Generation, meshing, contact and stress analysis of double circular-arc helical gears

The modern theory of gearing and finite element method have been applied to the tooth contact analysis and stress analysis for loaded double circular-arc helical gear drives. This thesis covers design, manufacturing, grinding and finite element stress analysis of the double circular-arc helical gears.; The main advantage of this type of gear is the low level of contact and bending stresses, that has been proven by stress calculation and analysis based on application of the finite element method. A disadvantage of this type of gearing is the sensitivity to the gear misalignment and increased noise and vibrations. The investigation performed in the thesis shows that linear functions of transmission errors caused by errors of alignment are the source of the noise and vibration. An approach to reduce the noise has been developed that is based on application of a predesigned parabolic function of transmission errors. Methods of manufacture of the low-noise N.-W. gears by milling or grinding with special relations between the parameters of motion have been proposed. A grinding worm has been developed for the generation of the pinion-gear tooth surfaces with new topology.; The meshing and contact of pinion-gear tooth surfaces of a misaligned gear drive are computerized, respective computer programs have been developed, and the influence of assembly errors has been investigated. Numerical examples that illustrate the developed theory are represented.