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ISO 21940-21:2012

Withdrawn
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A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

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withdrawn

A Withdrawn Standard is one, which is removed from sale, and its unique number can no longer be used. The Standard can be withdrawn and not replaced, or it can be withdrawn and replaced by a Standard with a different number.

Mechanical vibration — Rotor balancing — Part 21: Description and evaluation of balancing machines
Available format(s)

Hardcopy , PDF , PDF 3 Users , PDF 5 Users , PDF 9 Users

Withdrawn date

11-07-2022

Language(s)

English

Published date

07-10-2012

ISO 21940-21:2012 specifies requirements for evaluating the performance of machines for balancing rotating components by the following tests: a) test for minimum achievable residual unbalance, Umar test; 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 acceptance 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 ISO 21940-21:2012.

For these tests, three types of especially 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.

Moreover, ISO 21940-21:2012 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 given on the information by which users provide their data and requirements to a balancing machine manufacturer.

ISO 21940-21:2012 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 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 machines. Technical requirements for such balancing machines are included; however, special features, such as those associated with automatic correction, are excluded.

ISO 21940-21:2012 does not specify balancing criteria; such criteria are specified in ISO 1940-1 and ISO 11342 (only low-speed balancing procedures apply).

DevelopmentNote
Supersedes ISO/FDIS 21940-21 and ISO 2953. (07/2012)
DocumentType
Standard
Pages
53
PublisherName
International Organization for Standardization
Status
Withdrawn
SupersededBy

Standards Relationship
UNI ISO 21940-21 : 2013 Identical
DIN ISO 21940-21 E : 2013 Identical
DIN ISO 21940-21:2013-09 Identical
BS ISO 21940-21:2012 Identical

ISO 16084:2017 Balancing of rotating tools and tool systems
16/30320661 DC : 0 BS ISO 21940-2 - MECHANICAL VIBRATION - ROTOR BALANCING - PART 2: VOCABULARY
ISO 21940-14:2012 Mechanical vibration — Rotor balancing — Part 14: Procedures for assessing balance errors
BS ISO 21940-11:2016 Mechanical vibration. Rotor balancing Procedures and tolerances for rotors with rigid behaviour
BS ISO 21940-14:2012 Mechanical vibration. Rotor balancing Procedures for assessing balance errors
DIN ISO 21940-11:2016-01 (Draft) MECHANICAL VIBRATION - ROTOR BALANCING - PART 11: PROCEDURES AND TOLERANCES FOR ROTORS WITH RIGID BEHAVIOUR (ISO 21940-11:2016)
DIN ISO 21940-14:2012-10 Mechanical vibration - Rotor balancing - Part 14: Procedures for assessing balance errors (ISO 21940-14:2012)
UNI ISO 21940-14 : 2012 MECHANICAL VIBRATION - ROTOR BALANCING - PART 14: PROCEDURES FOR ASSESSING BALANCE ERRORS
SAE ARP 4050 : 2017 BALANCING MACHINES - DESCRIPTION AND EVALUATION VERTICAL, TWO-PLANE, HARD-BEARING TYPE FOR GAS TURBINE ROTORS
ISO 21940-11:2016 Mechanical vibration Rotor balancing Part 11: Procedures and tolerances for rotors with rigid behaviour
SAE ARP 5323 : 2017 BALANCING MACHINES - DESCRIPTION AND EVALUATION VERTICAL, SINGLE-PLANE, HARD-BEARING TYPE FOR GAS TURBINE ROTORS
BS ISO 16084:2017 Balancing of rotating tools and tool systems

ISO 2953:1999 Mechanical vibration Balancing machines Description and evaluation
SAE ARP 4162 : 2017 BALANCING MACHINE PROVING ROTORS
ISO 1940-1:2003 Mechanical vibration Balance quality requirements for rotors in a constant (rigid) state Part 1: Specification and verification of balance tolerances
ISO 1925:2001 Mechanical vibration Balancing Vocabulary

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