Computerized Design and Tooth Contact Analysis of Spiral Bevel Gears Generated by the Duplex Helical Method

Abstract

The duplex helical method, among the different generation methods of spiral bevel gears, has shorter times of manufacturing since both sides of the gear tooth are generated simultaneously. The duplex helical method is based on the application of a helical motion of the cradle respect to the gear blank during the infeed of the sliding base on which the work spindle is mounted. Computerized design and generation of spiral bevel gears by the duplex helical method is a complex problem since the machine-tool settings are specific for each hypoid generator and optimization of the contact pattern and the function of transmission errors is not straightforward. The proposed goals in this research paper are as follows: (i) conversion of the specific machine-tool settings of a given hypoid generator to the so-called neutral machine-tool settings that can be applied at any hypoid generator, (ii) computerized generation of the generated spiral bevel gears by the duplex helical method considering the neutral-machine tool settings, (iii) illustration of results of tooth contact analysis of a spiral bevel gear drive where the pinion has been generated by the duplex helical method for investigation of the contact pattern and the function of transmission errors, and (iv) adjustment of the contact pattern by considering parabolic profiles on the blades of the head-cutter. A numerical example is represented considering a spiral bevel gear drive generated at the Hypoid Generator 106 of Gleason.