Nut system and aircraft engine mounting structure comprising same

1. A device that resists thrusts generated by an aircraft engine, the device configured to be inserted between an engine and a rigid structure of a suspension pylon of the engine, and comprising:

a fitting configured to be fixed on the rigid structure;

a pin system passing through the fitting;

two lateral thrust resistance rods each comprising a forward end to be connected to the engine and an aft end;

a spreader beam onto which the two aft ends of the lateral thrust resistance rods are hinged, the spreader beam being passed through by the pin system; and

a nut system, comprising:

a nut comprising a main thread with pitch p 1 , the main thread arranged along a screwing axis of the nut; and

a threaded device coupled in rotation and translation with the nut about the screwing axis, the threaded device comprising a secondary thread non-screwed on the main thread from which the secondary thread is separated, the secondary thread arranged along the screwing axis of the nut and having a pitch p 2 different from p 1 , wherein

the pitches p 1 and p 2 have the same direction, and

the nut system is assembled on the pin system and bearing on the spreader beam.

2. A thrust resistance device according to claim 1 , wherein the main thread and the secondary thread are configured to be screwed onto a complementary main thread with pitch p 1 and onto a complementary secondary thread with pitch p 2 respectively.

3. A thrust resistance device according to claim 1 , wherein the threaded device is fixed to the nut.

4. A thrust resistance device according to claim 1 , wherein the threaded device is a screw passing through the nut.

5. A thrust resistance device according to claim 4 , wherein the screw is fixed to the nut through an anti-rotation plate fixed on the nut and cooperating with a head of the screw.

6. A thrust resistance device according to claim 1 , further comprising a pin extension device supported on an inside thereof by the pin system.

7. A thrust resistance device according to claim 6 , wherein the pin extension device is a screw fitted on the pin system, the screw penetrating inside the pin system.

8. A thrust resistance device according to claim 7 , wherein the threaded device of the nut system is screwed onto the pin extension device.

9. A thrust resistance device according to claim 6 , wherein the pin system comprises an inner pin and a concentric outer pin, the two pins being fixed to each other and the inner pin being hollow so that it can act as a housing for the pin extension device.

10. A thrust resistance device according to claim 9 , wherein the nut in the nut system is mounted on the outer pin.

11. A thrust resistance device according to claim 9 , further comprising an anti-rotation washer cooperating with the nut and being inserted between the nut and the spreader beam.

12. A suspension pylon for an engine configured to be inserted between an aircraft wing and the engine, the pylon comprising:

a rigid structure;

means for fastening the engine onto the rigid structure; and

suspension means comprising the thrust resistance device according to claim 1 to resist thrusts generated by the engine.

13. A thrust resistance device according to claim 1 , wherein the main thread is an inner thread of the nut.

14. A thrust resistance device according to claim 1 , wherein the threaded device is unthreaded with the nut.

15. A thrust resistance device according to claim 5 , wherein the threaded device is fixed to the nut only at the head of the screw.

16. A thrust resistance device according to claim 1 , wherein the pitch p 2 is less than the pitch p 1 .

17. A device that resists thrusts generated by an aircraft engine, the device configured to be inserted between an engine and a rigid structure of a suspension pylon of the engine, and comprising:

a fitting configured to be fixed on the rigid structure;

a pin system passing through the fitting;

two lateral thrust resistance rods each comprising a forward end to be connected to the engine and an aft end;

a spreader beam onto which the two aft ends of the lateral thrust resistance rods are hinged, the spreader beam being passed through by the pin system; and

a nut system, comprising:

a nut comprising a main thread with pitch p 1 , the main thread arranged along a screwing axis of the nut; and

a threaded device coupled in rotation and translation with the nut about the screwing axis, the threaded device comprising a secondary thread non-screwed on the main thread from which the secondary thread is separated, the secondary thread arranged along the screwing axis of the nut and having a pitch p 2 less than p 1 wherein the pitches p 1 and p 2 have the same direction.

18. An aircraft engine mounting assembly that resist thrust generated by an aircraft engine, comprising:

a receiving assembly; and

a nut system, comprising:

a nut comprising a main thread with pitch p 1 , the main thread arranged along a screwing axis of the nut; and

a threaded device coupled in rotation and translation with the nut about the screwing axis, the threaded device comprising a secondary thread non-screwed on the main thread from which the secondary thread is separated, the secondary thread arranged along the screwing axis of the nut and having a pitch p 2 different from p 1 , wherein

the pitches p 1 and p 2 have the same direction, and

the nut system is mounted on the receiving assembly, the main thread being screwed onto a complementary main thread with pitch p 1 formed on the receiving assembly, and the secondary thread being screwed on a complementary secondary thread with pitch p 2 formed on the receiving assembly.