CN109850132B

CN109850132B - Separable landing gear leg-retracting mechanism

Info

Publication number: CN109850132B
Application number: CN201811492795.7A
Authority: CN
Inventors: 赵嘉俊; 谷云峰; 刘远平; 林宏; 黄方略; 李晓霏
Original assignee: AVIC Chengdu Aircraft Design and Research Institute
Current assignee: AVIC Chengdu Aircraft Design and Research Institute
Priority date: 2018-12-07
Filing date: 2018-12-07
Publication date: 2022-08-09
Anticipated expiration: 2038-12-07
Also published as: CN109850132A

Abstract

A separable landing gear leg-retracting mechanism comprises a support column outer cylinder (1), a support column piston rod (9), an airplane wheel tire (4), an upper torsion arm (2) and a lower torsion arm (3), wherein the upper torsion arm (2) is hinged with the support column outer cylinder (1), the lower torsion arm (3) is hinged with the support column piston rod (9), the upper torsion arm (2) is hinged with the lower torsion arm (3), and the airplane wheel tire (4) is installed at the lower end of the support column piston rod (9).

Description

Separable landing gear leg-retracting mechanism

Technical Field

Aircraft landing gear mechanism design field, concretely relates to detachable undercarriage leg mechanism that contracts.

Background

Landing gear is a device for use in parking, taxiing, takeoff and landing an aircraft on the ground. During flight of an aircraft, most landing gears are stowed within the landing gear well of the aircraft in order to reduce flight drag. However, the space of the landing gear cabin is generally narrow, and for aircraft such as carrier-based aircraft with longer landing gear struts, the space of the landing gear cabin is more compact. In order to save the landing gear storage space, the landing gear strut can be compressed (leg-retracted) moderately, and then retracted into the landing gear cabin after the length of the landing gear strut is reduced.

At present, the aircraft mainly pulls a strut piston rod through a multi-link mechanism to realize leg contraction of a landing gear strut. However, the mechanism is complex, heavy, and the reliability and maintainability need to be improved. In addition, because the actuator is directly connected with the strut piston rod through the multiple connecting rods, when the airplane lands and the buffer strut is compressed, the actuator and the connecting rod mechanism move along with the strut piston rod, and the possibility of free movement or clamping stagnation of the buffer strut is influenced. And in case of clamping stagnation of the actuator or the link mechanism, the piston rod of the landing gear strut cannot normally move, so that the safety of the aircraft is threatened.

Disclosure of Invention

The purpose of the invention is as follows:

in order to solve the problems that the conventional leg-retracting mechanism of the landing gear has influence on the normal movement of the buffer support column, has clamping stagnation risk and is complex in mechanism, the invention provides a simple and light separable leg-retracting mechanism which can ensure that the landing gear support column is safely and reliably compressed and does not influence the normal use of the buffer support column.

The technical scheme is as follows:

a detachable landing gear leg contraction mechanism comprises a support outer cylinder 1, a support piston rod 9, an airplane wheel tire 4, an upper torsion arm 2 and a lower torsion arm 3, wherein the upper torsion arm 2 is hinged with the support outer cylinder 1, the lower torsion arm 3 is hinged with the support piston rod 9, the upper torsion arm 2 is hinged with the lower torsion arm 3, and the airplane wheel tire 4 is mounted at the lower end of the support piston rod 9.

The separable landing gear leg-retracting mechanism further comprises an actuating cylinder 5, an actuating cylinder piston rod 6, a pulley 7 and an L-shaped rocker arm 8, wherein the actuating cylinder 5 is fixedly arranged on the upper part of the strut outer cylinder 1 along the length direction of the strut, the actuating cylinder piston rod 6 can extend out or retract into the actuating cylinder 5 as required, the pulley 7 is arranged at the lower end of the actuating cylinder piston rod 6, and the pulley can freely rotate around a self-mounted shaft; the end of the L-shaped rocker arm 8 is fixedly connected with a lug at one side of the upper end of the upper torque arm 2, after the upper torque arm 2 and the L-shaped rocker arm 8 are hinged with the strut outer cylinder 1, the upper torque arm 2 and the L-shaped rocker arm 8 can synchronously rotate around a hinge hole, and the free end plane of the L-shaped rocker arm 8 is positioned below the pulley 7; when the piston rod 6 of the actuating cylinder extends downwards, the pulley 7 contacts the free end plane of the L-shaped rocker arm 8, so that the torque arm 2 and the L-shaped rocker arm 8 rotate to drive the lower torque arm 3 to contract upwards, and the leg folding action of the strut piston rod 9 is completed.

According to the detachable landing gear leg retracting mechanism, the plane of the upper torque arm 2 and the plane of the L-shaped rocker arm 8 form an included angle of 130 degrees.

According to the detachable landing gear leg retracting mechanism, the free end plane of the L-shaped rocker arm 8 and the hinged end plane of the L-shaped rocker arm 8 form an included angle of about 160 degrees.

In the detachable landing gear leg retracting mechanism, the actuator piston rod 6 can be locked at the upper limit position and the lower limit position in the actuator 5.

The beneficial effects include:

(a) the invention enables reliable compression of the landing gear strut. Through the separated design, the leg-retracting actuator cylinder can be separated from the strut piston rod, so that the normal use of the buffer strut is not influenced;

(b) the invention can reduce the complexity of the installation, the disassembly and the maintenance of the leg-retracting mechanism of the undercarriage, improve the reliability of the leg-retracting mechanism and reduce the weight of the undercarriage;

(c) the mechanism related by the invention has the advantages of simple manufacturing process, mature materials and easy realization, and can be widely applied to the strut type landing gear.

Drawings

FIG. 1 is a schematic diagram of the principal structural components of the present invention;

FIG. 2 is an isometric view of the upper torque arm and L-shaped rocker arm structure;

FIG. 3 is a side view of the upper torque arm and L-shaped rocker arm structure;

FIG. 4 is a fully extended state of the strut;

FIG. 5 is a fully compressed state of the strut;

fig. 6 shows the leg-retracted state of the strut.

Detailed Description

FIG. 1 is a schematic diagram of the main structure of the present invention. The invention is characterized in that an actuating cylinder 5 is fixedly arranged on the upper part of a strut outer cylinder 1 along the length direction of the strut, and a piston rod 6 of the actuating cylinder can extend out or retract into the actuating cylinder 5 according to requirements and can be locked at an upper limit position and a lower limit position. The lower end of the piston rod 6 of the actuator cylinder is provided with a pulley 7 which can rotate freely around a self-mounting shaft. The upper end of the upper torque arm 2 is hinged with the lower end of the strut outer cylinder 1, the lower end of the upper torque arm 2 is hinged with the upper end of the lower torque arm 3, and the lower end of the lower torque arm 3 is hinged with the lower end of the strut piston rod 9.

Fig. 2 and 3 are schematic structural diagrams of the upper torsion arm 2 fixedly connected with the L-shaped rocker arm 8. The end of the L-shaped rocker arm 8 is fixedly connected with a lug at one side of the upper end of the upper torque arm 2, so that the plane of the upper torque arm 2 and the plane of the L-shaped rocker arm 8 form an included angle of about 130 degrees. The free end of the L-shaped rocker arm 8 passes around the outer prop cylinder 1, and the plane of the free end forms an included angle of about 160 degrees with the plane of the hinged end, so that the plane of the free end is positioned below the pulley 7. The hinged hole runs through the end of the L-

shaped rocker arm

8 and 2 lug plates at the upper end of the upper torque arm 2. After the upper torque arm 2 and the L-shaped rocker arm 8 are hinged with the pillar outer cylinder 1, the upper torque arm 2 and the L-shaped rocker arm 8 can synchronously rotate around the hinge hole, and the free end cannot interfere with the pillar outer cylinder 1 in the rotating process.

Fig. 4, 5 and 6 are schematic diagrams of the working principle of the invention. During periods of aircraft parking and taxiing, the ram piston rod 6 is retracted into the ram 5 and locked in the retracted position. In the full-stroke motion process of the strut from the full-extension state to the full-compression state, the L-shaped rocker arm 8 rotates around the hinged shaft along with the upper torque arm 2, the L-shaped rocker arm 8 is not contacted with the pulley 7 all the time, and the motion of a strut piston rod 9 is prevented from being influenced. When the aircraft flies off the ground, the piston rod 6 of the actuator cylinder is unlocked and extends downwards from the actuator cylinder 5. The pulley 7 contacts with the free end surface of the L-shaped rocker arm 8 to push the end surface to move downwards, so that the L-shaped rocker arm 8 rotates around the articulated shaft, and further drives the upper torsion arm 2 and the lower torsion arm 3 to move, so that the strut piston rod 9 is compressed towards the inside of the strut outer cylinder 1, and the leg contraction is realized. When the actuator piston rod 6 is fully extended it will be locked in the down position, so that the strut remains in the retracted state and the landing gear can be stowed in the landing gear bay. When the aircraft lands, the strut is released from the landing gear bay and the ram piston rod 6 is unlocked and retracted into the ram 5. The pulley 7 is driven by the actuator cylinder piston rod 6 to move upwards to be separated from the contact with the L-shaped rocker arm 8, and the actuator cylinder piston rod 6 is finally locked at the take-up position. The strut piston rod 9 is freely extended under the action of the strut buffer pressure until the strut piston rod 9 can freely move in a full extension state.

Claims

1. A detachable landing gear leg-retracting mechanism comprises a strut outer cylinder (1), a strut piston rod (9) and an airplane wheel tire (4), and is characterized by further comprising an upper torsion arm (2) and a lower torsion arm (3), wherein the upper torsion arm (2) is hinged with the strut outer cylinder (1), the lower torsion arm (3) is hinged with the strut piston rod (9), the upper torsion arm (2) is hinged with the lower torsion arm (3), and the airplane wheel tire (4) is mounted at the lower end of the strut piston rod (9);

the hydraulic prop further comprises an actuating cylinder (5), an actuating cylinder piston rod (6), a pulley (7) and an L-shaped rocker arm (8), wherein the actuating cylinder (5) is fixedly arranged on the upper part of the prop outer cylinder (1) along the length direction of the prop, the actuating cylinder piston rod (6) can extend out of or retract into the actuating cylinder (5) as required, the pulley (7) is arranged at the lower end of the actuating cylinder piston rod (6), and the pulley can freely rotate around a self-mounted shaft; the end of the L-shaped rocker arm (8) is fixedly connected with a lug at one side of the upper end of the upper torque arm (2), after the upper torque arm (2) and the L-shaped rocker arm (8) are hinged with the pillar outer cylinder (1), the upper torque arm (2) and the L-shaped rocker arm (8) can synchronously rotate around a hinge hole, and the free end plane of the L-shaped rocker arm (8) is positioned below the pulley (7); when the piston rod (6) of the actuating cylinder extends downwards, the pulley (7) contacts the free end plane of the L-shaped rocker arm (8), the upper torque arm (2) and the L-shaped rocker arm (8) rotate to drive the lower torque arm (3) to contract upwards, and the leg contraction action of the strut piston rod (9) is completed.

2. A detachable landing gear leg retraction mechanism according to claim 1, wherein the plane of the upper torsion arm (2) forms an angle of 130 ° with the plane of the hinged end of the L-shaped rocker arm (8).

3. A detachable landing gear leg retraction mechanism according to claim 1, wherein the free end plane of the L-shaped rocker arm (8) forms an angle of 160 ° with the articulation end plane of the L-shaped rocker arm (8).

4. A detachable landing gear leg retraction mechanism according to claim 1, wherein the actuator piston rod (6) is lockable in the actuator cylinder (5) in upper and lower extreme positions.