| Fluctuation in static transmission error is the accepted principal cause of vibration excitation in meshing gear pairs and consequently gear noise. More accurately, there are two principal sources of vibration excitation in meshing gear pairs: transmission error fluctuation and fluctuation in the load transmitted by the gear mesh. This dissertation formulates the gear mesh vibration excitation problem in such a way that explicitly accounts for the aggregate contributions of these excitation components. The Fourier Null Matching Technique does this by imposing a constant value on the transmission error and solving for the requisite contact region on a tooth surface that yields a constant load transmitted by the gear mesh. An example helical gear is created to demonstrate this approach and the resultant compensatory geometry. The final gear tooth geometry is controlled in such a way that modifications to the nominal involute tooth form exactly account for deformation under load across a range of loadings. Effectively, the procedure adds material to the tooth face to control the contact area thereby negating the effects of deformation and deviation from involute. To assess the applicability of the technique, six deformation steps that correlate to loads ranging from light loading to the approximate full loading for steel gears are used. A nearly complete reduction in transmission error fluctuations for any given constant gear loading should result from the procedure solution. This overall method should provide a substantial reduction in the resultant vibration excitation and consequently, noise. |
