A torque transmission device for a motor vehicle comprising at least one motor, the transmission device comprising:
- a first input element and a second input element,
- a coupling system that includes:
- a first engagement interface able to rotate about an axis of revolution in a fixed frame of reference, and a second engagement interface able to rotate about the axis of revolution in the fixed frame of reference and relative to the first engagement interface;
- a sliding sleeve including an intermediate engagement interface engaged with one of the first and second engagement interfaces, the sliding sleeve being capable of moving, by translation parallel to the axis of revolution, from a retracted position in which the intermediate engagement interface is not engaged with the other of the first and second engagement interfaces to a coupling position in which the intermediate engagement interface is engaged with one and the other of the first and second engagement interfaces and produces a rotational coupling between the first engagement interface and the second engagement interface;
- an actuator comprising a fixed support in the fixed frame of reference and a mobile member, the mobile member being movable in translation parallel to the axis of revolution between a rest position and an activated position;
- a rotating kinematic link between the mobile member and the sliding sleeve, having a degree of freedom of rotation about the axis of revolution;
- a transmission shaft capable of rotating about the axis of revolution, the first engagement interface being secured to the transmission shaft;
- and
- an idle transmission wheel capable of rotating relative to the transmission shaft about the axis of revolution, the second engagement interface being secured to the idle transmission wheel;
- a first transmission mechanism, arranged to permanently transmit to the idle transmission wheel a rotational movement of the first input element, according to a first constant gear ratio, and
- a second transmission mechanism arranged to permanently transmit a rotational movement between the second input element and the transmission shaft, according to a second constant gear ratio different from the first gear ratio,
- wherein the actuator comprises an elastic return member fixed in rotation about the axis of revolution in the fixed frame of reference, the mobile member being capable, by means of the kinematic link, of driving the sliding sleeve from the retracted position to the coupling position and of loading the elastic return member by passing from the rest position to the activated position, the elastic return member being able, while unloading, to return, by means of the kinematic link, the mobile member from the activated position to the rest position and the sliding sleeve from the coupling position to the retracted position.