Buffer sealing device

Abstract

The invention belongs to the technical field of undercarriage design, and particularly relates to a buffer sealing device. The device comprises a supporting ring (6) arranged between a piston rod (5) of the undercarriage buffer and a shell (8) in a sleeving mode, and a gap (7) is formed between the supporting ring (6) and the piston rod (5); four inner wall ring grooves are formed in the inner wall of the supporting ring (6) from the front end to the rear end in the axial direction, the first inner wall ring groove and the third inner wall ring groove are each internally connected with a nonmetal guide ring (1) in a pressed mode, the second inner wall ring groove is internally connected with a combined sealing ring (2) in a pressed mode, and the fourth inner wall ring groove is internally connected with a dustproof ring (3) in a pressed mode. The outer wall of the supporting ring (6) is sleeved with a static sealing ring (4). The gap (7) has a minimum dimension between the two non-metallic guide rings (1) and a maximum dimension at the rear end. The problem of abrasion of the piston rod of the large-deformation and large-side-load buffer is solved, and the requirement for machining precision of the surface of the piston rod is lowered.

Description

Technical Field

[0001] The present application belongs to the technical field of landing gear design, and in particular relates to a buffer sealing device. Background Art

[0002] The function of the landing gear buffer sealing device is to seal the oil-gas mixture pressure inside the buffer. The more common sealing devices are composed of relatively simple O-rings and dust rings. With the development of sealing ring technology, T-rings and some combined sealing rings have been used in China. The clearance fit tolerance between the metal support ring and the piston rod is generally f7 / H8, which belongs to a small clearance fit. These sealing devices have solved the sealing problem of the buffer very well, but none of them have solved the contact wear problem between the piston rod and the metal support, especially for large aircraft landing gear. When the heading load and lateral load are large, the piston rod and the support are in contact and friction, and the piston rod surface will have different degrees of wear. Summary of the invention

[0003] In order to solve the above problems, the present application provides a buffer sealing device, including a support ring sleeved between a piston rod and a housing of a landing gear buffer, a gap is formed between the support ring and the piston rod, and the support ring includes a front end A and a rear end B along the axial direction;

[0004] The inner wall of the support ring is provided with four inner wall ring grooves along the axial direction from the front end A to the rear end B, a non-metallic guide ring is crimped in the first inner wall ring groove and the third inner wall ring groove respectively, a combined sealing ring is crimped in the second inner wall ring groove, and a dust ring is crimped in the fourth inner wall ring groove;

[0005] The outer wall of the support ring is provided with an outer wall annular groove, in which a static sealing ring is pressed;

[0006] The gap has a minimum dimension between the two non-metallic guide rings, a maximum dimension at the rear end, and a dimension at the front end between the minimum dimension and the maximum dimension.

[0007] Preferably, the combined sealing ring includes at least one hard retaining ring and one rubber ring.

[0008] Preferably, the hard retaining ring comprises a fluoroplastic sealing ring or a polyetheretherketone sealing ring.

[0009] Preferably, an oil film is provided between the hard retaining ring and the piston rod.

[0010] Preferably, an oil film is provided in the gap between the dust ring and the combined sealing ring.

[0011] Preferably, the outer wall annular groove is arranged between the front end along the axial direction of the support ring and the first inner wall annular groove.

[0012] Preferably, the minimum size of the gap between the two non-metallic guide rings is set to 0.1 mm-0.2 mm.

[0013] Preferably, the minimum dimension of the gap between two non-metallic guide rings is set to 0.15 mm.

[0014] Preferably, the maximum dimension of the gap at the rear end is set to 0.2 mm-1 mm.

[0015] Preferably, the maximum dimension of the gap at the rear end is set to 0.5 mm.

[0016] Preferably, the maximum dimension of the gap at the rear end is set to 0.8 mm.

[0017] Preferably, the size of the gap at the front end is set to 0.1 mm-0.5 mm.

[0018] Preferably, the size of the gap at the front end is set to 0.3 mm.

[0019] The present application solves the piston rod wear problem of a buffer with large deformation and large side load, and reduces the machining accuracy requirement for the piston rod surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural cross-sectional view of a preferred embodiment of the buffer sealing device of the present application.

[0021] Among them, 1- non-metallic guide ring, 2- combined sealing ring, 3- dust ring, 4- static sealing ring, 5- piston rod, 6- support ring, 7- gap, 8- housing. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the implementation of this application clearer, the technical scheme in the implementation of this application will be described in more detail in combination with the drawings in the implementation of this application. In the drawings, the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The described implementation is a part of the implementation of this application, not all of the implementations. The implementation described below with reference to the drawings is exemplary and is intended to be used to explain this application, and cannot be understood as a limitation on this application. Based on the implementation in this application, all other implementations obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application. The implementation of this application is described in detail below in combination with the drawings.

[0023] The present application provides a buffer sealing device, such as Figure 1 As shown, it mainly includes:

[0024] A support ring 6 is sleeved between the piston rod 5 and the outer shell 8 of the landing gear buffer, and a gap 7 is formed between the support ring 6 and the piston rod 5. The support ring 6 includes a front end A and a rear end B along the axial direction;

[0025] The inner wall of the support ring 6 is provided with four inner wall ring grooves along the axial direction from the front end A to the rear end B, a non-metallic guide ring 1 is crimped in the first inner wall ring groove and the third inner wall ring groove respectively, a combined sealing ring 2 is crimped in the second inner wall ring groove, and a dust ring 3 is crimped in the fourth inner wall ring groove;

[0026] The outer wall of the support ring 6 is provided with an outer wall annular groove, in which a static sealing ring 4 is pressed;

[0027] The gap 7 has a minimum size between the two non-metallic guide rings 1 , a maximum size at the rear end, and a size at the front end between the minimum size and the maximum size.

[0028] This application uses a non-metallic guide ring 1 as a spacer between the piston rod 5 and the support ring 6. The guide ring material has wear resistance and pressure resistance. The guide ring material is selected according to the buffer load and the size of the guide ring is designed; at the same time, the compression thickness deformation size of the guide ring is calculated; this size is the maximum allowable gap between the piston rod and the support ring. The dynamic seal ring, that is, the combined seal ring 2 is placed between the two non-metallic guide rings 1, and the pressure resistance of the non-metallic guide rings 1 on both sides is fully utilized to ensure that the sealing gap at the dynamic seal ring is a certain value; the compression amount of the dynamic seal ring is designed according to the calculated maximum gap.

[0029] The present application utilizes the non-metallic guide ring 1 to bear the lateral load of the buffer, enlarges the gap between the support ring 6 and the piston rod 5, avoids the deformation of the piston 5, and divides the gap between the piston rod 5 and the support ring 6 into three parts. The gaps on both sides of the combined sealing ring 2 are small to ensure the compression performance of the sealing ring. The gap corresponding to the static sealing ring 4 installed at the front end of the support ring 6 is relatively large, and the gap corresponding to the dust ring 3 installed at the rear end of the support ring 6 is even larger. In this way, the contact between the support ring 6 and the piston rod 5 can be avoided on the basis of ensuring the sealing performance.

[0030] In some optional embodiments, the combined sealing ring 2 includes at least one hard retaining ring and one rubber ring. In this embodiment, the hard retaining ring has a certain rigidity and strength to adapt to the large gap at the sealing position.

[0031] In some optional embodiments, the hard retaining ring includes a fluoroplastic sealing ring or a polyetheretherketone sealing ring.

[0032] In some optional embodiments, an oil film is provided between the hard retaining ring and the piston rod 5. In this embodiment, the hard retaining ring, such as a fluoroplastic sealing ring, leaves a thicker oil film during the movement of the buffer, thereby ensuring lubrication and sealing.

[0033] In some optional embodiments, an oil film is provided in the gap 7 between the dust ring 3 and the combined sealing ring 2. In this embodiment, a large gap is left between the dust ring 3 and the combined sealing ring 2, which can well store the oil film left by the dynamic sealing ring and play a role in lubricating the piston rod.

[0034] In some optional embodiments, the outer wall annular groove is arranged between the front end along the axial direction of the support ring 6 and the first inner wall annular groove.

[0035] In some optional embodiments, the minimum size of the gap 7 between the two non-metallic guide rings 1 is set to 0.1 mm-0.2 mm, for example, it can be 0.15 mm, 0.13 mm or 0.17 mm.

[0036] In some optional embodiments, the maximum size of the gap 7 at the rear end is set to 0.2 mm-1 mm, for example, 0.5 mm or 0.8 mm.

[0037] In some optional embodiments, the size of the gap 7 at the front end is set to 0.1 mm-0.5 mm, for example, 0.3 mm, 0.3 mm, etc.

[0038] The present application utilizes the ingenious arrangement of the guide ring, the dynamic seal ring, and the dust ring to effectively isolate the metal contact between the buffer piston rod and the support ring to avoid metal-to-metal friction. At the same time, the gap between the dust ring with certain sealing performance and the dynamic seal is used to store oil, ensuring the lubrication of the piston rod surface and solving the piston rod wear problem of the buffer with large deformation and large side load. At the same time, the machining accuracy requirements of the piston rod surface are reduced.

[0039] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A buffer sealing device, characterized in that: It comprises a support ring (6) sleeved between a piston rod (5) and a housing (8) of a landing gear buffer, a gap (7) being formed between the support ring (6) and the piston rod (5), and the support ring (6) comprises a front end A and a rear end B along the axial direction; The inner wall of the support ring (6) is provided with four inner wall ring grooves along the axial direction from the front end A to the rear end B, a non-metallic guide ring (1) is crimped into the first inner wall ring groove and the third inner wall ring groove respectively, a combined sealing ring (2) is crimped into the second inner wall ring groove, and a dustproof ring (3) is crimped into the fourth inner wall ring groove; The outer wall of the support ring (6) is provided with an outer wall annular groove, in which a static sealing ring (4) is pressed; The gap (7) has a minimum size between the two non-metallic guide rings (1), a maximum size at the rear end, and a size at the front end between the minimum size and the maximum size.

2. The buffer sealing device according to claim 1, characterized in that: The combined sealing ring (2) comprises at least a hard retaining ring and a rubber ring.

3. The buffer sealing device according to claim 2, characterized in that: The hard retaining ring includes a fluoroplastic sealing ring or a polyetheretherketone sealing ring.

4. The buffer sealing device according to claim 3, characterized in that: An oil film is provided between the hard retaining ring and the piston rod (5).

5. The buffer sealing device according to claim 4, characterized in that: An oil film is provided in the gap (7) between the dustproof ring (3) and the combined sealing ring (2).

6. The buffer sealing device according to claim 1, characterized in that: The outer wall annular groove is arranged between the front end along the axial direction of the support ring (6) and the first inner wall annular groove.

7. The buffer sealing device according to claim 1, characterized in that: The minimum size of the gap (7) between the two non-metallic guide rings (1) is set to 0.1 mm-0.2 mm.

8. The buffer sealing device according to claim 7, characterized in that: The minimum size of the gap (7) between the two non-metallic guide rings (1) is set to 0.15 mm.

9. The buffer sealing device according to claim 1, characterized in that: The maximum dimension of the gap (7) at the rear end is set to 0.2 mm-1 mm.

10. The buffer sealing device according to claim 9, characterized in that: The maximum dimension of the gap (7) at the rear end is set to 0.5 mm.

11. The buffer sealing device according to claim 9, characterized in that: The maximum dimension of the gap (7) at the rear end is set to 0.8 mm.

12. The buffer sealing device according to claim 1, characterized in that: The size of the gap (7) at the front end is set to 0.1 mm-0.5 mm.

13. The buffer sealing device according to claim 12, characterized in that: The size of the gap (7) at the front end is set to 0.3 mm.

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