Patent Grant
9404507
Turbine engines, and particularly gas turbine engines, also known as combustion turbine engines, are rotary engines that extract energy from a flow of combusted gases passing through the engine onto a multitude of turbine blades. Gas turbine engines have been used for land and nautical locomotion and power generation, but are most commonly used for aeronautical applications such as for airplanes. In airplanes, gas turbine engines are used for propulsion of the aircraft.
The engine is attached to a wing by a pylon, typically a metal arm that joins the engine to the wing or fuselage of the aircraft. Through pumps and feed tubes in the pylons, fuel is relayed from wing tanks to the engine. Additionally, electrical power generated by the engine, as well as hydraulic lines and air management system ducts, control system wiring, etc. are routed between the aircraft and engine through wires and piping also contained in the pylons. The engine is contained within external casings, called cowls. These cowls typically form the inner wall of a fan duct on aircraft applications. These engine cowls are supported in part by the pylon and in part by the engine.
Conventional cowl arrangements include the inner and outer cowls that are structurally attached to each other via bifurcation walls and beams that permit hinged opening and closing of the cowls for engine access, and in some cases permit sliding of the outer cowl for thrust reverser operations. In other arrangements the inner cowl remains independent from the outer cowl (i.e. has no direct structural attachment between the cowls). In this case the inner cowling covers the jet engine and has either a fixed frame structure with many access panels to provide engine access or hinged opening forward doors with a sliding aft cowl section that may be moved to provide access for maintenance of the jet engine.
In one aspect, an inner cowl structure for circumscribing at least a portion of a jet engine having at least one engine mount coupled to an engine pylon extending from an aircraft wing, the inner cowl structure includes an apron configured to mount directly to the engine independent of the pylon and overly an upper portion of the jet engine, and an inner body configured to circumscribe a portion of the jet engine not circumscribed by the apron, wherein the inner cowl body is coupled to the apron such that the resulting combination of the coupled apron and inner cowl body defines a hoop structure that is structurally independent of the pylon and completely circumscribes at least a portion of the jet engine.
In another aspect, an aircraft assembly including a wing, an engine pylon mounted to the wing, a jet engine mounted to the engine pylon with at least one engine mount connection, and an inner cowl structure. The inner cowl structure further includes an apron mounted directly to the engine independent of the pylon and overlying an upper portion of the jet engine, and an inner cowl body configured to circumscribe a portion of the jet engine not circumscribed by the apron. The inner cowl body is coupled to the apron such that the resulting combination of the coupled apron and inner cowl body defines a hoop structure that is structurally independent of the pylon and completely circumscribes at least a portion of the jet engine.
In the drawings:
The invention may be implemented in any environment using a gas turbine engine that provides propulsive force for aircraft. Additionally, embodiments of this description is also applicable to a turbine engine providing a power generation and/or providing both a driving force and power generation. Further, while embodiments of this description is directed toward a jet engine aircraft environment, the invention is applicable in any environment using a turbine engine that also uses cowls.
The engine 10 is shown mounted to the pylon assembly 38, at a pylon primary structure 40, by both aft and fore engine mounts 42. The pylon assembly 38, as illustrated, further secures to the aircraft wing 44 in a vertical orientation, but may be secured at alternate positions of the aircraft, such as to the fuselage in a horizontal orientation.
The engine 10 further includes an outer cowl 46 and an inner cowl 48, each having smooth surfaces to reduce the drag of air passing inside or outside the engine 10 in flight. The outer cowl 46 encircles at least a portion of the inner cowl 48 and the engine 10. The pylon assembly 38 further comprises bifurcation walls 50, connected to and extending from the pylon assembly 38 toward the inner cowl 48, defining a gap 52 which is sealed to preserve effective fan air passage along the fan duct between the inner cowl 48 and outer cowl 46.
Also illustrated are a multitude of connector lines 54, such as hydraulic lines, electrical lines and bypass air lines, extending from the engine 10 through the bifurcation walls 50 into the pylon assembly 38. These lines 54 coupling the engine 10 to subsystems necessary for operation, such as fuel pumps and flight control computers.
Turning now to
As shown in
Turning now to
The apron 58 yet further comprises a collar 72 that abuts the pylon assembly 38. The apron 58 yet further comprises at least one opening permitting a pass through connection to the engine 10. As illustrated, the collar 72 includes a collar opening 74, wherein the engine mount 42 passes through to secure the engine 10 to the pylon primary structure 40. The apron 58 is shown having additional openings 76 for the connector lines 54, however, it is envisioned that additional connections may be permitted to pass through the collar opening 74.
The collar 72 further comprises a seal structure 78 corresponding to and circumscribing the collar opening 74. The seal structure 78 is configured in such a way that when the collar 72 abuts the pylon assembly 38, the seal structure 78 seals the collar opening 74 relative to the pylon assembly 38. The seal structure 78 may comprise any suitable soft, flexible material able to form a substantially air and weather-proof seal.
Turning to
During flight operation, an inner cowl 48 circumscribing an engine 10 providing thrust to an aircraft, will experience gravitational and displacement loads. The gravitational loads, or weight of the inner cowl 48, are carried from the cowl doors 60, 62, through the apron 58, to the engine 10 by the apron mounts 70. The hoop-wise continuous structure of the apron 58 and cowl doors 60, 62 provide a structurally efficient design for carrying the weight of the inner cowling 48.
The displacement loads acting upon the inner cowl 48 originate, mainly, from airstream effects, turbulence, and vibration of the engines 10. While the apron mounts 70 may provide both structural stiffness and damping effects, the inner cowl 48 is still slightly displaced relative to the pylon assembly 38. This displacement is accounted for at the interface to the pylon assembly 38, by the aero seal 64 at the apron and bifurcation walls 50 and the seal structure 78 at the collar 72 and the pylon assembly 38. The soft, flexible material of each seal 64, 78 allows for displacement without separation at each interface. Furthermore, the hoop-wise continuous structure of the apron 58 and cowl doors 60, 62 provide a structurally efficient design for withstanding warping or deflection under displacement loads.
Many other possible embodiments and configurations in addition to that shown in the above figures are contemplated by the present disclosure. For example, one embodiment of the invention contemplates an apron 58 that further circumscribes the engine 10 or extends further axially, removing or reducing the need for additional cowl doors 60, 62. Furthermore, a multitude of embodiments having alternate cowl door 60, 62 designs may be employed, so long as the inner cowl 48 is structurally anchored to an apron 58 in each such embodiment. Additionally, the design and placement of the various components may be rearranged such that a number of different configurations could be realized.
The embodiments disclosed herein provide an inner cowl structure for a turbine engine. One advantage that may be realized in the above embodiments is that the above described embodiments have superior complexity and lower cost design advantages over the conventional type inner cowl structures. With the proposed apron mounting structure about the engine, a high structural integrity of the inner cowl can be achieved due to the hoop-wise strength, while structurally isolating the cowling from any direct connection to the pylon or pylon bracket. Moreover, given that the dominant loading cases of the inner cowl is pressure driven, the hoop-wise continuous structure of the described embodiments are especially efficient.
Another advantage that may be realized in the above embodiments is that the inner cowl provides a means to minimize the thermal effect of engine heat on the lower floor of the pylon due to the structural separation and isolation barrier between the apron and the bifurcation walls. Creating this isolation barrier also decreases the engine fire zone volume, benefiting other subsystems such as fire detection and suppression.
Additionally, the described embodiments have superior weight advantages over conventional type inner cowl structures. The design of the apron structure allows for decoupling of the inner cowl structure from the pylon or pylon bracket, removing the need for the pylon to bare the structural loads and displacement challenges of the inner cowl due to engine thrust and aerodynamic forces. Moreover, the lower temperatures on the pylon, as explained above, also allow for lighter materials to be used leading to lighter and simplified structures without displacing weight to another area of a propulsion system. Thus the pylon and pylon bracket may be designed, developed, and machined in alternate, lighter materials that are no longer required to withstand the forces or thermal loads that would otherwise be applied at pylon interfaces.
Yet another advantage that may be realized in the above embodiments is that the apron structure also provides a simpler means for sealing the inner cowl about the engine. The sealing of the inner cowl additionally reduces fan duct leakage of the engine, which will have a direct effect to engine fuel consumption.
When designing aircraft components, important factors to address are size and weight. The above described advantages of the inner cowl structure results in a lower weight, smaller sized, and increased performance engine system. Reduced weight and size correlate to competitive advantages during flight.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. 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.
| Number | Name | Date | Kind |
|---|---|---|---|
| 2496533 | Hendrickson et al. | Feb 1950 | A |
| 4278220 | Johnston et al. | Jul 1981 | A |
| 4442987 | Legrand et al. | Apr 1984 | A |
| 4634081 | Chee | Jan 1987 | A |
| 4683717 | Naud | Aug 1987 | A |
| 5085343 | Scarr | Feb 1992 | A |
| 5275357 | Seelen et al. | Jan 1994 | A |
| 5350136 | Prosser et al. | Sep 1994 | A |
| 6554224 | Sternberger | Apr 2003 | B2 |
| 6843449 | Manteiga et al. | Jan 2005 | B1 |
| 8016227 | Hammer | Sep 2011 | B2 |
| 8448896 | Caruel et al. | May 2013 | B2 |
| 8869507 | Cloft et al. | Oct 2014 | B2 |
| 20080169378 | Beaufort et al. | Jul 2008 | A1 |
| 20080251633 | Journade et al. | Oct 2008 | A1 |
| 20090165463 | Vauchel et al. | Jul 2009 | A1 |
| 20110284686 | Caruel et al. | Nov 2011 | A1 |
| 20120080554 | Lafont et al. | Apr 2012 | A1 |
| 20120247571 | Vauchel et al. | Oct 2012 | A1 |
| 20120308379 | Scarr | Dec 2012 | A1 |
| 20130105622 | Journade | May 2013 | A1 |
| 20130243589 | Caruel | Sep 2013 | A1 |
| 20130312387 | West et al. | Nov 2013 | A1 |
| 20140151497 | Weir et al. | Jun 2014 | A1 |
| 20140234090 | Hurlin et al. | Aug 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 0155887 | Sep 1985 | EP |
| 2896481 | Jul 2007 | FR |
| 2926790 | Jul 2009 | FR |
| 2941673 | Aug 2010 | FR |
| Entry |
|---|
| European Search Report and Written Opinion issued in connection with corresponding EP Application No. 14164001.1-1754 dated Jul. 8, 2014. |
| Number | Date | Country | |
|---|---|---|---|
| 20140319269 A1 | Oct 2014 | US |
