Propulsion unit for aircraft comprising an assembly box-type structure in the six o'clock position

Abstract

A propulsion unit for an aircraft including a nacelle with a D-shaped structure housing a thrust-reversing device with movable vanes, the nacelle containing two D-shaped half-structures each including an external reverser half-cowl. The propulsion unit contains an assembly box-type structure, attached in downstream cantilevered fashion to the turbojet engine fan casing, the box-type structure including two guide rails guiding the deflection vanes, a locking device between the assembly box-type structure and the half-beams in the six o'clock position of the D-shaped half-structures, the assembly box-type structure being arranged in the propulsion unit such that the guide rails guiding the vanes of the assembly box-type structure are situated in the continuation of the guide rails in the six o'clock position guiding the vanes attached to the fan casing, to provide continuity between the rails.

Claims

1. A propulsion unit for aircraft, comprising a nacelle supporting a turbojet engine, the nacelle comprising: an upstream air inlet section; a median section, in a downstream extension of the upstream air inlet section, comprising a fan cowl, an annular space between the fan cowl and a fan casing of the turbojet engine defining an annular envelope; and a D-shaped structure downstream section embedding a thrust reverser device, the D-shaped structure downstream section comprising cascade vanes movable between a retracted position wherein the cascade vanes are housed in the annular envelope of the median section and a deployed position wherein the cascade vanes are displaced downstream of the annular envelope, the D-shaped structure downstream section comprising two D-shaped half-structures, each comprising: an outer half-cowl, movable in translation during an activation of an actuator along a substantially longitudinal axis of the propulsion unit, between a retracted position providing aerodynamic continuity with the fan cowl and an annular flow path, for an operation of the nacelle in direct jet and a deployed position opening an annular passage in the nacelle for an operation of the nacelle in reverse jet; a connection device between the cascade vanes and the outer half-cowl, arranged so that the cascade vanes are displaced simultaneously with the outer half-cowl during the activation of the actuator; a six o'clock half-bifurcation; an inner half-structure defining an inner portion of the annular flow path of the nacelle when the nacelle is in operation, the inner half-structure being connected to the outer half-cowl by the six o'clock half-bifurcation; a six o'clock half-beam mounted on the six o'clock half-bifurcation, supporting a sliding rail in translation of the outer half-cowl; at least two six o'clock guiding rails for guiding the cascade vanes, affixed to the fan casing of the turbojet engine; and wherein the propulsion unit includes an assembly box, cantilever mounted downstream relative to the fan casing and directly affixed to the fan casing, the assembly box comprising: at least two guiding rails for guiding the cascade vanes, a locking device between the assembly box and each of the six o'clock half-beams of each of the D-shaped half-structures, and the assembly box being arranged in the propulsion unit so that the at least two guiding rails for guiding the cascade vanes of the assembly box are located in a downstream extension of the at least two six o'clock guiding rails for guiding the cascade vanes affixed to the fan casing, so as to provide continuity between the at least two guiding rails for guiding the cascade vanes of the assembly box and the at least two six o'clock guiding rails for guiding the cascade vanes affixed to the fan casing.

2. The propulsion unit according to claim 1, wherein the assembly box includes an annular fixing flange, mounted upstream of the assembly box and affixing to the fan casing.

3. The propulsion unit according to claim 2, wherein the assembly box includes a downstream compartment downstream of the annular fixing flange.

4. The propulsion unit according to claim 3, wherein the downstream compartment of the assembly box includes a hollow inner space, allowing passage of ancillaries of the turbojet engine.

5. The propulsion unit according to claim 3, wherein the downstream compartment of the assembly box has a substantially parallelepiped shape.

6. The propulsion unit according to claim 3, wherein the at least two guiding rails for guiding the cascade vanes of the assembly box are each integrated into a longitudinal outer wall of the downstream compartment of the assembly box.

7. The propulsion unit according to claim 3, wherein a length of the downstream compartment of the assembly box is between 25% and 75% of a length of the six o'clock half-beam of the D-shaped half-structure.

8. The propulsion unit according to claim 1, wherein the assembly box includes a bottom wall providing aerodynamic continuity with the two D-shaped half-structures, the bottom wall being configured to come into contact with an outer air flow flowing around the nacelle.

9. The propulsion unit according to claim 1, wherein the two D-shaped half-structures are connected together at a connection zone located downstream of the assembly box.

10. The propulsion unit according to claim 1, wherein the locking device between the assembly box and each of the six o'clock half-beams of each of the D-shaped half-structures is positioned at an upstream portion of each of the six o'clock half-beams.

11. The propulsion unit according to claim 1, wherein the assembly box includes a sealing device providing a seal with each of the six o'clock half-beams.

Description

DRAWINGS

(1) In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:

(2) FIG. 1 is an isometric view of a propulsion unit of the prior art;

(3) FIG. 2 illustrates a propulsion unit of the prior art, during the opening of the nacelle for the maintenance of the turbojet engine;

(4) FIG. 3 illustrates a propulsion unit of the prior art equipped with a D-shaped structure nacelle;

(5) FIG. 4 represents a D-shaped half-structure of the D-shaped structure nacelle of FIG. 3;

(6) FIG. 5 illustrates a propulsion unit of the prior art equipped with a C-shaped structure nacelle;

(7) FIG. 6 illustrates a six o'clock zone of a propulsion unit of the prior art equipped with a D-shaped structure nacelle;

(8) FIG. 7 illustrates in isometric view the propulsion unit according to the teachings of the present disclosure in the open position for the maintenance of the turbojet engine;

(9) FIG. 8 is FIG. 7 with the upstream and median sections of the nacelle removed for better visibility;

(10) FIG. 9 shows the propulsion unit of FIG. 7 in rear view;

(11) FIG. 10 illustrates the six o'clock zone of the propulsion unit according to the teachings of the present disclosure in longitudinal section, centered on the median and downstream sections of the nacelle;

(12) FIG. 11 is a cross-sectional view along the line XI-XI of FIG. 10;

(13) FIG. 12 represents the propulsion unit according to the teachings of the present disclosure in isometric view from below; and

(14) FIG. 13 shows the six o'clock zone of the propulsion unit, centered on the assembly box according to the teachings of the present disclosure.

(15) The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

(16) The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

(17) The terms “upstream” and “downstream” must be understood relative to the circulation of the air flow inside the propulsion unit formed by the nacelle and the turbojet engine, that is to say from left to right with reference to FIG. 1.

(18) Likewise, the expressions “inner” and “outer” will be used in a non-limiting manner with reference to the radial distancing relative to the longitudinal axis of the nacelle, the expression “inner” defining a zone radially closer to the longitudinal axis of the nacelle, as opposed to the expression “outer.”

(19) Furthermore, the longitudinal, vertical and transverse terminology will be adopted without limitation, with reference to the trihedron L, V, T indicated in the figures.

(20) Furthermore, in all of these figures, identical or similar reference numerals refer to identical or similar members or sets of members.

(21) Reference is made to FIGS. 7 to 9, illustrating a propulsion unit 101 according to the present disclosure.

(22) In FIG. 7, the propulsion unit 101 is in the open position for the maintenance of the turbojet engine. FIG. 8 is identical to FIG. 7, the upstream and median sections of the nacelle having been removed for better visibility. FIG. 9 represents the propulsion unit 101 in rear view.

(23) The propulsion unit 101 includes a nacelle 103 having a tubular structure and comprising an upstream section, or air inlet 107, located upstream of the turbojet engine 105, a median section 109 intended to surround a fan of the turbojet engine and including a fan cowl 110, a downstream section 111, intended to surround the combustion chamber of the turbojet engine, embedding thrust reversal devices, which can be terminated by an ejection nozzle located downstream of the turbojet engine. The nacelle 103 is connected via a suspension pylon 115 to the wing of the aircraft (not represented).

(24) The downstream section 111 has a D-structure 117. The D-structure 117 includes two D-shaped half-structures 117a, 117b, each including an inner half-structure 119a, 119b secured at twelve o'clock to a twelve o'clock half-bifurcation 121a, 121b and at six o'clock to a six o'clock half-bifurcation 123a, 123b.

(25) On the twelve o'clock half-bifurcation 121a, 121b is mounted to twelve o'clock half-beam 125a, 125b and on the six o'clock half-bifurcation 123a, 123b is mounted to six o'clock half-beams 127a, 127b.

(26) Each half-beam 125a, 125b, 127a, 127b supports a sliding rail (not visible in FIGS. 7 to 9) of two outer half-cowls 129a, 129b mounted in translation on each six o'clock and twelve o'clock half-beam.

(27) The downstream section 111 with a D-structure 117 comprises cascade vanes (not represented).

(28) The cascade vanes are movable between a retracted position according to which the cascade vanes are housed in an annular envelope 112 (visible in FIG. 8) defined by the annular space comprised between the fan cowl 110 and the fan casing 137 of the turbojet engine 105 and a deployed position according to which the cascade vanes are displaced downstream of the annular envelope 112.

(29) Actuating includes actuators 114 that are mounted on the fan casing 137 and include a rod affixed to the outer half-cowls 129a, 129b.

(30) The activation of these actuating devices allows for a displacement of the outer cowls 129a, 129b, which displacement causes in concert a displacement in translation of the cascade vanes, connected to the outer half-cowls by a connection device (not represented).

(31) In direct jet operation of the nacelle, the half-cowls 129a, 129b are in the retracted position and provide an aerodynamic continuity with the fan cowl 110. The cascade vanes are in the retracted position.

(32) During activation of the actuating devices, the outer half-cowls are translated downstream of the nacelle, until reaching a deployed position opening in the nacelle an annular passage, for an operation of the nacelle in reverse jet. The cascade vanes are deployed downstream of the nacelle thanks to connection with the outer half-cowls and are located in the annular passage thus defined in the nacelle.

(33) Reference is made to FIGS. 10 and 11. FIG. 10 illustrates the six o'clock zone of the propulsion unit 101 in longitudinal section, centered on the median section 109 and downstream 111 sections of the nacelle 103, and FIG. 11 is a cross-sectional view of the propulsion unit 101 according to line XI-XI of FIG. 10.

(34) The six o'clock half-beam 127a, respectively 127b, respectively mounted on the six o'clock half-bifurcation 123a, respectively 123b, supports a sliding rail 143a, respectively 143b of the outer half-cowl 129a, respectively 129b.

(35) On the fan casing 137 are affixed two six o'clock rails 145a, 145b for guiding the cascade vanes (only six o'clock rail 145b is visible in FIGS. 10 and 11).

(36) According to the present disclosure, the propulsion unit 101 includes an assembly box 147 cantilever mounted downstream relative to the fan casing 137.

(37) The assembly box 147 is affixed directly to the fan casing 137, for example by devices such as an annular fixing flange 149 which is an integral portion of the assembly box.

(38) The annular fixing flange 149 of the assembly box 147 is affixed to a downstream edge 151 of the fan casing 137. The annular fixing flange provides the passage of forces between the assembly box 147 and the fan casing 137.

(39) The assembly box 147 includes two rails 153a, 153b for guiding the cascade vanes. The rails 153a, 153b for guiding the cascade vanes mounted on the assembly box 147 are located in the extension of the six o'clock rails 145a, 145b for guiding the cascade vanes affixed to the fan casing.

(40) Continuity between the rails 153a, 153b for guiding the cascade vanes of the assembly box 147 and the six o'clock rails 145a, 145b for guiding the cascade vanes affixed to the fan casing is thus provided.

(41) A locking device 155a, 155b is mounted on the assembly box 147 between the assembly box and the six o'clock half-beams 127a, 127b of each D-shaped half-structure 117a, 117b. This allows locking of the six o'clock half-beams together via the assembly box.

(42) The locking device 155a, 155b is positioned at an upstream portion 157 of the half-beams 127a, 127b.

(43) Moreover, the two D-shaped half-structures 117a, 117b are connected together at a connection zone located downstream of the assembly box 147, via locks 159, 161, 163.

(44) The assembly box includes a downstream compartment 165 downstream of the annular fixing flange 149. The downstream compartment 165 has for example a substantially parallelepiped shape. The length of the downstream compartment of the assembly box is comprised between 25% and 75% of the length of one of the half-beams 127a, 127b of the D-shaped half-structure.

(45) The rails 153a, 153b for guiding the cascade vanes of the assembly box are respectively integrated into longitudinal outer walls 167a, 167b of the downstream compartment 165 of the assembly box 147.

(46) The assembly box 147 further includes a bottom wall 169 providing aerodynamic continuity with the two D-shaped half-structures 117a, 117b, and designed to come into contact with the outer air flow F flowing around the nacelle, as can be understood from FIG. 12 illustrating the propulsion unit 101 in an isometric view from below.

(47) Reference is made to FIG. 13, illustrating the six o'clock zone of the propulsion unit centered on the assembly box 147. The downstream compartment 165 includes a hollow inner space 171, allowing to pass ancillaries 173 of the turbojet engine such as for example tube paths, electrical harnesses or drains.

(48) The assembly box 147 includes a sealing device (not represented in the figures) providing a seal with the six o'clock half-beams 127a, 127b. The sealing device is designed and arranged in the nacelle to provide fluid, pressure and fire segregation between each compartment of the propulsion unit relative to the exterior of the propulsion unit.

(49) It goes without saying that the present disclosure is not limited to the only embodiments of this propulsion unit, described above only by way of illustrative examples, but on the contrary it encompasses all the variants involving the technical equivalents as well as their combinations if these fall within the scope of the present disclosure.

(50) Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

(51) As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

(52) The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.