Run-flat assembly for vehicle and safety wheel comprising same

A run-flat assembly for a vehicle comprises: a cylindrical auxiliary wheel, having a diameter-changeable structure, disposed on the circumferential surface of a wheel body; and an auxiliary wheel support, disposed between the circumferential surface of the wheel body and the inner side surface of the auxiliary wheel, for pushing up the auxiliary wheel from the original position thereof to the inner side surface of a tire mounted on the wheel body. Because the run-flat assembly for a vehicle comprises the auxiliary wheel support disposed on the wheel body and the auxiliary wheel, the run-flat assembly for a vehicle may be combined with a conventional wheel for a vehicle, thereby enabling a vehicle to drive safely in the event of a tire blowout.