Zvýšení únosnosti ozubení nad rámec standardně používaných řešení v rámci celého spektra zatížení zubů

Abstract

The present dissertation deals with root fillet of spur gears to increase the loading capacity of gears against bending stress. The topic of the work is based on the request of Škoda Auto a.s. The target of this thesis is to answer some questions that arose from everyday design tasks within the Škoda Auto gearbox development department. In the introductory chapter, the thesis deals with the findings so far in the framework of non-standard optimization tasks, which aim to increase the load-bearing capacity of gearing. Three main directions of possible research were identified, while the research of non-standard shapes of the transition curves of front gearing with involute gearing was chosen. For the entire work, it is essential to find out not only the possible shapes of the curves and their contribution in terms of bending stress, but also their manufacturability using an effective method by hobing. This ensures a possible benefit for series production, which is crucial for the car manufacturer. The correctness of the tool definition method is checked both theoretically and practically on a manufactured sample. In addition to FEM calculations, the thesis also contains analytical and numerical calculations. This is for example, the mathematical expression of a non-standard curve that is tangentially connected to the tooth profile, or the creation of mathematical equations to define the shape of the tool for a given heel curve. As a follow-up to these actions, a program was created to define the shape of the tool. Individual non-standard curves were compared in terms of strength, both in variants with different numbers of teeth and different profile angles, and with standard transition curves, and the possible benefits of these optimized variants were evaluated.