Turbine engine including air turbine starter

Abstract

The invention relates to a turbine engine including an air turbine starter. A turbine engine has an engine core having a compression section, a combustion section, a turbine section, and an engine driveshaft. A turbine engine includes an air turbine starter having a housing defining an air flow passage. The air turbine starter is operable in a start mode and a shutdown mode. The turbine engine further includes a gearbox and a drive unit.

Description

Technical Field

[0001] The present disclosure generally relates to a turbine engine, and more particularly, to a turbine engine including an air turbine starter. Background Art

[0002] Turbine engines (such as gas turbine engines) are typically started via an air turbine starter (ATS). The ATS is usually mounted near the turbine engine, and the ATS can be coupled to a high-pressure fluid source, such as compressed air, which impinges on a turbine rotor in the ATS, causing the turbine rotor to rotate at a relatively high rate. The ATS includes an output drive shaft typically driven by the turbine rotor through a reduction gearbox, where the output drive shaft provides rotational energy to a rotatable element (e.g., a crankshaft or a rotatable shaft) of the turbine engine to start rotating. The rotation through the ATS continues until the turbine engine reaches a self-sustaining operating rotational speed. Summary of the Invention

[0003] Technical Solution 1. A turbine engine, comprising:

[0004] An engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft;

[0005] An air turbine starter, comprising:

[0006] A housing defining an air flow passage; and

[0007] A turbine having a plurality of circumferentially spaced blades located within the air flow passage;

[0008] A gearbox that selectively couples the turbine to the engine drive shaft when the air turbine starter is operable in a start mode, in which air is supplied to the air turbine starter and flows through the air flow passage in a first direction to rotate the turbine; and

[0009] A drive unit that selectively couples to the turbine to rotate when the air turbine starter is operable in a shutdown mode, in which the drive unit drives the turbine to supply air through the air flow passage in a second direction, where the air from the air turbine starter is supplied to at least one of the compression section or the turbine section.

[0010] Technical solution 2. The turbine engine according to any of the foregoing technical solutions further includes a fluid control assembly having a controller for selectively fluidly coupling the air turbine starter to a pressurized air source when the air turbine starter is in the starting mode, or selectively fluidly coupling the air turbine starter to one or more parts of the turbine engine when the air turbine starter is in the shutdown mode.

[0011] Technical solution 3. The turbine engine according to any of the foregoing technical solutions, wherein the drive unit includes a power source operably coupled to a drive shaft, and wherein the drive shaft is selectively coupled to the turbine.

[0012] Technical solution 4. The turbine engine according to any of the foregoing technical solutions, wherein the power source is located outside the housing of the air turbine starter.

[0013] Technical solution 5. The turbine engine according to any of the foregoing technical solutions further includes at least one duct that fluidly couples a first opening of the air turbine starter to a high-pressure compressor of the compression section or a high-pressure turbine of the turbine section.

[0014] Technical solution 6. The turbine engine according to any of the foregoing technical solutions further includes a first set of circumferentially spaced guide vanes located in front of the turbine and a second set of circumferentially spaced guide vanes located behind the turbine.

[0015] Technical solution 7. The turbine engine according to any of the foregoing technical solutions, wherein the first set of circumferentially spaced guide vanes, the second set of circumferentially spaced guide vanes, or a combination thereof includes one or more variable guide vanes.

[0016] A turbine engine, comprising:

[0017] An engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft;

[0018] A two-way air turbine starter having a housing that defines a first opening, a second opening, and an air flow passage extending between the first opening and the second opening, the two-way air turbine starter being selectively coupled to the engine drive shaft;

[0019] A drive unit having a power source operably coupled to a drive shaft, wherein the drive shaft is selectively coupled to the two-way air turbine starter; and

[0020] A fluid control assembly that selectively fluidly couples the first opening of the bi-directional air turbine starter to one or more portions of the engine core.

[0021] Aspect 9. The turbine engine according to any of the preceding aspects, wherein the fluid control assembly includes at least one duct that fluidly couples the first opening to a high-pressure compressor of the compression section or a high-pressure turbine of the turbine section.

[0022] Aspect 10. The turbine engine according to any of the preceding aspects, wherein the power source includes an electric motor.

[0023] Aspect 11. The turbine engine according to any of the preceding aspects, further comprising a controller that communicates with a valve of the fluid control assembly.

[0024] Aspect 12. The turbine engine according to any of the preceding aspects, wherein when the bi-directional air turbine starter is selectively coupled to the engine drive shaft, the air turbine starter drive shaft rotates in a first direction.

[0025] Aspect 13. The turbine engine according to any of the preceding aspects, wherein when the bi-directional air turbine starter is selectively coupled to the engine drive shaft, compressed air flows from the first opening to the second opening.

[0026] Aspect 14. The turbine engine according to any of the preceding aspects, wherein when the bi-directional air turbine starter is selectively coupled to the power source, the air turbine starter drive shaft rotates in a second direction.

[0027] Aspect 15. The turbine engine according to any of the preceding aspects, wherein when the bi-directional air turbine starter is selectively coupled to the power source, compressed air flows from the second opening to the first opening.

[0028] Aspect 16. The turbine engine according to any of the preceding aspects, wherein when selectively coupled to the engine drive shaft, the bi-directional air turbine starter includes an air turbine starter, and when selectively coupled to the power source, the bi-directional air turbine starter is a compressor.

[0029] Aspect 17. A method of operating a turbine engine, comprising:

[0030] In a starting mode, pressurized air is caused to flow in a first direction through an air turbine starter to rotate a turbine of the air turbine starter, the turbine being operably coupled to an engine drive shaft of the turbine engine to affect rotation of the engine drive shaft by rotating the turbine; and

[0031] In a shutdown mode, the turbine of the air turbine starter is rotatably driven to generate a flow of pressurized air that flows through the air turbine starter in a second direction opposite the first direction and supply the flow of pressurized air from the air turbine starter to the turbine engine.

[0032] Technical solution 18. The method according to any one of the preceding technical solutions, wherein during the shutdown mode, the flow of pressurized air from the air turbine starter is supplied to one or more blades in a high-pressure compressor.

[0033] Technical solution 19. The method according to any one of the preceding technical solutions, further comprising adjusting one or more variable guide vanes between the starting mode and the shutdown mode.

[0034] Technical solution 20. The method according to any one of the preceding technical solutions, further comprising at least partially using the flow of pressurized air to rotate one or more blades of a high-pressure compressor or a high-pressure turbine. Description of the Drawings

[0035] A complete and enabling disclosure of the subject matter (including its best mode) for a person of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0036] Figure 1 is a schematic view of a turbine engine having an air turbine starter assembly and a drive unit according to various aspects described herein.

[0037] Figure 2 is according to various aspects described herein Figure 1 a schematic cross-section of an air turbine starter of an air turbine starter assembly.

[0038] Figure 3 is according to various aspects described herein and Figure 1 a schematic block diagram of a fluid control assembly docked with a turbine engine, an air turbine assembly, and a drive unit.

[0039] Figure 4 is a method of operating a turbine engine according to various aspects described herein.

[0040] Figure 5 is another method of operating a turbine engine according to various aspects described herein. Detailed implementation manners

[0041] Aspects of the present disclosure are directed to a turbine engine having an air turbine starter (ATS) and a drive unit, where the air turbine starter docks with or is included in an air turbine starter assembly. The ATS is a two-way ATS that causes air to flow in a first direction from a first opening to a second opening during startup of the turbine engine, and causes air to flow in a second direction when the turbine engine is shutting down, turned off, or during maintenance of the turbine engine.

[0042] When in the startup mode, pressurized air flows over at least one set of guide vanes and a turbine in the ATS in the first direction, which causes the ATS drive shaft to rotate. The rotational energy from the ATS drive shaft is provided to the engine drive shaft. The ATS continues to provide a rotational output to the engine drive shaft until the turbine engine becomes self-sustaining; at this time, the ATS is selectively disengaged or disconnected from the engine drive shaft. The selective coupling of the ATS and the engine drive shaft can be achieved through an accessory gearbox.

[0043] During shutdown of the turbine engine or during maintenance of the turbine engine, the drive unit is selectively coupled to the ATS. The drive unit includes a power source (e.g., an electric motor) that can rotatably drive the ATS drive shaft in a direction opposite to the direction of startup. The turbine in the ATS rotated by the drive unit draws air into the ATS through the second opening. The air flows over the turbine and at least one set of guide vanes in the ATS in the second direction and exits the ATS as compressed air at the first opening.

[0044] The compressed air provided at the first opening can be supplied to one or more parts of the turbine engine. More specifically, the compressed air can be provided to one or more parts of the engine core of the turbine engine. The compressed air can be used to rotate one or more parts of the engine core. The rotation of one or more parts of the turbine engine during shutdown can draw ambient air through the engine core; thereby cooling the core. In addition, the rotation of one or more parts of the turbine engine can allow maintenance of the engine without starting the engine or when additional equipment needs to be connected to the turbine engine to rotate one or more parts.

[0045] For illustrative purposes, the present disclosure will be described with respect to an engine starter assembly for a turbine engine. However, it will be understood that the aspects of the present disclosure described herein are not so limited and can have general applicability to other engines or other turbine engines. For example, the present disclosure can be applicable to an engine starter assembly used with any suitable engine or within any suitable vehicle, and can be used to provide benefits in industrial, commercial, and residential applications.

[0046] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Additionally, unless specifically identified otherwise, all examples described herein should be considered exemplary.

[0047] As used herein, terms such as "first", "second", "third", "fourth", etc. may be used interchangeably to distinguish one component from another and are not intended to denote the position or importance of individual components.

[0048] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle and to the normal operating attitude of the gas turbine engine or vehicle. For example, with respect to a gas turbine engine, front refers to a position closer to the engine inlet, and rear refers to a position closer to the engine nozzle or discharge section.

[0049] As used herein, the term "upstream" refers to a direction opposite to the direction of fluid flow, and the term "downstream" refers to a direction in the same direction as the fluid flow. The terms "ahead" or "front" mean in front of something, and "rear" or "behind" mean behind something. For example, when used in the context of fluid flow, ahead / front may mean upstream, and rear / behind may mean downstream.

[0050] Additionally, as used herein, the term "radial" or "radially" refers to a direction extending toward or away from a common center. For example, in the general context of a turbine engine, radial refers to the direction along a ray extending between the central longitudinal axis of the turbine engine and the outer circumference of the engine. Further, as used herein, the term "group" or "groups" of elements may be any number of elements, including only one.

[0051] All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, front, back, etc.) are for identification purposes only to assist the reader in understanding the disclosure and do not impose limitations, particularly as to the position, orientation, or use of aspects of the disclosure described herein. Connecting references (e.g., attached, coupled, fastened, connected, and joined) will be construed broadly and may include intermediate structural elements between a series of elements and relative movement between the elements, unless otherwise indicated. Accordingly, a connecting reference does not necessarily imply that two elements are directly connected to each other and in a fixed relationship. Exemplary drawings are for illustrative purposes only, and the dimensions, positions, sequences, and relative sizes reflected in the drawings appended hereto may vary.

[0052] As used herein, a "controller" may include at least one processor and a memory. Non-limiting examples of the memory may include random access memory (RAM), read only memory (ROM), flash memory, or one or more different types of portable electronic memory, such as optical disks, DVDs, CD-ROMs, etc., or any suitable combination of these types of memory. The processor may be configured to run any suitable program or executable instructions designed to perform various methods, functions, processing tasks, calculations, etc., to permit or implement the technical operations or operations described herein. The program may include a computer program product that may include a machine-readable medium for carrying or having stored thereon machine-executable instructions or data structures. Such a machine-readable medium may be any available medium accessible by a general purpose or special purpose computer or other machine having a processor. Generally, such computer programs may include routines, programs, objects, components, data structures, algorithms, etc., that have the technical effect of performing a particular task or implementing a particular abstract data type.

[0053] Exemplary drawings are for illustrative purposes only, and the dimensions, positions, sequences, and relative sizes reflected in the drawings appended hereto may vary.

[0054] Figure 1 is a schematic view of a turbine engine 10. As a non-limiting example, the turbine engine 10 may be used within an aircraft. The turbine engine 10 includes an engine core 11 having at least a compression section 12, a combustion section 14 having at least one burner 15, a turbine section 16, and an engine drive shaft 21 arranged in a series flow configuration. The turbine engine 10 further includes an air turbine starter assembly 18 and a drive unit 20. The engine drive shaft 21 is rotatably coupled to the compression section 12 and the turbine section 16 such that the rotation of one affects the rotation of the other and defines a rotational axis or centerline 22 for the turbine engine 10.

[0055] The compression section 12 may include a low pressure (LP) compressor 24 and a high pressure (HP) compressor 26 that are fluidly coupled in series with each other. The turbine section 16 may include a high pressure (HP) turbine 28 and a low pressure (LP) turbine 30 that are fluidly coupled in series with each other. An engine drive shaft 21 may operably couple the LP compressor 24, HP compressor 26, LP turbine 30, and HP turbine 28 together. Alternatively, the engine drive shaft 21 may be a drive shaft assembly including a plurality of drive shafts such as an LP drive shaft 23 and an HP drive shaft 25. The LP drive shaft 23 may couple the LP compressor 24 to the LP turbine 30, and the HP drive shaft 25 may couple the HP compressor 26 to the HP turbine 28. The LP rotor shaft may be defined as the combination of the LP compressor 24, LP turbine 30, and LP drive shaft 23 such that rotation of the LP turbine 30 may apply a driving force to the LP drive shaft 23, which in turn may cause the LP compressor 24 to rotate. The HP rotor shaft may be defined as the combination of the HP compressor 26, HP turbine 28, and HP drive shaft 25 such that rotation of the HP turbine 28 may apply a driving force to the HP drive shaft 25, which in turn may cause the HP compressor 26 to rotate.

[0056] The compression section 12 may include a plurality of axially spaced stages. That is, the LP compressor 24 and the HP compressor 26 may include a plurality of axially spaced stages. Each stage includes a set of circumferentially spaced rotating blades and a set of circumferentially spaced stationary guide vanes. The stages in the HP compressor 26 are illustrated by way of example as a set of circumferentially spaced guide vanes 36 and a set of circumferentially spaced blades 38.

[0057] The set of circumferentially spaced blades 38 for the stages of the compression section 12 may be mounted to a disk, which is mounted to the engine drive shaft 21. The set of circumferentially spaced blades 38 for a given stage may have its own disk. The set of circumferentially spaced guide vanes 36 of the compression section 12 may be mounted to a housing, which may extend circumferentially around the turbine engine 10. It will be appreciated that the representation of the compression section 12 is merely schematic and that any number of stages may be present. In addition, it is contemplated that any other number of components may be present within the compression section 12.

[0058] Similar to the compression section 12, the turbine section 16 may include a plurality of axially spaced stages, where the stages in the HP turbine 28 are illustrated by way of example as a set of circumferentially spaced guide vanes 37 and a set of circumferentially spaced blades 39.

[0059] The circumferentially spaced blades 39 for a stage of the turbine section 16 can be mounted to a disk that is mounted to the engine drive shaft 21. The circumferentially spaced blades 39 for a given stage can have their own disk. The circumferentially spaced guide vanes 37 of the turbine section 16 can be mounted to the casing in a circumferential and stationary manner. Note that any number of blades, guide vanes, and turbine stages can be present, as the illustrated turbine section is merely a schematic representation. Additionally, it is contemplated that any other number of components can be present within the turbine section 16.

[0060] The combustion section 14 can be arranged in series between the compression section 12 and the turbine section 16. The combustion section 14 can be fluidly coupled to at least portions of the compression section 12 and the turbine section 16 such that the combustion section 14 fluidly couples the compression section 12 to the turbine section 16 at least in part. As a non-limiting example, the combustion section 14 can be fluidly coupled to the HP compressor 26 at the upstream end of the combustion section 14 and to the HP turbine 28 at the downstream end of the combustion section 14.

[0061] Optionally, the fan section 32 can be located upstream of the compression section 12 and, more specifically, upstream of the LP compressor 24. The fan section 32 can include a fan casing 34 that encloses the fan 33. The fan 33 can be driven by the engine drive shaft 21; more specifically, by the LP drive shaft 23.

[0062] The air turbine starter assembly 18 may include an air turbine starter (ATS) 40 and an accessory gearbox (AGB) 42. The ATS 40 may be a two-way ATS. As used herein, the term "two-way ATS" is an ATS that can have a first air flow through the passage in a first direction and a second air flow through the passage at a separate time in a second direction. That is, during operation, the two-way ATS may have a first air flow at a first time or operating phase and a second air flow at a different time or different operating phase. In other words, the first air flow and the second air flow are not simultaneous. The ATS 40 is selectively coupled to the engine drive shaft 21. The selective coupling may be between the ATS 40 and the AGB 42. That is, the AGB 42 may selectively couple the ATS 40 and the engine drive shaft 21. Optionally, the AGB 42 may include one or more clutch assemblies to selectively couple the ATS 40 and the engine drive shaft 21. One or more additional shafts 44 couple the AGB 42 to the engine drive shaft 21. Optionally, a transmission gearbox, mechanical power output device, helical gear, or other connecting member 45 may be coupled to one or more portions of one or more of the additional shafts 44 or located between one or more portions of one or more of the additional shafts 44, or between the AGB 42 and the engine drive shaft 21. Although the ATS 40 is illustrated as the only accessory device coupled to the AGB 42, any number of accessory devices are contemplated.

[0063] The drive unit 20 may include a power source 46 and a drive shaft 48. The drive unit 20 is selectively coupled to the ATS 40. The drive shaft 48 may selectively provide rotational energy from the power source 46 to the ATS 40. Although illustrated as external to the housing of the ATS 40, it is contemplated that one or more portions of the power source 46 may be coupled to the ATS 40. The power source 46 may be an electric motor or any device capable of providing a rotational output or an output that can be converted into a rotational input for the ATS 40. The power source 46 may be coupled to one or more batteries or generators. One or more clutch assemblies may be used to selectively couple or decouple the power source 46 or the drive shaft 48 from the ATS 40.

[0064] The air turbine starter assembly 18 and the drive unit 20 are illustrated by way of example as being axially located in the fan section 32. However, one or more portions of the air turbine starter assembly 18, the drive unit 20, or both may be axially located in the compression section 12, the turbine section 16, or a combination thereof. It is also contemplated that although illustrated as being radially located at the fan case 34, one or more portions of the air turbine starter assembly 18 or the drive unit 20 may be positioned to be radially closer to portions of the compression section 12, e.g., in the engine core 11 or nacelle of the turbine engine 10. Additionally, it is contemplated that any location at which the ATS 40 may be coupled to the turbine engine 10 for the air turbine starter assembly 18. Further still, it is contemplated that any location at which the drive unit 20 may be rotatably coupled to the ATS 40 for the drive unit 20.

[0065] During start-up of the turbine engine 10, the ATS 40 is selectively coupled to the engine drive shaft 21 via the AGB 42. By way of non-limiting example, the ATS 40 receives pressurized air which is converted into rotational energy. The ATS 40 then provides a rotatable output via the AGB 42 which drives the engine drive shaft 21. The engine drive shaft 21 then rotates one or more portions of the fan section 32, the compression section 12, or the turbine section 16 to draw air into the turbine engine 10, where the air is subsequently compressed and combusted. Once the ATS 40 initiates the self-sustaining combustion or "normal operating" operating condition of the turbine engine 10, the ATS 40 is selectively disengaged from the engine drive shaft 21.

[0066] During operation or normal operation of the turbine engine 10, ambient or atmospheric air is drawn into the compression section 12 via the fan section 32 upstream of the compression section 12, where the air is compressed by the compression section 12 and a pressurized air flow is defined within the engine core 11. The pressurized air flow may then flow into the combustion section 14, where the pressurized air is mixed with fuel and ignited, thereby generating combustion gases. Some work is extracted from these combustion gases by the HP turbine 28, which drives the HP compressor 26. The combustion gases are discharged into the LP turbine 30, which extracts additional work to drive the LP compressor 24, and the exhaust gases are ultimately discharged from the turbine engine 10 via the exhaust section downstream of the turbine section 16. The driving of the LP turbine 30 drives at least the engine drive shaft 21 or the LP drive shaft 23, the fan 33, and the LP compressor 24. The pressurized air flow and the combustion gases may together define a working air flow passing through the fan section 32, the compression section 12, the combustion section 14, and the turbine section 16 of the turbine engine 10.

[0067] Before or after the normal operation of the turbine engine 10, the power source 46 can be selectively coupled to the ATS 40 and provide rotational energy to the ATS 40. Then, the ATS 40 can supply compressed air to one or more parts of the turbine engine 10 to cool one or more parts of the turbine engine 10, as described in further detail herein.

[0068] Figure 2 which can for example be included in Figure 1 is a schematic cross-section of an exemplary air turbine starter 40 that can be included in an embodiment of. Generally, the ATS 40 includes a housing 50 that defines an interior 52 and an exterior 54 of the housing 50. A first opening 56 and a second opening 58 are also defined by the housing 50. An air flow passage 60 extends between the first opening 56 and the second opening 58. That is, the air flow passage 60 fluidly couples the first opening 56 and the second opening 58, where the air flow passage 60 is at least partially defined by the housing 50.

[0069] The housing 50 can be formed in any suitable manner, including but not limited to, the housing 50 can be composed of two or more parts joined together or otherwise coupled together, or can be integrally formed as a single piece.

[0070] A turbine 62 is located within the interior 52 of the housing 50. The turbine 62 includes a rotor portion 64 and a plurality of circumferentially spaced blades 66. At least a portion of the turbine 62 is disposed within the air flow passage 60. The plurality of circumferentially spaced blades 66 are located within the air flow passage 60.

[0071] A stator 68 can be located within the interior 52 of the housing 50. The stator 68 can at least partially define the air flow passage 60. The stator 68 can be coupled to the housing 50 or formed with the housing 50.

[0072] A plurality of circumferentially spaced guide vanes 70 extend into the air flow passage 60. The plurality of circumferentially spaced guide vanes 70 can include a first set of circumferentially spaced guide vanes 70a. The first set of circumferentially spaced guide vanes 70a can extend from the stator 68 into the air flow passage 60. Optionally, the first set of circumferentially spaced guide vanes 70a can extend across the air flow passage 60 from the stator 68 to the housing 50. The first set of circumferentially spaced guide vanes 70a can be axially located between the first opening 56 and the turbine 62. That is, the first set of circumferentially spaced guide vanes 70a can be axially in front of the turbine 62.

[0073] Although illustrated as a single row of circumferentially spaced guide vanes, it is contemplated that the first set of circumferentially spaced guide vanes 70a can include multiple axially spaced rows of circumferentially spaced guide vanes.

[0074] A second set of circumferentially spaced guide vanes 70b may extend across the air flow passage 60. The second set of circumferentially spaced guide vanes 70b may extend between a radially inner portion 72 of the housing 50 and a radially outer portion 74 of the housing 50. The second set of circumferentially spaced guide vanes 70a may be axially located between the turbine 62 and the second opening 58. That is, the second set of circumferentially spaced guide vanes 70b may be axially behind the turbine 62.

[0075] Although shown as a single row of circumferentially spaced guide vanes, it is contemplated that the second set of circumferentially spaced guide vanes 70b may include multiple axially spaced rows of circumferentially spaced guide vanes.

[0076] The plurality of circumferentially spaced guide vanes 70 may include one or more adjustable portions 80. By way of non-limiting example, the one or more adjustable portions 80 may include points that can pivot rotatably or linearly adjustable portions.

[0077] That is, the first set of circumferentially spaced guide vanes 70a or the second set of circumferentially spaced guide vanes 70b may include a plurality of variable guide vanes. The first set of circumferentially spaced guide vanes 70a or the second set of circumferentially spaced guide vanes 70b that are variable guide vanes may be coupled to one or more attachment elements. By way of non-limiting example, the one or more attachment elements may include one or more of an actuator, a lever arm, a synchronizing ring, a bell crank, a torque tube, a vertical link, a U-bolt, or a servo device.

[0078] The ATS drive shaft 82 is coupled to the rotating turbine 62 such that the ATS drive shaft 82 can provide a rotational output from the turbine 62, such as provided to the AGB 42 or the engine drive shaft 21( Figure 1 ). Optionally, the ATS drive shaft 82 may provide a rotatable input to the turbine 62. The gear assembly 84 is coupled to the ATS drive shaft 82. Portions of the turbine 62, the ATS drive shaft 82, the gear assembly 84, or a combination thereof may rotate about the axis of rotation 86.

[0079] The gear assembly 84 may include a gear train 88. The ATS 40 includes an output shaft 90 and a disengager 92. The output shaft 90 may be operatively coupled to the turbine 62 via the gear assembly 84 including the gear train 88 and the disengager 92.

[0080] The output shaft 90 is selectively coupled to portions of the turbine engine 10( Figure 1 ) such that the output shaft 90 can rotate portions of the turbine engine 10. It is contemplated that the output shaft 90 may be operatively coupled to the compression section 12( Figure 1 ), the turbine section 16( Figure 1 ), or one or more portions of the compression section 12( Figure 1 ) and the turbine section 16( Figure 1 ).

[0081] The first bearing assembly 94 rotatably supports the ATS drive shaft 82. Optionally, the second bearing assembly 96 may rotatably support the ATS drive shaft 82, the output shaft 90, or both the ATS drive shaft 82 and the output shaft 90. The second bearing assembly 96 may be located behind the first bearing assembly 94. By way of non-limiting example, the second bearing assembly 96 may be disposed adjacent to the gear train 88, the gear assembly 84, or a combination thereof.

[0082] The starting flow path 98 is illustrated by arrows showing the fluid flowing through the air flow channel 60 in a first direction. The starting flow path 98 in the first direction includes flowing the fluid into the first opening 56 and through the air flow channel 60, where the fluid flow exits the housing 50 at the second opening 58.

[0083] The cooling flow path 100 is illustrated by arrows showing the fluid flowing through the air flow channel 60 in a second direction opposite the first direction. The cooling flow path 100 in the second direction includes flowing the fluid into the second opening 58 and through the air flow channel 60, where the fluid flow exits the housing 50 at the first opening 56.

[0084] Although Figure 2 both the starting flow path 98 and the cooling flow path 100 are illustrated, they do not occur simultaneously. As detailed below, during start-up of the turbine engine 10 ( Figure 1 ), the ATS 40 experiences an air flow traveling along the starting flow path 98 in the first direction. Once the turbine engine 10 ( Figure 1 ) reaches normal operating conditions, the air flow along the starting flow path 98 stops. During landing or during maintenance, the ATS 40 experiences an air flow traveling along the cooling flow path 100 in the second direction.

[0085] Figure 3 is a schematic block diagram of a turbine engine 10, which illustrates a fluid control assembly 102 that is coupled to or communicates with one or more components of the air turbine starter assembly 18 and the drive unit 20.

[0086] The fluid control assembly 102 includes a controller 104 that communicates with at least one selectively fluid-coupling device (illustrated as a valve 106). Although the valve 106 is illustrated as a single valve, the valve 106 may include any number of components or devices that selectively control the air flow through one or more ducts. The valve 106 may be, for example, a three-way valve or a four-way valve. It is also contemplated that the valve 106 may be a plurality of valves.

[0087] As illustrated, by way of non - limiting example, the controller 104 may communicate with a starter air valve (SAV) 108 and a power source 46 of the drive unit 20. The starter air valve (SAV) 108 may be included in the air turbine starter assembly 18. Although illustrated as being separated from the drive unit 20 or the air turbine starter assembly 18, it is contemplated that the controller 104 may be coupled to or housed within, for example, the power source 46, the ATS 40, or the valve 106.

[0088] The controller 104 may include a processor 103 and a memory 105. For example, the memory 105 may store code, executable instructions, commands, instructions, authorization keys, private data keys, passwords, etc. The memory 105 may be RAM, ROM, flash memory, or one or more different types of portable electronic memory, such as optical disks, DVDs, CD - ROMs, etc., or any suitable combination of these types of memory. The processor 103 may be defined as a part of the controller 104 that may receive inputs, perform calculations, and output executable data. The processor 103 may be a microprocessor. It is also contemplated that the controller 104 may be part of or communicate with a flight management system (FMS).

[0089] The first conduit 110 fluidly couples the ATS 40 and the valve 106. For example, the first conduit 110 fluidly couples a first opening 56 ( Figure 2 ) of the ATS 40 and the valve 106.

[0090] Optionally, a second conduit 112 fluidly couples the valve 106 to the SAV 108. Although illustrated as being separated from each other, it is contemplated that the valve 106 and the SAV 108 may be coupled or otherwise located within the same housing unit.

[0091] The third conduit 114 fluidly couples the SAV 108 to a pressurized air source 116. The pressurized air source 116 may be a ground - operated air cart, an auxiliary power unit, or a cross - bleed starting device from an already operating engine, among other sources.

[0092] The fourth conduit 118 fluidly couples the valve 106 and one or more parts of the turbine engine 10. Although illustrated as being fluidly coupled to the HP compressor 26, it is contemplated that the fourth conduit 118 may fluidly couple the first opening 56 ( Figure 2 ) of the ATS 40 and one or more parts or combinations of the fan section 32, the LP compressor 24, the HP compressor 26, the HP turbine 28, or the LP turbine 30.

[0093] The fourth duct 118 may supply air to one or more sets of circumferentially spaced vanes. By way of non-limiting example, the fourth duct 118 may supply air to a set of circumferentially spaced vanes 38. The air supplied to or flowing to the set of circumferentially spaced vanes 38 may rotate or assist in rotating the set of circumferentially spaced vanes 38.

[0094] Optionally, an additional fluid component 120 may be located in, coupled to, or replace the fourth duct 118 to control the air flow between the valve 106 and one or more portions of the turbine engine 10. By way of non-limiting example, the additional fluid component 120 may include one or more of a valve, a sensor, a duct, a manifold, optionally a set of tubes supplying the manifold, a flow nozzle, a bleed valve, an ambient air or bleed air inlet, or an outlet fluidly coupled to ambient air.

[0095] Although the first duct 110, the second duct 112, the third duct 114, and the fourth duct 118 are illustrated as single ducts, any of the first duct 110, the second duct 112, the third duct 114, or the fourth duct 118 may include any number of ducts and / or other air flow control devices or sensors.

[0096] Although illustrated as closed, it is contemplated that the valve 106, the first duct 110, the second duct 112, the third duct 114, the fourth duct 118, or the additional fluid component 120 may be fluidly coupled to one or more air systems. The air system may include, but is not limited to, a bleed air system that may, for example, draw air from one or more portions of the compression section 12, or another air system that may, for example, draw air at or near the nacelle. It is contemplated that any number of ducts, valves, or other air control members are fluidly coupled to or controlled by one or more portions or members of the fluid control assembly 102 for fluidly coupling to one or more air systems.

[0097] Figure 4 is a method 200 of operating a turbine engine 10 of an ATS 40 including Figure 1 - 3 . The method 200 includes starting the turbine engine 10 and then shutting down the turbine engine 10. It is contemplated that other processes may occur between starting the turbine engine 10 and shutting down the turbine engine 10. The method 200 will be referenced in relation to the physical aspects of Figure 1 the turbine engine 10, Figure 2 the ATS 40, and Figure 3 the fluid control assembly 102, the air turbine starter assembly 18, and the drive unit 20 Figure 1 - 3 .

[0098] Optionally, at 201, one or more of the plurality of circumferentially spaced guide vanes 70 are adjusted or positioned. By way of example, one or more adjustable portions 80 of one or more guide vanes in the first set of circumferentially spaced guide vanes 70a or the second set of circumferentially spaced guide vanes 70b pivot or otherwise vary to position the first set of circumferentially spaced guide vanes 70a, the second set of circumferentially spaced guide vanes 70b, or any combination thereof into a predetermined starting position. The predetermined starting position provides guidance to the pressurized air flow provided at the first opening 56 and flowing in the first direction to cause the turbine 62 to rotate in the first rotational direction.

[0099] At 202, in a starting mode, pressurized air flows to the ATS 40. For example, a pressurized air source 116 is fluidly coupled to provide pressurized air to the first opening 56 of the ATS 40 via at least the SAV 108 and the valve 106.

[0100] By way of non-limiting example, the pressurized air source 116 may cause pressurized air to flow to the SAV 108 via a third conduit 114. The controller 104 may position the SAV 108 to allow pressurized air from the pressurized air source 116 to the valve 106 (e.g., via a second conduit 112). The SAV 108 regulates the pressurized air flow from the pressurized air source 116 to the ATS 40.

[0101] The controller 104 may further position the valve 106 to allow pressurized air to flow to the ATS 40. For example, the controller 104 may further position the valve 106 to allow pressurized air to flow through a first conduit 110 and into the first opening 56 of the ATS 40. The pressurized air received at the first opening 56 flows in the first direction along a starting flow path 98. That is, when air is flowing through the starting flow path 98, the controller 104 selectively fluidly couples the ATS 40 to the pressurized air source 116.

[0102] At 204, the turbine 62 is rotated by pressurized air flowing through the air flow passage 60 in the first direction. The turbine 62 may extract mechanical power from the pressurized air flow along the starting flow path 98. When air is flowing through the starting flow path 98, the AGB 42 selectively connects the turbine 62 to the engine drive shaft 21. For example, an ATS drive shaft 82 rotatably coupled to the turbine 62 provides a rotational output to the AGB 42. The AGB 42 then transfers the rotational output from the ATS 40 to the engine drive shaft 21. The selective connection between the AGB 42 and the ATS drive shaft 82 may be controlled by a clutch assembly at the AGB 42 and / or a disengager 92 of the ATS 40.

[0103] At 206, once the turbine engine 10 reaches self-sustaining combustion for startup, the ATS 40 is selectively disengaged or disconnected from the engine drive shaft 21. One or more sensors may detect the torque, rotational speed, or both of the engine drive shaft 21, the ATS drive shaft 82, or both. Once a predetermined torque, rotational speed, or both are reached, the disengager 92 may disconnect the ATS drive shaft 82 from the AGB 42.

[0104] When the turbine engine 10 reaches a self-sustaining state, the disengagement of the ATS 40 from the engine drive shaft 21 indicates the end of the startup mode. The turbine engine 10 may participate in an operating cycle or run for a predetermined time. Once fuel is no longer supplied to the combustor, combustion stops and the turbine engine 10 shuts down or is considered to be in a shutdown mode. It is important to note that one or more parts of the turbine engine 10 may rotate during the shutdown mode.

[0105] Optionally, prior to the shutdown mode of the turbine engine 10, at 207, one or more of the circumferentially spaced vanes 70 of the ATS 40 are adjusted or positioned. By way of example, one or more adjustable portions 80 of one or more vanes of the first set of circumferentially spaced vanes 70a or the second set of circumferentially spaced vanes 70b pivot or otherwise vary to position the first set of circumferentially spaced vanes 70a, the second set of circumferentially spaced vanes 70b, or any combination thereof into a predetermined shutdown position. The predetermined shutdown position provides guidance or compression to ambient air drawn in by rotation of the turbine 62 in a second rotational direction opposite to the first rotational direction of startup.

[0106] When the turbine engine 10 begins or is in the shutdown mode, at 208, the drive unit 20 is selectively connected to the turbine 62 to rotate the turbine 62. That is, the power source 46 may be selectively coupled to the ATS 40 to provide rotational energy to the ATS 40. As used herein, shutdown of the turbine engine 10 refers to the time when combustion has stopped.

[0107] After the turbine engine 10 shuts down, the power source 46 may provide a rotational output to the drive shaft 48. The drive shaft 48, selectively coupled to the ATS 40, rotates the ATS drive shaft 82. The drive shaft 48 rotates the ATS drive shaft 82 and thus rotates the turbine 62 in a direction opposite to the rotational direction used during startup or at 204.

[0108] The turbine 62 rotated by the selective coupling of the drive unit 20 draws ambient air into the second opening 58 of the ATS 40. The air flows in a second direction along the cooling flow path 100. When the ambient air encounters the circumferentially spaced vanes 70 and the turbine 62, the ambient air becomes a compressed air stream and exits the ATS 40 at the first opening 56.

[0109] At 210, a compressed air flow from the ATS 40 flows to one or more parts of the turbine engine 10. That is, when the ATS 40 is powered by the power source 46, the compressed air flowing from the first opening 56 of the ATS 40 can enter the first duct 110.

[0110] The controller 104 can communicate with or position the valve 106 such that the compressed air from the first duct 110 can flow into the fourth duct 118. In other words, when air is flowing through the cooling flow path 100, the fluid control assembly 102 or the controller 104 selectively fluidly couples the ATS 40 to one or more parts of the turbine engine 10.

[0111] The compressed air from the fourth duct 118 can be delivered to one or more parts of the turbine engine 10. Examples of parts of the turbine engine 10 that can receive compressed air include, but are not limited to, the fan section 32, the compression section 12, or the turbine section 16. It is contemplated that the additional fluid assembly 120 can control, monitor, or both, the compressed air flow from the valve 106 to the turbine engine 10.

[0112] Optionally, at 212, the compressed air flow provided to or flowing to one or more parts of the turbine engine 10 causes one or more components of the turbine engine 10 to rotate. That is, when compressed air is provided to the turbine engine 10, the compressed air can cause one or more blades (such as the circumferentially spaced blades 38 in the compression section 12 or the circumferentially spaced blades 39 in the turbine section 16) to rotate. The rotation of one or more of the circumferentially spaced blades 38, 39 causes the turbine engine 10 to draw in ambient air that can cool the engine core components.

[0113] During a shutdown mode, the compressed air from the ATS 40 can maintain the rotation of one or more of the circumferentially spaced blades 38, 39 at a predetermined speed. Alternatively, the compressed air from the ATS 40 can be applied to one or more of the stationary circumferentially spaced blades 38, 39 to cause them to rotate at a predetermined speed.

[0114] By way of non-limiting example, pressurized air from the ATS 40 (illustrated as cooling flow path 100) can be directed to one or more of a group of circumferentially spaced blades 38, 39 such that the concentrated impact causes the group of circumferentially spaced blades 38 and / or the group of circumferentially spaced blades 39 to rotate, thereby causing the engine drive shaft 21 to rotate. The turbine engine 10 will draw in ambient air and cause the ambient air to flow through the fan section 32, the compression section 12, the combustion section 14, and the turbine section 16 when the engine drive shaft 21 rotates. This ambient air drawn in by the rotation of the engine drive shaft 21 through the compressed air can cool the components of the compression section 12, the combustion section 14, the turbine section 16, or any combination thereof. That is, when the pressurized air from the ATS 40 impacts at least one group of a plurality of circumferentially spaced blades 38, 39 of the engine core 11 such that it causes rotation of one or more portions of the engine drive shaft 21, a large amount of external or ambient air is drawn into the engine core 11.

[0115] In a different and non-limiting example, in addition to the impact and rotation of the engine core 11, the pressurized air from the ATS 40 provided at at least one group of a plurality of circumferentially spaced blades 38, 39 or at one or more portions of the engine core 11 can be used as a cooling air flow provided to one or more components of the engine core 11. That is, the pressurized air from the ATS 40 received by the turbine engine 10 or the engine core 11 can be used to cool one or more components of the turbine engine 10 or the engine core 11 and cause rotation of one or more portions of the engine drive shaft 21.

[0116] In yet another different and non-limiting example, the pressurized air from the ATS 40 received by the turbine engine 10 or the engine core 11 can be used to cool one or more components of the turbine engine 10 or the engine core 11 without causing rotation of one or more portions of the engine drive shaft 21. This provides the benefit of cooling one or more components of the turbine engine 10 or the engine core 11 without the need for the lubrication system required for rotation of one or more portions of the engine drive shaft 21.

[0117] Figure 5 Is a method 300 of operating a turbine engine 10 of the ATS 40 including Figure 1 - 3 The method 200 will be related to the physical aspects of the Figure 1 turbine engine 10, Figure 2 the ATS 40, and Figure 3 the fluid control assembly 102, the air turbine starter assembly 18, and the drive unit 20 by reference to Figure 1 - 3 .

[0118] Method 300 is similar to method 200, where it is understood that the description of the similar parts of method 200 applies to method 300 unless otherwise indicated.

[0119] Method 300 is a method of operating a turbine engine 10 after shutdown of the turbine engine 10 or during maintenance of the turbine engine 10.

[0120] Optionally, at 307, one or more of the plurality of circumferentially spaced guide vanes 70 of the ATS 40 are adjusted or positioned.

[0121] At 308, the power source 46 is selectively coupled to the ATS 40 to rotate the ATS drive shaft 82. The turbine 62 rotated by the power source 46 draws ambient air into the second opening 58 of the ATS 40. The air flows in a second direction along the cooling flow path 100. When the ambient air encounters the plurality of circumferentially spaced guide vanes 70 and the turbine 62, the ambient air becomes a compressed air stream and exits the ATS 40 at the first opening 56.

[0122] At 310, the compressed air stream from the ATS 40 flows to one or more parts of the turbine engine 10. That is, when the ATS 40 is powered by the power source 46, the compressed air flowing from the first opening 56 of the ATS 40 enters the first duct 110.

[0123] At 311, the controller 104 may communicate with or position the valve 106 such that the compressed air from the first duct 110 can flow into one or more parts of the engine core 11.

[0124] At 312, the compressed air stream provided to or flowing into one or more parts of the engine core 11 can cool the components of the engine core 11 and / or rotate one or more components of the turbine engine 10.

[0125] At 314, if the compressed air stream rotates one or more components of the turbine engine 10, then due to the compressed air causing one or more of the circumferentially spaced vanes 38, 39 in the compression section 12 or the turbine section 16 to rotate, ambient air flows through the compression section 12, the combustion section 14, and the turbine section 16. The ambient air and / or the compressed air stream cools the components of the turbine engine 10.

[0126] The rotation of the engine drive shaft 21 by the application of compressed air from the ATS 40 can also extend the time between engine shutdown and engine stop. As used herein, "engine stop" refers to a state in which the rotating components of the turbine engine 10 stop rotating. This increase in the time before stopping or coming to rest can allow for better cooling of the components and a smoother stop from rotation, which can extend component life.

[0127] The controller 104 may implement method 200( Figure 4 ), method 300, or some or all of both method 200( Figure 4 ) and method 300.

[0128] Advantages of the present disclosure, when compared to a conventional engine, include improved cooling efficiency of the engine. For example, a conventional engine may require an off-engine system to cool the conventional engine after shutdown of the conventional engine. However, an engine as described herein may utilize a power source (an electric motor) to supply a cooling fluid flow from a two-way ATS to the engine core and thus cool the engine core. This greatly improves the cooling efficiency of the engine when compared to a conventional engine. Additionally, using a two-way ATS to both start a turbine engine and operate as a compressor unit to supply a compressed air flow to the engine after shutdown may reduce weight.

[0129] Additional advantages of the present disclosure, when compared to a conventional ATS or a conventional engine, include a reduced maintenance burden on the engine or the ATS. For example, maintenance of a conventional ATS or a conventional engine may require disassembling the conventional ATS or the conventional engine and visually inspecting various components of the conventional ATS or the conventional engine. Alternatively, one or more additional pieces of equipment may be coupled to the conventional ATS or the conventional engine to attempt to rotate one or more parts of the conventional ATS or the conventional engine.

[0130] However, an air turbine starter as described herein may utilize a power source (an electric motor) to drive the ATS drive shaft such that maintenance requiring rotation of the ATS or the turbine engine can be performed without additional equipment or without removing parts of the turbine engine or the ATS.

[0131] Yet another advantage of the present disclosure may be to provide a cooling air flow to one or more parts of the turbine engine or the engine core without rotating one or more parts of the turbine engine. This provides the benefit of cooling one or more components of the turbine engine or the engine core without the lubrication system required for the rotating parts of the turbine engine.

[0132] A further advantage of the present disclosure is improved uniform cooling of one or more components. For example, uniform circumferential cooling of the rotating parts of a turbine engine may extend component life. Uniform cooling may reduce possible wear caused by movement or bending due to heat and / or non-uniform cooling.

[0133] To the extent not already described, the different features and structures of the various aspects may be combined with one another or used in place of one another as desired. The fact that a feature is not illustrated in all examples is not to be construed as meaning that it cannot be so illustrated, but rather is for the sake of brevity of description. Accordingly, the various features of the different aspects may be mixed and matched as desired to form new aspects, whether or not the new aspects are explicitly described. All combinations or permutations of the features described herein are covered by this disclosure.

[0134] This written description uses examples to describe aspects of the disclosure described herein (including the best mode), and also enables any person skilled in the art to practice aspects of the disclosure (including making and using any device or system, and performing any incorporated method). The patentable scope of the aspects of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if such other examples have structural elements that are not different from the literal language of the claims, or if such other examples include equivalent structural elements that are not materially different from the literal language of the claims.

[0135] Additional aspects are provided by the subject matter of the following clauses:

[0136] A turbine engine, comprising: an engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft; an air turbine starter including a housing defining an air flow passage and a turbine having a plurality of circumferentially spaced blades located within the air flow passage; a gearbox that selectively couples the turbine to the engine drive shaft when the air turbine starter is operable in a start mode, in which air is supplied to the air turbine starter and flows through the air flow passage in a first direction to rotate the turbine; and a drive unit that selectively couples to the turbine to rotate when the air turbine starter is operable in a shutdown mode, in which the drive unit drives the turbine to supply air through the air flow passage in a second direction, wherein air from the air turbine starter is supplied to at least one of the compression section or the turbine section.

[0137] The turbine engine according to any of the preceding clauses, further comprising a fluid control assembly having a controller for selectively fluidly coupling the air turbine starter to a pressurized air source when the air turbine starter is in the start mode, or selectively fluidly coupling the air turbine starter to one or more parts of the turbine engine when the air turbine starter is in the shutdown mode.

[0138] The turbine engine according to any of the preceding clauses, wherein the drive unit includes a power source operably coupled to a drive shaft, wherein the drive shaft is selectively coupled to the turbine.

[0139] A turbomachine according to any of the preceding clauses, wherein the power source is located outside the housing of the air turbine starter.

[0140] A turbomachine according to any of the preceding clauses, further comprising at least one duct fluidly connecting a first opening of the air turbine starter to a high-pressure compressor of the compression section or a high-pressure turbine of the turbine section.

[0141] A turbomachine according to any of the preceding clauses, further comprising a first circumferentially spaced set of guide vanes located upstream of the turbine and a second circumferentially spaced set of guide vanes located downstream of the turbine.

[0142] A turbomachine according to any of the preceding clauses, wherein the first circumferentially spaced set of guide vanes, the second circumferentially spaced set of guide vanes, or a combination thereof comprises one or more variable guide vanes.

[0143] A turbomachine comprising: an engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft; a two-way air turbine starter having a housing defining a first opening, a second opening, and an air flow passage extending between the first opening and the second opening, the two-way air turbine starter being selectively coupled to the engine drive shaft; a drive unit having a power source operably coupled to the drive shaft, wherein the drive shaft is selectively coupled to the two-way air turbine starter; and a fluid control assembly selectively fluidly connecting the first opening of the two-way air turbine starter to one or more portions of the engine core.

[0144] A turbomachine according to any of the preceding clauses, wherein the fluid control assembly comprises at least one duct fluidly connecting the first opening to a high-pressure compressor of the compression section or a high-pressure turbine of the turbine section.

[0145] A turbomachine according to any of the preceding clauses, wherein the power source comprises an electric motor.

[0146] A turbomachine according to any of the preceding clauses, further comprising a controller in communication with a valve of the fluid control assembly.

[0147] A turbomachine according to any of the preceding clauses, wherein when the two-way air turbine starter is selectively coupled to the engine drive shaft, the air turbine starter drive shaft rotates in a first direction.

[0148] A turbomachine according to any of the preceding clauses, wherein when the two-way air turbine starter is selectively coupled to the engine drive shaft, compressed air flows from the first opening to the second opening.

[0149] A turbine engine according to any of the preceding clauses, wherein when the two-way air turbine starter is selectively coupled to a power source, the air turbine starter drive shaft rotates in a second direction.

[0150] A turbine engine according to any of the preceding clauses, wherein when the two-way air turbine starter is selectively coupled to a power source, compressed air flows from a second opening to a first opening.

[0151] A turbine engine according to any of the preceding clauses, wherein when selectively coupled to the engine drive shaft, the two-way air turbine starter comprises an air turbine starter, and when selectively coupled to a power source, the two-way air turbine starter is a compressor.

[0152] A method of operating a turbine engine, comprising: in a start mode, causing pressurized air to flow through an air turbine starter in a first direction to cause rotation of a turbine of the air turbine starter, the turbine being operably coupled to an engine drive shaft of the turbine engine to affect rotation of the engine drive shaft by causing rotation of the turbine; and in a shutdown mode, rotatably driving the turbine of the air turbine starter to generate a flow of pressurized air flowing through the air turbine starter in a second direction opposite to the first direction and supplying the flow of pressurized air from the air turbine starter to the turbine engine.

[0153] The method according to any of the preceding clauses, wherein during the shutdown mode, the flow of pressurized air from the air turbine starter is supplied to one or more blades in a high-pressure compressor.

[0154] The method according to any of the preceding clauses, further comprising adjusting one or more variable guide vanes between the start mode and the shutdown mode.

[0155] The method according to any of the preceding clauses, further comprising at least partially using the flow of pressurized air to rotate one or more blades of a high-pressure compressor or a high-pressure turbine.

[0156] The method according to any of the preceding clauses, further comprising at least partially using the flow of pressurized air to rotate one or more blades of a high-pressure compressor and a high-pressure turbine.

Claims

1. A turbine engine, comprising: an engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft; An air turbine starter comprising: a housing defining an air flow passage; and a turbine having a plurality of circumferentially spaced blades positioned within the air flow passage; a gearbox that selectively connects the turbine to the engine drive shaft when the air turbine starter is operable in a starting mode in which air is provided to the air turbine starter and flows through the air flow passage in a first direction to rotate the turbine; and a drive unit selectively connected to the turbine for rotation when the air turbine starter is operable in a shutdown mode, wherein in the shutdown mode, the drive unit drives the turbine to provide air through the air flow passage in a second direction, wherein the air from the air turbine starter is provided to at least one of the compression section or the turbine section.

2. The turbine engine according to claim 1, further comprising a fluid control assembly having a controller, wherein the controller is used to selectively fluidly connect the air turbine starter to a pressurized air source when the air turbine starter is in the start mode, or to selectively fluidly connect the air turbine starter to one or more portions of the turbine engine when the air turbine starter is in the shutdown mode.

3. The turbine engine according to claim 1, wherein: The drive unit includes a power source operably coupled to a drive shaft, wherein the drive shaft is selectively coupled to the turbine.

4. The turbine engine according to claim 3, wherein: The power source is located outside the housing of the air turbine starter.

5. The turbine engine according to any one of claims 1 to 4, further comprising at least one duct fluidly coupling the first opening of the air turbine starter to a high pressure compressor of the compression section or a high pressure turbine of the turbine section.

6. The turbine engine of any one of claims 1 to 4, further comprising a first set of circumferentially spaced guide vanes located forwardly of the turbine and a second set of circumferentially spaced guide vanes located aft of the turbine.

7. The turbine engine according to claim 6, wherein: The first set of circumferentially spaced guide vanes, the second set of circumferentially spaced guide vanes, or a combination thereof includes one or more variable guide vanes.

8. A turbine engine comprising: an engine core having a compression section, a combustion section, and a turbine section arranged in series flow, the engine core having an engine drive shaft; a bidirectional air turbine starter having a housing defining a first opening, a second opening, and an air flow passage extending between the first opening and the second opening, the bidirectional air turbine starter selectively coupled to the engine drive shaft; a drive unit having a power source operably coupled to a drive shaft, wherein the drive shaft is selectively coupled to the bidirectional air turbine starter; as well as A fluid control assembly selectively fluidly couples the first opening of the bidirectional air turbine starter to one or more portions of the engine core.

9. The turbine engine according to claim 8, wherein: The fluid control assembly includes at least one conduit fluidly coupling the first opening to a high-pressure compressor of the compression section or a high-pressure turbine of the turbine section.

10. A method of operating a turbine engine, comprising: in a starting mode, flowing pressurized air in a first direction through an air turbine starter to rotate a turbine of the air turbine starter, the turbine operatively coupled to an engine drive shaft of the turbine engine to affect rotation of the engine drive shaft by rotating the turbine; as well as In a shutdown mode, the turbine of the air turbine starter is rotatably driven to generate a pressurized air flow through the air turbine starter in a second direction opposite to the first direction and to supply the pressurized air flow from the air turbine starter to the turbine engine.

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