System and method for detecting and reducing torque in a turbine engine

Abstract

A gas turbine engine includes: a fan section having a fan rotatable with a fan shaft; a turbomachine section having a turbine and a turbine shaft rotatable with the turbine; a power gearbox mechanically coupled to the fan shaft and the turbine shaft such that the fan shaft is rotatable by the turbine shaft across the power gearbox; the grounding structure is connected to the power gear box and supports the power gear box; and a torque monitoring system. The torque monitoring system includes a gearbox sensor. The gearbox sensor is coupled to the ground structure, and the torque monitoring system is configured to determine torque on the power gearbox using the gearbox sensor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is a non-provisional application claiming priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 63 / 537,393, filed on September 8, 2023, which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to systems and methods for detecting and reducing torque in a turbine engine. Background Art

[0004] Gas turbine engines generally include a turbine and a rotor assembly. Gas turbine engines, such as turbofan engines, can be used for aircraft propulsion. In the case of a turbofan engine, the turbine includes a compressor section, a combustion section, and a turbine section in a serial flow order, and the rotor assembly is configured as a fan assembly.

[0005] The fan of a gas turbine engine is typically driven by a shaft or spool coupled to a turbine within the turbine section of the gas turbine engine. For some gas turbine engines, a power gearbox is provided, wherein the spool drives the fan across the power gearbox. Such a drive system can allow the turbine to rotate at an increased speed while still allowing a relatively efficient fan speed.

[0006] Conventional gas turbine engines include sensors for determining torque on a power gearbox. However, such torque sensors are large and require a larger power gearbox that is difficult to integrate. Therefore, an improved system for detecting and reducing torque in a gas turbine engine is desired. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0008] Figure 1 is a schematic cross-sectional view of a gas turbine engine according to an exemplary aspect of the present disclosure.

[0009] Figure 2 According to an exemplary aspect of the present disclosure Figure 1 A detailed schematic cross-sectional view of a front end of an exemplary gas turbine engine.

[0010] Figure 3 According to an exemplary aspect of the present disclosure Figure 1 A cross-sectional view of an exemplary gas turbine engine power gearbox.

[0011] Figure 4 According to an exemplary aspect of the present disclosure Figure 3 Schematic cross-sectional view of an exemplary power gearbox.

[0012] Figure 5 is a schematic diagram of a control system according to an exemplary aspect of the present disclosure.

[0013] Fig. 6A is a flow chart of a method for monitoring and reducing torque within a gas turbine engine according to an exemplary aspect of the present disclosure.

[0014] Figure 6B According to an exemplary aspect of the present disclosure Fig. 6A A graphical representation of a method for monitoring and reducing torque.

[0015] Fig. 7A is a flow chart of a method for monitoring and reducing torque within a gas turbine engine according to an exemplary aspect of the present disclosure.

[0016] Figure 7B According to an exemplary aspect of the present disclosure Fig. 7A A graphical representation of a method for monitoring and reducing torque.

[0017] Figure 7C According to an exemplary aspect of the present disclosure Fig. 7A Another graphical representation of a method for monitoring and reducing torque.

[0018] Fig. 8A is a flow chart of a method for monitoring and reducing torque within a gas turbine engine according to an exemplary aspect of the present disclosure.

[0019] Figure 8B According to an exemplary aspect of the present disclosure Fig. 8A A graphical representation of a method for monitoring and reducing torque.

[0020] Figure 8C According to an exemplary aspect of the present disclosure Fig. 8A Another graphical representation of a method for monitoring and reducing torque.

[0021] Fig. 9 is a flow chart of a method for determining torque and thrust within a gas turbine engine according to an exemplary aspect of the present disclosure.

[0022] Fig.10 is a flow chart of a method for determining torque within a gas turbine engine according to an exemplary aspect of the present disclosure. DETAILED DESCRIPTION

[0023] Reference will now be made in detail to the present embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter references to refer to features in the drawings. Like or similar reference numbers in the drawings and description have been used to refer to like or similar parts of the present disclosure.

[0024] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless expressly stated otherwise, all embodiments described herein should be considered exemplary.

[0025] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0026] The term "at least one" in a context such as "at least one of A, B, and C" means only A, only B, only C, or any combination of A, B, and C.

[0027] The term "turbine engine" refers to an engine having a turbine as all or part of its power source. Example turbine engines include turbofan engines, turboprop engines, turbojets, turboshaft engines, etc., as well as hybrid electric versions of one or more of these engines.

[0028] The term "combustion section" refers to any heat addition system for a turbomachine. For example, the term combustion section may refer to a section that includes one or more of a deflagration combustion assembly, a rotating detonation combustion assembly, a pulse detonation combustion assembly, or other suitable heat addition assemblies. In certain example embodiments, the combustion section may include an annular combustor, a can combustor, a tubular combustor, a trapped vortex combustor (TVC), or other suitable combustion systems, or a combination thereof.

[0029] The terms "upstream" and "downstream" refer to relative directions relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0030] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of the gas turbine engine. Additionally, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of the gas turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc around the centerline of the gas turbine engine.

[0031] As used herein, the "bypass ratio" of a turbine engine is the ratio of bypass air passing through the bypass of the turbine engine to the core air passing through the core inlet of the turbine of the turbine engine. For example, the bypass ratio is the ratio of bypass air entering the bypass airflow passage to the core air entering the turbine.

[0032] Unless otherwise indicated herein, the terms "coupled," "fixed," "attached to," and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment via one or more intermediate components or features.

[0033] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another, and are not intended to indicate the position or importance of each component.

[0034] For the purposes of the description hereinafter, the terms "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal" and their derivatives shall relate to the embodiments as they are oriented in the accompanying drawings. However, it should be understood that the embodiments may assume various alternative variations unless expressly indicated to the contrary. It should also be understood that the specific devices shown in the drawings and described in the following specification are merely exemplary embodiments of the present disclosure. Therefore, specific dimensions and other physical characteristics related to the embodiments disclosed herein should not be considered limiting.

[0035] The term "adjacent" as used herein when referring to two walls and / or surfaces means that the two walls and / or surfaces are in contact with each other, or that the two walls and / or surfaces are separated only by one or more non-structural layers, and the two walls and / or surfaces are in a series contacting relationship with the one or more non-structural layers (i.e., a first wall / surface contacts the one or more non-structural layers, and the one or more non-structural layers contacts the second wall / surface).

[0036] Approximate language as used in the entire specification and claims herein is applied to modify any quantitative representation that can allow variation without causing the basic function associated therewith to change. Therefore, the value modified by terms such as "about", "approximately" and "substantially" is not limited to the specified exact value. In at least some cases, approximate language can correspond to the accuracy of the instrument used to measure the value, or the accuracy of the method or machine used to construct or manufacture parts and / or systems. For example, approximate language can refer to within a margin of 1%, 2%, 4%, 10%, 15% or 20%. These approximate margins can be applied to a single value, any endpoint or two endpoints that limit the range of values, and / or the margin of the range between the endpoints.

[0037] The present disclosure generally relates to systems and methods for detecting and reducing torque in a gas turbine engine. Conventional gas turbine engines include sensors for determining torque on a power gearbox. If the torque on the power gearbox is not limited, a large overload torque coefficient requires a larger power gearbox. However, larger power gearboxes are difficult to integrate, are heavier, and have increased surface area that results in higher thermal loads. In addition, conventional torque sensing methods are based on rotational sensing. These rotational based torque sensors are large and require sensing in a rotating reference frame.

[0038] Determining the torque on the power gearbox based on a static system allows for a smaller sensor, thereby allowing for a smaller power gearbox. For example, a sensor may be placed adjacent to the static side of the power gearbox to measure the torque reacted by the stator side of the power gearbox. This torque measurement does not require a sensor between the rotating interface and the static interface.

[0039] Now referring to the accompanying drawings, Figure 1 is a schematic cross-sectional view of a gas turbine engine 10 according to an exemplary aspect of the present disclosure. Figure 1 As shown, the gas turbine engine 10 defines an axial direction A (extending parallel to a longitudinal centerline 12 for reference), a radial direction R, and a circumferential direction (i.e., a direction extending about the axial direction A). Generally, the gas turbine engine 10 includes a fan section 14 and a turbomachinery section 16 disposed downstream of the fan section 14 .

[0040] The depicted exemplary turbomachinery section 16 generally includes a substantially tubular casing 18 defining an annular inlet 20. The casing 18 encloses, in serial flow relationship: a compressor section including a supercharger or low-pressure compressor ("LPC") 22 and a high-pressure compressor ("HPC") 24; a combustion section 26; a turbine section including a high-pressure turbine ("HPT") 28 and a low-pressure turbine ("LPT") 30; and an ejection exhaust nozzle section 32. A high-pressure ("HP") shaft or spool, such as an HP shaft 34, drivingly connects the HPT 28 to the HPC 24. A low-pressure ("LP") shaft or spool, such as an LP shaft 36, drivingly connects the LPT 30 to the LPC 22.

[0041] For the depicted embodiment, the fan section 14 includes a fan 38 having a plurality of fan blades 40 coupled to a disk 42 in a spaced-apart manner. As depicted, the fan blades 40 extend outwardly from the disk 42 generally along a radial direction R. In addition, the fan 38 can be configured as a fixed pitch fan such that each fan blade 40 is fixed relative to the pitch axis of the corresponding fan blade 40, or as a variable pitch fan such that one or more of the fan blades 40 can rotate or move relative to the pitch axis of the corresponding fan blade 40. Notably, the disk 42 is in turn attached to and rotatable by the fan shaft 44, such that the fan blades 40, the disk 42, and the fan shaft 44 together can rotate about the longitudinal centerline 12 via the LP shaft 36 across a power gearbox 46. The power gearbox 46 includes a plurality of gears for reducing the rotational speed of the fan shaft 44 to a more efficient rotating fan speed relative to the LP shaft 36. However, it should be understood that the term “shaft” or “spool” as used herein does not necessarily require a cylindrical member, but may refer to any rotatable structure extending generally along the axial direction A for driving components of the gas turbine engine 10 . The power gearbox 46 may be at least partially supported by a front frame of the gas turbine engine 10 , such as the front frame 100 .

[0042] Still reference Figure 1 In the exemplary embodiment of the present invention, the disk 42 is covered by a rotatable forward hub 48, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 40. In addition, the exemplary fan section 14 includes an annular fan case or outer nacelle 50 that circumferentially surrounds the fan 38 and / or at least a portion of the turbomachinery section 16. It should be understood that the nacelle 50 is supported relative to the turbomachinery section 16 by a plurality of circumferentially spaced outlet guide vanes 52. In addition, a downstream section 54 of the nacelle 50 extends over an outer portion of the turbomachinery section 16 so as to define a bypass airflow passage 56 therebetween.

[0043] During operation of gas turbine engine 10, a volume of air 58 enters gas turbine engine 10 through associated inlets 60 of nacelle 50 and / or fan section 14. As volume of air 58 passes through fan blades 40, a first portion of air 58, as indicated by arrow 62, is directed or directed into bypass airflow passage 56, and a second portion of air 58, as indicated by arrow 64, is directed or directed into LPC 22. The ratio between first portion of air 62 and second portion of air 64 is generally referred to as a bypass ratio. The pressure of second portion of air 64 is then increased as second portion of air 64 is directed through HPC 24 and into combustion section 26, where second portion of air 64 is mixed with fuel and combusted to provide combustion gases 66.

[0044] Combustion gases 66 are directed through HPT 28, wherein a portion of thermal and / or kinetic energy from combustion gases 66 is extracted via sequential stages of HP turbine stator blades 68 coupled to casing 18 and HP turbine rotor blades 70 coupled to HP shaft 34, thereby causing HP shaft 34 to rotate, which supports operation of HPC 24. Combustion gases 66 are then directed through LPT 30, wherein a second portion of thermal and kinetic energy is extracted from combustion gases 66 via sequential stages of LP turbine stator blades 72 coupled to casing 18 and LP turbine rotor blades 74 coupled to LP shaft 36, thereby causing LP shaft 36 to rotate, which supports operation of LPC 22 and / or rotation of fan 38.

[0045] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the turbomachinery section 16 to provide propulsive thrust. At the same time, the pressure of the first portion of air 62 is significantly increased, also providing propulsive thrust, as it is directed through the bypass airflow passage 56 before being discharged from the fan nozzle exhaust section 76 of the gas turbine engine 10. The HPT 28, LPT 30, and the jet exhaust nozzle section 32 at least partially define a hot gas path 78 for directing the combustion gases 66 through the turbomachinery section 16.

[0046] However, it should be understood that Figure 1 The exemplary single-rotor ducted engine depicted in FIG. 1 is provided as an example only, and in other exemplary embodiments, the gas turbine engine 10 may have any other suitable configuration, including, for example, any other suitable number of shafts or spools, turbines, compressors, etc. Additionally or alternatively, in other exemplary embodiments, any other suitable gas turbine engine may be provided. For example, in other exemplary embodiments, the gas turbine engine may be an open rotor engine, a turbofan engine, a turboshaft engine, a turboprop engine, a turbojet engine, etc.

[0047] Figure 2 According to an exemplary aspect of the present disclosure Figure 1 Detailed schematic cross-sectional view of the front end of an exemplary gas turbine engine 10. More specifically, Figure 2 The fan 38 of the fan section 14 , the LPC 22 of the compressor section, and a portion of the power gearbox 46 are depicted.

[0048] As described above, the fan section 14 of the gas turbine engine 10 includes the fan 38 rotatable with the fan shaft 44. In addition, the turbomachinery section 16 includes a turbine shaft rotatable with the turbine, or more specifically, the turbomachinery section 16 includes the LP shaft 36 rotatable with the LPT 30 and the LPC 22. Furthermore, the power gearbox 46 is mechanically coupled to the fan shaft 44 and the LP shaft 36 such that the fan shaft 44 can be rotated by the LP shaft 36 across the power gearbox 46.

[0049] For the depicted embodiment, the power gearbox 46 is configured as an epicyclic power gearbox, or more specifically, as a planetary gearbox. Figure 3 , provides Figure 2 Schematic cross-sectional view of an exemplary power gearbox 46, the exemplary power gearbox 46 generally includes a sun gear 80, a plurality of planet gears 82, and a ring gear 84. The sun gear 80 is fixedly attached to the LP shaft 36 so that the sun gear 80 rotates with the LP shaft 36. In addition, for the depicted embodiment, the ring gear 84 is fixedly connected to the fan shaft 44 so that the ring gear 84 rotates with the fan shaft 44. Each of the plurality of planet gears 82 is attached to a planet carrier 86. More specifically, each of the plurality of planet gears 82 is rotatably attached to the planet carrier 86 so that they can rotate relative to the planet carrier 86 about a corresponding planet gear axis 88. For the depicted embodiment, the planet carrier 86 remains stationary within the power gearbox 46.

[0050] During operation of the power gearbox 46, the plurality of teeth 90 of the sun gear 80 mesh with the plurality of teeth 92 of the planet gears 82, such that rotation of the sun gear 80 and the LP shaft 36, in turn, rotates each of the plurality of planet gears 82 about its respective planet gear axis 88. The plurality of teeth 92 of the planet gears 82 also mesh with the plurality of teeth 94 of the ring gear 84, such that rotation of the planet gears 82 about their respective planet gear axes 88, in turn, rotates the ring gear 84 and the fan shaft 44 about the longitudinal centerline 12.

[0051] Special return reference Figure 2 , the rotation of the LP shaft 36 is supported within the turbomachinery section 16 by one or more bearings. More specifically, for the depicted embodiment, the LP shaft 36 is supported within the turbomachinery section 16 by a thrust bearing 96. The thrust bearing 96 may be configured as a ball bearing, a tapered roller bearing, or any other suitable bearing configured to absorb forces along the axial direction A from the LP shaft 36. Notably, the thrust bearing 96 is in turn supported by a first frame member 98 of the front frame 100 of the gas turbine engine 10.

[0052] Similarly, the fan shaft 44 is also supported by one or more bearings. More specifically, the fan shaft 44 of the depicted embodiment is also supported by a thrust bearing 102, which in turn is supported by a second frame member 104 of the front frame 100 of the gas turbine engine 10. As depicted, the power gearbox 46 is also supported by the front frame 100, and more specifically, by a third frame member 106 and a fourth frame member 108 of the front frame 100. However, it should be understood that in other exemplary embodiments, the LP shaft 36 may be additionally or alternatively supported by any other suitable bearing at any other suitable location, and similarly, the fan shaft 44 may be additionally or alternatively supported by any other suitable bearing at any other suitable location. In addition, in other exemplary embodiments, the thrust bearing 96 supporting the LP shaft 36 may be supported within the turbomachinery section 16 in any other suitable manner, and further, the thrust bearing 102 supporting the fan shaft 44 may also be supported in any other suitable manner.

[0053] During certain operations of the gas turbine engine 10, it may be beneficial to monitor the amount of torque applied within the gas turbine engine 10, for example, to help ensure that the gas turbine engine 10 is operating within a desired operating range. More specifically, it may be beneficial to monitor the amount of torque applied to the power gearbox 46 of the gas turbine engine 10. Additionally, sensing the torque applied to the power gearbox 46 relative to the static, non-rotating portion of the power gearbox 46 may allow the size of the power gearbox 46 to be reduced. Reducing the size of the power gearbox 46 may also reduce the weight of the power gearbox 46, and may reduce the thermal loads experienced by the power gearbox 46. Accordingly, the depicted gas turbine engine 10 includes a torque monitoring system 110 for measuring the amount of torque applied to the power gearbox 46 from a shaft of the gas turbine engine 10.

[0054] For the depicted embodiment, the torque monitoring system 110 includes a gearbox sensor 112 operable with the power gearbox 46 and at least one grounded or stationary structure of the gas turbine engine 10. The torque monitoring system 110 is configured to determine the torque on the power gearbox 46 using the gearbox sensor 112, as will be described below with reference to FIG. Figure 4 described.

[0055] Also like Figure 2As depicted, the gearbox sensor 112 is operably connected to a controller or control device of the torque monitoring system 110, such as a controller 122. The controller 122 of the torque monitoring system 110 may include one or more controllers of a gas turbine engine (not shown) in which the torque monitoring system 110 is installed or an aircraft provided with an engine including the torque monitoring system 110. The gearbox sensor 112 may be operably connected to the controller 122 using any suitable wired or wireless communication network.

[0056] However, it should be understood that the above reference Figure 2-3 The exemplary turbofan engine and torque monitoring system 110 described are provided as examples only. In other exemplary embodiments, the turbofan engine and torque monitoring system 110 may be configured in any other suitable manner. For example, the torque monitoring system 110 may be configured with any other suitable gas turbine engine. In addition, the power gearbox 46 may alternatively be a star-shaped epicyclic power gearbox or a compound epicyclic power gearbox. In addition, in other exemplary embodiments, the gearbox sensor 112 may include, for example, a plurality of gearbox sensors 112 spaced apart in a circumferential manner.

[0057] Figure 4 According to an exemplary aspect of the present disclosure Figure 3 Schematic cross-sectional view of an exemplary power gearbox 46. The exemplary power gearbox 46 can be combined with the above reference Figure 1-2 The exemplary gas turbine engine 10 discussed may, or alternatively, be incorporated into any other suitable gas turbine engine (e.g., an open rotor engine, a ducted rotor engine, a turbofan engine, a turboshaft engine, a turboprop engine, a turbojet engine, etc.), any other suitable internal combustion engine utilizing a gearbox, etc.

[0058] In at least one exemplary embodiment, the power gearbox 46 may generally include a first attachment structure 168 coupled to the sun gear 80 and configured to be coupled to a first rotating component of the gas turbine engine 10. The first rotating component may be the LP shaft 36. Thus, the first attachment structure 168 may be coupled between the sun gear 80 and at least one of the HPT 28 and the LPT 30 of the gas turbine engine 10. However, in other embodiments, the sun gear 80 may be directly coupled to a rotating shaft of the gas turbine engine 10, such as the LP shaft 36 or the HP shaft 34. Additionally, the power gearbox 46 may generally include a second attachment structure 170 coupled to the ring gear 84 and configured to be coupled to a second rotating component of the gas turbine engine 10. In at least one exemplary embodiment, the second rotating component may be the fan 38. For example, the second attachment structure 170 may be coupled between the ring gear 84 and the fan shaft 44 of the gas turbine engine 10. In other embodiments, the ring gear 84 may be directly coupled to the fan 38. Alternatively, when incorporated into other engines or other gearboxes, one or both of the ring gear 84 and the sun gear 80 may alternatively be configured to couple to any other rotating shaft or component of the engine.

[0059] In at least one example embodiment, the static components of the power gearbox 46 may be coupled to a grounded structure of the gas turbine engine 10. Figure 4 As shown, for example, the planet carrier 86 of the power gearbox 46 can be coupled to the front frame 100 of the gas turbine engine 10. As shown, the planet carrier 86 can be coupled to or support a plurality of planetary gears 82 (at Figure 4 16 and 17. In the embodiment of FIG. 16 , only one of each planetary gear 82 and shaft 166 is shown. In addition, the planet carrier 86 can be coupled to the fourth frame member 108 of the gas turbine engine 10. Thus, the planet carrier 86 can be directly or indirectly coupled to the front frame 100 of the gas turbine engine 10 such that the planet carrier 86 supports the power gearbox 46 relative to the gas turbine engine 100. Additionally or alternatively, the planet carrier 86 can be coupled to the second attachment structure 170 or directly coupled with the fan 38 such that the planet carrier 86 rotates with the fan 38 about the longitudinal centerline 12 while the sun gear 80 is coupled to the frame of the engine (a planetary gearbox configuration).

[0060] In other example embodiments, planet carrier 86 may be directly coupled to casing 18 of gas turbine engine 10 , a gearbox assembly housing, or another suitable mounting structure of gas turbine engine 10 .

[0061] like Figure 4As shown, the power gearbox 46 may also include one or more bearing assemblies 171, each bearing assembly 171 corresponding to the shaft 166 and the planetary gear 82 of each shaft 166 and planetary gear 82 pair. Each bearing assembly 171 is generally configured to allow relative rotation of the corresponding planetary gear 82 around the shaft 166 (e.g., around the planetary gear axis 88). For example, the bearing assembly 171 may be arranged between the center ring 172 defining the center hole 164 of the corresponding planetary gear 82 and the outer surface 174 of the corresponding shaft 166. In the illustrated embodiment, the bearing assembly 171 may include a thrust bearing including a plurality of ball bearings or a roller bearing including a plurality of roller element bearings. The exemplary bearing assembly 171 may include an inner race (not shown) directly or indirectly coupled to the outer surface 174 of the corresponding shaft 166. In addition, the exemplary bearing assembly 171 may include an outer race (not shown) directly or indirectly coupled to the center ring 172 of the corresponding planetary gear 82. A plurality of ball bearings or roller bearings (not shown) may be arranged circumferentially about the planet gear axis 88 between the inner race and the outer race to permit relative rotation of the inner race and the outer race (and thus the shaft 166 and the planet gears 82) about the planet gear axis 88. However, it should be appreciated that in other example embodiments, the bearing assembly 171 may alternatively have any other suitable form or configuration.

[0062] In at least one example embodiment, torque monitoring system 110 is configured to measure torque on power gearbox 46 using gearbox sensor 112. Gearbox sensor 112 may be coupled between power gearbox 46 and a grounded structure of gas turbine engine 10, such as front frame 100. More specifically, as Figure 4 As shown, the gearbox sensor 112 can be coupled to the planet carrier 86 and the fourth frame member 108 of the front frame 100. The planet carrier 86 and the fourth frame member 108 can be stationary. The gearbox sensor 112 is operable to sense data indicating the torque on the torque reaction path defined by the fan shaft 44, the power gearbox 46, and the ground structure or the front frame 100. More specifically, the gearbox sensor 112 can be configured to sense data indicating the deflection of the planet carrier 86 relative to the fourth frame member 108 to determine the torque on the power gearbox 46. For example, the fan shaft 44 can apply a torque on the power gearbox 46. The torque applied to the power gearbox 46 can cause the planet carrier 86 to deflect relative to the fourth frame member 108. The gearbox sensor 112 can sense the amount of deflection of the planet carrier 86 relative to the fourth frame member 108 to determine the torque on the power gearbox 46. In at least one example embodiment, the gearbox sensor 112 can include a load cell, a strain gauge, a torque tube, or a combination thereof.

[0063] Figure 5 is a schematic diagram of a control system 150 according to an exemplary aspect of the present disclosure.

[0064] In at least one example embodiment, the controller 122 of the torque monitoring system 110 discussed above may be configured as part of a control system 150. The control system 150 may include one or more computing devices 152. Notably, Figure 2 The controller 122 depicted in FIG. 1 may be Figure 5 One of the one or more computing devices 152 of the exemplary control system 150 depicted in FIG. The computing device 152 may be configured to execute one or more methods according to exemplary aspects of the present disclosure (such as those described below with reference to Figure 6A-10 1000). The computing device 152 may include one or more processors 154 and one or more memory devices 156. The one or more processors 154 may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, or other suitable processing device. The one or more memory devices 156 may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard drive, flash drive, or other memory devices.

[0065] The one or more memory devices 156 may store information accessible by the one or more processors 154, including computer-readable instructions 158 executable by the one or more processors 154. The instructions 158 may be any set of instructions that, when executed by the one or more processors 154, cause the one or more processors 154 to perform operations. The instructions 158 may be software written in any suitable programming language or may be implemented in hardware. In some embodiments, the instructions 158 may be executed by the one or more processors 154 to cause the one or more processors 154 to perform operations, such as operations for regulating fuel flow as described herein, and / or any other operations or functions of the one or more computing devices 152. Additionally and / or alternatively, the instructions 158 may be executed in logically and / or virtually separate threads on the processors 154. The memory device 156 may also store data 160 accessible by the processors 154. The data 160 may include data indicating torque on the power gearbox 46, which will be described in more detail below.

[0066] The computing device 152 may also include a communication interface 162 for communicating, for example, with the gas turbine engine 10, the torque monitoring system 110, and / or other components of the computing device 152. The communication interface 162 may include any suitable components for interfacing with these components or one or more communication networks, including, for example, a transmitter, a receiver, a port, a controller, an antenna, a wired communication bus, or other suitable components. The control system 150 may also communicate with various sensors (such as the gearbox sensor 112 described above) (e.g., via the communication interface 162), and may selectively operate the gas turbine engine 10 in response to user input and feedback from these sensors. In addition, the control system may be configured to determine the torque on the power gearbox 46 via data received from the gearbox sensor 112 (such as data sensed by the gearbox sensor 112 indicating the deflection of the planet carrier 86 relative to the fourth frame member 108).

[0067] The technology discussed herein refers to computer-based systems, actions taken by computer-based systems, information sent to computer-based systems, and information from computer-based systems. It should be understood that the inherent flexibility of computer-based systems allows for multiple possible configurations, combinations, and divisions of tasks and functions between and among components. For example, the processing discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system or distributed on multiple systems. Distributed components can operate sequentially or in parallel.

[0068] Fig. 6A is a flow chart of a method 600 for monitoring and reducing torque within a gas turbine engine 10 according to an exemplary aspect of the present disclosure. Figure 6B is a method for monitoring and reducing Fig. 6A A graphical representation of a method 600 of torque.

[0069] In at least one example embodiment, method 600 includes receiving data indicating torque on the power gearbox 46 at 605, using the received data indicating torque on the power gearbox 46 to determine that the torque on the power gearbox 46 is less than a model torque for the power gearbox 46 at 610, and reducing fuel supply to the gas turbine engine 10 in response to determining that the torque on the power gearbox 46 is less than the model torque for the power gearbox 46 at 615.

[0070] In at least one example embodiment, the controller 122 is configured to receive data indicating the torque on the power gearbox 46 from the gearbox sensor 112 at 605. For example, the controller 122 may receive data indicating the torque on the power gearbox 46 from the gearbox sensor 112. Additionally or alternatively, the controller 122 may receive data indicating the torque on the power gearbox 46 from another sensor associated with the power gearbox 46 or the gas turbine engine.

[0071] Additionally, control system 150 may determine the torque on power gearbox 46 at 610 and determine whether the torque on power gearbox 46 is less than a model torque of power gearbox 46. The model torque may be determined based on a function of the speed of fan shaft 44, the pitch of fan blades 40 of fan 38, Mach number, ambient temperature, altitude, or a combination thereof.

[0072] refer to Figure 6B , the model torque may be represented by model torque line 620. Data received by controller 122 indicating the torque on power gearbox 46 is represented by torque line 625. Additionally, the supply of fuel to gas turbine engine 10 is represented by fuel supply line 630. If it is determined at 610 that the torque on power gearbox 46 is greater than or equal to the model torque of power gearbox 46, then gas turbine engine 10 is in normal operating mode. In normal operating mode, torque line 625 is higher than or greater than or equal to model torque line 620, as shown in FIG. Figure 6B If the gas turbine engine 10 is in a normal operating mode such that the torque on the power gearbox 46 at 610 is greater than or equal to the modeled torque of the power gearbox 46, the method 600 then proceeds to step 605 where data indicative of the torque on the power gearbox 46 is continuously monitored, such as by the gearbox sensor 112, and received by the controller 122 for monitoring by the control system 150.

[0073] If it is determined at 610 that the torque on the power gearbox 46 is less than the modeled torque of the power gearbox 46, then the fuel supply to the gas turbine engine 10 is reduced at 615. Figure 6B As shown, for example, the torque on the power gearbox 46 indicated by torque line 625 drops below the model torque line 620 at the fault point 640. In at least one example embodiment, the torque line 625 may drop below the model torque line 620 in the event of a shaft fault (such as the LP shaft 36, the fan shaft 44, or a combination thereof).

[0074] Additionally, when the torque line 625 drops below the model torque line 620, the gas turbine engine 10 may be in a shutdown mode, such as Figure 6BIf the gas turbine engine 10 is in shutdown mode such that the torque on the power gearbox 46 at 610 is less than the model torque of the power gearbox 46, the method 600 then proceeds to step 615 where the fuel supply to the gas turbine engine 10 is reduced. For example, Figure 6B As shown, fuel supply line 630 is reduced during shutdown period 645 compared to normal operating period 635 .

[0075] Fig. 7A is a flow chart of a method 700 for monitoring and reducing torque within a gas turbine engine 10 according to an exemplary aspect of the present disclosure. Figure 7B is a method for monitoring and reducing Fig. 7A A graphical representation of a method 700 of torque. Figure 7C is a method for monitoring and reducing Fig. 7A Another graphical representation of the method 700 of torque. More specifically, Figure 7B shows a shutdown condition, and Figure 7C A recovery condition of the gas turbine engine 10 in response to the torque on the power gearbox 46 exceeding one or more torque thresholds is shown.

[0076] In at least one example embodiment, the fan 38 of the gas turbine engine 10 may be a fixed pitch fan. Thus, the fan blades 40 of the fan 38 remain stationary. In such an embodiment, the method 700 includes receiving data indicating the torque on the power gearbox 46 at 705, using the received data indicating the torque on the power gearbox 46 to determine at 710 whether the torque on the power gearbox 46 exceeds the lower torque threshold 708 ( Figure 7B-7C ), at 715, in response to determining that the torque on the power gearbox 46 exceeds the lower torque threshold 708, performing at least one corrective action, at 720, using the received data indicating the torque on the power gearbox 46 to determine that the torque on the power gearbox exceeds the upper torque threshold 718 ( Figure 7B-7C ), reducing the fuel supply to the gas turbine engine 10 at 725 in response to determining that the torque on the power gearbox 46 exceeds the upper torque threshold 718, and determining at 730 that the torque on the power gearbox 46 is within the normal operating range 728 ( Figure 7B-7C shown).

[0077] In at least one example embodiment, the controller 122 is configured to receive data indicating the torque on the power gearbox 46. For example, the controller 122 may receive data indicating the torque on the power gearbox 46 from the gearbox sensor 112. Additionally or alternatively, the controller 122 may receive data indicating the torque on the power gearbox 46 from another sensor associated with the power gearbox 46 or the gas turbine engine 10.

[0078] At 710, the control system 150 may determine the torque on the power gearbox 46 based on the received data and determine whether the torque on the power gearbox 46 exceeds the lower torque threshold 708. If the torque on the power gearbox 46 does not exceed the lower torque threshold 708 at 710, the gas turbine engine 10 is operating in the normal operating mode. Figure 7B-7C , in the normal operating mode, the torque on the power gearbox 46 (represented by torque line 735) is less than or equal to the lower torque threshold 708, as shown during the normal operating period 740. In addition, if the torque on the power gearbox 46 does not exceed the lower torque threshold 708 at 710, the method 700 proceeds to step 705, where data indicative of the torque on the power gearbox 46 is continuously monitored, such as by the gearbox sensor 112, and received by the controller 122 for monitoring by the control system 150.

[0079] If the torque on the power gearbox 46 exceeds the lower torque threshold 708 at 710, at least one corrective action is taken at 715. Taking at least one corrective action at 715 includes reducing the rotational speed of the fan shaft 44, reducing the fuel flow rate of the gas turbine engine 10, or both. Figure 7B-7C , performing at least one corrective action at 715 may cause the gas turbine engine to operate at reduced thrust, as indicated during the reduced thrust period 750. The fuel supply to the gas turbine engine 10 during the reduced thrust period 750 may be reduced as compared to the fuel supply to the gas turbine engine 10 during the normal operation period 740, during which the fuel supply to the gas turbine engine may remain substantially constant or may be increased.

[0080] If the torque on the power gearbox 46 exceeds the upper torque threshold 718 at 720, the fuel supply to the gas turbine engine 10 may be reduced at 725. The fuel supply to the gas turbine engine 10 may be reduced during the reduced thrust period 750. Figure 7BAs shown, if the torque on the power gearbox 46 (as indicated by torque line 735) continues to increase during the reduced thrust period 750, such that the torque on the power gearbox 46 is greater than the upper torque threshold 718, the fuel supply to the gas turbine engine 10 may be cut off. For example, the fuel supply to the gas turbine engine 10 may be cut off during the shutdown period 755 to allow the torque on the power gearbox 46 to decrease. Figure 7B As shown, fuel supply line 745 goes to approximately zero (0) during shutdown period 755 and torque line 735 decreases.

[0081] If the torque on the power gearbox 46 does not exceed the upper torque threshold 718 at 720, the method 700 continues to determine whether the torque on the power gearbox 46 is within a normal operating range 728 at 730. The normal operating range 728 may be less than the lower torque threshold 708. In addition, the lower torque threshold 708 may be greater than the normal operating range 728, and the upper torque threshold 718 may be greater than the lower torque threshold 708.

[0082] If the torque on the power gearbox 46 is not within the normal operating range 728 at 730, the method 700 returns to step 715 where at least one corrective action is performed. After performing at least one corrective action at 715, the method returns to step 720 to determine whether the torque on the power gearbox 46 exceeds the upper torque threshold 718. If the torque still does not exceed the upper torque threshold 718 at 720, the method returns to step 730 to determine whether the torque on the power gearbox 46 is within the normal operating range 728 at 730. Therefore, the method 700 includes an iterative loop 760 that is configured to reduce the torque on the power gearbox 46 until the torque on the power gearbox 46 is within the normal operating range 728. For example, the iterative loop 760 includes performing at least one corrective action at 715 while the torque on the power gearbox 46 remains less than the upper torque threshold 718 during the reduced thrust period 750 until the torque on the power gearbox 46 is within the normal operating range 728. As shown in FIG. Figure 7C As shown, during the second normal operating period 765, the torque on the power gearbox 46 returns to within the normal operating range 728. Figure 7C In the example embodiment shown, after exceeding the lower torque threshold 708 and taking at least one corrective action during the reduced thrust period 750 , the torque on the power gearbox 46 is restored or returned to within the normal operating range 728 .

[0083] refer to Figure 7CDuring at least a portion of the reduced thrust period 750, the fuel supplied to the gas turbine engine 10 is reduced, as indicated by the fuel supply line 745. Reducing the fuel supply to the gas turbine engine 10 may reduce the torque on the power gearbox 46, as indicated by the torque line 735. Once the torque on the power gearbox 46 is less than or equal to the lower torque threshold 708, the fuel supply to the gas turbine engine 10 may be increased, as indicated by the fuel supply line 745. Figure 7C Additionally, if the torque on the power gearbox 46 is within the normal operating range 728 at 730, the gas turbine engine is in the normal operating mode, as shown during the second normal operating period 765. Thus, the method 700 proceeds from determining at 730 that the torque on the power gearbox 46 is within the normal operating range 728 to step 705, where data indicative of the torque on the power gearbox 46 is continuously monitored, such as by the gearbox sensor 112, and received by the controller 122 for monitoring by the control system 150.

[0084] Fig. 8A is a flow chart of a method 800 for monitoring and reducing torque within a gas turbine engine 10 according to an exemplary aspect of the present disclosure. Figure 8B is a method for monitoring and reducing Fig. 8A A graphical representation of method 800 of torque. Figure 8C is a method for monitoring and reducing Fig. 8A Another graphical representation of the method 800 of torque. More specifically, Figure 8B shows a shutdown condition, and Figure 8C A recovery condition of the gas turbine engine 10 in response to the torque on the power gearbox 46 exceeding one or more torque thresholds is shown.

[0085] In at least one example embodiment, the fan 38 of the gas turbine engine 10 may be a variable pitch fan. Thus, the pitch of one or more of the fan blades 40 of the fan 38 may be adjusted. In such an embodiment, the method 800 includes receiving data indicating the torque on the power gearbox 46 at 805, determining that the torque on the power gearbox 46 exceeds the normal operating range 728 using the received data indicating the torque on the power gearbox 46 at 810, and determining that the torque on the power gearbox 46 exceeds the lower torque threshold 708 using the received data indicating the torque on the power gearbox 46 at 815. Based on the torque on the power gearbox 46 exceeding the lower torque threshold 708 at 815, the method 800 includes taking a first corrective action at 820, determining that the torque on the power gearbox 46 is less than or equal to the middle torque threshold 823 (e.g., at 835). Figures 8B-8C), and determining at 840 that the torque on the power gearbox 46 is within the normal operating range 728. Based on the torque on the power gearbox 46 not exceeding or less than or equal to the lower torque threshold 708 at 815, the method 800 includes taking a second corrective action at 845, determining at 860 that the torque on the power gearbox 46 is less than or equal to the upper torque threshold 718, reducing the fuel supply to the gas turbine engine 10 at 865, and determining at 870 that the torque on the power gearbox 46 is within the normal operating range 728.

[0086] In at least one example embodiment, the controller 122 is configured to receive data indicating the torque on the power gearbox 46 at 805. For example, the controller 122 is configured to receive data indicating the torque on the power gearbox 46 from the gearbox sensor 112. Additionally or alternatively, the controller 122 may be configured to receive data indicating the torque on the power gearbox 46 from another sensor associated with the power gearbox 46 or the gas turbine engine 10. Further, at 810, the control system 150 may determine the torque on the power gearbox 46 based on the received data, and determine whether the torque on the power gearbox 46 exceeds the normal operating range 728.

[0087] If the torque on the power gearbox 46 does not exceed the normal operating range 728 at 810, the gas turbine engine 10 is operating in the normal operating mode. Figures 8B-8C , in the normal operating mode, the torque on the power gearbox 46 (represented by torque line 735) is less than or equal to the normal operating range 728, as shown during the normal operating period 740. During the normal operating period 740, the torque on the power gearbox 46 may also be less than or equal to the lower torque threshold 708. In addition, if the torque on the power gearbox 46 does not exceed the normal operating range 728 at 810, the method 800 returns to step 805, where data indicative of the torque on the power gearbox 46 is continuously monitored, such as by the gearbox sensor 112, and received by the controller 122 for monitoring by the control system 150.

[0088] If the torque on the power gearbox 46 exceeds the normal operating range 728 at 810, the method 800 continues to determine whether the torque on the power gearbox 46 exceeds the lower torque threshold 708 at 815. If the torque on the power gearbox 46 exceeds the lower torque threshold 708 at 815, a first corrective action is performed at 820. The first corrective action performed at 820 may include multiple corrective actions. For example, the first corrective action performed at 820 may include adjusting the pitch of one or more of the fan blades 40 of the fan 38 at 825, increasing the speed of the fan 38 at 830, or both.

[0089] refer to Figures 8A-8B , the first corrective action performed at 820 may be performed during the first adaptation period 872. The first corrective action performed at 820 during the first adaptation period 872 may include an action requiring a longer time constant. For example, reducing the torque on the power gearbox 46 in response to changing the pitch of one or more of the fan blades 40 of the fan 38 may require a longer time than reducing the fuel supply to the gas turbine engine 10. It may be beneficial to first perform an action requiring a longer time constant in order to maintain engine power and thrust before performing an action that requires adjusting the fuel supply and shutting down the gas turbine engine 10.

[0090] After taking the first corrective action at 820, method 800 continues at 835 to determine whether the torque on the power gearbox 46 exceeds the medium torque threshold 823. Figures 8B-8C As shown, the intermediate torque threshold 823 is greater than the lower torque threshold 708 and less than the upper torque threshold 718. The intermediate torque threshold 823 is a threshold at which the control system 150 may begin to take additional actions, such as in addition to the first corrective action taken at 820, to reduce the torque on the power gearbox 46. For example, if the intermediate torque threshold 823 is exceeded, the control system 150 may begin to take actions to reduce thrust in order to reduce the torque on the power gearbox 46, as will be discussed in more detail below.

[0091] If the torque on the power gearbox 46 does not exceed the middle torque threshold 823 at 835, the method 800 continues to determine whether the torque on the power gearbox 46 is within the normal operating range 728 at 840. If the torque on the power gearbox 46 is within the normal operating range 728, the method 800 returns to step 805. If the torque on the power gearbox 46 is outside the normal operating range 728, such as greater than the normal operating range 728, the method 800 returns to taking the first corrective action at 820. Therefore, the method 800 includes a first iterative loop 880 for reducing the torque on the power gearbox 46 to below the middle torque threshold 823 and the lower torque threshold 708.

[0092] refer to Figure 8C , the torque on the power gearbox 46 does not exceed the medium torque threshold 823, as indicated by torque line 735. During the first adaptation period 872, the first corrective action taken at 820 may have been taken at least once, such as via a first iteration loop 880, to reduce the torque on the power gearbox 46 to below the medium torque threshold 823. For example, the pitch of one or more of the fan blades 40 of the fan 38 may have been adjusted during the first adaptation period 872, as indicated by pitch line 875. Still referring to Figure 8C, the torque on the power gearbox 46 is also reduced during the first adaptation period 872 in response to the change in pitch. In addition, because the first corrective action at 820 during the first adaptation period 872 reduces the torque on the power gearbox 46, the fuel supply to the gas turbine engine 10 is maintained, as indicated by the fuel supply line 745, so that the power and thrust of the gas turbine engine 10 do not need to be affected.

[0093] like Figure 8C As shown, after the first adaptation period 872, the torque on the power gearbox 46 recovers or returns to the normal operating range 728 during the second normal operating period 878. For example, in the second normal operating period 878, the torque on the power gearbox 46 is lower than the normal operating range 728. Fig. 8A , at 840 the torque on the power gearbox is within the normal operating range 728 and the method 800 returns to step 805 .

[0094] Reference again Fig. 8A If, at 835, the torque on the power gearbox 46 exceeds the middle torque threshold 823, the method 800 continues with a second corrective action at 845. Additionally, if, at 815, the torque on the power gearbox 46 does not exceed (such as is less than or equal to) the lower torque threshold 708, the method 800 also continues with a second corrective action at 845.

[0095] In at least one example embodiment, performing the second corrective action at 845 includes performing a plurality of actions. For example, performing the second corrective action at 845 includes reducing the rotational speed of the fan 38 at 850, reducing the fuel supply to the gas turbine engine 10 at 850, adjusting the pitch of one or more of the fan blades 40 of the fan 38 to a failsafe speed schedule at 855, or a combination thereof. Additionally, in some example embodiments, performing the second corrective action at 845 may include adjusting a bleed air flow from a working gas flow path of the gas turbine engine 10 via a variable bleed valve. After performing the second corrective action at 845, the method 800 continues at 860 to determine whether the torque on the power gearbox 46 exceeds the upper torque threshold 718.

[0096] If the torque on the power gearbox 46 does not exceed the upper torque threshold 718 at 860, the method 800 continues to determine whether the torque on the power gearbox 46 is within the normal operating range 728 at 870. If the torque on the power gearbox 46 is within the normal operating range 728 at 870, the method 800 returns to step 805. If the torque on the power gearbox 46 is not within the normal operating range 728 at 870, the method 870 returns to taking a second corrective action at 845. Therefore, the method 800 includes a second iterative loop 885 for reducing the torque on the power gearbox 46 to below the upper torque threshold 718 and the lower torque threshold 708.

[0097] If the torque on the power gearbox 46 exceeds the upper torque threshold 718 at 860, the method 800 continues to reduce the fuel supply to the gas turbine engine 10 at 865. In at least one example embodiment, reducing the fuel supply to the gas turbine engine 10 at 865 includes shutting off the fuel supply to the gas turbine engine 10, as will be described below with reference to Figure 8B discussed in more detail.

[0098] refer to Figures 8B-8C , during the normal operating period 740, the torque on the power gearbox 46 may be within the normal operating range 728, or less than or equal to the lower torque threshold 708. As shown during the first adaptation period 872, if the torque on the power gearbox 46 exceeds the normal operating range 728 at 810, and exceeds the lower torque threshold 708 at 815, a first corrective action may be taken at 820. After the first corrective action is taken at 820, and if the torque on the power gearbox 46 does not exceed the middle torque threshold 823 at 835, the first iterative loop 880 may be repeated until the torque on the power gearbox 46 is within the normal operating range at 840. Therefore, as shown during the first adaptation period 872, Figure 8C As shown, during the second normal operation period 878 after the first adaptation period 872 , the torque on the power gearbox 46 may be within the normal operating range 728 .

[0099] If the torque on the power gearbox 46 exceeds the medium torque threshold 823 at 835, the method 800 continues with a second corrective action at 845. The second corrective action at 835 may be Figure 8B The corrective action or actions performed during the second adaptation period 874 may require a faster time constant. For example, such actions may reduce the torque on the power gearbox 46 faster than the corrective actions performed during the first adaptation period 872.

[0100] If, after taking the second corrective action at 845, the torque on the power gearbox 46 does not exceed the upper torque threshold 718 at 860, the method 800 continues to determine whether the torque on the power gearbox 46 is within the normal operating range 728 at 870. If the torque on the power gearbox 46 is within the normal operating range 728 at 870, the method returns to step 805. If the torque on the power gearbox 46 is outside the normal operating range 728 at 870, a second iterative loop 885 may be repeated, such as during a second adaptation period 874, until the torque on the power gearbox 46 is within the normal operating range 728 at 870. For example, in Figure 8B After the second adaptation period 874 shown, the torque on the power gearbox 46 may be such as at Figure 8C The second normal operating period 878 is shown as being within the normal operating range 728 .

[0101] If the second iteration loop 885 is performed such that the second corrective action performed at 845 does not reduce the torque on the power gearbox 46 to within the normal operating range 728, and the torque on the power gearbox 46 exceeds the upper torque threshold 718 at 860, then the fuel supply to the gas turbine engine 10 is reduced at 865. For example, if Figure 8B As shown, despite the fuel supply being reduced as indicated by fuel supply line 745, during the second adaptation period 874, the torque on the power gearbox 46 continues to increase to the upper torque threshold 718, as indicated by torque line 735. In response, the fuel supply to the gas turbine engine 10 may be further reduced at 865. Additionally or alternatively, the fuel supply to the gas turbine engine 10 may be cut off to allow the torque on the power gearbox 46 to be reduced during the shutdown period 876 of the gas turbine engine 10. For example, Figure 8B As shown, the fuel supply line 745 decreases to approximately zero (0) between the second adaptation period 874 and the shutdown period 876 , and the torque on the power gearbox 46 , indicated by the torque line 735 , decreases during the shutdown period 876 .

[0102] Fig. 9 is a flow chart of a method 900 for determining torque and thrust within a gas turbine engine 10 according to an exemplary aspect of the present disclosure. The method 900 may be incorporated into reference Figures 6A-8C For example, method 900 may be used to determine the torque received at step 605 of method 600 , step 705 of method 700 , and step 805 of method 800 .

[0103] In at least one example embodiment, method 900 includes, at 905, using data indicating the torque on the power gearbox 46 to determine the torque on the power gearbox 46, determining the speed of the fan 38, or both; at 910, determining the thrust of the gas turbine engine 10 based on one or both of the torque on the power gearbox 46 and the speed of the fan 38; and at 915, controlling the fuel supply to the gas turbine engine 10 based on the determined thrust.

[0104] In at least one example embodiment, the controller 122 is configured to receive data indicating the torque on the power gearbox 46. For example, the controller 122 may receive data indicating the torque on the power gearbox 46 from the gearbox sensor 112. Additionally or alternatively, the controller 122 may receive data indicating the torque on the power gearbox 46 from another sensor associated with the power gearbox 46 or the gas turbine engine 10. The controller 122 may also be configured to receive the rotational speed of the fan 38. Therefore, the control system 150 may determine the torque on the power gearbox 46, determine the rotational speed of the fan 38, or both based on the data indicating the torque on the power gearbox 46 at 905.

[0105] In response to determining the torque on the power gearbox 46 at 905, the control system 150 may determine the thrust of the gas turbine engine 10 at 910. The fuel supply to the gas turbine engine 10 may be controlled and adjusted based on the thrust of the gas turbine engine 10 at 915. Thus, the thrust of the gas turbine engine 10 may be determined and controlled based on the torque applied by the fan 38 to the power gearbox 46.

[0106] Fig.10 is a flow chart of a method 1000 for determining torque within a gas turbine engine 10 according to an exemplary aspect of the present disclosure. The method 1000 may be incorporated into reference Figures 6A-8C For example, method 1000 may be used to determine the torque received at step 605 of method 600 , step 705 of method 700 , and step 805 of method 800 .

[0107] In at least one example embodiment, method 1000 includes determining a first shaft speed of a first shaft at 1005, determining a second shaft speed of a second shaft at 1010, determining a first rate of change of the first shaft speed at 1015, determining a second rate of change of the second shaft speed at 1020, and calculating a torque on a power gearbox 46 based on the first rate of change and the second rate of change at 1025.

[0108] In at least one example embodiment, the first shaft includes the fan shaft 44, and the second shaft includes the LP shaft 36. Determining the first shaft speed of the first shaft at 1005 may include receiving data indicating a rotational speed of the fan shaft 44 from a first speed sensor coupled to the fan shaft 44. Additionally, determining the second shaft speed of the second shaft at 1010 may include receiving data indicating a rotational speed of the LP shaft 36 from a second speed sensor coupled to the LP shaft 36.

[0109] In at least one example embodiment, the controller 122 receives the first shaft speed and the second shaft speed from the first speed sensor and the second speed sensor. The control system 150 can determine a first rate of change of the first shaft speed at 1015 and a second rate of change of the second shaft speed at 1020 based on the first shaft speed and the second shaft speed, respectively.

[0110] The control system 150 may derive the torque on the power gearbox 46 from the first rate of change and the second rate of change at 1025. For example, the control system 150 may calculate the difference between the first rate of change and the second rate of change to determine the torque on the power gearbox 46. Additionally or alternatively, the control system 150 may determine a ratio of the first rate of change to the second rate of change. Based on the determined torque on the power gearbox 46, the control system 150 may adjust the fuel supply to the gas turbine engine 10.

[0111] Thus, systems and methods for detecting and reducing torque in a gas turbine engine are disclosed herein. For example, the torque on a power gearbox may be determined based on a static reference frame rather than a rotating reference frame. In some example embodiments, a sensor may be provided adjacent to the static side of the power gearbox to measure the torque reacted by the stator side of the power gearbox. Such torque measurement may allow the use of a smaller sensor, thereby allowing the use of a smaller power gearbox.

[0112] Further aspects are provided by the subject matter of the following clauses:

[0113] A gas turbine engine comprises: a fan section, the fan section including a fan capable of rotating with a fan shaft; a turbomachinery section, the turbomachinery section including a turbine and a turbine shaft capable of rotating with the turbine; a power gearbox, the power gearbox being mechanically coupled to the fan shaft and the turbine shaft so that the fan shaft can be rotated across the power gearbox by the turbine shaft; a grounding structure, the grounding structure being coupled to the power gearbox and supporting the power gearbox; and a torque monitoring system, the torque monitoring system including a gearbox sensor, the gearbox sensor being coupled to the grounding structure, the torque monitoring system being configured to determine the torque on the power gearbox using the gearbox sensor.

[0114] A gas turbine engine as described in any preceding clause, wherein the ground engaging structure is stationary.

[0115] A gas turbine engine as described in any preceding clause, wherein the power gearbox comprises an epicyclic power gearbox or a compound epicyclic power gearbox including a static member coupled to the ground engaging structure.

[0116] A gas turbine engine according to any one of the preceding clauses, wherein the power gearbox comprises: a sun gear, the sun gear comprising a plurality of teeth, the sun gear being drivingly connected to the turbine shaft of the gas turbine engine; a plurality of planetary gears, the plurality of planetary gears surrounding the sun gear, each of the planetary gears comprising a plurality of teeth meshing with the teeth of the sun gear, so that rotation of the sun gear causes rotation of each of the plurality of planetary gears; a ring gear, the ring gear surrounding the plurality of planetary gears, the ring gear comprising a plurality of teeth meshing with the teeth of each of the planetary gears, so that the ring gear rotates relative to the plurality of planetary gears; and a planet carrier, the planet carrier being connected to each of the plurality of planetary gears and the grounding structure, so that the planet carrier supports the power gearbox relative to the grounding structure.

[0117] The gas turbine engine according to any of the preceding clauses, further comprising: a frame, wherein the ground engaging structure is coupled to the frame of the gas turbine engine.

[0118] A gas turbine engine as described in any preceding clause, wherein the gearbox sensor is operable to sense data indicative of deflection of the ground engaging structure to thereby determine the torque on the power gearbox.

[0119] A gas turbine engine according to any preceding clause, wherein the planet carrier and the frame are stationary.

[0120] A gas turbine engine according to any of the preceding clauses, wherein the frame is a front frame of the gas turbine engine.

[0121] A gas turbine engine according to any of the preceding clauses, wherein the turbine is a low pressure turbine, wherein the turbine shaft is a low pressure shaft.

[0122] A gas turbine engine as described in any of the preceding clauses, wherein the turbomachinery section further comprises a low pressure compressor rotatable with the low pressure shaft.

[0123] A gas turbine engine as described in any preceding clause, wherein the gearbox sensor comprises a load cell, a strain gauge, a torque tube or a combination thereof.

[0124] A gas turbine engine as described in any preceding clause, wherein the torque monitoring system comprises a controller, and wherein the controller is operably coupled to the gearbox sensor.

[0125] A gas turbine engine according to any of the preceding clauses, wherein the controller is constructed to: receive data indicating the torque on the power gearbox; use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox is less than a model torque of the power gearbox; and reduce the fuel supply to the gas turbine engine in response to determining that the torque on the power gearbox is less than the model torque of the power gearbox.

[0126] A gas turbine engine as described in any preceding clause, wherein data indicative of the torque on the power gearbox is received from the gearbox sensor.

[0127] A gas turbine engine according to any of the preceding clauses, wherein the model torque is determined based on a function of the speed of the fan shaft, the pitch of the fan's blades, the Mach number, the ambient temperature, the altitude or a combination thereof.

[0128] A gas turbine engine according to any of the preceding clauses, wherein: the fan includes a fixed pitch fan; and the controller is constructed to: receive data indicating the torque on the power gearbox; use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds a lower torque threshold; in response to determining that the torque on the power gearbox exceeds the lower torque threshold, perform at least one corrective action; use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds an upper torque threshold; and reduce the fuel supply to the gas turbine engine in response to determining that the torque on the power gearbox exceeds the upper torque threshold.

[0129] A gas turbine engine as described in any preceding clause, wherein data indicative of the torque on the power gearbox is received from the gearbox sensor.

[0130] The gas turbine engine of any of the preceding clauses, wherein the at least one corrective action comprises reducing the rotational speed of the fan shaft, reducing fuel flow to the gas turbine engine, or both.

[0131] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox is less than or equal to the upper torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox is within a normal operating range.

[0132] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox is less than or equal to the upper torque threshold; in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox is outside the normal operating range; and perform at least one corrective action in response to determining that the torque on the power gearbox is outside the normal operating range.

[0133] A gas turbine engine as claimed in any preceding clause, wherein the lower torque threshold is above the normal operating range, and wherein the upper torque threshold is above the lower torque threshold.

[0134] A gas turbine engine according to any of the preceding clauses, wherein: the fan includes a variable pitch fan; and the controller is constructed to: receive data indicating the torque on the power gearbox; use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds a normal operating range; in response to determining that the torque on the power gearbox exceeds the normal operating range, use the received data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds a lower torque threshold; in response to determining that the torque on the power gearbox exceeds the lower torque threshold, perform a first corrective action; and in response to determining that the torque on the power gearbox is less than or equal to the lower torque threshold, perform a second corrective action.

[0135] A gas turbine engine as described in any preceding clause, wherein data indicative of the torque on the power gearbox is received from the gearbox sensor.

[0136] A gas turbine engine according to any of the preceding clauses, wherein: the first corrective action comprises adjusting the pitch of one or more blades of the fan, increasing the rotational speed of the fan, or both; and the second corrective action comprises reducing the rotational speed of the fan, reducing the fuel flow to the gas turbine engine, adjusting the pitch of one or more blades of the fan to a failsafe speed plan, adjusting the bleed air flow from the working gas flow path of the gas turbine engine via a variable bleed valve, or a combination thereof.

[0137] A gas turbine engine according to any of the preceding clauses, wherein, in response to determining that the torque on the power gearbox exceeds the lower torque threshold, the controller is further constructed to: determine that the torque on the power gearbox is less than or equal to a middle torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the middle torque threshold, determine that the torque on the power gearbox is within the normal operating range.

[0138] A gas turbine engine according to any of the preceding clauses, wherein, in response to determining that the torque on the power gearbox is less than or equal to the medium torque threshold, the controller is further constructed to: determine that the torque on the power gearbox is outside the normal operating range; perform the first corrective action; determine that the torque on the power gearbox is less than or equal to the medium torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the medium torque threshold, determine that the torque on the power gearbox is within the normal operating range.

[0139] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox exceeds the middle torque threshold; and in response to the torque on the power gearbox exceeding the middle torque threshold, perform the second corrective action to determine that the torque on the power gearbox is less than or equal to an upper torque threshold, and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determine that the torque on the power gearbox is within the normal operating range.

[0140] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox exceeds the upper torque threshold; and in response to the torque on the power gearbox exceeding the upper torque threshold, reduce the fuel flow to the gas turbine engine.

[0141] A gas turbine engine according to any of the preceding clauses, wherein, in response to the torque on the power gearbox being less than or equal to the upper torque threshold, the controller is further constructed to: determine that the torque on the power gearbox is outside the normal operating range; and in response to determining that the torque on the power gearbox is outside the normal operating range, perform the second corrective action to determine that the torque on the power gearbox is less than or equal to the upper torque threshold, and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determine that the torque on the power gearbox is within the normal operating range.

[0142] A gas turbine engine according to any of the preceding clauses, wherein, in response to determining that the torque on the power gearbox is less than or equal to the lower torque threshold and performing the second corrective action, the controller is further constructed to: determine that the torque on the power gearbox is less than or equal to an upper torque threshold; and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determine that the torque on the power gearbox is within the normal operating range.

[0143] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox exceeds the upper torque threshold; and in response to the torque on the power gearbox exceeding the upper torque threshold, reduce the fuel flow to the gas turbine engine.

[0144] A gas turbine engine according to any of the preceding clauses, wherein the controller is further constructed to: determine that the torque on the power gearbox is outside the normal operating range; and in response to determining that the torque on the power gearbox is outside the normal operating range, reduce the speed of the fan, reduce the fuel flow to the gas turbine engine, or both reduce the speed of the fan and reduce the fuel flow to the gas turbine engine, adjust the pitch of one or more blades of the fan to a failsafe speed plan, determine that the torque on the power gearbox is less than or equal to the upper torque threshold, and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determine that the torque on the power gearbox is healthy.

[0145] A gas turbine engine according to any of the preceding clauses, wherein the controller is constructed to: determine the torque on the power gearbox, determine the speed of the fan, or both determine the torque on the power gearbox and determine the speed of the fan using data indicating the torque on the power gearbox; determine thrust based on one or both of the torque on the power gearbox and the speed of the fan; and control fuel flow to the gas turbine engine based on the determined thrust.

[0146] A gas turbine engine as described in any preceding clause, wherein the controller is configured to receive data indicative of the torque on the power gearbox from the gearbox sensor.

[0147] A method for operating a gas turbine engine, the gas turbine engine comprising a fan section, a turbomachinery section and a power gearbox, the fan section having a fan capable of rotating together with a fan shaft, the turbomachinery section having a turbine and a turbine shaft capable of rotating together with the turbine, the power gearbox being mechanically connected to the fan shaft and the turbine shaft, the method comprising: receiving data indicating a torque on the power gearbox of the gas turbine engine; using the data indicating the torque on the power gearbox to determine that the torque on the power gearbox is less than a model torque of the power gearbox; and reducing the fuel supply to the gas turbine engine in response to determining that the torque on the power gearbox is less than the model torque of the power gearbox.

[0148] A method according to any of the preceding clauses, wherein determining the torque on the power gearbox comprises: determining a first shaft speed of a first shaft; determining a second shaft speed of a second shaft; determining a first rate of change of the first shaft speed; determining a second rate of change of the second shaft speed; and calculating the torque on the power gearbox based on the first rate of change and the second rate of change.

[0149] A method as in any preceding clause, wherein: the first shaft comprises the fan shaft; and the second shaft comprises the turbine shaft.

[0150] A method according to any of the preceding clauses, wherein determining the torque on the power gearbox comprises receiving data indicative of the torque from a gearbox sensor of a torque monitoring system, the gearbox sensor being coupled to a ground structure of the gas turbine engine, the ground structure being coupled to and supporting the power gearbox.

[0151] A method for a gas turbine engine, the gas turbine engine comprising a fan section, a turbomachinery section and a power gearbox, the fan section having a fan capable of rotating together with a fan shaft, the turbomachinery section having a turbine and a turbine shaft capable of rotating together with the turbine, the power gearbox being mechanically connected to the fan shaft and the turbine shaft, the method comprising: using data indicating the torque on the power gearbox to determine that the torque on the power gearbox is greater than a lower torque threshold; in response to determining that the torque on the power gearbox exceeds the lower torque threshold, performing at least one corrective action; using data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds an upper torque threshold; and reducing fuel supply to the gas turbine engine in response to determining that the torque on the power gearbox exceeds the upper torque threshold.

[0152] A method as in any preceding clause, wherein the fan comprises a fixed pitch fan.

[0153] The method of any of the preceding clauses, wherein the at least one corrective action comprises reducing the rotational speed of the fan shaft, reducing fuel flow to the gas turbine engine, or both.

[0154] The method according to any of the preceding clauses further includes: determining that the torque on the power gearbox is less than or equal to the upper torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, using data indicating the torque on the power gearbox to determine that the torque on the power gearbox is within a normal operating range.

[0155] A method as in any preceding clause, wherein the lower torque threshold is above the normal operating range, and wherein the upper torque threshold is above the lower torque threshold.

[0156] The method according to any of the preceding clauses further includes: determining that the torque on the power gearbox is less than or equal to the upper torque threshold; in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, using data indicating the torque on the power gearbox to determine that the torque on the power gearbox is outside the normal operating range; and performing the at least one corrective action in response to determining that the torque on the power gearbox is outside the normal operating range.

[0157] A method according to any one of the preceding clauses, wherein: the at least one corrective action includes a first corrective action and a second corrective action; and the method further includes: using data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds a normal operating range; in response to determining that the torque on the power gearbox exceeds the normal operating range, using data indicating the torque on the power gearbox to determine that the torque on the power gearbox exceeds the lower torque threshold; in response to determining that the torque on the power gearbox exceeds the lower torque threshold, performing the first corrective action; and in response to determining that the torque on the power gearbox is less than or equal to the lower torque threshold, performing the second corrective action.

[0158] A method as in any preceding clause, wherein the fan comprises a variable pitch fan.

[0159] A method according to any of the preceding clauses, wherein: the first corrective action includes adjusting the pitch of one or more blades of the fan, increasing the speed of the fan, or both; and the second corrective action includes reducing the speed of the fan, reducing the fuel flow to the gas turbine engine, adjusting the pitch of one or more blades of the fan to a failsafe speed plan, or a combination thereof.

[0160] The method according to any of the preceding clauses further includes: in response to performing the first corrective action, determining that the torque on the power gearbox is less than or equal to a medium torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the medium torque threshold, determining that the torque on the power gearbox is within the normal operating range.

[0161] A method according to any one of the preceding clauses, wherein, in response to determining that the torque on the power gearbox is less than or equal to the middle torque threshold, the method further includes: determining that the torque on the power gearbox is outside the normal operating range; performing the first corrective action; determining that the torque on the power gearbox is less than or equal to the middle torque threshold; and in response to determining that the torque on the power gearbox is less than or equal to the middle torque threshold, determining that the torque on the power gearbox is within the normal operating range.

[0162] The method according to any of the preceding clauses further includes: determining that the torque on the power gearbox exceeds the middle torque threshold; performing the second corrective action to determine that the torque on the power gearbox is less than or equal to the upper torque threshold, and in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, determining that the torque on the power gearbox is within the normal operating range.

[0163] A method according to any of the preceding clauses, further comprising: determining that the torque on the power gearbox exceeds the upper torque threshold; and reducing fuel flow to the gas turbine engine.

[0164] A method as in any preceding clause, wherein the lower torque threshold is above the normal operating range, the intermediate torque threshold is above the lower torque threshold, and wherein the upper torque threshold is above the intermediate torque threshold.

[0165] The method according to any of the preceding clauses further includes: determining that the torque on the power gearbox is outside the normal operating range; performing the second corrective action in response to determining that the torque on the power gearbox is outside the normal operating range; determining that the torque on the power gearbox is less than or equal to the upper torque threshold; and determining that the torque on the power gearbox is within the normal operating range in response to the torque on the power gearbox being less than or equal to the upper torque threshold.

[0166] The method according to any of the preceding clauses further includes: in response to performing the second corrective action, determining that the torque on the power gearbox is less than or equal to the upper torque threshold; and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determining that the torque on the power gearbox is within the normal operating range.

[0167] The method according to any of the preceding clauses further includes: in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determining that the torque on the power gearbox is outside the normal operating range; performing the second corrective action; determining that the torque on the power gearbox is less than or equal to the upper torque threshold; and in response to the torque on the power gearbox being less than or equal to the upper torque threshold, determining that the torque on the power gearbox is within the normal operating range.

[0168] The method according to any of the preceding clauses further includes: in response to performing the second corrective action, determining that the torque on the power gearbox exceeds the upper torque threshold; and in response to the torque on the power gearbox exceeding the upper torque threshold, reducing the fuel flow to the gas turbine engine.

[0169] A method according to any of the preceding clauses, wherein determining the torque on the power gearbox comprises: determining a first shaft speed of a first shaft; determining a second shaft speed of a second shaft; determining a first rate of change of the first shaft speed; determining a second rate of change of the second shaft speed; and calculating the torque on the power gearbox based on the first rate of change and the second rate of change.

[0170] A method as in any preceding clause, wherein: the first shaft comprises the fan shaft; and the second shaft comprises the turbine shaft.

[0171] A method according to any of the preceding clauses, wherein receiving data indicating the torque on the power gearbox comprises: receiving data indicating the torque on the power gearbox from a gearbox sensor of a torque monitoring system, the gearbox sensor being connected to a grounding structure of the gas turbine engine, the grounding structure being connected to the power gearbox and supporting the power gearbox.

[0172] This written description uses examples to disclose the present disclosure, including the best mode, and also to enable any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined method. The patentable scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. These other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims.

Claims

1. A gas turbine engine, characterized in that: include: a fan section including a fan rotatable with a fan shaft; a turbomachinery section including a turbine and a turbine shaft rotatable with the turbine; a power gearbox mechanically coupled to the fan shaft and the turbine shaft such that the fan shaft can be rotated by the turbine shaft across the power gearbox; a grounding structure coupled to the power gearbox and supporting the power gearbox; as well as A torque monitoring system includes a gearbox sensor coupled to the ground engaging structure, the torque monitoring system being configured to determine torque on the power gearbox using the gearbox sensor.

2. The gas turbine engine according to claim 1, characterized in that in, The power gearbox comprises an epicyclic power gearbox or a compound epicyclic power gearbox including a static member coupled to the ground engaging structure.

3. The gas turbine engine according to claim 1, characterized in that in, The power gearbox comprises: a sun gear including a plurality of teeth, the sun gear drivingly coupled to the turbine shaft of the gas turbine engine; a plurality of planet gears surrounding the sun gear, each of the planet gears including a plurality of teeth meshing with the teeth of the sun gear such that rotation of the sun gear causes rotation of each of the plurality of planet gears; a ring gear surrounding the plurality of planet gears, the ring gear including a plurality of teeth meshing with the teeth of each of the planet gears such that the ring gear rotates relative to the plurality of planet gears; and A planet carrier is coupled to each of the plurality of planet gears and the grounding structure such that the planet carrier supports the power gearbox relative to the grounding structure.

4. The gas turbine engine according to claim 3, characterized in that Further including: A frame is provided, wherein the grounding structure is coupled to the frame of the gas turbine engine.

5. The gas turbine engine according to claim 4, characterized in that in, The gearbox sensor is operable to sense data indicative of deflection of the ground engaging structure to thereby determine the torque on the power gearbox.

6. The gas turbine engine according to claim 1, characterized in that in, The torque monitoring system includes a controller, and wherein the controller is operably coupled to the gearbox sensor.

7. The gas turbine engine according to claim 6, characterized in that in: The fan comprises a fixed pitch fan; and The controller is constructed as follows: receiving data indicative of the torque on the power gearbox; using the received data indicative of the torque on the power gearbox to determine that the torque on the power gearbox exceeds a lower torque threshold; in response to determining that the torque on the power gearbox exceeds the lower torque threshold, performing at least one corrective action; using the received data indicative of the torque on the power gearbox to determine that the torque on the power gearbox exceeds an upper torque threshold; and In response to determining that the torque on the power gearbox exceeds the upper torque threshold, fuel supply to the gas turbine engine is reduced.

8. The gas turbine engine according to claim 7, characterized in that in, The at least one corrective action includes reducing the rotational speed of the fan shaft, reducing fuel flow to the gas turbine engine, or both.

9. The gas turbine engine according to claim 7, characterized in that in, The controller is further configured as follows: determining that the torque on the power gearbox is less than or equal to the upper torque threshold; and In response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, using the received data indicative of the torque on the power gearbox to determine that the torque on the power gearbox is within a normal operating range.

10. The gas turbine engine according to claim 7, characterized in that in, The controller is further configured as follows: determining that the torque on the power gearbox is less than or equal to the upper torque threshold; in response to determining that the torque on the power gearbox is less than or equal to the upper torque threshold, using the received data indicative of the torque on the power gearbox to determine that the torque on the power gearbox is outside of a normal operating range; and In response to determining that the torque on the power gearbox is outside of the normal operating range, taking the at least one corrective action.

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