Propeller comprising a moveable dynamic scoop

Abstract

The main purpose of the invention is a propeller (32) for a turbomachine (1) comprising a plurality of blades (48) and a blade support ring (47) fitted with housings (50) each of which holding a pivot (52) supporting the root (58) of one of said blades (48), characterized in that at least one of the pivots (52) is associated with at least one dynamic scoop (100), capable of moving between distinct positions, an open position in which a cooling airflow (F) can be captured, and a closed position as a function of the orientation of the corresponding blade.

Claims

1. Propeller for a turbomachine comprising: a plurality of blades; and a blade support ring fitted with housings each of which holds a pivot supporting the root of one of said blades, wherein at least one of the pivots is connected to a ring that supports at least one dynamic scoop, the scoop being capable of moving between distinct positions, an open position in which a cooling airflow can be captured, and a closed position as a function of the orientation of the corresponding blade, and wherein the at least one dynamic scoop is movable relative to the root supported by at least one of the pivots.

2. Propeller according to claim 1, wherein said at least one dynamic scoop is moved from the closed position to the open position by a centrifugal effect due to the rotation speed of the blade, when the blade moves into a position at a predetermined orientation.

3. Propeller according to claim 1, wherein the pivot is provided with at least one counterweight system, the movement from the closed position to the open position of said at least one dynamic scoop being obtained by actuation of said at least one counterweight system on said at least one dynamic scoop.

4. Propeller according to claim 3, wherein the counterweight system comprises a counterweight arm and a counterweight, the counterweight arm and/or the counterweight being capable of bearing on said at least one dynamic scoop to move it from the closed position to the open position.

5. The propeller of claim 1, further comprising an outer propeller cover from which the blades will project outwards, the cover comprising an orifice through which said at least one dynamic scoop is moved from the open position to the closed position and vice versa.

6. Propeller according to claim 1, wherein said at least one dynamic scoop is free to move between the open and closed positions through a pivot connection.

7. The propeller of claim 1, further comprising an outer propeller cover from which the blades will project outwards, and wherein the ring and said at least one dynamic scoop are located radially inwards under the cover.

8. Turbomachine comprising a propeller according to claim 1.

9. Turbomachine according to claim 8, wherein said propeller is located downstream from a combustion chamber of said turbomachine.

10. The propeller of claim 5, wherein said at least one dynamic scoop is configured to capture the cooling airflow disposed adjacent the cover.

11. Propeller according to claim 6, wherein said pivot connection is a hinge connection.

12. Propeller according to claim 6, wherein said pivot connection is a sliding connection.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood after reading the detailed description given below of non-limitative examples of the invention, and after examining the diagrammatic and partial figures in the appended drawing in which:

(2) FIG. 1 shows a diagrammatic longitudinal half-sectional view of a turbomachine for an aircraft provided with a conventionally designed engine casing for open rotors according to prior art,

(3) FIG. 2 shows a partial perspective view of one of the open rotors of the turbomachine shown in FIG. 1,

(4) FIG. 3 shows a partial sectional view showing the propeller blade support ring and surrounding elements in more detail,

(5) FIG. 4 shows an exploded perspective view of a blade and its associated pivot,

(6) FIG. 5 shows a perspective view of a propeller according to prior art, in which there are several blade root cavities,

(7) FIGS. 6, 7A and 7B contain a partial perspective and sectional view of an example embodiment of the invention,

(8) FIG. 8 shows a perspective view of an example of a dynamic scoop for a propeller according to the invention, and

(9) FIG. 9 shows a sectional partial view of another example embodiment according to the invention.

(10) Identical references of all these figures may refer to identical or similar elements.

(11) Furthermore, the different parts shown in the figures are not necessarily all shown at the same scale to make the figures more easily readable.

DETAILED PRESENTATION OF PARTICULAR EMBODIMENTS

(12) Two example embodiments of the invention will be described below with reference to FIGS. 6 to 9, related to an aircraft turbomachine with open rotors, however these examples are not limitative.

(13) FIGS. 6 to 9 are diagrammatic and partial, and FIGS. 1 to 5 described above should be referred to for the display of elements not shown in FIGS. 6 to 9.

(14) FIGS. 6, 7A and 7B show a first example embodiment of a propeller 32 according to the invention.

(15) FIGS. 7A and 7B show a sectional view of a configuration of the propeller in which the dynamic scoop 100 is in a closed position and a configuration of the propeller in which the dynamic scoop 100 is in the open position, respectively, to capture a cooling airflow F.

(16) FIG. 6 diagrammatically shows a pivot 52 supporting the blade root 58 of a blade 48 of the propeller 32.

(17) The pivot 52 comprises a platform 59 that will be placed inside an orifice provided through the outer cover of the propeller 46 (not shown in FIG. 6) so as to obtain approximately flush aerodynamic junctions.

(18) A ring 103 located radially inwards from the platform 59 is associated with the pivot 52. In particular, the ring 103 is connected to the pivot 52 of the blade root 58 through its two ends, one concentric end 103a and one eccentric end 103b connected to the cover 46, for example through dynamic joints. Thus, the ring 103 is located under the cover 46, radially inwards from the cover 46.

(19) According to the invention, the pivot 52 is associated with a dynamic scoop 100 fixed to the mobile ring 103.

(20) More particularly, the dynamic scoop 100 is connected to the ring 103 through a pivot connection 101 (see FIGS. 7A and 7B), and particularly a hinge connection, that enables displacement of the dynamic scoop 100 between the open position and the closed position. The hinged connection 101 is particularly straight to enable movement of the dynamic scoop 100.

(21) The closed position of the dynamic scoop 100 corresponds to a position in which the dynamic scoop 100 is located under the cover 46 as shown in FIG. 7A. In this position, the air flow F does not come into contact with the blade root 58.

(22) The open position of the dynamic scoop 100 corresponds to a position in which the dynamic scoop 100 is located above the cover 46 to allow capture of the cooling air flow F as shown in FIG. 7B.

(23) In FIGS. 7A and 7B, only the cover 46, the dynamic scoop 100 and the ring 103 are shown to make understanding easier. The rotation axis X of the turbomachine 1 is perpendicular to the plane of FIGS. 7A and 7B.

(24) The cover 46 comprises an orifice 102 through which the dynamic scoop 100 may be moved from the open position to the closed position and vice versa.

(25) In the configuration in FIG. 7A, the dynamic scoop 100 is in the closed position and is located under the cover 46. When the blade 48 is fixed in a predetermined position, for example the feathered position that may be a position corresponding to an idling phase and/or takeoff phase, the dynamic scoop 100 is in line with the orifice 102 just below the orifice 102 and opens to move to the open position due to the centrifugal effect (configuration in FIG. 7B). Opening of the dynamic scoop 100 by the centrifugal effect then allows the cooling air flow to enter so that the blade root 58 can be cooled.

(26) More specifically, the cooling air flow F may be routed in a blade cavity 64 associated with the blade 48 as described above, or it may be routed directly under the blade root 58, particularly through a flow channel provided between the dynamic scoop 100 and the pivot 52 to allow the cooling airflow F to pass from the dynamic scoop 100 to the pivot 52.

(27) In this case, the pivot 52 may comprise a communicating inner channel, one end of which opens up at the blade root 52 and the other end opens up at such a flow channel.

(28) Furthermore, for the case in which the pivot 52 is fitted with a counterweight system 90 as described with reference to FIG. 9, an inner flow channel for the cooling air flow F may be provided in the counterweight arm 90a of the counter weight system 90 so that the airflow F can pass from the dynamic scoop 100 to the blade root 58.

(29) FIG. 8 shows a perspective view of an example of a dynamic scoop 100 that can be used in a propeller 32 according to the invention.

(30) FIG. 9 shows a sectional view of a second example embodiment according to the invention.

(31) In this example, the pivot 52 is provided with two counterweight systems 90 each having a counterweight arm 90a and a counterweight 90b. The counterweight 90b may for example be made from tungsten.

(32) The movement of the dynamic scoop 100 from the closed position to the open position may be controlled by actuation of the counterweight system 90, for example by means of the counterweight 90b on the dynamic scoop 100. More precisely, the counterweight system 90 can bear on a specific part 100a of the dynamic scoop 100 to bring the dynamic scoop 100 into the open position when the blade 48 is brought into a predefined orientation, particularly through one or more counterweight systems 90, in other words when the dynamic scoop 100 reaches the orifice 102 formed in the cover 46.

(33) When the dynamic scoop 100 is in the closed position or when it moves away from the open position to reach the closed position, an elastic return spring (not shown) fixed to the dynamic scoop 100 may be used to bring the dynamic scoop 100 into the closed position and hold it there.

(34) Once the air flow F has ventilated the blade root 58 to cool it, it can be discharged.

(35) Airflow discharge means may also be provided particularly taking account of the position of the pitch of the blade 48 and the need for maximum ventilation to avoid making cooling less efficient due to the ingress of air discharged into a dynamic ventilation air flow inlet scoop.

(36) In all previously described examples, the blades 48 and particularly the blade roots 58 and/or the counterweight systems 90 and/or the dynamic scoop 100 may be made from composite materials.

(37) Obviously, the invention is not limited to the example embodiments that have just been disclosed. Those skilled in the art can make various modifications to it.

(38) In particular, the open and closed positions of the dynamic scoop 100 may be controlled other than through a pivot connection, and particularly the hinge connection. Different ways may be envisaged for routing the airflow F from the dynamic scoop 100 to the blade root 58.

(39) The expression “comprising a” must be understood as being synonymous with “comprising at least one”, unless specified otherwise.