Air turbine starter with lubrication recirculation circuit

Abstract

An air turbine starter (ATS) for a gas turbine engine having an auxiliary gearbox (AGB) with a lubricant reservoir, the air turbine starter comprising: a housing at least partially defining a working air flow path; a turbine section comprising a turbine having an output shaft and a plurality of blades circumferentially spaced about the output shaft and extending at least partially into the working air flow path; a drive section having a drive shaft operably coupled to the output shaft to engage the AGB; and a lubrication recirculation circuit fluidly coupled to the lubricant reservoir.

Description

[0001] Cross-references to related applications This application claims priority to Indian Patent Application No. 202211039930, filed on July 12, 2022, which is incorporated herein in its entirety. Technical Field

[0002] This topic generally relates to air turbine starters, and more specifically to the distribution of lubricant within air turbine starters. Background Technology

[0003] Aircraft engines (e.g., gas turbine engines) engage with air turbine starters during normal operation. The internal components of the air turbine starter require lubrication. The supply of lubricant (such as oil) to the air turbine starter may be self-sufficient or may be provided from an auxiliary gearbox. Summary of the Invention

[0004] Technical Solution 1. An air turbine starter (ATS) for a gas turbine engine, the gas turbine engine having an auxiliary gearbox (AGB) with a lubricant reservoir, the air turbine starter comprising: A housing that at least partially defines the path of working airflow; The turbine section includes a turbine having a turbine shaft and a plurality of blades spaced circumferentially around the turbine shaft, the plurality of blades extending at least partially into the working airflow path; A drive section having at least one lubricated member operably connecting the turbine shaft to the drive shaft of the AGB; and A lubrication recirculation circuit having a supply line fluidly connecting the lubricant reservoir to the at least one lubricated component, and a return line fluidly connecting the at least one lubricated component to the lubricant reservoir.

[0005] Technical Solution 2. An air turbine starter according to any of the foregoing technical solutions, wherein the air turbine starter further includes a bypass line that fluidly connects the supply line to the return line to bypass the at least one lubricated component.

[0006] Technical Solution 3. An air turbine starter according to any of the foregoing technical solutions, wherein the bypass line includes at least one return outlet that fluidly connects the supply line to the return line.

[0007] Technical Solution 4. An air turbine starter according to any of the foregoing technical solutions, wherein the air turbine starter further includes a valve for controlling the flow of lubricant through the lubrication recirculation circuit.

[0008] Technical Solution 5. An air turbine starter according to any of the foregoing technical solutions, wherein the valve is a pressure valve that responds to lubricant pressure.

[0009] Technical Solution 6. An air turbine starter according to any of the foregoing technical solutions, wherein the at least one return outlet includes a first return outlet, which is opened by the pressure valve to define a drive supply position when the lubricant pressure is between a low lubricant pressure value and a threshold pressure value.

[0010] Technical Solution 7. An air turbine starter according to any of the foregoing technical solutions, wherein, in the drive supply position, the supply line is fluidly connected to the drive section.

[0011] Technical Solution 8. An air turbine starter according to any of the foregoing technical solutions, wherein the at least one return outlet includes a second return outlet, which is opened by the pressure valve to define a bypass position when the lubricant pressure is higher than a threshold pressure value.

[0012] Technical Solution 9. An air turbine starter according to any of the foregoing technical solutions, wherein, in the bypass position, the supply line is fluidly blocked from the drive section and the turbine section.

[0013] Technical Solution 10. An air turbine starter according to any of the foregoing technical solutions, wherein when the lubricant pressure is between a minimum pressure requirement and a high lubricant pressure value, the supply line is fluidly connected to the turbine section by the pressure valve to define the turbine supply position.

[0014] Technical Solution 11. An air turbine starter according to any of the foregoing technical solutions, wherein the air turbine starter further includes a pressure valve for controlling the flow of lubricant between the supply line and the at least one lubricated component.

[0015] Technical Solution 12. An air turbine starter according to any of the foregoing technical solutions, wherein the pressure valve is a multi-way control valve, wherein the supply line is closed and the bypass line is opened when the pressure difference between the ATS and the AGB indicates a housing rupture, and the supply line is opened when the pressure in the pressure difference indicates normal operation of the ATS.

[0016] Technical Solution 13. An air turbine starter according to any of the foregoing technical solutions, wherein the air turbine starter further includes a pressure valve that closes the supply line when the pressure difference between the ATS and the AGB indicates a housing rupture, and opens the supply line when the pressure difference indicates normal operation of the ATS.

[0017] Technical Solution 14. An air turbine starter according to any of the foregoing technical solutions, wherein the air turbine starter further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the pressure valve between a first position and a second position, and the second spring switching the pressure valve between a fourth position and a fifth position.

[0018] Technical Solution 15. A lubrication recirculation circuit, comprising: Lubricant reservoir located in the auxiliary gearbox (AGB); A housing for an air turbine starter (ATS), the housing defining an interior having at least one lubricated member, a turbine section having a turbine shaft, and a drive section having a drive shaft operatively coupled to the turbine shaft located within the housing, an output shaft being at least partially disposed within the housing and operatively coupled to the drive shaft to the AGB; and The lubricant reservoir is fluidly connected to a supply line to the at least one lubricated component, and the at least one lubricated component is fluidly connected to a return line to the lubricant reservoir.

[0019] Technical Solution 16. The lubrication recirculation circuit according to any of the foregoing technical solutions, wherein the lubrication recirculation circuit further includes a bypass line that fluidly connects the supply line to the return line to bypass the at least one lubricated component.

[0020] Technical Solution 17. The lubrication recirculation circuit according to any of the foregoing technical solutions, wherein the supply line includes a set of distribution conduits, the distribution conduits including a turbine conduit fluidly connected to the turbine section and a drive conduit fluidly connected to the drive section.

[0021] Technical Solution 18. The lubrication recirculation circuit according to any of the foregoing technical solutions, wherein the lubrication recirculation circuit further includes valves for selectively opening and closing the bypass line, the turbine duct, and the drive duct.

[0022] Technical Solution 19. The lubrication recirculation circuit according to any of the foregoing technical solutions, wherein the lubrication recirculation circuit further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the valve between a turbine supply position and a drive supply position, and the second spring switching the valve to a bypass position.

[0023] Technical Solution 20. The lubrication recirculation circuit according to any of the foregoing technical solutions, wherein the lubrication recirculation circuit further includes a set of outlets located in the housing and a steering mechanism for moving the lubricant flow from rotational motion to the axial direction, wherein the steering mechanism is fluidly connected to the set of outlets. Attached Figure Description

[0024] In the attached diagram: Figure 1 This is a schematic diagram of a gas turbine engine with an air turbine starter, based on the various aspects described in this article.

[0025] Figure 2 This is a cross-sectional view of an air turbine starter with a lubrication recirculation circuit, according to the various aspects described herein.

[0026] Figure 3 It is based on one aspect disclosed in this article for use Figure 2 A schematic diagram of the lubrication recirculation circuit of an air turbine starter.

[0027] Figure 4 This is based on one aspect disclosed in this article. Figure 2 Methods for supplying lubrication to air turbine starters.

[0028] Figure 5 It is based on one aspect of the disclosure herein for a lubrication recirculation circuit for an air turbine starter. Figure 2 A cross-sectional view of line VV, with the valve in the turbine supply position.

[0029] Figure 6 This is based on another aspect disclosed in this article. Figure 5 The lubrication recirculation loop has a valve in the drive supply position.

[0030] Figure 7 This is based on another aspect disclosed in this article. Figure 5 The lubrication recirculation loop has the valve in the bypass position.

[0031] Figure 8 It is a variant of the air turbine starter with a lubricant steering gear (or diverter). Figure 2An enlarged view of a portion of an air turbine starter.

[0032] Figure 9 It is based on a variant of an air turbine starter with a set of intake ports. Figure 2 An enlarged view of a portion of an air turbine starter.

[0033] Figure 10 It is based on a variant of an air turbine starter with a lubricant steering system. Figure 2 An enlarged view of a portion of an air turbine starter. Detailed Implementation

[0034] This disclosure relates to a lubrication recirculation circuit in an air turbine starter. In one non-limiting example, the lubrication recirculation circuit includes an auxiliary gearbox (AGB) and an air turbine starter (ATS), wherein lubrication (in some cases, oil) is shared between the two. The lubrication recirculation circuit can operate under different operating conditions and may include a bypass to the AGB. The starter can have various applications, including starting a gas turbine engine and generating electricity while the gas turbine engine is in operation. Although the exemplary embodiments described herein are directed to the starter and AGB, embodiments of this disclosure can be applied to any implementation of a lubrication recirculation circuit shared between two engine components.

[0035] The term "exemplary" is used herein to mean "serving as an example, illustration, or demonstration." Any implementation described herein as "exemplary" is not necessarily to be considered preferred or advantageous over other implementations. Furthermore, unless otherwise specifically indicated, all embodiments described herein should be considered exemplary.

[0036] As used in this article, the terms "first," "second," and "third" are used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of an independent component.

[0037] The terms "front" and "rear" are used in this text to refer to relative positions within a gas turbine engine or vehicle, and to the normal operating posture of the gas turbine engine or vehicle. For example, regarding a gas turbine engine, "front" refers to the position closer to the engine inlet, while "rear" refers to the position closer to the engine nozzle or exhaust port.

[0038] As used herein, the term "upstream" can be used to refer to the direction opposite to the flow of lubricant, while the term "downstream" refers to the direction in the same direction as the flow of lubricant. The terms "before" or "in front" mean in front of something, while "behind" or "behind" means behind something. For example, when used in relation to lubricant flow, "before" or "in front" can mean upstream, while "behind" or "behind" can mean downstream. These terms can also be used to describe relative positions.

[0039] Additionally, as used herein, the term "radial" or "radially" refers to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to the direction of a ray extending between the engine's central longitudinal axis and its outer circumference.

[0040] All directional designations (e.g., radial, axial, proximal, distal, up, down, upward, downward, left, right, lateral, front, rear, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, front, rear, etc.) are for identification purposes only to aid the reader's understanding of this disclosure and do not impose any limitation on the location, orientation, or use of any aspect of the disclosure described herein. Unless otherwise indicated, connection designations (e.g., attachment, joint, connection, and link) should be understood broadly and may include intermediate structural elements between a series of elements, as well as relative movement between elements. Accordingly, connection designations do not necessarily imply that two elements are directly connected and fixed to each other. Schematic diagrams are for illustrative purposes only, and the sizes, positions, orders, and relative dimensions reflected in the drawings may vary.

[0041] Unless the context clearly indicates otherwise, the singular forms "a," "an," and "the" include plural objects. For example, as used herein, the terms "group" or "a set" of elements can be any number of elements, including only one.

[0042] The approximate language used throughout the specification and claims is intended to modify any quantitative expression that may be altered without causing a change in the essential function it relates to. Therefore, values ​​modified by one or more terms such as “about,” “approximately,” “generally,” and “substantially” are not limited to the specified exact values. In at least some instances, the approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or circuit. For example, the approximate language may refer to a margin of 1, 2, 4, 5, 10, 15, or 20% at the endpoints of a single value, a range of values, and / or a defined range of values. Scopes are combined and interchanged herein and throughout the specification and claims; unless otherwise indicated by context or language, these scopes are defined and include all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0043] The word "near" as used in this document is not restrictive, but rather a descriptive term used to locate the parts described herein. Furthermore, the term "closer" means more adjacent to or closer to the listed part than a later part. For example, in the case where the first hole and the second hole are a certain distance from the wall, or in the case where the first hole is closer to the wall, the first hole is closer to the wall than the second hole.

[0044] See Figure 1 The diagram illustrates a gas turbine engine 10 having a compressor section 12, a combustion section 14, and a turbine section 16. An intake 18, defined by a fan 20, supplies air to the compressor section 12 of the engine 10. The intake 18 and the compressor section 12 are collectively referred to as the "cold section" 22 of the gas turbine engine 10, located upstream of the combustion section 14. The compressor section 12 provides high-pressure air to the combustion section 14. The high-pressure air is mixed with fuel and burned in a combustion chamber (not shown) in the combustion section 14 to form hot and pressurized combustion gases. The hot and pressurized combustion gases pass through the turbine section 16 before exiting the gas turbine engine 10. As the pressurized gases pass through the high-pressure turbine (not shown) and low-pressure turbine (not shown) of the turbine section 16, the turbine extracts rotational energy from the airflow passing through the gas turbine engine 10. The compressor section 12 and the turbine section 16 can be shaft-connected to each other to provide power to the compressor section 12. The low-pressure turbine can be connected to the fan 20 at the air inlet 18 via a shaft to provide power to the fan 20.

[0045] The gas turbine engine 10 may be a turbofan engine commonly used in modern commercial and military aviation, or it may be any other known gas turbine engine such as a turboprop or turbine shaft. The gas turbine engine 10 may also have an afterburner that burns an additional amount of fuel downstream of the turbine section 16 to increase the velocity of the exhaust gases and thereby increase thrust.

[0046] A starter motor or air turbine starter (ATS) 100 may be driveably coupled to the gas turbine engine 10 via an auxiliary gearbox (AGB) 102 (also referred to as a gearbox housing), schematically shown as being mounted to the gas turbine engine 10. A horizontal drive shaft 104 may extend from the AGB 102 to the transmission gearbox 106. The AGB 102 may be coupled to the turbine shaft (coupled to the low-pressure turbine or high-pressure turbine) within the gas turbine engine 10 via a radial drive shaft (not shown) extending from the transmission gearbox 106 into the gas turbine engine 10.

[0047] Now see Figure 2The ATS 100 is shown in more detail below. The ATS 100 may include an ATS turbine section 107, which includes a turbine housing 108 defining an inlet 110 and an outlet 112, and a turbine section interior 164. A flow path 114 may extend between the inlet 110 and the outlet 112 to direct airflow from the inlet 110 to the outlet 112. A turbine component 116 may include a turbine shaft 118 and a plurality of blades 120 extending from the turbine shaft 118. The turbine shaft 118 may be journaled within the turbine housing 108. The plurality of blades 120 may be disposed within the flow path 114 to rotatably extract mechanical power from the airflow along the flow path 114.

[0048] Drive housing 122 may define drive section 123, wherein at least a portion of gearbox 124 defines drive section interior 166. Gear train 126 may be disposed within gearbox 124 and driveably coupled to turbine shaft 118. Gear train 126 may include ring gear 128 and may further include any gear assembly, including, for example, but not limited to, planetary gear assemblies or pinion assemblies. Turbine shaft 118 may be rotatably mounted to gear train 126 to allow mechanical power to be transmitted from turbine component 116 to gear train 126. Turbine shaft 118 may be supported by a pair of turbine bearings 130.

[0049] The bracket component 131 can be driveably coupled to the gear train 126. The driven component 132 may include a drive shaft 134 and is rotatably mounted to the bracket component 131. An aperture 136 in the bracket component 131 can receive the drive shaft 134. The bracket component 131 may be supported by a bracket bearing 138.

[0050] The turbine section interior 164 and the drive section interior 166 together define the housing interior 140. The housing interior 140 may contain a lubricant (oil, as a non-limiting example) to provide lubrication and cooling to at least one lubricated component 141 (i.e., mechanical parts contained within, such as gear train 126, ring gear 128, and bearings 130, 138).

[0051] Clutch 142 can be mounted to bracket assembly 131. Driven member 132 is coupled to clutch 142 and additionally supported by drive bearing 143. Driven member 132 is driven by bracket assembly 131, which in turn is driven by gear train 126, which in turn is driven by turbine assembly 116. Clutch 142 can be any type of shaft interface portion, forming a single rotatable shaft 144 including turbine assembly 116, bracket assembly 131, and driven member 132. The shaft interface portion can be coupled by any known method, including but not limited to gears, splines, clutch mechanisms, or combinations thereof.

[0052] The separator assembly 148 may be disposed within at least a portion of the driven member 132. The output shaft 149 may be mounted to the drive shaft 134. The output shaft 149 may be operatively coupled to the AGB 102, which in turn is operatively coupled to the engine 10.

[0053] A lubrication recirculation loop (LRC) 150 may be at least partially disposed within the drive housing 122. The LRC 150 may include a lubrication line 152 extending between the AGB 102 and the housing interior 140. The LRC 150 may further include a set of AGB outlets 153 fluidly coupled to the housing interior 140. After passing through the LRC 150, the set of AGB outlets 153 provides lubricant exit from the ATS 100 to the AGB 102.

[0054] The turbine housing 108 and drive housing 122 can be formed from any known materials and methods, including but not limited to die casting of high-strength and lightweight metals such as aluminum, stainless steel, iron, or titanium. The turbine housing 108 and drive housing 122 defining the ATS100 can be formed to have sufficient thickness to provide adequate mechanical rigidity without adding unnecessary weight to the entire assembly and thus to the aircraft.

[0055] The rotatable shaft 144 can be constructed using any known materials and methods, including but not limited to extrusion or machining of high-strength metal alloys (such as metal alloys containing aluminum, iron, nickel, chromium, titanium, tungsten, vanadium, or molybdenum). The diameters of the turbine shaft 118, drive shaft 134, and any other shafts defining the rotatable shaft 144 can be fixed or varied along the length of the rotatable shaft 144. The diameters can be varied to accommodate different dimensions and rotor-to-stator spacing.

[0056] During operation, air is introduced into inlet 110 and travels along flow path 114, causing the turbine component 116 to rotate. This rotation allows mechanical energy to be transmitted to AGB 102 via rotatable shaft 144, and subsequently via transmission gearbox 106. Figure 1 The transmission is transmitted to engine 10. When starting engine 10, clutch 142 can disconnect drive shaft 134 from bracket assembly 131. In reverse drive mode, ATS 100 should be disconnected from AGB 102. Separator assembly 148 enables disconnection from AGB 102.

[0057] Figure 3This is a schematic diagram illustrating an LRC150 according to one aspect of the disclosure herein. A valve 155 for controlling the passage of lubricant along a lubrication line 152 between AGB102 and ATS100 may be disposed within ATS100. A distribution chamber 154 may define at least a portion of the lubrication line 152. In a non-limiting example, valve 155 is a multi-way control valve having a first inlet 156 and a second inlet 158 ​​for dispensing lubricant and a first return outlet 160 and a second return outlet 162 for redirecting lubricant.

[0058] The housing interior 140 can be further divided into a turbine section interior 164 and a drive section interior 166. The turbine section interior 164 can be defined at least partially by the turbine housing 108, while the drive section interior 166 can be defined at least partially by the drive housing 122. AGB 102 may include a lubricant reservoir 168. The lubricant reservoir 168 may be a single reservoir or, as shown, divided into multiple reservoirs (by way of a non-limiting example, an oil supply section 170 and an oil storage section 172).

[0059] The lubrication line 152 may include a set of distribution conduits 174 extending between the distribution chamber 154 and the housing interior 140. This set of distribution conduits 174 may include a turbine conduit 176 and a drive conduit 178. The turbine conduit 176 may extend between a first inlet 156 and the turbine section interior 164. The turbine conduit 176 may define a turbine diameter (Dt). The drive conduit 178 may extend between a second inlet 158 ​​and the drive section interior 166. The drive conduit 178 may define a drive diameter (Dd). The lubrication line 152 may further include a set of connecting conduits 180 extending between a lubricant reservoir 168 and the distribution chamber 154. This set of connecting conduits 180 may include a supply line 182 and a return line 184. The supply line 182 may extend between the oil supply section 170 and the distribution chamber 154, and the return line 184 may extend between the distribution chamber 154 and the oil reservoir 172. The return line 184 can be fluidly connected to the distribution chamber 154 via the first return outlet 160 or the second return outlet 162.

[0060] Valve 155 controls the passage of lubricant (L) between lubricant reservoir 168 and housing interior 140. More specifically, at turbine supply position 330 (see... Figure 5 In this configuration, valve 155 allows passage of lubricant (L) from distribution chamber 154 to turbine duct 176 by opening first inlet 156. Similarly, in drive supply position 340 (see...),... Figure 6 In the process, valve 155 can allow the lubricant (L) to flow from distribution chamber 154 to drive conduit 178 by opening second inlet 158, so as to provide a reduced pressure flow rate to the drive section interior 166.

[0061] The valve 155 can open and close the first return outlet 160 and the second return outlet 162 to control the lubricant (L) from entering the return line 184. The first return outlet 160 can be open when in the drive supply position 340. In the bypass position 350 (see Figure 7 ), the second return outlet 162 can be open, while the first inlet 156, the second inlet 158 and the first return outlet 160 are closed, so that no lubricant (L) is delivered into the housing interior 140. In this way, the return line 184 can define a part of the bypass line 186 in both the drive supply position 340 and the bypass position 350. The bypass line 186 includes the lubricant reservoir 168, the supply line 182 and the distribution chamber 154.

[0062] In one aspect of the present disclosure, the valve 155 is a pressure valve responsive to lubricant pressure (P). The passage of the lubricant (L) through the lubrication line 152 is controlled by the lubricant pressure (P), which is defined as the pressure on the lubricant (L) generated by the pressure difference between the AGB 102 and the ATS 100. The lubricant pressure (P) is in turn converted to the pressure on the valve 155. The lubricant pressure (P) can be between 15psi and 50psi (15psi < P < 50psi). In some embodiments, this range is between 20psi and 45psi (20psi<P<45psi). At a low lubricant pressure below 30psi, the passage of the lubricant (L) to the drive section interior 166 is closed, while the passage of the lubricant (L) to the turbine section interior 164 is open. At a high lubricant pressure above 35psi, the passage of the lubricant (L) to the drive section interior 166 is open, while the passage of the lubricant (L) to the turbine section interior 164 is closed. For the range between 30psi and 35psi, the valve 155 can be partially open for one or both of the turbine conduit 176 and / or the drive conduit 178.

[0063] On the one hand, a higher lubricant pressure can result in a flow rate exceeding the required level. In this case, the drive diameter (Dd) of the drive conduit 178 can be formed to be smaller than the turbine diameter (Dt) to control the flow rate to the drive section interior 166. When the drive diameter is smaller than the turbine diameter (Dd<Dt), the bypass line 186 can be opened to provide an outlet via the first return outlet 160, so that excess lubricant (L) flows back to the lubricant reservoir 168. It should be understood that a higher lubricant pressure (above 35psi) can cause a flow rate to the drive section interior 166 that is higher than required. In this case, the bypass line 186 can be opened to provide a lower flow rate, the drive diameter (Dd) can be reduced to provide a lower flow rate, or a combination of both can be performed to provide a lower flow rate.

[0064] In the event of a housing rupture in either the turbine housing 108 or the drive housing 122 of the ATS100, the sudden drop in pressure differential generates an increased lubricant pressure exceeding a threshold pressure (P > 50 psi). This sudden pressure increase causes valve 155 to close the first inlet 156 and the second inlet 158, as well as the first return outlet 160, while keeping the second return outlet 162 open, allowing all lubricant (L) to be delivered back to the lubricant reservoir 168 via return line 184, and no lubricant (L) to be delivered into the housing interior 140. In other words, when the pressure differential between the ATS100 and AGB102 indicates a housing rupture, supply line 182 closes and bypass line 186 opens, and when the pressure differential indicates normal operation of the ATS100, supply line 182 opens.

[0065] Turn Figure 4 The flowchart illustrates a method 400 for supplying lubrication to an air turbine starter. At block 402, lubricant (L) is supplied from AGB 102 to ATS 100. At block 404, the distribution of lubricant (L) within ATS 100 is controlled using valve 155. At block 406, lubricant (L) is distributed to a first portion of housing interior 140 (either turbine section interior 164 or drive section interior 166, as a non-limiting example) when the lubricant pressure (P) is within a given range. The given range may be between 20 psi and 35 psi or between 30 psi and 45 psi. Distributing lubricant (L) may include distributing lubricant (L) to turbine section interior 164 when the lubricant pressure (P) is below 35 psi. Distributing lubricant (L) may also include distributing lubricant (L) to drive section interior 166 when the lubricant pressure (P) is above 30 psi. In addition, distributing lubricant (L) may include distributing lubricant (L) to return line 184 when the lubricant pressure (P) is higher than 30 psi. Furthermore, distributing lubricant (L) may include distributing lubricant (L) to return line 184 when the lubricant pressure (P) is higher than 50 psi.

[0066] At block 408, method 400 includes blocking the passage of lubricant (L) from a first portion of housing interior 140 when the lubricant pressure (P) is greater than or less than a given range. Blocking the passage of lubricant (L) may include blocking the passage of lubricant (L) from turbine section interior 164 when the lubricant pressure (P) is greater than 35 psi. Blocking the passage of lubricant (L) may include blocking the passage of lubricant (L) from drive section interior 166 when the lubricant pressure (P) is less than 30 psi. Blocking the passage of lubricant (L) may include blocking the passage of lubricant (L) from both turbine section interior 164 and drive section interior 166 when the lubricant pressure (P) is greater than 50 psi.

[0067] Turn Figure 5 ,along Figure 2 The cross-section taken by line VV illustrates an exemplary LRC250 according to one aspect disclosed herein. The LRC250 is substantially similar to the LRC150 already described herein, therefore similar portions will be identified with similarity numerals incremented by 100. It should be understood that, unless otherwise noted, the description of similar portions of the LRC150 applies to... Figure 5 The LRC250.

[0068] Lubrication line 252 in Figure 5 From right to left, it extends from AGB102 to ATS100. A distribution chamber 254 may define at least a portion of the lubrication line 252. The distribution chamber 254 may be disposed within the wall 287 of the drive housing 122 for ATS100. The distribution chamber 254 may accommodate a valve (as a non-limiting example, a pressure valve 255). On one hand, the pressure valve 255 may be a sliding multi-way control valve, which includes a plug 290 and a piston 288 disposed within a valve housing 291.

[0069] The lubrication line 252 may include a set of distribution conduits 274 formed in the wall 287 and extending from the distribution chamber 254 to fluidly connect the distribution chamber 254 to the housing interior (as a non-limiting example, housing interior 140). Figure 3 The distribution conduit 274 may include a turbine conduit 276 and a drive conduit 278. The turbine conduit 276 may be fluidly connected to the distribution chamber 254 at a first inlet 256. The drive conduit 278 may be fluidly connected to the distribution chamber 254 at a second inlet 258. The lubrication line 252 may further include a set of connecting conduits 280 that fluidly connect the lubricant reservoir 168 to the distribution chamber 254. The set of connecting conduits 280 may include a supply line 282 and a return line 284. The return line 284 may be fluidly connected to the distribution chamber 254 at a first return outlet 260 and a second return outlet 262.

[0070] Valve housing 291 may be located within distribution chamber 254 and extends between closed end 292 and open end 293 at wall 287 to define valve centerline (CL). Open end 293 may be fluidly coupled to supply line 282. Valve housing 291 may include a set of openings shown as a plurality of openings: a first opening 294, a second opening 295, a third opening 296, and a fourth opening 297 fluidly coupled to a first inlet 256 and a second inlet 258 and a first return outlet 260 and a second return outlet 262, respectively.

[0071] Piston 288 may have a substantially cylindrical shape, be located within valve housing 291, and be in a first position 298 and a second position 299. Figure 6The piston 288 can move axially relative to the valve centerline (CL). The piston 288 may include a piston wall 300 defining a piston interior 301. An inner wall 302 extending substantially perpendicular to the piston wall 300 divides the piston interior 301 into a first chamber 303 and a second chamber 304. A first spring 305 may be disposed in the first chamber 303, and a second spring 306, different from the first spring 305, may be disposed in the second chamber 304. The second spring 306 may have a higher strength or spring constant (k) than the first spring 305. The first spring 305 may have a strength configured to allow the piston 288 to switch between a first position 298 and a second position 299.

[0072] A set of through holes (first through hole 314, second through hole 315, and third through hole 316) may be located within the piston wall 300. The first through hole 314 extends from the second chamber 304 toward the valve housing 291 through the piston wall 300. The set of through holes 314, 315, and 316 may be selectively fluidly connected to the set of openings 294, 295, 296, and 297, as well as inlets 256, 258 and outlets 260, 262 of the valve housing 291.

[0073] A blocking element 290 may extend between a first end 317 and a second end 318. A blocking element wall 319 may define a hollow portion 320 therein, which defines at least a portion of a lubrication line 252. The hollow portion 320 may extend between a blocking element inlet 321 at the first end 317 and a first outlet 324 at the second end 318. The first outlet 324 may be fluidly coupled to a first through-hole 314 of the piston 288. The hollow portion 320 may be fluidly coupled to an open end 293 of the valve housing 291 and then fluidly coupled to a supply line 282 at the blocking element inlet 321. A nose 322 may extend axially from the second end 318 along the valve centerline (CL) through the inner wall 302 of the piston 288. A set of side outlets (second outlet 325 and third outlet 326), shown as multiple side outlets, may be disposed within the blocking wall 319 to selectively and fluidly connect the hollow portion 320 to the set of through holes 314, 315, 316.

[0074] The blocking element 290 can be in the third position 327 and the fourth position 328 (marked with dashed lines). Figure 6 ) and the fifth position 329 (with dashed lines, Figure 7 The piston 288 moves axially relative to the valve centerline (CL). As the piston 288 moves between the first position 298 and the second position 299, the blocking element 290 can move with the piston 288 between the third position 327 and the fourth position 328. As described below, the second spring 306 may have a strength configured to allow the blocking element 290 to switch between the fourth position 328 and the fifth position 329 under a specific pressure.

[0075] Turbine supply position 330 occurs above the minimum pressure requirement and below the high lubricant pressure, where the force applied to the first spring 305 and the second spring 306 by the lubricant pressure has so far caused little compression of the springs 305 and 306. The first through-hole 314 of the piston 288 and the first opening 294 of the valve housing 291 are aligned with the first inlet 256. In turbine supply position 330, the piston 288 is in the first position 298, and the plug 290 is in the third position 327 as shown, where the lubrication line 252 extends between the lubricant reservoir 168 and the turbine section interior 164. This opens the lubricant passage from the hollow portion 320 to the turbine duct 276, which in turn supplies lubricant (L) (oil, as a non-limiting example) from the lubricant reservoir 168 (particularly the oil supply section 170) to the turbine section interior 164.

[0076] When the lubricant pressure (P) is higher than the minimum pressure requirement or a high lubricant pressure above 10 psi but below 35 psi, lubricant (L) can be distributed into the turbine section interior 164. When the lubricant pressure (P) is between the minimum pressure requirement and the high lubricant pressure, thrust is applied from the inner wall 302 to the first spring 305. However, the first spring 305 compresses almost nothing until the pressure reaches or exceeds a certain amount (as a non-limiting example, a low lubricant pressure of 30 psi). Therefore, under low lubricant pressure, the piston 288 remains in the first position 298 until the pressure on the first spring 305 reaches a certain amount. Between low and high lubricant pressures, as the pressure increases and the first spring 305 springs together, the piston 288 moves toward the second position 299, while the blocker 290 moves toward the fourth position 328. When the first spring 305 is compressed, the lubricant pressure is not high enough to compress the second spring 306. Although shown as fully open, it should be understood that the first inlet 256 may be partially blocked as the first spring 305 moves.

[0077] In turbine supply position 330, the second through-hole 315 and the third through-hole 316 are fluidly connected to the second outlet 325 and the third outlet 326 in the blocker 290. However, in this position, when fluidly connected to each other, the second through-hole 315 and the third through-hole 316, as well as the second outlet 325 and the third outlet 326, are blocked by the valve housing 291 (as shown by 332 in circle x) and cannot be fluidly connected to the drive conduit 278 and the return line 284 via the second opening 295 and the third opening 296.

[0078] Turn Figure 6 The drive supply location 340 is shown. Some numbers have been removed for clarity only; these parts are not related to... Figure 5The portions shown are identical. Drive supply position 340 occurs between low lubricant pressure and threshold pressure. Force is applied to the first spring 305 and the second spring 306. This force is sufficient to compress the first spring 305 but insufficient to compress the second spring 306. Compression causes the second through-hole 315 of piston 288, the second opening 295 of valve housing 291, and the second outlet 325 of plug 290 to align with the second inlet 258. In drive supply position 340, piston 288 is in the second position 299, and plug 290 has moved with piston 288 to the fourth position 328. In drive supply position 340, lubrication line 252 extends between lubricant reservoir 168 and drive section interior 166. Additionally, bypass line 186 is open. In drive supply position 340, the second through-hole 315, second opening 295, and second outlet 325 are fluidly connected to the second inlet 258 of drive conduit 278. Furthermore, in the drive supply position 340, the third through hole 316, the third opening 296, and the third outlet 326 are aligned and fluidly connected to the first return outlet 260 of the return line 284.

[0079] As described earlier in this document, when the lubricant pressure (P) is above a low lubricant pressure of 30 psi, lubricant (L) can be distributed into the drive section interior 166. When the lubricant pressure (P) is above 30 psi, the pressure exerts a thrust from the inner wall 302 on the first spring 305, causing the piston 288 to move into the second position 299. When the lubricant pressure (P) is above a high lubricant pressure of 35 psi, the piston 288 is fully in the second position 299. This opens the lubricant passage from the hollow portion 320 to the drive conduit 278, which in turn supplies lubricant (L) (by way of a non-limiting example, oil) from the lubricant reservoir 168 (particularly the oil supply section 170) into the drive section interior 166. Due to the high lubricant pressure, this movement also opens the lubricant passage from the hollow portion 320 via the bypass line 186 to the lubricant reservoir 168 (particularly the oil storage section 172). This, combined with the smaller diameter described earlier in this paper, provides controlled flow into the interior of the drive section 166.

[0080] Turn Figure 7 The bypass location 350 is shown. Some numbers have been removed for clarity only; these parts are not directly related to the previous ones. Figure 5The portions shown are identical. Bypass position 350 occurs at or above the threshold pressure value or 50 psi. At this pressure, the force is sufficient to compress the second spring 306, causing all fluid openings to the turbine conduit 276 and drive conduit 278 to close. Bypass position 350 is defined when piston 288 is in the second position 299 and block 290 is in the fifth position 329. In bypass position 350, lubrication line 252 is defined only by return line 284, which defines the open bypass line 286. In bypass position 350, fourth opening 297, connecting to the second return outlet 262, opens to the opening end 293 of valve housing 291. In bypass position 350, no lubricant is supplied to the housing interior 140 of ATS100. Figure 2 ).

[0081] As described earlier in this document, when the lubricant pressure (P) exceeds the threshold pressure or 50 psi, the passage of lubricant (L) from both the turbine section interior 164 and the drive section interior 166 can be blocked. When the lubricant pressure (P) exceeds 50 psi, the pressure generates a thrust on the second spring 306 from the blocking element 290, causing the second spring 306 to compress and the blocking element 290 to move into the fifth position 329. This opens the bypass line 286 from the supply line 282 directly to the return line 284 and back to the lubricant reservoir 168 (specifically the oil reservoir 172).

[0082] Turning Figure 8 , showed Figure 2 An enlarged view of section VIII. A lubricant diverter 360 may be located within the drive housing 122 to retain lubricant within the housing interior 140. The lubricant diverter 360 may be mounted to the drive housing 122 by any suitable fastener 362. The lubricant diverter 360 may include a diverter body 364 shaped to move lubricant (L) from rotational motion (R) to the axial direction (A). The diverter body 364 may extend both axially and circumferentially (into the page) between a first end 366 and a second end 368 at the fastener 362. An outlet passage 370 may extend between the second end 368 and the set of outlets 153. A mesh 372 may be provided at a set of AGB outlets 153 within the drive housing 122. During operation, the lubricant diverter 360 enables the conversion from rotational motion (R) to axial motion (A).

[0083] Turning Figure 9 , showed Figure 2An enlarged view of section VIII. A set of suction conduits 380 may be located within a drive housing 122 having an orifice axis along the rotational motion (R) of the lubricant (L). The set of suction conduits 380 includes a suction passage 382 extending both axially and circumferentially (into the next page) between a suction inlet 384 and the set of outlets 153. During operation, the set of suction conduits 380 enables the conversion from rotational motion (R) to axial motion (A).

[0084] Turn Figure 10 , showed Figure 2 An enlarged view of section VIII. The eddy current diverter 390 may be located within the drive housing 122 to retain lubricant within the housing interior 140. The eddy current diverter 390 may be mounted within the drive housing 122 close to the driven member 132. The eddy current diverter 390 may include an eddy current 392 shaped to move lubricant (L) from rotational motion (R) to the axial direction (A). The eddy current 392 may extend both axially and circumferentially (into the next page). An outlet passage 394 may extend between the eddy current 392 and the set of outlets 153. During operation, the eddy current diverter 390 enables the conversion from rotational motion (R) to axial motion (A).

[0085] It should be understood that any of the lubricant steering mechanism 360, the intake conduit 380, or the eddy current steering mechanism 390 may be provided in the ATS100 described herein. It is further envisioned that each aspect may be combined or provided at different locations within the ATS100.

[0086] All directional indications (e.g., radial, up, down, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, etc.) are for identification purposes only to aid the reader's understanding of this disclosure and do not impose any limitation, particularly regarding their location, orientation, or use. Unless otherwise indicated, connection indications (e.g., attachment, joint, connection, and link) should be interpreted broadly and may include intermediate parts between a series of elements, as well as relative movement between elements. Thus, connection indications do not necessarily imply that two elements are directly connected and fixed to each other. Schematic diagrams are for illustrative purposes only, and the sizes, positions, orders, and relative dimensions reflected in the drawings may vary.

[0087] In addition to those shown in the figure above, many other possible embodiments and configurations are conceived from this disclosure. Furthermore, the design and placement of various components (such as starters, AGBs, or components thereof) can be rearranged to enable many different online configurations.

[0088] The lubrication recirculation circuit described herein provides a back-and-forth transfer of lubrication between the AGB and the air turbine starter for use in both zones. Since the lubricant, or in some cases oil pressure, is a function of the AGB shaft speed, the lubricant pressure will increase with increasing shaft speed. This pressure variation causes a difference in lubricant pressure. Introducing a lubrication recirculation circuit as described herein allows control of the flow rate of the lubricant (e.g., lubricating oil) to cool the bearings and rotating parts. At the lower pressures described herein, the lubricant will flow to the turbine section only during operation and will be cut off at the higher pressures discussed. At those higher pressures, the lubricant will only flow to the drive section during overspeed operation. Providing lubrication during extended operation extends the service life of the bearings and rotating parts in the turbine section.

[0089] The benefit associated with the two springs described herein is the provision of selective flow within the air turbine starter. Under normal operating conditions, the springs are activated by pressure, thereby closing the turbine section and drive section respectively when neither requires lubrication. In other words, lubrication is provided to the appropriate locations within the air turbine starter when necessary.

[0090] Furthermore, the benefit of providing a pressure valve is that it allows for complete disconnection of lubrication to the air turbine starter in the event of a housing rupture causing activation of the high-stiffness spring. This, in turn, shuts off the flow path to the air turbine starter, and lubricant bypasses to the AGB.

[0091] Furthermore, to maintain the proper oil level within the air turbine starter, the flow group outlets described herein can be coupled to various exemplary steering mechanisms. During drive shaft rotation, the lubricant will be in a vortex mode, and the lubricant will not be directed toward the group of outlets oriented vertically relative to the vortex motion. Without a steering mechanism, the lubricant level within the air turbine starter would increase. The steering mechanisms, lubricant steering mechanisms, the group of inlets, and the vortex steering mechanisms described herein are arranged along the vortex direction to transfer oil from the vortex or rotational motion to the axial direction and exit the air turbine starter.

[0092] Within the scope not described herein, various features and structures of the various embodiments may be used in combination or substituted for each other as desired. The fact that a feature is not shown in all embodiments does not mean that it could not be shown, but rather that it is done for the sake of brevity. Therefore, various features of different embodiments may be mixed and matched as needed to form new embodiments, whether or not the new embodiments are explicitly described. All combinations or permutations of the features described herein are covered by this disclosure.

[0093] This written description uses examples to illustrate aspects of the disclosure described herein, including the best mode, and also enables any person skilled in the art to implement aspects of this disclosure, including making and using any apparatus or system, and performing any incorporated methods. The patent scope of aspects of this disclosure is defined by the claims and may include other examples that would occur to a person skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that are not different from the written language of the claims, or if they include equivalent structural elements that are not substantially different from the written language of the claims.

[0094] Other aspects are provided by the subject of the following clauses: An air turbine starter (ATS) for a gas turbine engine having an auxiliary gearbox (AGB) with a lubricant reservoir, the air turbine starter comprising: a housing that at least partially defines a working airflow path; a turbine section including a turbine having a turbine shaft and a plurality of blades circumferentially spaced around the turbine shaft, the plurality of blades extending at least partially into the working airflow path; a drive section having at least one lubricated member and a drive shaft operatively connecting the turbine shaft to the AGB; and a lubrication recirculation circuit having a supply line fluidly connecting the lubricant reservoir to at least one lubricated member and a return line fluidly connecting the at least one lubricated member to the lubricant reservoir.

[0095] The air turbine starter of any of the foregoing provisions further includes a bypass line that fluidly connects the supply line to the return line for bypassing at least one lubricated component.

[0096] The air turbine starter of any of the foregoing provisions, wherein the bypass line includes at least one return outlet that fluidly connects the supply line to the return line.

[0097] The air turbine starter motor of any of the foregoing provisions further includes a valve for controlling the flow of lubricant through the lubrication recirculation loop.

[0098] The air turbine starter of any of the foregoing clauses, wherein the valve is a pressure valve that responds to lubricant pressure.

[0099] In any of the preceding clauses, an air turbine starter, wherein at least one return outlet includes a first return outlet, which is opened by a pressure valve to define a drive supply position when the lubricant pressure is between a low lubricant pressure and a threshold pressure value.

[0100] The air turbine starter of any of the foregoing clauses, wherein, in the drive supply position, the supply line is fluidly connected to the drive section.

[0101] In any of the preceding clauses, an air turbine starter, wherein at least one return outlet includes a second return outlet, which is opened by a pressure valve to define a bypass position when the lubricant pressure is above a threshold pressure value.

[0102] Any of the preceding clauses' air turbine starters, wherein in the bypass position, the supply line is fluidly blocked from the drive section and turbine section.

[0103] The air turbine starter of any of the foregoing clauses, wherein when the lubricant pressure is between the minimum pressure requirement and the high lubricant pressure, the supply line is fluidly connected to the turbine section by a pressure valve to define the turbine supply position.

[0104] The air turbine starter of any of the foregoing provisions further includes a pressure valve for controlling the flow of lubricant between the supply line and at least one lubricated component.

[0105] The air turbine starter of any of the foregoing clauses, wherein the pressure valve is a multi-way control valve that closes the supply line and opens the bypass line when the pressure difference between the ATS and AGB indicates a housing rupture, and opens the supply line when the pressure in the pressure difference indicates normal operation of the ATS.

[0106] The air turbine starter of any of the foregoing provisions further includes a pressure valve that closes the supply line when the pressure difference between the ATS and AGB indicates a housing rupture, and opens the supply line when the pressure difference indicates normal operation of the ATS.

[0107] The air turbine starter of any of the foregoing provisions further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the pressure valve between a first position and a second position, and the second spring switching the pressure valve between a third position and a fourth position.

[0108] A lubrication recirculation circuit includes a lubricant reservoir located in an auxiliary gearbox (AGB); a housing for an air turbine starter (ATS) defining an interior having at least one lubricated member, a turbine section having a turbine shaft, and a drive section having a drive shaft operatively coupled to the turbine shaft located within the housing, an output shaft being at least partially disposed within the housing and operatively coupled to the drive shaft to the AGB; a supply line fluidly connecting the lubricant reservoir to the at least one lubricated member, and a return line fluidly connecting the at least one lubricated member to the lubricant reservoir.

[0109] The lubrication recirculation loop of any of the foregoing provisions further includes a bypass line that fluidly connects the supply line to the return line to bypass at least one lubricated component.

[0110] The lubrication recirculation loop of any of the foregoing provisions, wherein the supply line includes a set of distribution conduits, the distribution conduits including a turbine conduit fluidly connected to the turbine section and a drive conduit fluidly connected to the drive section.

[0111] The lubrication recirculation loop of any of the foregoing provisions further includes valves for selectively opening and closing bypass lines, turbine ducts, and drive ducts.

[0112] The lubrication recirculation loop of any of the foregoing provisions further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the valve between a turbine supply position and a drive supply position, and the second spring switching the valve to a bypass position.

[0113] The lubrication recirculation circuit of any of the foregoing provisions further includes a set of outlets located in the housing and a steering mechanism for moving the lubricant flow from rotational motion to the axial direction, wherein the steering mechanism is fluidly coupled to the set of outlets.

[0114] A lubrication recirculation circuit includes: a housing having at least one opening; a set of distribution conduits having at least one inlet fluidly connected to the at least one opening; a piston disposed within the housing and movable between a first position and a second position, the piston having at least one through-hole fluidly connected to the at least one opening when the piston is in the first position; and a stopper disposed within the piston and movable between a third position, a fourth position, and a fifth position, the stopper having at least one outlet fluidly connected to the at least one through-hole when the stopper is in the third position; a reservoir fluidly connected to the at least one outlet; and a lubrication line extending between the reservoir and the set of distribution conduits, the lubrication line being open to lubricant flow when the piston is in the first position and closed to lubricant flow when the piston is in the second position.

[0115] The lubrication recirculation circuit of any of the foregoing provisions, wherein at least one opening is a plurality of openings, at least one inlet is a plurality of inlets, at least one through hole is a plurality of through holes, and at least one outlet is a plurality of outlets, wherein when the piston is in a first position and the blocker is in a third position, the first opening is fluidly connected to the first inlet, the first outlet and the first through hole, and when the piston is in a second position and the blocker is in a fourth position, the second opening is fluidly connected to the second inlet, the second outlet and the second through hole.

[0116] The lubrication recirculation circuit of any of the foregoing provisions, wherein when the piston is in the second position and the blocker is in the fourth position, the third opening is fluidly connected to the first return outlet, the third outlet and the third through hole, and when the piston is in the second position and the blocker is in the fifth position, the fourth opening is fluidly connected to the second return outlet.

[0117] The lubrication recirculation loop of any of the foregoing provisions, wherein the set of distribution conduits is a plurality of conduits, including a turbine conduit extending between a first inlet and a turbine section and a drive conduit extending between a second inlet and a drive section.

[0118] The lubrication recirculation loop of any of the foregoing provisions further includes a return line extending between the first return outlet and the reservoir, and a bypass line extending between the second return outlet and the reservoir.

Claims

1. An air turbine starter for a gas turbine engine, the gas turbine engine having an auxiliary gearbox with a lubricant reservoir, the air turbine starter comprising: A housing that at least partially defines the path of working airflow; The turbine section includes a turbine having a turbine shaft and a plurality of blades spaced circumferentially around the turbine shaft, the plurality of blades extending at least partially into the working airflow path; A drive section having at least one lubricated member operatively connecting the turbine shaft to the drive shaft of the auxiliary gearbox; A lubrication recirculation loop having a supply line fluidly connecting the lubricant reservoir to the at least one lubricated component, and a return line fluidly connecting the at least one lubricated component to the lubricant reservoir; A distribution chamber fluidly connected to the supply line, the return line, and the at least one lubricated component; as well as A bypass line fluidly connected to the distribution chamber, the bypass line fluidly connecting the supply line to the return line via the distribution chamber to bypass the at least one lubricated component.

2. The air turbine starter according to claim 1, wherein, The bypass line includes at least one return outlet that fluidly connects the supply line to the return line.

3. The air turbine starter according to claim 2, wherein, The air turbine starter further includes a valve for controlling the flow of lubricant through the lubrication recirculation circuit.

4. The air turbine starter according to claim 3, wherein, The valve is a pressure valve that responds to lubricant pressure.

5. The air turbine starter according to claim 4, wherein, The at least one return outlet includes a first return outlet, which is opened by the pressure valve to define the drive supply position when the lubricant pressure is between a low lubricant pressure value and a threshold pressure value.

6. The air turbine starter according to claim 5, wherein, In the drive supply location, the supply line is fluidly connected to the drive section.

7. The air turbine starter according to claim 4, wherein, The at least one return outlet includes a second return outlet, which is opened by the pressure valve to define a bypass position when the lubricant pressure is higher than a threshold pressure value.

8. The air turbine starter according to claim 7, wherein, In the bypass position, the supply line is fluidly blocked from the drive section and the turbine section.

9. The air turbine starter according to claim 4, wherein, When the lubricant pressure is between the minimum pressure requirement and the high lubricant pressure value, the supply line is fluidly connected to the turbine section by the pressure valve to define the turbine supply location.

10. The air turbine starter according to claim 1, wherein, The air turbine starter further includes a pressure valve for controlling the flow of lubricant between the supply line and the at least one lubricated component.

11. The air turbine starter according to claim 10, wherein, The pressure valve is a multi-way control valve. When the pressure difference indicator housing between the air turbine starter and the auxiliary gearbox ruptures, the supply line is closed and the bypass line is opened. When the pressure in the pressure difference indicates normal operation of the air turbine starter, the supply line is opened.

12. The air turbine starter according to any one of claims 1 to 3, wherein, The air turbine starter further includes a pressure valve that closes the supply line when the pressure difference between the air turbine starter and the auxiliary gearbox indicates a rupture in the housing, and opens the supply line when the pressure difference indicates normal operation of the air turbine starter.

13. The air turbine starter according to claim 12, wherein, The air turbine starter further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the pressure valve between a first position and a second position, and the second spring switching the pressure valve between a fourth position and a fifth position.

14. A lubrication recirculation circuit, comprising: Lubricant reservoir located in the auxiliary gearbox; A housing for an air turbine starter, the housing defining an interior having at least one lubricated member, a turbine section having a turbine shaft, and a drive section having a drive shaft operatively coupled to the turbine shaft located inside the housing, an output shaft being at least partially disposed within the housing and operatively coupled to the drive shaft to the auxiliary gearbox. The lubricant reservoir is fluidly connected to a supply line to the at least one lubricated component, and the at least one lubricated component is fluidly connected to a return line to the lubricant reservoir; A distribution chamber fluidly connected to the supply line, the return line, and the at least one lubricated component; as well as A bypass line fluidly connected to the distribution chamber, the bypass line fluidly connecting the supply line to the return line via the distribution chamber to bypass the at least one lubricated component.

15. The lubrication recirculation circuit according to claim 14, wherein, The supply line includes a set of distribution conduits, the distribution conduits including a turbine conduit fluidly connected to the turbine section and a drive conduit fluidly connected to the drive section.

16. The lubrication recirculation circuit according to claim 15, wherein, The lubrication recirculation circuit further includes valves for selectively opening and closing the bypass line, the turbine duct, and the drive duct.

17. The lubrication recirculation circuit according to claim 16, wherein, The lubrication recirculation loop further includes a first spring and a second spring having a different stiffness value than the first spring, the first spring switching the valve between a turbine supply position and a drive supply position, and the second spring switching the valve to a bypass position.

18. The lubrication recirculation circuit according to claim 17, wherein, The lubrication recirculation circuit further includes a set of outlets located in the housing and a steering mechanism for moving the lubricant flow from rotational motion to the axial direction, wherein the steering mechanism is fluidly coupled to the set of outlets.

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