GB/T 10095.2-2023 Cylindrical gears - ISO system of flank tolerance classification-Part 2 : Definitions and allowable values of double flank radial composite deviations
1 Scope
This document establishes a tolerance classification system relevant to double flank radial composite deviations of individual cylindrical involute gears and sector gears. It specifies the definitions of radial composite deviations, the structure of the tolerance classification system, and the allowable values of double flank radial composite 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.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 701 International gear notation - Symbols for geometrical data
Note: GB/T 2821-2003 Gear - Symbols for geometrical data (ISO 701:1998, IDT)
ISO 1122-1 Vocabulary of gear terms - Part 1 : Definitions related to geometry
Note: GB/T 3374.1-2010 Vocabulary of gear terms - Part 1 : Definitions related to geometry (ISO 1122-1:1998, IDT)
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 701 and ISO 1122-1 and the following apply.
3.1.1
double flank test
test where a master gear (3.1.4) and a product gear (3.1.5) are rotated in tight mesh contact, i.e. held together by a spring load so there is no backlash, while measuring the changes in center distance
3.1.2
elemental deviation
deviation, such as profile and helix deviation on individual teeth or pitch deviation between teeth, using a single point of contact probe
3.1.3
elemental method
method to measure elemental deviations (3.1.2)
Note: ISO 1328‑1 describes elemental methods and deviations.
3.1.4
master gear
gear with the required precision that is designed to measure double flank radial composite deviation in a double flank contact test with a product gear (3.1.5)
3.1.5
product gear
gear that is being measured or evaluated
3.1.6
tooth-to-tooth radial composite deviation
fid
value of the greatest change in center distance within any one pitch, found after evaluating all the teeth of a product gear (3.1.5) in a double flank test (3.1.1) with a master gear (3.1.4)
Note: See Figure 1.
3.1.7
tooth-to-tooth radial composite tolerance
fidT
maximum tooth-to-tooth radial composite deviation (3.1.6) allowable
3.1.8
total radial composite deviation
Fid
difference between the maximum and minimum values of center distance found after evaluating all the teeth of a product gear (3.1.5) in a double flank test (3.1.1) with a master gear (3.1.4)
Note: See Figure 2.
3.1.9
total radial composite tolerance
FidT
maximum total radial composite deviation (3.1.8) allowable
3.2 Symbols
For the purposes of this document, the symbols given in Table 1 apply. The symbols are based on those given in ISO 701.
