Road milling machine with replaceable milling drum with different cutting widths

A self-propelled road milling machine including a milling drum housing mounted on the chassis of the machine, said milling drum housing including a side comprising a power take-off able to transmit the rotational motion from an engine, inside said milling drum housing being alternatively mountable a series of milling drums each of which being made of a single piece including cutting tools on its external surface, said milling machine comprising one milling drum of said series being mounted in an axially sliding way from the side opposed with respect to the side of said power take-off in order to allow the replacement of said milling drum, said milling drum comprising fastening elements radially protruding from an internal surface of the milling drum, the rotation of said milling drum being realized by means of a reduction gear, said reduction gear being mounted at the end of a hollow spacer placed between said reduction gear and said side including the power take-off, in said hollow spacer being present the transmission shaft transmitting the rotatory motion from said power take-off to said reduction gear, said reduction gear being supported on the side opposed with respect to the side of said power take-off by a support wherein said hollow spacer rigidly connects the wall of the milling drum housing corresponding to the side of said power take-off to a support flange of said reduction gear, said reduction gear being connected to a spacer on the side opposed with respect to the side of said power take-off and said spacer engaging with a rotatable flange of said reduction gear, said spacer being connected to said fastening elements of said milling drum and with said support on the wall of said milling drum housing opposed with respect to said power take-off side, said support including bearings, all being coordinated and structured in such a way that said support flange and said hollow spacer are static with respect to the rotary movement of said milling drum.