Method for holding an adapter piece on a tubular housing of a turbo engine, and corresponding adapter piece and holding system

Abstract

An adapting part is designed to be held on a casing of a turbo-engine, partially covering the casing. The adapting part includes, in the extension of one of its axial ends, a first connector to engage with a first complementary connector associated with the casing to form a sliding connection. The adapting part also includes, at its other axial end, a second connector to be secured to a second complementary connector associated with the casing to form a rigid connection.

Claims

1. An adapting part designed to transmit forces between a tubular casing of a turbo-engine and a suspension of the turbo-engine to a pylon of an aircraft, by partially covering the tubular casing, the adapting part comprising: a hoop portion of predetermined angular sector; suspension devises arranged on a face of the hoop portion which faces outwards and designed to connect the adapting part to the suspension; in an extension of a first axial end of the adapting part, a projecting tab extending axially from the hoop portion and configured to engage with a groove of a connecting member associated with said tubular casing to form an axial sliding connection; and at a second axial end of the adapting part, a flange configured to be secured to a flange of said tubular casing to form a rigid connection, wherein the projecting tab is entirely circular or extends circumferentially over the predetermined angular sector.

2. The adapting part as claimed in claim 1, wherein the flange is entirely circular or extends circumferentially over the predetermined angular sector.

3. The adapting part as claimed in claim 1, wherein the predetermined angular sector of the hoop portion is equal to 120°.

4. A system, comprising: an adapting part comprising: a hoop portion of predetermined angular sector; suspension devises arranged on a face of the hoop portion which faces outwards and designed to connect the adapting part to the suspension; in an extension of a first axial end of the adapting part, a projecting tab extending axially from the hoop portion; and at a second axial end of the adapting part, a flange, wherein the projecting tab is entirely circular or extends circumferentially over the predetermined angular sector: a tubular casing of a turbo-engine arranged for holding, to the tubular casing, the adapting part; a groove of a connecting member associated with said tubular casing which engages with the projecting tab of the adapting part to form an axial sliding connection in a first axial end of the tubular casing; and a flange of said tubular casing which engages with the flange of the adapting part to form a rigid connection in a second axial end of the tubular casing.

5. The system as claimed in claim 4, wherein the connecting member is fitted on one end flange of said tubular casing.

6. The system as claimed in claim 4, wherein the connecting member radially extends to one end flange of said tubular casing.

7. A suspension for a turbo-engine on a pylon of an aircraft, comprising: a front suspension bracket mounted on an intermediate casing of the turbo-engine; a rear suspension bracket mounted on an inter-turbine casing of the turbo-engine; and wherein an adapting part as claimed in claim 1 connects the rear suspension bracket to the inter-turbine casing of the turbo-engine.

8. A turbo-engine attached to a pylon of an aircraft, comprising: a front suspension bracket mounted on an intermediate casing of the turbo-engine; a rear suspension bracket mounted on an inter-turbine casing of the turbo-engine; and a system as claimed in claim 4, wherein the adapting part of the system connects the rear suspension bracket to the inter-turbine casing of the turbo-engine.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) The figures of the appended drawing will make it easy to understand how the invention may be embodied. In these figures, identical references designate similar elements.

(2) FIG. 1 shows, very schematically and in profile, a turbo-engine attached to an attachment pylon of an aircraft via the intermediary of a suspension in accordance with the present invention.

(3) FIG. 2 shows, in a schematic perspective view, an example of a suspension implementing an adapting part in accordance with the present invention.

(4) FIG. 3 is a schematic axial section of the adapting part of FIG. 2, once mounted on the inter-turbine casing of the turbo-engine.

(5) FIG. 4 shows, in a schematic perspective view, the adapting part of FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

(6) As shown in FIG. 1, a suspension 3 is provided for mounting and attaching a turbo-engine 1, of longitudinal axis L-L, to a pylon 2 of an aircraft below the wings of the latter, so as to form an interface between the turbo-engine 1 and the pylon 2.

(7) Thus, the suspension 3 of the invention is positioned between the pylon 2 having a box-type attachment bracket (partially represented in FIG. 2) and intermediate 4 and inter-turbine 5 outer casings of the turbo-engine 1.

(8) Moreover, the suspension 3 is positioned and contained in two suspension planes P1 and P2 of the turbo-engine 1, which are mutually parallel and orthogonal to the longitudinal axis L-L thereof.

(9) With respect to an orthonormal reference frame XYZ (corresponding to that of the aircraft 1 with X being the roll axis, Y being the pitch axis and Z being the yaw axis), the longitudinal axis L-L of the turbo-engine 1 is parallel to X and the suspension planes, front P1 and rear P2, are contained in planes formed by the Y and Z axes.

(10) The front suspension plane P1 is arranged level with the intermediate casing 4 downstream of the fan of the turbo-engine 1 and the rear suspension plane P2 is, for its part, located level with the frustoconical inter-turbine casing 5, arranged between a high-pressure turbine casing 6 and a low-pressure turbine casing 7.

(11) The front suspension 3A and the rear suspension 3B—forming the overall suspension 3—are represented by rectangles 3A and 3B (FIG. 1) connecting the casings 4 and 5 corresponding to the attachment bracket of the pylon 2.

(12) As shown in FIG. 2, the suspensions, front 3A and rear 3B, respectively comprise a front suspension bracket 8, in the front suspension plane P1, and a rear suspension bracket 9, in the rear suspension plane P2.

(13) In particular, the front suspension bracket 8 comprises a fitting 10 and three articulated rods 11A and 11B. The upper portion 10A of the fitting 10 defines a platform for receiving the attachment bracket of the pylon 2 in the front suspension plane P1.

(14) The fitting 10 extends on either side of the engine axis L-L via two double clevises 12 into which are inserted, respectively, the ends of the lateral struts 11A, so as to form an articulated connection having a common spindle 13 passing through the two lugs of each of the clevises 11A and the ends of the corresponding struts 11A.

(15) The fitting 10 also comprises a central clevis 14 so as to form an articulated connection with the central strut 11B with a common spindle 13. The front suspension bracket 8 is designed to take up the forces taking up the torque of the turbo-engine 1 in particular via the intermediary of the central strut 11B. In this case (torque uptake at the front), the forces acting in the formed rear suspension 3B are reduced. Indeed, taking up the torque on the intermediate casing 4 at the front of the turbo-engine 1—which has a larger radius than the inter-turbine casing 5—allows a reduction of the torque uptake forces. Such an attachment configuration prevents any torque uptake at the rear of the turbo-engine 1 at the level of the rear suspension 3B, such that the latter is subjected to less force.

(16) Moreover, the rear suspension bracket 9 comprises a fitting 15 and two lateral articulated rods 16. The upper portion 15A of the fitting 15 forms a platform for receiving the attachment bracket of the pylon 2 in the rear suspension plane P2.

(17) The fitting 15 extends on either side of the engine axis L-L via two double clevises 17A into which are inserted, respectively, the ends of the lateral struts 16, so as to form an articulated connection having a common spindle 18 passing through the two lugs of each of the lateral clevises 17A and the ends of the corresponding struts 16.

(18) The fitting 15 also comprises a double central clevis 17B so as to form an articulated connection with a single clevis of an adapting part 19 in accordance with the invention, as is set out hereinbelow.

(19) Furthermore, as shown in FIG. 2, once mounted on the turbo-engine 1, the rear suspension bracket 9 is attached to the adapting part 19 designed to be fitted on the inter-turbine casing 5, in the rear suspension plane P2.

(20) As shown in FIGS. 2 and 4, the adapting part 19 is formed of a frustoconical hoop portion 20 of angular sector α approximately equal to 120°. The hoop portion 20 has a longitudinal extent along the axis L-L which is substantially equal to that of the inter-turbine casing 5.

(21) The adapting part 19 further comprises a tab 21 which extends, in the upstream direction, the axial end of the hoop portion 20. The upstream tab 21, which is partially cylindrical, extends over the angular sector α. It is inclined with respect to a generatrix T-T of the frustoconical portion 20.

(22) The adapting part 19 also comprises a downstream flange 22 secured to the downstream end of the hoop portion 20 and designed to be connected to the downstream flange 5B of the inter-turbine casing 5 (see FIG. 3). The downstream flange 22, in the form of a collar portion, extends over the angular sector α. In other words, when it is attached to the corresponding flange 5B of the inter-turbine casing 5, the attachment is effected only over an angle portion.

(23) Once the adapting part 19 is fitted on the inter-turbine casing 5, the downstream flange 22 is in a plane orthogonal to the longitudinal axis L-L, such that it is inclined with respect to the generatrix T-T.

(24) As shown in FIG. 3, the high-pressure turbine casing 6 comprises, at its downstream end, a circular flange 6A which extends axially via a connecting member 23 comprising a groove 24 which is circular in shape. The connecting member 23 extends over an angular sector equal to the angular sector α.

(25) The groove 24, delimited by two concentric ribs 23A and 23B, defines a receiving recess designed to accommodate the tab 21 of the adapting part 19. The depth of the groove 24 is such that, once the adapting part 19 is fitted on the inter-turbine casing 5, a clearance remains between the free end of the tab 21 and the bottom of the groove 24.

(26) Moreover, the circumferential ends of the groove 24 are closed, such that the angular extent of the groove 24 corresponds to that of the tab 21. Thus, once the tab 21 is accommodated with adjustment in the groove 24, it is possible to prevent any rotation of the adapting part 19 with respect to the inter-turbine casing 5 and high-pressure casing 6. Closing the circumferential ends of the groove 24 also facilitates the angular positioning of the adapting part 19.

(27) As a variant, the tab of the adapting part could comprise a plurality of notches, defining sub-tabs, and the groove of the connecting member could comprise radial walls, defining sub-grooves designed to accommodate the corresponding sub-tabs. In another variant, the sub-tabs could be flat and the sub-grooves straight.

(28) It will be noted that the connecting member 23 may comprise a shoulder 23C which is annular or partially annular and against which the upstream flange 5A of the inter-turbine casing 5 is designed to press, in order to facilitate the centering of the latter.

(29) Furthermore, as shown in FIGS. 2 to 4, orifices 25 are regularly distributed over the downstream flange 22 of the part 19 such that, for example, they may be bolted to the corresponding downstream flange 5B of the inter-turbine casing 5. Of course, other attachment means could equally be employed, such as for example rivets, so as to replace the bolts.

(30) When it is assembled on the turbo-engine 1, the adapting part 19 is first fitted on the inter-turbine casing 5 by inserting the tab 21 into the corresponding groove 24 of the connecting member 23. Once the tab 21 is accommodated in the groove 24, the downstream flange 22 is fixed, by bolting, to the downstream flange 5B of the inter-turbine casing 5 and to the upstream flange 7A of the low-pressure turbine casing 7. The connecting member 23 and the upstream flange 5A of the inter-turbine casing 5 then define a system for holding the adapting part 19 on the turbo-engine 1.

(31) Thus, once the adapting part 19 is fitted on the inter-turbine casing 5, the tab 21 engages with the groove 24 so as to form, on the upstream side, an axially sliding connection. On the downstream side of the adapting part 19, a rigid connection, obtained by bolting, is formed by assembling the flanges 22, 5B and 7A, respectively in this order.

(32) The differential expansion of the casings and of the adapting part is thus better managed, with at least part of the axial expansion being absorbed by the upstream sliding connection.

(33) Moreover, the forces supplied by the rear suspension bracket 9 on the adapting part 19 are transmitted directly to the sliding and rigid connections arranged at the axial ends of the inter-turbine casing 5.

(34) Furthermore, as shown in FIG. 4, the adapting part 19 also comprises three suspension clevises 26 and 27, of which two are lateral double clevises 26 and one is a central single clevis 27. It goes without saying that, as a variant, the number and shape of the clevises (single or double) could be different.

(35) The suspension clevises 26 and 27 are arranged on that face of the hoop portion 20 which faces outwards.

(36) Moreover, as shown in FIG. 2, the lateral articulated rods 16 which are articulated on the rear suspension bracket 9 are designed to form an articulated connection with the corresponding lateral clevises 26 of the part 19. The free ends of the articulated rods 16 are inserted between the two lugs of the lateral clevises 26 and a common spindle 28 passes through them, thus forming an articulated connection.

(37) The double central clevis 17B of the rear suspension bracket 9 receives the single clevis 27 of the adapting part 19, such that a common spindle 29 passes through it and thus forms an articulated connection.

(38) Furthermore, in the example shown, the hoop portion 20 comprises a plurality of rectangular cutouts 30 which are designed to lighten the adapting part 19 and to allow cables, equipment or any other element to pass through.

(39) FIG. 2 also shows two thrust uptake struts 31 which are connected to the rear suspension bracket 9 via the intermediary of a spreader 32.

(40) It is to be noted that, when mounting the suspension 3 on the turbo-engine 1, the adapting part 19 is preferably first attached to the inter-turbine casing 5. The rear suspension bracket 9 is then mounted on the adapting part 19 which is positioned in this manner. The attachment bracket of the pylon 2 is finally bolted to the corresponding platform of the rear suspension bracket 9.

(41) Of course, the present invention is in no way limited to the exemplary embodiment described hereinabove.

(42) Thus, in a first variant which is not illustrated, the connecting member may axially extend the upstream flange 5A of the inter-turbine casing 5 (and not the downstream flange 6A of the high-pressure turbine casing 6).

(43) In a second variant which is not illustrated, the connecting member may be independent and distinct from the flanges 5A and 6A, such that it can be fitted and attached to these flanges 5A and 6A, for example when they are assembled by bolting with one another. In this case, the distinct connecting member may be fitted on the upstream face of the downstream flange 6A of the high-pressure turbine casing 6, or on the downstream face of the upstream flange 5A of the inter-turbine casing 5. In this variant, shear pins may also be provided on one of the flanges 5A or 6A in order to facilitate the positioning thereon (in particular the angular centering) of the connecting member.

(44) Furthermore, the invention may equally apply to an adapting part and a tab of entirely circular shape.

(45) It will finally be noted that the adapting part in accordance with the invention is not limited to use in a rear suspension of a turbo-engine of an aircraft.