AGMA 20FTM02 PDF

For high-speed applications, gears of large dimensions and high power density are used. Temperature distribution in those rotors is much different in operation as compared to manufacturing. Therefore, the tooth contact as it can be validated by blue ink during assembly is not only affected by distortion and bending under load but also by non-uniform thermal growth. As power density and specific load are continuously increasing over time, for highly sophisticated applications, this influence should be accounted for with suitable lead modification, as it is demanded by the latest version of API 613.

For many years, RENK-MAAG has been using empirical methods for thermal lead corrections based on measurements and experience. Lately, the authors carried out complex finite element calculations to numerically investigate the influence of temperature distribution on tooth contact. This kind of detailed finite element modeling for tooth contact analyses requires a strong effort with respect to the corresponding finite element meshing as well as extended computation time. Therefore, the numerical method was further enhanced. As a result, a simplified approach for quick and reliable heat analyses for thermal lead correction of single-stage double helical high-speed gears was developed. The paper describes the theoretical background and gives a comparison of the results with the different calculation approaches.