Sealing structure

Abstract

A sealing structure is used for an oil damper and is arranged on a piston rod of the oil damper, the dustproof sealing structure comprises a gland and a corrugated pipe, and the corrugated pipe is provided with a first cavity capable of receiving hydraulic oil and adapting to piston movement of the piston rod; a backflow channel is arranged on the gland, and when the oil damper leaks hydraulic oil towards the gland along the piston rod, the backflow channel can guide the hydraulic oil back to the oil damper along a path different from the direction of the piston rod; hydraulic oil leaking towards the corrugated pipe through the gland along the piston rod can enter the first cavity to be collected. By means of the structure, oil leakage can be reduced, slight oil leakage or false oil leakage can be collected when a small amount of oil is leaked, and frequent replacement of the oil damper is avoided. In addition, the sealing structure is provided with multiple dustproof protections and is dustproof outwards and sealed inwards, and external foreign matter can be effectively prevented from entering the oil damper to avoid failure of the oil damper.

Description

Technical Field

[0001] This utility model relates to a dustproof sealing structure for hydraulic shock absorbers used in rail transit vehicles, and particularly to a sealing structure. Background Technology

[0002] Hydraulic dampers are components that use hydraulic oil as a damping medium and are devices used to dissipate energy. When a hydraulic damper is working, the piston rod reciprocates within the cylinder (piston motion), converting the vibrational energy in the system into heat energy in the oil, which is then dissipated into the air, thereby attenuating the vibration in the system. Hydraulic dampers are crucial to the smoothness, comfort, and safety of vehicle operation and are an important component of the suspension system of rail transit vehicles. Hydraulic shock absorbers for rail transit vehicles are functionally classified into primary vertical shock absorbers, secondary vertical shock absorbers, secondary lateral shock absorbers, motor shock absorbers, anti-hunting shock absorbers, and workshop shock absorbers. Unlike automotive shock absorbers, which are all vertically installed, about half of the hydraulic shock absorbers for rail transit vehicles are laterally installed. As vehicle operating speeds increase and the geographical application range expands, such as the Lanzhou-Xinjiang Railway and the Sichuan-Tibet Railway, which are often accompanied by harsh environmental conditions such as high altitudes and sandstorms, the reliability of hydraulic shock absorbers faces severe challenges. At the same time, the compact structure of vehicles limits the installation space of hydraulic shock absorbers. To ensure the reliability of hydraulic shock absorbers, they must have strong resistance to wind and sand weathering, resisting the intrusion of foreign objects such as dust, sand, rain, and snow. The intrusion of foreign objects will cause damage to the shock absorber piston rod and seals, hydraulic oil contamination, oil leakage, and performance failure.

[0003] Furthermore, during the assembly of the hydraulic shock absorber, a small amount of hydraulic oil may leak into the gaps outside the sealing lip, which may overflow onto the surface during use, creating a false leak. Additionally, during operation, the up-and-down movement of the piston rod can cause a small amount of hydraulic oil to seep from the oil seal, appearing as a small amount of oil stains on the outside of the shock absorber. When oil stains are found, the hydraulic shock absorber is usually replaced. However, research shows that false leaks and minor seepage do not affect the performance of the hydraulic shock absorber, but they do affect its appearance. Therefore, it is not necessary to replace the hydraulic shock absorber when there are false or minor seepages. However, in existing technology, it is impossible to distinguish between false, minor, and large leaks based solely on the oil stains on the outside of the shock absorber. Replacing the shock absorber whenever oil stains are found leads to frequent replacements, resulting in wasted components and increased costs. Utility Model Content

[0004] The present invention aims to solve the above problems by providing a sealing structure that can prevent oil leakage and collect minor oil leakage and false oil seepage.

[0005] To solve the above problems, this utility model provides a sealing structure for a hydraulic shock absorber, characterized in that it is installed on the piston rod of the hydraulic shock absorber, and the dustproof sealing structure includes:

[0006] A pressure cap is used to connect to the hydraulic damper and is sleeved on the piston rod;

[0007] The bellows has a first end with a sleeve hole that can be fitted onto the piston rod and form a sealed connection with the piston rod, and a second end that is connected to the gland and can be fitted onto the piston rod. The bellows has a first cavity that can receive hydraulic oil and adapt to the piston movement of the piston rod.

[0008] The gland is provided with a return channel. When the hydraulic damper leaks hydraulic oil along the piston rod toward the gland, the return channel can guide the hydraulic oil back to the hydraulic damper along a path different from that of the piston rod. The hydraulic oil leaking along the piston rod through the gland toward the bellows can enter the first cavity and be collected.

[0009] Furthermore, the gland includes:

[0010] The base can be fitted onto the piston rod and seal the port of the oil reservoir of the hydraulic damper;

[0011] A guide seat is connected to the bellows; the guide seat can be sleeved on the piston rod and connected to the oil reservoir of the hydraulic damper to press the base against the port of the oil reservoir;

[0012] The reflux channel is provided on the base.

[0013] Furthermore, the base is provided with a central hole for the piston rod to pass through.

[0014] An oil collection groove is provided at one end of the base facing the guide seat. The oil collection groove is in communication with the central hole. When the hydraulic damper leaks oil outward along the piston rod, the hydraulic oil can enter the oil collection groove through the central hole.

[0015] The pressure cap is provided with an oil return hole, which is connected to the oil accumulation groove and is used to guide the hydraulic oil in the oil accumulation groove back to the oil storage tank.

[0016] Furthermore, the oil return hole is inclined to the axial direction of the central hole.

[0017] Furthermore, the return oil hole and the central hole point to different chambers of the oil reservoir, wherein the return oil hole is used to point to the low-pressure chamber of the oil reservoir, and the central hole is used to point to the high-pressure chamber of the oil reservoir.

[0018] Furthermore, a skeleton oil seal is provided inside the gland, which is used to fit onto the piston rod to prevent hydraulic oil from leaking from the base toward the guide seat.

[0019] Furthermore, the skeleton oil seal has sealing lips at both ends along the piston rod direction, and a tension spring is fitted on the skeleton oil seal. The tension spring always has the tendency to drive the skeleton oil seal to be tightly connected with the piston rod.

[0020] Furthermore, a dustproof ring is provided inside the pressure cap, which is used to fit onto the piston rod to prevent foreign objects in the first cavity from entering the pressure cap.

[0021] Furthermore, the dust cover, at least partially covering the bellows and capable of being fitted onto the piston rod to form a sealed connection with the piston rod, forms a second cavity at least between the dust cover, the bellows, and the piston rod. The bellows is provided with a vent hole that connects the second cavity and the first cavity. When the hydraulic damper leaks oil outward along the piston rod, the leaked hydraulic oil can enter the first cavity through the pressure cap and be collected.

[0022] Furthermore, the base has a wedge structure on one end of its edge facing the guide seat. When the base is installed in the oil reservoir, a second annular groove is formed between the wedge structure and the inner wall of the oil reservoir. A sealing ring is provided in the second annular groove. A gasket is provided between the knife holder and the guide seat. The gasket closes the second annular groove and abuts against the sealing ring.

[0023] The beneficial contribution of this utility model lies in its effective solution to the aforementioned problems. The sealing structure of this utility model is equipped with a bellows and a dust cover. The bellows can receive oil leakage and also provide dust protection, while the dust cover also provides dust protection. Therefore, it can effectively prevent dust and collect oil leakage during minor leaks and pseudo-oil seepage. When the hydraulic damper leaks slightly along the piston rod, most of the leaking hydraulic oil can be guided back to the reservoir through the return channel. A small amount of leaking hydraulic oil will enter the first chamber of the bellows through the gland and be collected, preventing it from overflowing onto the outer surface of the hydraulic damper. However, if the hydraulic damper is not only leaking slightly or experiencing a false leak, the first chamber of the bellows cannot collect a large amount of leaking hydraulic oil. The hydraulic oil will then flow through the breather hole into the second chamber, eventually overflowing from the second chamber and becoming visible as oil stains. This allows for the differentiation between slight / false leaks and true leaks, avoiding the problem of frequent replacements of the hydraulic damper caused by slight or false leaks, thus extending the device's service life and reducing costs. Furthermore, compared to existing technologies, this invention has the following advantages:

[0024] 1. It is equipped with a return channel, which can guide the leaked hydraulic oil back to the oil reservoir, thereby reducing the occurrence of oil leakage incidents; moreover, the return channel can also relieve pressure on the sealing lip of the skeleton oil seal, reducing the pressure impact of hydraulic oil on the skeleton oil seal, thereby improving the sealing effect of the skeleton oil seal and reducing oil leakage incidents.

[0025] 2. The gland is equipped with a dustproof ring and a skeleton oil seal, which can further enhance the dustproof and oil leakage prevention effect.

[0026] 3. The triangular static seal structure formed between the glands helps to improve the sealing effect and prevent hydraulic oil from leaking out from parts other than the piston rod.

[0027] The sealing structure of this utility model provides internal sealing and external dust protection. It can be applied to hydraulic shock absorbers that use hydraulic oil as the working medium, such as automotive shock absorbers, motorcycle shock absorbers, rail transit vehicle shock absorbers, and engineering machinery shock absorbers. It can comprehensively improve the sealing and wind and sand protection safety factor of hydraulic shock absorbers, and is especially suitable for harsh working conditions such as high-frequency vibration and wind and sand environments, greatly reducing the frequency of oil leakage and replacement of hydraulic shock absorbers. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the present invention applied to a hydraulic vibration damper.

[0029] Figure 2 yes Figure 1 Longitudinal sectional view;

[0030] Figure 3 yes Figure 2 A magnified view of a portion of the image.

[0031] Attached image labels:

[0032] Sealing structure 100:

[0033] Gland 110: Return channel 112, base 113, center hole 1131, oil collection groove 1132, oil return hole 1133, guide seat 114, external thread 1141, dust ring 115, gasket 116, sealing ring 117, second annular groove 118, skeleton oil seal 119, sealing lip 1191, tension spring 1110;

[0034] Bellows 120: Socket hole 121, first cavity 122, bellows section 123, vent hole 124, expansion section 125;

[0035] Dust cover 130;

[0036] Second cavity 140;

[0037] Hydraulic damper 200: piston rod 210, oil reservoir 220, internal thread 2201, high pressure chamber 2202, low pressure chamber 2203. Detailed Implementation

[0038] The following embodiments are further explanations and supplements to the present invention and do not constitute any limitation on the present invention.

[0039] like Figures 1 to 3 As shown, the sealing structure 100 of this utility model is used for the hydraulic damper 200. Its main feature is that it is equipped with multiple protections to prevent the hydraulic damper 200 from leaking oil, so as to avoid the cost problem caused by frequent replacement of the hydraulic damper 200. It can also strengthen the protection to prevent the hydraulic damper 200 from failing due to the intrusion of foreign objects, thereby improving the service life of the hydraulic damper 200.

[0040] The sealing structure 100 of this utility model includes a gland 110 and a bellows 120.

[0041] The pressure cap 110 is used to connect with the hydraulic damper 200 and is sleeved on the piston rod 210;

[0042] The bellows 120 has two opposing ends: a first end and a second end. The first end has a fitting hole 121 and can be fitted onto the piston rod 210 to form a sealed connection. The second end is fixedly connected to or integrally formed with the pressure cap 110 and can be fitted onto the piston rod 210. The bellows 120 has a first cavity 122, the size of which is variable to accommodate the piston movement of the piston rod 210. The first cavity 122 also serves to receive leaked hydraulic oil.

[0043] The volume of the first cavity 122 can be set as needed, and it can at least receive hydraulic oil during slight oil leakage and / or pseudo-oil leakage.

[0044] For the hydraulic damper 200, since the piston rod 210 is a moving part, if the hydraulic oil inside the hydraulic damper 200 leaks, it generally leaks outward along the piston rod 210, that is, at the connection between the piston rod 210 and the hydraulic damper 200. Numerous tests and studies have shown that minor oil leaks or seepage do not affect the damper's performance, but they do affect its appearance. A high percentage of hydraulic dampers are replaced annually due to this, resulting in wasted components and increased costs. In this application, both the gland 110 and the bellows 120 are fitted onto the piston rod 210, and the end of the bellows 120 furthest from the gland 110—the first end—forms a sealed connection with the piston rod 210. In this embodiment, the sealed connection is formed by an interference fit. The bellows 120 has a first cavity 122 for collecting hydraulic oil. Therefore, when the hydraulic damper 200 leaks oil outward along the piston rod 210, the leaked hydraulic oil can enter the first cavity 122 through the gland 110 and be collected. In this way, the hydraulic oil in the event of slight leakage or false seepage will not overflow onto the outer surface of the hydraulic damper 200, thus preventing oil stains from appearing on the outside. This greatly reduces the replacement frequency of the hydraulic damper 200 due to slight leakage or false seepage, thereby increasing the service life of the hydraulic damper 200 and reducing costs. The first cavity 122 of the bellows 120 should be configured to be insufficient to receive hydraulic oil when there is a large amount of leakage. In this way, when a real oil seepage occurs, the first cavity 122 will be insufficient to receive it, so that the hydraulic oil continues to seep out and can be observed.

[0045] In addition, the bellows 120 sleeved on the piston rod 210 outside the hydraulic damper 200 can cover the connection between the piston rod 210 and the hydraulic damper 200, thus playing a dustproof protection role. It can prevent external dust, sand, rain, snow and other foreign objects from entering the hydraulic damper 200, avoiding phenomena such as seal damage, hydraulic oil contamination and performance failure of the hydraulic damper 200.

[0046] Furthermore, to prevent oil leakage, a return channel 112 is provided on the gland 110. When hydraulic oil leaks from the hydraulic damper 200 along the piston rod 210 towards the gland 110, the return channel 112 can guide the hydraulic oil back to the hydraulic damper 200 along a path different from that of the piston rod 210. In this way, when oil leakage occurs, the hydraulic oil can return to the hydraulic damper 200 through another path, thereby avoiding large-scale oil leakage. When a small amount of hydraulic oil leaks from the gland 110 towards the bellows 120, the hydraulic oil will enter the first cavity 122 of the bellows 120 and be collected.

[0047] Furthermore, the pressure cap 110 includes a base 113 and a guide seat 114.

[0048] The base 113 can be sleeved on the piston rod 210 and block the port of the oil reservoir 220 of the hydraulic damper 200 to prevent the hydraulic oil in the oil reservoir 220 from leaking out from parts other than the piston rod 210.

[0049] The guide seat 114 is connected to the bellows 120, and can be sleeved on the piston rod 210 and connected to the oil reservoir 220 of the hydraulic damper 200, so that the base 113 can be pressed against the port of the oil reservoir 220.

[0050] Furthermore, the guide seat 114 is threadedly connected to the oil reservoir 220: an external thread 1141 is provided on the outer circumferential wall of the guide seat 114, and an internal thread 2201 is provided on the inner wall of the oil reservoir 220. The external thread 1141 and the internal thread 2201 are matched, thus allowing the guide seat 114 to be threadedly connected inside the oil reservoir 220. After the guide seat 114 is connected to the oil reservoir 220, the base 113 can be pressed tightly between the guide seat 114 and the oil reservoir 220.

[0051] The shape of the end of the base 113 facing away from the guide seat 114 can be set according to the shape of the oil reservoir 220. It has a limiting structure to abut against the oil reservoir 220, so that it can be pressed tightly between the guide seat 114 and the oil reservoir 220 by the guide seat 114.

[0052] Furthermore, the base 113 is provided with the return channel 112, through which the leaked hydraulic oil can be guided back to the oil reservoir 220.

[0053] Furthermore, a central hole 1131 for the piston rod 210 to pass through is provided on the base 113. An oil collection groove 1132 is provided at one end of the base 113 facing the guide seat 114. The oil collection groove 1132 communicates with the central hole 1131, and the diameter of the oil collection groove 1132 is larger than the diameter of the central hole 1131, so as to collect hydraulic oil.

[0054] When the hydraulic damper 200 leaks oil outward along the piston rod 210, the hydraulic oil can enter the oil accumulation groove 1132 through the central hole 1131.

[0055] An oil return hole 1133 is provided on the base 113. The oil return hole 1133 is different from the central hole 1131 and communicates with the oil accumulation groove 1132. The oil return hole 1133 is a through hole structure, with its other end facing the oil storage cylinder 220, and is used to guide the hydraulic oil in the oil accumulation groove 1132 back to the oil storage cylinder 220.

[0056] The oil accumulation groove 1132, the central hole 1131, and the oil return hole 1133 can constitute the return channel 112.

[0057] Furthermore, the oil return hole 1133 is inclined to the axial direction of the central hole 1131.

[0058] Furthermore, the return oil hole 1133 and the center hole 1131 point to different chambers of the oil reservoir 220. For example, the center hole 1131 points to the high-pressure chamber 2202 of the oil reservoir 220, and the return oil hole 1133 points to the low-pressure chamber 2203 of the oil reservoir 220.

[0059] In this way, when hydraulic oil in the high-pressure chamber 2202 leaks due to the reciprocating motion of the piston rod 210, the hydraulic oil enters the oil accumulation groove 1132 through the central hole 1131, and then flows back to the low-pressure chamber 2203 through the return oil hole 1133. This greatly reduces oil leakage and protects the structure at the front end of the base 113 from pressure shocks, while also closing the oil circuit and reducing the temperature at the oil seal.

[0060] Furthermore, the pressure cap 110 also includes a gasket 116 and a sealing ring 117, which are used to enhance the sealing of the connection and prevent oil leakage from parts other than the piston rod 210.

[0061] The gasket 116 is disposed between the guide seat 114 and the base 113. The sealing ring 117 is disposed between the gasket 116 and the base 113.

[0062] The guide seat 114 and the base 113 are statically connected, meaning they do not move relative to each other. Therefore, a gasket 116 and a sealing ring 117 are provided between the guide seat 114 and the base 113 to further ensure the sealing of their joint and prevent hydraulic oil from leaking from the joint.

[0063] The gasket 116 and the sealing ring 117 can be made of known gaskets and sealing rings, such as rubber gaskets and rubber sealing rings.

[0064] Furthermore, to further enhance sealing, a wedge structure is provided on the edge of the base 113 facing the guide seat 114. When the base 113 is installed inside the oil reservoir 220, a second annular groove 118 is formed between the wedge structure and the inner wall of the oil reservoir 220. In this embodiment, the second annular groove 118 has a triangular cross-sectional shape.

[0065] The sealing ring 117 is disposed in the second annular groove 118, and the gasket 116 closes the second annular groove 118, so that the sealing ring 117 is pressed and sealed between the gasket 116 and the base 113. In this way, the gasket 116, the sealing ring 117, the base 113, and the guide seat 114 can form a triangular static seal structure, which enhances the sealing effect at the joint and prevents the hydraulic oil in the oil reservoir 220 from leaking out.

[0066] When the oil reservoir 220 is equipped with a low-pressure chamber 2203 and a high-pressure chamber 2202, the triangular static seal structure can prevent hydraulic oil leakage from the low-pressure chamber 2203.

[0067] In some embodiments, the structure of this utility model further includes a skeleton oil seal 119. The skeleton oil seal 119 is used to be sleeved on the piston rod 210 and is located between the piston rod 210 and the pressure cap 110 to prevent hydraulic oil from leaking from the knife holder 113 toward the guide seat 114, thereby enhancing the sealing performance of the piston rod 210 movement.

[0068] In some embodiments, the skeleton oil seal 119 is disposed within the base 113 and is at least partially located in the liquid collection tank.

[0069] In some embodiments, the skeleton oil seal 119 is disposed within the guide seat 114, facing the liquid collection tank.

[0070] In some embodiments, the skeleton oil seal 119 may be partially located within the base 113 and partially within the guide seat 114, and is connected at the junction of the base 113 and the guide seat 114.

[0071] Furthermore, the skeleton oil seal 119 has sealing lips 1191 at both ends, with the sealing lips 1191 spaced apart from each other. The sealing lips 1191 can strengthen the sealing connection with the piston rod 210. In this way, by setting the skeleton oil seal 119, the sealing performance can be improved, preventing hydraulic oil entering the oil accumulation groove 1132 from leaking towards the guide seat 114 through the base 113. This allows the hydraulic oil to flow back into the oil reservoir 220 through the return oil hole 1133 as much as possible.

[0072] Furthermore, a tension spring 1110 is fitted onto the skeleton oil seal 119. The tension spring 1110 constantly tends to drive the skeleton oil seal 119 to grip the piston rod 210. In this way, the tension spring 1110 makes the skeleton oil seal 119 and the piston rod 210 more tightly connected, ensuring the follow-up sealing performance of the skeleton oil seal 119 when the hydraulic damper 200 is under off-center load, thereby enhancing the sealing effect and preventing hydraulic oil from leaking into the first cavity 122.

[0073] Furthermore, the second end port of the bellows 120 is larger than the diameter of the central hole 1131; when the bellows 120 is sleeved on the piston rod 210, a gap channel is formed between the second end of the bellows 120 and the piston rod 210 to allow hydraulic oil to pass through. In this way, if the hydraulic oil leaks through the skeleton oil seal 119 and along the piston rod 210 to the bellows 120, the hydraulic oil can easily enter the first cavity 122 and be collected, instead of leaking outwards along other joints.

[0074] In some embodiments, a dustproof ring 115 is also provided inside the pressure cap 110. The dustproof ring 115 is used to be sleeved on the piston rod 210, and it is used to prevent foreign objects in the first cavity 122 from entering the pressure cap 110, so as to avoid foreign objects from intruding into the hydraulic damper and thus avoid the failure of the hydraulic damper.

[0075] Furthermore, the dustproof ring 115 may be configured in the shape of a horn, with its open end forming a sealed connection with the guide seat 114, and its constricted end sleeved on the piston rod 210, with the constricted end located at one end close to the bellows 120.

[0076] The dustproof ring 115 can prevent foreign objects from entering the gland 110 from the first cavity 122, and at the same time prevent hydraulic oil in the gland 110 from leaking towards the bellows 120, thereby improving the dustproof and oil leakage prevention performance.

[0077] In some embodiments, a dust cover 130 may also be included.

[0078] The dust cover 130 at least partially covers the bellows 120 and can be sleeved on the piston rod 210 to form a sealed connection with the piston rod 210. The dust cover 130 is used to enhance protection and prevent external foreign objects from entering the hydraulic damper 200, thereby improving the service life of the hydraulic damper 200.

[0079] The dust cover 130 forms a second cavity 140 at least between the bellows 120 and the piston rod 210. This second cavity 140 enhances the dust protection effect.

[0080] The dust cover 130 is not completely sealed to the outer surface of the hydraulic damper 200; at least some parts of it have gaps that allow it to communicate with the outside, so that in the event of a large oil leak, hydraulic oil can leak to the surface of the hydraulic damper 200 and be observed. In this embodiment, the dust cover 130 is cylindrical, with one end sealed to the piston rod 210, and the other end being an open end fitted over the oil reservoir 220, forming a gap between it and the surface of the hydraulic damper 200.

[0081] Furthermore, the bellows 120 includes a plurality of bellows 123 that can extend and retract along the movement direction of the piston rod 210. The arrangement of the plurality of bellows 123 enables the bellows 120 to have the ability to extend and retract to change the size of the first cavity 122, thus adapting to the piston movement of the piston rod 210.

[0082] When the bellows 120 expands or contracts, the size of the first cavity 122 changes. To adapt to pressure changes, at least one vent 124 is provided on at least one of the bellows sections 123. The vent 124 is a through-hole structure that connects the first cavity 122 and the second cavity 140. Thus, when the piston rod 210 performs piston movement, the bellows 120 can expand and contract along with the piston rod 210.

[0083] Furthermore, the second cavity 140 surrounds the first cavity 122.

[0084] Preferably, the breather hole 124 is located on the corrugated portion 123 away from the pressure cap 110. This prevents hydraulic oil entering the first chamber 122 from overflowing through the breather hole 124. When slight or false oil leakage occurs, hydraulic oil enters the first chamber 122 and is unlikely to overflow into the second chamber 140 through the breather hole 124, so no oil stains are visible on the outside. When the amount of hydraulic oil collected in the first chamber 122 reaches a certain level, the hydraulic oil may overflow into the second chamber 140 through the breather hole 124, and eventually leak to the outside through the second chamber 140 (there is a gap between the dust cover 130 and the hydraulic damper). At this time, the outside of the hydraulic damper 200 will show oil stains due to the leakage, indicating a true oil leak.

[0085] The number of the breathing holes 124 is not limited; there can be one, two, or more. Of course, for better dust prevention, it is preferable to have one breathing hole 124.

[0086] The breathing hole 124 is a small hole structure, and its diameter can be set as needed.

[0087] Furthermore, the socket 121 is provided on the corrugated portion 123 at the first end.

[0088] To form a sealed connection with the piston rod 210, an enlarged portion 125 is provided at the edge of the socket 121. Specifically, the enlarged portion 125 is formed by expanding the edge of the corrugated portion 123 defining the socket 121. The bellows 120 can form a sealed connection with the piston rod 210 through the enlarged portion 125. More specifically, the enlarged portion 125 is used for an interference fit with the piston rod 210 to achieve a sealed connection.

[0089] An enlarged portion 125 is formed at the edge of the socket 121, which helps to enhance the reliability of the sealing connection and can prevent the connection between the socket 121 and the piston rod 210 from failing due to the piston movement of the piston rod 210.

[0090] Furthermore, the bellows 120 is made of rubber material, so that the multiple corrugations 123 can be easily extended and retracted to adapt to the piston movement of the piston rod 210.

[0091] The bellows 120 is fixedly connected to or integrally formed with the gland 110, forming a single unit that is sleeved onto the piston rod 210. In this embodiment, to enhance the connection reliability between the bellows 120 and the gland 110, the second end of the bellows 120 is fixedly bonded to the gland 110 via a vulcanization process. In other embodiments, the second end of the bellows 120 is fixedly bonded to the gland 110 via adhesive bonding.

[0092] When the piston rod 210 reciprocates, if hydraulic oil leaks from the reservoir 220, it will flow along the piston rod 210 into the gland 110, and then into the oil collection tank 1132. Most of the hydraulic oil in the oil collection tank 1132 will flow back into the reservoir 220 through the return oil hole 1133. If the hydraulic oil in the oil collection tank 1132 continues to leak along the piston rod 210, it may enter the guide seat 114 through the skeleton oil seal 119, and then leak into the bellows 120, where it will be collected in the first cavity 122. If the hydraulic damper 200 experiences a false leak or slight seepage, the small amount of hydraulic oil leaking out will be received by the first chamber 122 and stored inside the bellows 120, thus making the oil stains invisible from the outside of the hydraulic damper. However, if the hydraulic damper 200 experiences a serious leak, a large amount of hydraulic oil will enter the first chamber 122 and flow through the breather hole 124 into the second chamber 140, eventually flowing out of the second chamber 140 and becoming visible as oil stains. In this way, the presence of oil stains on the surface of the hydraulic damper 200 can accurately determine whether the leak is genuine or false, avoiding the problem of frequent replacement of the hydraulic damper 200 for slight or false seepage, thereby greatly reducing the replacement frequency of the hydraulic damper 200. In addition, the bellows 120, dust cover 130 and dust ring 115 of this application can also be used for multiple dust protection to prevent foreign objects from entering the interior of the hydraulic damper 200, thereby avoiding the problem of failure of the hydraulic damper 200 due to the entry of foreign objects. As the first layer of dust protection, the dust cover 130 can block foreign objects such as sand and gravel from hitting the piston rod 210 and the dust bellows, thus providing dust protection. If sand, rain, snow, etc. enter the interior of the dust cover 130, i.e., the second cavity 140, through the gap between the dust cover 130 and the oil reservoir 220, it can be protected by the bellows 120. The first end of the bellows 120 is sealed to the piston rod 210, and only the breather hole 124 is connected to the second cavity 140. Therefore, the bellows 120 can prevent most foreign objects from entering the interior of the bellows 120. Only a very small amount of fine sand can enter the first cavity 122 through the breather hole 124. The dust ring 115 and the sealing lip 1191 of the skeleton oil seal 119 can provide further protection, effectively preventing fine sand from continuing to enter the interior of the hydraulic damper 200. In this way, through multiple protections, foreign objects can be effectively prevented from entering the interior of the hydraulic damper 200, thus avoiding the failure of the hydraulic damper 200 due to foreign object intrusion.

[0093] In this application, when the external environment in which the hydraulic damper 200 operates is good and the stroke of the hydraulic damper 200 is large, the dustproof ring 115 may not be provided, so that the pressure cover 110, especially the base 113, is thinner, so that the hydraulic damper 200 has a larger stroke space, lower cost and simpler installation.

[0094] Although the present invention has been disclosed through the above embodiments, the scope of the present invention is not limited thereto. Without departing from the concept of the present invention, the above components can be replaced by similar or equivalent elements known to those skilled in the art.

Claims

1. A seal structure for an oil pressure shock absorber (200), characterized by, The sealing structure is arranged on a piston rod (210) of the oil damper (200), and comprises: a gland (110) for connecting with the oil damper (200) and sleeving on the piston rod (210); a bellows (120) having a sleeving hole (121) at a first end for sleeving on the piston rod (210) and sealingly connecting with the piston rod (210), and having a second end connected with the gland (110) and sleeving on the piston rod (210), the bellows (120) being provided with a first cavity (122) for receiving hydraulic oil and being capable of adapting to the piston movement of the piston rod (210); the gland (110) is provided with a backflow channel (112) for guiding the hydraulic oil leaked from the oil damper (200) along the piston rod (210) towards the gland (110) to the oil damper (200) along a path different from the direction of the piston rod (210), and the hydraulic oil leaked from the piston rod (210) through the gland (110) towards the bellows (120) can enter the first cavity (122) for collection.

2. The seal structure of claim 1, wherein The gland (110) comprises: a base (113) for sleeving on the piston rod (210) and blocking the port of an oil storage cylinder (220) of the oil damper (200); a guide seat (114) connected with the bellows (120), the guide seat (114) being capable of sleeving on the piston rod (210) and connecting with the oil storage cylinder (220) of the oil damper (200) to press the base (113) against the port of the oil storage cylinder (220); wherein the backflow channel (112) is arranged on the base (113).

3. The sealing structure according to claim 2, wherein: the base (113) is provided with a central hole (1131) for the piston rod (210) to pass through, an oil accumulation groove (1132) is arranged at an end of the base (113) facing the guide seat (114), the oil accumulation groove (1132) being through with the central hole (1131), and when the oil damper (200) leaks hydraulic oil along the piston rod (210), the hydraulic oil can enter the oil accumulation groove (1132) through the central hole (1131); a backflow hole (1133) is arranged on the gland (110) and is through with the oil accumulation groove (1132) for guiding the hydraulic oil in the oil accumulation groove (1132) back to the oil storage cylinder (220).

4. The seal structure of claim 3, wherein The backflow hole (1133) is arranged obliquely to the axial direction of the central hole (1131).

5. The seal structure of claim 3, wherein The oil return hole (1133) and the center hole (1131) are directed to different chambers of the oil storage cylinder (220), wherein the oil return hole (1133) is directed to a low pressure chamber (2203) of the oil storage cylinder (220), and the center hole (1131) is directed to a high pressure chamber (2202) of the oil storage cylinder (220).

6. The seal structure of claim 2, wherein A skeleton oil seal (119) is arranged in the gland (110), and the skeleton oil seal (119) is arranged on the piston rod (210) to prevent hydraulic oil from leaking from the base (113) to the guide seat (114).

7. The seal structure of claim 6, wherein Both ends of the skeleton oil seal (119) in the direction of the piston rod (210) are respectively provided with a sealing lip (1191), and a tension spring (1110) is arranged on the skeleton oil seal (119), and the tension spring (1110) always has a tendency to drive the skeleton oil seal (119) to be tightly connected with the piston rod (210).

8. The sealed structure of claim 1, wherein, A dustproof ring (115) is arranged in the gland (110), and the dustproof ring (115) is arranged on the piston rod (210) to prevent foreign matters in the first cavity (122) from entering the gland (110).

9. The seal structure of claim 1, wherein It also includes: A dust cover (130) is at least partially arranged outside the bellows (120) and can be arranged on the piston rod (210) to form a sealed connection with the piston rod (210), The dust cover (130) forms a second cavity (140) with at least the bellows (120) and the piston rod (210), The bellows (120) is provided with a breathing hole (124) penetrating the second cavity (140) and the first cavity (122); When the oil pressure shock absorber (200) leaks oil along the piston rod (210), the leaked hydraulic oil can enter the first cavity (122) through the gland (110) and be collected.

10. The sealing structure of claim 2, wherein An edge of the base (113) towards the guide seat (114) is provided with a wedge structure, and when the base (113) is arranged in the oil storage cylinder (220), the wedge structure and the inner wall of the oil storage cylinder (220) form a second annular groove (118), A sealing ring (117) is arranged in the second annular groove (118), and a gasket (116) is arranged between the base (113) and the guide seat (114), and the gasket (116) closes the second annular groove (118) and abuts against the sealing ring (117).

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