The modern bevel gear design engineer is often faced with knowing the basic appearance of the bevel
gear tooth that he is designing. The geometry of the bevel gear is quite complicated to describe
mathematically, and much of the overall surface topology of the tooth flank is dependent on machine
settings and the cutting method employed. AGMA 929-A06, Calculation of Bevel Gear Top Land and
Guidance on Cutter Edge Radius, lays out a practical approach for predicting the approximate top land
thicknesses at certain points of interest regardless of the exact machine settings that will generate the
tooth form. The points of interest that AGMA 929-A06 is concerned with consists of toe, mean, heel, and
the point of involute lengthwise curvature.
The following method expands upon the concepts described in AGMA 929-A06 to allow the user to
calculate not only the top land thickness, but the more general case, the normal tooth thickness anywhere
along the face and profile of the bevel gear tooth. This method does not rely on any additional machine
settings; only basic geometry of the cutter, blank, and teeth are required to calculate fairly accurate tooth
thicknesses. The tooth thicknesses are then transformed into a point cloud describing both the convex
and concave flanks in a global Cartesian coordinate system. These points can be utilized in any modern
computer aided design software package to assist in the generation of a 3D solid model. All pertinent
macro tooth geometry can be closely simulated using this technique. Furthermore, a case study will be
presented evaluating the accuracy of the point cloud data to a physical part.