Sealing structures, shock absorbers and vehicles

Abstract

The present invention provides a sealing structure, a shock absorber, and a vehicle, wherein the sealing structure includes a frame, a first oil seal, and a second oil seal supported on the frame. The first oil seal and the second oil seal are respectively adapted to adhere to the external surface of the component to be sealed and, together with the external surface, define a pressure compensation cavity. The sealing structure also includes a one-way pressure compensation channel for connecting an external pressure source and the pressure compensation cavity. Oil from the pressure source flows into the pressure compensation cavity via the one-way pressure compensation channel, and the oil presses the first and second oil seals against the external surface of the component to be sealed. According to the sealing structure disclosed herein, the use of oil, in place of conventional spring coils, ensures a more reliable compression force.

Description

Technical Field

[0001] The present invention relates to a sealing structure, and a shock absorber and a vehicle including the sealing structure. Background Art

[0002] As a key component of the vehicle chassis system, the shock absorber achieves its own damping effect through the movement of internal oil, attenuating vibrations and thereby improving vehicle handling and comfort. During this damping process, the interior of the shock absorber is exposed to high temperatures and high pressures, placing stringent requirements on the performance of the sealing structure at the end of the shock absorber.

[0003] A known sealing structure for a shock absorber comprises a metal frame, an oil-resistant rubber coating, and a spring ring for pressing the rubber against the shock absorber piston rod. The sealing effect is achieved through the interference fit of the rubber and the spring ring. However, over time and due to aging of the spring ring, the spring ring may no longer provide sufficient compression, leading to shock absorber oil leakage.

[0004] Furthermore, for shock absorbers, the upper and lower portions of the sealing structure are exposed to different operating environments. Specifically, the portion closer to the exterior primarily protects against dust, while the portion closer to the oil reservoir, located within, is exposed to high temperatures and high pressures. The rubber portion of the shock absorber sealing structure described above is often constructed as a single piece, making it incompatible with diverse operating environments. This issue can also arise in other components with varying internal and external sealing requirements, such as shaft-hole structures. Summary of the Invention

[0005] According to different aspects, the object of the present invention is to provide an improved sealing structure as well as a shock absorber and a vehicle having such a sealing structure.

[0006] In addition, the present invention is also intended to solve or alleviate other technical problems existing in the prior art.

[0007] The present invention solves the above-mentioned problem by providing a sealing structure for a shock absorber. Specifically, it includes a skeleton, a first oil seal and a second oil seal supported on the skeleton. The first oil seal and the second oil seal are respectively used to fit on the outer surface of the component to be sealed and together with the outer surface define a pressure compensation cavity. The sealing structure also includes a one-way pressure compensation channel for connecting an external pressure source and the pressure compensation cavity. The oil of the pressure source flows into the pressure compensation cavity through the one-way pressure compensation channel, and the oil presses the first oil seal and the second oil seal against the outer surface of the component to be sealed.

[0008] According to the sealing structure proposed in one aspect of the present invention, the one-way pressure compensation channel extends in the skeleton and has a one-way valve accommodated in the skeleton.

[0009] According to the sealing structure proposed in one aspect of the present invention, the first oil seal and the second oil seal respectively have an inner lip, which protrudes into the pressure compensation cavity and is hydraulically tightened against the outer surface of the component to be sealed by the oil in the pressure compensation cavity.

[0010] According to the sealing structure proposed in one aspect of the present invention, the first oil seal and the second oil seal further have an outer lip located outside the pressure compensation cavity, respectively. The inner lip and outer lip of the first oil seal and the second oil seal respectively define an annular sub-cavity around the outer surface of the component to be sealed, for accommodating oil or dirt from the outside.

[0011] According to the sealing structure proposed in one aspect of the present invention, the sealing structure further includes a compensation oil seal, and the compensation oil seal is arranged in the pressure compensation cavity in an interference fit manner.

[0012] According to the sealing structure proposed in one aspect of the present invention, the compensating oil seal has a multi-lip sealing rubber and a skeleton for supporting the multi-lip sealing rubber, and the compensating oil seal is fixed in the pressure compensation cavity by means of the skeleton.

[0013] According to the sealing structure proposed in one aspect of the present invention, the first oil seal and the second oil seal are made of different materials according to the environmental parameters in which they are located, and the environmental parameters include temperature and pressure.

[0014] According to another aspect of the present invention, a shock absorber is provided, which includes a piston rod, an oil storage cylinder and a working cylinder, wherein the piston rod is movably arranged in the working cylinder along the axial direction, and a sealing structure according to the present invention is provided at the end of the shock absorber, and the first oil seal and the second oil seal of the sealing structure are respectively attached to the outer circumferential surface of the piston rod.

[0015] According to another aspect of the present invention, the second oil seal is arranged closer to the oil reservoir than the first oil seal, and the second oil seal is made of hydrogenated nitrile rubber.

[0016] According to another aspect of the present invention, a vibration absorber is provided, which has the advantages described above and will not be described in detail.

[0017] According to the sealing structure of the present invention, instead of the common spring ring, a more reliable pressing force can be provided by oil from an external pressure source, and the pressing force presses the sealing structure against the outer surface of the component to be sealed, for example, against the outer circumferential surface of the piston rod of the shock absorber. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The above and other features of the present invention will become apparent with reference to the accompanying drawings, in which:

[0019] Figure 1 A schematic diagram showing a sealing structure according to the present invention used in a vibration damper is shown. DETAILED DESCRIPTION

[0020] It is easy to understand that according to the technical solution of the present invention, without changing the essential spirit of the present invention, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific embodiments and drawings are only exemplary descriptions of the technical solution of the present invention and should not be regarded as the entire invention or as a limitation or restriction of the technical solution of the present invention.

[0021] The terms "up," "down," "left," "right," "front," "back," "front," "back," "top," and "bottom" mentioned or potentially mentioned in this specification are defined relative to the structures shown in the accompanying drawings. They are relative concepts and may vary depending on their location or usage. Therefore, these or other directional terms should not be interpreted as restrictive. In addition, the terms "first," "second," "third," and similar expressions are used only for descriptive and distinguishing purposes and should not be understood to indicate or imply the relative importance of the corresponding components.

[0022] To more clearly illustrate the coordination and interaction between the sealing structure according to the present invention and the component to be sealed (the component to be sealed by the sealing structure), this sealing structure will be described in detail using the example of its application in a shock absorber. Specifically, the component to be sealed is the shock absorber's piston rod, and the outer surface of the component to be sealed is the outer circumferential surface of the piston rod. For descriptions of other applications of the sealing structure, reference can be made to the following explanation of its application in a shock absorber.

[0023] refer to Figure 1, which shows a cross-sectional view of a sealing structure 100 according to the present invention. The sealing structure 100 includes a first oil seal 110, a second oil seal 120, and a frame 130 for supporting the first and second oil seals. The frame 130 is optionally made of a high-strength material, such as metal, and has a concave shape. The concave recess faces the component to be sealed (here, the shock absorber piston rod 200), and the first and second oil seals 110, 120 are arranged on its protruding portion. The first and second oil seals 110, 120 are arranged one after the other in the axial direction of the piston rod 200 and, together with the outer circumference of the piston rod 200, define a substantially annular pressure compensation cavity 140 surrounding the piston rod for accommodating oil. This cavity allows the oil to be stored in a pressure source external to the sealing structure. Furthermore, when used in a shock absorber, the shock absorber's oil reservoir can be simply used as the pressure source. In this case, using the shock absorber's own oil ensures a reliable oil supply and reduces structural complexity.

[0024] Here, the first oil seal 110 can be positioned relatively close to the outside and primarily functions to prevent external contaminants from entering the pressure compensation cavity 140 and the shock absorber oil reservoir below. In contrast, the second oil seal 120 is positioned internally, closer to the oil reservoir below, and is exposed to high temperatures and high pressures due to the rapid axial reciprocating motion of the piston rod 200. Therefore, the first and second oil seals 110, 120 can be made of different materials to accommodate different protection requirements (e.g., varying environmental parameters such as temperature, pressure, or corrosion). For example, the external first oil seal 110, primarily used for dust protection, can be made of conventional rubber or wear-resistant rubber, while the internal second oil seal 120 can be made of a high-temperature-resistant rubber, such as hydrogenated nitrile rubber. While the first and second oil seals 110, 120 can be constructed separately and subsequently secured to the frame 130, they can also be integrally molded from different materials, such as by casting. This dual-layer oil seal construction according to the present invention effectively matches the sealing rubber with diverse environmental requirements. This seal structure effectively meets both dustproofing requirements and stringent high-temperature and high-pressure sealing requirements.

[0025] Furthermore, the sealing structure 100 according to the present invention includes a one-way pressure compensation channel 150 connecting the pressure compensation chamber 140 with a pressure source (here, the pressure source can be the shock absorber's oil reservoir). This channel replaces conventional spring coils to provide a preload force, which compresses the first and second oil seals 110 and 120 against the outer circumferential surface of the piston rod 200. Specifically, the one-way pressure compensation channel 150 connects the shock absorber's oil reservoir with the pressure compensation chamber 140 defined by the sealing structure and only allows oil from the oil reservoir to flow into the pressure compensation chamber 140. This creates a consistently higher pressure in the pressure compensation chamber than in the oil reservoir, thereby ensuring a tight fit between the sealing structure 100 and the outer circumferential surface of the piston rod 200. Providing the compressive force using the shock absorber's own oil ensures a reliable compressive force.

[0026] Optionally, a one-way pressure compensation passage 150 extends within the frame and includes a one-way valve 151, which can also be housed within the frame 130. When the upper pressure (i.e., the pressure within the pressure compensation chamber 140) is higher than the lower pressure (i.e., the pressure within the oil reservoir), the one-way valve 151 closes and prevents oil from flowing through (i.e., preventing the pressure compensation chamber 140 from being unloaded). Conversely, when the upper pressure is lower than the lower pressure due to the reciprocating motion of the piston rod 200, the one-way valve 151 opens, allowing oil to flow from the oil reservoir into the pressure compensation chamber 140. In this way, high-pressure oil is always present within the pressure compensation chamber 140, pressing the sealing structure 100 against the piston rod 200.

[0027] Optionally, the first oil seal 110 and the second oil seal 120 each have an inner lip that protrudes toward the pressure compensation cavity and defines the boundary of the pressure compensation cavity 140. With the aid of the high-pressure oil, the sealing structure 100 is pressed against the outer circumferential surface of the piston rod 200 with the inner lip. As shown in the drawings, the inner lip can be configured in an arc shape to increase the effective surface of the high-pressure oil.

[0028] Optionally, the first and second oil seals 110 and 120 are configured as double-lip oil seals, meaning that each of the first and second oil seals 110 and 120 further includes an outer lip. The "inner lip" is defined relative to the pressure compensation cavity, wherein the inner lip is exposed to the high-pressure oil stored in the pressure compensation cavity, while the "outer lip" is not. Similarly, the outer lip can be arcuately configured and, together with the matching inner lip, define an annular sub-cavity surrounding the outer circumference of the piston rod (that is, the outer surface of the component to be sealed). This annular sub-cavity is used to accommodate the oil necessary for piston rod lubrication and to collect external contaminants to prevent contamination of the underlying oil reservoir.

[0029] Optionally, the sealing structure 100 further includes a compensating oil seal 160, which is arranged in the pressure compensation cavity 140, for example, with an interference fit. The seal divides the pressure compensation cavity 140 into two sections, allowing a small amount of oil to flow through the compensating oil seal between the two sections. Even if the check valve 151 fails, the compensating oil seal 160 effectively ensures the flow direction of the oil and thus maintains the high pressure in the pressure compensation cavity 140. Furthermore, the provision of the compensating oil seal 160 further protects the interior of the shock absorber from contaminants in the pressure compensation cavity.

[0030] Compensating oil seal 160 can optionally be constructed as a multi-lip oil seal, comprising a multi-lip sealing rubber and a framework (as shown in the figures, an inner framework and an outer framework) for supporting and retaining the multi-lip sealing rubber. This framework secures compensating oil seal 160 within pressure compensation cavity 140. This multi-lip seal structure forms multiple smaller cavities for storing oil. The inner framework, outer framework, and multi-lip sealing rubber can be integrally constructed and can also be made of hydrogenated nitrile rubber or other high-temperature-resistant rubber.

[0031] It should be noted here that the compensating oil seal is not limited to the multi-lip seal structure described above, and can also be configured as a single-lip seal structure, a double-lip seal structure, or a sealing film or a sealing film group.

[0032] The present invention also provides a shock absorber having a sealing structure, comprising a piston rod, an oil reservoir, a working cylinder, and a guide structure. The piston rod is axially movably accommodated in the working cylinder, and the sealing structure is supported on the guide structure at the end of the shock absorber to prevent oil leakage. The sealing structure, with its first and second oil seals, contacts the outer circumference of the piston rod and is hydraulically tightened against the piston rod by high-pressure oil in a pressure compensation chamber. The first oil seal can be positioned relatively close to the outside (i.e., farther from the oil reservoir) and primarily serves to prevent dust, and can also be referred to as a dustproof oil seal. In contrast, the second oil seal is positioned within the shock absorber and is subject to high-temperature and high-pressure environments. Therefore, the second oil seal can be made of a high-temperature-resistant rubber, such as hydrogenated nitrile rubber. Reference is made to the description of the sealing structure according to the present invention for the description of the shock absorber.

[0033] Finally, the present invention also relates to a vehicle having such a shock absorber, which can have the advantages explained above, and will not be described in detail.

[0034] In summary, the sealing structure according to the present invention replaces the conventional spring coil and ensures the provision of a more reliable clamping force through the use of oil. When used in a shock absorber, its pressure source can be implemented as the shock absorber's own oil reservoir, which can further simplify the structural complexity while ensuring a reliable sealing effect. In one embodiment of the present invention, the first oil seal and the second oil seal can be made separately or from different materials, which facilitates the matching of the sealing structure to different environmental parameters. In another embodiment of the present invention, the provision of an additional compensating oil seal can further ensure the flow direction of the oil used to provide the clamping force and further block external dirt.

[0035] It should be understood that all the above preferred embodiments are illustrative rather than restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of the present invention should be within the legal protection scope of the present invention.

Claims

1. A sealing structure, characterized in that: The invention also comprises a skeleton, a first oil seal and a second oil seal supported on the skeleton, the first oil seal and the second oil seal being respectively used to fit on the outer surface of the component to be sealed and jointly define a pressure compensation cavity with the outer surface, the sealing structure also comprises a one-way pressure compensation channel for connecting an external pressure source and the pressure compensation cavity, the oil of the pressure source flows into the pressure compensation cavity via the one-way pressure compensation channel, and the oil presses the first oil seal and the second oil seal against the outer surface of the component to be sealed, wherein the one-way pressure compensation channel extends in the skeleton and has a one-way valve accommodated in the skeleton, the sealing structure also comprises a compensation oil seal, the compensation oil seal is arranged in the pressure compensation cavity in an interference fit manner with the aid of the skeleton, wherein the compensation oil seal divides the pressure compensation chamber into two parts and allows oil to flow unidirectionally to the chamber where the first oil seal and the second oil seal are located, so that the first oil seal and the second oil seal are pressed against the outer surface of the component to be sealed.

2. The sealing structure according to claim 1, wherein: The first oil seal and the second oil seal each have an inner lip, which protrudes into the pressure compensation cavity and is hydraulically pressed against the outer surface of the component to be sealed by the oil in the pressure compensation cavity.

3. The sealing structure according to claim 2, characterized in that: The first oil seal and the second oil seal also have an outer lip outside the pressure compensation cavity, respectively. The inner lip and outer lip of the first oil seal and the second oil seal respectively define an annular sub-cavity around the outer surface of the component to be sealed for accommodating oil or dirt from the outside.

4. The sealing structure according to claim 1, wherein: The compensating oil seal comprises a multi-lip sealing rubber and a skeleton for supporting the multi-lip sealing rubber. The compensating oil seal is fixed in the pressure compensation cavity by means of the skeleton.

5. The sealing structure according to any one of claims 1 to 4, characterized in that: The first oil seal and the second oil seal are made of different materials according to the environmental parameters in which they are located. The environmental parameters include temperature and pressure.

6. A shock absorber, characterized in that: It includes a piston rod, an oil storage cylinder and a working cylinder, wherein the piston rod is movably arranged in the working cylinder along the axial direction, and a sealing structure according to any one of claims 1 to 5 is provided at the end of the shock absorber, and the first oil seal and the second oil seal of the sealing structure are respectively attached to the outer circumferential surface of the piston rod.

7. The shock absorber according to claim 6, characterized in that The second oil seal is arranged closer to the oil reservoir than the first oil seal, and is made of hydrogenated nitrile rubber.

8. A vehicle, characterized in that: The vehicle has the shock absorber according to claim 6 or 7.

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