Lubrication system for a turbine engine

Abstract

A lubrication system for a turbine engine includes one or more rotating components. The lubrication system includes one or more tanks that store lubricant, a primary lubrication system, and an auxiliary lubrication system. The primary lubrication system supplies lubricant from the one or more tanks to the one or more rotating components during stable operating conditions of the lubrication system. The auxiliary lubrication system includes an auxiliary feed line and an auxiliary supply line. The auxiliary lubrication system receives lubricant from the one or more tanks through an auxiliary feed line. When there is a potential lubricant interruption in the lubrication system, the auxiliary lubrication system supplies lubricant to the one or more rotating components through the auxiliary supply line.

Description

Technical Field

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

[0002] A turbine engine typically includes a fan and a core section arranged in fluid communication with each other. The turbine engine includes one or more rotating components that rotate or support the rotation of other components of the turbine engine. A lubrication system provides lubrication for the one or more rotating components. 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 Details in 2 Figure 1 A schematic cross-sectional side view of a turbine engine gearbox assembly.

[0006] Figure 3 According to the present disclosure, Figure 1 Schematic diagram of the lubrication system of a turbine engine.

[0007] Figure 4 According to another embodiment, Figure 1 Schematic diagram of the lubrication system of a turbine engine.

[0008] Figure 5 According to another embodiment, Figure 1 Schematic diagram of the lubrication system of a turbine engine.

[0009] Figure 6 According to another embodiment, Figure 1 Schematic diagram of the lubrication system of a turbine engine.

[0010] Figure 7 According to another embodiment, Figure 1 Schematic diagram of the lubrication system of a turbine engine.

[0011] Figure 8 is a flow chart of a method of lubricating one or more rotating components of a turbine engine having a lubrication system according to the present disclosure. DETAILED DESCRIPTION

[0012] The features, advantages and embodiments of the present invention are set forth or apparent from 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 disclosure claimed.

[0013] 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 art will recognize that other components and configurations may be used without departing from the present disclosure.

[0014] The terms “first,” “second,” and “third” may be used interchangeably herein to distinguish one component from another and are not intended to indicate the position or importance of each component.

[0015] The terms "upstream" and "downstream" refer to relative directions relative to the flow of fluid in a fluid channel. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction toward which the fluid flows.

[0016] The terms "fore" and "aft" 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, in a high-bypass turbine engine, the front position refers to a position near the engine inlet, and the aft position refers to a position near the engine nozzle or exhaust. In one example, in a reverse-flow turbine engine, the front position refers to a position near the engine nozzle or exhaust, and the aft position refers to a position near the engine inlet.

[0017] Unless otherwise specified 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.

[0018] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0019] As used herein, the terms "axial" and "axially" refer to directions and orientations extending substantially parallel to the centerline of a turbine engine. Furthermore, the terms "radial" and "radially" refer to directions and orientations extending substantially perpendicular to the centerline of a turbine engine. Furthermore, as used herein, the terms "circumferential" and "circumferentially" refer to directions and orientations extending in an arc about the centerline of a turbine engine.

[0020] As used herein, "normal operation" of a turbine engine refers to operation of the turbine engine while the primary lubrication system of the turbine engine is supplying lubricant to one or more rotating components of the turbine engine.

[0021] As used herein, a "positive-G condition" occurs when the G force experienced by the turbine engine is positive, such as when the turbine engine is subjected to an acceleration having at least one vector component directed toward the bottom of the turbine engine due to a combination of G force and maneuvering acceleration. For example, a positive-G condition occurs when the turbine engine is parked on the ground or in a horizontal or substantially horizontal phase of flight.

[0022] As used herein, "negative gravity" or a "negative gravity condition" occurs when the gravity experienced by the turbine engine is negative, e.g., when the turbine engine is subjected to an acceleration having at least one vector component directed toward the top of the turbine engine due to a combination of gravity and maneuvering acceleration. For example, a negative gravity condition may occur when the turbine engine is accelerating toward the Earth at a rate equal to or greater than the rate of gravity, or when decelerating at the end of a vertical ascent.

[0023] As used herein, a "stable operating condition" occurs when the turbine engine is operating under positive g-force conditions and the primary lubrication system supplies lubricant to one or more rotating components at a continuous pressure greater than a minimum lubricant pressure threshold. Thus, the primary lubrication system is capable of adequately pumping lubricant to the one or more rotating components. Thus, during a stable operating condition, lubricant in the one or more tanks is supplied to the pump.

[0024] As used herein, a "minimum lubricant pressure threshold" or "lubricant pressure threshold" is the minimum pressure supplied from the primary lubrication system to one or more rotating components to balance the pressure between the rotating components (and their seals) to minimize the intrusion of air into the primary lubrication system and to minimize the loss of lubricant through the seals. The minimum lubricant pressure threshold is based on the operating pressure of the primary lubrication system of the engine, which depends on the rotating components (e.g., based on the type of bearings) and on the operating pressure ratio of the engine. The operating pressure ratio defines the pressure rating of the bearings and seals. In examples where the rotating components are journal bearings, the minimum lubricant pressure threshold is also based on the design of the bearings and the load on the bearings. In some examples, the minimum lubricant pressure threshold is approximately seventy-five percent of the normal operating pressure.

[0025] As used herein, "windover" or "windward" refers to a condition in which the fan 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. Windover may occur when the turbine engine is shut down but air is still flowing through the fan, such as during an in-flight engine shutdown, or when the turbine engine is on the ground and the fan rotates in the presence of wind while the turbine engine is shut down. During shutdown, such as when the aircraft is on the ground, the fan may also rotate in either direction relative to the ambient wind depending on the fixed position of the turbine engine. Airflow entering the fan exhaust may exit the fan inlet in the opposite direction as the operating direction, causing the fan to rotate in the opposite direction of rotation relative to the intended operating direction of rotation.

[0026] As used herein, a "check valve" is a one-way valve that allows fluid to flow through the check valve in only one direction. The check valves detailed herein may include any type of valve that allows fluid to move in only one direction.

[0027] As used herein, a "control valve" is a valve used to control the flow of a fluid by changing the size of a flow passage of the valve as directed by a signal from a controller. The control valves detailed herein may include any type of valve controlled by a controller.

[0028] As used herein throughout the specification and claims, approximating language is used to modify any quantitative expression that is permissible to vary without resulting in a change in the basic function to which it is associated. Thus, a value modified by one or more terms such as "about," "approximately," "generally," and "substantially" is not limited to the precise value specified. In at least some cases, approximating language may correspond to the precision of an instrument used to measure a value, or the precision of a method or machine used to construct or manufacture a component or system. For example, approximating language may refer to being within one percent, two percent, four percent, ten percent, fifteen percent, or twenty percent of a single value, a range of values, or an endpoint of a defined range of values.

[0029] The present disclosure provides a turbine engine having a lubrication system. The turbine engine includes one or more rotating components that rotate within the turbine engine. The one or more rotating components may include, for example, one or more shafts, one or more gears, or one or more bearings. The one or more bearings may 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 gear bearings for a gear assembly of the turbine engine. The one or more gear bearings allow one or more gears of the gear assembly to rotate about the one or more gear bearings. In one embodiment, the one or more bearings are journal bearings. The one or more bearings may include any type of bearing, such as roller bearings. The lubrication system supplies lubricant (e.g., oil) to the one or more rotating components. The lubrication system includes one or more tanks for storing the lubricant, and a primary lubrication system having a primary pump and a primary supply line. During normal operation of the turbine engine, the primary pump pumps lubricant from the one or more tanks to the one or more rotating components via the primary supply line. The primary lubrication system generally requires positive gravity conditions to effectively pump the lubricant from the one or more tanks. For example, the lubricant flows through the bottom of the one or more tanks, and gravity helps maintain fluid communication between the lubricant and the pump. In this way, the pump pumps the lubricant without pumping air within the one or more tanks.

[0030] Bearings, particularly journal bearings, are hydrodynamic bearings that typically require a steady supply of lubricant during all phases of operation of the turbine engine to properly lubricate the bearings to prevent damage due to sliding contact of the hydrodynamic journal bearings and even the gear meshing interfaces in general. The turbine engine may experience negative g-force conditions during operation. For example, under negative g-force conditions, lubricant will float to the top of one or more tanks, which can interrupt the flow of lubricant through the primary lubrication system. Similarly, the flow of lubricant through the primary lubrication system may be interrupted by violent maneuvers, such as collision avoidance, aircraft yaw, turbulence, flying through air pockets, or downdrafts in the atmosphere. In such circumstances, one or more rotating components, particularly one or more bearings, may be affected by not receiving sufficient lubricant to lubricate the one or more rotating components.

[0031] The severity of lubrication interruptions is increased when the bearing is a journal bearing, as a lack of lubricant in the journal bearing can lead to journal bearing failure and subsequent gearbox failure, which can cause permanent locking of the low-speed shaft. This type of journal bearing failure is called journal bearing seizure and occurs when contact between the planet pin and the gear bore occurs, which causes increased 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 friction. Even brief lubrication interruptions (e.g., 30 to 50 milliseconds) can cause journal bearing seizure.

[0032] Some turbine engines include auxiliary lubrication systems that provide lubricant to one or more rotating components to prevent damage to the rotating components due to insufficient lubricant supply. However, such auxiliary lubrication systems may experience delays in the delivery of lubricant to the one or more components. For example, such auxiliary lubrication systems typically deliver lubricant only after the primary lubrication system loses pressure. Consequently, such auxiliary lubrication systems cannot prevent interruptions in the flow of lubricant to the one or more rotating components.

[0033] Thus, the present invention provides an auxiliary lubrication system that supplies lubricant to one or more rotating components when a turbine engine approaches a negative g-force condition to avoid any interruption in the flow of lubricant to the one or more rotating components. In some embodiments, the auxiliary lubrication system incorporates a three-axis accelerometer for measuring the inertia of the turbine engine and a controller for predicting potential lubricant pressure interruptions due to negative g-force conditions. In some embodiments, the auxiliary lubrication system includes a gyroscope for measuring rotational forces acting on the turbine engine and the lubrication system. The auxiliary lubrication system anticipates potential lubricant interruptions based on the predictions and supplies lubricant to the one or more rotating components before the interruption actually occurs.

[0034] In one exemplary embodiment, the auxiliary lubrication system is an actively controlled system controlled by a controller. The controller determines inertial and gravitational forces acting on the turbine engine and lubrication system to predict a lubricant interruption in the primary lubrication system. Under stable operating conditions (e.g., positive g-force conditions), the controller fills an auxiliary accumulator with lubricant and pressurizes the auxiliary accumulator using a pressure source. The pressure source can be pressurized air or an actuator in the auxiliary accumulator. The pressurized air is regulated to maintain the pressure in the auxiliary accumulator slightly below the lubricant pressure in the primary lubrication system. The actuator pushes lubricant out of the auxiliary accumulator. The auxiliary accumulator includes a lubricant bladder that stores lubricant. The lubricant bladder is coupled to the bottom of the auxiliary accumulator so that the bladder prevents lubricant from floating to the top of the auxiliary accumulator. When the controller determines that the forces acting on the turbine engine indicate a negative g-force condition that could interrupt the flow of lubricant from one or more tanks to the primary pump, the controller controls the auxiliary lubrication system to release lubricant from the auxiliary accumulator. In this way, the auxiliary lubrication system provides lubricant to replenish lubricant in the primary lubrication system before the interruption. Thus, the auxiliary lubrication system helps avoid any lubricant interruptions.

[0035] In one exemplary embodiment, the auxiliary lubrication system is a semi-active control system. A controller controls the auxiliary lubrication system to fill the auxiliary accumulator with lubricant. The auxiliary lubrication system passively supplies lubricant to one or more rotating components without requiring the controller to control valves or actuators to force lubricant out of the auxiliary accumulator. Thus, the auxiliary accumulator is charged by pressurizing the lubricant at a predetermined pressure. When the lubricant pressure in the primary lubrication system is less than the lubricant pressure in the auxiliary accumulator, the auxiliary lubrication system supplies lubricant to the one or more rotating components. In one exemplary embodiment, the auxiliary lubrication system is a passive system, such that lubricant is supplied from the primary lubrication system to the auxiliary accumulator without the use of a controller-controlled component.

[0036] Referring now to the accompanying drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 according to an embodiment of the present disclosure, taken along the longitudinal centerline axis 12 of the turbine engine 10. Figure 1 As shown, the turbine engine 10 defines an axial direction A (extending parallel to a longitudinal centerline axis 12 provided for reference) and a radial direction R orthogonal to the axial direction A. Generally, the turbine engine 10 includes a fan section 14 and a turbocharger 16 disposed downstream of the fan section 14 .

[0037] The turbocharger engine 16 includes a compressor section 21, a combustion section 26, and a turbine section 27 in series flow relationship. The turbocharger engine 16 is substantially enclosed within an outer casing 18, which is substantially tubular and defines an annular core inlet 20. Figure 1As shown schematically, compressor section 21 includes a supercharger or low-pressure (LP) compressor 22, downstream of which is a high-pressure (HP) compressor 24. A combustion section 26 is located downstream of compressor section 21. A turbine section 27 is located downstream of combustion section 26 and includes a high-pressure (HP) turbine 28, downstream of which is a low-pressure (LP) turbine 30. Turbocharged engine 16 also includes an exhaust nozzle section 32, a high-pressure (HP) shaft 34 or HP spool, and a low-pressure (LP) shaft 36 or LP spool, located downstream of turbine section 27. HP shaft 34 drivingly connects HP turbine 28 to HP compressor 24. HP turbine 28 and HP compressor 24 rotate in unison via HP shaft 34. LP shaft 36 drivingly connects LP turbine 30 to LP compressor 22. LP turbine 30 and LP compressor 22 rotate in unison via LP shaft 36. The compressor section 21, combustion section 26, turbine section 27, and exhaust nozzle section 32 together define a core air flow path.

[0038] The turbine engine 10 includes one or more rotating components 37 that are lubricated by a lubricant (e.g., oil) to support rotation of the one or more rotating components 37, as described in further detail below. 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 39 to allow rotation of the HP shaft 34 and the LP shaft 36. The one or more engine bearings 39 may include any type of bearing, such as a roller bearing, etc. The turbine engine 10 may include any number of engine bearings 39 for supporting various rotating components within the turbine engine 10. Thus, the one or more rotating components 37 may include one or more engine bearings 39.

[0039] for Figure 1 In the illustrated embodiment, fan section 14 includes a fan 38 (eg, a variable pitch fan) having a plurality of fan blades 40 coupled to a disk 42 in a spaced-apart manner. Figure 1 As shown, a plurality of fan blades 40 generally extend outwardly from a disk 42 in a radial direction R. In the case of a variable pitch fan, the plurality of fan blades 40 can rotate about a pitch axis P relative to the disk 42 because the plurality of fan blades 40 are operably coupled to an actuating member 44 that is configured to collectively and uniformly change the pitch of the fan blades 40, as described in further detail below. The plurality of fan blades 40, the disk 42, and the actuating member 44 can rotate together about the longitudinal centerline axis 12 via a fan shaft 45 that is powered by the LP shaft 36 across a power gearbox (also referred to as a gearbox assembly 46). In this way, the fan 38 is drivingly coupled to and powered by the turbocharger engine 16, which is an indirectly driven engine. The gearbox assembly 46 is Figure 1The gearbox assembly 46 is a reduction gearbox assembly for adjusting the rotational speed of the fan shaft 45 when power is transmitted from the LP shaft 36 to the fan shaft 45 , thereby adjusting the rotational speed of the fan 38 relative to the LP shaft 36 .

[0040] Still refer to Figure 1 In an exemplary embodiment, the disk 42 is covered by a fan hub 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. In one non-limiting embodiment, the fan section 14 includes an annular fan casing or nacelle 50 that circumferentially surrounds the fan 38. In some embodiments, the nacelle 50 circumferentially surrounds 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 outside of the turbocharger engine 16 and, together with the outer casing 18, defines a bypass airflow passage 56 therebetween.

[0041] During operation of turbine engine 10, a volume of air 58 enters turbine engine 10 through nacelle 50 or an inlet 60 of fan section 14. As volume of air 58 passes through fan blades 40, a first portion of the air, also referred to as bypass air 62, is directed into bypass airflow passage 56, and a second portion of the air, referred to as core air 64, is directed into an upstream section of the core air flow path through core inlet 20 of LP compressor 22. The ratio between bypass air 62 and core air 64 is generally referred to as the bypass ratio. The pressure of core air 64 is then increased, producing compressed air 65. Compressed air 65 is directed through HP compressor 24 and into combustion section 26, where compressed air 65 is mixed with fuel and ignited to produce combustion gases 66.

[0042] The combustion gases 66 are directed into and expanded by the HP turbine 28, where a portion of the thermal and kinetic energy from the combustion gases 66 is extracted via one or more stages of HP turbine stator vanes 68 and HP turbine rotor blades 70 coupled to the HP shaft 34. This causes the HP shaft 34 to rotate, thereby supporting the operation of the HP compressor 24 (a self-sustaining cycle). Thus, the combustion gases 66 perform work on the HP turbine 28. The combustion gases 66 are then directed into and expanded by the LP turbine 30. Here, a second portion of the thermal and kinetic energy is extracted from the combustion gases 66 via one or more stages of LP turbine stator vanes 72 and LP turbine rotor blades 74 coupled to the LP shaft 36. This causes the LP shaft 36 to rotate, which, via the gearbox assembly 46, supports the operation of the LP compressor 22 (a self-sustaining cycle) and the rotation of the fan 38. Thus, the combustion gases 66 perform work on the LP turbine 30.

[0043] The combustion gases 66 are then directed through the jet exhaust nozzle section 32 of the turbocharger engine 16 to provide propulsive thrust. Simultaneously, the bypass air 62 is directed through the bypass airflow passage 56 before being discharged from the fan nozzle exhaust section 76 of the turbine engine 10, also providing propulsive thrust. 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.

[0044] The controller 100 is in communication with the turbine engine 10 for controlling aspects of the turbine engine 10. For example, the controller 100 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 100 or components thereof may be located on the turbine engine 10, on the aircraft, or may be located remotely from each of the turbine engine 10 and the aircraft. The controller 100 may be a full authority digital engine control (FADEC) that controls various aspects of the turbine engine 10.

[0045] The controller 100 can be a stand-alone controller or part of an engine controller to operate various systems of the turbine engine 10. In the present embodiment, the controller 100 is a computing device having one or more processors and a memory. The one or more processors can 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 can include one or more computer-readable media, including but not limited to non-transitory computer-readable media, computer-readable non-volatile media (e.g., flash memory), RAM, ROM, a hard drive, a flash drive, or other memory devices.

[0046] The memory can store information accessible to 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, when executed by one or more processors, cause the one or more processors and the controller 100 to perform operations. The controller 100, and more specifically, the 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 the one or more processors to perform any operations and functions configured for the controller 100, as will be further described below. The instructions can be software written in any suitable programming language or can be implemented in hardware. In addition, or alternatively, the instructions can be executed on the processor in logically or virtually separate threads. The memory can also store data accessible by one or more processors.

[0047] The technology discussed herein relates to computer-based systems and actions taken by computer-based systems, as well as information sent to and from computer-based systems. Those skilled in the art will recognize that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions between 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 distributed across multiple systems. Distributed components can operate sequentially or in parallel.

[0048] Figure 1 The turbine engine 10 shown is for example only. In other exemplary embodiments, the turbine engine 10 can have any other suitable configuration. For example, in other exemplary embodiments, the fan 38 can be configured in any other suitable manner (e.g., as a fixed pitch fan) and can also be supported using any other suitable fan frame configuration. The turbine engine 10 can also be a direct drive engine without a power gearbox. The fan speed is the same as the low-pressure shaft speed of the direct drive engine. In addition, in other exemplary embodiments, any other suitable number or configuration of compressors, turbines, shafts, or combinations thereof can be provided. In other exemplary embodiments, aspects of the present disclosure can be incorporated into any other suitable turbine engine, such as a turbofan engine, an open rotor engine, a turbojet engine, a turboprop engine, or a turboshaft engine.

[0049] Figure 2 is a schematic cross-sectional side view of a gearbox assembly 46 of a turbine engine 10 according to the present disclosure, taken from Figure 1Detail 2. The gearbox assembly 46 includes a gear assembly 47 enclosed by a gearbox housing 49. The gear assembly 47 includes a plurality of gears 51. The plurality of gears 51 include a first gear 51a, one or more second gears 51b and a third gear 51c fixed by a planet carrier 53. Figure 2 In the embodiment, first gear 51a is a sun gear, one or more second gears 51b are planetary gears, and third gear 51c is a ring gear. Gear assembly 47 may be an epicyclic gear assembly. When gear assembly 47 is an epicyclic gear assembly, one or more second gears 51b include a plurality of second gears 51b (e.g., two or more second gears 51b).

[0050] In a planetary gear assembly, the gear assembly 47 may be a star arrangement or a rotating ring gear type gear assembly (e.g., the third gear 51c rotates and the planet carrier 53 is fixed stationary). In such an arrangement, the fan 38 ( Figure 1 ) is driven by the third gear 51c. For example, the third gear 51c is coupled to the fan shaft 45 so that rotation of the third gear 51c causes the fan shaft 45 to rotate, thereby rotating the fan 38. Thus, the third gear 51c is the output of the gear assembly 47. However, other suitable types of gear assemblies may be employed. In one non-limiting embodiment, the gear assembly 47 is a planetary arrangement in which the third gear 51c is held stationary, allowing the planet carrier 53 to rotate. In such an arrangement, the fan 38 is driven by the planet carrier 53. For example, the planet carrier 53 is coupled to the fan shaft 45 so that rotation of the planet carrier 53 causes the fan shaft 45 to rotate, thereby causing the fan 38 to rotate. Thus, one or more second gears 51b (e.g., via the planet carrier 53) are the outputs of the gear assembly 47. In another non-limiting embodiment, the gear assembly 47 may be a differential gear assembly that allows both the third gear 51c and the planet carrier 53 to rotate. Although an epicyclic gear assembly is described in detail herein, the gear assembly may include any type of gear assembly, such as a compound gear assembly, a multi-stage gear assembly, a gear assembly for driving a propeller, a gear assembly for driving accessories of the turbine engine 10 or accessories of an aircraft, etc.

[0051] The first gear 51a is coupled to the input shaft of the turbine engine 10. For example, the first gear 51a is coupled to the LP shaft 36 such that rotation of the LP shaft 36 causes the first gear 51a to rotate. One or more second gears 51b are radially outwardly of the first gear 51a and intermesh with the first gear 51a. The one or more second gears 51b are coupled together and supported by a planet carrier 53. The planet carrier 53 supports and constrains the one or more second gears 51b, allowing each of the one or more second gears 51b to rotate about its respective axis, rather than around the periphery of the first gear 51a. The third gear 51c is radially outwardly of the one or more second gears 51b and intermeshes with the one or more second gears 51b. The third gear 51c is a ring gear. The third gear 51c is coupled to the fan 38 via an output shaft and rotates to drive the fan 38 to rotate about the longitudinal centerline axis 12. For example, the fan shaft 45 is coupled to the third gear 51c.

[0052] The plurality of gears 51 include one or more gear bearings 55 disposed therein. For example, the one or more second gears 51b each include one or more gear bearings 55 disposed therein. The one or more gear bearings 55 enable the plurality of gears 51 to rotate around the one or more gear bearings 55, so that the plurality of gears 51 rotate. The one or more gear bearings 55 may include any type of bearing used for gears, such as a journal bearing, a roller bearing, etc. Figure 2 In the embodiment of the present invention, the one or more gear bearings 55 are journal bearings defined between the one or more second gears 51b and a pin 57 provided through the one or more second gears 51b. For example, lubricant is provided between the pin 57 and the corresponding second gear 51b, thereby generating a lubricant film to allow the corresponding second gear 51b to rotate relative to the pin 57. The plurality of gears 51 and the one or more gear bearings 55 are rotating components of the turbine engine 10. In some embodiments, the one or more rotating components 37 include one or more shafts of the turbine engine 10 (e.g., the HP shaft 34, the LP shaft 36, or the fan shaft 45). Therefore, the one or more rotating components 37 include at least one of the one or more shafts 34, 36, 45, the one or more engine bearings 39, the plurality of gears 51, or the one or more gear bearings 55.

[0053] The turbine engine 10 includes a lubrication system 200 for supplying lubricant to one or more rotating components 37, as described in further detail below. The lubrication system 200 may embody any lubrication system described in detail herein. The lubricant may include any type of lubricant for lubricating one or more rotating components 37 of the turbine engine 10.

[0054] During operation, as described above, the LP shaft 36 rotates, causing the first gear 51a to rotate. The first gear 51a meshes with one or more second gears 51b, causing the one or more second gears 51b to rotate about their respective rotational axes. The one or more second gears 51b rotate relative to one or more gear bearings 55 within the planet carrier 53. When the gear assembly 47 is in a star arrangement, the one or more second gears 51b meshing with the third gear 51c cause the third gear 51c to rotate about the longitudinal centerline axis 12. In such an embodiment, the planet carrier 53 remains stationary, preventing the one or more second gears 51b from rotating about the longitudinal centerline axis 12. When the gear assembly 47 is in a planetary arrangement, the third gear 51c is stationary, and the planet carrier 53 and the one or more second gears 51b rotate about the longitudinal centerline axis 12. When the gear assembly 47 is in a differential gear assembly, both the planet carrier 53 (e.g., the one or more second gears 51b 51b ) and the third gear 51c rotate about the longitudinal centerline axis 12.

[0055] At the same time, one or more engine bearings 39 rotate to allow the LP shaft 36, fan shaft 45, or HP shaft 34 ( Figure 1 ) rotates. Thus, one or more rotating components 37 rotate. As the rotating components 37 rotate, the lubrication system 200 supplies lubricant to the one or more rotating components 37 to lubricate the one or more rotating components. As previously described, the one or more rotating components 37 require a supply of lubricant to support uninterrupted rotation of the one or more rotating components 3 (e.g., during negative G-force conditions). Therefore, the lubrication system 200 supplies lubricant to the one or more rotating components 37 prior to the negative G-force condition, as described in further detail below.

[0056] Figure 3 is a device for a turbine engine 10 ( Figure 1 ) is a schematic diagram of a lubrication system 300. The lubrication system 300 can be used as Figure 2 Lubrication system 200 is shown. Lubrication system 300 includes a primary lubrication system 302, one or more tanks 304, and an auxiliary lubrication system 320. Primary lubrication system 302 includes a primary pump 306 and a primary supply line 308. One or more tanks 304 store lubricant therein. Primary supply line 308 is in fluid communication with one or more tanks 304 and one or more rotating components 37 for supplying lubricant from one or more tanks 304 to one or more rotating components 37. Primary pump 306 is in fluid communication with primary supply line 308 for pumping lubricant from one or more tanks 304 to one or more rotating components 37 via primary supply line 308.

[0057] The primary lubrication system 302 includes a primary supply line check valve 310 in fluid communication with a primary supply line 308. The primary supply line check valve 310 is disposed downstream of the one or more tanks 304 (e.g., downstream of the primary pump 306) and upstream of the one or more rotating components 37. The primary supply line check valve 310 allows lubricant to flow from the one or more tanks 304 to the one or more rotating components 37 when the pressure of the lubricant in the primary supply line 308 upstream of the primary supply line check valve 310 is greater than the pressure of the lubricant in the primary supply line 308 downstream of the primary supply line check valve 310. The primary supply line check valve 310 prevents lubricant from flowing from the one or more tanks 304 to the one or more rotating components 37 when the pressure of the lubricant in the primary supply line 308 upstream of the primary supply line check valve 310 is less than or equal to the pressure of the lubricant in the primary supply line 308 downstream of the primary supply line check valve 310.

[0058] The auxiliary lubrication system 320 includes an auxiliary accumulator 322, which includes a lubricant bladder 324 therein. The auxiliary accumulator 322 stores lubricant therein. Specifically, the lubricant bladder 324 stores lubricant therein. The lubricant bladder 324 is coupled to the bottom of the auxiliary accumulator 322 so that the lubricant is prevented from migrating to the top of the auxiliary accumulator 322 during negative gravity conditions. The lubricant bladder 324 has a lubricant bladder volume that is smaller than the auxiliary storage volume of the auxiliary accumulator 322. The lubricant bladder 324 is made of an expandable material so that the lubricant bladder 324 expands when lubricant fills the lubricant bladder 324 and contracts when lubricant is discharged from the lubricant bladder 324.

[0059] The auxiliary accumulator 322 has an auxiliary accumulator volume that is less than the tank volume of the one or more tanks 304. Thus, the auxiliary accumulator 322 stores less lubricant therein than the one or more tanks 304. For example, the auxiliary accumulator volume is in the range of 3% to 25% of the tank volume. In one embodiment, the auxiliary accumulator volume is equal to or less than ten percent (10%) of the tank volume. The auxiliary accumulator 322 is sized to provide sufficient lubricant to the one or more rotating components 37 during negative gravity conditions while minimizing the size of the auxiliary accumulator 322 to reduce the weight of the auxiliary accumulator 322, thereby reducing the weight of the turbine engine 10 (compared to turbine engines that use additional pumps (e.g., fan-driven pumps or electric pumps). Figure 1) weight. For example, negative g-forces typically occur for a short period of time, such that the auxiliary accumulator 322 only needs to store a small amount of lubricant to supply lubricant to one or more rotating components 37 during the negative g-force condition to prevent damage to the one or more rotating components 37 (e.g., journal bearing seizure). "Short time" as used in this paragraph relates to a period of time during which the aircraft may experience a rapid decrease in altitude, for example, due to ambient weather conditions such as cavitation, downdrafts, or wind shear events. In some examples, a short time is less than twenty seconds. In some examples, a short time is less than three seconds. In some examples, a short time is from three seconds to eighteen seconds. "Small amount of lubricant" as used in this paragraph refers to the volume of lubricant that flows through the system in a short period of time (e.g., from three seconds to eighteen seconds).

[0060] The auxiliary lubrication system includes an auxiliary feed line 326 and an auxiliary supply line 328. The auxiliary feed line 326 is in fluid communication with the primary supply line 308 and the auxiliary accumulator 322 (e.g., a lubricant bladder 324) for supplying lubricant from the primary supply line 308 to the auxiliary accumulator 322. The auxiliary feed line 326 is fluidly coupled to the primary supply line 308 upstream of the primary supply line check valve 310 and downstream of the one or more tanks 304. The auxiliary supply line 328 is in fluid communication with the auxiliary accumulator 322 (e.g., a lubricant bladder 324) and the primary supply line 308. The auxiliary supply line 328 is fluidly coupled to the primary supply line 308 downstream of the primary supply line check valve 310 and upstream of the one or more rotating components 37. As such, the auxiliary accumulator 322 (e.g., lubricant bladder 324) is in fluid communication with the primary supply line 308 upstream of the primary supply line check valve 310 to receive lubricant from the primary supply line 308. The auxiliary accumulator 322 (e.g., lubricant bladder 324) is in fluid communication with the primary supply line 308 downstream of the primary supply line check valve 310 to supply lubricant from the auxiliary accumulator 322 to one or more rotating components 37 through the primary supply line 308. Although the auxiliary feed line 326 and the auxiliary supply line 328 are shown as separate components from the primary supply line 308, the auxiliary feed line 326 or the auxiliary supply line 328 may form part of the primary supply line 308.

[0061] The auxiliary lubrication system 320 includes an auxiliary feed line check valve 330 in fluid communication with the auxiliary feed line 326. The auxiliary feed line check valve 330 is disposed within the auxiliary feed line 326. When the pressure of the lubricant in the primary supply line 308 is greater than the pressure of the lubricant in the auxiliary accumulator 322, the auxiliary feed line check valve 330 allows lubricant to flow from the primary supply line 308 to the auxiliary accumulator 322 through the auxiliary feed line 326. When the pressure of the lubricant in the primary supply line 308 is less than or equal to the pressure of the lubricant in the auxiliary accumulator 322, the auxiliary feed line check valve 330 prevents lubricant from flowing from the primary supply line 308 to the auxiliary accumulator 322.

[0062] The auxiliary lubrication system 320 includes an auxiliary supply line check valve 332 in fluid communication with the auxiliary supply line 328. The auxiliary supply line check valve 332 is disposed within the auxiliary supply line 328. When the pressure of lubricant in the auxiliary accumulator 322 is greater than the pressure of lubricant in the primary supply line 308, the auxiliary supply line check valve 332 allows lubricant to flow from the auxiliary accumulator 322 through the auxiliary feed line 326 (e.g., and through the primary supply line 308) to the one or more rotating components 37. When the pressure of lubricant in the auxiliary accumulator 322 is less than or equal to the pressure of lubricant in the primary supply line 308, the auxiliary supply line check valve 332 prevents lubricant from flowing from the auxiliary accumulator 322 to the one or more rotating components 37.

[0063] The auxiliary lubrication system 320 includes a pressure source 340 for supplying pressurized air to the auxiliary accumulator 322. In this way, the pressure source 340 pressurizes the lubricant in the auxiliary accumulator 322. The pressure source 340 can be any type of pressure source for supplying pressurized air to the auxiliary accumulator 322. In one embodiment, the pressure source 340 is the HP compressor 24 ( Figure 1 ), the HP compressor 24 supplies bleed air to the auxiliary accumulator 322. The pressure source 340 includes a pressurized air supply line 342 and a pressure source check valve 344 in fluid communication with the pressurized air supply line 342. The pressure source 340 supplies pressurized air to the auxiliary accumulator 322 through the pressurized air supply line 342. The pressure source check valve 344 helps regulate the pressure of the pressurized air to the auxiliary accumulator 322. In this way, the pressure source 340 pressurizes the lubricant in the auxiliary accumulator 322 to an auxiliary lubricant pressure. The auxiliary lubricant pressure is less than the primary lubricant pressure of the lubricant in the primary lubrication system 302. For example, the auxiliary lubricant pressure is in a range of 75% to 95% of the primary lubricant pressure (e.g., the minimum operating primary lubricant pressure in the primary lubrication system 302).

[0064] In operation, lubrication system 300 supplies lubricant to one or more rotating components 37 to lubricate the one or more rotating components 37. During normal operation of turbine engine 10, primary lubrication system 302 supplies lubricant to one or more rotating components 37. For example, primary pump 306 pumps lubricant from one or more tanks 304 to one or more rotating components 37 through primary supply line 308. During normal operation (and steady state operating conditions), the pressure of the lubricant in primary lubrication system 302 causes primary supply line check valve 310 to open, and thus, primary supply line 308 supplies lubricant from one or more tanks 304 to one or more rotating components 37.

[0065] At the same time, auxiliary feed line 326 supplies a portion of lubricant from primary lubrication system 302 to auxiliary accumulator 322, filling auxiliary accumulator 322 with a portion of the lubricant. When auxiliary accumulator 322 is not partially filled with lubricant, auxiliary feed line check valve 330 opens to allow lubricant to flow from primary supply line 308 to auxiliary accumulator 322. In this condition, the primary lubricant pressure of the lubricant in primary lubrication system 302 (e.g., upstream of primary supply line check valve 310) is greater than the auxiliary lubricant pressure of the lubricant in auxiliary accumulator 322. Therefore, during normal operation of turbine engine 10 (e.g., during steady-state operating conditions of lubrication system 300), a portion of the lubricant fills auxiliary accumulator 322. Specifically, a portion of the lubricant fills lubricant bladder 324, causing the lubricant bladder to expand within auxiliary accumulator 322.

[0066] The portion of lubricant fills the auxiliary accumulator 322 until the level of the portion of lubricant in the auxiliary accumulator 322 equals a predetermined auxiliary lubricant level. The predetermined auxiliary lubricant level can be when the auxiliary accumulator 322 is full (e.g., approximately 100% of the capacity of the auxiliary accumulator 322) or when the lubricant bladder 324 is full (e.g., approximately 100% of the capacity of the lubricant bladder 324). The pressure source 340 supplies pressurized air to the auxiliary accumulator 322 to pressurize the portion of lubricant in the auxiliary accumulator 322. When the level of the portion of lubricant in the auxiliary accumulator 322 equals the predetermined auxiliary lubricant level, the auxiliary feed line check valve 330 closes, preventing additional lubricant from flowing into the auxiliary accumulator 322. In this manner, the auxiliary accumulator 322 is passively pressurized by the pressurized air from the pressure source 340.

[0067] When there is a potential lubricant interruption in the lubrication system 300 (e.g., the primary lubrication system 302) (e.g., during a negative g-force condition), the lubrication system 300 may be unable to supply lubricant to one or more rotating components 37. For example, when a negative g-force condition occurs, the primary lubrication system 302 may be unable to supply lubricant from the one or more tanks 304 to the one or more rotating components 37. In this case, the primary lubricant pressure of the lubricant in the primary lubrication system 302 decreases because there is insufficient lubricant within the primary supply line 308 to be supplied to the one or more rotating components 37. As described above, if there is insufficient lubricant supplied to the one or more rotating components 37, the one or more rotating components 37 may be damaged.

[0068] When a potential lubricant interruption exists in the lubrication system 300 (e.g., the primary lubrication system 302), the auxiliary lubrication system 320 supplies lubricant to one or more rotating components 37. For example, when the primary lubricant pressure in the primary lubrication system 302 is less than the auxiliary lubricant pressure in the auxiliary accumulator 322, the auxiliary lubricating system 320 supplies lubricant to the one or more rotating components. In this case, the auxiliary accumulator 322 supplies a portion of the lubricant from the auxiliary accumulator 322 to the one or more rotating components 37. For example, because the auxiliary lubricant pressure of the lubricant in the auxiliary accumulator 322 is greater than the primary lubricant pressure of the lubricant in the primary lubrication system 302 (e.g., within the primary supply line 308), the auxiliary supply line check valve 332 opens. A portion of the lubricant flows through the auxiliary supply line 328, passes through the auxiliary supply line check valve 332, enters the primary supply line 308, and reaches the one or more rotating components 37. The auxiliary lubricant pressure of the lubricant from the auxiliary accumulator 322 causes the primary supply line check valve 310 to close, preventing a portion of the lubricant from flowing to the one or more tanks 304. When the auxiliary accumulator 322 is empty or not full and the turbine engine 10 is operating in positive gravity conditions, the auxiliary accumulator 322 will partially fill with lubricant, as described above.

[0069] Therefore, when the primary lubricant pressure in the primary lubrication system 302 is less than the auxiliary lubricant pressure in the auxiliary accumulator 322, the auxiliary lubrication system 320 supplies a portion of the lubricant to the one or more rotating components 37. In this way, when there is a potential lubricant interruption in the lubrication system 300, the auxiliary lubrication system 320 supplies a portion of the lubricant to the one or more rotating components 37. Therefore, the auxiliary lubrication system 320 avoids an interruption in the lubricant supply to the one or more rotating components 37.

[0070] Figure 4 According to another embodiment, a turbine engine 10 ( Figure 1) is a schematic diagram of a lubrication system 400. Components of the lubrication system 400 that are identical or similar to the components of the lubrication system 300 discussed above will be given the same or similar reference numerals. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here.

[0071] Lubrication system 400 includes primary lubrication system 302 and auxiliary lubrication system 420. Auxiliary lubrication system 420 includes auxiliary accumulator 422, lubricant bladder 424, auxiliary feed line 426, auxiliary supply line 428, auxiliary feed line check valve 430, and auxiliary supply line check valve 432. Auxiliary lubrication system 420 also includes auxiliary feed line control valve 427. Auxiliary feed line control valve 427 is in fluid communication with auxiliary feed line 426 and is disposed upstream of auxiliary feed line check valve 430. Auxiliary feed line control valve 427 is controlled to open to allow a portion of lubricant to flow from primary supply line 308 to auxiliary accumulator 422. Auxiliary feed line control valve 427 is controlled to close to prevent lubricant from flowing from primary supply line 308 to auxiliary accumulator 422.

[0072] The auxiliary lubrication system 420 includes a controller 100, a lubricant pressure sensor 102, and one or more inertial sensors 104. The lubricant pressure sensor 102 is in communication with the primary lubrication system 302 to sense the primary lubricant pressure in the primary lubrication system. For example, the lubricant pressure sensor 102 is in communication with the primary supply line 308 downstream of the primary pump 306 and upstream of the primary supply line check valve 310. The one or more inertial sensors 104 are disposed around the turbine engine 10 to sense the inertia or angular velocity and motion acceleration of the turbine engine 10. Figure 4 In the embodiment, the one or more inertial sensors 104 include at least one of one or more three-axis accelerometers 104a or one or more gyroscopes 104b. The one or more three-axis accelerometers 104a are sensors that sense gravity on the turbine engine 10 along three perpendicular axes. The one or more gyroscopes 104b sense the rotational forces of the turbine engine 10. The one or more gyroscopes 104b can be single-axis gyroscopes or three-axis gyroscopes. The controller 100 is in communication with the lubricant pressure sensor 102, the one or more inertial sensors 104, and the auxiliary feed line control valve 427.

[0073] The operation of lubrication system 400 is substantially similar to lubrication system 300. Controller 100 determines whether lubrication system 400 (e.g., primary lubrication system 302) is operating under stable operating conditions or whether a potential lubricant interruption exists in lubrication system 400 (e.g., primary lubrication system 302). Controller 100 receives sensed inertia of turbine engine 10 from one or more inertial sensors 104. Controller 100 determines the operating state of turbine engine 10 based on the sensed inertia. For example, controller 100 determines whether turbine engine 10 is operating under a positive gravity condition or whether turbine engine 10 is approaching a negative gravity condition. If the sensed inertia indicates that the gravity experienced by the turbine engine is positive, controller 100 determines that turbine engine 10 is operating under a positive gravity condition. Thus, a positive gravity condition occurs when the net gravity vector of turbine engine 10 is downward. If the sensed inertia indicates that the gravity experienced by turbine engine 10 is approaching zero, such that the net gravity vector approaches zero (e.g., decreases in magnitude from downward toward zero), controller 100 determines that turbine engine 10 is approaching a negative gravity condition. A negative gravity condition occurs when the net gravity vector is negative (e.g., less than zero and pointing upward).

[0074] If the primary lubrication system 302 is operating during stable operating conditions (e.g., when the turbine engine 10 is operating under positive gravity), the controller 100 controls the auxiliary feed line control valve 427 to open, allowing a portion of the lubricant to flow from the primary supply line 308 to the auxiliary accumulator 422. As described above, the pressure source 340 pressurizes a portion of the lubricant in the auxiliary accumulator 422. When the auxiliary accumulator 422 (e.g., the lubricant bladder 424) is full, the controller 100 controls the auxiliary feed line control valve 427 to close, preventing lubricant from flowing from the primary supply line 308 to the auxiliary accumulator 422. When there is a potential lubricant outage in the lubrication system 400 (e.g., when the turbine engine 10 is approaching negative gravity, as described above), the auxiliary lubrication system 420 supplies a portion of the lubricant from the auxiliary accumulator 422 to one or more rotating components 37. In this way, the lubrication system 400 actively controls the auxiliary lubrication system 420 (e.g., the auxiliary feed line control valve 427) to fill the auxiliary accumulator 422. When a potential lubricant interruption exists in the lubrication system 400, the auxiliary lubrication system 420 passively (e.g., without active control from the controller 100) supplies a portion of the lubricant from the auxiliary accumulator 422 to one or more rotating components 37 by using pressurized air within the auxiliary accumulator 422, which pressurizes a portion of the lubricant in the auxiliary accumulator 422.

[0075] In some embodiments, when the turbine engine 10 ( Figure 1) is in a steady-state operating condition or at or above an idle condition, the controller 100 controls the auxiliary feed line control valve 427 to open, allowing a portion of lubricant to flow from the primary supply line 308 to the auxiliary accumulator 422. In this way, the lubrication system 400 supplies a portion of the lubricant to the auxiliary accumulator 422 to fill the auxiliary accumulator 422 with a portion of lubricant during steady-state operating conditions, rather than during the engine startup sequence. If a portion of the lubricant were supplied to the auxiliary accumulator 422 during the engine startup sequence, the lubricant pressure in the primary lubrication system 302 would be insufficient to supply lubricant to the one or more rotating components 37 during the engine startup sequence. In this case, the one or more rotating components 37 would be starved of lubricant and potentially damaged. Therefore, when the turbine engine 10 is at or above an idle condition, the lubrication system 400 supplies a portion of the lubricant to the auxiliary accumulator 422 to ensure that sufficient lubricant is provided to the one or more rotating components 37 during the engine startup sequence. This configuration also ensures that the lubricant pressure of a portion of the lubricant in the auxiliary accumulator 422 is greater than an auxiliary lubricant pressure threshold (e.g., at least 75% to 95% of the lubricant pressure of the lubricant in the primary lubrication system 302) for supplying a portion of the lubricant from the auxiliary accumulator 422 to one or more rotating components 37 under negative g-force conditions. In some embodiments, when the turbocharged engine 16 ( Figure 1 ), the lubrication system 400 supplies a portion of the lubricant to the auxiliary accumulator 422 when the rotational speed of the turbine core 37 is greater than a speed threshold, to further ensure that sufficient lubricant is supplied to the one or more rotating components 37 during the engine startup sequence to lubricate the rotating components 37. The speed threshold is a speed of the turbine engine that is lower than the speed required for airflow through the engine core to drive the fan or the LP shaft, so that the fan and LP shaft overcome inertia and friction and begin to rotate. For example, the speed threshold may be 5 to 15 percent of the rated speed of the turbine engine core.

[0076] When the auxiliary accumulator 422 is empty or not full and the turbine engine 10 is operating under positive gravity conditions, the auxiliary accumulator 422 is partially filled with lubricant, as described above. The controller 100 also receives the lubricant pressure sensed in the primary lubrication system 302 from the lubricant pressure sensor 102. Based on the lubricant pressure being less than the lubricant pressure threshold, the controller 100 determines that the lubricant in the auxiliary accumulator 422 has been at least partially used. The controller 100 then controls the auxiliary feed line control valve 427 to open, allowing a portion of the lubricant to flow from the primary supply line 308 to the auxiliary accumulator 422 to refill the auxiliary accumulator 422 with a portion of the lubricant (e.g., if the primary lubrication system 302 is operating under stable operating conditions). The controller 100 may also display an indication of the lubricant pressure on a display to a user (e.g., a pilot or co-pilot on an aircraft or a user on the ground) to indicate that there is a fault or loss of lubricant pressure in the lubrication system 400, or that maintenance is required.

[0077] Figure 5 According to another embodiment, a turbine engine 10 ( Figure 1 ) is a schematic diagram of a lubrication system 500. The lubrication system 500 is respectively Figure 3 and Figure 4 The lubrication systems 300 and 400 are substantially similar. Components of the lubrication system 500 that are identical or similar to the components of the lubrication systems 300 and 400 described above will be given the same or similar reference numerals. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here.

[0078] Lubrication system 500 includes primary lubrication system 302 and auxiliary lubrication system 520. Auxiliary lubrication system 520 includes auxiliary accumulator 522, lubricant bladder 524, auxiliary feed line 526, auxiliary supply line 528, auxiliary feed line check valve 530, and auxiliary supply line check valve 532. Auxiliary lubrication system 520 also includes auxiliary feed line control valve 527 and auxiliary supply line control valve 529.

[0079] The auxiliary feed line control valve 527 is in fluid communication with the auxiliary feed line 526 and is disposed upstream of the auxiliary feed line check valve 530. The auxiliary feed line control valve 527 is controlled to open to allow a portion of the lubricant to flow from the primary supply line 308 to the auxiliary accumulator 522. The auxiliary feed line control valve 527 is controlled to close to prevent the lubricant from flowing from the primary supply line 308 to the auxiliary accumulator 522.

[0080] The auxiliary supply line control valve 529 is in fluid communication with the auxiliary supply line 528 and is disposed upstream of the auxiliary supply line check valve 532. The auxiliary supply line control valve 529 is controlled to open to allow a portion of the lubricant to flow from the auxiliary accumulator 522 to the one or more rotating components 37 through the auxiliary supply line 528 and the primary supply line 308. The auxiliary supply line control valve 529 is controlled to close to prevent lubricant from flowing from the auxiliary accumulator 522 to the one or more rotating components 37.

[0081] The auxiliary lubrication system 520 includes a pressure source 540, a pressurized air supply line 542, a pressure source control valve 543, and a pressure source check valve 544. The pressure source control valve 543 is in fluid communication with the pressurized air supply line 542 and is disposed upstream of the pressure source check valve 544. The pressure source control valve 543 is controlled to open to allow pressurized air to flow from the pressure source 540 to the auxiliary accumulator 522. The pressure source control valve 543 is controlled to close to prevent pressurized air from the pressure source 540 from flowing to the auxiliary accumulator 522. The pressure source control valve 543 can be controlled to partially open (e.g., by changing the size of the passage of the pressure source control valve 543) to change the flow rate of pressurized air from the pressure source 540 to the auxiliary accumulator 522.

[0082] Auxiliary lubrication system 520 includes controller 100, lubricant pressure sensor 102, and one or more inertial sensors 104. Controller 100 communicates with lubricant pressure sensor 102, one or more inertial sensors 104, auxiliary feed line control valve 527, auxiliary supply line control valve 529, and pressure source control valve 543.

[0083] The operation of lubrication system 500 is substantially similar to lubrication systems 300 and 400. Controller 100 determines whether lubrication system 500 is operating under stable operating conditions or whether a potential lubricant outage exists within lubrication system 500. For example, as described above, controller 100 determines whether turbine engine 10 is operating under positive gravity conditions or whether turbine engine 10 is approaching negative gravity conditions. If lubrication system 500 is operating under stable operating control (e.g., if turbine engine 10 is operating under positive gravity conditions), controller 100 controls auxiliary feed line control valve 527 to open, allowing a portion of lubricant to flow from primary supply line 308 to auxiliary accumulator 522. As described above, pressure source 540 pressurizes a portion of the lubricant in auxiliary accumulator 522. When auxiliary accumulator 522 (e.g., lubricant bladder 524) is full, controller 100 controls auxiliary feed line control valve 527 to close, preventing lubricant from flowing from primary supply line 308 to auxiliary accumulator 522.

[0084] The controller 100 controls the pressure source control valve 543 to change the pressure of the pressurized air supplied to the auxiliary accumulator 522. In this way, the controller 100 controls the auxiliary lubricant pressure in the auxiliary accumulator 522 so that the auxiliary lubricant pressure is lower than the primary lubricant pressure. The controller 100 controls the pressure source control valve 543 to maintain the auxiliary lubricant pressure lower than the primary lubricant pressure. For example, the controller 100 controls the pressure source control valve 543 to maintain the auxiliary lubricant pressure within a range of 75% to 95% of the primary lubricant pressure.

[0085] When a potential lubricant outage exists in the lubrication system 500, the auxiliary lubrication system 520 supplies a portion of lubricant from the auxiliary accumulator 522 to one or more rotating components 37. For example, when the turbine engine 10 approaches a negative g-force condition, the auxiliary lubrication system 520 supplies a portion of lubricant from the auxiliary accumulator 522 to one or more rotating components 37. When a potential lubricant outage exists in the lubrication system 500 (e.g., if the turbine engine 10 approaches a negative g-force condition), the controller 100 controls the auxiliary supply line control valve 529 to open, allowing a portion of lubricant to flow from the auxiliary accumulator 522 (e.g., from the lubricant bladder 524) to the one or more rotating components 37 (e.g., through the auxiliary supply line 528 and the primary supply line 308). When the lubrication system 500 is operating during a stable operating condition (e.g., if the turbine engine 10 is operating under a positive g-force condition), the controller 100 controls the auxiliary supply line control valve 529 to close, preventing lubricant from flowing from the auxiliary accumulator 522 to the one or more rotating components 37. Thus, when a potential lubricant outage exists in the lubrication system 500 (e.g., when the turbine engine 10 approaches a negative g-force condition), the lubrication system 400 actively controls the auxiliary lubrication system 520 (e.g., the auxiliary supply line control valve 529) to supply a portion of lubricant from the auxiliary accumulator 522 to one or more rotating components 37. When the auxiliary accumulator 522 is empty or not full, and the lubrication system 500 is operating under stable operating conditions (e.g., the turbine engine 10 is operating under a positive g-force condition), the auxiliary accumulator 522 is filled with a portion of the lubricant, as described above.

[0086] Figure 6 According to another embodiment, a turbine engine 10 ( Figure 1 ) is a schematic diagram of a lubrication system 600. The lubrication system 600 is respectively Figure 3 and Figure 5 The lubrication systems 300 and 500 are substantially similar. Components of the lubrication system 600 that are identical or similar to the components of the lubrication systems 300 and 500 described above will be given the same or similar reference numerals. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here.

[0087] Lubrication system 600 includes primary lubrication system 302 and auxiliary lubrication system 620. Auxiliary lubrication system 620 includes auxiliary accumulator 622, lubricant bladder 624, auxiliary feed line 626, auxiliary supply line 628, auxiliary feed line check valve 630, and auxiliary supply line check valve 632. Auxiliary lubrication system 620 also includes auxiliary feed line control valve 627 and auxiliary supply line control valve 629.

[0088] The auxiliary lubrication system 620 includes a pressure source 640. The pressure source 640 is an actuator 641 disposed within the auxiliary accumulator 622. The actuator 641 is controlled to reciprocate (e.g., up and down) within the auxiliary accumulator 622 to pressurize a portion of the lubricant in the auxiliary accumulator 622. The actuator 641 includes a diaphragm 643 that contacts a portion of the lubricant in the auxiliary accumulator 622. Specifically, the actuator 641 is controlled to reciprocate downward, causing the diaphragm 643 to contact a portion of the lubricant (e.g., contact the lubricant bladder 624), thereby exerting a force on a portion of the lubricant in the auxiliary accumulator 622. In this way, the actuator 641 pressurizes a portion of the lubricant in the auxiliary accumulator 622.

[0089] Auxiliary lubrication system 620 includes controller 100, lubricant pressure sensor 102, and one or more inertial sensors 104. Controller 100 communicates with lubricant pressure sensor 102, one or more inertial sensors 104, auxiliary feed line control valve 627, auxiliary supply line control valve 629, and actuator 641.

[0090] The operation of lubrication system 600 is substantially similar to lubrication systems 300 and 500. As described above, controller 100 determines whether lubrication system 600 is operating under stable operating conditions or whether a potential lubricant outage exists within lubrication system 600. When auxiliary accumulator 622 is partially filled with lubricant, controller 100 controls actuator 641 to reciprocate downward to apply pressure to a portion of the lubricant in auxiliary accumulator 622. In this way, controller 100 controls the auxiliary lubricant pressure in auxiliary accumulator 622 so that the auxiliary lubricant pressure is less than the primary lubricant pressure. Controller 100 controls actuator 641 to maintain the auxiliary lubricant pressure less than the primary lubricant pressure. For example, controller 100 controls actuator 641 to maintain the auxiliary lubricant pressure within a range of 75% to 95% of the primary lubricant pressure.

[0091] When a potential lubricant outage exists in the lubrication system 600, the auxiliary lubrication system 620 supplies a portion of lubricant from the auxiliary accumulator 622 to one or more rotating components 37. If a potential lubricant outage exists in the lubrication system 600, the controller 100 controls the auxiliary supply line control valve 629 to open, allowing a portion of lubricant to flow from the auxiliary accumulator 622 (e.g., from the lubricant bladder 624) to the one or more rotating components 37 (e.g., through the auxiliary supply line 628 and the primary supply line 308). The controller 100 also controls the actuator 641 to reciprocate downward to continue applying pressure to a portion of the lubricant in the auxiliary accumulator 622, thereby forcing a portion of the lubricant to leave the auxiliary accumulator 622 and reach the one or more rotating components 37. If the lubrication system 600 is operating under stable operating conditions, the controller 100 controls the auxiliary supply line control valve 629 to close, preventing lubricant from flowing from the auxiliary accumulator 622 to the one or more rotating components 37. In this way, when there is a potential lubricant interruption in the lubrication system 600 (e.g., in the primary lubrication system 302), the lubrication system 600 actively controls the auxiliary lubrication system 620 (e.g., the auxiliary supply line control valve 629) to supply a portion of lubricant from the auxiliary accumulator 622 to one or more rotating components 37. When the auxiliary accumulator 622 is empty or not full and the lubrication system 600 is operating under stable operating conditions, the controller 100 controls the actuator 641 to reciprocate upward, and the auxiliary accumulator 622 is filled with a portion of lubricant, as described above.

[0092] Figure 7 According to another embodiment, a turbine engine 10 ( Figure 1 ) is a schematic diagram of a lubrication system 700. The lubrication system 700 and Figure 5 The lubrication system 500 is substantially similar to the lubrication system 500. Components of the lubrication system 700 that are identical or similar to the components of the lubrication system 500 described above will use the same or similar reference numerals. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here.

[0093] Lubrication system 700 includes a primary lubrication system 702, one or more tanks 704, a sump 709, and an auxiliary lubrication system 720. Primary lubrication system 702 includes a primary pump 706, a primary supply line 708, and a primary supply line check valve 710. Auxiliary lubrication system 720 includes an auxiliary feed line 726, an auxiliary feed line control valve 727, an auxiliary supply line 728, and an auxiliary supply line check valve 732. Auxiliary lubrication system 720 includes a controller 100 and one or more inertial sensors 104.

[0094] The auxiliary lubrication system 720 includes an auxiliary pump 752. The auxiliary pump 752 is coupled to the fan shaft 45. For example, the auxiliary pump 752 includes a pump shaft 754 coupled to the fan shaft 45. The pump shaft 754 includes a pump shaft gear 756, and the fan shaft 45 includes a fan shaft gear 758. The pump shaft gear 756 and the fan shaft gear 758 are meshed with each other so that rotation of the fan shaft 45 causes the pump shaft 754 to rotate, thereby providing power to the auxiliary pump 752. The auxiliary pump 752 is a bidirectional pump that pumps lubricant from one or more tanks 704 to one or more rotating components 37 via the auxiliary supply line 728, regardless of the direction of rotation of the fan shaft 45. The auxiliary pump 752 can include any type of bidirectional pump, such as a positive displacement pump, such as a piston pump, a gear pump, a generator rotor (cycloidal rotor), a rotary pump, a peristaltic pump, etc. Auxiliary pump 752 pumps lubricant from one or more tanks 704 to one or more rotating components 37 when fan shaft 45 rotates in a first rotational direction and when fan shaft 45 rotates in a second rotational direction opposite to the first rotational direction. For example, the first rotational direction is the rotational direction of fan shaft 45 during operation of turbine engine 10, and the second rotational direction is opposite to the rotational direction of fan shaft 45 during operation. In this way, auxiliary lubrication system 720 supplies lubricant from one or more tanks 704 to one or more rotating components 37 during wind-up conditions of turbine engine 10.

[0095] The auxiliary lubrication system 720 includes a clutch 760 that controls the operation of the auxiliary pump 752. For example, the clutch 760 couples with the pump shaft 754 and engages the pump shaft 754 to operate the auxiliary pump 752, and disengages the pump shaft 754 to prevent operation of the auxiliary pump 752. The clutch 760 may include any type of clutch for engaging or disengaging the pump shaft 754. The clutch 760 is an electromechanical clutch controlled by a lubricant pressure switch 762, a control signal switch 764, and a power source 766. The lubricant pressure switch 762 and the control signal switch 764 are in communication with the clutch 760, and the power source 766 is in communication with the lubricant pressure switch 762 and the control signal switch 764. The lubricant pressure switch 762 is in fluid communication with the primary lubrication system 702 via a lubricant pressure signal line 763. The control signal switch 764 is in communication with the controller 100, such that the control signal switch 764 receives signals from the controller 100, and the controller 100 controls the control signal switch 764. The power source 766 may be electricity from the turbine engine 10 (e.g., electricity supplied to the controller 100 or other systems of the turbine engine 10). Thus, the clutch 760 engages or disengages the pump shaft 754 based on at least one of the pressure of the lubricant in the primary lubrication system 702, a control signal from the controller 100, or a power supply from the power source 766. Thus, when the fan 38 is running, the clutch 760 engages the pump shaft 754 to provide power to the auxiliary pump 752.

[0096] The auxiliary feed line 726 includes a first auxiliary branch line 731a and a second auxiliary branch line 731b. The first auxiliary branch line 731a is located at the bottom of the one or more tanks 704 so that during positive gravity conditions, gravity helps maintain the lubricant in the one or more tanks 704 in fluid communication with the first auxiliary branch line 731a. The second auxiliary branch line 731b is located approximately at the top of the one or more tanks 704 so that the lubricant is in fluid communication with the second auxiliary branch line 731b during negative gravity conditions. The auxiliary feed line control valve 727 is in communication with the first auxiliary branch line 731a and the second auxiliary branch line 731b.

[0097] The operation of lubrication system 700 is substantially similar to lubrication system 600. Under normal operating conditions, primary lubrication system 702 supplies lubricant from one or more tanks 704 to one or more rotating components 37. Lubricant drains from one or more rotating components 37 into sump 709. The lubricant then returns to one or more tanks 704. Thus, after the lubricant drains from one or more rotating components 37, lubrication system 700 resupplies lubricant to the one or more rotating components. During normal operating conditions, clutch 760 disengages pump shaft 754, causing auxiliary pump 752 to not operate. During wind-down conditions (e.g., when primary lubrication system 702 is unable to supply lubricant to one or more rotating components 37), clutch 760 engages pump shaft 754, causing fan shaft 45 to power auxiliary pump 752.

[0098] The controller 100 determines whether a potential lubricant interruption exists in the lubrication system 700 (e.g., in the primary lubrication system 702 or in the auxiliary lubrication system 720). When the lubrication system 700 is operating under stable operating conditions (e.g., positive gravity conditions, such as when the turbine engine is parked on the ground or during horizontal or substantially horizontal flight), the controller 100 controls the auxiliary feed line control valve 727 to open the first auxiliary branch line 731a, allowing lubricant to flow from the one or more tanks 704 through the first auxiliary branch line 731a and to the one or more rotating components 37 through the auxiliary feed line 726. The second auxiliary branch line 731b is closed during stable operating conditions. When a potential lubricant interruption exists (e.g., negative gravity conditions, such as when the turbine engine is accelerating toward the Earth at a rate equal to or greater than gravity, or decelerating at the end of a vertical ascent), the lubricant in the one or more tanks 704 moves toward the top of the one or more tanks 704. In this case, the controller 100 controls the auxiliary feed line control valve 727 to open the second auxiliary branch line 731b, allowing lubricant to flow through the second auxiliary branch line 731b and to the one or more rotating components 37 through the auxiliary feed line 726. Therefore, when the fan 38 is spinning and there is a potential lubricant interruption in the lubrication system 700 (for example, when the turbine engine 10 is approaching or operating under negative gravity conditions), the auxiliary lubrication system 720 supplies lubricant to the one or more rotating components 37.

[0099] Figure 88 is a flow chart of a method 800 for lubricating one or more rotating components 37 of a turbine engine 10 using a lubrication system 200, 300, 400, 500, 600, 700 according to the present disclosure. In step 805, method 800 includes supplying lubricant from one or more tanks 304, 704 of the lubrication system 200, 300, 400, 500, 600, 700 to the one or more rotating components 37 during steady-state operating conditions of the lubrication system 200, 300, 400, 500, 600, 700. For example, step 805 may occur while the aircraft including the turbine engine is parked on the ground or during a horizontal or substantially horizontal phase of flight. In step 810, method 800 includes supplying a portion of the lubricant from the one or more tanks 304, 704 to the auxiliary lubrication system 320, 420, 520, 620, 720 via an auxiliary feed line 326, 426, 526, 626, 726. In step 815, method 800 includes supplying a portion of lubricant from the auxiliary lubrication system 320, 420, 520, 620, 720 to one or more rotating components 37 when a potential lubricant interruption exists in the lubrication system 200, 300, 400, 500, 600, 700. For example, a potential lubricant interruption may occur when the vehicle is accelerating toward the earth or decelerating at the end of a vertical ascent, and the auxiliary lubrication system may provide lubricant, as previously described herein. Method 800 may include the above-described respective references to Figures 1 to 7 Describe any operation in detail.

[0100] Therefore, the lubrication system described herein starts supplying lubricant to one or more rotating components before the lubricant in the lubrication system is interrupted. In this way, the lubrication system avoids potential loss of lubricant pressure, which avoids damage to one or more rotating components 37 under negative g-force conditions.

[0101] As described herein, lubrication system 300 provides a simple passive lubrication system. Lubrication system 300 is lightweight and reliable. Lubrication system 300 and lubrication system 600 provide lubrication systems that rely on the volume of the accumulator to limit the duration of the event to be accommodated. Lubrication system 600 and lubrication system 700 provide actively controlled lubrication systems. Although lubrication system 600 and lubrication system 700 may be heavier than lubrication system 300, lubrication system 600 and lubrication system 700 can detect system failures (and avoid the possibility of potential system failures not being detected, for example, if there is a leak in the diaphragm of the accumulator). In addition, lubrication system 600 and lubrication system 700 ensure that the auxiliary system starts before the lubrication pressure in the engine drops. Lubrication system 700 also includes an auxiliary pump, which allows the system to operate for a long time, including during an engine shutdown event that may cause the engine to wind up.

[0102] Further aspects of the disclosure are provided by the subject matter of the following clauses.

[0103] A lubrication system for a turbine engine, the turbine engine including one or more rotating components, the lubrication system comprising: one or more tanks storing lubricant therein; a primary lubrication system supplying the lubricant from the one or more tanks to the one or more rotating components during stable operating conditions of the lubrication system; and an auxiliary lubrication system comprising: an auxiliary feed line in fluid communication with the one or more tanks, the auxiliary lubrication system receiving the lubricant from the one or more tanks through the auxiliary feed line; and an auxiliary supply line in fluid communication with the auxiliary feed line and the one or more rotating components, the auxiliary lubrication system supplying the lubricant to the one or more rotating components through the auxiliary supply line when a potential lubricant interruption exists in the lubrication system.

[0104] According to the lubrication system described in the preceding clause, the primary lubrication system includes a primary pump, which pumps the lubricant from the one or more tanks to the one or more rotating components, and when the primary pump is unable to pump the lubricant from the one or more tanks, a lubrication interruption occurs.

[0105] A lubrication system as claimed in any preceding clause, wherein when the potential lubrication interruption occurs, the auxiliary lubrication system begins supplying the lubricant to the one or more rotating components.

[0106] A lubrication system according to any preceding clause, wherein said stable operating condition of said lubrication system occurs when said turbine engine is operating in positive g-force conditions, and said potential lubricant disruption occurs when said turbine engine approaches negative g-force conditions.

[0107] A lubrication system according to any preceding clause, further comprising a controller to control the auxiliary lubrication system to supply the lubricant to the one or more rotating components when the potential lubricant interruption occurs in the lubrication system.

[0108] The lubrication system of any preceding clause, wherein the turbine engine includes one or more inertial sensors that sense inertia of the turbine engine, and wherein the controller controls the auxiliary lubrication system to supply lubricant to the one or more rotating components when the sensed inertia indicates the potential lubricant interruption.

[0109] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary accumulator in fluid communication with the auxiliary feed line and the auxiliary supply line, the auxiliary accumulator filling with a portion of the lubricant from the primary lubrication system during the stable operating conditions and supplying the portion of the lubricant to the one or more rotating components when the potential lubrication interruption occurs.

[0110] A lubrication system according to any preceding clause, further comprising a pressure source that pressurizes the portion of the lubricant in the auxiliary accumulator to an auxiliary lubricant pressure.

[0111] A lubrication system as claimed in any preceding clause, the lubricant in the primary lubrication system having a primary lubricant pressure, and the secondary lubricant pressure in the secondary accumulator being less than the primary lubricant pressure in the primary lubrication system.

[0112] A lubrication system as claimed in any preceding clause, wherein the auxiliary lubricant pressure in the auxiliary accumulator is in the range of 75% to 95% of the primary lubricant pressure in the primary lubrication system.

[0113] A lubrication system as claimed in any preceding clause, wherein the one or more rotating components comprise one or more journal bearings.

[0114] A lubrication system as recited in any preceding clause, the turbine engine comprising a gearbox assembly having one or more gear bearings, and the one or more rotating components comprising the one or more gear bearings.

[0115] A lubrication system as claimed in any preceding clause, wherein the gearbox assembly comprises one or more gears.

[0116] A lubrication system as claimed in any preceding clause, at least one of the one or more gears comprising a pin, and wherein the one or more diametrical bearings are defined between the pin and the at least one of the one or more gears.

[0117] A lubrication system according to any preceding clause, the turbine engine having one or more shafts and one or more engine bearings, the one or more engine bearings permitting the one or more shafts to rotate, and the one or more rotating components comprising the one or more engine bearings.

[0118] A lubrication system according to any preceding clause, the primary lubrication system comprising a primary supply line in fluid communication with the one or more tanks and the one or more rotating components for supplying the lubricant from the one or more tanks to the one or more rotating components.

[0119] A lubrication system according to any preceding clause, the primary lubrication system comprising a primary supply line check valve, the primary supply line check valve allowing the lubricant to flow from the one or more tanks to the one or more rotating components during the stable operating conditions and preventing the lubricant from flowing to the one or more tanks during the potential lubrication interruption.

[0120] The lubrication system of any preceding clause, the auxiliary accumulator including a lubricant bladder disposed therein, the lubricant bladder storing the lubricant therein and preventing the lubricant from migrating to a top portion of the auxiliary accumulator during the negative gravity condition.

[0121] A lubrication system as in any preceding clause, the lubricant bladder being coupled to a bottom portion of the auxiliary accumulator.

[0122] A lubrication system as claimed in any preceding clause, the lubricant bladder having a lubricant bladder volume that is less than a volume of the auxiliary accumulator.

[0123] The lubrication system of any preceding clause, the lubricant bladder being expandable such that when the lubricant fills the bladder, the lubricant bladder expands, and when the lubricant is drained from the bladder, the lubricant bladder contracts.

[0124] A lubrication system as claimed in any preceding clause, wherein the one or more tanks have a tank volume, the auxiliary accumulator has an auxiliary accumulator volume, and the auxiliary accumulator volume is between 3% and 25% of the tank volume.

[0125] A lubrication system as claimed in any preceding clause, wherein the auxiliary accumulator volume is equal to or less than 10% of the tank volume.

[0126] A lubrication system as claimed in any preceding clause, the auxiliary feed line being fluidly coupled to the primary supply line upstream of the primary supply line check valve and downstream of the one or more tanks.

[0127] A lubrication system as claimed in any preceding clause, the auxiliary supply line being fluidly coupled to the primary supply line downstream of the primary supply line check valve and upstream of the one or more rotating components.

[0128] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary feed line check valve in fluid communication with the auxiliary feed line, the auxiliary feed line check valve allowing the lubricant to flow from the primary supply line to the auxiliary accumulator during the stable operating conditions to fill the auxiliary accumulator with the lubricant, and preventing the lubricant from flowing to the auxiliary accumulator when the auxiliary accumulator is full of the lubricant.

[0129] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary supply line check valve in fluid communication with the auxiliary supply line, the auxiliary supply line check valve allowing lubricant to flow from the auxiliary accumulator to the one or more rotating components during the potential lubricant interruption and preventing lubricant from flowing out of the auxiliary accumulator during the stable operating condition.

[0130] A lubrication system as claimed in any preceding clause, the turbine engine comprising a high pressure compressor and the pressure source being the high pressure compressor supplying bleed air to the auxiliary accumulator.

[0131] A lubrication system as claimed in any preceding clause, wherein the pressure source comprises a pressurised air supply line and wherein the pressure source supplies the pressurised air to the auxiliary accumulator via the pressurised air supply line.

[0132] A lubrication system according to any preceding clause, wherein the pressure source comprises a pressure source check valve that regulates the pressure of the pressurized air flowing to the auxiliary accumulator to a predetermined pressure.

[0133] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary feed line control valve controlled to open to allow the lubricant to flow to the auxiliary accumulator and controlled to close to prevent the lubricant from flowing to the auxiliary accumulator.

[0134] A lubrication system as claimed in any preceding clause, wherein the controller controls the auxiliary feed line control valve.

[0135] A lubrication system according to any preceding clause, further comprising a lubricant pressure sensor sensing the primary lubricant pressure.

[0136] The lubrication system of any preceding clause, further comprising one or more inertial sensors that sense the inertia of the turbine engine.

[0137] The lubrication system of any preceding clause, the one or more inertial sensors comprising one or more three-axis accelerometers that sense gravity on the turbine engine in three perpendicular axes.

[0138] The lubrication system of any preceding clause, the one or more inertial sensors comprising one or more gyroscopes, the one or more gyroscopes sensing rotational forces of the turbine engine.

[0139] The lubrication system of any preceding clause, the controller determining an operating condition of the turbine engine based on the sensed inertia.

[0140] The lubrication system of any preceding clause, wherein the controller determines the operating condition to be the positive gravity condition if the sensed inertia indicates that the gravity force on the turbine engine is positive.

[0141] The lubrication system of any preceding clause, the controller determining that the operating condition is approaching the negative g-force condition when the sensed inertia indicates that the g-force on the turbine engine is approaching zero.

[0142] The lubrication system according to any preceding clause, wherein if the primary lubrication system is operating under the stable operating condition, the controller controls the auxiliary feed line control valve to open so that the lubricant flows to the auxiliary accumulator.

[0143] The lubrication system according to any preceding clause, wherein when the auxiliary accumulator is full, the controller controls the auxiliary feed line control valve to close to prevent the lubricant from flowing to the auxiliary accumulator.

[0144] The lubrication system of any preceding clause, wherein the controller controls the auxiliary feed line control valve to open when the operating condition is greater than or equal to an idle condition.

[0145] The lubrication system of any preceding clause, wherein the turbine engine comprises a turbocharged engine, and wherein the controller controls the auxiliary supply line control valve to open when a speed of the turbocharged engine is greater than a speed threshold.

[0146] The lubrication system of any preceding clause, wherein the controller controls the auxiliary feed line control valve to open when the primary lubricant pressure is below a lubricant pressure threshold.

[0147] The lubrication system of any preceding clause, further comprising a lubricant pressure sensor that senses the primary lubricant pressure, the controller determining the primary lubricant pressure based on the sensed primary lubricant pressure from the lubricant pressure sensor.

[0148] A lubrication system according to any preceding clause, the auxiliary lubrication system comprising an auxiliary supply line control valve in fluid communication with the auxiliary supply line and controlled to open to allow the lubricant to flow from the auxiliary accumulator to the one or more rotating components, and controlled to close to prevent the lubricant from flowing from the auxiliary accumulator to the one or more rotating components.

[0149] A lubrication system according to any preceding clause, wherein the controller controls the auxiliary supply line control valve to open and close.

[0150] The lubrication system according to any preceding clause, wherein when the potential lubricant interruption exists, the controller controls the auxiliary supply line control valve to open, so that the lubricant flows from the auxiliary accumulator to the one or more rotating components.

[0151] The lubrication system according to any preceding clause, wherein when the lubrication system operates under the stable operating condition, the controller controls the auxiliary supply line control valve to close so that the lubricant is prevented from flowing out of the auxiliary accumulator.

[0152] A lubrication system according to any preceding clause, wherein the auxiliary lubrication system includes a pressure source control valve in fluid communication with the pressurized air supply line and controlled to open to allow the pressurized air to flow from the pressure source to the auxiliary accumulator, and controlled to close to prevent the pressurized air from flowing to the auxiliary accumulator.

[0153] A lubrication system as claimed in any preceding clause, wherein the controller controls the pressure source control valve to vary the flow rate of the pressurised air from the pressure source to the auxiliary accumulator.

[0154] A lubrication system as claimed in any preceding clause, wherein the pressure source is an actuator disposed within the auxiliary accumulator.

[0155] A lubrication system as claimed in any preceding clause, wherein the actuator is controlled to reciprocate within the auxiliary accumulator to pressurise the lubricant in the auxiliary accumulator.

[0156] A lubrication system as claimed in any preceding clause, wherein the controller controls the actuator.

[0157] A lubrication system as claimed in any preceding clause, the actuator comprising a diaphragm in contact with the lubricant in the auxiliary accumulator to apply a force to the lubricant to pressurise the lubricant.

[0158] The lubrication system of any preceding clause, when the auxiliary accumulator is empty and the lubrication system is operating under the stable operating condition, the controller controls the actuator to reciprocate upwards so that the auxiliary accumulator is filled with the lubricant.

[0159] A lubrication system as claimed in any preceding clause, the auxiliary lubrication system comprising an auxiliary pump for pumping lubricant from the one or more tanks to the one or more rotating components when there is a potential lubricant interruption.

[0160] A lubrication system according to any preceding clause, the turbine engine including a fan having a rotating fan shaft, and the auxiliary pump including a pump shaft coupled to the fan shaft such that rotation of the fan shaft causes the pump shaft to rotate to provide power to the auxiliary pump.

[0161] A lubrication system as claimed in any preceding clause, wherein the auxiliary pump is a bidirectional pump such that the auxiliary pump pumps the lubricant in both directions of rotation of the pump shaft.

[0162] A lubrication system as claimed in any preceding clause, the auxiliary lubrication system comprising a clutch engaging the pump shaft to operate the auxiliary pump and disengaging the pump shaft to prevent operation of the auxiliary pump.

[0163] A lubrication system according to any preceding clause, further comprising a lubricant pressure switch in fluid communication with the primary lubrication system for receiving an indication of the primary lubricant pressure and in communication with the clutch.

[0164] A lubrication system according to any preceding clause, further comprising a control signal switch in communication with the controller and the clutch.

[0165] A lubrication system according to any preceding clause, further comprising a power source for powering the clutch.

[0166] The lubrication system of any preceding clause, wherein the clutch engages the pump shaft when at least one of the primary lubricant pressure is less than the lubricant pressure threshold, the control switch is not receiving a signal from the controller, or the clutch is not receiving power from the power source.

[0167] The lubrication system of any preceding clause, wherein the clutch disengages the pump shaft when the primary lubricant pressure is greater than the lubricant pressure threshold, the control switch receiving a signal from the controller, and the clutch receiving power from the power source.

[0168] A lubrication system as claimed in any preceding clause, the auxiliary feed line comprising a first auxiliary branch line and a second auxiliary branch line.

[0169] A lubrication system as claimed in any preceding clause, the first auxiliary branch being fluidly coupled to a bottom of the one or more tanks such that gravity assists in maintaining the lubricant in fluid communication with the first auxiliary branch during the stable operating conditions.

[0170] A lubrication system as in any preceding clause, the second auxiliary branch line being fluidly coupled substantially at a top of the one or more tanks such that the lubricant is in fluid communication with the second auxiliary branch line during the negative gravity condition.

[0171] A lubrication system as claimed in any preceding clause, the auxiliary feed line control valve being in fluid communication with the first and second auxiliary branch lines.

[0172] A lubrication system according to any preceding clause, wherein the controller controls the auxiliary feed line control valve to open the first auxiliary branch line during the stable operating condition so that the lubricant flows from the one or more tanks to the one or more rotating components through the first auxiliary branch line.

[0173] The lubrication system of any preceding clause, wherein during the potential lubricant interruption, the controller controls the auxiliary feed line control valve to open the second auxiliary branch line so that the lubricant flows from the one or more tanks to the one or more rotating components through the second auxiliary branch line.

[0174] A turbine engine comprising a turbocharger engine, the turbocharger engine including a shaft, a fan drivingly coupled to the shaft of the turbocharger engine, rotation of the shaft causing the fan to rotate, one or more rotating components in at least one of the turbocharger engine or the fan, and a lubrication system for lubricating the one or more rotating components, the lubrication system comprising one or more tanks storing lubricant therein, a primary lubrication system supplying lubricant from the one or more tanks to the one or more rotating components during steady-state operating conditions of the lubrication system, and an auxiliary lubrication system comprising an auxiliary feed line in fluid communication with the one or more tanks, the auxiliary lubrication system receiving lubricant from the one or more tanks via the auxiliary feed line, and an auxiliary supply line in fluid communication with the auxiliary feed line and the one or more rotating components, the auxiliary lubrication system supplying lubricant to the one or more rotating components via the auxiliary supply line when a potential lubricant interruption exists in the lubrication system.

[0175] The turbine engine according to the preceding clause, wherein the primary lubrication system includes a primary pump that pumps the lubricant from the one or more tanks to the one or more rotating components, and a lubrication interruption occurs when the primary pump is unable to pump the lubricant from the one or more tanks.

[0176] A turbine engine according to any preceding clause, wherein when the potential lubrication interruption occurs, the auxiliary lubrication system begins supplying the lubricant to the one or more rotating components.

[0177] A turbine engine according to any preceding clause, wherein said stable operating condition of said lubrication system occurs when said turbine engine is operating in positive gravity conditions, and said potential lubricant disruption occurs when said turbine engine approaches negative gravity conditions.

[0178] The turbine engine of any preceding clause, further comprising a controller that controls the auxiliary lubrication system to supply the lubricant to the one or more rotating components when the potential lubricant interruption occurs in the lubrication system.

[0179] The turbine engine of any preceding clause, further comprising one or more inertial sensors that sense inertia of the turbine engine, wherein when the sensed inertia indicates the potential lubricant interruption, the controller controls the auxiliary lubrication system to supply the lubricant to the one or more rotating components.

[0180] A turbine engine according to any preceding clause, wherein the auxiliary lubrication system includes an auxiliary accumulator in fluid communication with the auxiliary feed line and the auxiliary supply line, the auxiliary accumulator filling with a portion of the lubricant from the primary lubrication system during the stable operating conditions and supplying the portion of the lubricant to one or more rotating components when the potential lubrication interruption occurs.

[0181] A turbine engine according to any preceding clause, further comprising a pressure source that pressurizes a portion of the lubricant in the auxiliary accumulator to an auxiliary lubricant pressure.

[0182] A turbine engine as claimed in any preceding clause, wherein the lubricant in the primary lubrication system has a primary lubricant pressure, and wherein the auxiliary lubricant pressure in the auxiliary accumulator is less than the primary lubricant pressure in the primary lubrication system.

[0183] A turbine engine as claimed in any preceding clause, wherein the auxiliary lubricant pressure in the auxiliary accumulator is in the range of 75% to 95% of the primary lubricant pressure in the primary lubrication system.

[0184] A turbine engine as claimed in any preceding clause, wherein the lubrication system is a lubrication system as claimed in any preceding clause.

[0185] A method of lubricating one or more rotating components of a turbine engine with a lubrication system, the method comprising supplying lubricant from one or more tanks of a primary lubrication system to the one or more rotating components during steady-state operating conditions of the lubrication system, supplying a portion of the lubricant from the one or more tanks to an auxiliary lubrication system through an auxiliary feed line, and supplying the portion of the lubricant from the auxiliary lubrication system to the one or more rotating components when a potential lubrication interruption exists in the lubrication system.

[0186] The method of the preceding clause, further comprising pumping the lubricant from the one or more tanks to the one or more rotating components with a primary pump, and wherein a lubricant interruption occurs when the primary pump is unable to pump the lubricant from the one or more tanks.

[0187] A method as defined in any preceding clause, further comprising commencing supply of the lubricant to the one or more rotating components when the potential lubricant interruption occurs.

[0188] The method of any preceding clause, wherein the stable operating condition of the lubrication system occurs when the turbine engine is operating in positive g-force conditions, and the potential lubricant disruption occurs when the turbine engine approaches negative g-force conditions.

[0189] The method of any preceding clause, further comprising controlling the lubrication system with a controller to supply the lubricant to the one or more rotating components when the potential lubricant interruption occurs in the lubrication system.

[0190] The method of any preceding clause, further comprising sensing inertia of the turbine with one or more inertial sensors and supplying the lubricant to the one or more rotating components when the sensed inertia indicates the potential lubricant interruption.

[0191] The method of any preceding clause, further comprising filling an auxiliary accumulator with a portion of the lubricant from the lubrication system during the stable operating conditions and supplying the portion of the lubricant to the one or more rotating components when the potential lubrication interruption occurs.

[0192] A method as defined in any preceding clause, further comprising pressurizing the portion of the lubricant in the auxiliary accumulator to an auxiliary lubricant pressure with a pressure source.

[0193] A method as defined in any preceding clause, wherein the lubricant in a primary lubrication system has a primary lubricant pressure within the primary lubrication system, and further comprising pressurizing the portion of the lubricant in the auxiliary accumulator such that the auxiliary lubricant pressure in the auxiliary accumulator is less than the primary lubricant pressure in the primary lubrication system.

[0194] A method according to any preceding clause, further comprising pressurizing the portion of the lubricant such that the auxiliary lubricant pressure in the auxiliary accumulator is in the range of 75% to 95% of the primary lubricant pressure in the primary lubrication system.

[0195] A method as in any preceding clause, wherein the one or more rotating components comprise one or more journal bearings.

[0196] A method as recited in any preceding clause, the turbine engine comprising a gearbox assembly having one or more gear bearings, and the one or more rotating components comprising the one or more gear bearings.

[0197] A method as described in any preceding clause, wherein the gearbox assembly comprises one or more gears.

[0198] A method as in any preceding clause, at least one of the one or more gears comprising a pin, and wherein the one or more diametrical bearings are defined between the pin and the at least one of the one or more gears.

[0199] A method as defined in any preceding clause, the turbine engine having one or more shafts and one or more engine bearings allowing the one or more shafts to rotate, and the one or more rotating components comprising the one or more engine bearings.

[0200] A method as in any preceding clause, the primary lubrication system comprising a primary supply line in fluid communication with the one or more tanks and the one or more rotating components for supplying the lubricant from the one or more tanks to the one or more rotating components.

[0201] A method as in any preceding clause, the primary lubrication system comprising a primary supply line check valve, and the method further comprising opening the primary supply line check valve to allow lubricant to flow from the one or more tanks to the one or more rotating components during the stable operating conditions, and closing the primary supply line check valve to prevent lubricant from flowing to the one or more tanks during the potential lubricant interruption.

[0202] A method as in any preceding clause, said auxiliary accumulator including a lubricant bladder disposed therein, said lubricant bladder storing said lubricant therein and preventing said lubricant from migrating to a top portion of said auxiliary accumulator during said negative gravity condition.

[0203] A method as in any preceding clause, coupling the lubricant bladder to a bottom of the auxiliary accumulator.

[0204] A method as in any preceding clause, the lubrication bladder having a lubricant bladder volume that is less than the auxiliary accumulator volume.

[0205] The method of any preceding clause, the lubricant bladder being expandable, and the method further comprising expanding the lubricant bladder as the lubricant fills the lubricant bladder and deflation of the lubricant bladder as the lubricant drains from the lubricant bladder.

[0206] A method as in any preceding clause, wherein the one or more tanks have a tank volume, the auxiliary reservoir has an auxiliary reservoir volume, and the auxiliary reservoir volume is between 3% and 25% of the tank volume.

[0207] A method as in any preceding clause, wherein the auxiliary accumulator volume is equal to or less than 10% of the tank volume.

[0208] A method as in any preceding clause, the auxiliary feed line being fluidly coupled to the primary supply line upstream of the primary supply line check valve and downstream of the one or more tanks.

[0209] A method as in any preceding clause, the auxiliary supply line being fluidly coupled to the primary supply line downstream of the primary supply line check valve and upstream of the one or more rotating components.

[0210] The method of any preceding clause, the auxiliary lubrication system comprising an auxiliary feed line check valve in fluid communication with the auxiliary feed line, and the method further comprising allowing the lubricant to flow from the primary supply line to the auxiliary accumulator to fill the auxiliary accumulator with the lubricant during the stable operating condition, and preventing the lubricant from flowing to the auxiliary accumulator using the auxiliary supply line check valve when the auxiliary accumulator is full of lubricant.

[0211] The method of any preceding clause, the auxiliary lubrication system comprising an auxiliary supply line check valve in fluid communication with the auxiliary supply line, and the method further comprising allowing lubricant to flow from the auxiliary accumulator to the one or more rotating components via the auxiliary supply line check valve during the potential lubricant interruption, and preventing lubricant from flowing out of the auxiliary accumulator via the auxiliary supply line check valve during the stable operating condition.

[0212] A method as claimed in any preceding clause, the turbine engine comprising a high pressure compressor, the pressure source being the high pressure compressor, and the method further comprising supplying bleed air to the auxiliary accumulator using the high pressure compressor.

[0213] A method as claimed in any preceding clause, wherein the pressure source comprises a pressurized air supply line and wherein the pressure source supplies the pressurized air to the auxiliary accumulator via the pressurized air supply line.

[0214] A method as defined in any preceding clause, the pressure source comprising a pressure source check valve, and the method further comprising regulating the pressure of the pressurized air to the auxiliary accumulator to a predetermined pressure using the pressure source check valve.

[0215] A method according to any preceding clause, the auxiliary lubrication system comprising an auxiliary feed line control valve, and the method further comprising opening the auxiliary feed line control valve to allow the lubricant to flow to the auxiliary accumulator, and closing the auxiliary feed line control valve to prevent the lubricant from flowing to the auxiliary accumulator.

[0216] A method as defined in any preceding clause, further comprising sensing the primary lubricant pressure with a lubricant pressure sensor.

[0217] The method of any preceding clause, further comprising sensing the inertia of the turbine engine with one or more inertial sensors.

[0218] A method as in any preceding clause, the one or more inertial sensors comprising one or more three-axis accelerometers that sense gravity on the turbine engine in three perpendicular axes.

[0219] A method as in any preceding clause, the one or more inertial sensors comprising one or more gyroscopes, the one or more gyroscopes sensing rotational forces of the turbine engine.

[0220] A method as recited in any preceding clause, further comprising determining an operating state of the turbine engine based on the sensed inertia.

[0221] The method of any preceding clause, further comprising determining that the operating condition is the positive-g condition if the sensed inertia indicates that the g-force on the turbine engine is positive.

[0222] The method of any preceding clause, further comprising determining that the operating condition is approaching the negative g-force condition when the sensed inertia indicates that the g-force on the turbine engine is approaching zero.

[0223] A method as defined in any preceding clause, further comprising opening the auxiliary feed line control valve if the primary lubrication system is operating under the stable operating condition.

[0224] A method according to any preceding clause, further comprising closing the auxiliary feed line control valve when the auxiliary accumulator is full to prevent lubricant from flowing to the auxiliary accumulator.

[0225] A method as defined in any preceding clause, further comprising opening the auxiliary feed line control valve when the operating condition is greater than or equal to an idle state.

[0226] A method as described in any preceding clause, the turbine engine comprising a turbocharged engine, and the method further comprising opening the auxiliary feed line control valve when a speed of the turbocharged engine is greater than a speed threshold.

[0227] A method as defined in any preceding clause, further comprising opening the auxiliary feed line control valve when the primary lubricant pressure is less than a lubricant pressure threshold.

[0228] The method of any preceding clause, further comprising sensing the primary lubricant pressure with a lubricant pressure sensor, and determining the primary lubricant pressure based on the sensed primary lubricant pressure from the lubricant pressure sensor.

[0229] The method of any preceding clause, the auxiliary lubrication system comprising an auxiliary supply line control valve in fluid communication with the auxiliary supply line, and the method further comprising opening the auxiliary supply line control valve to allow the lubricant to flow from the auxiliary accumulator to the one or more rotating components, and closing the auxiliary supply line control valve to prevent the lubricant from flowing from the auxiliary accumulator to the one or more rotating components.

[0230] A method according to any preceding clause, further comprising controlling the auxiliary supply line control valve to open and close with a controller.

[0231] The method of any preceding clause, further comprising opening the auxiliary supply line control valve such that lubricant flows from the auxiliary accumulator to the one or more rotating components when the potential lubricant interruption exists.

[0232] A method according to any preceding clause, further comprising closing the auxiliary supply line control valve such that the lubricant is prevented from flowing from the auxiliary accumulator when the lubrication system is operating under the stable operating conditions.

[0233] The method of any preceding clause, the auxiliary lubrication system comprising a pressure source control valve in fluid communication with the pressurized air supply line, and the method further comprising opening the pressure source control valve to allow the pressurized air to flow from the pressure source to the auxiliary accumulator, and closing the pressure source control valve to prevent the pressurized air from flowing to the auxiliary accumulator.

[0234] A method as defined in any preceding clause, further comprising controlling the pressure source control valve to vary the flow rate of the pressurized air from the pressure source to the auxiliary accumulator.

[0235] A method as in any preceding clause, wherein the pressure source is an actuator disposed within the auxiliary accumulator.

[0236] A method as defined in any preceding clause, further comprising reciprocating the actuator within the auxiliary reservoir to pressurize the lubricant in the auxiliary reservoir.

[0237] A method as in any preceding clause, further comprising controlling the actuator with the controller.

[0238] A method as in any preceding clause, the actuator comprising a diaphragm contacting the lubricant in the auxiliary accumulator to exert a force on the lubricant to pressurize the lubricant.

[0239] A method as defined in any preceding clause, further comprising reciprocating the actuator upwardly when the auxiliary accumulator is empty and the lubrication system is operating under the stable operating condition.

[0240] A method as in any preceding clause, the auxiliary lubrication system comprising an auxiliary pump, and the method further comprising pumping lubricant from the one or more tanks to the one or more rotating components using the auxiliary pump when there is a potential lubricant interruption.

[0241] The method of any preceding clause, the turbine engine comprising a fan having a rotating fan shaft, and the auxiliary pump comprising a pump shaft coupled to the fan shaft such that rotation of the fan shaft causes the pump shaft to rotate to provide power to the auxiliary pump.

[0242] A method as in any preceding clause, wherein the auxiliary pump is a bidirectional pump such that the auxiliary pump pumps the lubricant in both directions of rotation of the pump shaft.

[0243] A method as in any preceding clause, the auxiliary lubrication system comprising a clutch, and the method further comprising engaging the pump shaft with the clutch to operate the auxiliary pump, and disengaging the pump shaft from the clutch to prevent operation of the auxiliary pump.

[0244] A method as defined in any preceding clause, further comprising a lubricant pressure switch in fluid communication with the primary lubrication system for receiving an indication of the primary lubricant pressure and in communication with the clutch.

[0245] A method as defined in any preceding clause, further comprising a control signal switch in communication with the controller and the clutch.

[0246] A method as defined in any preceding clause, further comprising a power source providing power to the clutch.

[0247] The method of any preceding clause, further comprising engaging the pump shaft with the clutch when at least one of the primary lubricant pressure is less than the lubricant pressure threshold, the control switch is not receiving a signal from the controller, or the clutch is not receiving power from the power source.

[0248] The method of any preceding clause, further comprising disengaging the pump shaft from the clutch when the primary lubricant pressure is greater than the lubricant pressure threshold, the control switch receives a signal from the controller, and the clutch receives power from the power source.

[0249] A method as claimed in any preceding clause, wherein the auxiliary feed line comprises a first auxiliary branch line and a second auxiliary branch line.

[0250] A method as in any preceding clause, the first auxiliary branch line being fluidly coupled to a bottom of the one or more tanks such that gravity assists in maintaining the lubricant in fluid communication with the first auxiliary branch line under the stable operating conditions.

[0251] A method as in any preceding clause, the second auxiliary branch being fluidly coupled substantially at a top portion of the one or more tanks such that the lubricant is in fluid communication with the third auxiliary branch during the negative gravity condition.

[0252] A method as defined in any preceding clause, wherein the auxiliary feed line control valve is in fluid communication with the first and second auxiliary branches.

[0253] The method of any preceding clause, further comprising, during said stable operating conditions, opening said first auxiliary branch line with said auxiliary feed line control valve such that said lubricant flows from said one or more tanks to said one or more rotating components through said first auxiliary branch line.

[0254] The method of any preceding clause, further comprising opening the second auxiliary branch line with the auxiliary feed line control valve during the potential lubricant interruption such that the lubricant flows from the one or more tanks to the one or more rotating components through the second auxiliary branch line.

[0255] Although the above description is directed to certain embodiments of the present disclosure, it will be apparent to those skilled in the art that other changes and modifications may be made without departing from the present disclosure. In addition, even if not explicitly stated above, features described in connection with one embodiment of the present disclosure may also be used in conjunction with other embodiments.

Claims

1. A lubrication system for a turbine engine comprising one or more rotating parts, characterized in that: The lubrication system comprises: one or more tanks storing lubricant therein; a primary lubrication system that supplies the lubricant from the one or more tanks to the one or more rotating components during steady operating conditions of the lubrication system; and An auxiliary lubrication system, the auxiliary lubrication system comprising: an auxiliary feed line in fluid communication with the one or more tanks, wherein the auxiliary lubrication system receives the lubricant from the one or more tanks through the auxiliary feed line; and an auxiliary supply line in fluid communication with the auxiliary feed line and the one or more rotating components, Wherein, when there is a potential lubricant interruption in the lubrication system, the auxiliary lubrication system supplies the lubricant to the one or more rotating components through the auxiliary supply line.

2. The lubrication system according to claim 1, characterized in that in, The primary lubrication system includes a primary pump that pumps the lubricant from the one or more tanks to the one or more rotating components, and a lubricant outage occurs when the primary pump is unable to pump the lubricant from the one or more tanks.

3. The lubrication system according to claim 1, characterized in that in, When the potential lubrication interruption occurs, the auxiliary lubrication system begins supplying the lubricant to the one or more rotating components.

4. The lubrication system according to claim 1, characterized in that in, The stable operating condition of the lubrication system occurs when the turbine engine operates in positive g-force conditions, and the potential lubricant disruption occurs when the turbine engine approaches negative g-force conditions.

5. The lubrication system according to claim 1, characterized in that: Further included is a controller that controls the auxiliary lubrication system to supply the lubricant to the one or more rotating components when the potential lubricant interruption occurs in the lubrication system.

6. The lubrication system according to claim 5, characterized in that in, The turbine engine includes one or more inertial sensors that sense inertia of the turbine engine, and when the sensed inertia indicates the potential lubricant interruption, the controller controls the auxiliary lubrication system to supply the lubricant to the one or more rotating components.

7. The lubrication system according to claim 1, characterized in that in, The auxiliary lubrication system includes an auxiliary accumulator in fluid communication with the auxiliary feed line and the auxiliary supply line, the auxiliary accumulator filling with a portion of the lubricant from the primary lubrication system during the stable operating conditions and supplying the portion of the lubricant to the one or more rotating components when the potential lubrication interruption occurs.

8. The lubrication system according to claim 7, characterized in that Further included is a pressure source that pressurizes the portion of the lubricant in the auxiliary accumulator to an auxiliary lubricant pressure.

9. The lubrication system according to claim 8, characterized in that in, The lubricant in the primary lubricating system has a primary lubricant pressure, and the auxiliary lubricant pressure in the auxiliary accumulator is lower than the primary lubricant pressure in the primary lubricating system.

10. The lubrication system according to claim 9, characterized in that in, The auxiliary lubricant pressure in the auxiliary accumulator is in the range of 75% to 95% of the primary lubricant pressure in the primary lubrication system.

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