Rotary damper (15), comprising a casing (17), an intermediate element (31) mounted movably on the casing (17), a braking fluid provided between the casing (17) and the intermediate element (31) so as to brake the movement of the intermediate element (31) relative to the casing (17), a rotor (50) mounted on the intermediate element (31) rotatably about an axis of rotation (x), and a unidirectional coupling arranged between the intermediate element (31) and the rotor (50). The unidirectional coupling comprises at least one radial block (60) arranged between a radially outer surface (52) of the rotor (50) and a radially inner surface (34) of the intermediate element (31), and at least one actuating lobe (55) formed on the rotor (50) and projecting radially from the radially outer surface (52) thereof, the radial bock (60) comprising a wedge part (61) designed to be engaged by the actuating lobe (55) of the rotor (50) during rotation in the first direction of rotation (A) so as to push the radial block (60) in the centrifugal direction and lock it between the rotor (50) and the intermediate element (31).