Self-cleaning conduit for hydrocarbon fluids

Abstract

A self-cleaning conduit for hydrocarbon fluids. The conduit includes a tube and a movable sleeve. The tube has an interior surface that defines a flow passage for the hydrocarbon fluids. The movable sleeve is positioned within the flow passage to abut the interior surface and is movable along the interior surface in response to changes in an operating characteristic of the conduit to break up deposits on the interior surface.

Description

Technical Field

[0001] This disclosure relates to conduits for carrying hydrocarbon fluids, and more particularly to conduits used in gas turbine engines for aircraft. Background Technology

[0002] Gas turbine engines use hydrocarbon fluids, such as fuel and lubricating oil. This hydrocarbon fluid is transported through the engine in various conduits, and the inner surfaces of these conduits are in contact with the hydrocarbon fluid. When exposed to the hydrocarbon fluid at elevated temperatures, carbonaceous deposits (also known as coke) can form on these surfaces, causing carbon to adhere to these surfaces and accumulate as deposits. Attached Figure Description

[0003] The features and advantages of this disclosure will become apparent from the following description of various exemplary embodiments as shown in the accompanying drawings, wherein similar reference numerals generally indicate the same, functionally similar and / or structurally similar elements.

[0004] Figure 1 It is a schematic perspective view of an aircraft with a gas turbine engine.

[0005] Figure 2 yes Figure 1 One of the gas turbine engines of the aircraft shown is along Figure 1 A schematic cross-sectional view taken from line 2-2 in the diagram.

[0006] Figure 3 This is a detailed cross-sectional view of the turbine of a gas turbine engine, showing... Figure 2 Detail 3 in the text.

[0007] Figure 4 yes Figure 2 The diagram shows the oil system of a gas turbine engine.

[0008] Figure 5 This is a detailed cross-sectional view of the service tube assembly of the turbine rear frame, showing... Figure 3 Detail 5.

[0009] Figure 6 Showing Figure 5 The oil pipe of the service pipe component shown.

[0010] Figure 7 yes Figure 5 The oil pipe shown is along Figure 6 The cross-sectional view taken by line 7-7 in the figure.

[0011] Figure 8It is a graph showing the temperature of the oil and the temperature of the oil lines during different stages of flight.

[0012] Figure 9 It is along the oil pipeline Figure 7 The cross-sectional view is taken from line 9-9 in the diagram. The mesh sleeve contained within the tube is not shown in the cross-section to illustrate its features.

[0013] Figure 10A , 10B 10C and 10D show different patterns of the mesh in the mesh sleeve.

[0014] Figures 11A to 11R An additional pattern of the mesh of the mesh sleeve is shown.

[0015] Figure 12A , 12B And 12C are along the oil pipe Figure 7 The cross-sectional view taken from line 9-9 shows the different attachments of the mesh sleeve.

[0016] Figures 13A to 13D The process of installing the mesh sleeve into the tubing is shown. Figure 13A The memory structure of the mesh sleeve is shown. Figure 13B The compression structure of the mesh sleeve is shown. Figure 13C The mesh sleeve is shown being inserted into the tubing in a compression configuration. Figure 13D The image shows a mesh sleeve in an expanded (installed) configuration inside the tubing.

[0017] Figure 14 This is a cross-sectional view of an oil pipe according to another embodiment. Figure 14 This shows the oil lines when there is no oil flow (such as when the machine is off).

[0018] Figure 15 yes Figure 14 The image shows a cross-sectional view of the oil pipe. Figure 15 It shows the oil lines when oil flows through them (such as when the engine is running).

[0019] Figure 16 yes Figure 14 The oil pipe shown is along Figure 14 The cross-sectional view taken from line 16-16 in the figure.

[0020] Figure 17 This is a cross-sectional view of an oil pipe according to another embodiment. Figure 17 The oil lines are shown when the engine is off.

[0021] Figure 18 yes Figure 17 The image shows a cross-sectional view of the oil pipe. Figure 18 The oil lines are shown when the engine is running.

[0022] Figure 19 yes Figure 17 The oil pipe shown is along Figure 17 The cross-sectional view taken from line 19-19 in the figure.

[0023] Figure 20 This is a detailed cross-sectional view of the movable sleeve assembly, showing... Figure 17 Details 20.

[0024] Figure 21 This is a cross-sectional view of an oil pipe according to another embodiment. Figure 21 The oil lines are shown when the engine is off.

[0025] Figure 22 yes Figure 21 The image shows a cross-sectional view of the oil pipe. Figure 22 The oil lines are shown when the engine is running.

[0026] Figure 23 yes Figure 22 The oil pipe shown is along Figure 22 Cross-sectional view taken along centerline 23-23.

[0027] Figure 24 This is a cross-sectional view of an oil pipe according to another embodiment. Figure 24 The oil lines are shown when the engine is off.

[0028] Figure 25 yes Figure 24 The image shows a cross-sectional view of the oil pipe. Figure 25 The oil lines are shown when the engine is running.

[0029] Figure 26 This is a graph showing the mesh activation parameter (MAP) as a function of the ratio of oil temperature to tubing temperature according to embodiments of the present disclosure.

[0030] Figure 27 This is another graph showing the mesh activation parameter (MAP) as a function of the ratio of oil temperature to tubing temperature according to an embodiment of the present disclosure. Detailed Implementation

[0031] The features, advantages, and embodiments of this disclosure are set forth or become apparent from consideration of the following detailed description, drawings, and claims. Furthermore, the following detailed description is exemplary and intended to provide further explanation, without limiting the scope of the claimed disclosure.

[0032] Various embodiments are discussed in detail below. Although specific embodiments are discussed, they are for illustrative purposes only. Those skilled in the art will recognize that other components and constructions can be used without departing from the spirit and scope of this disclosure.

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

[0034] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, in the context of a gas turbine engine, "front" refers to the position closer to the engine inlet, and "rear" refers to the position closer to the engine nozzle or exhaust port.

[0035] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction from which the fluid flows.

[0036] The terms “connection,” “fixation,” “attachment,” “linkage,” etc., refer to both direct connection, fixation, attachment, or linking, and indirect connection, fixation, attachment, or linking through one or more intermediate components or features, unless otherwise specified herein.

[0037] The singular forms “a,” “a,” and “the” include plural references unless the context clearly indicates otherwise.

[0038] Scope limitations are combined and interchanged herein and throughout the specification and claims. Such scope is identified and includes all subscopes contained herein, unless otherwise indicated by context or language. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0039] As described above, coke deposits can occur on the surfaces of gas turbine engines exposed to hydrocarbon fluids (such as fuel and lubricating oil) at elevated temperatures. These hydrocarbon fluids flow through various conduits, including pipes, and the inner walls of these conduits are exposed to the hydrocarbon fluids. On such surfaces, coke can accumulate to a considerable thickness, restricting or even blocking fluid flow in these channels. In other cases, large chunks of coke can detach from these surfaces, causing blockages or even damage to downstream components. In some components, these deposits can be removed through regular maintenance, such as cleaning or replacement of the components. However, such maintenance can be expensive and time-consuming, and there may be components where such maintenance is not feasible.

[0040] Pipes that may be particularly susceptible to this coking effect are the oil lines located in the cowling of the engine frame, which supports the gas turbine engine, and more specifically, the high-pressure and low-pressure shafts. Oil is used to lubricate various components of the gas turbine engine, including, for example, the bearings supporting the high-pressure and low-pressure shafts. To supply oil to these bearings, oil flows through oil lines located in the engine frame. A portion of these oil lines lies within the core airflow path of the gas turbine engine, and these sections of the lines, especially after shutdown during so-called backflow conditions, may experience elevated temperatures suitable for coking. These oil lines may be relatively narrow and may be susceptible to blockages that form within them due to coking.

[0041] The embodiments discussed herein include self-cleaning hydrocarbon fluid conduits, such as oil pipes. Some embodiments employ a mesh sleeve formed of shape memory alloy (SMA) or bimetallic material, positioned along the inner surface of the hydrocarbon fluid conduit. As the hydrocarbon fluid conduit (oil pipe) undergoes thermal cycling occurring during normal operation of the gas turbine engine, the mesh sleeve is configured to change length, breaking up deposits already formed on the inner surface of the hydrocarbon fluid conduit. In other embodiments, the sleeve moves along the inner surface of the hydrocarbon fluid conduit by changes in temperature (such as the thermal cycling discussed above) or pressure occurring in the oil pipe during normal operation of the gas turbine engine. The movement of the sleeve breaks up (or scrapes away) deposits already formed on the inner surface of the hydrocarbon fluid conduit. The broken-up coke deposits can then be removed by the natural flow of a hydrocarbon fluid (e.g., oil) over the surface, thus preventing the accumulation of coke deposits. This is referred to herein as a self-cleaning effect.

[0042] Hydrocarbon fluid conduits, including the mesh sleeves or movable sleeves discussed in this article, are particularly suitable for engines, such as gas turbine engines used in aircraft. Figure 1 This is a perspective view of an aircraft 10 that can be implemented in various preferred embodiments. The aircraft 10 includes a fuselage 12, wings 14 attached to the fuselage 12, and a tail 16. The aircraft 10 also includes a propulsion system that generates the thrust required to propel the aircraft 10 during flight, during taxiing operations, etc. Figure 1 The propulsion system of the aircraft 10 shown includes a pair of engines 100. In this embodiment, each engine 100 is attached to one of the wings 14 in an underwing configuration via a pylon 18. Although the engines 100 are in Figure 1The engine 100 is shown attached to the wing 14 in an underwing configuration, but in other embodiments, the engine 100 may have an alternative configuration and be coupled to other parts of the aircraft 10. For example, the engine 100 may additionally or alternatively include one or more aspects coupled to other parts of the aircraft 10 (e.g., such as the tail 16 and fuselage 12).

[0043] Please refer to the following: Figure 2 Further description, Figure 1 The engine 100 shown is a gas turbine engine, each capable of selectively generating propulsive thrust for the aircraft 10. This can be at least partially based on a fuel system 150 (see fuel system 150). Figure 2 A certain amount of fuel is supplied to the gas turbine engine to control the amount of propulsive thrust. In the embodiments discussed herein, the aviation turbine fuel is a combustible hydrocarbon liquid fuel with the desired carbon number (such as kerosene-based fuel), synthetic aviation fuel, biofuel, biodiesel, ethanol, bio-alcohol, etc. The fuel is stored in fuel tank 151 of fuel system 150. Figure 1 As shown, at least a portion of the fuel tank 151 is located in each wing 14, and a portion of the fuel tank 151 is located in the fuselage 12 between the wings 14. However, the fuel tank 151 may be located in other suitable locations within the fuselage 12 or the wings 14. The fuel tank 151 may also be entirely located within the fuselage 12 or the wings 14. The fuel tank 151 may also be a separate tank, rather than a single unit, such as two tanks each located within the respective wing 14.

[0044] Although Figure 1 The aircraft 10 shown is an airplane, but the embodiments described herein can also be applied to other aircraft, such as helicopters and unmanned aerial vehicles (UAVs). Furthermore, although not depicted herein, in other embodiments, the gas turbine engine can be any other suitable type of gas turbine engine, such as an industrial gas turbine engine incorporated into a power generation system, a marine gas turbine engine, etc.

[0045] Figure 2 Is Figure 1 A schematic cross-sectional view of one of the engines 100 used in the propulsion system of the aircraft 10 shown. Figure 2 Cross-sectional view along Figure 1 Line 2-2 in the middle is cut off. For Figure 2 In the embodiment depicted herein, engine 100 is a high-bypass turbofan engine. Engine 100 may also be referred to herein as turbofan engine 100. Turbofan engine 100 has an axial direction A (parallel to...) Figure 2 The longitudinal centerline 101 shown for reference extends in the center, along with the radial direction R and the circumferential direction. The circumferential direction ( Figure 2(Not depicted) extends in a direction of rotation about the longitudinal centerline 101 (axial direction A). The turbofan engine 100 includes a fan section 102 and a turbine 104 disposed downstream of the fan section 102.

[0046] Figure 2 The turbine 104 depicted includes a tubular housing 106 (also referred to as a casing or nacelle) defining an inlet 108. In this embodiment, the inlet 108 is annular. The housing 106 encloses an engine core, which, in a series flow relationship, includes: a compressor section comprising a turbocharger or low-pressure (LP) compressor 110 and a high-pressure (HP) compressor 112; a combustion section 114; a turbine section comprising a high-pressure (HP) turbine 116 and a low-pressure (LP) turbine 118; and an exhaust nozzle section 120. The compressor section, combustion section 114, and turbine section together at least partially define a core airflow path 121 extending from the inlet 108 to the exhaust nozzle section 120. The turbofan engine 100 further includes one or more drive shafts. More specifically, the turbofan engine 100 includes a high-pressure (HP) shaft or spool 122 that drives an HP turbine 116 to an HP compressor 112, and a low-pressure (LP) shaft or spool 124 that drives an LP turbine 118 to an LP compressor 110.

[0047] Figure 2 The fan section 102 shown includes a fan 126 having multiple fan blades 128 connected to a disk 130. The fan blades 128 and the disk 130 are capable of rotating together about a longitudinal centerline (axis) 101 via an LP shaft 124. The LP compressor 110 can also be directly driven by the LP shaft 124, as... Figure 2 As depicted in the image, the disc 130 is covered by a rotatable front hub 132, which conforms to an aerodynamic profile to facilitate airflow through multiple fan blades 128. Further, an annular fan housing or outer nacelle 134 circumferentially surrounds at least a portion of the fan 126 and / or turbine 104. The nacelle 134 is supported relative to the turbine 104 by multiple circumferentially spaced outlet guide vanes 136. A downstream section 138 of the nacelle 134 extends over the outer portion of the turbine 104 to define a bypass airflow passage 140 therebetween.

[0048] The turbofan engine 100 is capable of operating in conjunction with the fuel system 150 and receives a fuel flow from the fuel system 150. The fuel system 150 includes a fuel delivery assembly 153 that supplies a fuel flow from a fuel tank 151 to the turbofan engine 100, and more specifically, to a plurality of fuel nozzles 162 in the combustion chamber 164 of a combustor 160 that injects fuel into the combustion section 114. Components of the fuel system 150, more specifically the fuel tank 151, are examples of fuel sources that supply fuel to the fuel nozzles 162, as discussed in more detail below. The fuel delivery assembly 153 includes pipes, conduits, ducts, etc., to fluidly connect various components of the fuel system 150 to the engine 100. The fuel tank 151 is configured to store hydrocarbon fuel, and hydrocarbon fuel is supplied from the fuel tank 151 to the fuel delivery assembly 153. The fuel delivery assembly 153 is configured to carry hydrocarbon fuel between the fuel tank 151 and the engine 100, thus providing a flow path (fluid path) for the hydrocarbon fuel from the fuel tank 151 to the engine 100.

[0049] Fuel system 150 includes at least one fuel pump fluidly connected to fuel delivery assembly 153 to direct fuel flow to engine 100 via fuel delivery assembly 153. One such pump is a main fuel pump 155. The main fuel pump 155 is a high-pressure pump and is the primary source of pressure increase in the fuel delivery assembly 153 between fuel tank 151 and engine 100. The main fuel pump 155 may be configured to increase the pressure in fuel delivery assembly 153 to a pressure higher than the pressure within combustion chamber 164 of burner 160.

[0050] Fuel system 150 also includes a fuel metering unit 157 in fluid communication with fuel delivery assembly 153. Any suitable fuel metering unit 157 can be used, for example, including a metering valve. Fuel metering unit 157 is positioned downstream of main fuel pump 155 and upstream of fuel manifold 159, which is configured to dispense fuel to fuel nozzles 162. Fuel system 150 is configured to supply fuel to fuel metering unit 157, and fuel metering unit 157 is configured to receive fuel from fuel tank 151. Fuel metering unit 157 is further configured to supply fuel flow to engine 100 in a desired manner. More specifically, fuel metering unit 157 is configured to meter fuel and supply a desired amount of fuel to fuel manifold 159 of engine 100 at, for example, a desired flow rate. Fuel manifold 159 is fluidly connected to fuel nozzles 162 and dispenses (provides) the received fuel to a plurality of fuel nozzles 162, where the fuel is injected into combustion chamber 164 and burned. The regulating fuel metering unit 157 changes the amount of fuel supplied to the combustion chamber 164, thus changing the amount of propulsive thrust generated by the engine 100 to propel the aircraft 10.

[0051] Figure 3 This is a detailed cross-sectional view of the turbine section. Figure 3 Showing Figure 2 Detail 3. Compressor section, more specifically, LP compressor 110 and HP compressor 112 (see...) Figure 2 Compressed air is supplied to combustion chamber 164, where it mixes with and burns with fuel to generate hot combustion gases (combustion products). For example, LP compressor 110 and HP compressor 112 each include at least one rotor, such as compressor blades connected to a hub. The combustion gases are discharged to a turbine section, more specifically, to HP turbine 116 and LP turbine 118. HP turbine 116 may include alternating rows of fixed impeller blades 172 (or nozzles) and rotating turbine blades 174 (or buckets). The combustion gases expand in HP turbine 116, and the expanded combustion gases rotate (drive) turbine blades 174. Turbine blades 174 of HP turbine 116 are connected to HP shaft 122, thereby driving HP compressor 112 via HP shaft 122. LP turbine 118 may also include alternating rows of fixed impeller blades 172 and rotating turbine blades 174. The combustion gases expand further in LP turbine 118, and the expanded combustion gases rotate (drive) turbine blades 174. The turbine blades 174 of the LP turbine 118 are connected to the LP shaft 124, thereby driving the LP compressor 110 and the fan 126 through the LP shaft 124.

[0052] HP shaft 122 and LP shaft 124 are supported for rotation in one or more bearings 176. One or more turbine frames 180 provide a structural load path from the bearings 176 to the housing 106, which forms the skeleton structure of the engine 100. Figure 3 The turbine frame shown is the turbine rear frame 180. Engine 100 may also include other frames not shown, such as the front frame in front of the HP compressor 112 and the turbine center frame. The following discussion focuses on the turbine rear frame 180, but also applies to other frames of engine 100.

[0053] The turbine rear frame 180 includes an annular, centrally located hub 182 surrounded by an annular outer ring 184. The hub 182 and the outer ring 184 are interconnected by a plurality of radially extending struts (not shown). For example, the turbine rear frame 180 may have six equidistant struts in a circumferential direction. The turbine rear frame 180 may be a single monolithic unit or may be constructed from individual components. The struts may be hollow and include bleed ports for cooling the struts. The turbine rear frame 180 may also include a plurality of service pipe assemblies 186 mounted within the turbine rear frame 180. The service pipe assemblies 186 may be positioned between the struts and extend between the hub 182 and the outer ring 184. In this example, the six service pipe assemblies 186 are circumferentially spaced between each strut. As will be discussed in more detail below, each service pipe assembly 186 includes a hollow service pipe for supplying fluid to and from the core of the engine 100. The service tube may be a hydrocarbon fluid conduit according to the embodiments discussed herein, and in the specific embodiments discussed below, the service tube is the main lubrication system 200 (see...). Figure 4 ) oil pipe 300 (see Figure 5 ).

[0054] Figure 4 This is a schematic diagram of the main lubrication system 200 of engine 100. The main lubrication system 200 includes an oil reservoir 202 configured to store oil. The main lubrication system 200 also includes an oil delivery assembly 204. The oil delivery assembly 204 is fluidly connected to the oil reservoir 202 and is configured to distribute oil to components of the main lubrication system 200, including various oil collection channels 210 within engine 100. The oil delivery assembly 204 includes pipes, conduits, guides, etc., to fluidly connect the various components of the main lubrication system 200. The oil delivery assembly 204 is configured to connect the oil reservoir 202 and engine 100 (see...) Figure 2 Oil is transported between various oil collection tanks 210 within the reservoir 202, thereby providing a flow path (fluid path) for the oil between the reservoir 202 and one or more oil collection tanks 210. For example, the oil delivery assembly 204 includes a supply line 206 and a return line 208. The supply line 206 is configured to supply oil from the reservoir 202 to each oil collection tank 210, and the return line 208 is configured to provide a flow path for oil to return from each oil collection tank 210 to the reservoir 202. The supply line 206... Figure 4 The middle section is shown with a dashed line, and the return oil line 208 is... Figure 4 The text is displayed using solid lines.

[0055] Oil collection tank 210 (in) Figure 4The oil sump (described as oil sump A, oil sump B, or oil sump C) can be any component of engine 100 requiring lubrication, such as bearing 176. Other oil sump 210s, for example, include accessory gearbox 212 or drive gearbox 214. Accessory gearbox 212 can be configured to transmit power from the main drivetrain of engine 100 to various accessory systems of engine 100 or aircraft 10. Drive gearbox 214 (also called reduction gearbox or power gearbox) can be used in the drivetrain of engine 100 to transmit power and torque from turbine 104 to fan section 102 (see [link to relevant documentation]). Figure 2 In some embodiments, disk 130 (see...) Figure 2 ) is connected to the fan shaft, and the fan shaft is connected to the LP shaft 124 via the transmission gearbox 214 (see Figure 2 ), and the LP shaft 124 drives (rotates) the fan shaft by transmitting power and torque via the transmission gearbox 214.

[0056] Some oil collection grooves 210 of the engine 100 are radially located within the core airflow path 121, for example, such as bearing 176 (see...). Figure 3 ) and transmission gearbox 214. To supply oil to and remove oil from these oil collection tanks 210, the oil passes through the core airflow path 121. Therefore, a portion of the oil delivery assembly 204 includes the oil pipe 300 of the service pipe assembly 186 (see...). Figure 5 As will be discussed further below, the oil line 300 is self-cleaning to remove coke that may accumulate within it. Therefore, the main lubrication system 200 may also include multiple filters 216 located within various oil lines of the oil delivery assembly 204. The filters 216 are sized and positioned within the oil delivery assembly 204 to collect coke particles that may detach from the oil line 300, and to collect these particles before they enter portions of the main lubrication system 200 that could potentially clog them, such as oil nozzles that supply oil to the bearing 176 or the transmission gearbox 214.

[0057] The main lubrication system 200 includes at least one oil pump 220 fluidly connected to an oil delivery assembly 204 to guide oil flow through the assembly. For example, the main lubrication system 200 may include a supply pump 222 configured to draw oil from an oil reservoir 202 and supply oil to each oil collection trough 210. The supply pump 222 may be positioned downstream of the oil reservoir 202 and upstream of the oil collection trough 210 relative to the oil flow within the oil delivery assembly 204. The main lubrication system 200 may also include a plurality of return pumps 224 configured to remove (draw) oil from each oil collection trough 210 and return the removed oil to the oil reservoir 202. One return pump 224 may be used for each oil collection trough 210, and each return pump 224 may be positioned downstream of the corresponding oil collection trough 210 and upstream of the oil reservoir 202 relative to the oil flow within the oil delivery assembly 204. The oil pump 220 can be driven by the accessory gearbox 212.

[0058] The main lubrication system 200 may further include at least one heat exchanger configured to extract heat from the oil. In this embodiment, the main lubrication system 200 includes a fuel-to-oil heat exchanger 232 and an oil-to-oil heat exchanger 234. In this embodiment, the fuel-to-oil heat exchanger 232 and the oil-to-oil heat exchanger 234 are positioned downstream of the supply pump 222 and upstream of the oil collection tank 210 relative to the oil flow within the oil delivery assembly 204. A main filter 236 may be positioned between the supply pump 222 and the fuel-to-oil heat exchanger 232 and / or the oil-to-oil heat exchanger 234 to remove any debris from the oil before it flows to the fuel-to-oil heat exchanger 232, the oil-to-oil heat exchanger 234, and the oil collection tank 210.

[0059] Figure 5 This is a detailed cross-sectional view of the service pipe assembly 186 of the turbine rear frame 180, showing... Figure 3 Detail 5. The service pipe assembly 186 may include a service pipe fairing 188. In this embodiment, the service pipe fairing 188 is an airfoil-shaped blade supported between the hub 182 and the outer ring 184. The service pipe fairing 188 is hollow, having a cavity 189, and the oil pipe 300 is located within the cavity 189 of the service pipe fairing 188. The service pipe fairing 188 may include a plurality of holes, and when the engine 100 is operating, compressor bleed air 22 from the compressor section may be supplied to the cavity 189 and discharged outward through the holes to cool the service pipe fairing 188.

[0060] Figure 6 The service pipe assembly 186's oil pipe 300 is shown, and Figure 7 The oil pipe 300 is shown along Figure 6Cross-sectional view taken along centerline 7-7. The tubing 300 has a central section 312 disposed between a decreasing diameter outer end 314 and a decreasing diameter inner end 316. The central section 312 is located within the cavity 189 of the service pipe shroud 188 (see...). Figure 5 The inner end 316 may include a generally cylindrical male fitting, which is connected to the oil collection groove 210 (see...). Figure 4 One of the female sockets (such as bearing 176 located within the turbine rear frame 180) (see Figure 3 The outer end 314 includes a connector for connecting the oil pipe 300 to the supply line 206 or the return line 208 (see...). Figure 4 A fluid connection fitting in ) . The tubing 300 has an axial direction a, a radial direction r, and a circumferential direction c (see Figure 7 In this text, lowercase letters are used relative to the direction of oil pipe 300, while uppercase letters are used relative to the direction of engine 100. The axial direction 'a' of oil pipe 300 is generally relative to engine 100 (see...). Figure 2 Extending in the radial direction R, and in this embodiment, in the turbine rear frame 180 (see... Figure 5 It extends in the radial direction. The circumferential direction extends in the direction of rotation about the axial direction a.

[0061] like Figure 7 As shown, the oil pipe 300 includes a wall 320 having an inner surface 322. The inner surface 322 defines a flow channel 302 for oil (hydrocarbon fluid). More specifically, the wall 320 of the oil pipe 300 is annular. While the oil pipe 300 can have any suitable shape (e.g., circular), the wall 320 of the oil pipe 300 is elliptical, and in this embodiment, has a shape consistent with that of the engine 100 (see [link to engine 100]). Figure 2 The long axis is aligned with the axial direction A of the wall. Wall 320 can be formed of any of stainless steel, corrosion-resistant alloys of nickel and chromium, and high-strength nickel-based alloys. Wall 320 can be formed of a metallic alloy selected from the group consisting of iron-based alloys, nickel-based alloys, and chromium-based alloys.

[0062] Figure 8 It displays the oil temperature (T) during different stages of flight. oil ) and the temperature of the wall at 320°C (T) metal The diagram shows wall 320, and more specifically, interior surface 322 (see diagram). Figure 7 The pipe 300 may be exposed to elevated temperatures during operation. For example, such elevated temperatures could include temperatures greater than 350 degrees Fahrenheit. As described above, the pipe 300 is positioned within the core airflow path 121, so that the temperature of the wall 320 follows the flow through the core airflow path 121 (see...). Figure 2 The temperature of the air. For example... Figure 8As can be seen, the temperature of the wall at 320°C (T) metal The temperature of wall 320 increases from ambient temperature to high temperature during startup and takeoff, and the temperature of the air flowing through the core airflow path 121 decreases during cruise. metal The temperature (T) of the oil flowing through the flow channel 302 of the oil pipe 300 also decreases. Similarly, during startup, takeoff, and cruise, the temperature (T) of the oil flowing through the flow channel 302 of the oil pipe 300 also decreases. oil The temperature also rises from ambient temperature to operating temperature. When the oil flows through the oil pipe 300, the oil temperature is less affected by the air temperature flowing through the core airflow path 121 compared to other heat sources within the engine 100.

[0063] Immediately after shutdown, a so-called backflow heating occurs. During shutdown, the oil flows through channel 302 (see...). Figure 7 ) inside and against the inner surface 322 (see Figure 7 The flow of air in the compressor bleed air 22 is stagnant (or at least greatly reduced). Additionally, there is no flow in the compressor bleed air 22 to cool the service pipe shroud 188 (see...). Figure 5 ) and wall 320 (see Figure 7 Meanwhile, service management components such as 186 (see...) Figure 5 The components remain very hot. Therefore, both the oil temperature and the wall temperature (320°C) increase above the coke formation temperature (T). coke The temperature of the oil. At these temperatures, the internal surface 322, exposed to oil and made of the metals discussed above, may be susceptible to significant coke buildup. Under these conditions, coke can accumulate to a considerable thickness over time, restricting or even blocking oil flow through the flow passage 302. As the components of the engine 100 release their heat into the environment, the oil lines 300 and the oil within them will begin to cool.

[0064] The tubing 300 discussed in this article is self-cleaning and can be removed using a movable sleeve from the internal surface 322 of the wall 320 (see...). Figure 7 The movable sleeve in the embodiment discussed herein is passive, moving by means of changes in the operating conditions of the engine 100, such as temperature and pressure variations. The movable sleeve can move along the inner surface 322 of the wall 320, breaking up (or scraping off) the coke deposits that have formed on the inner surface 322. The broken coke deposits can then be allowed to flow naturally through the flow channel 302 (see...). Figure 7 This allows the coke deposits to be removed, thus preventing their accumulation. As mentioned above, this is referred to in this paper as a self-cleaning effect.

[0065] Figure 9 A movable sleeve according to an embodiment is shown. Figure 9 It is along the 300mm oil pipe. Figure 7Cross-sectional view taken along centerline 9-9. The movable sleeve in this embodiment is a mesh sleeve 330. The mesh sleeve 330 is also shown. Figure 7 In the middle. The mesh sleeve 330 is positioned within the flow channel 302 of the oil pipe 300, such that the mesh sleeve 330 abuts the inner surface 322 (see...). Figure 7 The mesh sleeve 330 is formed of a mesh 332, which is made of a shape memory alloy (SMA). The mesh 332 of the mesh sleeve 330 can be formed of one of a variety of materials generally considered to belong to the category of "shape memory alloys". In the applications discussed herein, the shape memory alloy is preferably a high-temperature shape memory alloy. For example, a suitable high-temperature shape memory alloy is a nickel-titanium alloy known as the trademark Nitinol. Other suitable shape memory alloys include cobalt-nickel-aluminum alloys, nickel-iron-gallium alloys, iron-manganese-gallium alloys, and cobalt-nickel-gallium alloys.

[0066] Shape memory alloys can undergo phase transitions in response to changes in temperature (increasing or decreasing). For example, It can transform between austenitic and martensitic phases. The temperature (or temperature range) at which this phase transformation occurs can be called the transformation temperature. The shape memory alloy of the mesh 332 used to form the oil pipe 300 preferably has the above-mentioned characteristics. Figure 8 The transformation temperature range discussed is suitable for the thermal cycling of tubing 300, and tubing 300 is configured to be exposed to thermal cycling through the transformation temperature range of the selected shape memory alloy. Many shape memory alloys discussed above, such as... The transition temperature can be adjusted to range from room temperature (e.g., 20 degrees Celsius) to 100 degrees Celsius. For example, when the temperature of the tubing 300 increases during startup or decreases during cooling, the mesh sleeve 330 will pass through the transition temperature, and the shape memory alloy will undergo a phase transformation. With this phase transformation, the mesh sleeve 330 will change shape. For example, the mesh sleeve 330 has an axial length, and the axial length can expand or contract as the mesh sleeve 330 passes through the transition temperature. As described above, the mesh sleeve 330 abuts the inner surface 322, and with the phase transformation, the mesh sleeve 330 will break up deposits already formed on the inner surface 322.

[0067] Figure 9 The mesh 332 of the mesh sleeve 330 shown comprises a network formed by a plurality of wire bundles 334 of shape memory alloy. In this embodiment, the wire bundles 334 are integrally formed with each other, but the wire bundles 334 may also be individual wire bundles 334 that are patterned mechanically or metallurgically connected to each other to form the mesh 332. The wire bundles 334 are positioned relative to each other to define a plurality of openings 336 therebetween. In this embodiment, the openings 336 are diamond-shaped.

[0068] Figure 10A ,10B 10C and 10D show grids 340, 350, 360, and 370 with different patterns. Grids 340, 350, 360, and 370 can be used in place of grid 332 of the mesh sleeve 330 discussed above, and unless otherwise specifically indicated, these grids 340, 350, 360, and 370 can be used in any of the embodiments discussed herein. Figure 10A , 10B The grids 340, 350, 360, and 370 shown in 10C and 10D are the same as grid 332 discussed above, except for the grid pattern.

[0069] Figure 10A The grid 340 shown includes a plurality of helical wire bundles 342. Each helical wire bundle 342 in this embodiment is parallel to another helical wire bundle 342 and also intersects another helical wire bundle 342 that is helical in the opposite direction. The plurality of helical wire bundles 342 are positioned to form an opening 344. In this embodiment, the opening 344 has a rhomboid shape. Besides the shape, the characteristics of the wire bundles 334 and openings 336 of the embodiments discussed above also apply to the helical wire bundles 342 and openings 344 of this embodiment.

[0070] Figure 10B , 10C The grids 350, 360, and 370 shown in 10D include harnesses 352, 362, and 372, which are in tubing 300 (see...). Figure 7 Extending in the circumferential direction c, openings 354, 364, and 374 are formed in the axial direction between adjacent wire bundles 352, 362, and 372. Besides the shape, the features of wire bundle 334 and opening 336 in the embodiments discussed above also apply to the adjacent wire bundles 352, 362, and 372 and openings 354, 364, and 374 in this embodiment. Figure 10B In the mesh 350, there is a wire harness 352 having a toothed serrated pattern, the teeth being generally regular and having a generally uniform triangular shape. Figure 10C In the mesh 360, there is a wire harness 362 with a serrated pattern. The teeth are irregular, for example, having different heights and widths. Figure 10D The wire bundles 372 of the grid 370 shown also have a serrated shape, but each wire bundle 372 is nested with the adjacent wire bundle 372.

[0071] Figures 11A to 11RThe diagram shows grids 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, and 399 according to a further embodiment. Grids 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, and 399 can be used to replace grid 332 of the mesh sleeve 330 discussed above (see...). Figure 7 ), and unless otherwise specifically indicated, these grids 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, and 399 can be used in any of the embodiments discussed herein. Similar to grid 332 discussed above, Figures 11A to 11R The grids 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, and 399 shown each have multiple bundles of shape memory alloy wires positioned relative to each other to form openings. The bundles and openings can have different shapes or sizes as shown in these figures, as will be discussed further below, resulting in different grid densities and deformation factors for each grid. In addition to these differences, the above discussion regarding… Figure 9 The description of the wire bundle 334 and opening 336 of the discussed grid 332 also applies here, and detailed descriptions of these features are omitted here.

[0072] The following discussion of the mesh sleeve 330 uses mesh 332 as an example, but the same applies to mesh sleeves using meshes 340, 350, 360, 370, 381, 382, ​​383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, and 399.

[0073] Figure 12A , 12B And 12C is the oil pipe 300 along Figure 7 The cross-sectional view taken by line 9-9 in the figure shows different attachments of the mesh sleeve 330 to the tubing 300. The mesh sleeve 330 can be attached and positioned within the tubing 300 using various suitable methods. However, the chosen attachment method should allow the mesh 332 to move along the inner surface 322 in the axial direction a of the tubing 300. If the mesh 332 is over-constrained, it will bend instead of sliding along the inner surface 322 and may not break the coke layer.

[0074] Figure 12A A first attachment method and construction of the mesh sleeve 330 are shown. The mesh sleeve 330 includes a solid (non-mesh) portion, referred to herein as a collar 338. The collar 338 may be annular, and a mesh 332 is attached to the collar 338. In this embodiment, the collar 338 is attached to a wall 320, and more specifically, to an inner surface 322. Any suitable attachment means, including mechanical fasteners, metallurgical bonding, or even interface mating, may be used to attach the collar 338 to the inner surface 322. The mesh 332 extends above or below the collar 338 and is freely movable relative to the inner surface 322, and under the thermal cycling discussed above, the mesh 332 moves toward or away from the collar 338, breaking up the coke formed on the inner surface 322.

[0075] Figure 12B Another mesh sleeve 330 is shown attached to wall 320. The mesh sleeve 330 may have at least one collar 338, and in this embodiment, the mesh sleeve 330 includes a plurality of collars 338. One of the collars 338 is attached to wall 320 in the manner discussed above. The other collars 338 are free to move. The collars 338 are attached to each other by a mesh 332. The movement of the mesh 332 under the thermal cycling discussed above changes the relative distance between adjacent collars 338. In this embodiment, each collar 338 abuts the inner surface 322, and the movement of the collars 338 scrapes the inner surface 322, disrupting coke formation.

[0076] Figure 12C Another mesh sleeve 330 is shown attached to wall 320. The mesh sleeve 330 is... Figure 12A and 12B The mesh sleeve 330 shown is a hybrid. In this embodiment, the mesh sleeve 330 includes two collars 338 positioned at the top and bottom of the mesh 332, respectively. Only one collar 338 is attached to the wall 320 in the manner discussed above.

[0077] Figures 13A to 13D The process of installing the mesh sleeve 330 into the tubing 300 is shown. Figure 13A The initial or shape memory configuration of the mesh sleeve 330 is shown. The mesh sleeve 330 is then rolled (or otherwise extruded) into a thin tube. The selected rolling temperature is based on the specific shape memory alloy used. Figure 13B The compression configuration of the mesh sleeve 330 is shown. Depending on the specific shape memory alloy used, the curling force is maintained or released. Figure 13CA mesh sleeve 330, in a compressed configuration, is shown inserted into tubing 300. The insertion temperature range is preferably set to maintain the mesh 332 of the mesh sleeve 330 in the same metallurgical phase as used in the coiling step. The mesh sleeve 330 is then heated, or the coiling force is released, to cause the mesh sleeve 330 to expand within tubing 300. Figure 13D The mesh sleeve 330 is shown in an expanded (installed) configuration inside the tubing.

[0078] In the embodiments discussed above, the mesh 332 is formed of a shape memory alloy; however, the mesh 332 can also be formed using, for example, a bimetallic wire harness 334 having a first metal and a second metal. The two different metals used to form the mesh 332 have different coefficients of thermal expansion, such that the different coefficients of thermal expansion drive the movement of the mesh sleeve 330 in the manner discussed above during the thermal cycling of the engine 100. The first and second metals used in the bimetallic wire harness 334 for the applications discussed herein include, for example, steel (such as stainless steel), titanium, titanium alloys, nickel, and nickel alloys (such as...). RENE TM and Hastalloy TM ).

[0079] Figures 14 to 16 A movable sleeve assembly 410 according to another embodiment is shown. Figure 14 and 15 This is a cross-sectional view of the 300mm oil pipe. Figure 14 and 15 With and along Figure 7 The cross-sectional view taken by line 9-9 is similar to a perspective view, but... Figure 14 and 15 This includes the movable sleeve assembly 410 of this embodiment. Figure 16 It is the oil pipe 300 and the movable sleeve assembly 410 along Figure 14 The cross-sectional view is taken by line 16-16. Although shown as circular in this embodiment, wall 320 can have other suitable shapes, such as Figure 7 The elliptical shape is shown in the figure. The movable sleeve assembly 410 includes a movable sleeve 412 and a spring 414. In this embodiment, the movable sleeve assembly 410 uses the oil flow in the flow channel 302 together with the spring 414 to move the movable sleeve 412.

[0080] Figure 14 The oil line 300 is shown when oil is not flowing through the flow channel 302 (e.g., under shutdown conditions), and Figure 15The oil pipe 300 is shown as oil flows through the flow channel 302 (e.g., when the engine 100 is operating). The movable sleeve 412 may be a solid annular ring, similar to the collar 338 discussed above. The movable sleeve 412 is positioned within the oil pipe 300 such that the outer edge of the movable sleeve 412 abuts the inner surface 322. The movable sleeve 412 is attached to one end of a spring 414, and in this embodiment, the other end of the spring 414 is attached to the flange 416 of the oil pipe 300.

[0081] Oil flowing through flow channel 302 is pressurized. Therefore, the oil presses against the circumferential surface 418 of the movable sleeve 412 in the axial direction a of the oil pipe 300. The oil resists the spring force of the spring 414. The size of the circumferential surface 418 and the spring force of the spring 414 are configured such that the oil pressure moves the movable sleeve 412 toward one end of the oil pipe 300. The circumferential surface 418 is an example of a contact surface to which pressure can be applied to move the movable sleeve 412. In this embodiment, the oil pressure and the flow of oil in flow channel 302 press the movable sleeve 412 toward the inner end 316 (see...). Figure 6 Compression spring 414, such as Figure 15 As shown in the diagram. When oil stops flowing through flow channel 302, such as when engine 100 is turned off, spring 414 presses movable sleeve 412 against the other end of oil pipe 300 (in this embodiment, outer end 314, see...). Figure 6 ),like Figure 14 As shown in the diagram, this movement of the movable sleeve 412 scrapes the inner surface 322 and disrupts the coke deposits formed on the inner surface 322.

[0082] Spring 414 can be any suitable spring, including, for example, wave springs or bellows springs. Suitable wave springs include those manufactured by Smalley of Lake Zurich, Illinois. Preferably, spring 414 is suitable for a relatively large stroke, such that one spring 414 and a movable sleeve 412 are used within the tubing 300, and the movable sleeve 412 almost covers the central section 312 of the tubing 300 (see [link to tubing description]). Figure 6 The entire length of ).

[0083] Figures 17 to 20 A movable sleeve assembly 420 according to another embodiment is shown. Figure 17 and 18 This is a cross-sectional view of oil pipe 300a. Figure 17 and 18 With and along Figure 7 The cross-sectional view taken by line 9-9 is similar to a perspective view, but... Figure 17 and18 This includes the movable sleeve assembly 420 of this embodiment. Figure 19 It is an oil pipe 300 along Figure 17 The cross-sectional view taken by line 19-19 in the middle, and Figure 20 This is a detailed view of the inner movable sleeve 422 of the movable sleeve assembly 420, showing... Figure 17 Detail 20. Above about Figures 14 to 16 In the discussed embodiment, hydraulic pressure and the flow of oil through flow channel 302 are used to drive the movement of the movable sleeve 412. In this embodiment, another pressure source is used to drive the movement of the movable sleeve assembly 420. In this embodiment, the other pressure source is compressor bleed air 22, but any suitable pneumatic or hydraulic pressure source can be used. The same reference numerals will be used for components of the movable sleeve assembly 420 in this embodiment that are the same as or similar to those of the movable sleeve assembly 410 discussed above. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here.

[0084] The tubing 300a is similar to the tubing 300 discussed above and can be used in place of the tubing 300 discussed above. The same reference numerals will be used for components of the tubing 300a in this embodiment that are the same as or similar to those of the tubing 300 discussed above. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here. The tubing 300a in this embodiment is a double-walled tube, having an inner wall 324 and an outer wall 326. An inner surface 322 is formed on the inner wall 324, and the inner wall 324 and the outer wall 326 are positioned to define a cavity 304 therebetween. Although shown as circular in this embodiment, the inner wall 324 and the outer wall 326 can have other suitable shapes, such as... Figure 7 The ellipse shown.

[0085] The movable sleeve assembly 420 of this embodiment includes an inner movable sleeve 422 and an outer movable sleeve 424. The outer movable sleeve 424 is positioned within a cavity 304 and is connected to a spring 414. In this embodiment, the spring 414 is located within the cavity 304. The cavity 304 is fluidly connected to a pressure source, such as compressor bleed air 22. When the engine 100 is operating, compressor bleed air 22 is supplied to the cavity 304 and pressed against the circumferential surface 426 of the outer movable sleeve 424 in the axial direction a of the oil line 300a. The compressor bleed air 22 resists the spring force of the spring 414. The size of the circumferential surface 426 and the spring force of the spring 414 are configured such that the pressure of the compressor bleed air 22 moves the outer movable sleeve 424 toward one end of the oil line 300. In this embodiment, the compressor bleed air 22 presses the outer movable sleeve 424 toward the inner end 316 (see...). Figure 6 Compression spring 414, such as Figure 18As shown. When the engine 100 is off, the compressor bleed air 22 is not supplied to the cavity 304, and the spring 414 presses the outer movable sleeve 424 against the other end of the oil pipe 300 (in this embodiment, the outer end 314, see...). Figure 6 ),like Figure 17 As shown.

[0086] The inner movable sleeve 422 is coupled to the outer movable sleeve 424, and the inner movable sleeve 422 moves together with the outer movable sleeve 424. In this embodiment, the inner movable sleeve 422 is magnetically coupled to the outer movable sleeve 424. For example, the outer movable sleeve 424 may be magnetic, and the inner movable sleeve 422 may include, for example, […]. Figure 20 As shown, a plurality of balls 428 are attracted to an outer movable sleeve 424. The balls 428 can also be used to help guide the inner movable sleeve 422 along the inner surface 322. The inner movable sleeve 422 abuts the inner surface 322, and the movement of the inner movable sleeve 422 scrapes the inner surface 322, breaking up coke deposits formed on the inner surface 322. The inner movable sleeve 422 has a shape suitable for breaking up coke deposits.

[0087] Figures 21 to 23 A movable sleeve assembly 430 according to another embodiment is shown. Figure 21 and 22 This is a cross-sectional view of oil pipe 300b. Figure 21 and 22 With and along Figure 7 The cross-sectional view taken by line 9-9 is similar to a perspective view, but... Figure 22 and 22 This includes the movable sleeve assembly 430 of this embodiment. Figure 23 It is oil pipe 300b along Figure 22 The cross-sectional view is taken from line 23-23 in the diagram. For clarity, in... Figure 23 The second spring 444 (discussed further below) is omitted. The movable sleeve assembly 430 of this embodiment is the same as the one referenced above. Figures 17 to 20The movable sleeve assembly 420 of the discussed embodiment is similar. In the following discussion, the same reference numerals are used for similar components, and detailed descriptions of these components are omitted herein. In this embodiment, the outer movable sleeve 424 is attached to two springs, a first spring 442 and a second spring 444. The first spring 442 is positioned and operated similarly to the spring 414 discussed in the above embodiments. The second spring 444 is attached to the outer movable sleeve 424 on the side opposite to the first spring 442. The first spring 442 and the second spring 444 have different spring constants; in this embodiment, the first spring 442 has a larger spring constant than the second spring 444. The second spring 444 facilitates movement of the movable sleeve assembly 430, and more specifically, facilitates movement of the outer movable sleeve 424 in either direction. In this embodiment, the second spring 444 is shown as a leaf spring; however, as discussed above, any suitable spring can be used.

[0088] The compressor bleed air 22 provides pressure to move the movable sleeve assembly 430, and more specifically, to move the outer movable sleeve 424. To accommodate the compressor bleed air 22, the first spring 442, and the second spring 444, the oil pipe 300b of this embodiment is a three-walled pipe. The oil pipe 300b is similar to and can be used in place of the oil pipe 300a discussed above. The same reference numerals will be used for components of the oil pipe 300b of this embodiment that are the same as or similar to those of the oil pipe 300a discussed above. The above description of these components also applies to this embodiment, and detailed descriptions of these components are omitted here. The oil pipe 300b has an intermediate wall 328 positioned between the inner wall 324 and the outer wall 326. An inner cavity 306 is defined between the inner wall 324 and the intermediate wall 328, and an outer cavity 308 is defined between the intermediate wall 328 and the outer wall 326. The outer movable sleeve 424 includes an inner portion 432 and an outer portion 434, each located in both the inner cavity 306 and the outer cavity 308. In this embodiment, the outer cavity 308 is fluidly connected to a pressure source, such as compressor bleed air 22, and a circumferential surface 426 is located on the portion of the outer movable sleeve 424 in the outer cavity 308 (outer portion 434). A first spring 442 and a second spring 444 are located in the inner cavity 306 and are connected to the portion of the outer movable sleeve 424 in the inner cavity 306 (inner portion 432). The intermediate wall 328 may include a plurality of slots 329, and the inner portion 432 of the outer movable sleeve 424 is connected to the outer portion 434 of the outer movable sleeve 424 via a connection portion 436 through the plurality of slots 329.

[0089] Figure 21 The construction of the movable sleeve assembly 430 is shown, wherein the engine 100 is off, and Figure 22A movable sleeve assembly 430 is shown, in which the engine 100 is operated and compressor bleed air 22 is supplied to the outer cavity 308.

[0090] Figure 24 and 25 A movable sleeve assembly 450 according to another embodiment is shown. The movable sleeve assembly 450 of this embodiment is similar to that referenced above. Figure 21 and 22 The movable sleeve assembly 430 of the discussed embodiment is similar. In the following discussion, the same reference numerals are used for similar components, and detailed descriptions of these components are omitted herein. Similar to the foregoing embodiments, the movable sleeve assembly 450 of this embodiment includes a movable sleeve 452 attached to a first spring 442 and a second spring 444. In this embodiment, the first spring 442 and the second spring 444 are each preferably bellows springs, as the first spring 442 and the second spring 444 together form the wall of the tubing with the movable sleeve 452, and the separating wall is omitted. Therefore, the movable sleeve assembly 450 can be used in place of any of the tubing 300, 300a, 300b discussed above. The movable sleeve 452 is connected to the tubing via oil as described above. Figures 14 to 16 The flow path is moved through the flow channel 302, and the movement of the movable sleeve 452 causes the first spring 442 and the second spring 444 to move. The movement of the first spring 442 and the second spring 444 breaks up the coke deposits.

[0091] Return to the reference above Figures 7 to 13C In the discussed embodiments, different variations of the mesh sleeve 330 formed from shape memory alloy are possible, provided that the resulting combination of mesh and tube meets certain criteria described below. (Refer to the above...) Figures 10A to 11R The mesh sleeve 330 discussed, for example, may include meshes (e.g., mesh 332) with many different geometries and shapes. Furthermore, the size and attachment arrangement of the wire harnesses (e.g., wire harness 334) and the resulting size and shape of the openings (e.g., opening 336) can also vary. Different shape memory alloys can be used. Selecting the correct combination of these features for a specific application is crucial. Otherwise, the mesh sleeve 330 may not have sufficient range of motion to disrupt coke formation for a given application. For clarity in the following discussion, the mesh sleeve 330 is used for… Figure 9 The reference number for grid 332 is used as a representative of the different grids discussed above.

[0092] In evaluating the benefits of possible variations in the design, such as scrapping efficiency versus reliability or efficiency in removing or mitigating coke, the inventors unexpectedly discovered a relationship among the selected features of grid 332, the operating temperature of wall 320 and the oil, and the material of wall 320 that resulted in superior outcomes compared to many other designs considered. The inventors refer to this relationship as the Grid Activation Parameter (MAP) for Lubricating Oil Coke Cleaning. MAP is a dimensionless factor defined by the following relationship (1):

[0093]

[0094] The first factor of MAP, as shown in equation (1), is referred to herein as the mesh density (V' / V). As mentioned above, mesh 332 includes openings 336, and thus the volume (V') of mesh 332 is smaller than the volume (V) of the solid mesh sleeve 330, and is referred to herein as the solid sleeve volume. The mesh density (V' / V) is the volume (V') of mesh 332 divided by the solid sleeve volume (V). The volume (V') of mesh 332 can be calculated by suitable methods, such as calculations from computer-aided design (CAD) models or displacement methods, in which the mesh is immersed in a liquid and the volume of the displacement liquid is used to calculate the volume (V') of mesh 332. The solid sleeve volume (V) can be calculated using the overall dimensions of the mesh sleeve 330. These volume calculations or measurements are performed under assembly conditions, such as at room temperature.

[0095] The second factor of MAP, as shown in relation (1), is referred to in this paper as the operating temperature ratio (T). oil / T metal Operating temperature ratio (T) oil / T metal ) is the temperature of the oil (T) oil ) and the temperature of the wall at 320°C (T) metal The ratio of these temperatures is considered to be the maximum expected normal operating temperature of the oil and wall at 320°C.

[0096] The third factor of MAP as shown in equation (1) is referred to herein as the deformation factor (ΔH / H). The mesh sleeve 330 has an initial shape, which includes its axial length and diameter in the assembled state. The position on the mesh sleeve 330 also has an initial angular position. This initial axial length, initial diameter, or initial angular position is considered as the initial shape (H). The length, diameter, and / or angular position of the mesh sleeve 330 will change under the thermal cycling conditions discussed above. For example, the angular position changes due to the torsion of the mesh sleeve 330. The change in length, diameter, or angular position is referred herein as the shape change ΔH. The deformation factor is the shape change (ΔH) divided by the initial shape (H), such as the length change divided by the initial length, or the diameter change divided by the initial diameter, or the angular position change divided by the initial angular position. In some embodiments, the mesh sleeve 330 will be grown at a higher temperature, and in other embodiments, the mesh sleeve 330 will shrink at a higher temperature. Therefore, the absolute value of the deformation factor is used to calculate MAP.

[0097] The fourth factor of MAP, as shown in relation (1), is referred to in this paper as the stiffness ratio (E). mesh / E tube The shape memory alloy used for grid 332 and the material used for wall 320 each have an elastic modulus, and more specifically, a Young's modulus. Stiffness ratio (E) mesh / E tube The modulus of elasticity (E) is the ratio of the elastic modulus of mesh 332 to the elastic modulus of wall 320, and more specifically, it is the Young's modulus (E) of the shape memory alloy used for mesh 332. mesh ) and Young's modulus (E) of the material used for wall 320 tube The ratio of Young's modulus (elastic modulus) to the extent that Young's modulus (elastic modulus) exhibits temperature dependence is taken under assembly conditions (such as at room temperature).

[0098] As discussed further below, we have identified the MAP range for a set of operating conditions that prevents coke blockage in tubing 300. More specifically, at a given set of return oil temperatures and operating temperatures of tubing 300 (conduit), the identified range of MAP will result in sufficient thermal deformation of the mesh sleeve 330 to break up coke deposits on the inner surface 322 of the wall 320.

[0099] Tables 1 and 2 illustrate exemplary embodiments 1 through 22. Table 1 provides values ​​for the temperature and Young's modulus (MAP) used to calculate different engine environments. Each engine is a high-bypass turbofan engine, such as those described above. Figure 2 The engine is 100, but different operating conditions and sizes result in different oil temperatures (T). oil ) and the temperature of the wall at 320°C (T) metal).

[0100]

[0101] Table 1

[0102] Each embodiment uses a mesh sleeve 330 located within the tubing 300. The mesh sleeve 330 and the mesh 332 can be any of the mesh sleeve 330 and mesh 332 discussed above. Table 2 provides the MAP values ​​used to calculate the mesh 332 used in the mesh sleeve 330 of each embodiment. Table 2 also identifies the resulting MAP for each embodiment.

[0103]

[0104] Table 2

[0105] The mesh density (V' / V) can be between one-tenth and one. To withstand the operating conditions of the tubing 300, the mesh 332 of the mesh sleeve 330 will include a minimum number of wire bundles 334, thus the mesh density (V' / V) is preferably greater than one-tenth. The mesh density (V' / V) is limited by the solid sleeve, therefore the mesh density (V' / V) is preferably less than one. The mesh density affects the flow dynamics of oil through the flow channel 302 of the tubing 300, thus different densities result in different resistances (pressure drops) within the flow channel 302. The mesh density can also affect the amount of movement, thus the ability of the mesh sleeve 330 to break up coke deposits with higher density results in less movement. Balancing these considerations and other considerations discussed below, the mesh density (V' / V) is more preferably between two-tenths and five-tenths.

[0106] Some small amount of movement of the mesh sleeve 330 is necessary to break up coke deposits, and in some embodiments, the absolute value of the deformation factor (ΔH / H) can be one-tenth or greater. However, larger amounts of movement are beneficial for breaking up coke deposits, and the absolute value of the deformation factor (ΔH / H) is preferably seven-tenths or greater. However, too much movement may introduce other problems, such as reduced reliability or blockage. To avoid some of the problems related to the dynamic response of the mesh sleeve 330 and tubing 300 discussed below, the absolute value of the deformation factor (ΔH / H) is preferably nine-tenths or less. Therefore, the absolute value of the deformation factor (ΔH / H) can be from one-tenth to nine-tenths, and preferably from seven-tenths to nine-tenths.

[0107] There are many shape memory alloys that can be used to move the mesh sleeve 330 in the manner discussed in this paper, and the Young's modulus (E) of these shape memory alloys used for the mesh 332 is... meshThe range of stiffness is from fifty gigapascals to two hundred and ten gigapascals. Therefore, when considering the typical materials used for tubing 300, the stiffness ratio (E) is... mesh / E tube The stiffness ratio (E) can range from 20% to 96%. As discussed above, the engine 100 includes many rotating parts that generate various vibrations at different excitation frequencies. As discussed above, the mesh sleeve 330 is fixed, therefore it can move. Because the mesh sleeve 330 can move, the mesh sleeve can dynamically respond to vibrations. mesh / E tube The selection of the mesh density (V' / V) and deformation factor (ΔH / H) is preferably chosen to avoid the resonant frequencies and other dynamic responses of the mesh sleeve 330 and tubing 300, particularly those frequencies that may lead to inelastic acoustic responses and other responses that cause cyclic failure of the tubing 300. Therefore, the stiffness ratio (E...) mesh / Et ube Preferably, it is between five and seven tenths.

[0108] Figure 26 and 27 The ratio of operating temperature (T) is presented in graphical form. oil / T metal ) Changing MAP. In Figure 26 In the diagram, the cross-hatched areas represent the boundaries of the MAP used to construct grid 332, which can lead to a mesh sleeve 330 that provides sufficient movement to interfere with coke formation within the engine 100. Figure 26 As can be seen, the boundary of the MAP, and therefore the appropriate construction of mesh 332, is based on the oil temperature (T). oil ) and the temperature of the wall at 320°C (T) metal The variation, more specifically, is based on the operating temperature ratio (T) of a given engine application. oil / T metal The MAP varies. A preferred set of boundaries for the MAP is shown in region 510. The MAP can be six-tenths or smaller, and can range from one ten-thousandth to six-tenths. Figure 26 As can be seen, this range of MAP is given to achieve a working temperature ratio (T). oil / T metal MAP is the operating temperature ratio (T). oil / T metal It is a linear function of MAP. The upper limit of MAP can be determined from the operating temperature ratio (T). oil / T metal The MAP of region 510 decreases linearly by six-tenths, therefore the upper limit of the MAP of region 510 is given by the following relation (2):

[0109]

[0110] A preferred set of boundaries for the MAP is shown in region 520. The MAP can be three-tenths or smaller and can range from one-tenth to three-tenths. Figure 26 As can be seen, this range of MAP is given to provide a working temperature ratio (T). oil / T metal The preferred upper limit of MAP is given by the following relation (3):

[0111]

[0112] For many of the aircraft applications discussed in this article, coke will not be used at a temperature ratio of less than four-tenths of the operating temperature (T). oil / T metal Therefore, in some embodiments, the operating temperature is higher than (T). oil / T metal It goes from four-tenths to one-tenth. Figure 27 A set of preferred boundaries for the MAP given by region 512 and a set of more preferred boundaries for the MAP given by region 522 are shown. The boundaries of regions 512 and 522 are respectively... Figure 26 Regions 510 and 520 have the same boundary, but their operating temperatures are different (T). oil / T metal The lower limit is four-tenths. At four-tenths of the operating temperature (T... oil / T metal Under these conditions, MAP can range from 0.01% to 24%, and more preferably from 0.1% to 12%.

[0113] Further aspects of this disclosure are provided by the subject matter of the following provisions.

[0114] A self-cleaning conduit for hydrocarbon fluids includes a tube and a movable sleeve. The tube has an inner surface that defines a flow channel for the hydrocarbon fluid. The movable sleeve is positioned within the flow channel to abut the inner surface and is capable of moving along the inner surface in response to changes in the operating characteristics of the conduit to break up deposits on the inner surface.

[0115] According to the conduit described in the foregoing clauses, the movable sleeve is a mesh sleeve comprising a grid.

[0116] The conduit according to any one of the foregoing clauses, wherein the mesh comprises a plurality of bimetallic wire bundles, and the change in the operating characteristic is a temperature change of the mesh.

[0117] The conduit according to any one of the foregoing clauses, wherein the movable sleeve includes a collar abutting the inner surface of the conduit and being movable along the inner surface via the mesh.

[0118] The conduit according to any one of the foregoing clauses, wherein the movable sleeve comprises a plurality of collars abutting the inner surface of the conduit, and at least one of the plurality of collars is movable along the inner surface through the mesh.

[0119] The conduit according to any one of the foregoing clauses, wherein the movable sleeve includes a collar attached to the inner surface of the conduit.

[0120] The conduit according to any one of the foregoing clauses, wherein the collar is attached to the inner surface of the conduit by an interference fit.

[0121] The conduit according to any one of the foregoing clauses, wherein the mesh comprises a plurality of wire bundles formed of shape memory alloy, and the change in the operating characteristic is a temperature change of the mesh.

[0122] The conduit according to any one of the foregoing clauses, wherein the shape memory alloy is one of a nickel-titanium alloy, a cobalt-nickel-aluminum alloy, or a nickel-iron-gallium alloy.

[0123] The catheter according to any one of the foregoing clauses further includes a movable sleeve assembly, the movable sleeve assembly including the movable sleeve and at least one spring connected to the movable sleeve.

[0124] According to any one of the foregoing clauses, the conduit wherein the movable sleeve includes a contact surface, the movable sleeve being positioned in the flow channel such that when the hydrocarbon fluid flows through the flow channel and the movable sleeve moves toward one end of the conduit against the spring force of the spring, the hydrocarbon fluid is pressed against the contact surface, the flow of the hydrocarbon fluid within the flow channel being the change in the operating characteristics of the conduit.

[0125] The conduit according to any one of the foregoing clauses, wherein the movable sleeve is annular and has a circumferential surface, the circumferential surface being the contact surface.

[0126] The conduit according to any one of the foregoing clauses, wherein the tube is a multi-walled tube having an inner wall and an outer wall, the inner surface being formed on the inner wall, and the inner wall and the outer wall being positioned therebetween to define a cavity, the cavity being fluidly connected to a pressure source, the pressure within the cavity from the pressure source being a variation of the operating characteristics of the conduit, and wherein the movable sleeve includes an inner movable sleeve and an outer movable sleeve, the spring being attached to the outer movable sleeve, the outer movable sleeve being positioned within the cavity and including a contact surface, and when the cavity receives pressure from the pressure source, the pressure presses against the contact surface to cause the outer movable sleeve to move toward one end of the tube against the spring force of the spring, the inner movable sleeve being positioned within the flow channel to abut the inner surface, and the inner movable sleeve being coupled to the outer movable sleeve so as to move along the inner surface when the outer movable sleeve moves.

[0127] The catheter according to any one of the foregoing clauses, wherein the inner movable sleeve is magnetically coupled to the outer movable sleeve.

[0128] According to any one of the preceding clauses, the spring is a first spring, and the movable sleeve assembly further includes a second spring attached to the outer movable sleeve on the side opposite to the first spring.

[0129] The conduit according to any one of the foregoing clauses, wherein the first spring has a spring constant greater than that of the second spring.

[0130] A lubrication system includes an oil reservoir and an oil collection tank. The oil reservoir is configured to store oil. The oil collection tank is fluidly connected to the oil reservoir via a conduit according to any one of the preceding clauses, wherein the hydrocarbon fluid is the oil.

[0131] The lubrication system according to the foregoing clauses further includes a pump fluidly connected to each of the oil reservoir and the oil collection tank, and configured to circulate the oil through the conduit.

[0132] A gas turbine engine includes a lubrication system according to any one of the preceding clauses, a compressor section, a combustion section, and a turbine section. The compressor section includes at least one rotor configured to compress air flowing through it. The combustion section is configured to mix fuel with compressed air and to combust the fuel-air mixture to produce combustion products. The turbine section includes at least one turbine configured to be driven by the combustion products, wherein the compressor section, the combustion section, and the turbine section together define at least a portion of a core airflow path, and the duct is located within the core airflow path.

[0133] The gas turbine engine according to the foregoing provisions further includes at least one frame, the frame including at least one service pipe assembly, the service pipe assembly including the conduit.

[0134] The gas turbine engine according to any one of the foregoing clauses, wherein the frame includes a plurality of service pipe assemblies.

[0135] The gas turbine engine according to any one of the foregoing clauses, wherein the frame is a turbine rear frame.

[0136] The gas turbine engine according to any one of the foregoing clauses further includes a shaft connecting the at least one turbine to the at least one rotor; and a bearing supporting the shaft, the frame providing a structural load path from the bearing.

[0137] In a gas turbine engine according to any one of the foregoing clauses, the lubrication system is configured to supply oil to the bearing.

[0138] A self-cleaning conduit for hydrocarbon fluids includes a tube and a mesh. The tube has an inner surface that defines a flow channel for the hydrocarbon fluid. The mesh is positioned within the flow channel, adjacent to the inner surface, and is movable along the inner surface to break up deposits on the inner surface. The mesh is characterized in that its mesh activation parameter (MAP) is between 0.01% and 0.6%.

[0139] According to the conduit described in the foregoing clauses, the mesh activation parameter (MAP) is between one-tenth and three-tenths.

[0140] The conduit according to any one of the foregoing clauses, wherein the hydrocarbon fluid is oil, and wherein the conduit is configured to operate at a temperature ratio of four-tenths to one-tenth of the operating temperature.

[0141] The conduit according to any one of the foregoing clauses, wherein the mesh is characterized in that the absolute value of the deformation factor is one-tenth to nine-tenths.

[0142] The conduit according to any one of the foregoing clauses, wherein the mesh is characterized in that the absolute value of the deformation factor is between seven and nine tenths.

[0143] The conduit according to any one of the foregoing clauses, wherein the mesh has a mesh density between one-tenth and one.

[0144] The conduit according to any one of the foregoing clauses, wherein the mesh has a mesh density of two to five tenths.

[0145] The conduit according to any one of the foregoing clauses, wherein the mesh is a sleeve.

[0146] The conduit according to any one of the foregoing clauses, wherein the mesh is formed of a shape memory alloy.

[0147] The conduit according to any one of the foregoing clauses, wherein the shape memory alloy is one of a nickel-titanium alloy, a cobalt-nickel-aluminum alloy, or a nickel-iron-gallium alloy.

[0148] The conduit according to any one of the foregoing clauses, wherein the tube is a metal having a Young's modulus, the shape memory alloy having a Young's modulus, and the ratio of the Young's modulus of the mesh to the Young's modulus of the tube is a stiffness ratio. The stiffness ratio is between two tenths and ninety-six percent.

[0149] The conduit according to any one of the foregoing clauses, wherein the stiffness ratio is from five to seven tenths.

[0150] A lubrication system includes an oil reservoir and an oil collection tank. The oil reservoir is configured to store oil. The oil collection tank is fluidly connected to the oil reservoir via a conduit according to any one of the preceding clauses, wherein the hydrocarbon fluid is the oil.

[0151] The lubrication system according to the foregoing clauses further includes a pump fluidly connected to each of the oil reservoir and the oil collection tank, and configured to circulate the oil through the conduit.

[0152] A gas turbine engine includes a lubrication system according to any one of the preceding clauses, a compressor section, a combustion section, and a turbine section. The compressor section includes at least one rotor configured to compress air flowing therethrough. The combustion section is configured to mix fuel with compressed air and to combust the fuel-air mixture to generate combustion products. The turbine section includes at least one turbine configured to be driven by the combustion products. The compressor section, the combustion section, and the turbine section together define at least a portion of a core airflow path, and the duct is located within the core airflow path.

[0153] The gas turbine engine according to the foregoing provisions further includes at least one frame, the frame including at least one service pipe assembly having the conduit.

[0154] The gas turbine engine according to any one of the foregoing clauses, wherein the frame includes a plurality of service pipe assemblies.

[0155] The gas turbine engine according to any one of the foregoing clauses, wherein the frame is a turbine rear frame.

[0156] The gas turbine engine according to any one of the foregoing clauses further includes a shaft connecting the at least one turbine to the at least one rotor; and a bearing supporting the shaft, the frame providing a structural load path from the bearing.

[0157] In a gas turbine engine according to any one of the foregoing clauses, the lubrication system is configured to supply oil to the bearing.

[0158] A method for installing a movable sleeve into a conduit for hydrocarbon fluids. The movable sleeve is a mesh sleeve comprising a grid, and the conduit comprises a tube. The method includes: curling the mesh sleeve, and inserting the curled mesh sleeve into the tube.

[0159] According to the method described in the foregoing clauses, the mesh comprises multiple wire bundles formed of shape memory alloy.

[0160] According to any one of the preceding clauses, the mesh sleeve is rolled up at a certain temperature, and the mesh sleeve is inserted into the tube at a temperature that maintains the mesh of the mesh sleeve at the same metallurgical phase as the metallurgical phase used in the rolling step.

[0161] The method according to any one of the foregoing clauses further includes: heating the mesh sleeve to cause the curled mesh sleeve to expand inside the tube.

[0162] The method according to any one of the foregoing clauses further includes: maintaining a curling force when the curled mesh sleeve is inserted into the tube; and releasing the curling force to cause the curled mesh sleeve to expand within the tube.

[0163] While the foregoing description is directed toward preferred embodiments, other variations and modifications will be apparent to those skilled in the art and can be made without departing from the spirit or scope of this disclosure. Furthermore, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A self-cleaning conduit for hydrocarbon fluids, characterized in that, The catheter includes: A tube having an internal surface defining a flow channel for the hydrocarbon fluid; and A mesh sleeve comprising a mesh formed of a shape memory alloy, the mesh sleeve being positioned within the flow channel to abut the inner surface and being capable of moving along the inner surface in response to temperature changes in the mesh to break up deposits on the inner surface.

2. The catheter according to claim 1, characterized in that, The mesh comprises a plurality of wire bundles positioned relative to each other to define a plurality of openings therebetween.

3. The catheter according to claim 1, characterized in that, It further includes a collar attached to the inner surface of the tube, wherein the mesh sleeve is connected to the collar.

4. A self-cleaning conduit for hydrocarbon fluids, characterized in that, The catheter includes: A tube having an internal surface defining a flow channel for the hydrocarbon fluid; and A movable sleeve assembly, the movable sleeve assembly comprising: A movable sleeve, positioned within the flow channel to abut the inner surface and having a contact surface; and A spring, which is connected to the movable sleeve, When the hydrocarbon fluid flows through the flow channel, the hydrocarbon fluid presses against the contact surface, causing the movable sleeve to move along the inner surface against the spring force of the spring, thereby breaking up the deposits on the inner surface.

5. The catheter according to claim 4, characterized in that, The movable sleeve is annular and has a circumferential surface, which is the contact surface.

6. A self-cleaning conduit for hydrocarbon fluids, characterized in that, The catheter includes: A tube having an inner wall and an outer wall, the inner wall having an internal surface defining a flow channel for the hydrocarbon fluid, wherein the inner wall and the outer wall are positioned therebetween to define a cavity; and A movable sleeve assembly, the movable sleeve assembly comprising: An outer movable sleeve, the outer movable sleeve being positioned within the cavity and including a contact surface; An inner movable sleeve, positioned within the flow channel to abut the inner surface and connected to the outer movable sleeve; and A spring, which is attached to the outer movable sleeve, The cavity is configured to be fluidly connected to a pressure source, and when the cavity receives pressure from the pressure source, the pressure presses against the contact surface to cause the outer movable sleeve to move against the spring force of the spring, and the inner movable sleeve moves together with the outer movable sleeve to break up deposits on the inner surface.

7. The catheter according to claim 6, characterized in that, The inner movable sleeve is magnetically connected to the outer movable sleeve.

8. The catheter according to claim 6, characterized in that, The spring is a first spring, and the movable sleeve assembly further includes a second spring attached to the outer movable sleeve on the side opposite to the first spring.

9. The catheter according to claim 8, characterized in that, The first spring has a larger spring constant than the second spring.

10. A lubrication system, characterized in that, include: An oil reservoir, the oil reservoir being configured to store oil; and An oil collection tank, which is fluidly connected to the oil reservoir via a conduit according to any one of claims 1, 4 or 6, wherein the hydrocarbon fluid is the oil.

11. The lubrication system according to claim 10, characterized in that, It further includes a pump fluidly connected to each of the oil reservoir and the oil collection tank, and is configured to circulate the oil through the conduit.

12. A gas turbine engine, characterized in that, include: The lubrication system according to claim 10; A compressor section, the compressor section including at least one rotor, the at least one rotor being configured to compress air flowing therethrough; Combustion zone, the combustion zone being configured to mix fuel with compressed air and to combust the fuel-air mixture to produce combustion products; and A turbine section, comprising at least one turbine configured to be driven by the combustion products. The compressor section, the combustion section, and the turbine section together define at least a portion of the core airflow path, and the duct is located within the core airflow path.

13. The gas turbine engine according to claim 12, characterized in that, It further includes at least one frame, the frame including at least one service pipe component, the service pipe component including the conduit.

14. The gas turbine engine according to claim 13, characterized in that, The framework includes multiple service management components.

15. The gas turbine engine according to claim 13, characterized in that, The frame mentioned above is a turbine rear frame.

16. The gas turbine engine according to claim 13, characterized in that, Further includes a shaft connecting the at least one turbine to the at least one rotor; and The frame provides a structural load path from the bearing to the shaft.

17. The gas turbine engine according to claim 16, characterized in that, The lubrication system is configured to supply oil to the bearing.

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