Test bench for a turbomachine rectifier including a cable guide dome

Abstract

The present invention relates to a test bench for a turbomachine rectifier, the turbomachine rectifier comprising a hub (4) and several blades arranged in each housing (41) of the hub (4) via a blade root fixed to a flange (52) for fixing the blade root in the housing (41); the test bench comprising: - measuring equipment configured to support a turbomachine rectifier; and - instrumentation cables (11); and - a holding dome (9) intended to be arranged inside each housing (41), the holding dome (9) being configured to guide the instrumentation cables (11) in the hub (4) in order to avoid any contact between the instrumentation cables (11) linked to the vanes of the rectifier and the measuring equipment during the test of the turbomachine rectifier. Figure for abstract: Fig.5

Description

Title of the invention: Test bench for a turbomachine rectifier comprising a cable guide dome FIELD OF THE INVENTION

[0001] The present invention relates to the field of turbomachines and turbomachine test benches. It relates in particular to a test bench for a turbomachine rectifier, for example a turbomachine rectifier comprising variable-pitch stator blades. This is in particular a shrouded or unshrouded turbomachine rectifier. STATE OF THE ART

[0002] Turbomachines comprising at least one unducted propeller are known by the English term "open rotor" or "unducted fan". Such turbomachines may comprise two unducted and contra-rotating propellers (known by the English acronym CROR for "Contra-Rotating Open Rotor") or a single unducted propeller and a rectifier comprising several blades (known by the English acronym USF for "Unducted Single Fan"). The propellers may be placed at the rear of the gas generator (or engine) so as to be of the pusher type or at the front of the gas generator so as to be of the tractor type. These turbomachines are turboprops which are distinguished from turbojets by the use of a propeller outside the nacelle (unducted) instead of an internal fan.The use of a turboprop engine makes it possible to increase the bypass ratio significantly without being penalized by the mass of the casings or nacelles intended to surround the propeller blades.

[0003] The vanes of the rectifier are generally installed on a hub which carries a nozzle for separating the primary and secondary flows circulating respectively in a primary vein and around an inlet casing. Unlike the upstream propeller of a USF type turbomachine, the vanes of the rectifier are fixed in rotation relative to the axis of rotation of the upstream propeller and consequently do not undergo centrifugal force.

[0004] The implementation of various tests on the rectifier by means of a test bench makes the integration zone of the rectifier blades highly constrained by the presence of numerous measuring equipments near the hub and by the passage of instrumentation cables. Contact between the instrumentation cables and the measuring equipments of the test bench can cause disturbances in the measurement results. It is therefore necessary to avoid any contact between the instrumentation cables and the measuring equipments of the test bench during the test of the turbomachine rectifier on the test bench. Statement of the invention

[0005] An aim of the present disclosure is to avoid any contact between the instrumentation cables present at the level of a rectifier blade with the measuring equipment of the test bench.

[0006] To this end, according to one aspect of the present disclosure, there is provided a test bench for a turbomachine rectifier, the test bench comprising annular measuring equipment extending around a first axis, the measuring equipment being configured to support a turbomachine rectifier; and instrumentation cables. The turbomachine rectifier comprises:

[0007] -a hub extending around the first axis, the hub comprising several housings arranged radially in the hub, and

[0008] - several blades arranged in each housing by means of a foot blade fixed to a blade root fixing flange in the housing, each flange having an inner surface and an outer surface, the inner surface being directed towards the inside of the hub.

[0009] The test bench comprises a holding dome intended to be arranged inside each housing, opposite the internal surface of the flange, the holding dome being configured to guide the instrumentation cables in the hub in order to avoid any contact between the instrumentation cables linked to the vanes of the rectifier and the measuring equipment during the test of the turbomachine rectifier.

[0010] This makes it possible to guide the instrumentation cables of a vane of a rectifier from the vane root and into the hub without them being able to come into contact with measuring equipment of the test bench positioned radially internal to the hub.

[0011] The holding dome makes it possible to maintain a constant orientation of the instrumentation cables despite a modification of the orientation of the blade root.

[0012] Advantageously, but optionally, the test bench disclosed comprises at least one of the characteristics:

[0013] - the holding dome comprises a channel configured to guide the cables instrumentation from the blade root, the channel comprising an inlet facing the flange and an outlet radially internal to the inlet and oriented in a direction parallel to the first axis;

[0014] - the holding dome comprises an annular groove extending around the first portion of the channel, the groove being configured to accommodate nuts for fixing the blade root to the flange;

[0015] - the holding dome comprises a rim configured to secure the holding dome hub retention;

[0016] - each housing comprises a retaining wall comprising a window introduction suitable for allowing the flange and the holding dome to be inserted into the housing and suitable for retaining the flange in the housing following a rotation of the flange by a fraction of a turn;

[0017] - the fixing edge of the holding dome comprises an adhesive configured to fix the edge of the retaining dome to the housing.

[0018] According to another aspect, there is provided a test assembly for a turbomachine rectifier, comprising a test bench as previously described and a turbomachine rectifier.

[0019] Advantageously, but optionally, the disclosed assembly comprises the rectifier comprising clamping members configured to clamp the flange and the blade root to the retaining wall so as to immobilize the blade root in the housing in a desired angular position.

[0020] According to another aspect, there is provided a turbomachine comprising a rectifier configured by means of a test bench or an assembly as previously described. DESCRIPTION OF FIGURES

[0021] Other characteristics, aims and advantages will emerge from the following description, which is purely illustrative and non-limiting, and which must be read in conjunction with the appended drawings in which:

[0022] [Fig.l] illustrates a longitudinal schematic view of a turbomachine;

[0023] [Fig.2] illustrates a perspective view of an aircraft turbomachine rectifier according to an embodiment of the present disclosure;

[0024] [Fig. 3] illustrates a longitudinal sectional view of a test assembly of a turbomachine rectifier mounted on a test bench, according to an embodiment of the present disclosure;

[0025] [Fig.4] illustrates an exploded perspective view of a test assembly of a re aircraft turbomachine trainer, according to an embodiment of the present disclosure;

[0026] [Fig.5] illustrates a longitudinal sectional view of a holding dome, according to an embodiment of the present disclosure.

[0027] Throughout the figures, identical elements bear identical references. DETAILED DESCRIPTION OF THE INVENTION

[0028] Turbomachine

[0029] A turbomachine 1, as shown for example in [Fig.l], is an aircraft turbomachine 1 configured to be attached to an aircraft to propel it. The turbomachine 1 may be a single, double or triple-spool and single or double-flow turbojet. The turbomachine 1 may further be a turbojet with a drive fan via a reducer (or "geared engine" in Anglo-Saxon terminology), a turboprop or an unducted turbojet (or "unducted fan", "propfan" or "open rotor", in Anglo-Saxon terminology), of the pusher or tractor type. The turbomachine 1 may in particular be a USF type turboprop ("unducted single fan", according to Anglo-Saxon terminology).

[0030] The turbomachine 1 has a longitudinal axis X and comprises a fan 2 or a propeller 2, a compression section, a combustion chamber, a turbine section downstream of the combustion chamber, and a crankcase 6.

[0031] The turbomachine 1 further comprises a static vane 3. The static vane 3 is arranged to straighten an air flow downstream of the propeller 2. However, the invention applies to any static vane 3 (i.e. not rotating around the longitudinal axis X) of a turbomachine 1, whether it is a rectifier vane 3 of a fan 2 or a propeller 2, a rectifier vane 3 of a compression section, or a distributor vane of a turbine section. In the case of an unducted turbomachine 1, the static vane 3 may correspond to the unducted rectifier 3 extending downstream of the fan 2 (or “outlet guide vane”, according to English terminology). Subsequently, and for simplicity, we will speak of rectifier 3 to refer to static blading 3.

[0032] Unless otherwise specified, the terms “upstream” and “downstream” are used with reference to the overall direction of airflow through the turbomachine 1 in operation. Similarly, an axial direction corresponds to the direction of the longitudinal axis X and a radial direction is a direction orthogonal to the longitudinal axis X and intersecting the longitudinal axis X. Furthermore, an axial plane is a plane containing the longitudinal axis X and a radial plane is a plane orthogonal to the longitudinal axis X. A circumference is understood to be a circle belonging to a radial plane and whose center belongs to the longitudinal axis X. A tangential or circumferential direction is a direction tangent to a circumference: it is orthogonal to the longitudinal axis X but does not pass through the longitudinal axis X.Finally, the adjectives "inner" (or "internal") and "outer" (or "external") are used in reference to a radial direction so that the inner part of an element is, in a radial direction, closer to the longitudinal axis X than the outer part of the same element.

[0033] Rectifier

[0034] The rectifier 3, as illustrated in Figures 2 to 4, comprises a hub 4 fixedly mounted relative to the motor casing 6, illustrated in [Fig. 1], and at least one blade 5 extending from the hub 4. The hub 4 extends around the longitudinal axis X and comprises a plurality of blade root housings 41, called housing 41, extending radially in the hub 4. The housings 41 are preferably distributed uniformly on the hub 4 around the longitudinal axis X. Advantageously, the hub 4 is a single-piece hub. Alternatively, the hub 4 could be formed by two coaxial annular elements fixed to each other and defining between them the housings 41.

[0035] Advantageously, the rectifier 3 comprises a plurality of blades 5 extending radially from the hub 4. The blades 5 each extend radially along a radial axis Y, perpendicular to the longitudinal axis X, towards the outside of the hub 4. The blades 5 are distributed angularly in a regular manner around the longitudinal axis X of the hub 4. Each blade 5 is provided with a blade root 51 intended to be arranged inside the corresponding housing 41. And each blade 5 preferably comprises a flange 52 connecting the blade 5 to the hub 4. More precisely, each blade 5 comprises a blade root 51 which is mounted in a housing 41 of the hub 4 via the flange 52.

[0036] The blade root 51 comprises a first lower blade root portion 51 intended to be connected to the hub 4 via the flange 52 and a second upper blade root portion 51 extending radially relative to the longitudinal axis X from the first portion. The second portion is therefore connected to the blade 5, optionally monolithically.

[0037] According to one embodiment, the orientation of the blades 5 on the hub 4, around their respective radial axis Y can be modified, in other words, the blades 5 are variable-pitch. In the embodiment in which the blades 5 are variable-pitch, the pitch angle of each blade 5 of the rectifier 3 can be modified in order to adapt the performance of the turbomachine 1 to the different flight phases.

[0038] In the remainder of the description, for the sake of simplicity, the invention will be described in the case of a rectifier 3 comprising variable-pitch blades 5 whose blade root 51 is mounted in the hub 4 via the flange 52. However, the present description is not limited to this configuration and could be applied to a fixed blade 5 whose blade root 51 is mounted directly on the hub 4.

[0039] A retaining wall 42 is arranged inside each housing 41 of the blade root 51. The retaining wall 42 comes from an internal face of the housing 41 and extends radially from the internal face of the housing 41 towards the center of the housing 41.

[0040] An insertion window 43 for flange 52 is made in the retaining wall 42. The insertion window 43 has a shape corresponding to that of the flange 52. The insertion window 43 is an opening made in the retaining wall 42 in a direction parallel to the radial axis Y.

[0041] The flange 52 has an elongated shape extending perpendicularly relative to the respective radial axis Y of the blade 5. The flange 52 comprises a central opening 521 intended to be mounted coaxially with a cylindrical portion of the blade root 51. This makes it possible to ensure guidance and centering of the flange 52 relative to the root dawn 51.

[0042] The flange 52 comprises an inner surface 522 and an outer surface 525. The inner surface 522 is directed towards the inside of the hub 4 and the outer surface 525 is directed towards the blade root 51.

[0043] The flange 52 comprises two complementary ends 523 of the introduction window 43 and configured to bear against a portion of the retaining wall 42 in the locked position. In the locked position, the flange 52 is positioned radially internal to the retaining wall 42 along the radial axis Y of the blade 5 in question. The retaining wall 42 may have a notch for receiving the flange 52 in the locked position.

[0044] The flange 52 is mounted on the blade root 51 using clamping members 7, as illustrated in Figures 4 and 5. The clamping members 7 may be two fixing screws 71 and two corresponding nuts 72. For this purpose, each fixing screw 71 is inserted inside a passage opening 511 made in the blade root 51, then a through opening 524 made in one end 523 of the flange 52 so as to finally cooperate with a respective nut 72. The fixing screw 71 therefore passes through the blade root 51 and the flange 52 and cooperates with a nut 72 to tighten the blade root 51 and the flange 52 on either side of the retaining wall 42.

[0045] It is then sufficient to rotate the blade 5 with its flange 52 a fraction of a turn, preferably a quarter of a turn, in the housing 41 to prevent it from coming out of the housing 41. Indeed, following the rotation, the flange 52 comes opposite the retaining wall 42 which ensures radial retention of the blade 5. In other words, the flange 52 and the housing 41 are fixed to each other by a fixing called a bayonet fixing. This fixing requires a single push-turn movement to fix the flange 52 in the housing 41.

[0046] An angular setting of the blade 5 can then be chosen. Once the blade 5 is positioned in the desired orientation, the two fixing screws 71 which ensure tightening of the flange 52 against the retaining wall 42 are tightened so as to immobilize the blade 5 in the desired angular position. The retaining wall 42 is then clamped between a cylindrical portion of the blade root 51 located in an upper part of the housing 41 and the flange 52 located in a lower part of the housing 41 along the radial axis Y of the blade of the housing 41 in question.

[0047] In order to modify the angular position of a blade 5 around its radial axis Y, the flange 52 is slightly loosened in order to be able to modify the inclination of the blades 5 according to the desired angle. In the case where it is desired to dismantle a blade 5, it is sufficient to loosen the flange 52 then to rotate it a fraction of a turn so as to align the flange 52 with the introduction window 43. It is then possible to separate the blade 5 from the hub 4 by moving the blade 5 in a direction parallel to the radial axis Y of the blade 5 in question and towards the outside of the housing 41.

[0048] The operations of handling the blade 5 and tightening or loosening the fixing screws 71 can be carried out by a human operator or a robot. Such positioning thus makes it possible to quickly modify the setting of the blades 5. Furthermore, in the event of a problem with a blade 5, disassembly can be carried out in situ, which constitutes a significant time saving.

[0049] Such a configuration makes it possible, in an unlocked state, to allow rotation of the blade root 51 around the radial axis Y inside a corresponding housing 41 so as to select a desired angular position of the blade 5 for a test and, in a locked state, to immobilize the blade 5 inside the housing 41 in the desired angular position.

[0050] To carry out measurements, such as those necessary for choosing an orientation of the blades 5 on the hub 4, the rectifier 3 is placed on a test bench 8.

[0051] Test bench and test assembly for a rectifier

[0052] The test bench 8 and the rectifier 3 together constitute a test assembly 10.

[0053] The test bench 8 comprises measuring equipment 81 extending around the axis longitudinal X and being configured to receive a rectifier 3. In other words, the rectifier 3 of the test assembly 10 is fitted onto the measuring equipment 81 of the test bench 8, as illustrated in [Fig.3], in order to be tested under operating conditions.

[0054] The test bench 8 further comprises instrumentation cables 11 and integrated electrical / or electronic components. The electrical / or electronic components may be integrated on each blade 5 of the rectifier 3. The electrical / or electronic components are, for example, one or more sensors for measuring operational parameters relating to the air flow or to the state of the turbomachine 1. These may be temperature, pressure, air flow sensors, etc. Other electrical components may be present at the blades 5, for example the power supply of resistors to ensure defrosting of the rectifier 3.

[0055] Such electrical components integrated into the vanes 5 of the rectifier 3 are electrically connected to processing and / or measuring units of the test bench 8 via the instrumentation cables 11 of the test bench 8 fixed to the vane 5 on the one hand, and to the processing and / or measuring units on the other hand by passing inside the hub 4. In other words, the instrumentation cables 11 of the test bench 8 pass through the vane root 51 and pass through the central opening 521 of the flange 52 before extending longitudinally between the hub 4 and the measuring equipment 81.

[0056] Holding dome

[0057] The test bench 8 comprises a holding dome 9, as illustrated by the Figures 3 to 5. The holding dome 9 prevents the instrumentation cables 11 from coming into contact with the measuring equipment 81.

[0058] Preferably, for the test of a rectifier 3 on the test bench 8, a holding dome 9 is positioned inside each housing 41 of the hub 4 of the rectifier 3. The test bench 8 of a test assembly 10 therefore comprises a plurality of holding domes 9 in order to guide the instrumentation cables 11 of each blade 5 of the rectifier 3 in the hub 4. The holding dome 9 thus makes it possible to prevent the instrumentation cables 11 of the test bench 8 from coming into contact with the measuring equipment 81 positioned radially internal to the hub 4 of the rectifier 3.

[0059] The holding dome 9 of each housing 41, as illustrated by [Fig. 5], comprises a so-called upper part 91 and a so-called lower part 92. The upper part 91 is positioned opposite the internal surface 522 of the flange 52 and the lower part 92 of the holding dome 9 is positioned radially internally in the hub 4 and therefore radially internally relative to the upper part 91. The holding dome 9 is positioned, in the housing 41, radially internally to the flange 52.

[0060] Each holding dome 9 comprises a channel 93, configured to guide the instrumentation cables 11 coming from the blade root 51, an annular groove 94, configured to house the nuts 72 for fixing the blade root 51 on the flange 52, and a rim 95 configured to fix the holding dome 9 in the housing 41. The holding dome 9 of each housing 41 advantageously extends around a direction parallel to the radial axis Y of the blade 5 of the housing 41 in which the holding dome 9 is positioned.

[0061] The rim 95 is disposed on the upper portion 91 of the holding dome 9, facing the inner surface 522 of the flange 52. The rim 95 extends radially from the holding dome 9 outwardly relative to the radial axis Y. The rim 95 comprises an adhesive 96 configured to secure the rim 95 of the holding dome 9 to the housing 41.

[0062] The channel 93 of the holding dome 9 passes through the holding dome 9 and comprises end-to-end a first portion 931 and a second portion 932. The first portion 931 extends radially, that is to say parallel to the radial axis Y of the blade 5 in question. The first portion 931 comprises an orifice forming an inlet 933 of the channel 93. The inlet 933 is preferably centered on the central opening 521 of the flange 52. The inlet 933 opens onto the upper part 91 of the holding dome 9, and therefore opposite the flange 52. The second portion 932 extends parallel to the longitudinal axis X from a radially internal end of the first portion 931. The second portion 932 comprises an orifice forming an outlet 934 of the channel 93. The outlet 934 is oriented in a direction parallel to the longitudinal axis X. Advantageously preferably, the outlet 934 opens from the holding dome 9 towards the downstream of the rectifier 3 and on the side of the lower part 92 of the holding dome 9. Optionally, the first portion 931 of the channel 93 is cylindrical in shape and the second portion 932 of the channel 93 is oblong in shape. The first portion 931 makes it possible to guide the instrumentation cables 11 radially and inwards in the hub 4 and the second portion 932 makes it possible to guide the instrumentation cables 11 longitudinally in the hub 4. The first portion 931 is therefore positioned in the annular dome 9 radially external to the second portion 932.

[0063] The holding dome 9 comprises an annular groove 94 extending around the first portion 931 of the channel 93. In other words, the annular groove 94 extends around the radial axis Y of the blade 5 in question. The annular groove 94 is configured to house the nuts 72 for fixing the blade root 51 to the flange 52.Thus, the rotation of the flange 52 in the housing 41 induced by the change in orientation of the blade 5 on the hub 4 is permitted by the annular groove 94 in which the nuts 72 are free to move.

[0064] The holding dome 9 is positioned in each housing 41 radially internal to the flange 52 of the blade root 51. The holding dome 9 is inserted into the housing 41 by a single push-turn movement in order to make the rim 95 of the holding dome 9 cooperate with the introduction window 43 of the retaining wall 42 of the housing 41. In other words, the positioning of the holding dome 9 in the housing 41 can be done in a manner similar to the positioning of the flange 52 previously described.

[0065] The holding dome 9 is fixed in the housing 41 by means of the adhesive 96 positioned between the rim 95 of the holding dome 9 and an internal wall of the housing 41. The blade 5 is positioned in the housing 41 so that the internal surface 522 of the flange 52 faces the upper part 91 of the holding dome 9. The nuts 72 for fixing the blade root 51 on the flange 52 are positioned in the annular groove 94 of the holding dome 9 and the central opening 521 is advantageously centered on the inlet of the first portion 931. The instrumentation cables 11 passing through the central opening 521 of the flange 52 are guided by the holding dome 9 by passing through the first portion 931 then the second portion 932 of the channel 93 of the holding dome 9.

[0066] Thus, the holding dome 9 can be positioned in the housing 41 of each blade 5 without requiring modification of the shape of the housing 41.

[0067] The holding dome 9 makes it possible to guide the instrumentation cables 11 of each blade 5 in the hub 4 in order to avoid any contact with the measuring equipment 81 positioned radially internal to the hub 4. The holding dome 9 being fixed in the housing 41 it maintains the guidance of the instrumentation cables 11 despite the rotation of the blade root 51 in the housing 41 necessary for the modification of its orientation relative to the hub 4.

[0068] Furthermore, the holding dome 9 of the test bench 8 prevents any contact between the instrumentation cables 11 and the flange 52 of the blade root 51 of the rectifier 3. The instrumentation cables 11 cannot therefore become blocked in the nuts 72 for fixing the blade root 51 to the flange 52.

[0069] Each blade 5 of the rectifier 3 to be tested can thus be fixed on the hub 4 of the rectifier 3 while being variable-pitch without the movements of the blade 5 inducing measurement disturbances of the measuring equipment 81 caused by contact with the instrumentation cables 11.

Claims

Claims

1. Test bench (8) for a rectifier (3) of a turbomachine (1), the test bench (8) comprising: - annular measuring equipment (81) extending around a first axis (X), the measuring equipment (81) being configured to support a rectifier (3) of a turbomachine (1); and - instrumentation cables (11); the rectifier (3) of a turbomachine (1) comprising: - a hub (4) extending around the first axis (X), the hub (4) comprising several housings (41) arranged radially in the hub (4), and - several blades (5) arranged in each housing (41) by means of a blade root (51) fixed to a flange (52) for fixing the blade root (51) in the housing (41), each flange (52) comprising an internal surface (522) and an external surface (525), the internal surface (522) being directed towards the inside of the hub (4);the test bench (8) comprising a holding dome (9) intended to be arranged inside each housing (41), opposite the internal surface (522) of the flange (52), the holding dome (9) being configured to guide the instrumentation cables (11) in the hub (4) in order to avoid any contact between the instrumentation cables (11) linked to the blades (5) of the rectifier (3) and the measuring equipment (81) during the test of the rectifier (3) of the turbomachine (1).;

2. Test bench (8) according to claim 1, wherein the holding dome (9) comprises a channel (93) configured to guide the instrumentation cables (11) coming from the blade root (51), the channel (93) comprising an inlet (933) facing the flange (52) and an outlet (934) radially internal to the inlet and oriented in a direction parallel to the first axis (X).

3. Test bench (8) according to claim 2, wherein the holding dome (9) comprises an annular groove (94) extending around a first portion (931) of the channel (93), the groove being configured to house nuts (72) for fixing the blade root (51) to the flange (52).

4. A test bench (8) according to any one of claims 1 to 3, wherein the holding dome (9) comprises a rim (95) configured to secure the holding dome (9) to the hub (4).

5. Test bench (8) according to any one of claims 1 to 4, in wherein each housing (41) comprises a retaining wall (42) comprising an introduction window (43) suitable for allowing the flange (52) and the holding dome (9) to be inserted into the housing (41) and suitable for retaining the flange (52) in the housing (41) following a rotation of the flange (52) by a fraction of a turn.

6. A test bench (8) according to claim 4, wherein the flange (95) for securing the holding dome (9) comprises an adhesive configured to secure the flange (95) of the holding dome (9) to the housing (41).

7. Assembly (10) for testing a rectifier (3) of a turbomachine (1), comprising a test bench (8) according to one of claims 1 to 6 and a rectifier (3) of a turbomachine (1).

8. An assembly (10) according to claims 5 and 7, wherein the rectifier comprises clamping members (7) configured to clamp the flange (52) and the blade root (51) to the retaining wall (42) so as to immobilize the blade root (51) in the housing (41) in a desired angular position.

9. Turbomachine (1) comprising a rectifier (3) configured by means of a test bench (8) according to one of claims 1 to 6, or an assembly (10) according to one of claims 7 and 8.

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