A ceiling driving unit for moving doors comprises a motor unit (12) arranged at the end of a running rail (11) for a door-dragging carriage (17). The motor unit has a driven axis (14) that engages a mechanism in the rail to transmit movement to the carriage and between the rail and motor unit there are mutual coupling means (26-27-28-29, 30-31-32-33) for connecting the motor unit to the rail and which are driven by manual rotation of the motor unit around the driven axis.