Semi-rocker arm type main landing gear structure of eVTOL aircraft

Abstract

The invention relates to the technical field of electric vertical take-off and landing aircrafts, and discloses an eVTOL aircraft semi-rocker arm type main landing gear structure which is fixedly installed below an aircraft body structure and comprises a main landing beam, an oil gas shock absorber, a rocker arm, a wheel shaft, aircraft wheels and hinge bolts. One end of the main lifting beam is fixedly connected with the machine body structure, the other end of the main lifting beam is hinged to the rocker arm through a hinge bolt, the machine wheel is installed at the end, away from the main lifting beam, of the rocker arm through a horizontally-arranged wheel shaft, and the two ends of the oil-gas shock absorber are hinged between the main lifting beam and the rocker arm through hinge bolts. The airplane wheel is vertically arranged, the straight line where the length direction of the oil-gas shock absorber is located and the straight line where the length direction of the rocker arm is located are located in the same plane perpendicular to the horizontal plane, and the hinge point between the main lifting beam and the rocker arm is located in the plane. The invention not only can meet necessary functions and safety requirements, but also has the characteristics of simple structure, easiness in manufacturing, high impact resistance, high energy absorption capacity and the like.

Description

Technical Field

[0001] The present invention relates to the field of electric vertical take-off and landing aircraft, and in particular to a semi-rocker main landing gear structure for an eVTOL aircraft. Background Art

[0002] In recent years, eVTOL (electric vertical take-off and landing) vehicles have become a leading urban air mobility solution, leveraging their environmentally friendly nature and minimal infrastructure dependence. The landing gear, a key component of an aircraft, works together with tires and shock absorbers to reduce the impact forces between the aircraft and the ground to a level below which the structure can withstand during takeoff and landing, ensuring safe takeoff and landing. The main landing gear of currently deployed 1-2 ton general-purpose aircraft generally utilizes steel leaf springs in conjunction with tires for impact resistance and shock absorption. This simple structure withstands heavy loads, absorbing impact energy through elastic deformation of the leaf springs, meeting the requirements for safe flight and operation.

[0003] However, the main landing gear with a leaf spring structure also has many shortcomings. For example, the leaf spring deforms elastically and has low efficiency in absorbing impact energy. In order to absorb enough energy, the leaf spring needs to deform a lot, which also requires a sufficient leaf spring length, resulting in a heavy structural weight. When the aircraft lands, the leaf spring bends upward, causing the wheel to roll forward on the ground while being forced to slide outward, causing greater wear on the tire. The leaf spring has high requirements for heat treatment and processing technology of the steel plate raw materials, otherwise it is easy to fail to meet the design indicators. After the leaf spring is elastically deformed, the elastic recovery process is very fast, which imposes a large overload on the aircraft body and poor occupant comfort. Therefore, the main landing gear with a leaf spring structure needs to be improved. Summary of the Invention

[0004] In response to the problems existing in the prior art: the existing leaf spring structure of the main landing gear structure is heavy, has low impact energy absorption efficiency, and poor occupant comfort. The purpose of the present invention is to provide an eVTOL aircraft semi-rocker main landing gear structure that can not only meet the necessary functional and safety requirements, but also has the characteristics of simple configuration, easy manufacturing, strong impact resistance and energy absorption capacity, and meets the safety, comfort, economy and other requirements required for long-term operation of the aircraft.

[0005] To achieve the above object, the technical solution of the present invention is:

[0006] A semi-rocker main landing gear structure for an eVTOL aircraft is fixedly installed below the fuselage structure. The landing gear structure includes a main lifting beam, an oil-gas shock absorber, a rocker arm, an axle, a wheel and an articulation bolt. One end of the main lifting beam is fixedly connected to the fuselage structure, and the other end is hinged to the rocker arm by an articulation bolt. The wheel is installed on the end of the rocker arm away from the main lifting beam through a horizontally arranged axle. The two ends of the oil-gas shock absorber are respectively hinged between the main lifting beam and the rocker arm by articulation bolts; the wheel is vertically arranged, and the straight line in the length direction of the oil-gas shock absorber and the straight line in the length direction of the rocker arm are located in the same plane perpendicular to the horizontal plane, and the hinge point between the main lifting beam and the rocker arm is located in this plane.

[0007] The present invention is further configured as follows: the main lifting beam is arranged obliquely, and the end of the main lifting beam connected to the body structure is higher than the end of the main lifting beam hinged to the rocker arm.

[0008] The present invention is further configured as follows: the hinged joint between the main lifting beam and the rocker arm is vertically arranged, and the hinged bolts between the main lifting beam and the rocker arm are always parallel to the horizontal plane.

[0009] The present invention is further configured such that the hinge point between the oil-gas shock absorber and the main lifting beam, the hinge point between the oil-gas shock absorber and the rocker arm, and the hinge point between the main lifting beam and the rocker arm form a triangle.

[0010] The present invention is further configured such that the angle between the straight line formed by the hinge point between the oil-gas shock absorber and the main lifting beam and the hinge point between the main lifting beam and the rocker arm and the straight line formed by the hinge point between the oil-gas shock absorber and the rocker arm and the hinge point between the main lifting beam and the rocker arm is an obtuse angle in a natural state.

[0011] The present invention is further configured such that the side of the rocker arm in contact with the oil-gas shock absorber is recessed in a direction away from the oil-gas shock absorber.

[0012] The present invention is further configured as follows: the body structure includes a left longitudinal beam and a right longitudinal beam, and the two main lifting beams are fixedly connected to the left longitudinal beam and the right longitudinal beam respectively.

[0013] The present invention is further configured as follows: the body structure further includes a longitudinal beam joint fixed between the left longitudinal beam and the right longitudinal beam.

[0014] The present invention is further configured as follows: the main lifting beam, rocker arm and wheel axle are all parts of steel structures.

[0015] The present invention is further configured such that: the longitudinal beam joint is a part made of aluminum alloy material.

[0016] In summary, the beneficial effects achieved by the present invention are as follows:

[0017] (1) When the aircraft lands, the impact load is transmitted from the wheel along the axle, rocker arm and oil-gas shock absorber to the main lifting beam and finally to the fuselage structure. The load transfer path is simple and clear, and the weight of the entire landing gear structure is low;

[0018] (2) The landing gear structure is simple in design and configuration, with low design and manufacturing costs; the number of parts is small, the assembly difficulty is low, and maintenance is easy;

[0019] (3) The landing gear structure uses oil-gas shock absorbers, which have high efficiency in absorbing impact energy, good buffering performance, small overload transmitted to the aircraft body, and high passenger comfort;

[0020] (4) During the take-off and landing process, the wheels always remain perpendicular to the ground, no lateral slippage occurs, the tires are not easy to wear, and the service life is long. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments described in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0022] Figure 1 This is a front view of the semi-rocker main landing gear structure of the eVTOL aircraft in the present invention;

[0023] Figure 2 A top view of the semi-rocker main landing gear structure of the eVTOL aircraft in the present invention;

[0024] Figure 3 This is a side view of the semi-rocker main landing gear structure of the eVTOL aircraft in the present invention;

[0025] Figure 4 for Figure 1 Sectional view on plane AA.

[0026] In the figure: 1. Airframe structure; 11. Front frame; 12. Rear frame; 13. Left longitudinal beam; 14. Right longitudinal beam; 15. Longitudinal beam joint; 2. Landing gear structure; 21. Main lifting beam; 22. Oil-gas shock absorber; 23. Rocker arm; 24. Axle; 25. Wheel; 26. Articulated bolt. DETAILED DESCRIPTION

[0027] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. For ease of explanation, the terms "vertical", "horizontal", "left", "right", "up", "down", "inside", "outside", "bottom", etc. used in this specification to indicate the orientation or position relationship are based on the orientation or position relationship shown in the drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limiting this application.

[0028] It should be noted that the embodiments of the present invention and the features involved in the embodiments can be combined with each other without conflict. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0029] As attached Figure 1-4 As shown, a semi-rocker main landing gear structure of an eVTOL aircraft is fixedly installed under a fuselage structure 1, wherein the fuselage structure 1 includes a front frame 11, a rear frame 12, a left longitudinal beam 13, a right longitudinal beam 14 and a longitudinal beam joint 15.

[0030] The length direction of the left longitudinal beam 13 and the right longitudinal beam 14 is the same as the heading of the aircraft, that is, Figure 1 The left longitudinal beam 13 and the right longitudinal beam 14 are parallel to each other and are located on the left and right sides of the fuselage (i.e. Figure 1 The Y direction is the vertical height direction, and the Z direction is the vertical height direction), which is used to enhance the structural strength of the fuselage.

[0031] The front frame 11 is located at the front of the fuselage, and the rear frame 12 is located at the rear of the fuselage. In this embodiment, the front frame 11, rear frame 12, left longitudinal beam 13, and right longitudinal beam 14 are all made of lightweight and high-strength composite materials and are fixed to each other by bonding, thereby achieving a weight reduction effect while maintaining the structural strength of the fuselage.

[0032] The longitudinal beam joint 15 is fixed horizontally between the left longitudinal beam 13 and the right longitudinal beam 14. It provides support and improves the structural rigidity between the left and right longitudinal beams 13 and 14. In this embodiment, the longitudinal beam joint 15 is made of aluminum alloy, which also features light weight and high strength. The longitudinal beam joint 15 is fixed to both the left and right longitudinal beams 13 and 14 via bolts.

[0033] The main landing gear arranged below the fuselage structure 1 includes two symmetrical landing gear structures 2. Each landing gear structure 2 includes a main beam 21, an oil-gas shock absorber 22, a rocker arm 23, an axle 24, a wheel 25 and a hinge bolt 26.

[0034] The main lifting beam 21 is tilted, with one end fixedly connected to the airframe structure 1 and the other end hinged to the rocker arm 23 via a hinge bolt 26. The end of the main lifting beam 21 connected to the airframe structure 1 is higher than the end hinged to the rocker arm 23. The end faces of the two main lifting beams 21 are fixedly connected to the left and right longitudinal beams 13 and 14, respectively, via bolts. At the hinged joint between the main lifting beam 21 and the rocker arm 23, the rocker arm 23 can rotate within a certain angle around the axis of the hinge bolt 26.

[0035] The hinge between the main lifting beam 21 and the rocker arm 23 is vertically arranged to ensure that the length direction of the hinge bolt 26 between the main lifting beam 21 and the rocker arm 23 is always parallel to the horizontal plane during the take-off and landing of the aircraft.

[0036] The oil-gas shock absorber 22 is a conventional device and comprises a piston rod and an outer tube. The piston rod slides inside the outer tube to bear the load and absorb the impact energy. The ends of the oil-gas shock absorber 22 are respectively hinged between the main lifting beam 21 and the rocker arm 23 by hinge bolts 26.

[0037] The rocker arm 23 is a crescent-shaped plate structure. The side of the rocker arm 23 that contacts the oil-gas shock absorber 22 is recessed away from the oil-gas shock absorber 22, thereby preventing interference with the rocker arm 23 when relative sliding occurs between the piston rod and the outer tube of the oil-gas shock absorber 22.

[0038] In the present invention, the straight line along the length of the oil-gas shock absorber 22 and the straight line along the length of the rocker arm 23 lie in the same plane perpendicular to the horizontal plane, and the hinge point between the main lifting beam 21 and the rocker arm 23 also lies in this plane. Therefore, the hinge point between the oil-gas shock absorber 22 and the main lifting beam 21, the hinge point between the oil-gas shock absorber 22 and the rocker arm 23, and the hinge point between the main lifting beam 21 and the rocker arm 23 form a triangle, and the plane in which this triangle lies is perpendicular to the horizontal plane. Furthermore, the angle between the straight line formed by the hinge point between the oil-gas shock absorber 22 and the main lifting beam 21, the hinge point between the main lifting beam 21 and the rocker arm 23, the hinge point between the oil-gas shock absorber 22 and the rocker arm 23, and the hinge point between the main lifting beam 21 and the rocker arm 23 is an obtuse angle in its natural state, that is, when the landing gear is not bearing any load. That is to say, when the landing gear is not under load, the oil-gas shock absorber 22 is in an extended state, and the angle between the main lifting beam 21 and the rocker arm 23 is large; when the aircraft lands, the oil-gas shock absorber 22 is compressed to absorb the impact load, and at the same time the angle between the main lifting beam 21 and the rocker arm 23 becomes smaller.

[0039] The wheel 25 is mounted on the end of the rocker arm 23 away from the main lifting beam 21 through the horizontally arranged wheel shaft 24. The wheel 25 is vertically arranged, and the rolling direction of the wheel 25 is the auxiliary Figure 1 The X direction in .

[0040] In this embodiment, the main lifting beam 21, the rocker arm 23 and the wheel axle 24 are all parts made of high-strength steel structures to meet the load-bearing requirements when the aircraft lands.

[0041] The implementation principle of the above embodiment is:

[0042] During landing, the wheels 25 first contact the ground. Compressed and deformed, they absorb and dissipate some of the impact energy, while the majority of the load is transferred through the wheels 25 and axle 24 to the rocker arms 23. Under the action of the vertical upward load and bending moment, the angle between the main lifting beam 21 and the rocker arms 23 decreases, compressing the hydro-pneumatic shock absorbers 22 and absorbing a significant portion of the impact load. Ultimately, the load is transferred to the integral load-bearing structure comprised of the longitudinal beam joints 15, the left longitudinal beam 13, and the right longitudinal beam 14, and then diffused to the rear frame 12 and the front frame 11, resulting in a simple and clear load transfer path. In particular, throughout the landing process, while the hydro-pneumatic shock absorbers 22 undergo telescopic deformation and the rocker arms 23 rotate a certain angle relative to the main lifting beam 21, the wheels 25 remain perpendicular to the ground, preventing lateral slippage. This reduces tire wear and extends the tire's service life.

[0043] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they are aware of the basic inventive concepts. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the invention. Thus, the present invention is intended to include such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A semi-rocker main landing gear structure for an eVTOL aircraft, fixedly mounted below an aircraft body structure (1), characterized in that: The landing gear structure (2) comprises a main lifting beam (21), an oil-gas shock absorber (22), a rocker arm (23), an axle (24), a wheel (25) and an articulated bolt (26); one end of the main lifting beam (21) is fixedly connected to the body structure (1) and the other end is articulated to the rocker arm (23) through an articulated bolt (26); the wheel (25) is mounted on an end of the rocker arm (23) away from the main lifting beam (21) through a horizontally arranged axle (24); both ends of the oil-gas shock absorber (22) are articulated between the main lifting beam (21) and the rocker arm (23) through articulated bolts (26); the wheel (25) is vertically arranged; the straight line of the length direction of the oil-gas shock absorber (22) and the straight line of the length direction of the rocker arm (23) are located in the same plane perpendicular to the horizontal plane, and the hinge point between the main lifting beam (21) and the rocker arm (23) is located in the plane.

2. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 1, characterized in that: The main lifting beam (21) is arranged tilted, and one end of the main lifting beam (21) connected to the machine body structure (1) is higher than one end of the main lifting beam (21) hinged to the rocker arm (23).

3. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 1, characterized in that: The hinged portion between the main lifting beam (21) and the rocker arm (23) is vertically arranged, and the hinged bolt (26) between the main lifting beam (21) and the rocker arm (23) is always parallel to the horizontal plane.

4. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 1, characterized in that: The hinge point between the oil-gas shock absorber (22) and the main lifting beam (21), the hinge point between the oil-gas shock absorber (22) and the rocker arm (23), and the hinge point between the main lifting beam (21) and the rocker arm (23) form a triangle.

5. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 4, characterized in that: The angle between the straight line formed by the hinge point between the oil-gas shock absorber (22) and the main lifting beam (21) and the hinge point between the main lifting beam (21) and the rocker arm (23) and the straight line formed by the hinge point between the oil-gas shock absorber (22) and the rocker arm (23) and the hinge point between the main lifting beam (21) and the rocker arm (23) is an obtuse angle in a natural state.

6. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 2, characterized in that: The side of the rocker arm (23) that contacts the oil-gas shock absorber (22) is recessed in a direction away from the oil-gas shock absorber (22).

7. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 1, characterized in that: The machine body structure (1) comprises a left longitudinal beam (13) and a right longitudinal beam (14), and the two main lifting beams (21) are fixedly connected to the left longitudinal beam (13) and the right longitudinal beam (14) respectively.

8. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 7, characterized in that: The machine body structure (1) further comprises a longitudinal beam joint (15) fixed between the left longitudinal beam (13) and the right longitudinal beam (14).

9. The semi-levered main landing gear structure of an eVTOL aircraft according to any one of claims 1 to 8, characterized in that: The main lifting beam (21), rocker arm (23) and wheel axle (24) are all parts of steel structure.

10. The semi-levered main landing gear structure of the eVTOL aircraft according to claim 8, characterized in that: The longitudinal beam joint (15) is a part made of aluminum alloy material.

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