Motorized split-hinge device for a very heavy double door, designed to be motorized and consisting of at least one flap or panel (1) that is mounted to pivot, around an essentially vertical axis of rotation, on a frame (2), comprising a stationary split-hinge part (3) that is integral with said frame (2) and a movable split-hinge part (4) that is integral with said flap (1) and mounted in rotation relative to said stationary split-hinge part (3) around a pivoting shaft.The movable split-hinge part (4) comprises a drive mechanism that is driven by a motor unit (7) that is able to drive said movable split-hinge part (4) in rotation around its pivoting shaft and starting said flap (1) moving by pivoting when opening or closing, whereby said motor unit (7), on the one hand, is mounted in a removable manner on said drive mechanism and on a stationary part (3) 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 (1).