Patent ID: 12258878

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the disclosure described herein are broadly directed to a method and apparatus for sensing and controlling aspects of lubricant to a component. For the purposes of illustration, one exemplary environment within which the lubricant system can be utilized will be described in the form of a turbine engine. Such a turbine engine can be in the form of a gas turbine engine, a turboprop, turboshaft or a turbofan engine having a power gearbox, in non-limiting examples. For example, lubricant measurements can be performed within the engine in real time, as well as between operations and while the engine is on-wing. It will be understood, however, that aspects of the disclosure described herein are not so limited and can have general applicability within other lubricant systems. For example, the disclosure can have applicability for a lubricant system in other engines or vehicles, and may be used to provide benefits in industrial, commercial, and residential applications.

Traditional lubricant systems in turbine engines generally include a pump supplying lubricant, such as oil, from a reservoir to various engine components such as gears or bearings. Such pumps can be driven by a rotating portion, or rotor, of the engine core and operate with a volumetric flow rate that increases with pump speed. In such a system, the supplied flow rate to the various engine components can increase in proportion to engine speed, where certain operations (such as an aircraft during take-off) will deliver a high flow rate to the engine components. However, such systems can supply needlessly high flow rates during other operations of the engine, such as during cruise periods where the engine operates at a moderately high, but steady, rate.

As used herein, the term “upstream” refers to a direction that is opposite the fluid flow direction, and the term “downstream” refers to a direction that is in the same direction as the fluid flow. The term “fore” or “forward” means in front of something and “aft” or “rearward” means behind something. For example, when used in terms of fluid flow, fore/forward can mean upstream and aft/rearward can mean downstream.

Additionally, as used herein, the terms “radial” or “radially” refer to a direction away from a common center. For example, in the overall context of a turbine engine, radial refers to a direction along a ray extending between a center longitudinal axis of the engine and an outer engine circumference. Furthermore, as used herein, the term “set” or a “set” of elements can be any number of elements, including only one.

Additionally, as used herein, a “controller” or “controller module” can include a component configured or adapted to provide instruction, control, operation, or any form of communication for operable components to effect the operation thereof. A controller module can include any known processor, microcontroller, or logic device, including, but not limited to: field programmable gate arrays (FPGA), an application specific integrated circuit (ASIC), a full authority digital engine control (FADEC), a proportional controller (P), a proportional integral controller (PI), a proportional derivative controller (PD), a proportional integral derivative controller (PID controller), a hardware-accelerated logic controller (e.g. for encoding, decoding, transcoding, etc.), the like, or a combination thereof. Non-limiting examples of a controller module can be configured or adapted to run, operate, or otherwise execute program code to effect operational or functional outcomes, including carrying out various methods, functionality, processing tasks, calculations, comparisons, sensing or measuring of values, or the like, to enable or achieve the technical operations or operations described herein. The operation or functional outcomes can be based on one or more inputs, stored data values, sensed or measured values, true or false indications, or the like. While “program code” is described, non-limiting examples of operable or executable instruction sets can include routines, programs, objects, components, data structures, algorithms, etc., that have the technical effect of performing particular tasks or implement particular abstract data types. In another non-limiting example, a controller module can also include a data storage component accessible by the processor, including memory, whether transient, volatile or non-transient, or non-volatile memory. Additional non-limiting examples of the memory can include Random Access Memory (RAM), Read-Only Memory (ROM), flash memory, or one or more different types of portable electronic memory, such as discs, DVDs, CD-ROMs, flash drives, universal serial bus (USB) drives, the like, or any suitable combination of these types of memory. In one example, the program code can be stored within the memory in a machine-readable format accessible by the processor. Additionally, the memory can store various data, data types, sensed or measured data values, inputs, generated or processed data, or the like, accessible by the processor in providing instruction, control, or operation to effect a functional or operable outcome, as described herein.

Additionally, as used herein, elements being “electrically connected,” “electrically coupled,” or “in signal communication” can include an electric transmission or signal being sent, received, or communicated to or from such connected or coupled elements. Furthermore, such electrical connections or couplings can include a wired or wireless connection, or a combination thereof.

Also, as used herein, while sensors can be described as “sensing” or “measuring” a respective value, sensing or measuring can include determining a value indicative of or related to the respective value, rather than directly sensing or measuring the value itself. The sensed or measured values can further be provided to additional components. For instance, the value can be provided to a controller module or processor as defined above, and the controller module or processor can perform processing on the value to determine a representative value or an electrical characteristic representative of said value.

All directional references (e.g., radial, axial, proximal, distal, upper, lower, upward, downward, left, right, lateral, front, back, top, bottom, above, below, vertical, horizontal, clockwise, counterclockwise, upstream, downstream, forward, aft, etc.) are used only for identification purposes to aid the reader's understanding of the present disclosure, and should not be construed as limiting on an embodiment, particularly as to the position, orientation, or use of aspects of the disclosure described herein. Connection references (e.g., attached, coupled, connected, and joined) are to be construed broadly and can include intermediate members between a collection of elements and relative movement between elements unless otherwise indicated. As such, connection references do not necessarily infer that two elements are directly connected and in fixed relation to one another. The exemplary drawings are for purposes of illustration only and the dimensions, positions, order and relative sizes reflected in the drawings attached hereto can vary.

FIG.1is a schematic cross-sectional diagram of a gas turbine engine10for an aircraft. The engine10has a generally longitudinally extending axis or centerline12extending forward14to aft16. The engine10includes, in downstream serial flow relationship, a fan section18including a fan20, a compressor section22including a booster or low pressure (LP) compressor24and a high pressure (HP) compressor26, a combustion section28including a combustor30, a turbine section32including a HP turbine34, and a LP turbine36, and an exhaust section38.

The fan section18includes a fan casing40surrounding the fan20. The fan20includes a plurality of fan blades42disposed radially about the centerline12. The HP compressor26, the combustor30, and the HP turbine34form a core44of the engine10, which generates combustion gases. The core44is surrounded by core casing46, which can be coupled with the fan casing40.

A HP shaft or spool48disposed coaxially about the centerline12of the engine10drivingly connects the HP turbine34to the HP compressor26. A LP shaft or spool50, which is disposed coaxially about the centerline12of the engine10within the larger diameter annular HP spool48, drivingly connects the LP turbine36to the LP compressor24and fan20. The spools48,50are rotatable about the engine centerline and couple to a plurality of rotatable elements, which can collectively define a rotor51.

The LP compressor24and the HP compressor26respectively include a plurality of compressor stages52,54, in which a set of compressor blades56,58rotate relative to a corresponding set of static compressor vanes60,62to compress or pressurize the stream of fluid passing through the stage. In a single compressor stage52,54, multiple compressor blades56,58can be provided in a ring and can extend radially outwardly relative to the centerline12, from a blade platform to a blade tip, while the corresponding static compressor vanes60,62are positioned upstream of and adjacent to the rotating blades56,58. It is noted that the number of blades, vanes, and compressor stages shown inFIG.1were selected for illustrative purposes only, and that other numbers are possible.

The blades56,58for a stage of the compressor can be mounted to (or integral to) a disk61, which is mounted to the corresponding one of the HP and LP spools48,50. The vanes60,62for a stage of the compressor can be mounted to the core casing46in a circumferential arrangement.

The HP turbine34and the LP turbine36respectively include a plurality of turbine stages64,66, in which a set of turbine blades68,70are rotated relative to a corresponding set of static turbine vanes72,74, also referred to as a nozzle, to extract energy from the stream of fluid passing through the stage. In a single turbine stage64,66, multiple turbine blades68,70can be provided in a ring and can extend radially outwardly relative to the centerline12while the corresponding static turbine vanes72,74are positioned upstream of and adjacent to the rotating blades68,70. It is noted that the number of blades, vanes, and turbine stages shown inFIG.1were selected for illustrative purposes only, and that other numbers are possible.

The blades68,70for a stage of the turbine can be mounted to a disk71, which is mounted to the corresponding one of the HP and LP spools48,50. The vanes72,74for a stage of the compressor can be mounted to the core casing46in a circumferential arrangement.

Complementary to the rotor portion, the stationary portions of the engine10, such as the static vanes60,62,72,74among the compressor and turbine section22,32are also referred to individually or collectively as a stator63. As such, the stator63can refer to the combination of non-rotating elements throughout the engine10.

In operation, the airflow exiting the fan section18is split such that a portion of the airflow is channeled into the LP compressor24, which then supplies pressurized air76to the HP compressor26, which further pressurizes the air. The pressurized air76from the HP compressor26is mixed with fuel in the combustor30and ignited, thereby generating combustion gases. Some work is extracted from these gases by the HP turbine34, which drives the HP compressor26. The combustion gases are discharged into the LP turbine36, which extracts additional work to drive the LP compressor24, and the exhaust gas is ultimately discharged from the engine10via the exhaust section38. The driving of the LP turbine36drives the LP spool50to rotate the fan20and the LP compressor24.

A portion of the pressurized airflow76can be drawn from the compressor section22as bleed air77. The bleed air77can be drawn from the pressurized airflow76and provided to engine components requiring cooling. The temperature of pressurized airflow76entering the combustor30is significantly increased above the bleed air temperature. The bleed air77may be used to reduce the temperature of the core components downstream of the combustor.

A remaining portion of the airflow78bypasses the LP compressor24and engine core44and exits the engine assembly10through a stationary vane row, and more particularly an outlet guide vane assembly80, comprising a plurality of airfoil guide vanes82, at the fan exhaust side84. More specifically, a circumferential row of radially extending airfoil guide vanes82are utilized adjacent the fan section18to exert some directional control of the airflow78.

Some of the air supplied by the fan20can bypass the engine core44and be used for cooling of portions, especially hot portions, of the engine10, and/or used to cool or power other aspects of the aircraft. In the context of a turbine engine, the hot portions of the engine are normally downstream of the combustor30, especially the turbine section32, with the HP turbine34being the hottest portion as it is directly downstream of the combustion section28. Other sources of cooling fluid can be, but are not limited to, fluid discharged from the LP compressor24or the HP compressor26.

Portions of a lubricant system100are schematically illustrated inFIG.1in the form of a vehicle lubrication system arranged throughout the engine10. The lubricant system100includes a lubricant reservoir102that can contain a volume of lubricant to circulate through the lubricant system100. A series of lubricant conduits103can interconnect multiple elements of the lubricant system100providing for provision or circulation of the lubricant throughout the lubricant system and any engine components coupled thereto.

Optionally, at least one heat exchanger105can be included in the lubricant system200. Non-limiting examples of the heat exchanger105can include a fuel/lubricant (fuel-to-lubricant) heat exchanger, an oil/lubricant heat exchanger, or an air cooled oil cooler, or the like. For example, a fuel/lubricant heat exchanger can be used to heat or cool engine fuel with lubricant passing through the heat exchanger. In another example, a lubricant/oil heat exchanger can be used to heat or cool additional lubricants passing within the engine10, fluidly separate from the lubricant passing along the lubricant system100. Such a lubricant/oil heat exchanger can also include a servo/lubricant heat exchanger. Optionally, a second heat exchanger (not shown) can be provided along the exterior of the engine core44, downstream of the outlet guide vane assembly. The second heat exchanger can be an air/lubricant heat exchanger, for example, adapted to convectively cool lubricant in the lubricant system100utilizing the airflow passing through the outlet guide vane assembly80.

It should be understood that the organization of the lubricant system100as shown is by way of example only to illustrate an exemplary system within the engine10for circulating lubricant for purposes such as lubrication or heat transfer. Any organization for the lubricant system100is contemplated, with or without the elements as shown, or including additional elements interconnected by any necessary conduit system.

Turning toFIG.2, the lubricant system100is schematically illustrated in isolation from the turbine engine10. The lubricant system100includes the lubricant reservoir102configured to store a coolant or lubricant, including organic or mineral oils, synthetic oils, or fuel, or mixtures or combinations thereof. A supply line104and a scavenge line106are fluidly coupled to the reservoir102and collectively form a lubricant circuit to which the reservoir102and component110can be fluidly coupled. The component110can be supplied with lubrication by way of a fluid coupling with the supply line104and can return the supplied lubricant to the reservoir102by fluidly coupling to the scavenge line106. More specifically, a component supply line111can be fluidly coupled between the supply line104and the component110. It is further contemplated that multiple types of lubricant can be provided in other lines not explicitly shown, but nonetheless included in the lubricant system100.

A pump108can be provided in the lubricant system100to aid in recirculating lubricant from the reservoir102to the component110via the supply line104. For example, the pump108can be driven by a rotating component of the turbine engine10, such as the HP shaft48or the LP shaft50(FIG.1).

Lubricant can be recovered from the component110by way of the scavenge line106and returned to the reservoir102. In the illustrated example, the pump108is illustrated along the supply line104downstream of the reservoir102. The pump108can be located in any suitable position within the lubricant system100, including along the scavenge line106upstream of the reservoir102. In addition, while not shown, multiple pumps can be provided in the lubricant system100.

A bypass line112can be fluidly coupled to the supply line104and scavenge line106in a manner that bypasses the component110. A bypass valve115is fluidly coupled to the supply line104, component supply line111, and bypass line112. The bypass valve115is configured to control a flow of lubricant through at least one of the component supply line111or the bypass line112. The bypass valve115can include any suitable valve including, but not limited to, a differential thermal valve, rotary valve, flow control valve, or pressure safety valve.

During operation, a supply flow120can move from the reservoir102, through the supply line104, and to the bypass valve115. A component input flow122can move from the bypass valve115through the component supply line111to the component110. A scavenge flow124can move from the component110through the scavenge line106and back to the reservoir102. Optionally, a bypass flow126can move from the bypass valve115through the bypass line112and to the scavenge line106. The bypass flow126can mix with the scavenge flow124and define a return flow128moving toward the lubricant reservoir102.

In one example where no bypass flow exists, it is contemplated that the supply flow120can be the same as the component input flow122and that the scavenge flow124can be the same as the return flow128. In another example where the bypass flow126has a nonzero flow rate, the supply flow120can be divided at the bypass valve115into the component input flow122and bypass flow126. It will also be understood that additional components, valves, sensors, or conduit lines can be provided in the lubricant system100, and that the example shown inFIG.2is simplified with a single component110for illustrative purposes only.

The lubricant system100can further include at least one sensing position at which at least one lubricant parameter can be sensed or detected. The at least one lubricant parameter can include, but is not limited to, a temperature, a pressure, a viscosity, a chemical composition of the lubricant, or the like. In the illustrated example, a first sensing position116is located in the supply line104upstream of the component110, and a second sensing position118is located in the scavenge line106downstream of the component110.

In one example, the bypass valve115can be in the form of a differential thermal valve configured to sense or detect at least one lubricant parameter in the form of a temperature of the lubricant. In such a case, the fluid coupling of the bypass valve115to the first and second sensing positions116,118can provide for bypass valve115sensing or detecting the lubricant temperature at the sensing positions116,18as lubricant flows to or from the bypass valve115. The bypass valve115can be configured to control the component input flow122or the bypass flow126based on the sensed or detected temperature.

It is contemplated that the bypass valve115, supply line104, and bypass line112can at least partially define a closed loop control system for the component110. As used herein, a “closed loop control system” will refer to a system having mechanical or electronic components that can automatically regulate, adjust, modify, or control a system variable without manual input or other human interaction. Such closed loop control systems can include sensing components to sense or detect parameters related to the desired variable to be controlled, and the sensed or detected parameters can be utilized as feedback in a “closed loop” manner to change the system variable and alter the sensed or detected parameters back toward a target state. In the example of the lubricant system100, the bypass valve115(e.g. mechanical or electrical component) can sense a parameter, such as the lubricant parameter (e.g. temperature), and automatically adjust a system variable, e.g. flow rate to either or both of the bypass line112or component110, without need of additional or manual input. In one example, the bypass valve can be automatically adjustable or self-adjustable such as a thermal differential bypass valve. In another example, the bypass valve can be operated or actuated via a separate controller. It will be understood that a closed loop control system as described herein can incorporate such a self-adjustable bypass valve or a controllable bypass valve.

Turning toFIG.3, a portion of the lubricant system100is illustrated supplying lubricant to a particular component110in the form of a gearbox150within the turbine engine10(FIG.1). The gearbox150can include an input shaft152, an output shaft154, and a gear assembly155. In one example, the gear assembly155can be in the form of an epicyclic gear assembly as known in the art having a ring gear, sun gear, and at least one planet gear. An outer housing156can at least partially surround the gear assembly155and form a structural support for the gears and bearings therein. Either or both of the input and output shafts152,154can be coupled to the turbine engine10(FIG.1). In one non-limiting example, the input and output shafts152,154can be utilized to decouple the LP turbine36from the LP compressor24and the fan20, such as for improving engine efficiency. In another non-limiting example (not shown) where the lubricant system is utilized in a turboprop engine, the input shaft can provide torque from the engine to drive a propeller through the output shaft.

The supply line104can be fluidly coupled to the gearbox150, such as to the gear assembly155, to supply lubricant to gears or bearings to the gearbox150during operation. The scavenge line106can be fluidly coupled to the gearbox150, such as to the gear assembly155or outer housing156, to collect lubricant. The bypass line112can be fluidly coupled to the bypass valve115, supply line104, and scavenge line106as shown. A return line114can also be fluidly coupled to the bypass valve115, such as for directing the return flow128to the lubricant reservoir102for recirculation. While not shown inFIG.3for brevity, the lubricant reservoir102or pump108(FIG.2) can also be fluidly coupled to the gearbox150. In this manner, the supply line104, bypass line112, scavenge line106, and return line114can at least partially define a recirculation line130for the lubricant system100.

The supply flow120divides at the bypass line into the component input flow122and the bypass flow126. In the example shown, the bypass valve115is in the form of a differential thermal valve that is fluidly coupled to the first and second sensing positions116,118.

Lubricant flowing proximate the first and second sensing positions116,118provides the respective first and second outputs141,142indicative of the temperature of the lubricant at those sensing positions116,118. It will be understood that the supply line104is thermally coupled to the bypass line112and bypass valve115such that the temperature of the fluid in the supply line104proximate the first sensing position116is approximately the same as fluid in the bypass line112adjacent the bypass valve115. Two values being “approximately the same” as used herein will refer to the two values not differing by more than a predetermined amount, such as by more than 20%, or by more than 5 degrees, in non-limiting examples. In this manner, the bypass valve115can sense the lubricant temperature in the supply line104and scavenge line106via the first and second outputs141,142. It can be appreciated that the bypass line112can form a sensing line for the valve115to sense the lubricant parameter, such as temperature, at the first sensing position116.

During operation of the engine10(FIG.1), the lubricant temperature can increase within the gearbox150, such as due to heat generation of the gearbox150, and throughout the lubricant system100. In one example, if a lubricant temperature exceeds a predetermined threshold temperature at either sensing position116,118, the bypass valve115can automatically increase the component input flow122, e.g. from the supply line104to the gearbox150, by decreasing the bypass flow126. Such a predetermined threshold temperature can be any suitable operating temperature for the gearbox150, such as 150° C. in one non-limiting example. Increasing the component input flow122can provide for cooling of the gearbox150, thereby reducing the lubricant temperature sensed in the various lines104,106,112,114as lubricant recirculates through the lubricant system100.

In another example, if a temperature difference between the sensing positions116,118exceeds a predetermined threshold temperature difference, the bypass valve can automatically increase the component input flow122by decreasing the bypass flow126. Such a predetermined threshold temperature difference can be any suitable operating temperature for the gearbox150, such as 20° C., or differing by more than 30%, in non-limiting examples. In yet another example, if a temperature difference between the sensing positions116,118is below the predetermined threshold temperature difference, the bypass valve can automatically decrease the component input flow122or increase the bypass flow126. In this manner the lubricant system100can provide for the gearbox to operate with a constant temperature difference between the supply and scavenge lines204,106.

Turning toFIG.4, another exemplary lubricant system200is illustrated, which is a variation to lubricant system100. The lubricant system200, as a variation, is similar to the lubricant system100; therefore, like parts will be identified with like numerals increased by 100, with it being understood that the description of the like parts of the lubricant system100applies to the lubricant system200, except where noted.

The lubricant system200is shown fluidly coupled to a lubricated component210in the form of a gearbox250. A first sensing position216is shown in the supply line204, and a second sensing position218is located in the scavenge line206. A component supply line211is fluidly coupled to the supply line204and provides a component input flow222to the gearbox250. A bypass valve215is fluidly coupled to the supply line204, component supply line211, and bypass line212. A supply flow220moves through the supply line204toward the bypass valve215, and the component input flow222and bypass flow226move from the bypass valve215as shown.

One difference between the lubricant systems200and100is that a dedicated sensing line219is provided between, fluidly coupled to, and thermally coupled to, the bypass valve215and the second sensing position218. The sensing line219can be in the form of a small fluid conduit filled with lubricant by way of the fluid coupling between the bypass valve215and scavenge line206.

During operation, the supply flow220can divide into the component input flow222and bypass flow226via the bypass valve215. A scavenge flow224can exit the gearbox250and join with the bypass flow226to form a return flow228. The fluid flow proximate the first sensing position216can provide a first output241to the bypass valve215, and fluid flow proximate the second sensing position218can provide a second output242to the bypass valve215as shown. The first and second outputs241,242can represent a temperature of the lubricant at the respective first and second sensing positions216,218. In one example, if a lubricant temperature exceeds a predetermined threshold temperature at either sensing position216,218, the bypass valve215can automatically increase the component input flow222, e.g. by decreasing the bypass flow226. In another example, if a lubricant temperature difference between the sensing positions216,218is above a predetermined threshold temperature difference as described above, the bypass valve215can increase the component input flow222or decrease the bypass flow226. In yet another example, if a lubricant temperature difference between the sensing positions216,218, is below a predetermined threshold temperature difference as described above, the bypass valve215can decrease the component input flow222or increase the bypass flow226.

Referring now toFIG.5, another lubricant system300, which is a variation of lubricant systems100and200, is shown that can be utilized in the turbine engine10(FIG.1). The lubricant system300is similar to the lubricant system100,200; therefore, like parts will be identified with like numerals further increased by 100. It will be understood that the description of the like parts of the lubricant system100,200applies to the lubricant system300, except where noted.

The lubricant system300is schematically illustrated in isolation from the turbine engine10(FIG.1) for clarity. The lubricant system300includes a lubricant reservoir302configured to store a lubricant, such as oil. A supply line304and a scavenge line306are fluidly coupled to the reservoir302. A turbine engine component310can be supplied with lubrication by way of a fluid coupling to the supply line304and scavenge line306. More specifically, a component supply line311can be fluidly coupled between the supply line304and the component310.

A pump308can be provided in the lubricant system300to aid in recirculating lubricant from the reservoir302to the component310via the supply line304. The pump308can be utilized to recover lubricant from the component310or recirculate the lubricant via the reservoir302. The pump308can be located at any suitable position in the lubricant system for recovering or recirculating lubricant. While not shown, multiple pumps can be included in the lubricant system300for separately recovering lubricant from the component310and for recirculating lubricant via the reservoir302.

A bypass line312can be fluidly coupled to the supply line304and scavenge line306in a manner that bypasses around the component310. A bypass valve315is fluidly coupled to the supply line304, component supply line311, and bypass line312and configured to control a flow of lubricant through the bypass line312. The bypass valve315can include any suitable valve including, but not limited to, a differential thermal valve, rotary valve, flow control valve, or pressure safety valve.

A supply flow320can move toward the component310. The supply flow320can divide at the bypass valve315into a component input flow322and a bypass flow326as shown. A scavenge flow324can exit the component310and combine with the bypass flow326to form a return flow328as shown. In this manner, the supply line304, bypass line312, scavenge line306, and return line314can at least partially define a recirculation line330for the lubricant system300.

The lubricant system300can further include at least one sensing position at which at least one lubricant parameter can be sensed or detected. In the example shown, a first sensing position316is located in the supply line304upstream of the component310, and a second sensing position318is located in the scavenge line106downstream of the component310.

One difference between the lubricant systems200,100and300is that the lubricant system300includes at least one sensor configured to sense or detect the at least one lubricant parameter. For example, a first sensor331can be provided at the first sensing position316, and a second sensor332can be provided at the second sensing position318. A controller335can be communicatively coupled to the first and second sensors331,332.

The first sensor331can provide a first output341indicative of a first lubricant parameter in the supply line304. The second sensor332can provide a second output342indicative of a second lubricant parameter in the scavenge line306. For example, the first and second lubricant parameters can be a temperature of the lubricant at the first and second sensing positions316,318, e.g. upstream and downstream of the component310. The controller335can receive the first and second outputs341,342and operably control the bypass valve315based on the outputs341,342. For example, the controller335can transmit a control signal343to the bypass valve315to operably control the bypass valve315.

It is contemplated that any or all of the bypass valve315, supply line304, bypass line312, sensing positions316,318, sensors331,332, and controller335can at least partially define a closed loop control system as described above. The controller335can sense a parameter, e.g. lubricant parameter, via the sensors331,332, and control the bypass valve315to adjust a system variable, e.g. supply flow, component supply flow, or bypass flow, to effect a change in the sensed parameter.

FIG.6illustrates one example of the lubricant system300supplying lubricant to the component310in the form of a gearbox350within the turbine engine10(FIG.1). The gearbox350can include an input shaft352, an output shaft354, and a gear assembly355. An outer housing356can surround or support the gear assembly355or shafts352,354. In one example, the gear assembly355can be in the form of an epicyclic gear assembly as known in the art having a ring gear, sun gear, and at least one planet gear. An outer housing356can at least partially surround the gear assembly355and form a structural support for the gears and bearings therein.

The supply line304can be fluidly coupled to the gearbox350, such as to the gear assembly355, to supply lubricant to gears or bearings to the gearbox350during operation. The scavenge line306can be fluidly coupled to the gearbox350, such as to the gear assembly355or outer housing356, to collect lubricant for recirculation. The bypass line312can be fluidly coupled to the bypass valve315, supply line304, and scavenge line306as shown. A return line314can also be fluidly coupled to the bypass valve315, such as for directing the return flow328to the lubricant reservoir302(FIG.5) for recirculation. The supply flow320divides at the bypass valve315into the component input flow322and the bypass flow326. The bypass flow326combines with the scavenge flow324to form the return flow328.

The controller335is illustrated in signal communication with the first and second sensors331,332located at the first and second sensing positions316,318. Such signal communication can be in the form of a wired or wireless electrical connection as described above. The controller335is also illustrated as being electrically coupled to the bypass valve315, where the control signal343can be transmitted from the controller335to the bypass valve315. In addition, the controller335can be communicatively coupled to any other suitable system (not shown), such as in the engine10or elsewhere. In one example where the turbine engine10is provided on an aircraft, a flight management system, engine control system, or FADEC system can transmit or receive a signal345to or from the controller335. The controller335can operate the bypass valve315in response to the signal345, including in combination with the first and second outputs341,342. For example, the controller335can receive the signal345from a PID controller and send an actuation signal to the bypass valve315to control or actuate the valve315. Optionally, the controller335can be incorporated directly into a FADEC among other controlling functions thereof, as an alternative to using a separate FADEC and controller335.

With reference to aspects of the disclosure described inFIGS.1-6, some exemplary descriptions of the lubricant system in operation will be described below. It will be understood that the following non-limiting descriptions are provided by way of illustration only.

In one example, a lubricant system can supply an engine component on an aircraft having a FADEC. The lubricant system can include a remote controller in wired or wireless communication with a first sensor located at a first sensing position and a second sensor located at a second sensing position. A lubricant parameter in the form of fluid pressure can be sensed at the two sensing positions and transmitted to the remote controller. The remote controller can receive a signal from the FADEC that the engine is being “throttled up” to increase speed. The remote controller can determine, based on the FADEC signal and the sensed lubricant parameters, that additional lubricant is desired to flow to the engine component. Based on the determination, the remote controller can transmit an operation signal to the bypass valve to adjust such that the component supply flow is increased and the bypass flow is decreased.

In another example, a lubricant system can supply an engine component on an unmanned aircraft. The lubricant system can include a controllable thermal bypass valve that can also be capable of automatically adjusting a flow rate without an external control signal, such as that from a controller. Sensors can be located at respective sensing locations throughout the lubricant system, and a controller can be communicatively coupled to the bypass valve and sensors. For example, the controller can monitor a status of the bypass valve as it automatically adjusts a bypass flow or component supply flow, and can also provide an override signal to operate the bypass valve based on output from the sensors.

During a “cruise” period in which the unmanned aircraft is flying at a near-constant speed and altitude, the controller can receive output from the sensors indicating that a temperature difference of the lubricant between two sensing positions is lower than a predetermined target difference, e.g. differing by less than 30° C. The controller can override the bypass valve to decrease the component supply flow, thereby utilizing less lubricant based on the sensed need of the engine component for lubrication.

Turning toFIG.7, a method400of supplying lubricant to a component, such as the component110,210,310, is illustrated. The method400includes, at402, recirculating lubricant through a recirculation line from a reservoir, through the component, and back to the reservoir. For example, the recirculation line can include any or all of the supply line104,204,304, or scavenge line106,206,306. The reservoir can include the lubricant reservoir102,302. At404, a first parameter of the lubricant can be sensed upstream of the component, and at406a second parameter of the lubricant can be sensed downstream of the component. The first and second parameters in one example can be a temperature of the lubricant as described above. The method also includes at408controlling a flow rate of lubricant to the component based on the sensed first and second parameters.

In one example, the sensing of lubricant parameters at404and406can be performed via a thermal differential bypass valve. In such a case, sensing the parameter at404and406can include directly sensing the lubricant parameter, and such sensing can be automatically performed by the bypass valve as described above. For example, if a temperature difference between the lubricant in the supply line and scavenge line is below a predetermined threshold temperature difference, e.g. 20-30° C., the thermal differential bypass valve can automatically direct at least some lubricant from the supply line to the bypass line, which joins with the scavenge line downstream of the component. In this manner heat generation of the component can be limited via a windage effect, which can enhance the efficiency.

In another example, the sensing at404and406can be performed by sensors, such as the first and second sensors331,332as described above. In such a case, the bypass valve can be operably controlled by a controller based on first and second outputs from the respective first and second sensors. For example, if a temperature of the lubricant sensed by either sensor exceeds a predetermined threshold temperature, such as 150° C., the controller can operate the bypass valve to increase a component supply flow or decrease a bypass flow as described above. In another example, if the controller determines that a temperature difference between the sensors exceeds a predetermined threshold temperature difference, such as 40-50° C., the controller can operate the bypass valve to increase a component supply flow or decrease a bypass flow as described above.

It is further contemplated that the lubricant system of any of the above-described examples can be utilized with multiple, differing lubricants. For example, the lubricant system can include a first lubricant reservoir storing a first lubricant, such as oil, as well as a second lubricant reservoir storing a second lubricant, such as fuel. A first sensing position can be located on a first line through which the first lubricant flows, and a second sensing position can be located on a second line through which the second lubricant flows. The bypass valve can be operated based on a first lubricant parameter of the first lubricant and a second lubricant parameter of the second lubricant. For example, if a sensed or detected temperature of either the first lubricant or second lubricant exceeds a predetermined threshold, the bypass valve can be operated to provide additional first lubricant or additional second lubricant to the component. Additionally or alternatively, if a sensed or detected difference between the first lubricant parameter of the first lubricant and the second lubricant parameter of the second lubricant is below a predetermined threshold difference, the bypass valve can be operated to increase a flow of either the first or second lubricants through the bypass line.

Aspects of the disclosure provide for a variety of benefits, including that aspects provide for a closed loop control system for an engine component. Such closed loop control can be accomplished via mechanical components, such as the thermal differential bypass valve, or via electronic components such as the sensors and controller, as described above. In one example in the context of an aircraft engine environment, aspects of the disclosure provide for more efficient use of lubricant in the lubricant system. Compared to traditional methods of oil supply that are directly tied to engine speed, the lubricant system described herein can have the technical effect of providing for an oil flow reduction at cruise of 30-60% compared to oil flow needed during take-off. In one example, aspects of the disclosure provide for an improvement in gearbox efficiency, including an improvement of up to 0.5-1% at low power conditions (e.g. cruise) compared to traditional lubricant supply systems. It can be appreciated that such a reduction also provides for reducing of engine fuel consumption, improving engine efficiency and performance and reducing costs during operation.

In addition, the temperature-based closed loop control of engine gearbox performance can have the technical effect of improving efficiency of other engine components across all flight conditions, regardless of ambient conditions and hardware-to-hardware scatter that may be present. Scavenge temperature control can also provide for safer gearbox performance optimization, as the scavenge temperature can be correlated with a temperature of gear teeth or bearings within the gearbox. For example, the lubricant system can provide for operation of the gearbox at a constant temperature differential which can reduce component wear due to undesirable high-temperature operation. Furthermore, such a constant temperature differential can provide for improved engine efficiency and performance across multiple operating conditions, e.g. low-power and high-power conditions.

It should be appreciated that application of the disclosed design is not limited to turbine engines with fan and booster sections, but is applicable to turbojets and turboshaft engines as well. Further still, such disclosures are applicable to other lubricant systems and vehicles.

To the extent not already described, the different features and structures of the various aspects can be used in combination, or in substitution with each other as desired. That one feature is not illustrated in all of the examples is not meant to be construed that it cannot be so illustrated, but is done for brevity of description. Thus, the various features of the different aspects can be mixed and matched as desired to form new aspects, whether or not the new aspects are expressly described. All combinations or permutations of features described herein are covered by this disclosure.

This written description uses examples to describe aspects of the disclosure described herein, including the best mode, and also to enable any person skilled in the art to practice aspects of the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of aspects of the disclosure is defined by the claims, and can 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 they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Various characteristics, aspects, and advantages of the present disclosure may also be embodied in any permutation of aspects of the disclosure including, but not limited to, the following technical solutions as defined in the enumerated aspects:1. A lubricant system for supplying lubrication to a component in a turbine engine, the lubricant system comprising:a lubricant reservoir;a supply line fluidly coupling the lubricant reservoir to the component in the turbine engine;a scavenge line fluidly coupling the component to the lubricant reservoir;a bypass line fluidly coupling the supply line to the scavenge line and bypassing the component;a first sensing position providing a first output indicative of a first lubricant parameter in the supply line;a second sensing position providing a second output indicative of a second lubricant parameter in the scavenge line; and a bypass valve fluidly coupled to the first sensing position and second sensing position and controlling the flow of lubricant through the bypass line based on the first and second outputs.2. The lubricant system of any of the disclosed aspects wherein the first and second lubricant parameters comprise a temperature of the lubricant at the respective first and second sensing positions.3. The lubricant system of any of the disclosed aspects wherein the bypass valve comprises a differential thermal valve receiving the first and second outputs.4. The lubricant system of any of the disclosed aspects wherein the first and second outputs are provided from lubricant flowing proximate the respective first and second sensing positions.5. The lubricant system of any of the disclosed aspects further comprising a controller receiving the first and second outputs and operably controlling the bypass valve based on the first and second outputs.6. The lubricant system of any of the disclosed aspects further comprising first and second sensors communicatively coupled to the controller, with the first sensor located at the first sensing position and the second sensor located at the second sensing position.7. The lubricant system of any of the disclosed aspects wherein the first and second sensor are configured to transmit the respective first and second outputs to the controller.8. The lubricant system of any of the disclosed aspects wherein at least one of the first sensor or the second sensor comprises a thermocouple.9. The lubricant system of any of the disclosed aspects wherein the bypass valve is configured to decrease lubricant flow through the bypass line when at least one of the first or second lubricant parameters exceeds a predetermined threshold temperature.10. The lubricant system of any of the disclosed aspects wherein the bypass valve is configured to increase lubricant flow through the bypass line when a difference between the first and second lubricant parameters is below a predetermined threshold temperature difference.11. The lubricant system of any of the disclosed aspects wherein the bypass valve is configured to decrease lubricant flow through the bypass line when a difference between the first and second lubricant parameters exceeds the predetermined threshold temperature difference.12. The lubricant system of any of the disclosed aspects wherein the supply line, bypass line, bypass valve, and sensor at least partially define a closed loop control system for the component.13. The lubricant system of any of the disclosed aspects wherein the controller further comprises a remote controller in signal communication with the first sensor and the second sensor.14. The lubricant system of any of the disclosed aspects wherein the remote controller is configured to transmit an operation signal to the bypass valve based on an engine throttle condition.15. The lubricant system of any of the disclosed aspects wherein the bypass valve further comprises an independently-controllable thermal bypass valve and configured to adjust a flow rate through the bypass valve.16. The lubricant system of any of the disclosed aspects wherein the controller is further configured to override the bypass valve based on an engine condition.17. The lubricant system of any of the disclosed aspects further comprising multiple lubricant reservoirs each storing a corresponding lubricant.18. The lubricant system of any of the disclosed aspects wherein a first lubricant reservoir stores a first lubricant and a second lubricant stores a second lubricant different from the first lubricant.19. The lubricant system of any of the disclosed aspects wherein the first lubricant parameter corresponds to the first lubricant and the second lubricant parameter corresponds to the second lubricant.20. The lubricant system of any of the disclosed aspects wherein the supply line is configured to supply at least one of the first lubricant and the second lubricant to the component.21. The lubricant system of any of the disclosed aspects further comprising a first line carrying the first lubricant and a second line carrying the second lubricant.22. The lubricant system of any of the disclosed aspects wherein the first sensing position is located in the first line and the second sensing position is located in the second line.23. A turbine engine, comprising:a compressor, combustor, and turbine in axial flow arrangement;a shaft operably coupled to at least one of the compressor, combustor, or turbine;a lubricated component operably coupled to at least one of the compressor, combustor, turbine, or shaft; anda lubricant system fluidly coupled to the lubricated component and comprising:a lubricant reservoir;a supply line fluidly coupling the lubricant reservoir to the lubricated component;a scavenge line fluidly coupling the lubricate component to the lubricant reservoir;a bypass line fluidly coupling the supply line to the scavenge line and bypassing the lubricated component;a first sensing position providing a first output indicative of a temperature of the lubricant in the supply line;a second sensing position providing a second output indicative of a temperature of the lubricant in the scavenge line; anda bypass valve fluidly coupled to the first sensing position and second sensing position and controlling the flow of lubricant through the bypass line based on the first and second outputs.24. The turbine engine of any of the disclosed aspects wherein the bypass valve comprises a differential thermal valve receiving the first and second outputs from lubricant flowing proximate the respective first and second sensing positions.25. The turbine engine of any of the disclosed aspects further comprising a controller receiving the first and second outputs and operably controlling the bypass valve based on the first and second outputs.26. The turbine engine of any of the disclosed aspects wherein the lubricated component comprises a gearbox having at least an epicyclic gear assembly, an outer housing surrounding the epicyclic gear assembly, an input shaft, and an output shaft.27. The turbine engine of any of the disclosed aspects wherein the bypass valve is configured to decrease lubricant flow from the supply line to the bypass line when at least one of the first or second lubricant parameters exceeds a predetermined threshold temperature.28. The turbine engine of any of the disclosed aspects wherein the bypass valve is configured to increase lubricant flow from the supply line to the bypass line when a difference between the first and second lubricant parameters is below a predetermined threshold temperature difference.29. A method of supplying lubricant to a component within a turbine engine, the method comprising:recirculating lubricant through a recirculation line from a reservoir, through the component, and back to the reservoir;sensing a first parameter of the lubricant upstream of the component;sensing a second parameter of the lubricant downstream of the component; andcontrolling a flow rate of lubricant to the component based on the sensed first and second parameters.30. The method of any of the disclosed aspects wherein the first and second lubricant parameters comprise a temperature of the lubricant.31. The method of any of the disclosed aspects wherein the sensing a first parameter further comprises directly sensing the temperature of the lubricant via a bypass valve fluidly and thermally coupled to the lubricant upstream of the component.32. The method of any of the disclosed aspects wherein the sensing a first parameter further comprises sensing the temperature of the lubricant via a sensor fluidly coupled to the lubricant upstream of the component and communicatively coupled to a controller.33. The method of any of the disclosed aspects wherein the controlling further comprises controlling a bypass valve via the controller.34. The method of any of the disclosed aspects wherein the controlling further comprises increasing the flow rate of lubricant to the component when at least one of the first or second lubricant parameters exceeds a predetermined threshold temperature.35. The method of any of the disclosed aspects wherein the controlling further comprises bypassing at least some of the lubricant in the recirculation line around the component when a difference between the first and second lubricant parameters is below a predetermined threshold temperature difference.36. The method of any of the disclosed aspects wherein the recirculating further comprises recirculating a first lubricant through a first line and a recirculating a second lubricant through a second line.37. The method of any of the disclosed aspects wherein the first sensing position is located in the first line and the second sensing position is located in the second line.38. The method of any of the disclosed aspects wherein the sensing a first lubricant parameter further comprises transmitting a signal from the first sensor to a remote controller.39. The method of any of the disclosed aspects wherein the sensing a second lubricant parameter further comprises transmitting a signal from the second sensor to a remote controller.40. The method of any of the disclosed aspects further comprising transmitting an operation signal from a controller to the bypass valve based on an engine throttle condition.41. The method of any of the disclosed aspects wherein the bypass valve further comprises an independently-controllable thermal bypass valve and configured to adjust a flow rate through the bypass valve.42. The method of any of the disclosed aspects further comprising overriding the bypass valve via a controller based on an engine condition.