Deployable divergent nozzle for a propulsive unit

1. A deployable diverging bell for a thruster, the bell comprising a stationary first diverging bell portion suitable for being connected to a stationary support of the thruster; a movable second diverging bell portion that is movable between a refracted position and a deployed position in which said second diverging bell portion is connected to a downstream end of the first diverging bell portion in order to extend said first diverging bell portion; at least one deployment mechanism adapted to move said movable second diverging bell portion relative to said stationary first diverging bell portion in order to deploy said movable second diverging bell portion from the refracted position thereof to the deployed position thereof;

the deployment mechanism comprising:

at least one arm fastened to a part that is stationary relative to the stationary first diverging bell portion and to a connection part; and

at least one rotatable threaded rod fastened to the connection part and to a fitting fastened to the second diverging bell portion;

at least one damper for damping vibration coming from at least one of said movable second diverging bell portion and the deployment mechanism, the damper being positioned between the connection part and said arm.

2. The diverging bell as claimed in claim 1 , wherein the arm is fastened firstly to the stationary support of the thruster and secondly to the connection part.

3. The diverging bell as claimed in claim 1 , wherein the deployment mechanism is adapted to move the second diverging bell portion in translation.

4. The diverging bell as claimed in claim 1 , including three fastener assemblies distributed uniformly around a circumference of the stationary diverging bell.

5. The diverging bell as claimed in claim 1 , wherein the deployment mechanism is controlled by a control unit situated at a distance from said diverging bell.

6. A deployable diverging bell for a thruster, the bell comprising:

a stationary first diverging bell portion suitable for being connected to a stationary support of the thruster;

a movable second diverging bell portion that is movable between a refracted position and a deployed position in which said second diverging bell portion is connected to a downstream end of the first diverging bell portion in order to extend said first diverging bell portion;

at least one deployment mechanism adapted to move said movable second diverging bell portion relative to said stationary first diverging bell portion in order to deploy said movable second diverging bell portion from the refracted position thereof to the deployed position thereof;

at least one damper for damping vibration coming from at least one of said movable second diverging bell portion and the deployment mechanism, the damper being positioned between the deployment mechanism and at least one of a stationary support of the thruster and the stationary first diverging bell portion;

wherein:

the deployment mechanism includes:

at least one fastener assembly for fastening the deployment mechanism of the movable second diverging bell portion,

the fastener assembly comprising a plurality of arms and a connection part, said arms being suitable for being fastened firstly to the stationary support of the thruster and being fastened secondly to the connection part, and wherein the angle between said arm and the connection part is an acute angle.

7. The diverging bell as claimed in claim 6 , wherein the damper is included in the fastener assembly.

8. The diverging bell as claimed in claim 6 , wherein the deployment mechanism comprises a ball screw.

9. The diverging bell as claimed in claim 6 , wherein the arm is fastened firstly to the stationary support of the thruster and secondly to the connection part.

10. A deployable diverging bell for a thruster, the bell comprising:

a stationary first diverging bell portion suitable for being connected to a stationary support of the thruster;

a movable second diverging bell portion that is movable between a refracted position and a deployed position in which said second diverging bell portion is connected to a downstream end of the first diverging bell portion in order to extend said first diverging bell portion;

at least one deployment mechanism adapted to move said movable second diverging bell portion relative to said stationary first diverging bell portion in order to deploy said movable second diverging bell portion from the refracted position thereof to the deployed position thereof;

at least one damper for damping vibration coming from at least one of said movable second diverging bell portion and the deployment mechanism, the damper being positioned between the deployment mechanism and at least one of a stationary support of the thruster and the stationary first diverging bell portion;

the deployment mechanism including at least one fastener assembly for fastening the deployment mechanism of the movable second diverging bell portion;

the fastener assembly comprising a plurality of arms and a connection part, said arms being suitable for being fastened firstly to the stationary support of the thruster and being fastened secondly to the connection part, and wherein the angle between the damper and the deployment mechanism and the angle between the damper and said arm are acute angles.

11. The diverging bell as claimed in claim 10 , wherein the arm is fastened firstly to the stationary support of the thruster and secondly to the connection part.

12. The diverging bell as claimed in claim 10 , wherein the deployment mechanism comprises a ball screw.

13. The diverging bell as claimed in claim 10 , wherein the damper is included in the fastener assembly.