AGMA 04FTM8 PDF

Dynamic loading at tooth mesh frequency and its harmonics excites traveling wave vibration in gears. The associated alternating stress can be large enough to cause high cycle fatigue failure of the gears. In this paper a generalized excitation of traveling wave vibration in gears is developed for both forward and backward waves. Although they do not predict the actual dynamic response of the gear, the developed expressions quantify the relative excitation as a function of nodal diameter allowing the analyst to place modes with constructive excitation outside the gear's operating range. These generalized equations allow the following effects to be addressed: any combination of tooth counts, any number of gears in mesh with the center gear, symmetric or non-symmetric spacing of these surrounding gears, and non-equal power extraction from the surrounding gears. The equations presented are thus applicable for configurations ranging from a single gear set to a sequential, non-symmetric planetary system. Dynamic response from a finite element model is presented to verify the generalized excitation for the various configurations