Undercarriage and aircraft

Abstract

The undercarriage comprises a front undercarriage and two main undercarriages, the front undercarriage is arranged on the front side of the bottom of an aircraft body and comprises a front aircraft wheel and a front buffering supporting column, one end of the front buffering supporting column is connected with the aircraft body and arranged in the aircraft body, and the other end of the front buffering supporting column is connected with the aircraft body. The other end penetrates out of the machine body and is elastically connected with the front machine wheel; the two main undercarriages are arranged on the two opposite sides of the bottom of the aircraft body respectively, each main undercarriage comprises a buffer frame body, the two ends of each buffer frame body are a hinged end and a free end respectively, the hinged ends are hinged to the inner side of the aircraft body, and the free ends are connected with main aircraft wheels. Part of the structure of the front undercarriage is arranged in the aircraft body, and the rocker arm of the main undercarriage is directly hinged with the aircraft body, so that the overall windward area of the undercarriage is reduced, the aerodynamic resistance and the overall weight of the aircraft are reduced, the overall performance and the endurance of the aircraft are improved, and meanwhile, the aircraft is suitable for the aircraft with a shorter aircraft body.

Description

Technical Field

[0001] The utility model relates to the technical field of aircraft structural parts, in particular to a landing gear and an aircraft. Background Art

[0002] With the rapid development of the low-altitude economy, UAM (Urban Air Mobility) and eVTOL (Electric Vertical Takeoff and Landing) aircraft have become two of the most popular concepts within this sector. The landing gear system is a crucial component of an aircraft, enabling it to perform ground support, takeoff, landing, and taxiing.

[0003] The wheeled landing gear used in existing eVTOLs is typically non-retractable and accounts for 4% to 6% of the total aircraft weight. However, for eVTOLs, this 4% to 6% weight is too heavy, and the non-retractable landing gear has an excessively large frontal area, resulting in excessive aerodynamic drag. Both factors affect the overall performance and endurance of the aircraft, and the existing landing gear is not suitable for aircraft with shorter fuselages. Utility Model Content

[0004] The main purpose of the present invention is to provide a landing gear and an aircraft, aiming to solve the problems in the prior art that the landing gear is too heavy and has too much aerodynamic resistance, thereby affecting the overall performance and endurance of the aircraft, and is not suitable for aircraft with shorter fuselages.

[0005] To achieve the above-mentioned purpose, the present invention provides a landing gear, which is arranged at the bottom of the aircraft body and includes:

[0006] a front landing gear, the front landing gear being disposed on the front side of the bottom of the fuselage, the front landing gear comprising a front wheel and a front buffer strut, one end of the front buffer strut being connected to the fuselage and disposed inside the fuselage, the other end of the front buffer strut extending outside the fuselage and elastically connected to the front wheel, the front buffer strut being inclined from top to bottom toward the nose side of the fuselage;

[0007] Two main landing gears, the two main landing gears are respectively arranged on opposite sides of the bottom of the fuselage, each of the main landing gears includes a buffer frame body, the two ends of the buffer frame body are respectively a hinged end and a free end, the hinged end is hinged to the inner side of the fuselage so that the buffer frame body can only swing along the heading of the aircraft, the free end is connected to the main wheel, at least part of the structure of the buffer frame body is inclined toward the tail side of the fuselage from the hinged end to the free end, and is inclined from the hinged end to the free end in a direction away from the other buffer frame body.

[0008] In one embodiment, the buffer frame includes a rocker arm and a main buffer, the two ends of the rocker arm are the hinged end and the free end respectively, the rocker arm can only swing along the heading of the aircraft, the rocker arm is tilted outward from the hinged end to the free end toward the tail side of the body, and the position on the rocker arm located between the hinged end and the free end is elastically connected to the body through the main buffer.

[0009] In one embodiment, the main buffer includes a main sleeve and a first buffer rod, the main sleeve is hinged to the inner side of the body, the first end of the first buffer rod is sleeved in the main sleeve, the second end of the first buffer rod extends out of the main sleeve and is hinged to a position on the rocker arm near the hinge end, and the first buffer rod can be extended and retracted along the extension direction of the main sleeve.

[0010] In one embodiment, the two main landing gears are symmetrically arranged about the symmetry plane of the fuselage, and the hinged ends are hinged to the inner side of the fuselage via a hinged rod, and the hinged rod is perpendicular to the symmetry plane of the fuselage.

[0011] In one embodiment, the rocker arm includes an elastic shock-absorbing rod and a rocker arm joint that are interconnected, and the end of the rocker arm joint away from the elastic shock-absorbing rod forms the hinged end, and the end of the rocker arm joint close to the elastic shock-absorbing rod is provided with a hinged seat hinged to the second end of the first buffer rod; the hinged end is provided with a hinge ring, and the hinge rod is rotatably inserted into the hinge ring, and the end of the elastic shock-absorbing rod away from the rocker arm joint forms the free end.

[0012] In one embodiment, the cross section of the rocker arm is elliptical, and a long axis side of the cross section of the rocker arm faces the nose side of the machine body;

[0013] And / or, each main wheel is inclined from top to bottom toward another main wheel, and the angle between the axis of each main wheel and the horizontal plane is 1° to 1.5°;

[0014] And / or, the angle between the axis of the front buffer pillar and the vertical line is 7° to 7.5°.

[0015] In one embodiment, the front buffer support includes a front sleeve and a second buffer rod, the front sleeve is connected to the body, and at least a portion of the front sleeve is arranged inside the body, the first end of the second buffer rod is sleeved in the front sleeve, the second end of the second buffer rod is passed through the body and extends out of the front sleeve, and the second buffer rod can be extended and retracted along the extension direction of the front sleeve; the front wheel is connected to the second end of the second buffer rod through a wheel fork.

[0016] In one embodiment, the front landing gear also includes a sway reduction assembly, which includes a sway reduction body, a torque arm and a transmission ring. The sway reduction body is sleeved on the outside of the front sleeve, and the transmission ring is sleeved on the outside of the second end of the second buffer rod. The torque arm includes two mutually hinged first force arms and second force arms, and the end of the first force arm away from the second force arm is hinged to the sway reduction body, and the end of the second force arm away from the first force arm is hinged to the transmission ring, wherein the sway reduction body is a sway reducer or a turning servo.

[0017] In one embodiment, the front wheel and / or each main wheel housing is provided with a fairing.

[0018] The present invention also provides an aircraft, which comprises a body, and the above-mentioned landing gear is arranged at the bottom of the body.

[0019] The technical solution of the present invention is to dispose a portion of the front bumper strut of the front landing gear inside the fuselage, with only one end of the front bumper strut extending outside the fuselage and elastically connected to the front wheel, so that most of the front landing gear structure is contained inside the fuselage, thereby reducing the front landing gear's frontal area and lowering aerodynamic drag. At the same time, the main landing gear's bumper frame is directly hinged to the outside of the fuselage without being indirectly connected to the fuselage through an intermediate transition structure, thereby reducing the number of main landing gear structural components, thereby reducing the main landing gear's frontal area and reducing the overall weight of the main landing gear. The bumper frame is tilted rearward and downward and has a low height, which reduces the overall height of the main landing gear and is suitable for aircraft with shorter fuselages, thereby lowering the overall center of gravity of the aircraft and improving stability. The present invention disposes part of the front landing gear structure inside the fuselage and directly hinges the main landing gear's bumper frame to the fuselage, thereby reducing the overall frontal area of ​​the landing gear, reducing the aerodynamic drag and overall weight of the aircraft, thereby improving the overall performance and endurance of the aircraft. At the same time, the low height of the bumper frame is suitable for aircraft with shorter fuselages. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0021] Figure 1 A schematic diagram of the assembly relationship between the landing gear and the fuselage provided by the utility model;

[0022] Figure 2 A schematic structural diagram of the landing gear provided by the present utility model;

[0023] Figure 3 A schematic structural diagram of the front landing gear provided by the present invention;

[0024] Figure 4 A schematic structural diagram of the main landing gear provided by the present utility model;

[0025] Figure 5 This is a schematic diagram of the angle of the main landing gear provided by the present invention;

[0026] Figure 6 This is a diagram of the assembly structure of the landing gear and fairing provided by the present invention.

[0027] Description of Figure Numbers:

[0028] 100. Landing gear; 1. Front landing gear; 11. Front wheel; 12. Front buffer strut; 121. Front sleeve; 122. Second buffer rod; 13. Swing reduction assembly; 131. Swing reduction body; 132. Torque arm; 133. Transmission ring; 134. First lever arm; 135. Second lever arm; 14. Front wheel load switch; 15. Wheel fork; 16. Front strut; 17. Baffle; 2. Main landing gear; 20. Buffer frame; 21. Rocker arm; 211. Articulated end; 212. Free end; 213. Elastic shock absorber rod; 214. Rocker arm joint; 215. Articulated seat; 216. Articulated ring; 22. Main buffer; 221. Main sleeve; 222. First buffer rod; 23. Main wheel; 24. Articulated rod; 25. Main wheel load switch; 3. Airframe; 4. Fairing.

[0029] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0032] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of such features. In addition, if "and / or" or "and / or" appears in the full text, its meaning includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] The wheeled landing gear used in existing eVTOLs is typically non-retractable and accounts for 4% to 6% of the total aircraft weight. However, for eVTOLs, this 4% to 6% weight is too heavy, and the non-retractable landing gear has an excessively large frontal area, resulting in excessive aerodynamic drag. Both factors affect the overall performance and endurance of the aircraft, and the existing landing gear is not suitable for aircraft with shorter fuselages.

[0034] In order to solve the above problems, the present invention provides a landing gear 100 .

[0035] Please combine Figures 1 to 4 The landing gear 100 of this embodiment is arranged at the bottom of the fuselage 3 of the aircraft. The landing gear 100 includes a front landing gear 1 and two main landing gears 2. The front landing gear 1 is arranged at the front side of the bottom of the fuselage 3. The front landing gear 1 includes a front wheel 11 and a front buffer strut. One end of the front buffer strut is connected to the fuselage 3 and is arranged inside the fuselage 3, and the other end passes through the outside of the fuselage 3 and is elastically connected to the front wheel 11. The front buffer strut is inclined from top to bottom toward the nose side of the fuselage 3; the two main landing gears 2 are respectively arranged at the bottom of the fuselage 3. On opposite sides, each main landing gear 2 includes a buffer frame body 20, the two ends of which are respectively a hinged end 211 and a free end 212. The hinged end 211 is hinged to the inner side of the fuselage 3 so that the buffer frame body 20 can only swing along the heading of the aircraft. The free end 212 is connected to the main wheel 23. At least part of the structure of the buffer frame body 20 is inclined toward the tail side of the fuselage 3 from the hinged end 211 to the free end 212, and is inclined from the hinged end 211 to the free end 212 in a direction away from the other buffer frame body 20.

[0036] The technical solution of the present invention is to arrange a part of the front buffer strut of the front landing gear 1 inside the fuselage 3, and only extend one end of the front buffer strut outside the fuselage 3 and elastically connected to the front wheel 11, so that most of the structure of the front landing gear 1 is accommodated inside the fuselage 3, thereby reducing the frontal area of ​​the front landing gear 1 and reducing aerodynamic resistance. At the same time, the buffer frame body 20 of the main landing gear 2 is directly hinged to the outside of the fuselage 3 without being indirectly connected to the fuselage 3 by setting an intermediate transfer structure, thereby reducing the number of structural parts of the main landing gear 2, thereby reducing the frontal area of ​​the main landing gear 2 and reducing the overall weight of the main landing gear 2. The buffer frame body 20 is inclined toward the rear and downward, and has a lower height, which reduces the overall height of the main landing gear 2. It is suitable for aircraft with a shorter fuselage, lowers the overall center of gravity of the aircraft, and improves stability. The present invention reduces the overall frontal area of ​​the landing gear 100 by arranging part of the structure of the front landing gear 1 within the fuselage 3 and directly hinges the buffer frame 20 of the main landing gear 2 to the fuselage 3, thereby reducing the aerodynamic resistance and overall weight of the aircraft, thereby improving the overall performance and endurance of the aircraft. At the same time, the height of the buffer frame 20 is relatively low, which is suitable for aircraft with shorter fuselages.

[0037] The front buffer pillar 12 is tilted forward at a certain angle ( Figure 5 B), and the strut axis is at a certain distance from the wheel axis, which increases the mechanical stability distance L1 and geometric stability distance L2 of the front landing gear 1 (see Figure 5 L1 and L2 in the figure), so that the front wheels of the aircraft can generate a centering torque during the taxiing process and are less likely to vibrate.

[0038] In one embodiment, the buffer frame 20 includes a rocker arm 21 and a main buffer 22. The two ends of the rocker arm 21 are a hinged end 211 and a free end 212. The rocker arm 21 can only swing along the heading of the aircraft. The rocker arm 21 tilts outward from the hinged end 211 to the free end 212 toward the tail side of the fuselage 3. The position on the rocker arm 21 between the hinged end 211 and the free end 212 is elastically connected to the fuselage 3 through the main buffer 22.

[0039] The main landing gear 2 adopts a rocker-type landing gear. The rocker arm 21 can be set at any position to meet the aircraft's parameter requirements, thereby improving the layout flexibility and reducing the overall volume of the landing gear 100. It should be noted that the rocker arm 21 can only swing along the aircraft's heading. This avoids the rocker arm 21 from swinging left and right due to excessive friction between the tires and the ground during vertical landing, resulting in the rocker arm 21 not being able to fully swing along the heading. This also avoids the main buffer 22 from being stuck and reducing its efficiency due to the rocker arm 21 swinging left and right. It also avoids the problem of increasing the overload of the landing gear 100 and reducing the life of the landing gear 100, and can prevent the tire from being deformed and causing air leakage or blowout.

[0040] The rocker arm 21 is tilted from the hinged end 211 to the free end 212 toward the tail side of the fuselage 3, and also tilts away from the other rocker arm 21 from the hinged end 211 to the free end 212, forming an outward-facing "X"-shaped structure tilted toward the tail side. On the one hand, this increases the main wheelbase to meet the requirements of the anti-rollover angle and anti-backward angle. On the other hand, the rocker arm 21 is tilted rearward and downward, reducing the overall height of the main landing gear 2, making it suitable for aircraft with shorter fuselages, lowering the overall center of gravity of the aircraft, and improving stability. At the same time, the front landing gear 1 adopts a strut-type landing gear 100, and the main landing gear 2 adopts a rocker arm 21-type landing gear 100, allowing the aircraft to meet both vertical take-off and landing functions and taxiing take-off and landing functions, thereby improving the aircraft's applicability.

[0041] As can be understood, the aircraft travels in a forward-backward direction, with two main landing gears 2 disposed on the left and right sides of the fuselage 3, respectively. Typically, the two main landing gears 2 are symmetrically arranged. During landing, the front wheel 11 contacts the ground, and its deformation absorbs a portion of the impact force. The front buffer strut 12, elastically connected to the front wheel 11, elastically compresses under the impact force generated by the weight of the fuselage, thereby absorbing another portion of the impact force. Furthermore, when the main wheels 23 contact the ground, their deformation absorbs a portion of the impact force. The rocker arm 21 rotates relative to the fuselage 3 under the impact force, absorbing another portion of the impact force. The main buffer 22, elastically connected to the rocker arm 21, elastically compresses under the impact force, thereby absorbing another portion of the impact force, allowing the aircraft to land smoothly.

[0042] In one embodiment, the main buffer 22 includes a main sleeve 221 and a first buffer rod 222. The main sleeve 221 is hinged to the inner side of the body 3. The first end of the first buffer rod 222 is sleeved in the main sleeve 221. The second end of the first buffer rod 222 extends out of the main sleeve 221 and is hinged to a position on the rocker arm 21 near the hinge end 211. The first buffer rod 222 can be extended and retracted along the extension direction of the main sleeve 221.

[0043] The first buffer rod 222 is hinged to the rocker arm 21, so that when the rocker arm 21 rotates relative to the body 3, the first buffer rod 222 can adaptively adjust its direct connection angle with the rocker arm 21, thereby better buffering and absorbing impact forces. The swing of the rocker arm 21 along the heading direction can prevent the rocker arm 21 from being subjected to the bending moment generated by the lateral and transverse forces, and prevent the main buffer 22 from being stuck or damaged by the bending moment. At the same time, the hinge between the rocker arm 21 and the first buffer rod 222 is set close to the hinge end 211 of the first buffer rod 222 to avoid excessive torque at the hinge end 211, thereby improving safety. The retractable setting of the first buffer rod 222 reduces the overall volume of the main buffer 22, reducing the frontal area and aerodynamic drag. The main landing gear absorbs landing energy through three levels of buffering, which increases material utilization and reduces landing overload. Its three-level buffer structure is the main wheel, the elastic shock-absorbing rod of the rocker arm, and the main buffer.

[0044] It should be noted that the main sleeve 221 and the first buffer rod 222 can be buffered by the hydraulic method in the existing technology, that is, the main sleeve 221 is the outer cylinder, and the first buffer rod 222 is the inner cylinder also called the piston rod. The interior of the piston rod is hollow and filled with oil, and the outer cylinder is filled with air, thereby achieving the effect of compression buffering. The relevant applications in the existing technology are relatively mature and will not be elaborated here.

[0045] In one embodiment, the two main landing gears 2 are symmetrical about the plane of symmetry of the fuselage 3 (see Figure 2 The dotted line P) is symmetrically arranged, and the hinge end 211 is hinged to the inner side of the body 3 through a hinge rod 24, and the hinge rod 24 is perpendicular to the symmetry plane of the body 3.

[0046] The symmetrically arranged main landing gear 2 can provide uniform support during takeoff, landing and taxiing, balance the center of gravity of the aircraft, avoid tilting and rolling due to unbalanced loading, and improve the overall stability of the landing gear 100. At the same time, the symmetrical arrangement allows the impact force of the aircraft during landing to be evenly transmitted to the fuselage 3, reducing local stress concentration, reducing fatigue and damage caused by uneven force, and extending the life of the aircraft and the landing gear 100.

[0047] Furthermore, the rocker arm 21 includes an elastic shock-absorbing rod 213 and a rocker arm joint 214 that are interconnected. The end of the rocker arm joint 214 away from the elastic shock-absorbing rod 213 forms a hinged end 211, and the end of the rocker arm joint 214 close to the elastic shock-absorbing rod 213 is provided with a hinged seat 215 hinged to the second end of the first buffer rod 222; the hinged end 211 is provided with a hinge ring 216, and the hinge rod 24 is rotatably inserted into the hinge ring 216, and the end of the elastic shock-absorbing rod 213 away from the rocker arm joint 214 forms a free end 212.

[0048] The shock absorber rod is an elastic shock absorber rod 213 made of elastic material. If the impact force is too large during landing, or the buffering stroke of the landing gear 100 is limited, the elastic shock absorber rod 213 can absorb the impact force through its own deformation, thereby further improving the buffering performance of the front landing gear 1. At the same time, the rocker arm joint 214 is connected to the first buffer rod 222 through the hinge seat 215, which improves the articulation stability of the first buffer rod 222 and the rocker arm joint 214. The rocker arm 21 is made of rigid material, which makes it difficult for the rocker arm 21 to deform. It can avoid the deformation of the rocker arm 21 causing the main buffer 22 to bear the bending moment caused by the lateral force and the transverse force, and avoid the main buffer 22 from being stuck or damaged due to the bending moment. The first buffer rod 222 is not connected to the elastic shock absorber rod 213, which avoids the deformation of the elastic shock absorber rod 213 affecting the stability of the articulation, and can also avoid the main buffer 22 from bearing the bending moment caused by the lateral force and the transverse force, thereby extending the service life of the main buffer 22.

[0049] It should be noted that the number of hinge rings 216 can be one or two. One hinge ring 216 has higher rigidity, while two hinge rings 216 can increase the contact area between the hinge rod 24 and the hinge end 211, improve the pressure bearing capacity, and also improve the force uniformity, thereby preventing the hinge end 211 from falling off or being damaged. The number of hinge rings 216 can be selected according to actual design requirements; the hinge rod 24 is perpendicular to the symmetry plane, so that it can limit the rotation direction of the rocker arm 21, so that the rocker arm 21 can only rotate with the hinge rod 24 as the rotation axis. Directional rotation, that is, swinging along the heading, can prevent the rocker arm 21 from being unable to swing fully due to excessive friction between the tire and the ground when the aircraft lands vertically, and can also prevent the main buffer 22 from being subjected to the bending moment caused by the lateral force and the transverse force when the rocker arm 21 swings, so that the main buffer 22 will not be stuck or damaged due to the bending moment caused by the lateral force and the transverse force, thereby reducing the increase in the overload of the landing gear 100, extending the life of the landing gear 100, and preventing the main wheel 23 from being deformed and causing air leakage or tire blowout, thereby improving the overall stability of the aircraft.

[0050] It should be noted that the elastic shock-absorbing rod 213 can be a metal part with a low elastic modulus, such as a tube spring, a leaf spring, or elastic steel. Specifically, elastic steel with an elastic modulus of 210 Gpa, a titanium alloy with an elastic modulus of 110 Gpa, or an aluminum alloy with an elastic modulus of 70 Gpa can be selected. The elastic modulus of the material of the elastic shock-absorbing rod 213 needs to be lower than 210 Gpa to meet its deformation requirements.

[0051] In one embodiment, the rocker arm 21 has an elliptical cross-section, with one of its major axes facing the nose of the aircraft body 3. The elliptical cross-section of the rocker arm 21 effectively reduces air resistance. When the major axis aligns with the aircraft's flight direction (nose orientation), the frontal area can be further reduced, thereby reducing the impact of airflow on the rocker arm 21 during flight and optimizing the aircraft's aerodynamic performance.

[0052] In one embodiment, each main wheel 23 is tilted from top to bottom toward another main wheel 23, and the angle between the axis of each main wheel 23 and the horizontal plane is 1° to 1.5°. It can be understood that since the rocker arm 21 is tilted toward the outside, the impact force received during the landing process will cause the main wheel 23 to generate lateral friction toward the outside. In order to avoid excessive lateral friction causing the main wheel 23 to deform, leak or be damaged, each main wheel 23 is tilted from top to bottom toward another main wheel 23 at a certain angle to form an inward tilt angle. The inward tilt angle causes the outer side of the main wheel 23 to be slightly lifted when it contacts the ground, reducing the lateral friction between the main wheel 23 and the ground, protecting the main wheel 23 while reducing the stress on the hub and bearing, thereby improving the safety and stability of the main wheel 23. The tilt angle of the main wheel 23 (see Figure 2 The best effect is achieved when the angle A) is 1° to 1.5°, and the inclination angle of the main wheel 23 is the same as the angle between the axis of the main wheel 23 and the horizontal plane. Therefore, the angle between the axis of each main wheel 23 and the horizontal plane is 1° to 1.5°.

[0053] See also Figure 5 In one embodiment, the angle between the axis of the front buffer pillar 12 and the vertical line is 7° to 7.5°. The front buffer pillar 12 is tilted forward at a certain angle ( Figure 5 The angle B in the middle) and the distance between the strut axis and the wheel axis increase the mechanical stability distance L1 and the geometric stability distance L2 of the front landing gear 1 (see Figure 5 L1 and L2 in the figure), so that the front wheels of the aircraft can generate a centering torque during the taxiing process and are less likely to vibrate.

[0054] In one embodiment, the front buffer pillar 12 includes a front sleeve 121 and a second buffer rod 122. The front sleeve 121 is connected to the body 3, and the front sleeve 121 is at least partially arranged inside the body 3. The first end of the second buffer rod 122 is sleeved in the front sleeve 121, and the second end of the second buffer rod 122 is passed through the body 3 and extends out of the front sleeve 121. The second buffer rod 122 can be extended and retracted along the extension direction of the front sleeve 121; the front wheel 11 is connected to the second end of the second buffer rod 122 through a fork 15.

[0055] At least part of the front sleeve is arranged inside the body, and only a part of the front sleeve and the second buffer rod 122 extend outside the body 3, so that the volume of the front buffer strut 12 exposed outside the body is reduced, reducing the windward area and aerodynamic resistance.

[0056] It should be noted that the hydraulic method in the existing technology can be used for buffering between the front sleeve 121 and the second buffer rod 122, that is, the front sleeve 121 is the outer cylinder, and the second buffer rod 122 is the inner cylinder also called the piston rod. The interior of the piston rod is hollow and filled with oil, and the outer cylinder is filled with air, thereby achieving the effect of compression buffering. The relevant applications in the existing technology are relatively mature and will not be elaborated here.

[0057] In one embodiment, the front sleeve 121 is hinged to the body 3, and the front landing gear 1 also includes a front strut 16, one end of the front strut 16 is connected to the body 3, and the other end is connected to the front sleeve 121. The front strut 16 is used to stabilize and limit the front landing gear 1 to prevent the front landing gear 1 from rotating too much.

[0058] In one embodiment, the front landing gear 1 also includes a sway reduction assembly 13, which includes a sway reduction body 131, a torque arm 132 and a transmission ring 133. The sway reduction body 131 is sleeved on the outside of the front sleeve 121, and the transmission ring 133 is sleeved on the outside of the second end of the second buffer rod 122. The torque arm 132 includes two first lever arms 134 and second lever arms 135 that are hinged to each other. The end of the first lever arm 134 away from the second lever arm 135 is hinged to the sway reduction body 131, and the end of the second lever arm 135 away from the first lever arm 134 is hinged to the transmission ring 133.

[0059] The rotation of the wheel fork 15 is transmitted to the torque arm 132 via the transmission ring 133, and then to the shimmy damper body 131 via the torque arm 132. During landing or high-speed taxiing, the front wheel 11 may experience high-frequency oscillation due to uneven ground or other factors. The shimmy damper body 131 provides a damping effect, reducing the rapid side-to-side oscillation of the front wheel and preventing shimmy. This allows the aircraft to maintain a stable driving direction during ground taxiing, reducing the risk of yaw and runway deviation caused by tire oscillation. The hinged connection between the first and second lever arms 134, 135, the shimmy damper body 131, and the transmission ring 133 allows the torque arm 132 to extend and retract by swinging to adjust the angle between the first and second lever arms 134, 135, thus preventing damage to the torque arm 132 during the extension and retraction of the second buffer rod 122.

[0060] In one embodiment, the shimmy reduction body 131 is a shimmy damper or a turning servo. The shimmy damper can be any conventional shimmy damper. When the shimmy reduction body 131 is a turning servo, it can provide the front wheels 11 with active steering capability. The turning servo itself also has a shimmy reduction function, thereby improving both the stability and functionality of the aircraft.

[0061] See also Figure 6 In one embodiment, the front wheel 11 is covered with a fairing, and in another embodiment, each main wheel 23 is covered with a fairing 4. It can be understood that the fairing 4 is used to reduce wind resistance, and the fairing 4 is designed in a teardrop shape to further reduce the aerodynamic drag at the main wheels 23 and the front wheel 11 of the aircraft.

[0062] In one embodiment, a wheel-mounted switch is configured on the nose landing gear 1 and / or the main landing gear 2 , and the wheel-mounted switch is configured to send an air-to-ground signal.

[0063] Specifically, in one embodiment, a main wheel-mounted switch 25 is provided at the hinged end 211 of the rocker arm joint 214. The main wheel-mounted switch 25 is used to send a ground-to-air signal to the flight control computer when the rocker arm 21 swings, so as to determine whether the aircraft is in the take-off state or the landing state. It can be understood that the main wheel-mounted switch 25 can adopt a mature wheel-mounted switch in the existing technology, which will not be explained here.

[0064] In one embodiment, a baffle 17 and a front wheel-loaded switch 14 are provided at the hinge of the first lever 134 and the second lever 135. The baffle 17 is used to cooperate with the front wheel-loaded switch 14 to send a ground-to-air signal to the flight control computer when the second buffer rod 122 moves, so as to determine whether the aircraft is in the take-off state or the landing state. It can be understood that the front wheel-loaded switch 14 can adopt a mature wheel-loaded switch in the existing technology, which will not be explained here.

[0065] The present invention also provides an aircraft comprising a body 3, with the aforementioned landing gear 100 disposed at the bottom of the body 3. The specific structure of the landing gear 100 is similar to that of the aforementioned embodiments. Since the present aircraft utilizes all of the technical solutions of all of the aforementioned embodiments, it at least possesses all of the beneficial effects brought about by the technical solutions of the aforementioned embodiments, and therefore, no further details will be given here.

[0066] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made based on the contents of the present invention specification and drawings, or direct / indirect application in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A landing gear, characterized in that: The landing gear is arranged at the bottom of the aircraft body, and the landing gear includes: a front landing gear, the front landing gear being disposed on the front side of the bottom of the fuselage, the front landing gear comprising a front wheel and a front buffer strut, one end of the front buffer strut being connected to the fuselage and disposed inside the fuselage, the other end of the front buffer strut extending outside the fuselage and elastically connected to the front wheel, the front buffer strut being inclined from top to bottom toward the nose side of the fuselage; Two main landing gears, the two main landing gears are respectively arranged on opposite sides of the bottom of the fuselage, each main landing gear includes a buffer frame body, the two ends of the buffer frame body are respectively a hinged end and a free end, the hinged end is hinged to the inner side of the fuselage so that the buffer frame body can only swing along the heading of the aircraft, the free end is connected to the main wheel, at least part of the structure of the buffer frame body is inclined toward the tail side of the fuselage from the hinged end to the free end, and is inclined from the hinged end to the free end in a direction away from the other buffer frame body.

2. The landing gear according to claim 1, wherein: The buffer frame includes a rocker arm and a main buffer, the two ends of the rocker arm are the hinged end and the free end respectively, the rocker arm can only swing along the heading of the aircraft, the rocker arm is tilted outward from the hinged end to the free end toward the tail side of the body, and the position on the rocker arm located between the hinged end and the free end is elastically connected to the body through the main buffer.

3. The landing gear according to claim 2, characterized in that The main buffer includes a main sleeve and a first buffer rod. The main sleeve is hinged to the inner side of the body. The first end of the first buffer rod is sleeved in the main sleeve. The second end of the first buffer rod extends out of the main sleeve and is hinged to a position on the rocker arm near the hinge end. The first buffer rod can be extended and retracted along the extension direction of the main sleeve.

4. The landing gear according to claim 3, characterized in that The two main landing gears are symmetrically arranged with respect to the symmetry plane of the fuselage, and the hinged ends are hinged to the inner side of the fuselage through a hinged rod, and the hinged rod is perpendicular to the symmetry plane of the fuselage.

5. The landing gear according to claim 4, characterized in that The rocker arm includes an elastic shock-absorbing rod and a rocker arm joint that are connected to each other. The end of the rocker arm joint away from the elastic shock-absorbing rod forms the hinged end. The end of the rocker arm joint close to the elastic shock-absorbing rod is provided with a hinged seat hinged to the second end of the first buffer rod; the hinged end is provided with a hinge ring, the hinge rod is rotatably inserted into the hinge ring, and the end of the elastic shock-absorbing rod away from the rocker arm joint forms the free end.

6. The landing gear according to any one of claims 1 to 5, characterized in that The cross section of the rocker arm is elliptical, and a long axis side of the cross section of the rocker arm faces the nose side of the machine body; And / or, each main wheel is inclined from top to bottom toward another main wheel, and the angle between the axis of each main wheel and the horizontal plane is 1° to 1.5°; And / or, the angle between the axis of the front buffer pillar and the vertical line is 7° to 7.5°.

7. The landing gear according to any one of claims 1 to 5, characterized in that The front buffer support includes a front sleeve and a second buffer rod. The front sleeve is connected to the body, and at least a portion of the front sleeve is arranged inside the body. The first end of the second buffer rod is sleeved in the front sleeve, and the second end of the second buffer rod is passed through the body and extends out of the front sleeve. The second buffer rod can be extended and retracted along the extension direction of the front sleeve; the front wheel is connected to the second end of the second buffer rod through a wheel fork.

8. The landing gear according to claim 7, characterized in that The front landing gear also includes a sway reduction assembly, which includes a sway reduction body, a torque arm and a transmission ring. The sway reduction body is sleeved on the outside of the front sleeve, and the transmission ring is sleeved on the outside of the second end of the second buffer rod. The torque arm includes two mutually hinged first and second levers, and the end of the first lever away from the second lever is hinged to the sway reduction body, and the end of the second lever away from the first lever is hinged to the transmission ring, wherein the sway reduction body is a sway reducer or a turning servo.

9. The landing gear according to any one of claims 1 to 5, characterized in that The front wheel and / or each main wheel outer cover is provided with a fairing.

10. An aircraft, characterized in that: The aircraft comprises a fuselage, and a landing gear according to any one of claims 1 to 9 is provided at the bottom of the fuselage.

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