Undercarriage with multi-stage height adjusting function
By designing a multi-stage height adjustment landing gear and using a hydraulic system to adjust the landing gear compression, the problems of tail door length and bridge length are solved, and a larger range of height adjustment and precise control are achieved, which improves transportation efficiency and loading and unloading convenience.
Patent Information
- Application Number
- CN202510505770.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-22
- Publication Date
- 2025-07-29
AI Technical Summary
In the prior art, when the tail is in and out of large cargo or vehicles, it is necessary to increase the length of the tail door or increase the length of the slab bridge, resulting in the weight gain of the tail door and the transportation space being limited, and the addition of pads on the ground affects the loading and unloading efficiency.
Design a landing gear with multi-stage height adjustment function, control the compression amount of the buffer through the hydraulic system, adjust the stop angle and machine belly from the ground level of the landing gear to achieve multi-stage height adjustment.
Provide a larger range of ground-off height for carriers, reduce the length requirements of tail hatch doors and slab bridges, cancel the transportation of pads, reduce the labor intensity of loading and unloading personnel, and accurately control the ground-off height and shutdown angle.
Smart Images
Figure CN120382998A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of landing gear design, and in particular relates to a landing gear with a multi-stage height adjustment function. Background Art
[0002] The landing gear is an important component of an aircraft. It is mainly used to support the aircraft and absorb the impact energy of the aircraft and buffer the ground load during the landing or take-off process.
[0003] For aircraft / helicopters designed for transport with a tailgate, to accommodate the entry and exit of large cargo or vehicles, it is often necessary to increase the tailgate length, increase the length of the platform bridge, or add ground blocks to accommodate loading and unloading vehicles or transport vehicles. Increasing the tailgate length and platform bridge length impose greater requirements on the size and rigidity of the tailgate, resulting in a significant increase in weight. Adding ground blocks requires the aircraft to carry the blocks when transporting large cargo or vehicles, which reduces transportation space and loading and unloading efficiency. Summary of the Invention
[0004] To address the existing problem of loading and unloading large cargo or vehicles from the rear, the present invention provides a landing gear with multi-level height adjustment. In conjunction with the onboard hydraulic system, the landing gear compression can be adjusted to adjust the landing angle or belly height above the ground to meet the requirements of cargo loading and unloading. The technical solution is as follows:
[0005] In a first aspect, a landing gear with a multi-level height adjustment function is provided, comprising: a front landing gear and two main landing gears, each landing gear comprising a buffer, a wheel, and a tire, wherein the buffer comprises: an outer cylinder 1, a first flow control valve 2, a secondary oil reservoir 3, an intermediate cylinder 4, a piston rod 6, a floating piston 8, a second flow control valve 10, a primary oil reservoir 11, and a top guide cylinder 12.
[0006] A pipeline connection joint is provided on the outer cylinder 1, and the first flow control valve 2 is connected to the outer cylinder 1 through a pipeline; one end of the secondary oil storage cylinder 3 is connected to the first flow control valve 2 through a pipeline, and the other end is connected to the hydraulic system; a top guide cylinder 12 is installed inside the outer cylinder 1 to form a secondary oil chamber, and is provided with upper and lower limit structures; a first-level oil storage cylinder 11 is installed inside the top guide cylinder 12, and one end of the first-level oil storage cylinder 11 is connected to the second flow control valve 10 through a pipeline, and the other end is connected to the hydraulic system; one end of the second flow control valve 10 is connected to the first-level oil chamber through a pipeline; the lower part of the top guide cylinder 12 is fixedly connected to the intermediate cylinder 4; a piston rod 6 is installed in the intermediate cylinder 4; a floating piston 8 is installed in the piston rod 6 to isolate the air chamber and the oil chamber.
[0007] The process of lowering the height of the carrier aircraft from the ground is as follows:
[0008] Synchronously open the first flow control valve 2 of the 3 landing gears. Under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber enters the secondary oil storage cylinder 3 through the first flow control valve 2 under the action of gravity. The oil in the secondary oil storage cylinder 3 enters the hydraulic system, and the top guide cylinder 12 and the intermediate cylinder 4 move upward under the action of gravity, realizing the reduction of the landing gear height; when the secondary height adjustment does not meet the requirements, synchronously open the second flow control valve 10 of the 3 landing gears. Under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber enters the primary oil storage cylinder 11 through the second flow control valve 10 under the action of gravity. The oil in the primary oil storage cylinder 11 enters the hydraulic system, the floating piston 8 moves upward to the limit under the action of the air chamber, and the piston rod 6 moves upward under the action of gravity, realizing the reduction of the landing gear height; when the required height is reached, close the first flow control valve 2, and the landing gear maintains the existing height.
[0009] Among them, the process of reducing the height of the tail door from the ground is as follows:
[0010] Synchronously open the first flow control valve 2 of the 2 main landing gears. Under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber enters the secondary oil storage cylinder 3 through the first flow control valve 2 under the action of gravity. The oil in the secondary oil storage cylinder 3 enters the hydraulic system, and the top guide cylinder 12 and the intermediate cylinder 4 move upward under the action of gravity, realizing the reduction of the landing gear height; when the secondary height adjustment does not meet the requirements, synchronously open the second flow control valve 10 of the 2 main landing gears. Under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber enters the primary oil storage cylinder 11 through the second flow control valve 10 under the action of gravity. The oil in the primary oil storage cylinder 11 enters the hydraulic system, the floating piston 8 moves upward to the limit under the action of the air chamber, and the piston rod 6 moves upward under the action of gravity, realizing the reduction of the landing gear height; when the required height is reached, close the first flow control valve 2, and the landing gear maintains the existing height.
[0011] Among them, the process of restoring the landing gear height is as follows: when the loading and unloading of large goods or vehicles is completed, open the first flow control valve 2, and push the oil in the secondary oil storage cylinder 3 back into the secondary oil chamber by pressurizing the hydraulic system, and then close the first flow control valve 2; open the second flow control valve 10, and push the oil in the primary oil storage cylinder 11 back into the primary oil chamber by pressurizing the hydraulic system, and then close the second flow control valve 10.
[0012] Among them, the upper and lower limit structures of the outer cylinder 1 include a lower limit boss and an upper limit end cover. The lower limit boss is located at the upper part of the intermediate cylinder 4 and is used to limit the downward movement of the intermediate cylinder 4; the upper limit end cover is located at the top of the outer cylinder 1 and is used to seal the secondary fuel tank and limit the upward movement of the top guide cylinder 12.
[0013] Among them, the buffer further includes a limiting structure for preventing relative rotation between the intermediate cylinder 4 and the piston rod 6.
[0014] Among them, the limiting structure includes a lower torsion arm 7 and an upper torsion arm 9.
[0015] One end of the lower torsion arm 7 is hinged to one end of the upper torsion arm 9. The other end of the lower torsion arm 7 is connected to the intermediate cylinder 4, and the other end of the upper torsion arm 9 is connected to the piston rod 6.
[0016] Furthermore, the buffer further includes a throttle valve 5 fixedly connected to the upper part of the piston rod 6.
[0017] The beneficial effects of the present invention are at least as follows:
[0018] Provide a larger range of the carrier's ground clearance, facilitating the entry and exit of large goods or vehicles through the carrier's tailgate, contributing to reducing the lengths of the rear cabin door and the bridge plate; at the same time, the transportation of cushion blocks can be cancelled and the labor intensity of cargo loading and unloading personnel can be reduced; the ground clearance and the parking angle of the carrier can be accurately controlled. It can be applied to airplanes / helicopters for transporting large goods or vehicles. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a schematic diagram of the landing gear structure of the present invention;
[0020] Figure 2 It is a schematic diagram of the buffer of the present invention (uncompressed);
[0021] Figure 3 It is a schematic diagram of the compression of the secondary oil cavity of the present invention;
[0022] Figure 4 It is a schematic diagram of the simultaneous compression of the primary and secondary oil cavities provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.
[0024] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a comprehensive understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is only intended to provide a better understanding of the present invention by showing examples of the present invention. The present invention is in no way limited to any specific settings and methods set forth below, but covers any improvements, substitutions, and modifications of structures, methods, and devices without departing from the spirit of the present invention. In the drawings and the following description, well-known structures and technologies are not shown to avoid unnecessarily obscuring the present invention.
[0025] It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other, and the various embodiments may be referenced and cited with each other.
[0026] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.
[0027] The present invention provides a landing gear with multi-stage height adjustment ability, including primary height adjustment and secondary height adjustment. The landing gear mainly consists of a buffer, a wheel, and a tire, and a braking device can be added as needed, such as Figure 1 as shown, Figure 1 Taking the nose landing gear as an example. The design focus of this landing gear is the buffer, please refer to Figure 2 , and the buffer mainly consists of an outer cylinder 1, a first flow control valve 2, a secondary oil storage cylinder 3, an intermediate cylinder 4, a throttle valve 5, a piston rod 6, a lower torsion arm 7, a floating piston 8, an upper torsion arm 9, a second flow control valve 10, a primary oil storage cylinder 11, and a top guide cylinder 12.
[0028] The outer cylinder 1 is designed with a pipeline connection joint, and the first flow control valve 2 is connected to the outer cylinder 1 through a pipeline; one end of the secondary oil storage cylinder 3 is connected to the first flow control valve 2 through a pipeline, and the other end is connected to the hydraulic system; the top guide cylinder 12 is installed inside the outer cylinder 1 to form a secondary oil chamber and is designed with upper and lower limits; the primary oil storage cylinder 11 is installed inside the top guide cylinder 12, one end of the primary oil storage cylinder 11 is connected to the second flow control valve 10 through a pipeline, and the other end is connected to the hydraulic system; one end of the second flow control valve 10 is connected to the primary oil chamber through a pipeline; the lower part of the top guide cylinder 12 is fixedly connected with the intermediate cylinder 4; the piston rod 6 is installed in the intermediate cylinder 4 and is hinged through the lower torsion arm 7 and the upper torsion arm 9 to prevent relative rotation between the intermediate cylinder 4 and the piston rod 6; the throttle valve 5 is fixedly connected to the upper part of the piston rod 6; the floating piston 8 is installed inside the piston rod 6 to isolate the air chamber and the oil chamber.
[0029] The working principle of the present invention is as follows:
[0030] 1) Refer to Figure 2 , Figure 3 and Figure 4 , lower the height of the carrier aircraft from the ground: By synchronously controlling the opening of the first flow control valves 2 of the three landing gears, under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber enters the secondary oil storage cylinder 3 through the first flow control valve 2 under the action of gravity. The oil on the other side in the secondary oil storage cylinder 3 enters the hydraulic system. The top guide cylinder 12 and the middle cylinder 4 move upward under the action of gravity, realizing the reduction of the landing gear height. When the secondary height adjustment does not meet the requirements, by synchronously controlling the opening of the second flow control valves 10 of the three landing gears, under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber enters the primary oil storage cylinder 11 through the second flow control valve 10 under the action of gravity. The oil on the other side in the primary oil storage cylinder 11 enters the hydraulic system. The piston rod 6 moves upward under the action of gravity, realizing the reduction of the landing gear height. When the required height is reached, close the first flow control valve 2, and the landing gear can maintain the existing height.
[0031] 2) Refer to Figure 2 , Figure 3 and Figure 4 , lower the height of the tail compartment door from the ground: By synchronously controlling the opening of the first flow control valve 2 of the rear landing gear, under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber enters the secondary oil storage cylinder 3 through the first flow control valve 2 under the action of gravity. The oil on the other side in the secondary oil storage cylinder 3 enters the hydraulic system. The top guide cylinder 12 and the middle cylinder 4 move upward under the action of gravity, realizing the reduction of the landing gear height. When the secondary height adjustment does not meet the requirements, by synchronously controlling the opening of the second flow control valve 10 of the rear landing gear, under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber enters the primary oil storage cylinder 11 through the second flow control valve 10 under the action of gravity. The oil on the other side in the primary oil storage cylinder 11 enters the hydraulic system. The piston rod 6 moves upward under the action of gravity, realizing the reduction of the landing gear height. When the required height is reached, close the first flow control valve 2, and the landing gear can maintain the existing height.
[0032] 3) Refer to Figure 2 , restoration of the landing gear height: When the loading and unloading of large goods or vehicles are completed, open the first flow control valve 2, and push the oil in the secondary oil storage cylinder 3 back into the secondary oil chamber by pressurizing the hydraulic system, and then close the first flow control valve 2; open the second flow control valve 10, and push the oil in the primary oil storage cylinder 11 back into the primary oil chamber by pressurizing the hydraulic system, and then close the second flow control valve 10.
[0033] The advantages of the buffer of the present invention are mainly as follows:
[0034] 1) It can provide a larger range of height adjustment;
[0035] 2) The height adjustment amount of the landing gear can be accurately controlled;
[0036] 3) The landing gear oil and the hydraulic system oil can be well isolated.
[0037] The key points of the present invention are as follows:
[0038] 1) It is designed with two-stage oil cavities, which can provide a larger range of height adjustment;
[0039] 2) It is designed with a flow control valve, which can accurately control the height adjustment amount of the landing gear;
[0040] 3) It is designed with an oil storage cylinder, which can well isolate the landing gear oil and the hydraulic system oil.
[0041] The above only expresses the implementation modes of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. In addition, the parts not detailed in the present invention are all conventional technologies.
Claims
1. A landing gear with a multi-level height adjustment function, comprising: The nose landing gear and two main landing gears, each landing gear comprising a buffer, a wheel and a tire, characterized in that the buffer comprises: an outer cylinder (1), a first flow control valve (2), a secondary oil storage cylinder (3), an intermediate cylinder (4), a piston rod (6), a floating piston (8), a second flow control valve (10), a primary oil storage cylinder (11) and a top guide cylinder (12). The outer cylinder (1) is provided with a pipeline connection joint, and the first flow control valve (2) is connected to the outer cylinder (1) through a pipeline; one end of the secondary oil storage cylinder (3) is connected to the first flow control valve (2) through a pipeline, and the other end is connected to the hydraulic system; the top guide cylinder (12) is installed inside the outer cylinder (1) to form a secondary oil chamber, and upper and lower limit structures are provided; the primary oil storage cylinder (11) is installed inside the top guide cylinder (12), one end of the primary oil storage cylinder (11) is connected to the second flow control valve (10) through a pipeline, and the other end is connected to the hydraulic system; one end of the second flow control valve (10) is connected to the primary oil chamber through a pipeline; the lower part of the top guide cylinder (12) is fixedly connected to the intermediate cylinder (4); the piston rod (6) is installed in the intermediate cylinder (4); a floating piston (8) is installed inside the piston rod (6) to isolate the air chamber and the oil chamber.
2. The landing gear with a multi-stage height adjustment function according to claim 1, characterized in that, The process of reducing the height of the carrier aircraft from the ground is as follows: The first flow control valves (2) of the 3 landing gears are opened synchronously. Under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber flows through the first flow control valve (2) under the action of gravity into the secondary oil storage cylinder (3), and the oil in the secondary oil storage cylinder (3) enters the hydraulic system. The top guide cylinder (12) and the intermediate cylinder (4) move upward under the action of gravity to reduce the height of the landing gear; when the secondary height adjustment does not meet the requirements, the second flow control valves (10) of the 3 landing gears are opened synchronously. Under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber flows through the second flow control valve (10) under the action of gravity into the primary oil storage cylinder (11), and the oil in the primary oil storage cylinder (11) enters the hydraulic system. The floating piston (8) moves upward to the limit under the action of the air chamber, and the piston rod (6) moves upward under the action of gravity to reduce the height of the landing gear; when the required height is reached, the first flow control valve (2) is closed, and the landing gear maintains the existing height.
3. The landing gear with multi-level height adjustment ability according to claim 1, characterized in that, The process of reducing the height of the tail door from the ground is as follows: Synchronously open the first flow control valve (2) of the two main landing gears. Under the action of the gravity of the carrier aircraft, the oil in the secondary oil chamber enters the secondary oil storage cylinder (3) through the first flow control valve (2) under the action of gravity. The oil in the secondary oil storage cylinder (3) enters the hydraulic system, and the top guide cylinder (12) and the intermediate cylinder (4) move upward under the action of gravity, realizing the reduction of the landing gear height. When the secondary height adjustment does not meet the requirements, synchronously open the second flow control valve (10) of the two main landing gears. Under the action of the gravity of the carrier aircraft, the oil in the primary oil chamber enters the primary oil storage cylinder (11) through the second flow control valve (10) under the action of gravity. The oil in the primary oil storage cylinder (11) enters the hydraulic system, and the floating piston (8) moves upward to the limit under the action of the air chamber, and the piston rod (6) moves upward under the action of gravity, realizing the reduction of the landing gear height. When the required height is reached, close the first flow control valve (2), and the landing gear maintains the existing height.
4. The landing gear with multi-stage height adjustment ability according to claim 1, characterized in that, The process of restoring the landing gear height is as follows: When the loading and unloading of large goods or vehicles are completed, open the first flow control valve (2), and push the oil in the secondary oil storage cylinder (3) back into the secondary oil chamber by pressurizing the hydraulic system, and then close the first flow control valve (2); open the second flow control valve (10), and push the oil in the primary oil storage cylinder (11) back into the primary oil chamber by pressurizing the hydraulic system, and then close the second flow control valve (10).
5. The landing gear with multi-stage height adjustment ability according to claim 1, characterized in that The upper and lower limit structures of the outer cylinder (1) include a lower limit boss and an upper limit end cover. The lower limit boss is located at the upper part of the intermediate cylinder (4) and is used to limit the downward movement of the intermediate cylinder (4); the upper limit end cover is located at the top of the outer cylinder (1) and is used to seal the secondary fuel tank and limit the upward movement of the top guide cylinder (12).
6. The landing gear with multi-level height adjustment ability according to claim 1, characterized in that, The buffer also includes a limit structure for preventing the relative rotation of the intermediate cylinder (4) and the piston rod (6).
7. The landing gear with multi-level height adjustment ability according to claim 5, characterized in that, The limit structure includes a lower torsion arm (7) and an upper torsion arm (9). One end of the lower torsion arm (7) is hinged to one end of the upper torsion arm (9). The other end of the lower torsion arm (7) is connected to the intermediate cylinder (4), and the other end of the upper torsion arm (9) is connected to the piston rod (6).
8. The landing gear with multi-level height adjustment ability according to claim 1, characterized in that, The buffer also includes a throttle valve (5) fixedly connected to the upper part of the piston rod (6).