Landing gear shock absorber seal structure and assembly method

Abstract

The application provides a landing gear buffer sealing structure and an assembling method. The structure comprises an outer cylinder (1), a piston rod (2), a supporting sleeve (4), a first clamping ring (10), a check ring (11) and a second clamping ring (12). The head of the piston rod (2) is inserted into the outer cylinder (1) from the first end, and the outer side of the rod part of the piston rod (2) is sleeved with the supporting sleeve (4). The outer side of the supporting sleeve (4) is further sleeved with the check ring (11) and the second clamping ring (12). The first clamping ring (10) and the second clamping ring (12) are used for limiting the axial movement of the supporting sleeve (4). The problem that the sealing structure of super-high-strength steel is not suitable for thread connection is effectively solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of buffer technology, in particular to a landing gear buffer sealing structure and assembly method. BACKGROUND

[0002] The landing gear is a device located at the bottom of an airplane or helicopter for supporting the body and absorbing landing energy. The buffer is the core component of the landing gear for achieving buffer energy absorption, and is usually of an oil-gas type. The oil-gas buffer generates air spring force by compressing the buffer piston rod to compress the internal gas, and generates oil damping force by oil passing through the throttle hole, thereby achieving the function of buffer energy absorption. During the compression of the buffer, the pressure inside the buffer gradually rises and can reach tens of megapascals. How to seal the high-pressure oil and gas is a key problem to be solved in the design of the buffer sealing.

[0003] The buffer is composed of multiple cylinders with different diameters, which are sleeved together to form various cavities of the buffer, and the cavities need to be sealed. The sealing of the buffer can be divided into three types, namely fixed sealing, sliding sealing and rotating sealing, wherein the sliding sealing and the rotating sealing are also called movable sealing. In the movable sealing, relative motion exists for a long time, and in addition to the sealing problem, the friction between the cylinders also needs to be solved.

[0004] In recent years, super high strength steel has been increasingly used in landing gears. These materials are prone to fatigue problems due to their high strength. When designing the buffer structure, threaded connection should be avoided as much as possible. This also brings great challenges to the design of the buffer structure.

[0005] The conventional way is to achieve the movable sealing structure of the buffer by threaded connection. In order to avoid the fatigue problem of the structure using super high strength steel caused by threads, a non-threaded sealing structure needs to be designed. SUMMARY

[0006] The present application provides a landing gear buffer sealing structure and assembly method, which is a non-threaded sealing structure.

[0007] The first aspect of the present application provides a landing gear buffer sealing structure, comprising: an outer cylinder 1, a piston rod 2, a support sleeve 4, a first collar 10, a check ring 11 and a second collar 12.

[0008] The first end of the outer cylinder 1 is provided with an inner diameter increasing section;

[0009] The head of the piston rod 2 is inserted into the outer cylinder 1 from the first end and passes through the inner diameter increasing section,

[0010] The outer side of the rod part of the piston rod 2 is sleeved with the support sleeve 4,

[0011] The middle part of the outer side of the support sleeve 4 has an annular boss which is matched with the inner wall of the inner diameter increasing section with a small gap,

[0012] The first annular groove is arranged in the inner diameter increasing section; the first collar 10 is arranged in the first annular groove and is sleeved outside the support sleeve 4 and located outside the annular boss; the support sleeve 4 further has a stop ring 11 and a second collar 12 sleeved outside;

[0013] The second annular groove is arranged outside the first end of the support sleeve 4; the second collar 12 is arranged in the second annular groove and is attached to the outer end surface of the first end of the outer cylinder 1; the first collar 10 and the second collar 12 are used to limit the axial movement of the support sleeve 4;

[0014] The annular cavity is formed between the annular boss of the support sleeve 4, the second end head and the inner diameter increasing section, and the length of the annular cavity is L; the length of the annular cavity is greater than the length of the annular boss of the support sleeve 4 to the first end head.

[0015] Optionally, the landing gear shock absorber sealing structure further comprises a first support ring 3.

[0016] The third annular groove is arranged outside the head of the piston rod 2; the first support ring 3 is arranged inside the third annular groove; one side of the first support ring 3 is attached to the inner wall of the outer cylinder 1, and the other side is attached to the outer wall of the third annular groove on the piston rod 2.

[0017] Optionally, the landing gear shock absorber sealing structure further comprises a fixed sealing ring 5.

[0018] The recess is arranged outside the first end of the support sleeve 4; the fixed sealing ring 5 is arranged in the recess; one side of the fixed sealing ring 5 is attached to the inner wall of the outer cylinder 1, and the other side is attached to the outer wall of the recess.

[0019] Optionally, the landing gear shock absorber sealing structure further comprises a fixed sealing protection ring 6.

[0020] The fixed sealing protection ring 6 is arranged on the outer end surface of the fixed sealing ring 5.

[0021] The fixed sealing protection ring 6 is arranged on the outer end surface of the fixed sealing ring 5.

[0022] Optionally, the landing gear shock absorber sealing structure further comprises a second support ring 9.

[0023] The fourth annular groove is arranged inside the support sleeve 4; the second support ring 9 is arranged inside the fourth annular groove; one side of the second support ring 9 is attached to the outer wall of the piston rod 2, and the other side is attached to the inner wall of the fourth annular groove on the support sleeve 4.

[0024] Optionally, the landing gear shock absorber sealing structure further comprises a movable sealing ring 7.

[0025] The support sleeve 4 further has two movable sealing rings 7 arranged inside.

[0026] Optionally, the landing gear shock absorber sealing structure further comprises: a movable sealing protection ring 8.

[0027] The inner side of the support sleeve 4 is further provided with a movable sealing protection ring 8, which is arranged on the outer side end face of the movable sealing ring 7.

[0028] Optionally, the landing gear shock absorber sealing structure further comprises: a dustproof ring.

[0029] The outer side of the support sleeve 4 is provided with a dustproof ring on the matching surface of the piston rod 2.

[0030] The second aspect of the present application provides an assembly method for the landing gear shock absorber sealing structure as any one of the first aspect, comprising:

[0031] The support sleeve 4 is sleeved on the piston rod 2;

[0032] The support sleeve 4 and the piston rod 2 are pushed into the inner part of the outer cylinder 1, so that the first annular groove for installing the first clamping ring 10 is exposed, and the first clamping ring 10 is installed.

[0033] Air is filled into the landing gear shock absorber from the inflation nozzle of the piston rod 2, so that the piston rod 2 is extended outward, thereby driving the support sleeve 4 to extend outward until the first clamping ring 10 is contacted.

[0034] The stop ring 11 and the second clamping ring 12 are installed on the support sleeve 4.

[0035] The present application provides a landing gear shock absorber sealing structure and an assembly method, which is a sealing structure and an assembly method without threaded connection, effectively solving the problem that the threaded connection is not suitable for the sealing structure of ultra-high strength steel. The fatigue problem of ultra-high strength steel caused by threaded structure can be avoided, and the service life of the shock absorber is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is a cross-sectional view of the shock absorber;

[0037] Figure 2 It is an A-A cross-sectional view of Figure 1 ; and

[0038] Figure 3 It is a schematic view of the annular cavity;

[0039] MARKED DESCRIPTION:

[0040] The outer cylinder 1, the piston rod 2, the first support ring 3, the support sleeve 4, the fixed sealing ring 5, the fixed sealing protection ring 6, the movable sealing ring 7, the movable sealing protection ring 8, the second support ring 9, the first clamping ring 10, the stop ring 11, the second clamping ring 12, the dustproof ring 13 and the inflation nozzle 14. DETAILED DESCRIPTION

[0041] The technical solutions of the present application are explained below with reference to the drawings.

[0042] The present application provides a landing gear buffer sealing structure and an assembling method.

[0043] As Figures 1-3 shown, the landing gear buffer sealing structure provided by the present application comprises an outer cylinder 1, a piston rod 2, a first support ring 3, a support sleeve 4, a fixed sealing ring 5, a fixed sealing protection ring 6, a movable sealing ring 7, a movable sealing protection ring 8, a second support ring 9, a first clamping ring 10, a blocking ring 11, a second clamping ring 12, a dustproof ring 13, and an inflation valve 14.

[0044] The outer cylinder 1 and the piston rod 2 are the main structural components of the buffer. One end of the piston rod is inserted into the inner part of the outer cylinder, forming a cavity inside the buffer. When the buffer is working, there is relative movement between the outer cylinder 1 and the piston rod 2. When the buffer is compressed, the piston rod 2 moves from right to left as shown by the arrow, and when the buffer is stretched, it moves from left to right. Figure 1 The inner cavity of the outer cylinder 1 and the piston rod 2 is filled with oil and gas, and the pressure increases with the compression of the buffer and decreases with the stretching of the buffer.

[0045] One end of the piston rod 2 is the head, and the outer side of the head is provided with a third annular groove. The first support ring 3 is installed in the third annular groove. One side of the first support ring 3 is attached to the inner wall of the outer cylinder 1, and the other side is attached to the outer wall of the third annular groove on the piston rod 2, so that a certain gap is left between the outer cylinder 1 and the piston rod 2 to prevent friction between the outer cylinder 1 and the piston rod 2.

[0046] The support sleeve 4 is used to seal the outer cylinder 1 and the piston rod 2 and the piston rod. As Figure 3 shown, the inner diameter of one end of the outer cylinder 1 is increased. The support sleeve 4 is installed between the outer cylinder 1 and the piston rod 2, and one end is matched with the inner wall of the outer cylinder with a small gap (D2), and the middle part has an annular boss matched with the inner wall of the increased inner diameter of the outer cylinder with a small gap (D1). After installation, an annular cavity is formed between the support sleeve 4 and the outer cylinder 1, and the length of the annular cavity is L.

[0047] The support sleeve 4 and the outer cylinder 1 are sealed at the matching surface with a diameter of D2 by the fixed sealing ring 5. The fixed sealing protection ring 6 is installed on the outer side of the fixed sealing ring 5 to protect the fixed sealing ring 5.

[0048] The support sleeve 4 has a fourth annular groove on the side close to the piston rod 2, and the second support ring 9 is installed in the fourth annular groove. One side of the second support ring 9 is attached to the outer wall of the piston rod 2, and the other side is attached to the inner wall of the fourth annular groove on the support sleeve 4, so that a certain gap is left between the support sleeve 4 and the piston rod 2 to prevent friction between the support sleeve 4 and the piston rod 2. The support sleeve 4 and the piston rod 2 are sealed by two movable sealing rings 7 at the cooperation surface with a diameter of D3. The movable sealing rings 7 are respectively installed with movable sealing protection rings 8 on the outside to protect the fixed sealing ring 7.

[0049] The outer cylinder 1 has a first annular groove at the position where the inner diameter is increased, and the first clamping ring 10 is installed in the first annular groove. The first clamping ring 10 contacts with the boss on the support sleeve 4 to limit the outward movement of the support sleeve. The first clamping ring 10 includes three sections.

[0050] The buffer has pressure inside, and the piston rod 2 will extend outward under the action of the pressure. The annular boss at one end of the piston rod 2 contacts with the support sleeve 4 when the piston rod extends outward, which can prevent the piston rod 2 from being pulled out of the outer cylinder 1 and plays a limiting role.

[0051] The first clamping ring 10 is installed with a check ring 11 and a second clamping ring 12 on the outside. The second clamping ring 12 is installed in the second annular groove on the support sleeve 4 and contacts with the check ring 11 on one side to limit the inward movement of the support sleeve 4. The dustproof ring is installed on the cooperation surface between the outer side of the support sleeve 4 and the piston rod 2 to prevent dust from entering the inside of the buffer.

[0052] The piston rod 2 is arranged with an inflation nozzle to inflate the inside of the buffer. By reasonably setting the distance between the boss on the support sleeve 4 and the outer side end face of the support sleeve 4, the length L of the annular cavity formed between the support sleeve 4 and the outer cylinder 1 is less than the distance. When assembling the buffer, the sealing ring and the dustproof ring are installed on the support sleeve 4 first. The support sleeve 4 is sleeved on the piston rod 2. The support sleeve 4 and the piston rod 2 are pushed into the inside of the outer cylinder 1 to expose the first annular groove where the first clamping ring 10 is installed. The first clamping ring 10 is installed. The inside of the buffer is inflated from the inflation nozzle, so that the piston rod 2 extends outward, thereby driving the support sleeve 4 to extend outward until it contacts with the first clamping ring 10. The check ring 11 and the second clamping ring 12 are installed on the support sleeve.

[0053] The key points of the present application are as follows:

[0054] By setting the annular cavity between the support sleeve 4 and the outer cylinder 1, the length L of the annular cavity is greater than the distance between the boss on the support sleeve 4 and the outer side end face of the support sleeve 4. The installation problem of the first clamping ring 10 is solved.

[0055] The first clamping ring 10 is used to limit the movement of the support sleeve 4, and the check ring 11 and the second clamping ring 12 are used to limit the inward movement of the support sleeve 4 with the first clamping ring 10. The movement of the support sleeve 4 relative to the outer cylinder 1 is limited by the clamping ring.

[0056] In the assembly process, first, the support sleeve 4 is pushed into the outer cylinder 1, and the first collar 10 is installed. Then, the support sleeve 4 is moved outward and contacted with the first collar 10 by inflating the air cavity.

Claims

1. A landing gear bumper seal structure, characterized by, Comprise: The outer cylinder (1), the piston rod (2), the support sleeve (4), the first collar (10), the check ring (11) and the second collar (12); The first end of the outer cylinder (1) is provided with an inner diameter increasing section; The head of the piston rod (2) is inserted into the outer cylinder (1) from the first end and passes through the inner diameter increasing section, The rod part of the piston rod (2) is provided with the support sleeve (4) outside, The middle part of the support sleeve (4) outside has an annular boss, which is matched with the inner wall of the inner diameter increasing section with small gap, The inner diameter increasing section is provided with a first annular groove; The first annular groove is provided with a first collar (10), and the first collar (10) is provided outside the support sleeve (4) and located outside the annular boss; The support sleeve (4) is further provided with a check ring (11) and a second collar (12) outside; The first end of the support sleeve (4) is provided with a second annular groove outside; The second collar (12) is clamped in the second annular groove and is attached to the outer end face of the first end of the outer cylinder (1), and the first collar (10) and the second collar (12) are used to limit the axial movement of the support sleeve (4); The annular boss of the support sleeve (4), the second end head and the inner diameter increasing section form an annular cavity, and the length of the annular cavity is L; The length of the annular cavity is greater than the length of the annular boss to the first end head of the support sleeve (4); The landing gear buffer sealing structure further comprises: a fixed sealing ring (5); The first end of the support sleeve (4) is provided with a groove outside, and the fixed sealing ring (5) is arranged in the groove, one side of the fixed sealing ring (5) is attached to the inner wall of the outer cylinder (1), and the other side is attached to the outer wall of the groove; The landing gear buffer sealing structure further comprises: a movable sealing ring (7); The inner side of the support sleeve (4) is further provided with two movable sealing rings (7).

2. The landing gear bumper seal structure of claim 1, wherein Also include: The first support ring (3); The outer side of the head of the piston rod (2) is provided with a third annular groove, and the first support ring (3) is installed inside the third annular groove, one side of the first support ring (3) is attached to the inner wall of the outer cylinder (1), and the other side is attached to the outer wall of the third annular groove on the piston rod (2).

3. A landing gear bumper seal structure according to claim 2, wherein Also include: Fixed sealing protection ring (6); The fixed sealing protection ring (6) is further arranged in the groove; The fixed sealing protection ring (6) is arranged on the outer side end face of the fixed sealing ring (5).

4. The landing gear bumper seal structure of claim 1, wherein Also include: The second support ring (9); The inner side of the support sleeve (4) is provided with a fourth annular groove, and the second support ring (9) is installed inside the fourth annular groove, one side of the second support ring (9) is attached to the outer wall of the piston rod (2), and the other side is attached to the inner wall of the fourth annular groove on the support sleeve (4).

5. The landing gear seal structure of claim 1, wherein Also include: Movable sealing protection ring (8); The inner side of the support sleeve (4) is further provided with a movable sealing protection ring (8), and the movable sealing protection ring (8) is arranged on the outer side end face of the movable sealing ring (7).

6. The landing gear seal structure of claim 1, wherein Also include: Dustproof ring; The outer side of the support sleeve (4) and the matching surface of the piston rod (2) are provided with a dustproof ring.

7. A method of assembly for a landing gear bumper seal structure as claimed in any one of claims 1 to 6, characterised in that, Include: Put the support sleeve (4) on the piston rod (2); Push the support sleeve (4) and the piston rod (2) into the outer cylinder (1) to expose the first annular groove where the first collar (10) is installed, and install the first collar (10); The piston rod (2) is extended outwards by inflating the landing gear buffer from the inflation nozzle of the piston rod (2), so as to drive the support sleeve (4) to extend outwards until the first collar (10) is contacted; The retainer ring (11) and the second collar (12) are installed on the support sleeve (4).

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