing, this can be done using the designation Fr* or Fax*. However, if several different bearing force parameter
33、s are used, they can be distinguished in the relevant standard or publication by appropriate subscripts, e.g. 1, 2, 3. 6 Symbols and terms 6.1 General The following listings are not necessarily complete. They may be enlarged, if necessary. NOTE Some letters of the Roman and Greek alphabet have not y
34、et been used. Nevertheless, for the sake of completeness, these letters are also included below. 6.2 Basic characters of the Roman alphabet The basic characters of the Roman alphabet include the following: A area, elongation at fracture a distance, acceleration, thermal diffusivity, inertia factor B
35、 width parallel to the sliding surface, normal to the direction of motion (breadth); BS ISO 4378-4:2009ISO 4378-4:2009(E) ISO 2009 All rights reserved 3b width parallel to the sliding surface, normal to the direction of motion or flow (breadth); C clearance, circumference, chamfer, concentration c s
36、pecific heat capacity, stiffness D diameter d diameter, distance, depth, damping E Youngs modulus (modulus of elasticity) e eccentricity (distance between the centre points or the centre axes of two shaped elements) F force, load, load-carrying capacity f friction factor (coefficient of friction), d
37、eflection, function, frequency G shear modulus g acceleration due to gravity H height, hardness h height, depth, thickness, gap I geometrical moment of inertia i 1 J mass moment of inertia j 1 K coefficient, constant, factor, parameter, auxiliary variable k heat transition coefficient L length; leng
38、th parallel to the sliding surface, in the direction of motion l length, length in the circumferential direction or in the direction of flow, exponent M moment, mixing factor m mass, preload N rotational speed (rotational frequency) (revolutions per time unit) Nu Nusselt number n number O point of o
39、rigin, centre, centreline, order of magnitude o N/A P power, heat flow BS ISO 4378-4:2009ISO 4378-4:2009(E) 4 ISO 2009 All rights reservedPr Prandtl number p pressure, surface pressure Q flow rate (volume flow) q flow rate (volume flow) R radius, roughness (surface finish), resistance, material stre
40、ngth Re Reynolds number r radius, coordinate in radial direction S safety factor, displacement amplitude (mechanical oscillation), S number (special form of reciprocal Sommerfeld number So) So Sommerfeld number (special form of bearing force parameter F*) SP switching period s wall thickness, lining
41、 thickness, displacement T temperature Ta Taylor number t time, thickness, wall thickness, lining thickness U surface velocity in x- or -direction, sliding velocity, circumferential speed u velocity component in x- or -direction, deformation in x-direction V volume, surface velocity in y-direction V
42、G viscosity grade VI viscosity index v velocity component in y-direction, deformation in y-direction W surface velocity in z-direction, work (energy) w velocity component in z-direction, deformation in z-direction X Cartesian coordinate x Cartesian coordinate, distance Y Cartesian coordinate y Carte
43、sian coordinate, distance Z Cartesian coordinate, number, necking after fracture z Cartesian coordinate, coordinate in axial direction, distance BS ISO 4378-4:2009ISO 4378-4:2009(E) ISO 2009 All rights reserved 56.3 Basic characters of the Greek alphabet The basic characters of the Greek alphabet in
44、clude the following. As there is a risk of confusion with the corresponding Roman letters, the following Greek Ietters have not been specified: , , , , , , , , , , , , , , . angle, coefficient, heat transfer coefficient, coefficient of thermal expansion, viscosity coefficient angle, temperature/visc
45、osity coefficient N/A angle difference, tolerance, change angle relative eccentricity, relative strain hydraulic resistance coefficient, nozzle coefficient dynamic viscosity N/A angle, angular coordinate N/A resistance ratio N/A thermal conductivity relative bearing stiffness, relative shaft flexibi
46、lity; friction factor (coefficient of friction), dynamic viscosity kinematic viscosity, Poissons ratio N/A restrictor ratio N/A circular constant (Ludolphs number) ( = 3,141 592 .) density N/A normal stress, standard deviation shearing stress BS ISO 4378-4:2009ISO 4378-4:2009(E) 6 ISO 2009 All right
47、s reserved N/A dissipation function, sliding surface utilization ratio (0 1) angular coordinate N/A N/A relative clearance angular span angular speed ( = 2N) 7 Additional signs 7.1 Subscripts A area a average (for surface finish) abs absolute amb ambient ax axial B bearing, bearing shell, bush, bush
48、ing, segment (pad), sliding surface Bu Bunsen b spherical (ball) C thrust collar (thrust bearing) CG centre of gravity c circumferential cal calculation cl coolant, cooling, cooler, heat exchanger cor correction cp capillary cr criticaI ct contact cv convection D diameter BS ISO 4378-4:2009ISO 4378-
49、4:2009(E) ISO 2009 All rights reserved 7d depth d damping, dissipation dr dry dyn dynamic dw downwards EHD elastohydrodynamic e eigen, eigenfrequency el elastic eff effective en entrance ex exit exc excitation F force, load f friction fi fixed fil fill fl flange flo floating G groove g weight, gravity gl glass transition gr grease H housing h height, depth, thickness h horizontal, gap hd hydrodynamic hs hydrostatic I
