Cylindrical gears — ISO system of flank tolerance classification — Part 1: Definitions and allowable values of deviations relevant to flanks of gear teeth

SCOPE:

This part of ISO 1328 establishes a tolerance classification system relevant to manufacturing and conformity assessment of tooth flanks of individual cylindrical involute gears. It specifies definitions for gear flank tolerance terms, the structure of the flank tolerance class system, and allowable values.

This part of ISO 1328 provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances. Eleven flank tolerance classes are defined, numbered 1 to 11, in order of increasing tolerance. Formulae for tolerances are provided in 5.3. These tolerances are applicable to the following ranges:

5 ≤ z ≤ 1 000

5 mm ≤ d ≤ 15 000 mm

0,5 mm ≤ m_n ≤ 70 mm

4 mm ≤ b ≤ 1 200 mm

β ≤ 45°

where

d is the reference diameter;
m_n is the normal module;
b is the facewidth (axial);
z is the number of teeth;
β is the helix angle.

See Clause 4 for required and optional measuring methods.

Gear design is beyond the scope of this part of ISO 1328.

Surface texture is not considered in this part of ISO 1328. For additional information on surface texture, see ISO/TR 10064-4.

FORWARD:

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. Each 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 International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. 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 casting a vote.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 1328-1 was prepared by Technical Committee ISO/TC 60, Gears.

This second edition cancels and replaces the first edition (ISO 1328-1:1995), which has been technically revised. In particular, the following are the major changes:

— the scope of applicability has been expanded;
— revisions have been made to the formulae which define the flank tolerances;
— annexes have been added to describe additional methods for analysis of modified profiles and helices;
— the evaluation of runout, previously handled in ISO 1328-2, has been brought back into this part of ISO 1328.

ISO 1328 consists of the following parts, under the general title Cylindrical gears — ISO system of flank tolerance classification:

— Part 1: Definitions and allowable values of deviations relevant to flanks of gear teeth.
— Part 2: Definitions and allowable values of deviations relevant to radial composite deviations and runout information.

NORMATIVE REFERENCES:

ISO 701, International gear notation — Symbols for geometrical data

ISO 1122-1, Vocabulary of gear terms — Part 1: Definitions related to geometry

ISO 1328-2, Cylindrical gears — ISO system of accuracy — Part 2: Definitions and allowable values of
deviations relevant to radial composite deviations and runout information

ISO/TR 10064-1, Code of inspection practice — Part 1: Inspection of corresponding flanks of gear teeth

ISO/TS 16610-1, Geometrical product specifications (GPS) — Filtration — Part 1: Overview and basic concepts

ISO 16610-21, Geometrical product specifications (GPS) — Filtration — Part 21: Linear profile filters: Gaussian filters

ISO 21771, Gears — Cylindrical involute gears and gear pairs — Concepts and geometry

REFERENCE NUMBER: ISO 1328-1:2013(E)