New approach for the dimensional synthesis of gear basic surfaces

The authors present a new method for establishing the relations between the primitive surfaces and the teeth basic surfaces in a gear transmission. This new approach allows to make the synthesis not only by considering as known the gear pitch radius, or what is the same, its transverse module, as existing approaches, but also from the normal module in the pitch mean cone or the pinion pitch radius. There are two main factors that affect the size of the gears: the limit pressure angle and the mean tooth curvature or mean radius of the head cutter. This method allows to study the influence of the tooth normal module on the limit pressure angle, and the valid range of mean radius of the head cutter, according to the recommendation of Wildhaber, and their influence on the size of gears.