Lubrication system for a turbine engine

Abstract

A lubrication system for a turbine engine. The turbine engine includes a propeller and a rotating component. The lubricating system comprises a storage tank, a main lubricating system, an auxiliary lubricating system and a kinetic energy storage system. The reservoir stores a lubricant. The main lubrication system supplies lubricant from the sump to the rotating component during normal operation of the turbine engine. The auxiliary lubrication system comprises an auxiliary pump. The kinetic energy storage system includes a rotary lubricant accumulator. During normal operation of the turbine engine, the auxiliary pump pumps lubricant from the sump to the rotary lubricant accumulator to at least partially fill the rotary lubricant accumulator with lubricant to store kinetic energy. The rotating lubricant accumulator releases kinetic energy to supply the rotating component with lubricant from the rotating lubricant accumulator as the propeller is wind-driven to rotate.

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, a thruster) 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 places 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 turbo-engine such that rotation of the component of the turbo-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 opening a valve so that lubricant flows through the auxiliary lubrication system to one or more rotating components of the turbine engine.

[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, a valve is closed to prevent lubricant from flowing through the auxiliary lubrication system to one or more rotating components of the turbine engine.

[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, or 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 gear 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 parts to prevent damage to the rotating parts due to insufficient lubricant supply during wind rotation. Such an auxiliary pump can be drivingly coupled to a propeller shaft and requires increased complexity for driving the auxiliary pump through the propeller shaft. 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 rotation (e.g., in flight or on the ground)). Further, the auxiliary pump requires increased complexity to provide lubricant when the propeller is wind-rotated in either direction (e.g., the propeller rotates 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 wind-driven to avoid the journal bearings from seizing. The present disclosure provides a kinetic energy storage system that stores kinetic energy during normal operation of the turbine engine. In particular, the kinetic energy storage system is drivingly coupled to an accessory gearbox of the turbine engine and is started when the turbine engine is shut down or otherwise wind-driven. When the turbine engine is shut down or the propeller is otherwise wind-driven, the kinetic energy storage system releases the stored kinetic energy to supply lubricant to one or more rotating parts.

[0025] The kinetic energy storage system includes a rotating lubricant accumulator filled with an inert gas (e.g., nitrogen), and a diaphragm that separates the inert gas from the lubricant in the rotating lubricant accumulator. In this way, when the lubricant fills the rotating lubricant accumulator, the rotating lubricant accumulator stores kinetic energy in the form of increased gas pressure of the inert gas. At the same time, the rotating lubricant accumulator rotates, thereby storing additional kinetic energy in the form of angular momentum (e.g., moment of inertia). During normal operation of the turbine engine, the auxiliary pump fills the rotating lubricant accumulator with lubricant, and the hydraulic motor rotates the rotating lubricant accumulator, thereby allowing the rotating lubricant accumulator to rotate to store kinetic energy. When the turbine engine is shut down and the propeller wind is rotating, the first valve is switched to closed to keep the lubricant in the circuit, and the second valve is switched to open to allow the lubricant to flow from the rotating lubricant accumulator to one or more rotating parts to lubricate the one or more rotating parts.

[0026] Thus, the auxiliary lubrication system supplies lubricant to one or more rotating components when the turbine engine is shut down or otherwise rotating under wind power. The kinetic energy storage system 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 power rotation (e.g., whether the propeller is rotating clockwise or counterclockwise). The kinetic energy storage system provides significant energy storage density due to both the pressurized gas and the rotational energy provided by the system.

[0027] 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 1 In 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 turbocharger engine 16 disposed downstream of the propeller section 14.

[0028] The depicted turbocharged engine 16 generally includes a housing 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.

[0029] 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 1In some embodiments, the propeller 38 is a fan driven by the turbocharger engine 16. In some embodiments, the propeller 38 is a propeller driven by the turbocharger 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, the disk 42, and the actuation member 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 1 The 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.

[0030] 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 turbocharger engine 16. The nacelle 50 is supported relative to the turbocharger engine 16 by a plurality of outlet guide vanes 52 that are circumferentially spaced about the nacelle 50 and the turbocharger engine 16. In addition, a downstream section 54 of the nacelle 50 extends over an outer portion of the turbocharger engine 16 to define a bypass airflow passage 56 therebetween.

[0031] 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.

[0032] 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.

[0033] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the turbocharger 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 turbocharger engine 16.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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).

[0039] 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.

[0040] 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).

[0041] 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.

[0042] 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.

[0043] 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 outward of the first power gearbox gear 49a and intermeshing therewith is 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 outward 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 accessory gearbox 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.

[0044] Turbine engine 10 includes an accessory gearbox assembly 80. One or more accessories for turbine engine 10 or the aircraft may be coupled to accessory gearbox assembly 80 for providing power to the one or more accessories. Figure 2 As shown, the accessory gearbox assembly 80 includes an accessory gearbox housing 82 and an accessory gearbox gear assembly 83 including a plurality of accessory gearbox gears 84. The accessory gearbox gear assembly 83 is disposed in the accessory gearbox housing 82. The plurality of accessory gearbox gears 84 include a first accessory gearbox gear 84a and a second accessory gearbox gear 84b that meshes with the first accessory gearbox gear 84a. The plurality of accessory gearbox gears 84 may include any number of gears as desired, and may include any type of gears, such as, for example, spur gears, bevel gears, compound gears, etc.

[0045] The accessory gearbox assembly 80 includes an accessory gearbox input shaft 86 and an accessory gearbox output shaft 88. In an example where the accessory gearbox assembly 80 drives the main pump 108, the accessory gearbox output shaft 88 may include a first output shaft 88a and a second output shaft 88b. The accessory gearbox input shaft 86 is coupled to one of the plurality of accessory gearbox gears 84 to rotate the plurality of accessory gearbox gears 84, as described in further detail below. Figure 2, the accessory gearbox input shaft 86 is coupled to the first accessory gearbox gear 84a. In this manner, rotation of the accessory gearbox input shaft 86 causes the first accessory gearbox gear 84a to rotate. The accessory gearbox output shaft 88 is coupled to at least one of the plurality of accessory gearbox gears 84, such that rotation of the plurality of accessory gearbox gears 84 causes the accessory gearbox output shaft 88 to rotate. Figure 2 , the accessory gearbox output shaft 88 is coupled to the second accessory gearbox gear 84 b such that rotation of the second accessory gearbox gear 84 b rotates the accessory gearbox output shaft 88 .

[0046] The accessory gearbox assembly 80 is coupled to the HP shaft 34 via a tower shaft 90 that extends from and is rotatable with the HP shaft 34. In some embodiments, the accessory gearbox assembly 80 is coupled to the LP shaft 36. Figure 2 , the tower shaft 90 generally extends at least partially in a radial direction R from the HP shaft 34. The tower shaft 90 may extend at an acute angle relative to the longitudinal centerline axis 12, such as Figure 2 . In some embodiments, the tower shaft 90 can extend substantially perpendicular to the HP shaft 34. The tower shaft 90 can be coupled to the HP shaft 34 by a plurality of gears. The tower shaft 90 is coupled to the accessory gearbox input shaft 86 by a tower shaft gear assembly 92 having a plurality of tower shaft gears 94. The plurality of tower shaft gears 94 can be bevel gears or the like. The plurality of tower shaft gears 94 include a first tower shaft gear 94a coupled to the tower shaft 90 and a second tower shaft gear 94b coupled to the accessory gearbox input shaft 86. The first tower shaft gear 94a meshes with the second tower shaft gear 94b so that the rotation of the tower shaft 90 rotates the accessory gearbox input shaft 86. In this way, the tower shaft 90 transmits mechanical energy from the HP shaft 34 to the accessory gearbox output shaft 88 through the accessory gearbox assembly 80, as described in further detail below. One or more rotating components 55 can include the tower shaft 90 or a plurality of tower shaft gears 94.

[0047] 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 Schematically shown in FIG. 1 ) is a reservoir in which lubricant is collected and stored. In some embodiments, the lubrication system 100 may include one or more tanks in which lubricant is stored. Preferably, the lubricant is oil. The lubricant may be any type of lubricant used to lubricate one or more rotating components 55 of the turbine engine 10 (e.g., a plurality of power gearbox gears 49 or one or more power gearbox bearings 53).

[0048] 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 power gearbox assembly 46. The main pump 108 pumps lubricant from the sump 106 to the one or more rotating components 55 through the main lubricant supply line 110 for supplying lubricant to the 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 the accessory gearbox assembly 80 and powered by the accessory gearbox assembly 80, so that the accessory gearbox assembly 80 drives the main pump 108. In this example, the main pump 108 is coupled to the second output shaft 88b, so that the rotation of the second output shaft 88b provides power for the main pump 108. In this way, the second output shaft 88b is the main pump shaft of 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 .

[0049] 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.

[0050] The auxiliary lubrication system 104 includes an auxiliary pump 120, an auxiliary lubricant supply line 122, an auxiliary lubricant supply line valve 124 disposed in the auxiliary lubricant supply line 122, and an auxiliary lubricant return line 126. The auxiliary lubricant supply line 122 is in fluid communication with the sump 106 and one or more rotating components 55. Although the auxiliary lubricant supply line 122 is in fluid communication with the sump 106, the auxiliary lubricant supply line 122 is in fluid communication with the sump 106 and one or more rotating components 55. Figure 2 Although 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 2106, 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 a mechanical pump that is powered by the accessory gearbox assembly 80. The auxiliary lubricant supply line valve 124 is a check valve that opens or closes based on the pressure of the lubricant in the auxiliary lubricant supply line 122 from the sump 106. For example, when the pressure of the lubricant in the auxiliary lubricant supply line 122 from the sump 106 is greater than a lubricant pressure threshold, the auxiliary lubricant supply line valve 124 opens. When the pressure of the lubricant in the auxiliary lubricant supply line 122 from the sump 106 is less than the lubricant pressure threshold, the auxiliary lubricant supply line valve 124 closes. The auxiliary lubricant return line 126 is in fluid communication with the auxiliary lubricant supply line 122 and the sump 106 such that a portion of the lubricant is returned to the sump 106 through the auxiliary lubricant supply line 122 , as described in further detail below.

[0051] The lubrication system 100 includes a kinetic energy storage system 130 that stores kinetic energy and releases kinetic energy to provide power for the auxiliary lubrication system 104, as described in further detail below. The kinetic energy storage system 130 includes a rotating lubricant accumulator 132 that accumulates lubricant during normal operation of the turbine engine 10 and supplies lubricant to one or more rotating components 55 during wind-driven rotation of the turbine engine 10, as described in further detail below. The rotating lubricant accumulator 132 is cylindrical or has a similar shape and includes a first chamber 134 and a second chamber 136, which are fluidly separated by a diaphragm 138. During normal operation of the turbine engine 10, the first chamber 134 is filled with lubricant, as described in further detail below. The second chamber 136 is filled with an inert gas, such as nitrogen, for example. The inert gas in the second chamber 136 has a gas pressure that biases the diaphragm 138 toward the first chamber 134. The diaphragm 138 is a metal disk or the like and is axially movable within the rotational lubricant accumulator 132. In some embodiments, the rotational lubricant accumulator 132 includes one or more springs coupled to the diaphragm 138 and disposed in the second chamber 136 such that the one or more springs bias the diaphragm 138 toward the first chamber 134.

[0052] The auxiliary lubrication system 104 includes an auxiliary lubricant branch line 140 that is fluidly coupled to the auxiliary lubricant supply line 122 and the first chamber 134 of the rotating lubricant accumulator 132. In this manner, a portion of the lubricant is supplied from the sump 106 to the first chamber 134 of the rotating lubricant accumulator 132 through the auxiliary lubricant branch line 140, as described in further detail below.

[0053] The kinetic energy storage system 130 includes a motor 150 having a motor shaft 152, a first kinetic energy storage system valve 160, and a second kinetic energy storage system valve 162. The rotational lubricant accumulator 132 is drivingly coupled to the motor 150 via the motor shaft 152. In this manner, the motor 150 drives the rotational lubricant accumulator 132 to rotate the rotational lubricant accumulator 132, thereby storing kinetic energy, as further described below. The motor 150 is in fluid communication with the auxiliary lubricant return line 126, so that lubricant flows from the auxiliary lubricant supply line 122 through the auxiliary lubricant return line 126, through the motor 150, and into the sump 106 for providing power to the motor 150, as further described below. The first kinetic energy storage system valve 160 is disposed in the auxiliary lubricant supply line 122 (e.g., upstream of the motor 150). The second kinetic energy storage system valve 162 is disposed in the auxiliary lubricant return line 126 (e.g., downstream of the motor 150). The first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162 are, for example, two-way solenoid valves, which are controlled by the controller 79 ( Figure 1 ) is controlled to be open or closed. The first kinetic energy storage system valve 160 is biased to be closed during normal operation of the turbine engine 10, and is opened during wind-driven rotation. The second kinetic energy storage system valve 162 is biased to be closed during wind-driven rotation, and is opened during normal operation of the turbine engine 10, as further described below.

[0054] 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.

[0055] At the same time, the HP shaft 34 rotates and rotates the tower shaft 90, thereby rotating the accessory gearbox input shaft 86 and the plurality of accessory gearbox gears 84 of the accessory gearbox gear assembly 83. The rotation of the plurality of accessory gearbox gears 84 rotates the accessory gearbox output shaft 88. In particular, the rotation of the plurality of accessory gearbox gears 84 rotates the accessory gearbox output shaft 88, thereby providing power to the main pump 108. In this manner, 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 turbine engine 10, lubricant in sump 106 is returned through primary lubrication system 102 so that primary lubrication system 102 continuously supplies lubricant to one or more rotating components 55. In this manner, lubricant may be reused to lubricate one or more rotating components 55.

[0056] When the primary lubrication system 102 is in operation, such as when the turbine engine 10 is operating under normal operation, the auxiliary lubrication system 104 is not in operation. When the auxiliary lubrication system 104 is not in operation, the first kinetic energy storage system valve 160 is closed to prevent lubricant from flowing from the auxiliary lubrication system 104 to one or more rotating components 55. The rotation of the accessory gearbox output shaft 88 provides power to the auxiliary pump 120, causing the auxiliary pump 120 to pump lubricant from the sump 106. The pressure of the lubricant from the auxiliary pump 120 is greater than the lubricant pressure threshold of the auxiliary lubricant supply line valve 124, causing the auxiliary lubricant supply line valve 124 to open and lubricant to flow through the auxiliary lubricant supply line 122 upstream of the first kinetic energy storage system valve 160.

[0057] The auxiliary lubricant branch line 140 directs lubricant into the rotating lubricant accumulator 132. For example, the auxiliary lubricant branch line 140 directs lubricant into the first chamber 134 to fill the first chamber 134 with lubricant. When the lubricant fills the first chamber 134, the lubricant forces the diaphragm 138 to move axially toward the second chamber 136, thereby compressing the inert gas and increasing the gas pressure of the inert gas in the second chamber 136. In this way, the kinetic energy storage system 130 (e.g., the rotating lubricant accumulator 132) stores kinetic energy in the form of increased gas pressure of the inert gas in the second chamber 136.

[0058] At the same time, the auxiliary lubricant return line 126 directs lubricant to the motor 150. The lubricant flows through the motor 150 to power the motor 150, thereby rotating the motor shaft 152. The rotation of the motor shaft 152 rotates the rotating lubricant accumulator 132. In this way, the rotating lubricant accumulator 132 stores additional kinetic energy in the form of angular momentum. In this way, the rotating lubricant accumulator 132 will tend to continue to rotate after the motor 150 stops powering the rotating lubricant accumulator 132.

[0059] During normal operation of the turbine engine 10, the second kinetic energy storage system valve 162 is open, and the auxiliary lubricant return line 126 directs lubricant from the motor 150 to the sump 106. The auxiliary pump 120 continues to pump lubricant from the sump 106, so that the lubricant is recirculated through the kinetic energy storage system 130. In this manner, the lubricant fills the rotating lubricant accumulator 132 (e.g., the first chamber 134) until the gas pressure of the inert gas in the rotating lubricant accumulator 132 increases to the gas pressure threshold. Then, because the rotating lubricant accumulator 132 cannot be further filled, the lubricant is prevented from flowing through the auxiliary lubricant branch line 140. The lubricant then continues to flow through the motor 150 to power the motor 150, so that the motor 150 rotates the rotating lubricant accumulator 132.

[0060] Controller 79( Figure 1 ) controls the first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162 to be opened or closed. In some embodiments, the controller 79 controls the first kinetic energy storage system valve 160 to be closed and the second kinetic energy storage system valve 162 to be opened by providing electrical signals to the first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162, respectively. In some embodiments, the controller 79 controls the first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162 to be opened or closed based on the rotation speed of at least one of the HP shaft 34, the LP shaft 36, or the propeller shaft 45. For example, when the rotation speed of at least one of the HP shaft 34, the LP shaft 36, or the propeller shaft 45 is greater than the rotation speed threshold, the controller 79 controls the first kinetic energy storage system valve 160 to be closed and the second kinetic energy storage system valve 162 to be opened. In some embodiments, the controller 79 controls the first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162 to be opened or closed based on the pressure of the lubricant in the main lubrication system 102. For example, when the pressure of the lubricant in the main lubrication system 102 is greater than the main pressure threshold, the controller 79 controls the first kinetic energy storage system valve 160 to close and the second kinetic energy storage system valve 162 to open.

[0061] 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. 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.

[0062] Therefore, during this situation, the auxiliary lubrication system 104 is activated to supply lubricant to one or more rotating components 55. The first kinetic energy storage system valve 160 is opened to allow lubricant to flow to one or more rotating components 55 through the auxiliary lubricant supply line 122. At the same time, the second kinetic energy storage system valve 162 is closed to prevent lubricant from flowing through the auxiliary lubricant return line 126. In this way, the motor 150 stops rotating the rotating lubricant accumulator 132. In some embodiments, when the first kinetic energy storage system valve 160 and the second kinetic energy storage system valve 162 are not activated by the controller 79 ( Figure 1 ) receives the electrical signal, the first kinetic energy storage system valve 160 is opened and the second kinetic energy storage system valve 162 is closed. In some embodiments, when the rotation speed of at least one of the HP shaft 34, the LP shaft 36, or the propeller shaft 45 is less than the rotation speed threshold, the controller 79 controls the first kinetic energy storage system valve 160 to be opened and the second kinetic energy storage system valve 162 to be closed. In some embodiments, when the pressure of the lubricant in the main lubrication system 102 is less than the main pressure threshold, the controller 79 controls the first kinetic energy storage system valve 160 to be opened and the second kinetic energy storage system valve 162 to be closed.

[0063] When the turbine engine 10 is shut down, or the propeller 38 is otherwise spinning due to wind, the accessory gearbox output shaft 88 does not rotate fast enough to properly power the auxiliary pump 120. In this manner, the pressure of the lubricant from the auxiliary pump 120 is less than the lubricant pressure threshold of the auxiliary lubricant supply line valve 124, causing the auxiliary lubricant supply line valve 124 to close.

[0064] When the turbine engine 10 is shut down, or the propeller 38 is otherwise wind-driven, the kinetic energy storage system 130 releases the stored kinetic energy. The lubricant pressure of the lubricant in the rotating lubricant accumulator 132 (e.g., the first chamber 134) is greater than the lubricant pressure of the lubricant from the auxiliary pump 120. In this manner, the gas pressure of the inert gas in the rotating lubricant accumulator 132 (e.g., the second chamber 136) forces the diaphragm 138 toward the first chamber 134, so that the diaphragm 138 exerts a force on the lubricant in the first chamber 134 to push the lubricant out of the first chamber 134 and through the auxiliary lubricant branch line 140. In this manner, the kinetic energy storage system 130 releases the stored kinetic energy in the form of increased gas pressure of the inert gas. In an embodiment utilizing a spring coupled to the diaphragm 138, the spring can be stretched to release the stored kinetic energy and force the diaphragm 138 toward the first chamber 134.

[0065] At the same time, when the motor 150 no longer rotates the rotating lubricant accumulator 132, the rotating lubricant accumulator 132 releases the stored additional kinetic energy. For example, the angular momentum of the rotating lubricant accumulator 132 continues the rotation of the rotating lubricant accumulator 132. In this way, the rotating lubricant accumulator 132 rotates at a high speed (e.g., between 500 rpm and 5000 rpm). Therefore, the additional kinetic energy stored by the rotating lubricant accumulator 132 is transferred to the diaphragm 138 to help force the diaphragm 138 toward the first chamber 134, thereby forcing the lubricant to leave the rotating lubricant accumulator 132.

[0066] Auxiliary lubricant branch line 140 directs lubricant from rotating lubricant reservoir 132 through auxiliary lubricant supply line 122 and to one or more rotating components 55. In this manner, auxiliary lubrication system 104 supplies lubricant to one or more rotating components 55 when turbine engine 10 is shut down or propeller 38 is otherwise spinning under wind.

[0067] 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 kinetic energy storage system 130 ensures that the auxiliary lubrication system 104 operates to supply lubricant to the one or more rotating components 55, regardless of the direction of rotation of the propeller 38 during wind-driven rotation (e.g., whether the propeller is rotating clockwise or counterclockwise). The kinetic energy storage system 130 also reduces the complexity of the auxiliary lubrication system 104 by providing power to the auxiliary pump 120, without being constrained by the rotation of the propeller shaft or other shafts of the turbine engine 10, compared to an auxiliary lubrication system without the benefit of the present disclosure.

[0068] Further aspects of the disclosure are provided by the subject matter of the following clauses.

[0069] 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, the main lubrication system 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 kinetic energy storage system, the kinetic energy storage system comprising a rotating lubricant accumulator, during the normal operation of the turbine engine, the auxiliary pump pumps the lubricant from the tank to the rotating lubricant accumulator to at least partially fill the rotating lubricant accumulator with the lubricant, thereby storing kinetic energy, and when the propeller rotates due to wind force, the rotating lubricant accumulator releases the kinetic energy to supply the lubricant from the rotating lubricant accumulator to the one or more rotating parts.

[0070] Lubrication system according to the preceding clause, wherein during the normal operation of the turbine engine, the auxiliary pump pumps the lubricant from the sump to the rotating lubricant accumulator to fill the rotating lubricant accumulator with the lubricant.

[0071] A lubrication system according to any preceding clause, the turbine engine comprising an accessory gearbox assembly having a plurality of accessory gearbox gears, and the auxiliary pump being drivingly coupled to the plurality of accessory gearbox gears such that rotation of the plurality of accessory gearbox gears provides power to the auxiliary pump.

[0072] According to the lubrication system described in any of the preceding clauses, the kinetic energy storage system includes a first kinetic energy storage system valve, which is closed during normal operation of the turbine engine, and the first kinetic energy storage system valve prevents the lubricant from flowing through the auxiliary lubrication system to the one or more rotating parts, so that the auxiliary lubrication system does not operate during normal operation of the turbine engine.

[0073] A lubrication system according to any preceding clause, wherein when the propeller is wind-driven, the first kinetic energy storage system valve opens such that lubricant is supplied from the rotational lubricant reservoir to the one or more rotating components.

[0074] According to the lubrication system described in any of the preceding clauses, the kinetic energy storage system includes a second kinetic energy storage system valve, which is opened during the normal operation of the turbine engine so that a portion of the lubricant passing through the auxiliary lubrication system flows to the storage tank through the second kinetic energy storage system valve, and when the propeller is rotated by wind, the second kinetic energy storage system valve is closed, thereby preventing the portion of the lubricant passing through the auxiliary lubrication system from flowing to the storage tank.

[0075] According to the lubrication system of any preceding clause, the rotating lubricant accumulator includes a first chamber, a second chamber, and a diaphragm arranged between the first chamber and the second chamber, and the first chamber is filled with the lubricant, and during normal operation of the turbine engine, the diaphragm moves axially toward the second chamber to store the kinetic energy.

[0076] A lubrication system as described in any preceding clause, wherein when the propeller is wind-driven, the diaphragm moves axially towards the first chamber to force the lubricant from the rotating lubricant reservoir to the one or more rotating components.

[0077] A lubrication system according to any preceding clause, the second chamber being filled with an inert gas and the gas pressure of the inert gas increasing when the diaphragm moves axially towards the second chamber to store the kinetic energy.

[0078] A lubrication system according to any preceding clause, the kinetic energy storage system comprising an electric motor which, during normal operation of the turbine engine, powers the rotating lubricant accumulator, causing it to rotate and store additional kinetic energy.

[0079] According to the lubrication system described in any preceding clause, when the propeller is rotated by wind power, the rotating lubricant accumulator releases the additional kinetic energy to supply the lubricant from the rotating lubricant accumulator by continuing to rotate after the electric motor stops providing power to the rotating lubricant accumulator.

[0080] A lubrication system as described in any preceding clause, the turbine engine comprising a power gearbox assembly having a plurality of power gearbox gears.

[0081] 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.

[0082] A lubrication system according to any preceding clause, wherein the one or more power gearbox bearings are journal bearings.

[0083] The lubrication system of any preceding clause, the turbine engine further comprising a tower shaft coupled to at least one of the high pressure shaft or the low pressure shaft.

[0084] A lubrication system as described in any preceding clause, the accessory gearbox assembly further comprising an accessory gearbox input shaft and an accessory gearbox output shaft.

[0085] A lubrication system as described in any preceding clause, the accessory gearbox input shaft being drivingly coupled to the tower shaft.

[0086] A lubrication system as described in any preceding clause, the accessory gearbox input shaft being drivingly coupled to the tower shaft via a tower shaft gear assembly.

[0087] A lubrication system as described in any preceding clause, the accessory gearbox assembly having an accessory gearbox housing, the plurality of accessory gearbox gears being disposed within the accessory gearbox housing.

[0088] A lubrication system as described in any preceding clause, the plurality of accessory gearbox gears comprising a first accessory gearbox gear and a second accessory gearbox gear.

[0089] A lubrication system as described in any preceding clause, the accessory gearbox input shaft being coupled to the first accessory gearbox gear.

[0090] A lubrication system as described in any preceding clause, the accessory gearbox output shaft being coupled to the second accessory gearbox gear.

[0091] A lubrication system as claimed in any preceding clause, the auxiliary lubrication system comprising an auxiliary lubricant supply line in fluid communication with the sump and the one or more rotating components.

[0092] A lubrication system as claimed in any preceding clause, the main lubrication system comprising a main lubricant supply line in fluid communication with the sump and the one or more rotating components.

[0093] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary lubricant supply line valve which opens to allow the lubricant to flow from the sump to the rotating lubricant accumulator during normal operation of the turbine engine.

[0094] A lubrication system according to any preceding clause, wherein when the propeller is wind-driven, the auxiliary lubricant supply line valve is closed to prevent the lubricant from flowing from the sump to the rotating lubricant reservoir.

[0095] A lubrication system according to any preceding clause, the auxiliary lubrication system further comprising an auxiliary lubricant branch line in fluid communication with the auxiliary lubricant supply line and the rotating lubricant accumulator.

[0096] A lubrication system according to any preceding clause, wherein the inert gas is nitrogen.

[0097] A turbine engine comprising a propeller and a turbocharger having a shaft, the propeller being drivingly coupled to the shaft. The turbine engine comprises a lubrication system according to any preceding clause.

[0098] 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 via a main lubrication system during normal operation of the turbine engine; pumping the lubricant from the storage tank to the rotating lubricant accumulator with the auxiliary pump during normal operation of the turbine engine; storing kinetic energy in the rotating lubricant accumulator by filling the rotating lubricant accumulator with the lubricant during normal operation of the turbine engine; and supplying the lubricant from the rotating lubricant accumulator to the one or more rotating components by releasing the kinetic energy when the propeller is rotated by wind force.

[0099] A method according to any preceding clause, the turbine engine comprising an accessory gearbox assembly having a plurality of accessory gearbox gears, and the method further comprising driving the auxiliary pump with the plurality of accessory gearbox gears such that rotation of the plurality of accessory gearbox gears provides power to the auxiliary pump.

[0100] A method according to any preceding clause, the kinetic energy storage system comprising a first kinetic energy storage system valve, and the method further comprising preventing the lubricant from flowing through the auxiliary lubrication system to the one or more rotating components by closing the first kinetic energy storage system valve during normal operation of the turbine engine.

[0101] A method according to any preceding clause, further comprising opening the first kinetic energy storage system valve when the propeller is wind-driven, such that the lubricant is supplied from the rotational lubricant reservoir to the one or more rotating components.

[0102] A method according to any preceding clause, wherein the kinetic energy storage system includes a second kinetic energy storage system valve, and the method further includes directing a portion of the lubricant through the auxiliary lubrication system to the storage tank by opening the second kinetic energy storage system valve during normal operation of the turbine engine, and preventing the portion of the lubricant from flowing through the auxiliary lubrication system and to the storage tank by closing the second kinetic energy storage system valve when the propeller is wind-driven.

[0103] According to a method according to any preceding clause, the rotational lubricant accumulator comprises a first chamber, a second chamber, and a diaphragm disposed between the first chamber and the second chamber, and the method further comprises filling the first chamber with the lubricant so that during normal operation of the turbine engine, the diaphragm moves axially toward the second chamber to store the kinetic energy.

[0104] A method according to any preceding clause, further comprising moving the diaphragm axially towards the first chamber when the propeller is wind-driven to force the lubricant from the rotational lubricant reservoir to the one or more rotating components.

[0105] A method according to any preceding clause, the second chamber being filled with an inert gas, and the method further comprising increasing a gas pressure of the inert gas when the diaphragm is moved axially towards the second chamber to store the kinetic energy.

[0106] A method according to any preceding clause, the kinetic energy storage system comprising an electric motor, and the method further comprising powering the rotating lubricant accumulator with the electric motor during normal operation of the turbine engine, causing the rotating lubricant accumulator to rotate and store additional kinetic energy.

[0107] The method according to any preceding clause further comprises, when the propeller is wind-driven, releasing the additional kinetic energy from the rotating lubricant accumulator to supply the lubricant from the rotating lubricant accumulator by continuing to rotate after the electric motor stops powering the rotating lubricant accumulator.

[0108] A method as in any preceding clause, the lubrication system being a lubrication system as in any preceding clause.

[0109] 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 kinetic energy storage system comprising a rotating lubricant accumulator, wherein during the normal operation of the turbine engine, the auxiliary pump pumps the lubricant from the storage tank to the rotating lubricant accumulator to at least partially fill the rotating lubricant accumulator with the lubricant, thereby storing kinetic energy, and when the propeller is wind-drivenly rotated, the rotating lubricant accumulator releases the kinetic energy to supply the lubricant from the rotating lubricant accumulator to the one or more rotating components.

2. The lubrication system according to claim 1, characterized in that: Wherein the turbine engine includes an accessory gearbox assembly having a plurality of accessory gearbox gears, and the auxiliary pump is drivingly coupled to the plurality of accessory gearbox gears such that rotation of the plurality of accessory gearbox gears powers the auxiliary pump.

3. The lubrication system according to claim 1, characterized in that: The kinetic energy storage system includes a first kinetic energy storage system valve, which is closed during normal operation of the turbine engine, and the first kinetic energy storage system valve prevents the lubricant from flowing to the one or more rotating components through the auxiliary lubrication system, so that the auxiliary lubrication system does not operate during normal operation of the turbine engine.

4. The lubrication system according to claim 3, characterized in that: When the propeller is rotated by wind, the first kinetic energy storage system valve opens, so that the lubricant is supplied from the rotating lubricant reservoir to the one or more rotating components.

5. The lubrication system according to claim 3, characterized in that: The kinetic energy storage system includes a second kinetic energy storage system valve, which is opened during the normal operation of the turbine engine so that a portion of the lubricant passing through the auxiliary lubrication system flows to the storage tank through the second kinetic energy storage system valve, and when the propeller rotates by wind, the second kinetic energy storage system valve is closed, thereby preventing the portion of the lubricant passing through the auxiliary lubrication system from flowing to the storage tank.

6. The lubrication system according to claim 1, characterized in that: The rotary lubricant accumulator includes a first chamber, a second chamber, and a diaphragm disposed between the first chamber and the second chamber, and the first chamber is filled with the lubricant, and during the normal operation of the turbine engine, the diaphragm moves axially toward the second chamber to store the kinetic energy.

7. The lubrication system according to claim 6, characterized in that: Wherein when the propeller is rotated by wind force, the diaphragm moves axially toward the first chamber to force the lubricant from the rotating lubricant reservoir to the one or more rotating components.

8. The lubrication system according to claim 7, characterized in that: The second chamber is filled with an inert gas, and when the diaphragm moves axially toward the second chamber to store the kinetic energy, a gas pressure of the inert gas increases.

9. The lubrication system according to claim 6, characterized in that: The kinetic energy storage system includes an electric motor that powers the rotating lubricant accumulator during normal operation of the turbine engine, causing the rotating lubricant accumulator to rotate and store additional kinetic energy.

10. The lubrication system according to claim 9, characterized in that: Wherein when the propeller is rotated by wind, the rotating lubricant accumulator releases the additional kinetic energy to supply the lubricant from the rotating lubricant accumulator to the one or more rotating components by continuing to rotate after the electric motor stops providing power to the rotating lubricant accumulator.

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