First a short survey of modelling of technical systems is presented. The di
fferent methods of modelling are applied to hydrodynamic torque converters
and couplings. The results of linear modelling around an operating point, o
f nonlinear modelling for larger operating areas and of hybrid modelling us
ing simplified physical laws are illustrated. Simulations for large excitat
ions show the validity of the models. The advantages and disadvantages of t
he different methods are discussed.