Theory of critical distances in analysis of the influence of tooth profile on gears bending capacity

Abstract

The fatigue cracks and failures in tooth roots are still one of the most common problems in gear pairs operation. Therefore, the application of new methods and up-to-date calculation procedures is welcome. This paper presents the benefits which Theory of Critical Distances (TCD) could make in creation the more precise and applicable calculation procedure for gears bending capacity. The new procedure described in this paper completely excludes all conventional standard defined calculation procedures. One particular spur gear pair for large transport machine is used for procedure presentation. Few different values of tooth root radius and profile shift (modification) coefficients are considered. The Finite Element Analysis for gear pairs with different profile parameters are performed and obtained stress states are used for TCD application. The conclusions about the influence of tooth profile parameters on tooth root fatigue capacity and suggestions about application of TCD are discussed.