Non-linear dynamic response of a spur gear pair: Modelling and experimental comparisons

The dynamic response of a spur gear pair is investigated using a finite ele ment/contact mechanics model that offers significant advantages for dynamic gear analyses. The gear pair is analyzed across a wide range of operating speeds and torques. Comparisons are made to other researchers' published ex periments that reveal complex non-linear phenomena. The non-linearity sourc e is contact loss of the meshing teeth, which, in contrast to the prevailin g understanding, occurs even for large torques despite the use of high-prec ision gears. A primary feature of the modelling is that dynamic mesh forces are calculated using a detailed contact analysis at each time step as the gears roll through the mesh; there is no need to externally specify the exc itation in the form of time-varying mesh stiffness, static transmission err or input, or the like. A semi-analytical model near the tooth surface is ma tched to a finite element solution away from the tooth surface, and the com putational efficiency that results permits dynamic analysis. Two-single-deg ree-of-freedom models are also studied. While one gives encouragingly good results, the other, which appears to have better mesh stiffness modelling, gives poor comparisons with experiments. The results indicate the sensitivi ty of such models to the Fourier spectrum of the changing mesh stiffness. ( C) 2000 Academic Press.