Aircraft landing gear assembly and method of assembling the same

A landing gear assembly for use with an aircraft includes a housing including a trunnion brace, a drag brace, and an aft brace that together define an opening through the housing. The landing gear assembly also includes a shrink link assembly coupled to the housing such that the shrink link assembly is accessible through the opening.

BACKGROUND

The field of the disclosure relates generally to aircraft landing gear assemblies, and more specifically, to aircraft landing gear assemblies that include a housing and a shrink link assembly positioned within the housing.

At least some known aircraft include landing gear assemblies including an outer cylinder and an inner cylinder positioned therein. The inner cylinder slides within the outer cylinder, via a shrink link assembly, to deploy or retract a wheel assembly. However the length of travel of the inner cylinder may be limited by the shape of the outer cylinder and the configuration of the shrink link assembly. Furthermore, the shape of at least some known outer cylinders restricts access to the inner cylinder, which may increase the complexity, and therefore the costs and duration, of required maintenance on the inner cylinder. Additionally, at least some known shrink link assemblies are connected to the inner cylinder using intermediary components, such as cranks and gears that form an offset torsion load path through the shrink link assembly. Such a offset load paths may load components of the shrink link assembly or other components of the landing gear assembly under high forces. These high forces may lead to a shortened service lifetime of the components or may lead to larger components that increase the weight of the aircraft.

BRIEF DESCRIPTION

In one aspect, a landing gear assembly for use with an aircraft is provided. The landing gear assembly includes a housing including a trunnion brace, a drag brace, and an aft brace that together define an opening through the housing. The landing gear assembly also includes a shrink link assembly coupled to the housing such that the shrink link assembly is accessible through the opening.

In another aspect, an aircraft is provided. The aircraft includes a wing structure and a landing gear assembly pivotally coupled to the wing structure. The landing gear assembly is moveable between a deployed position and a retracted position and includes a housing including a trunnion brace, a drag brace, and an aft brace that together define an opening through the housing. The landing gear assembly also includes a shrink link assembly coupled to the housing such that the shrink link assembly is accessible through the opening.

In yet another aspect, a method of assembling a landing gear assembly for use in an aircraft is provided. The method includes coupling a trunnion brace, a drag brace, and an aft brace of a landing gear assembly housing together to define an opening through the housing. The method also includes coupling a shrink link assembly to the housing such that the shrink link assembly is accessible through the opening.

DETAILED DESCRIPTION

The examples described herein include an aircraft landing gear assembly having an open area that enables maintenance access to components and that also enables direct connection to fixed components of the aircraft. The landing gear assembly described herein includes a housing having a trunnion brace, a drag brace, and an aft brace that together define an opening through the housing. The landing gear assembly also includes a shrink link assembly coupled to the housing such that the shrink link assembly is accessible through the opening. A connecting link of the shrink link assembly extends through the opening in the housing to directly couple a shrink link in the housing to a fixed wing structure. The opening formed in the housing enables a technician to access the shrink links within the housing and also to access an inner cylinder, or oleo strut, which slides within the housing to change the length of the landing gear assembly. Such access allows for simplified maintenance, which reduces the maintenance costs and duration. Furthermore, the opening in the housing enables the direct connection of the connecting link between the shrink links and the wing structure. Such a direct connection simplifies the load path of the shrink link assembly and at least one of increases the service lifetime of the landing gear components and allows for the use of lower weight components, which reduces manufacturing and operating costs.

FIG. 1is a rear view of an exemplary aircraft100illustrating an exemplary landing gear assembly102in a deployed position104illustrated in solid lines and in a retracted position106illustrated in broken lines. In the exemplary implementation, aircraft100is a low-wing aircraft and landing gear assembly102is a wing-mounted assembly. In another implementation, aircraft100includes any wing-configuration and landing gear assembly102may be wing-mounted or fuselage-mounted. In the exemplary implementation, aircraft100includes a fuselage108and a wing110coupled to fuselage108. Aircraft100also includes landing gear assembly102pivotally coupled to wing110such that landing gear assembly102is rotatable about an axis112between the deployed position104when landing gear assembly102is positioned below wing110and the retracted position106when landing gear assembly102is positioned within a landing gear bay114of fuselage108.

In the exemplary implementation, landing gear assembly102includes a wheel assembly116coupled to an inner shaft or inner cylinder118, which is slidably coupled within an outer cylinder or housing120, as described in further detail below. Inner cylinder118is also known as an oleo strut. Housing120is coupled to wing110at axis112. More specifically, housing is coupled between a first wing structure122, such as, but not limited to, a wing spar, and a second wing structure (not shown inFIG. 1). Additionally, landing gear assembly102includes a side brace124coupled between housing120and one of wing110or fuselage108. A connecting link126of landing gear assembly102extends from housing120and is coupled to a third wing structure128, such as, but not limited to, a wing rib.

FIGS. 2-6illustrate landing gear assembly102including housing120and a shrink link assembly130that may be used on aircraft100to enable landing gear assembly102and wheel assembly116to be moved between deployed position104that is sufficiently outboard of fuselage108to meet all stability requirements and, at the same time, enables storage of landing gear assembly102and wheel assembly116within portions of wing110and fuselage108when landing gear assembly102and wheel assembly116are in retracted position106. In particular,FIG. 2is a perspective view of landing gear assembly102illustrating housing120,FIG. 3is an enlarged perspective view of landing gear assembly102illustrating shrink link assembly130,FIG. 4is a side view of landing gear assembly102looking inwardly towards fuselage108,FIG. 5is a cross-sectional side view of landing gear assembly102and shrink link assembly130looking outwardly away from fuselage108, andFIG. 6is a perspective cross-sectional view of housing120taken along line6-6shown inFIG. 4.

In the exemplary implementation, landing gear assembly102includes housing120and shrink link assembly130. As shown inFIGS. 2-6, housing120includes an upper portion132coupled to wing110and a lower portion134coupled about inner cylinder118. More specifically, upper portion132includes a trunnion136, a drag brace138, and an aft brace140that together define an opening142that extends through upper portion132of housing120. In the exemplary implementation, housing120is a single-piece component such that upper portion132and lower portion134are integrally formed. More specifically, trunnion136, drag brace138, and aft brace140are integrally formed together to define opening142. As described in further details herein, shrink link assembly130is coupled to housing120and is accessible through opening142.

As best shown inFIG. 4, drag brace138includes a first distal end144, aft brace140includes a second distal end146, and trunnion136is coupled to and extends between distal ends144and146. Also as shown inFIG. 4, drag brace138and aft brace140extend obliquely away from each other such that drag brace138and aft brace140form a V-shape that at least partially defines opening142therebetween. Additionally, as described herein, trunnion136extends along axis112and is pivotally coupled, at a forward end148of trunnion134, to first wing structure122via a bearing150, and is also pivotally coupled, at an aft end152of trunnion134, to a second wing structure154, such as, but not limited to a wing rib or a landing gear beam, via a bearing156. Landing gear assembly102pivots about axis112and trunnion136to facilitate moving between the deployed position104and the retracted position106.

As best shown inFIG. 5, lower portion134of housing120includes a cylinder portion158that defines a cavity160that is coupled in flow communication with opening142. More specifically, a portion of shrink link assembly130, such as inner cylinder118, is slidably coupled within cavity160such that inner cylinder118is accessible through opening142, as described in further detail herein.

In the exemplary implementation, and as best shown inFIG. 5, shrink link assembly130includes a first link162coupled to aft brace140of housing120, a second link164coupled to first link162, and inner cylinder118coupled to second link164and slidably coupled within with cavity160of cylinder portion158of housing120such that inner cylinder118is accessible through opening142. More specifically, as best shown inFIG. 6where shrink link assembly130is not shown for clarity, aft brace140includes a first sidewall166, an opposing second sidewall168, and a channel170defined therebetween. In the exemplary implementation, at least a portion of shrink link assembly130, and, more specifically, at least first link162, is positioned within channel170. Channel170is open to and coupled in flow communication with opening142and with cavity160such that channel170, opening142, and cavity160combine to form a chamber172within housing120. As best shown inFIG. 3, shrink link assembly130also includes a shaft172coupled to and extending between sidewalls166and168of aft brace140. First link162is pivotally coupled to shaft172to enable shrink link assembly130to move between the deployed position104and the retracted position106, as described herein.

Shrink link assembly130also includes a connecting link174including a first end176coupled to second wing structure128(shown inFIG. 1) and an opposing second end178directly coupled to first link162of shrink link assembly130. In such a configuration, connecting link174extends at least partially through opening142. In the exemplary implementation, connecting link174includes a fixed portion180pivotally coupled to second wing structure128and a rod portion182pivotally coupled to both fixed portion180and first link162. Specifically, rod portion182includes second end178that extends into opening142from outside housing120and is directly coupled to first link162. More specifically, first link162includes a coupling mechanism184integrally formed on first link162that enables direct pivotal connection of rod portion182of connecting link174.

FIGS. 7A-9Billustrate landing gear assembly102during the retraction process after takeoff of aircraft100.FIG. 7Ais a front view of landing gear assembly102in the deployed position104.FIG. 7Bis a side view of landing gear assembly102in the deployed position104.FIG. 8Ais a front view of landing gear assembly102in an intermediate position105.FIG. 8Bis a side view of landing gear assembly102in the intermediate position105.FIG. 9Ais a front view of landing gear assembly102in the retracted position106.FIG. 9Bis a side view of landing gear assembly102in the retracted position106.

As shown inFIGS. 7A and 7B, and as described above, when landing gear assembly102is in the deployed position104, first and second links162and164are positioned within chamber172, and more specifically, within channel170of aft brace140. Connecting link174extends from first link162out of opening142and is coupled to second wing structure128(shown inFIG. 1). More specifically, rod portion182extends from within opening142and is coupled to fixed portion180, which is coupled to second wing structure128.

As landing gear assembly102moves into the intermediate position105, as shown inFIGS. 8A and 8B, housing120and shrink link assembly130rotate about axis112, while connecting link174rotates about a second axis113. More specifically, fixed link180is pivotally coupled to second wing structure128such that fixed portion180moves rotationally only, similar to trunnion136, and does not move translationally with respect to wing110. As housing120and shrink link assembly130rotate about axis112, shrink link assembly130begins to move away from axis113. However, because fixed portion180is fixed to second wing structure128at axis113, and because rod portion182is directly coupled to first link162through opening142, connecting link174pulls up on first link162.

As housing120continues to rotate about axis112toward the retracted position shown inFIGS. 9A and 9B, first link162and second link164rotate independently within opening142. More specifically, first link162pulls up on second link164, which consequently pulls up on inner cylinder118to retract inner cylinder118within cavity160of cylinder portion158of housing120. When inner cylinder118is retracted, wheel assembly116(shown inFIG. 1) has moved towards trunnion136and the overall length of landing gear assembly102is reduced to enable landing gear assembly102to fit within landing gear bay114(shown inFIG. 1) of fuselage108(shown inFIG. 1). As such, connecting link174extends through opening142to directly couple shrink links162and164to second wing structure128to control the position of inner cylinder118within housing120.

The examples described herein include an aircraft landing gear assembly having an open area that enables maintenance access to components and that also enables direct connection to fixed components of the aircraft. The landing gear assembly described herein includes a housing having a trunnion brace, a drag brace, and an aft brace that together define an opening through the housing. The landing gear assembly also includes a shrink link assembly coupled to the housing such that the shrink link assembly is accessible through the opening. A connecting link of the shrink link assembly extends through the opening in the housing to directly couple a shrink link in the housing to a fixed wing structure. The opening formed in the housing enables a technician to access the shrink links within the housing and also to access an inner cylinder, or oleo strut, which slides within the housing to change the length of the landing gear assembly. Such access allows for simplified maintenance, which reduces the maintenance costs and duration. Furthermore, the opening in the housing enables the direct connection of the connecting link between the shrink links and the wing structure. Such a direct connection simplifies the load path of the shrink link assembly and at least one of increases the service lifetime of the landing gear components and allows for the use of lower weight components, which reduces manufacturing and operating costs.