Ignacio Gonzalez-Perez

Modified involute helical gears: computerized design, simulation of meshing and stress analysis

The contents of the paper cover: (i) computerized design, (ii) methods for generation, (iii) simulation of meshing, and (iv) enhanced stress analysis of modified involute helical gears. The approaches proposed for modification of conventional involute helical gears are based on conjugation of double-crowned pinion with a conventional helical involute gear. Double-crowning of the pinion means deviation of cross-profile from an involute one and deviation in longitudinal direction from a helicoid surface. The pinion-gear tooth surfaces are in point contact, the bearing contact is localized and oriented longitudinally, edge contact is avoided, the influence of errors of alignment on the shift of bearing contact and vibration and noise are reduced substantially. The developed theory is illustrated with numerical examples that confirm the advantages of the gear drives of the modified geometry in comparison with conventional helical involute gears.

New version of Novikov–Wildhaber helical gears: computerized design, simulation of meshing and stress analysis

Abstract A new version of Novikov–Wildhaber gear drive is considered. The contents of the paper cover design, generation, tooth contact analysis (TCA), and stress analysis of a new type of Novikov–Wildhaber helical gear drive. The great advantages of the developed gear drive in comparison with the previous ones are (i) reduction of noise and vibration caused by errors of alignment, (ii) the possibility of grinding and application of hardened materials, and (iii) reduction of stresses. These achievements are obtained by application of (i) new geometry (based on application of parabolic rack-cutters), (ii) double-crowning of pinion, and (iii) parabolic type of transmission errors. The manufacture of gears is based on application of grinding or cutting disks, and grinding or cutting worms. The advantages of the developed gear drive have been confirmed by simulation of meshing and contact, stress analysis, and investigation of formation of bearing contact. Computer programs that cover computerized design, TCA, and automatic development of finite element models of new version of Novikov–Wildhaber gear drives have been developed. A general purpose finite element analysis computer program has been used for stress analysis and investigation of formation of bearing contact. Helical gears of new geometry can be applied in high-speed transmissions. The developed theory is illustrated with numerical examples.