Main landing gear cabin door linkage assembly and aircraft

Abstract

The utility model relates to a main landing gear cabin door linkage assembly and an airplane. The main landing gear cabin door linkage assembly comprises a cabin door assembly which sequentially comprises an upper cabin door, a middle cabin door and a lower cabin door, the first end of the upper cabin door is pivotally connected to an airframe of the aircraft, the cabin door assembly further comprises an upper cabin door connecting rod, the two ends of the upper cabin door are pivotally connected in a pivoted mode, and the middle section of the upper cabin door is pivotally connected to a main landing gear through the upper cabin door connecting rod; the middle door is fixed to the middle section of the outer cylinder of the main landing gear, the first end of the lower door comprises a lower door extension part, the lower door extension part extends towards the middle door and towards the main landing gear, and the middle section of the lower door extension part is pivotally connected to the middle door; and a linkage link assembly pivotally connected at both ends as a whole, the lower door extension being pivotally connected to the middle section of the upper door link via the linkage link assembly such that the lower door follows the stowing and lowering movement of the main landing gear.

Description

Technical Field

[0001] The utility model relates to a main landing gear door linkage assembly, which can follow the retraction and extension processes of the main landing gear. The utility model also relates to an aircraft including the main landing gear door linkage assembly. The utility model belongs to the field of main landing gear structure design. Background Art

[0002] Some aircraft's main landing gears are provided with upper, middle, and lower doors. The lower door corresponds to the axle area of the main landing gear and is used to at least partially shield the tires of the main landing gear.

[0003] The middle door of the main landing gear of these aircraft is fixed on the main landing gear strut; the lower door is hinged to the middle door through a pin shaft and is connected to the side strut of the main landing gear through a connecting rod to realize the linkage retraction and extension with the main landing gear.

[0004] During the retraction process of the main landing gear, the side strut will be folded and retracted. Since the side strut is linked to the lower door through a connecting rod, it will drive the lower door to move together, causing the lower door to move synchronously from the original "open" state to the "retracted" state.

[0005] Due to the limitation of the aircraft space and the form of the landing gear retraction and extension mechanism, during the retraction process of the lower door of the main landing gear of these aircraft, it does not gradually move from the "open" state to the "retracted" state relative to the main landing gear. Instead, in the initial stage, the lower door gradually approaches the main landing gear tire, and after reaching an extreme state, it moves slightly away from the main landing gear tire, and finally moves to the "retracted" position. That is, there is an "over-retraction" phenomenon during the retraction process of the lower door.

[0006] In order to ensure that the minimum clearance requirement between each other is still met when the lower door is closest to the main landing gear tire, it is necessary to reserve sufficient structural clearance between the lower door and the tire. This will result in a gap between the lower door and the main tire greater than the above minimum structural clearance when the main landing gear returns to the "retracted" state. The smaller the clearance between the door components and between the door and the components of the main landing gear, the smoother the aerodynamic shape. Excessive clearance will cause an increase in noise and aerodynamic drag.

[0007] Therefore, there is an urgent need to propose a main landing gear door linkage assembly with a simple structure, small space requirements, and no "over-retraction" phenomenon, which can avoid the situation of excessive clearance between the lower door and the main tire. Summary of the Utility Model

[0008] In view of the above problems in the prior art, the inventor provides a main landing gear door linkage assembly, which can realize the one-way movement of the lower door of the main landing gear during the retraction process of the main landing gear until the lower door reaches the retracted position state.

[0009] In a first example of the main landing gear door linkage assembly, the main landing gear door linkage assembly includes: a door assembly, the door assembly sequentially includes an upper door, a middle door, and a lower door, and in the case where the main landing gear is in the retracted position, the door assembly integrally forms a door for the main landing gear below the main landing gear, wherein a first end of the upper door is pivotally connected to the airframe of the aircraft, and further includes an upper door link, the upper door link is pivotally connected at both ends, and an intermediate section of the upper door is pivotally connected to the main landing gear via the upper door link, so that the upper door follows the retraction movement and the lowering movement of the main landing gear and moves in a follow-up manner, wherein the middle door is fixed to an intermediate section of the outer cylinder of the main landing gear, wherein a lower door extension is included at a first end of the lower door, the lower door extension extends towards the middle door and towards the main landing gear, and an intermediate section of the lower door extension is pivotally connected to the middle door; and a linkage link assembly, the linkage link assembly is pivotally connected at both ends as a whole, and the lower door extension is pivotally connected to an intermediate section of the upper door link via the linkage link assembly, so that the lower door follows the retraction movement and the lowering movement of the main landing gear and moves in a follow-up manner.

[0010] In a second example of the main landing gear door linkage assembly, optionally including the first example, the linkage link assembly includes a linkage link, the linkage link is pivotally connected at both ends as a whole, and the lower door extension is pivotally connected to an intermediate section of the upper door link via the linkage link, so that the lower door follows the retraction movement and the lowering movement of the main landing gear and moves in a follow-up manner.

[0011] In a third example of the main landing gear door linkage assembly, optionally including one or more of the first example and the second example, the linkage link assembly includes a first link, a second link, and a torsion rocker assembly, wherein the first link and the second link are pivotally connected at both ends, and wherein the torsion rocker assembly is pivotally connected to a side of the middle door facing the main landing gear, and the torsion rocker assembly includes a first rocker and a second rocker at a predetermined angle, the first rocker is pivotally connected to an intermediate section of the upper door link via the first link, and the lower door extension is pivotally connected to the second rocker via the second link. The first link and the second link can obtain different movement amplitudes at the torsion rocker assembly.

[0012] In the fourth example of the main landing gear door linkage assembly, optionally including one or more of the first to third examples, the torsion rocker arm assembly includes a torsion shaft in the pivot connection portion with the middle door. The torsion shaft extends perpendicular to the pivot plane of the torsion rocker arm assembly, and the first rocker arm and the second rocker arm are respectively connected to both ends of the torsion shaft. The length of the torsion shaft is such that the second rocker arm can be connected to the lower door extension. The length of the torsion shaft extending perpendicular to the pivot plane of the torsion rocker arm assembly is designed such that the second link can be connected to the lower door extension on the pivot reinforcement of the different lower doors. This enables flexible utilization of the space between the doors, i.e., the main landing gear door linkage assembly and the main landing gear, for the interspersed connection link assembly. Therefore, the design of the connection link assembly is more flexible.

[0013] In the fifth example of the main landing gear door linkage assembly, optionally including one or more of the first to fourth examples, the first rocker arm and the second rocker arm are different connection points on the same rocker arm member. The distances of these two connection points from the pivot connection portion of the torsion rocker arm assembly can be the same or different, and their relative positions are determined according to specific requirements. Therefore, the first link and the second link can obtain different movement amplitudes at the torsion rocker arm assembly.

[0014] An aircraft according to the present invention, wherein the aircraft includes a main landing gear door linkage assembly according to an aspect of the present invention.

[0015] The main landing gear door linkage assembly of the present invention uses the linkage link assembly of the upper door as a driving member to drive the movement of the lower door, ultimately realizing the linkage between the lower door and the main landing gear. And the lower door moves unidirectionally relative to the landing gear during the retraction process of the main landing gear until the lower door reaches the retracted position state. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] To describe the embodiments of the above and other features of the present invention, a more specific description of the present invention briefly described above will be presented with reference to the exemplary embodiments of the present invention shown in the drawings. It can be understood that these drawings only depict the exemplary embodiments of the present invention and should not be considered as limiting its scope. The present invention will be described and explained by using the drawings and additional features and details. In the drawings:

[0017] Figure 1 is a perspective view of the main landing gear door linkage assembly and the main landing gear in the retracted position according to an embodiment of the present invention;

[0018] Figure 2A is Figure 1 a schematic diagram of the mechanism movement in side view of the main landing gear door linkage assembly and the main landing gear in the retracted position;

[0019] Figure 2B is Figure 1 a schematic diagram of the mechanism in side view of the main landing gear door linkage assembly and the main landing gear in the lowered position;

[0020] Figure 3 is a perspective view of the main landing gear door linkage assembly according to another embodiment of the present utility model;

[0021] Figure 4A is Figure 3 a schematic diagram of the mechanism in side view of the main landing gear door linkage assembly and the main landing gear in the stowed position;

[0022] Figure 4B is Figure 3 a schematic diagram of the mechanism in side view of the main landing gear door linkage assembly and the main landing gear in the lowered position; and

[0023] Figure 5 is a perspective view of the main landing gear door linkage assembly according to yet another embodiment of the present utility model.

[0024] The drawings are generally drawn to scale. However, the dimensions in the drawings are only illustrative and do not have to be drawn strictly to scale, but are intended to illustrate more clearly. In other embodiments, other relative dimensions may be used. Throughout this and the following content, the same features appearing in different drawings are denoted by the same or similar reference numerals.

[0025] List of reference numerals:

[0026] 1 Main landing gear door linkage assembly

[0027] 3 Main landing gear

[0028] 100 Door assembly

[0029] 110 Upper door

[0030] 111 Upper door link

[0031] 120 Middle door

[0032] 130 Lower door

[0033] 131 Lower door extension

[0034] 200 Linkage link assembly

[0035] 211 Linkage link

[0036] 221 First link

[0037] 222 Second link

[0038] 223 Torsion Rocker Arm Assembly

[0039] 2231 First Rocker Arm

[0040] 2232 Second Rocker Arm

[0041] 2223 Torsion Shaft Detailed Implementation Modes

[0042] The term "fixed" used herein is intended to describe that one component is connected to another component and can maintain the relative positions of each other unchanged, so that forces, torques, etc. can be transmitted from one component to another component.

[0043] The term "connected" used herein is intended to describe that there is a direct or indirect force transmission path from one component to another component, that is, direct or indirect contact, so that forces, torques, etc. can be transmitted from one component to another component.

[0044] The directional terms used herein, such as "upper part", "lower part", "inner part", "inward", "outer part" and "outward", are used to assist in describing the present utility model according to the directions of the embodiments shown in the drawings. Unless otherwise specified, such as "horizontal direction", "direction of gravity", etc., the directional terms are not absolute up, down, horizontal, vertical, etc., and should not be construed as limiting the present utility model to any specific direction.

[0045] The terms "comprising", "having", "including" and their variants used herein are intended to be open transitional phrases, terms or words, requiring the presence of the specified components / steps, and also allowing the presence of other components / steps.

[0046] In the present utility model, unless explicitly stated to the contrary, the terms "first", "second", etc. are not intended to indicate any difference in order, position, quantity or importance, but are merely used as labels to distinguish different positions and components, for distinguishing one element, component, region and / or position from another element, component, region and / or position.

[0047] In a non-limiting example, the main landing gear door linkage assembly 1 of the present utility model is used for the main landing gear 3 of an aircraft. The main landing gear 3 is pivotally connected to the airframe of the aircraft via the main landing gear mounting portion 4. The main landing gear 3 includes a wheel axle 31 on which the main landing gear tire is mounted. The main landing gear door linkage assembly 1 is linked with the main landing gear 3 to achieve the synchronous retraction or lowering of the door and the main landing gear 3 as a whole.

[0048] In a non - restrictive example, the main landing gear door linkage assembly 1 of the present utility model includes a door assembly 100. The door assembly 100 successively includes an upper door 110, a middle door 120, and a lower door 130, which integrally form a door for the main landing gear 3. The door assembly 100 can transition from a door - closed position to a door - opened position following the main landing gear 3 from a stowed position to a lowered position, and vice versa.

[0049] The upper door 110 includes a first end 110a close to the airframe of the aircraft and a second end 110b close to the middle door 120. The first end 110a of the upper door 110 is pivotally connected to the airframe of the aircraft via an upper - door mounting portion 2, and the second end 110b of the upper door 110 is close to but does not contact the first end 120a of the middle door 120. The gap between the door members is small, so the aerodynamic profile is relatively smooth. Here, the pivot connection portion can be a lug - type connection portion, but is not limited to this, and can also be other connection - portion forms such as a rotating - shaft connection that allows a single rotational degree of freedom.

[0050] The upper door 110 further includes an upper - door link 111, which can be pivotally connected at both ends. The middle section of the upper door 110 can be pivotally connected to the main landing gear 3 via the upper - door link 111. Among them, based on actual needs, the specific connection point at the middle section of the upper door 110 can be designed such that the upper door 110 can follow the stowing movement and lowering movement of the main landing gear 3, and it can be ensured that when the landing gear is in the stowed state, the door assembly 100 is in the door - closed position, where the upper door 110 reaches a predetermined closed position.

[0051] The middle door 120 is fixed to the middle section of the outer cylinder of the main landing gear 3, as shown below with reference to Figure 2A As shown, the section of the main landing gear 3 fixed to the fuselage can be referred to as the outer cylinder, and the retractable and movable section of the main landing gear can be referred to as the inner cylinder. The middle door 120 is fixed to the middle section of the outer cylinder of the main landing gear 3, so that the middle door 120 remains relatively stationary with respect to the main landing gear 3. Thus, in the state of the stowed position of the main landing gear 3, the middle door 120 shields the main landing gear 3 below the middle section of the main landing gear 3.

[0052] At the first end 130a of the lower door 130, there is a lower - door extension 131, which extends towards the middle door 120 and towards the main landing gear 3, and the middle section of the lower - door extension 131 is pivotally connected to the middle door 120.

[0053] Generally, the lower door extension 131 can be a part of the rocker arm of the lower door 130, which is used to keep the central axis of the linkage link 211 or the second link 222 of the linkage link assembly 200 described below at a predetermined distance from the rotation axis of the lower door 130 pivotally fixed to the middle door 120, so as to meet the needs of the overall mechanism movement of the main landing gear door linkage assembly, that is, to make the lower door 130 follow the retraction movement and lowering movement of the main landing gear 3. It can be understood that its specific form is not limited to the illustration shown.

[0054] In a non-limiting example, the main landing gear door linkage assembly 1 of the present utility model includes a linkage link assembly 200, which is pivotally connected at both ends as a whole. The lower door extension 131 can be pivotally connected to the middle section of the upper door link 111 via the linkage link assembly 200, so that the lower door 130 follows the retraction movement and lowering movement of the main landing gear 3.

[0055] The present utility model will be further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description for a full understanding of the present utility model. However, the present utility model can obviously be implemented in many other ways different from this description. Those skilled in the art can make similar generalizations and deductions according to the actual application situation without departing from the connotation of the present utility model. Therefore, the protection scope of the present utility model should not be limited by the content of this specific embodiment.

[0056] Figure 1 A perspective view of the main landing gear door linkage assembly 1 and the main landing gear 3 in the installed state according to an embodiment of the present utility model is schematically shown, where the main landing gear 3 is shown in dashed lines to avoid obscuring the main landing gear door linkage assembly 1. The door assembly 100 sequentially includes an upper door 110, a middle door 120, and a lower door 130, which integrally form a door for the main landing gear 3 below the main landing gear 3.

[0057] As Figure 1 shown, when the main landing gear 3 is in the retracted position, the door assembly 100 integrally forms a door below the main landing gear 3. Specifically, the middle door 120 is kept below the middle section of the main landing gear 3, and the lower door 130 is kept below the axle 31 of the main landing gear 3.

[0058] Preferably, the lower door 130 is pivotally connected to the second end 120b of the middle door 120 through its shaft reinforcing rib, and at this time, the lower door extension 131 is integrated with the shaft reinforcing rib of the lower door 130. For example, as Figure 1 shown, the lower door extension 131 starts from the one closest to Figure 1The reinforcing rib of the right lower rotating shaft faces the main landing gear 3 and extends a predetermined distance towards the middle cabin door 120.

[0059] In this example, the linkage rod assembly 200 includes a linkage rod 211 which is pivotally connected at both ends. The lower cabin door extension 131 is pivotally connected to the middle section of the upper cabin door link 111 via the linkage rod 211. The connection point of the middle section of the upper cabin door link 111 is designed such that the lower cabin door 130 follows the retraction movement and the lowering movement of the main landing gear 3.

[0060] In Figure 2A and Figure 2B schematically shows Figure 1 the mechanism kinematic diagrams of the main landing gear door linkage assembly 1 and the main landing gear 3 in the retracted position and in the lowered position.

[0061] Figure 3 Schematically shows a perspective view of the main landing gear door linkage assembly according to another embodiment of the present invention. Among them, the door assembly 100 is similar to the example described above Figure 1 and will not be described again for the sake of brevity.

[0062] In this example, the linkage rod assembly 200 includes a first link 221, a second link 222 and a torsion rocker arm assembly 223.

[0063] The first link 221 and the second link 222 are pivotally connected at both ends. Here, the pivot connection part can be a pin shaft connection part, but is not limited thereto, and can also be other connection part forms allowing a single rotational degree of freedom.

[0064] The torsion rocker arm assembly 223 is pivotally connected to the side of the middle cabin door 120 facing the main landing gear 3. Specifically, in Figure 3 it is the top of the middle cabin door 120.

[0065] The torsion rocker arm assembly 223 includes a first rocker arm 2231 and a second rocker arm 2232 at a predetermined angle. The first rocker arm 2231 is pivotally connected to the middle section of the upper cabin door link 111 via the first link 221, and the lower cabin door extension 131 is pivotally connected to the second rocker arm 2232 via the second link 222.

[0066] In Figure 3The medium torsion arm assembly 223 includes a torsion shaft 2223 in the pivotal connection portion with the medium hatch 120. The torsion shaft 2223 extends perpendicular to the pivotal plane of the torsion arm assembly 223. The first arm 2231 and the second arm 2232 are respectively connected to both ends of the torsion shaft 2223. The length of the torsion shaft 2223 is such that the second arm 2232 can be connected to the lower hatch extension 131. Here, the distances between the pivotal connection portions of the first arm 2231 and the second arm 2232 and the torsion shaft 2223 can be the same or different, and their relative positions are determined according to specific requirements. Therefore, the first link 221 and the second link 222 can obtain different movement amplitudes at the torsion arm assembly 223.

[0067] Preferably, the length of the torsion shaft 2223 extending perpendicular to the pivotal plane of the torsion arm assembly 223 is designed such that the second link 222 can be connected to the lower hatch extension 131 on the shaft reinforcing rib of different lower hatches 130. This can flexibly utilize the space between the hatch, i.e., the main landing gear hatch linkage assembly 1 and the main landing gear 3 for the interpenetration of the linkage rod assembly 200. Therefore, the design of the linkage rod assembly 200 is more flexible.

[0068] Figure 4A Schematically shows Figure 3 the mechanism kinematic diagram of the main landing gear hatch linkage assembly and the main landing gear in the retracted position. Figure 4B Schematically shows Figure 3 the mechanism kinematic diagram of the main landing gear hatch linkage assembly and the main landing gear in the lowered position.

[0069] Figure 5 Schematically shows a perspective view of the main landing gear hatch linkage assembly according to another embodiment of the present invention.

[0070] The torsion arm assembly 223 similarly includes a first arm 2231 and a second arm 2232 at a predetermined angle. The first arm 2231 is pivotally connected to the middle section of the upper hatch link 111 via the first link 221, and the lower hatch extension 131 is pivotally connected to the second arm 2232 via the second link 222.

[0071] In Figure 5 the first arm 2231 and the second arm 2232 of the medium torsion arm assembly 223 are different connection points on the same arm member. The distances between these two connection points and the pivotal connection portion of the torsion arm assembly 223 can be the same or different, and their relative positions are determined according to specific requirements. Therefore, the first link 221 and the second link 222 can obtain different movement amplitudes at the torsion arm assembly 223.

[0072] Above, for the purpose of making the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions of the present utility model have been clearly and completely described in combination with the specific embodiments and drawings of the present utility model.

[0073] Although various embodiments have been described above, it should be understood that the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments, and they are presented by way of example rather than limitation. It will be obvious to those skilled in the relevant art that the disclosed subject matter can be implemented in other specific forms without departing from its spirit and essential features.

[0074] In the process, various elements important to the present utility model or elements conducive to the further development of the present utility model will be mentioned in the content of specific examples. However, some of these elements can also be used for the further development of the present utility model when separated from the content of the corresponding examples and other features of the corresponding examples. Therefore, the embodiments described above are considered to be exemplary rather than restrictive in all aspects and do not serve as a basis for any limitation to the present utility model.

[0075] Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present utility model. The present disclosure also includes various variations and variations within the equivalent scope. In addition, various combinations, methods, further including only one element, other combinations, methods of more than one or less than one also fall within the scope and thinking scope of the present disclosure.

Claims

1. A main landing gear door linkage assembly for the main landing gear (3) of an aircraft, characterized in that, The main landing gear door linkage assembly (1) includes: A door assembly (100), the door assembly (100) sequentially includes an upper door (110), a middle door (120) and a lower door (130), and when the main landing gear (3) is in the retracted position, the door assembly (100) integrally forms a door for the main landing gear (3) below the main landing gear (3). Wherein, a first end of the upper door (110) is pivotally connected to the airframe of the aircraft, and further includes an upper door link (111), the upper door link (111) is pivotally connected at both ends, and an intermediate section of the upper door (110) is pivotally connected to the main landing gear (3) via the upper door link (111), so that the upper door (110) follows the retraction movement and lowering movement of the main landing gear (3). Wherein, the middle door (120) is fixed to an intermediate section of the outer cylinder of the main landing gear (3). Wherein, a lower door extension (131) is included at a first end of the lower door (130), the lower door extension (131) extends towards the middle door (120) and towards the main landing gear (3), and an intermediate section of the lower door extension (131) is pivotally connected to the middle door (120); and A linkage link assembly (200), the linkage link assembly (200) is pivotally connected at both ends as a whole, and the lower door extension (131) is pivotally connected to an intermediate section of the upper door link (111) via the linkage link assembly (200), so that the lower door (130) follows the retraction movement and lowering movement of the main landing gear (3).

2. The main landing gear door linkage assembly according to claim 1, characterized in that The linkage link assembly (200) includes a linkage link (211), the linkage link (211) is pivotally connected at both ends, and the lower door extension (131) is pivotally connected to an intermediate section of the upper door link (111) via the linkage link (211).

3. The main landing gear door linkage assembly according to claim 1, characterized in that The linkage link assembly (200) includes a first link (221), a second link (222) and a torsion rocker arm assembly (223). Wherein, the first link (221) and the second link (222) are pivotally connected at both ends, and Wherein, the torsion rocker arm assembly (223) is pivotally connected to a side of the middle door (120) facing the main landing gear (3), and the torsion rocker arm assembly (223) includes a first rocker arm (2231) and a second rocker arm (2232) at a predetermined angle, the first rocker arm (2231) is pivotally connected to an intermediate section of the upper door link (111) via the first link (221), and the lower door extension (131) is pivotally connected to the second rocker arm (2232) via the second link (222).

4. The main landing gear door linkage assembly according to claim 3, wherein the torsion rocker arm assembly (223) includes a torsion shaft (2223) in the pivot connection portion with the middle door (120), the torsion shaft (2223) extends perpendicular to the pivot plane of the torsion rocker arm assembly (223), and the first rocker arm (2231) and the second rocker arm (2232) are respectively connected to both ends of the torsion shaft (2223), and the length of the torsion shaft (2223) enables the second rocker arm (2232) to be connected to the lower door extension (131).

5. The main landing gear door linkage assembly according to claim 3, wherein the first rocker arm (2231) and the second rocker arm (2232) are different connection points on the same rocker arm member.

6. An aircraft, characterized in that, The aircraft includes the main landing gear door linkage assembly (1) according to any one of claims 1-5.

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