A main landing gear mounting structure and design method

Abstract

The application discloses a main landing gear mounting structure and a design method, and relates to the technical field of aviation equipment. The main landing gear mounting structure comprises a main landing gear retraction and extension actuating cylinder connected with a main landing gear support provided with a main landing gear tire, and the main landing gear retraction and extension actuating cylinder is used for driving the main landing gear support to rotate; a main landing gear actuating cylinder beam; the main landing gear retraction and extension actuating cylinder is arranged on a fixed surface of an upper section of the main landing gear actuating cylinder beam; a lower section of the main landing gear actuating cylinder beam is a bent section; the bent section is provided with a cavity extending in a direction away from the main landing gear retraction and extension actuating cylinder; and the cavity is used for avoiding the main landing gear retraction and extension actuating cylinder. The main landing gear mounting structure and the design method can form the cavity through the arrangement of the bent section, the cavity can avoid the main landing gear retraction and extension actuating cylinder, and the design structure of the bent section has higher bearing efficiency.

Description

Technical Field

[0001] This invention relates to the field of aviation equipment technology, and more specifically, to a main landing gear mounting structure. Furthermore, this invention also relates to a design method for a main landing gear actuation tube beam suitable for the aforementioned main landing gear mounting structure. Background Technology

[0002] With the development of technology, airplanes have become a rigid infrastructure for global spatial and temporal connectivity: their transportation speed is 30 to 50 times faster than sea freight, accounting for 54% of international passenger trips and 35% of the value of time-sensitive goods; in public health and disaster relief, air logistics can deliver emergency supplies to 90% of the world's population within 48 hours; the aviation industry itself contributes 3.5% to global GDP and directly drives high-value industrial chains such as tourism, manufacturing, and electronics.

[0003] Because the fuselage space is often tight, the longitudinal main starter actuation beam is often forced to open to avoid the main starter retraction mechanism. When subjected to large eccentric loads, the conventional I-beam structure has low load-bearing capacity and cannot guarantee structural strength.

[0004] In conclusion, how to improve the structural strength of the main starter beam is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a main landing gear mounting structure, wherein the upper end of the main landing gear actuation cylinder beam is connected to the main landing gear retraction actuation cylinder, and the lower end is provided with a bent section, which can form a cavity extending away from the main landing gear retraction actuation cylinder, and the bent section has a high structural load-bearing efficiency.

[0006] Another object of the present invention is to provide a method for designing a main landing gear mounting structure applicable to the main landing gear mounting structure with a main actuation tube beam.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A main landing gear mounting structure, comprising:

[0009] A main lifting retraction actuator is connected to a main lifting strut equipped with a main lifting tire, and the main lifting retraction actuator is used to drive the main lifting strut to rotate.

[0010] The main lifting and retraction actuating cylinder is located on the fixed surface of the upper section of the main lifting and retraction actuating cylinder. The lower section of the main lifting and retraction actuating cylinder is a bent section. The bent section has a cavity extending in a direction away from the main lifting and retraction actuating cylinder. The cavity is used to avoid the main lifting and retraction actuating cylinder.

[0011] Preferably, the main lifting and retracting actuator includes a left main lifting and retracting actuator and a right main lifting and retracting actuator, and the main lifting actuator beam includes a left main lifting actuator beam and a right main lifting actuator beam, with a reinforcing frame between the left main lifting actuator beam and the right main lifting actuator beam for connecting the two.

[0012] Preferably, it also includes a left main lift strut and a left main lift tire, the left main lift retraction actuator is rotatably connected to the left main lift strut, and the left main lift tire is provided at the end of the left main lift strut opposite to the left main lift retraction actuator.

[0013] Preferably, it further includes a right main starter actuator cylinder and a right main starter tire, wherein the right main starter actuator cylinder is connected to the right main starter retraction actuator cylinder, and the right main starter tire is located at the end of the right main starter retraction actuator cylinder on the side opposite to the right main starter actuator cylinder.

[0014] Preferably, it also includes a left main starting diplomatic point beam and a right main starting diplomatic point beam, wherein the left main starting diplomatic point beam is connected to the left main starting actuation tube beam, and the right main starting diplomatic point beam is connected to the right main starting actuation tube beam.

[0015] Preferably, it also includes a left main starter inner intersection beam and a right main starter inner intersection beam, both of which are located between the left main starter actuating tube beam and the right main starter actuating tube beam.

[0016] Preferably, the main actuating tube beam includes a first vertical rib, a diagonal rib, a transverse rib, a center rib, a second vertical rib, and an arc-shaped rib. The first vertical rib has the diagonal rib at its top end. There are two transverse ribs, which are perpendicular to the first vertical rib and extend in the opposite direction. The center rib is located at the end of the first vertical rib on the side away from the diagonal rib. The fixing surface is located between the center rib and the transverse rib. The second vertical rib is connected to the end of the center rib. The arc-shaped rib is connected to the end of the second vertical rib on the side away from the center rib.

[0017] A design method for a main landing gear mounting structure, applicable to the design of the main landing gear actuation beam in the aforementioned main landing gear mounting structure, the method comprising:

[0018] Step S1: Establish a coordinate system with the intersection of the main lifting and retracting actuator cylinder and the main lifting actuator beam as the center point;

[0019] Step S2: List the mathematical models of the structural schemes;

[0020] Step S3: A preliminary mathematical model is selected based on the intersection position of the main hoisting and retracting actuator cylinder and the main hoisting actuator cylinder beam and the intersection load.

[0021] Step S4: Determine the structural form and dimensions;

[0022] Step S5: Perform strength analysis. If the strength is qualified, the final model is obtained. If the strength is not qualified, return to step S4 and readjust the structural form and dimensions.

[0023] Preferably, before step S3, the method further includes:

[0024] Step S23: Perform topology optimization based on the intersection position of the main lifting and retracting actuator cylinder and the main lifting actuator cylinder beam and the intersection load, so as to adjust the setting of the reinforcing bars near the intersection position.

[0025] Preferably, before step S4, the method further includes:

[0026] Step S34: Design the cross-section by referring to a typical beam.

[0027] The present invention provides a main landing gear mounting structure in which the main landing gear retraction actuator is connected to the main landing gear strut with the main landing gear tire. The main landing gear retraction actuator is connected to the fixed surface of the upper section of the main landing gear actuator beam. The lower end of the main landing gear actuator beam is a bent section, which can form a cavity extending away from the main landing gear retraction actuator. This cavity can avoid the main landing gear retraction actuator. Moreover, the design of the bent section has a higher structural load-bearing efficiency compared with the I-beam structure in the prior art. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the topology optimization results provided by the present invention;

[0030] Figure 2 This is a schematic diagram of the main landing gear mounting structure provided by the present invention.

[0031] Figure 3 A schematic diagram of the forces acting on the main actuating cylinder beam provided by the present invention;

[0032] Figure 4 A schematic diagram of the inertia product calculation formula provided by this invention;

[0033] Figure 5 This is a structural schematic diagram of the main actuation tube beam section provided by the present invention;

[0034] Figure 6 A schematic diagram of the main actuating cylindrical beam avoidance structure provided by the present invention;

[0035] Figure 7 A flowchart illustrating the design method of the main actuating tube beam provided by this invention;

[0036] Figure 8 This is a structural schematic diagram of the left main starter cylinder and the left main starter cylinder beam provided by the present invention;

[0037] Figure 9 for Figure 8 Cross-sectional view at position AA.

[0038] Figure label:

[0039] 1-Left main lifting tire; 2-Left main lifting support; 3-Left main lifting outer point beam; 4-Left main lifting inner intersection beam; 5-Right main lifting inner intersection beam; 6-Right main lifting outer point beam; 7-Strengthening frame; 8-Left main lifting retraction and extension actuation cylinder; 9-Left main lifting actuation cylinder beam; 10-Right main lifting retraction and extension actuation cylinder; 11-Right main lifting tire; 12-Right main lifting actuation cylinder beam; 13-Right main lifting actuation cylinder; 14-Fixed surface; 15-First vertical reinforcement; 16-Diagonal reinforcement; 17-Horizontal reinforcement; 18-Middle reinforcement; 19-Second vertical reinforcement; 20-Arc reinforcement; 21-Main lifting actuation cylinder joint pivot; 22-Middle surface of the web of the actuation cylinder beam. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] The core of this invention is to provide a main landing gear mounting structure in which the lower section of the main actuation beam is a bent section, resulting in high structural load-bearing efficiency.

[0042] Another core aspect of this invention is to provide a method for designing the main lifting actuator beam suitable for the aforementioned main landing gear mounting structure.

[0043] It should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", and "rear" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating the description of this application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0044] This application provides a main landing gear mounting structure, including: a main landing gear retraction and extension actuator cylinder and a main landing gear actuator beam;

[0045] The main lifting retraction actuator is connected to the main lifting strut equipped with the main lifting tire, and the main lifting retraction actuator is used to drive the main lifting strut to rotate.

[0046] The main lifting actuator is located on the fixed surface 14 of the upper section of the main lifting actuator. The lower section of the main lifting actuator is a bent section with a cavity extending away from the main lifting actuator. The cavity is used to avoid the main lifting actuator.

[0047] For details, please refer to the appendix. Figure 2 Appendix Figure 8 With appendix Figure 9 The main lifting retraction actuator is connected to the main lifting support. A rotatable main lifting tire is located at the end of the main lifting support opposite to the main lifting retraction actuator. A fixed surface 14 is provided on the upper section of the main lifting actuator beam, and the main lifting retraction actuator is connected to the fixed surface 14. The lower end of the main lifting actuator beam is a bent section, according to the attached... Figure 5 The structure in the design allows for the formation of a cavity between the bending sections. This cavity is designed to resemble a U-shape, which helps to avoid obstructing the main lifting and retraction actuator. Compared to the I-beam structure used in existing technologies, the bending section design offers superior structural load-bearing efficiency.

[0048] Based on the above embodiment, the main lifting and retracting actuator cylinder includes a left main lifting and retracting actuator cylinder 8 and a right main lifting and retracting actuator cylinder 10, and the main lifting actuator cylinder beam includes a left main lifting actuator cylinder beam 9 and a right main lifting actuator cylinder beam 12. A reinforcing frame 7 is provided between the left main lifting actuator cylinder beam 9 and the right main lifting actuator cylinder beam 12 to realize the connection between the two.

[0049] For details, please refer to the appendix. Figure 2 The left main landing gear retraction and extension actuator 8 and the right main landing gear retraction and extension actuator 10 are respectively set, and the left main landing gear actuator beam 9 and the right main landing gear actuator beam 12 are respectively set. The main landing gear actuator beam provides a stable mounting support for the main landing gear retraction and extension actuator and effectively transfers the retraction and extension load generated by the actuator to the main load-bearing structure of the wing or fuselage. At the same time, it reduces the stress concentration on the connection parts during the operation. The main landing gear retraction and extension actuator is the core actuator in the main landing gear installation structure. Its function is to realize the two key actions of retraction and extension of the main landing gear through hydraulic (or electro-hydraulic) drive, and ensure the reliable conversion of the landing gear between the flight state and the landing state.

[0050] Based on the above embodiment, it also includes a left main lifting strut 2 and a left main lifting tire 1. The left main lifting retraction actuator 8 is rotatably connected to the left main lifting strut 2. The left main lifting strut 2 is provided with a left main lifting tire 1 at the end of the side opposite to the left main lifting retraction actuator 8.

[0051] Specifically, in the main landing gear installation structure, the main landing strut and the main landing tire are two key components that bear the ground load of the aircraft, absorb shocks, and ensure the safety of the taxiing run. The main landing strut is used to bear all the vertical gravity and impact loads of the aircraft when it is parked, taxiing, and landing on the ground, to absorb and buffer energy, and to realize structural connection and force transmission. The main landing tire is used for rolling and taxiing, and converts the concentrated load transmitted from the strut into distributed pressure on the tire-pavement contact surface to prevent the pavement from crushing.

[0052] Based on the above embodiment, it also includes a right main starter actuator cylinder 13 and a right main starter tire 11. The right main starter actuator cylinder 13 is connected to the right main starter retraction actuator cylinder 10, and the right main starter tire 11 is located at the end of the right main starter retraction actuator cylinder 10 on the side away from the right main starter actuator cylinder 13.

[0053] Specifically, the right main lift actuator 13 and the right main lift tire 11 have the same function as the left main lift strut 2 and the left main lift tire 1, which will not be elaborated here. In short, the main lift strut is a "shock-absorbing load-bearing frame", and the main lift tire is a "buffered ground interface". The two work together to stably support the aircraft on the ground.

[0054] Based on the above embodiment, it also includes a left main starting diplomatic point beam 3 and a right main starting diplomatic point beam 6. The left main starting diplomatic point beam 3 is connected to the left main starting actuation tube beam 9, and the right main starting diplomatic point beam 6 is connected to the right main starting actuation tube beam 12.

[0055] Specifically, the left main landing gear outer junction beam 3 and the right main landing gear outer junction beam 6 are located at the connection point on the outside of the main landing gear. They are usually connected to the wing rear spars or auxiliary structures. Their function is to form a closed loop structure with the inner junction beam to enhance the rigidity of the landing gear installation; to share lateral and torsional loads to prevent excessive deformation of the landing gear when it is taxiing on the ground; and to serve as an outer support point to assist the inner junction beam of the main landing gear in completing load transfer and improve the overall structural redundancy.

[0056] Based on the above embodiment, it also includes a left main starter inner intersection beam 4 and a right main starter inner intersection beam 5, both of which are located between the left main starter actuating tube beam 9 and the right main starter actuating tube beam 12.

[0057] Specifically, the left main landing gear inner intersection beam 4 and the right main landing gear inner intersection beam 5 are located at the connection between the main landing gear and the inner side of the wing. They are the main force transmission paths between the main landing gear main shaft and the main load-bearing structure of the wing. Their functions are to bear vertical loads (such as landing impact); transmit longitudinal loads (such as braking and acceleration); transmit lateral loads (such as turning and sideslip); and serve as inner hinge points to restrict the degrees of freedom of the landing gear movement and ensure accurate retraction and extension paths.

[0058] Based on the above embodiment, the main actuating tube beam includes a first vertical rib 15, a diagonal rib 16, a horizontal rib 17, a central rib 18, a second vertical rib 19, and an arc-shaped rib 20. The top of the first vertical rib 15 is provided with a diagonal rib 16, and there are two horizontal ribs 17. The two horizontal ribs 17 are perpendicular to the first vertical rib 15 and extend in the opposite direction. The central rib 18 is located at the end of the first vertical rib 15 on the side away from the diagonal rib 16. The fixing surface 14 is located between the central rib 18 and the horizontal rib 17. The second vertical rib 19 is connected to the end of the central rib 18, and the arc-shaped rib 20 is connected to the end of the second vertical rib 19 on the side away from the central rib 18.

[0059] For details, please refer to the appendix. Figure 5 Taking the central reinforcement 18 as a reference, the upper part of it is the upper section of the main actuating tube beam, and the lower part of it is the lower section of the main actuating tube beam, which is the aforementioned bending section, with attachment Figure 5 With the direction of the center as the reference, the central rib 18 is set horizontally, and its two ends are respectively provided with a first vertical rib 15 and a second vertical rib 19. The first vertical rib 15 and the second vertical rib 19 are both perpendicular to the central rib 18. The top of the first vertical rib 15 is provided with a diagonal rib 16. A horizontal rib 17 is provided on the left and right sides of the first vertical rib 15, and the two horizontal ribs 17 are located in different horizontal planes. The lower end of the second vertical rib 19 is connected to the arc-shaped rib 20. The arc-shaped rib 20, the second vertical rib 19 and the central rib 18 can form the aforementioned cavity, so as to avoid the main lifting and retraction actuator. Compared with the existing I-shaped structure, the arc-shaped rib 20, the second vertical rib 19 and the central rib 18 have better structural bearing efficiency and improved lateral bending stiffness.

[0060] In addition to the main landing gear mounting structure described above, the present invention also provides a design for a main landing gear actuation beam in a main landing gear mounting structure applicable to any of the above embodiments, the method comprising:

[0061] Step S1: Establish a coordinate system with the intersection of the main hoisting and retracting actuator cylinder and the main hoisting actuator cylinder beam as the center point;

[0062] Step S2: List the mathematical models of the structural schemes;

[0063] Step S3: Select a preliminary mathematical model based on the intersection position of the main hoisting and retraction actuator cylinder and the main hoisting actuator cylinder beam and the intersection load;

[0064] Step S4: Determine the structural form and dimensions;

[0065] Step S5: Perform strength analysis. If the strength is qualified, the final model is obtained. If the strength is not qualified, return to step S4 and readjust the structural form and dimensions.

[0066] For details, please refer to the appendix. Figure 7First, a hazardous condition is selected from the main landing gear intersection load conditions. For this main landing gear actuator beam, the hazardous condition is the maximum rebound condition during tail descent. In the body coordinate system, F X It is around 11000M, F Y It is around -115000N, F Z The load is approximately -25000N, with a safety factor of 1.3. Here, X is the left wing pointing towards the right wing, Y is the nose pointing towards the tail, and Z is the belly pointing towards the back. As the load indicates, the main starter actuation cylinder mainly bears concentrated lateral and vertical loads. To ensure direct load transfer and high structural efficiency, given the considerable distance (approximately 50mm) between the main starter actuation cylinder mounting point and the cylinder web, the impact of additional bending moments on the structure must be carefully considered.

[0067] During the design phase, a digital model of the main starting tube beam structure is established based on the initial beam reference plane.

[0068] During the preliminary design phase, the arrangement of ribs near the intersection of the actuator cylinders is adjusted based on the location of the actuator cylinder intersection and the load at the main starter intersection.

[0069] During the detailed design phase, the structural digital model is designed in detail, and the structural type and dimensions are determined. Conventional design usually involves establishing a three-dimensional digital model and a finite element model, and conducting multiple iterations of structural strength testing.

[0070] Finally, the structural strength is analyzed to determine whether the final digital model is suitable. If it is not up to standard, the structural form and dimensions need to be readjusted.

[0071] Based on the above method, before step S3, the following is also included:

[0072] Step S23: Perform topology optimization based on the intersection position of the main hoisting and retracting actuator cylinder and the main hoisting actuator cylinder beam and the intersection load, so as to adjust the setting of the reinforcing bars near the intersection position.

[0073] Specifically, topology optimization is used to guide the arrangement of ribs near the intersection of actuator cylinders. (See attached image) Figure 1 As shown, during topology optimization, the surrounding area and the local joint area are set as non-design domains, while other areas are set as design domains. Fixed constraints are applied to the surrounding edge area, and loads are applied at the joint position according to the maximum rebound condition of the tail sinking. In this way, the rib arrangement of the main starter cylinder joint accessory is obtained. Combined with the topology optimization results and considering the process processing and assembly model design, a more detailed first round of structural design is designed.

[0074] Based on the above method, before step S4, the following is also included:

[0075] Step S34: Design the cross-section by referring to a typical beam.

[0076] Specifically, as shown in the attached document Figure 9 As shown, the distance between the main actuator joint shaft 21 and the mid-surface 22 of the actuator beam web is relatively large, and from the load perspective, the F at the actuator intersection point is... Y Much greater than F X and F Z Assuming the actuated cylindrical beam is constrained on all four sides, the forces it bears are mainly tensile forces in the Y direction and lateral bending moments. (See attached diagram) Figure 3 As shown, the main actuating cylinder beam bears a force F far from the web surface at the intersection point on the actuating cylinder. Y This is equivalent to the main starting tube beam bearing an F near the web. Y 'and a large lateral bending moment M, therefore designers need to focus on increasing the lateral bending stiffness of the structure.

[0077] The lateral bending stiffness is equal to E*I, where E is material-dependent. The calculation principle of the product of inertia I is shown in the attached figure. Figure 4 As shown, the formula for calculating the product of inertia... It is evident that, with the structural materials remaining unchanged, the area furthest from the axis of rotation should be increased as much as possible to improve the bending stiffness of the cross-section. Considering the installation of the main actuator cylinder, the upper half of the original I-beam cross-section is kept stationary, while the web of the lower half can be adjusted. This allows for adjustments to the existing I-beam cross-section and its attachments. Figure 5 Analysis and calculation of the two cross sections show that the transverse bending stiffness of the Z-shaped web beam section is 28572.9 N•m2, while the transverse bending stiffness of the traditional I-beam section is 17843.4 N•m2. The transverse bending stiffness of the Z-shaped web beam section is about 60% higher than that of the traditional I-beam section.

[0078] After completing the design of typical cross-sections, a Z-shaped web-type main starting tube beam structure was obtained, as shown in the appendix. Figure 5 Compared to conventional I-beams, the cross-section of this section exhibits a significant improvement in lateral bending stiffness. Based on this cross-section, the main lifting actuator girder is designed in detail and its digital model is refined. The coordination between the main landing gear and the structure is considered in the structural design process. This coordination mainly includes actuator installation, door joint support installation, door joint motion envelope avoidance, and main lifting actuator motion envelope avoidance, as shown in the attached diagram. Figure 6 As shown.

[0079] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0080] The foregoing has provided a detailed description of the main landing gear installation structure and design method provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are merely for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make various improvements and modifications to the present invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A main landing gear mounting structure, characterized in that, include: A main lifting retraction actuator is connected to a main lifting strut equipped with a main lifting tire, and the main lifting retraction actuator is used to drive the main lifting strut to rotate. The main lifting and retraction actuating cylinder is located on the fixed surface (14) of the upper section of the main lifting and retraction actuating cylinder. The lower section of the main lifting and retraction actuating cylinder is a bent section. The bent section has a cavity extending in a direction away from the main lifting and retraction actuating cylinder. The cavity is used to avoid the main lifting and retraction actuating cylinder. The main actuating tube beam includes a first vertical rib (15), a diagonal rib (16), a horizontal rib (17), a central rib (18), a second vertical rib (19), and an arc-shaped rib (20). The first vertical rib (15) is provided with the diagonal rib (16) at its top. There are two horizontal ribs (17), which are perpendicular to the first vertical rib (15) and extend in the opposite direction. The central rib (18) is located at the end of the first vertical rib (15) away from the diagonal rib (16). The fixed surface (14) is located between the central rib (18) and the horizontal rib (17). The second vertical rib (19) is connected to the end of the central rib (18). The arc-shaped rib (20) is connected to the end of the second vertical rib (19) away from the central rib (18).

2. The main landing gear mounting structure according to claim 1, characterized in that, The main lifting and retracting actuator includes a left main lifting and retracting actuator (8) and a right main lifting and retracting actuator (10). The main lifting actuator beam includes a left main lifting actuator beam (9) and a right main lifting actuator beam (12). A reinforcing frame (7) is provided between the left main lifting actuator beam (9) and the right main lifting actuator beam (12) to realize the connection between the two.

3. The main landing gear mounting structure according to claim 2, characterized in that, It also includes a left main lift support (2) and a left main lift tire (1). The left main lift retraction actuator (8) is rotatably connected to the left main lift support (2). The left main lift support (2) is provided with the left main lift tire (1) at the end of the side away from the left main lift retraction actuator (8).

4. The main landing gear mounting structure according to claim 3, characterized in that, It also includes a right main starter actuator cylinder (13) and a right main starter tire (11), the right main starter actuator cylinder (13) is connected to the right main starter retraction actuator cylinder (10), and the right main starter tire (11) is located at the end of the right main starter retraction actuator cylinder (10) on the side away from the right main starter actuator cylinder (13).

5. The main landing gear mounting structure according to claim 4, characterized in that, It also includes a left main starting diplomatic point beam (3) and a right main starting diplomatic point beam (6), wherein the left main starting diplomatic point beam (3) is connected to the left main starting actuation tube beam (9), and the right main starting diplomatic point beam (6) is connected to the right main starting actuation tube beam (12).

6. The main landing gear mounting structure according to claim 5, characterized in that, It also includes the left main starter inner intersection beam (4) and the right main starter inner intersection beam (5), both of which are located between the left main starter actuating tube beam (9) and the right main starter actuating tube beam (12).

7. A design method for a main landing gear mounting structure, characterized in that, The method applicable to the design of the main landing gear mounting structure according to any one of claims 1 to 6, comprising: Step S1: Establish a coordinate system with the intersection of the main lifting and retracting actuator cylinder and the main lifting actuator beam as the center point; Step S2: List the mathematical models of the structural schemes; Step S3: A preliminary mathematical model is selected based on the intersection position of the main hoisting and retracting actuator cylinder and the main hoisting actuator cylinder beam and the intersection load. Step S4: Determine the structural form and dimensions; Step S5: Perform strength analysis. If the strength is qualified, the final model is obtained. If the strength is not qualified, return to step S4 and readjust the structural form and dimensions.

8. The main landing gear installation structure design method according to claim 7, characterized in that, Before step S3, the following are also included: Step S23: Perform topology optimization based on the intersection position of the main lifting and retracting actuator cylinder and the main lifting actuator cylinder beam and the intersection load, so as to adjust the setting of the reinforcing bars near the intersection position.

9. The main landing gear installation structure design method according to claim 8, characterized in that, Before step S4, the following are also included: Step S34: Design the cross-section by referring to a typical beam.

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