An active retractable compact space main landing gear

Abstract

An active retractable compact space main landing gear, wherein one end of the strut is connected to the body structure, the other end of the strut is connected to the main pillar, the upper part of the main pillar is respectively connected to one end of the upper support arm, one end of the retracting actuator cylinder and the body structure, the lower part of the main pillar is connected to the lower rocker arm, the retracting actuator cylinder is connected to the upper support arm; the lower rocker arm is connected to the wheel tire; one end of the buffer is connected to the upper support arm, and the other end of the buffer is connected to the lower rocker arm; one end of the retracting actuator cylinder is connected to the main pillar, and the other end of the retracting actuator cylinder is connected to the body structure; the upper lock is connected to the body structure. The present invention forms a four-bar linkage through the main pillar, the upper support arm, the buffer and the lower rocker arm, and the retracting actuator cylinder drives the upper support arm in the four-bar linkage to rotate, thereby driving the four-bar linkage to cause the main landing gear to actively retract its legs, and the retracting angle reaches nearly about 80°, which greatly improves the retracting angle, so that the storage space requirement is greatly reduced after the main landing gear is retracted.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft structures, and in particular to an active retractable main landing gear with a compact space. Background Art

[0002] The main landing gear is one of the most important and essential functional accessories of an aircraft. Its functions are to provide stable support for the aircraft, to absorb and dissipate the kinetic energy during takeoff and landing, and to perform braking functions. Normally, the main landing gear does not have a retraction function. For some aircraft with limited landing gear storage space, the landing gear is generally retracted when the main landing gear is retracted through a related linkage mechanism to reduce the storage space. However, for aircraft with small tonnage, compact structure and limited internal storage space, the main landing gear design is more significantly restricted by overall parameters, weight center of gravity, internal layout, etc. The method of retracting the main landing gear when the main landing gear is retracted through a linkage mechanism still cannot meet the landing gear storage space requirements.

[0003] British patents with publication numbers GB1216421A and GB591902A disclose a retractable main landing gear design for vertical take-off and landing and a retractable landing gear design for short take-off and landing, respectively. Both landing gears are rocker-arm landing gears, which achieve leg retraction when the landing gear is retracted through the cooperation of a connecting rod mechanism and an actuator cylinder. The actuator cylinder is extended or retracted to drive the lower rocker arm to rotate and then realize steering, thereby achieving the leg retraction effect; however, the landing gear is designed to be retracted in the heading direction, which takes up a large space. Summary of the Invention

[0004] The technical problem solved by the present invention is to provide an active retractable compact main landing gear to solve the problems in the above-mentioned background technology.

[0005] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0006] An active retractable compact space main landing gear comprises a strut, a main pillar, a lower rocker arm, a wheel tire, a buffer, a retractable actuator, an upper support arm, a retraction actuator, an upper lock and a body structure, wherein one end of the strut is connected to the body structure, and the other end of the strut is connected to the main pillar; the upper part of the main pillar is respectively connected to one end of the upper support arm, one end of the retractable actuator and the body structure; the lower part of the main pillar is connected to the lower rocker arm, and the retractable actuator is rotatably connected to the upper support arm; the lower rocker arm is connected to the wheel tire; one end of the buffer is connected to the upper support arm, and the other end of the buffer is connected to the lower rocker arm; one end of the retraction actuator is connected to the main pillar, and the other end of the retraction actuator is connected to the body structure; and the upper lock is connected to the body structure.

[0007] In the present invention, the strut is a foldable strut having a locking function in a lowered state, a hydraulic unlocking function, and a follow-up folding function when the main landing gear is retracted.

[0008] In the present invention, the main support is a steel forging, which is machined.

[0009] In the present invention, a support structure for connecting with an upper arm is provided on the upper portion of the main support.

[0010] In the present invention, the lower rocker arm is a steel forging and is machined.

[0011] In the present invention, the buffer is a buffer structure of a rocker-type landing gear, which adopts a single-cavity or double-cavity structure and is designed according to the overall design requirements of the aircraft and the landing gear.

[0012] In the present invention, the retracting actuator is an actuator with mechanical interlocks at both ends. Other methods can also be used to ensure that the main landing gear is locked in the extended state and the retracted state.

[0013] In the present invention, the upper support arm is a steel forging formed by machining.

[0014] In the present invention, the retractable actuator is an actuator without mechanical internal lock, and its main function is to retract and lower the main landing gear, and it has an emergency lowering function.

[0015] In the present invention, the main support, the upper support arm, the buffer and the lower rocker arm form a four-bar linkage, and the four-bar linkage is supported and locked by the retracting actuator.

[0016] In the present invention, when the main landing gear is lowered, the retraction actuator extends, the upper lock and the strut are in the unlocked state, and the retraction actuator is in the extended state. At this time, the main strut, the upper support arm, the buffer and the lower rocker arm form a four-bar linkage. The retraction actuator is used to support and lock the four-bar linkage. The retraction actuator drives the main strut to be lowered. After the main strut is lowered, the retraction actuator retracts and drives the four-bar linkage to move until the wheels and tires are lowered, and the main landing gear is lowered into place.

[0017] When the main landing gear is retracted, the upper lock is in the unlocked state, the retraction actuator begins to extend to push the upper support arm to rotate, the rotation of the upper support arm drives the buffer and the lower rocker arm to move, and the rotation of the lower rocker arm causes the wheel tire to be pulled toward the main support until the main landing gear completes the retraction action; the strut is unlocked from the locked state, the retraction actuator retracts, and the strut begins to fold with the retraction of the main landing gear until the main landing gear is retracted and locked in the retracted state by the upper lock.

[0018] Beneficial effects: The present invention forms a four-bar linkage through the main support, upper support arm, buffer and lower rocker arm. The retraction actuator drives the upper support arm in the four-bar linkage to rotate, thereby driving the four-bar linkage to actively retract the main landing gear. The retraction angle is close to about 80°, which greatly improves the retraction angle, so that the storage space requirement after the main landing gear is retracted is greatly reduced, especially the aircraft heading storage space requirement is greatly reduced. It is suitable for aircraft with compact body structure and tight landing gear wheel well space. According to the overall requirements of the aircraft, the dimensions of the relevant structures can be adjusted to meet the aircraft's wheel well space requirements. The principle is clear, production is convenient, practicality is strong, and it is easy to promote and apply, and it has great value. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of a preferred embodiment of the present invention.

[0020] Figure 2 Schematic diagram of the main landing gear in the retracted state in a preferred embodiment of the present invention.

[0021] Figure 3 Schematic diagram of the main landing gear retracted state in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below with reference to specific illustrations.

[0023] See also Figures 1 to 3 The active retraction type compact space main landing gear shown in the figure includes a strut 1, a main support 2, a lower rocker arm 3, a wheel tire 4, a buffer 5, a retraction actuator 6, an upper support arm 7, a retraction actuator 8, an upper lock 9 and a body structure, wherein one end of the strut 1 is connected to the body structure via a bolt and a nut, and the other end of the strut 1 is connected to the main support 2 via a bearing and a nut. The upper part of the main support 2 is connected to one end of the upper support arm 7 via a bolt and a nut, connected to one end of the retraction actuator 6 via a bearing and a nut, and connected to the body structure via a bearing, a bolt, and a nut. The lower part of the main pillar 2 is connected to the lower rocker arm 3 by bolts and nuts, and the retraction actuator 6 is rotatably connected to the upper support arm 7; the lower rocker arm 3 is connected to the wheel tire 4 by nuts and bearings; one end of the buffer 5 is connected to the upper support arm 7 by bearings, bolts and nuts, and the other end of the buffer 5 is connected to the lower rocker arm 3 by bearings, bolts and nuts; one end of the retractable actuator 8 is connected to the main pillar 2 by bearings, bolts and nuts, and the other end of the retractable actuator 8 is connected to the body structure; the upper lock 9 is connected to the body structure by bolts and nuts.

[0024] In this embodiment, the strut 1 is a foldable strut having a locking function in a lowered state, a hydraulic unlocking function, and a follow-up folding function when the main landing gear is retracted.

[0025] In this embodiment, the main support 2 is a steel forging formed by machining.

[0026] In this embodiment, a support structure for connecting with an upper arm is provided on the upper portion of the main support column 2 .

[0027] In this embodiment, the lower rocker arm 3 is a steel forging and is machined.

[0028] In this embodiment, the wheel tire 4 is a finished product, which is manufactured according to the overall design requirements of the aircraft and the landing gear.

[0029] In this embodiment, the buffer 5 is a buffer structure of a rocker-type landing gear, which adopts a single-cavity or double-cavity structure and is designed according to the overall design requirements of the aircraft and the landing gear.

[0030] In this embodiment, the retraction actuator 6 is an actuator with mechanical interlocks at both ends. Other methods can also be used to ensure that the main landing gear is locked in the extended state and the retracted state.

[0031] In this embodiment, the upper support arm 7 is a steel forging and is machined.

[0032] In this embodiment, the retractable actuator 8 is an actuator without mechanical interlock, and its main function is to retract and lower the main landing gear, and it also has an emergency lowering function.

[0033] In this embodiment, the uplock 9 is a common uplock structure. Existing uplocks or other types of uplocks can be selected. It should have a locking function in the retracted state of the main landing gear and a hydraulic and pneumatic unlocking function.

[0034] In this embodiment, when the main landing gear is lowered, the retraction actuator 8 extends, the upper lock 9 and the strut 1 are unlocked, and the retraction actuator 6 is extended. At this time, the main strut 2, the upper support arm 7, the buffer 5 and the lower rocker arm 3 form a four-bar linkage. The retraction actuator 6 is used to support and lock the four-bar linkage. The retraction actuator 8 drives the main strut 2 to be lowered. After the main strut 2 is lowered, the retraction actuator 6 retracts and drives the four-bar linkage to move until the wheel tire 4 is lowered, and the main landing gear is fully lowered. When the main landing gear is retracted, the upper lock 9 is in the unlocked state, the retraction actuator 6 begins to extend to push the upper support arm 7 to rotate, and the rotation of the upper support arm 7 drives the buffer 5 and the lower rocker arm 3 to move. The rotation of the lower rocker arm 3 causes the wheel tire 4 to be pulled toward the main support 2 until the main landing gear completes the retraction action; the strut 1 is unlocked from the locked state, the retraction actuator 6 retracts, and the strut 1 begins to fold with the retraction of the main landing gear until the main landing gear is retracted and is locked in the retracted state by the upper lock 9.

[0035] In this embodiment, the manufacturing steps of the active retractable compact space main landing gear are as follows:

[0036] 1) Based on the preliminary overall technical requirements of the aircraft, carry out the main landing gear overall layout, retraction and extension mechanism scheme design, motion simulation analysis, main force transmission path design, strength analysis and structural optimization, material selection, and weight reduction optimization design to form a main landing gear technical plan;

[0037] 2) Conduct landing cushioning performance design and analysis to obtain cushioning performance parameters that meet the requirements of sinking speed impact energy absorption and shutdown attitude control;

[0038] 3) Carry out detailed design of main landing gear and complete detailed design and drawing of test piece;

[0039] 4) Conduct test piece manufacturing to verify the manufacturability of the main landing gear technical solution;

[0040] 5) Conduct retraction and extension principle tests and retraction and extension durability tests to verify the feasibility and reliability of the retraction and extension mechanism;

[0041] 6) Conduct drop tests to verify the ability of the main landing gear test article's cushioning system to absorb landing energy, and the conformity of the ground impact load and filling parameters with design requirements;

[0042] 7) Conduct static tests to assess whether the main landing gear test piece structure meets the strength design requirements;

[0043] 8) Confirm whether the main landing gear meets the design specifications through theoretical and experimental analysis.

[0044] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. An active retractable compact space main landing gear, comprising a strut, a main support, a lower rocker arm, a wheel tire, a buffer, a retractable actuator, an upper support arm, a retractable actuator, an upper lock and a body structure, It is characterized in that One end of the strut is connected to the machine body structure, and the other end of the strut is connected to the main support. The upper part of the main support is respectively connected to one end of the upper support arm, one end of the retracting leg actuator and the machine body structure. The lower part of the main support is connected to the lower rocker arm, and the retracting leg actuator is rotatably connected to the upper support arm; the lower rocker arm is connected to the wheel tire; one end of the buffer is connected to the upper support arm, and the other end of the buffer is connected to the lower rocker arm; one end of the retracting actuator is connected to the main support, and the other end of the retracting actuator is connected to the machine body structure; the upper lock is connected to the machine body structure; When the main landing gear is lowered, the retracting actuator extends, the upper lock and the strut are in the unlocked state, and the retracting actuator is in the extended state. At this time, the main strut, the upper support arm, the buffer and the lower rocker arm form a four-bar linkage. The retracting actuator is used to support and lock the four-bar linkage. The retracting actuator drives the main strut to be lowered. After the main strut is lowered, the retracting actuator retracts and drives the four-bar linkage to move until the wheels and tires are lowered, and the main landing gear is lowered into place. When the main landing gear is retracted, the upper lock is in the unlocked state, the retraction actuator begins to extend to push the upper support arm to rotate, the rotation of the upper support arm drives the buffer and the lower rocker arm to move, and the rotation of the lower rocker arm causes the wheel tire to be pulled toward the main support until the main landing gear completes the retraction action; the strut is unlocked from the locked state, the retraction actuator retracts, and the strut begins to fold with the retraction of the main landing gear until the main landing gear is retracted, and is locked in the retracted state by the upper lock.

2. The active retractable compact space main landing gear according to claim 1, It is characterized in that The support rod is a foldable support rod having a locking function in a lowered state, a hydraulic unlocking function, and a function of folding with the main landing gear being retracted.

3. The active retractable compact space main landing gear according to claim 1, It is characterized in that A supporting structure for connecting with an upper support arm is arranged on the upper portion of the main support.

4. The active retractable compact space main landing gear according to claim 1, It is characterized in that The buffer is a buffer structure of a rocker-type landing gear.

5. The active retractable compact space main landing gear according to claim 1, It is characterized in that The leg-retracting actuator is an actuator with mechanical internal locks at both ends.

6. The active retractable compact space main landing gear according to claim 1, It is characterized in that The retractable actuator cylinder is an actuator cylinder without mechanical internal lock.

7. The active retractable compact space main landing gear according to claim 6, It is characterized in that The retractable actuator has an emergency lowering function.

8. The active retractable compact space main landing gear according to claim 1, It is characterized in that The main support, lower rocker arm and upper support arm are all steel forgings.

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