Motorized split-hinge device for a very heavy double door, designed to be motorized and consisting of at least one flap or panel that is mounted to pivot, around an essentially vertical axis of rotation, on a frame, comprising a stationary split-hinge part that is integral with said frame and a movable split-hinge part that is integral with said flap and mounted in rotation relative to said stationary split-hinge part around a pivoting shaft. The movable split-hinge part comprises a drive mechanism that is driven by a motor unit that is able to drive said movable split-hinge part in rotation around its pivoting shaft and starting said flap moving by pivoting when opening or closing, whereby said motor unit, on the one hand, is mounted in a removable manner on said drive mechanism and on a stationary part of said door, and, on the other hand, is kept in drive position of said mechanism with anti-rotational locking, optionally with radial play, relative to said flap.