ISO 1940-1-2003 PDF

Full title and description

Mechanical vibration — Balance quality requirements for rotors in a constant (rigid) state — Part 1: Specification and verification of balance tolerances. This International Standard gives requirements and procedures for specifying permissible unbalance (balance tolerances), selecting the number of correction planes and verifying residual unbalance for rigid rotors used in rotating machinery.

Abstract

ISO 1940-1:2003 provides specifications for balance quality of rotors in a constant (rigid) state. It defines balance tolerance grades, methods to represent unbalance (single- or two-plane), guidance on the number and location of correction planes, and procedures for verifying residual unbalance after correction. The standard excludes flexible rotors (different rules apply).

General information

• Status: Withdrawn.
• Publication date: August 2003 (2003-08).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 21.120.40 (Mechanical vibration).
• Edition / version: Edition 2 (2003).
• Number of pages: 28.

Information in this section is based on the ISO bibliographic record for ISO 1940-1:2003.

Scope

Specifies permissible residual unbalance for rotors considered rigid at operating speed and gives rules to allocate those tolerances to correction planes. The standard covers representation of unbalance (single- and two-plane), permissible specific unbalance relative to rotor mass and service speed, similarity considerations for using published tolerances, and methods for verification and acceptance of residual unbalance. It does not apply to rotors that behave as flexible systems at operating speed (see standards for flexible rotors).

Key topics and requirements

• Definition of balance quality grades (tolerance classes) and permissible residual unbalance values.
• Representation of unbalance in one- or two-plane models and conversion rules between representations.
• Criteria for selecting the necessary number of correction planes.
• Methods and procedures for measuring and verifying residual unbalance after correction.
• Similarity rules to apply tolerances between rotors of different size or speed.
• Allocation rules for distributing tolerance values from tolerance planes to correction planes (informative annex material).
• Recommendations for acceptance criteria to be used in supplier–user relationships.

Typical use and users

Used by rotating-equipment designers, balance-shop technicians, test laboratories, maintenance engineers, OEMs and purchasers specifying acceptance criteria for rotating machinery. It is applied when specifying balance quality in procurement documents, during in‑shop balancing and factory acceptance testing, and when defining repair/refurbishment tolerances for shafts, rotors, fans, turbines, pumps and electric motors that behave rigidly at running speed.

Related standards

ISO 1940-1:2003 has been revised in later work and is part of a family of standards addressing balancing and vibration. Key related documents include ISO 1940-2 (balance errors), standards on balancing machines and vocabulary (for example ISO 2953 and ISO 2041), and the later replacement work in the ISO 21940 series. ISO 1940-1:2003 has been superseded by subsequent ISO work in the 21940 series.

Keywords

balance quality, unbalance, residual unbalance, rotors, rigid rotors, correction planes, balance tolerances, mechanical vibration, rotor balancing, acceptance criteria

FAQ

Q: What is this standard?

A: ISO 1940-1:2003 is an International Standard that specifies balance quality requirements and verification methods for rotors that behave as rigid bodies at operating speed.

Q: What does it cover?

A: It covers specification of permissible residual unbalance (tolerance classes), representation of unbalance (one- or two-plane), selection of correction planes, methods to verify residual unbalance and similarity considerations for applying tolerances between rotors.

Q: Who typically uses it?

A: Mechanical designers, balancing workshops, maintenance and reliability engineers, test laboratories, OEMs and procurement specialists use it to specify and verify rotor balance quality.

Q: Is it current or superseded?

A: ISO 1940-1:2003 is withdrawn and its contents have been superseded by later ISO work (the balance/rotor-related material has been incorporated and updated within the ISO 21940 series and associated corrigenda). A technical corrigendum ISO 1940-1:2003/Cor 1:2005 was published for the 2003 edition.

Q: Is it part of a series?

A: Yes — it is Part 1 of the ISO 1940 series (Part 2 deals with balance errors); related balancing and vibration vocabulary and measurement standards form a group of standards that together support rotor balancing practice. Later related work appears in the ISO 21940 series.

Q: What are the key keywords?

A: Balance quality, permissible unbalance, residual unbalance, rigid rotor, correction plane, tolerance class, mechanical vibration.