ARTICULATING SLIDER TRACK

Abstract

A variable fan nozzle assembly includes a cowl member mounted on a slider track. The slider track may be articulated relative to a support member to slightly modify the position of the cowl member to vary the fan nozzle exit area. At least one 4-bar linkage may be utilized to allow articulation of the slider track responsive to an actuator. A method for varying a fan nozzle exit area includes mounting a first slider track in articulatable relationship with a support member; mounting a first cowl member in slidable relationship with a first slider track such that a fan nozzle is at least partially defined by a surface of the first cowl member; varying the operational position of the first cowl member by articulating the first slider track without sliding the first cowl member with respect to the first slider track to vary the fan nozzle exit area.

Description

BACKGROUND OF THE INVENTION

Embodiments disclosed herein relate generally to an articulating slider track for a cowl member to provide a variable area fan nozzle for a gas turbine engine.

Conventional gas turbine engines include a fan section and a core engine with the fan section having a larger outer diameter than that of the core engine. The fan section and the core engine are disposed sequentially about a longitudinal axis and are enclosed in a nacelle. An annular path of primary airflow passes through the fan section and the core engine to generate primary thrust. An annular path of duct or fan flow (bypass air), disposed radially outward of the primary airflow path, passes through the fan section and exits through a fan nozzle to generate fan thrust. In general terms, the bypass air flows through a region defined between an outer surface of an engine core cowl and an inner surface of the nacelle. Such an arrangement is well known to those with skill in the art.

The fan nozzles of certain conventional gas turbine engines have fixed geometry. The fixed geometry fan nozzles must be suitable for take-off and landing conditions, as well as for cruise conditions. However, the requirements for take-off and landing conditions are different from requirements for the cruise condition. For cruise conditions, it is desirable to have a smaller area or smaller diameter fan nozzle for increasing cruise performance and for maximizing fuel efficiency, whereas, for take-off and landing conditions, smaller diameter fan nozzles will create more noise and may cause an engine stall. Therefore, in many conventional engines, the cruise performance and fuel efficiency are often compromised to ensure safety of the gas turbine engine at take-off and landing.

Some gas turbine engines have implemented variable area nozzles. The variable area nozzles have the ability of having a smaller fan exit nozzle diameter during cruise conditions and a larger fan exit nozzle diameter during take-off and landing conditions. Known existing variable area nozzles may employ complex mechanisms that require extensive maintenance, which is desirably avoided for commercial aircraft. Further, known variable area nozzle mechanisms may add significant weight to the engine, which adversely affects performance.

Thus, although variable area nozzles have been introduced into some gas turbine engines, there remains a need for a variable area nozzle that does not require extensive maintenance, and does not add significant weight to the gas turbine engine.

Certain known gas turbine engine designs include thrust reverser assemblies. For example, known cascade type thrust reverser assemblies employ an aft translatable cowl (transcowl) that engages with a stationary cowl member in a nacelle assembly. The transcowl cooperates with a core engine cowl to define at least a portion of the annular bypass duct that terminates at the exit nozzle.

Movement of the translatable cowl (transcowl) away from the stationary cowl member opens a passageway through which fan by-pass air may flow. A cascade structure disposed in the passageway is selectively covered and uncovered by movement of the transcowl. The cascade structure includes flow directing louvers to redirect by-pass air outward and forward to provide reverse thrust. A plurality of actuators may be utilized to effect movement of the transcowl.

The thrust reverser assembly may include blocker doors that move into the bypass duct to inhibit passage of the bypass air through the exit nozzle. Alternately, some thrust reversers are known as “blocker-door-less” types in which the translatable cowl cooperates with the engine core cowl to inhibit passage of the bypass air without employing blocker doors.

The thrust reverser assembly may include two half-cowls, sometimes referred to as C-ducts or D-ducts that include upper (hinge) and lower (latch) beams. The transcowl(s) may be mounted on rails or slider tracks fixed to upper and lower beams. The upper beam is the main hinge beam that allows the thrust reverser assembly to open for engine access and removal. The lower beam provides a means for locking together the two half-cowls.

It would be advantageous to utilize certain structures associated with a translating cowl thrust reverser assembly to provide a desired variable area fan nozzle.

BRIEF DESCRIPTION OF THE INVENTION

The above-mentioned needs may be met by exemplary embodiments that provide an assembly comprising a first slider track able to support a first cowl member; a support member; and a mechanism in supported connection with the first slider track and the support member; wherein the mechanism is operable to mount the first slider track in articulatable relationship relative to the support member.

Another exemplary embodiment includes an assembly comprising a first cowl member; and a fan nozzle at least partially defined by a surface of the first cowl member, wherein the fan nozzle is associated with a fan nozzle exit area; and a mechanism in operable connection with the first cowl member being operable to slightly modify a position of the first cowl member between a nominal stowed position and a modified stowed position such that the fan nozzle exit area is variable with the position of the first cowl member.

Another exemplary embodiment provides a method for varying a fan nozzle exit area. The method comprises mounting a first slider track in articualtable relationship with a support member; mounting a first cowl member in supported slidable relationship with a first slider track such that a fan nozzle is at least partially defined by a surface of the first cowl member; varying an operational position of the first cowl member by articulating the first slider track without sliding the first cowl member with respect to the first slider track such that the first cowl member moves between a stowed position and a modified stowed position, wherein a first nozzle exit area is associated with the stowed position of the first cowl member and a second, different nozzle exit area is associated with the modified stowed position of the first cowl member.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding part of the specification. The invention, however, may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:

FIG. 1 is a schematic representation of a gas turbine engine.

FIG. 2 is a side view of a gas turbine engine with a transcowl not shown for simplicity.

FIG. 3 is a schematic representation of a portion of a thrust reverser assembly.

FIG. 4 is a schematic top view of a hinge beam and a slider track showing a plurality of 4-bar linkages.

FIG. 5 is a schematic side view showing a slider track and a 4-bar linkage.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments disclosed herein provide thrust reverser assemblies that may be utilized to provide the desired variable area of fan exit nozzles.

FIG. 1 illustrates a schematic view of selected portion of an exemplary gas turbine engine 10 suspended from an engine pylon 12 of an associated aircraft. The gas turbine engine 10 is circumferentially disposed about an engine centerline, or axial centerline axis A. The gas turbine engine 10 includes a fan 14 and a core engine 16. An outer housing, nacelle 28 (or fan nacelle) extends circumferentially about the fan 14. A fan bypass passage 32 extends between the nacelle 28 and an inner housing, engine cowl 34, which generally surrounds a low pressure compressor, a high pressure compressor, a low pressure turbine, and a high pressure turbine (all not illustrated here for simplicity, but well known in the art).

In operation, the fan 14 draws air into the gas turbine engine 10 as a core flow, C, and into the bypass passage 32 as a bypass air flow, D. The bypass air flow D is discharged as a discharge flow through a fan nozzle 40 defined at the rear of the nacelle 28. The fan nozzle exit area is thus defined by the position of the rear of the nacelle in relationship to the engine cowl 34. Exemplary embodiments disclosed herein are operable to change the position of the rear of the nacelle relative to the engine cowl 34, and thus affect the fan nozzle exit area.

In an exemplary embodiment, nacelle 28 includes a thrust reverser assembly 50, illustrated without the translatable cowl member in FIG. 2. In an exemplary embodiment, upper hinge beam 53 and lower latch beam 54 include slider tracks 58 or rails to support the translation of the translatable cowl member. In an exemplary embodiment, thrust reverser assembly 50 is a cascade type reverser employing a cascade structure 64, as is known in the art. In an exemplary embodiment, aft movement of the translatable cowl member along the slider tracks or rails uncovers the cascades 66 and opens a passage through which fan air is discharged in forward and outward directions. One or more transcowl actuators (not shown in this view) are utilized to translate the translatable cowl member between the stowed position and the deployed position.

With respect to FIGS. 3 and 4, translatable cowl member 52 is supported in a nominal stowed position during flight, and may be translated aft into one or more deployed positions after landing to allow fan air to be utilized for reverse thrust as discussed in the background section. Thrust reverser assembly 50 may include any configuration which utilizes one or more translatable cowl members 52 able to translate forward and aft in a direction generally parallel to axis A.

In exemplary embodiments, translatable cowl member 52 may be supported in one or more “modified” stowed positions as discussed in greater detail below in order to provide variation in the fan nozzle area. In an exemplary embodiment, the slider tracks or rails 58 are mounted in movable relationship relative to its respective hinge or latch beam (hinge beam 53, shown). In an exemplary embodiment, a plurality of 4-bar linkages 60 is utilized with each slider track such that each of the slider tracks articulate responsive to a track actuator 62. The 4-bar linkages may be arranged and coordinated such that activation of the track actuator causes articulation of the slider tracks and produces slight outward motion at the rear of the translatable cowl member, while minimizing movement of the forward region of the translatable cowl member. Thus the translatable cowl member remains in a stowed position relative to the slider tracks, but its position is slightly modified with respect to the core cowl 34. The modified position of the translatable cowl member provides an opportunity for variation in the area of the fan nozzle 40 as illustrated in FIG. 3. In an exemplary embodiment, in a modified position, the fan nozzle area may be increased as compared to the fan nozzle area when the translatable cowl member is in the nominal stowed position. Movement of the track actuator(s) 62 may be modified to provide various modified positions of the translatable cowl member.

As illustrated in FIG. 4, in an exemplary embodiment, up to five 4-bar linkages may be used for each slider track 58. In other embodiments, any suitable number of 4-bar linkages may be utilized for each slider track. It is envisioned that other mechanisms may be utilized to provide movement of the slider track 58 relative to its respective support member (upper or lower beam). Thus for a split transcowl that is supported on its upper and lower ends, four track actuators 62 having synchronized motion could be employed.

With reference to FIG. 3, a transcowl actuator 70 is illustrated. (Although shown as appearing to be floating, it is understood that the illustration shows an exemplary position of a transcowl actuator 70 understood to be coupled to the body of revolution of the transcowl). Those having skill in the art will appreciate that the transcowl actuator(s) 70 should accommodate the movement of the transcowl into the modified position(s) due to articulation of the slider tracks. It is envisioned that, for example, transcowl actuators 70 may include a gimbal joint 72. Those having skill in the art will also appreciate that certain seals may be required to avoid overboard leakage at the slider tracks.

FIG. 5 provides a side view of a slider track and one of the 4-bar linkages.

Thus, the benefits of a variable fan nozzle area such as increased climb thrust, reduced noise, and improved fuel burn may be realized without complicated or heavy mechanisms. Because the translatable cowl member remains in a stowed position relative to the slider tracks, safety issues associated with inadvertent deployment of the thrust reverser is avoided. It is envisioned that those having skill in the art may envision certain modifications to the specific embodiments disclosed herein without departing from the general principles set forth herein.

This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if 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.

Claims

1. An assembly comprising: a first slider track able to support a first cowl member;a support member; anda mechanism in supported connection with the first slider track and the support member;wherein the mechanism is operable to mount the first slider track in articulatable relationship relative to the support member.

2. The assembly according to claim 1 further including a first actuator in operable association with the mechanism, wherein the mechanism is responsive to the first actuator to articulate the first slider track relative to the support member.

3. The assembly according to claim 2 wherein the mechanism includes at least one 4-bar linkage.

5. The assembly according to claim 1 further including the first cowl member mounted in slidable relationship with the first slider track, wherein the first cowl member is operable to translate between a nominal stowed position and at least one deployed position.

6. The assembly according to claim 5 wherein when the first cowl member is in the nominal stowed position, the first cowl member is movable with articulation of the first slider track between the nominal stowed position and a modified stowed position.

7. The assembly according to claim 5 further comprising a fan nozzle at least partly defined by the first cowl member, wherein the fan nozzle is associated with a first fan nozzle exit area when the first cowl member is in the nominal stowed position and a different second fan nozzle exit area when the first cowl member is in the modified stowed position.

8. An assembly comprising: a first cowl member; anda fan nozzle at least partially defined by a surface of the first cowl member, wherein the fan nozzle is associated with a fan nozzle exit area; anda mechanism in operable connection with the first cowl member being operable to slightly modify a position of the first cowl member between a nominal stowed position and a modified stowed position such that the fan nozzle exit area is variable with the position of the first cowl member.

9. The assembly according to claim 8 wherein the mechanism comprises at least one 4-bar linkage responsive to operation of an actuator.

10. The assembly according to claim 8 further including: a support member; anda slider track mounted in articulatable relationship relative to the support member;wherein the first cowl member is mounted in slidable relationship with the first slider track, wherein the first cowl member is operable to translate between a nominal stowed position and at least one deployed position.

11. A method for varying a fan nozzle exit area comprising: mounting a first slider track in articualtable relationship with a support member;mounting a first cowl member in supported slidable relationship with a first slider track such that a fan nozzle is at least partially defined by a surface of the first cowl member;varying an operational position of the first cowl member by articulating the first slider track without sliding the first cowl member with respect to the first slider track such that the first cowl member moves between a stowed position and a modified stowed position, wherein a first nozzle exit area is associated with the stowed position of the first cowl member and a second, different nozzle exit area is associated with the modified stowed position of the first cowl member.