Patent Application
20140151497
Contemporary aircraft include pylon structures to support an engine on a wing of the aircraft. Contemporary engine pylons are built from many separate parts including frames, longerons, and skins, which may be assembled together using hundreds, if not more, high tolerance fasteners, which adds weight and cost. Holes to accommodate the fasteners for coupling the parts together may need to be drilled in the separate parts and makes the assembly process time consuming
In one embodiment, the invention relates to an engine pylon for an aircraft including a box-beam having multiple spaced bulkheads and multiple longerons connecting the bulkheads to define a frame with multiple bays, and skins provided on the frame to at least partially enclose at least one of the multiple bays, wherein at least a subset of the spaced bulkheads, multiple longerons, and skins are a monolithic structure.
In another embodiment, the invention relates to an engine pylon for attaching an engine to an aircraft, that includes a monolithic support structure having a body having an upper and a lower face spaced by a first sidewall and a second sidewall, multiple bays with each bay having an inlet adjacent at least one of the upper face, lower face, first sidewall, and second sidewall, skin on at least two of the upper face, lower face, first sidewall, and second sidewall.
In the drawings:
At least a subset of a portion of the spaced bulkheads 22, multiple longerons 24, and skins 30 form a monolithic support structure 32. In the illustrated example, the monolithic support structure 32 includes an upper face 40 and a lower face 42 spaced by a first sidewall 44 and a second sidewall 46. The multiple bays 28 each have an inlet 48 adjacent to the upper face 40. It will be understood that the inlet 48 may be adjacent to any of at least one of the upper face 40, lower face 42, first sidewall 44, and second sidewall 46. The box-beam 20 may be shaped in any suitable manner including that the body may taper from the upper face 40 to the lower face 42.
Skin 30 may be included on at least two of the upper face 40, lower face 42, first sidewall 44, and second sidewall 46. In
It is also contemplated that a thrust reverser with at least one movable element, which is movable to and from a reversing position, may be included on the engine to change the direction of airflow. There are several methods of obtaining reverse thrust on engine assemblies; however, these components these components are not germane to the present invention and will not be described further herein. As illustrated, an integrated thrust reverser track 52 may extend from a side of the box-beam 20. One or more of the components of the thrust reverser may utilize the thrust reverser track 52 for movement of the thrust reverser to and from the reversing position. In the illustrated example in
The box-beam 20 of the engine pylon 10 has been illustrated as including two opposing monolithic structures, left and right longitudinal halves, which may be joined together to form the monolithic support structure 32. It will be understood that the monolithic support structure 32 may be formed from any suitable material. Further, the monolithic structure may be formed using any suitable manufacturing process. By way of non-limiting example, the monolithic support structure 32 may be forged or machined from one or more pieces of aluminum and then joined together. Splitting the monolithic support structure 32 into two sections facilitates conventional machining operations. The two opposing monolithic structures may be joined in any suitable manner including through fastening, welding, friction-stir welding, etc. The monolithic support structure 32 is unique as compared to a contemporary pylon in that a subset of the spaced bulkheads 22, multiple longerons 24, and skin 30 are integrally formed to create the monolithic structure 32. For example, as indicated above, each of the opposing monolithic structures, including the spaced bulkheads 22, multiple longerons 24, and skin 30 may be machined from a single piece of material. It will be understood that while the spaced bulkheads 22, multiple longerons 24, and skin 30 have been called out within the monolithic structure 32 that each of these components is not typical of the bulkheads, longerons, and skin in a contemporary pylon because the spaced bulkheads 22, multiple longerons 24, and skin 30 as well as other features of the above embodiment are integrally formed together instead of being separate parts.
While the monolithic support structure 32 has been illustrated as being split into the two exemplary opposing pieces in
One difference is that the body or box-beam 120 includes a single-piece monolithic support structure 132 forming all of the spaced bulkheads 122, longerons 124, and skins 130. As with the previously described engine pylon 10 it will be understood that the monolithic support structure 132 may be formed from any suitable material using any suitable manufacturing process. For example, the monolithic support structure 132 may be formed from a single piece of machined aluminum. By way of non-limiting example, the inlets 148 or portions of the inlets 148 may initially be formed by an EDM wire and an initial portion of the aluminum may be removed. Following the removal of the initial portions the spaced bulkheads 122, multiple longerons 124, multiple bays 128, and any integral internal support web members 150 may be formed through additional machining. The separate steps in the thickness of the monolithic support structure 132 allow for the right amount of structure needed for the anticipated loads without having too much structure. This results in weight savings, which translates to fuel and cost savings.
The embodiments described above both include a monolithic structure incorporating at least some of the skins, longerons, and bulkheads. This is in contrast to the historically-used, separate mechanically attached parts used for conventional pylon construction.
In addition to the weight and cost savings, the embodiments described above provide for a variety of additional benefits including that numerous fastener holes likely to induce fatigue cracks are eliminated as the monolithic structure is not built from many separate parts like a contemporary pylon is. Further, fastened joints that result in heavier structure are reduced. Further still, shim gaps that increase assembly time, and weaken the fastened joint are eliminated.
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.
