The invention relates to an improved hitch coupling assembly which dampens the hunting movements of a road trailer being towed by a motor vehicle and which is intended for a vehicle combination comprising a motor vehicle and a trailer. More specifically, the inventive hitch coupling assembly (4) comprises: (i) a first pivot coupling (12) for the hunting movements, consisting of a pivoting device which dampens the hunting movements (40) of the trailer and which is housed in a closed space such that it is sheltered from the ingress of pollutant materials; and (ii) a second coupling (21) for the rolling and pitching movements, which is used for the play-free transmission of the hunting movements to the first coupling, the axis of the hunting movements being thus decoupled from the rolling and pitching movements. The damping device preferably comprises a stack of friction disks (41) which are alternately solidly connected to the vehicle or the trailer and which pivot in relation to one another under the effect of the hunting movements.