Actuating cylinder for folding and unfolding undercarriage

By designing an actuator suitable for landing gear retraction and extension, including a follower cylinder extension lock assembly, the problem that existing actuators are unsuitable as follower cylinders is solved, achieving lightweighting and improved stability, reducing costs and preventing accidental activation.

CN223686820UActive Publication Date: 2025-12-19SICHUAN LINGFENG AVIATION HYDRAULIC MACHINERY
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Patent Information

Application Number
CN202423161560.3
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Filing Date
2024-12-20
Publication Date
2025-12-19
Estimated Expiration
2034-12-20

AI Technical Summary

Technical Problem

Existing actuators are not convenient to use as follower actuators, and in order to ensure the stability of the landing gear retraction and extension process, a locking structure is usually added, which makes the structure complex and unsuitable as a follower actuator.

Method used

An actuating cylinder is designed, comprising a follower cylinder, a follower cylinder end cap assembly, a follower cylinder outer cylinder assembly, a follower cylinder piston rod assembly, and a follower cylinder ear bolt assembly. By setting a follower cylinder extension lock assembly, the cylinder can only be unlocked when the input oil pressure is greater than a preset value, thus ensuring the stable extension and retraction of the follower cylinder.

Benefits of technology

The lightweight design of the follower cylinder reduces costs, and the locking components prevent accidental activation, ensuring the stability and safety of landing gear retraction and extension.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model relates to the technical field of undercarriages, and discloses an actuating cylinder for folding and unfolding an undercarriage, which comprises a follow-up cylinder, and the follow-up cylinder comprises a follow-up cylinder end cover assembly, a follow-up cylinder outer cylinder assembly, a follow-up cylinder piston rod assembly and a follow-up cylinder earring bolt assembly. The hydraulic cylinder further comprises a follow-up cylinder extending lock assembly, the follow-up cylinder extending lock assembly and the follow-up cylinder piston rod assembly are matched to form a locking part, and the locking part can be unlocked only when input oil pressure is larger than a preset value. According to the servo cylinder, the function that the servo cylinder is only driven by the driving cylinder to stretch out and draw back is achieved, compared with a common actuator cylinder, the servo cylinder is lighter in configuration, and cost is effectively reduced; by arranging the locking part, the follow-up cylinder has a locking function, the second follow-up cylinder piston rod can be released only when input oil pressure is larger than the elastic force of the extending spring, and it is ensured that the follow-up cylinder cannot be started by mistake.
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Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of landing gear, specifically is a kind of for the operation cylinder of landing gear retraction. BACKGROUND

[0002] The aircraft landing gear is mainly controlled by the extension of hydraulic actuator during retraction process. However, the weight and space requirements are often high during the design process of the aircraft landing gear, and it is difficult to meet the space requirements of the aircraft landing gear retraction actuator in a small aircraft space by a single large-diameter actuator. Therefore, a small-diameter actuator is needed to achieve synchronous extension by setting a main drive and a follow-up. Figure 1 As shown in the accompanying drawings, the oil circuit of the oil supply and return system 1 is communicated with the main cylinder 2 and the follow-up cylinder 3, and the extension of the main cylinder 2 and the follow-up cylinder 3 is controlled by the oil supply and return system 1. The main cylinder 2 and the follow-up cylinder 3 are installed on the same connecting rod, and the output ends of the main cylinder 2 and the follow-up cylinder 3 are also installed on the same connecting rod. The main cylinder 2 drives the follow-up cylinder 3 to extend and retract through the connecting rod to complete the retraction of the landing gear.

[0003] For the follow-up actuator, its extension can only be driven by the main cylinder and does not need to be driven by hydraulic oil, so the existing actuator is not convenient to use as a follow-up cylinder. On the other hand, in order to ensure the stability during the retraction of the landing gear, a locking structure is usually added to the actuator to ensure that the actuator will not be started by mistake. INVENTION CONTENTS

[0004] The utility model aims at providing an actuator for landing gear retraction to solve the problem that the existing actuator is not convenient to use as a follow-up cylinder.

[0005] The utility model is implemented by the following technical scheme: an actuator for landing gear retraction, comprising a follow-up cylinder, the follow-up cylinder comprising a follow-up cylinder end cover assembly, a follow-up cylinder outer cylinder assembly, a follow-up cylinder piston rod assembly and a follow-up cylinder ear bolt assembly, the follow-up cylinder end cover assembly comprising a follow-up cylinder end cover, the follow-up cylinder outer cylinder assembly comprising a follow-up cylinder outer cylinder, the follow-up cylinder outer cylinder being provided with a follow-up cylinder extension nozzle; the follow-up cylinder piston rod assembly comprising a second follow-up cylinder piston rod, and the follow-up cylinder ear bolt assembly comprising a follow-up cylinder ear bolt assembly oil supply and return system; the follow-up cylinder piston rod assembly comprising a second follow-up cylinder piston rod.

[0006] It also comprises a follow-up cylinder extension lock assembly, which cooperates with the follow-up cylinder piston rod assembly to form a locking component, and the locking component needs to input oil pressure greater than a preset value to be unlocked.

[0007] For better implementation of the utility model, further, the follow-up cylinder extension lock assembly further includes an adjusting gasket, the adjusting gasket is installed on the follow-up cylinder outer cylinder, and the adjusting gasket is matched with the lock ring.

[0008] For better implementation of the utility model, further, the follow-up cylinder extension lock assembly further includes an adjusting gasket, the adjusting gasket is installed on the follow-up cylinder outer cylinder, and the adjusting gasket is matched with the lock ring.

[0009] For better implementation of the utility model, further, the follow-up cylinder extension lock assembly further includes an adjusting gasket, the adjusting gasket is installed on the follow-up cylinder outer cylinder, and the adjusting gasket is matched with the lock ring.

[0010] For better implementation of the utility model, further, the follow-up cylinder extension lock assembly further includes an adjusting gasket, the adjusting gasket is installed on the follow-up cylinder outer cylinder, and the adjusting gasket is matched with the lock ring.

[0011] For better implementation of the utility model, further, the follow-up cylinder extension lock assembly further includes an adjusting gasket, the adjusting gasket is installed on the follow-up cylinder outer cylinder, and the adjusting gasket is matched with the lock ring.

[0012] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0013] (1) the utility model discloses the function that the follow-up cylinder only is driven and is retracted by the driving cylinder, compared with the ordinary follow-up cylinder, the configuration of the utility model is lighter, and cost is effectively reduced, and it is more suitable as the follow-up cylinder.

[0014] (2) the utility model discloses the locking function of follow-up cylinder by setting locking part, and the second follow-up cylinder piston rod can be released only when the input oil pressure is greater than the extension spring elasticity, so that the follow-up cylinder is prevented from being misstarted. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a schematic diagram of double-acting cylinder landing gear structure.

[0016] Figure 2 It is a schematic diagram of the whole structure of the utility model.

[0017] Figure 3 It is a sectional view of the locking component structure.

[0018] 1-oil supply and return system; 2-driving cylinder; 3-following cylinder; 31-following cylinder end cover assembly; 32-following cylinder extension lock assembly; 33-following cylinder outer cylinder assembly; 34-following cylinder piston rod assembly; 35-following cylinder ear bolt assembly; 311-following cylinder end cover; 312-first following cylinder joint bearing; 321-sealing sleeve; 322-following cylinder spring sleeve; 323-extension spring; 324-adjusting gasket; 325-lock ring; 331-following cylinder outer cylinder; 332-following cylinder extension nozzle; 333-sealing cover; 341-second following cylinder piston rod; 342-extension ring; 343-sliding block; 344-following cylinder piston rod support ring. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the utility model.

[0020] In the description of the utility model, it should be explained that, unless explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0021] Embodiment 1:

[0022] The embodiment provides an acting cylinder for landing gear retraction and extension, specifically as follows Figures 1-3As shown, including follow-up cylinder 3, the follow-up cylinder 3 includes follow-up cylinder end cap assembly 31, follow-up cylinder outer cylinder assembly 33, follow-up cylinder piston rod assembly 34, follow-up cylinder ear bolt assembly 35, the follow-up cylinder end cap assembly 31 includes follow-up cylinder end cap 311, the follow-up cylinder outer cylinder assembly 33 includes follow-up cylinder outer cylinder 331, the follow-up cylinder outer cylinder 331 is provided with follow-up cylinder extension nozzle 332; the follow-up cylinder piston rod assembly 34 includes the second follow-up cylinder piston rod 341, the follow-up cylinder ear bolt assembly 35 includes the follow-up cylinder ear bolt assembly 35 oil supply and oil return system 1; follow-up cylinder piston rod assembly 34 includes the second follow-up cylinder piston rod 341;

[0023] Also includes follow-up cylinder extension lock assembly 32, the follow-up cylinder extension lock assembly 32 and follow-up cylinder piston rod assembly 34 cooperate to form a locking component, the locking component needs to input oil pressure greater than the preset value to unlock.

[0024] The follow-up cylinder extension lock assembly 32 includes a sealing sleeve 321, a follow-up cylinder spring sleeve 322, an extension spring 323, a lock ring 325; the follow-up cylinder piston rod assembly 34 further includes an extension ring 342, a slider 343, the sealing sleeve 321, the sealing sleeve 321 is installed on the follow-up cylinder outer cylinder 331, the follow-up cylinder outer cylinder 331 cooperates with the sealing sleeve 321 to realize sealing, the sealing sleeve 321 is provided with an unlocking cavity, the unlocking cavity is connected with the follow-up cylinder extension nozzle 332, the follow-up cylinder spring sleeve 322 slides in the unlocking cavity of the sealing sleeve 321, the outer edge of the follow-up cylinder spring sleeve 322 is a stepped cylindrical shape, the extension spring 323 is installed on the follow-up cylinder end cap 311, the extension spring 323 is connected with the follow-up cylinder spring sleeve 322, the lock ring 325 is installed on the follow-up cylinder outer cylinder 331; the second follow-up cylinder piston rod 341 is provided with an extension ring 342, a plurality of sliders 343 are radially slidably connected on the second follow-up cylinder piston rod 341, the extension ring 342 has an outer taper surface, the lock ring 325 has an inner taper surface, and the end of the follow-up cylinder spring sleeve 322 away from the extension spring 323 has an outer taper surface.

[0025] When the oil at the oil supply and oil return system 1 enters the unlocking cavity from the follow-up cylinder extension nozzle 332, the oil extrudes the follow-up cylinder spring sleeve 322, so that the follow-up cylinder spring sleeve 322 approaches the follow-up cylinder end cap 311, at this time the extension spring 323 is extruded, when the follow-up cylinder spring sleeve 322 contacts the follow-up cylinder end cap 311, the outer taper surface of the follow-up cylinder spring sleeve 322 is at the lock ring 325, because the radius of the outer taper surface is reduced, therefore the follow-up cylinder spring sleeve 322 will not support the lock ring 325, and the unlocking is completed.

[0026] When the active cylinder 2 drives the follow-up cylinder 3 to extend, the second follow-up cylinder piston rod 341 starts to move away from the follow-up cylinder extension lock assembly 32, at this time the second follow-up cylinder piston rod 341 drives the extension snap ring 342 to move synchronously, because the outer taper surface of the extension snap ring 342 is pressed by the inner taper surface of the lock ring 325, so the extension snap ring 342 starts to shrink and press the sliding block 343, at this time the sliding block 343 can smoothly retract along the radial direction because it is not supported by the follow-up cylinder spring sleeve 322; at this time the second follow-up cylinder piston rod 341 smoothly extends.

[0027] When the second follow-up cylinder piston rod 341 is retracted and reset, the oil pressure in the unlocking cavity is gradually reduced, at this time the follow-up cylinder spring sleeve 322 starts to reset away from the follow-up cylinder end cover 311 under the action of the extension spring 323, that is, the follow-up cylinder spring sleeve 322 starts to support the sliding block 343, and the sliding block 343 pushes the extension snap ring 342, at this time if the second follow-up cylinder piston rod 341 is to be extended, the lock ring 325 will limit and block the extension snap ring 342, causing the second follow-up cylinder piston rod 341 to be unable to extend.

[0028] Embodiment 2:

[0029] This embodiment is further expanded on the basis of the above-mentioned embodiments, and specifically as shown in Figure 3 The follow-up cylinder extension lock assembly 32 further includes an adjusting washer 324, which is installed on the follow-up cylinder outer cylinder 331, and the adjusting washer 324 cooperates with the lock ring 325.

[0030] The thickness of the adjusting washer 324 is polished to adjust the gap between the lock ring 325 and the sliding block 343, that is, to facilitate the adjustment of the lock gap.

[0031] The other parts of this embodiment are the same as those of the above-mentioned embodiments and will not be described again.

[0032] Embodiment 3:

[0033] This embodiment is further expanded on the basis of the above-mentioned embodiments, and specifically as shown in Figure 3 The follow-up cylinder piston rod assembly 34 further includes a follow-up cylinder piston rod support ring 344, which is sleeved on the second follow-up cylinder piston rod 341. By sleeving the follow-up cylinder piston rod support ring 344, the running stability of the second follow-up cylinder piston rod 341 is improved.

[0034] The other parts of this embodiment are the same as those of the above-mentioned embodiments and will not be described again.

[0035] Embodiment 4:

[0036] This embodiment is further expanded on the basis of the above-mentioned embodiments, and specifically as shown in Figure 2As shown, the follow-up cylinder end cover assembly 31 further comprises a first follow-up cylinder joint bearing 312, which is installed on the follow-up cylinder end cover 311; the follow-up cylinder lug bolt assembly 35 further comprises a follow-up cylinder lug bolt assembly 35 driving cylinder 2, which is installed on the follow-up cylinder lug bolt assembly 35 oil supply and oil return system 1.

[0037] The first follow-up cylinder joint bearing 312 and the follow-up cylinder lug bolt assembly 35 driving cylinder 2 are used for installing the connecting rod, and the relative movement between the connecting rod and the driving cylinder 2 and the follow-up cylinder 3 is more convenient and the resistance is smaller by setting the first follow-up cylinder joint bearing 312 and the follow-up cylinder lug bolt assembly 35 driving cylinder 2.

[0038] The other parts of the embodiment are the same as those of the above-mentioned embodiments, and will not be described again.

[0039] Embodiment 5:

[0040] The embodiment is further extended on the basis of the above-mentioned embodiments, and specifically as Figure 2 As shown, the follow-up cylinder lug bolt assembly 35 further comprises a follow-up cylinder lug bolt assembly 35 follow-up cylinder 3, which is arranged between the follow-up cylinder outer cylinder 331 and the follow-up cylinder lug bolt assembly 35 oil supply and oil return system 1. The follow-up cylinder lug bolt assembly 35 follow-up cylinder 3 seals the follow-up cylinder outer cylinder 331 and the follow-up cylinder lug bolt assembly 35 oil supply and oil return system 1, improves the sealing degree of the follow-up cylinder 3, and prevents impurities from entering the inside.

[0041] The other parts of the embodiment are the same as those of the above-mentioned embodiments, and will not be described again.

[0042] The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form, and any simple modification and equivalent change according to the technical essence of the utility model to the above-mentioned embodiment all fall within the protection scope of the utility model.

Claims

1. An actuator cylinder for landing gear retraction, characterised in that: The followings are included: a follow-up cylinder (3) including a follow-up cylinder end cover assembly (31), a follow-up cylinder outer cylinder assembly (33), a follow-up cylinder piston rod assembly (34), a follow-up cylinder ear bolt assembly (35), the follow-up cylinder end cover assembly (31) including a follow-up cylinder end cover (311), the follow-up cylinder outer cylinder assembly (33) including a follow-up cylinder outer cylinder (331), the follow-up cylinder outer cylinder (331) being provided with a follow-up cylinder extension nozzle (332); the follow-up cylinder piston rod assembly (34) including a second follow-up cylinder piston rod (341), the follow-up cylinder ear bolt assembly (35) including a follow-up cylinder ear bolt assembly (35) oil supply and return system (1); the follow-up cylinder piston rod assembly (34) including a second follow-up cylinder piston rod (341); Further including a follow-up cylinder extension lock assembly (32), the follow-up cylinder extension lock assembly (32) cooperating with the follow-up cylinder piston rod assembly (34) to form a locking component, the locking component requiring an input oil pressure greater than a preset value to be unlocked.

2. An actuating cylinder for the retraction and extension of a landing gear according to claim 1, characterized in that: The follow-up cylinder extension lock assembly (32) includes a sealing sleeve (321), a follow-up cylinder spring sleeve (322), an extension spring (323), and a lock ring (325); the follow-up cylinder piston rod assembly (34) further includes an extension snap ring (342) and a sliding block (343), the sealing sleeve (321) is installed on the follow-up cylinder outer cylinder (331), the follow-up cylinder outer cylinder (331) cooperates with the sealing sleeve (321) to realize sealing, the sealing sleeve (321) is provided with an unlocking cavity, the unlocking cavity is connected with the follow-up cylinder extension nozzle (332), the follow-up cylinder spring sleeve (322) slides in the unlocking cavity of the sealing sleeve (321), the outer edge of the follow-up cylinder spring sleeve (322) is a stepped cylindrical shape, the extension spring (323) is installed on the follow-up cylinder end cover (311), the extension spring (323) is connected with the follow-up cylinder spring sleeve (322), and the lock ring (325) is installed on the follow-up cylinder outer cylinder (331); the second follow-up cylinder piston rod (341) is provided with the extension snap ring (342), and a plurality of sliding blocks (343) are radially and slidably connected on the second follow-up cylinder piston rod (341), the extension snap ring (342) has an outer taper surface, the lock ring (325) has an inner taper surface, and the end of the follow-up cylinder spring sleeve (322) away from the extension spring (323) has an outer taper surface.

3. An actuator cylinder for landing gear retraction according to claim 2, characterised in that: The follow-up cylinder extension lock assembly (32) further includes an adjusting gasket (324), the adjusting gasket (324) is installed on the follow-up cylinder outer cylinder (331), and the adjusting gasket (324) cooperates with the lock ring (325).

4. An actuating cylinder for landing gear retraction according to claim 1, characterized in that: The follow-up cylinder piston rod assembly (34) further includes a follow-up cylinder piston rod support ring (344), and the follow-up cylinder piston rod support ring (344) is sleeved on the second follow-up cylinder piston rod (341).

5. An actuating cylinder for landing gear retraction according to claim 1, characterized in that: The follow-up cylinder end cover assembly (31) further comprises a first follow-up cylinder knuckle bearing (312) mounted on the follow-up cylinder end cover (311); the follow-up cylinder lug bolt assembly (35) further comprises a follow-up cylinder lug bolt assembly (35) driving cylinder (2) mounted on the follow-up cylinder lug bolt assembly (35) oil supply and return system (1).

6. An actuating cylinder for landing gear retraction according to claim 1, characterized in that: The follow-up cylinder lug bolt assembly (35) further comprises a follow-up cylinder lug bolt assembly (35) follow-up cylinder (3) arranged between the follow-up cylinder outer cylinder (331) and the follow-up cylinder lug bolt assembly (35) oil supply and return system (1).