Thickened short-height outer lip oil seal and air spring shock absorber

Abstract

The utility model relates to the technical field of air shock absorber oil seals, and discloses a thickened short-height outer lip oil seal which comprises a metal framework and an elastic sealing body bonded to the metal framework in a vulcanization mode. An outer lip and an inner lip are arranged on the elastic sealing body, the outer lip is used for sealing gas, and the inner lip is used for sealing oil; the height H and the thickness T of the outer lip satisfy 0.3 < = H / T < = 0.8; according to the scheme, through the thickened short lip design that the height H and the thickness T of the outer lip are limited to meet 0.3 < = H / T < = 0.8, it is ensured that the outer lip has a new structural state, that is, the height of the outer lip is shortened, the thickness of the outer lip is increased, it is ensured that the outer lip has the high pressure bearing capacity and has the small contact area with a piston rod, the deformation resistance of an elastic sealing body after the outer lip of the oil seal is pressed is improved, and the service life of the oil seal is prolonged. Excessive deformation can be prevented, and abrasion and heating of the outer lip can be effectively reduced.

Description

Technical Field

[0001] This utility model relates to the field of automotive air spring oil seal technology, and more specifically, to a thickened short-height outer lip oil seal and an air spring damper. Background Technology

[0002] The air spring shock absorber of a car consists of a damper and a high-pressure airbag. The high-pressure airbag replaces the spring at the top of the damper in the traditional spring shock absorber, changing the working environment of the oil seal of the original spring shock absorber. The damper includes a piston rod and a piston cylinder.

[0003] The structure of the oil seal currently used in air spring dampers is shown in the attached figure. Figure 2 As shown, the device includes an elastic seal 121, a metal frame 122, and an inner lip spring 123. The elastic seal 121 is wrapped around the metal frame 122. The upper side of the elastic seal 121 is the outer lip, and the lower side is the inner lip. The inner lip spring 123 is located on the inner lip. When applied to an air shock absorber, because the outer lip is too high and not thick enough, the high-pressure gas can easily cause excessive deformation of the outer lip during airbag compression. Furthermore, the outer lip is not lubricated with the piston rod, and during operation, the outer lip will wear and heat up more quickly, leading to easy deformation (rubber usually becomes softer at high temperatures, reducing its elastic modulus and increasing its deformation capacity). The deformation of the outer lip will increase its contact area with the piston rod, increasing the contact stress and causing a surge in friction, accelerating lip wear and heat up, further aggravating the deformation of the outer lip, thus creating a vicious cycle that leads to oil and gas leakage. In addition, the outer lip only has a single lip opening, which is insufficient for sealing air, allowing high-pressure gas in the airbag to enter the shock absorber's working cylinder. Utility Model Content

[0004] The present invention aims to overcome at least one of the defects of the prior art and provides a thickened short-height outer lip oil seal to solve the technical problem that when the outer lip is too high and the thickness is insufficient, the outer lip will deform excessively during operation, the contact stress will increase, the friction will surge, the wear and heat will be accelerated, and oil and gas leakage will occur.

[0005] The technical solution adopted by this utility model is a thickened short-height outer lip oil seal, comprising: a metal skeleton and an elastic sealing body vulcanized and bonded to the metal skeleton; the elastic sealing body is provided with an outer lip and an inner lip, the outer lip is used to seal gas, and the inner lip is used to seal oil; the height H of the outer lip and the thickness T satisfy 0.3≤H / T≤0.8.

[0006] This design employs a thickened short lip with a height H and thickness T that satisfy 0.3 ≤ H / T ≤ 0.8. This ensures a new structural state for the outer lip, namely, shortening its height and increasing its thickness. This design ensures the outer lip has a high pressure-bearing capacity and a small contact area with the piston rod, improving the elastic sealing body's resistance to deformation under pressure. It prevents excessive deformation, thus avoiding the increased contact area and stress between the outer lip and piston rod caused by excessive deformation, which could lead to a surge in friction, accelerated lip wear, and overheating, resulting in oil and gas leakage.

[0007] Furthermore, the oil seal is provided with an annular microgroove. After the oil seal is installed, the microgroove mates with the outer surface of the piston rod to form a grease reservoir for storing lubricating grease. This grease reservoir design effectively reduces wear and heat generation on the outer lip during operation, further preventing deformation of the outer lip. This avoids increased contact area and stress between the outer lip and piston rod due to deformation, which could lead to a surge in friction, accelerated lip wear, and oil / gas leakage.

[0008] Furthermore, the outer lip is provided with no fewer than two lip openings, including at least an outer lip opening and an outer support lip opening, and the microgrooves are respectively provided on each lip opening of the outer lip. By providing at least two lip openings (outer lip opening and outer support lip opening) on ​​the outer lip and configuring microgrooves on each lip opening, a multi-layer sealing barrier and pressure-sharing structure are formed, effectively dispersing air pressure impact and reducing contact stress and friction loss of a single lip opening; the distribution design of the microgrooves further ensures uniform coverage of grease, reduces frictional heat generation, and improves sealing reliability and service life. The outer support lip can support the outer lip, further reducing the contact area between the outer lip and the piston rod, reducing lip wear and heat generation.

[0009] Furthermore, the inner lip is provided with no fewer than two lip openings, including at least an inner support lip and an inner lip opening. The outer periphery of the inner lip is provided with an inner lip opening spring groove and an inner lip opening spring. By providing two sealing structures—the inner support lip and the inner lip opening—and the continuous preload of the inner lip spring, the inner lip significantly improves its dynamic sealing adaptability to high-pressure oil environments, ensuring stable contact pressure between the lip and the piston rod during oil pressure fluctuations. The double-sealing lip design reduces oil leakage, while the spring compensation mechanism effectively slows lip wear and extends service life.

[0010] Furthermore, each lip opening of the inner lip is provided with microgrooves. The microgrooves of each lip opening of the inner lip are designed to form a multi-level lubrication reservoir structure, which can effectively reduce the friction coefficient between the inner lip and the piston rod during operation, and avoid boundary lubrication failure caused by oil penetration; at the same time, the evenly distributed microgrooves balance the contact stress and prevent local wear.

[0011] Furthermore, the height H of the outer lip of the oil seal is 1–1.5 mm, and the thickness T is 1.5–2.5 mm. This height and thickness range meets the requirements of typical automotive air spring shock absorbers.

[0012] Furthermore, the thickness of the elastic sealing body at the attachment point of the metal skeleton is as follows: 0.8–1.2 mm near the airbag 2 side and 0.5–0.8 mm near the piston rod 11 side. This enhances the structural strength at the connection between the outer lip and the metal skeleton. The thickened design near the airbag side effectively disperses the local pressure generated during airbag compression, preventing the sealing body from cracking due to uneven stress; the thickness adjustment near the piston rod side balances the flexibility and support of the sealing body, ensuring that the outer lip maintains stable contact pressure during reciprocating motion.

[0013] Furthermore, the elastic sealing material is selected from one of nitrile rubber, hydrogenated nitrile rubber, or fluororubber. Using nitrile rubber, hydrogenated nitrile rubber, or fluororubber as the elastic sealing material, combined with their high elastic modulus and low compression set characteristics, significantly improves the deformation recovery capability of the outer and inner lips, ensuring long-term sealing of gases and oils under high temperature and alternating pressure.

[0014] An air spring vibration damper includes a damper and an air bladder, the air bladder being disposed on the damper, and an air spring oil seal being disposed between the piston cylinder and piston rod of the damper. By employing an optimized oil seal structure, this air spring vibration damper achieves dual-medium gas-liquid sealing under high-pressure alternating conditions, while simultaneously reducing the oil seal friction resistance and significantly extending its service life.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: This solution, by limiting the height H and thickness T of the outer lip to meet the requirement of 0.3≤H / T≤0.8, ensures that the outer lip has a new structural state, that is, shortening the height of the outer lip and increasing the thickness of the outer lip, ensuring that the outer lip has a higher pressure bearing capacity and a smaller contact area with the piston rod, improving the deformation resistance of the elastic sealing body of the oil seal outer lip after being compressed, and preventing its excessive deformation; thereby avoiding the phenomenon of increased contact area between the outer lip and the piston rod due to excessive deformation of the outer lip, increased contact stress, increased friction, accelerated lip wear and heat generation, and oil and gas leakage. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of an existing air damper.

[0017] Figure 2 This is a schematic diagram of the internal oil seal in an existing air damper.

[0018] Figure 3 This is a schematic diagram of the overall structure of this utility model.

[0019] Figure 4 This is a schematic diagram of the structure of the outer lip, outer supporting lip, inner supporting lip, and inner lip of this utility model.

[0020] Figure 5 This utility model Figure 4 Enlarged view of the local structure at point A in the middle.

[0021] Figure 6 This is a schematic diagram of the structure of the outer lip edge and the outer supporting lip edge of this utility model.

[0022] In the diagram: 1. Damper; 11. Piston rod; 12. Oil seal; 121. Elastic seal; 121a. Outer lip; 121b. Outer support lip; 121c. Inner support lip; 121d. Inner lip; 121e. Microgroove; 121f. Inner lip spring groove; 122. Metal frame; 123. Inner lip spring; 2. Airbag. Detailed Implementation

[0023] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0024] like Figure 1 As shown, this utility model relates to an air damper in a vehicle suspension system, including a damper 1 and a high-pressure airbag 2. The airbag 2 is mounted on the damper 1. An oil seal 12 is provided between the piston cylinder and the piston rod 11 of the damper 1. The oil seal 12 is used to seal the gas in the upper airbag 2 and also to seal the oil in the lower piston cylinder.

[0025] like Figure 2 As shown, the oil seal 12 in the prior art includes a metal skeleton 122 and an elastic sealing body 121. The metal skeleton 122 and the elastic sealing body 121 are connected by vulcanization bonding. Both the metal skeleton 122 and the elastic sealing body 121 are annular structures. The upper part of the elastic sealing body 121 is provided with an outer lip on the side near the airbag 2, and the lower part is provided with an inner lip on the side near the piston cylinder. The outer lip is used to seal the gas in the airbag 2, and the inner lip is used to seal the oil in the piston cylinder.

[0026] like Figure 3 and 4 As shown, as an improvement to this solution, the outer lip is provided with at least two lip openings, such as: outer lip opening 121a and outer support lip opening 121b; the inner lip is provided with at least two lip openings, such as: inner support lip opening 121c and inner lip opening 121d; an inner lip opening spring groove 121f is also provided on the outer circumferential surface of the inner lip, and an inner lip opening spring 123 is provided in the inner lip opening spring groove 121f.

[0027] like Figure 4 and 5 As shown, several annular micro-grooves 121e for storing lubricating grease are provided on the relatively gentle edges of the outer lip 121a, outer support lip 121b, inner lip 121d, and inner support lip 121c. After installation, the micro-grooves 121e cooperate with the outer surface of the piston rod 11 to form a grease reservoir. When the piston rod 11 moves relative to the elastic seal 121, the lubricating grease in the reservoir can play a lubricating role, preventing dry friction between the elastic seal 121 and the metal skeleton 122, avoiding acceleration and excessive heating, and effectively improving its service life.

[0028] The microgroove dimensions range from 0.02 to 0.08 mm in depth and 0.1 to 0.2 mm in width; the depth-to-width ratio of the microgroove ranges from 0.2 to 0.8, with 3 to 8 grooves on each lip, thus storing sufficient grease for adequate lubrication during operation.

[0029] The elastic seal 121 is made of nitrile rubber, hydrogenated nitrile rubber or fluororubber. Nitrile rubber, hydrogenated nitrile rubber or fluororubber are all materials known in the art and will not be described in detail here.

[0030] like Figure 6 As shown, the thickness of the elastic sealing body 121 attached to the metal skeleton 122 near the airbag 2 is L2 in the figure. Compared with the prior art, the thickness has increased by 0.8 to 1.2 mm from the original thickness of 0.2 to 0.5 mm. The thickness of the elastic sealing body 121 attached to the metal skeleton 122 near the piston rod 11 is L1 in the figure. Compared with the prior art, the thickness has increased from the original thickness of 0.3 to 0.5 mm to 0.5 to 0.8 mm. By increasing the thickness of L1 and L2, the structural strength of the connection between the outer lip and the skeleton 122 is improved, and the compressive strength and deformation resistance of the outer lip are enhanced.

[0031] Meanwhile, compared to existing technologies, the overall height H of the outer lip is reduced from 2-2.5 mm to 1-1.5 mm, and the thickness T of the outer lip is increased from 0.5-1 mm to 1.5-2.5 mm. After the improvement, when selecting dimensions, the height / thickness of the oil seal must satisfy 0.3 ≤ H / T ≤ 0.8. This ratio was determined through the following tests:

[0032] Test setup: The oil seal 12 is installed on the test shaft inside a sealed cavity. The oil seal 12 seals the sealed cavity, similar to the structure of the airbag 2 and piston rod 11 (the test equipment does not have many requirements, it just needs to include the test shaft and the sealed cavity, and be able to simulate the working state of the airbag 2 and piston rod 11).

[0033] Test shaft: 20mm in diameter, surface roughness Ra0.8μm;

[0034] Medium: Dry air (dew point ≤ -40℃).

[0035] Test conditions:

[0036] Initial pressure: 1.5 MPa (gauge pressure);

[0037] Temperature: 25±5℃;

[0038] Pressure holding time: 72 hours.

[0039] Ensuring all other test conditions are the same, the following sets of experiments were conducted for comparison:

[0040]

[0041] As shown in the table above, when the outer lip meets the design requirements of a thickened short lip with a height H and thickness T of 0.3 ≤ H / T ≤ 0.8, the leakage is significantly reduced and meets the design requirements. The contact width is less than 0.3, resulting in a narrower contact area with the piston rod 11. The outer lip has a high pressure-bearing capacity, which improves the resistance to deformation of the elastic sealing body after the outer lip is under pressure, preventing excessive deformation. During operation, it can effectively reduce the wear and heat generation of the outer lip, avoiding the phenomenon of increased contact area between the outer lip and the piston rod due to deformation of the outer lip, increased contact stress, increased friction, accelerated lip wear and heat generation, and oil and gas leakage.

[0042] After installation, the interference fit between the outer lip 121a and the piston rod 11 is reduced from 1.5mm to 1.2mm. The outer support lip 121b, which previously contacted the piston rod 11, now has a 0.2mm interference fit. The reduction in height decreases the contact width between the outer lip and the piston rod 11, thus reducing the contact area and friction. Furthermore, the reduced height of the outer lip increases the thickness of the elastic sealing body 121 attached to the metal frame 122 near the airbag 2, thereby increasing the outer lip's resistance to deformation and further reducing wear and high-temperature aging caused by excessive deformation.

[0043] like Figure 6As shown, the inclination angles of the two lips of the outer lip 121a from the outside to the inside are 55° and 28° respectively (angles b and d in the figure), and the inclination angles of the two lips of the outer support lip 121b from the outside to the inside are 45° and 27° respectively (angles a and c in the figure). The lip inclination angle refers to the angle between the lip slope and the reference axis. The reference axis here is usually the axis of the piston rod 11 or the theoretical center line of the oil seal 12 after installation. This setting ensures that the lip angle of the outer support lip 121b (180-45-27=108) is greater than 100°, and the large lip tip angle enhances the support effect of 121b. This design incorporates the following improvements: 1. The design of multiple sealing lips enhances the oil-sealing capability of the inner lip and the air-sealing capability of the outer lip; 2. The height and thickness ratio of the outer lip is used to define a pressure-resistant and pressure-reducing structural design, improving the deformation resistance of the outer lip of the oil seal 12 under pressure and reducing the contact area between the outer lip of the oil seal 12 and the piston rod 11 of the shock absorber; 3. A grease reservoir is designed in the contact area between the lip of the oil seal 12 and the piston rod 11, improving the lubrication performance of the contact area, reducing the friction between the lip of the oil seal 12 and the piston rod 11, and reducing lip wear. These combined improvements effectively extend the service life of the air spring shock absorber.

[0044] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A thickened, short-height outer lip oil seal, characterized in that, include: Metal skeleton (122) and elastic sealant (121) vulcanized and bonded to the metal skeleton. The elastic sealing body (121) is provided with an outer lip and an inner lip. The outer lip is used to seal gas, and the inner lip is used to seal oil. The height H and thickness T of the outer lip satisfy 0.3≤H / T≤0.

8.

2. The thickened short-height outer lip oil seal according to claim 1, characterized in that, The oil seal is provided with an annular micro groove (121e). After the oil seal is installed, the micro groove (121e) and the outer surface of the piston rod (11) cooperate to form a grease reservoir for storing lubricating grease.

3. The thickened short-height outer lip oil seal according to claim 2, characterized in that, The outer lip is provided with no less than two openings, including at least an outer lip opening (121a) and an outer support lip opening (121b), and the micro groove (121e) is provided on each opening of the outer lip.

4. A thickened short-height outer lip oil seal according to claim 2, characterized in that, The inner lip is provided with no less than two openings, including at least an inner support lip (121c) and an inner lip opening (121d). The outer periphery of the inner lip is provided with an inner lip opening spring groove (121f) and an inner lip opening spring (123).

5. A thickened short-height outer lip oil seal according to claim 4, characterized in that, Each lip opening of the inner lip is provided with a micro-groove (121e).

6. A thickened short-height outer lip oil seal according to claim 2, characterized in that, The height H of the outer lip of the oil seal is 1 to 1.5 mm, and the thickness T is 1.5 to 2.5 mm.

7. A thickened short-height outer lip oil seal according to claim 6, characterized in that, The thickness of the elastic seal (121) at the attachment site of the metal skeleton (122) is: 0.8-1.2 mm near the airbag (2) and 0.5-0.8 mm near the piston rod (11).

8. A thickened short-height outer lip oil seal according to claim 6, characterized in that, The depth of the microgroove (121e) ranges from 0.02 to 0.08 mm, and the width ranges from 0.1 to 0.2 mm.

9. A thickened short-height outer lip oil seal according to any one of claims 1-8, characterized in that, The material of the elastic seal (121) is selected from one of nitrile rubber, hydrogenated nitrile rubber or fluororubber.

10. An air spring vibration damper, characterized in that, It includes a damper (1) and an airbag (2), the airbag (2) being disposed on the damper (1), and a thickened short-height outer lip oil seal as described in any one of claims 1-9 being disposed between the piston cylinder and the piston rod (11) of the damper (1).

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