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GB/T 9239.1-2006 PDF in English

GB/T 9239.1-2006 (GB/T9239.1-2006, GBT 9239.1-2006, GBT9239.1-2006)
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Standards related to: GB/T 9239.1-2006

GB/T 9239.1-2006: PDF in English (GBT 9239.1-2006)

GB/T 9239.1-2006
ICS 21.120.40
N 73
GB/T 9239.1-2006 / ISO 1940-1:2003
Replacing GB/T 9239-1988
Mechanical vibration - Balance quality requirements
for rotors in a constant (rigid) state - Part 1:
Specification and verification of balance tolerances
(ISO 1940-1:2003, IDT)
Issued by:
General Administration of Quality Supervision, Inspection
and Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of
Table of Contents
Foreword ... 3 
Introduction ... 5 
1 Scope ... 6 
2 Normative references ... 6 
3 Terms and definitions ... 7 
4 Pertinent aspects of balancing ... 11 
5 Similarity considerations ... 15 
6 Specification of balance tolerances ... 20 
7 Allocation of permissible residual unbalance to tolerance planes ... 22 
8 Allocation of balance tolerances to correction planes ... 24 
9 Assembled rotors ... 26 
10 Verification of residual unbalance ... 27 
Annex A ... 30 
Annex B ... 34 
Annex C ... 36 
Annex D ... 37 
Annex E ... 39 
Bibliography ... 42 
GB/T 9239 “Mechanical vibration - Balance quality requirements for rotors in a
constant (rigid) state” consists of the following two parts:
— Part 1: Specification and verification of balance tolerances;
— Part 2: Balance errors.
This Part is Part 1 of GB/T 9239.
This Part is identical to ISO 1940-1:2003 “Mechanical vibration - Balance quality
requirements for rotors in a constant (rigid) state - Part 1: Specification and verification
of balance tolerances” (English version, Second edition).
This Part is drafted in accordance with ISO 1940-1:2003 and its technical
corrigendum 1 published in 2005 by using translation method. The text structure and
technical content are consistent with that of ISO 1940-1:2003.
For convenience of use, this Part has made the following editorial modifications:
— DELETE the foreword of ISO 1940-1:2003;
— REPLACE the decimal point symbol “,” with the decimal point symbol “.”;
— MODIFY the introductory phrase in Clause 2 “Normative references”;
— The international standards referenced in Clause 2 of ISO 1904-1:2003 are
changed into the corresponding national standards directly referenced by this
— CORRECT the misprints (see the footnote of A.3).
This Part replaces GB/T 9239-1988 “Balance quality of rigid rotors - Determination of
permissible residual unbalance”.
This Part has made the following modifications to GB/T 9239-1988:
— MODIFY the standard name;
— ADD table of contents, foreword, introduction, and normative references;
— ADJUST the overall structure of the standard according to ISO 1940-1:2003;
— REDEFINE parts of terms;
— INTRODUCE reference planes for balance tolerances; tolerance planes replace
the using correction planes;
— DELETE some examples;
— MODIFY the Annex A;
— MODIFY the Annex B;
— ADD Annex C, Annex D, and Annex E;
— ADD the bibliography.
Annex A, Annex B, Annex C, Annex D, and Annex E of this Part are informative.
This Part was proposed by China Machinery Industry Federation.
This Part shall be under the jurisdiction of National Standardization Technical
Committee of Mechanical Vibration and Impact.
Responsible drafting organization of this Part: Changchun Institute of Test Machine.
Participating drafting organizations of this Part: Xiaogan Songlin International
Measuring Device Co., Ltd., Changchun Zhonglian Test Equipment Co., Ltd.,
Shanghai Schenck Machinery Co., Ltd., No. 6354 Institute of China State Shipbuilding
Corporation, and Zhengzhou Machinery Research Institute.
Main drafters of this Part: Liu Zhili, Zhang Shimin, Shao Chunping, Wang Chaorong,
Yang Dechun, and Huang Runhua.
The historical version replaced by this Part is as follows:
— GB/T 9239-1988.
Mechanical vibration - Balance quality requirements
for rotors in a constant (rigid) state - Part 1:
Specification and verification of balance tolerances
1 Scope
This Part of GB/T 9239 gives specifications for rotors in a constant (rigid) state. It
a) balance tolerances,
b) the necessary number of correction planes, and
c) methods for verifying the residual unbalance.
Recommendations are also given concerning the balance quality requirements for
rotors in a constant (rigid) state, according to their machinery type and maximum
service speed. These recommendations are based on worldwide experience.
This Part of GB/T 9239 is also intended to facilitate the relationship between the
manufacturer and user of rotating machines, by stating acceptance criteria for the
verification of residual unbalances.
Detailed consideration of errors associated with balancing and verification of residual
unbalance are given in GB/T 9239.2.
This Part of GB/T 9239 does not cover rotors in a flexible state. The balance quality
requirements for rotors in a flexible state are covered by GB/T 6557.
2 Normative references
The provisions in following documents become the provisions of this Part through
reference in this Part of GB/T 9239. For dated references, the subsequent
amendments (excluding corrections) or revisions do not apply to this Part, however,
parties who reach an agreement based on this Part are encouraged to study if the
latest versions of these documents are applicable. For undated references, the latest
edition of the referenced document applies.
9 Assembled rotors
9.1 General
Assembled rotors may be balanced as integral rotors or on the component level. For
each assembly, the unbalances of the components superimpose and assembly errors
create additional unbalances, for instance, because of runout and play (see GB/T
9239.2 for details).
NOTE: If assembly errors are not decisive, the choice of balancing process may be governed
by the availability of balancing machines.
9.2 Balanced as a unit
The best way to take care of all unbalances in the rotor and all related assembly
errors in one step is to balance the rotor as a fully assembled unit.
If a rotor is balanced as an assembly but needs to be disassembled afterwards (e.g.
for mounting into the housing), it is recommended to mark each component angularly
to ensure identical angular positions during reassembly.
NOTE: The above-mentioned problems with runout and play can still exist.
9.3 Balanced on component level
If individual components are balanced separately, the following comments are
a) Usually all components are balanced to the same specific residual unbalance
(see Clause 5). However, allowing for additional assembly errors (see GB/T
9239.2) means that the specific residual unbalance of each component shall be
smaller than the specific residual unbalance for the assembly.
b) If this causes problems (e.g. with a light fan or pulley on a heavy armature) any
distribution rule is allowed, provided that the total unbalance of the assembly is
kept within tolerance.
c) Prior agreement between the manufacturer and user should be reached as to
the attachment of connecting elements such as keys (see GB/T 16808).
If the balance tolerance for an assembly cannot be achieved by balancing each
component separately, the assembly shall be balanced finally as a unit. In such cases,
it is recommended to reconsider whether balancing on the component level is really
necessary or if it may be omitted.
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.