CN110834719B

CN110834719B - Bionic leg landing gear system

Info

Publication number: CN110834719B
Application number: CN201810940636.2A
Authority: CN
Inventors: 任佳; 刘小川; 王计真; 牟让科
Original assignee: AVIC Aircraft Strength Research Institute
Current assignee: AVIC Aircraft Strength Research Institute
Priority date: 2018-08-17
Filing date: 2018-08-17
Publication date: 2023-05-23
Anticipated expiration: 2038-08-17
Also published as: CN110834719A

Abstract

The invention discloses a bionic leg landing gear system, which comprises a plurality of bionic leg mechanisms, wherein each bionic leg mechanism comprises at least two joints; the bionic leg mechanism is connected to the frame through a base joint; each joint of the bionic leg mechanism is provided with an independent joint driving device. The landing gear system of the invention overturns the design concept of the traditional landing gear, and enhances the intelligent level of the helicopter; the leg structure design has universality and universality, the size of the legs is determined according to the size and bearing capacity of the helicopter, and the helicopter is suitable for various types of helicopters; the invention has the advantages of compact structure, easy control, small volume and high bearing capacity, and is suitable for the field complex terrain of the helicopter.

Description

Bionic leg landing gear system

Technical Field

The present invention relates to the field of helicopter landing gear design, and more particularly to a bionic leg landing gear system.

Background

At present, a helicopter landing gear generally adopts two structures of a skid type and a wheel type, and because two conventional landing gears have the limitations of the structural characteristics, the helicopter is required to take off and land only on a firm, flat and stable ground (at least a half-paved runway), the helicopter also does not have the capability of autonomous ground movement, and in addition, the helicopter mostly adopts a non-retractable design form, so that the resistance in the flight process is large. The landing gear based on the bionic leg structure can overcome the defects, so that the helicopter has better complex terrain adaptability, landing, parking and walking on irregular ground are realized, the landing gear can be retracted at the bottom of the belly in the flight process, and the flight resistance is reduced. Therefore, the landing gear with the bionic leg structure has wide application prospect in the military and civil fields.

The bionic leg mechanism is used as a key component of the landing gear, and the form and the structure of the bionic leg mechanism are important for realizing functions. At present, bionic legs are mainly used in the field of robots, and in the robots, the legs adopt two forms of a serial mechanism and a parallel structure. The serial structure adopts a pure rotation joint combination and direct driving mode, and has the problems of insufficient output load force although the mechanism is simple and easy to control, and the serial structure has the problems of large flexibility, poor stability and large control error due to the design mode of an open chain mechanism, so that the serial structure is only suitable for a small ground crawling robot. The parallel structure has the advantages of larger output load force, better rigidity and stability, but because of complex structure, larger structure weight and incapability of being retracted, and because of lower load, the parallel structure is only suitable for large-scale ground walking robots. As a landing gear system of a helicopter, the weight and the loading capacity of the landing gear system are strictly limited, and the two common forms are not suitable for leg mechanisms of bionic leg landing gears of the helicopter.

Therefore, aiming at the application scene and the structural characteristics of the bionic leg landing gear of the helicopter, the leg structure of the bionic leg landing gear is disclosed. The landing gear system adopts a mode of supporting a plurality of legs, driving a single leg by adopting a multi-link mechanism, independently controlling each leg and independently controlling each joint to compensate each other. The helicopter landing gear has larger load capacity and more compact structure, and meets the application scene requirements of the helicopter landing gear.

Disclosure of Invention

Object of the Invention

The invention aims to provide a bionic leg landing gear system applied to a helicopter, which is different from the existing serial-type and parallel-type bionic leg structures, effectively overcomes the defects of the two structures, and has the characteristics of small mass, large bearing capacity and attractive and compact structure. The structure is realized by adopting a four-bar mechanism and parallelogram mechanism combination mode, and has the characteristics of stable motion gesture, flexible action, wide movable range and strong terrain adaptability. The landing gear has the function of passive support of the traditional landing gear, and can effectively solve the problem of terrain self-adaption when the landing gear with bionic legs lands and walks and the problem of retraction and extension of the landing gear in the flying process.

Technical solution of the invention

In order to achieve the above object, the present invention adopts the following technical scheme:

a bionic leg landing gear system comprises a plurality of bionic leg mechanisms, wherein each bionic leg mechanism comprises at least two joints; the bionic leg mechanism is connected to the frame through a base joint; and a joint driving device for independently driving the joints to move is arranged at each joint of the base joint and the bionic leg mechanism.

Preferably, the joint driving device comprises a power system and a plurality of connecting rod mechanisms forming the bionic leg mechanism, wherein the power system is connected to a crank of the connecting rod mechanisms through a transmission shaft. The movable connection parts of the connecting rod mechanisms are all hinged, the rotating parts are connected by adopting bearings to reduce friction, the bearings are placed in bearing covers, interference fit is adopted between the outer rings of the bearings and the bearing covers, and the bearing covers are connected with the connecting rods by screws. The pin shaft passes through the bearing inner ring, and the bearing inner ring is tightly pressed with the other connecting rod through the shaft sleeve.

Preferably, the joint driving device is arranged on the frame below the machine body.

Preferably, the power system adopts an electric steering engine.

Preferably, the output end of the transmission shaft adopts a square shaft, a T-shaped shaft or a D-shaped shaft.

Preferably, the linkage mechanism adopts a structure of combining a four-bar linkage mechanism and a parallelogram linkage mechanism.

Preferably, the bionic leg mechanisms are even in number.

Preferably, the number of the bionic leg mechanisms is more than or equal to 4, more preferably, the number of the bionic leg mechanisms is 6.

Preferably, each bionic leg mechanism is connected to one base joint or a plurality of bionic leg mechanisms are connected to one base joint.

THE ADVANTAGES OF THE PRESENT INVENTION

The invention has the advantages that:

(1) The design mode of the traditional undercarriage of the helicopter is overturned, so that the limitation of the traditional undercarriage is effectively overcome, and the intelligent level of the helicopter is effectively improved;

(2) The advantages of the serial mechanism and the parallel mechanism are integrated, the joint driving device is arranged on the frame below the belly, the driving force is transmitted by adopting the connecting rod structure, the rigidity and the bearing capacity of legs are increased, the leg structure design is more compact, and the folding and the retraction of the bionic leg landing gear are facilitated;

(3) Compared with the traditional landing gear, the bionic leg landing gear has higher universality and replaceability, the number and the installation layout of the leg mechanisms can be selected according to the bearing requirement, the driving device is easy to disassemble and assemble, and the bearing capacity of the bionic leg landing gear can be changed according to the weight change of the helicopter without redesigning and disassembling the leg structures;

(4) Different from the design form that the driving device is directly arranged at the joint, the length of each connecting rod of the leg mechanism can be adjusted according to the bearing requirement, the dependence on the bearing capacity of the joint during landing is reduced, a low-power motor and a low-bearing speed reducer can be selected for use during the type selection of the joint driving device, and the weight of the bionic leg landing gear system is effectively reduced;

(5) The bionic leg landing gear has the characteristics of light weight, small volume and large bearing capacity, also enables the landing gear posture to have an autonomous control function, can control the posture of the landing gear according to the terrain characteristics and the machine body posture, has terrain adaptability, and meets landing and parking requirements of the helicopter landing gear.

Drawings

FIG. 1 is a schematic illustration of a bionic leg mechanism in a bionic leg landing gear system of the present invention when deployed.

FIG. 2 is a schematic view of the bionic leg mechanism of the bionic leg landing gear system of the present invention when stowed.

Fig. 3 is a schematic structural diagram of a single bionic leg mechanism in a bionic leg landing gear system according to the present invention.

FIG. 4 is a front view of a single bionic leg mechanism in a bionic leg landing gear system of the invention.

FIG. 5 is a side view of a single bionic leg mechanism in a bionic leg landing gear system of the invention.

In the accompanying drawings: 1-frame, 2-linkage, 3-thigh section, 4-shank section, 5-lightening hole, 6-bearing, 7-pin, ABCD-four-bar linkage, EFGD-four-bar linkage, AB-drive crank, EF-drive crank, CD-rocker, GD-rocker, DGHI-parallelogram mechanism.

Detailed Description

Specific embodiments of the present invention will be described in detail with reference to the summary of the invention and the accompanying drawings.

Taking a bionic leg comprising 6 legs as an example, each bionic leg comprises a landing gear system of 2 joints.

The bionic leg landing gear system consists of 6 identical bionic leg mechanisms, the bionic leg mechanisms are symmetrically distributed, each bionic leg mechanism is provided with 2 joints, each bionic leg mechanism comprises a thigh section 3 and a shank section 4, the thigh section 3 is rotationally connected with the shank section 4, the thigh section 3 is rotationally connected to the frame 1, the joint of the thigh section 3 and the frame 1 is a thigh joint, and the joint of the thigh section 3 and the shank section 4 is a shank joint. Every 3 bionic leg mechanisms share one base joint, namely 2 base joints, the bionic leg landing gear system is 14 joints in total, each joint is independently driven by a joint driving device, the bionic leg landing gear system is controlled by 1 set of control system, and each joint can be independently controlled. Every 3 bionic leg mechanisms share one base joint, so that the landing gear systems are symmetrically distributed, and the aircraft is more stable when landing.

The joint driving devices for driving/controlling the joints of the bionic legs are all positioned on a frame 1 below a machine body and are connected to a vertical plate of a left/right frame of the frame through flange plates and are connected through socket head cap bolts, the joint driving devices comprise a power system and a plurality of link mechanisms 2 forming the bionic leg mechanisms, the power system is formed by installing corresponding transmission shafts through electric steering engine design, the output ends of the transmission shafts are in the form of square shafts, T-shaped shafts or D-shaped shafts, the transmission shafts are connected with crank connecting blocks, and the central hole forms of the crank connecting blocks are matched with the output forms of the transmission shafts and meet the bearing requirements of output torque.

The link mechanism 2 forming each bionic leg comprises two four-link mechanisms ABCD and EFGD and a parallelogram mechanism DGHI, wherein AB and EF are driving cranks, CD and GD are rocker arms, and the links forming the link mechanism 2 are rigid links, so that the bionic leg has enough strength, rigidity and higher machining precision. The connecting rods forming the thigh section 3 are provided with a plurality of lightening holes 5 for lightening the weight, the size of each connecting rod mechanism 2 is comprehensively determined according to the outline size of the helicopter and the bearing capacity requirement of the landing gear, and the specific process is as follows: the force of the foot of the bionic leg landing gear of the helicopter is determined according to the load and landing conditions of the helicopter, then the moment output analytic type at each joint is determined, the minimum output moment at each joint is taken as a target, and the optimal solution of the length of each connecting rod is solved, so that the connecting rod size is obtained. The movable connection of the connecting rod mechanisms is hinged, and the rotating parts are connected by adopting bearings 6 in order to reduce the rotating friction force at the connecting parts. The bearing 6 is placed in a bearing cover, the outer ring of the bearing 6 is in interference fit with the bearing cover, the bearing cover is connected with a connecting rod through a screw, the pin shaft 7 passes through the inner ring of the bearing, and the inner ring of the bearing is tightly pressed with the other connecting rod through a shaft sleeve. In the rotating process, the bearing inner ring, the pin shaft 7 and the shaft sleeve are kept static, and the connecting rod drives the bearing outer ring to rotate through the bearing cover. When designing each connecting rod of the bionic leg landing gear, besides reducing the bearing capacity of the joint part, the joint part is required to be designed to be insensitive to installation errors, the requirement of the fit tolerance is ensured, and the stable work and no rotation clamping stagnation phenomenon in the rotation process are ensured.

The bionic leg landing gear of the helicopter can finish actions such as landing, walking, folding and the like of multiple terrains, and when in actual work, the lateral swing of the legs is realized through the femoral joints of the single bionic leg mechanism, the integral posture of the bionic leg mechanism is adjusted, and the adjustment of the positions of the feet in the plane of the leg mechanism is realized through the base joints, so that the matching of terrains is realized. The straight walking and landing posture adjustment of the helicopter can be realized through the two joints of the legs. The function of the base joint shared by the three legs is the steering of the machine body when walking on the ground and the integral rotation of the legs when the landing gear is retracted/opened, namely the landing gear is fully retracted under the machine body and is rotated out from the machine body.

During actual work (comprising actions of landing, walking, folding and the like), the thigh joints of the single bionic leg mechanism realize lateral swinging of legs, the base joints realize the adjustment of the cooperative foot positions in the plane of the leg mechanism, and the base joints shared by the three legs realize steering and retraction/opening actions of the landing gear during walking.

The landing gear system of the invention overturns the design concept of the traditional landing gear, and enhances the intelligent level of the helicopter; the leg structure design has universality and universality, the size of the legs is determined according to the size and bearing capacity of the helicopter, and the helicopter is suitable for various types of helicopters; the invention has the advantages of compact structure, easy control, small volume and high bearing capacity, and is suitable for the field complex terrain of the helicopter.

Claims

1. A bionic leg landing gear system, characterized by: comprises a plurality of bionic leg mechanisms, wherein each bionic leg mechanism comprises at least two joints; the bionic leg mechanism is connected to the frame through a base joint; each joint of the bionic leg mechanism is provided with a joint driving device for independently driving the joints to move;

the joint driving device comprises a power system and a plurality of connecting rod mechanisms forming the bionic leg mechanism, and the power system is connected to a crank of the connecting rod mechanisms through a transmission shaft; the connecting rod mechanism adopts a structure of combining a four-bar mechanism and a parallelogram connecting rod mechanism; the lateral swing of the legs is realized through the femoral joints of the single bionic leg mechanism, the overall posture of the bionic leg mechanism is adjusted, and then the adjustment of the positions of the feet in the plane of the leg mechanism is realized through the base joints, so that the matching of the topography is realized; the straight line walking and landing posture adjustment of the helicopter are realized through two joints of the legs.

2. A bionic leg landing gear system according to claim 1, wherein: the joint driving device is arranged on the frame.

3. A bionic leg landing gear system according to claim 1, wherein: the power system adopts an electric steering engine.

4. A bionic leg landing gear system according to claim 1, wherein: and the output end of the transmission shaft adopts a square shaft, a T-shaped shaft or a D-shaped shaft.

5. A bionic leg landing gear system according to claim 1, wherein: the bionic leg mechanisms are even in number.

6. A bionic leg landing gear system according to claim 1, wherein: the number of the bionic leg mechanisms is more than or equal to 4.

7. A bionic leg landing gear system according to claim 1, wherein: each bionic leg mechanism is connected with one base joint or a plurality of bionic leg mechanisms are connected with one base joint.