Flank modifications for optimal excitation behaviour

Abstract

Considering the layout of flank micro geometries for gearboxes, several goals must be fulfilled namely a high load carrying capacity, a low noise mesh design for a desired load range and the manufacturability. A conventional approach in order to achieve these features relies on various combinations of standard modifications. Normally compromises regarding the different design goals have to be picked from a mass calculation and the different mesh orders cannot be optimized independently using standard modifications. Pitch periodic flank modifications that directly compensate for the transmission error provide an alternative approach. Since these modifications just shift the level of each line of action in order to eliminate the inconstant part of the elastic deformations in the mesh, they can be designed separately after the load distribution was optimized. Theoretical studies show that these flank forms promise very low excitation levels at a chosen target load range while the target of a high load carrying capacity is achieved in another design stage. Experimental investigations with ground specimen funded by FVA/AiF at the FZG dynamics test rig underline these statements. The measured torsional acceleration levels prove that the theoretical advantages of the suggested flank forms – in comparison to standard modifications – can be realised. Limitations of this kind of flank designs result from the complexity of the flank forms or the implications of the gear main geometry on the modifications.