AGMA ISO 17485-A08

This standard establishes a classification system, which can beused to communicate geometrical accuracy specifications ofunassembled bevel gears, hypoid gears, and gear pairs. It definesgear tooth accuracy terms and specifies the structure of the gearaccuracy grade system and allowable values.

This standard provides the gear manufacturer and the gear buyerwith a mutually advantageous reference for uniform tolerances. Tenaccuracy grades are defined, numbered 2 to 11, in order ofdecreasing precision. Equations for tolerances and their ranges ofvalidity are provided in 5.4 for the defined accuracy of gearing.In general, these tolerances cover the following ranges:

1.0 mm ≤ mmn ≤ 50 mm

5 ≤ z ≤ 400

5 mm≤ dT ≤ 2500 mm

where

dT is tolerance diameter;

m_mn is mean normal module;

z is number of teeth.

See clause 6 for required and optional measuring methods. Astolerances are calculated from the actual dimensions of a bevelgear, tolerance tables are not provided. In order to get anoverview, example values of tolerances and graphs are given inannex A.

This standard does not apply to enclosed gear unit assemblies,including speed reducers or increasers, gear motors, shaft mountedreducers, high speed units, or other enclosed gear units which aremanufactured for a given power, speed, ratio or application.

Gear design is beyond the scope of this Standard. The use of theaccuracy grades for the determination of gear performance requiresextensive experience with specific applications. Therefore, theusers of this standard are cautioned against the direct applicationof tolerance values to a projected performance of unassembled(loose) gears when they are assembled.

Tolerance values for gears outside the limits stated in thisstandard will need to be established by determining the specificapplication requirements. This could require the setting of atolerance other than calculated by the formulas in thisstandard.

Edition:

A08

Published:

05/20/2008

ANSI:

ANSI Approved

Number of Pages:

30