1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 21940-23:2012Mechanical vibration RotorbalancingPart 23: Enclosures and other protectivemeasures for the measuring station ofbalancing machinesBS ISO 21940-23:2012 BRITISH
2、 STANDARDNational forewordThis British Standard is the UK implementation of ISO21940-23:2012. It supersedes BS ISO 7475:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee GME/21/5, Mechanical vibration, shock and conditionmonitoring - Vibration of mac
3、hines.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI St
4、andardsLimited 2012ISBN 978 0 580 70353 9ICS 21.120.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 June 2012.Amendments issued since publicationDate Text aff
5、ectedBS ISO 21940-23:2012 ISO 2012Mechanical vibration Rotor balancing Part 23: Enclosures and other protective measures for the measuring station of balancing machinesVibrations mcaniques quilibrage des rotors Partie 23: Enceintes et autres mesures de protection pour le poste de mesurage des machin
6、es quilibrerINTERNATIONAL STANDARDISO21940-23First edition2012-06-01Reference numberISO 21940-23:2012(E)BS ISO 21940-23:2012ISO 21940-23:2012(E)ii ISO 2012 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2012All rights reserved. Unless otherwise specified, no part of this publication may be repr
7、oduced 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 the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749
8、 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 21940-23:2012ISO 21940-23:2012(E) ISO 2012 All rights reserved iiiContents PageForeword ivIntroduction . vi1 Scope 12 Normative references . 13 Terms and definitions . 14 List of significant hazards . 14.
9、1 General . 14.2 Risk assessment . 14.3 Access to balancing machine 35 Safety requirements and protective measures . 35.1 General requirements . 35.2 Specific requirements 56 Verification of safety requirements and protective measures 57 Information for use . 97.1 General requirements . 97.2 Instruc
10、tion handbook . 97.3 Marking . 9Annex A (normative) Class C enclosure selection 11Annex B (informative) Equipment for impact tests .19Annex C (informative) Examples of protective devices .20Bibliography .23BS ISO 21940-23:2012ISO 21940-23:2012(E)ForewordISO (the International Organization for Standa
11、rdization) 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 established has the right t
12、o 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 standardization.International Stan
13、dards 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. Publication as an Inte
14、rnational 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 patent rights.ISO 21940-23
15、 was prepared by Technical Committee ISO/TC 108, Mechanical vibration, shock and condition monitoring, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures.This first edition cancels and replaces ISO 7475:2002, which has been
16、 technically revised. The main change is deletion of protection class 0.ISO 21940 consists of the following parts, under the general title Mechanical vibration Rotor balancing: Part 1: Introduction1) Part 2: Vocabulary2) Part 11: Procedures and tolerances for rotors with rigid behaviour3) Part 12: P
17、rocedures and tolerances for rotors with flexible behaviour4) Part 13: Criteria and safeguards for the in-situ balancing of medium and large rotors5) Part 14: Procedures for assessing balance errors6) Part 21: Description and evaluation of balancing machines7) Part 23: Enclosures and other protectiv
18、e measures for the measuring station of balancing machines8)1) Revision of ISO 19499:2007, Mechanical vibration Balancing Guidance on the use and application of balancing standards2) Revision of ISO 1925:2001, Mechanical vibration Balancing Vocabulary3) Revision of ISO 1940-1:2003 + Cor.1:2005, Mech
19、anical vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances4) Revision of ISO 11342:1998 + Cor.1:2000, Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors5) Revision of ISO 208
20、06:2009, Mechanical vibration Criteria and safeguards for the in-situ balancing of medium and large rotors6) Revision of ISO 1940-2:1997, Mechanical vibration Balance quality requirements of rigid rotors Part 2: Balance errors7) Revision of ISO 2953:1999, Mechanical vibration Balancing machines Desc
21、ription and evaluation8) Revision of ISO 7475:2002, Mechanical vibration Balancing machines Enclosures and other protective measures for the measuring stationiv ISO 2012 All rights reservedBS ISO 21940-23:2012ISO 21940-23:2012(E) Part 31: Susceptibility and sensitivity of machines to unbalance9) Par
22、t 32: Shaft and fitment key convention10)9) Revision of ISO 10814:1996, Mechanical vibration Susceptibility and sensitivity of machines to unbalance10) Revision of ISO 8821:1989, Mechanical vibration Balancing Shaft and fitment key convention ISO 2012 All rights reserved vBS ISO 21940-23:2012ISO 219
23、40-23:2012(E)IntroductionIn designing and operating balancing machines, efforts already are made to minimize hazards arising from the use of the machines themselves. Rising demand for still greater safety in the working environment, however, requires additional protective measures, especially with r
24、espect to the rotor to be balanced. Potential hazards to the balancing machine operator or the surrounding workshop area can exist, e.g. by personnel coming into contact with machine components or the rotor, by rotor components or unbalance correction masses detaching and flying off or by the rotor
25、lifting from the supports or disintegrating.Special-purpose balancing machines, e.g. those used in the mass production automotive industry, normally incorporate all necessary protective measures because the workpiece, as well as the operating conditions of the machine, are known and can be taken int
26、o account by the machine manufacturer. For multipurpose balancing machines, however, where the workpieces to be balanced are generally unknown to the machine manufacturer, and are thus beyond his control, basic protective measures are limited to obvious hazards, e.g. from end-drive or belt-drive sys
27、tems. However, the balancing machine manufacturer has to provide sufficient information for the user to assess possible hazards originating from a rotor when in the balancing machine, and from the intended use of the balancing machine. Together with this information, the user of the balancing machin
28、e has to state the possible hazards originating in his rotors in order to allow the balancing machine manufacturer to supply equivalent protective measures or the user has to provide adequate protective measures on his own.When the rotors are not known in advance, e.g. in service and repair, a good
29、estimation is needed. Table A.2 states typical values for different balancing machine sizes. But for each individual type of rotor to be balanced, the user of the balancing machine needs to check if the protective measures cover all hazards.Most local regulations require certain minimum protective m
30、easures to be taken. Observance of such requirements in conjunction with the recommendations contained in this part of ISO 21940 will generally provide an adequate measure of protection to the balancing machine operator and surrounding workshop personnel. There may be applications, however, in which
31、 the recommended enclosures or other protective measures are so costly, or their use so time-consuming, that other protective precautions have to be considered, such as vacating the surrounding area for a sufficient distance, remote control of the balancing machine or work outside normal hours.The c
32、onsideration of accident probability can be important if a rotor needs to be balanced or spin-tested at or above its service speed, where major rotor failure cannot be excluded with as much certainty as during low-speed balancing.On the other hand, a rotor being balanced at low speed may consist of
33、an assembly of several components, such as a bladed turbine wheel. It is then important to consider whether an enclosure for low-speed balancing should withstand penetration of a turbine blade or whether it is sufficient to protect against unbalance correction masses that might fly off during balanc
34、ing. If the probability of blade separation is practically non-existent, a light enclosure, which just protects against correction masses, may be sufficient.Since this part of ISO 21940 deals with balancing machines and protective measures in general, no details of the risk can be stated for specifi
35、c rotor types and balancing machines. Individual investigations, based on actual rotor parameters, will probably be required in each specific case. In this connection, risk analysis of possible accidents should include the characteristics of the balancing machine itself. For the extent of the ensuin
36、g damages, it may be of decisive importance to know how much unbalance can be endured by its supports and bearings due to partial rotor failure, e.g. rotor components becoming detached.The significant hazards covered by this part of ISO 21940 are listed in Clause 4. The safety requirements and prote
37、ctive measures to prevent or minimize those hazards are identified in Clause 5, and procedures for verification of these requirements and protective measures are found in Clause 6.vi ISO 2012 All rights reservedBS ISO 21940-23:2012INTERNATIONAL STANDARD ISO 21940-23:2012(E)Mechanical vibration Rotor
38、 balancing Part 23: Enclosures and other protective measures for the measuring station of balancing machines1 ScopeThis part of ISO 21940 specifies requirements for enclosures and other protective measures used to minimize mechanical hazards produced by the rotor in the unbalance measuring station o
39、f centrifugal (rotational) balancing machines. The hazards are associated with the operation of balancing machines under a variety of rotor and balancing conditions. This part of ISO 21940 defines different classes of protection that enclosures and other protective measures provide and describes the
40、 limits of applicability for each class of protection.Devices for adjusting the mass distribution of a rotor and devices to transfer the rotor are not covered by this part of ISO 21940, even if they are combined with the measuring station.Special enclosure features, such as noise reduction, windage
41、reduction or vacuum (which may be required to spin bladed rotors at balancing speed), are not covered by this part of ISO 21940.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For u
42、ndated references, the latest edition of the referenced document (including any amendments) applies.ISO 1925, Mechanical vibration Balancing Vocabulary11)ISO 4849, Personal eye-protectors Specifications3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 1
43、925 apply.4 List of significant hazards4.1 GeneralSignificant hazards identified at measuring stations of centrifugal (rotational) balancing machines are listed in Table 1 together with examples of associated hazardous situations, activities and danger zones.4.2 Risk assessmentThe user of this part
44、of ISO 21940 (i.e. the balancing machine user, designer, manufacturer or supplier) shall conduct a risk assessment. As part of the risk assessment, the user of this part of ISO 21940 shall describe the intended use of the balancing machine including manual tool loading, workpiece set-up, maintenance
45、, repair and cleaning, together with reasonably foreseeable misuse of the machine. As part of the risk assessment, the user of this part of ISO 21940 shall also verify whether the list of hazards in Table 1 is applicable to the balancing machine under consideration.11) To become ISO 21940-2 when rev
46、ised. ISO 2012 All rights reserved 1BS ISO 21940-23:2012ISO 21940-23:2012(E)Table 1 List of significant specific hazards and examples of hazard sources associated with the measuring station of balancing machinesItem Specific hazard Example of hazard source Associated activity Related danger zone1 Me
47、chanical1.1 Crushing workpiece moving loading the workpiece between rotor and pedestal1.2 Shearingworkpiece rotatingcheck of belt drivearound drive shaft and rotor/guide rollerslubrication of rollers between journal and rollerworkpiece moving in axial direction when rotatingduring process controlbet
48、ween rotor and pedestal, access area around machinepower operation of clamping deviceloading of rotorbetween rotor and clamping device1.3 Impact of massejection of rotorprotective bracket not closed, large unbalances, high balancing speedarea around machine and remote, depending on speed and energy
49、of massesejection of rotor partsparts loose, excessive balancing speedrotor burstingejection of correction masses masses insufficiently fixed1.4Stabbing or punctureend drive not coupled to rotor and drive actuatedstart of drive around end driverotor with protruding parts rotatingchecking set-up while rotor runningat rotor1.5 Entanglementbelt drive running check of belt drivebetween belt and rotor/guide rollersrotor with protruding parts rotatingchecking set-up while rotor runningat rotor1.6 Slip,
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