Attachment system, attachment element, receiving element and aircraft

Abstract

The invention provides an attachment system, an attachment element, a receiving element and an aircraft. An attachment system is used to mount a landing gear into a landing gear compartment of an aircraft. The attachment system includes an attachment element configured to be attachable to the landing gear; and a receiving element configured to receive the attachment element and to secure the landing gear within the landing gear compartment. The receiving element is configured such that the attachment element can be inserted into the receiving element from the mounting direction, and the attachment element is configured to receive the fastener in the mounting direction to fasten the attachment element to the receiving element.

Description

Technical Field

[0001] The present invention relates to an undercarriage for an aircraft, and more particularly, to a system for mounting the undercarriage to an undercarriage bay of an aircraft. Background Art

[0002] Mounting an aircraft undercarriage to an undercarriage bay can be a complex and time-consuming process in which the undercarriage is aligned and fastened to the internal structure of the undercarriage bay. The installation of the undercarriage typically requires multiple and often repetitive operations to ensure correct alignment with the aircraft fuselage and may also include the disassembly and reconstruction of various components of the undercarriage. There is a desire to improve the installation of aircraft undercarriages. Summary of the Invention

[0003] A first aspect of the present invention provides an attachment system for mounting an undercarriage to an undercarriage bay of an aircraft. The attachment system includes an attachment element and a receiving element. The attachment element is configured to be attachable to a pivot pin of the undercarriage. The receiving element is configured to receive the attachment element and secure the undercarriage in the undercarriage bay when the attachment element is attached to the pivot pin. The pivot pin is configured to form a rotational connection between the undercarriage and the attachment element, and the receiving element is configured to allow the attachment element to be inserted into the receiving element from an installation direction when attached to the pivot pin. The attachment element is further configured to receive a fastener in the installation direction to fasten the attachment element to the receiving element.

[0004] The insight of the inventors was to recognize the following installation direction, which can be regarded as the general direction in which the undercarriage moves into the undercarriage bay during the installation process, and to recognize the development of an attachment system that is consistent with this installation direction. Typically, the undercarriage bay is oriented downward because, during the assembly of the aircraft, the undercarriage bay faces the ground, and thus, during installation, the undercarriage is typically lifted vertically into the undercarriage bay. Since the attachment element is allowed to be inserted into the receiving element along the installation direction, the attachment system is easily operable during the installation phase, and thus the need for other operations and reorientations for engaging the attachment element with the receiving element can be avoided.

[0005] In addition, since the attachment element is configured to receive the fastener in the installation direction, the attachment element can be fastened to the receiving element in a relatively straightforward manner. For example, the landing gear can be lifted into the landing gear bay in the installation direction, the attachment element is inserted into the receiving element in the installation direction, and the attachment element is fastened to the receiving element in the installation direction. Thus, the installation operations as described above can be performed from the same direction. This can prevent the engineer or the tool itself used in the installation process from needing to be reoriented during the installation process, thereby increasing the installation speed. In addition, this installation operation can reduce the risk of unwanted movement of the landing gear relative to the landing gear bay that may be caused by such movement of the engineer or the tool, thereby increasing the reliability of the installation process and further reducing the time spent in performing the installation process.

[0006] The attachment system can be contrasted with previous methods or systems used to install landing gears, in which the landing gear was lifted into the landing gear bay and then attached to the structure of the landing gear bay by fasteners arranged perpendicular to the installation direction. For example, this may require the operator to reposition, and / or may require the disassembly and subsequent reassembly of components such as pivots, bearing inserts, and receiving brackets to install the landing gear. In contrast, lifting the landing gear into the landing gear bay, engaging the receiving element with the attachment element, and fastening the receiving element to the attachment element can occur in a relatively continuous phase, all of which occur in the installation direction.

[0007] As used herein, the landing gear can be understood as, for example, the lower load-bearing member of an aircraft, and the landing gear facilitates movement along the floor when the aircraft is on the ground. As used herein, the landing gear bay can be understood as a cavity provided in the aircraft fuselage into which the landing gear can be retracted during flight. As used herein, the pivot pin can be understood as, for example, a pivot pin or trunnion that allows rotational movement during the extension and retraction of the landing gear, such as when the landing gear is deployed or retracted into the landing gear bay. As used herein, the receiving element and the attachment element can be understood as a bracket, or a recess, or a mousehole-like portion, or a notch, as the case may be, and the attachment element can be understood as an insert that can be inserted into the receiving element. As used herein, the fastener can be understood as a device that mechanically fixes or connects two or more objects together. For example, the fastener can be understood as including any one or more of nuts, bolts, screws, clamps, straps, anchors, latches, hook-and-loop fasteners, staples, retainers, and rivets.

[0008] Optionally, the attachment element can include a certain shape, and the receiving element can include a corresponding or complementary shape, where the shape can, for example, facilitate easy installation by helping the receiving element and the attachment element to self-align during insertion, or facilitate the distribution of load or force between the receiving element and the attachment element, or both.

[0009] Thus, in some examples, the attachment element can include a tapered portion configured to be inserted into a corresponding draft portion of the receiving element. The tapered portion can refer to a portion including a first width at a first distance along an axis and a second width at a second distance along the axis, the first width being different from the second width. The tapered portion can be, for example, chamfered or beveled. The tapered portion can be a wedge shape. The presence of the tapered portion of the attachment element and the corresponding draft portion of the receiving element can be helpful during insertion of the attachment element into the receiving element. For example, the tapered portion and the corresponding draft portion can act as guides such that, during installation, the attachment element is correctly positioned relative to the receiving element. In this sense, the tapered portion and the corresponding draft portion can cause the attachment element to self-align relative to the receiving element without the need for external assistance, such as from an engineer or a tool. Substantially all parts of the attachment element can be considered tapered, or only individual parts of the attachment element can be considered tapered.

[0010] Thus, in some examples, the attachment element includes a bent portion and the receiving element includes a corresponding bent portion. For example, the bent portion can allow forces experienced by the attachment element to be easily and evenly transferred to the receiving element. The even transfer of forces can reduce the risk of failure of a portion of the receiving element and / or the attachment element due to, for example, overloading, and can thus extend the life of the receiving element and / or the attachment element. Substantially all parts of the attachment element can be considered bent, or only individual parts of the attachment element can be considered bent.

[0011] Thus, in some examples, the bent portion of the attachment element is semi-circular. In other examples, the bent portion can include a large or small segment of a circle such that the bent exterior of the attachment element is an arc of a circle. In other examples, the bent portion can be a major small segment of an ellipse such that the bent exterior of the attachment element is an arc of an ellipse. In an example, the attachment element can include a plurality of bent portions that combine to form a composite structure of the bent portion, such as a combination of semi-circles, for example. The circular shape can allow for improved load transfer from any combination of upward, forward, and backward loads originating from the landing gear.

[0012] The attachment element can be, for example, tapered and bent in different cross-sectional planes. In a first cross-section, the attachment element can have straight sides but still be tapered. In a second cross-section, such as perpendicular to the first cross-section, the attachment element can have curved sides.

[0013] Thus, in some examples, the attachment element includes a flange and the receiving element includes a corresponding groove for receiving the flange, the flange and the groove being configured to distribute forces between the attachment element and the receiving element. In an example, the flange may have a constant thickness and be disposed around the outer surface of the attachment element that engages the receiving element. In other examples, the flange may be disposed at one or more specific portions of the outer surface of the attachment element that engages the receiving element. Similarly, the groove may be disposed around the inner surface of the receiving element for engaging the outer surface of the attachment element, while in other examples, the groove is disposed at one or more specific portions of the inner surface of the receiving element and corresponds to the position of the flange of the attachment element. In an example, the flange and the groove are tapered portions and / or curved portions of the attachment element and the receiving element.

[0014] Optionally, the attachment element further includes a bearing element for receiving a pivot pin of the landing gear. The bearing element can improve the rotational coupling of the pivot pin with the attachment element such that, for example, the landing gear can be deployed and retracted more easily. For example, the bearing element may be a bushing.

[0015] Optionally, the installation direction extends vertically through an opening in the landing gear bay. The landing gear can thereby be lifted directly into the landing gear bay, where the landing gear bay is oriented in the same direction as during normal operation of the aircraft. This can reduce the need to reorient the aircraft during installation.

[0016] Optionally, the receiving element is capable of being attached to a structural element of the landing gear bay. That is, the receiving element is a separate structure relative to the landing gear bay and can be attached to a structural element of the landing gear bay. This can allow for retrofitting, for example, where the receiving element can be attached to a pre-existing landing gear bay and thus the attachment system can be used within a pre-existing aircraft.

[0017] Optionally, in the case where the receiving element is capable of being attached to a structural element of the landing gear bay, the structural element of the landing gear bay is a side panel of the landing gear bay. In other examples, the attachment can be attached to, for example, a rib or a spar.

[0018] Optionally, the receiving element includes a surface for reaming a hole for fastening the receiving element to a structural element of the landing gear bay. This can allow the receiving element to be positioned relative to the structural element and, once correctly positioned, form a hole such that fasteners can be received for fastening the receiving element to, for example, a structural element of the landing gear bay. This can simplify installation by reducing orientation restrictions since the receiving element is positioned more flexibly before fastening.

[0019] Optionally, the attachment system further includes a spacer element that can be disposed between the receiving element and the structural element of the landing gear bay. Such a spacer element can be, for example, a gasket. This can allow the receiving element to be positioned more precisely relative to the structural element of the landing gear bay, such that the landing gear can thus be correctly positioned relative to the landing gear bay.

[0020] Optionally, the receiving element is formed within the structural element of the landing gear bay. That is, the receiving element can be integrally incorporated within the structural element of the landing gear bay, or otherwise incorporated within the volume of the structural element of the landing gear bay. In an example, the receiving element can be a mousehole-like portion, or a recess, or a notch formed in the structural element of the landing gear bay. This can reduce the space occupied by the attachment system, as the receiving element is disposed within the same volume as the structural element of the landing gear bay, which can reduce the space required to install the attachment system into the landing gear bay.

[0021] Optionally, in the case where the receiving element is formed within the structural element of the landing gear bay, the structural element is a side panel of the landing gear bay. In other examples, the structural element can be, for example, a rib or a spar.

[0022] Optionally, the attachment system further includes an aircraft skin portion that can be attached to the attachment element such that when the attachment element is received by the receiving element, the aircraft skin portion is coplanar with the outer skin of the aircraft. A receiving element formed within the structural element of the landing gear bay may involve removing a portion of the outer skin of the aircraft until the landing gear is installed. The corresponding skin portion can be attached coplanarly with the outer skin to thereby extend the outer skin back over the removed portion. This can improve the aerodynamic performance of the outer skin of the aircraft.

[0023] Optionally, the attachment system further includes a load transfer cover that can be attached between the aircraft skin portion and the structural element of the landing gear bay and is configured to distribute loads between the aircraft skin portion and the structural element of the landing gear bay. This can improve the load transfer on the aircraft skin, thereby reducing the risk of damage to the skin due to, for example, excessive loads.

[0024] Optionally, two or more of the attachment element, the receiving element, and the structural element of the landing gear bay are each formed of the same material. The same material can mean, for example, that for each of the attachment element, the receiving element, and the structural element of the landing gear bay, the coefficient of thermal expansion is the same. This can mean that in response to a change in temperature, such as a temperature change experienced due to an increase or decrease in altitude, each of the attachment element, the receiving element, and the structural element of the landing gear bay can expand or contract in the same proportion. This can reduce the risk of causing unwanted strain through a particular element of the landing gear bay, and thereby increase the service life of the attachment system.

[0025] Optionally, the attachment system further includes a retaining element configured to hold the attachment element in an installation orientation relative to the landing gear. This can allow the attachment element to be initially correctly oriented and remain in place during the installation process. For example, before the landing gear is lifted into the landing gear bay, the operator can first align the attachment element relative to the orientation of the receiving element. For example, the retaining element can hold the attachment element in the orientation when the landing gear is lifted into the landing gear bay, such that the attachment element can be received by the receiving element without further orientation adjustment or with only minor orientation adjustment. In an example, the retaining element can be a spring that is connected between the attachment element and the landing gear and is configured to allow a certain degree of movement but still return the attachment element to a specific orientation relative to the landing gear.

[0026] Optionally, when the installation direction extends vertically through the opening of the landing gear bay, the retaining element is a heavy object disposed in the attachment element and configured to hold the attachment element in a vertical orientation.

[0027] Optionally, the attachment system further includes a guiding element that can be disposed on at least one of the attachment element and the retaining element and is configured to assist the attachment element in moving along the installation direction such that the attachment element can be received by the retaining element. For example, the guiding element can be a temporary element that is disposed during the installation process and then removed. The guiding element can be a rod that is disposed on the receiving element and positioned to pass through the fastener receiving portion, for example, once the attachment element is received by the receiving element, the rod is removed and replaced by a fastener. In other examples, the guiding element can be a permanent element but does not serve any other function except guiding the attachment element along the installation direction during the installation process. The guiding element can include, for example, one or more magnets distributed between the receiving element and the guiding element and corresponding magnetic surfaces for attracting the attachment element in a specific direction towards the receiving element and thereby guiding the attachment element to be received by the receiving element.

[0028] A second aspect of the present invention provides an attachment element for attaching a landing gear to a landing gear bay of an aircraft. The attachment element includes: a body configured to be attachable to a pivot pin of the landing gear, the pivot pin forming a rotational connection between the landing gear and the attachment element, the body further configured to be insertable into a receiving element of the landing gear bay along an installation direction; and a receiving portion for a fastener for fastening the body to the receiving element; wherein the receiving portion is configured to receive the fastener from the installation direction.

[0029] A third aspect of the present invention provides a receiving element for mounting a landing gear to a landing gear bay of an aircraft. The receiving element includes a recess configured to receive a body of an attachment element that is attached to a pivot pin of the landing gear. The recess is configured such that the body can be inserted into the recess from an installation direction. The receiving element is configured to receive a fastener for fastening the attachment element to the receiving element, and the receiving element is configured to receive the fastener in the installation direction.

[0030] It will be understood that the benefits previously described for the first aspect of the present invention apply equally to the second and third aspects of the present invention, where applicable.

[0031] A fourth aspect of the present invention provides an aircraft that includes the attachment system of the first aspect, the attachment element of the second aspect, or the receiving element of the third aspect.

[0032] In cases where an attachment system, an attachment element, or a receiving element is included, the landing gear can be installed and removed more directly. Therefore, due to the simplified installation process described above, such an aircraft can be manufactured more quickly. Additionally or alternatively, performing maintenance on the aircraft can be more straightforward, and thus, for example, the operational downtime of the aircraft can be reduced because the landing gear is easier to remove and reinstall. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0034] Figure 1 A schematic side view of an attachment system according to an embodiment of the present invention is shown;

[0035] Figure 2 A schematic view of an attachment system according to an embodiment of the present invention is shown in a front view;

[0036] Figure 3 and Figure 4 A schematic view of an attachment system according to an embodiment of the present invention is shown in a side view;

[0037] Figure 5 A schematic view of an attachment system according to another embodiment of the present invention is shown in a front view;

[0038] Figure 6 and Figure 7 A schematic view of an attachment system according to an embodiment of the present invention is shown;

[0039] Figures 8a to 8f A schematic view of an attachment element and a receiving element according to an embodiment of the present invention is shown;

[0040] Figure 9 and Figure 10A schematic diagram showing a guide element and a retaining element according to an embodiment of the present invention;

[0041] Figure 11a , Figure 11b A schematic diagram showing an aircraft skin and attachment system according to an embodiment of the present invention is shown;

[0042] Figure 12 An aircraft including the attachment system of the present invention is illustrated. DETAILED DESCRIPTION

[0043] Figure 1 An example of an attachment system 100 according to an embodiment of the invention is schematically illustrated.

[0044] First, consider the general purpose of the attachment system 100: the attachment system 100 is used to install the landing gear 20 into the landing gear well 1100 of the aircraft 1000. The attachment system 100 includes an attachment element 150 attached to the landing gear 20 and a receiving element 120 arranged in the landing gear well 1100. The landing gear 20 can be installed by placing the landing gear 20 along the landing gear well 1100. Figure 1 The attachment element 150 is inserted into the receiving element 120 and is fixed by the fastener 130 (in the installation direction indicated by the arrow ID). Figure 1 The receiving element 120 is fastened to the receiving element 120 to fix the landing gear 20 in the landing gear bay 1100. The receiving element 120 and the attachment element 150 are configured so that the attachment element 150 is inserted into the receiving element 120 in the installation direction and the fastener is received in the installation direction. The attachment element 150 is attached to the pivot pin 24 at the end of the portion 22 of the landing gear 20, which is the portion of the landing gear 20 that is usually formed as the attachment point of the landing gear to the landing gear bay, such as, for example, a main fitting or a trailing stay.

[0045] Examples of attachment elements 150 and receiving elements 120 of attachment system 100 will now be described in greater detail.

[0046] Figure 2 The attachment system 100 according to the first embodiment is illustrated in a front view, and Figure 3 The attachment system of the first embodiment is illustrated in side view.In the first embodiment, the receiving element 120 is a separate element from the structure of the landing gear bay 1100 and the receiving element 120 can be arranged on the landing gear bay 1100 by attaching to those structures generally designated 1102 .

[0047] The attachment element 150 includes a body 152. Generally, the body 152 is a load-bearing structure that can be received by the receiving element 120, and the exact shape of the body 152 can vary between examples. The geometry of the body 152 is described relative to the Figure 2 direction axes x, y, z determined in Figure 1 . The y-axis is parallel to the mounting direction depicted in

[0048] , and thus, when the landing gear bay faces downward, the y-axis is the vertical direction. In this example, the body 152 includes a head portion 152a and a foot portion 152b. The head portion 152a is located above the foot portion 152b relative to the y-axis. The geometry of the head portion 152a includes, in this example, a semi-circular portion, a curved portion having a radius of curvature in the x-y plane, and a portion having straight edges and a constant width relative to the x-axis. In other words, the head portion 152a includes an outer surface that includes a curved portion and a portion with straight edges and can be considered arched. The foot portion 152b is adjacent to the head portion and is connected to the portion of the head portion 152a that includes the straight edges such that the semi-circular portion is formed as the distal end of the body 152 relative to the foot portion 152b. Relative to the x-axis, the width of the foot portion 152b is greater than the width of the head portion 152a such that the foot portion 152b includes protruding portions 158 that extend on either side of the width of the head portion 152a. Figure 2 The receiving element 120 includes a recess 122. Generally, the recess 122 is for receiving the attachment element 150, and the receiving element 120 is for supporting the load of the attachment element 150, which, in use, includes the attached landing gear 20. The recess 122 can be considered complementary to the body 152 such that the surface of the recess 122 substantially matches the outer surface of the body 152. In this example, the recess 122 includes a surface that includes a curved portion and a portion with straight edges, and the surface matches the head portion 152a such that when the head portion 152a is inserted into the recess 122 of the receiving element 120, the recess 122 and the head portion 152a of the body 152 form a continuous engagement of the contact surfaces. As observed in

[0049] The leg portion 152b of the body 152 of the attachment element 150 includes a fastener receiving portion 154. In this example, two receiving portions 154 are provided, but more generally, there may be a single receiving portion or multiple receiving portions for use with a corresponding number of fasteners. The fastener receiving portions 154 are through-holes that are aligned in the y-direction, i.e., extend from the leg portion 152b of the body 152 towards the head portion 152a in the mounting direction. The horizontal bottom surface 129 of the receiving element 128 also includes a fastener receiving portion 124. In this example, the fastener receiving portion 124 of the receiving element is a cylindrical bore that extends vertically in the y-axis direction and thus in the mounting direction through the receiving element 120. At the distal end of the fastener receiving portion 124 of the receiving element that is located away from the horizontal bottom surface 129, a barrel nut 126a is disposed within a horizontal bore 126b. A fastener 130, such as a bolt in this example, can be inserted through the fastener receiving portion 154 of the attachment element 150 and the fastener receiving portion 124 of the receiving element 120. When the attachment element 150 is received by the receiving element 120, the fastener 130 is inserted through the fastener receiving portion 154 of the attachment element 150 and the fastener receiving portion 124 of the receiving element 120 and engages with the barrel nut 126a located within the horizontal bore 126b. The fastener receiving portions 154, 124 and the contact surfaces 129, 158 are configured such that the fastener 130 is thereby operative to fasten the attachment element 150 to the receiving element 120. More generally than the specific example illustrated herein, it will be understood that the receiving element 120 and the attachment element 150 include features such as contact surfaces perpendicular to the fastener direction that enable the fastener 130 to secure the receiving element 120 and the attachment element 150 together, thereby preventing their relative movement, and thus the loads on the attachment element 150 and the attached landing gear 20 can be supported by the receiving element 120.

[0050] The landing gear 20 is attached to the attachment element 150 by a pivot pin 24. The pivot pin 20 is disposed at the end of a portion of the landing gear, such as a strut or a pillar, and allows a rotational coupling between the attachment element 150 and the landing gear 20. In various examples, the pivot pin 20 can be considered a trunnion or a pivot, but more generally can be understood to represent a rotational coupling between the landing gear 20 and the attachment system 100, the exact form of which can vary between examples. Generally, the pivot pin 24 is received by an aperture 156a in the body 152 of the attachment element 150. In this example, the aperture 156a includes a bearing 156b that further improves the rotational coupling between the attachment element 150 and the landing gear 20. In other examples, the pivot pin 24 itself can include elements that allow a rotational coupling such that the attachment element 150 itself does not require a bearing.

[0051] In this example, the receiving element 120 further includes a backplate 128. The backplate is used to attach the receiving element 120 to a structural element 1102 of the landing gear bay 1100. The backplate 128 extends away from the recess 122 in the x and y planes to increase the surface area of contact between the receiving element 128 and the structural element 1102. This can allow the load to be distributed over a larger area of the structural element 1102 of the landing gear bay 1100. The surface 129 of the backplate 128 can be used for reaming so that the backplate 128 and thus the receiving element 128 can be fastened to the structural element 1102 of the landing gear bay 1100. In some examples, the backplate 128 can have a thicker portion specifically designated for reaming, while in other examples, all or substantially all of the backplate 128 can be suitable for reaming. In the case of providing a relatively blank surface for reaming, the receiving element can first be accurately aligned relative to the structural element 1102 based on the necessary positioning of the landing gear 20 within the landing gear bay 1100, and then once the alignment occurs, the backplate 128 is reamed to be fastened to the structural element 1102. This can allow for a more precise installation of the landing gear 20.

[0052] In other examples, in addition to or instead of fastening the backplate 128 to the structural member 1102, the use of an adhesive or an alternative fastening mechanism can be utilized. In other examples, the receiving element 120 may not have a backplate 128, but the fastening of the receiving element 120 to the structural element 1102 is provided by, for example, additional fastener receptacles.

[0053] In some examples, the attachment system 100 further includes a spacer element 330 that can be disposed between the receiving element and the structural element 1102. The spacer element can assist in accurately aligning the receiving element 120 relative to the structural element 1102 such that the landing gear 20 is properly positioned within the landing gear bay 1100 once installed. The spacer element 330 can be considered, for example, a shim. For example, the attachment system 100 can include a plurality of spacer elements 330 having different respective thicknesses so that an engineer can select a spacer element 330 of a suitable size for use during installation.

[0054] Figure 4The attachment element 150 is schematically illustrated in a side view. The pivot pin 24 may include a flared end 27 that, when the pivot pin 24 is pulled in a direction out of the aperture 156a, prevents the pivot pin 24 from slipping out of the aperture 156a and the bearing 156b because the flared end 27 is wider than the aperture 156a and the contact surface of the body 152. The flared end 27 may be incorporated within the pivot pin 24 itself or may be a separate attachment that is attached to the end of the pivot pin 24 during installation. Thus, in some examples, the attachment element 150 may be attached to the pivot pin 24 before the pivot pin 24 is attached to the landing gear 20.

[0055] Figure 5 The attachment system 100 according to a second embodiment is illustrated in a front view. In the second embodiment, a receiving element, designated herein as 220, is formed within a structural element, designated as 1104, of the landing gear bay 1100. The attachment element 150 may be the same or substantially similar to those examples described for the first embodiment. Similarly, the structural element 1104 within which the receiving element 220 of the second embodiment is formed may correspond to the structural element 1102 to which the receiving element 120 of the first embodiment is attached. For example, both structural elements 1102, 1104 may be side panels of the landing gear bay.

[0056] In the second embodiment, a recess 222 is formed in the structure 1104 of the landing gear bay 1100. In this example, the structure 1104 is a side panel of the landing gear bay. The recess 222 is a mousehole-like portion formed in the structure 1104. In some examples, the structure 1104 is initially manufactured with the recess 222, while in other examples, an existing structure 1104 is modified to include the recess 222. As described for the first embodiment, the recess 222 is complementary in shape to the body 152 of the attachment element 150. Thus, in this example, the recess 222 is generally arched, but in other examples, the recess 222 may have other shapes depending on the attachment element 150 to be used with it. The structure 1104 also includes a fastener receiving portion 224 for receiving a fastener 130 provided through the fastener receiving portion 154 of the attachment element 150. Corresponding horizontal bores 226a and a barrel nut 126b are provided for engaging the fastener 130.

[0057] Figure 6Schematically illustrates the attachment system 100 of the first embodiment and the attachment system 200 of the second embodiment, with the attachment systems 100 and 200 each in an assembled form, wherein the attachment element 150 is inserted into the receiving elements 120, 220, and the fastener 130 is fastened to fix the attachment element 150 to the receiving elements 120, 220. In this way, the landing gear 20 is attached to the structure 1102 of the landing gear bay 1100 through the attachment system 100. Similarly, the landing gear 20 is attached to the structure 1104 of the landing gear bay 1100 through the attachment system 200. When attached through either attachment system 100, 200, the landing gear 20 is movably coupled to the landing gear bay 1100 such that the landing gear 20 can be reoriented to allow retraction into the stowed position in the landing gear bay 1100 and deployment from the landing gear bay 1100.

[0058] Figure 7 Schematically illustrates the attachment system 100 of the first embodiment and the attachment system 200 of the second embodiment, with both attachment systems 100 and 200 within the field of view of the landing gear bay 1000. Each embodiment can allow the installation of the landing gear 20 in the installation direction, since the attachment element 150 is received by the receiving elements 120, 220 in the installation direction and is subsequently fastened by the fastener 130 ( Figure 7 not shown in the figure). As previously described, the attachment system 100 of the first embodiment is attached to the structural element 1102 and protrudes into the landing gear bay 1100. As previously described, the attachment system 200 of the second embodiment is formed within the structural element 1104, and thus the receiving element 220 can be aligned with the boundary of the landing gear bay. The structural element 1102 of the landing gear bay 1100 described for the first embodiment and the structural element 1102 of the landing gear bay 1100 described for the second embodiment can be the same structural element in other respects except for the previously described differences. For example, both attachment systems 100, 200 can use the side panel of the landing gear bay 1100 as the structural element to which they are fixed or formed.

[0059] In the example, four pairs of attachment elements and receiving elements are used for mounting the landing gear 20. For example, the first attachment element and the second attachment element are attached to the main fitting pivot of the landing gear, and the third attachment element and the fourth attachment element are attached to the drag strut pivot of the landing gear. Each of the main fitting pivot and the cable pivot can be part 22 of the landing gear 20. According to the first embodiment or according to the second embodiment, the first receiving element, the second receiving element, the third receiving element, and the fourth receiving element are correspondingly positioned in the landing gear bay. A mixture of receiving elements can be used. For example, the cable pivot attachment element is received by the receiving element of the first embodiment, and the main fitting pivot attachment element is received by the receiving element of the second embodiment.

[0060] Figures 8a to 8f Illustrated are variants of the attachment element 150 and corresponding variants of the receiving elements 120, 220. These variants apply equally to the first and second embodiments. Those skilled in the art will understand, upon reading the following description of the drawings, how each of the described variants combines with the others such that the illustrated variants do not represent an exhaustive list, but rather each variant highlights a particular feature that may be included in embodiments of the attachment systems 100, 200. Thus, the "first" example is referred to herein Figures 8a to 8f The set of depicted variants is labeled "first" rather than being first in the context of the overall description.

[0061] Figure 8a A side view of a first example of the attachment element body 152-1 is illustrated, where the body 152-1 includes parallel sides. That is, the top and bottom sides of the body 152-1 are parallel, where top and bottom are with reference to the y-axis or the mounting direction. Similarly, the front and rear sides are parallel, where front and rear refer to sides at different positions along the z-axis. Accordingly, a first example of the recess 122-1 of the receiving element 120 also includes parallel sides having the same cross-section, since the recess 122-1 has a shape complementary to the first example of the attachment element body 152-1.

[0062] Figure 8b A side view of a second example of the attachment element body 152-2 is illustrated, where the body 152-2 is tapered. For clarity, the entire body 152-2 is illustrated as tapered in the cross-section presented by Figure 8b but more generally, only a portion of the attachment element body 152-2 may be tapered. Relative to the y-axis or the mounting direction, the thickness of the entire body 152-2 measured between the front and rear sides decreases along the height of the attachment element body 152-2 with respect to the z-axis. The top of the attachment element body 152-2 is narrower than the bottom of the attachment element body 152-2, and the top of the attachment element body 152-2 is the highest point on the z-axis and can be considered to extend farthest into the recess 122 of the receiving element 120. In other words, the attachment element body 152-2 includes opposite sides that are not parallel. Accordingly, a second example of the recess 122-2 correspondingly includes tapered sides having a shape complementary to the second example of the attachment element body 152-2.

[0063] Providing the tapered portion in this way can assist the insertion of the attachment element 150 into the receiving element 120 because the top of the attachment element body 152-2 is narrower than the opening of the recess 122-2 into which the attachment element body 152-2 is inserted, which can make it easier to insert the attachment element body 152-2. Since the recess 122-2 is tapered corresponding to the tapered attachment element body 152-2, a contact interface is formed between the recess 122-2 and the attachment element body 150-2 when the attachment element 150 is fully inserted into the receiving element 120. Forces can be transmitted through this contact interface.

[0064] Figure 8c A third example of the attachment element 150 is illustrated, in which the attachment element body 152-3 is provided with a flange 153. The flange is provided on the top surface of the attachment element body 152-3, but other variations are possible, as illustrated and briefly described by Figure 8e and Figure 8f In the example of Figure 8c , the flange 153 is tapered, but in other examples, the flange 153 can include parallel sides. That is, similar to the tapered profile of the second example of the attachment element body 152-2 in the y-direction or the mounting direction, the thickness of the flange 153 decreases in the front-to-back direction or the z-direction. A third example of the recess 122-3 includes a groove 123 corresponding to the flange 153 such that when the attachment element body 152-3 is inserted into the recess 122-3, the flange 153 is received by the groove 123. For example, the flange can also improve the distribution of forces between the attachment element 150 and the receiving element 120 by reacting to lateral loads applied to the attachment element, and can also act as a confirmation of the correct insertion of the attachment element 150 into the receiving element 120 by ensuring that the attachment element 150 is held away from the receiving element 120 until the flange 153 is inserted into the groove 123.

[0065] Figure 8d A fourth example of the attachment element body 152-4 is illustrated in a front view. For example, compared to the example illustrated in Figures 2 to 6 , the attachment element body 152-4 of Figure 8d does not include a bent portion. Instead, the attachment element body 152-4 includes a tapered profile in the front view. That is, the lateral sides are not parallel with respect to the x-axis, and the thickness changes with respect to the height of the attachment element body 152-4. Similar to the tapered profile described in Figure 8b , in this example in the x-axis direction, towards the top of the attachment element body 152-4, the attachment element body 152-4 is thinner, while towards the bottom of the attachment element 152-4, the attachment element body 152-4 is thicker. In the example, the attachment element body 152 can be tapered in both the x-axis and the y-axis, in other words, combining Figure 8a andFigure 8d features. Although not depicted in Figure 8d , it will be understood that the receiving element is correspondingly tapered to be complementary to the tapered attachment element body 152-4.

[0066] Figure 8e FIG. illustrates a fifth example of the attachment element 150, the attachment element 150 including an attachment element body 152 that is substantially similar to the attachment element body depicted in Figures 2 to 6 , but including a plurality of flange portions 153-a, 153-b, 153-c. The plurality of flange portions are distributed around the outer surface of the attachment element body 152. The first flange portion 153-a is formed on the first lateral side of the attachment element body 152. The second flange portion 153-b is formed on the top side of the attachment element body 152. The third flange portion 153-c is formed on the second lateral side of the attachment element opposite the first lateral side, such that the attachment element body 152 is between the first flange portion 153-a and the third flange portion 152-b. The receiving element 120 (not depicted in Figure 8e ) includes corresponding first, second, and third grooves for receiving the flange portions 153-a to 153-c, respectively. In this configuration, during insertion of the attachment element 150 into the receiving element 120, when the first flange portion 153-a and the third flange portion 153-c are received by their corresponding grooves, the second flange portion 153-b can be guided into position in its receiving groove. This can further improve the convenience of installation. When all of the flanges 153-a to 153-c are received by their corresponding grooves, they can assist in transferring loads between the attachment element and the receiving element. Additionally, in the example of Figure 8e , each flange itself is curved in the x-y plane. This curvature can further assist the flange in being inserted into the groove in a manner similar to that described for the tapered profile in Figures 8b to 8d . In the example, the curved flange may also include a tapered profile, for example, in the front-to-back direction.

[0067] Figure 8f FIG. depicts a fourth example of a flange 153-d that may be provided on the attachment element body 152. In this example, the flange is disposed around most of the attachment element body 152 and may be considered to provide a periphery around the attachment element body 152.

[0068] More generally considering the shapes of the receiving element 120 and the attachment element 150: In some examples, the recess of the receiving element is formed by surfaces in the x-plane and the z-plane such that the inserted attachment element is prevented from moving in the x-direction and the z-direction by the surrounding recess surfaces. In other words, the receiving element encloses the attachment element in the x-direction and the z-direction during insertion of the attachment element, such as Figures 8a to 8cThe example illustrated therein. However, in other examples, the front and rear portions of the attachment element are flush with the front and rear portions of the receiving element, such as Figure 11b as visible in the cross-section of Figure 8c . That is, the front and rear portions of the attachment element are aligned with the front and rear portions of the attachment element with respect to the z-axis. In such an example, movement in the z-axis can be prevented by the presence of flanges and grooves positioned more inwardly with respect to the recess and the attachment element, as described for Figure 8e and Figure 8f . For example, making the front and rear surfaces of the receiving element and the attachment element flush can reduce the space occupied by the attachment system in the z-direction, which can increase the available space in the landing gear bay 1100.

[0069] Figure 9 and Figure 10 illustrate additional elements, which in the example can be provided within the attachment systems 100, 200 to assist in the installation of the landing gear 20.

[0070] In Figure 9 , a counterweight element 160 is provided on the attachment element 150. The attachment element 150, which is movably coupled to the landing gear 20 by the pivot pin 24, can undergo reorientation during the installation of the landing gear 20, such as when the landing gear 20 is lifted into the landing gear bay 1100. The counterweight element 160 is provided to reduce or prevent the reorientation of the attachment element 150 and thereby ensure that the attachment element 150 is directly received by the receiving element 120. For example, the counterweight element 160 can be provided below the connection point formed by the pivot pin 24, the bearing 156b, and the orifice 156a of the attachment element 150. This can lower the center of mass of the attachment element 150 and increase the mass of the attachment element 150, thereby increasing the swing period of the attachment element 150 and enhancing the stability of the attachment element 150 during the installation process. More generally, the counterweight element 160 is provided on the attachment element 150 and is pulled downward by the gravity indicated by the arrow g, thereby ensuring that the attachment element is correctly oriented with respect to the installation direction even if it is assumed that the attachment element is movably connected to the landing gear 20.

[0071] The counterweight element 160 can be regarded as a retaining element that holds the components of the attachment system in a certain orientation such that the attachment element 150 can be inserted into the receiving element 120. In other examples, other examples of retaining elements can be additionally or alternatively provided. For example, a spring can be attached between the landing gear 20 and the attachment element 150. The compressible and expandable spring allows a certain degree of movement of the attachment element 150 relative to the landing gear 20, but returns the attachment element 150 to a neutral position that can be arranged to be aligned with the receiving element 120. This can allow for small adjustments to the attachment element 150 during insertion of the attachment element 150 into the receiving element 120, while preventing or resisting larger reorientations that would prevent the attachment element 150 from being inserted into the receiving element 120.

[0072] In Figure 10 two examples of guiding elements are illustrated.

[0073] In Figure 10 an example of, a pair of magnets 164a, 164b is provided. In Figure 10 the example of, the first magnet 164a in the pair is provided on the receiving element 120, and the second magnet 164b in the pair is provided on the attachment element 150. The first magnet 164a is arranged towards the opening of the recess 122, and the second magnet 164b is provided on the top of the attachment element 150 such that when the attachment element 150 approaches the receiving element 120 for insertion, the first magnet and the second magnet attract each other, and thereby assist in guiding the attachment element 150 into the receiving element 120. In other examples, only one permanent magnet can be provided, and the permanent magnet can be used, for example, to attract magnetic material on a corresponding element. For example, the magnet can be provided on the receiving element, while the attachment element includes a paramagnetic material for attracting the magnet.

[0074] In Figure 10In the example, a pair of guide rods 162a, 162b are provided. The guide rods 162a, 162b are attached to the receiving element 120 and extend in the vertical direction, i.e., the y-direction or the installation direction. For purposes of explanation, two example configurations of the guide rods are presented herein. The first guide rod 162a is positioned such that it can be received by the fastener receiving portion 154. When the guide rod 162a is received by the fastener receiving portion 154, the guide rod 162a is used to guide the attachment element 150 into the receiving element 120. The first guide rod 162a is removable such that once the guiding element 150 is inserted into the receiving element 120, the guide rod 162a can be removed and replaced by the fastener 130 to fasten the attachment element 150 to the receiving element 120. The second guide rod 162b is positioned such that it can be received by a dedicated guide rod receiving portion 166 provided on the attachment element 150. The second guide rod 162b can also be temporary and removed once the attachment element 150 is inserted into the receiving element 120, or the second guide rod 162b can be permanent and its sole purpose is, for example, to guide the attachment element 150 into the receiving element 120 but remains in place once inserted.

[0075] In other examples, magnets can be provided for the guide rod and the receiving portion, for example, to assist the insertion of the guide rod through its corresponding receiving portion.

[0076] Figure 11a and Figure 11b illustrates other features that can be provided to the attachment system 200 of the second embodiment. It will be understood that in an example, directly disposing the receiving element 120 within the structural element 1104 of the landing gear bay 1100 may damage the external aircraft skin 1110. In Figure 11a and Figure 11b 's example, a portion 1111a of the aircraft skin has been removed such that the attachment element 150 can be inserted into the receiving element 120. Thus, after the attachment element 150 is inserted into the receiving element 120, a replacement aircraft skin portion 1111b is provided. The replacement aircraft skin portion 1111b is attached to the bottom of the attachment element 150 such that the replacement aircraft skin portion 1111b is coplanar with the external aircraft skin 1110. This can improve the aerodynamic performance of the aircraft around the landing gear bay area. A skin doubler 1112 can be provided to further strengthen the replacement aircraft skin portion 1111b. A load transfer cover 170 can be provided to be fastened to any one of the external aircraft skin 1110, the replacement aircraft skin portion 1111b, the structural element 1104, and the attachment element 150 and transfer loads therebetween.

[0077] More generally, the attachment system may include other components for locally reinforcing the surrounding structure, such as other structural elements of the landing gear bay, the outer skin of the aircraft, or combinations thereof.

[0078] The receiving element 120 and the attachment element 150 may be formed of metal or composite materials. In some embodiments, the structural elements 1102, 1104 of the landing gear bay 1100 are also formed of the same metal or composite materials.

[0079] Figure 12 An aircraft 1000 is illustrated, which includes a landing gear 20 installed in a landing gear bay 1100 through the attachment systems 100, 200 described herein. Due to the reduced complexity of the installation process, the aircraft 1000 including the attachment systems 100, 200 can be manufactured more quickly. In addition, maintenance of the aircraft 1000 should be required.

[0080] In an example, the attachment systems 100, 200 are provided in the nose landing gear of the aircraft and the attachment systems 100, 200 are attached to the side panels of the nose landing gear bay, or the receiving element 220 is formed within the side panels of the nose landing gear bay.

[0081] The attachment systems 100, 200 described herein may be provided, for example, as a kit of parts, and the attachment elements may be provided, for example, separately from the receiving elements. For example, different attachment elements may be used with the receiving elements, and different receiving elements may be used with the attachment elements. For example, this may allow the selection of attachment elements or receiving elements based on the landing gear or the aircraft. For example, providing the attachment elements and the receiving elements separately may allow replacement attachment elements or receiving elements to be provided for maintenance purposes.

[0082] The above-described embodiments should be understood as illustrative examples of the present invention. Other embodiments of the present invention are contemplated:

[0083] For example, in the above example, the fastener for fastening the attachment element to the receiving element is in the form of a bolt that passes through the attachment element and engages a tubular nut provided in the receiving element. Those skilled in the art will understand that other fasteners can be provided that can be similarly installed and fixed in the installation direction.

[0084] In the above example, fasteners have been provided in the installation direction. However, this does not exclude the provision of other fasteners, such as those used to reinforce the aforementioned fasteners provided in the installation direction when the attachment element is initially fixed by the receiving element.

[0085] It should be understood that any feature described with respect to any one embodiment can be used alone, or in combination with other features described, and can also be combined with one or more features of any other embodiment in the embodiment or any combination of any other embodiments. In addition, equivalents and modifications not described above can also be employed without departing from the scope of the present invention as defined by the appended claims.

[0086] It should be noted that unless otherwise clearly stated, the term "or" as used herein should be understood to mean "and / or".

Claims

1. An attachment system for mounting a landing gear in a landing gear bay of an aircraft, the attachment system comprising: an attachment element configured to be attachable to a pivot pin of the landing gear, the pivot pin forming a rotational coupling between the landing gear and the attachment element; as well as a receiving element configured to receive the attachment element when the attachment element is attached to the pivot pin and secure the landing gear within the landing gear bay; wherein, The receiving element is configured such that the attachment element can be inserted into the receiving element from a mounting direction, and The attachment element is configured to receive a fastener in the mounting direction to secure the attachment element to the receiving element.

2. The attachment system of claim 1, wherein: The attachment member includes a tapered portion configured to be inserted into a corresponding draft portion of the receiving member.

3. An attachment system according to claim 1 or 2, wherein: The attachment element includes a curved portion, and the receiving element includes a corresponding curved portion.

4. The attachment system of claim 3, wherein: The curved portion of the attachment element is semicircular.

5. An attachment system according to any preceding claim, wherein: The attachment element includes a flange and the receiving element includes a corresponding groove for receiving the flange, the flange and the groove being configured to distribute force between the attachment element and the receiving element.

6. An attachment system according to any preceding claim, wherein: The attachment element further comprises a bearing element for receiving the pivot pin of the landing gear.

7. An attachment system according to any preceding claim, wherein: The mounting direction extends vertically through an opening of the landing gear bay.

8. An attachment system according to any preceding claim, wherein: The receiving element is attachable to a structural element of the landing gear bay.

9. The attachment system of claim 8, wherein: The structural element of the landing gear well is a side panel of the landing gear well.

10. An attachment system according to claim 8 or 9, wherein: The receiving element comprises a surface for enlarging a hole for fastening the receiving element to the structural element of the landing gear bay.

11. The attachment system according to any one of claims 8 to 10, further comprising a spacing element arrangeable between the receiving element and the structural element of the landing gear bay.

12. An attachment system according to any one of claims 1 to 7, wherein: The receiving element is formed in a structural element of the landing gear bay.

13. The attachment system of claim 12, wherein: The structural element of the landing gear well is a side panel of the landing gear well.

14. The attachment system of claim 12 or 13, further comprising an aircraft skin portion attachable to the attachment element such that the aircraft skin portion is coplanar with an outer skin of the aircraft when the attachment element is received by the receiving element.

15. The attachment system of claim 14, further comprising a load transfer cover, which is attachable between the aircraft skin portion and the structural element of the landing gear bay and is configured to distribute loads between the aircraft skin portion and the structural element of the landing gear bay.

16. An attachment system according to any one of claims 8 to 15, wherein: The attachment element, the receiving element and the structural element of the landing gear bay are all formed from the same material.

17. An attachment system according to any preceding claim, further comprising a retaining element configured to retain the attachment element in a mounted orientation relative to the landing gear.

18. The attachment system of claim 17, wherein: The retaining element is a weight disposed in the attachment element and configured to retain the attachment element in a vertical orientation.

19. The attachment system according to any of the preceding claims further includes a guide element, which can be set on at least one of the attachment element and the retaining element and is configured to help the attachment element move along the installation direction so that the attachment element can be received by the retaining element.

20. An attachment element for mounting a landing gear in a landing gear bay of an aircraft, the attachment element comprising: a body configured to be attachable to a pivot pin of the landing gear, the pivot pin forming a rotational coupling between the landing gear and the attachment element, the body also configured to be insertable into a receiving element of the landing gear bay in a mounting direction; as well as a receiving portion for a fastener for fastening the body to the receiving element; Wherein, the receiving portion is configured to receive the fastener from the installation direction.

21. A receiving element, the receiving element being used to install a landing gear into a landing gear bay of an aircraft, the receiving element comprising: a recess configured to receive a body of an attachment element attached to a pivot pin of the landing gear, the recess configured such that the body can be inserted into the recess from a mounting direction, The receiving element is configured to receive a fastener for fastening the attachment element to the receiving element, the receiving element being configured to receive the fastener in the mounting direction.

22. An aircraft comprising the attachment system of any one of claims 1 to 19, the attachment element of claim 20 or the receiving element of claim 21.

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