1、March 2008DEUTSCHE NORM English price group 17No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 17.160; 21.120.40!$LMV“1
2、414251www.din.deDDIN ISO 19499Mechanical vibration Balancing Guidance on the use and application of balancing standards(ISO 19499:2007)English version of DIN ISO 19499:2008-03Mechanische Schwingungen Auswuchttechnik Einfhrung und Leitfaden fr die Auswahl und Anwendung von Auswuchtnormen(ISO 19499:20
3、07)Englische Fassung DIN ISO 19499:2008-03www.beuth.deDocument comprises 41 pagesDIN ISO 19499:2008-03 2 National foreword This standard has been prepared by Technical Committee ISO/TC 108 “Mechanical vibration, shock and condition monitoring”. The responsible German body involved in its preparation
4、 was the Normenausschuss Akustik, Lrmminderung und Schwingungstechnik im DIN und VDI (Acoustics, Noise Control and Vibration Engineering Standards Committee in DIN and VDI), Technical Committee NA 001-03-06-01 (NALS/VDI C 6.1) Auswuchten und Auswuchtmaschinen. Work on this standard began with the in
5、tention of overcoming the rather simplified division of rotors and of the relevant standards into “rigid” (in German starre) or “flexible” (in German nachgiebig) rotors. Since rotors which were formerly considered as being “rigid” are increasingly being reclassified as “flexible”, and since some rot
6、ors can be classified as either rigid or flexible depending on operating conditions, an attempt has been made to identify a means of describing rotors that allows an overview of all applications. The expression “rotor behaviour” used here facilitates a description of the entire range of balancing pr
7、oblems, which is all the more important because the various behaviours need to be approached with totally different balancing techniques. In the title, the word “guidance” was translated into the German “Einfhrung und Leitfaden” (“Introduction and guidelines”) because a large part of the standard gi
8、ves a basic introduction to the unbalance and behaviour of rotors which is not contained in any other standard. There is also a brief description of the various standards on balancing, providing a quick overview of the balancing technology sector. The present standard is a starting point which can s
9、erve as a basis for further developments in the coming years. Any suggestions and remarks from industry and research are essential building blocks for this development. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 1925:2001 DIN ISO 1
10、925:2002 ISO 1940-1 DIN ISO 1940-1 ISO 1940-2 DIN ISO 1940-2 ISO 7475 DIN ISO 7475 ISO 7919 DIN ISO 7919 standards series standards series ISO 8821 DIN ISO 8821 ISO 10816 DIN ISO 10816 standards series standards series ISO 11342:1998 DIN ISO 11342:1999 ISO 20806 DIN ISO 20806 ISO 3719 has not been p
11、ublished as a DIN ISO Standard as the ISO Standard already contains the essential German terms. DIN ISO 19499:2008-03 3 National Annex NA (informative) Bibliography DIN ISO 1925:2002-05, Mechanical vibration Balancing Vocabulary (ISO 1925:2001) DIN ISO 1940-1, Mechanical vibration Balance quality re
12、quirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances (including Corrigendum 1) DIN ISO 7475, Mechanical vibration Balancing machines Enclosures and other protective measures for the measuring station Standards series DIN ISO 7919, Mechanical
13、vibration Evaluation of machine vibration by measurements on rotating shafts DIN ISO 8821, Mechanical vibration Balancing shaft and fitment key convention Standards series DIN ISO 10816, Mechanical vibration Evaluation of machine vibration by measurements on non-rotating parts DIN ISO 11342:1999-05,
14、 Mechanical vibration Methods and criteria for the mechanical balancing of flexible rotors (ISO 11342:1998) (including Corrigendum 1) DIN ISO 20806, Mechanical vibration Criteria and safeguards for the in-situ balancing of medium and large rotors DIN ISO 1940-2, Mechanical vibration Balance quality
15、requirements of rigid rotors Part 2: Balance errors DIN ISO 19499:2007 (E) 4 Mechanical vibration Balancing Guidance on the use and application of balancing standards Contents Page Introduction .5 1 Scope 6 2 Normative references 6 3 Terms and definitions .6 4 Fundamentals of balancing 6 4.1 General
16、6 4.2 Unbalance distribution7 4.3 Unbalance representation.7 5 Balancing considerations .8 5.1 General8 5.2 Rotors with rigid behaviour 8 5.3 Rotors with flexible behaviour .9 5.4 Rotors with special behaviour. 10 5.5 Examples of rotor behaviours. 10 5.6 Influencing factors 11 6 Balance tolerances .
17、 12 6.1 General. 12 6.2 Permissible residual unbalances 12 6.3 Vibration limits 12 7 Selection of a balancing procedure 12 7.1 General. 12 7.2 Selection of a balancing procedure when none is specified . 13 8 International Standards on balancing 18 8.1 General. 18 8.2 Vocabulary. 18 8.3 Balancing pro
18、cedures and tolerances .19 8.4 Balancing machines . 20 8.5 Machine design for balancing . 20 8.6 Machine vibration . 21 Annex A (informative) Mathematical and graphical representation of unbalance 22 Annex B (informative) Examples of different rotor behaviours. 33 Annex C (informative) How to determ
19、ine rotor flexibility based on an estimation from its geometric design 38 Bibliography. 41 DIN ISO 19499:2007 (E) 5Introduction Vibration caused by rotor unbalance is one of the most critical issues in the design and maintenance of machines. It gives rise to dynamic forces which adversely impact bot
20、h machine and human health and well-being. The purpose of this International Standard is to provide a common framework for balancing rotors so that appropriate methods will be used. This standard serves essentially as guidance on the usage of other International Standards on balancing in that it cat
21、egorizes types of machine unbalance. As such, it can be viewed as an introductory standard to the series of International Standards on balancing developed by ISO/TC 108. Balancing is explained in a general manner, as well as the unbalance of a rotor. A certain representation of the unbalance is reco
22、mmended for an easier understanding of the necessary unbalance corrections. DIN ISO 19499:2007 (E) 6 1 Scope This International Standard provides an introduction to balancing and directs the user through the available International Standards associated with rotor balancing. It gives guidance on whic
23、h of these standards should be used. Individual procedures are not included here as these will be found in the appropriate International Standards. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition
24、 cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 1925:2001, Mechanical vibration Balancing Vocabulary ISO 2041, Vibration and shock Vocabulary 3 Terms and definitions For the purposes of this document, the terms and definit
25、ions given in ISO 1925 and ISO 2041 apply. 4 Fundamentals of balancing 4.1 General Balancing is a procedure by which the mass distribution of a rotor (or part or module) is checked and, if necessary, adjusted to ensure that balance tolerances are met. Rotor unbalance may be caused by many factors, i
26、ncluding material, manufacture and assembly, wear during operation, debris or an operational event. It is important to understand that every rotor, even in series production, has an individual unbalance distribution. New rotors are commonly balanced by the manufacturer in specially designed balancin
27、g machines before installation into their operational environment. Following rework or repair, rotors may be rebalanced in a balancing machine or, if appropriate facilities are not available, the rotor may be balanced in situ (see ISO 20806 for details). In the latter case, the rotor is held in its
28、normal service bearings and support structure and installed within its operational drive train. The unbalance on the rotor generates centrifugal forces when it is rotated in a balancing machine or in situ. These forces may be directly measured by force gauges mounted on the structures supporting the
29、 bearings or indirectly by measuring either the motion of the pedestal or the shaft. From these measurements, the unbalance can be calculated and balancing achieved by adding, removing or shifting of correction masses on the rotor. Depending on the particular balancing task, the corrections are perf
30、ormed in one, two or more correction planes. DIN ISO 19499:2007 (E) 74.2 Unbalance distribution In reality, unbalance is made up of an infinite number of unbalance vectors, distributed along the shaft axis of the rotor. If a lumped-mass model is used to represent the rotor, unbalance may be represen
31、ted by a finite number of unbalance vectors of different magnitude and angular direction as illustrated in Figure 1. Figure 1 Unbalance distribution in a rotor modelled as 10 elements perpendicular to the z-axis If all unbalance vectors were corrected in their respective planes, then the rotor would
32、 be perfectly balanced. In practice, it is not possible to measure these individual unbalances and it is not necessary. A more condensed description is needed, leading to practical balancing procedures. 4.3 Unbalance representation Rotor unbalance can be expressed by a combination of the following t
33、hree kinds of unbalance representations: a) resultant unbalance, r,UGthe vector sum of all unbalance vectors distributed along the rotor; b) resultant moment unbalance, r,PGthe vector sum of the moments of all the unbalance vectors distributed along the rotor about the arbitrarily selected plane of
34、the resultant unbalance; c) modal unbalance, ,nUGthat unbalance distribution which affects only the nth natural mode of a rotor/bearing system. Mathematical and graphical representations of unbalances are shown in Annex A. NOTE Resultant unbalance see 4.3 a) and resultant moment unbalance see 4.3 b)
35、 can be combined. The combination is called “dynamic unbalance” and is represented by two unbalances in two arbitrarily chosen planes perpendicular to the shaft axis. DIN ISO 19499:2007 (E) 8 5 Balancing considerations 5.1 General In the past, International Standards classified all rotors to be eith
36、er rigid or flexible, and balancing procedures for these two main classes of rotors are given in ISO 1940-1 and ISO 11342, respectively (see Table 1). However, the simple rigid/flexible classification is a gross simplification, which can lead to a misinterpretation and suggests that the balance clas
37、sification of the rotor is only dependent on its physical construction. Unbalance is an intrinsic property of the rotor, but the behaviour of the rotor and its response to unbalance in its normal operating environment are affected by the dynamics of the bearings and support structure, and by its ope
38、rating speed. Furthermore, the balance quality to which the rotor is expected to run and the magnitude and distribution of the initial unbalance along the rotor will dictate which balancing procedure is necessary; see Table 1. Table 1 Overview of rotor behaviour, related International Standards and
39、balancing procedures Rotor behaviour (Numbers refer to subclauses in this International Standard) Example Related International Standard Balancing task or procedure (Letters as used in ISO 11342:1998) Rigid behaviour (5.2) Figure 4 a) ISO 1940-1 One- and two-plane balancingaFlexible behaviour (5.3)
40、Figure 4 b) Six low-speed balancing procedures (A to F) Balancing procedure at multiple speeds (G) Balancing procedure for one speed only (usually service speed) (H) Component elastic behaviour (5.4.2) Figure 4 c) Fixed-speed balancing procedure (I) Component seating behaviour (5.4.3) Figure 4 d) IS
41、O 11342bSettling of components at high speedcaOne- and two-plane balancing includes balancing the resultant unbalance and the resultant moment unbalance. bISO 11342:1998 uses “flexible” as a generic term that includes flexible, component elastic and component seating behaviours. cThis procedure is m
42、entioned in Clause 7 of ISO 11342:1998, but no designated letter is given. 5.2 Rotors with rigid behaviour An ideal rotor when rotating, with rigid behaviour on elastic supports, will undergo displacements that are combinations of the two dynamic rigid-body modes, as seen in Figure 2 for a simple sy
43、mmetric rotor with unbalance. There is no flexure of the rotor and all displacements of the rotor arise from movements of the bearings and their support structure. Figure 2 Rigid-body modes of a symmetric rotor on a symmetric elastic support structure DIN ISO 19499:2007 (E) 9In reality, no rotor wil
44、l be totally rigid and will have small flexural deflections in relation to the gross rigid-body motion of the rotor. However, the rotor may be regarded as rigid provided these deflections caused by a given unbalance distribution are below the required tolerances at any speed up to the maximum servic
45、e speed. The majority of such rotors, and indeed many manufactured rotors, can be balanced as rigid rotors, in accordance with the requirements of ISO 1940-1. This aims at balancing the resultant unbalance with at least a single-plane balance correction, or the dynamic unbalance with a two-plane bal
46、ance correction. NOTE Rotors designated to have rigid behaviour in the operating environment can be balanced at any speed on the balancing machine provided the speed is sufficiently low to ensure the rotor still operates with a rigid behaviour. 5.3 Rotors with flexible behaviour 5.3.1 General If the
47、 speed is increased or the tolerance reduced for the same rotor described in 5.2, it may become necessary to take flexible behaviour into account. Here the deflection of the rotor is significant, and rigid-body balancing procedures are not sufficient to achieve a desired balance condition. Figure 3
48、shows typical flexural mode shapes for a symmetric rotor. For these rotors that exhibit flexural behaviour, the balancing procedures in ISO 11342 should be adopted. 5.3.2 Low-speed balancing In special circumstances, even rotors with flexible behaviour may be balanced satisfactorily at low speed. IS
49、O 11342:1998 describes procedures A to F, which, as far as possible, all aim to correct the unbalance in their planes of origin. 5.3.3 Multiple-speed balancing This procedure should be used to balance the resultant unbalance, the resultant moment unbalance and the relevant modal unbalances, according to ISO 11342:1998, procedure G. a) First mode b) Second mode c) Third mode Figure 3 Schematic representation of the first three flexural modes of a rotor with flexible behaviour on an elastic support structure DIN ISO 19499:2007
