ISO/TC 60/SC 1/WG 4 - Terminology and notation of gears

Concerns the part of the international vocabulary of gears which is devoted solely to geometrical definitions. It gives, for each of the geometrical terms relative to gears, a standard definitions which will be valid internationally, to corresponding term in each langauge being chosen as far as possible in such a way as to directly reflect the meaning of the definition.

ISO 21771:2007 specifies the geometric concepts and parameters for cylindrical gears with involute helicoid tooth flanks. Flank modifications are included. It also covers the concepts and parameters for cylindrical gear pairs with parallel axes and a constant gear ratio, which consist of cylindrical gears according to it. Gear and mating gear in these gear pairs have the same basic rack tooth profile.

This part of ISO 1122 concerns the part of the international vocabulary of gears which is devoted solely to geometrical definitions. It gives, for each of the geometrical terms relative to gears, a standard definition which will be valid internationally, the corresponding term in each language being chosen as far as possible in such a way as to directly reflect the meaning of the definition. NOTE — Since the choice of corresponding terms can only be partially fulfilled in any particular language, due to the necessity of respecting certain established conventions, it is advisable, as far as translation into other languages is concerned, to refer always to the meaning of the definition itself, rather than to a simple transposition of the original term.

Defines terms used to describe the appearance of the visible surfaces of tooth flanks or the damage that can be observed on gears. Causes and preventive measures are not discussed.