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1、BRITISH STANDARD BS ISO 7919-3:1996 Implementation of ISO 7919-3:1996 Mechanical vibration of non-reciprocating machines Measurements on rotating shafts and evaluation criteria Part 3: Coupled industrial machines ICS 17.160 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 20
2、06, Uncontrolled Copy, (c) BSI BS ISO 7919-3:1996 This British Standard, having been prepared under the direction of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 November 1996 BSI 11-1998 The following BSI references relate to the
3、 work on this standard: Committee reference GME/21 Draft for comment 89/79538 DC ISBN 0 580 26753 9 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Committee GME/21. Mechanical vibration and shock, upon which the following bodies w
4、ere represented. Federation of Civil Engineering Contractors Imperial College of Science and Technology Institute of Sound and Vibration Research Institute of Mechanical Engineers Lloyds Register of Shipping Ministry of Defence Open University Power Generation Contractors Association (PGCA (BEAMA Lt
5、d.) Railway Industry Association Society of British Aerospace Companies Limited Society of Environmental Engineers The following bodies were also represented in the drafting of the standard, through subcommittees and panels: Electricity Association Amendments issued since publication Amd. No.DateCon
6、tents Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7919-3:1996 BSI 11-1998i Contents Page Commitees responsibleInside front cover National forewordii Forewordiii Text of ISO 7919-31 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 2
7、6 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7919-3:1996 ii BSI 11-1998 National foreword This British Standard reproduces verbatim ISO 7919-3:1996 and implements it as the UK national standard. This British Standard is published under the direction of the Engineering Sector Board whose
8、Technical Committee GME/21 has the responsibility to: aid enquirers to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulg
9、ate them in the UK. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, BSI, 389 Chiswick High Road, London W4 4AL. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are res
10、ponsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the ISO title page, pages ii to iv, pages 1 to 5 and a back cover. This
11、 standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun she
12、ffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7919-3:1996 ii BSI 11-1998 Contents Page Forewordiii Introduction1 1Scope1 2Normative references1 3Measurement procedures1 4Evaluation critria2 Annex A (normative) Evaluation criteria for relative shaft vibration of coup
13、led industrial machines under specified operating conditions3 Figure A.1 Recommended values for maximum relative displacement of the shaft as a function of the maximum service speed for coupled industrial machines5 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncon
14、trolled Copy, (c) BSI BS 7919-3:1996 BSI 11-1998iii 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. Ea
15、ch 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 Internatio
16、nal Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies
17、 casting a vote. International Standard ISO 7919-3 was prepared by Technical Committee ISO/TC 108, Mechanical vibration and shock, Subcommittee SC 2, Measurement and evaluation of mechanical vibration and shock as applied to machines, vehicles and structures. ISO 7919 consists of the following parts
18、, under the general title Mechanical vibration of non-reciprocating machines Measurements on rotating shafts and evaluation criteria: Part 1: General guidelines; Part 2: Large land-based steam turbine generator sets; Part 3: Coupled industrial machines; Part 4: Gas turbine sets; Part 5: Machine sets
19、 in hydraulic power generating and pumping plants. Annex A forms an integral part of this part of ISO 7919. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 20
20、06, Uncontrolled Copy, (c) BSI BS 7919-3:1996 BSI 11-19981 Introduction This part of ISO 7919 deals with the special features required for measuring transverse shaft vibration on coupled industrial machines. Evaluation criteria, based on previous experience, are presented which may be used as guidel
21、ines for assessing the vibratory conditions of such machines. A general description of the principles which are generally applicable for the measurement and evaluation of shaft vibration of non-reciprocating machines is given in ISO 7919-1. 1 Scope This part of ISO 7919 gives guidelines for applying
22、 evaluation criteria for shaft vibration under normal operating conditions, measured at or close to the bearings of coupled industrial machines. These guidelines are presented in terms of both steady running vibration and any magnitude changes which may occur in these steady values. The numerical va
23、lues specified are not intended to serve as the only basis for vibration evaluation since, in general, the vibratory condition of a machine is assessed by consideration of both the shaft vibration and the associated structural vibration (see the introduction to ISO 7919-1). This part of ISO 7919 app
24、lies to coupled industrial machines with fluid-film bearings, having maximum continuous rated speeds in the range 1 000 r/min to 30 000 r/min, and not limited by size and power, comprising steam turbines; turbocompressors; turbopumps; turbogenerators; turbofans; electric drives and associated gears,
25、 where relevant. This part of ISO 7919 does not apply to large land-based steam turbine generator sets for power stations with outputs greater than 50 MW (see ISO 7919-2), nor to machine sets in hydraulic power generating and pumping plants with outputs of 1 MW or greater (see ISO 7919-5). 2 Normati
26、ve references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO 7919. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO 79
27、19 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 7919-1:1996, Mechanical vibration of non-reciprocating machines Measurements on rotating s
28、hafts and evaluation criteria Part 1: General guidelines. ISO 7919-2:1996, Mechanical vibration of non-reciprocating machines Measurements on rotating shafts and evaluation criteria Part 2: Large land-based steam turbine generator sets. ISO 7919-5:1), Mechanical vibration of non-reciprocating machin
29、es Measurements on rotating shafts and evaluation criteria Part 5: Machine sets in hydraulic power generating and pumping plants. ISO 10816-1:1995, Mechanical vibration Evaluation of machine vibration by measurements on non-rotating parts Part 1: General guidelines. 3 Measurement procedures The meas
30、urement procedures to be followed and the instrumentation used shall be as described in ISO 7919-1. In industrial machines, shaft vibration relative to the bearing is normally measured. Therefore, unless stated otherwise, this part of ISO 7919 always refers to relative vibration displacement. In vie
31、w of the relatively high rotational frequencies involved with industrial machines, measuring methods using non-contacting transducers are most common and are generally preferred on rotor elements with operating frequencies of 3 000 r/min and above. For monitoring purposes, the measuring system shall
32、 be capable of covering overall vibration up to a frequency equivalent to 2,5 times the maximum service speed. However, it should be noted that for diagnostic purposes it may be desirable to cover a wider frequency range. 1) To be published. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:
33、03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7919-3:1996 2 BSI 11-1998 4 Evaluation criteria Criteria for vibration magnitude, changes in vibration magnitude and operational limits are presented in annex A. The vibration magnitude is the higher value of the peak-to-peak displacement measured
34、in two selected orthogonal measurement directions. The values presented are the result of experience with machinery of this type and, if due regard is paid to them, acceptable operation may be expected. If only one measuring direction is used, care should be taken to ensure that it provides adequate
35、 information (see ISO 7919-1). The criteria are presented for the specified steady-state operating conditions at the rated speed and load ranges. They apply for normal slow changes in load but do not apply when different conditions exist or during transient changes, for example during start-up and s
36、hut-down and when passing through resonance ranges. In these cases alternative criteria are necessary. It should be noted that an overall judgement of the vibratory state of a machine is often made on the basis of both relative shaft vibration as defined above and of measurements made on non-rotatin
37、g parts (see ISO 10816-1). Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 26 04:03:37 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 7919-3:1996 BSI 11-19983 Annex A (normative) Evaluation criteria for relative shaft vibration of coupled industrial machines under specified operating conditions A
38、.1 General Two evaluation criteria are used to assess the relative shaft vibration of coupled industrial machines, measured at or close to the bearings. One criterion considers the magnitude of the observed broad-band relative shaft vibration; the second considers changes in magnitude, irrespective
39、of whether they are increases or decreases. A.2 Criterion I: Vibration magnitude at rated speed under steady operating conditions This criterion is concerned with defining limits for shaft vibration magnitude consistent with acceptable dynamic loads on the bearing, adequate margins on the radial cle
40、arance envelope of the machine, and acceptable vibration transmission into the support structure and foundation. The maximum shaft vibration magnitude observed at each bearing is assessed against four evaluation zones established from international experience. A.2.1 Evaluation zones The following ty
41、pical evaluation zones are defined to permit a qualitative assessment of the shaft vibration on a given machine and provide guidelines on possible actions. Zone A: The vibration of newly commissioned machines would normally fall within this zone. Zone B: Machines with vibration within this zone are
42、normally considered acceptable for unrestricted long-term operation. Zone C: Machines with vibration within this zone are normally considered unsatisfactory for long-term continuous operation. Generally, the machine may be operated for a limited period in this condition until a suitable opportunity
43、arises for remedial action. Zone D: Vibration values within this zone are normally considered to be of sufficient severity to cause damage to the machine. A.2.2 Evaluation zone limits In accordance with present accumulated experience of shaft vibration measurements in this field, the recommended val
44、ues for the zone boundaries are inversely proportional to the square root of the shaft rotational frequency n (in revolutions per minute). The recommended values presented in Figure A.1 are derived from the expressions below: Zone boundary A/B Zone boundary B/C Zone boundary C/D NOTE 1For a definiti
45、on of S(p-p), see ISO 7919-1. These values are not intended to serve as acceptance specifications, which shall be subject to agreement between the machine manufacturer and customer. However, they provide guidelines for ensuring that gross deficiencies or unrealistic requirements are avoided. In cert
46、ain cases, there may be specific features associated with a particular machine which would require different zone boundary values (higher or lower) to be used. For example, with a tilting pad bearing it may be necessary to specify alternative vibration values, whilst in the case of an elliptical bea
47、ring, different vibration criteria may apply for the directions of maximum and minimum bearing clearances. In particular, it should be recognised that the allowable vibration may be related to the journal diameter since, generally, running clearances will be greater for larger diameter bearings. Con
48、sequently different values may apply for measurements taken at different bearings on the same rotor line. In such cases, it is normally necessary to explain the reasons for this and, in particular, to confirm that the machine will not be endangered by operating with higher vibration values. Higher v
49、alues of vibration can be permitted at other measuring positions and under transient conditions, such as start-up and run-down (including passage through critical speed ranges). A.3 Criterion II: Change in vibration magnitude This criterion provides an assessment of a change in vibration magnitude from a previously established reference or baseline value. A significant increase or decrease in shaft vibration magnitude may occur which requires some action even though zone C of Criterion I has not been reached. Such changes