AGMA 913-A98 pdf free.Method for Specifying the Geometry of Spur and Helical Gears.
This information sheet provides a general method for specifying profile shift and rack shift, with gear nomenclature and definitions. This document describes the effect that profile shift has on the geometry and performance of gears, but does not make specific design recommendations.
The equations in the first part of this document (clauses 3 and 4) apply to external gear pairs only.
The corresponding equations for internal gear pairs are contained in clause 5.
2 Terms and symbols
2.1 Terms
The terms used, wherever applicable conform to the following standards.Iso 701:1998, International gear notation – Symbols for geometrical data ANSI/AGMA 1012- F90, Gear Nomenclature, Def initioris of Terms with Symbols
2.2 Symbols
This information sheet uses the ISO symbols in table 1. In cases where there are no ISO symbols, or the definitions are different, other symbols are used.
NOTE: The symbols, definitions and terminology used in this information sheet may differ from other AGMA publications The user should not assume that familiar symbols can be used without a careful study of these definitions.
This information sheet provides definitions of profile shift and rack shift and shows the relations between them and other gear quantities. The terms profile shift and rack shift are used in this information sheet for standardization. The intention is to replace the similar or related terms listed in table 2.
3.1 Basic rack
The standard basic rack tooth profile is the tooth profile normal section through the teeth of a basic rack which corresponds to an external gear with number of teeth z = c and diameter d = x, see figure 1.
A gear with normal module, in,,, and normal pressure angle, z,,, has a basic rack whose normal circular pitch, p, iSIIm,, and whose normal pressure angle is (La.
The reference plane of the basic rack is parallel to its tooth tip plane and is the plane on which the normal circular tooth thickness, s, is equal to one half the normal circular pitch. From this definition it follows that the normal circular tooth thickness on the reference plane is equal to the normal circular space width.AGMA 913 pdf download.