ABRADABLE MATERIAL RING INCLUDING A DETECTION ELEMENT, ASSEMBLY INCLUDING SUCH A RING AND TURBOMACHINE EQUIPPED WITH SUCH AN ASSEMBLY AND / OR RING

Abstract

The invention relates to a ring (20) of abradable material for a turbomachine with a longitudinal axis (X), intended to surround a rotor (33) of the turbomachine and capable of crumbling upon radial contact or friction with at least a portion of the rotor (33). The ring (20) of abradable material comprises, within its thickness (e1), a device (23) for detecting the level of crumbling or wear of the abradable material. The detection device (23) comprises at least one conductive wire (24) intended to be supplied with an electric current and having a resistance that varies upon breakage or damage thereof, so as to measure the level of wear of the abradable material. Figure for the abstract: Fig. 4

Description

Title of the invention: RING OF ABRADABLE MATERIAL COMPRISING A DETECTION ELEMENT, ASSEMBLY COMPRISING SUCH A RING AND TURBOMACHINE EQUIPPED WITH SUCH AN ASSEMBLY AND / OR RING Technical field of the invention

[0001] The present invention relates to the field of turbomachines, and in particular aircraft. It relates in particular to the wear of abradable materials equipping assemblies and in particular turbomachine casings. Technological background

[0002] It is known to use abradable materials in an aircraft turbomachine so as to ensure dynamic sealing between a stator and a rotor. Indeed, there may be clearances between the rotors and the stators which involve air leaks and which reduce the performance of the turbomachine. The abradable materials, which are friable materials, are generally arranged on a radially internal surface of a stator such as a casing and opposite a rotor of the turbomachine so as to minimize a clearance existing between the rotor and the stator. This rotor may be a fan blade, a compressor or turbine blade of the turbomachine or even a labyrinth-type annular sealing lip.

[0003] In operation, the rotors may come into contact with the abradable material, which may cause it to crumble. Friction of the rotors on the abradable material may be due to expansion of the rotors in operation, misalignment of the rotor carrying the rotors, ingestion of foreign objects (FOD), etc. The arrangement of the abradable materials also makes it possible to limit wear on the rotors.

[0004] However, the abradable material can undergo significant friction leading to a reduction in its thickness and its sealing function. It is currently complicated and expensive to carry out wear measurements of abradable materials due to their inaccessibility. The measurement when carried out is often imprecise and the process difficult to repeat, making understanding the wear of the abradable material complex.

[0005] In the event of an exceptional event, such as the loss of a fan, compressor or turbine blade or the ingestion of foreign objects (FOD), the turbomachine is removed in order to examine it in detail and assess whether it can be put back into service. Abradable materials are examined during these events to detect damage. It is necessary to dismantle the modules and visually inspect them to determine their level of wear, which is long and can delay the return to service of the turbomachine.

[0006] There is a need to resolve all or part of the aforementioned drawbacks. Summary of the invention

[0007] The objective of the present invention is to provide a simple, economical and robust solution, which makes it possible to determine wear and its extent in a safe and efficient manner.

[0008] We achieve this objective in accordance with the invention by means of a ring of abradable material for a turbomachine with a longitudinal axis, intended to surround a rotor of the turbomachine and capable of crumbling in the event of radial contact or friction with at least one part of the rotor, the ring of abradable material comprising in its thickness a device for detecting the level of crumbling or wear of the abradable material, the detection device comprising at least one conductive wire intended to be supplied with an electric current and having a resistance which varies in the event of breakage or damage thereof so as to measure the level of wear of the abradable material.

[0009] Thus, this solution makes it possible to achieve the aforementioned objective. In particular, the conductive wires are a simple means for determining the actual wear within a ring of abradable material following certain events and / or during the operation of the turbomachine in which it is intended to be installed. The arrangement of the conductive wires makes it possible to determine more precisely the depth and the angular position of the wear. Indeed, the characteristics of the conductive wire(s) at certain locations of the ring of abradable material change according to the wear in the turbomachine. The measurement of the wear is non-intrusive and can be carried out directly (in real time) or a posteriori.

[0010] The ring of abradable material also comprises one or more of the following features, taken alone or in combination:

[0011] - several conductive wires are distributed along at least one annular row around the longitudinal axis.

[0012] - each conductive wire of the annular row is independently connected to a electrical circuit integrated at least partly in the abradable material.

[0013] - the ring of abradable material is in the form of several sectors arranged around the longitudinal axis and in the form of a cartridge, at least one conductive wire and at least part of an electrical circuit are integrated in each sector.

[0014] - the ring of abradable material is formed from a single annular piece.

[0015] - the ring of abradable material comprises several annular rows of wires conductors which are arranged around the longitudinal axis and in radial stacks, the conductive wires arranged in the same radial stack are connected to the same electrical circuit.

[0016] - the abradable material of the ring comprises at least one metallic material.

[0017] - - each electrical circuit is connected to a device for measuring the resistance of each common thread.

[0018] The invention also relates to a turbomachine assembly comprising a stator extending around a longitudinal axis and a rotor, the stator being intended to surround the rotor and comprising a ring of abradable material having any one of the preceding characteristics, the ring of abradable material being arranged opposite the rotor.

[0019] The assembly also includes one or more of the following features, taken alone or in combination:

[0020] - the rotor comprises at least one movable blade facing the ring of material abradable, the moving blade being a fan moving blade, a compressor moving blade or a turbine moving blade.

[0021] - the rotor comprises at least one labyrinth-type annular sealing lip opposite the ring of abradable material, the sealing lip being mounted at one end of a blade of the turbomachine.

[0022] - the rotor comprises a disc centered on the longitudinal axis and on which is mounted the or each magnet.

[0023] The invention relates to a turbomachine, in particular for an aircraft, comprising at least one ring of abradable material as mentioned above and / or at least one assembly having any one of the above-mentioned characteristics.

[0024] According to the invention, the turbomachine comprises a power source supplying one or more electrical circuits, the electrical circuit(s) being intended to be connected to a processing unit of an aircraft.

[0025] The invention finally relates to an aircraft which comprises at least one turbomachine as mentioned above and the processing unit. Brief description of the figures

[0026] The invention will be better understood, and other aims, details, characteristics and advantages thereof will appear more clearly on reading the detailed explanatory description which follows, of embodiments of the invention given as purely illustrative and non-limiting examples, with reference to the appended schematic drawings in which:

[0027] - [Fig.l] is a partial axial sectional view of an example of a turbomachine with to which the invention applies;

[0028] - [Fig.2] is a partial axial sectional view of an example of a tur- turbomachine with rings of abradable materials facing rotor members of the turbomachine according to the invention;

[0029] - [Fig.3] is a partial axial sectional view of an example of a tur assembly bomachine with a ring of abradable material opposite a rotor member according to the invention;

[0030] - [Fig.4] is an axial sectional view of an assembly comprising a stator equipped of a ring of abradable material facing a rotor according to the invention;

[0031] - [Fig.5] is a radial sectional view of a ring of abradable material equipped of a detection device and surrounding moving blades of a turbomachine according to the invention;

[0032] - [Fig.6] illustrates a portion of a rotor in contact with the ring of material abradable and a detection device according to the invention; and

[0033] - [Fig.7] shows an offset of an example of a rotor carrying moving blades coming into contact with a ring of abradable material equipped with a detection device according to the invention. Detailed description of the invention

[0034] [Fig. 1] represents a turbomachine 1 with longitudinal axis X to which the invention applies. The turbomachine 1 is a double-flow, double-spool turbojet intended to be mounted on an aircraft, such as an airplane. Of course, the invention can be applied to other types of turbomachine, such as a turboprop, a turboshaft, or it applies generally to a turbomachine which comprises a fan or a propeller which is ducted or not ducted.

[0035] In the present invention, and generally, the terms "upstream" and "downstream" are defined with respect to the circulation of gases or air flows in the turbomachine and here along the longitudinal axis X. The terms "axial" and "axially" are defined with respect to the longitudinal axis X. The terms "external", "external", "internal", "internal" and "radial" are defined with respect to a radial axis Z which extends from the longitudinal axis X and with respect to the distance from the longitudinal axis X. The radial axis is perpendicular to the longitudinal axis.

[0036] The turbomachine 1 comprises, from upstream to downstream, a low pressure compressor 2, a high pressure compressor 3, a combustion chamber 4, a high pressure turbine 5 and a low pressure turbine 6.

[0037] Conventionally, the turbomachine 1 comprises a low pressure shaft 7 which connects the rotor of the low pressure compressor 2 and the rotor of the low pressure turbine 6 to form a low pressure body and a high pressure shaft 8 which connects the rotor of the high pressure compressor 3 and the rotor of the high pressure turbine 5 to form a body high pressure.

[0038] The turbomachine 1 comprises a fan 9 which is arranged upstream of the low pressure compressor 2. The fan 9 is coupled to the low pressure shaft 7 which drives it in rotation around the longitudinal axis X. A power transmission mechanism (not shown) such as a speed reducer can be interposed between the low pressure shaft 7 and a fan shaft 10 (or the disc 11 of the fan 9). An air flow F which passes through the fan 9 is divided by a separation nozzle 12 into a primary flow F1 circulating in a primary vein 13 passing through the compressor assembly 2, 3, the combustion chamber 4 and the turbine assembly 5, 6 and into a secondary flow F2 circulating radially outside the primary vein 13. In the case of the turbojet engine which is shown in [Fig.l], the secondary air flow F2 circulates in a secondary vein 14.

[0039] The fan 9 comprises fan blades 15 which are carried here by the disc 11 centered on the longitudinal axis X. The fan blades 15 are surrounded by a fan casing 16 centered on the longitudinal axis X. This fan casing 16 which is a retention casing in the event of rupture of the fan blades 15, is intended to carry a nacelle (not shown) which is connected to an aircraft wing in the present example. The fan casing 16 and a portion of the nacelle at least partially delimit the secondary flow path 14. Each fan blade 15 extends radially outward through the secondary flow. In particular, each fan blade 15 comprises a root 15a housed in a cell 11a of the disc 11 and a free end 15b facing the fan casing 16.

[0040] Each compressor 2, 3 and each turbine 5, 6 comprises several stages of stator blades and several stages of moving blades which are regularly alternated along the longitudinal axis X. In the present invention, we understand by the term "stator blade" or "fixed blade", a blade which is not driven in rotation around the longitudinal axis X of the turbomachine. In other words, the stator blade is distinct from and opposite a moving blade (rotor blade) of the turbomachine. The stator blades deflect and straighten the primary flow F1 at the outlet of each moving blade located upstream of them. Some of the stator blades may be of variable pitch.

[0041] Each compressor 2, 3 and each turbine 5, 6 comprises an annular casing 17 which is centered on the longitudinal axis X and which surrounds the moving blades 2a, 3a, 5a, 6a and the stator blades 2b, 3b, 6b. The moving blades of the compressor and / or the turbine may comprise a heel (not shown) which is opposite the annular casing 17. The heel (at a radially internal end) comprises wipers which extend radially outwards (and towards the annular casing 17 in the installation situation).

[0042] Other stator blades 18 may be arranged downstream of the fan blades 15 to straighten the secondary flow F2. These stator blades 18 are called stator blades. outlet guide and labeled “OGV” for “Outlet Guide Vane” in English. The stator vanes 18 are arranged transversely in the nacelle substantially in a plane transverse to the longitudinal axis X. These are regularly distributed in this exemplary embodiment around the longitudinal axis X of the turbomachine 1.

[0043] With reference to [Fig. 2], a ring 20 of abradable material may be arranged in the turbomachine so as to surround at least one rotor 33 of the turbomachine. The rotor 33 may be a moving blade of the fan 9, a moving blade 2a of the compressor, etc. The ring 20 of abradable material is arranged opposite each of these moving blades. The ring 20 of abradable material may also be opposite a sealing lip 31 carried by a stator blade 2b at one or other of its ends.

[0044] [Fig. 3] also represents a turbomachine assembly which comprises a ring 20 of abradable material arranged so as to surround the rotor 33 of the turbomachine. The rotor 33 is here a labyrinth-type sealing lip 31. The latter is annular, centered on the longitudinal axis, and extends radially outwards. The sealing lip 31 surrounds the free ends of the moving blades of the turbomachine and can form grooves in the ring of abradable material.

[0045] In [Fig.4], the ring 20 is mounted on a stator 34 of the turbomachine which can be one of the casings of the turbomachine such as the fan casing 16, the annular casing 17 of the compressor or even of the turbine. More precisely, the ring 20 of abradable material covers a radially internal surface 19 (see [Fig.l]) of at least one of the casings of the turbomachine. The rotor 33 comprises in this example a disk 32 (centered on the longitudinal axis) and at least one moving blade which may be a fan blade 15, a moving blade 2a, 3a of the compressor or a moving blade 5a, 6a of the turbine which extends from the disk 32.

[0046] The ring 20 of abradable material is capable of crumbling or wearing away by friction in the event of radial contact with at least one portion of the rotor 33, here one of the moving blades 15, 2a, 3a, 5a, 6a. Indeed, the ring 20 of abradable material is arranged opposite the free ends 15b (comprising wipers or not) of the moving blades 15, 2a, 3a, 5a, 6a so as to reduce the radial clearances between the free ends and the ring 20 of abradable material, and consequently to reduce the air flow leaks which can harm the performance of the turbomachine.

[0047] The ring 20 of abradable material has a thickness el measured between a first surface 21 and a second surface 22 (opposite along the radial axis). In the present example, the first surface 21 is oriented opposite the moving blades and the second surface 22 is secured to the radially internal surface 19 of the casing 16, 17 of the turbomachine.

[0048] The abradable material that makes up the ring 20 advantageously, but not limited to, comprises at least one metallic material or an alloy of metallic material. Examples of a metallic material are aluminum, iron, nickel and chromium. These metallic materials may be in powder form and / or comprise a powder mixture as well as a binder. An example of a powder mixture is sold by the company METCO. The ring of abradable material may also be in the form of a thin metal sheet, for example nickel, oriented towards the blades and carrying a honeycomb. The sheet has a thickness of less than 3 mm.

[0049] The material may also be a polymer. This polymer may, for example, be homogeneous and crumble into granules.

[0050] The abradable material may be in the form of a honeycomb known as “HONEYCOMB”.

[0051] In [Fig. 4], the ring 20 of abradable material comprises in its thickness a device 23 for detecting the level of crumbling or wear. In particular, the detection device 23 is configured so as to determine a thickness or a quantity of material of the abradable material removed by friction or contact of the rotor, here the moving blades.

[0052] The detection device 23 comprises at least one conductive wire 24 intended to be supplied with an electric current and the conductive wire 24 has a resistance which can vary in the event of breakage or of a portion thereof being removed. Advantageously, the detection device 23 comprises several conductive wires 24 which are distributed in at least one annular row C1 around the longitudinal axis X. In this way, the entire surface of the ring 20 of abradable material can be monitored. The conductive wires 24 are advantageously spaced and regularly distributed around the longitudinal axis X. According to another advantageous characteristic, the conductive wires 24 are independent of each other. An azimuthal distribution of several conductive wires 24 makes it possible to know the exact angular position of the wear of the abradable material.

[0053] Advantageously, each conductive wire 24 of the annular row C1 is connected to an electrical circuit 25. In other words, on an annular row, there are as many conductive wires 24 as there are electrical circuits 25. The electrical circuits 25 of the annular row C1 are independent of each other.

[0054] The electrical circuits 25 are connected to an electrical power source 26 allowing the circulation of the electric current in each conductive wire 24. The electrical power source 26 delivers a current of the same intensity in each conductive wire 24. At least a part of each electrical circuit 25 is integrated in the abradable material.

[0055] Advantageously, but not limited to, the electrical power source is arranged in the aircraft. The turbomachine generally generates electricity to power the various equipment of the aircraft. The detection device 23 can be powered by a closed circuit within the turbomachine.

[0056] Advantageously, but not limitingly, the electrical circuits 25 are positioned independently of the thickness el of the ring 20 of abradable material. In an exemplary embodiment, the conductive wires 24 are positioned 2 mm from each other and the ring 20 of abradable material extends by an additional 1 mm relative to the conductive wires radially inwards. More particularly, for three conductive wires 24 stacked radially and connected to the same circuit 25, the thickness el of the ring of abradable material is of the order of 6 mm (+ or - 10%) with the conductive wires 24 spaced 2 mm apart. In other words, the thickness el is a function of the distance between each conductive wire 24 and the distance relative to the casing 16, 17.

[0057] Each conductive wire 24 is made of an electrically conductive material whose electrical resistance is known. The material is chosen, in particular, from copper, aluminum, iron, silver, nickel, and their alloys. An example of an alloy is constantan. Preferably, each conductive wire 24 is made of constantan. Constantan is an alloy having an electrical resistance that is highly independent of temperature, making it possible to obtain a more precise value than with other types of material. In addition, it is thus not necessary to compensate for the error by a potential increase in temperature.

[0058] According to an advantageous, but non-limiting, characteristic, each conductive wire 24 is composed of one or more conductive strands. The strands can be arranged in several layers around a main strand.

[0059] Optionally, each conductive wire 24 may be wrapped by an insulating sheath. The insulating sheath may be necessary when the abradable material of the ring is conductive.

[0060] Each conductive wire 24 has, for example, a circular section and may have a total diameter of between 0.05 mm and 0.10 mm.

[0061] According to an advantageous, but non-limiting, characteristic, the ring 20 of abradable material is in the form of several sectors arranged around the longitudinal axis X and in the form of a cartridge. At least one conductive wire 24 and at least part of an electrical circuit 25 are integrated in each sector S. Figures 5 and 7 illustrate a ring 20 comprising eight sectors S1, .. ., S8. Of course, the ring 20 can comprise more or fewer sectors depending on its dimensions. This sector configuration makes it easier to replace and mount the abradable material with the integrated conductive wires 24. The replacement may be carried out during maintenance operations on the turbomachine following events or excessive wear of the abradable material.

[0062] Alternatively, the ring 20 of abradable material is formed from a single annular piece.

[0063] Advantageously, but not limited to, the abradable material is obtained by projection. In this case, the projection of the abradable material is carried out around the detection device 23, i.e. conductive wires. In the case, for example, where the abradable material is in the form of a honeycomb and is sectorized, the conductive wires 24 are arranged between two contiguous honeycomb sectors around the longitudinal axis X.

[0064] Advantageously and as shown in Figures 4 and 5, several annular rows C1, C2, C3 of conductive wires 24 are arranged around the longitudinal axis X. The conductive wires 24 are also arranged in one or more radial stacks P1, P2, P3. In other words, several radial stacks P1, P2, P3 of conductive wires 24 are arranged around the longitudinal axis X. The conductive wires 24 arranged in the same radial stack are connected to the same electrical circuit 25. Each radial stack P1, P2, P3 of conductive wires 24 is integrated in a ring sector 20 of abradable material for example. Such a configuration provides parallel mounting of the electrical circuit 25 from an electrical point of view in the thickness of the abradable material. The azimuthal and radial distribution also allows to obtain angular precision and the maximum depth of wear as well as their chronology.

[0065] The electrical circuits 25 are connected to a processing unit 30 which is capable of processing a signal corresponding to a resistance value of at least one electrical wire 24. The processing unit 30 is configured to process in real time the signals corresponding to the resistance value of the conductive wires 24. In other words, it is possible to continuously measure the current passing through the electrical circuit 25 in order to directly measure the wear of the abradable material as a function of time. The processing unit 30 may be the computer of the turbomachine known by the English acronym FADEC for Full Authority Digital Engine Control. The real-time measurement also makes it possible to determine during operation of the turbomachine at what time (flight phase for example) the maximum wear has occurred.Post-processing is carried out either by the processing unit 30 (or by a health monitoring box (known as Health Monitoring) of the turbomachine modules), or by acquisition bays on the bench during development and / or reception tests.

[0066] The processing unit 30 may comprise a digital model of the ring 20 of abradable material so as to be able to identify the damaged parts or sectors. in the abradable material. The electrical power source 26 is advantageously connected to the processing unit 30.

[0067] In the present embodiment, each conductive wire 24 has the same resistance. Similarly, each sector S1,..., S8 has the same number of conductive wires 24 (or resistors) and therefore the same overall resistance V1. The section of one or more conductive wires 24 of a given resistor gives a new overall resistance V2,..., Vn and provides information on the penetration of the blades into the ring 20 of abradable material. Here, Vn corresponds to the total number of conductive wires 24 having a given resistance in a sector or in an electrical circuit 25.

[0068] The measurement can be carried out after the occurrence of an event. In this case, the recovery of the data relating to the wear of the ring 20 of abradable material is carried out when the aircraft is on the ground. This will make it possible to avoid dismantling the modules and lengthy inspections.

[0069] Figures 6 and 7 illustrate an example of radial contact or friction of at least one moving blade 15, 2a, 3a, 5a, 6a with the ring 20 of abradable material. In this example, the radial contact is due to an offset of the axis of the rotor carrying the moving blades. We see that the free ends 15b of the moving blades penetrate into the thickness of the abradable material. In the event of radial contact, one or more conductive wires 24 may be cut or partially cut, which modifies their electrical resistance. The variation in resistance makes it possible to measure the level of wear or crumbling of the abradable material.

[0070] In [Fig. 6], the moving blade cuts a conductive wire 24 of the first annular row CL. This annular row Cl is radially close to the first surface 21 of the ring 20 of abradable material. The electrical resistance of the conductive wire 24 in a first thickness level comprising the first row Cl of conductive wires 24 has a value different from the known value of the electrical resistance. The known resistance is stored in the processing unit 30 which allows a comparison to be made with the measured value. In particular, a measuring device 27 such as an ohmmeter allows the resistance (which is known from the time of installation) to be continuously measured. The measuring device 27 shown in particular in [Fig. 4] is connected to the processing unit 30 and is also connected to the electrical power source 26. The value of the electrical resistance of the damaged or cut conductive wire 24 measured by the measuring device 27 varies.The wear in the abradable material is then detected. The resistors are buried at known depths and this information makes it possible to know the actual wear. The current continues to flow in the conductive wires 24 of the other two annular rows. In the case of [Fig.6], the voltage V2 across the terminals of the circuit 25 is equal to the value of two resistances of the undamaged conductive wires. Conversely, the voltage VI across the terminals. of the circuit for three conductive wires 24 of the same stack which are healthy, is equal to the value of the three resistances of the conductive wires 24.

[0071] Advantageously, but not limited to, the measured and recorded data are processed in several ways. In a first processing example, the measured resistance value or the critical health value is transmitted to the pilot via a signal that may be an audible signal or a visual signal. This signal is advantageously transmitted by the processing unit 30 which processes the information relating to the measured values. In a second processing example, the measured values ​​are stored in a memory of the processing unit 30 during operation of the turbomachine (in flight for example) and will then be analyzed once the turbomachine is stopped (on the ground for example). The measured values ​​are extracted by an operator for example from the processing unit 30 and a possible replacement or repair based on the data will be ordered.In a third processing example, the measured values ​​are analyzed by an algorithm which, based on the various comparisons with the reference values ​​measured in the processing unit 30, directly gives the wear status of the ring 20 of abradable material. The program is advantageously stored in the processing unit 30. In the latter case, there is no human action or intervention.

[0072] The intervention on the ring 20 of abradable material will depend on the critical or significant nature of the wear of the abradable material. The critical or significant nature is evaluated in relation to a critical health value which has been set for the ring 20 of abradable material. This critical health value is determined by a simulation and / or by different tests for each ring 20 of abradable material and each type / version of turbomachine. Advantageously, but not limitingly, the critical health value is recorded in a memory of the processing unit 30. In the case of excessively damaged abradable material, the turbomachine loses too much power or has a loss of ventilation. This is moving away from the intrinsic properties of the turbomachine. There could be a risk in continuing to fly with a turbomachine equipped with a ring of abradable material with significant damage or wear.

[0073] In [Fig.7], several moving vanes 15, 2a, 3a, 5a, 6a have penetrated into the thickness of the abradable material and following different angular positions of the conductive wires 24. In particular, the conductive wire 24 of the first annular row and located at 12 o'clock following the dial of a clock has been damaged, or even cut. The conductive wires 24 of the first row and of the second annular row (from the first surface 21) and located between 12 o'clock and 3 o'clock have been damaged. The measured values ​​of the resistances of these conductive wires 24 are different from the known values. If the measured value is equal to or greater than the critical health value, this implies that the abradable material at this location has significant wear on this angular sector. and that intervention is necessary.

[0074] Advantageously, the resistance value of the severed conductive wires 24 is zero. These conductive wires 24 being also located in three independent ring sectors, it will be possible to replace them easily without changing the entire ring 20, which allows for an economic gain and a reduction in the environmental impact. Indeed, the replacement of the damaged sectors makes it possible to reduce waste, which contributes to reducing the environmental impact of the turbomachine.

[0075] In this way, with one or more conductive wires 24 distributed around the longitudinal axis X, and possibly depending on the thickness of the abradable material, it is possible to quantify the wear of the abradable material in a precise and reliable manner. The sector S, S1, S2, S3, ...S8 of the ring of abradable material is replaced during maintenance if the wear of the abradable material is deemed significant. Disassembly and replacement are thus facilitated with such a configuration.

Claims

Claims

1. Ring (20) of abradable material for a turbomachine with a longitudinal axis (X), intended to surround a rotor (33) of the turbomachine and capable of crumbling in the event of radial contact or friction with at least one part of the rotor (33), the ring (20) of abradable material comprising in its thickness (el) a device (23) for detecting the level of crumbling or wear of the abradable material, the detection device (23) comprising at least one conductive wire (24) intended to be supplied with an electric current and having a resistance which varies in the event of breakage or damage thereof so as to measure the level of wear of the abradable material.

2. Ring (20) of abradable material according to the preceding claim, characterized in that several conductive wires (24) are distributed in at least one annular row (Cl, C2, C3) around the longitudinal axis (X).

3. Ring (20) of abradable material according to the preceding claim, characterized in that each conductive wire (24) of the annular row (Cl, C2, C3) is independently connected to an electrical circuit (25) integrated at least in part in the abradable material.

4. Ring (20) of abradable material according to one of the preceding claims, characterized in that it is in the form of several sectors (S, S1,...S8) arranged around the longitudinal axis (X) and in the form of a cartridge, at least one conductive wire (24) and at least part of an electrical circuit (25) are integrated in each sector (S, S1,...S8).

5. Ring (20) of abradable material according to one of claims 1 to 3, characterized in that it is formed from a single annular piece.

6. Ring (20) of abradable material according to one of the preceding claims, characterized in that it comprises several annular rows (Cl, C2, C3) of conductive wires (24) which are arranged around the longitudinal axis (X) and in radial stacks (PI, P2, P3), the conductive wires (24) arranged in the same radial stack (PI, P2, P3) are connected to the same electrical circuit (25).

7. Ring (20) of abradable material according to the preceding claim, characterized in that the abradable material of the ring (20) comprises at least one metallic material.

8. A turbomachine assembly comprising a stator (34) extending around of a longitudinal axis (X) and a rotor (33), the casing (16, 17) being intended to surround the rotor (33) and comprising a ring (20) of abradable material according to any one of the preceding claims, the ring (20) of abradable material being arranged opposite the rotor (33).

9. Assembly according to the preceding claim, characterized in that the rotor (33) comprises at least one moving blade facing the ring (20) of abradable material, the moving blade being a moving blade of the fan (9), a moving blade (2a, 3a) of a compressor or a moving blade (5a, 6a) of a turbine.

10. Assembly according to claim 8, characterized in that the rotor (33) comprises an annular labyrinth-type sealing lip (31) opposite the ring (20) of abradable material, the sealing lip (31) being mounted at one of the ends of a blade of the turbomachine.

11. Turbomachine (1), in particular for an aircraft, comprising at least one ring (20) of abradable material according to any one of claims 1 to 7 and / or an assembly according to one of claims 8 to 10.

12. Turbomachine (1) according to claim 11, characterized in that it comprises a power source (26) supplying one or more electrical circuits (25), the electrical circuit(s) being intended to be connected to a processing unit (30) of an aircraft.

Images