Multi-dustproof sealing structure

Abstract

A multi-dustproof sealing structure is used for an oil damper, is arranged on a piston rod of the oil damper and is used for receiving hydraulic oil leaked by the oil damper, the dustproof sealing structure comprises a gland, a corrugated pipe and a dustproof cover, a first end of the corrugated pipe is provided with a first opening part, and the corrugated pipe can be arranged on the piston rod in a sleeving mode and is in sealing connection with the piston rod; the second end of the corrugated pipe is connected with the gland and can sleeve the piston rod; the corrugated pipe is provided with a first accommodating cavity which can receive hydraulic oil and can adapt to piston movement of the piston rod; the dustproof cover at least partially covers the corrugated pipe and can be arranged on the piston rod in a sleeving mode to be in sealed connection with the piston rod, a second containing cavity is at least formed between the dustproof cover and the corrugated pipe and between the dustproof cover and the piston rod, and when the oil damper leaks oil outwards along the piston rod, leaked hydraulic oil can enter the first containing cavity through the gland to be collected. According to the structure, dust can be prevented outwards, inner sealing can be achieved, dust prevention and protection can be effectively achieved, slight oil leakage or false oil leakage can be collected, and frequent replacement of the oil damper is avoided.

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 multi-layer dustproof 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 multi-layered dustproof sealing structure that can prevent oil leakage and collect minor oil leaks and false oil seepage.

[0005] To solve the above problems, this utility model provides a multi-layer dustproof sealing structure for a hydraulic damper, characterized in that it is installed on the piston rod of the hydraulic damper to receive hydraulic oil leaked from the hydraulic damper. 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 opening at one end 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] A dust cover, at least partially covering the bellows, can be fitted onto the piston rod to form a sealed connection with it.

[0009] The dust cover forms a second cavity at least between itself and the bellows and piston rod.

[0010] When the hydraulic damper leaks oil outward along the piston rod, the leaked hydraulic oil can enter the first cavity through the gland and be collected.

[0011] Furthermore, the bellows is provided with a vent hole, which connects the second cavity and the first cavity.

[0012] Furthermore, the second cavity surrounds the first cavity.

[0013] Furthermore, the pressure cap is provided with an oil leakage return channel. When the hydraulic damper leaks hydraulic oil along the piston rod toward the pressure cap, the oil leakage return channel can guide the hydraulic oil back to the hydraulic damper along a path different from that of the piston rod.

[0014] Furthermore, the gland includes:

[0015] A guide seat can be fitted onto the piston rod and block the port of the oil reservoir of the hydraulic damper;

[0016] A pressure cap is connected to the bellows; the pressure cap can be sleeved on the piston rod and connected to the oil reservoir of the hydraulic damper to press the guide seat against the port of the oil reservoir;

[0017] The guide seat is provided with the oil leakage return channel.

[0018] Furthermore, the guide seat is provided with a first shaft hole for the piston rod to pass through.

[0019] An oil collection groove is provided at one end of the guide seat facing the pressure cover. The oil collection groove is in communication with the first shaft hole. When the hydraulic damper leaks oil outward along the piston rod, the hydraulic oil can enter the oil collection groove through the first shaft hole.

[0020] 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.

[0021] Furthermore, the oil return hole is inclined to the axial direction of the first shaft hole.

[0022] Furthermore, it also includes a bearing, which is installed in the first shaft hole and can be sleeved on the piston rod.

[0023] Furthermore, the gland also includes:

[0024] A gasket is provided between the pressure cap and the guide seat;

[0025] A sealing ring is provided between the gasket and the guide seat.

[0026] Furthermore, the guide seat has a wedge structure on one edge facing the pressure cap. When the guide seat is installed inside the oil reservoir, the wedge structure forms an annular groove with the inner wall of the oil reservoir.

[0027] The sealing ring is disposed in the annular groove; the gasket closes the annular groove.

[0028] The beneficial contribution of this utility model lies in its effective solution to the aforementioned problems. The multi-layered dustproof sealing structure of this utility model includes a bellows and a dust cover. The bellows can receive leaked oil and provide dust protection, while the dust cover also provides dust protection. Therefore, it effectively prevents dust and collects oil leaks, including minor leaks and pseudo-leaks. When the hydraulic damper leaks slightly along the piston rod, the leaking hydraulic oil enters the first cavity of the bellows through the gland and is collected, preventing it from overflowing onto the outer surface of the hydraulic damper. However, if the hydraulic damper is not experiencing minor or pseudo-leaks, the first cavity of the bellows cannot collect a large amount of leaked hydraulic oil. The hydraulic oil then flows through the breather hole into the second cavity, eventually overflowing from the second cavity to the surface and becoming visible as oil stains. This allows for the differentiation between minor / pseudo-leaks and true leaks, thus avoiding the problem of frequent replacements of the hydraulic damper caused by minor or pseudo-leaks, thereby extending the service life of the device and reducing costs. Furthermore, compared with the prior art, this utility model has the following advantages:

[0029] 1. An oil leakage return channel is provided, which can guide leaked hydraulic oil back to the oil reservoir, thereby reducing the occurrence of oil leakage incidents; moreover, the oil leakage 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.

[0030] 2. 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.

[0031] 3. The pressure cap is equipped with a bearing, which can play a role in high pressure relief and support and guidance to resist eccentric load, thereby improving the side load bearing capacity.

[0032] This utility model's multi-layered dustproof sealing structure can prevent dust from the outside and seal the inside. 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 dustproof safety factor of hydraulic shock absorbers, and is especially suitable for harsh working conditions such as high-frequency vibration and sandstorm environments, greatly reducing the frequency of oil leakage and replacement of hydraulic shock absorbers. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the present invention applied to a hydraulic vibration damper.

[0034] Figure 2 yes Figure 1 A magnified view of a portion of the image.

[0035] Attached image labels:

[0036] Multiple dustproof sealing structure 100:

[0037] Pressure cap assembly 110: First annular groove 111, oil leakage return channel 112, guide seat 113, first shaft hole 1131, oil accumulation groove 1132, oil return hole 1133, pressure cap 114, external thread 1141, bearing 115, gasket 116, sealing ring 117, second annular groove 118, skeleton oil seal 119, sealing lip 1191, annular locking position 1192, preload spring 1110;

[0038] Bellows 120: First opening 121, first cavity 122, bellows section 123, vent 124, enlarged section 125, outer edge section 126;

[0039] Dust cover 130;

[0040] Second cavity 140;

[0041] 150 ring-shaped pressing block;

[0042] Fastener 160;

[0043] Hydraulic damper 200: piston rod 210, oil reservoir 220, internal thread 2201, high pressure chamber 2202, low pressure chamber 2203. Detailed Implementation

[0044] The following embodiments are further explanations and supplements to the present invention and do not constitute any limitation on the present invention.

[0045] like Figure 1 , Figure 2 As shown, the multi-dustproof sealing structure 100 of this utility model is used for hydraulic shock absorber 200. Its main feature is that it is equipped with multiple protections to prevent oil leakage of hydraulic shock absorber 200, so as to avoid the cost problem caused by frequent replacement of hydraulic shock absorber 200, and can strengthen protection to prevent hydraulic shock absorber 200 from failing due to foreign object intrusion, thereby improving the service life of hydraulic shock absorber 200.

[0046] The multi-dustproof sealing structure 100 of this utility model includes a pressure cap assembly 110, a bellows 120, and a dust cover 130.

[0047] The pressure cap assembly 110 is used to connect with the hydraulic damper 200 and is sleeved on the piston rod 210;

[0048] The bellows 120 has two opposing ends: a first end and a second end. The first end has a first opening 121 that can be fitted onto the piston rod 210 and form a sealed connection with it. The second end is fixedly connected to or integrally formed with the gland assembly 110, and can also 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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 slight oil leakage or seepage does not affect the damper's performance, but it does 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 assembly 110 and the bellows 120 are fitted onto the piston rod 210, and the end of the bellows 120 furthest from the gland assembly 110—the first end—forms a sealed connection with the piston rod 210. 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 assembly 110 and be collected. In this way, hydraulic oil in the event of minor leaks or pseudo-seepage will not overflow onto the outer surface of the hydraulic damper 200, thus preventing external oil contamination. This significantly reduces the replacement frequency of the hydraulic damper 200 due to minor leaks or pseudo-seepage, thereby increasing its service life and reducing costs. The first cavity 122 of the bellows 120 should be configured to be insufficient to receive hydraulic oil in the event of a large leak. Thus, when a true seepage occurs, the first cavity 122 will be insufficient to receive the leaked oil, allowing the hydraulic oil to continue to seep out and become observable.

[0054] Furthermore, the bellows 120 fitted onto the piston rod 210 outside the hydraulic damper 200 can cover the connection between the piston rod 210 and the hydraulic damper 200, thus providing dust protection. The dust cover 130 covering the bellows 120 provides double dust protection. Both the dust cover 130 and the bellows 120 can prevent external dust, sand, rain, snow, and other foreign objects from entering the hydraulic damper 200, avoiding damage to the seals, hydraulic oil contamination, and performance failure.

[0055] Furthermore, the bellows 120 includes a plurality of corrugated portions 123 that can extend and retract along the movement direction of the piston rod 210. The arrangement of multiple corrugated portions 123 enables the bellows 120 to have the ability to extend and retract, thereby changing the size of the first cavity 122, so as to adapt to the piston movement of the piston rod 210.

[0056] When the bellows 120 expands or contracts, the size of the first cavity 122 changes. To adapt to the pressure change, 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 moves, the bellows 120 can expand or contract with the piston rod 210.

[0057] Furthermore, the second cavity 140 surrounds the first cavity 122.

[0058] Preferably, the breather hole 124 is located on the corrugated portion 123 away from the gland assembly 110. This prevents hydraulic oil entering the first cavity 122 from overflowing through the breather hole 124. When slight or false oil leakage occurs, hydraulic oil enters the first cavity 122 and is unlikely to overflow into the second cavity 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 cavity 122 reaches a certain level, the hydraulic oil may overflow into the second cavity 140 through the breather hole 124, and eventually leak to the outside through the second cavity 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 oil leakage, indicating a true oil leakage.

[0059] 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.

[0060] The breathing hole 124 is a small hole structure, and its diameter can be set as needed.

[0061] Furthermore, the first opening 121 is provided on the corrugated portion 123 at the first end.

[0062] To form a sealed connection with the piston rod 210, an enlarged portion 125 is provided at the edge of the first opening 121. Specifically, the enlarged portion 125 is formed by enlarging the edge of the corrugated portion 123 defining the first opening 121. The corrugated tube 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.

[0063] An enlarged portion 125 is formed at the edge of the first opening 121, which helps to enhance the reliability of the sealing connection and can prevent the piston movement of the piston rod 210 from causing the connection between the first opening 121 and the piston rod 210 to fail.

[0064] 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.

[0065] The bellows 120 is fixedly connected to or integrally formed with the cap assembly 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 cap assembly 110, the second end of the bellows 120 is fixedly connected to the cap assembly 110 via a vulcanization process. In other embodiments, the second end of the bellows 120 is fixedly connected to the cap assembly 110 via adhesive bonding.

[0066] Furthermore, to enhance the connection reliability between the bellows 120 and the gland assembly 110, such as... Figure 2 As shown, the cap assembly 110 has a first annular groove 111 circumferentially arranged around the piston rod 210. The second end of the bellows 120 has an annular outer edge 126, which is installed in the first annular groove 111 and fits against the bottom of the first annular groove 111. An annular pressure block 150 is also provided between the second end of the bellows 120 and the first annular groove 111. The annular pressure block 150 is connected to the cap assembly 110 by a fastener 160, thereby clamping the outer edge 126 between the annular pressure block 150 and the cap assembly 110, so that the bellows 120 and the cap assembly 110 are connected together.

[0067] The annular pressure block 150 can be a nut structure or a block structure.

[0068] The bellows 120 and the gland assembly 110 are connected as a whole, and the whole can be fitted onto the piston rod 210 of the hydraulic damper 200. The gland assembly 110 is connected to the oil reservoir 220 of the hydraulic damper 200, while the bellows 120 is away from the oil reservoir 220 of the hydraulic damper 200.

[0069] To prevent oil leakage, an oil return channel 112 is provided on the gland assembly 110. When hydraulic oil leaks from the hydraulic damper 200 along the piston rod 210 toward the gland assembly 110, the oil 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.

[0070] Furthermore, the pressure cap assembly 110 includes a guide seat 113 and a pressure cap 114.

[0071] The guide seat 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.

[0072] The pressure cap 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 guide seat 113 can be pressed at the port of the oil reservoir 220.

[0073] Furthermore, the pressure cap 114 is threadedly connected to the oil reservoir 220: an external thread 1141 is provided on the outer circumference of the pressure cap 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, so that the pressure cap 114 can be threadedly connected to the oil reservoir 220. After the pressure cap 114 is connected to the oil reservoir 220, the guide seat 113 can be pressed between the pressure cap 114 and the oil reservoir 220.

[0074] The shape of the end of the guide seat 113 facing away from the pressure cap 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 pressure cap 114 and the oil reservoir 220.

[0075] Furthermore, the guide seat 113 is provided with the oil leakage return channel 112, through which the leaked hydraulic oil can be guided back to the oil reservoir 220.

[0076] Furthermore, the guide seat 113 is provided with a first shaft hole 1131 for the piston rod 210 to pass through. An oil collection groove 1132 is provided at one end of the guide seat 113 facing the pressure cap 114. The oil collection groove 1132 communicates with the first shaft hole 1131, and the diameter of the oil collection groove 1132 is larger than the diameter of the first shaft hole 1131, for collecting hydraulic oil.

[0077] 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 first shaft hole 1131.

[0078] An oil return hole 1133 is provided on the guide seat 113. The oil return hole 1133 is different from the first shaft 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.

[0079] The oil accumulation groove 1132, the first shaft hole 1131, and the oil return hole 1133 can constitute the oil leakage return channel 112.

[0080] Furthermore, the oil return hole 1133 is inclined to the axial direction of the first shaft hole 1131.

[0081] Furthermore, the oil return hole 1133 and the first shaft hole 1131 point to different chambers of the oil reservoir 220. For example, the first shaft hole 1131 points to the high-pressure chamber 2202 of the oil reservoir 220, and the oil return hole 1133 points to the low-pressure chamber 2203 of the oil reservoir 220.

[0082] 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 first shaft 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 guide seat 113 from pressure shocks, while also closing the oil circuit and reducing the temperature at the oil seal.

[0083] Furthermore, the structure of this utility model also includes a bearing 115. The bearing 115 is installed in the first shaft hole 1131 and can be sleeved on the piston rod 210. The bearing 115 can support the lateral load of the piston rod 210 and retain the internal high pressure, and plays a supporting, guiding, and anti-eccentric load role. Preferably, in this embodiment, the bearing 115 is a metal polymer self-lubricating rolling bearing 115, which has a simple assembly process and is suitable for higher vibration frequencies and speeds, stronger lateral load bearing capacity, and less affected by temperature compared with non-metallic bearings 115, thus having better performance.

[0084] Furthermore, the gland assembly 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.

[0085] The gasket 116 is disposed between the pressure cap 114 and the guide seat 113. The sealing ring 117 is disposed between the gasket 116 and the guide seat 113.

[0086] The gland 114 and the guide seat 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 gland 114 and the guide seat 113 to further ensure the sealing of their joint and prevent hydraulic oil from leaking from the joint.

[0087] 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.

[0088] Furthermore, to further enhance sealing, a wedge structure is provided on the edge of the guide seat 113 facing the pressure cap 114. When the guide seat 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.

[0089] 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 guide seat 113. In this way, the gasket 116, the sealing ring 117, the guide seat 113, and the pressure cap 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.

[0090] 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.

[0091] Furthermore, the structure of this utility model also 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 assembly 110. It is used to prevent hydraulic oil from flowing into the first cavity 122, so as to enhance the sealing of the piston rod 210 movement and achieve the effect of internal sealing and external dust prevention.

[0092] In some embodiments, the skeleton oil seal 119 is disposed within the guide seat 113 and is at least partially located in the oil accumulation groove.

[0093] In some embodiments, the skeleton oil seal 119 is disposed inside the pressure cap 114, directly opposite the oil accumulation groove.

[0094] In some embodiments, the skeleton oil seal 119 may be partially located within the guide seat 113 and partially within the pressure cap 114, and is connected at the junction of the guide seat 113 and the pressure cap 114.

[0095] Furthermore, the skeleton oil seal 119 has sealing lips 1191 at both ends, with the sealing lips 1191 spaced apart and forming an annular locking position 1192 between them. The skeleton oil seal 119 cooperates with the gland assembly 110 through the annular locking position 1192. The sealing lips 1191 can enhance the sealing performance of the connection between the annular locking position 1192 and the gland assembly 110. The skeleton oil seal 119, when fitted onto the piston rod 210, can enhance the sealing performance at the piston rod 210. In this way, by setting the skeleton oil seal 119, the sealing performance can be improved, preventing the hydraulic oil that has entered the oil accumulation groove 1132 from flowing into the first cavity 122 through the gland assembly 110, thus sealing the inside and preventing dust from the outside. This allows the hydraulic oil to flow back to the oil reservoir 220 through the oil return hole 1133 as much as possible.

[0096] Furthermore, a preload spring 1110 is fitted onto the skeleton oil seal 119. The preload spring 1110 constantly tends to drive the skeleton oil seal 119 to grip the piston rod 210. In this way, the preload 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.

[0097] Furthermore, the second end port of the bellows 120 is larger than the diameter of the first shaft 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.

[0098] 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 assembly 110, particularly between the bearing 115 and the piston rod 210, and thus into the oil collection tank 1132. Most of the hydraulic oil entering the oil collection tank 1132 will flow back into the reservoir 220 through the return port 1133. If the hydraulic oil in the oil collection tank 1132 continues to leak along the piston rod 210, it may enter the first cavity 122 through the skeleton oil seal 119 and be collected. 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 cavity 122 and stored inside the bellows 120, thus the oil stains will not be visible on 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 cavity 122 and flow through the breather hole 124 into the second cavity 140, eventually flowing out of the second cavity 140 and becoming visible on the outside of the hydraulic damper 200. 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 and dust cover 130 of this application can also be used for double dust protection to prevent foreign objects from entering the interior of the hydraulic damper 200, thereby avoiding the problem of the hydraulic damper 200 failing 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 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.

[0099] 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 multi-layer dustproof sealing structure for a hydraulic shock absorber (200), characterized in that, It is mounted on the piston rod (210) of the hydraulic damper (200) for receiving hydraulic oil leaked from the hydraulic damper (200), and the dustproof sealing structure includes; A gland assembly (110) is used to connect to the hydraulic damper (200) and is sleeved on the piston rod (210); The bellows (120) has a first opening (121) at its first end, which can be sleeved on the piston rod (210) and form a sealed connection with the piston rod (210). The second end is connected to the pressure cap assembly (110) and can be sleeved on the piston rod (210). The bellows (120) has a first cavity (122) that can receive hydraulic oil and adapt to the piston movement of the piston rod (210). A dust cover (130) is at least partially installed over the bellows (120) and can be fitted onto the piston rod (210) to form a sealed connection with the piston rod (210). The dust cover (130) forms a second cavity (140) at least between the bellows (120) and the piston rod (210). 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 assembly (110) and be collected.

2. The multi-layer dustproof sealing structure as described in claim 1, characterized in that, The bellows (120) is provided with a vent (124), which connects the second cavity (140) and the first cavity (122).

3. The multi-layer dustproof sealing structure as described in claim 1, characterized in that, The second cavity (140) surrounds the first cavity (122).

4. The multi-layer dustproof sealing structure as described in claim 1, characterized in that, The gland assembly (110) is provided with an oil leakage return channel (112). When the hydraulic damper (200) leaks hydraulic oil along the piston rod (210) toward the gland assembly (110), the oil leakage 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).

5. The multi-layer dustproof sealing structure as described in claim 4, characterized in that, The gland assembly (110) includes: The guide seat (113) can be sleeved on the piston rod (210) and block the port of the oil reservoir (220) of the hydraulic damper (200); A pressure cap (114) is connected to the bellows (120); the pressure cap (114) can be sleeved on the piston rod (210) and connected to the oil reservoir (220) of the hydraulic damper (200) to press the guide seat (113) at the port of the oil reservoir (220); The guide seat (113) is provided with the oil leakage return channel (112).

6. The multi-layer dustproof sealing structure as described in claim 5, characterized in that, The guide seat (113) is provided with a first shaft hole (1131) for the piston rod (210) to pass through. An oil collection groove (1132) is provided at one end of the guide seat (113) facing the pressure cap (114). The oil collection groove (1132) communicates with the first shaft hole (1131). When the hydraulic damper (200) leaks oil outward along the piston rod (210), the hydraulic oil can enter the oil collection groove (1132) through the first shaft hole (1131). The pressure cap assembly (110) is provided with an oil return hole (1133), which is in communication with the oil accumulation groove (1132) and is used to guide the hydraulic oil in the oil accumulation groove (1132) back to the oil reservoir (220).

7. The multi-layer dustproof sealing structure as described in claim 6, characterized in that, The oil return hole (1133) is inclined to the axial direction of the first shaft hole (1131).

8. The multi-layer dustproof sealing structure as described in claim 6, characterized in that, It also includes a bearing (115), which is installed in the first shaft hole (1131) and can be sleeved on the piston rod (210).

9. The multi-layer dustproof sealing structure as described in claim 5, characterized in that, The gland assembly (110) also includes: A gasket (116) is disposed between the pressure cap (114) and the guide seat (113); A sealing ring (117) is disposed between the gasket (116) and the guide seat (113).

10. The multi-layer dustproof sealing structure as described in claim 9, characterized in that, The guide seat (113) has a wedge structure on one end facing the pressure cap (114). When the guide seat (113) is installed in the oil reservoir (220), a second annular groove (118) is formed between the wedge structure and the inner wall of the oil reservoir (220). The sealing ring (117) is disposed in the second annular groove (118); the gasket (116) closes the second annular groove (118).

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