Measurement of a displacement or force in a speed reduction device of an aeronautical propulsion system.

Abstract

An aeronautical propulsion system (1) comprising a stator (34), a drive shaft (30), a fan section (2) comprising a fan shaft (20) and a fan rotor (9), a speed reduction device (19) rotationally coupling the drive shaft (30) and the fan shaft (20), the reduction device (19) comprising a sun pinion (19a), a ring gear (19b), a ring gear diameter being greater than a sun pinion diameter, a planet carrier (19d), at least one planet pinion (19c) rotatably mounted on the planet carrier (19d), and a support (32) fixed to the stator (34), the ring gear (19b) or the planet carrier (19d) being fixed against rotation relative to the support (32), the propulsion system (1) comprising a measuring device (36) configured to measure a relative displacement between the support (32) and the stator (34), and / or a force exerted by the support (32) on the stator (34). Figure to be published for the abstract: Figure 7

Description

Title of the invention: Measurement of a displacement or force in a speed reduction device of an aeronautical propulsion system. DOMAIN

[0001] The present application relates generally to the field of propulsion systems, and more particularly to aeronautical propulsion systems comprising a shrouded or unshrouded fan and exhibiting a high, or even very high, dilution ratio. STATE OF THE ART

[0002] A propulsion system generally comprises, from upstream to downstream in the direction of gas flow, a fan section, a compressor section which may include a low-pressure compressor and a high-pressure compressor, a combustion chamber, and a turbine section which may include, in particular, a high-pressure turbine and a low-pressure turbine. The high-pressure compressor is driven in rotation by the high-pressure turbine via a high-pressure shaft. The fan and, where applicable, the low-pressure compressor are driven in rotation by the low-pressure turbine via a low-pressure shaft.

[0003] Technological research efforts have already led to very significant improvements in the environmental performance of aircraft. The Applicant takes into account the impacting factors in all phases of design and development in order to obtain less energy-intensive and more environmentally friendly aeronautical components and products, whose integration and use in civil aviation have moderate environmental consequences, with the aim of improving the energy efficiency of aircraft.

[0004] Thus, in order to improve the propulsive efficiency of the propulsion system and reduce its specific fuel consumption as well as the noise emitted by the fan section, propulsion systems with a high bypass ratio (BPR, corresponding to the ratio between the secondary airflow rate and the primary airflow rate) have been proposed. To achieve such bypass ratios, the fan section can be decoupled from the low-pressure turbine, thereby allowing their respective rotational speeds to be optimized independently. Generally, decoupling is achieved using a reduction device placed between the upstream end of the low-pressure shaft and a rotor of the fan section. The rotor of the fan section is then driven by the low-pressure shaft via the reduction device at a rotational speed lower than that of the low-pressure shaft. pressure.

[0005] When the propulsion system is a variable-pitch turboprop or a variable-pitch turbomachine, thrust control is generally achieved by measuring the torque on the power transmission chain from the turbine section to the fan (typically referred to as a propeller for an unshod fan or sometimes as a "fan" for a shod fan). The transmitted torque, as well as the service life of the reduction gear, is highly dependent on the control of the pitch angle. Furthermore, monitoring the mechanical behavior of the reduction gear makes it possible to assess and track the viability of the reduction gear throughout its service life and to anticipate its maintenance.

[0006] Various solutions exist for measuring torque at the input or output of a rotating machine. A distinction is made between rotating measurements (typically by measuring the phase shift or deformation of a rotating shaft deformed under the action of the torque) and static measurements (typically by measuring the deformation of a part through which all or part of the torque passes using a strain gauge).

[0007] More generally, various solutions exist for measuring different physical quantities related to engine control and mechanical behavior. However, these solutions are generally quite bulky, not always versatile, and the reliability or accuracy of the measurements they provide can be improved.

[0008] There is therefore a need to provide a mechanical behavior measurement device within a propulsion system that is reliable, accurate, compact and simple. EXPOSED

[0009] One aim of the present presentation is to propose a device for measuring mechanical behavior within a propulsion system that is more reliable, more precise, less bulky and simpler than in the prior art.

[0010] The goal is achieved through an aeronautical propulsion system comprising:

[0011] - a stator,

[0012] - a drive shaft,

[0013] - a blower section comprising a blower shaft and a rotor blower, the blower rotor being configured to be driven in rotation by the blower shaft,

[0014] - a speed reduction device coupling the drive shaft in rotation and the blower shaft, so as to drive the blower shaft at a rotational speed lower than the rotational speed of the drive shaft, the reduction device comprising:

[0015] — a solar gable,

[0016] — a crown, the diameter of the crown being greater than the diameter of the pinion solar,

[0017] — a satellite carrier,

[0018] — at least one satellite pinion mounted for rotation on the satellite carrier, and

[0019] — a support fixed to the stator, the ring or the planet carrier being held fixed in rotation relative to the support,

[0020] the propulsion system comprising a measuring device configured to measure:

[0021] — a relative displacement between the support and the stator, and / or

[0022] — a force exerted by the support on the stator.

[0023] Such a system is optionally supplemented by the following various features, taken alone or in combination: - the measuring device is configured to measure relative displacement and / or force as a function of time; - the relative displacement and force are measured in a circumferential direction with respect to an axis of rotation of the solar pinion; - the support comprises a body and a relief which extends radially from the body with respect to an axis of rotation of the solar pinion, the stator comprising a base and a stop which extends radially from the base, the stop being arranged circumferentially with respect to the axis of rotation, opposite the relief, the measuring device comprising at least one sensor, the at least one sensor comprising a part mounted on an element among the stop and the relief, the propulsion system comprising a measuring assembly comprising the relief, the stop and the at least one sensor; - the part of the at least one sensor is a first part, the at least one sensor comprising a second part mounted on the other element between the bumper and the relief; - the measuring assembly includes a second stator stop, the second stop extending radially from the base, the second stop being arranged circumferentially opposite the relief, the relief being situated circumferentially between the first stop and the second stop; - the measurement set comprises two located circumferentially on either side of the relief, each of the sensors cooperating respectively with a single stop from the first stop and the second stop; - the measurement set includes a sensor configured to measure relative displacement and a sensor configured to measure force; - the measurement set is a first measurement set, from a plurality of measurement sets included in the system and regularly distributed circumferentially, for example the system comprising two sets which are diametrically opposed to each other; and - the measuring device includes at least one sensor chosen from: • a proximity sensor, such as a magnetic proximity sensor, an inductive proximity sensor, or a capacitive proximity sensor, • a piezoelectric sensor, • an ultrasonic sensor, • an optical sensor, • an LVDT type sensor, • an RVDT-type sensor, and • a hydraulic cylinder sensor.

[0024] The present exposition also relates to an aircraft comprising a propulsion system as just described. DESCRIPTION OF THE FIGURES

[0025] Other features will become apparent from the following description, which is purely illustrative and not limiting, and should be read in conjunction with the accompanying drawings on which:

[0026] [Fig.l] is a schematic, partial and cross-sectional view of an example of a propulsion system according to a first embodiment, in which the blower section is faired;

[0027] [Fig.2] is a schematic, partial and cross-sectional view of an example of a propulsion system according to a second embodiment, in which the blower section is unfaired;

[0028] [Fig.3] is a schematic cross-sectional view of an example of a reduction device according to a first variant;

[0029] [Fig.4] is a schematic cross-sectional view of an example of a reduction device according to a second variant;

[0030] [Fig.5] is a schematic cross-sectional view of a first embodiment of details associated with the reduction device;

[0031] [Fig.6], [Fig.7], [Fig.8], [Fig.9], [Fig.10], [Fig.11], [Fig.12] are schematic representations of the details of different embodiments associated with the reduction device; and

[0032] [Fig. 13] is an example of an aircraft that may include at least one propulsion system conforming to the first or second embodiment; DETAILED DESCRIPTION

[0033] With reference to Figures 1 and 2, a propulsion system 1 has a principal direction extending along a longitudinal axis X and comprises, from upstream to downstream in the direction of gas flow in the propulsion system 1 when it is in operation operation, a blower section 2 and a primary body 3, often called a "gas generator", comprising a compressor section 4, 5, a combustion chamber 6 and a turbine section 7, 8.

[0034] The propulsion system 1 is here an aeronautical propulsion system 1 configured to be fixed on an aircraft 100 by means of a pylon (or mast), as illustrated in [Fig. 13].

[0035] The compressor section 4, 5 comprises a series of stages, each including a rotating blade wheel (rotor) 4a, 5a in front of a fixed blade wheel (stator) 4b, 5b. The turbine section 7, 8 also comprises a series of stages, each including a fixed blade wheel (stator) 7b, 8b behind which a rotating blade wheel (rotor) 7a, 8a rotates.

[0036] In the present application, the axial direction corresponds to the direction of the longitudinal axis X, corresponding to the rotation of the shafts of the gas generator, and a radial direction is a direction perpendicular to and passing through this axis X. Furthermore, the circumferential (or lateral, or tangential) direction corresponds to a direction perpendicular to and not passing through the longitudinal axis X. Unless otherwise specified, internal (respectively, inside) and external (respectively, outside) are used with reference to a radial direction such that the inner part or face of an element is closer to the axis X than the outer part or face of the same element.

[0037] In operation, an airflow F entering the propulsion system 1 is divided between a primary airflow Fl and a secondary airflow F2, which flow from upstream to downstream in the propulsion system 1.

[0038] The secondary airflow F2 (also called "bypass airflow") flows around the primary body 3. The secondary airflow F2 cools the periphery of the primary body 3 and is used to generate most of the thrust provided by the propulsion system 1.

[0039] The primary airflow Fl flows in a primary channel inside the primary body 3, passing successively through the compressor section 4, 5, the combustion chamber 6 where it is mixed with fuel to serve as an oxidizer, and the turbine section 7, 8. The passage of the primary airflow Fl through the turbine section 7, 8 receiving energy from the combustion chamber 6 causes a rotation of the rotor of the turbine section 7, 8, which in turn drives the rotation of the rotor of the compressor section 4, 5 as well as a rotor part 9 of the blower section 2.

[0040] In a twin-spool propulsion system 1, the compressor section 4, 5 may include a low-pressure compressor 4 and a high-pressure compressor 5. The turbine section 7, 8 may include a high-pressure turbine 7 and a turbine low pressure 8. The rotor of the high pressure compressor 5 is driven in rotation by the rotor of the high pressure turbine 7 via a high pressure shaft 10. The rotor of the low pressure compressor 4 and the rotor part 9 of the blower section 2 are driven in rotation by the rotor of the low pressure turbine 8 via a low pressure shaft 11. Thus, the primary body 3 comprises a high pressure body including the high pressure compressor 5, the high pressure turbine 7 and the high pressure shaft 10, and a low pressure body including the blower section 2, the low pressure compressor 4, the low pressure turbine 8 and the low pressure shaft 11. The rotational speed of the high pressure body is greater than the rotational speed of the low pressure body.In a three-body propulsion system 1, the turbine section 7, 8 further comprises an intermediate turbine, positioned between the high-pressure turbine 7 and the low-pressure turbine 8 and configured to drive the rotor of the low-pressure compressor 4 via an intermediate shaft. The blower rotor 9 and the rotor of the high-pressure compressor 5 remain driven by the low-pressure shaft 11 and the high-pressure shaft 10, respectively.

[0041] The low-pressure shaft 11 is generally housed, along a portion of its length, within the high-pressure shaft 10 and is coaxial with the high-pressure shaft 10. The low-pressure shaft 11 and the high-pressure shaft 10 may be co-rotating, that is, driven in the same direction around the longitudinal axis X. Alternatively, the low-pressure shaft 11 and the high-pressure shaft may be counter-rotating, that is, driven in opposite directions around the longitudinal axis X. If applicable, the intermediate shaft is housed between the high-pressure shaft 10 and the low-pressure shaft 11. The intermediate shaft and the low-pressure shaft 11 may be co-rotating or counter-rotating.

[0042] The fan section 2 comprises at least the fan rotor 9, which is driven in rotation relative to a stator portion of the propulsion system 1 by the turbine section 7, 8. Each fan rotor 9 comprises a hub 13 and blades 14 extending radially from the hub 13. The blades 14 of each rotor 9 may be fixed relative to the hub 13 or have variable pitch. In this case, the root of the blades 14 of each rotor 9 is pivotally mounted about a pitch axis and is connected to a pitch-changing mechanism 15 mounted in the propulsion system 1, the pitch being adjusted according to the flight phases by the pitch-changing mechanism 15. The pitch-changing mechanism 15 is shown in dashed lines in [Fig. 1] to show that this feature is optional.

[0043] The blower section 2 may further include a blower stator 16, or rectifier, which comprises blades 17 mounted on a hub of the blower stator 16 and whose function is to rectify the secondary airflow F2 that flows from the blower rotor 9. The blades 17 of the blower stator 16 may be fixed relative to the hub or have variable pitch. Similarly to the blades 14 of rotor, the base of the stator blades 17 is mounted pivoting along a pitching axis X and is connected to a pitch changing mechanism 15a, which is generally separate from that of the fan rotor 9, the pitch being adjusted according to the flight phases by the pitch changing mechanism.

[0044] The diameter D of the fan rotor can then be between 80 inches (203.2 cm) and 185 inches (469.9 cm) inclusive. When the fan rotor 9 is shrouded, the diameter D is, for example, between 85 inches (215.9 cm) and 120 inches (304.8 cm) inclusive, for example, on the order of 90 inches (228.6 cm), which allows the propulsion system 1 to be integrated in a conventional manner, in particular under the wing of an aircraft. When the fan rotor 9 is unshrouded, the diameter D is, for example, greater than or equal to 100 inches (254 cm), for example, between 120 inches (304.8 cm) and 156 inches (396.2 cm). The diameter of the fan rotor 9 is measured here in a plane normal to the X-axis of rotation at the intersection between a vertex 21 and a leading edge 22 of the fan rotor blades 14, and is expressed in meters. Note that since Figures 1 and 2 are partial views, the diameter D is only partially visible.

[0045] The fan rotor 9 also comprises at least 12 blades 14 and at most 24 blades 14, for example at least 16 blades 14 and at most 22 blades 14. The number of blades 16 in the fan stator 17 depends on the acoustic criteria defined for the propulsion system 1 and is at least equal to the number of blades 14.

[0046] In order to improve the propulsive efficiency of propulsion system 1 and reduce its specific fuel consumption as well as the noise emitted by the fan section 2, propulsion system 1 has a high bypass ratio. A high bypass ratio is understood here to be a ratio greater than or equal to 10, for example, between 10 and 80 inclusive. To calculate the bypass ratio, the mass flow rate of the secondary airflow F2 and the mass flow rate of the primary airflow Fl are measured when propulsion system 1 is stationary, uninstalled, in takeoff mode in a standard atmosphere (as defined by the International Civil Aviation Organization (ICAO) Manual, Doc 7488 / 3, 3rd edition) and at sea level. It should be noted that, in this application, the parameters (pressure, flow rate, thrust, speed, etc.) are systematically determined under these conditions.By "not installed," we mean here that the measurements are taken when the propulsion system 1 is in a test bench (and not installed on an aircraft 100), as the measurements are then simpler to perform. The distances (length, radius, diameter, etc.) are, however, measured at ambient temperature (approximately 20°C) when the propulsion system 1 is cold, that is, when the propulsion system 1 has been stopped for a sufficient period for the parts of the propulsion system to reach ambient temperature, it being understood that these dimensions vary little compared to the . conditions in which the propulsion system 1 is in takeoff mode.

[0047] The fan rotor 9 is decoupled from the low-pressure shaft 11 by means of a reduction device 19, located between an upstream end of the low-pressure shaft 11 and the fan rotor 9, in order to optimize their respective rotational speeds. In this case, which actually corresponds to an indirect coupling provided by the reduction device, the propulsion system 1 further includes an additional shaft, called the fan shaft 20. The low-pressure shaft 11 connects the low-pressure turbine 8 to an inlet of the reduction device 19, while the fan shaft 20 connects the outlet of the reduction device 19 to the fan rotor 9. The fan rotor 9 is therefore driven by the low-pressure shaft 11 via the reduction device 19 and the fan shaft 20 at a rotational speed lower than the rotational speed of the low-pressure turbine 8.

[0048] This "decoupling" via the reduction device makes it possible to reduce the rotational speed and pressure ratio of the fan rotor 9 and to increase the power extracted by the low-pressure turbine 8. Indeed, the overall efficiency of the propulsion systems is conditioned to the first order by the propulsion efficiency, which is favorably influenced by minimizing the variation in kinetic energy of the air as it passes through the propulsion system 1. In a propulsion system 1 with a high dilution ratio, the bulk of the flow generating the propulsive force consists of the secondary airflow F2 of the propulsion system 1, the kinetic energy of the secondary airflow F2 being mainly affected by the compression that the secondary airflow F2 undergoes when passing through the fan section 2.The propulsive efficiency and the pressure ratio of the fan section 2 are therefore linked: the lower the pressure ratio of the fan section 2, the better the propulsive efficiency. In order to optimize the propulsive efficiency of the propulsion system 1, the fan pressure ratio, which corresponds to the ratio between the average pressure at the outlet of the fan stator 17 (or, in the absence of a stator, of the fan rotor 9) and the average pressure at the inlet of the fan rotor 9, is less than or equal to 1.70, for example less than or equal to 1.50, for example between 1.05 and 1.45. The average pressures are measured here over the height of the blade 14 (from the surface that radially delimits the flow path inside the inlet of the fan rotor 9 to the tip 21 of the fan blade 14).

[0049] The propulsion system 1 is configured to provide a thrust of between 18,000 Ibf (80,068 N) and 51,000 Ibf (222,411 N), for example between 20,000 Ibf (88,964 N) and 35,000 Ibf (155,688 N).

[0050] The blower section 2 may be shrouded or unshrouded. In the case of a shrouded blower section 2, the blower section 2 comprises a blower housing 12 and the blower rotor 9 is housed in the blower housing 12.

[0051] A shrouded fan section 2 comprises a fan rotor 9 extending upstream of a fan stator. The fan stator blades are then generally called outlet guide vanes (OGVs) and have a fixed pitch relative to the fan stator hub. Furthermore, the bypass ratio of the propulsion system 1 is, for example, greater than or equal to 10, for example, between 10 and 35 inclusive, for example, between 10 and 18 inclusive. The peripheral velocity at the tip 21 of the fan rotor blades 9 can also be between 260 m / s and 400 m / s. The fan rotor blades 14 can be fixed or have a variable pitch. The fan pressure ratio can then be between 1.20 and 1.45.

[0052] In an unfaired fan section 2, the fan section 2 (which may also be referred to as the propeller) is not enclosed by a fan casing. Since the fan section 2 is unfaired, the blades 14 of the fan rotor 9 have variable pitch. Propulsion systems comprising at least one unfaired fan rotor 9 are known as "open rotors" or "unducted fans." The propulsion system 1 may comprise two unfaired, counter-rotating fan rotors 9. Such a propulsion system 1 is known by the acronym CROR for "Contra-Rotating Open Rotor" or UDF for "Unducted Double Fan." The blower rotor(s) 9 can be placed at the rear of the primary body 3 so as to be of the pusher type or at the front of the primary body 3 so as to be of the tractor type.Alternatively, the propulsion system 1 may comprise a single unducted fan rotor 9 and an unducted fan stator 16 (rectifier). Such a propulsion system 1 is known by the English acronym USF for "Unducted Single Fan". In the case of a USF-type propulsion system 1, the blades 17 of the rectifier 16 are fixed in rotation relative to the X-axis of rotation of the upstream fan rotor 9 and therefore do not experience centrifugal force. The blades 17 of the rectifier 16 also have variable pitch.

[0053] Removing the fairing around the fan section 2 significantly increases the bypass ratio without the propulsion system 1 being negatively impacted by the mass of the housings or nacelles intended to surround the fan section 2. The bypass ratio of the propulsion system 1, including an unfaired fan section 2, is thus greater than or equal to 40, for example, between 40 and 80 inclusive. Furthermore, the peripheral velocity at the tip 21 of the fan blades 14 of the fan rotor(s) 9 can be between 210 m / s and 260 m / s. The fan pressure ratio can then be, for example, between 1.05 and 1.20.

[0054] With reference to Figures 3 and 4, the reduction device 19 may include an epicyclic gear train reduction device, for example of the type “Epicycloidal” or “planetary” type, single-stage or two-stage.

[0055] According to a first variant illustrated in [Fig.3], the reduction device 19 can be of the planetary type (“star” in English) and comprise a sun pinion 19a (input of the reduction device 19), centered on an axis X of rotation of the reduction device 19 (generally coincident with the longitudinal axis X) and configured to be driven in rotation by a transmission shaft 30 (such as for example the low-pressure shaft), a ring gear 19b (output of the reduction device 19) coaxial with the sun pinion 19a and configured to drive in rotation the blower shaft 20 around the axis X of rotation, and at least one satellite pinion 19c between the sun pinion 19a and the ring gear 19b, the satellite gear 19c being internally meshed with the sun pinion 19a and externally with the ring gear 19b.When the reduction device 19 includes several satellite pinions 19c, these are distributed circumferentially around the X axis of rotation between the sun pinion 19a and the ring gear 19b, each satellite 19c.

[0056] Each planetary gear 19c is mounted freely to rotate about a direction parallel to, or almost parallel to, the X-axis on a planetary carrier 19d. The planetary carrier 19d is held fixed against rotation relative to a support 32. The support 32 is itself fixed to a stator 34 of the propulsion system 1. The stator 34 is, for example, a housing of the compressor section 4, 5.

[0057] According to a second variant illustrated in [Fig. 4], the reduction device 19 can be of the epicyclic type (or "planetary" in English), in which case the ring 19b is held fixed in rotation relative to the support 32. The support 32 is itself fixed to the stator 34 of the propulsion system 1. The stator 34 is, for example, a housing of the compressor section 4, 5. The blower shaft 20 is driven in rotation by the planet carrier 19d, which is therefore free to rotate relative to the stator 34 of the propulsion system 1.

[0058] Regardless of the configuration of the reduction device 19, the support 32 can be an annular support, and the stator 34 can be a fixed annular housing, or an air inlet housing or an enclosure housing.

[0059] Regardless of the configuration of the reduction device 19, the diameters of the ring gear 19b and the satellite carrier 19d are greater than the diameter of the solar pinion 19a, so that the rotational speed of the blower rotor 9 is less than the rotational speed of the low pressure shaft 11.

[0060] The reduction ratio of the reduction device 19 is greater than or equal to 2.5 and less than or equal to 11. In the case of a propulsion system 1 comprising a shrouded fan rotor 9, the reduction ratio may be greater than or equal to 2.7 and less than or equal to 6.0, typically around 3.0. In the case of a propulsion system 1 comprising an unshrouded fan rotor, the reduction ratio can be between 9.0 and 11.0.

[0061] The twin-body propulsion system 1 may in particular include a two-stage high-pressure turbine 7, a high-pressure compressor 5 comprising at least eight stages and at most eleven stages, a low-pressure turbine 8 comprising at least three stages and at most five stages and a low-pressure compressor 4 comprising at least two stages and at most four stages.

[0062] The redline speed of the low-pressure shaft 11, which corresponds to the absolute maximum speed that the low-pressure shaft 11 is likely to encounter during the entire flight (according to European certification regulation EASA CS-E 740 (or according to US certification regulation 14-CFR Part 33.87)), is between 8,500 rpm and 12,000 rpm, for example, between 9,000 rpm and 11,000 rpm. The redline speed corresponds to the maximum rotational speed when the propulsion system is in good condition (and potentially at the end of its service life). It is therefore likely to be reached by the low-pressure shaft 11 under flight conditions. This redline speed is part of the data declared in the engine certification (type certification data sheet).Indeed, this rotational speed is usually used as a reference speed for the sizing of propulsion systems 1 and in certain certification tests (such as blade loss or rotor integrity tests). Measuring device

[0063] The propulsion system 1 includes a measuring device 36 configured to measure a relative displacement between the support 32 and the stator 34, and / or a force exerted by the support 32 on the stator 34.

[0064] Such a measuring device makes it possible to monitor the mechanical behavior of the reduction device.

[0065] In operation, the support 32 is a part which takes back at least part of the forces applied to the reduction device 19 so that the support 34 keeps the planet carrier 19d fixed in rotation when the reduction device 19 is of the planetary type or the ring 19b when the reduction device 19 is of the epi-cycloidal type.

[0066] Under the action of part of the forces applied to the reduction device 19, the support 32 can transmit part of these forces to the stator 34.

[0067] The support 32 can be more flexible than the stator 34, particularly in torsion about the X-axis. In this way, when the support 32 is subjected to forces, it can deform relative to the stator 34, the stator 34 being considered as a fixed reference. This flexibility of the support makes it possible, in particular, to compensate for any misalignments (relative to the motor axis) between the drive shaft 30 and the blower shaft 20. This flexibility also allows filter vibrations.

[0068] Monitoring the forces exerted by the support 32 on the stator 34 and / or the relative displacements between the support 32 and the stator 34 provides more general information on the forces applied to the reduction device 19. This monitoring makes it possible, for example, to monitor the displacements or local vibrations of the reduction device 19, and more generally to monitor the health of the reduction device 19.

[0069] These measurements, alone or in combination, make it possible to estimate the torque (for example, using charts) applied to the support 32, and therefore the torque transmitted via the reduction device 19 from the low-pressure shaft to the blower shaft. These measurements make it possible to estimate the mechanical behavior of the support and / or the speed reduction device 19.

[0070] The measurement is performed in relation to the support 32, which is one of the parts of the speed reducer 19 most subjected to vibrations, forces, displacements, and torques during the operation of the reduction device 19. The measurement produced is therefore rich in information; for example, it is possible to estimate the meshing frequency of the gears, which is a key parameter for monitoring the condition of the reducer.

[0071] The measuring device 36 also makes it possible to detect a possible failure of the support 32, in particular by detecting the loss of one or more sensors, or when the measurement of the displacement indicates contact between the support 32 and the stator 34. The identification of contacts is a normative obligation with regard to dormant failures (i.e. failures which are not immediately detectable or detected) of the support.

[0072] The measurement of the displacement and / or force is carried out in a fixed frame of reference between the stator 34 and the support 32, the support 32 moving very little in comparison with the parts set in motion in the speed reducer 19. The measurement therefore does not require the use of a rotating transfer, with the backlash problems associated with it, or the problem of transmitting acquisition signals for example by telemetry.

[0073] The stator 34 may include an orifice 44 as illustrated in [Fig.6], which allows a physical connection 42c to be made linking the sensor 42 to a memory or a computer so as to transmit the measurement signal from the sensor 42 to this memory or computer.

[0074] Such a measuring device 36 is simple to implement, because the parts of the measuring device 36 involved in the measurement are fixed or almost fixed, and one simply measures a relative deformation and / or a force (effort, stress, pressure or other) exerted by the support 32 on the stator 34.

[0075] Furthermore, such a measuring device can be arranged between the support 32 and the stator 34, that is to say, in an area of ​​the propulsion system that is generally not very cluttered. The measuring device 36 as described allows for a saving of space.

[0076] The measuring device 36 can be configured to measure relative displacement and / or force as a function of time, i.e. the measuring device 36 can allow monitoring of relative displacement and / or force over time by providing a series of time measurements of relative displacement and / or force.

[0077] Such a measuring device 36 can enable frequency analysis of the measured values, allowing for a more detailed understanding of the mechanical, and in particular vibrational, behavior of the support 32. This analysis eliminates the need for any additional frequency monitoring devices, and thus indirectly saves space and mass. It should be noted in this regard that a device for measuring torque normally requires a significant axial length, which may necessitate lengthening the motor.

[0078] For example, the relative displacement and / or force are measured in a circumferential direction with respect to an X-axis of rotation of the solar pinion 19a. In operation, the support 32 is subjected, in particular, to torques centered on the X-axis of rotation of the solar pinion. This X-axis is the main axis of rotation of the speed reduction device and generally corresponds to the axis of rotation of the transmission shaft 30 and the axis of rotation of the blower shaft 20. When the relative displacement and / or force are measured in the circumferential direction around the X-axis, the measuring device 36 provides information, in particular, on the torques involved around the main axis of rotation of the speed reduction device.

[0079] A circumferential measurement of the forces and / or displacement allows a torque to be measured reliably.

[0080] The torque range that the measuring device 36 can measure extends, for example, from 0 to 500,000 Nm. This torque monitoring can be adapted to configurations where the blower (propeller or fan) has blades with variable pitch. Controlling the pitch can have a significant impact on the torque, and therefore on the gearbox's lifespan.

[0081] In one embodiment of the measuring device 36, the support 32 comprises a body 33 and a relief 38 which extends radially from the body 33 with respect to the X axis and the stator 34 comprises a base 35 and a stop 40 which extends radially from the base 35 with respect to the X axis.

[0082] With reference to Figures 3, 4 and 5, the body 33 of the support 32 can be an annular piece surrounding the X axis and the base 35 of the stator 34 can be an annular housing surrounding the body 33 of the support 32. The body 33 of the support 32 and the base 35 of the stator 34 can be placed opposite each other.

[0083] The diameter of the body 33 or of the stator 34 can in particular be between 200 mm and 3000 mm.

[0084] The relief 38 is for example an outgrowth or projection of the body 33 which extends from the body 33 of the support 32 radially outwards, that is to say which extends from the body 33 away from the axis X.

[0085] The stop 40 is for example an outgrowth or projection of the base 35 which extends from the base 35 of the stator 34 radially inwards, that is to say which extends from the base 35 approaching the X axis.

[0086] The bumper 40 is arranged circumferentially with respect to the X axis of rotation, opposite the relief 38.

[0087] The measuring device 36 includes at least one sensor 42, the at least one sensor comprising a first part 42a mounted on an element among the stop 40 or the relief 38.

[0088] Optionally, at least one sensor 42 comprises a second part 42b mounted on the other element between the bumper 40 and the relief 38, respectively.

[0089] A measurement set 50a included in the propulsion system 1 can be defined which in this case includes the relief 38, the bumper 40 and at least one sensor 42.

[0090] The sensor 42 can measure the relative displacement between the relief 38 and the buffer 40, or a force exerted by the relief 38 on the buffer 40.

[0091] This embodiment of the measuring device 36 can be implemented in particular with a relief 38 and a stop 40, which are respectively a shoulder of the support 32 and a shoulder of the stator 34. These shoulders can be designed to cooperate within a protective mechanism against a possible breakage of the support 32. This protective mechanism is known as a dog clutch or anti-rotation dog clutch. It can be provided in the propulsion system so that, in the event of accidental breakage of the support 32, the support 32 is not driven into rotation by the planet carrier 19d or by the ring 19b. In the event of accidental breakage of the support 32, the relief 38 is driven with the support 32 in a circumferential direction. The relief 38 comes to rest against the stop 40, and by this blocking, the support 32 is held in rotation by the stator 34.In this case, the measuring device 36 acts as a safety device to limit deformations of the support 32 and / or block the movement of the support 32 in case of breakage. This embodiment allows for better integration of the monitoring device by reducing the size of the propulsion system 1.

[0092] The propulsion system can be configured so that, under normal operation, the relief 38 is not in contact (i.e., remains distant) from the buffer 40. In this case, the measuring device 36 makes it possible to detect a possible failure of the support 32, when the sensor indicates that the relief 38 has come into contact with the buffer 40. This indication can to enable fulfillment of a normative obligation with regard to dormant failures (i.e. failures which are not immediately detectable or detected) of the support.

[0093] Optionally, the measuring assembly 50a includes a second stop 46 of the stator 34. The second stop 46 extends, like the first stop 40, radially from the base 35. The second stop 46 is arranged circumferentially opposite the relief 38, and the relief 38 is located circumferentially between the first stop 40 and the second stop 46.

[0094] In this option, and as illustrated in [Fig.5], the relief 38 is framed in the circumferential direction by the two bumpers 40 and 46.

[0095] The second stop 46 can be, in the same way as the first stop 40, an outgrowth of the base 35 which extends from the base 35 of the stator 34 radially inwards, that is to say from the base 35 approaching the X axis.

[0096] In this option, the second stop can also be part of a protection mechanism against a possible accidental breakage of the support 32. In this case, regardless of the direction of the rotational movement in which the relief 38 is driven, it comes to rest against the first stop 40 or against the second stop 46. The reliability of the propulsion system 1 is increased.

[0097] In this option, the measuring assembly 50a may include two sensors 42, 48 which are located circumferentially on either side of the relief 38. Each of the sensors 42, 48 cooperates respectively with a single stop between the first stop 40 and the second stop 46.

[0098] The sensor 42 initially included in the measuring assembly 50a being fixed to the first stop 40, the sensor 42 cooperates with the first stop 40. The second sensor 48 cooperates with the second stop 46. For example, a second sensor 48 comprises a first part mounted on the relief 38 and a second part mounted on the second stop 46.

[0099] In this case, the second sensor 48 provides a second measurement which can be used in combination with the first measurement provided by the first sensor 42.

[0100] If the two measurements relate to the same quantity, one can, in particular, take an average of these two measurements and / or a differential measurement from these two measurements. The average value provides access to averaged information, for example, a first movement of the support 32 relative to the stator 34, the effect of which is identical on each sensor. The value of the differential measurement provides access to information of a different nature than the average value, for example, a second movement of the support 32 relative to the stator 34, the effect of which is different on each sensor. This makes it possible, in particular, to eliminate the deformations and tolerances of each part, and therefore to improve accuracy.

[0101] It is also possible to determine, from these two measurements, the value other quantities. For example, if each sensor provides a distance measurement between one of the stops 40, 46 and the relief 38 respectively, knowing these two measurements allows us to determine the displacement of the relief 38, firstly along the circumferential direction and secondly along the radial direction. This is particularly relevant when the faces of the relief are angled.

[0102] The two measurements can also be relative to quantities of a different nature, for example the first sensor can measure a relative displacement and the other sensor can measure a force exerted by the support 32 on the stator 34.

[0103] According to the present example, the monitoring of the mechanical behavior of the reduction device is finer and more precise, which makes it possible to refine the monitoring of the health of the reduction device and the anticipation of its maintenance and / or the measurement of the torque.

[0104] The measuring assembly 50a, as described so far, can include a sensor configured to measure relative displacement and a sensor configured to measure force. With these two sensors, the measuring device 36 is configured to measure both relative displacement and force. The reliability and accuracy of the measurements produced by the measuring device 36 are increased. In particular, this can extend the range of measurements that the measuring device 36 can perform, across a wider range of operating conditions. The overall increase in information provided by the measuring device facilitates monitoring of the speed reduction device and its condition.

[0105] The measuring assembly 50a, as described so far, comprises the relief 38, the first stop 40, a first sensor 42, and optionally a second stop 46 with a possible second sensor 48. This assembly can be a first assembly, the propulsion system 1 being able to comprise a plurality of measuring assemblies 50a, 50b, 50c, 50d. Each assembly occupies a limited angular sector, and it is possible to distribute the different measuring assemblies regularly around the X-axis. [Fig. 5] illustrates the situation where the system comprises four measuring assemblies distributed in a cross shape around the X-axis, each assembly comprising two stops and two sensors.

[0106] According to a particular example, the propulsion system 1 comprises two sets that are diametrically opposed to each other. More generally, the propulsion system can comprise a plurality of pairs of sets, the two sets in each pair being diametrically opposed to each other. According to another example, the system comprises two sets, the two sets being arranged at 90° to each other.

[0107] Each measurement set provides one or more measurements if the measurement set includes several sensors. It should be noted that the different sets may or may not be identical; in particular, each set includes one on one side one or two stops, and on the other side one sensor, two sensors or more sensors.

[0108] The propulsion system 1 may comprise a large number of reliefs 38, each forming part of a measurement set. This number may be less than or equal to 200.

[0109] The propulsion system 1 can produce a large number of measurements in parallel, for example, 400 or fewer measurements, 200 or fewer measurements, or 100 or fewer measurements. These different measurements can be provided in parallel and recorded for later processing. They can also be provided simultaneously, processed simultaneously, or recorded for later processing. In one embodiment, these measurements are processed in real time, for example, to estimate the torque and control the fan blade pitch.

[0110] For example, increasing the number of measurement sets and therefore sensors makes it possible to enrich the measurements provided on the support and its behavior relative to the stator. The reliability and accuracy of the measurements are improved.

[0111] It is possible, for sensors of the same type located at different radial positions around the X-axis, to determine averaged and / or differential measurements, as previously mentioned. This is particularly the case when the system comprises two sets that are diametrically opposed to each other, each set including at least one sensor of the same type. Sensor types

[0112] In relation to the measuring device, measuring assembly or measuring assemblies as described so far, these may include at least one sensor selected from:

[0113] - a proximity sensor, such as for example a magnetic proximity sensor, or a an inductive proximity sensor or a capacitive proximity sensor,

[0114] - a piezoelectric sensor,

[0115] - an ultrasonic sensor,

[0116] - a surface acoustic wave (SAW) sensor,

[0117] - an optical sensor,

[0118] - an LVDT type sensor,

[0119] - an RVDT-type sensor, and

[0120] - a hydraulic cylinder sensor.

[0121] A proximity sensor or proximeter is a sensor configured to measure the distance separating the sensor from a studied object located nearby, i.e. at a distance less than the maximum distance measurable by the sensor.

[0122] Different types of proximity sensors are distinguished, such as a magnetic proximity sensor, an inductive proximity sensor or a capacitive proximity sensor.

[0123] A magnetic proximity meter is a proximity meter whose measurement is based on an effect magnetic.

[0124] In an example of a magnetic proximity sensor embodiment, the sensor 42 illustrated in [Fig.7] comprises:

[0125] - a magnet 42b which forms part of a second part of the sensor 42 fixed to the relief 38 of support 32, and

[0126] - a coil 52 which surrounds an armature 54 made of “soft iron”, that is to say made of a magnetizable material; the coil 52 and the armature 54 are part of the first part 42a of the sensor 42 fixed to the stop 40 of the stator 34.

[0127] The axis around which the coil 52 is wound corresponds here to a circumferential direction which is identical or almost identical to the axis of the magnet 42b.

[0128] The coil 52 is part of an electrical circuit through which an alternating current flows. This alternating current is supplied by a measuring system which is also part of the measuring device 36. The electrical circuit is an oscillating circuit whose resonant frequency can be determined. For this purpose, electrical wires 42c connect the coil 52 to the measuring system, the electrical wires being, for example, passed through an orifice 44 in the stator 34.

[0129] The alternating current which passes through the coil 52 creates a magnetic field and a magnetic interaction with the magnet 42b, or in other words a magnetic coupling with the magnet 42b.

[0130] The relative movement of the magnet 42b with respect to the coil 52, due in particular to the movement of the support 32 with respect to the stator 34, modifies the magnetic coupling between the coil 52 and the magnet 42b. The impedance of the coil 52 seen by the oscillating circuit is modified, as is the resonant frequency of the oscillating circuit. The variation in the resonant frequency of the circuit is detected by the measuring system, which can then deduce the distance separating the coil 52 from the magnet 42b.

[0131] It should be noted that if the support 32 is made of a magnetizable material, such as steel, the magnet 42b can be surrounded by a paramagnetic material 50, such as titanium. Thus surrounded, the magnet 42b produces field lines that are not detected within the magnetizable material of the support 32. This makes it possible to produce a magnetic coupling between the coil 52 and the magnet 42b strong enough to be detectable.

[0132] It should also be noted that the first part 42a of the sensor 42 and the stop 40 can be fixed to the base 35, which is itself removably mounted relative to the stator 34. Fasteners 37 can be provided for fixing the base 35, which carries the sensor 42 and the stop 40, to the stator 34. Such a removable mounting simplifies the assembly of the system as well as the disassembly and maintenance of the sensor.

[0133] Alternatively, the magnetic proximity sensor can be mounted so that the magnet 42b is part of the first part 42a of the sensor 42 fixed to the stop 40 of the stator 34, and the coil 52 and the armature 54 are part of the second part 42b of the sensor 42 fixed to the relief 38 of the support 32.

[0134] The magnetic proximity meter as presented here allows the distance separating the relief 38 and the stop 40 to be measured in the circumferential direction parallel to the axis of the winding of the coil 52 and the axis of the magnet 42b.

[0135] For example, a second coil 52 can be placed on a second stop located on the stator on the opposite side of the relief 38 from the first stop 40. The relief 38 is thus framed in the circumferential direction by two stops, each carrying a coil. This provides two distance measurements of the relief relative to the first stop and relative to the second stop. This symmetrization of the distance measurement makes it possible to obtain a differential measurement and to eliminate the effects of deformations and tolerances of each individual part, thereby improving the overall accuracy of the measurement.

[0136] An inductive proximity meter is a proximity meter whose measurement is based on a magnetic induction effect.

[0137] In an example of an embodiment of an inductive proximity sensor, called a lateral proximity sensor or circumferential proximity sensor, the sensor 42 illustrated in [Fig.8] comprises:

[0138] - a magnet 56 which forms part of the first part 42a of the sensor 42 fixed to the stop 40 of the stator 34,

[0139] - a coil 52 which surrounds the magnet 56, the coil also forming part of the first part 42a of the sensor 42 fixed to the stop 40 of the stator 34.

[0140] The magnet 56 and the coil have the same axis which is oriented along the circumferential direction.

[0141] In a second embodiment of an inductive proximity sensor, called a radial inductive proximity sensor, the sensor 42 illustrated in Figures 9 and 10 differs in that the magnet 56 and the coil 52 have the same axis, which is oriented this time in a radial direction. This second embodiment is particularly useful when the measuring assembly includes two stops 40 and 46 placed on either side of the relief 38. The two stops allow the channeling of the magnetic lines to be symmetrical on the stator 34 side. Thus, the measuring device is more sensitive to the movements of the relief 38 and the support 32.

[0142] In both examples of embodiment of the inductive sensor, the relative movement of the magnet 56 with respect to the relief 38 due in particular to the movement of the support 32 with respect to the stator 34, modifies the magnetic flux which passes through the coil 52. By effect of magnetic induction, a voltage appears across the terminals of the electrical dipole formed by the coil 52.

[0143] A circumferential movement of the support 32 and its relief 38 is shown between Figures 9 and 10. Figure 9 illustrates a reference situation in which the axis of the coil 52 and the magnet 56 is centered with respect to the relief 38. Figure 10 illustrates a situation of circumferential displacement Dr of the support 32 with respect to the stator 34. The axis of the coil 52 and the magnet 56 is not centered with respect to the relief 38, so the magnetic flux through the coil is not the same as in the reference situation. A voltage appears across the terminals of the electrical dipole formed by the coil 52.

[0144] The detection of this voltage, for example by a measuring system, makes it possible to determine the distance separating the coil 52 from the relief 38.

[0145] Such an inductive sensor can be simpler to mount, with the magnet 56 and the winding fixed only to the stator. Since the relief 38 is itself made of a material with high magnetic permeability, it is not necessary to provide a second part of the sensor 42 fixed to the relief 38.

[0146] It should be noted that such an inductive sensor is sensitive to the circumferential displacement of the support 32 relative to the stator 34, but that it is also sensitive to the radial displacement of the support 32 relative to the stator 34.

[0147] A second measurement set comprising the same inductive sensor may be provided, the two measurement sets being placed diametrically opposite on the support 32 with respect to the X-axis. The differential measurement between the two sensors would then make it possible to determine the radial movements of the support 32, and the average measurement between the two sensors would then make it possible to determine the circumferential movements of the support 32.

[0148] A capacitive proximity meter measures the distance between the object being studied and a detection plate within the meter. The object and the plate form an electrical capacitor whose capacitance depends on the distance being measured. The capacitance can be pre-calibrated and measured during the experiment via the oscillation frequency of an electrical circuit involving the aforementioned capacitor.

[0149] A capacitive proximity sensor measures the distance between the object being studied and a detection plate within the sensor. The object and the plate form a capacitor whose capacitance depends on the distance being measured. The capacitance can be pre-calibrated before the experiment and measured during the experiment via the oscillation frequency of an electrical circuit involving the aforementioned capacitor. For example, the detection plate is fixed to the stop 40 and thus forms part of the sensor 42. The relief 38 acts as the object being studied, so the sensor does not include a second part fixed to the relief 38 or the support 32. This makes the sensor 42 easier to mount in the speed reducer 19.

[0150] A piezoelectric sensor is a device which, under the effect of a stress, produces a measurable electrical signal. Such a sensor therefore makes it possible to measure a force or a torque.

[0151] An example of an embodiment of a measuring device 36 which uses a piezoelectric sensor, is illustrated in [Fig.5].

[0152] In this example embodiment, four measuring sets 50a, 50b, 50c and 50d are arranged regularly around the X axis. Each set includes a relief 38 and two platforms 40 and 46, the two platforms 40 and 46 being located on either side of the relief 38 in a circumferential direction.

[0153] Between the platform 40 and the relief 38, a piezoelectric sensor 42 is arranged so as to be in contact with both the platform 40 and the relief 38.

[0154] Similarly, between the platform 46 and the relief 38, a piezoelectric sensor 42 is arranged so as to be in contact with both the platform 46 and the relief 38.

[0155] Each piezo sensor 42 is thus configured to measure a stress along the circumferential direction that the relief 38 exerts on one of the bearings surrounding it.

[0156] In operation, the pair of piezo sensors provides two measurements which make it possible to evaluate the force exerted by the support 32 on the stator 34.

[0157] It should be noted that only one of the piezo sensors alone provides a measurement that makes it possible to evaluate the force exerted by the support 32 on the stator 34

[0158] It should be noted that other types of strain-sensitive sensors such as magnetostrictive sensors can be used instead of a piezoelectric sensor.

[0159] It should also be noted that when using a sensor that requires contact between the relief 38 and one of the bearings 40, 46, there is a preload effect during sensor mounting. The default stress exerted on the sensor once it has been mounted and before the speed reducer is started has the effect of shifting the measurements subsequently produced by this sensor. It is therefore advantageous to provide for a calibration with the motor stationary, consisting of canceling the residual torque, for example, by means of software. Furthermore, this type of contact sensor must withstand the vibrations generated by the gearing, vibrations which are experienced by the support 32 and transmitted to the sensor.

[0160] An ultrasonic sensor is a device configured to send a high-frequency sound signal toward an object under study. This signal propagates from the device to the object at the speed of sound. When the signal encounters the object, it is at least partially reflected, and an echo signal from the initial signal propagates back toward the sensor. This echo signal is detected by the sensor. From the time delay between the emission of the initial signal and the detection of the echo signal, the detector determines its distance from the object under study. An ultrasonic sensor can be attached to the stator 34, in particular to a bearing 40 of the stator 34. The sensor is configured to send the initial signal toward a specific part of the support. 32, in particular in the direction of a relief 38 of the support 32. The signal is emitted towards the particular part, for example in the circumferential direction, and the detection of the echo makes it possible to determine a relative displacement between the support 32 and the stator 24, for example in the circumferential direction.

[0161] An optical sensor is a device configured to send a light signal toward an object under study. This signal propagates from the device to the object at the speed of light. When the signal encounters the object, it is reflected back toward the sensor. This echo of the initial signal is detected by the sensor. For example, the sensor includes a laser that creates a point of light on a surface. The sensor further includes a lens and a line of photodiodes to evaluate the position of the laser reflection.

[0162] According to another example, the sensor is of the interferometric type. The sensor comprises a coherent light source, such as a laser. The emitted light is divided into two paths, a reference path and a measurement path, the length of which depends on the distance to be measured. For example, the light source is fixed to the stator 34, and the measurement path includes a round trip against a reflective surface of a relief 38 of the support 32. The lights from the two paths are then superimposed. Due to the wave nature of light, this superposition exhibits a brightness that depends on the phase difference between the lights from the two paths, a brightness which allows the distance to be determined.

[0163] Alternatively, the reflection of the light signal on the object can be made dependent on the object's position. By performing a preliminary calibration to identify a correspondence between the object's position and the measured optical signal, the object's position can then be determined by optical measurement.

[0164] A particular embodiment of non-contact proximity sensors is illustrated in Figures 11 and in a radial configuration of the optical measurement. This embodiment is not exclusive to optical measurement; it is valid for any non-contact proximity sensor. According to this embodiment for an optical sensor, an optical sensor 60 is fixed to the base 35 of the stator 34 radially outside a relief 38 of the support. It can be provided that, for the reference position of the support 32, the optical sensor 60 is radially aligned with the relief 38, that is to say, the direction passing through the sensor 60 and the relief 38 intersects the X-axis perpendicularly. The relief 38 has, on the side of the sensor 60, an external radial surface 58. The sensor 60 is configured to send an optical signal onto this surface 58, at least a portion of which is reflected back to the sensor 60 and measured by the sensor 60.The surface 58 is not homogeneous, so that depending on the angle around the X-axis of the support 32 relative to the stator 34, the signal reflection is not the same. For example, the surface 58 has a particular curvature in the circumferential direction, or the surface 58 is treated so that the co. The efficient reflection is not homogeneous in the circumferential direction. Thus, when the support 32 rotates, the signal detected by the sensor 60 changes. By performing a preliminary calibration, it is possible to relate the displacement to the measured signal. The preliminary calibration can be carried out by varying the displacement and measuring the corresponding signal. It is also possible to perform a preliminary calibration by varying the force or torque exerted by the support 32 on the stator and measuring the corresponding signal. The force or torque corresponds to a particular displacement of the support 32 relative to the stator 34.In all cases, we obtain a calibration curve 62 relating the measurement, i.e. the value of the signal measured by the sensor 60, to the torque or force exerted by the support 32 on the stator 34, or a calibration curve relating the measurement, i.e. the value of the signal measured by the sensor 60, to the displacement of the support 32 relative to the stator 34.

[0165] Figures 11 and 12 illustrate an example of a calibration curve 62 relating the measurement to the torque exerted by the support 32 on the stator 34.

[0166] Fig. 11 illustrates a reference situation where the sensor 60 is radially aligned with the sensor 38. The optical signal reaches point 64C of the surface 58, it is returned to the sensor 60 which measures a value 64B which appears on the ordinate of the curve 62. This ordinate 64B corresponds to point 64 of the calibration curve, point 64 whose abscissa 64A gives the value of the torque exerted by the support 32 on the stator 34.

[0167] Figure 12 illustrates a shifted situation where the sensor 60 is no longer radially aligned with the sensor 38. The optical signal reaches point 66C on the surface 58 and is returned to the sensor 60, which measures a value 66B that appears on the ordinate of the same curve 62. This ordinate 66B corresponds to point 66 of the calibration curve, point 66 whose abscissa 66A gives the value of the torque exerted by the support 32 on the stator 34. The difference between the torque values ​​66A and 64A gives the difference in torque exerted by the support 32 on the stator 34, a difference in torque that corresponds to the displacement of the support 32 relative to the stator 34 between the reference situation and the shifted situation.

[0168] It should be noted that here the surface 58 was chosen to be symmetrical with respect to its center, which corresponds to point 64C. In this case, the calibration curve relating the measurement, i.e., the value of the signal measured by the sensor 60, to the displacement of the support 32 with respect to the stator 34 is symmetrical with respect to the reference situation where the light signal arrives at point 64C. An angular displacement of a certain value in one direction or the other will produce the same optical signal.

[0169] It is possible to choose a surface 58 whose optical inhomogeneity is not symmetrical with respect to its center, which corresponds to point 64C. In this case the curve calibration linking the measurement, i.e. the value of the signal measured by the sensor 60, to the displacement of the support 32 relative to the stator 34 is not symmetrical with respect to the reference situation where the light signal arrives at point 64C.

[0170] An LVDT sensor – short for Linear Variable Displacement Transducer – is an electromechanical device used to convert linear mechanical motion into an electrical voltage. The operating principle of the LVDT sensor is as follows. The LVDT sensor comprises a primary coil that is energized by an alternating current. The LVDT sensor includes two secondary coils positioned on either side of the primary coil, the three coils being coaxial along an axis of the LVDT sensor. Referring to [Fig. 6], the LVDT sensor comprises a portion 42a fixed to the stator 34, for example to the base 35 or a stop 40, and a portion 42b fixed to the support 32, for example to the body 33 or a relief 38. At these two fixings, the sensor is mounted by means of a pivot joint with an axis that may be parallel to the X-axis.The LVDT sensor comprises a rod fixed to one of the parts attached to the stator 34 or the support 32. The rod is mounted to move freely along the axis of the LVDT sensor relative to the other fixed part. During the movement of the rod, it passes more or less through the three coils. Depending on the relative movement of the support 32 with respect to the stator 34, the LVDT sensor changes position: on the one hand, the distance between the fixed parts changes, and on the other hand, the angle of the rod with respect to the stator 34 changes. The movement of the rod modifies the magnetic coupling of each secondary coil with the primary coil. The voltages due to the induction effect across the secondary coils can be measured, transmitted via the connections 42c, and compared, thus allowing the position of the LVDT sensor to be determined. The LVDT sensor provides a circumferential displacement measurement of the support 32 with respect to the stator 34.However, it is also possible, via calibration, to determine the torque exerted by the support 32 on the stator 34 from the measurement of the LVDT sensor. It should be noted that the angle of the LVDT sensor in its reference position can be chosen to maximize torque sensitivity.

[0171] The LVDT sensor needs to be fixed partly on the stator 34 and partly on the support 32. On the other hand, the LVDT sensor is not necessarily fixed to a relief 38 or to a stop 40.

[0172] Alternatively, the LVDT sensor can be replaced by an RVDT sensor – an abbreviation for Rotary Variable Displacement Transducer. The RVDT sensor is an electromechanical device used to convert a mechanical rotational motion into voltage. In this case, it is the rotation of a part of the sensor that modifies the coupling between the primary coil and the secondary windings.

[0173] Finally, it is possible to use a sensor per hydraulic cylinder. Such a sensor has a first part 42a fixed to the stator 34 and a second part 42b fixed to the support 32. The first part 42a and the second part 42b are connected together by a set of cylinders. These cylinders are controlled so as to maintain the first part 42a and the second part 42b at a certain position relative to each other. In particular, a regulated system can be used which adjusts the pressure in each cylinder according to a measurement of the relative position between the first part 42a and the second part 42b. The pressure adjusted in the cylinder is an indirect measure of the torque.

[0174] The measuring device 36 may include a combination of several types of sensors, for example to have a wider measuring range at a given accuracy, or to combine information on different parameters.

Claims

Demands

1. Aeronautical propulsion system (1) comprising: - a stator (34), - a drive shaft (30), - a blower section (2) comprising a blower shaft (20) and a blower rotor (9), the blower rotor (9) being configured to be driven in rotation by the blower shaft (20), - a speed reduction device (19) coupling in rotation the drive shaft (30) and the blower shaft (20), so as to drive the blower shaft (20) at a rotational speed lower than the rotational speed of the drive shaft (30), the reduction device (19) comprising: — a solar pinion (19a), — a ring (19b), the diameter of the ring being greater than the diameter of the solar pinion, — a satellite carrier (19d), — at least one satellite pinion (19c) mounted for rotation on the satellite carrier (19d), and — a support (32) fixed to the stator (34), the ring (19b) or the planet carrier (19d) being held fixed in rotation relative to the support (32), the propulsion system (1) comprising a measuring device (36) configured to measure: — a relative displacement between the support (32) and the stator (34), and / or — a force exerted by the support (32) on the stator (34), the support (32) comprising a body (33) and a relief (38) which projects radially from the body (33) with respect to an axis (X) of rotation of the solar pinion (19a), the stator (34) comprising a base (35) and a stop (40) which projects radially from the base (35), the stop (40) being arranged circumferentially with respect to the axis (X) of rotation, opposite the relief (38), the measuring device (36) comprising at least one sensor (42), the at least one sensor comprising a part (42a) mounted on an element among the stop (40) and the relief (38), the propulsion system (1) comprising a measuring assembly (50a) including the relief (38), the stop (40) and at least one sensor (42), the measuring assembly (50a) comprising a second stop (46) of the stator (34), the second stop (46) extending radially from the base (35),the second buffer, (46) being arranged circumferentially opposite the relief (38), the relief (38) being situated circumferentially between the first stop (40) and the second stop (46).

2. Propulsion system (1) according to claim 1 wherein the measuring device is configured to measure relative displacement and / or force as a function of time.

3. Propulsion system (1) according to any one of claims 1 to 2 wherein the relative displacement and force are measured in a circumferential direction with respect to an axis (X) of rotation of the solar pinion (19a).

4. Propulsion system (1) according to any one of claims 1 to 3 wherein part (42a) of at least one sensor (42) is a first part, the at least one sensor (42) comprising a second part (42b) mounted on the other element among the bumper (40) and the relief (38).

5. Propulsion system (1) according to any one of claims 1 to 4, wherein the measuring assembly (50a) comprises two sensors (42, 48) located circumferentially on either side of the relief (38), each of the sensors (42, 48) cooperating respectively with a single stop among the first stop (40) and the second stop (46).

6. Propulsion system (1) according to any one of claims 1 to 5 wherein the measuring assembly (50a) comprises a sensor configured to measure relative displacement and a sensor configured to measure force.

7. Propulsion system (1) according to any one of claims 1 to 6 wherein the measuring set (50a) is a first measuring set (50a), of a plurality of measuring sets (50a, 50b, 50c, 50d) included in the system (1) and regularly distributed circumferentially, for example the system comprising two sets which are diametrically opposed to each other.

8. Propulsion system (1) according to any one of claims 1 to 7, wherein the measuring device comprises at least one sensor selected from: - a proximity sensor, such as, for example, a magnetic proximity sensor, or an inductive proximity sensor or a capacitive proximity sensor, - a piezoelectric sensor, - an ultrasonic sensor, - an optical sensor, - an LVDT type sensor, - an RVDT type sensor, and - a hydraulic cylinder sensor.

9. Aircraft comprising a propulsion system (1) according to any one of claims 1 to 8.

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