AGMA 96FTM1 PDF

In the spiral bevel and hypoid gear manufacturing industry, master pinions and gears are usually developed from initial machine settings obtained from computer software such as The Gleason Works’ TCA, which are then modified until a satisfactory bearing pattern is obtained, as “the target tooth flank form” to compensate for heat treatment distortions and to consider lapping cannot be accounted for by existing computer software. Once a satisfactory combination of master pinion and gear is obtained, their actual tooth surfaces may not correspond to those of the theoretical model. In this case, corrective machine settings calculated from the measurement of the production tooth flanks by a Coordinate Measuring Machine (CMM) are applicable only in relation to the actual target tooth flank measurement data, as the theoretical tooth flank definition is unknown. This paper presents a computer based approach used to find the machine settings producing a theoretical tooth surface closest to that of a measured surface, which incidentally can be the target tooth flank, what the authors call Surface Matching, in order to effectively use corrective machine settings in reference to the theoretical surface. The approach is applicable to both first and second order surface match, for the Fixed Setting, Spread Blade, Formate and Helixform cutting processes. The Surface Matching algorithm can then be used in the opposite direction, e.g., to match the measured data to the theoretical target tooth form definition, such as to calculate corrective machine settings.