ISO/TC 60/WG 2 - Accuracy of gears

This document establishes a gear tooth classification system relevant to double flank radial composite deviations of individual cylindrical involute gears and sector gears. It specifies the appropriate definitions of gear tooth deviations, the structure of the gear tooth flank classification system, and the allowable values of the gear tooth deviations. It provides formulae to calculate tolerances for individual product gears when mated in double flank contact with a master gear. Tolerance tables are not included. This document is applicable to gears with three or more teeth that have reference diameters of up to 600 mm. This document does not provide guidance on gear design nor does it recommend tolerances.

This document supplements ISO 1328‑1:2013. It provides a code of practice dealing with measurements on flanks of individual cylindrical involute gears, i.e. with the measurement of pitch, profile, helix and tangential composite characteristics. It describes measuring equipment, provides advice for gear measuring methods and for the analysis of measurement results, and discusses the interpretation of results. Measurements using a double flank tester are not included (see ISO/TR 10064‑2). This document only applies to involute gears.

ISO 1328-1:2013 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. ISO 1328-1:2013 provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances.

ISO/TR 10064-6:2009 provides information on measuring methods and practices of unassembled bevel and hypoid gears and gear pairs. It includes methods and practices, which permit the manufacturer and purchaser to conduct measuring procedures which are accurate and repeatable to a degree compatible with the specified tolerance grade of ISO 17485. Tolerances are given in Clause 5 of ISO 17485:2006, for calculating the maximum values allowed by the specific tolerance grade. Required and optional measuring methods are provided in Clause 6 of ISO 17485:2006. ISO/TR 10064-6:2009 applies to bevel gear components as defined in ISO 17485. It does not apply to enclosed gear unit assemblies, including speed reducers or increasers, gear motors, shaft mounted reducers, high speed units, or other enclosed gear units which are manufactured for a given power, speed, ratio or application.

Provides recommended values for dimensional deviations on blanks, centre distance and parallelism of axes of gears. Numerical values given in this document are not to be regarded as strict ISO quality criteria, but may serve as a guide for mutual agreements, for steel or iron components.

Provides recommendations on measurement considerations for surface roughness and tooth contact pattern checking of gear flanks.

Constitutes a code of practice dealing with inspection relevant to radial composite deviations, runout, tooth thickness and backlash of cylindrical involute gears; i.e. with measurements referred to double flank contact.

This part of ISO/TR 10064 provides additional information and examples to support the implementation of ISO 18653. It proposes evaluation and calibration procedures for involute, helix, pitch, runout, and tooth thickness measurement processes. Methods are given for evaluation of the condition and alignments of instrument elements such as centres, guideways, probe systems, etc. Recommendations are included for establishment of a proper environment and for statistical data evaluation procedures. It also covers the application of gear artifacts to the estimation of U95 measurement process uncertainty. Guidance on the application of measurement processes to the inspection of product gears is provided, including fitness for use and the recommended limits for U95 uncertainty based upon the accuracy tolerances of product gears to be inspected. Many of its recommendations may also be applicable to the measurement of worms, worm wheels, bevel gears and gear cutting tools.

ISO 17485:2006 establishes a classification system that can be used to communicate geometrical accuracy specifications of unassembled bevel gears, hypoid gears, and gear pairs. It defines gear tooth accuracy terms, and specifies the structure of the gear accuracy grade system and allowable values. ISO 17485:2006 provides the gear manufacturer and the gear buyer with a mutually advantageous reference for uniform tolerances. Ten accuracy grades are defined, numbered 2 to 11 in order of decreasing precision. ISO 17485:2006 does not apply to enclosed gear unit assemblies, including speed reducers or increasers, gear motors, shaft mounted reducers, high speed units, or other enclosed gear units manufactured for a given power, speed, ratio or application. Gear design is beyond the scope of ISO 17485:2006. The use of the accuracy grades for the determination of gear performance requires extensive experience with specific applications. Therefore, the users of this International Standard are cautioned against the direct application of tolerance values to a projected performance of unassembled (loose) gears when they are assembled.

ISO/TR 10064-5:2005 provides additional information and examples to support the implementation of ISO 18653. It proposes evaluation and calibration procedures for involute, helix, pitch, runout, and tooth thickness measurement processes. Methods are given for evaluation of the condition and alignments of instrument elements such as centres, guideways, probe systems, etc. Recommendations are included for establishment of a proper environment and for statistical data evaluation procedures. It also covers the application of gear artefacts to the estimation of U95 measurement process uncertainty. Guidance on the application of measurement processes to the inspection of product gears is provided, including fitness for use and the recommended limits for U95 uncertainty based upon the accuracy tolerances of product gears to be inspected. Many of its recommendations may also be applicable to the measurement of worms, worm wheels, bevel gears and gear cutting tools

ISO 18653:2003 specifies methods for the evaluation of measuring instruments used for gear measurements of involute, helix, pitch and runout. It is applicable both to instruments that measure runout directly and to those that compute it from index measurements. It also gives recommendations for the evaluation of tooth thickness measuring instruments and, of necessity, includes the estimation of measurement uncertainty with the use of calibrated gear artifacts. It does not address the calibration of artifacts by laboratories accredited in accordance with ISO 17025; nor are its requirements intended as an acceptance specification of product gears (see ISO 1328-1, ISO 1328-2, ISO/TR 10064-1 and ISO/TR 10064-2). The estimation of product gear measurement uncertainty is beyond its scope (see ISO/TR 10064-5 for recommendations).

Provides recommended values for dimensional deviations on blanks, centre distance and parallelism of axes of gears. Numerical values given are not to be regarded as strict ISO quality criteria, but may serve as a guide for mutual agreements.

Gives advice on gear checking methods and the analysis of measurement results. Supplements the standard ISO 1382-2.

ISO/TR 10064-1:2017 supplements ISO 1328‑1:2013. It provides a code of practice dealing with measurements on flanks of individual cylindrical involute gears, i.e. with the measurement of pitch, profile, helix and tangential composite characteristics. It describes measuring equipment, provides advice for gear measuring methods and for the analysis of measurement results, and discusses the interpretation of results. Measurements using a double flank tester are not included (see ISO/TR 10064‑2). This document only applies to involute gears.

Provides advice on gear inspection methods and gives an analysis of measurement results, so it supplements the standard ISO 1328, Part 1.

Cancels and replaces ISO 1328 (1975). Establishes a system of accuracy relevant to corresponding flanks of individual cylindrical involute gears. Specifies appropriate definitions for gear tooth accuracy terms, the structure of the gear accuracy system and the allowable values of pitch deviations, total profile deviations and total helix deviations. Applies only to each element of a toothed wheel taken individually. Does not cover gear pairs as such.

Provides advice on gear inspection methods and gives an analysis of measurement results, so it supplements the standard ISO 1328, Part 1.