TURBOMACHINE ROTOR

Abstract

The invention concerns a turbomachine rotor (1), characterised in that it comprises a threaded or tapped part (3, 6) and a damping nut (8) screwed onto the threaded or tapped part (3, 6) so as to allow the threads of the nut (8) and of the threaded or tapped part (3, 6) to rub against each other in the event of vibration of the rotor (1).

Claims

1.-10. (canceled)

11. A turbomachine rotor (1), characterised in that it comprises a threaded or tapped part (3, 6) and a damping nut (8) screwed onto the threaded or tapped part (3, 6) so as to allow the threads of the nut (8) and of the threaded or tapped part (3, 6) to rub against one another in the event of vibration of the rotor (1), the nut (8) comprising a stop (10) capable of bearing axially on a complementary stop (5) of the threaded or tapped part (3), the stop of the nut (8) being formed by a radially extending flange (10), the stop (5) of the threaded part (3) being formed by an end surface (5) or a radial shoulder, the threaded or tapped part (3) comprising an end area comprising teeth (4).

12. A rotor (1) according to claim 11, characterized in that the threads (9) of the nut (8) are located axially opposite the external teeth (4).

13. A rotor (1) according to claim 11, characterized in that the number of threads of the nut (8) engaging the threaded or tapped part (3, 6) is at least five.

14. A rotor (1) according to claim 12, characterized in that the number of threads of the nut (8) engaging the threaded or tapped part (3, 6) is at least five.

15. A rotor (1) according to claim 11, characterized in that an elastically deformable seal (12) is mounted between the nut (8) and the threaded or tapped part (3, 6) of the rotor (1).

16. A rotor (1) according to claim 12, characterized in that an elastically deformable seal (12) is mounted between the nut (8) and the threaded or tapped part (3, 6) of the rotor (1).

17. A rotor (1) according to claim 13, characterized in that an elastically deformable seal (12) is mounted between the nut (8) and the threaded or tapped part (3, 6) of the rotor (1).

18. A rotor (1) according to claim 15, characterized in that said seal (12) is an O-ring.

19. A rotor (1) according to claim 11, characterized in that the rotor (1) comprises a hollow rotatable shaft (2) and an annular coupling part (3) mounted around the shaft (2) and rotatably coupled thereto, the annular coupling part (3) forming the threaded or tapped part.

20. A rotor (1) according to claim 12, characterized in that the rotor (1) comprises a hollow rotatable shaft (2) and an annular coupling part (3) mounted around the shaft (2) and rotatably coupled thereto, the annular coupling part (3) forming the threaded or tapped part.

21. A rotor (1) according to claim 13, characterized in that the rotor (1) comprises a hollow rotatable shaft (2) and an annular coupling part (3) mounted around the shaft (2) and rotatably coupled thereto, the annular coupling part (3) forming the threaded or tapped part.

22. A rotor (1) according to claim 15, characterized in that the rotor (1) comprises a hollow rotatable shaft (2) and an annular coupling part (3) mounted around the shaft (2) and rotatably coupled thereto, the annular coupling part (3) forming the threaded or tapped part.

23. A rotor (1) according to claim 18, characterized in that the rotor (1) comprises a hollow rotatable shaft (2) and an annular coupling part (3) mounted around the shaft (2) and rotatably coupled thereto, the annular coupling part (3) forming the threaded or tapped part.

24. A rotor (1) according to claim 19, characterized in that the coupling part (3) is screwed onto the shaft (2), with axial-retention means (13) holding the coupling part (3) axially relative to the shaft (2).

25. A rotor (1) according to claim 24, characterized in that the coupling part (3) comprises an axially extending tubular area (3b) surrounding the axial-retention means (13).

26. A method for managing vibrations within a turbomachine rotor (1), characterized in that it consists in screwing a damping nut (8) onto a threaded or tapped part (3, 6) of the rotor (1) in such a way as to allow the threads (9, 6) of the nut (8) and of the threaded or tapped part (3) to rub against one another in the event of vibration of the rotor (1), the nut (8) comprising a stop (10) capable of bearing axially on a complementary stop (5) of the threaded or tapped part (3), the stop of the nut (8) being formed by a radially extending flange (10), the stop (5) of the threaded part (3) being formed by an end surface (5) or a radial shoulder, the threaded or tapped part (3) comprising an end area comprising teeth (4).

27. A method according to claim 26, characterized in that the implantation area of the nut (8) is determined by a vibration analysis of the rotor (1) during operation.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0040] FIG. 1 is an axial sectional view of a part of a rotor according to one embodiment of the invention;

[0041] FIG. 2 is a perspective view, with partial cutaway, of a part of the rotor of FIG. 1;

[0042] FIG. 3 is a view corresponding to FIG. 1, illustrating another embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0043] FIGS. 1 and 2 illustrate a rotor 1 of a turbomachine according to a first embodiment of the invention. The latter comprises a hollow rotary shaft 2 of axis X. An annular coupling part 3 is mounted around the shaft 2 and rotationally coupled thereto. The part 3 has an end area comprising external teeth 4, a radial end surface 5 and a threaded part 6. The end area of the coupling part has a step 7 located axially between the radial surface 5 and the threaded part 6.

[0044] The terms ‘upstream’ and ‘downstream’ are defined relative to the gas flow through the turbomachine. The terms ‘axial’ and ‘radial’ are defined relative to the X-axis of the rotor 1, which in this case is the same as the X-axis of the turbomachine.

[0045] The rotor 1 also has a nut 8 comprising a threaded area 9, which cooperates with the threaded area 6 of the coupling part 3. The number of threads of the nut 8 engaging the threads of the threaded area 6 is at least five. The threads 9 of the nut 8 and the threaded area 6 are located axially opposite the external teeth 4.

[0046] The nut 8 further comprises a radially outwardly extending flange 10, bearing on the radial surface 5 of the end of the coupling part 3.

[0047] Additional energy is dissipated by the friction of the flange 10 on the radial surface 5, thus further improving the damping of the vibrations.

[0048] The radially inner surface 11 of the nut 8 is tapered and flares downstream.

[0049] The part 3 can be screwed onto the shaft 2. The part 3 can be held axially at the bottom of the screwing or against an axial stop of the shaft 2, by means of axial-retention means 13. These means 13 comprise a seal 14 of U-shaped cross-section and axially deformable, a nut 15 and a lock nut 16. The seal 14 is axially interposed between the nut 15 and a bearing surface 3a formed by a shoulder of the part 3. The seal 14 thus exerts a force tending to press the part 3 against the corresponding axial stop of the shaft 2.

[0050] The part 3 comprises an upstream tubular area 3b surrounding the axial-retention means 13.

[0051] During operation, when the rotor 1 is rotated, the component 3 is subject to local vibrations located mainly in parts 4, 5 and 6. These vibrations are damped by the friction generated at the engaged threads of the nut 8 and the threaded part 6, allowing energy dissipation and vibration damping of the component 3.

[0052] As illustrated in FIG. 3, an elastically deformable O-ring 12 can be accommodated between the nut 8 and the downstream end of the coupling part 3, said O-ring 12 being accommodated in part in the recess 7 of the coupling part 3. The seal 12 is located axially between the flange 10 and the threaded part 9 of the nut 8.

[0053] The deformations of the seal 12 allow additional energy to be dissipated, thereby further improving the damping of the vibrations.

[0054] In each of these embodiments, the nut 8 does not serve to hold a component, as is typically the case with a screwed assembly. The damping nut 8 is preferably located in an area of the rotor 1 which has vibration displacements to be damped. This area can be defined by numerical analysis, for example by finite element analysis, or by laboratory tests.

[0055] It should be noted that the addition of the damping nut 8 leads to a modification of the natural frequencies of the assembly. A frequency-positioning check can be performed to ensure that the change in natural frequency remains acceptable.