Abstract: An aerodynamic blade for a motor vehicle includes a shutter mounted on a support shaft having an axis and connected to a chassis of a vehicle by at least one support, and driven in rotation around said axis between an open position and a closed position by a motor assembly. The motor assembly includes one or more elements configured to accumulate mechanical energy and having an adjustable stored energy level to meet a demand for a sufficient torque to change a position of the shutter in a time of less than one second.

Abstract: A disengaging member for releasing a link between a motor and a shaft rotated by the motor, the disengaging member including first and second elements capable of fitting together in a direction substantially parallel to the shaft, one element being capable of being connected to the motor by a link that enables the element to be rotated by the motor, and the other element being capable of being attached to the shaft. The first element includes at least one recess at the fitting interface between the two elements, the second element includes at least one resilient member exerting a radial force on the fitting interface via an insertion member capable of being inserted into the recess, keeping the two elements secured to one another for rotation therewith up until a predefined transmission torque between the insertion member and the first element.