BS ISO 21771:2007
Current
The latest, up-to-date edition.
Gears. Cylindrical involute gears and gear pairs. Concepts and geometry
Hardcopy , PDF
English
28-09-2007
Foreword
1 Scope
2 Normative references
3 Symbols, subscripts and units
3.1 Symbols
3.2 Subscripts
3.3 Units
4 Individual cylindrical gears
4.1 Concepts for an individual gear
4.2 Reference surfaces, datum lines and reference
quantities
4.3 Involute helicoids
4.4 Angular pitch and pitches
4.5 Diameters of gear teeth
4.6 Gear tooth height
4.7 Tooth thickness, space width
5 Cylindrical gear pairs
5.1 Concepts for a gear pair
5.2 Mating quantities
5.3 Calculation of the sum of the profile shift
coefficients
5.4 Tooth engagement
5.5 Backlash
5.6 Sliding conditions at the tooth flanks
6 Tooth flank modifications
6.1 Tooth flank modifications which restrict the usable
flank
6.2 Transverse profile modifications
6.3 Flank line (helix) modifications
6.4 Flank face modifications
6.5 Descriptions of modifications by functions
7 Geometrical limits
7.1 Counterpart rack tooth profile
7.2 Machining allowance
7.3 Deviations in tooth thickness
7.4 Generating profile shift, generating profile shift
coefficient
7.5 Generated root diameter
7.6 Usable area of the tooth flank, tip and root form
diameter
7.7 Undercut
7.8 Overcut
7.9 Minimum tooth thickness at the tip circle of a gear
Annex A (informative) Calculations related to tooth thickness
Bibliography
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