IDENTIFICATION OF THE MACHINE SETTINGS OF REAL HYPOID GEAR TOOTH SURFACES

In the spiral bevel and hypoid gear manufacturing industry, master gea r sets are usually developed om initial machine settings obtained from computer. software or instruction sheets. These initial machine setti ngs are then modified until a satisfactory bearing pattern is obtained , a process called bearing pattern development Once a satisfactory bea ring pattern is obtained manufacturing errors and heat treatment disto rsions can be accounted for by proportionally changing the machine set tings according to the results of a V-H test in which the pinion verti cal and horizontal positions are modified until the bearing pattern is acceptable. Once a satisfactory combination of master pinion and gear is obtained their actual tooth surfaces usually do not correspond to those of the initial theoretical model, and the theoretical pinion and gear surface definitions are unknown. This paper presents a computer algorithm used to identify the machine settings producing a theoretica l tooth surface closest to that of a measured surface, what the author s call Surface Match, in order to effectively simulate the kinematical behavior of real gear teeth. The approach is applicable to both Ist a nd 2nd order surface errors, including profile deviation, for any cutt ing process. However given the availability of experimental data for t he Fixed Setting(TM), Formate(TM) and Helixform(TM) cutting processes, the examples presented in the paper are related to these cutting proc esses.