Lubrication system for a turbine engine

Abstract

A lubrication system for a turbine engine. The turbine engine includes a propeller and one or more rotating components. The lubrication system comprises a storage tank, a main lubrication system, an auxiliary lubrication system and a fuel system. The reservoir stores a lubricant therein. The main lubrication system supplies lubricant from the sump to one or more rotating components during normal operation of the turbine engine. The auxiliary lubrication system comprises an auxiliary pump. The fuel system stores hydrogen fuel. The fuel system includes a fuel cell controller that generates power from a hydrogen fuel. When the thruster is wind-rotated, electrical power powers the auxiliary pump such that the auxiliary pump pumps lubricant from the sump to one or more rotating components.

Description

Technical Field

[0001] The present disclosure relates generally to lubrication systems, for example, lubrication systems for turbine engines. Background Art

[0002] Turbine engines generally include a propeller (eg, fan) and a core section arranged in flow communication with each other. Some turbine engines include one or more rotating components that rotate. A lubrication system provides lubricant to one or more rotating components of a turbine engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The foregoing and other features and advantages will be apparent from the following more particular description of various exemplary embodiments, as illustrated in the accompanying drawings, in which like reference numerals generally indicate identical, functionally similar, or structurally similar elements.

[0004] Figure 1 is a schematic cross-sectional view of a turbine engine according to the present disclosure, taken along a longitudinal centerline axis of the turbine engine.

[0005] Figure 2 According to the present disclosure Figure 1 The details are captured from 2 Figure 1 Detailed schematic cross-sectional view of a portion of a turbine engine. DETAILED DESCRIPTION

[0006] Features, advantages and embodiments of the present disclosure are set forth or apparent through consideration of the following detailed description, drawings and claims.In addition, the following detailed description is exemplary and is intended to provide further explanation without limiting the scope of the present disclosure as claimed.

[0007] Various embodiments of the present disclosure are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and scope of the present disclosure.

[0008] 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.

[0009] 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.

[0010] The terms "front" and "rear" refer to relative positions within a turbine engine or vehicle, and refer to the normal operating attitude of the turbine engine or vehicle. For example, with respect to a turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0011] Unless otherwise indicated herein, the terms "coupled," "fixed," "attached," "connected," and the like refer to both direct coupling, fixing, attachment, or connection as well as indirect coupling, fixing, attachment, or connection through one or more intermediate components or features.

[0012] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0013] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of the turbine engine. Additionally, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of the 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 turbine engine.

[0014] As used herein, a "propeller" is a component of a turbine engine that is drivingly coupled to a core turbine engine such that rotation of the component of the core turbine engine causes the propeller to rotate and generate thrust. The propeller may include a fan or a propeller. In a turbofan engine or an open fan engine, the propeller is a fan. In a turboprop engine, the propeller is a propeller.

[0015] As used herein, "normal operation" of a turbine engine is intended to mean when the turbine engine is operating and the primary lubrication system of the turbine engine is supplying lubricant to one or more rotating components of the turbine engine. Normal operation may include a mission cycle of the turbine engine after the turbine engine is powered on, including, for example, an idle condition, a taxi condition, a takeoff condition, a cruise condition, a descent condition, or a landing condition.

[0016] As used herein, "wind turn" or "wind rotation" is a condition when the propeller and low-pressure shaft of a turbine engine continue to rotate at a low speed while the high-pressure shaft rotates slowly or even stops. Wind rotation may occur when the turbine engine is shut down, but air still flows through the propeller, such as during an engine shutdown in flight, or when the turbine engine is on the ground and the propeller rotates in windy conditions when the turbine engine is shut down. During shutdown, for example, when the aircraft is on the ground, the propeller may also rotate in either direction depending on the fixed position of the turbine engine relative to the ambient wind. Airflow entering the propeller exhaust may exit the propeller inlet in a direction opposite to the operating direction and cause the propeller to rotate in a rotational direction opposite to the intended operating rotational direction.

[0017] As used herein, "operating," "starting," or "activating" an auxiliary lubrication system includes causing lubricant to flow within the auxiliary lubrication system. For example, starting the auxiliary lubrication system includes powering an auxiliary pump to pump lubricant through the auxiliary lubrication system.

[0018] As used herein, "deactivating" an auxiliary lubrication system or an "inoperative" auxiliary lubrication system includes preventing lubricant from flowing within the auxiliary lubrication system. For example, when the auxiliary lubrication system is inoperative, the auxiliary pump is de-energized and is prevented from pumping lubricant through the auxiliary lubrication system.

[0019] Approximate language as used herein throughout the specification and claims is applied to modify any quantitative representation that can allow variation without causing a change in the basic function associated therewith. Therefore, values ​​modified by terms such as "approximately", "approximately", "substantially" and "substantially" are not limited to the specified precise values. In at least some cases, approximate language can correspond to the accuracy of an instrument used to measure a value, or the accuracy of a method or machine used to construct a component or system or to manufacture a component or system. For example, approximate language can refer to within a margin of one, two, four, ten, fifteen or twenty percent in a single value, a range of values ​​or an endpoint of a range of defined values.

[0020] The present disclosure provides a turbine engine with a lubrication system. The turbine engine includes a propeller having a propeller shaft. The turbine engine includes one or more rotating parts rotating in the turbine engine. The one or more rotating parts may include, for example, one or more shafts, one or more gears, one or more bearings, and the one or more bearings include one or more engine bearings for one or more shafts (e.g., a low-pressure shaft or a high-pressure shaft) of the turbine engine, or one or more power gearbox bearings for a power gearbox assembly of the turbine engine. One or more power gearbox bearings allow one or more power gearbox gears of the power gearbox assembly to rotate around one or more power gearbox bearings. In one embodiment, one or more bearings are journal bearings. One or more bearings may include any type of bearing, for example, such as roller bearings, etc. The lubrication system supplies lubricant (e.g., oil) to one or more rotating parts. The lubrication system includes a storage tank in which the lubricant is stored, and a main lubrication system having a main pump and a main lubricant supply line. During normal operation of the turbine engine, the main pump pumps the lubricant from the storage tank to the one or more rotating parts through the main lubricant supply line.

[0021] Bearings, especially journal bearings, are fluid dynamic bearings that typically require a steady supply of lubricant to properly lubricate the bearings during all phases of operation of the turbine engine to prevent damage caused by sliding contact of the fluid dynamic journal bearings or even the universal gear meshing interface. After the turbine engine is shut down, the shaft of the turbine engine may experience long-term continuous rotation, such as what happens during wind power rotation. In this case, one or more rotating parts, and in particular one or more bearings, may be affected by not receiving enough lubricant to lubricate one or more rotating parts. For example, during wind power rotation, the rotation speed of the shaft may be too low to drive the main pump to pump lubricant to one or more rotating parts. In some cases, for example, during the operation of the turbine engine (e.g., in flight), the lubrication system may lose pressure (e.g., due to a failure of the main pump or other components of the main lubrication system), so that the main lubrication system cannot provide lubricant to one or more rotating parts via the main pump and the main lubricant supply line.

[0022] The severity of lubrication interruption increases when the bearing is a journal bearing, as lack of lubricant at the journal bearing can lead to journal bearing failure and subsequent gearbox failure, which can cause the low-speed shaft to permanently lock up. This failure of the journal bearing is called journal bearing seizure and occurs when there is contact between the planetary gear pin and the gear bore, resulting in a significant increase in wear and friction leading to bearing failure. If contact occurs between the journal bearing and the pin during high power operation, the two components may weld together due to the high temperatures generated by the friction.

[0023] Some turbine engines include an auxiliary lubrication system that includes an auxiliary pump to supply lubricant to one or more rotating components to prevent damage to the rotating components due to insufficient lubricant supply during wind-driven rotation. Further, the auxiliary pump requires increased complexity to provide lubricant during high speeds, such as during operation of the turbine engine, and during low speeds, such as during wind-driven rotation (e.g., in flight or on the ground). Such an auxiliary pump may be drivingly coupled to a propeller shaft and requires increased complexity for driving the auxiliary pump via the propeller shaft. Further, the auxiliary pump requires increased complexity to provide lubricant when the propeller is rotating in either direction due to wind-driven rotation (e.g., the propeller is rotating clockwise or counterclockwise).

[0024] Therefore, the present disclosure provides an auxiliary lubrication system that supplies lubricant to one or more rotating parts during any time when the main lubrication system is unable to supply lubricant. In particular, the present disclosure provides for supplying lubricant to one or more rotating parts (e.g., journal bearings) when the turbine engine is shut down or whenever the turbine engine is rotated by wind to avoid the journal bearings from seizing. The present disclosure provides a fuel cell that converts the chemical energy of gaseous hydrogen fuel into electricity. In this way, the fuel cell generates a voltage for operating an electric auxiliary lubricant pump, which can be used to supply lubricant to one or more rotating parts, particularly to the journal bearings. In this way, the fuel cell powers the electric auxiliary lubricant pump so that whenever the shaft of the turbine engine rotates at a low speed (e.g., below a speed threshold) and is unable to provide power to the main pump to supply lubricant to one or more rotating parts, the electric auxiliary lubricant pump supplies lubricant to the one or more rotating parts.

[0025] Thus, the auxiliary lubrication system supplies lubricant to one or more rotating components when the turbine engine is shut down or otherwise rotating in wind. The fuel system of the present disclosure ensures that the auxiliary pump operates to pump lubricant to the one or more rotating components regardless of the direction of rotation of the propeller during wind rotation (e.g., whether the propeller is rotating clockwise or counterclockwise).

[0026] Now referring to the accompanying drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 taken along a longitudinal centerline axis 12 of the turbine engine 10 according to an embodiment of the present disclosure. Figure 1 As shown, the turbine engine 10 defines an axial direction A (extending parallel to the longitudinal centerline axis 12 for reference) and a radial direction R perpendicular to the axial direction A. Figure 1In the orientation of FIG. 1 , the portion of the turbine engine 10 above the longitudinal centerline axis 12 is referred to as the top portion 11, and the portion of the turbine engine 10 below the longitudinal centerline axis 12 is referred to as the bottom portion 13. Typically, the turbine engine 10 includes a propeller section 14 and a core turbine engine 16 disposed downstream of the propeller section 14.

[0027] The depicted core turbine engine 16 generally includes a casing 18 that is substantially tubular and defines an annular inlet 20. Figure 1 As shown schematically, the casing 18 encloses in a serial flow relationship: a compressor section 21, which includes a supercharger or low pressure (LP) compressor 22, followed downstream by a high pressure (HP) compressor 24; a combustion section 26; a turbine section 27, which includes a high pressure (HP) turbine 28, followed downstream by a low pressure (LP) turbine 30; and an ejection exhaust nozzle section 32. A high pressure (HP) shaft 34 or spool drives the HP turbine 28 to the HP compressor 24 so that the HP turbine 28 and the HP compressor 24 rotate in unison. A low pressure (LP) shaft 36 drives the LP turbine 30 to the LP compressor 22 so that the LP turbine 30 and the LP compressor 22 rotate in unison. The HP shaft 34, the LP shaft 36, or both the HP shaft 34 and the LP shaft 36 are supported by one or more engine bearings that allow the HP shaft 34 or the LP shaft 36 to rotate, as described in further detail below. The compressor section 21, the combustion section 26, the turbine section 27, and the ejection exhaust nozzle section 32 together define a core air flow path.

[0028] for Figure 1 In the embodiment depicted in FIG. 1 , the propeller section 14 includes a propeller 38 (eg, a variable pitch propeller) having a plurality of propeller blades 40 coupled to a disk 42 in a spaced-apart manner. Figure 1 In some embodiments, the propeller 38 is a fan driven by the core turbine engine 16. In some embodiments, the propeller 38 is a propeller driven by the core turbine engine 16. The propeller blades 40 extend outwardly from the disk 42 generally in a radial direction R. Each propeller blade 40 is capable of rotating about a pitch axis P relative to the disk 42 by means of the propeller blades 40 being operably connected to an actuation member 44, and the actuation member 44 is configured to collectively and uniformly change the pitch of the propeller blades 40, as further detailed below. The propeller blades 40, disk 42, and actuation members 44 are capable of rotating together about the longitudinal centerline axis 12 via a propeller shaft 45, and the propeller shaft 45 is powered by the LP shaft 36 across a power gearbox (also referred to as a power gearbox assembly 46). The power gearbox assembly 46 is Figure 1The power gearbox assembly 46 includes a plurality of power gearbox gears for adjusting the rotational speed of the propeller shaft 45, and thus adjusting the rotational speed of the propeller 38 relative to the LP shaft 36. The power gearbox assembly 46 also includes one or more power gearbox bearings for supporting the rotation of one or more power gearbox gears in the plurality of power gearbox gears, as described in further detail below.

[0029] Still reference Figure 1 In an exemplary embodiment of the present invention, the disk 42 is covered by a propeller hub 48 that is aerodynamically shaped to facilitate airflow through the plurality of propeller blades 40. In addition, the propeller section 14 includes an annular propeller casing or nacelle 50 that circumferentially surrounds the propeller 38 and at least a portion of the core turbine engine 16. The nacelle 50 is supported relative to the core turbine engine 16 by a plurality of outlet guide vanes 52 that are circumferentially spaced about the nacelle 50 and the core turbine engine 16. In addition, a downstream section 54 of the nacelle 50 extends over an outer portion of the core turbine engine 16 to define a bypass airflow passage 56 therebetween.

[0030] During operation of the turbine engine 10, a quantity of air 58 enters the turbine engine 10 through an inlet 60 of the nacelle 50 or the propeller section 14. As the quantity of air 58 passes through the propeller blades 40, a first portion of the air (referred to as bypass air) 62 is directed or directed into the bypass airflow passage 56, and a second portion of the air (referred to as core air) 64 is directed or directed into an upstream section of the core air flow path, or more specifically, into the annular inlet 20 of the LP compressor 22. The ratio between the bypass air 62 and the core air 64 is generally referred to as the bypass ratio. The pressure of the core air 64 is then increased, generating compressed air 65, and the compressed air 65 is directed through the HP compressor 24 and into the combustion section 26, where the compressed air 65 is mixed with fuel and combusted to generate combustion gases 66.

[0031] The combustion gases 66 are directed into and expanded through the HP turbine 28, wherein a portion of the heat or kinetic energy from the combustion gases 66 is extracted via successive stages of HP turbine stator blades 68 coupled to the casing 18 and HP turbine rotor blades 70 coupled to the HP shaft 34, thereby rotating the HP shaft 34, thereby supporting the operation of the HP compressor 24. The combustion gases 66 are then directed into and expanded through the LP turbine 30. Here, a second portion of the heat or kinetic energy is extracted from the combustion gases 66 via successive stages of LP turbine stator blades 72 coupled to the casing 18 and LP turbine rotor blades 74 coupled to the LP shaft 36, thereby rotating the LP shaft 36, thereby supporting the operation of the LP compressor 22 and the rotation of the propeller 38 via the power gearbox assembly 46.

[0032] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the core turbine engine 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 thruster nozzle exhaust section 76 of the turbine engine 10. The HP turbine 28, the LP turbine 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 core turbine engine 16.

[0033] The controller 79 communicates with the turbine engine 10 for controlling various aspects of the turbine engine 10. For example, the controller 79 is in bidirectional communication with the turbine engine 10 for receiving signals from various sensors and control systems of the turbine engine 10, and for controlling components of the turbine engine 10, as described in further detail below. The controller 79 or components thereof may be onboard the turbine engine 10, onboard an aircraft (not shown), or may be remote from each of the turbine engine 10 and the aircraft. The controller 79 may be a full authority digital engine control (FADEC) that controls various aspects of the turbine engine 10.

[0034] The controller 79 may be a stand-alone controller or may be part of an engine controller to operate various systems of the turbine engine 10. In this embodiment, the controller 79 is a computing device having one or more processors and a memory. The one or more processors may be any suitable processing device, including but not limited to a microprocessor, a microcontroller, an integrated circuit, a logic device, a programmable logic controller (PLC), an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA). The memory may include one or more computer-readable media, including but not limited to non-temporary computer-readable media, computer-readable non-volatile media (e.g., flash memory), RAM, ROM, a hard drive, a flash drive, or other memory devices.

[0035] The memory can store information that can be accessed by one or more processors, including computer-readable instructions that can be executed by one or more processors. The instructions can be any set of instructions or sequence of instructions that cause one or more processors and the controller 79 to operate when executed by one or more processors. The controller 79, and more specifically, one or more processors are programmed or configured to perform these operations, such as the operations discussed further below. In some embodiments, the instructions can be executed by one or more processors to cause one or more processors to complete any operations and functions that the controller 79 is configured for, as will be further described below. The instructions can be software written in any suitable programming language or can be implemented in hardware. Additionally or alternatively, the instructions can be executed in logically or virtually independent threads on the processor. The memory can further store data that can be accessed by one or more processors.

[0036] The techniques discussed herein refer to computer-based systems and the actions taken by computer-based systems and information sent to and from computer-based systems. It will be appreciated by those of ordinary skill in the art that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions between and within components. For example, the processes discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memory, instructions, and applications can be implemented on a single system, or can be distributed on multiple systems. Distributed components can operate sequentially or in parallel.

[0037] Figure 1 The turbine engine 10 depicted in the drawings is for example only. In other exemplary embodiments, the turbine engine 10 may have any other suitable configuration. For example, in other exemplary embodiments, the propeller 38 may be configured in any other suitable manner (e.g., as a fixed pitch propeller) and may also be supported using any other suitable propeller frame configuration. In addition, in other exemplary embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof may be provided. In other exemplary embodiments, aspects of the present disclosure may be incorporated into any other suitable turbine engine (e.g., such as a turbofan engine, a propfan engine, a turbojet engine, a turboprop engine, or a turboshaft engine).

[0038] Figure 2 According to the present disclosure Figure 1 Detailed schematic cross-sectional view of a portion of turbine engine 10 taken at Detail 2 in FIG. Figure 2As shown, the turbine engine 10 includes one or more engine bearings 37 that support the rotation of the LP shaft 36 and the propeller shaft 45. The one or more engine bearings 37 may also support the rotation of the HP shaft 34. The one or more engine bearings 37 may include any number of engine bearings 37 for supporting the rotation of the shafts of the turbine engine 10. The one or more engine bearings 37 are referred to as rotating components of the turbine engine 10 and may include any type of bearing, such as, for example, a journal bearing, a roller bearing, etc.

[0039] The power gearbox assembly 46 includes a power gearbox gear assembly 47 having a plurality of power gearbox gears 49. The plurality of power gearbox gears 49 include a first power gearbox gear 49a, one or more second power gearbox gears 49b fixed by a planet carrier 51, and a third power gearbox gear 49c. Figure 2 In the embodiment of the present invention, the first power gearbox gear 49a is a sun gear, the one or more second power gearbox gears 49b are planetary gears, and the third power gearbox gear 49c is a ring gear. The power gearbox gear assembly 47 may be an epicyclic gear assembly. When the power gearbox gear assembly 47 is an epicyclic gear assembly, the one or more second power gearbox gears 49b include a plurality of second power gearbox gears 49b (e.g., two or more second power gearbox gears 49b).

[0040] In the epicyclic gear assembly, the power gearbox gear assembly 47 can be in a star arrangement or a rotating ring gear type gear assembly (e.g., the third power gearbox gear 49c is rotating, while the planet carrier 51 is fixed and stationary). In this arrangement, the propeller 38 is driven by the third power gearbox gear 49c. For example, the third power gearbox gear 49c is coupled to the propeller shaft 45 so that the rotation of the third power gearbox gear 49c rotates the propeller shaft 45, and thus rotates the propeller 38. In this way, the third power gearbox gear 49c is the output of the power gearbox gear assembly 47. However, other suitable types of gear assemblies can be used. In a non-limiting embodiment, the power gearbox gear assembly 47 is a planetary arrangement in which the third power gearbox gear 49c remains fixed and the planet carrier 51 is allowed to rotate. In this arrangement, the propeller 38 is driven by the planet carrier 51. For example, the planet carrier 51 is coupled to the propeller shaft 45 so that the rotation of the planet carrier 51 rotates the propeller shaft 45, and thus rotates the propeller 38. In this manner, one or more second power gearbox gears 49b (e.g., via the planet carrier 51) are outputs of the power gearbox gear assembly 47. In another non-limiting embodiment, the power gearbox gear assembly 47 may be a differential gear assembly in which both the third power gearbox gear 49c and the planet carrier 51 are allowed to rotate. Although an epicyclic gear assembly is described in detail herein, the power gearbox gear assembly may include any type of gear assembly, including, for example, a compound gear assembly, a multi-stage gear assembly, etc.

[0041] The plurality of power gearbox gears 49 include one or more power gearbox bearings 53 disposed therein. For example, the one or more second power gearbox gears 49b each include one or more power gearbox bearings 53 disposed therein. The one or more power gearbox bearings 53 enable the plurality of power gearbox gears 49 to rotate about the one or more power gearbox bearings 53, so that the plurality of power gearbox gears 49 rotate. The one or more power gearbox bearings 53 may include any type of bearing for a gear, such as, for example, a journal bearing, a roller bearing, etc. The plurality of power gearbox gears 49 and the one or more power gearbox bearings 53 are rotating components of the turbine engine 10. Therefore, the turbine engine 10 includes one or more rotating components 55, the one or more rotating components 55 including at least one of the one or more engine bearings 37, the plurality of power gearbox gears 49, or the one or more power gearbox bearings 53. The one or more rotating components 55 may also include the HP shaft 34 or the LP shaft 36.

[0042] The first power gearbox gear 49a is coupled to the input shaft of the turbine engine 10. For example, the first power gearbox gear 49a is coupled to the LP shaft 36 so that the rotation of the LP shaft 36 rotates the first power gearbox gear 49a. Radially outwardly of the first power gearbox gear 49a and intermeshing therewith are one or more second power gearbox gears 49b, which are coupled together and supported by the planet carrier 51. The planet carrier 51 supports and limits the one or more second power gearbox gears 49b so that each of the one or more second power gearbox gears 49b can rotate around the corresponding axis of each second power gearbox gear 49b without rotating around the periphery of the first power gearbox gear 49a. Radially outwardly of the one or more second power gearbox gears 49b and intermeshing therewith is the third power gearbox gear 49c, which is an annular ring gear. The third power gearbox gear 49c is coupled to the propeller 38 via the output shaft and rotates to drive the propeller 38 to rotate around the longitudinal centerline axis 12. For example, the propeller shaft 45 is coupled to the third power gearbox gear 49c.

[0043] Turbine engine 10 includes a fuel system 80 for generating electricity. Fuel system 80 includes a fuel tank 82 for storing fuel therein, a fuel pump 84, a vaporizer 86, and a fuel cell controller 88. Fuel tank 82 may be located on an aircraft (not shown) to which turbine engine 10 is attached. Figure 1 8, but the fuel system 80 may include any number of fuel tanks 82 as desired. The fuel system 80 includes one or more lines, conduits, pipes, tubes, etc. configured to carry fuel from the fuel tank 82 to the fuel cell controller 88. The fuel pump 84 directs the flow of fuel through the fuel system 80 to the fuel cell controller 88. In this manner, the fuel pump 84 pumps the fuel from the fuel tank 82 through the fuel system 80 and into the fuel cell controller 88. In some embodiments, the fuel system 80 provides fuel to the combustion section 26 ( Figure 1 ) supplies fuel to be combusted for generating thrust for the turbine engine 10.

[0044] exist Figure 2 In the embodiment of the present invention, the fuel is hydrogen fuel stored as liquid hydrogen fuel in the fuel tank 82. The vaporizer 86 heats the liquid hydrogen fuel flowing through the fuel system 80. The vaporizer 86 is positioned in the flow path of the fuel between the fuel tank 82 and the fuel cell controller 88 and is located downstream of the fuel pump 84. Although Figure 2One vaporizer 86 is shown in the figure, but the fuel system 80 can include any number of vaporizers 86 as needed. The vaporizer 86 is thermally connected to at least one heat source, for example, thermally connected to waste heat such as from the turbine engine 10 or from one or more aircraft systems 96 of the aircraft. The vaporizer 86 heats the liquid hydrogen fuel, and the liquid hydrogen fuel is converted into gaseous hydrogen fuel within the vaporizer 86. The fuel system 80 directs the gaseous hydrogen fuel to the fuel cell controller 88. The fuel cell controller 88 includes a fuel cell that converts the chemical energy of a fuel (e.g., gaseous hydrogen fuel) and an oxidant (e.g., oxygen) into electricity through a pair of redox reactions. In this way, the fuel cell controller 88 receives the gaseous hydrogen fuel and the oxidant and generates electricity. The fuel cell controller 88 outputs the electricity to the electrical system 90. In some embodiments, the fuel system 80 supplies gaseous hydrogen fuel for providing auxiliary power to the turbine engine 10. In some embodiments, the fuel system 80 supplies gaseous hydrogen fuel to the combustion section 26 ( Figure 1 ) supplies gaseous hydrogen fuel for combusting the gaseous hydrogen fuel and generating thrust for the turbine engine 10.

[0045] The electrical system 90 includes a direct current (DC) converter 92, a power distribution system 94, and one or more aircraft systems 96 of the aircraft. The electrical system 90 supplies power from the fuel cell controller 88 to the lubrication system 100 of the turbine engine 10 for powering one or more components of the lubrication system 100, as described in further detail below. The electrical system 90 may also supply power to one or more aircraft systems 96 for powering one or more aircraft systems 96. The one or more aircraft systems 96 may include, for example, electric motors for the turbine engine 10 (e.g., for providing additional power to the power gearbox assembly 46, so that the turbine engine 10 is a hybrid electric engine), avionics systems, electric pumps (e.g., for controlling flaps), air conditioning, interior lights, exterior lights, passenger accessories (e.g., video screens, LCD screens, power connections or USB connections, etc., or combinations thereof), electric motors interconnected with thrusters or propellers (in the case of a hybrid electric engine) or other electrical systems of the aircraft, or combinations thereof. The DC converter 92 is a DC / DC converter, which is an electronic circuit or electromechanical device that converts a DC power source from one voltage level to another voltage level. DC converter 92 receives power at a first voltage level from fuel cell controller 88 and converts the power to a second voltage level. Power distribution system 94 receives power at the second voltage level and distributes the power to various systems of turbine engine 10 (e.g., lubrication system 100) or various systems of the aircraft (e.g., one or more aircraft systems 96), as described in further detail below.

[0046] The turbine engine 10 includes a lubrication system 100, which includes a main lubrication system 102, an auxiliary lubrication system 104, and a storage tank 106. The storage tank 106 ( Figure 2 ) is a reservoir in which lubricant is collected and stored. In some embodiments, the lubrication system 100 may include one or more boxes or one or more storage tanks in which lubricant is stored. When more than one storage tank is used, each of the main lubrication system 102 and the auxiliary lubrication system 104 can be in fluid communication with a different storage tank and / or each of the multiple storage tanks. Preferably, the lubricant is oil. The lubricant can be any type of lubricant used to lubricate one or more rotating components 55 of the turbine engine 10 (e.g., multiple power gearbox gears 49 or one or more power gearbox bearings 53).

[0047] The main lubrication system 102 includes a main pump 108 and a main lubricant supply line 110. The main pump 108 is in fluid communication with the sump 106 and the main lubricant supply line 110. The main lubricant supply line 110 is in fluid communication with one or more rotating components 55 of the turbine engine 10. The main pump 108 pumps lubricant from the sump 106 to one or more rotating components 55 through the main lubricant supply line 110 for supplying lubricant to one or more rotating components 55, as described in further detail below. In some embodiments, the main pump 108 is a mechanical pump. For example, the main pump 108 can be coupled to an accessory gearbox assembly (not shown), the LP shaft 36, or the HP shaft 34, and powered by the accessory gearbox assembly (not shown), the LP shaft 36, or the HP shaft 34, so that the above-mentioned corresponding components drive the main pump 108. In some embodiments, the primary lubrication system 102 supplies lubricant from a sump 106 to one or more rotating components 55 without a pump, such as by gravity or by centrifugal force due to rotation of the planet carrier 51 in the planetary arrangement of the power gearbox gear assembly 47 .

[0048] The reservoir 106 is in fluid communication with one or more rotating components 55 so that lubricant can be removed from the reservoir 106, for example, via a purge line (for clarity, Figure 2 106. In some embodiments, the lubrication system 100 includes a sump pump in fluid communication with the main lubrication system 102 and the auxiliary lubrication system 104. The sump pump pumps lubricant from the sump 106 to the main lubrication system 102 or the auxiliary lubrication system 104.

[0049] The auxiliary lubrication system 104 includes an auxiliary pump 120, an auxiliary lubricant supply line 122, an electric motor 124, and an auxiliary pump shaft 126. The auxiliary lubricant supply line 122 is in fluid communication with the sump 106 and one or more rotating components 55 of the power gearbox assembly 46. Figure 2Although depicted as being in fluid communication with the power gearbox assembly 46, the auxiliary lubricant supply line 122 may be in fluid communication with any of the one or more rotating components 55 of the turbine engine 10. Further, although the auxiliary lubricant supply line 122 is depicted as being in fluid communication with the power gearbox assembly 46, the auxiliary lubricant supply line 122 may be in fluid communication with any of the one or more rotating components 55 of the turbine engine 10. Figure 2 106, but the auxiliary lubricant supply line 122 may form a part of the main lubricant supply line 110. The auxiliary pump 120 is in fluid communication with the sump 106 and the auxiliary lubricant supply line 122. The auxiliary pump 120 is an electric pump that is powered by electricity from the electrical system 90, as described in further detail below. The auxiliary pump 120 is drivingly coupled to the motor 124 via an auxiliary pump shaft 126. In this manner, the motor 124 drives the auxiliary pump shaft 126 to rotate, thereby causing the auxiliary pump 120 to pump lubricant from the sump 106 to one or more rotating components 55 through the auxiliary lubricant supply line 122.

[0050] In operation, the LP shaft 36 rotates as described above and rotates the first power gearbox gear 49a. The first power gearbox gear 49a, which is meshed with the one or more second power gearbox gears 49b, rotates the one or more second power gearbox gears 49b about their corresponding rotational axes. The one or more second power gearbox gears 49b rotate relative to the one or more power gearbox bearings 53 within the planet carrier 51. When the power gearbox gear assembly 47 is a star arrangement, the one or more second power gearbox gears 49b, which are meshed with the third power gearbox gear 49c, rotate the third power gearbox gear 49c about the longitudinal centerline axis 12. In such an embodiment, the planet carrier 51 remains stationary so that the one or more second power gearbox gears 49b do not rotate about the longitudinal centerline axis 12. When the power gearbox gear assembly 47 is a planetary arrangement, the third power gearbox gear 49c is stationary in the planet carrier 51, and the one or more second power gearbox gears 49b rotate about the longitudinal centerline axis 12. When the power gearbox gear assembly 47 is a differential gear assembly, both the planet carrier 51 (eg, the one or more second power gearbox gears 49b) and the third power gearbox gear 49c rotate about the longitudinal centerline axis 12. In this manner, the one or more rotating members 55 rotate.

[0051] At the same time, the main lubrication system 102 supplies lubricant to one or more rotating components 55 to lubricate the one or more rotating components 55. During normal operation of the turbine engine 10, the main pump 108 pumps lubricant from the sump 106 and pumps the lubricant to the one or more rotating components 55 through the main lubricant supply line 110. The main lubrication system 102 supplies lubricant to the one or more rotating components 55. The lubricant is discharged from the one or more rotating components 55 and enters the sump 106. During normal operation of the turbine engine 10, the lubricant in the sump 106 is returned through the main lubrication system 102, so that the main lubrication system 102 continuously supplies lubricant to the one or more rotating components 55. In this way, the lubricant can be reused to lubricate the one or more rotating components 55.

[0052] When the primary lubrication system 102 is operating, such as when the turbine engine 10 is operating under normal operation, the auxiliary lubrication system 104 is not operating. When the auxiliary lubrication system 104 is not operating, the electrical system 90 does not provide power to the motor 124, so that the motor 124 does not power the auxiliary pump 120. For example, the controller 79 controls the power distribution system 94 to prevent the power distribution system 94 from supplying power to the motor 124 during normal operation of the turbine engine 10.

[0053] In some cases, the main lubrication system 102 may be unable to provide lubricant to one or more rotating components 55. For example, the main lubrication system 102 may be unable to pressurize lubricant to supply lubricant to one or more rotating components 55 during wind-driven rotation when the turbine engine 10 is shut down, or during a turbine engine 10 failure or a main lubrication system 102 (e.g., main pump 108) failure in flight. This may be due to the main pump 108 being driven by a component of the turbine engine 10. In this case, the wind-driven rotation may cause the shafts of the turbine engine 10 (e.g., propeller shaft 45, HP shaft 34, and LP shaft 36) to rotate, thereby causing one or more rotating components 55 to continue to rotate. As described above, if there is not enough lubricant supplied to one or more rotating components 55, one or more rotating components 55 (e.g., multiple power gearbox gears 49 or one or more power gearbox bearings 53) may become damaged.

[0054] Therefore, during this situation, the auxiliary lubrication system 104 is activated to supply lubricant to one or more rotating components 55. For example, the controller 79 ( Figure 1) controls the power distribution system 94 to supply power to the motor 124. In this case, the fuel system 80 generates power (e.g., using the fuel cell controller 88), and the power is supplied to the motor 124 when the turbine engine 10 is off and when the propeller 38 is wind-driven. In this way, the motor 124 is powered by power from the electrical system 90, which is generated by the fuel cell controller 88, because power is continuously generated by the fuel system 80 even when the turbine engine 10 is off. The motor 124 rotates the auxiliary pump shaft 126, thereby causing the auxiliary pump 120 to pump lubricant from the sump 106 to one or more rotating components 55 through the auxiliary lubricant supply line 122. The lubricant is discharged from the one or more rotating components 55 and enters the sump 106. When the auxiliary lubrication system 104 is operating, the lubricant in the sump 106 is returned through the auxiliary lubrication system 104, so that when power is supplied to the auxiliary pump 120, the auxiliary lubrication system 104 continuously supplies lubricant to the one or more rotating components 55.

[0055] The controller 79 activates the auxiliary lubrication system 104 based on at least one of the pressure of the lubricant in the main lubrication system 102 (e.g., in the main lubricant supply line 110) or the rotational speed of at least one of the HP shaft 34, the LP shaft 36, or the propeller shaft 45. For example, when the pressure of the lubricant in the main lubrication system 102 is less than a main pressure threshold, the controller 79 activates the auxiliary lubrication system 104. In some embodiments, when the rotational speed of at least one of the HP shaft 34, the LP shaft 36, or the propeller shaft 45 is less than a rotational speed threshold, the controller 79 activates the auxiliary lubrication system 104.

[0056] Thus, when the turbine engine 10 is shut down or otherwise wind-driven, the auxiliary lubrication system 104 supplies lubricant to the one or more rotating components 55. The fuel cell controller 88, electrical system 90, and electric motor 124 ensure that the auxiliary pump 120 operates to pump lubricant to the one or more rotating components 55 even when the turbine engine 10 is shut down and is not constrained by the direction of rotation of the propeller 38 during wind-driven rotation (e.g., whether the propeller is rotating clockwise or counterclockwise).

[0057] Further aspects of the disclosure are provided by the subject matter of the following clauses.

[0058] A lubrication system for a turbine engine, the turbine engine comprising a propeller and one or more rotating parts, the lubrication system comprising: a tank in which lubricant is stored; a main lubrication system, which supplies the lubricant from the tank to the one or more rotating parts during normal operation of the turbine engine; an auxiliary lubrication system, the auxiliary lubrication system comprising an auxiliary pump; and a fuel system, the fuel system storing hydrogen fuel, the fuel system comprising a fuel cell controller, the fuel cell controller generating electricity from the hydrogen fuel, when the propeller is rotated by wind, the electricity powers the auxiliary pump so that the auxiliary pump pumps the lubricant from the tank to the one or more rotating parts.

[0059] According to the lubrication system described in the preceding clause, the auxiliary lubrication system includes an auxiliary lubricant supply pipeline fluidly connected to the storage tank and the one or more rotating components, and when the propeller rotates by wind force, the lubricant flows from the storage tank to the one or more rotating components through the auxiliary lubricant supply pipeline.

[0060] A lubrication system according to any preceding clause, the main lubrication system comprising a main pump and a main lubricant supply line in fluid communication with the reservoir and the one or more rotating components, and during normal operation of the turbine engine, the main pump pumps the lubricant from the reservoir to the one or more rotating components through the main lubricant supply line.

[0061] According to the lubrication system described in any of the preceding clauses, the fuel system includes a fuel tank storing liquid hydrogen fuel, a fuel pump and a vaporizer, the fuel pump pumps the liquid hydrogen fuel to the vaporizer, and the vaporizer heats the liquid hydrogen fuel to generate gaseous hydrogen fuel, and the gaseous hydrogen fuel is supplied to the fuel cell controller to generate the electricity.

[0062] A lubrication system according to any preceding clause, wherein during normal operation of the turbine engine, the fuel cell controller is prevented from supplying the power to the auxiliary pump.

[0063] A lubrication system according to any preceding clause, wherein the auxiliary pump comprises an electric motor powered by the electric power, the electric motor providing power for the auxiliary pump.

[0064] A lubrication system according to any preceding clause, the auxiliary pump comprising an auxiliary pump shaft coupled to the electric motor, and the electric motor rotates the auxiliary pump shaft to power the auxiliary pump.

[0065] A lubrication system according to any preceding clause, further comprising an electrical system that receives the power from the fuel cell controller and supplies the power to the auxiliary pump.

[0066] A lubrication system according to any preceding clause, the electrical system comprising a DC converter which changes the voltage of the electrical power from the fuel cell controller.

[0067] A lubrication system according to any preceding clause, the electrical system comprising a power distribution system in communication with the auxiliary pump, the power distribution system supplying the power from the fuel cell controller to the auxiliary pump.

[0068] A lubrication system as described in any preceding clause, the turbine engine comprising a power gearbox assembly having a plurality of power gearbox gears.

[0069] A lubrication system as claimed in any preceding clause, wherein the one or more rotating components are one or more power gearbox bearings of the power gearbox assembly.

[0070] A lubrication system according to any preceding clause, wherein the one or more power gearbox bearings are journal bearings.

[0071] A lubrication system as described in any preceding clause, wherein the electrical system further supplies the electrical power to one or more aircraft systems.

[0072] A lubrication system according to any preceding clause, wherein the impeller is a fan.

[0073] A lubrication system according to any preceding clause, wherein the propeller is a propeller.

[0074] A method of operating a lubrication system according to any of the preceding clauses, the method comprising: supplying the lubricant to the one or more rotating components through the main lubrication system during normal operation of the turbine engine; generating the electricity from the hydrogen fuel with the fuel cell controller; and pumping the lubricant from the tank to the one or more rotating components with the auxiliary pump by powering the auxiliary pump with the electricity when the propeller is wind-driven.

[0075] According to the method of any preceding clause, the auxiliary lubrication system includes an auxiliary lubricant supply pipeline fluidly connected to the tank and the one or more rotating components, and the method further includes directing the lubricant from the tank to the one or more rotating components through the auxiliary lubricant supply pipeline when the propeller is wind-driven rotation.

[0076] A method according to any preceding clause, wherein the main lubrication system comprises a main pump and a main lubricant supply line in fluid communication with the reservoir and the one or more rotating components, and the method further comprises, during normal operation of the turbine engine, pumping the lubricant from the reservoir to the one or more rotating components via the main lubricant supply line with the main pump.

[0077] According to the method described in any of the preceding clauses, the fuel system includes a fuel tank for storing liquid hydrogen fuel, a fuel pump and a vaporizer, and the method further includes: pumping the liquid hydrogen fuel to the vaporizer with the fuel pump; heating the liquid hydrogen fuel with the vaporizer to generate gaseous hydrogen fuel; and generating the electricity with the gaseous hydrogen fuel with the fuel cell controller.

[0078] The method of any preceding clause, further comprising preventing the fuel cell controller from supplying the power to the auxiliary pump during the normal operation of the turbine engine.

[0079] A method according to any preceding clause, the auxiliary pump comprising an electric motor, the electric motor being powered by the electric power, and the method further comprising powering the auxiliary pump with the electric motor.

[0080] A method according to any preceding clause, the auxiliary pump comprising an auxiliary pump shaft coupled to the electric motor, and the method further comprising rotating the auxiliary pump shaft with the electric motor to power the auxiliary pump.

[0081] A method according to any preceding clause, the lubrication system further comprising an electrical system, and the method further comprising: receiving the power from the fuel cell controller with the electrical system; and supplying the power to the auxiliary pump with the electrical system.

[0082] A method as described in any preceding clause, the electrical system comprising a DC converter, and the method further comprising varying the voltage of the electrical power from the fuel cell controller with the DC converter.

[0083] A method according to any preceding clause, the electrical system comprising a power distribution system in communication with the auxiliary pump, and the method further comprising supplying the power from the fuel cell controller to the auxiliary pump with the power distribution system.

[0084] A method as in any preceding clause, the lubrication system being a lubrication system as in any preceding clause.

[0085] A turbine engine comprising a propeller and a core turbine engine having a shaft, the propeller being drivingly coupled to the shaft. The turbine engine comprises a lubrication system according to any preceding clause.

[0086] A turbine engine according to the preceding clause, wherein the propeller is a fan.

[0087] A turbine engine according to any preceding clause, wherein the propeller is a propeller.

[0088] Although the foregoing description is directed to the preferred embodiments of the present disclosure, other changes and modifications are apparent to those skilled in the art and may be made without departing from the spirit or scope of the present disclosure. In addition, the features described in conjunction with one embodiment of the present disclosure may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A lubrication system for a turbine engine, the turbine engine comprising a propeller and one or more rotating parts, characterized in that: The lubrication system comprises: a reservoir storing lubricant therein; a primary lubrication system that supplies the lubricant from the reservoir to the one or more rotating components during normal operation of the turbine engine; an auxiliary lubrication system, the auxiliary lubrication system comprising an auxiliary pump; and A fuel system that stores hydrogen fuel, the fuel system including a fuel cell controller that generates electricity from the hydrogen fuel, wherein when the propeller is wind-driven, the electricity powers the auxiliary pump so that the auxiliary pump pumps the lubricant from the storage tank to the one or more rotating components.

2. The lubrication system according to claim 1, characterized in that: The auxiliary lubrication system comprises an auxiliary lubricant supply line in fluid communication with the reservoir and the one or more rotating components, and when the propeller rotates by wind force, the lubricant flows from the reservoir to the one or more rotating components through the auxiliary lubricant supply line.

3. The lubrication system according to claim 1, characterized in that: The main lubrication system comprises a main pump and a main lubricant supply line in fluid communication with the reservoir and the one or more rotating components, and during normal operation of the turbine engine, the main pump pumps the lubricant from the reservoir to the one or more rotating components through the main lubricant supply line.

4. The lubrication system according to claim 1, characterized in that: The fuel system includes a fuel tank storing liquid hydrogen fuel, a fuel pump and a vaporizer, wherein the fuel pump pumps the liquid hydrogen fuel to the vaporizer, and the vaporizer heats the liquid hydrogen fuel to generate gaseous hydrogen fuel, and the gaseous hydrogen fuel is supplied to the fuel cell controller to generate the electricity.

5. The lubrication system according to claim 1, characterized in that: Wherein during the normal operation of the turbine engine, the fuel cell controller is prevented from supplying the power to the auxiliary pump.

6. The lubrication system according to claim 1, characterized in that: The auxiliary pump includes an electric motor, which is powered by the electric power and provides power for the auxiliary pump.

7. The lubrication system according to claim 6, characterized in that: The auxiliary pump includes an auxiliary pump shaft coupled to the electric motor, and the electric motor rotates the auxiliary pump shaft to provide power to the auxiliary pump.

8. The lubrication system according to claim 1, characterized in that: Further included is an electrical system that receives the power from the fuel cell controller and supplies the power to the auxiliary pump.

9. The lubrication system according to claim 8, characterized in that: The electrical system includes a DC converter that changes the voltage of the power from the fuel cell controller.

10. The lubrication system according to claim 8, characterized in that: The electrical system includes a power distribution system in communication with the auxiliary pump, the power distribution system supplies the power from the fuel cell controller to the auxiliary pump.

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