Influence de l'\'{e}lasticit\'{e} des lignes d'arbres, des roulements et du carter sur les vitesses critiques de rotation d'une transmission par engrenages

The dynamic behaviour of a gearbox fitted out with a helical gear pair is studied. Shafts, bearings and housing are discretised using the finite element method. The elastic coupling between the toothed wheels is characterised by a 12x12 stiffness matrix. The calculation of the vibration response induced by the static transmission error shows that the highest dynamic mesh forces correspond to a resonant excitation of modes which have a high mesh stiffness energy. The numerical simulations show that a realistic prediction of the critical rotational speeds should take account of all the components of the gearbox.