1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 21940-21:2012Mechanical vibration RotorbalancingPart 21: Description and evaluation ofbalancing machinesBS ISO 21940-21:2012 BRITISH STANDARDNational forewordThis British
2、Standard is the UK implementation of ISO21940-21:2012. It supersedes BS ISO 2953:1999 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee GME/21/5, Mechanical vibration, shock and conditionmonitoring - Vibration of machines.A list of organizations represent
3、ed 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 StandardsLimited 2012ISBN 978 0 580 71413
4、 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 31 July 2012.Amendments issued since publicationDate Text affectedBS ISO 21940-21:2012Reference numb
5、erISO 21940-21:2012(E)ISO 2012INTERNATIONAL STANDARD ISO21940-21First edition2012-07-15Mechanical vibration Rotor balancing Part 21: Description and evaluation of balancing machines Vibrations mcaniques quilibrage des rotors Partie 21: Description et valuation des machines quilibrer BS ISO 21940-21:
6、2012ISO 21940-21:2012(E) COPYRIGHT PROTECTED DOCUMENT ISO 2012 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 permission in writing from ei
7、ther 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 2012 All rights reservedBS ISO 21940-21:2012I
8、SO 21940-21:2012(E) ISO 2012 All rights reserved iiiContents Page Foreword iv 1 Scope 1 2 Normative references 2 3 Terms and definitions . 2 4 Capacity and performance data of the balancing machine 2 4.1 General . 2 4.2 Data for horizontal balancing machines . 2 4.3 Data for vertical balancing machi
9、nes 6 5 Machine features . 10 5.1 Principle of operation 10 5.2 Arrangement of the machine 10 5.3 Indicating system 11 5.4 Plane separation system 12 5.5 Setting and calibration of indication . 12 5.6 Other devices . 13 6 Minimum achievable residual unbalance 13 7 Production efficiency 13 7.1 Genera
10、l . 13 7.2 Time per measuring run 14 7.3 Unbalance reduction ratio 14 8 Performance qualifying factors . 14 9 Installation requirements 15 9.1 General . 15 9.2 Electrical and pneumatic requirements 15 9.3 Foundation . 15 10 Proving rotors and test masses . 15 10.1 General . 15 10.2 Proving rotors 15
11、 10.3 Test masses . 17 11 Verification tests 26 11.1 Requirements for performance and parameter verification 26 11.2 Duties of manufacturer and user . 26 11.3 Requirement for weighing scale 27 11.4 Test and rechecks . 27 11.5 Test speed 27 11.6 Test for minimum achievable residual unbalance, Umar. 2
12、7 11.7 Test for unbalance reduction ratio, URR 31 11.8 Test for couple unbalance interference on single-plane machines . 40 11.9 Compensator test 40 11.10 Simplified tests 41 Annex A (informative) Information provided by the user to the balancing machine manufacturer . 42 Annex B (informative) URR l
13、imit diagrams . 47 Annex C (informative) Shafts of outboard proving rotors type C 50 Annex D (informative) Modifications of proving rotors prepared in accordance with ISO 2953:1985 to this part of ISO 21940 . 52 Bibliography 53 BS ISO 21940-21:2012ISO 21940-21:2012(E) iv ISO 2012 All rights reserved
14、Foreword ISO (the International Organization 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 t
15、echnical 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
16、 of electrotechnical standardization. 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 circulate
17、d to the member bodies for voting. 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
18、for identifying any or all such patent rights. ISO 21940-21 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 firs
19、t edition of ISO 21940-21 cancels and replaces ISO 2953:1999, of which it constitutes an editorial revision. The main change is that for all definitions, reference is made to ISO 1925. Additionally, the Scope has been reworded in order to exactly reflect what this part of ISO 21940 is dealing with.
20、Furthermore, some rough rounding in the numbers given in the Tables has been smoothened, and some Figures drawn more exactly. 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 t
21、olerances for rotors with rigid behaviour3) Part 12: Procedures and tolerances for rotors with flexible behaviour4) Part 13: Criteria and safeguards for the in-situ balancing of medium and large rotors5)1)Revision of ISO 19499:2007, Mechanical vibration Balancing Guidance on the use and application
22、of balancing standards 2)Revision of ISO 1925:2001, Mechanical vibration Balancing Vocabulary 3)Revision of ISO 1940-1:2003 + Cor.1:2005, Mechanical vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances 4)Revision o
23、f ISO 11342:1998 + Cor.1:2000, Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors 5)Revision of ISO 20806:2009, Mechanical vibration Criteria and safeguards for the in-situ balancing of medium and large rotors BS ISO 21940-21:2012ISO 21940-21:2012(E) ISO 2012 A
24、ll rights reserved v Part 14: Procedures for assessing balance errors6) Part 21: Description and evaluation of balancing machine7) Part 23: Enclosures and other protective measures for the measuring station of balancing machines8) Part 31: Susceptibility and sensitivity of machines to unbalance9) Pa
25、rt 32: Shaft and fitment key convention10)6)Revision of ISO 1940-2:1997, Mechanical vibration Balance quality requirements of rigid rotors Part 2: Balance errors 7)Revision of ISO 2953:1999, Mechanical vibration Balancing machines Description and evaluation 8)Revision of ISO 7475:2002, Mechanical vi
26、bration Balancing machines Enclosures and other protective measures for the measuring station 9)Revision of ISO 10814:1996, Mechanical vibration Susceptibility and sensitivity of machines to unbalance 10)Revision of ISO 8821:1989, Mechanical vibration Balancing Shaft and fitment key convention BS IS
27、O 21940-21:2012BS ISO 21940-21:2012INTERNATIONAL STANDARD ISO 21940-21:2012(E) ISO 2012 All rights reserved 1Mechanical vibration Rotor balancing Part 21: Description and evaluation of balancing machines 1 Scope This part of ISO 21940 specifies requirements for evaluating the performance of machines
28、 for balancing rotating components by the following tests: a) test for minimum achievable residual unbalance, Umartest; b) test for unbalance reduction ratio, URR test; c) test for couple unbalance interference on single-plane machines; d) compensator test. These tests are performed during acceptanc
29、e of a balancing machine and also later, on a periodic basis, to ensure that the balancing machine is capable of handling the actual balancing tasks. For periodic tests, simplified procedures are specified. Tests for other machine capacities and performance parameters, however, are not contained in
30、this part of ISO 21940. For these tests, three types of specially prepared proving rotors are specified, covering a wide range of applications on horizontal and vertical balancing machines. An annex describes recommended modifications of proving rotors prepared in acccordance with ISO 2953:1985.2Mor
31、eover, this part of ISO 21940 also stresses the importance attached to the form in which the balancing machine characteristics are specified by the manufacturer. Adoption of the format specified enables users to compare products from different manufacturers. Additionally, in an annex, guidelines are
32、 given on the information by which users provide their data and requirements to a balancing machine manufacturer. This part of ISO 21940 is applicable to balancing machines that support and rotate rotors with rigid behaviour at balancing speed and that indicate the amounts and angular locations of a
33、 required unbalance correction in one or more planes. Therefore, it is applicable to rotors with rigid behaviour as well as to rotors with shaft-elastic behaviour balanced in accordance with low-speed balancing procedures. It covers both soft-bearing balancing machines and hard-bearing balancing mac
34、hines. Technical requirements for such balancing machines are included; however, special features, such as those associated with automatic correction, are excluded. This part of ISO 21940 does not specify balancing criteria; such criteria are specified in ISO 1940-11and ISO 113423(only low-speed bal
35、ancing procedures apply). BS ISO 21940-21:2012ISO 21940-21:2012(E) 2 ISO 2012 All rights reserved2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest
36、edition of the referenced document (including any amendments) applies. ISO 1925, Mechanical vibration Balancing Vocabulary11)3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1925 apply. 4 Capacity and performance data of the balancing machine 4.1 Gene
37、ral The manufacturer shall specify the data listed in 4.2 for horizontal or 4.3 for vertical balancing machines, as applicable, and in a similar format. NOTE Information provided by the user to the balancing machine manufacturer is summarized in Annex A. 4.2 Data for horizontal balancing machines 4.
38、2.1 Rotor mass and unbalance limitations 4.2.1.1 The maximum mass of a rotor, m, which can be balanced shall be stated over the range of balancing speeds (n1, n2, .). The maximum moment of inertia of a rotor with respect to the shaft axis, m r2, where m is the rotor mass and r is the radius of gyrat
39、ion, which the machine can accelerate in a stated acceleration time shall be given for the range of balancing speeds (n1, n2, .) together with the corresponding cycle rate (see Table 1). 4.2.1.2 Production efficiency (see Clause 7) shall be stated, as follows. 4.2.1.2.1 Time per measuring run: a) Ti
40、me for mechanical adjustment: . s b) Time for setting indicating system: s c) Time for preparation of rotor: . s d) Average acceleration time: s e) Reading time (including time to stabilize): . s f) Average deceleration time: s g) Relating readings to rotor: . s h) Other necessary time: . s i) Total
41、 time per measuring run a) to h) in the preceding: s 11)To become ISO 21940-2 when revised. BS ISO 21940-21:2012ISO 21940-21:2012(E) ISO 2012 All rights reserved 34.2.1.2.2 Unbalance reduction ratio, URR, for inboard rotors: . % 4.2.1.2.3 Unbalance reduction ratio for outboard rotors: % Table 1 Data
42、 for horizontal balancing machines Manufacturer: . Model: Balancing speeds or speed ranges (see also 4.2.3.1) n1n2n3n4 Rotor mass (see Note 1) kg maximum, mmaxminimum Occasional overload force per support (see Note 1) N Maximum negative force per support (see Note 1) N Maximum rotor moment of inerti
43、a with respect to the shaft axis (see Note 2) kgm2Cycle rate (see Note 2) Maximum unbalance (see Note 3) gmm/kg or gmm measurable permissible a) For inboard rotors Minimum achievable residual specific unbalance, emar(see Note 4 and Clause 6) gmm/kg maximum mass, mmax0,2 mmaxminimum mass Correspondin
44、g deflection of analogue amount-of-unbalance indicator, mm or Number of digital units (see Note 4) maximum mass, mmax0,2 mmaxminimum mass b) For outboard rotors Minimum achievable residual specific unbalance, emar(see Note 4 and Clause 6) gmm/kg maximum mass, mmax0,2 mmaxminimum mass Corresponding d
45、eflection of analogue amount-of-unbalance indicator, mm or Number of digital units (see Note 4) maximum mass, mmax0,2 mmaxminimum mass NOTE 1 The occasional overload force is only stated for the lowest balancing speed. It is the maximum force per support that can be accommodated by the machine witho
46、ut immediate damage. The negative force is the static upward force resulting from a rotor having its centre of mass outside the bearing support. NOTE 2 Cycle rate for a given balancing speed is the number of starts and stops which the machine can perform per hour without damage to the machine when b
47、alancing a rotor of the maximum moment of inertia. NOTE 3 In general, for rotors with rigid behaviour with two correction planes, one-half of the stated value pertains to each plane; for disc-shaped rotors, the full stated value holds for one plane. NOTE 4 Limits for soft-bearing machines are genera
48、lly stated in gram millimetres per kilogram (specific unbalance, gmm/kg), since this value represents a measure of rotor displacement and, therefore, motion of the balancing machine bearings. For hard-bearing machines, the limits are generally stated in gram millimetres (gmm), since these machines a
49、re usually factory calibrated to indicated unbalance in such units (see Clause 6). For two-plane machines, this is the result obtained when the minimum achievable residual unbalance is distributed between the two planes. BS ISO 21940-21:2012ISO 21940-21:2012(E) 4 ISO 2012 All rights reserved4.2.2 Rotor dimensions 4.2.2.1 Adequate envelope drawings of the pedestals and of other obstructions, such as belt-drive mechanism, shroud mounting pads, thrust arms and ti
